Next Issue
Previous Issue

Table of Contents

Appl. Sci., Volume 7, Issue 8 (August 2017)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Cover Story (view full-size image) The suppression of the cavity tone by plasma actuators was investigated by the computations along [...] Read more.
View options order results:
result details:
Displaying articles 1-114
Export citation of selected articles as:
Open AccessArticle
Characterizing Flow-Induced Vibrations of Fuel Assemblies for Future Liquid Metal Cooled Nuclear Reactors Using Quasi-Distributed Fibre-Optic Sensors
Appl. Sci. 2017, 7(8), 864; https://doi.org/10.3390/app7080864
Received: 1 August 2017 / Revised: 16 August 2017 / Accepted: 19 August 2017 / Published: 22 August 2017
Cited by 3 | Viewed by 1758 | PDF Full-text (5589 KB) | HTML Full-text | XML Full-text
Abstract
Excessive vibration of nuclear reactor components, such as the heat exchanger or the fuel assembly should be avoided as these can compromise the lifetime of these components and potentially lead to safety hazards. This issue is particularly relevant to new reactor designs that [...] Read more.
Excessive vibration of nuclear reactor components, such as the heat exchanger or the fuel assembly should be avoided as these can compromise the lifetime of these components and potentially lead to safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants. However, identifying adequate sensors or techniques that can be successfully applied to record the vibrations of the components in a flow of liquid metal at elevated temperatures is very challenging. In this paper, we demonstrate the precise measurements of the vibrations of a very representative mock-up of a fuel assembly in a lead-bismuth eutectic cooled installation using quasi-distributed fibre Bragg grating (FBG) based sensors. The unique properties of these sensors, in combination with a dedicated integration and mounting approach, allows for accounting of the severe geometrical constraints and allows characterizing the vibration of the fuel assembly elements under nominal operation conditions. To that aim, we instrumented a single fuel pin within the fuel assembly with 84 FBGs, and conducted spectral measurements with an acquisition rate of up to 5000 measurements per second, enabling the monitoring of local strains of a few με. These measurements provide the information required to assess vibration-related safety hazards. Full article
(This article belongs to the Special Issue Distributed Optical Fiber Sensors)
Figures

Figure 1

Open AccessPerspective
Paper and Fiber-Based Bio-Diagnostic Platforms: Current Challenges and Future Needs
Appl. Sci. 2017, 7(8), 863; https://doi.org/10.3390/app7080863
Received: 14 July 2017 / Revised: 17 August 2017 / Accepted: 18 August 2017 / Published: 22 August 2017
Cited by 4 | Viewed by 1375 | PDF Full-text (308 KB) | HTML Full-text | XML Full-text
Abstract
In this perspective article, some of the latest paper and fiber-based bio-analytical platforms are summarized, along with their fabrication strategies, the processing behind the product development, and the embedded systems in which paper or fiber materials were integrated. The article also reviews bio-recognition [...] Read more.
In this perspective article, some of the latest paper and fiber-based bio-analytical platforms are summarized, along with their fabrication strategies, the processing behind the product development, and the embedded systems in which paper or fiber materials were integrated. The article also reviews bio-recognition applications of paper/fiber-based devices, the detected analytes of interest, applied detection techniques, the related evaluation parameters, the type and duration of the assays, as well as the advantages and disadvantages of each technique. Moreover, some of the existing challenges of utilizing paper and/or fiber materials are discussed. These include control over the physical characteristics (porosity, permeability, wettability) and the chemical properties (surface functionality) of paper/fiber materials are discussed. Other aspects of the review focus on shelf life, the multi-functionality of the platforms, readout strategies, and other challenges that have to be addressed in order to obtain reliable detection outcomes. Full article
Open AccessArticle
Axial Fan Blade Vibration Assessment under Inlet Cross-Flow Conditions Using Laser Scanning Vibrometry
Appl. Sci. 2017, 7(8), 862; https://doi.org/10.3390/app7080862
Received: 4 July 2017 / Revised: 13 August 2017 / Accepted: 14 August 2017 / Published: 22 August 2017
Cited by 2 | Viewed by 1760 | PDF Full-text (1689 KB) | HTML Full-text | XML Full-text
Abstract
In thermal power plants equipped with air-cooled condensers (ACCs), axial cooling fans operate under the influence of ambient flow fields. Under inlet cross-flow conditions, the resultant asymmetric flow field is known to introduce additional harmonic forces to the fan blades. This effect has [...] Read more.
In thermal power plants equipped with air-cooled condensers (ACCs), axial cooling fans operate under the influence of ambient flow fields. Under inlet cross-flow conditions, the resultant asymmetric flow field is known to introduce additional harmonic forces to the fan blades. This effect has previously only been studied numerically or by using blade-mounted strain gauges. For this study, laser scanning vibrometry (LSV) was used to assess fan blade vibration under inlet cross-flow conditions in an adapted fan test rig inside a wind tunnel test section. Two co-rotating laser beams scanned a low-pressure axial fan, resulting in spectral, phase-resolved surface vibration patterns of the fan blades. Two distinct operating points with flow coefficients of 0.17 and 0.28 were examined, with and without inlet cross-flow influence. While almost identical fan vibration patterns were found for both reference operating points, the overall blade vibration increased by 100% at the low fan flow rate as a result of cross-flow, and by 20% at the high fan flow rate. While numerically predicted natural frequency modes could be confirmed from experimental data as minor peaks in the vibration amplitude spectrum, they were not excited significantly by cross-flow. Instead, primarily higher rotation-rate harmonics were amplified; that is, a synchronous blade-tip flapping was strongly excited at the blade-pass frequency. Full article
(This article belongs to the Special Issue Laser Scanning)
Figures

Graphical abstract

Open AccessArticle
Global Analysis for an HIV Infection Model with CTL Immune Response and Infected Cells in Eclipse Phase
Appl. Sci. 2017, 7(8), 861; https://doi.org/10.3390/app7080861
Received: 27 July 2017 / Revised: 12 August 2017 / Accepted: 17 August 2017 / Published: 21 August 2017
Cited by 1 | Viewed by 1438 | PDF Full-text (891 KB) | HTML Full-text | XML Full-text
Abstract
A modified mathematical model describing the human immunodeficiency virus (HIV) pathogenesis with cytotoxic T-lymphocytes (CTL) and infected cells in eclipse phase is presented and studied in this paper. The model under consideration also includes a saturated rate describing viral infection. First, the positivity [...] Read more.
A modified mathematical model describing the human immunodeficiency virus (HIV) pathogenesis with cytotoxic T-lymphocytes (CTL) and infected cells in eclipse phase is presented and studied in this paper. The model under consideration also includes a saturated rate describing viral infection. First, the positivity and boundedness of solutions for nonnegative initial data are proved. Next, the global stability of the disease free steady state and the endemic steady states are established depending on the basic reproduction number R 0 and the CTL immune response reproduction number R C T L . Moreover, numerical simulations are performed in order to show the numerical stability for each steady state and to support our theoretical findings. Our model based findings suggest that system immunity represented by CTL may control viral replication and reduce the infection. Full article
Figures

