bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical isolator with TiO2/magnetic garnet waveguide employing nonreciprocal phase shift
Authors: Yokoi Hideki , Kono Hideki , Sekine Kenichi , Shoji Yuya , Mizumoto Tetsuya 
Published: June 2008

AbstractAn interferometric optical isolator, with a TiO2/magnetic garnet waveguide, employing a nonreciprocal phase shift was studied. The nonreciprocal phase shift in the magneto‐optic waveguide was calculated at a wavelength of 1.55 μm. The large nonreciprocal phase shift was obtained when the magneto‐optic waveguide had a TiO2/magnetic garnet guiding layer. An optical isolator which could be operated in a unidirectional magnetic field was also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The contact characteristics of Al p‐GaSe Schottky diode
Authors: Huang Wen‐Chang , Horng Chia‐Tsung , Chen Yu‐Min , Hsu Yu‐Kuei , Chang Chen‐Shiung 
Published: June 2008

AbstractThe Schottky barrier characteristics of Al on a Bridgman grown p‐GaSe layered semiconductor have been investigated using current‐voltage‐temperature (I‐V‐T) characteristics over a temperature range of 198 K∼373 K. The forward I‐V‐T data reveals a decrease at the barrier height, but an increase at the ideality factor with decreasing in measurement temperature. For the 300 °C‐annealed diode, the barrier height decreased from 1.04 eV to 0.6 eV and the ideality increased from 1.4 to 2.4, as the temperature decreased from 373 K to 198 K. The Richardson plot showed activation energy of 0.26 eV at high temperature region, while showed a lower energy of 0.07eV at low temperature region. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxygen permeation in PET bottles with passive and active walls
Authors: Di Felice Renzo , Cazzola Daniela , Cobror Sandro , Oriani Luis 
Published: June 2008

AbstractThe aim of this paper is to provide a framework, whereby gas permeation rates through plastic packaging walls, and hence, food shelf life may be estimated. Although the approach is quite general, specific attention is given to the case of liquid‐filled polyethylene terephthalate (PET) bottles with oxygen as the permeating gas.Two situations are considered: when the walls simply provide a passive resistance to the flux (as is the case for standard PET or PET blended with some other low permeability material) and when an active gas scavenger is incorporated within the boundary material.For the passive wall, permeability data relative to oxygen have been collected from literature sources and also measured using specific oxygen transmission rate experiments. For the active walls, scavenger kinetic constants were estimated from data obtained using test bottles prepared with varying scavenger concentrations. Numerical predictions in both cases have been verified by comparison with data on gas concentration in water‐filled bottles maintained under controlled conditions for periods of up to 6 months. Copyright © 2008 John Wiley & Sons, Ltd.
Photoelastic stress and thermographic measurements of automotive windscreen defects generated by projectile impact
Authors: Donne Kelvin E. , Thomas Richard D. , Davies Christopher , Calvert Geoffrey 
Published: June 2008

AbstractThis paper describes an experimental technique to evaluate the stress distribution around an automotive windscreen ‘chip’, which is created by projectile impact. This stress distribution is measured before and after a typical resin injection repair procedure, and the results indicate a significant reduction in the residual shear stress. Concurrent thermographic measurements of the impact region during the repair procedure also suggest that the quality of the repair is dependent on the temperature profile at the time of repair. Preliminary computational modelling of a representative windscreen defect illustrates the predisposition of ‘star‐shaped’ chips to crack‐off to a windscreen edge under typical vehicle usage. Copyright © 2008 John Wiley & Sons, Ltd.
Principles of evaluating quality investments
Authors: Freiesleben Johannes 
Published: June 2008

