http://www.mdpi.com/journal/applsci Latest open access articles published in Appl. Sci. at http://www.mdpi.com/journal/applsci http://www.mdpi.com/2076-3417/3/2/545 This paper proposes a novel Maximum Power Point Tracking (MPPT) control method of thermoelectric power generation for the constant load. This paper reveals the characteristics and the internal resistance of thermoelectric power module (TM). Analyzing the thermoelectric power generation system with boost chopper by state space averaging method, the output voltage and current of TM are estimated by with only single current sensor. The proposed method can seek without calculating the output power of TM in this proposed method. The basic principle of the proposed MPPT control method is discussed, and then confirmed by digital computer simulation using PSIM. Simulation results demonstrate that the output voltage can track the maximum power point voltage by the proposed MPPT control method. The generated power of the TM is 0.36 W when the temperature difference is 35 °C. This is well accorded with the V-P characteristics. Applied Sciences 2013-04-29 3 2 Article 10.3390/app3020545 545 558 2076-3417 2013-04-29 doi: 10.3390/app3020545 Hiroaki Yamada Koji Kimura Tsuyoshi Hanamoto Toshihiko Ishiyama Tadashi Sakaguchi Tsuyoshi Takahashi http://www.mdpi.com/2076-3417/3/2/515 Spatiotemporal compression of ultrashort pulses is one of the key issues of chirped pulse amplification (CPA), the most common method to achieve high intensity laser beams. Successful shaping of the temporal envelope and recombination of the spectral components of the broadband pulses need careful alignment of the stretcher-compressor stages. Pulse parameters are required to be measured at the target as well. Several diagnostic techniques have been developed so far for the characterization of ultrashort pulses. Some of these methods utilize nonlinear optical processes, while others based on purely linear optics, in most cases, combined with spectrally resolving device. The goal of this work is to provide a review on the capabilities and limitations of the latter category of the ultrafast diagnostical methods. We feel that the importance of these powerful, easy-to-align, high-precision techniques needs to be emphasized, since their use could gradually improve the efficiency of different CPA systems. We give a general description on the background of spectrally resolved linear interferometry and demonstrate various schematic experimental layouts for the detection of material dispersion, angular dispersion and carrier-envelope phase drift. Precision estimations and discussion of potential applications are also provided. Applied Sciences 2013-04-26 3 2 Review 10.3390/app3020515 515 544 2076-3417 2013-04-26 doi: 10.3390/app3020515 Adam Borzsonyi Attila Kovacs Karoly Osvay http://www.mdpi.com/2076-3417/3/2/490 The present paper reviews some aspects concerned with the development of green technologies in the photopolymerization area: use of visible light sources (Xe and Hg-Xe lamps, diode lasers), soft irradiation conditions (household lamps: halogen lamp, fluorescence bulbs, LED bulbs), sunlight exposure, development of very efficient photoinitiating systems and use of renewable monomers. The drawbacks/breakthroughs encountered when going on the way of a greener approach are discussed. Examples of recent achievements are presented. Applied Sciences 2013-04-24 3 2 Article 10.3390/app3020490 490 514 2076-3417 2013-04-24 doi: 10.3390/app3020490 Mohamad Tehfe Fanny Louradour Jacques Lalevée Jean-Pierre Fouassier http://www.mdpi.com/2076-3417/3/2/469 Given the water scarcity becoming endemic to a large portion of the globe, arid region irrigation has resorted to the use of treated, partially treated, or even untreated wastewaters. Such waters contain a number of pollutants, including surfactants. Applied to agricultural lands, these surfactants could affect the fate and transport of other chemicals in the soil, particularly pesticides. A field lysimeter study was undertaken to investigate the effect of nonionic surfactant, Brij35, on the in-soil fate and transport of a commonly used herbicide, metribuzin [4-amino-6-tert-butyl-3-(methylthio)-1,2,4-triazin-5(4H)-one]. Nine PVC lysimeters, 1.0 m long × 0.45 m diameter, were packed with a sandy soil to a bulk density of 1.35 mg m−3. Antibiotic-free cattle manure was applied (10 mg ha−1) at the surface of the lysimeters. Metribuzin was then applied to the soil surface of all lysimeters at a rate of 1.00 kg a.i. ha−1. Each of three aqueous Brij35 solutions, 0, 0.5 and 5 mg L−1 (i.e., “good”, “poor” and “very poor” quality irrigation water) were each applied to the lysimeters in triplicate. Analysis for metribuzin residues in samples of both soil and leachate, collected over a 90-day period, showed the surfactant Brij35 to have increased the mobility of metribuzin in soil, indicating that continued use of poor quality water could influence pesticide transport in agricultural soils, and increase the risk of groundwater contamination. Applied Sciences 2013-04-24 3 2 Article 10.3390/app3020469 469 489 2076-3417 2013-04-24 doi: 10.3390/app3020469 Eman ElSayed Shiv Prasher http://www.mdpi.com/2076-3417/3/2/457 A series of new 1,3-diaryl-5-(1-phenyl-3-methyl-5-chloropyrazol-4-yl)-4,5-dihydropyrazole derivatives have been synthesized under sonication conditions in ethanol or methanol/glacial acetic acid mixture (5/1 ratio) with two equivalents of hydrazines and seven kinds of chalcone-like heteroanalogues obtained from 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde. The structures were established on the basis of NMR, IR, MS and element analysis. This method provides several advantages over current reaction methodologies, including a simple work-up procedure, shorter reaction times (2–20 min) and good yields (65%–80%). Applied Sciences 2013-04-16 3 2 Article 10.3390/app3020457 457 468 2076-3417 2013-04-16 doi: 10.3390/app3020457 Jorge Trilleras Efraín Polo Jairo Quiroga Justo Cobo Manuel Nogueras http://www.mdpi.com/2076-3417/3/2/437 This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG). The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK. Applied Sciences 2013-04-11 3 2 Article 10.3390/app3020437 437 456 2076-3417 2013-04-11 doi: 10.3390/app3020437 Mahmoud Hussein Tomonobu Senjyu Mohamed Orabi Mohamed Wahab Mohamed Hamada http://www.mdpi.com/2076-3417/3/2/420 Most Wave Energy Converters (WECs) produce highly distorted power due to thereciprocal motion induced by ocean waves. Some WEC systems have integrated energystorage that overcomes this limitation, but add significant expenses to an already costlysystem. As an alternative approach, this article investigates the direct export option thatrelies on aggregate smoothing among several WECs. By optimizing the positioning of theWEC devices with respect to the incoming waves, fluctuations may be mutually canceledout between the devices. This work is based on Fred. Olsen’s WEC system Lifesaver, anda WEC farm consisting of 48 devices is designed in detail and simulated. The major costdriver for the electrical export system is the required oversize factor necessary for transferof the average power output. Due to the low power quality, this number can be as high as20 at the entry point of the electrical system, and it is thus crucial to quickly improve thepower quality so that the downstream power system is efficiently utilized. The simulationsundertaken in this work indicate that a high quality power output can be achieved at the farmlevel, but that a significant oversize factor will be required in the intermediate power systemwithin the farm. Applied Sciences 2013-04-02 3 2 Article 10.3390/app3020420 420 436 2076-3417 2013-04-02 doi: 10.3390/app3020420 Jonas Sjolte Gaute Tjensvoll Marta Molinas http://www.mdpi.com/2076-3417/3/2/396 One of the concerns for economical production of ethanol from biomass is the large volume and high cost of the cellulolytic enzymes used to convert biomass into fermentable sugars. The presence of acetyl groups in hemicellulose and lignin in plant cell walls reduces accessibility of biomass to the enzymes and makes conversion a slow process. In addition to low enzyme accessibility, a rapid deactivation of cellulases during biomass hydrolysis can be another factor contributing to the low sugar recovery. As of now, the economical reduction in lignin content of the biomass is considered a bottleneck, and raises issues for several reasons. The presence of lignin in biomass reduces the swelling of cellulose fibrils and accessibility of enzyme to carbohydrate polymers. It also causes an irreversible adsorption of the cellulolytic enzymes that prevents effective enzyme activity and recycling. Amphiphiles, such as surfactants and proteins have been found to improve enzyme activity by several mechanisms of action that are not yet fully understood. Reduction in irreversible adsorption of enzyme to non-specific sites, reduction in viscosity of liquid and surface tension and consequently reduced contact of enzyme with air-liquid interface, and modifications in biomass chemical structure are some of the benefits derived from surface active molecules. Application of some of these amphiphiles could potentially reduce the capital and operating costs of bioethanol production by reducing fermentation time and the amount of enzyme used for saccharification of biomass. In this review article, the benefit of applying amphiphiles at various stages of ethanol production (i.e., pretreatment, hydrolysis and hydrolysis-fermentation) is reviewed and the proposed mechanisms of actions are described. Applied Sciences 2013-04-02 3 2 Review 10.3390/app3020396 396 419 2076-3417 2013-04-02 doi: 10.3390/app3020396 Anahita Eckard Kasiviswanathan Muthukumarappan William Gibbons http://www.mdpi.com/2076-3417/3/2/355 A growing number of applications in science and industry are currently pushing the development of ultrafast laser technologies that enable high average powers. SESAM modelocked thin disk lasers (TDLs) currently achieve higher pulse energies and average powers than any other ultrafast oscillator technology, making them excellent candidates in this goal. Recently, 275 W of average power with a pulse duration of 583 fs were demonstrated, which represents the highest average power so far demonstrated from an ultrafast oscillator. In terms of pulse energy, TDLs reach more than 40 μJ pulses directly from the oscillator. In addition, another major milestone was recently achieved, with the demonstration of a TDL with nearly bandwidth-limited 96-fs long pulses. The progress achieved in terms of pulse duration of such sources enabled the first measurement of the carrier-envelope offset frequency of a modelocked TDL, which is the first key step towards full stabilization of such a source. We will present the key elements that enabled these latest results, as well as an outlook towards the next scaling steps in average power, pulse energy and pulse duration of such sources. These cutting-edge sources will enable exciting new applications, and open the door to further extending the current performance milestones. Applied Sciences 2013-04-02 3 2 Review 10.3390/app3020355 355 395 2076-3417 2013-04-02 doi: 10.3390/app3020355 Clara Saraceno Cinia Schriber Florian Emaury Oliver Heckl Cyrill Baer Martin Hoffmann Kolja Beil Christian Kränkel Matthias Golling Thomas Südmeyer Ursula Keller http://www.mdpi.com/2076-3417/3/2/338 The UK Government has ambitious targets for CO2 emissions reductions, particularly for the domestic housing stock. One technology that is expected to contribute significantly is heat pumps, both air and ground source. However, recent field trial results suggest that heat pumps in the UK are not delivering to performance expectations. This paper looks at the implications of these results for the UK housing stock’s future CO2 emissions. The English Housing Condition Survey dataset is used as the basis for a Monte Carlo simulation in order to model CO2 emissions and energy consumption for the whole of English housing stock out to 2050. The results suggest that, given the current UK electricity grid CO2 emission factor, in the short term poor heat pump performance could lead to a rise in emissions where natural gas boilers are displaced. In the longer term, heat pumps can realise emissions reductions when installed at high penetration levels when combined with a grid decarbonisation strategy. Until grid decarbonisation occurs, an alternative phased strategy is proposed that includes phased replacement of resistive electric heating, first in households in fuel poverty and then the remainder of properties with this heating type. Following this phased strategy, real emissions savings are possible along with a potential reduction in fuel poverty. Applied Sciences 2013-03-28 3 2 