bluuebunny/crossref_metadata_2025 huggingface dataset:
Torquoselectivity in the electrocyclic ring‐opening of cyclopropyl anions
Authors: Faza Olalla Nieto , López Carlos Silva , Pérez Adán B. González , Rodríguez Martín Pérez , de Lera Ángel Rodríguez
Published: October 2008

Ring‐opening reactions of substituted cyclopropanes are a convenient synthetic method for the preparation of functionalized alkenes. The Woodward–Hoffmann‐DePuy rule governs the selectivity of the cationic process, as exemplified by the solvolysis of substituted halocyclopropanes but, although the reaction has been studied in detail, the torquoselectivity in the ring‐opening of cyclopropyl anions has never been addressed. In this work, we use DFT calculations to study the two Woodward–Hoffmann allowed ring‐opening paths available to cyclopropyl anions with different substitution patterns. We find that the reaction proceeds with torquoselectivity, evaluate the applicability of Houk's model to explain the effect of the substituents in the product distribution and correlate this effect with the aromaticity of the corresponding transition states. Copyright © 2008 John Wiley & Sons, Ltd.
Molecular engineering of photoactive liquid crystalline polyester epoxies containing benzylidene moiety
Authors: Rao V. Srinivasa , Samui A. B.
Published: October 2008

A series of photoactive liquid crystalline polyester epoxies incorporating bisbenzylidene segments as photoactive mesogenic cores were synthesized by polyaddition of diepoxy monomers and terephthalic acid/trimesic acid. To investigate the influence of structural parameters such as, molecular architecture, structural rigidity of mesogenic unit and substituents on thermal, mesogenic, and photoactive properties, the bisbenzylidene segment was incorporated into one acyclic and two cycloalkanone units with two and four substituents, respectively in both linear and hyperbranched architectures. Degree of branching of hyperbranched polymers was found to be in the range of 0.49–0.62. All polymers exhibited nematic mesophase (nematic droplets). Photo induced (2π + 2π) cycloaddition reaction, upon exposure to light at 365 nm, was examined. Inter molecular photocycloaddition was confirmed by photoviscosity measurement of UV irradiated polymer solutions. Faster photo induced reactivity of polymers in hyperbranched architecture was observed when compared to linear structure. Acyclic units facilitated photocycloaddition, and five‐membered ring showed higher photoactivity compared to six‐membered ring. The steric hindrance caused by substituents decreased the photoactivity of polymers. Refractive index change was found to be in the range of 0.015–0.024. Substantial variation of refractive index indicates that these polymers could be used for optical recording. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7637–7655, 2008
Poly(methyl methacrylate) copolymers containing pendant carbazole and oxadiazole moieties for applications in single‐layer organic light emitting devices
Authors: Evanoff David D. , Carroll Joseph B. , Roeder Ryan D. , Hunt Zachary J. , Lawrence Justin R. , Foulger Stephen H.
Published: October 2008

Methyl methacrylate derived monomers functionalized with pendant carbazole and oxadiazole moieties were synthesized and could be copolymerized to form a random copolymer. The glass transition temperature of the copolymers could be predicted with a Fox equation and ranged from 140 to 191 °C. The photoluminescent characteristics of the copolymers, both in solution and in solid films, exhibited emission that was a combination of sharp and broad peaks, suggestive of monomeric and chromophore aggregation emission. These trends were also apparent in the electroluminescent response of the copolymers, where the appearance of an electromer emission was evident and was tentatively assigned to the carbazole moieties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7882–7897, 2008
The role of mid‐chain radicals in acrylate free radical polymerization: Branching and scission
Authors: Junkers Tanja , Barner‐Kowollik Christopher
Published: October 2008

The past 5 years have seen a significant increase in the understanding of the fate of so‐called mid‐chain radicals (MCR), which are formed during the free radical polymerization of monomers that form highly reactive propagating radicals and contain an easily abstractable hydrogen atom. Among these monomers, acrylates are, beside ethylene, among the most prominent. Typically, a secondary propagating acrylate‐type macroradical (SPR) can easily transfer its radical functionality via a six‐membered transition state to a position within the polymer chain (in a so‐called backbiting reaction), creating a tertiary MCR. Alternatively, the radical function can be transferred intramolecularly to any position within the chain (also forming an MCR) or intermolecularly to another polymer strand. This article aims at providing a comprehensive overview of the up‐to‐date knowledge about the rates at which MCRs are formed, their secondary reactions as well as the consequences of their occurrence under variable reaction conditions. We explore the latest aspects of their detection (via electron spin resonance spectroscopy) as well as the characterization of the polymer structures to which they lead (via high resolution mass spectrometry). The presence of MCRs leads to the formation of branched polymers and the partial formation of polymer networks. They also limit the measurement of kinetic parameters (such as the SPR propagation rate coefficient) with conventional methods. However, their occurrence can also be used as a synthetic handle, for example, the high‐temperature preparation of macromonomers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7585–7605, 2008
Alternating fluorene‐di(thiophene)quinoxaline copolymers via microwave‐supported suzuki cross‐coupling reactions
Authors: Tsami Argiri , Yang Xiao‐Hui , Farrell Tony , Neher Dieter , Holder Elisabeth
Published: October 2008