AbstractQuality departments often experience difficulties selling the idea that first priority should be given to quality improvement. Most approaches to project budgeting favour traditional investments such as new product development, which are perceived as potential profit boosters. To compete with such investments, a clear economic logic is needed, which stresses the long‐term benefits of better quality. The aim of this paper, therefore, is to provide a concise framework of how to think about quality investments in economic terms. By focusing on the principles of an economic evaluation, it highlights the major aspects of an improvement assessment and derives a simple measure for helping practitioners to determine the advantageousness of a quality initiative. Copyright © 2008 John Wiley & Sons, Ltd.
Quantitative Structure–Activity Relationship Study on Fish Toxicity of Substituted Benzenes
Authors: Gong Zhiguo , Xia Binbin , Zhang Ruisheng , Zhang Xiaoyun , Fan Botao 
Published: June 2008

AbstractMany chemicals cause latent harm, such as erratic diseases and change of climate, and therefore it is necessary to evaluate environmentally safe levels of dangerous chemicals. Quantitative Structure–Toxicity Relationship (QSTR) analysis has become an indispensable tool in ecotoxicological risk assessments. Our paper used QSTR to deal with the modeling of the acute toxicity of 92 substituted benzenes. The molecular descriptors representing the structural features of the compounds were calculated by CODESSA program. Heuristic Method (HM) and Radial Basis Function Neural Networks (RBFNNs) were utilized to construct the linear and the nonlinear QSTR models, respectively. The predictive results were in agreement with the experimental values. The optimal QSTR model which was established based on RBFNNs gave a correlation coefficient (R2) of 0.893, 0.876, 0.889 and Root‐Mean‐Square Error (RMSE) of 0.220, 0.205, 0.218 for the training set, the test set, and the whole set, respectively. RBFNNs proved to be a very good method to assess acute aquatic toxicity of these compounds, and more importantly, the RBFNNs model established in this paper has fewer descriptors and better results than other models reported in previous literatures. The current model allows a more transparent chemical interpretation of the acute toxicity in terms of intermolecular interactions.
3D‐QSAR and Docking Studies of Quinazoline Derivatives with the Inhibitory Activity Toward NF‐κB
Authors: Qian Li , Shen Yong , Chen Jin‐Can , Wang Ya‐Xue , Wu Xiao‐Tian , Chen Tao‐Ju , Zheng Kang‐Cheng 
Published: June 2008

AbstractNuclear Factor‐κB (NF‐κB) is an important transcription factor for regulation expression of many cytokines that are involved in the pathogenesis of inflammatory diseases such as Adult Respiratory Distress Syndrome (ARDS), sepsis syndrome, and HIV. It is recently proposed that quinazoline derivatives are capable of inhibiting the activation of NF‐κB. To study the inhibiting mechanism and obtain some helpful information for designing functional inhibitor against the protein, 3‐D Quantitative Structure–Activity Relationship (3D‐QSAR) studies such as Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) and docking analysis on 29 inhibitors, quinazoline derivatives, have been carried out. The CoMFA and CoMSIA models give a cross‐validated coefficient q2 of 0.822 and 0.801, respectively. The binding pockets around the DNA binding sites in p50 and p65 have been tested for docking. The docking results at site 1 of p50 show a significant correlation between the energy scores and the corresponding experimental values with the correlation coefficient R=0.817. The contour maps of 3D‐QSAR model are shown in a good agreement with the structural characteristics of the corresponding binding site. These results indicate a NF‐κB‐DNA binding inhibiting mechanism for these compounds, which prevent free NF‐κB from binding to DNA. Therefore, the final 3D‐QSAR models and the information of the binding site would be useful in developing new quinazoline derivatives with favorable activity.
The Quantitative Structure–Retention Relationship (QSRR) Analysis of Some Centrally Acting Antihypertensives and Diuretics
Authors: Filipic Slavica , Nikolic Katarina , Krizman Mitja , Agbaba Danica 
Published: June 2008