Article 10.3390/app3020338 338 354 2076-3417 2013-03-28 doi: 10.3390/app3020338 David Braun Paul Rowley http://www.mdpi.com/2076-3417/3/2/325 Global installed capacity of renewable energy technologies is growing rapidly. The ability of renewable technologies to enable a rapid transition to a low carbon energy system is highly dependent on the energy that must be “consumed” during their life-cycle. This paper presents the results of meta-analyses of life-cycle assessments (LCA) of energy costs of three renewable technologies: solar photovoltaic (PV), concentrating solar power (CSP), and wind. The paper presents these findings as energetic analogies with financial cost parameters for assessing energy technologies: overnight capital cost, operating costs and levelized cost of electricity (LCOE). The findings suggest that wind energy has the lowest energy costs, followed by CSP and then PV. Applied Sciences 2013-03-25 3 2 Article 10.3390/app3020325 325 337 2076-3417 2013-03-25 doi: 10.3390/app3020325 Michael Dale http://www.mdpi.com/2076-3417/3/1/314 We present the current development of an injector for a high-contrast, ultrashort laser system devoted to relativistic laser-plasma interaction in the few-cycle regime. The front-end is based on CEP-stabilized Ti:Sa CPA followed by XPW filter designed at the mJ level for temporal cleaning and shortening. Accurate characterization highlights the fidelity of the proposed injector. Measured CEP drift is 170 mrad rms. Applied Sciences 2013-03-18 3 1 Article 10.3390/app3010314 314 324 2076-3417 2013-03-18 doi: 10.3390/app3010314 Aurélien Ricci Aurélie Jullien Jean-Philippe Rousseau Rodrigo Lopez-Martens http://www.mdpi.com/2076-3417/3/1/299 As many high-intensity ultrafast-optical measurements involve more than one pulse—typically one to excite a medium under study and another to probe it—a technique for measuring two pulses simultaneously is highly desirable. In two decades, two-pulse measurement techniques have advanced from ambiguity-laden to a recently developed technique that can measure a pulse pair with arbitrary central wavelengths, complexities and bandwidths. Here, we review recent efforts to simultaneously measure two ultrashort laser pulses using a single device. Applied Sciences 2013-03-18 3 1 Review 10.3390/app3010299 299 313 2076-3417 2013-03-18 doi: 10.3390/app3010299 Tsz Wong Rick Trebino http://www.mdpi.com/2076-3417/3/1/288 The study of wavelength tunability for the gain media Yb:CaF2 and Yb:YAG in a regenerative amplifier configuration, was performed by using a simulation code previously benchmarked with real data. The results demonstrate that both materials have potential for amplifying pulses up to the milijoule level for wavelengths around 1048–1049 nm. In light of this, we propose and evaluate their performance as gain media in the pre-amplifier of a hybrid chain operating at 1053 nm. Applied Sciences 2013-03-13 3 1 Article 10.3390/app3010288 288 298 2076-3417 2013-03-13 doi: 10.3390/app3010288 Celso João João Wemans Gonçalo Figueira http://www.mdpi.com/2076-3417/3/1/278 We perform first-principles calculations to study the high-order harmonic generation induced in graphene nanostructures by the laser field. Three distinct signals are noticed: the integer higher-order harmonic generation (HHG), the shifted fractional order peaks from the integer order harmonics, and the intrinsic emissions. Due to the small gap between HOMO and LUMO of graphene molecule, the HHG can be generated for the infrared laser pulse with the photon energy ranging from 20 meV to 1 eV. The intrinsic emission corresponds to the electron excitation between eigenstates. Using a laser pulse with a photon energy of 0.042 eV and amplitude of 0.2 V/A° , HHGs up to 19th order are identified. Unsaturated graphene molecule is an excellent media for HHG. Moreover, the HHG signals are very sensitive to the hydrogen passivation. Our results also indicate that HHG can be a promising method for detecting the product in the fabrication of graphene molecules. Applied Sciences 2013-03-13 3 1 Article 10.3390/app3010278 278 287 2076-3417 2013-03-13 doi: 10.3390/app3010278 Mingqiang Gu Guoping Zhang Xiaoshan Wu http://www.mdpi.com/2076-3417/3/1/267 High-order harmonic generation (HHG) is a nonlinear nonperturbative process in ultrashort intense laser-matter interaction. It is the main source of coherent attosecond (1 as = 10−18 s) laser pulses to investigate ultrafast electron dynamics. HHG has become an important table-top source covering a spectral range from infrared to extreme ultraviolet (XUV). One way to extend the cutoff energy of HHG is to increase the intensity of the laser pulses. A consequence of HHG in such intense short laser fields is the characteristic nonadiabatic red and blue shifts of the spectrum, which are reviewed in the present work. An example of this nonperturbative light-matter interaction is presented for the one-electron nonsymmetric molecular ion HeH2+, as molecular systems allow for the study of the laser-molecule orientation dependence of such new effects including a four-step model of MHOHG (Molecular High-order Harmonic Generation). Applied Sciences 2013-03-13 3 1 Review 10.3390/app3010267 267 277 2076-3417 2013-03-13 doi: 10.3390/app3010267 Xue-Bin Bian André Bandrauk http://www.mdpi.com/2076-3417/3/1/251 In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL) and their progress are reviewed. Self-amplified spontaneous emission (SASE) schemes, the high gain harmonic generation (HGHG) scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the generation of attosecond hard X-ray pulses is also discussed. In our study, the enhanced SASE scheme is utilized, using electron beam parameters of an XFEL under construction at Pohang Accelerator Laboratory (PAL). Laser, chicane and electron beam parameters are optimized to generate an isolated attosecond hard X-ray pulse at 0.1 nm (12.4 keV). The simulations show that the manipulation of electron energy beam profile may lead to the generation of an isolated attosecond hard X-ray of 150 attosecond pulse at 0.1 nm. Applied Sciences 2013-03-12 3 1 Review 10.3390/app3010251 251 266 2076-3417 2013-03-12 doi: 10.3390/app3010251 Sandeep Kumar Heung-Sik Kang Dong-Eon Kim http://www.mdpi.com/2076-3417/3/1/214 This paper reviews techniques for improving the temporal contrast and spatial beam quality in an ultra-intense laser system that is based on chirped-pulse amplification (CPA). We describe the design, performance, and characterization of our laser system, which has the potential for achieving a peak power of 600 TW. We also describe applications of the laser system in the relativistically dominant regime of laser-matter interactions and discuss a compact, high efficiency diode-pumped laser system. Applied Sciences 2013-03-07 3 1 Review 10.3390/app3010214 214 250 2076-3417 2013-03-07 doi: 10.3390/app3010214 Hiromitsu Kiriyama Takuya Shimomura Michiaki Mori Yoshiki Nakai Manabu Tanoue Shuji Kondo Shuhei Kanazawa Alexander Pirozhkov Timur Esirkepov Yukio Hayashi Koichi Ogura Hideyuki Kotaki Masayuki Suzuki Izuru Daito Hajime Okada Atsushi Kosuge Yuji Fukuda Mamiko Nishiuchi Masaki Kando Sergei Bulanov Keisuke Nagashima Mitsuru Yamagiwa Kiminori Kondo Akira Sugiyama Paul Bolton Shinichi Matsuoka Hirofumi Kan http://www.mdpi.com/2076-3417/3/1/189 We theoretically study the photoelectron angular distribution (PAD) from the two-photon single ionization of H and He by femtosecond and attosecond extreme-ultraviolet pulses, based on the time-dependent perturbation theory and simulations with the full time-dependent Schrodinger equation. The PAD is formed by the interference of the s and d continuum wave packets, and, thus, contains the information on the relative phase and amplitude ratio between them. We find that, when a spectrally broadened femtosecond pulse is resonant with an excited level, the PAD substantially changes with pulse width, since the competition between resonant and nonresonant ionization paths, leading to distinct from the scattering phase shift difference, changes with it. In contrast, when the Rydberg manifold is excited, and for the case of above-threshold two-photon ionization, and the PAD do not depend much on pulse width, except for the attosecond region. Thus, the Rydberg manifold and the continuum behave similarly in this respect. For a high-harmonic pulse composed of multiple harmonic orders, while the value is different from that for a single-component pulse, the PAD still rapidly varies with pulse width. The present results illustrate a new way to tailor the continuum wave packet. Applied Sciences 2013-03-05 3 1 Article 10.3390/app3010189 189 213 2076-3417 2013-03-05 doi: 10.3390/app3010189 Kenichi Ishikawa Kiyoshi Ueda http://www.mdpi.com/2076-3417/3/1/168 This paper is devoted to analyzing the principle and applications of the linear electro-optic (EO) effect for the control of the carrier-envelope-phase (CEP). We introduce and detail here an original method, which relies on the use of an EO dispersive prism pair in a compressor-like configuration. We show that, by choosing an adequate geometry, it is possible to shift the CEP without changing the group delay (isochronous carrier-envelope-phase shifter) or change the induced group delay without varying the CEP. According to our calculations, when applying an electric field around 400 V/cm to the rubidium titanyle phosphate (RTP) prisms in a double pass configuration (2 × 40 mm total length), one obtains a CEP shift of π rad at 800 nm without inducing a group delay. In contrast, this CEP shift is obtained for an electric field around 1.4 kV/cm in a RTP rectangular slab of the same total length and, in this case, the group delay is of the order of a few fs. Applied Sciences 2013-02-26 3 1 Article 10.3390/app3010168 168 188 2076-3417 2013-02-26 doi: 10.3390/app3010168 Olivier Gobert Daniele Rovera Gabriel Mennerat Michel Comte http://www.mdpi.com/2076-3417/3/1/153 The bandwidth of ultrafast pulses in the UV is limited by the finite acceptance bandwidth of the nonlinear crystals used for their generation. For fundamental laser pulses it is well established that spectral broadening can be used to overcome intrinsic bandwidth limits. We show that self-phase modulation of UV pulses in bulk materials leads to large spectral broadening and allows for a significant reduction of the pulse duration. We find that for pulse energies in the range of a few μJ, a thin crystal is favorable due to the strong dispersion in the UV and the limitations set by self-focusing. In contrast to spectral broadening in gaseous media, the self-focus has to lie outside the crystal to avoid beam break up. We focus UV pulses into a 1 mm thick CaF2 crystal. For moderately short input pulses, a shortening factor up to 2.4 is achieved: the 120 fs long third harmonic output of a Ti:sapphire amplifier is compressed down to 50 fs FWHM. For a central wavelength of 315 nm, we generate pulses as short as 14.9 fs after compression with an UV pulse shaper. In both cases the resulting beam shape is close to Gaussian and fully usable for spectroscopic experiments. We use the pulses in a collinear 2D-UV experiment and clearly resolve vibronic off-diagonal peaks of the S2 1B2u vibronic progression of pyrene. Applied Sciences 2013-02-08 3 1 Article 10.3390/app3010153 153 167 2076-3417 2013-02-08 doi: 10.3390/app3010153 Nils Krebs Igor Pugliesi Eberhard Riedle http://www.mdpi.com/2076-3417/3/1/139 Recently we introduced the class of highly localized wavepackets (HLWs) as a generalization of optical Bessel-like needle beams. Here we report on the progress in this field. In contrast to pulsed Bessel beams and Airy beams, ultrashort-pulsed HLWs propagate with high stability in both spatial and temporal domain, are nearly paraxial (supercollimated), have fringe-less spatial profiles and thus represent the best possible approximation to linear “light bullets”. Like Bessel beams and Airy beams, HLWs show self-reconstructing behavior. Adaptive HLWs can be shaped by ultraflat three-dimensional phase profiles (generalized axicons) which are programmed via calibrated grayscale maps of liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs). Light bullets of even higher complexity can either be freely formed from quasi-continuous phase maps or discretely composed from addressable arrays of identical nondiffracting beams. The characterization of few-cycle light bullets requires spatially resolved measuring techniques. In our experiments, wavefront, pulse and phase were detected with a Shack-Hartmann wavefront sensor, 2D-autocorrelation and spectral phase interferometry for direct electric-field reconstruction (SPIDER). The combination of the unique propagation properties of light bullets with the flexibility of adaptive optics opens new prospects for applications of structured light like