Figure 1

Open AccessArticle
Design, Analysis and Fabrication of a Novel Transverse Flux Permanent Magnet Machine with Disk Rotor
Appl. Sci. 2017, 7(8), 860; https://doi.org/10.3390/app7080860
Received: 20 July 2017 / Revised: 11 August 2017 / Accepted: 18 August 2017 / Published: 21 August 2017
Viewed by 1229 | PDF Full-text (4969 KB) | HTML Full-text | XML Full-text
Abstract
The purpose of this paper is to propose a novel design for the transverse flux permanent magnet (TFPM) disk-rotor generator with E and I-shaped cores (TFPMDEIG). Disk-shape structure increases the machine’s power factor, allows for high rotational speeds, decreases centrifugal force over permanent [...] Read more.
The purpose of this paper is to propose a novel design for the transverse flux permanent magnet (TFPM) disk-rotor generator with E and I-shaped cores (TFPMDEIG). Disk-shape structure increases the machine’s power factor, allows for high rotational speeds, decreases centrifugal force over permanent magnets, and is employed in wind turbines, due to its compact structures. As for other advantages for this structure, one can point to the fact that there are as many windings as machine’s pole pairs; these windings become parallel by observing the polarity. In other words, the total power of this machine is distributed between pole pairs, increasing the overall reliability of the machine. In this paper, first, the initial design algorithm and the basic formulas governing the behavior of the proposed structure using the equivalent magnetic circuit for each pole are provided, and the three-dimensional finite element method (3D-FEM) is used for verification of the algorithm. To validate the simulation results (3D-FEM), then, a prototype has been fabricated and experienced. The experimental results are in good agreement with simulation results. Full article
Figures

Figure 1

Open AccessArticle
Influences of Doping and Crystal Orientation on Surface Roughening upon Alcohol Grafting onto Silicon Hydride
Appl. Sci. 2017, 7(8), 859; https://doi.org/10.3390/app7080859
Received: 12 July 2017 / Revised: 17 August 2017 / Accepted: 18 August 2017 / Published: 21 August 2017
Cited by 3 | Viewed by 1542 | PDF Full-text (2106 KB) | HTML Full-text | XML Full-text
Abstract
An alcohol bearing alkyne was thermally grafted to both p-type and n-type silicon (111) and (100) substrate of comparable doping levels and surface flatness. The surface topography as well as the surface chemistry was examined via atomic force microscopy (AFM), X-ray [...] Read more.
An alcohol bearing alkyne was thermally grafted to both p-type and n-type silicon (111) and (100) substrate of comparable doping levels and surface flatness. The surface topography as well as the surface chemistry was examined via atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. P-type silicon (111) was observed to experience roughening on the surface upon functionalization while n-type silicon (111) surfaces remained relatively unchanged. When the alcohol was grafted onto silicon (100) surface, the roughening effect was found to be even more profound for the p-type while the effects were marginal for the n-type surfaces. Both roughening effects were attributed to the differential weakening of the Si–Si backbond induced by majority carriers in p- and n-type silicon while (111) was observed to be able to resist the roughening effect better and this was explained by the notion of its denser adatom surface packing as well as the presence of surface defects. Full article
(This article belongs to the Section Chemistry)
Figures

Graphical abstract

Open AccessArticle
Image Analysis of Dynamic Brain Activity Based on Gray Distance Compensation
Appl. Sci. 2017, 7(8), 858; https://doi.org/10.3390/app7080858
Received: 24 July 2017 / Revised: 8 August 2017 / Accepted: 15 August 2017 / Published: 19 August 2017
Cited by 1 | Viewed by 1228 | PDF Full-text (2614 KB) | HTML Full-text | XML Full-text
Abstract
Assessing time-dependent changes in brain activity is of crucial importance in neuroscience. Here, we propose a novel image processing method to automatically identify active regions and assess time-dependent changes in fluorescence arising from genetically encoded indicators of activity. First, potential active regions and [...] Read more.
Assessing time-dependent changes in brain activity is of crucial importance in neuroscience. Here, we propose a novel image processing method to automatically identify active regions and assess time-dependent changes in fluorescence arising from genetically encoded indicators of activity. First, potential active regions and the corresponding active centers were extracted based on gray distance compensation. Then potential active regions were aligned through frames and, if meeting pre-determined intensity criteria, were accepted as active regions and the fluorescence changes were quantified. We validated this method with independent in vivo imaging datasets collected from transgenic mice that express the genetically encoded calcium indicator GCaMP3. Our studies indicate that the incorporation of this gray distance compensation-based algorithm substantially improves the accuracy and efficiency of detecting and quantifying cellular activity in the intact brain. Full article
(This article belongs to the Section Optics and Lasers)
Figures

Figure 1

Open AccessArticle
Development and Application of Sub-Cycle Mid-Infrared Source Based on Laser Filamentation
Appl. Sci. 2017, 7(8), 857; https://doi.org/10.3390/app7080857
Received: 27 July 2017 / Revised: 11 August 2017 / Accepted: 13 August 2017 / Published: 19 August 2017
Cited by 1 | Viewed by 1229 | PDF Full-text (299 KB) | HTML Full-text | XML Full-text
Abstract
This paper is a perspective article which summarizes the development and application of sub-cycle mid-infrared (MIR) pulses generated through a laser filament. The generation scheme was published in Applied Sciences in 2013. The spectrum of the MIR pulse spreads from 2 to 50 [...] Read more.
This paper is a perspective article which summarizes the development and application of sub-cycle mid-infrared (MIR) pulses generated through a laser filament. The generation scheme was published in Applied Sciences in 2013. The spectrum of the MIR pulse spreads from 2 to 50 μ m, corresponding to multiple octaves, and the pulse duration is 6.9 fs, namely, 0.63 times the period of the carrier wavelength, 3.3 μ m. The extremely broadband and highly coherent light source has potential for various applications. The light source has been applied for advanced ultrafast pump–probe spectroscopy by several research groups. As another application example, single-shot detection of absorption spectra in the entire MIR range by the use of chirped-pulse upconversion with a gas medium has been demonstrated. Although the measurement of the field oscillation of the sub-cycle MIR pulse was not trivial, the waveform of the sub-cycle pulse has been completely characterized with a newly developed method, frequency-resolved optical gating capable of carrier-envelope phase determination. A particular behavior of the spectral phase of the sub-cycle pulse has been revealed through the waveform characterization. Full article
(This article belongs to the Section Optics and Lasers)
Figures

