Special Issue "Feature Papers"

Guest Editor
Prof. Dr. Takayoshi Kobayashi
Advanced Ultrafast Laser Research Center, The University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182-8585, Japan
Website: http://femto.pc.uec.ac.jp/
E-Mail: kobayashi@ils.uec.ac.jp
Phone: +81 42 443 5845
Fax: +81 42 443 5825
Interests: ultrafast and nonlinear optical processes; quantum optics; quantum photobiology

Dear Colleagues,

This is a collection of top quality papers published free of charge in Open Access form by the editorial board members, or those invited by the editorial office and the Editor-in-Chief. The papers should be long research papers (or review papers) with full and detailed summary of the author's own work done so far.

Prof. Dr. Takayoshi Kobayashi
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

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• Applied Sciences Feature Papers

Type of Paper: Article
Title: Perceptions of Offshore Wind Farms and Monetary Trade-Offs Do They Differ?
Authors: Jacob Ladenburg et al.
Affiliation: Danish Institute of Governmental Research, Nyropsgade 37, DK-1602, Copenhagen V, Denmark; E-Mail: JAL@akf.dk
Abstract: Attitude and perception surveys are inexpensive and popular tools to assess the acceptance of wind power development. This article compares such relatively simple statements of perceptions with preferences, as measured by their willingness to pay for reducing visual impacts using the visual impacts from offshore wind farms as the case. The results strongly indicate that perceptions appear to convey different information compared to preferences. Respondents who have stated a positive or neutral perception of visual impacts of offshore wind farms express equally strong preferences for reducing visual disamenities compared to respondents who have stated a negative attitude. These differences might result from differences in decision protocols due to information effects. In application, these results indicate that it is important that policy makers pay attention to the different types of information that attitude and perception surveys and polls obtain compared to preferences surveys in relation to wind power development.

Type of Paper: Article
Title: Electrically Small Resonators for Planar Metamaterial, Microwave Circuit and Antenna Design: A Comparative Analysis
Authors: Ferran Martín et al.
Affiliations: GEMMA/CIMITEC, Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 BELLATERRA (Barcelona), Spain; E-Mail: ferran.martin@uab.es
Abstract: 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's size, bandwidth, their circuit models when they are coupled to transmission lines (as is usually required), as well as key applications, will be considered.

Type of Paper: Review
Title: Fluorinated Side Chain Organic Electro-Optic Copolymers: Determination of the Time and Temperature Stability of the Induced Electro-Optic Coefficient
Authors: Alessandro Belardini et al.
Affiliations: Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Via A. Scarpa 16, Roma I-00161, Italy; E-Mail: alessandro.belardini@uniroma1.it
Abstract: Organic fluorinated materials demonstrates 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 ellisometry, second harmonic generation, temperature scanning and isothermal relaxation) were shown and applied to a variety of fluorinated electro-optic compounds.

Type of Paper: Review
Title: A Review of the Energy Behaviour of Residential Buildings in Southern Europe
Authors: Soteris A. Kalogirou and Gregoris Panayiotou
Affiliation: Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, P. O. Box 50329, 3603 Limassol, Cyprus; E-Mail: Soteris.kalogirou@cut.ac.cy
Abstract: The existing building stock in the EU-27 is responsible for over 40% of final energy consumption while residential buildings alone account for 63% of the latter value. The energy behaviour of residential buildings located in Southern Europe and specifically those of the Mediterranean region significantly differentiates from the corresponding ones of the Northern Europe. The predominant load is that of the cooling load which is opposite to what happens in Central and Northern Europe. Therefore, cooling loads of the buildings in this area are much higher while heating loads are much lower. In this view the knowledge of the energy behaviour of the residential building stock of Southern Europe will assist policy makers to formulate targeted measures aiming to improve energy efficiency and will provide valuable information for setting current legal standards and benchmarks in the energy performance certificate, a requirement of the 2002/91/EC Directive. This paper presents a review of the energy behaviour of residential buildings in Southern Europe in order to constitute a base for improving their energy performance. Finally, an increase of the energy performance of the residential buildings is an important instrument in the efforts to lessen Europe’s dependency on energy imports as well as carbon dioxide emissions.

