bluuebunny/crossref_metadata_2025 huggingface dataset:
Further investigation into ICP-induced elemental fractionation in LA-ICP-MS using a local aerosol extraction strategy
Authors: Luo Tao , Wang Yu , Hu Zhaochu , Günther Detlef , Liu Yongsheng , Gao Shan , Li Ming , Hu Shenghong
Published: February 2015

The increased size of aerosol agglomerates or particles because of the reduced carrier gas velocity on the ablation site deteriorates the vaporization of aerosol particles in ICP, which induces similar elemental fractionation to laser ablation-induced fractionation.
Predicting selective liver X receptor β agonists using multiple machine learning methods
Authors: Li Yali , Wang Ling , Liu Zhihong , Li Chanjuan , Xu Jiake , Gu Qiong , Xu Jun
Published: February 2015

The classification models for predicting selective LXRβ agonists were firstly established using multiple machine learning methods. The top models can predict selective LXRβ agonists with chemical structure diversity.
Synthesis of polymeric dyes based on waterborne polyurethane for improved color stability
Authors: Mao Haiyan , Wang Chaoxia , Wang Youjiang
Published: February 2015

The color stability of disperse dye was enhancedviacovalent bonding to waterborne polyurethane.
Molecular nitrogen in N-doped TiO2 nanoribbons
Authors: Bittencourt C. , Rutar M. , Umek P. , Mrzel A. , Vozel K. , Arčon D. , Henzler K. , Krüger P. , Guttmann P.
Published: February 2015

X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) support the idea that during nitrogen doping of TiO2 nanoribbons N2 molecules may be formed and trapped in the nanostructures.
Role of Al doping in structural, microstructural, electrical and optical characteristics of as-deposited and annealed ZnO thin films
Authors: Shinde Shashikant D. , Date S. K. , Deshmukh Alka V. , Das Amit , Misra Pankaj , Kukreja L. M. , Adhi K. P.
Published: February 2015

Aluminium dopant segregation from AD-xAZO thin films on annealing is established by structural, optical and electrical characterizations.
Synthesis, characterization and antibacterial activities of N-tert-butoxycarbonyl-thiazolidine carboxylic acid
Authors: Song Zhong-Cheng , Ma Gao-Yuan , Zhu Hai-Liang
Published: February 2015

The mechanism of dynamic kinetic resolution, a nucleophilic substitution through an intramolecular hydrogen bonding by the formation of N-Boc-TCAs was proposed and a qualitative explanation was interpretated according to Curtin–Hammett principle.
Selective Co(ii) removal from aqueous media by immobilizing silver nanoparticles within a polymer-matrix through a formaldehyde cross linking agent
Authors: Siva S. , Sudharsan S. , Sayee Kannan R.
Published: February 2015

A novel hybrid cation exchange resin was developed by encapsulating AgNPs within a macroporous phenol–formaldehyde cation exchanger for the removal of cobalt from aqueous solution.
Recent progress in organic sensitizers for dye-sensitized solar cells
Authors: Lee Chuan-Pei , Lin Ryan Yeh-Yung , Lin Lu-Yin , Li Chun-Ting , Chu Te-Chun , Sun Shih-Sheng , Lin Jiann T. , Ho Kuo-Chuan
Published: February 2015

This review focuses on recent progress of metal-free sensitizers and on panchromatic engineering of co-sensitization in dye-sensitized solar cells (DSSCs).
O2-mediated C(sp2)–X bond oxygenation: autoxidative carbon–heteroatom bond formation using activated alkenes as a linkage
Authors: Lu Qingquan , Chen Jiyong , Liu Chao , Huang Zhiyuan , Peng Pan , Wang Huamin , Lei Aiwen
Published: February 2015

An aerobic dehalogenative oxygenation reaction under mild and simple conditions towards a series of valuable β-keto compounds was developed, in which dioxygen serves as the sole promoter.
A thin film sorbent of layered organo-MnO2 for the extraction of p-aminoazobenzene from aqueous solution
Authors: Mori Katsumasa , Iguchi Sohei , Takebe Shusuke , Nakayama Masaharu
Published: February 2015

We fabricated a thin film-type sorbent consisting of layered organo-MnO2 for the extraction of p-aminoazobenzene from aqueous solution.
Magnetic and hydrazine-decomposition catalytic properties of ε-Fe3N synthesized from a novel precursor
Authors: Zhang Peng , Wang Xiaobai , Wang Wei , Lei Xiang , Yang Hua
Published: February 2015

ε-Fe3N was synthesized from a complex precursor prepared by combining anhydrous ferric chloride and triethylamine.
Sn-doped hematite films as photoanodes for efficient photoelectrochemical water oxidation
Authors: Qin Dong-Dong , Li Yun-Lei , Wang Ting , Li Yang , Lu Xiao-Quan , Gu Jing , Zhao Yi-Xin , Song Yu-Min , Tao Chun-Lan
Published: February 2015

Sn-doped hematite films were electrochemically deposited on a fluorine-doped tin oxide substrate for use as an anode for efficient photoelectrochemical water oxidation.
Advancing polymers of intrinsic microporosity by mechanochemistry
Authors: Zhang Pengfei , Jiang Xueguang , Wan Shun , Dai Sheng
Published: February 2015

Polymers of intrinsic microporosity can be constructed in several minutes via mechanochemical synthesis.
Controlled release kinetics from a surface modified microgel-based reservoir device
Authors: Guo Siyuan , Gao Yongfeng , Wei Menglian , Zhang Qiang Matthew , Serpe Michael J.
Published: February 2015