Figure 1

Open AccessFeature PaperArticle
Suppressing Salt Transport through Composite Pervaporation Membranes for Brine Desalination
Appl. Sci. 2017, 7(8), 856; https://doi.org/10.3390/app7080856
Received: 30 June 2017 / Revised: 15 August 2017 / Accepted: 16 August 2017 / Published: 19 August 2017
Cited by 6 | Viewed by 2085 | PDF Full-text (8964 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Pervaporation membranes have gained renewed interest in challenging feedwaters desalination, such as reverse osmosis (RO) concentrated brine wastewater. In this study, composite polyvinyl alcohol (PVA)/polyvinylidene fluoride (PVDF) pervaporation membranes were prepared for brine treatment. The composite membrane was firstly studied by adjusting the [...] Read more.
Pervaporation membranes have gained renewed interest in challenging feedwaters desalination, such as reverse osmosis (RO) concentrated brine wastewater. In this study, composite polyvinyl alcohol (PVA)/polyvinylidene fluoride (PVDF) pervaporation membranes were prepared for brine treatment. The composite membrane was firstly studied by adjusting the cross-linking density of PVA by glutaraldehyde: the membrane with higher cross-linking density exhibited much higher salt rejection efficiency for long-term operation. A trace of salt on the permeate side was found to diffuse through the membrane in the form of hydrated ions, following solution-diffusion mechanism. To further suppress the salt transport and achieve long-term stable operation, graphene oxide (GO) was incorporated into the PVA layer: the addition of GO had minor effects on water permeation but significantly suppressed the salt passage, compared to the pure PVA/PVDF membranes. In terms of brine wastewater containing organic/inorganic foulant, improved anti-fouling performance was also observed with GO-containing membranes. Furthermore, the highest flux of 28 L/m2h was obtained for the membrane with 0.1 wt. % of GO using 100 g/L NaCl as the feed at 65 °C by optimising the pervaporation rig, with permeate conductivity below 1.2 µS/cm over 24 h (equivalent to a salt rejection of >99.99%). Full article
(This article belongs to the Special Issue Wastewater Treatment and Reuse Technologies) Printed Edition available
Figures

Graphical abstract

Open AccessArticle
Probing Structures of Interfacial 1-Butyl-3-Methylimidazolium Trifluoromethanesulfonate Ionic Liquid on Nano-Aluminum Oxide Surfaces Using High-Pressure Infrared Spectroscopy
Appl. Sci. 2017, 7(8), 855; https://doi.org/10.3390/app7080855
Received: 20 July 2017 / Revised: 14 August 2017 / Accepted: 15 August 2017 / Published: 18 August 2017
Cited by 6 | Viewed by 1066 | PDF Full-text (1190 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The interactions between 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][TFS]) and nano-Al2O3 are studied using high-pressure infrared spectroscopy. The thickness of the [BMIM][TFS] interfacial layer on the aluminum oxide are adjusted by controlling the number of washes with ethanol. In contrast to the results [...] Read more.
The interactions between 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][TFS]) and nano-Al2O3 are studied using high-pressure infrared spectroscopy. The thickness of the [BMIM][TFS] interfacial layer on the aluminum oxide are adjusted by controlling the number of washes with ethanol. In contrast to the results obtained under ambient pressure, local structures of both the cations and anions of [BMIM][TFS] are disturbed under high pressures. For example, bands due to C-H stretching motions display remarkable blue-shifts in frequency as the pressure of the [BMIM][TFS]/Al2O3 composites is increased to 0.4 GPa. The bands then undergo mild shifts in frequency upon further compression. The discontinuous jump occurring around 0.4 GPa becomes less obvious when the amount of ionic liquid on the Al2O3 is reduced by washing with ethanol. The nano-Al2O3 with surfaces may weaken the cation/anion interactions in the interfacial area as a result of the formation of pressure-enhanced Al2O3/ionic liquid interactions under high pressures. Full article
Figures

Figure 1

Open AccessArticle
Irradiation Induced Defect Clustering in Zircaloy-2
Appl. Sci. 2017, 7(8), 854; https://doi.org/10.3390/app7080854
Received: 6 July 2017 / Revised: 6 August 2017 / Accepted: 7 August 2017 / Published: 18 August 2017
Viewed by 1234 | PDF Full-text (3050 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The effect of irradiation temperature and alloying elements on defect clustering behaviour directly from the cascade collapse in Zircaloy-2 is examined. The in-situ ioWn irradiation technique was employed to study the formation of <a>-type dislocation loops by Kr ion irradiation at 573 K [...] Read more.
The effect of irradiation temperature and alloying elements on defect clustering behaviour directly from the cascade collapse in Zircaloy-2 is examined. The in-situ ioWn irradiation technique was employed to study the formation of <a>-type dislocation loops by Kr ion irradiation at 573 K and 773 K, while the dependence of dislocation loop formationon the presence of alloying elements was investigated by comparing with the defect microstructures of pure Zr irradiated under similar conditions. The experimentally observed temperature dependence of defect clustering was further investigated using molecular dynamics (MD) simulations near the experimental irradiation temperatures. We particularly concentrate on yield and morphology of small defect clusters formed directly from cascade collapse at very low ion doses. Smaller loop size and higher defect yield (DY) in Zircaloy-2 as compared to pure Zr suggests that the presence of the major alloying element Sn increases the number of nucleation sites for the defect clusters but suppresses the point defect recombination. MD simulations at 600 and 800 K revealed that the production of both vacancy and interstitial clusters drops significantly with an increase of irradiation temperature, which is reflected in experimentally collected DY data. Full article
(This article belongs to the Special Issue Radiation Effects of Materials with Laser, Ion Beam and Rays)
Figures

Figure 1

Open AccessArticle
FE Model and Operational Modal Analysis of Lower Limbs
Appl. Sci. 2017, 7(8), 853; https://doi.org/10.3390/app7080853
Received: 26 May 2017 / Revised: 30 June 2017 / Accepted: 8 August 2017 / Published: 18 August 2017
Viewed by 1330 | PDF Full-text (1153 KB) | HTML Full-text | XML Full-text
Abstract
Human lower limbs are exposed to vibrations on a daily basis, during work, transport or sports. However, most of the FE (Finite Elements) and OMA (Operational Modal Analysis) studies focus either on the whole body or on the hand-arm system. The study presented [...] Read more.
Human lower limbs are exposed to vibrations on a daily basis, during work, transport or sports. However, most of the FE (Finite Elements) and OMA (Operational Modal Analysis) studies focus either on the whole body or on the hand-arm system. The study presented herein aims at identifying the modal parameters of the lower limbs using a 2D FE model updated using OMA. A numerical model is proposed, and a modal analysis has been performed on 11 subjects. Two repeatable modal frequencies were extracted: 52 . 54 ± 2 . 05 Hz and 118 . 94 ± 2 . 70 Hz , which were used to update the mechanical properties of the numerical model. The knowledge of these modal characteristics makes it possible to design new equipment that would absorb these specific vibrations and possibly reduce the risk of related diseases in the field of sports and transport. Full article
(This article belongs to the Section Mechanical Engineering)
Figures