AbstractThe complete separation of 15 guanidine/imidazoline derivatives, acting as antihypertensive drugs, was achieved by capillary electrophoresis employing 30 mM phosphate background electrolyte (pH 1.5) containing 15 mM β‐Cyclodextrin (BCD). Here the Quantitative Structure–Retention Relationship (QSRR) models of the inclusion complexes between the analyzed compounds (ligands) and BCD were performed to investigate the correlations between electrophoresis migration order and the constitutional, geometrical, physico‐chemical, and electronical properties of the molecular models. The ChemPro, Marvin 4.0.5 ChemAxon, and CS Gaussian 98 [B3LYP/6–31G+(d,p) and HF/3–21G(d) basis sets] programs were applied for molecular parameters computation of the optimized ligands and ligand–BCD complexes. Total charge of the analyzed compounds at experimental pH 1.5, HOMO (BCD–ligand) energy, and Solvent‐Accessible Surface (SAS) (BCD–ligand) area account for the electrophoresis retention parameter log(t). The multiple linear regression models with three variables, log(t)=f [Total Charge (ligand), SAS (BCD–ligand), HOMO (BCD–ligand)], were obtained with R2=0.914 and crossvalidation parameter of prediction $\rm{ q_{{\rm{pre}}}^{\rm{2}} }$=0.778. The developed QSRR approach can help in understanding the structural features that contribute to the electrophoresis retention parameter [log(t)] of the investigated antihypertensives. Therefore, the theoretical method presented could be used as a fast, easy, and reliable tool for electrophoretic migration parameters prediction of other related antihypertensives.
Synchronization of uncertain complex dynamical networks via adaptive control
Authors: Wang Lei , Dai Huaping , Kong Xiangjie , Sun Youxian 
Published: June 2008

AbstractIn this paper, synchronization of an uncertain dynamical network with time‐varying delay is investigated by means of adaptive control schemes. Time delays and uncertainties exist universally in real‐world complex networks. Especially, parameters of nodes in these complex networks are usually partially or completely uncertain. Considering the networks with unknown or partially known nodes, we design adaptive controllers for the corresponding complex dynamical networks, respectively. Several criteria guaranteeing synchronization of such systems are established by employing the Lyapunov stability theorem. Analytical and numerical results show that the proposed controllers have high robustness against parameter variations including network topologies, coupling structures, and strength. Copyright © 2008 John Wiley & Sons, Ltd.
On the use of mixed‐integer linear programming for predictive control with avoidance constraints
Authors: Maia Marcelo H. , Galvão Roberto K. H. 
Published: June 2008

AbstractThis technical note concerns the predictive control of discrete‐time linear models subject to state, input and avoidance polyhedral constraints. Owing to the presence of avoidance constraints, the optimization associated with the predictive control law is non‐convex, even though the constraints themselves are convex. The inclusion of the avoidance constraints in the predictive control law is achieved by the use of a modified version of a mixed‐integer programming approach previously derived in the literature. The proposed modification consists of adding constraints to ensure that linear segments of the system trajectories between consecutive sampling times do not cross existing obstacles. This avoids the significant extra computation that would be incurred if the sampling time was reduced to prevent these crossings. Simulation results show that the inclusion of these additional constraints successfully prevents obstacle collisions that would otherwise occur. Copyright © 2008 John Wiley & Sons, Ltd.
Passivity‐based control of a magnetically levitated flexible beam
Authors: Shimizu T. , Kobayashi Y. , Sasaki M. , Okada T. 
Published: June 2008

AbstractThis paper solves the asymptotic stabilization problem for a magnetically levitated flexible beam using a nested‐loop passivity‐based controller design. Passivity analyses reveal that the system can be decomposed into two passive subsystems: a mechanical subsystem that consists of a flexible beam with both ends free and that defines a passive map from external forces to the velocity of the points on the flexible beam at which the external forces act; and an electrical subsystem that consists of a pair of electromagnets and that defines a strictly output‐passive map from voltages applied across the electromagnets to magnetic fluxes. The standard method for designing passivity‐based controllers leads to a nonlinear feed‐forward controller for the electrical subsystem, which enables the electrical subsystem to generate given desired magnetic forces, and an output feedback compensator for the mechanical subsystem, which computes the desired forces required to regulate the position and vibration of the beam. The asymptotic stability of each controller may be proven using Lyapunov's stability theory and LaSalle's invariant set theorem. Numerical simulations confirm the asymptotic stability of the equilibrium configuration of the closed‐loop system formed by the magnetically levitated flexible beam together with the proposed controllers. Copyright © 2008 John Wiley & Sons, Ltd.
Strongly absolute stability of Lur'e descriptor systems: Popov‐type criteria
Authors: Yang Chunyu , Zhang Qingling , Zhou Linna 
Published: June 2008

