bluuebunny/crossref_metadata_2025 huggingface dataset:
Teaching Active Citizenship: A Companion to the Traditional Political Science Curriculum
Authors: Smith Michael , Bob Graham The Honorable
Published: June 2014

The authors of this article advocate a new curriculum that can be applied to American government, introduction to political science, and state and local government courses. For the past half-century, high school and college general-education requirements have deemphasized civics, government, and political science. In response to the corresponding decrease in the nation’s civic health, this proposal is based on three principles. First, teaching citizenship is different than teaching civics. Second, citizenship is taught most effectively by engagement in the “real world,” with students completing projects that take them step by step through the policy-change process. Finally, the education and preparation of future high school government teachers needs to change to encourage them to teach their students the rights, responsibilities, and competencies of active citizenship.
Prenatal risk factors for depression: a critical review of the evidence and potential mechanisms
Authors: Braithwaite E. C. , Murphy S. E. , Ramchandani P. G.
Published: June 2014

Exposure to adverse experiences in early life increases the risk of depression during adulthood. Recent findings have highlighted that exposure of a fetus to an adverse intrauterine environment may also have implications for later offspring depression. This review considers the status of the evidence for these associations and the potential mechanisms underlying prenatal developmental risks for later depression, addressing the challenging possibility that environmental predisposition to depression may begin before birth.
Effekte der Abklärungsuntersuchung auf Behandlungsdauer und die Wahrscheinlichkeit zur Aufnahme ambulanter Behandlung
Authors: Dau Wolfgang , Heese Peter , Banger Markus
Published: June 2014

Fragestellung: Die Effekte der Abklärungsuntersuchung auf die stationäre Behandlungsdauer, Aufnahmehäufigkeit und die Wahrscheinlichkeit für ambulante Behandlungskontakte sollen überprüft werden. Methodik: In einem quasi-experimentellen Untersuchungsdesign mit historischer Kontrollgruppe wurde die Abklärungsuntersuchung über einen Zeitraum von einem Jahr konsekutiv bei 235 Fällen angewendet (Experimentalgruppe; EG). Als Kontrollgruppe (KG) dienten die Daten zweier Patientenjahrgänge vor Einführung der Abklärungsuntersuchung (AbU), die sich in der Notaufnahme vorstellten (N = 662). Die Daten wurden mittels logistischer und Negativ-Binomialer Regression ausgewertet.Ergebnisse: Die AbU konnte dazu beitragen, die stationären Behandlungszeiten pro Aufenthalt um 34 % (RR = 0.66) zu verringern und die Wahrscheinlichkeit einer Kontaktaufnahme zur Institutsambulanz (OR = 2.60) zu steigern. Demgegenüber zeigte sich eine Reduktion der Aufnahmehäufigkeit nur in Interaktion mit der Anzahl der Abhängigkeitsdiagnosen (RR = 0.77). In einer Subgruppe von Patienten (”Heavy User”) zeigten sich schwache Effekte (Behandlungsdauer: d = 0.37; Aufnahmehäufigkeit d = 0.44). Schlussfolgerung: Die Abklärungsuntersuchung zeigte ermutigende Effekte. Angesichts sich ständig verkürzender Behandlungszeiten scheint weitere Forschung im Interesse der Qualitätssicherung der Behandlung sinnvoll und notwendig.
Bromide-bridged palladium(iii) chain complexes showing charge bistability near room temperature
Authors: Kumagai Shohei , Takaishi Shinya , Breedlove Brian K. , Okamoto Hiroshi , Tanaka Hisaaki , Kuroda Shin-ichi , Yamashita Masahiro
Published: June 2014

We synthesized and characterized bromide-bridged Pd(iii) chain complexes, [Pd(en)2Br](MalCn–Y)2·H2O (en = ethylenediamine; MalCn–Y = dialkyl sulfomalonate; n: the number of carbon atoms) (n = 7 and 12), which were in averaged valence states at room temperature.
Postsynthetic modification of an amino-tagged MOF using peptide coupling reagents: a comparative study
Authors: Hintz Henrik , Wuttke Stefan
Published: June 2014

First comparative study about postsynthetic modification of an amino-tagged MOF with drugs and biomolecules using peptide coupling reagents.
A strain-promoted alkyne–azide cycloaddition (SPAAC) reaction of a novel EpCAM aptamer–fluorescent conjugate for imaging of cancer cells
Authors: Subramanian Nithya , Sreemanthula Jagadeesh Babu , Balaji Baghavathi , Kanwar Jagat R. , Biswas Jyotirmay , Krishnakumar Subramanian
Published: June 2014

A novel EpCAM aptamer-DIBO-AF594 fluorescent conjugate was synthesised using bio-orthogonal chemistry employing copper free, strain promoted alkyne–azide cycloaddition (SPAAC) reaction.
Aerobic copper-catalyzed oxidative [6C+1C] annulation: an efficient route to seven-membered carbocycles
Authors: Liu Xiao , Zhang Lingjuan , Xu Xianxiu , Wang Shan , Pan Ling , Zhang Qian , Liu Qun
Published: June 2014

A copper-catalyzed aerobic tandem Michael addition–intramolecular radical cyclization–benzyl C(sp3)–H bond oxidation reaction of dicinnamoyl ketene dithioacetals and ethyl cyanoacetate was developed for the diastereoselective synthesis of seven-membered carbocycles.
Molecular brass: Cu4Zn4, a ligand protected superatom cluster
Authors: Freitag Kerstin , Banh Hung , Gemel Christian , Seidel Rüdiger W. , Kahlal Samia , Saillard Jean-Yves , Fischer Roland A.
Published: June 2014