Figure 1

Open AccessArticle
Silver Nanoparticles-Loaded Exfoliated Graphite and Its Anti-Bacterial Performance
Appl. Sci. 2017, 7(8), 852; https://doi.org/10.3390/app7080852
Received: 11 July 2017 / Revised: 13 August 2017 / Accepted: 15 August 2017 / Published: 18 August 2017
Cited by 2 | Viewed by 1714 | PDF Full-text (3286 KB) | HTML Full-text | XML Full-text
Abstract
One antibacterial material was prepared from exfoliated graphite (EG) decorated with silver nanoparticles (AgNPs). The EG was prepared by the graphite intercalated compound process, AgNPs were prepared by chemical reduction of AgNO3 in the presence of NaBH4. The AgNPs-loaded EG [...] Read more.
One antibacterial material was prepared from exfoliated graphite (EG) decorated with silver nanoparticles (AgNPs). The EG was prepared by the graphite intercalated compound process, AgNPs were prepared by chemical reduction of AgNO3 in the presence of NaBH4. The AgNPs-loaded EG (Ag-EG) composite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption, mercury intrusion porosimetry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The antibacterial effect of the Ag-EG was evaluated by using the zone of inhibition method. The loaded AgNPs were highly dispersed on EG sheets and most of them have a size less than 10 nm. The Ag loading slightly increased the surface area of EG. It is shown that the Ag-EG had antibacterial activity and anti-adhesion properties against Pseudomonas aeruginosa and Staphylococcus aureus. It suggests that Ag-EG composites could be used in a variety of industrial applications that require an antibacterial effect. Full article
(This article belongs to the Special Issue Nano-systems for Antimicrobial Therapy)
Figures

Figure 1

Open AccessFeature PaperArticle
Formulation of Laccase Nanobiocatalysts Based on Ionic and Covalent Interactions for the Enhanced Oxidation of Phenolic Compounds
Appl. Sci. 2017, 7(8), 851; https://doi.org/10.3390/app7080851
Received: 20 July 2017 / Revised: 14 August 2017 / Accepted: 16 August 2017 / Published: 18 August 2017
Cited by 4 | Viewed by 1503 | PDF Full-text (523 KB) | HTML Full-text | XML Full-text
Abstract
Oxidative biocatalysis by laccase arises as a promising alternative in the development of advanced oxidation processes for the removal of xenobiotics. The aim of this work is to develop various types of nanobiocatalysts based on laccase immobilized on different superparamagnetic and non-magnetic nanoparticles [...] Read more.
Oxidative biocatalysis by laccase arises as a promising alternative in the development of advanced oxidation processes for the removal of xenobiotics. The aim of this work is to develop various types of nanobiocatalysts based on laccase immobilized on different superparamagnetic and non-magnetic nanoparticles to improve the stability of the biocatalysts. Several techniques of enzyme immobilization were evaluated based on ionic exchange and covalent bonding. The highest yields of laccase immobilization were achieved for the covalent laccase nanoconjugates of silica-coated magnetic nanoparticles (2.66 U mg−1 NPs), formed by the covalent attachment of the enzyme between the aldehyde groups of the glutaraldehyde-functionalized nanoparticle and the amino groups of the enzyme. Moreover, its application in the biotransformation of phenol as a model recalcitrant compound was tested at different pH and successfully achieved at pH 6 for 24 h. A sequential batch operation was carried out, with complete recovery of the nanobiocatalyst and minimal deactivation of the enzyme after four cycles of phenol oxidation. The major drawback associated with the use of the nanoparticles relies on the energy consumption required for their production and the use of chemicals, that account for a major contribution in the normalized index of 5.28 × 10−3. The reduction of cyclohexane (used in the synthesis of silica-coated magnetic nanoparticles) led to a significant lower index (3.62 × 10−3); however, the immobilization was negatively affected, which discouraged this alternative. Full article
(This article belongs to the Special Issue Wastewater Treatment and Reuse Technologies) Printed Edition available
Figures

Figure 1

Open AccessFeature PaperReview
The Linac Coherent Light Source: Recent Developments and Future Plans
Appl. Sci. 2017, 7(8), 850; https://doi.org/10.3390/app7080850
Received: 31 July 2017 / Accepted: 10 August 2017 / Published: 18 August 2017
Cited by 10 | Viewed by 1813 | PDF Full-text (5424 KB) | HTML Full-text | XML Full-text
Abstract
The development of X-ray free-electron lasers (XFELs) has launched a new era in X-ray science by providing ultrafast coherent X-ray pulses with a peak brightness that is approximately one billion times higher than previous X-ray sources. The Linac Coherent Light Source (LCLS) facility [...] Read more.
The development of X-ray free-electron lasers (XFELs) has launched a new era in X-ray science by providing ultrafast coherent X-ray pulses with a peak brightness that is approximately one billion times higher than previous X-ray sources. The Linac Coherent Light Source (LCLS) facility at the SLAC National Accelerator Laboratory, the world’s first hard X-ray FEL, has already demonstrated a tremendous scientific impact across broad areas of science. Here, a few of the more recent representative highlights from LCLS are presented in the areas of atomic, molecular, and optical science; chemistry; condensed matter physics; matter in extreme conditions; and biology. This paper also outlines the near term upgrade (LCLS-II) and motivating science opportunities for ultrafast X-rays in the 0.25–5 keV range at repetition rates up to 1 MHz. Future plans to extend the X-ray energy reach to beyond 13 keV (<1 Å) at high repetition rate (LCLS-II-HE) are envisioned, motivated by compelling new science of structural dynamics at the atomic scale. Full article
(This article belongs to the Special Issue X-Ray Free-Electron Laser) Printed Edition available
Figures