Deposition of Si-based layers on top of a polymer-based “drug” delivery device allows fine-tuning of “drug” release kinetics.
Silica@proton-alginate microreactors: a versatile platform for cell encapsulation
Authors: Spedalieri Cecilia , Sicard Clémence , Perullini Mercedes , Brayner Roberta , Coradin Thibaud , Livage Jacques , Bilmes Sara A. , Jobbágy Matías
Published: February 2015

Acid gelation of alginate allows the inclusion of living cultures within sol–gel silica hydrogels. The formed beads spontaneously revert into a liquid viable culture.
An ABA triblock copolymer strategy for intrinsically stretchable semiconductors
Authors: Peng Rui , Pang Bo , Hu Daqing , Chen Mengjie , Zhang Guobing , Wang Xianghua , Lu Hongbo , Cho Kilwon , Qiu Longzhen
Published: February 2015

A novel semiconductor–rubber–semiconductor triblock copolymer has been designed and prepared according to the principle of thermoplastic elastomers (TPEs). It behaves as a TPE and exhibits good electrical properties.
Sensing of enantiomeric excess in chiral carboxylic acids
Authors: Akdeniz Ali , Mosca Lorenzo , Minami Tsuyoshi , Anzenbacher Pavel
Published: February 2015

Cinchona-derived fluorescent molecules are used in a cross-reactive sensor array for the sensing of enantiomeric excess (ee) in carboxylate drugs analysis.
Engineering of a lipid-polymer nanoarchitectural platform for highly effective combination therapy of doxorubicin and irinotecan
Authors: Ramasamy T. , Ruttala H. B. , Choi J. Y. , Tran T. H. , Kim J. H. , Ku S. K. , Choi H. G. , Yong C. S. , Kim J. O.
Published: February 2015

We developed a highly stable lipid-polymer nanoarchitectural platform for effective combination therapy of doxorubicin and irinotecan in the polyelectrolyte complex nanoparticle core, followed by incorporation of the whole assembly into a lecithin bilayer.
Photoswitchable organic field-effect transistors and memory elements comprising an interfacial photochromic layer
Authors: Frolova Lyubov A. , Troshin Pavel A. , Susarova Diana K. , Kulikov Alexander V. , Sanina Nataliya A. , Aldoshin Sergey M.
Published: February 2015

Memory devices with superior electrical characteristics were designed using an interfacial spirooxazine layer introduced between dielectric and semiconductor layers in OFETs.
On Zn(ii) 2,2′-bisdipyrrin circular helicates
Authors: Baudron Stéphane A. , Ruffin Hervé , Hosseini Mir Wais
Published: February 2015

Coordination of two 2,2′-bisdipyrrin ligands, bearing either methyl ester or methylthioether peripheral groups, with Zn(ii) cations leads not only to the formation of the expected linear helicates but also concomitantly to novel tri- and tetra-nuclear circular species that have been isolated and fully characterized in solution and in the solid state by single-crystal X-ray diffraction.
Exploring the pressure–temperature behaviour of crystalline and plastic crystalline phases of N-isopropylpropionamide
Authors: Quesada-Cabrera R. , Filinchuk Y. , McMillan P. F. , Nies E. , Dmitriev V. , Meersman F.
Published: February 2015

The phase behaviour of crystalline and plastic crystalline phases of N-(isopropyl)propionamide (NiPPA) has been investigated by X-ray diffraction and a tentative P,T diagram has been constructed.
Polymorphism in anti-hyperammonemic agent N-carbamoyl-l-glutamic acid
Authors: Maddileti D. , Nangia Ashwini
Published: February 2015

Solid form screen of anti-hyperammonemic drug carglumic acid (CGA) resulted in two polymorphs, Form-I and Form-II. The crystal structure of Form-I is sustained by an acid catemer synthon, whereas Form-II has an acid–amide heterosynthon. Slurry grinding, thermal stress, stability measurements, and DVS analysis confirm the thermodynamic stability of Form-I.
Flux-assisted single crystal growth and heteroepitaxy of perovskite-type mixed-metal borohydrides
Authors: Schouwink Pascal , Ramel Adrien , Giannini Enrico , Černý Radovan
Published: February 2015

Single crystals of mixed-metal perovskite-type borohydride KCa(BH4)3 are prepared by using an easily generalized flux melting procedure based on eutectic borohydride systems.
Boron nitride nanosheets as improved and reusable substrates for gold nanoparticles enabled surface enhanced Raman spectroscopy
Authors: Cai Qiran , Li Lu Hua , Yu Yuanlie , Liu Yun , Huang Shaoming , Chen Ying , Watanabe Kenji , Taniguchi Takashi
Published: February 2015

Boron nitride nanosheets covered by gold nanoparticles are controllably fabricated for highly-sensitive and reusable substrates for surface enhanced Raman spectroscopy.
Core-level photoemission spectra of Mo0.3Cu0.7Sr2ErCu2Oy, a superconducting perovskite derivative. Unconventional structure–property relationships
Authors: Marik Sourav , Labrugere Christine , Toulemonde O. , Morán Emilio , Alario-Franco M. A.
Published: February 2015

The correlation between the critical temperature, Tc, and the apical oxygen distance, the buckling angle and the charge transfer energy (Δ) with the oxidation, in the family of materials: Mo0.3Cu0.7Sr2ErCu2Oy.
An enzymatic protocol for absolute quantification of analogues: application to specific protopanoxadiol-type ginsenosides
Authors: Lai Chang-Jiang-Sheng , Tan Ting , Zeng Su-Ling , Xu Lin-Ru , Qi Lian-Wen , Liu E-Hu , Li Ping
Published: February 2015