optical tweezers, microscopy, data transfer and storage, laser fusion, plasmon control or nonlinear spectroscopy. Applied Sciences 2013-02-08 3 1 Article 10.3390/app3010139 139 152 2076-3417 2013-02-08 doi: 10.3390/app3010139 Martin Bock Ruediger Grunwald http://www.mdpi.com/2076-3417/3/1/122 Sub-single-cycle pulses in the mid-infrared (MIR) region were generated through a laser-induced filament. The fundamental (ω1) and second harmonic (ω2) output of a 30-fs Ti:sapphire amplifier were focused into nitrogen gas and produce phase-stable broadband MIR pulses (ω0) by using a four-wave mixing process (ω1 + ω1 - ω2 → ω0) through filamentation. The spectrum spread from 400 cm-1 to 5500 cm-1, which completely covered the MIR region. The low frequency components were detected by using an electro-optic sampling technique with a gaseous medium. The efficiency of the MIR pulse generation was very sensitive to the delay between the fundamental and second harmonic pulses. It was revealed that the delay dependence of the efficiency came from the interference between two opposite parametric processes, ω1 + ω1 - ω2 → ω0 and ω2 - ω1 - ω1 → ω0. The pulse duration was measured as 6.9 fs with cross-correlation frequency-resolved optical gating by using four-wave mixing in nitrogen. The carrier-envelope phase of the MIR pulse was passively stabilized. The instability was estimated as 154 mrad rms in 2.5 h. Applied Sciences 2013-02-06 3 1 Article 10.3390/app3010122 122 138 2076-3417 2013-02-06 doi: 10.3390/app3010122 Takao Fuji Yutaka Nomura http://www.mdpi.com/2076-3417/3/1/107 Adverse environmental impacts of carbon emissions are causing increasing concerns to the general public throughout the world. Electric energy generation from conventional energy sources is considered to be a major contributor to these harmful emissions. High emphasis is therefore being given to green alternatives of energy, such as wind and solar. Wind energy is being perceived as a promising alternative. This source of energy technology and its applications have undergone significant research and development over the past decade. As a result, many modern power systems include a significant portion of power generation from wind energy sources. The impact of wind generation on the overall system performance increases substantially as wind penetration in power systems continues to increase to relatively high levels. It becomes increasingly important to accurately model the wind behavior, the interaction with other wind sources and conventional sources, and incorporate the characteristics of the energy demand in order to carry out a realistic evaluation of system reliability. Power systems with high wind penetrations are often connected to multiple wind farms at different geographic locations. Wind speed correlations between the different wind farms largely affect the total wind power generation characteristics of such systems, and therefore should be an important parameter in the wind modeling process. This paper evaluates the effect of the correlation between multiple wind farms on the adequacy indices of wind-integrated systems. The paper also proposes a simple and appropriate probabilistic analytical model that incorporates wind correlations, and can be used for adequacy evaluation of multiple wind-integrated systems. Applied Sciences 2013-02-06 3 1 Article 10.3390/app3010107 107 121 2076-3417 2013-02-06 doi: 10.3390/app3010107 Rajesh Karki Dinesh Dhungana Roy Billinton http://www.mdpi.com/2076-3417/3/1/94 In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning between the target width, intensity and laser pulse duration. The optimal parameters were obtained from a self-consistent system of Maxwell equations and the equation of motion of electron layer. For thin relativistic electron layers, the gaining of maximum electron energies requires a second additional overdense plasma layer, thus cutting the laser radiation off the plasma screen at the instant of gaining the maximum energy (DREAM-schema). Applied Sciences 2013-02-04 3 1 Article 10.3390/app3010094 94 106 2076-3417 2013-02-04 doi: 10.3390/app3010094 Alexander Andreev Konstantin Platonov Saltanat Sadykova http://www.mdpi.com/2076-3417/3/1/70 In the past years, there has been a growing interest in innovative applications of radially polarized laser beams. Among them, the particular field of laser-driven electron acceleration has received much attention. Recent developments in high-power infrared laser sources at the INRS Advanced Laser Light Source (Varennes, Qc, Canada) allowed the experimental observation of a quasi-monoenergetic 23-keV electron beam produced by a radially polarized laser pulse tightly focused into a low density gas. Theoretical analyses suggest that the production of collimated attosecond electron pulses is within reach of the actual technology. Such an ultrashort electron pulse source would be a unique tool for fundamental and applied research. In this paper, we propose an overview of this emerging topic and expose some of the challenges to meet in the future. Applied Sciences 2013-01-30 3 1 Review 10.3390/app3010070 70 93 2076-3417 2013-01-30 doi: 10.3390/app3010070 Charles Varin Stéphane Payeur Vincent Marceau Sylvain Fourmaux Alexandre April Bruno Schmidt Pierre-Louis Fortin Nicolas Thiré Thomas Brabec François Légaré Jean-Claude Kieffer Michel Piché http://www.mdpi.com/2076-3417/3/1/55 Glycerol is a non-toxic, non-hazardous, non-volatile, biodegradable, and recyclable liquid that is generated as a byproduct in the manufacture of biodiesel fuel from vegetable oils. Due to its easy availability, along with its unique combination of physical and chemical properties, glycerol has recently emerged as an economically appealing and safe solvent for organic synthesis. Recent works have also demonstrated that glycerol can be used as a hydrogen source in metal-catalyzed transfer hydrogenation of organic compounds, such as aldehydes, ketones, olefins and nitroarenes. Herein, the advances reached in this emerging field are reviewed. The utility of glycerol as solvent and reducing agent for the generation of metal nanoparticles is also briefly discussed. Applied Sciences 2013-01-23 3 1 Review 10.3390/app3010055 55 69 2076-3417 2013-01-23 doi: 10.3390/app3010055 Alba Díaz-Álvarez Victorio Cadierno http://www.mdpi.com/2076-3417/3/1/39 A fiber Bragg grating (FBG) strain patch specially adapted for long-term and high-strain applications has been developed and characterized. The design concept for the patch is based on a glass-fiber reinforced plastic (gfrp) carrier material. The developed concept for the FBG integration into the carrier material was derived from reliable integration procedure of FBG sensors into composite structures. The patches’ temperature sensitivity, strain gauge factor, fiber–matrix interface adhesion and fatigue behavior were characterized. As a result, FBG strain patches with linear temperature and strain behavior, as well as excellent fatigue resistance, were developed and can be used as part of a monitoring system for advanced composite materials in aerospace structures or wind turbine power plants. Applied Sciences 2013-01-16 3 1 Article 10.3390/app3010039 39 54 2076-3417 2013-01-16 doi: 10.3390/app3010039 Vivien Schukar Nadine Kusche Gerhard Kalinka Wolfgang Habel http://www.mdpi.com/2076-3417/3/1/14 Biofuels impact on global land use has been a controversial yet important topic. Up until recently, there has not been enough biofuels to have caused major land use change, so the evidence from actual global land use data has been scant. However, in the past decade, there have been 72 million hectares added to global crop cover. In this research we take advantage of this new data to calibrate the Global Trade Analysis Project (GTAP) model and parameters. We make two major changes. First, we calibrate the land transformation parameters (called constant elasticity of transformation, CET) to global regions so that the parameters better reflect the actual land cover change that has occurred. Second, we alter the land cover nesting structure. In the old GTAP model, cropland, pasture, and forest were all in the same nest suggesting, everything else being equal, that pasture or forest convert to cropland with equal ease and cost. However, we now take advantage of the fact that pasture converts to cropland at lower cost than forest. The paper provides the theoretical and empirical justification for these two model improvements. Then it re-evaluates the global land use impacts due to the USA ethanol program using the improved model tuned with actual observations. Finally, it shows that compared to the old model, the new model projects: (1) less expansion in global cropland due to ethanol expansion; (2) lower U.S. share in global cropland expansion; (3) and lower forest share in global cropland expansion. Applied Sciences 2013-01-11 3 1 Article 10.3390/app3010014 14 38 2076-3417 2013-01-11 doi: 10.3390/app3010014 Farzad Taheripour Wallace Tyner http://www.mdpi.com/2076-3417/3/1/1 A single-grating monochromator can be used for the spectral selection of ultrashort pulses without altering in a significant way the pulse duration, provided that the number of illuminated grooves is equal to the resolution. Two configurations are compared: the classical-diffraction mount (CDM) and the off-plane mount (OPM). The advantages and drawbacks of both configurations are presented. The two geometries can be joined in a new and innovative design of a monochromator with two interchangeable diffracting stages both used at grazing incidence, one with the gratings in the CDM and the other in the OPM. The use of two stages gives great flexibility: the OPM stage is used for sub-50 fs time response and low spectral resolution and the CDM stage for 100-200 fs time response and high spectral resolution. The design overcomes the limits of the two single configurations, giving on the same instrument either ultrafast response with low spectral resolution or slower response with higher resolution. Applied Sciences 2012-12-27 3 1 Article 10.3390/app3010001 1 13 2076-3417 2012-12-27 doi: 10.3390/app3010001 Luca Poletto Fabio Frassetto http://www.mdpi.com/2076-3417/2/4/816 A technique for broadband spectral amplitude control of light pulses produced in high-order harmonic generation (HHG) is presented. It has been shown elsewhere that broadband spectral phase control in HHG is achievable using a computerized feedback loop scheme by coherently adding a filtered region of the HHG emission to the intense IR driving pulse with optimal attenuation and time delay parameters. In the present study, further computational evidence of the capabilities of this control scheme is provided by considering the spectral amplitude in a broadband region of the HHG spectrum as the control target for the production of isolated attosecond pulses. Different spectral widths and central photon energies are examined, such as a spectral width of 30 eV centered at 36 eV, well in the plateau, and a width of 20 eV centered at 60 eV in the cutoff region. An iterative procedure of the method is implemented and optimal isolated single cycle pulses at a central photon energy of 36 eV are obtained. This control scheme is a fundamental tool that can be implemented for amplitude and phase shaping of any suitable spectral region in HHG. Applied Sciences 2012-12-19 2 4 Article 10.3390/app2040816 816 830 2076-3417 2012-12-19 doi: 10.3390/app2040816 Carles Serrat http://www.mdpi.com/2076-3417/2/4/801 An automatic power management system, to monitor the distribution of power to a set of load banks, is presented in this paper. The required power is generated from a laboratory-size pitch-controlled wind turbine experimental workstation. The management system is a sequence of logic expressions, based on the generated power, a profile of the banks’ states provided by the supervisor and the banks’ priorities, to obtain an optimal behavior of the system and to ensure the load requirement. A modified PI pitch angle control is proposed to regulate the generated power for tracking the power reference in order to maintain a consistent brilliance of the load’s LEDs, to reduce the activity of the pitch actuator and to deal with fluctuation problems. Experimental results are provided to show the effectiveness of the proposed automatic power management system for load banks supplied by a pitch controlled wind turbine. Applied Sciences 2012-11-28 2 4 Article 10.3390/app2040801 801 815 2076-3417 2012-11-28 doi: 10.3390/app2040801 Adel Merabet Raquel Keeble Vigneshwaran Rajasekaran Rachid Beguenane Hussein Ibrahim Jogendra Thongam http://www.mdpi.com/2076-3417/2/4/780 In this paper, a design fuzzy logic controller for a variable speed permanent magnet wind generator connected to a grid system through a LC-filter is proposed. A new current