Graphical abstract

Open AccessArticle
An Efficient Retrieval Technique for Trademarks Based on the Fuzzy Inference System
Appl. Sci. 2017, 7(8), 849; https://doi.org/10.3390/app7080849
Received: 7 July 2017 / Revised: 4 August 2017 / Accepted: 14 August 2017 / Published: 18 August 2017
Cited by 1 | Viewed by 1122 | PDF Full-text (3323 KB) | HTML Full-text | XML Full-text
Abstract
The existing trademark image retrieval (TIR) approaches mostly use complex image features, the integration of multi features, a tree structure, etc. to enable highly accurate retrieval. However, there is the heavy computational burden for complex image features and maximum similarity subtree isomorphism (MSSI) [...] Read more.
The existing trademark image retrieval (TIR) approaches mostly use complex image features, the integration of multi features, a tree structure, etc. to enable highly accurate retrieval. However, there is the heavy computational burden for complex image features and maximum similarity subtree isomorphism (MSSI) measurement. This paper aims to provide an efficient solution for TIR in real-time applications, especially in measuring the similarity between multi-object trademark images. In particular, we propose a novel algorithm for tree similarity measurement based on the fuzzy inference system (FIS) to improve retrieval efficiency. Furthermore, the integration of global and local geometric descriptors is used to enable accurate retrieval. The global descriptor is computed by employing the Hu moments, while the local descriptors are generated by using a tree structure based on the five geometric features: convexity, eccentricity, compactness, circle variance, and elliptic variance. During the retrieval process, the similarity coefficient between the query and the database image is obtained from the similarity of the global and local descriptors. The proposed technique is evaluated using 1800 trademark images, including 12 different classes and 416 trademark images. Additionally, the three common indices, the precision/recall rate, the Bull’s eye score, and the average normalized modified retrieval rank (ANMRR) are used as the performance indices. The experimental results show that the proposed technique is superior to the other two competitive approaches. It shows 19.43% and 26.78% precision/recall improvement, 19.56% and 30.58% improvement in the average Bull’s eye score, and 0.167 and 0.236 improvement in the ANMRR score, respectively, for the 416 query images. It can be concluded from the experimental analysis that the proposed technique not only provides reliable retrieval results but also improves the retrieval efficiency by 151 times in the retrieval process. Full article
(This article belongs to the Special Issue Selected Papers from IEEE ICASI 2017)
Figures

Figure 1

Open AccessArticle
Thermo-Responsive Shape-Memory Effect and Surface Features in Polycarbonate (PC)
Appl. Sci. 2017, 7(8), 848; https://doi.org/10.3390/app7080848
Received: 9 July 2017 / Revised: 20 July 2017 / Accepted: 16 August 2017 / Published: 17 August 2017
Cited by 1 | Viewed by 1603 | PDF Full-text (10477 KB) | HTML Full-text | XML Full-text
Abstract
The influence of programming strain and temperature on the shape memory effect and surface morphology in programmed polycarbonate (PC) samples via uni-axial stretching is investigated. It is found that the samples programmed at around the glass transition start temperature not only have micro-cracks [...] Read more.
The influence of programming strain and temperature on the shape memory effect and surface morphology in programmed polycarbonate (PC) samples via uni-axial stretching is investigated. It is found that the samples programmed at around the glass transition start temperature not only have micro-cracks on their surface, but also show a necking phenomenon. Furthermore, the surface of the necked area is concave, but the surface of the non-necked area is convex. On the other hand, despite the samples programmed at high temperatures being able to deform in a uniform manner at macroscopic scale, their surfaces are still uneven, either concave or convex. While the samples programmed at low temperatures are able to achieve full shape recovery, stretching at higher temperatures over the glass transition range to a higher strain may result in non-recoverable deformation. Full article
(This article belongs to the Special Issue Shape Memory Polymers)
Figures

Figure 1

Open AccessArticle
Reformulation-Linearization Technique Approach for Kidney Exchange Program IT Healthcare Platforms
Appl. Sci. 2017, 7(8), 847; https://doi.org/10.3390/app7080847
Received: 8 July 2017 / Revised: 10 August 2017 / Accepted: 11 August 2017 / Published: 17 August 2017
Cited by 2 | Viewed by 1348 | PDF Full-text (1584 KB) | HTML Full-text | XML Full-text
Abstract
Kidney exchange allows a potential living donor whose kidney is incompatible with his intended recipient to donate a kidney to another patient so that the donor’s intended recipient can receive a compatible kidney from another donor. These exchanges can include cycles of longer [...] Read more.
Kidney exchange allows a potential living donor whose kidney is incompatible with his intended recipient to donate a kidney to another patient so that the donor’s intended recipient can receive a compatible kidney from another donor. These exchanges can include cycles of longer than two donor–patient pairs and chains produced by altruistic donors. Kidney exchange programs (KEPs) can be modeled as a maximum-weight cycle-packing problem in a directed graph. This paper develops a new integer programming model for KEPs by applying the reformulation-linearization technique (RLT) to enhance a lower bound obtained by its linear programming (LP) relaxation. Given the results obtained from the proposed model, the model is expected to be utilized in the integrated KEP IT (Information Technology) healthcare platform to obtain plans for optimized kidney exchanges. Full article
(This article belongs to the Special Issue Smart Healthcare) Printed Edition available
Figures

Figure 1

Open AccessArticle
Learning Word Embeddings with Chi-Square Weights for Healthcare Tweet Classification
Appl. Sci. 2017, 7(8), 846; https://doi.org/10.3390/app7080846
Received: 16 July 2017 / Revised: 10 August 2017 / Accepted: 11 August 2017 / Published: 17 August 2017
Cited by 4 | Viewed by 1139 | PDF Full-text (252 KB) | HTML Full-text | XML Full-text
Abstract
Twitter is a popular source for the monitoring of healthcare information and public disease. However, there exists much noise in the tweets. Even though appropriate keywords appear in the tweets, they do not guarantee the identification of a truly health-related tweet. Thus, the [...] Read more.
Twitter is a popular source for the monitoring of healthcare information and public disease. However, there exists much noise in the tweets. Even though appropriate keywords appear in the tweets, they do not guarantee the identification of a truly health-related tweet. Thus, the traditional keyword-based classification task is largely ineffective. Algorithms for word embeddings have proved to be useful in many natural language processing (NLP) tasks. We introduce two algorithms based on an existing word embedding learning algorithm: the continuous bag-of-words model (CBOW). We apply the proposed algorithms to the task of recognizing healthcare-related tweets. In the CBOW model, the vector representation of words is learned from their contexts. To simplify the computation, the context is represented by an average of all words inside the context window. However, not all words in the context window contribute equally to the prediction of the target word. Greedily incorporating all the words in the context window will largely limit the contribution of the useful semantic words and bring noisy or irrelevant words into the learning process, while existing word embedding algorithms also try to learn a weighted CBOW model. Their weights are based on existing pre-defined syntactic rules while ignoring the task of the learned embedding. We propose learning weights based on the words’ relative importance in the classification task. Our intuition is that such learned weights place more emphasis on words that have comparatively more to contribute to the later task. We evaluate the embeddings learned from our algorithms on two healthcare-related datasets. The experimental results demonstrate that embeddings learned from the proposed algorithms outperform existing techniques by a relative accuracy improvement of over 9%. Full article
(This article belongs to the Special Issue Smart Healthcare) Printed Edition available
Figures