An enzymatic protocol for simultaneous quantification of analogues in a complex extract was proposed.
Efficient, metal-free production of succinic acid by oxidation of biomass-derived levulinic acid with hydrogen peroxide
Authors: Dutta Saikat , Wu Linglin , Mascal Mark
Published: February 2015

A simple, non-fermentative, high-yielding, metal-free, chemical-catalytic pathway to succinic acid from biomass-derived levulinic acid is reported.
A highly selective fluorescent sensor for Hg(ii) based on an NTe2 chelating motif and its application to living cell imaging
Authors: Kao Shao-Lun , Venkatesan Parthiban , Wu Shu-Pao
Published: February 2015

A fluorescent probe (NBDTe) based on an NTe2 chelating motif has been developed for Hg2+ detection.
Progress in the preparation and application of three-dimensional graphene-based porous nanocomposites
Authors: Yan Zhengquan , Yao Wenli , Hu Lei , Liu Dandan , Wang Chundong , Lee Chun-Sing
Published: February 2015

We will highlight the main achievements made recently in the preparation and application of 3D graphene porous materials in lithium-ion batteries, super-capacitors, solar cells, catalysis, thermal management, environment pollution enrichment and separation, chemical sensors, etc.
Facile synthesis of three-dimensional Pt–Pd alloyed multipods with enhanced electrocatalytic activity and stability for ethylene glycol oxidation
Authors: Lv Jing-Jing , Mei Li-Ping , Weng Xuexiang , Wang Ai-Jun , Chen Li-Li , Liu Xiang-Feng , Feng Jiu-Ju
Published: February 2015

A facile one-pot solvothermal strategy was designed for the preparation of three-dimensional Pt–Pd multipods using ethylene glycol as a solvent and a reducing agent, along with N-methylimidazole as a structure-directing agent, without any seed, template, or surfactant.
Contact angle and adsorption energies of nanoparticles at the air–liquid interface determined by neutron reflectivity and molecular dynamics
Authors: Reguera Javier , Ponomarev Evgeniy , Geue Thomas , Stellacci Francesco , Bresme Fernando , Moglianetti Mauro
Published: February 2015

A new approach, based on in situ neutron reflectivity and molecular dynamics has been developed for calculating contact angles of nanoparticles at interfaces.
Well-controlled and stable emulsion ATRP of MMA with low surfactant concentration using surfactant–ligand design as the copper capture agent
Authors: Wei Yipeng , Liu Pingwei , Wang Wen-Jun , Li Bo-Geng , Zhu Shiping
Published: February 2015

In this work, we improved the stability of emulsion ATRP at a low concentration of the emulsifier with our designed Cu capture agent.
Study of ion dynamics in lanthanum aluminate probed by conductivity spectroscopy
Authors: Verma Onkar Nath , Singh Nitish Kumar , Raghvendra Raghvendra , Singh Prabhakar
Published: February 2015

Conductivity Spectra of LaAlO3.
Bead beating-based continuous flow cell lysis in a microfluidic device
Authors: Berasaluce A. , Matthys L. , Mujika J. , Antoñana-Díez M. , Valero A. , Agirregabiria M.
Published: February 2015

This paper describes a bead beating-based miniaturized cell lysis device that works in continuous flow allowing the analysis of large volumes of samples without previous treatment.
One-pot synthesis of bicyclic sugar oxazolidinone from d-glucosamine
Authors: Sanapala Someswara Rao , Kulkarni Suvarn S.
Published: February 2015

Herein we report a one-pot and efficient method for the synthesis of a 1,2-cis fused furanoside bicyclic oxazolidinone derivative of d-glucosamine via pyranose to furanose conversion and concomitant cyclization involving the N-Troc group.
Oxygen reduction reaction at MWCNT-modified nanoscale iron(ii) tetrasulfophthalocyanine: remarkable performance over platinum and tolerance toward methanol in alkaline medium
Authors: Fashedemi Omobosede O. , Ozoemena Kenneth I.
Published: February 2015

A novel nanoscale iron(ii) tetrasulfophthalocyanine complex catalyzes oxygen reduction reaction in alkaline medium more efficiently than the expensive state-of-the-art Pt catalyst.
Li3Fe2(HPO3)3Cl: an electroactive iron phosphite as a new polyanionic cathode material for Li-ion battery
Authors: Asl Hooman Yaghoobnejad , Ghosh Kartik , Vidal Meza Melissa P. , Choudhury Amitava
Published: February 2015

Low melting phosphorous acid flux has been used to synthesize a novel iron-chloro-phosphite, Li3Fe2(HPO3)3Cl, which is electrochemically active and exhibits interesting metamagnetic transition.
Preparing Bi12SiO20 crystals at low temperature through nontopotactic solid-state transformation and improving its photocatalytic activity by etching
Authors: Han Qiaofeng , Zhang Juan , Wang Xin , Zhu Junwu
Published: February 2015

The egg-tart shaped BiOCl hierarchitectures with efficient visible-light photocatalytic activity were prepared through etching of Bi12SiO20 obtained at low temperature.
A metallic CoS2nanopyramid array grown on 3D carbon fiber paper as an excellent electrocatalyst for hydrogen evolution
Authors: Zhang Haichuan , Li Yingjie , Zhang Guoxin , Xu Tianhao , Wan Pengbo , Sun Xiaoming
Published: February 2015