Three different acceptor moieties, 2,3‐di‐n‐octyl‐5,8‐bis(5‐bromothiophene‐2‐yl)quinoxaline, 2,3‐bis(4′‐tert‐butylbiphenyl‐4‐yl)‐5,8‐bis(5‐bromothiophene‐2‐yl)quinoxaline, and 2,3‐bis(4′‐n‐octylbiphenyl‐4‐yl)‐5,8‐bis(5‐bromothiophene‐2‐yl)quinoxaline, have been designed und synthesized utilizing Suzuki cross‐couplings. Subsequently, these acceptor units have been connected to thiophene donor units by Stille cross‐couplings, resulting in three novel donor–acceptor–donor moieties. In addition, alternating copolymers of these donor–acceptor–donor building blocks with fluorene units have been prepared by microwave‐supported Suzuki cross‐couplings. The materials have been fully characterized and the optical properties have been analyzed. Single‐layer polymer red‐light‐emitting diodes have been prepared by blending 3 wt % of the alternating copolymers with poly(9,9′‐(bis(n‐octyl)fluorene‐co‐benzothiadiazole), revealing efficiencies ranging from 0.19 to 0.75 cd/A. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7794–7808, 2008
Click chemistry‐assisted triazole‐substituted azobenzene and fulgimide units in the pendant‐based copoly(decyloxymethacrylate)s for dual‐mode optical switches
Authors: Saravanan Chinnusamy , Senthil Sengodan , Kannan Palaninathan
Published: October 2008

Copolymer containing new thermally reversible click chemistry‐assisted triazole‐substituted azobenzene and fulgimide units in the pendant F‐co‐A was prepared by free‐radical solution addition polymerization technique. The F and A were also prepared for comparison. The DSC analysis of F indicates that the polymer possessing the C‐form of fulgimide unit exhibited higher Tm than that of E‐form of the same polymer and revealed that the C‐form of fulgimide unit in F is highly ordered. The cis‐trans back isomerization behavior of the click chemistry‐assisted triazole‐substituted azobenzene unit in film A has thermal irreversibility, while in F‐co‐A it exhibited thermal reversibility. The UV‐exposed film of F‐co‐A heated around Tg leads to cis‐trans back isomerization of azobenzene unit and thermally stable C‐form of fulgimide which retains its conjugated structure where both the photochromic units are converted into planar conformations and exhibit high fluorescence properties. The fluorescence maxima of C‐form in F‐co‐A red shifted compared with F, because the substituted triazole ring in the azobenzene unit stabilized the C‐form of fulgimide unit. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7843–7860, 2008
Bipolar copolymers comprised mesogen‐jacketed polymer containing oxadiazole units and PVK as host materials for electroluminescent devices
Authors: Wang Ping , Jin Hao , Liu Wanli , Chai Chunpeng , Shen Zhihao , Guo Haiqing , Chen Xiaofang , Fan Xinghe , Zou Dechun , Zhou Qifeng
Published: October 2008

Nonconjugated bipolar transport polymers have been developed as host materials for electroluminescent devices by incorporating both electron‐transporting and hole‐transporting functionalities into copolymers. The random copolymer PCt‐nvk3‐7 containing mesogen‐jacketed segment of P‐Ct have been synthesized and characterized. The effect of mesogen‐jacketed segment content of these bipolar copolymers on device performance has been investigated. The results of polymer light‐emitting diodes (PLEDs) show that the jacketed content of copolymers has a significant effect on device performance: lowering charge transport and facilitating the hole‐electron recombination leads to much higher current efficiency. Applying these high triplet random copolymers as host, the maximum current efficiency of 0.70 cd/A and the maximum brightness of 1872.8 cd/m2 was achieved for PCt‐nvk3‐7 with an orange‐emitting complex dopant. The results suggest that the bipolar copolymers PCt‐nvks can be good host polymers for electrophosphorescent devices. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7861–7867, 2008
Effects of microparticles on isotactic polypropylene: Thermomechanical and thermal properties
Authors: Salaün Fabien , Vroman Isabelle , Bedek Gauthier , Lewandowski Maryline
Published: October 2008

Five types of melamine‐formaldehyde microcapsules, that is, with shells of different compositions [melamine formaldehyde shell or a melamine formaldehyde‐poly(hexamethylene adipate glycol) shell] and containing or not a flame retardant, diammonium hydrogen phosphate (DAHP), have been prepared by an in situ polymerization method and have been added to an isotactic polypropylene matrix (iPP) by melt blending at 5 wt %. Wide‐angle X‐ray diffraction and differential scanning calorimetry were employed to investigate the crystallization behavior of the prepared iPP/microparticles composites. The tensile properties and the thermal stability were also evaluated. It was stated that the morphology and the shape of the microparticles not only influence the crystallization behavior but also the thermomechanical properties of these composites. Thus, rougher microparticles act as a nucleating agent for the iPP, and in the presence of microparticles containing DAHP, the α‐ and the β‐crystals are formed. Moreover, the presence of microparticles improves the thermal stability of the iPP. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2566–2576, 2008
Morphology and mechanical properties of a novel amorphous polyamide/nanoclay nanocomposite
Authors: Zhang Xingui , Loo Leslie S.
Published: October 2008