control method of grid side conversion is developed by integrating the fuzzy controller, in which both active and reactive power, delivered to a power grid system, is controlled effectively. The fuzzy logic controller is designed to adjust the gain parameters of the PI controllers under any operating conditions, so that the dynamic stability is enhanced. A new simple method, based on frequency response of the bode diagram, is proposed in the design of the fuzzy logic controller. To evaluate the controller system capabilities, simulation analyses are performed on a small wind farm model system including an induction wind generator connected to an infinite bus. The simulations have been performed using PSCAD/EMTDC. Simulation results show that the proposed control scheme is more effective for enhancing the stability of wind farms during temporary and permanent network disturbances and randomly fluctuating wind speed, compared with that of a conventional PI controller. Applied Sciences 2012-11-22 2 4 Article 10.3390/app2040780 780 800 2076-3417 2012-11-22 doi: 10.3390/app2040780 Marwan Rosyadi S. M. Muyeen Rion Takahashi Junji Tamura http://www.mdpi.com/2076-3417/2/4/773 An inclusion complex of β-cyclodextrin and 4-aminothiophenol was assembled by hydrophobic interaction of the host (β-cyclodextrin) and guest (4-aminothiophenol). The complex was isolated as crystalline solid and studied by single crystal X-ray diffraction method along with NMR and IR spectroscopy. Two cyclodextrin rings each containing one disulfide form of 4-aminothiophenol were found to pair up by hydrogen bonding of the outer rim -OH groups. The phenyl disulfide moiety of 4-aminophenyl disulfide molecule was found in the core of β-cyclodextrin, while the amino functional groups were positioned to the exterior of the cyclodextrin ring. Phenyl rings of the guest molecule from each partner of the paired cyclodextrin complex were found parallel to each other, indicating possible π-π stacking interaction between them. Applied Sciences 2012-10-25 2 4 Article 10.3390/app2040773 773 779 2076-3417 2012-10-25 doi: 10.3390/app2040773 Taylor Cappadona Lee Daniels Tasneem Siddiquee http://www.mdpi.com/2076-3417/2/4/754 Pretreated dirty cotton residue (PDCR) from the textile industry was used as an alternative carbon source for the submerged cultivation of Aspergillus oryzae and the production of xylanases. The filtered culture supernatant was fractionated by ultrafiltration followed by three chromatographic steps, which resulted in the isolation of a homogeneous low-molecular-weight xylanase (Xyl-O1) with a mass of 21.5 kDa as determined by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE) co-polymerized with 0.1% oat spelt xylan. Enzyme catalysis was the most efficient at 50 °C and pH 6.0. The Km values (mg·mL−1) for the soluble fraction of oat spelt and birchwood xylans were 10.05 and 3.34, respectively. Xyl-O1 was more stable in the presence of 5,5-dithio-bis-(2-nitrobenzoic acid) (DTNB), 1,4-dithiothreitol (DTT), l-cysteine or β-mercaptoethanol, which increased the rate of catalysis by 40%, 14%, 40% or 37%, respectively. The enzyme stability was improved at pH 7.0 in the presence of 20 mM l-cysteine, with the retention of nearly 100% of the activity after 6 h at 50 °C. Xyl-O1 catalyzed the cleavage of internal β-1,4 linkages of the soluble substrates containing d-xylose residues, with a maximum efficiency of 33% for the hydrolysis of birchwood xylan after 12 h of incubation. Identification of the hydrolysis products by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) indicated the predominance of the hydrolysis products X2-X6 during the first 12 h of incubation and the accumulation of higher xylooligomers after the elution of the last xylooligomer standard, xylohexaose. Applied Sciences 2012-10-23 2 4 Article 10.3390/app2040754 754 772 2076-3417 2012-10-23 doi: 10.3390/app2040754 Gilvan Caetano Duarte Leonora Rios de Souza Moreira Diana Paola Gómez-Mendoza Félix Gonçalves de Siqueira Luís Roberto Batista Lourdes Isabel Velho do Amaral Carlos André Ornelas Ricart Edivaldo Ximenes Ferreira Filho http://www.mdpi.com/2076-3417/2/4/738 Bio-ethanol is one of the energy sources that can be produced by renewable sources. Waste potato mash was chosen as a renewable carbon source for ethanol fermentation because it is relatively inexpensive compared with other feedstock considered as food sources. However, a pretreatment process is needed: specifically, liquefaction and saccharification processes are needed to convert starch of potato into fermentable sugars before ethanol fermentation. In this study, hydrolysis of waste potato mash and growth parameters of the ethanol fermentation were optimized to obtain maximum ethanol production. In order to obtain maximum glucose conversions, the relationship among parameters of the liquefaction and saccharification process was investigated by a response surface method. The optimum combination of temperature, dose of enzyme (α-amylase) and amount of waste potato mash was 95 °C, 1 mL of enzyme (18.8 mg protein/mL) and 4.04 g dry-weight/100 mL DI water, with a 68.86% loss in dry weight for liquefaction. For saccharification, temperature, dose of enzyme and saccharification time were optimized and optimum condition was determined as 60 °C-72 h-0.8 mL (300 Unit/mL) of amyloglucosidase combination, yielded 34.9 g/L glucose. After optimization of hydrolysis of the waste potato mash, ethanol fermentation was studied. Effects of pH and inoculum size were evaluated to obtain maximum ethanol. Results showed that pH of 5.5 and 3% inolculum size were optimum pH and inoculum size, respectively for maximum ethanol concentration and production rate. The maximum bio-ethanol production rate was obtained at the optimum conditions of 30.99 g/L ethanol. Since yeast extract is not the most economical nitrogen source, four animal-based substitutes (poultry meal, hull and fines mix, feather meal, and meat and bone meal) were evaluated to determine an economical alternative nitrogen source to yeast extract. Poultry meal and feather meal were able to produce 35 g/L and 32.9 g/L ethanol, respectively, which is higher than yeast extract (30.8 g/L). In conclusion, waste potato mash was found as a promising carbon source for ethanol fermentation with alternate nitrogen sources. Applied Sciences 2012-10-22 2 4 Article 10.3390/app2040738 738 753 2076-3417 2012-10-22 doi: 10.3390/app2040738 Gulten Izmirlioglu Ali Demirci http://www.mdpi.com/2076-3417/2/4/726 With an increased focus on solutions to the ensuing “climate crisis”, the need for energy storage systems is becoming increasingly important as a means to increase the penetration of renewable technologies such as wind energy. The Vanadium Redox Battery is one such energy storage system showing considerable potential owing to its flexibility in power output and capacity, high efficiency and long operating life. This study models the use of the Vanadium Redox Battery as an integration technology in realistic large-scale remote wind/diesel power systems using the HOMER Micropower Optimization Model computer program developed by the US National Renewable Energy Laboratory. Results from this modelling demonstrate the significant financial and environmental benefits to be gained in installing energy storage in a wind farm. The storage system considered here was a Vanadium Redox Battery. Applied Sciences 2012-10-18 2 4 Article 10.3390/app2040726 726 737 2076-3417 2012-10-18 doi: 10.3390/app2040726 Andrew Stiel Maria Skyllas-Kazacos http://www.mdpi.com/2076-3417/2/4/709 This paper presents a computer model that will evaluate the performance of a thermo-chemical accumulator. The model is based on operational data such as temperatures and flow rates. The ultimate goal for this model is to estimate the coefficient of performance (COP) of this unit when run on hot water from biomass combustion as the heat source. The outputs of the model are verified by comparing the simulation of the actual machine with published experimental data. The computed results for cooling COP are within 10% of the measured data. The simulations are all run for heat load temperatures varying between 80 °C and 110 °C. As expected, simulation results showed an increase in COP with increased heat source temperatures. The results demonstrate that the potential of combined solar and biomass combustion as a heat source for absorption cooling/heating in climates with low solar radiation can be coupled with biomass waste. Applied Sciences 2012-10-10 2 4 Article 10.3390/app2040709 709 725 2076-3417 2012-10-10 doi: 10.3390/app2040709 Sacha Oberweis Tariq Al-Shemmeri http://www.mdpi.com/2076-3417/2/4/682 Organic fluorinated materials demonstrate their excellent electro-optic properties and versatility for technological applications. The partial substitution of hydrogen with fluorine in carbon-halides bounds allows the reduction of absorption losses at the telecommunication wavelengths. In these interesting compounds, the electro-optic coefficient was typically induced by a poling procedure. The magnitude and the time stability of the coefficient is an important issue to be investigated in order to compare copolymer species. Here, a review of different measurement techniques (such as nonlinear ellipsometry, second harmonic generation, temperature scanning and isothermal relaxation) was shown and applied to a variety of fluorinated and non-fluorinated electro-optic compounds. Applied Sciences 2012-10-09 2 4 Review 10.3390/app2040682 682 708 2076-3417 2012-10-09 doi: 10.3390/app2040682 Alessandro Belardini http://www.mdpi.com/2076-3417/2/3/669 One of the many singularities of Frank-Kasper phases is their ability to accommodate extremely large composition ranges by atom mixing on the different sites of the crystal structures. This phenomenon will be reviewed in the present paper with special emphasis on the experimental demonstration of this phenomenon, the theoretical calculation of disordered structures and the modeling of these phases. Applied Sciences 2012-09-10 2 3 Review 10.3390/app2030669 669 681 2076-3417 2012-09-10 doi: 10.3390/app2030669 Jean-Marc Joubert Jean-Claude Crivello http://www.mdpi.com/2076-3417/2/3/654 The site occupation of binary Fe-Cr, Co-Cr, Re-W and Fe-V sigma phases is studied in the present work with a first-principles-based single-site mean field theory. We show that the alloy components in these systems exhibit similar site preferences except for the Re-W system, where the occupation of two sites is reversed in agreement with previously published works. In case of the FeV sigma phase, for which the size mismatch between the alloy components is large, we also include into our consideration the effect of local lattice relaxations. The obtained results are found in good agreement with the experimental data and previous theoretical studies. Applied Sciences 2012-09-03 2 3 Article 10.3390/app2030654 654 668 2076-3417 2012-09-03 doi: 10.3390/app2030654 Evgeniya Kabliman Andrei V. Ruban Peter Blaha Oleg Peil Karlheinz Schwarz http://www.mdpi.com/2076-3417/2/3/641 The transesterification of waste frying oil (WFO) with methanol in the presence of potassium hydroxide catalyst supported on Jatropha curcas fruit shell activated carbon (KOH/JS) was studied. The catalyst systems were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the Brunauer–Emmett–Teller (BET) method. The effects of reaction variables such as residence time, reaction temperature, methanol/oil molar ratio and catalyst bed height in packed bed reactor (PBR) on the yield of biodiesel were investigated. SEM images showed that KOH was well distributed on the catalyst support. The optimum conditions for achieving the conversion yield of 86.7% consisted of a residence time of 2 h, reaction temperature of 60 °C, methanol/oil molar ratio of 16 and catalyst bed height of 250 mm. KOH/JS could be used repeatedly five times without any activation treatment, and no significant activity loss was observed. The results confirmed that KOH/JS catalyst had a great potential to be used for industrial application in the transesterification of WFO. The fuel properties of biodiesel were also determined. Applied Sciences 2012-08-29 2 3 Article 10.3390/app2030641 641 653 2076-3417 2012-08-29 doi: 10.3390/app2030641 Achanai Buasri Nattawut Chaiyut Vorrada Loryuenyong Chao Rodklum Techit Chaikwan Nanthakrit Kumphan http://www.mdpi.com/2076-3417/2/3/629 Linear Shaped Charges (LSCs) have been assumed to function in the same manner as Conical Shaped Charges (CSCs) in the published literature that describes a metallic jet process for penetration. However, based on the facts that the LSC liner is composed of flat surfaces instead of the curved cone shaped liner of a CSC and the LSC detonation propagation is perpendicular to the penetrator projection direction, the