A metallic CoS2nanopyramid array on 3D carbon fiber paper with ultrahigh HER activity was preparedviasolvothermal synthesis.
CN foam loaded with few-layer graphene nanosheets for high-performance supercapacitor electrodes
Authors: Zhu Guoxing , Xi Chunyan , Liu Yuanjun , Zhu Jun , Shen Xiaoping
Published: February 2015

A CN–RGO composite with excellent capacitive performance was prepared through a facile and rapid two-step strategy.
Ag/AgCl plasmonic cubes with ultrahigh activity as advanced visible-light photocatalysts for photodegrading dyes
Authors: Lin Z. Y. , Xiao J. , Yan J. H. , Liu P. , Li L. H. , Yang G. W.
Published: February 2015

Ag/AgCl heterostructured nanocubes have been fabricated and used as advanced visible-light photocatalysts for the photodegradation of dyes.
Correction: High-efficiency solid-state polymer electrolyte dye-sensitized solar cells with a bi-functional porous layer
Authors: Cho Woohyung , Kim Young Rae , Song Donghoon , Choi Hyung Woo , Kang Yong Soo
Published: February 2015

Correction for ‘High-efficiency solid-state polymer electrolyte dye-sensitized solar cells with a bi-functional porous layer’ by Woohyung Cho et al., J. Mater. Chem. A, 2014, 2, 17746–17750.
PT-1 selectively activates AMPK-γ1 complexes in mouse skeletal muscle, but activates all three γ subunit complexes in cultured human cells by inhibiting the respiratory chain
Authors: Jensen Thomas E. , Ross Fiona A. , Kleinert Maximilian , Sylow Lykke , Knudsen Jonas R. , Gowans Graeme J. , Hardie D. Grahame , Richter Erik A.
Published: February 2015

PT-1 activates AMP-activated protein kinase (AMPK)-γ1- but not-γ3-containing complexes in mouse muscle, but PT-1 activates all three γ isoforms in HEK293 cells. PT-1 activates AMPK not by direct binding to α subunits, but by inhibiting the respiratory chain and increasing cellular AMP.
Structural mechanisms underlying sequence-dependent variations in GAG affinities of decorin binding protein A, a Borrelia burgdorferi adhesin
Authors: Morgan Ashli M. , Wang Xu
Published: February 2015

Structural mechanisms behind variations in glycosaminoglycan (GAG) affinities of decorin-binding protein As (DBPAs) from different Borrelia strains were investigated using NMR. DBPA from strain PBr was revealed to have an additional GAG-binding epitope and a retracted linker allowing more access to its GAG-binding sites.
Comparative structural analysis of the caspase family with other clan CD cysteine peptidases
Authors: McLuskey Karen , Mottram Jeremy C.
Published: February 2015

Clan CD forms a structural group of cysteine peptidases, containing seven individual families and two subfamilies of structurally related enzymes. Historically, it is most notable for containing the mammalian caspases, on which the structures of the clan were founded. Interestingly, the caspase family is split into two subfamilies: the caspases, and a second subfamily containing both the paracaspases and the metacaspases. Structural data are now available for both the paracaspases and the metacaspases, allowing a comprehensive structural analysis of the entire caspase family. In addition, a relative plethora of structural data has recently become available for many of the other families in the clan, allowing both the structures and the structure–function relationships of clan CD to be fully explored. The present review compares the enzymes in the caspase subfamilies with each other, together with a comprehensive comparison of all the structural families in clan CD. This reveals a diverse group of structures with highly conserved structural elements that provide the peptidases with a variety of substrate specificities and activation mechanisms. It also reveals conserved structural elements involved in substrate binding, and potential autoinhibitory functions, throughout the clan, and confirms that the metacaspases are structurally diverse from the caspases (and paracaspases), suggesting that they should form a distinct family of clan CD peptidases.
The Leishmania donovani histidine acid ecto-phosphatase LdMAcP: insight into its structure and function
Authors: Papadaki Amalia , Politou Anastasia S. , Smirlis Despina , Kotini Maria P. , Kourou Konstadina , Papamarcaki Thomais , Boleti Haralabia
Published: February 2015

Acid ecto-phosphatase activity has been linked to Leishmania donovani virulence. In the present study, we confirm the molecular identity and characterize molecular and functional properties of an enzyme contributing to this activity, the LdMAcP, an L. donovani specific membrane histidine acid phosphatase (HAcP).
Simple outage probability bound for two‐way relay networks with joint antenna and relay selection over Nakagami‐m fading channels
Authors: Erdoğan E. , Güçlüoğlu T.
Published: February 2015

The performance of a multiple‐input multiple‐output amplify‐and‐forward two‐way relay network with joint antenna and relay selection is analysed over Nakagami‐m fading channels. Both approximate and asymptotic system outage probability expressions are derived, and diversity and coding gains for an arbitrary number of antennas, relays and fading severity are presented. Finally, the analytical findings are verified by numerical examples.
Wideband CTL cell to measure operating range of UHF RFID
Authors: Yun Jaehoon , Jung Yongchae , Novotny David R. , Guerrieri Jeffrey R.
Published: February 2015

A wideband coupled transmission line (CTL) cell to measure the operating range of an UHF RFID (ORUR) is presented. Also, an ORUR test system is proposed to increase the isolation to more than 55 dB. It is shown that the ORUR measured by this proposed cell agrees well with the measured data using a fully anechoic chamber.
Control of inter‐resonator coupling using defected ground structure lattice
Authors: Radonić V. , Crnojević‐Bengin V.
Published: February 2015