A novel amorphous polyamide/montmorillonite nanocomposite based on poly(hexamethylene isophthalamide) was successfully prepared by melt intercalation. Wide angle X‐ray diffraction and transmission electron microscopy showed that organoclay containing quaternary amine surfactants with phenyl and hydroxyl groups was delaminated in the polymer matrix resulting in well‐exfoliated morphologies even at high montmorillonite content. Differential scanning calorimetry results indicated that clay platelets did not induce the formation of a crystalline phase in this amorphous polymer. Tensile tests demonstrated that the addition of nanoclay caused a dramatic increase in Young's modulus (almost twofold) and yield strength of the nanocomposites compared with the homopolymer. The nanocomposites exhibited ductile behavior up to 5 wt % of nanoclay. The improvement in Young's modulus is comparable with semicrystalline aliphatic nylon 6 nanocomposites. Both the main chain amide groups and the amorphous nature of the polyamide are responsible for enhancing the dispersion of the nanofillers, thereby, leading to improved properties of the nanocomposites. The structure‐property relationship for these nanocomposites was also explored. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2605–2617, 2008
An investigation of change management processes involved in the implementation of clinical governance by allied health professionals in Scotland
Authors: Hall H. , Curzio J.
Published: October 2008

Purpose and relevance. Clinical Governance (CG) has been a major ‘change’ initiative for facilitating quality accountability in health care. Responsibilities of Allied Health Professionals (AHPs) within CG have included the application of evidence into practice, risk management, audit, team‐ship and an engagement in the learning underpinning quality‐based care. The purpose of this study was to enlighten change management processes concerning the implementation of CG within AHP practice through: 1) examining the current ‘context of change’ surrounding AHPs and CG; and 2) determining the factors influencing AHP engagement in CG. Methods. A CG questionnaire was devised, peer‐reviewed and piloted in Wales. Subsequently a national survey of 3901 AHPs from 16 Scottish Trusts was undertaken. The sample consisted of a representative grouping of the six largest disciplines (Radiography, Occupational Therapy, Physiotherapy, Dietetics, Speech and Language Therapy and Podiatry). Analysis. Responses from 1714 participants (RR = 44%) were analysed (SPSS, Version 12). Content Analysis was undertaken on the textural data, analysis of variance to compare responses and Multiple Regression to predict the factors influencing AHP engagement in CG. Results. While AHPs were positive about and partially involved in CG, they did not have the appropriate skill, attitude or support to fully engage or take leadership roles in CG. AHPs experienced barriers to instigating change in practice, sharing and putting evidence into practice and to engaging in CG. Differences in perceptions of CG support and attitudes existed between the professions and grades. Certain professions felt significantly more positive and supported in their practice of CG than others. Levels of engagement, awareness, skill, attitude and perceptions of support for CG increased with grade. Part‐timers and newly qualified AHPs were less aware of CG than their full‐time or longer‐qualified AHP colleagues. Five predictors of engagement in CG were found: 1) perception of support for CG; 2) values and belief towards CG; 3) knowledge and skill in CG; 4) grade; and 5) hours of service. Conclusion. A multifaceted ‘change management’ approach, which would increase levels of CG knowledge and skill, provide support and enable positive attitudinal change among AHPs, would be the most successful strategy to facilitate future engagement of Scottish AHPs in CG. Copyright © 2008 John Wiley & Sons, Ltd.
Massive boson‐fermion degeneracy and the early structure of the universe
Authors: Kounnas C.
Published: October 2008

The existence of a new kind of massive boson‐fermion symmetry is shown explicitly in the framework of the heterotic, type II and type II orientifold superstring theories. The target space‐time is two‐dimensional. Higher dimensional models are defined via large marginal deformations of JJ‐type. The spectrum of the initial undeformed two dimensional vacuum consists of massless boson degrees of freedom, while all massive boson and fermion degrees of freedom exhibit a new Massive Spectrum Degeneracy Symmetry (MSDS). This precise property, distinguishes the MSDS theories from the well known supersymmetric SUSY‐theories. Some proposals are stated in the framework of these theories concerning the structure of: (i) The Early Non‐singular Phase of the Universe, (ii) The two dimensional boundary theory of AdS3 Black‐Holes, (iii) Plausible applications of the MSDS theories in particle physics, alternative to SUSY.
Melatonin (Circadin): a novel hypnotic for use in older patients
Authors: Chaplin Steve , Nutt David
Published: October 2008

Melatonin is a new hypnotic with a novel mode of action for the short‐term treatment of insomnia in older patients. In this New products review, Steve Chaplin discusses the clinical trial evidence for its efficacy, and Professor David Nutt describes its place in treatment. Copyright © 2008 Wiley Interface Ltd
Coherence length of high‐βsemiconductor microcavity lasers
Authors: Ates Serkan , Gies Christopher , Ulrich Sven M. , Wiersig Jan , Reitzenstein Stephan , Löffler Andreas , Forchel Alfred , Jahnke Frank , Michler Peter
Published: October 2008

Detailed experimental and theoretical investigations on coherence properties of high‐β(In,Ga)As/GaAs quantum dot‐based microcavity lasers are presented. Power dependent micro‐photoluminescence measurements on the fundamental mode of the studied micropillar cavities exhibited a smooth transition from spontaneous into stimulated emission with a strong linewidth narrowing around the onset of lasing. This is accompanied by a steep increase in the coherence time of the fundamental mode emission, as derived from first‐order field correlation measurements which revealed a gradual change in theg(1)(τ) lineshapes from Gaussian‐like to more exponential. In addition, systematic coherence time measurements on various micropillars demonstrated that devices with smaller spontaneous emission coupling factorβreveal longer coherence time of the lasing emission. All experimental results are fully verified by an enhanced microscopic theory which describes the lasing properties of quantum dot (QD) micropillars. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Single entangled photon pair emission from an InGaAs/GaAs quantum dot up to temperatures of 30 K
Authors: Hafenbrak R. , Ulrich S. M. , Wang L. , Rastelli A. , Schmidt O. G. , Michler P.
Published: October 2008