The first examples of structurally characterized “molecular brass”, [(CuCNtBu)4(ZnCp*)4] and [(CuCNtBu)4(ZnCp*)3ZnCp] exhibit the structural motif of a [Cu4Zn4] tetrahedral star, which is inversely found in the γ-brass phase Cu5Zn8.
Role of water in metal catalyst performance for ketone hydrogenation: a joint experimental and theoretical study on levulinic acid conversion into gamma-valerolactone
Authors: Michel Carine , Zaffran Jérémie , Ruppert Agnieszka M. , Matras-Michalska Joanna , Jędrzejczyk Marcin , Grams Jacek , Sautet Philippe
Published: June 2014

Water is essential to attain good performance in a hydrogenation reaction with a ruthenium catalyst.
Molecular basis of the exciton–phonon interactions in the PE545 light-harvesting complex
Authors: Viani Lucas , Corbella Marina , Curutchet Carles , O'Reilly Edward J. , Olaya-Castro Alexandra , Mennucci Benedetta
Published: June 2014

A fully polarizable QM/MM approach is used in combination with classical MD simulations to predict the pigment-dependent spectral densities of the PE545 antenna complex and account for their effects on the exciton dynamics.
Are hot charge transfer states the primary cause of efficient free-charge generation in polymer:fullerene organic photovoltaic devices? A kinetic Monte Carlo study
Authors: Jones Matthew L. , Dyer Reesha , Clarke Nigel , Groves Chris
Published: June 2014

In this paper we use a Kinetic Monte Carlo model to examine whether hot charge transfer states are the primary cause of efficient free-charge generation in organic photovoltaic devices.
Semi-crystalline photovoltaic polymers with efficiency exceeding 9% in a ∼300 nm thick conventional single-cell device
Authors: Nguyen T. L. , Choi H. , Ko S.-J. , Uddin M. A. , Walker B. , Yum S. , Jeong J.-E. , Yun M. H. , Shin T. J. , Hwang S. , Kim J. Y. , Woo H. Y.
Published: June 2014

New semi-crystalline photovoltaic polymers were synthesized and the optimized device exhibited 9.39% efficiency in a ∼300 nm thick single-cell device.
Original polyols based on organosolv lignin and fatty acids: new bio-based building blocks for segmented polyurethane synthesis
Authors: Laurichesse Stéphanie , Huillet Cédric , Avérous Luc
Published: June 2014

A macropolyol based on lignin can be used as a building block to design PU architectures with advanced properties.
Understanding the structural requirements of hybrid (S)-6-((2-(4-phenylpiperazin-1-yl)ethyl)(propyl)amino)-5,6,7,8-tetrahydronaphthalen-1-ol and its analogs as D2/D3 receptor ligands: a 3D QSAR investigation
Authors: Modi Gyan , Sharma Horrick , Kharkar Prashant S. , Dutta Aloke K.
Published: June 2014

The present study reports the 3D QSAR of dopamine D2/D3 ligands to gain insights into the structural factors responsible for affinity and D3 selectivity.
Conformational analysis of peramivir reveals critical differences between free and enzyme-bound states
Authors: Richards Michele R. , Brant Michael G. , Boulanger Martin J. , Cairo Christopher W. , Wulff Jeremy E.
Published: June 2014

An analysis of the conformational distribution of peramivir, a potent anti-influenza compound, in solution and the solid state reveals a large conformational change required for enzyme binding.
Zampanolide and dactylolide: cytotoxic tubulin-assembly agents and promising anticancer leads
Authors: Chen Qiao-Hong , Kingston David G. I.
Published: June 2014

Zampanolide and its structural relative dactylolide are promising new tubulin-assembly agents with the potential to become new anticancer drugs. This review covers their sources and isolation, structures, anticancer potential, mechanism of action, and syntheses.
3D graphene supported MoO2 for high performance binder-free lithium ion battery
Authors: Huang Zhi Xiang , Wang Ye , Zhu Yun Guang , Shi Yumeng , Wong Jen It , Yang Hui Ying
Published: June 2014

MoO2 nanoparticles were uniformly distributed on 3D graphene foam via a facile CVD method, which displayed an enhanced lithium-ion battery performance.
Programmability of nanowire networks
Authors: Bellew A. T. , Bell A. P. , McCarthy E. K. , Fairfield J. A. , Boland J. J.
Published: June 2014

The natural connectivity behaviour found in random Ni nanowire networks presents a new paradigm for creating multi-functional, programmable materials.
Length scale of Leidenfrost ratchet switches droplet directionality
Authors: Agapov Rebecca L. , Boreyko Jonathan B. , Briggs Dayrl P. , Srijanto Bernadeta R. , Retterer Scott T. , Collier C. Patrick , Lavrik Nickolay V.
Published: June 2014

A remarkable switch in the preferential directionality of Leidenfrost droplets was observed on tilted pillar ratchets of different length scales.
Ionic liquid-induced three-dimensional macroassembly of graphene and its applications in electrochemical energy storage
Authors: Zhu Chengzhou , Zhai Junfeng , Dong Shaojun
Published: June 2014

Ionic liquid-induced three-dimensional macroassembly of graphene has been reported, which provides ideal electrode materials for supercapacitors.
Reduced graphene oxide growth on 316L stainless steel for medical applications
Authors: Cardenas L. , MacLeod J. , Lipton-Duffin J. , Seifu D. G. , Popescu F. , Siaj M. , Mantovani D. , Rosei F.
Published: June 2014