A novel method to control inter‐resonator coupling using the defected ground structure lattice (DGS‐L) is proposed. The influence of the geometrical parameters of the lattice on the intensity of the coupling between ring resonators is analysed in detail. It is shown that the inter‐resonator coupling can be increased significantly by using DGS‐L, which leads to the miniaturisation of wideband bandpass filters designed using standard filter design theory. To illustrate the effect of incorporating the proposed DGS‐L, the direct‐coupled bandpass filter of the third order has been designed, fabricated and measured. The filter exhibits ∼40% wider bandwidth compared with the same filter designed without the use of DGS‐L, while its footprint remains unchanged.
Modelling of foil‐type transformer windings for computation of terminal impedance and internal voltage propagation
Authors: Theocharis Andreas , Popov Marjan
Published: February 2015

The goal of this work is to develop an efficient numerical model of foil‐type windings. An equivalent lumped‐parameter circuit model is presented, which is suitable for the computation of the terminal impedance within a broad frequency range and for internal voltage propagation studies. Owing to the special geometrical winding shape, particular attention has been paid to the calculation of the involved lumped parameters where efficient and accurate formulas for parameter determination are presented. The core influence is investigated for the broad frequency range by taking into account the frequency dependency of core material properties. Simulated results compared to measurements show that the proposed equivalent circuit in combination with the applied formulas for parameter determination can be used with full success for the computation of the terminal impedance and internal voltage distribution studies.
Critical clearing time estimation using synchrophasor data‐based equivalent dynamic model
Authors: Paul Avishek , Senroy Nilanjan
Published: February 2015

A critical aspect of online dynamic security assessment is the ranking of probable contingencies based on the critical clearing time. Ordinarily critical clearing time involves simulation of contingencies requiring extensive computational resources and updated network data. This study proposes to use reduced order equivalents of the network around a critical tie line, to estimate the critical clearing time. It is proposed to derive the reduced order model from synchrophasor data in real time, so as to replicate the most updated system dynamics. The stability margins in the reduced order model and the original detailed model are correlated using a transient energy function that considers the kinetic and potential energy gained by any system during a fault. It is shown that it is possible to arrive at a relatively accurate estimate of the critical clearing time of a contingency in the detailed model, using the equivalent model obtained using synchrophasors data.
Comparative performance assessment of a novel quasi‐oppositional harmony search algorithm and internal model control method for automatic generation control of power systems
Authors: Shiva Chandan Kumar , Mukherjee Vivekananda
Published: February 2015

This initiative work addresses the comparative performance assessment of a novel quasi‐oppositional harmony search (QOHS) algorithm and internal model control (IMC) method, in the environment of automatic generation control. These two techniques are applied to a single‐area non‐reheat and reheat turbine with and without droop characteristic, and four‐area hydro‐thermal interconnected power system under various operating conditions. Later on, robustness analysis of both the two test systems is carried out by varying the speed regulating parameters, time constants of governor, turbine, power system and the gain of power system in the range of ±50% in case of single‐area test system. In four‐area test system, the same is carried out with the consonance of step load perturbation in different control area at distinct time‐interval. Simulation results show that the proposed QOHS algorithm offers better dynamic control with robust performance as compared with IMC based approach. For on‐line, off‐nominal operating conditions, fast acting Sugeno fuzzy logic (SFL) is applied to obtain on‐line dynamic responses of the studied power system model. Moreover, time‐domain simulation of the investigated four‐area test system reveals that the proposed QOHS‐SFL based intelligent controller yields on‐line, off‐nominal controller parameters, resulting in on‐line optimal dynamic response profile.
Simultaneous denoising and compression of power system disturbances using sparse representation on overcomplete hybrid dictionaries
Authors: Sabarimalai Manikandan M. , Samantaray Subhransu Ranjan , Kamwa Innocent
Published: February 2015

This study introduces a novel unified framework for simultaneous denoising and compression of electric power system disturbance signals using sparse signal decomposition and reconstruction on overcomplete hybrid dictionary (OHD) matrix. In the proposed method, the power quality signal is first decomposed into deterministic sinusoidal components and non‐deterministic components using the OHD matrix, including discrete impulse dictionary (I), cosine dictionary (C), sine dictionary (S) and the ℓ1‐norm optimisation algorithm. Then, the hard‐thresholding, uniform threshold dead‐zone quantisation, modified index coding and Huffman coding techniques are used for compression of significant detail signal samples and approximation coefficients. To justify the selection of OHD matrix, four compression methods are implemented using the decomposition techniques based on the dictionaries Ψ = [I C S] and Ψ = [I C], the wavelet transform (WT) and the discrete cosine transform (DCT). The performance of each method is tested and validated using a wide variety of typical power quality disturbance (PQD) signals taken from the IEEE‐1159‐PQE and GIM–PQE databases and generated using the Microgrid model. The results show that the method with dictionary Ψ = [I C S] is capable of effectively compressing the PQD signals as well as suppressing the noise components in the signals.
Impact of static synchronous compensator on flux‐based synchronous generator loss of excitation protection
Authors: Yaghobi Hamid
Published: February 2015