Photon pairs emitted from the biexciton‐exciton cascade of a single self‐assembled InGaAs/GaAs quantum dot can be polarization‐entangled. The degree of entanglement is reduced by the fine structure splitting of the involved exciton level. We measure this splitting in high resolution using a scanning Fabry‐Pérot interferometer. By quantum state tomographywe can determine the twophoton polarization state.We are able to verify the conditions of entangled or classically correlated photon pairs in full consistence with the observed fine structure splittings. The entanglement remains relatively unaffected for elevated sample temperatures where we observe reliable entanglement up to 30 K. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weak coupling effects in high‐Q electrically driven micropillars
Authors: Kistner C. , Reitzenstein S. , Böckler C. , Debusmann R. , Claudon J. , Grenouillet L. , Höfling S. , Gérard J. M. , Forchel A.
Published: October 2008

We present cavity quantum electrodynamics (cQED) effects in electrically driven high quality (high‐Q) quantum dot‐micropillar cavities. An optimized current injection scheme is employed, which enables simultaneously efficient electrical pumping and efficient out‐coupling of light: A ring‐shaped electrical contact leaving the upper facet of the pillars free from any absorbing material is used for efficient current injection and additionally serves as an aperture. This approach helps to suppress the detection of spontaneous emission from QDs through the sidewalls of the micropillars and leads to very clean electroluminescence spectra. Temperature tuning of single quantum dots (QDs) excitons allows us to observe Purcell‐enhancement of the spontaneous emission for QDs interaction with the fundamental mode as well as higher order modes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coherent resonant scattering and free induction decay of 2D‐excitons in GaAs SQW
Authors: Poltavtsev Sergey V. , Ovsyankin Vladimir V. , Stroganov Boris V.
Published: October 2008

Stationary and transient spectroscopy of excitonic induction is applied for measuring the rates of the processes controlling the efficiency of the coherence transfer under the photon‐exciton transformations in GaAs/AlGaAs structures with single quantum wells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generation and time‐resolved detection of coherently controlled electric currents at surfaces
Authors: Güdde Jens , Rohleder Marcus , Meier Torsten , Koch Stephan W. , Höfer Ulrich
Published: October 2008

We demonstrate a technique for the generation and detection of electron currents at surfaces on a femtosecond time scale with a contact‐free experimental setup based on a combination of coherent control and photoemission spectroscopy. We have applied this technique for electrons excited into image‐potential states on a Cu(100) surface that form a free‐electron‐like band in the direction parallel to the surface. The photogeneration of currents is described by optical Bloch equations for a multiband model. By incorporating field‐induced interband and intersubband transitions together with intraband accelerations into the model, the observed phase dependence of the population and of the current can be reproduced. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous anodic alumina thin films on Si: interface characterization
Authors: Gianneta V. , Nassiopoulou A. G. , Krontiras C. A. , Georga S. N.
Published: October 2008

The cover picture of this issue of physica status solidi (c) has been taken from the article [1]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tall building acoustics and the challenges of sustainability
Authors: Swift P. B. , Stead M. J.
Published: October 2008

All buildings with noise‐sensitive spaces, and residential occupancy in particular, require noise mitigation to be incorporated throughout the architectural, structural and building services design. For tall buildings, the number and type of noise and vibration sources increase, particularly where sustainable design features are incorporated, such as natural ventilation, that can reduce the acoustic performance of facades. Additional noise sources located on and near the facade of a building and the reduced noise isolation afforded by the facade have a detrimental effect on the acoustical amenity within the occupied spaces. This paper reviews noise source identification and mitigation for tall buildings, and considers additional acoustic issues associated with green buildings. In particular, approaches to achieving improved noise transmission loss performance across facades, and the identification and mitigation of the effects of noise and vibration sources located internal and external to the building are considered. Copyright © 2008 John Wiley & Sons, Ltd.
Wettability control of a solid surface by utilizing photocatalysis
Authors: Watanabe Toshiya , Yoshida Naoya
Published: October 2008

This paper describes a strategic approach utilizing a photocatalyst to obtain a solid surface with a high level of sustainable wettability (hydrophilicity or hydrophobicity). We clarified that the substances adsorbed on the surface could be successfully removed by photocatalytic oxidation resulting in sustainable high hydrophilic and high hydrophobic states. In addition to the conventional redox reaction, photoinduced wettability conversion plays an inevitable role in obtaining a superhydrophilic state. Both of the aforementioned photoinduced properties can be applied to sustain a high level of hydrophilicity. A superhydrophobic surface can be designed based on the Cassie theory. However, a combination with the usual TiO2 photocatalyst leads to a decrease in hydrophobicity because the photocatalyst becomes hydrophilic itself as a result of the photoinduced hydrophilic reaction. Utilizing the newly developed hydroxyapatite doped with Ti(IV) ions (TiHAP) photocatalyst, which has a considerably reduced hydrophilic effect, a superhydrophobic surface can be sustained after exposing it to outdoor conditions for a long period. As for sustaining the hydrophobic state, the introduction of a material design based on dynamic wettability leads to the possibility of novel functional materials with a high dynamic hydrophobicity. Our study shows that a high level of wettability (hydrophilic or hydrophobic) of a solid surface as that sustained by biologic action is possible by utilizing photocatalysis. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 279–290; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20154
Stereocontrolled alkylation of unsaturated compounds with alkoxytitanacyclopropane reagents
Authors: Kulinkovich Oleg , Isakov Vladimir , Kananovich Dzmitry
Published: October 2008