Type of Paper: Review
Title: Two-Dimensional Nano-crystals beyond Graphene: Silicene and Germanene
Authors: Guy Le Lay¹, Patrick Vogt² and Paola De Padova³
Affiliations: ¹Aix-Marseille University, CNRS-CINaM, Campus de Luminy, Case 913, 13288, Marseille Cedex 09, France; E-Mail: guy.lelay@univ-provence.fr
²Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany; E-Mail: patrick.vogt@tu-berlin.de
³CNR-ISM, via Fosso del Cavaliere 100, Rome, Italy; E-Mail: depadova@ism.cnr.it
Abstract: Due to its unique physical properties graphene has attracted tremendous attention over the last years. Silicene and germanene, the graphene equivalent for silicon and germanium, could follow this trend, opening new perspectives for applications, especially due to their compatibility with Si-based electronics. Free standing silicene and germanene have been theoretically predicted and are conjectured to have a buckled honeycomb atomic arrangement of sp3/sp2-like hybridized Si/Ge-atoms. Still, silicene/germanene would share essentially the same electronic properties as graphene, i.e. an electronic dispersion resembling that of relativistic Dirac fermions at the K points of the Brillouin-zone. One-dimensional silicene nanoribbons have been grown for the first time few years ago in Marseille, but an inevitable proof of the existence of epitaxial two-dimensional silicene has just been demonstrated by our group recently, while the synthesis of germanene is still to be achieved. In the paper we will comparatively review all literature on these novel two-dimensional nanocrystals and draw perspectives for their potential integration in ultimately scaled electronic devices.

Type of Paper: Article
Title: Reduction and Immobilization of Potassium Permanganate on Iron Oxide Catalyst by Fluidized-Bed Crystallization Technology
Authors: Hui Zhang ³,Yao-Hui Huaug ^1,2,*, Teng-Chien Chen ¹, Yu-Jen Shih ¹, Guang-Xia Li ³
Affiliations: ¹ Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; E-Mail: yhhuang@mail.ncku.edu.tw
² Sustainable Environment Research Center, National Cheng Kung University, Tainan 701, Taiwan
³ Department of Environmental Engineering, Wuhan University, P.O. Box C319 Luoyu Road 129#, Wuhan 430079, China
Abstract: 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 potassium permanganate (KMnO4) reduce to MnO2. Furthermore, MnO2 could deposition 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 effect of KMnO4 concentration, BT-3 dosage, and initial solution pH. The results showed that solution pH was a significant factor on the reduction of KMnO4. At the optimum pHi 6, KMnO4 could be virtually reduced in 10 minutes. A pseudo-first order reaction was employed to describe the reduction rate of KMnO4.
Keywords: Fluidized-bed reactor (FBR)；Iron oxide; Potassium permanganate

Type of Paper: Review
Title: Optical Current Sensors for High Power Systems: A Review
Authors: Ricardo Silva, Hugo Martins, Ivo Nascimento, José M. Baptista,  Pedro Jorge, António Lobo Ribeiro, Orlando Frazão
Affiliation: INESC Porto e Faculdade de Ciências da Universidade do porto, Rua do campo Alegre, 687, Porto Portugal; E-Mail: ofrazao@fc.up.pt
Abstract: 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 fibre sensors, bulk magneto-optical sensors, piezoelectric transducers, magnetic force sensors and hybrid sensors. The physical principles and  main advantages and disadvantages are explained. 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 system.

Type of Paper: Article
Title: Determination of Morphological Parameters of Supported Gold Nanoparticles
Authors: Frank Hubenthal et al.
Affiliation: Institut für Physik and Center for Interdisciplinary Nanostructure Science and Technology – CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, D-34132 Kassel, Germany; E-Mail: hubentha@physik.uni-kassel.de
Abstract: A new simulation technique, based on fitting the results of calculations in quasistatic approximation to inhomogeneously broadened extinction profiles of noble metal nanoparticle ensembles with a broad size and shape distribution, will be introduced. The technique can be applied to oblate nanoparticles, which exhibit a strong correlation between their shape and size. It permits to extract the axial ratio distribution of the particles and, most importantly, the functional dependence between the axial ratio and the radius of particles within the ensemble. To demonstrate its effectiveness, we apply our new technique to noble metal nanoparticles prepared by Volmer-Weber-growth and find a perfect agreement between the calculated and experimental data. Moreover, our technique reveals important and new information about the morphology of the nanoparticle ensembles.