In order to increase the power transfer and providing the optimum utilisation of the power system capability, application of flexible alternating current transmission system (FACTS) devices technology, such as static synchronous compensator (STATCOM), has been attracted, in recent years. However, the STATCOM changes the voltage and current of the power system that disturb the operation of the impedance‐based synchronous generator loss of excitation (LOE) protection. Then, this study proposes a new flux‐based LOE protection method, in the presence of STATCOM, that is based on the local variation of the flux linkage of the generator available at the location of relay. The mentioned relay is independent of other generator protection relays without any coordination. In order to show the satisfying operation of the proposed method, some simulations have been carried out in the Matlab/Simulink software. A single‐machine infinite bus and a three‐machine infinite bus systems have been used in simulations. The results show that the presence of STATCOM has no important effect on the performance of proposed relay opposite to a negative offset relay with two protective zones (the widely used impedance method) which is affected by STATCOM operation.
Gain, amplified spontaneous emission and noise figure of bulk InGaAs/InGaAsP/InP semiconductor optical amplifiers
Authors: Mazzucato Simone , Carrère Helene , Marie Xavier , Amand Thierry , Achouche Mohand , Caillaud Christophe , Brenot Romain
Published: February 2015

Bulk InGaAs layer under slight tensile strain, embedded in InGaAsP barriers and grown on InP, was used as semiconductor optical amplifier active layer for polarisation insensitive amplification. The material bandstructure was obtained by solving the Lüttinger–Kohn Hamiltonian, including tetragonal strain contribution. Study of the InGaAs material gain was performed by taking into account the effect of k‐dependent bandgap shrinkage. The semiconductor optical amplifiers device amplified spontaneous emission and noise figure have been investigated as a function of temperature, carrier density and barrier height. Good agreement was obtained with the trends observed in the experimental characteristics. The authors show that a 100 nm bandwidth can be obtained with a difference between transverse electric and transverse magnetic emission kept constant, as required for polarisation independent amplifiers.
Battery ripple effects in cascaded and parallel connected converters
Authors: Kok Dirk , Morris Adrian , Knowles Michael , Baglee David
Published: February 2015

The area of interest in this study is the current ripple the battery sees as part of the EV drive train. Current research is focussing on using converters in different topologies to reduce the battery peak demand to reduce rate capacity effect. This study describes the effects the choice of topology can have on the battery current ripple. Any ripple as seen by the battery increases losses and temperature which results in a reduced capacity and battery life span. Therefore it is important to be able to control the size of the ripple and its frequency. The research presented in this study analyses two topologies popular in EV drive trains and shows a clear advantage in terms of battery current ripple reduction of parallel topology over the cascaded topology. The method of simulation, the simulation results and the conclusions are presented and discussed in this study.
Class of high boost inverters based on switched‐inductor structure
Authors: Nguyen Minh‐Khai , Le Tuan‐Vu , Park Sung‐Jun , Lim Young‐Cheol , Yoo Ji‐Yoon
Published: February 2015

This study deals with a class of the switched‐inductor boost inverters (SLBIs) including the DC‐linked type, continuous, discontinuous and ripple input current topologies. Compared with the conventional switched boost inverters, the SLBIs add only three diodes and one inductor to obtain a strong boost factor. In comparison with the conventional switched‐inductor Z‐source inverters (ZSIs) for the same voltage gain at the same modulation indexes, the proposed SLBIs use one more active switch and less passive components which results in reducing the size and cost. Moreover, the efficiency of the proposed inverters is improved in comparison with the conventional switched‐inductor ZSIs. Analysis and operating principles are presented. A laboratory prototype was built with 24, 36, 48 V DC input and 127 Vrms output voltage to test high boost ability of the proposed inverters.
Efficiency comparison between Si and SiC‐based implementations in a high gain DC–DC boost converter
Authors: León‐Masich Antonio , Valderrama‐Blavi Hugo , Bosque‐Moncusí Josep María , Martínez‐Salamero Luís
Published: February 2015

An efficiency comparison between a boost converter implemented with silicon (Si) devices and the same converter implemented in the other three cases, that is, employing two combinations of silicon carbide (SiC) devices and a mixture of Si and SiC elements is presented. The converter has been designed for high‐voltage low‐power applications required by light‐emitting diode (LED) lighting. The comparison is performed on an equal basis and discusses the influence on the converter efficiency of the semiconductor power devices and the passive components. The experiments are carried out in a single‐stage boost converter prototype delivering a maximum output voltage of 1200 V when supplied by a 12 V battery. The measurements show that the highest efficiency is obtained when the power transistor is implemented by a normally‐off junction field‐effect transistor and the diode by a SiC Schottky device with a small parasitic capacitance. The implementation with the highest efficiency has been selected for supplying a light spot of 320 LEDs in series, which results in an output voltage of 956 V and an output power of 20.6 W.
Power management of an isolated hybrid AC/DC micro‐grid with fuzzy control of battery banks
Authors: Hosseinzadeh Mehdi , Salmasi Farzad Rajaei
Published: February 2015

This study focuses on the development of a supervisory control scheme for power management and operation of an isolated hybrid AC/DC micro‐grid, which consists of an AC micro‐grid and a DC micro‐grid. In the proposed hybrid micro‐grid, wind and diesel generators and AC loads are connected to the AC micro‐grid, whereas photovoltaic array and DC loads are tied to the DC micro‐grid. Moreover, the authors consider two independent battery banks in the AC and DC micro‐grids. Furthermore, the AC and the DC micro‐grids are coupled through a bidirectional converter, which can act as an inverter or rectifier. The objectives of the proposed supervisory controller are listed as follows: (i) maximum utilisation of renewable energy sources along with satisfying the load power demand in both AC and DC micro‐grids, (ii) maintaining state of charge (SOC) of battery banks in both AC and DC micro‐grids and (iii) managing the power exchange between the AC and the DC micro‐grids while the reliability of the whole system is taken into account. The supervisory controller is formalised using a state machine approach. For these purposes, 15 distinct operation modes are considered. Furthermore, in order to extend the battery life cycle, a fuzzy controller manages the desired SOC controlling the charge and discharge currents. The effectiveness of the proposed supervisory controller is evaluated through extensive numerical simulations.
Improved control strategy for the three‐phase grid‐connected inverter
Authors: Yao Zhilei , Xiao Lan , Guerrero Josep M.
Published: February 2015