Interaction of titanium(IV) isopropoxide with ethylmagnesium bromide and its higher homologs leads to the generation of alkoxytitanacyclopropane species, which are able to act in the reactions with unsaturated compounds as 1,2‐dicarbanionic alkylating agents. The present review is focused on the processes of intermolecular regio‐ and stereoselective alkylation of carboxylic esters and allylic alcohol derivatives with alkoxytitanacyclopropane reagents. The oxophilicity of the titanium atom and its tendency to form sterically crowded ate complexes are probably the main factors providing a high level of selectivity of these transformations. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 269–278; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20155
Self evolution algorithm to minimize earliness and tardiness penalties with a common due date on a single machine
Authors: Weng Wei , Fujimura Shigeru
Published: October 2008

Earliness and tardiness penalties are designed for such scheduling problems where the popular Just‐In‐Time (JIT) concept is considered to be of significant importance. In this paper, a self evolution (SE) algorithm is proposed to solve the problem of single‐machine total earliness and tardiness penalties with a common due date. Up to now, no specific attention has been paid to straddling V‐shaped schedules of such problems, which may be better than pure V‐shaped schedules for the early due date cases; and no specific discussions have been made on the start time setting of the first job in a schedule. Therefore, in this research, efforts have been made on digging out the straddling V‐shaped schedules, improving the efficiency of setting the start time of a schedule, and reducing the execution time. In addition, a new RHRM approach is proposed to create the initial solution for evolution, which helps in achieving the fast contingency of the algorithm. The performance of the proposed algorithm has been tested on 280 benchmark instances ranging from 10 to 1000 jobs from the OR Library, and the results show that the proposed SE algorithm delivers much higher efficiency in finding optimal or near‐optimal solutions with both better results in total penalties and significant execution time reduction. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Identification of continuous‐time nonlinear systems by using a gaussian process model
Authors: Hachino Tomohiro , Takata Hitoshi
Published: October 2008

This paper deals with a nonparametric identification of continuous‐time nonlinear systems by using a Gaussian process model. Genetic algorithm is applied to train the Gaussian process prior model by minimizing the negative log marginal likelihood of the identification data. The nonlinear term of the objective system is estimated as the predictive mean function of the Gaussian process, and the confidence measure of the estimated nonlinear function is given by the predictive covariance function of the Gaussian process. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Evolutionary computation system for musical composition using listener's heartbeat information
Authors: Fukumoto Makoto , Imai Jun‐ichi
Published: October 2008

Interactive evolutionary computation (EC) creates media contents that fit on a user; however, user's fatigue problem still remains. Takagi et al. proposed a framework of EC that evaluates media contents based on a user's physiological indices, and this technique is expected to solve the problem. In this study, we constructed an EC system that creates musical melody using listener's heartbeat intervals. Based on the constructed system, we proposed a method that creates media contents and presents them to a user automatically using blank. The constructed system and the proposed method have the possibility to reduce user's fatigue. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Potentialities of the pneumatic biosensing bed as a network terminal for ubiquitous health monitoring and medical care
Authors: Kurihara Yosuke , Watanabe Kajiro , Kikuchi Toshiyuki , Namba Takashi , Tanaka Hiroshi
Published: October 2008

This paper examines how the pneumatic biosensing bed works as a network terminal for ubiquitous health monitoring and medical care. A constraint‐free biosensing bed, which is an ordinary family bed optimally equipped with a sensing device connected to a ubiquitous network, was designed. Heartbeat, respiration, snoring and body movements of 32 subjects while in bed at their homes for 14 months were measured and transmitted to a data center via the network. The system provided clear, real‐time biosignals on apnea from subjects with Sleep Apnea Syndrome, and arrhythmia from subjects with myocardial infarction. It also provided a variety of one‐night, one‐week and one‐year medical information required for in‐home health monitoring. The measurement availability of the proposed system was 76.08% of the total time. The pneumatic biosensing bed connected to the network showed high potential for ubiquitous health monitoring and in‐home medical care. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Observer based on body movement information in sleeping and estimation of sleep stage appearance probability
Authors: Kurihara Yosuke , Watanabe Kajiro , Kobayashi Kazuyuki , Tanaka Hiroshi
Published: October 2008