We describe a new method for the growth of reduced graphene oxide rGO on the 316L alloy of stainless steel 316L. Cell viability studies reveal that these rGO coatings do not have toxic effects on mammalian cells.
A simple one-step method to prepare fluorescent carbon dots and their potential application in non-invasive glioma imaging
Authors: Ruan Shaobo , Qian Jun , Shen Shun , Zhu Jianhua , Jiang Xinguo , He Qin , Gao Huile
Published: June 2014

A kind of CD was prepared using a simple one-step method and was applied for non-invasive glioma imaging.
MRI nanoprobes based on chemical exchange saturation transfer: LnIIIchelates anchored on the surface of mesoporous silica nanoparticles
Authors: Ferrauto Giuseppe , Carniato Fabio , Tei Lorenzo , Hu He , Aime Silvio , Botta Mauro
Published: June 2014

LnIII–DO3A complexes anchored to MCM-41 mesoporous silica nanoparticles induce a strong paramagnetic shift of proximate silanol protons behaving as highly sensitive chemical exchange saturation transfer (CEST) MRI nanoprobes.
Radical vinylation of dioxolanes and N-acylpyrrolidines using vinyl bromides
Authors: Kippo Takashi , Kimura Yuki , Maeda Ayami , Matsubara Hiroshi , Fukuyama Takahide , Ryu Ilhyong
Published: June 2014

Radical vinylation of 1,3-dioxolanes and N-acylpyrrolidines using vinyl bromides with an electron-withdrawing substituent proceeded well to give the vinylated products.
Pt-doped graphene oxide/MIL-101 nanocomposites exhibiting enhanced hydrogen uptake at ambient temperature
Authors: Zhang Jun , Liu Xiaoqing , Zhou Hu , Yan Xiufen , Liu Yuanjun , Yuan Aihua
Published: June 2014

Composites of Pt-doped graphene oxide (GO) and a chromate–organic framework (MIL-101) were prepared through the in situ solvent-thermal method. The significant enhancement of hydrogen storage capacities at ambient temperature for the composites with low Pt/GO contents can be attributed to the spillover mechanism in such system.
A pendant drop method for the production of calibrated double emulsions and emulsion gels
Authors: Schmit Alexandre , Courbin Laurent , Marquis Mélanie , Renard Denis , Panizza Pascal
Published: June 2014

We introduce a convenient pendant drop method for making double emulsions and emulsion gels in a predictable way.
Light-induced wide range color switching of liquid crystal blue phase doped with hydrogen-bonded chiral azobenzene switches
Authors: Jin Ouyu , Fu Dengwei , Wei Jie , Yang Huai , Guo Jinbao
Published: June 2014

Reversible phototuning of the reflection color of BP I over the visible wavelength region was achieved in a LC-BPs by employing a new kind of H-bonded chiral azobenzene switches.
Gene expression and metabolic pathways related to cell growth and lipid synthesis in diatom Nitzschia ZJU2 after two rounds of mutagenesis by γ-rays
Authors: Cheng Jun , Feng Jia , Cheng Ruolin , Zhang Chuanxi , Zhou Junhu , Cen Kefa
Published: June 2014

3939 genes including cell growth and lipid synthesis key enzymes were up-regulated in mutant Nitzschia ZJU2 after two mutations by γ-rays which exhibited rapid growth and higher lipid productivity.
Hopeachinols E–K, novel oligostilbenoids from the stem bark of Hopea chinensis
Authors: Cheng Yi-Qing , Jiang Rong , Huang Wei , Wei Wei , Chen Chao-Jun , Tan Ren-Xiang , Ge Hui-Ming
Published: June 2014

Seven novel oligostilbenoids, isolated from Hopea chinensis, may biosynthetically derived from the common intermediate vaticanol A.
Structural properties and electrical characteristics of Ho2O3 and HoTixOy gate dielectrics for a-InGaZnO thin-film transistors
Authors: Pan Tung-Ming , Chen Ching-Hung , Liu Jiang-Hung
Published: June 2014

Transfer and output characteristics of high-κ Ho2O3 and HoTixOy a-IGZO TFT devices.
The electrical double layer at the ionic liquid/Au and Pt electrode interface
Authors: Gomes Cristiana , Costa Renata , Pereira Carlos M. , Silva A. Fernando
Published: June 2014

The role of the electrode material on the interfacial double layer structure of a series of ionic liquids comprising 1-butyl-3-methylimidazolium hexafluorophosphate (C4MIM][PF6]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4MIM][Tf2N]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) was investigated on gold (Au) and platinum (Pt) electrodes.
The photocatalytic activity and degradation mechanism of methylene blue over copper(ii) tetra(4-carboxyphenyl) porphyrin sensitized TiO2under visible light irradiation
Authors: Wang Huigang , Zhou Dongmei , Shen Shaosong , Wan Junmin , Zheng Xuming , Yu Lihong , Lee Phillips David
Published: June 2014

Copper(ii)tetra(4-carboxyphenyl) porphyrin were chemically sensitized on TiO2, its electronic relaxation dynamics and the visible-light induced catalytic mechanism are discussed.
Polymer thermoelectric modules screen-printed on paper
Authors: Wei Qingshuo , Mukaida Masakazu , Kirihara Kazuhiro , Naitoh Yasuhisa , Ishida Takao
Published: June 2014