approach to investigate the penetrator formation process of LSCs should be examined from a different perspective. Because there are fundamental differences between CSCs and LSCs in the formation of a jet, the cutting performances would be under different regimes. As a preliminary investigation, in this paper, we report a numerical observation of the LSC jetting properties using AUTODYN®. Applied Sciences 2012-07-06 2 3 Article 10.3390/app2030629 629 640 2076-3417 2012-07-06 doi: 10.3390/app2030629 Matthew Johnston Seokbin Lim http://www.mdpi.com/2076-3417/2/3/602 The intrinsic advantages of optical sensor technology are very appealing for high voltage applications and can become a valuable asset in a new generation of smart grids. In this paper the authors present a review of optical sensors technologies for electrical current metering in high voltage applications. A brief historical overview is given together with a more detailed focus on recent developments. Technologies addressed include all fiber sensors, bulk magneto-optical sensors, piezoelectric transducers, magnetic force sensors and hybrid sensors. The physical principles and main advantages and disadvantages are discussed. Configurations and strategies to overcome common problems, such as interference from external currents and magnetic fields induced linear birefringence and others are discussed. The state-of-the-art is presented including commercial available systems. Applied Sciences 2012-07-02 2 3 Review 10.3390/app2030602 602 628 2076-3417 2012-07-02 doi: 10.3390/app2030602 Ricardo M. Silva Hugo Martins Ivo Nascimento José M. Baptista António Lobo Ribeiro José L. Santos Pedro Jorge Orlando Frazão http://www.mdpi.com/2076-3417/2/3/584 Intense urbanization, large scale industrialization and unprecedented population growth in the last few decades have been responsible for lowering environmental quality. Soil contamination with metals is a serious concern due to their toxicity and ability to accumulate in the biota. The present work assessed the heavy metal contamination of agricultural soil in the close vicinity of the Dhaka Export Processing Zone (DEPZ) in both dry and wet seasons using different indices viz., index of geoaccumulation (Igeo), contamination factor ( ), degree of contamination ( ), modified degree of contamination (mCd) and pollution load index (PLI). Samples were collected from the surface layer of soil and analyzed by Atomic Absorption Spectrophotometer (AAS). The trend of metals according to average concentration during the dry and wet seasons was As > Fe > Hg > Mn > Zn > Cu > Cr > Ni > Pb > Cd and As > Fe > Mn > Zn > Hg > Cu > Ni > Cr > Pb > Cd, respectively. Because of seasonal rainfall, dilution and other run-off during the wet season, metals from the upper layer of soil were flushed out to some extent and hence all the indices values were lower in this season compared to that of the dry season. Igeo results revealed that the study area was strongly and moderately contaminated with As and Hg in the dry and wet seasons respectively. According to , soil was classified as moderately contaminated with Zn, Cr, Pb and Ni, considerably contaminated with Cu and highly contaminated with As and Hg. The general trend of the mean was Hg > As > Cu > Zn > Ni > Cr > Pb > Fe > Mn > Cd and As > Hg > Cu > Cd > Zn > Ni >Pb > Fe > Mn in dry and wet seasons, respectively. The mCf values in the dry and wet seasons were 575.13 and 244.44 respectively indicating an ultra high degree of contamination. The Cd values in both seasons were associated with a very high degree of contamination. PLI results indicated immediate intervention to ameliorate pollution in both seasons. The main sources of metals included effluents from wastewater treatment plants, treated and untreated wastewater from surrounding industrial establishments as well as agricultural activities. Protecting the agricultural soil is a formidable challenge in the study area, which requires modernization of industries, thereby improving the recovery and recycling of wastewater. Indices analysis presented in the present work could serve as a landmark for contemporary research in toxicology. Applied Sciences 2012-07-02 2 3 Article 10.3390/app2030584 584 601 2076-3417 2012-07-02 doi: 10.3390/app2030584 Syed Hafizur Rahman Dilara Khanam Tanveer Mehedi Adyel Mohammad Shahidul Islam Mohammad Aminul Ahsan Mohammad Ahedul Akbor http://www.mdpi.com/2076-3417/2/3/566 The morphology of small gold particles prepared by Volmer–Weber growth on sapphire substrates have been investigated by two different characterization techniques. First, by non-extensive atomic force microscopy (AFM) in combination with optical spectroscopy and modeling of the optical properties using a theoretical model, recently developed in our group. Second, by extensive transmission electron microscopy (TEM). Comparing the results obtained with both techniques demonstrate that for small gold nanoparticles within the quasistatic limit, the morphological properties can be precisely determined by an appropriate theoretical modeling of the optical properties in combination with simple AFM measurements. The apparent mean axial ratio of the nanoparticles, i.e., the axial ratio that corresponds to the center frequency of the ensemble plasmon resonance, is obtained easily from the extinction spectrum. The mean size is determined by the nanoparticle number density and the amount of deposited material, measured by AFM and a quartz micro balance, respectively. To extract the most probable axial ratio of the nanoparticle ensemble, i.e., the axial ratio that corresponds to the most probable nanoparticle size in the ensemble, we apply the new theoretical model, which allows to extract the functional dependence of the nanoparticle shape on its size. The morphological parameters obtained with this procedure will be afterwards compared to extensive TEM measurements. The results obtained with both techniques yield excellent agreement. For example, the lateral dimensions of the nanoparticles after deposition of 15.2 × 1015 atoms/cm2 of gold has been compared. While a mean lateral diameter of (13 ± 2) nm has been extracted from AFM, optical spectroscopy and modeling, a value of (12 ± 2) nm is derived from TEM. The consistency of the results demonstrate the precision of our new model. Moreover, since our theoretical model allows to extract the functional dependence of the nanoparticle size and shape, a relatively simple analysis is sufficient for a full characterization of small noble metal nanoparticles. Applied Sciences 2012-07-02 2 3 Article 10.3390/app2030566 566 583 2076-3417 2012-07-02 doi: 10.3390/app2030566 Frank Hubenthal David Blázquez Sánchez Frank Träger http://www.mdpi.com/2076-3417/2/2/558 Fluorine is the 13th most abundant element and, with other fluorine containing functional groups, is a most effective element in biological substances, pharmaceuticals, agrochemicals, liquid crystals, dyes, polymers and a wide range of consumer products. This reflects its resistance to metabolic change due to the strength of the C-F bond providing biological stability and the application of its nonstick-interfacial physical characteristics. Its introduction often remains a synthetic challenge. The widespread use of organofluorines has increased the demand for the development of practical and simple reagents and experimental strategies for the incorporation of fluorine into all types of molecular structures and this was the reasoning behind this special feature on Organo-Fluorine Chemical Science.The contributed articles belong to two broad groups: (i) preparation of fluorine materials, polymers; (ii) the synthesis/applications of organo-fluorine molecules. [...] Applied Sciences 2012-06-04 2 2 Editorial 10.3390/app2020558 558 565 2076-3417 2012-06-04 doi: 10.3390/app2020558 Helmut Martin Hügel Neale Jackson http://www.mdpi.com/2076-3417/2/2/549 In this article, we analytically investigate the spectral broadening by self-phase modulation of strongly chirped optical pulses. The dispersion due to the nonlinear optical process is expressed as functions of a linear and a nonlinear initial chirp. As a result, it is found that the third-order dispersion strongly depends on the initial linear chirp and the nonlinearity for self-phase modulation. Applied Sciences 2012-06-04 2 2 Article 10.3390/app2020549 549 557 2076-3417 2012-06-04 doi: 10.3390/app2020549 Akira Suda Takanori Takeda http://www.mdpi.com/2076-3417/2/2/535 Shape memory polyurethanes (SMPUs) are typically synthesized using polyols of low molecular weight (MW~2,000 g/mol) as it is believed that the high density of cross-links in these low molecular weight polyols are essential for high mechanical strength and good shape memory effect. In this study, polyethylene glycol (PEG-6000) with MW ~6000 g/mol as the soft segment and diisocyanate as the hard segment were used to synthesize SMPUs, and the results were compared with the SMPUs with polycaprolactone PCL-2000. The study revealed that although the PEG-6000-based SMPUs have lower maximum elongations at break (425%) and recovery stresses than those of PCL-based SMPUs, they have much better recovery ratios (up to 98%) and shape fixity (up to 95%), hence better shape memory effect. Furthermore, PEG-based SMPUs showed a much shorter actuation time of < 10 s for up to 90% shape recovery compared to typical actuation times of tens of seconds to a few minutes for common SMPUs, demonstrated their great potential for applications in microsystems and other engineering components. Applied Sciences 2012-05-31 2 2 Article 10.3390/app2020535 535 548 2076-3417 2012-05-31 doi: 10.3390/app2020535 Manzoor Ahmad Bin Xu Hendra Purnawali Yongqing Fu Weimin Huang Mohsen Miraftab Jikui Luo http://www.mdpi.com/2076-3417/2/2/525 Angiogenesis, the growth of new capillary blood vessels, is central to the growth of tumors. Non-invasive imaging of tumor angiogenesis will allow for earlier detection of tumors and also the development of surrogate markers for assessing response to treatment. Steady state magnetic resonance imaging with magnetic nanoparticles is one method to assess angiogenesis. In this article we explain the theory behind steady state magnetic resonance imaging and review the available literature. Applied Sciences 2012-05-29 2 2 Review 10.3390/app2020525 525 534 2076-3417 2012-05-29 doi: 10.3390/app2020525 Shaunagh McDermott Alexander R. Guimaraes http://www.mdpi.com/2076-3417/2/2/513 In this work, new magnetic amphiphilic composites were prepared by chemical vapor deposition with ethanol on the surface of hydrophilic natural chrysotile matrix containing Fe catalyst. XRD, Raman, Mössbauer and SEM analyses suggest the formation of a complex nanostructured material composed of hydrophobic carbon nanotubes/nanofibers grown on the hydrophilic surface of the MgSi fiber mineral and the presence of Fe metallic nanoparticles coated by carbon. These nanostructured particles show amphiphilic properties and interact very well with both oil and aqueous phases. When added to emulsions the amphiphilic particles locate on the oil/water interface and, under a magnetic field, the oil droplets collapsed leading to the separation of the aqueous and oil phases. Preliminary work showed excellent results on the use of these particles to break wastewater emulsions in the biodiesel process. Applied Sciences 2012-05-29 2 2 Article 10.3390/app2020513 513 524 2076-3417 2012-05-29 doi: 10.3390/app2020513 Bruno R. S. Lemos Ana Paula C. Teixeira José D. Ardisson Waldemar A. A. Macedo Luis E. Fernandez-Outon Camila C. Amorim Flávia C. C. Moura Rochel M. Lago http://www.mdpi.com/2076-3417/2/2/496 The present review briefly describes the development of the fluoropolymer industry in the past 70 years. Discussed are industrial fluoropolymers including polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidenefluoride, polyvinylfluoride, ETFE, ECTFE, FEP, PFA, THV, Teflon AF and Cytop. Nafion is included as a special functional fluoropolymer material. These industrial fluoropolymers are introduced in the order of their discovery or time of first production, included are their chemical structures, thermal properties, mechanical properties, electrical and electronic properties, optical properties, chemical resistance, oxidative stabilities, weather stabilities, processabilities and their general applications. The main manufacturing companies for the different types of fluoropolymer products are also mentioned. Applied Sciences 2012-05-29 2 2 Review 10.3390/app2020496 496 512 2076-3417 2012-05-29 doi: 10.3390/app2020496 Hongxiang Teng http://www.mdpi.com/2076-3417/2/2/485 In this article, we present an efficient synthesis pathway of polydimethylsiloxane (PDMS) coated magnetic nanoparticles from hydrophilic polyacrylate coated ferrofluids (NPPAA). A block copolymer based