The manual for scoring sleep defined by the American Academy of Sleep Medicine in 2007 contains some rules that, even as an international standard of sleep stage judgment, include ambiguities and are therefore compensated by subjective interpretations of sleep stage scorers. This paper presents a novel method for compensating the subjective interpretations and judgments and describing the judgments in probabilistic terms. We employed a full‐order Luenberger observer (state estimation method) based on two models of sleep transition: no body movement and body movement. Sleep stages judged by three different scorers under the rules of the manual were rejudged by the observer. The average values of κ statistics, which show the degree of agreement, were 0.83, 0.89 and 0.81, respectively, for the original sleep stages. Because the new method provides probabilities on how surely the sleep belongs to each sleep stage, we were able to determine the most probable, the second most probable and the third most probable sleep stages. The κ statistics between the most probable sleep stages were improved to 0.89, 0.93 and 0.85, respectively. Those of sleep stages determined from the most and second most probable were 0.93, 0.96 and 0.90 and those from the most, second most and third most probable were 0.95, 0.97 and 0.92. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Application and comparison of metaheuristic techniques to reactive power planning problem
Authors: Eghbal Mehdi , Yorino Naoto , Zoka Yoshifumi , El‐Araby E. E.
Published: October 2008

This paper presents the application and comparison of metaheuristic techniques to reactive power planning (RPP) problem which involves optimal allocation and combination of to‐be‐installed VAr sources to satisfy voltage constraints during normal and contingency states for multiple load levels. The main objective of the proposed RPP problem is to minimize the investment cost through balanced installation of SCs and SVCs while keeping a specified security level and minimizing the amount of load shedding. The problem is formulated as a large scale mixed integer nonlinear programming problem, which is a nonsmooth and nondifferentiable optimization problem using conventional optimization techniques and induces lots of local minima. Among the metaheuristic techniques, genetic algorithm (GA), particle swarm optimization (PSO) and evolutionary particle swarm optimization (EPSO) are applied to solve the RPP problem. To investigate the effectiveness of the metaheuristic techniques, the proposed approaches have been successfully tested on IEEE‐14 buses, as well as IEEE‐57 buses test system. The results obtained are compared and the effectiveness of each technique has been illustrated. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Properties of ball lightning generated by a pulsed discharge on surface of an electrolyte in the atmosphere
Authors: Hayashi Noriyuki , Satomi Hiroko , Kajiwara Toshinori , Tanabe Tetsuo
Published: October 2008

A simple reactor system, which involved a pulsed discharge occurring on the surface of an electrolyte in the atmosphere, was installed to generate ball lightning (BL), and BL with a lifetime of 0.5 s and a size of 250 mm maximum was observed. Meanwhile, a single current pulse with the peak value up to 90 A and full width at half maximum (FWHM) of 5–62 ms appears immediately after the system was triggered. It is concluded that such a long‐life BL is maintained without the external supply of electrical energy, since BL is visible for a significantly longer time than the current pulse duration. It is found that a power law with the scaling exponent of 2/3 can be applied between the lifetime and size of the BL, independently of the experimental conditions. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Coextruded PVC/wood‐flour composites with WPC cap layers
Authors: Jin Shan , Matuana Laurent M.
Published: October 2008

Wood‐plastic composites (WPCs) can absorb moisture in a humid environment owing to the hydrophilic nature of the wood, thereby making the products susceptible to microbial growth and loss of mechanical properties. In this study, rigid poly(vinyl chloride) (PVC)/wood‐flour composites (core layer) were coextruded with either unfilled rigid PVC (cap layer) or rigid PVC filled with a small amount (5–27.5%) of wood flour (composite cap layers) in order to decrease or delay the moisture uptake. The thickness of the cap layer and its composition in terms of wood flour content were the variables examined during coextrusion. Surface color, moisture absorption, and flexural properties of both coextruded and noncoextruded (control) composite samples were characterized. The experimental results indicated that both unfilled PVC and composite cap layers can be encapsulated over rigid PVC/wood‐flour composites in a coextrusion process. The moisture uptake rate was lower when a cap layer was applied in the composites, and the extent of the decrease was a strong function of the amount of wood flour in the cap layer but insensitive to cap layer thickness. Overall, coextruding PVC surface‐rich cap layers on WPCs significantly increased the flexural strength but decreased the flexural modulus as compared with those of control samples. The changes in bending properties were sensitive to both cap layer thickness and wood flour content. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers
PVC nanocomposites—Nanoclay chemistry and performance
Authors: Benderly Daphne , Osorio Frank , IJdo Wouter L.
Published: October 2008

Nanoclay applications in poly(vinyl chloride) (PVC) have been limited, as the organic modifier of conventional nanoclays can promote PVC degradation. Novel nanoclays designed for enhanced PVC compatibility were compounded with PVC. Hectorite and bentonite clays were studied as nanoclay fillers. Two incorporation methods were evaluated to determine the effect on nanoclay dispersion and composite performance. A two‐stage method, in which the nanoclay was predispersed in plasticizer, resulted in good nanoclay dispersion at both the micrometer and nanometer scales. The nanocomposites were characterized by using a wide range of analytical tools. They exhibited significantly improved heat stability, an increase of up to 200% in storage modulus, and a decrease of up to 77% in oxygen permeation, as compared to unfilled PVC. Bentonite nanoclays provided a greater increase in barrier and mechanical properties. No change was seen in the PVC glass transition temperature. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers
Uplink and downlink scheduling for point to multipoint WiMAX Networks
Authors: Mohammad Hayajneh , Najah Abu Ali , Issa Khalil
Published: October 2008