Screen-printed polymer thermoelectric devices provided sufficient power to illuminate light-emitting diodes.
A general approach to mono- and bimetallic organometallic nanoparticles
Authors: Mavila Sudheendran , Rozenberg Illya , Lemcoff N. Gabriel
Published: June 2014

Rhodium, nickel and iridium are introduced into polycyclooctadiene to generate organometallic nanoparticles with different ratios of metals and catalytic properties.
Photoinduced sequence-control via one pot living radical polymerization of acrylates
Authors: Anastasaki Athina , Nikolaou Vasiliki , Pappas George S. , Zhang Qiang , Wan Chaoying , Wilson Paul , Davis Thomas P. , Whittaker Michael R. , Haddleton David M.
Published: June 2014

A versatile and inexpensive photochemical platform for the preparation of high-order multiblock functional materials.
Characterization of caulonodin lasso peptides revealed unprecedented N-terminal residues and a precursor motif essential for peptide maturation
Authors: Zimmermann Marcel , Hegemann Julian D. , Xie Xiulan , Marahiel Mohamed A.
Published: June 2014

We report four new class II lasso peptides featuring alanine and serine at position 1, a bioinformatically identified leader motif and its mutational analysis revealing significant impact on precursor processing.
The role of protein content on the steady and oscillatory shear rheology of model synovial fluids
Authors: Zhang Z. , Barman S. , Christopher G. F.
Published: June 2014

Model synovial fluid steady shear viscosity to hyaluronic acid solution are identical when interfacial rheology effects are removed.
Fibrillogenesis from nanosurfaces: multiphoton imaging and stereological analysis of collagen 3D self-assembly dynamics
Authors: Bancelin Stéphane , Decencière Etienne , Machairas Vaïa , Albert Claire , Coradin Thibaud , Schanne-Klein Marie-Claire , Aimé Carole
Published: June 2014

Surface-mediated collagen fibrillogenesis studied with multiphoton imaging and mathematical morphology.
Poly(N-isopropylacrylamide) microgels at the oil–water interface: temperature effect
Authors: Li Zifu , Richtering Walter , Ngai To
Published: June 2014

The heptane–water interfacial tension exhibits a minimum in the presence of PNIPAM microgels, particularly in the vicinity of the volume phase transition temperature (VPTT) of PNIPAM microgels. The origin of such interfacial tension minima contributes to the microgel spreading at the oil–water interface in the early states and is then governed by the microgels' packing and interactions in the final static equilibrium states.
Hydrodynamic effects of the tip movement on surface nanobubbles: a combined tapping mode, lift mode and force volume mode AFM study
Authors: Walczyk Wiktoria , Hain Nicole , Schönherr Holger
Published: June 2014

Individual argon surface nanobubbles on highly oriented pyrolytic graphite were analysed in three different AFM imaging modes to assess the impact of the effect of different tip-sample interactions on the apparent nanobubble dimensions.
CO2-switchable multi-compartment micelles with segregated corona
Authors: Liu Hanbin , Zhao Ying , Dreiss Cécile A. , Feng Yujun
Published: June 2014

Multi-compartment micelles (MCMs) with segregated corona formed from a specifically-tailored linear ABC triblock copolymer can be switched “on” and “off” when sequentially treated with CO2 and N2.
Redox-responsive, reversibly fluorescent nanoparticles from sustainable cellulose derivatives
Authors: Li Wei , Wang Wei , Yang Yongbiao , Zhang Kai
Published: June 2014

Multi-stimuli responsive and reversibly fluorescent compounds from sustainable cellulose were synthesized after the introduction of thiol and rhodamine spiroamide groups.
Nanodiamond/carbon nitride hybrid nanoarchitecture as an efficient metal-free catalyst for oxidant- and steam-free dehydrogenation
Authors: Zhao Zhongkui , Dai Yitao
Published: June 2014

A nanodiamond/CNx hybrid fabricated through a facile pyrolysis approach exhibits superior catalysis that is dependent on the structure and surface chemical properties.
Improving the photovoltaic performance of ladder-type dithienonaphthalene-containing copolymers through structural isomerization
Authors: Ma Yunlong , Zheng Qingdong , Wang Lixin , Cai Dongdong , Tang Changquan , Wang Meng , Yin Zhigang , Chen Shan-Ci
Published: June 2014

The photovoltaic device based on copolymer PaDTNBTO shows an efficiency of 6.44% with a Voc of 0.92 V.
Facile and rapid ruthenium mediated photo-crosslinking of Bombyx mori silk fibroin
Authors: Whittaker Jasmin L. , Choudhury Namita R. , Dutta Naba K. , Zannettino Andrew
Published: June 2014

We report a unique and facile way of preparing silk fibroin gel by ruthenium-mediated photocrosslinking of silk solution. Compared to existing methods, this approach is faster, taking only a few minutes to form the gel with tunable modulus. Hydrogels demonstrate their potential suitability as biomaterials for tissue engineering applications.
Computational exploration of newly synthesized zirconium metal–organic frameworks UiO-66, -67, -68 and analogues
Authors: Yang Li-Ming , Ganz Eric , Svelle Stian , Tilset Mats
Published: June 2014

Metal–organic frameworks UiO-66, -67, -68 and analogues have exceptional thermal and chemical stability, are resistant to water, acid, and base for use in real-world applications.
Two novel organic–inorganic hybrid molybdenum(v) cobalt/nickel phosphate compounds based on isolated nanosized Mo/Co(Ni)/P cluster wheels
Authors: Miao Hao , Wan Hong-Xiang , Liu Ming , Zhang Yu , Xu Xiao , Ju Wei-Wei , Zhu Dun-ru , Xu Yan
Published: June 2014