on polydimethylsiloxane is selected for its propensity to interact with the carboxylate functions on the NPPAA. The interaction is due to negative charges on NPPAA and positive ones on the amphiphilic copolymer. The synthesis is achieved by interfacial interaction, simplifying the purification of the PDMS-coated nanoparticles (NPPDMS) from subproducts such as ions and water. NPPDMS are well dispersed in hydrophobic solvents (toluene, diethyl ether) and can then be embedded into a curable PDMS polymer. Applied Sciences 2012-05-29 2 2 Communication 10.3390/app2020485 485 495 2076-3417 2012-05-29 doi: 10.3390/app2020485 Carina Sötebier Aude Michel Jérôme Fresnais http://www.mdpi.com/2076-3417/2/2/479 Compressible squeeze film damping is a phenomenon of great importance for micromachines. For example, for the optimal design of an electrostatically actuated micro-cantilever mass sensor that operates in air, it is essential to have a model for the system behavior that can be evaluated efficiently. An analytical model that is based upon a solution of the linearized Reynolds equation has been given by R.B. Darling. In this paper we explain how some infinite sums that appear in Darling’s model can be evaluated analytically. As an example of applications of these closed form representations, we compute an approximation for the critical frequency where the spring component of the reaction force on the microplate, due to the motion through the air, is equal to a certain given multiple of the damping component. We also show how some double series that appear in the model can be reduced to a single infinite series that can be approximated efficiently. Applied Sciences 2012-05-21 2 2 Article 10.3390/app2020479 479 484 2076-3417 2012-05-21 doi: 10.3390/app2020479 Martin Gugat http://www.mdpi.com/2076-3417/2/2/465 The current report describes the development of a dual modality tomographic agent for both positron emission tomography and magnetic resonance imaging (PET/MRI). The dual-modality agent in this study was based on a 124I (PET) radiolabeled tri-gadolinium endohedral metallofullerene Gd3N@C80 (MRI) nanoprobe platform. The outer surface of the fullerene cage of the Gd3N@C80 metallofullerenes was surface functionalized with carboxyl and hydroxyl groups (f-Gd3N@C80) using previously developed procedures and subsequently iodinated with 124I to produce 124I-f-Gd3N@C80 nanoprobe. Orthotopic tumor-bearing rats were infused intratumorally by convection-enhanced delivery (CED) with the 124I-f-Gd3N@C80 agent and imaged by MRI or micro PET. The anatomical positioning and distribution of the 124I-f-Gd3N@C80 agent were comparable between the MRI and PET scans. The 124I-f-Gd3N@C80­ dual-agent distribution and infusion site within the tumor was clearly evident in both T1- and T2-weighted MR images. The results demonstrate the successful preparation of a dual-modality imaging agent, 124I-f-Gd3N@C80, which could ultimately be used for simultaneous PET/MR imaging. Applied Sciences 2012-05-10 2 2 Communication 10.3390/app2020465 465 478 2076-3417 2012-05-10 doi: 10.3390/app2020465 Jianqiao Luo John D. Wilson Jianyuan Zhang Jerry I. Hirsch Harry C. Dorn Panos P. Fatouros Michael D. Shultz http://www.mdpi.com/2076-3417/2/2/453 Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17) molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR) by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings. Applied Sciences 2012-05-08 2 2 Article 10.3390/app2020453 453 464 2076-3417 2012-05-08 doi: 10.3390/app2020453 Jean-Denis Brassard D.K. Sarkar Jean Perron http://www.mdpi.com/2076-3417/2/2/443 Our simple Meisenheimer model for predicting the principal site for nucleophilic substitution in aromatic perfluorocarbons is further tested on a series of recently published reactions in liquid ammonia primarily from Malykhin and coworkers. The model accurately predicts the experimental results for all of the reactions reported further confirming its general applicability. Applied Sciences 2012-05-04 2 2 Article 10.3390/app2020443 443 452 2076-3417 2012-05-04 doi: 10.3390/app2020443 Jon Baker Baker Max Muir http://www.mdpi.com/2076-3417/2/2/396 This article reviews the size-dependent structural properties of ion beam synthesized Co nanoparticles (NPs) and the influence of ion irradiation on the size, shape, phase and structure. The evolution of the aforementioned properties were determined using complementary laboratory- and advanced synchrotron-based techniques, including cross-sectional transmission electron microscopy, small-angle X-ray scattering and X-ray absorption spectroscopy. Combining such techniques reveals a rich array of transformations particular to Co NPs. This methodology highlights the effectiveness of ion implantation and ion irradiation procedures as a means of fine tuning NP properties to best suit specific technological applications. Furthermore, our results facilitate a better understanding and aid in identifying the underlying physics particular to this potentially technologically important class of nanomaterials. Applied Sciences 2012-04-27 2 2 Review 10.3390/app2020396 396 442 2076-3417 2012-04-27 doi: 10.3390/app2020396 David J. Sprouster Mark C. Ridgway http://www.mdpi.com/2076-3417/2/2/375 Planar metamaterials and many microwave circuits and antennas are designed by means of resonators with dimensions much smaller than the wavelength at their resonance frequency. There are many types of such electrically small resonators, and the main purpose of this paper is to compare them as building blocks for the implementation of microwave components. Aspects such as resonator size, bandwidth, their circuit models when they are coupled to transmission lines (as is usually required), as well as key applications, will be considered. Applied Sciences 2012-04-20 2 2 Article 10.3390/app2020375 375 395 2076-3417 2012-04-20 doi: 10.3390/app2020375 Miguel Durán-Sindreu Jordi Naqui Ferran Paredes Jordi Bonache Ferran Martín http://www.mdpi.com/2076-3417/2/2/368 This article describes one-pot synthesis of new fluorinated hexahydroquinoline derivatives via unsymmetric Hantzsch reaction involving 5-trifluoromethyl-1,3-cyclohexanedione, aldehydes, acetoacetate ester, and ammonium acetate in trifluoroethanol (TFE). The reaction is simple and rapid with high yield. Applied Sciences 2012-04-18 2 2 Article 10.3390/app2020368 368 374 2076-3417 2012-04-18 doi: 10.3390/app2020368 Cosmas O. Okoro Mumiye A. Ogunwale Tasneem Siddiquee http://www.mdpi.com/2076-3417/2/2/351 The α,ω-dialkoxyfluoropolyethers (DA-FPEs) characterized by the structure RHO(CF2CF2O)n(CF2O)mRH have been developed as a new class of environmentally friendly hydrofluoroethers (HFEs) suitable as solvents, long-term refrigerants, cleaning fluids, and heat transfer fluids. Synthetic methodologies for DA-FPEs described here consist of radical-initiated oxypolymerization of olefin, peroxy-elimination reaction in peroxidic perfluoropolyethers (P-PFPEs) and further chemical modification of α,ω-diacylfluoride PFPE. The physical properties of selected α,ω-dimethoxyfluoropolyethers (DM-FPEs) have been evaluated and compared with analogous hydrofluoropolyethers (HFPEs) having -OCF2H as end-groups. Atmospheric implications and global warming potentials (GWPs) of selected DA-FPEs are also considered. Applied Sciences 2012-04-11 2 2 Review 10.3390/app2020351 351 367 2076-3417 2012-04-11 doi: 10.3390/app2020351 Menghua Wu Walter Navarrini Gianfranco Spataro Francesco Venturini Maurizio Sansotera http://www.mdpi.com/2076-3417/2/2/342 Aggregation of magnetic nanoparticles immobilized in polymer gels was studied by ferromagnetic resonance and paramagnetic sensor techniques. Ferromagnetic resonance spectra of magnetic gels prepared in the presence of external magnetic field of 1.5 kG were compared to the spectra of gels synthesized in the absence of a magnetic field. Application of a magnetic field led to formation of linear aggregates of magnetic particles in the polymer matrix. The aggregates did not come apart after the field was switched off. The fraction of aggregated particles (of 62(6)%) and aspect ratio (elongation) of the aggregates (12.6(1.3)) was determined using paramagnetic sensor technique. Applied Sciences 2012-04-10 2 2 Article 10.3390/app2020342 342 350 2076-3417 2012-04-10 doi: 10.3390/app2020342 Olga N. Sorokina Alexander L. Kovarski Marina A. Lagutina Sergey A. Dubrovskii Fridrikh S. Dzheparov http://www.mdpi.com/2076-3417/2/2/327 A new polyfluorinated anti-staining coating material CF3O(CF2CF2O)xCF2-CONHCH2CH2CH2Si(OCH3)3 has been developed by utilizing the PERFECT method, which employs a liquid-phase direct fluorination reaction with elemental fluorine as a key step. Direct fluorination of a partially-fluorinated ester, which was prepared from a non-fluorinated poly(ethylene glycol) and a perfluorinated acyl fluoride, followed by methanolysis, gave the perfluorinated corresponding compound, which was led to the coating material for surface treating agents, and the methyl ester of the starting perfluorinated acyl fluoride. Application to the synthesis of a new perfluorinated bifunctional sulfonate monomer CF2=CFOCF2CF2CF2OCF(CF2SO2F)2 for polymer electrolyte membranes (PEMs) of fuel cells was also developed. Applied Sciences 2012-04-10 2 2 Article 10.3390/app2020327 327 341 2076-3417 2012-04-10 doi: 10.3390/app2020327 Takashi Okazoe Daisuke Shirakawa Koichi Murata http://www.mdpi.com/2076-3417/2/2/315 We have studied the internal magnetic order of 3-nm (Fe0.69Co0.31)0.6B0.4 amorphous nanoparticles. These nanoparticles were dispersed in a non-magnetic matrix (non-interacting nanoparticles) to contrast them with the powder samples, where strong interparticle interactions are present. In similar fashion to the bulk alloy, this system exhibits a saturation magnetization maximum as a function of Fe composition near 69 at% Fe for the powder and dispersed samples at all temperatures. The saturation magnetization (MS) of the dispersed sample shows anomalous behavior, revealing frustration in the internal magnetic order of the particles. Unexpectedly, the MS of the non-interacting sample at low temperatures is larger than the corresponding bulk alloy or the calculated value of MS for the same Fe-Co composition. By contrast, the powder sample has low MS values and it is approximately constant in temperature. Applied Sciences 2012-04-02 2 2 Article 10.3390/app2020315 315 326 2076-3417 2012-04-02 doi: 10.3390/app2020315 Belén Molina-Concha Roberto D. Zysler Héctor Romero http://www.mdpi.com/2076-3417/2/2/303 The polymerase chain reaction (PCR) method is widely used for the reproduction and amplification of specific DNA segments, and a novel PCR method using nanomaterials such as gold nanoparticles has recently been reported. This paper reports on the effects of superparamagnetic nanoparticles on PCR amplification without an external magnetic field, and clarifies the mechanism behind the effects of superparamagnetic particle clusters on PCR efficiency by estimating the structures of such clusters in PCR. It was found that superparamagnetic nanoparticles tend to inhibit PCR amplification depending on the structure of the magnetic nanoparticle clusters. The paper also clarifies that Taq polymerase is captured in the spaces formed among magnetic nanoparticle clusters, and that it is captured more efficiently as a result of their motion from heat treatment in PCR thermal cycles. Consequently, Taq polymerase that should be used in PCR is reduced in the PCR solution. These outcomes will be applied to novel PCR techniques using magnetic particles in an external magnetic field. Applied Sciences 2012-04-02 2 2 Article 10.3390/app2020303 303 314 2076-3417 2012-04-02 doi: 10.3390/app2020303 Toshiaki Higashi Hiroaki Minegishi Yutaka Nagaoka Takahiro Fukuda Akinobu Echigo Ron Usami Toru Maekawa Tatsuro Hanajiri http://www.mdpi.com/2076-3417/2/2/277 Silicon-[18F]fluorine (Si-18F) radiochemistry has recently emerged alongside other unconventional approaches such as aluminum-18F and boron-18F based labeling strategies, reshaping the landscape of modern 18F-radiochemistry. All these novel methodologies are driven by the demand for more convenient 18F-labeling procedures to further disseminate one of the most sophisticated imaging technologies, Positron Emission Tomography (PET). The PET methodology requires special radionuclides such as 18F (one of the most prominent examples) to be introduced into bioactive molecules. Si-18F radiochemistry contributed greatly towards the development of new radiopharmaceuticals for PET imaging. Herein, we describe the radiochemical basics of Si-18F bond formation, the application of Si-18F tracers for PET imaging, and additionally, the inherent chemical intricacies of this methodology. Applied Sciences 2012-03-28 2 2 Review 10.3390/app2020277 277 302 2076-3417 