IEEE 802.16 standard lacks a Media Access Control (MAC) scheduling architecture to enforce Quality of Service (QoS) requirements of different services classes. In this paper, we propose an opportunistic and optimized scheduler that meets connections' QoS requirements while it pledges fairness among admitted connections. Our approach involves separating the scheduling problem into two sub‐problems. In the first sub‐problem, which addresses interclass time‐slots allocation, the proposed scheduler calculates the optimum number of time‐slots in each time frame corresponding to the service classes with the objective of minimizing the blocking probability of each class. In the second sub‐problem, the intraclass slot allocation problem, time‐slots for each class are allocated using an integrated cross‐layer priority functions (PFs) that provide proportional fairness among a class connections. The simulation results reveal that the proposed scheduler realizes our objectives, and provides efficient QoS scheduling without starving the connections of the BE class. Copyright © 2008 John Wiley & Sons, Ltd.
Incorporation of a new wind turbine generating system model into distribution systems load flow analysis
Authors: Eminoglu Ulas , Dursun Bahtiyar , Hocaoglu M. Hakan
Published: October 2008

This paper describes a new model for wind turbine generating systems (WTGSs) that is widely used as distributed generation sources. The model is developed by using the bi‐quadratic equation, which is generally used for the calculation of the line voltages in distribution systems' load flow analysis, and facilitates computation of real and reactive power outputs of the WTGSs for a specified wind speed and terminal voltage. The developed model is validated with an experimental setup composed by an induction generator coupled with an induction motor as a prime mover. In addition to that, measured values are also compared with the calculated values, obtained by using the turbine models found in the literature. The incorporation of the developed model into some well‐known distribution systems' load flow algorithms is detailed. The effect of WTGSs on the power losses, voltage profile of radial distribution systems are evaluated for the sample test systems. Additionally, the performance of the load flow algorithms with the new model are examined and found to be robust and reliable. Copyright © 2008 John Wiley & Sons, Ltd.
Synthese und Kristallstruktur von Ammin(μ3‐L‐glutamato)kupfer(II)
Authors: Rohde Dorothea , Merzweiler Kurt
Published: October 2008

Synthesis and Crystal Structure of Ammine(μ3‐L‐glutamato)copper(II)

[Cu(L‐Glu)H2O]·H2O reacts with aqueous ammonia to give the ammine complex [Cu(L‐Glu)NH3] (1). 1 forms orthorhombic crystals, space group P 21212 with a = 1585,1(1) pm; b = 979,46(7) pm and c = 504,70(5) pm. In the crystal structure of 1 the copper atoms are linked by μ3‐glutamate units to give a 2D layer structure. The copper atoms exhibit a square‐pyramidal coordination with two N atoms and two O atoms in the base plane and one O atom at the apex of the pyramid. The crystal structure is stabilized by a 3D network of N–H···O hydrogen bridges.
Systematische Studie zu den Koordinationseigenschaften des Guanidin‐Liganden N1,N2‐Bis(1,3‐dimethylimidazolidin‐2‐yliden)‐ethan‐1,2‐diamin mit den Metallen Mn, Co, Ni, Ag und Cu
Authors: Neuba Adam , Haase Roxana , Bernard Martin , Flörke Ulrich , Herres‐Pawlis Sonja
Published: October 2008

A Systematic Study on the Coordination Properties of the Guanidine Ligand N1,N2‐Bis(1,3‐dimethylimidazolidin‐2‐ylidene)‐ethane‐1,2‐diamine with the Metals Mn, Co, Ni, Ag and Cu

The syntheses and characterization of the compounds [Mn(DMEG2e)Cl2] (1), [Co(DMEG2e)Cl2] (2), [Ni(DMEG2e)2]I2 (3), [Cu(DMEG2e)I] (4) and {[Ag(DMEG2e)]BF4}n (5) with the bisguanidine ligand N1,N2‐bis(1,3‐dimethylimidazolidin‐2‐ylidene)ethane‐1,2‐diamine (DMEG2e) are described. All complexes are synthesized by the reaction of the corresponding metal salt with the DMEG2e ligand in MeCN or THF. The coordination of the metal atoms vary from a distorted tetrahedron in 1 and 2, a distorted trigonal planar coordination in 4 to linear coordination in 5. Contrasting to the compounds 1, 2, 4 and 5 which exhibit a 1:1 ratio of metal to ligand, two DMEG2e ligands are bound to the Ni atom in the case of 3 resulting in a coordination polyhedron which represents the stage exactly in the middle between the square‐planar and the tetrahedral geometry. Whereas crystals of 1, 2, 3 and 4 contain discrete molecules, in 5 the Ag atoms are alternately linked by two different DMEG2e ligands to form a chain structure. The comparative discussion of several DMEG2e containing complexes with the compounds reported herein supplements this systematic study.
Luminescent Study on Nd3+ Complexes Containing Carboxylate‐Dithiolene and Alkoxide‐Dithiolene Ligands
Authors: Veith Michael , Ndiaye Amadou L. , Huch Volker , Cui Hailing , Wickleder Claudia
Published: October 2008