Compounds 1 and 2 are the first two isolated structures in the family of 2D layered high-nuclear wheel-shaped {Mo/TM/P} clusters. Both compounds show good NLO activities, which are rare in compounds containing POM anions.
Insights into Hippocampal-Dependent Declarative Memory: Recent Findings and Clinical Implications
Authors: Rubin Rachael D. , Cohen Neal J.
Published: June 2014

The hippocampus, a structure within the medial temporal lobe, is critical for declarative memory — the form of memory that allows us to remember our experiences and the events of daily life. Traditional descriptions of hippocampal function focus on the explicit nature of declarative memory and emphasize long-term declarative memories in particular. However, recent findings suggest the hippocampus is more precisely characterized by the ability to bind arbitrary relations and flexibly link distinct aspects of experience (i.e., relational memory). This conceptualization does not limit the contribution of the hippocampus to a particular time-scale or domain, but suggests its contribution is determined by task demands. Indeed, we present a set of studies demonstrating the hippocampus contributes to memory for “common ground” —the mutually shared knowledge that is essential to language processing and communication—but only when arbitrary, flexible representations are required. This outcome has clinical implications for patients with hippocampal dysfunction, a feature of many neurological and psychiatric conditions. These patients may experience related language processing, communication, and even social deficits; however, these patients may benefit from rehabilitation strategies that draw upon residual skills and knowledge to promote processing in complimentary, intact neural systems that rely less on declarative memory.
Measurement threshold configuration scheme based on the traffic load
Authors: Mach Tomasz Henryk , Tafazolli Rahim , Dianati Mehrdad
Published: June 2014

This study proposes a performance analysis of the measurements mechanism applicable to the terminal controlled cell reselection algorithm in a mobile cellular communication system. The cell reselection mechanism decides on which cell, a user equipment (UE) is camped on, when it is in the idle mode. The analysis demonstrates the impact of the neighbour cells measurement threshold setting during the reselection on the serving cell pilot channel quality and a measurement effort in the UE, in terms of the time spent measuring neighbour cells. The authors demonstrate that there is a trade‐off between the cell reselection performance, in terms of the signal quality during the mobility and the battery life in the mobile terminal with different system configurations. Furthermore, a novel approach and enhanced load based measurement threshold configuration scheme is proposed, in order to improve this trade‐off and also the overall system performance and the user experience. Performance analysis results are given in different scenarios to demonstrate the efficacy of the proposed scheme.
Securing the cloud storage audit service: defending against frame and collude attacks of third party auditor
Authors: Huang Kun , Xian Ming , Fu Shaojing , Liu Jian
Published: June 2014

Cloud computing has been envisioned as the next generation architecture of the IT enterprise, but there exist many security problems. A significant problem encountered in the context of cloud storage is whether there exists some potential vulnerabilities towards cloud storage system after introducing third parties. Public verification enables a third party auditor (TPA), on behalf of users who lack the resources and expertise, to verify the integrity of the stored data. Many existing auditing schemes always assume TPA is reliable and independent. This work studies the problem what if certain TPAs are semi‐trusted or even potentially malicious in some situations. Actually, the authors consider the task of allowing such a TPA to involve in the audit scheme. They propose a feedback‐based audit scheme via which users are relaxed from interacting with cloud service provider (CSP) and can check the integrity of stored data by themselves instead of TPA yet. Specifically, TPA generates the feedback through processing the proof from CSP and returns it to user which is yet unforgeable to TPA and checked exclusively by user. Through detailed security and performance analysis, the author's scheme is shown to be more secure and lightweight.
Expectation‐maximisation‐based localisation using anchors with uncertainties in wireless sensor networks
Authors: Li Bin , Wu Nan , Wang Hua , Kuang Jingming
Published: June 2014

Localisation in wireless sensor networks (WSNs) has received much attention, where most studies focus on mitigating the effects of measurement noise under the assumption of accurate anchors’ positions. However, anchors’ positions could be inaccurate for the inevitable errors in practical observations. This paper studies the sensor localisation with both inaccurate anchors’ positions and noisy range measurements in WSNs. To solve the intractable integrals in likelihood function, the authors propose to use expectation‐maximisation (EM) algorithm to obtain the maximum likelihood (ML) estimation iteratively. The ‘a posteriori’ distribution of the anchor's position uncertainty is approximated to a circularly symmetric Gaussian distribution by minimising the Kullback‐Leibler divergence between them. Building on this, the authors derive the expectation step in a closed‐form expression. In the maximisation step, based on the Taylor expansion of the confluent hypergeometric function of the first kind presented in the expectation step, analytical solutions are obtained. Simulation results show that the proposed EM estimator significantly outperforms the approximated ML estimator. The performance gain by using the EM estimator becomes larger as the increase of anchors’ position uncertainties. Moreover, the performance of the EM estimator is close to that of the Monte Carlo‐based estimator with much less computational complexities.
Pilot‐assisted linear turbo equaliser over doubly selective channels
Authors: Qi Xiaoke , Li Yu , Huang Haining
Published: June 2014