An improved control strategy for the three‐phase grid‐connected inverter with space vector pulse‐width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d‐ and q‐axis grid currents will be interacted, and then the waveform quality of the grid current will be poorer. As the reference output voltage cannot directly reflect the change of the reference grid current, the dynamic response of the grid‐connected inverter is slow. In order to solve the aforementioned problems, the d‐ and q‐axis grid currents in the decoupled components of the grid current controller can be substituted by the d‐ and q‐axis reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results for a 15‐kVA three‐phase grid‐connected inverter with SVPWM verify the theoretical analysis. Compared with the traditional control strategy, the grid‐connected inverter with the improved control strategy has a high waveform quality of the grid current, small ripple power and fast dynamic response.
Three‐dimensional defect inversion from magnetic flux leakage signals using iterative neural network
Authors: Chen Junjie , Huang Songling , Zhao Wei
Published: February 2015

Defect inversion is of special interest to magnetic flux leakage (MFL) inspection in industry. This study proposes an iterative neural network to reconstruct three‐dimensional defect profiles from three‐axial MFL signals in pipeline inspection. A radial basis function neural network is utilised as the forward model to predict the MFL signals given a defect profile, and the defect profile gets updated based on a combination of gradient descent and simulated annealing in the iterative inversion procedure. Accuracy of the proposed inversion procedure is demonstrated in estimating the profile of different defects in steel pipes. Experimental result based on three‐axial simulated MFL data also shows that the proposed inversion approach is robust even in presence of reasonable noise.
Outcomes of Two Different Techniques Using the Lateral Approach for Lumbar Interbody Arthrodesis
Authors: Cheng Ivan , Briseño Michael R. , Arrigo Robert T. , Bains Navpreet , Ravi Shashank , Tran Andrew
Published: February 2015

Study Design

Retrospective cohort study.

Objective

To determine the short-term outcomes of two different lateral approaches to the lumbar spine.

Methods

This was a retrospective review performed with four fellowship-trained spine surgeons from a single institution. Two different approach techniques were identified. (1) Traditional transpsoas (TP) approach: dissection was performed through the psoas performed using neuromonitored sequential dilation. (2) Direct visualization (DV) approach: retractors are placed superficial to the psoas followed by directly visualized dissection through psoas. Outcome measures included radiographic fusion and adverse event (AE) rate.

Results

In all, 120 patients were identified, 79 women and 41 men. Average age was 64.2 years (22 to 86). When looking at all medical and surgical AEs, 31 patients (25.8%) had one or more AEs; 22 patients (18.3%) had a total of 24 neurologically related AEs; 15 patients (12.5%) had anterior/lateral thigh dysesthesias; 6 patients (5.0%) had radiculopathic pain; and 3 patients (2.5%) had postoperative weakness. Specifically, for neurologic AEs, the DV group had a rate of 28.0% and the TP group had a rate of 14.2% ( p < 0.18). When looking at the rate of neurologic AEs in patients undergoing single-level fusions only, the DV group rate was 28.6% versus 10.2% for the TP group ( p < 0.03).

Conclusion

Overall, 18.3% of patients sustained a postoperative neurologic AE following lateral interbody fusions. The TP approach had a statistically lower rate of neurologic-specific AE for single-level fusions.
The Politics of Austerity and the Affective Economy of Hostility: Racialised Gendered Violence and Crises of Belonging in Greece
Authors: Carastathis Anna
Published: February 2015

In this article I examine the friction between xenophobic discourses on migration and the crisis caused by the politics of austerity in Greece. On the one hand, an ‘excessive’ influx of migration is managed through violent means by the state and the para-state; on the other, a ‘scarcity’ of domestic resources is blamed for a ‘rise’ in racist attitudes, and the political ascent of a fascist movement-cum-parliamentary party, Xρνσή Aνγή (Golden Dawn). ‘Crisis’ is said to give rise to ‘austerity'—and hostility. Inverting the inverted causal relationship between crisis, austerity and hostility, I problematise representations of hostility towards migrants that construct racism as a consequence of economic conditions or even as the antidote to the ‘bitter pill’ Greeks have been forced to swallow. I examine how racialised and gendered violence secures the politics of austerity in Greece focusing on three eruptions of violence (the feminicidal acid attack on Konstantina Kouneva, the murder of Shehzad Luqman and the drowning of eleven refugees near the island of Farmakonisi). I draw concrete connections between the politics of austerity and what, drawing on Sara Ahmed, might be termed an ‘affective economy of hostility’ that articulates racialised and gendered modes of belonging and estrangement. Some bodies are rendered vulnerable and precarious, while others assert an entitled relation to national space while being economically disentitled by austerity measures.
Low irradiance loss quantification in c-Si panels for photovoltaic systems
Authors: Pervaiz Saad , Khan Hassan Abbas
Published: February 2015