2012-03-28 doi: 10.3390/app2020277 Carmen Wängler Alexey Kostikov Jun Zhu Joshua Chin Björn Wängler Ralf Schirrmacher http://www.mdpi.com/2076-3417/2/2/260 The synthesis of magnetically separable quasi-homogeneous base catalyst and heterogeneous base catalyst is described. The quasi-homogeneous catalyst is achieved by supporting silane monomers functionalized with different amine groups directly on the surface of magnetite nanoparticles. The heterogeneous catalyst is prepared via a sol-gel process in which silane monomers containing different amine groups are copolymerized with tetraethoxysilane in the presence of magnetite nanoparticles functionalized with ionic liquid moieties. The reactivity of the quasi-homogeneous and the heterogeneous base catalysts is compared in the nitroaldol condensation. Applied Sciences 2012-03-26 2 2 Article 10.3390/app2020260 260 276 2076-3417 2012-03-26 doi: 10.3390/app2020260 Raed Abu-Reziq Howard Alper http://www.mdpi.com/2076-3417/2/2/245 Nucleic acid-based fluorinated derivatives, e.g., nucleosides or oligonucleotides connected to highly fluorinated chains or labeled with one or more fluorine atoms, have been investigated recently due to their high potential for biomedical applications. This review deals with recent works on nucleoside and oligonucleotide fluorocarbon amphiphiles as well as with properties and applications of fluorine-labeled oligonucleotide analogues. Applied Sciences 2012-03-23 2 2 Review 10.3390/app2020245 245 259 2076-3417 2012-03-23 doi: 10.3390/app2020245 Christel Dolain Amit Patwa Guilhem Godeau Philippe Barthélémy http://www.mdpi.com/2076-3417/2/1/233 This paper reports significant improvements in the electrical performance of In0.53Ga0.47As metal-oxide-semiconductor field-effect transistors (MOSFET) by a post-gate CF4/O2 plasma treatment. The optimum condition of CF4/O2 plasma treatment has been systematically studied and found to be 30 W for 3–5 min. Approximately 5× reduction in interface trap density from 2.8 × 1012 to 4.9 × 1011 cm−2eV−1 has been demonstrated with fluorine (F) incorporation. Subthreshold swing has been improved from 127 to 109 mV/dec. Effective channel mobility has been enhanced from 826 to 1,144 cm2/Vs. Applied Sciences 2012-03-19 2 1 Article 10.3390/app2010233 233 244 2076-3417 2012-03-19 doi: 10.3390/app2010233 Yen-Ting Chen Yanzhen Wang Fei Xue Fei Zhou Jack C. Lee http://www.mdpi.com/2076-3417/2/1/220 The scattering of the unpolarized beams of electrons by nanomagnets in the vicinity of some scattering angles leads to complete spin polarized electrons. This result is obtained with the help of the perturbation theory. The dipole-dipole interaction between the magnetic moment of the nanomagnet and the magnetic moment of electron is treated as perturbation. This interaction is not spherically symmetric. Rather it depends on the electron spin variables. It in turn results in spinor character of the scattering amplitudes. Due to the smallness of the magnetic interactions, the scattering length of this process is very small to be proved experimentally. To enhance the relevant scattering lengths, we considered the diffraction of unpolarized beams of electrons by linear chains of nanomagnets. By tuning the distance between the scatterers it is possible to obtain the diffraction maximum of the scattered electrons at scattering angles which corresponds to complete spin polarization of electrons. It is shown that the total differential scattering length is proportional to N2 (N is a number of scatterers). Even small number of nanomagnets in the chain helps to obtain experimentally visible enhancement of spin polarization of the scattered electrons. Applied Sciences 2012-03-06 2 1 Article 10.3390/app2010220 220 232 2076-3417 2012-03-06 doi: 10.3390/app2010220 Teshome Senbeta Vadim N. Mal’nev http://www.mdpi.com/2076-3417/2/1/206 In this paper, we review recent progress and new challenges in the area of oxyfluoride perovskite, especially layered systems including Ruddlesden-Popper (RP), Dion-Jacobson (DJ) and Aurivillius (AV) type perovskite families. It is difficult to synthesize oxyfluoride perovskite using a conventional solid-state reaction because of the high chemical stability of the simple fluoride starting materials. Nevertheless, persistent efforts made by solid-state chemists have led to a major breakthrough in stabilizing such a mixed anion system. In particular, it is known that layered perovskite compounds exhibit a rich variety of O/F site occupation according to the synthesis used. We also present the synthetic strategies to further extend RP type perovskite compounds, with particular reference to newly synthesized oxyfluorides, Sr2CoO3F and Sr3Fe2O5+xF2−x (x ~ 0.44). Applied Sciences 2012-03-06 2 1 Review 10.3390/app2010206 206 219 2076-3417 2012-03-06 doi: 10.3390/app2010206 Yoshihiro Tsujimoto Kazunari Yamaura Eiji Takayama-Muromachi http://www.mdpi.com/2076-3417/2/1/192 Environmental concerns related to perfluoroctanoic acid (PFOA) led to a re-examination of the methods for imparting stain resistance and stain repellency to textiles. Non-PFOA fluoropolymer finishes have been formed on cotton knits by admicellar polymerization, a surface analogue of emulsion polymerization. Fabric samples were characterized by a drop test, contact angle measurements, SEM, elemental analysis and durability studies. Stain resistance and stain release properties were assessed by reflectance and AATCC tests with results comparing favorably with swatches from commercially available garments. Admicellar polymerization enabled the formation of durable finishes that exhibited high performance in stain resistance and stain repellency. Applied Sciences 2012-03-05 2 1 Article 10.3390/app2010192 192 205 2076-3417 2012-03-05 doi: 10.3390/app2010192 Srinivas Hanumansetty Jayanta Maity Rod Foster Edgar A. O’Rear http://www.mdpi.com/2076-3417/2/1/175 A new class of alkyl- and perfluoroalkyl-containing urea and amide derivatives was synthesized from amino acid derivatives. Most of these compounds showed excellent gelation behavior in organic solvents at low concentrations. A few organogelators selected from the initial screening were used for surface modification of fibrous substrates to create hydrophobic and oleophobic composites. The hydrophobic and oleophobic behaviors of these composites were ascribed to a combination of increased surface roughness and the alkyl/fluorinated functionalities present in the gelator backbone. Applied Sciences 2012-03-01 2 1 Article 10.3390/app2010175 175 191 2076-3417 2012-03-01 doi: 10.3390/app2010175 Anilkumar Raghavanpillai Vincent A. Franco http://www.mdpi.com/2076-3417/2/1/166 A manganese immobilization technology in a fluidized-bed reactor (FBR) was developed by using a waste iron oxide (i.e., BT-3) as catalyst which is a by-product from the fluidized-bed Fenton reaction (FBR-Fenton). It was found that BT-3 could easily reduce potassium permanganate (KMnO4) to MnO2. Furthermore, MnO2 could accumulate on the surface of BT-3 catalyst to form a new Fe-Mn oxide. Laboratory experiments were carried out to investigate the KMnO4-reduction mechanism, including the effect of KMnO4 concentration, BT-3 dosage, and operational solution pH. The results showed that the pH solution was a significant factor in the reduction of KMnO4. At the optimum level, pHf 6, KMnO4 was virtually reduced in 10 min. A pseudo-first order reaction was employed to describe the reduction rate of KMnO4. Applied Sciences 2012-03-01 2 1 Article 10.3390/app2010166 166 174 2076-3417 2012-03-01 doi: 10.3390/app2010166 Guang-Xia Li Yao-Hui Huaug Teng-Chien Chen Yu-Jen Shih Hui Zhang http://www.mdpi.com/2076-3417/2/1/160 Past work has demonstrated the value of a random walk theory (RWT) to solve multiple-scattering problems arising in numerous contexts. This paper’s goal is to investigate the application range of the RWT using Monte Carlo simulations and extending it to anisotropic media using scaling laws. Meanwhile, this paper also reiterates rules for converting RWT formulas to real physical dimensions, and corrects some errors which appear in an earlier publication. The RWT theory, validated by the Monte Carlo simulations and combined with the scaling law, is expected to be useful to study multiple scattering and to greatly reduce the computation cost. Applied Sciences 2012-03-01 2 1 Article 10.3390/app2010160 160 165 2076-3417 2012-03-01 doi: 10.3390/app2010160 Xuesong Li Lin Ma http://www.mdpi.com/2076-3417/2/1/139 Currently, quantitative real-time PCR (Q-PCR) of archival formalin-fixed, paraffin embedded (FFPE) tissue is a critical tool for research and is not well established in routine diagnostics. Therefore, continuous improvement in mathematics and statistics associated with interpreting final accurate and reproducible results are fundamental. This project describes and discusses specificity and sensitivity with respect to intra- and inter-assay variances by use of a commercial Human Reference RNA and individual RNA derived from colorectal cancer patients (n = 25). All patients were treated with 5-fluoruracil (5-FU) and a concomitant pelvic radiotherapy (50.4 Gy). Quality assessment of target tissue samples was evaluated by clinicopathological findings and optical density (OD) measurements. We analyzed the steady state messenger RNA (mRNA) expression level of a small panel of cancer relevant genes, excision repair cross-complementing group 1 (ERCC1), ribonucleoside-diphosphate reductase subunit M1 (RRM1), thymidylate synthase (TYMS) and ß-2microglobulin (ß-2M) as endogenous control. The mRNA of a Human Reference RNA, tumor and non-neoplastic material was reverse transcribed into its complementary DNA (cDNA). cDNA was amplified based on dual-labeled TaqMan real-time fluorescence measurements. The real-time efficiency and therefore the output data can be influenced through the kind of calibrator used, the amount and quality of used RNA and by the degree of individual assay variability. Each sample presents an individual amplification curve. Thus, confirmation of primer specificity, one or more invariant endogenous controls, RNA and cDNA quality, as well as real-time PCR amplification efficiencies and linearity calculations from individual slopes or R2-values must be included in each study. Applied Sciences 2012-02-24 2 1 Article 10.3390/app2010139 139 159 2076-3417 2012-02-24 doi: 10.3390/app2010139 Melanie Demes Holger Bartsch Stefanie Scheil-Bertram Ralph Mücke Annette Fisseler-Eckhoff http://www.mdpi.com/2076-3417/2/1/129 The reaction of 2,4-diethoxy-6-trifluoromethyl-3,4-dihydro-2H-pyran (1) with aromatic compounds in refluxing acetonitrile in the presence of p-toluenesulfonic acid gave the mixture of 4-aryl-2-trifluoromethyl-4H-pyrans (3) and 6-aryl-1,1,1-trifluorohexa-3,5-dien-2-ones (4). In contrast, the same reaction carried out in trifluoroacetic acid at ambient temperature afforded 4-aryl-2-ethoxy-6-trifluoromethyl-3,4-dihydro-2H-pyrans (2) selectively. These two types of reactions giving quite different products under each condition were studied on the basis of DFT calculations. Moreover, the proposed mechanism for the reaction of 5-trifluoroacetyl-6-trifluoromethyl-3,4-dihydro-2H-pyran (5) with aromatic compounds affording butadiene derivatives (6) exclusively was also discussed based on the calculations and comparison with the reactivity of pyrylium intermediate (7). Applied Sciences 2012-02-24 2 1 Article 10.3390/app2010129 129 138 2076-3417 2012-02-24 doi: 10.3390/app2010129 Norio Ota Yasuhiro Kamitori Ryusuke Shirai Mizuki Hatakenaka Etsuji Okada http://www.mdpi.com/2076-3417/2/1/114 The effect of variously fluorine-substituted β-methyl-β-nitrostyrenes on their antimicrobial activity was investigated. Their efficacy was determined by minimum inhibition concentration (MIC) in cultures of Gram positive and Gram negative bacteria and a fungus. Highest activity against the Gram negative bacterium, E.coli, was achieved with 4-fluorine-aryl substituted β-methyl-β-nitrostyrenes, while most compounds gave excellent results against gram positive bacteria. Importantly, the addition of the β-methyl group profoundly enhanced the antibacterial activity of the compounds tested. The comparative KD values for the most potent compounds against E.coli were much lower than those required for the gram positive and fungus counterparts. This investigation illustrated that fluorine substituted nitropropenylarenes have enhanced antimicrobial activity suitable for antibiotic applications. Applied Sciences 2012-02-23 2 1 Article 10.3390/app2010114 114 128 2076-3417 2012-02-23 doi: 10.3390/app2010114 King Lo Hugh Cornell Gina Nicoletti Neale Jackson Helmut Hügel http://www.mdpi.com/2076-3417/2/1/100 This paper presents a logic-based supervisor controller designed for trackers for a 1MW HCPV demo plant in Taiwan. A sun position