The underwater acoustic channel is considered as one of the most challenging channels for reliable communications. Long delay spread and Doppler effect bring a great challenge to directly apply the algorithms in radio communications to underwater communications, which calls for modification and enhancement. In this study, a pilot‐assisted linear turbo equalisation algorithm termed P‐TE is proposed. Unlike the existing pilot methods that insert pilot into the modulated symbols to facilitate the channel estimation, the authors insert the known bits into the uncoded binary sequence to assist equalisation as well as decoding with the careful design of the bit positions. A second‐order least mean square adaptive algorithm as well as adaptive step size method is introduced for weights update. Furthermore, a modified low‐density parity‐check decoding algorithm is presented to describe the pilot‐assisted decoding algorithm, which does not increase the complexity. Moreover, pilot extraction from error‐free blocks is proposed for enhanced performance. Experimental results have indicated that P‐TE can significantly improve the performance and reduce the required number of the iterations, leading to lower complexity. Furthermore, experiments show that the effective throughput of P‐TE can be higher than the method without pilot at a signal‐to‐noise ratio of 10 dB.
Image clustering using exponential discriminant analysis
Authors: Ahmed Nasir
Published: June 2014

Local learning based image clustering models are usually employed to deal with images sampled from the non‐linear manifold. Recently, linear discriminant analysis (LDA) based various clustering models were proposed. However, in these clustering models, regularisation parameter was added to handle the small‐sample‐size (SSS) problem of LDA for high‐dimensional image data. Owing to this, the authors had to tune a number of clustering parameters for optimal clustering performance in existing local learning based clustering approaches. In this study, the less‐parameterised local learning based image clustering model is proposed. The proposed local exponential discriminant clustering (LEDC) model is based on exponential discriminant analysis (EDA). In the LEDC model, local scatter matrices are projected in the exponential domain in order to handle the SSS problem of LDA without adding regularisation parameter. In the proposed LEDC model, k‐nearest neighbours are the only clustering parameter as compared with existing local learning based clustering approaches such as normalised cut, spectral embedded clustering and local discriminant model and global integration (LDMGI). Experimental results on twelve benchmark image datasets show that the LEDC model achieved a comparable clustering performance as that of the near competitor LDMGI model. Clustering performance is comparable because no discriminant information of LDA is lost in EDA. The authors concluded that the proposed LEDC clustering model is less‐parameterised with a comparable clustering performance as that of existing state‐of‐the‐art local learning based clustering approaches.
Short primary linear drive designed for synchronous and induction operation in different sections
Authors: Fernandes Neto Tobias Rafael , Mutschler Peter , Pontes Ricardo Silva Thé
Published: June 2014

The potential for very long tracks, multiple vehicles travelling at high speed, high positioning repeatability and rapid acceleration turns the short primary linear drive into a good candidate for use in material transfer and processing lines. To implement this system, the linear motor was designed for synchronous and induction operation, since the costs can be considerably reduced by using a simple induction rail at the long transporting sections, instead of permanent magnets. This study is focused on the vehicle motion control strategy of a short primary linear drive, in order to regulate the speed without jerks. The implemented control algorithm for both the operations is based on a field oriented control, which uses a moving AB‐reference frame. The position information was obtained by using a magneto‐resistive incremental encoder, which was mounted on the vehicle, and a magnetic linear scale, which was installed along the passive track. Furthermore, force generation which depends on the vehicle's position will be discussed. Finally, experimental tests are performed to demonstrate the feasibility of the employed control strategy.
Modelling and forecasting of electric daily peak load movement based on the elliptic‐orbit model with weekly periodic extension: a case study
Authors: Zong‐chang Yang
Published: June 2014

Electric load movement analysis is an important task for effective operation and planning of power systems. It is shown that a weekly quasi‐periodicity is enclosed in electric daily peak load movement. On the basis of weekly periodic extension for electric daily peak load movement, the so‐called elliptic‐orbit model is introduced to describe its movement. Electric daily peak load movement as time series is mapped into the polar coordinates to form the elliptic‐orbit model, in which each 7‐day‐movement is depicted as one elliptic orbit. Experimental results of the Great Britain National Grid and Analysis indicate workability and effectiveness of the proposed method. It is shown that the electric daily peak load movement with weekly periodic extension is well described by the elliptic‐orbit model, which presents a vivid description for analysing electric daily peak load movement in a concise and intuitive way, and others may benefit from it.
Differential evolution method‐based output power optimisation of switched reluctance generator for wind turbine applications
Authors: Yahia Hedi , Liouane Noureddine , Dhifaoui Rachid
Published: June 2014

The use of wind energy for electric power generation provides a clean and renewable source. Therefore there is an increasing interest in developing and exploiting natural energy generation system. Switched reluctance generators (SRGs) have the potential to be a robust and highly efficient electrical conversion system for variable‐speed wind applications. This study presents a new approach for optimising performance of a SRG intended for variable‐speed direct drive wind turbine applications. DC bus voltage level and phase voltage switching angles have been identified as control variables affecting power generation. Owing to highly non‐linear characteristics of SRG, iterative simulation of the generator model on the range of control variables can be used for finding output power profile. Since it is a multidimensional search space, the number of iterations is very big. Differential evolution (DE) strategy has been introduced to find optimal firing angles and DC bus voltage level under multiple operating conditions. Optimisation of the control variables is performed using a machine model based on the measured characteristics. Selected operating points are experimentally tested using a 4 kW 1500 rpm SRG prototype. DE algorithm is a viable alternative for generating optimal control in multidimensional optimisation of SRG wind energy generation.
Contacts on polyester textile as a flexible substrate for solar cells
Authors: Diyaf Adel G. , Mather Robert R. , Wilson John I.B.
Published: June 2014