Performance of bulk Si based solar photovoltaic (PV) panels deteriorate in weak light conditions. This generally affects the efficiency of associated power electronic components and compounds the overall loss in the yield of a PV system. It is, therefore, imperative to carefully plan the PV sizing and quantify this inherent loss in the efficiency of PV panels. In this work, the impact of varying solar irradiation on the efficiency of crystalline Si based solar panels has been quantified through a novel mathematical formulation, which models the deterioration in performance based on actual insolation and temperature profiles. This loss phenomenon is attributed mainly to a reduction in open circuit voltage and fill factor of a panel which in turn lowers the conversion efficiency. An empirical relationship is also derived which relates the loss in energy harvested to the actual peak-sunlight hours of a region. Results indicate that this low irradiance loss has approximately a linear dependence on equivalent peak sunlight hours (EPSH). For instance, the loss of 3.8%, 4%, 4.5% for Austin, Washington and Seattle was observed for EPSH of 4.4, 4, and 3.4, respectively. Moreover, the loss variation from one year to another for a region has been approximately constant. Finally, a comparison was performed for predicted energy harvested to the measured yield and a good fit has been observed between predicted and actual values.
Dynamical role of phosphorylation on serine/threonine-proline Pin1 substrates from constant force molecular dynamics simulations
Authors: Velazquez Hector A. , Hamelberg Donald
Published: February 2015

Cis-trans isomerization of peptidyl-prolyl bonds of the protein backbone plays an important role in numerous biological processes. Cis-trans isomerization can be the rate-limiting step due its extremely slow dynamics, compared to the millisecond time scale of many processes, and is catalyzed by a widely studied family of peptidyl-prolyl cis-trans isomerase enzymes. Also, mechanical forces along the peptide chain can speed up the rate of isomerization, resulting in “mechanical catalysis,” and have been used to study peptidyl-prolyl cis-trans isomerization and other mechanical properties of proteins. Here, we use constant force molecular dynamics simulations to study the dynamical effects of phosphorylation on serine/threonine-proline protein motifs that are involved in the function of many proteins and have been implicated in many aberrant biological processes. We show that the rate of cis-trans isomerization is slowed down by phosphorylation, in excellent agreement with experiments. We use a well-grounded theory to describe the force dependent rate of isomerization. The calculated rates at zero force are also in excellent agreement with experimentally measured rates, providing additional validation of the models and force field parameters. Our results suggest that the slowdown in the rate upon phosphorylation is mainly due to an increase in the friction along the peptidyl-prolyl bond angle during isomerization. Our results provide a microscopic description of the dynamical effects of post-translational phosphorylation on cis-trans isomerization and insights into the properties of proteins under tension.
Synthesis and magnetism of single-phase Mn-Ga films
Authors: Zhang W. Y. , Kharel P. , Valloppilly S. , Skomski R. , Sellmyer D. J.
Published: February 2015

Single-phase noncubic Mn-Ga films with a thickness of about 200 nm were fabricated by an in situ annealing of [Mn(x)/Ga(y)/Mn(x)]5 multilayers deposited by e-beam evaporation. Mn-Ga alloys prepared in three different compositions Mn2Ga5 and Mn2Ga were found to crystallize in the tetragonal tP14 and tP2 structures, respectively. Mn3Ga crystallizes in the hexagonal hp8 or tetragonal tI8 structures. All three alloys show substantial magnetocrystalline anisotropy between 7 and 10 Mergs/cm3. The samples show hard magnetic properties including coercivities of Mn2Ga5 and Mn2Ga about 12.0 kOe and of Mn3Ga about 13.4 kOe. The saturation magnetization and Curie temperature of Mn2Ga5, Mn2Ga, and Mn3Ga are 183 emu/cm3 and 435 K, 342 emu/cm3 and 697 K, and 151 emu/cm3 and 798 K, respectively. The samples show metallic electron transport up to room temperature.
Higher dimensional nonclassical eigenvalue asymptotics
Authors: Camus Brice , Rautenberg Nils
Published: February 2015

In this article, we extend Simon’s construction and results [B. Simon, J. Funct. Anal. 53(1), 84-98 (1983)] for leading order eigenvalue asymptotics to n-dimensional Schrödinger operators with non-confining potentials given by Hnα=−Δ+∏i=1nxiαi on ℝn (n > 2), α≔(α1,…,αn)∈(R+∗)n. We apply the results to also derive the leading order spectral asymptotics in the case of the Dirichlet Laplacian −ΔD on domains Ωnα={x∈Rn:∏j=1nxjαjαn<1}.
Cholesterics of colloidal helices: Predicting the macroscopic pitch from the particle shape and thermodynamic state
Authors: Dussi Simone , Belli Simone , van Roij René , Dijkstra Marjolein
Published: February 2015

Building a general theoretical framework to describe the microscopic origin of macroscopic chirality in (colloidal) liquid crystals is a long-standing challenge. Here, we combine classical density functional theory with Monte Carlo calculations of virial-type coefficients to obtain the equilibrium cholesteric pitch as a function of thermodynamic state and microscopic details. Applying the theory to hard helices, we observe both right- and left-handed cholesteric phases that depend on a subtle combination of particle geometry and system density. In particular, we find that entropy alone can even lead to a (double) inversion in the cholesteric sense of twist upon changing the packing fraction. We show how the competition between single-particle properties (shape) and thermodynamics (local alignment) dictates the macroscopic chiral behavior. Moreover, by expanding our free-energy functional, we are able to assess, quantitatively, Straley’s theory of weak chirality, which is used in several earlier studies. Furthermore, by extending our theory to different lyotropic and thermotropic liquid-crystal models, we analyze the effect of an additional soft interaction on the chiral behavior of the helices. Finally, we provide some guidelines for the description of more complex chiral phases, like twist-bend nematics. Our results provide new insights into the role of entropy in the microscopic origin of this state of matter.