Graphical abstract

Open AccessArticle
Broken Rotor Bar Detection in LS-PMSM Based on Startup Current Analysis Using Wavelet Entropy Features
Appl. Sci. 2017, 7(8), 845; https://doi.org/10.3390/app7080845
Received: 16 June 2017 / Revised: 3 August 2017 / Accepted: 9 August 2017 / Published: 17 August 2017
Cited by 2 | Viewed by 1784 | PDF Full-text (8247 KB) | HTML Full-text | XML Full-text
Abstract
High-efficiency motors are being gradually introduced in many industrial applications because of their positive impacts on the environment by reducing energy consumption and CO2 emission. In this respect, line start permanent magnet synchronous motors (LS-PMSMs) have been introduced recently. Due to their [...] Read more.
High-efficiency motors are being gradually introduced in many industrial applications because of their positive impacts on the environment by reducing energy consumption and CO2 emission. In this respect, line start permanent magnet synchronous motors (LS-PMSMs) have been introduced recently. Due to their unique configuration, LS-PMSMs allow the obtaining of super premium efficiency levels, accompanied with a high torque and power factor. However, since the use of LS-PMSMs in the industry is in its infancy, no efficient scheme has yet been reported for broken rotor bar (BRB) fault detection in this type of motor. Accordingly, the main aim of this research is to investigate the fault-related feature for BRB faults on LS-PMSMs. In this regard, a simulation model and experimental setup for the investigation of BRB in LS-PMSM are implemented. The detection strategy for BRB in LS-PMSM proposed here is based on the monitoring of the start-up current signal and discrete wavelet transform. The entropy features are used as fault-related features for BRB faults. Finally, the ability of these features is validated for the detection of BRB in LS-PMSM through statistical analysis. In this research, the importance of the starting load is also considered for BRB detection in LS-PMSMs. Full article
Figures

Figure 1

Open AccessArticle
Towards a Predictive Analytics-Based Intelligent Malaria Outbreak Warning System
Appl. Sci. 2017, 7(8), 836; https://doi.org/10.3390/app7080836
Received: 14 July 2017 / Revised: 8 August 2017 / Accepted: 9 August 2017 / Published: 17 August 2017
Cited by 1 | Viewed by 1368 | PDF Full-text (981 KB) | HTML Full-text | XML Full-text
Abstract
Malaria, as one of the most serious infectious diseases causing public health problems in the world, affects about two-thirds of the world population, with estimated resultant deaths close to a million annually. The effects of this disease are much more profound in third [...] Read more.
Malaria, as one of the most serious infectious diseases causing public health problems in the world, affects about two-thirds of the world population, with estimated resultant deaths close to a million annually. The effects of this disease are much more profound in third world countries, which have very limited medical resources. When an intense outbreak occurs, most of these countries cannot cope with the high number of patients due to the lack of medicine, equipment and hospital facilities. The prevention or reduction of the risk factor of this disease is very challenging, especially in third world countries, due to poverty and economic insatiability. Technology can offer alternative solutions by providing early detection mechanisms that help to control the spread of the disease and allow the management of treatment facilities in advance to ensure a more timely health service, which can save thousands of lives. In this study, we have deployed an intelligent malaria outbreak early warning system, which is a mobile application that predicts malaria outbreak based on climatic factors using machine learning algorithms. The system will help hospitals, healthcare providers, and health organizations take precautions in time and utilize their resources in case of emergency. To our best knowledge, the system developed in this paper is the first publicly available application. Since confounding effects of climatic factors have a greater influence on the incidence of malaria, we have also conducted extensive research on exploring a new ecosystem model for the assessment of hidden ecological factors and identified three confounding factors that significantly influence the malaria incidence. Additionally, we deploy a smart healthcare application; this paper also makes a significant contribution by identifying hidden ecological factors of malaria. Full article
(This article belongs to the Special Issue Smart Healthcare) Printed Edition available
Figures

Figure 1

Open AccessArticle
Amorphous InGaZnO Thin Film Transistor Fabricated with Printed Silver Salt Ink Source/Drain Electrodes
Appl. Sci. 2017, 7(8), 844; https://doi.org/10.3390/app7080844
Received: 25 June 2017 / Revised: 9 August 2017 / Accepted: 14 August 2017 / Published: 16 August 2017
Cited by 3 | Viewed by 1927 | PDF Full-text (2075 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Recently, amorphous indium-gallium-zinc-oxide thin film transistors (a-IGZO TFTs) with inkjet printing silver source/drain electrodes have attracted great attention, especially for large area and flexible electronics applications. The silver ink could be divided into two types: one is based on silver nanoparticles, and the [...] Read more.
Recently, amorphous indium-gallium-zinc-oxide thin film transistors (a-IGZO TFTs) with inkjet printing silver source/drain electrodes have attracted great attention, especially for large area and flexible electronics applications. The silver ink could be divided into two types: one is based on silver nanoparticles, and the other is silver salt ink. Organic materials are essential in the formulation of nanoparticle ink as a strong disperse stabilizer to prevent agglomeration of silver particles, but will introduce contact problems between the silver electrodes and the a-IGZO active layer after annealing, which is difficult to eliminate and leads to poor device properties. Our experiment is aimed to reduce this effect by using a silver salt ink without stabilizer component. With optimized inkjet printing conditions, the high performance of a-IGZO TFT was obtained with a mobility of 4.28 cm2/V·s and an on/off current ratio over 106. The results have demonstrated a significant improvement for a-IGZO TFTs with directly printed silver electrodes. This work presents a promising platform for future printed electronic applications. Full article
(This article belongs to the Special Issue Thin-Film Transistors)
Figures

Figure 1

Open AccessFeature PaperArticle
New Approaches for Supervision of Systems with Sliding Wear: Fundamental Problems and Experimental Results Using Different Approaches
Appl. Sci. 2017, 7(8), 843; https://doi.org/10.3390/app7080843
Received: 10 July 2017 / Revised: 9 August 2017 / Accepted: 12 August 2017 / Published: 16 August 2017
Viewed by 1041 | PDF Full-text (3639 KB) | HTML Full-text | XML Full-text
Abstract
Reliability and availability of technically complex and safety-critical systems are of increasing importance. Besides the degree of wear, the quality of mechanical systems is significant for the system reliability. The focus of this contribution is the development and application of readily applicable and [...] Read more.
Reliability and availability of technically complex and safety-critical systems are of increasing importance. Besides the degree of wear, the quality of mechanical systems is significant for the system reliability. The focus of this contribution is the development and application of readily applicable and easily interpretable algorithms for industrial data obtained from technical systems during operation. The methods are within the focus of the production-oriented automation programs (Industrial Internet, Automation 4.0, China 2025). In this contribution as example a hydraulically driven machine in which parts slide over each other is chosen as sliding wear example. Monitoring is applied to distinguish normal and abnormal operation as well as to define end of useful lifetime. In this contribution four different methods will be introduced and experimentally compared without the availability of objective information about the wear state. The approaches differ with respect to the used measurements and data preparation. As measurements Acoustic Emission and the hydraulic pressure of the driving machine are used. For processing the accumulation of damage related values, a machine learning algorithm, and a sensitivity matrix are used. For comparison the experimental validation is based on identical data sets. Different operational states of the system denoted as actual system state are defined and classified. The comparison shows that the four introduced methods provide similar classification results although the underlying measurements are based on different physical principles. The newly introduced approaches allow online evaluation of the actual system state and can serve within improved maintenance strategies. Full article
Figures