In the present work, the authors have studied conductive surfaces on polyester fabrics by using two types of commercially available conductive polymers; polyaniline and poly (3,4‐ethylenedioxythiophene)‐poly (styrenesulphonate) (PEDOT: PSS) with 100 nm aluminium thin film evaporated on top of the polymer so the fabric becomes a conductive substrate for inorganic thin film solar cells. Conductive polymer surfaces on woven polyester fabrics were obtained by knife‐over‐table coating technique. Surface resistivities for polyaniline and PEDOT: PSS coated fabrics were measured and found in the range of 400 × 103 and 1 × 103 Ω/□, respectively. Thermal stability tests were carried out to evaluate the effect of specific periods of heal treatment at different elevated temperatures on resistance of polymer coated conducting textiles. PEDOT: PSS exhibited better stability than panipol. According to long term tests, PEDOT: PSS coated samples showed improvement in conductivity over 3 days whereas panipol showed the opposite. Transmission Line Model tests were performed to measure aluminium/polymer contact resistances which were found to be 120 × 103 Ω for polyaniline and about 46.3 Ω for PEDOT: PSS. Mechanical bending tests for aluminium/PEDOT: PSS/fabric samples showed that the polymer can maintain the conductivity of samples by bridging micro‐cracks in the metal film.
Simplified levelised cost of the domestic photovoltaic energy in the UK: the importance of the feed‐in tariff scheme
Authors: Georgitsioti Tatiani , Pearsall Nicola , Forbes Ian
Published: June 2014

This study examines the cost‐effectiveness of residential photovoltaic (PV) systems in the UK by considering the changes occurring in the supporting mechanism, the Feed‐in Tariff (FiT). The metric used is the levelised cost of energy. The analysis stresses the importance of the FiT scheme and demonstrates the lowest cost of produced energy that domestic PV systems can achieve with the current policies. In this study, the term grid parity is used when the levelised cost of the PV generated energy is lower than the retail electricity cost that the consumer pays. It is observed that, for certain scenarios and in certain UK cities, a domestic PV system can reach grid parity without using the FiT scheme, but it might not constitute a sufficient reason to invest in a PV system.
Non‐linear pitch control of wind turbines for tower load reduction
Authors: Xiao Shuai , Geng Hua , Yang Geng
Published: June 2014

As the modern wind turbines (WTs) become larger in size, the structural loads experienced by the WTs increase dramatically, which would shorten the working life of the WTs and increase the maintenance cost. To mitigate such problem, this study proposes a non‐linear pitch control strategy including tower load reducing objective for the WTs operating in the above‐rated wind speed region. The proposed non‐linear controller consists of a rotor speed regulator, a tower oscillation damper and a lead compensator. The rotor speed regulator and tower oscillation damper are designed separately based on inverse system method, which is a powerful tool in solving the control problem of non‐affine non‐linear system. The lead compensator is utilised to compensate for the phase lag of the pitch angle command caused by the pitch actuator. Furthermore, light detection and ranging (LIDAR) preview measurements are introduced to provide wind information for the proposed controller in order to improve its control performance. The simulation results with the aero‐elastic model of fatigue, aerodynamics, structures and turbulence (FAST) show that, the proposed non‐linear controller outperforms the baseline gain‐scheduled proportional–integral controller. The proposed non‐linear controller can work well in the whole above‐rated wind speed region, and is easy to implement for application.
Wireless sensor network‐based solution for environmental monitoring: water quality assessment case study
Authors: Postolache Octavian , Pereira José Dias , Silva Girão Pedro
Published: June 2014

The challenges of climate change, population growth, demographic change, urbanization and resource depletion mean that the world's great cities need to adapt to survive and thrive over the coming decades. Slashing greenhouse gas emissions to prevent catastrophic climate change, while maintaining or increasing quality of life, can be a costly and difficult process. Two factors that directly affect the life quality in the XXI century cities are the water and air quality that can be monitored using the combination of low cost sensing modules, machine to machine (M2M) and internet of things (IoT) technologies. In this context, this study presents a wireless sensor network architecture that combines low cost sensing nodes and a low cost multi‐parameters sensing probe for reliable monitoring of water quality parameters of surface waters (lakes, estuaries and rivers) in urban areas. A particular attention is dedicated to the design of the conductivity, temperature and turbidity signal conditioning circuits, highlighting important issues related to linearisation, measuring dynamic range and low‐cost implementation by using commercial off‐the‐shelf components and devices. Several issues related to the wireless sensor network implementation are included in this study, as well as several simulation and experimental results.
Bio‐inspired energy and channel management in distributed wireless multi‐radio networks
Authors: Olwal Thomas Otieno , Masonta Moshe Timothy , Mekura Fisseha
Published: June 2014

In the recent past, research in the next generation wireless heterogeneous broadband networks has favoured the design of multi‐radio interface over the single radio interface architectures to support desirable features such as a self‐organisation, self‐configuration, reliability and robustness of network operations in a resource‐constrained environment. However, such autonomous network behaviours have been seen to cause an inefficient consumption of energy and frequency channel resources, impacting negatively on the economy and environment. To address the inefficient energy and frequency channel utilisation problems, this study proposes a biological behaviour‐based network resource management method. The research is inspired by such a well‐established optimal foraging theory whereby a solitary biological forager in a random ecosystem makes optimal decisions that maximise its own nutrients consumption, survival probability and lifetime, whereas minimising possible risks associated with its own behaviour. This study has applied this natural principle and developed a Bio‐inspired Energy and Channel (BEACH) management method. The BEACH method is aimed at achieving both efficient communication energy and frequency channel utilisation in the considered distributed wireless multi‐radio network. The efficacy of the developed BEACH method has been extensively validated through computer simulations and shown to yield improved energy‐efficiency and throughput performance.
Energetic barrier for penetration of N, N+ and N++ through the centre of hexagonal rings of a C60 cage. A stability study of the endohedral complexes (N@C60, N+@C60 and N++@C60)
Authors: Mędrek Marzena , Pluciński Franciszek , Mazurek Aleksander Paweł
Published: June 2014