Reaction of ligand LH2 (4,5‐bis[carboxymethylthio]‐1,3‐dithiol‐2‐thione) with neodymium silyl‐amide (Nd[N(TMS)2]3; TMS= ‐SiMe3), in a ratio 2:1, yields a neodymium‐dithiolene‐carboxylato complex (1) (Nd(LH)L). Similarly, reaction of 2 equivalents of L′H2 (4,5‐bis[2′‐hydroxyethyl)thio]‐1,3‐dithiol‐2‐thione) and one equivalent of neodymium silyl‐amide (Nd[N(TMS)2]3) allowed the isolation of complex 2, with a ligand:metal ratio of 3:2. ATR‐IR spectrum of 1 displays a broad band characteristic of an OH group showing that one carboxylate group remains protonated. Emission spectrum of complex 1 under excitation in the visible region (at 360 nm i.e. on the ligand) displayed typical emission bands of the Nd3+, showing that energy transfer from the ligand to the lanthanide was achieved (i.e. “antenna effect”). No significant quenching from the remaining –OH group was detected. In the case of complex 2, the main emission bands characteristic of the Nd3+ ion have been observed, by excitation at 495 nm.
Zur Reaktivität von Titanocenkomplexen [Ti(Cp′)2(η2‐Me3SiC≡CSiMe3)] (Cp′ = Cp, Cp*) gegenüber Benzoldicarbonsäuren
Authors: Albrecht Carolin , Krüger Thomas , Wagner Christoph , Rüffer Tobias , Lang Heinrich , Steinborn Dirk
Published: October 2008

On the Reactivity of Titanocene Complexes [Ti(Cp′)2(η2‐Me3SiC≡CSiMe3)] (Cp′ = Cp, Cp*) towards Benzenedicarboxylic Acids

Titanocene complexes [Ti(Cp′)2(BTMSA)] (1a, Cp′ = Cp = η5‐C5H5; 1b, Cp′ = Cp* = η5‐C5Me5; BTMSA = Me3SiC≡CSiMe3) were found to react with iodine and methyl iodide yielding [Ti(Cp′)2(μ‐I)2] (2a/b; a refers to Cp′ = Cp and b to Cp′ = Cp*), [Ti(Cp′)2I2] (3a/b) and [Ti(Cp′)2(Me)I] (4a/b), respectively. In contrast to 2a, complex 2b proved to be highly moisture sensitive yielding with cleavage of HCp* [{Ti(Cp*)I}2(μ‐O)] (7). The corresponding reactions of 1a/b with p‐cresol and thiophenol resulted in the formation of [Ti(Cp′)2{O(p‐Tol)}2] (5a/b) and [Ti(Cp′)2(SPh)2] (6a/b), respectively. Reactions of 1a and 1b with 1,n‐benzenedicarboxylic acids (n = 2–4) resulted in the formation of dinuclear titanium(III) complexes of the type [{Ti(Cp′)2}2{μ‐1,n‐(O2C)2C6H4}] (n = 2, 8a/b; n = 3, 9a/b; n = 4, 10a/b). All complexes were fully characterized analytically and spectroscopically. Furthermore, complexes 7, 8b, 9a·THF, 10a/b were also be characterized by single‐crystal X‐ray diffraction analyses.
A New Sulfur‐containing Schiff‐Base Ligand and Binding to Copper(II) and Cobalt(II)
Authors: González Castro Adriana , Sánchez Costa José , Pievo Roberta , Massera Chiara , Mutikainen Ilpo , Turpeinen Urho , Gamez Patrick , Reedijk Jan
Published: October 2008

A new Schiff‐base ligand having a potentially coordinating thioether group (2‐quinoline‐N‐(2′‐methylthiophenyl)methyleneimine, qmtpm) has been prepared. The synthesis, structure, UV‐Vis and EPR studies of one copper(II) and two cobalt(II) complexes from this ligand is reported. The X‐ray structures of the CuII and CoII chlorido complexes 1 and 2 reveal the metal atoms in highly distorted square‐pyramidal environments constituted of one tridentate ligand and two anions. On the other hand, the thiocyanato CoII compound 3 exhibits a distorted trigonal‐bipyramidal structure. These structural variations are apparently due to the different counter‐ions which leads to distinct lattice interactions. The spectroscopic data obtained by EPR and UV‐Vis investigations are in agreement with the solid‐state structures of the coordination compounds.
Treatment of a citrin‐deficient patient at the early stage of adult‐onset type II citrullinaemia with arginine and sodium pyruvate
Authors: Mutoh K. , Kurokawa K. , Kobayashi K. , Saheki T.
Published: October 2008

Citrin deficiency is a common congenital metabolic defect not only in East Asian populations but also in other populations around the world. It has been shown that although liver transplantation is ultimately required in many patients to prevent neurological decompensation associated with hyperammonaemia, arginine is effective in lowering ammonia in hyperammonaemic patients, and a high‐protein low‐carbohydrate diet may provide some benefit to infants in improving failure to thrive. In the present study, the clinical symptoms and laboratory findings are reported for a 13‐year‐old citrin‐deficient girl in the early stage of adult‐onset type II citrullinaemia (CTLN2), and the therapeutic effect of orally administered arginine and sodium pyruvate was investigated. The patient complained of anorexia, lethargy, fatigue and poor growth, and showed laboratory findings typical of CTLN2; elevated levels of plasma citrulline, threonine‐to‐serine ratio, and serum pancreatic secretory trypsin inhibitor. Oral administration of arginine and sodium pyruvate for over 3 years improved her clinical symptoms and has almost completely normalized her laboratory findings. It is suggested that the administration of arginine and sodium pyruvate with low‐carbohydrate meals may be an effective therapy in patients with citrin deficiency in order either to prolong metabolic normalcy or to provide a safer and more affordable alternative to liver transplantation.