Figure 1

Open AccessArticle
Spectral Correction of CPV Modules Equipped with GaInP/GaInAs/Ge Solar Cells and Fresnel Lenses
Appl. Sci. 2017, 7(8), 842; https://doi.org/10.3390/app7080842
Received: 24 July 2017 / Revised: 10 August 2017 / Accepted: 11 August 2017 / Published: 16 August 2017
Cited by 4 | Viewed by 1217 | PDF Full-text (804 KB) | HTML Full-text | XML Full-text
Abstract
Photovoltaic (PV) devices are spectrally selective, and their performance is influenced by unavoidable spectral variations. In addition, multijunction-based concentrating photovoltaic (CPV) devices show a strong spectral dependence due to the series connection of various junctions with different absorption bands, and also due to [...] Read more.
Photovoltaic (PV) devices are spectrally selective, and their performance is influenced by unavoidable spectral variations. In addition, multijunction-based concentrating photovoltaic (CPV) devices show a strong spectral dependence due to the series connection of various junctions with different absorption bands, and also due to the use of concentrator optics. In this work, the accuracy of a new set of analytical equations that quantify the spectral impact caused by the changes in air mass (AM), aerosol optical depth (AOD) and precipitable water (PW) is discussed. Four different CPV devices based on lattice-matched and metamorphic triple-junction solar cells and a poly(methyl methacrylate) (PMMA) and silicon-on-glass (SoG) Fresnel lenses are considered. A long-term outdoor experimental campaign was carried out at the Centre for Advanced Studies on Energy and Environment (CEAEMA) of the University of Jaén, Spain. Results show a high accuracy in the estimations of the spectral factor (SF), with an average mean absolute percentage error (MAPE) within 0.91% and a mean relative error (MRE) within −0.32%. Full article
(This article belongs to the Special Issue Renewable Energy 2018)
Figures

Figure 1

Open AccessFeature PaperReview
Machine Learning Methods for Pipeline Surveillance Systems Based on Distributed Acoustic Sensing: A Review
Appl. Sci. 2017, 7(8), 841; https://doi.org/10.3390/app7080841
Received: 19 July 2017 / Revised: 7 August 2017 / Accepted: 10 August 2017 / Published: 16 August 2017
Cited by 7 | Viewed by 2657 | PDF Full-text (414 KB) | HTML Full-text | XML Full-text
Abstract
There is an increasing interest in researchers and companies on the combination of Distributed Acoustic Sensing (DAS) and a Pattern Recognition System (PRS) to detect and classify potentially dangerous events that occur in areas above fiber optic cables deployed along active pipelines, aiming [...] Read more.
There is an increasing interest in researchers and companies on the combination of Distributed Acoustic Sensing (DAS) and a Pattern Recognition System (PRS) to detect and classify potentially dangerous events that occur in areas above fiber optic cables deployed along active pipelines, aiming to construct pipeline surveillance systems. This paper presents a review of the literature in what respect to machine learning techniques applied to pipeline surveillance systems based on DAS+PRS (although its scope can also be extended to any other environment in which DAS+PRS strategies are to be used). To do so, we describe the fundamentals of the machine learning approaches when applied to DAS systems, and also do a detailed literature review of the main contributions on this topic. Additionally, this paper addresses the most common issues related to real field deployment and evaluation of DAS+PRS for pipeline threat monitoring, and intends to provide useful insights and recommendations in what respect to the design of such systems. The literature review concludes that a real field deployment of a PRS based on DAS technology is still a challenging area of research, far from being fully solved. Full article
(This article belongs to the Special Issue Distributed Optical Fiber Sensors)
Figures

Figure 1

Open AccessArticle
Effect of Ultrafast Imaging on Shear Wave Visualization and Characterization: An Experimental and Computational Study in a Pediatric Ventricular Model
Appl. Sci. 2017, 7(8), 840; https://doi.org/10.3390/app7080840
Received: 14 July 2017 / Revised: 3 August 2017 / Accepted: 12 August 2017 / Published: 16 August 2017
Cited by 1 | Viewed by 1483 | PDF Full-text (2613 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Plane wave imaging in Shear Wave Elastography (SWE) captures shear wave propagation in real-time at ultrafast frame rates. To assess the capability of this technique in accurately visualizing the underlying shear wave mechanics, this work presents a multiphysics modeling approach providing access to [...] Read more.
Plane wave imaging in Shear Wave Elastography (SWE) captures shear wave propagation in real-time at ultrafast frame rates. To assess the capability of this technique in accurately visualizing the underlying shear wave mechanics, this work presents a multiphysics modeling approach providing access to the true biomechanical wave propagation behind the virtual image. This methodology was applied to a pediatric ventricular model, a setting shown to induce complex shear wave propagation due to geometry. Phantom experiments are conducted in support of the simulations. The model revealed that plane wave imaging altered the visualization of the shear wave pattern in the time (broadened front and negatively biased velocity estimates) and frequency domain (shifted and/or decreased signal frequency content). Furthermore, coherent plane wave compounding (effective frame rate of 2.3 kHz) altered the visual appearance of shear wave dispersion in both the experiment and model. This mainly affected stiffness characterization based on group speed, whereas phase velocity analysis provided a more accurate and robust stiffness estimate independent of the use of the compounding technique. This paper thus presents a versatile and flexible simulation environment to identify potential pitfalls in accurately capturing shear wave propagation in dispersive settings. Full article
(This article belongs to the Special Issue Ultrafast Ultrasound Imaging) Printed Edition available
Figures

Figure 1

Open AccessFeature PaperArticle
Removal of Escherichia coli by Intermittent Operation of Saturated Sand Columns Supplemented with Hydrochar Derived from Sewage Sludge
Appl. Sci. 2017, 7(8), 839; https://doi.org/10.3390/app7080839
Received: 19 June 2017 / Revised: 9 August 2017 / Accepted: 10 August 2017 / Published: 15 August 2017
Cited by 3 | Viewed by 1371 | PDF Full-text (3134 KB) | HTML Full-text | XML Full-text
Abstract
Hydrothermal carbonization (HTC) technology can convert various types of waste biomass into a carbon-rich product referred to as hydrochar. In order to verify the potential of hydrochar produced from stabilized sewage sludge to be an adsorbent for bacterial pathogen removal in water treatment, [...] Read more.
Hydrothermal carbonization (HTC) technology can convert various types of waste biomass into a carbon-rich product referred to as hydrochar. In order to verify the potential of hydrochar produced from stabilized sewage sludge to be an adsorbent for bacterial pathogen removal in water treatment, the Escherichia coli’s removal efficiency was determined by using 10 cm sand columns loaded with 1.5% (w/w) hydrochar. Furthermore, the removal of E. coli based on intermittent operation in larger columns of 50 cm was measured for 30 days. Since the removal of E. coli was not sufficient when the sand columns were supplemented with raw hydrochar, an additional cold-alkali activation of the hydrochar using potassium hydroxide was applied. This enabled more than 90% of E. coli removal in both the 10 cm and 50 cm column experiments. The enhancement of the E. coli removal efficiency could be attributed to the more hydrophobic surface of the KOH pre-treated hydrochar. The idle time during the intermittent flushing experiments in the sand-only columns without the hydrochar supplement had a significant effect on the E. coli removal (p < 0.05), resulting in a removal efficiency of 55.2%. This research suggested the possible utilization of hydrochar produced from sewage sludge as an adsorbent in water treatment for the removal of bacterial contaminants. Full article
(This article belongs to the Special Issue Wastewater Treatment and Reuse Technologies) Printed Edition available
Figures