Theoretical studies of model endohedral fullerenes N@C60, N+@C60 and N++@C60 were performed, from their stability aspect. The possibility of N, N+ and N++ entering a fullerene cage without breaking any C–C bonds was investigated. Assuming the inclusion energy and the height of the energetic barrier of transfer of N, N+ and N++ through the hexagons of a C60 cage as the determinants of the stability of studied complexes their values were calculated by the quantum chemical DFT/B3LYP/6‐31G* method. The calculated inclusion energies with the BSSE correction in the cases of N++, N+ and N are −603.4, −149.6 and 3.9 kcal/mol, respectively.
Analysis of InGaN light-emitting diodes with GaN-AlGaN and AlGaN-GaN composition-graded barriers
Authors: Yang Yujue , Wang Junxi , Li Jinmin , Zeng Yiping
Published: June 2014

The effects of InGaN-based light-emitting diodes (LEDs) with Al composition increasing and decreasing GaN-AlGaN barriers along the growth direction are studied numerically. Simulation results suggest that the LEDs with GaN-AlGaN composition-decreased barriers show more significant enhancement of light-output power and internal quantum efficiency than LEDs with composition-increasing GaN-AlGaN barriers when compared with the conventional LED with GaN barriers, due to the improvement in hole injection efficiency and electron blocking capability. Moreover, the optical performance is further improved by replacing GaN-AlGaN barriers with AlGaN-GaN barriers of the same Al composition-decreasing range, which are mainly attributed to the modified band diagrams. In addition, the major causes of the different efficiency droop behaviors for all the designed structures are explained by the electron leakage current and the different increase rates of hole concentration with injection current.
Effect of doping on growth and field emission properties of spherical carbon nanotube tip placed over cylindrical surface
Authors: Santolia Isha , Tewari Aarti , Sharma Suresh C. , Sharma Rinku
Published: June 2014

Theoretical investigations to study the effect of doping of hetero-atoms on the growth and field emission properties of Carbon Nanotubes (CNTs) tip placed over a cylindrical surface in complex plasma have been carried out. A theoretical model incorporating kinetics of plasma species such as electron, ions, and neutral atoms including doping elements like nitrogen (N) and boron (B) and energy balance of CNTs in a complex plasma has been developed. The effect of doping elements of N and B on the growth of CNTs, namely, the tip radius has been carried out for typical glow discharge plasma parameters. It is found that N and B as doping elements affect the radius of CNTs extensively. We obtain small radii of CNT doped with N and large radius of CNT doped with B. The field emission characteristics from CNTs have therefore been suggested on the basis of results obtained. Some of theoretical results are in compliance with the existing experimental observations.
Far-field imaging with a multi-frequency metalens
Authors: Jouvaud C. , Ourir A. , de Rosny J.
Published: June 2014

A metalens, i.e., a dense array of identical resonators, allows to image an object pattern at subwavelength scale from far field radiation field. Here, we show that the efficiency can be improved when the resonant frequencies of the cell are distributed over a given frequency range. Because in such systems each eigen mode is localized, the subwavelength image is built from a spectral analysis of the radiated field. A simple model based on coupled resonant dipoles is used to find the best frequency distribution. This multifrequency metalens approach is validated using a flat array of split ring resonators. We experimentally demonstrate the subwavelength resolution of such a device at microwave range.
UMEL: A new regression tool to identify measurement peaks in LIDAR/DIAL systems for environmental physics applications
Authors: Gelfusa M. , Gaudio P. , Malizia A. , Murari A. , Vega J. , Richetta M. , Gonzalez S.
Published: June 2014

Recently, surveying large areas in an automatic way, for early detection of both harmful chemical agents and forest fires, has become a strategic objective of defence and public health organisations. The Lidar and Dial techniques are widely recognized as a cost-effective alternative to monitor large portions of the atmosphere. To maximize the effectiveness of the measurements and to guarantee reliable monitoring of large areas, new data analysis techniques are required. In this paper, an original tool, the Universal Multi Event Locator, is applied to the problem of automatically identifying the time location of peaks in Lidar and Dial measurements for environmental physics applications. This analysis technique improves various aspects of the measurements, ranging from the resilience to drift in the laser sources to the increase of the system sensitivity. The method is also fully general, purely software, and can therefore be applied to a large variety of problems without any additional cost. The potential of the proposed technique is exemplified with the help of data of various instruments acquired during several experimental campaigns in the field.
Conditions for uniqueness of product representations for separable quantum channels and separable quantum states
Authors: Cohen Scott M.
Published: June 2014

We give a sufficient condition that an operator sum representation of a separable quantum channel in terms of product operators is the unique product representation for that channel, and then provide examples of such channels for any number of parties. This result has implications for efforts to determine whether or not a given separable channel can be exactly implemented by local operations and classical communication. By the Choi-Jamiolkowski isomorphism, it also translates to a condition for the uniqueness of product state ensembles representing a given quantum state. These ideas follow from considerations concerning whether or not a subspace spanned by a given set of product operators contains at least one additional product operator.