sensor on the tracker is used to detect the sun position, as the sensor is sensitive to the intensity of sun light. The signal output of the sensor is partially affected by the cloud, which has a hard control position with the traditional PID control. Therefore we have used logic-based supervisor (LBS) control which permits switching the PID control to sun trajectory under sunny or cloudy conditions. To verify the stability of the proposed control, an experiment was performed and the results show that the proposed control can efficiently achieve stabilization of the trackers of the 1MW HCPV demo plant. Applied Sciences 2012-02-07 2 1 Article 10.3390/app2010100 100 113 2076-3417 2012-02-07 doi: 10.3390/app2010100 Hong-Yih Yeh Cheng-Dar Lee http://www.mdpi.com/2076-3417/2/1/61 Several fluorinated and trifluoromethylated indanone, tetralone and naphthone derivatives have been prepared via Claisen condensations and selective fluorinations in yields ranging from 22–60%. In addition, we report the synthesis of new, selectively fluorinated bindones in yields ranging from 72–92%. Of particular interest is the fluorination and trifluoroacetylation regiochemistry observed in these fluorinated products. We also note unusual transformations including a novel one pot, dual trifluoroacetylation, trifluoroacetylnaphthone synthesis via a deacetylation as well as an acetyl-trifluoroacetyl group exchange. Solid-state structural features exhibited by these compounds were investigated using crystallographic methods. Crystallographic results, supported by spectroscopic data, show that trifluoroacetylated ketones prefer a chelated cis-enol form whereas fluorinated bindone products exist primarily as the cross-conjugated triketo form. Applied Sciences 2012-02-01 2 1 Article 10.3390/app2010061 61 99 2076-3417 2012-02-01 doi: 10.3390/app2010061 Joseph C. Sloop Paul D. Boyle Augustus W. Fountain Cristina Gomez James L. Jackson William F. Pearman Robert D. Schmidt Jonathan Weyand http://www.mdpi.com/2076-3417/2/1/46 Perfluorinated graded-index polymer optical fibers (PFGI-POFs), fabricated by replacing the hydrogen atoms of standard polymethyl methacrylate-based POFs with fluorine atoms, have been extensively studied due to their relatively low propagation loss even at telecommunication wavelength. Recently, Brillouin scattering, which is one of the most significant nonlinear effects in optical fibers, has been successfully observed in PFGI-POFs at 1.55-μm wavelength. The Brillouin Stokes signal was, however, not large enough for practical applications or for detailed investigations of the Brillouin properties. In this paper, we review our recent work on Stokes signal enhancement. First, we induce stimulated Brillouin scattering based on the so-called pump-probe technique, and discuss its applicability to temperature sensors. Then, we investigate the influence of the core diameter and length of PFGI-POFs on Stokes signal, and observe the Brillouin linewidth narrowing effect. We believe our work is an important technological step toward the implementation of practical Brillouin-based devices and systems including distributed strain and temperature sensors. Applied Sciences 2012-01-31 2 1 Review 10.3390/app2010046 46 60 2076-3417 2012-01-31 doi: 10.3390/app2010046 Yosuke Mizuno Kentaro Nakamura http://www.mdpi.com/2076-3417/2/1/35 Birkhoff theory exhibits an analytical steady state liner collapse model of shaped charges followed by jetting process. It also provides the fundamental idea in study of shaped charges and has widened its application in many areas, including a configuration where the detonation front strikes the entire liner surface at the same time providing the α = β (liner apex angle α, and the liner collapse point angle β) condition in the literature. Upon consideration of the detonation front propagation along the lateral length of the core charge in LSCs (linear shaped charges), a further modification of the Birkhoff theory motivated by the unique geometrical condition of LSCs and the α = β condition is necessary to correctly describe the jetting behavior of LSCs which is different than that of CSCs (conical shaped charges). Based on such unique geometrical properties of LSCs, the original Birkhoff theory was modified and an analytical steady state LSCs model was built. The analytical model was then compared to the numerical simulation results created from Autodyn™ in terms of M/C ratio and apex angles in three different sized LSCs, and it exhibits favorable results in a limited range. Applied Sciences 2012-01-31 2 1 Article 10.3390/app2010035 35 45 2076-3417 2012-01-31 doi: 10.3390/app2010035 Seokbin Lim http://www.mdpi.com/2076-3417/2/1/24 The generated resist based defects on the template in addition to the presence of particles and contaminants is critical for ultraviolet curing of nanoimprint lithographic fabrication. This procedure is proven to be suitable for advanced resist material design under the process conditions. Nanoimprint resist material containing an ultraviolet reactive fluorine surfactant was developed to modify the fundamental surface interactions between resists and the template for defect reduction in nanoimprint patterning replication. The developed acrylate type nanoimprint resist material containing 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoro-2-hydroxyundecyl acrylate as an ultraviolet reactive fluorine surfactant, indicated excellent patterning dimensional accuracy by minimizing surface free energy, and having the effect of improving the generated resist based defect numbers on the template, with a 500 nm contact hole and 2 μm line patterns, in the replication of 20 nanoimprint process cycles. This desirable concept using an ultraviolet reactive fluorine surfactant with an acrylate group in the acrylate type nanoimprint resist material is one of the most promising processes ready to be incorporated into mass fabrication in the next generation of electronic devices. Applied Sciences 2012-01-16 2 1 Article 10.3390/app2010024 24 34 2076-3417 2012-01-16 doi: 10.3390/app2010024 Satoshi Takei Atsushi Sekiguchi http://www.mdpi.com/2076-3417/2/1/13 Sampling of small molecules from both porous and non-porous surfaces poses a significant challenge across biological agents. Particle sizes of toxins are smaller than living organisms and can be extremely toxic at low level concentrations. A small number of studies evaluating sampling efficiencies of commercial off the shelf (COTS) materials have been performed with toxins and proteins. However, they have been limited to non-ricin stimulants with drastically different physical properties than their native counterparts. We have identified a commercially available non-toxic recombinant ricin, complete with both A and B subunits present, which can be recognized by antibodies commonly used to assay native ricin. In evaluating recovery efficiency, we deposited the recombinant ricin by both liquid deposition, and as a dry aerosol. Our studies demonstrated a significant difference in recovery efficiencies from liquid deposited ricin, ranging between 30% and 70%, than from an aerosol generated deposition ranging from below detectable levels to 22%, depending on the contaminated surface and swab material being used. This study demonstrates the necessity for accurate dissemination techniques of sampling technologies for the consideration of use in an environment where suspected toxin contamination is being evaluated. Applied Sciences 2012-01-13 2 1 Article 10.3390/app2010013 13 23 2076-3417 2012-01-13 doi: 10.3390/app2010013 Jason M. Edmonds Patricia J. Collett Rebecca L. Brown Kishna Mangaya http://www.mdpi.com/2076-3417/2/1/1 Some chiral β-amino alcohols have been evaluated as potential ligands for the ruthenium-catalyzed asymmetric transfer hydrogenation (ATH) of N-phosphinyl ketimines in isopropyl alcohol. The ruthenium complex prepared from [RuCl2(p-cymene)]2 and (1S,2R)-1-amino-2-indanol has shown to be an efficient catalyst for the ATH of several N-(diphenylphosphinyl)imines, affording the reduction products in very good isolated yields and enantiomeric excesses up to 82%. The inherent rigidity of the indane ring system present in the ligand seems to be very important to achieve good enantioselectivities. Applied Sciences 2012-01-09 2 1 Communication 10.3390/app2010001 1 12 2076-3417 2012-01-09 doi: 10.3390/app2010001 Óscar Pablo David Guijarro Miguel Yus http://www.mdpi.com/2076-3417/1/1/13 Cellular life is reliant upon rapid and efficient responses to internal and external conditions. The basic molecular events associated with these processes are the structural transitions of the proteins (structural protein allostery) involved. From this view, the human hemoglobin (Hb) molecule (α2β2) holds a special position in this field. Hb has two types of αβ interface (i.e., α1β1 [and α2β2] and α1β2 [and α2β1]). The latter α1–β2 (and α2–β1) interface is known to be associated with cooperative O2 binding, and exhibits principal roles if the molecule goes from its deoxy to oxy quaternary structure. However, the role of the former α1–β1 (and α2–β2) interface has been unclear for a long time. In this regard, important and intriguing observations have been accumulating. A new role was attributed first as stabilizing the HbO2 tetramer against acidic autoxidation. That is, the α1–β1 (and α2–β2) interface produces a conformational constraint in the β chain whereby the distal (E7) histidine (His) residue is tilted slightly away from the bound O2 so as to prevent proton-catalyzed displacement of O2– by a solvent water molecule. The β chains thus acquire pH-dependent delayed autoxidation in the HbO2 tetramer. The next role was suggested by our studies searching for similar phenomena in normal human erythrocytes under mild heating. Tilting of the distal (E7) His in turn triggered degradation of the Hb molecule to hemichrome, and subsequent clustering of Heinz bodies within the erythrocyte. As Heinz body-containing red cells become trapped in the spleen, it was demonstrated that the α1–β1 (and α2–β2) interface may exert delicate control of the fate (removal) of its own erythrocyte. Herein we review and summarize the related results and current interpretation of the oxidative behavior of human Hb, emphasizing the correlation between hemichrome emergence and Heinz-body formation, and specifically discuss the new roles assigned to the α1–β1 (and α2–β2) interface. The α1–β1 (and α2–β2) interface seems to adequately differentiate between the two types of function (dual roles) from physiological to cellular. Applied Sciences 2011-11-17 1 1 Review 10.3390/app1010013 13 55 2076-3417 2011-11-17 doi: 10.3390/app1010013 Yoshiaki Sugawara Mai Yamada Eriko Ueno Mai Okazaki Aya Okamoto Mariko Miyake Fusako Fukami Ai Yano http://www.mdpi.com/2076-3417/1/1/12 Applied sciences cover many interdisciplinary fields that put basic sciences to application and make big changes by taking the one not-so-small step from “knowing how” to “knowing how-to”, the serendipity of which is often intriguing. Applied sciences are so deeply entrenched in almost all aspects of our daily lives. To provide an advanced forum for scholars all over the world to discuss and communicate the cutting-edge development in this field, on behalf of the Editorial Board members, I am honored to introduce Applied Sciences, a scholarly, peer-reviewed open access journal. [...] Applied Sciences 2011-09-16 1 1 Editorial 10.3390/app1010012 12 12 2076-3417 2011-09-16 doi: 10.3390/app1010012 Takayoshi Kobayashi http://www.mdpi.com/2076-3417/1/1/1 Previous studies were able to demonstrate different verbally stated affective responses to environments. In the present study we used objective measures of emotion. We examined startle reflex modulation as well as changes in heart rate and skin conductance while subjects virtually walked through six different areas of urban Paris using the StreetView tool of Google maps. Unknown to the subjects, these areas were selected based on their median real estate prices. First, we found that price highly correlated with subjective rating of pleasantness. In addition, relative startle amplitude differed significantly between the area with lowest versus highest median real estate price while no differences in heart rate and skin conductance were found across conditions. We conclude that interaction with environmental scenes does elicit emotional responses which can be objectively measured and quantified. Environments activate motivational and emotional brain circuits, which is in line with the notion of an evolutionary developed system of environmental preference. Results are discussed in the frame of environmental psychology and aesthetics. Applied Sciences 2011-07-01 1 1 Article 10.3390/app1010001 1 11 2076-3417 2011-07-01 doi: 10.3390/app1010001 Moritz Geiser Peter Walla