Figure 1

Open AccessArticle
Effect of Polishing-Induced Subsurface Impurity Defects on Laser Damage Resistance of Fused Silica Optics and Their Removal with HF Acid Etching
Appl. Sci. 2017, 7(8), 838; https://doi.org/10.3390/app7080838
Received: 11 July 2017 / Revised: 7 August 2017 / Accepted: 11 August 2017 / Published: 15 August 2017
Cited by 2 | Viewed by 1758 | PDF Full-text (4341 KB) | HTML Full-text | XML Full-text
Abstract
Laser-induced damage on fused silica optics remains a major issue that limits the promotion of energy output of large laser systems. Subsurface impurity defects inevitably introduced in the practical polishing process incur strong thermal absorption for incident lasers, seriously lowering the laser-induced damage [...] Read more.
Laser-induced damage on fused silica optics remains a major issue that limits the promotion of energy output of large laser systems. Subsurface impurity defects inevitably introduced in the practical polishing process incur strong thermal absorption for incident lasers, seriously lowering the laser-induced damage threshold (LIDT). Here, we simulate the temperature and thermal stress distributions involved in the laser irradiation process to investigate the effect of impurity defects on laser damage resistance. Then, HF-based etchants (HF:NH4F) are applied to remove the subsurface impurity defects and the surface quality, impurity contents and laser damage resistance of etched silica surfaces are tested. The results indicate that the presence of impurity defects could induce a dramatic rise of local temperature and thermal stress. The maximum temperature and stress can reach up to 7073 K and 8739 MPa, respectively, far higher than the melting point and compressive strength of fused silica, resulting in serious laser damage. The effect of impurity defects on laser damage resistance is dependent on the species, size and spatial location of the defects, and CeO2 defects play a dominant role in lowering the LIDT, followed by Fe and Al defects. CeO2 defects with radius of 0.3 μm, which reside 0.15 μm beneath the surface, are the most dangerous defects for incurring laser damage. By HF acid etching, the negative effect of impurity defects on laser damage resistance could be effectively mitigated. It is validated that with HF acid etching, the number of dangerous CeO2 defects is decreased by more than half, and the LIDT could be improved to 27.1 J/cm2. Full article
Figures

Graphical abstract

Open AccessArticle
BIM-Based Approach to Simulate Building Adaptive Performance and Life Cycle Costs for an Open Building Design
Appl. Sci. 2017, 7(8), 837; https://doi.org/10.3390/app7080837
Received: 24 July 2017 / Revised: 3 August 2017 / Accepted: 9 August 2017 / Published: 15 August 2017
Cited by 1 | Viewed by 1818 | PDF Full-text (2209 KB) | HTML Full-text | XML Full-text
Abstract
In the long-term use of buildings, renovations are sometimes required as usage behaviors have changed and residents’ demands for space are adjusted. However, the public in general are deficient in renovation knowledge and information regarding building use and its maintenance phases; thus, the [...] Read more.
In the long-term use of buildings, renovations are sometimes required as usage behaviors have changed and residents’ demands for space are adjusted. However, the public in general are deficient in renovation knowledge and information regarding building use and its maintenance phases; thus, the initial stage of planning and design often lacks flexibility, leading to waste materials in the subsequent renovation project. Theoretically, Building Information Modeling (BIM) can be used as a building unit resume and renovation benefit prediction tool; moreover, it plays an important role in the usage and maintenance phases. This study develops three design proposals that target different service lives (30 years, 50 years, 100 years), as based on the building’s expected life, and uses BIM technology to simulate the life cycle cost and design performance, as based on the renovation scenario analysis of the building’s life cycle. The findings show that under the service condition target of 100 years, when the open flexible technique is used for the design, space utilization flexibility is enhanced, pipeline maintenance is convenient, waste is reduced, and performance in life cycle cost is better. BIM can predict performance simply and rapidly according to future usage demand adjustments after the initial design. Full article
(This article belongs to the Special Issue The Industrialization of the Building Construction Process)
Figures

Figure 1

Open AccessArticle
Longitudinal Removal of Bisphenol-A and Nonylphenols from Pretreated Domestic Wastewater by Tropical Horizontal Sub-SurfaceConstructed Wetlands
Appl. Sci. 2017, 7(8), 834; https://doi.org/10.3390/app7080834
Received: 30 June 2017 / Revised: 20 July 2017 / Accepted: 20 July 2017 / Published: 15 August 2017
Cited by 3 | Viewed by 1281 | PDF Full-text (1656 KB) | HTML Full-text | XML Full-text
Abstract
Bisphenol A (BPA) and nonylphenols (NPs), with a high potential to cause endocrine disruption, have been identified at levels of nanograms per liter and even micrograms per liter in effluents from wastewater treatment plants. Constructed wetlands (CWs) are a cost-effective wastewater treatment alternative [...] Read more.
Bisphenol A (BPA) and nonylphenols (NPs), with a high potential to cause endocrine disruption, have been identified at levels of nanograms per liter and even micrograms per liter in effluents from wastewater treatment plants. Constructed wetlands (CWs) are a cost-effective wastewater treatment alternative due to the low operational cost, reduced energy consumption, and lower sludge production, and have shown promising performance for treating these compounds. A CW pilot study was undertaken todetermine its potential to remove BPA and NP from municipal wastewater. Three CWs were used: the first CW was planted with Heliconia sp., a second CW was planted with Phragmites sp., and the third CW was an unplanted control. The removal efficiency of the Heliconia-CW was 73 ± 19% for BPA and 63 ± 20% for NP, which was more efficient than the Phragmites-CW (BPA 70 ± 28% and NP 52 ± 23%) and the unplanted-CW (BPA 62 ± 33% and NP 25 ± 37%). The higher capacity of the Heliconia-CW for BPA and NP removal suggests that a native plant from the tropics can contribute to a better performance of CW for removing these compounds. Full article
(This article belongs to the Special Issue Wastewater Treatment and Reuse Technologies) Printed Edition available
Figures

Graphical abstract

Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top