AbstractIn this paper, we consider the strongly absolute stability problem of Lur'e descriptor systems (LDSs). First, we define a generalized Lur'e Lyapunov function (GLLF) and show that the negative‐definite property of the derivative of the GLLF guarantees strongly absolute stability of LDSs. As a result, the existing Popov‐type criteria are reduced to sufficient conditions for the existence of the GLLF. Then, we propose a necessary and sufficient condition for the existence of the GLLF to guarantee the strongly absolute stability of LDSs. This criterion is shown to be less conservative than the existing ones. Finally, we discuss the computational issues and present two numerical examples to illustrate the effectiveness of the obtained results. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive observer design for a chaotic Duffing system
Authors: Bobtsov Alexey , Pyrkin Anton , Nikolaev Nikolay , Slita Olga 
Published: June 2008

AbstractThe problem of unknown encoded parameter reconstruction is solved by means of an adaptive observer design procedure for a chaotic Duffing system. Unlike the known analogues, the problem in question is solved by using only the output measurements of the chaotic system and in conditions of full parametrical uncertainty. Copyright © 2008 John Wiley & Sons, Ltd.
Beta‐binomial/Poisson regression models for repeated bivariate counts
Authors: Lora Mayra Ivanoff , Singer Julio M. 
Published: June 2008

AbstractWe analyze data obtained from a study designed to evaluate training effects on the performance of certain motor activities of Parkinson's disease patients. Maximum likelihood methods were used to fit beta‐binomial/Poisson regression models tailored to evaluate the effects of training on the numbers of attempted and successful specified manual movements in 1 min periods, controlling for disease stage and use of the preferred hand. We extend models previously considered by other authors in univariate settings to account for the repeated measures nature of the data. The results suggest that the expected number of attempts and successes increase with training, except for patients with advanced stages of the disease using the non‐preferred hand. Copyright © 2008 John Wiley & Sons, Ltd.
The determination of optimal software release times at different confidence levels with consideration of learning effects
Authors: Ho Jyh‐Wen , Fang Chih‐Chiang , Huang Yeu‐Shiang 
Published: June 2008

AbstractAs most software reliability models do not clearly explain the variance in the mean value function of cumulative software errors, they might not be effective in deducing the confidence interval regarding the mean value function. In such cases, software developers cannot estimate the possible risk variation in software reliability by using the randomness of the mean value function, thus reducing the decision‐making reliability when determining an optimal software release time. In this paper, the method of stochastic differential equations is used to build a software reliability model, which is validated based on practical data previously used in six published papers. Moreover, the estimation of the parameters of the proposed model, which can be defined as the autonomous error‐detected factor and the learning factor, is also illustrated, and the results of model validation empirically confirm that the proposed model is able to account for a fairly large portion of the variance of the mean value function. Additionally, the confidence intervals of the mean value function regarding software faults are employed to assist software developers in determining the optimal release times at different confidence levels. Finally, a numerical example is given to verify the effectiveness of the proposed model. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluating product development systems using network analysis
Authors: Collins Shawn T. , Yassine Ali A. , Borgatti Stephen P. 
Published: June 2008

AbstractThis paper proposes the integration of two systems engineering analysis tools, the Design Structure Matrix (DSM) and Network Analysis (NA), to study task interactions in a Product Development Process (PDP). The DSM is a matrix‐based systems engineering tool that analyzes task sequences to improve PDP execution. Using NA metrics to measure properties of information flow helps to identify important product development tasks and interactions that constrain PDP execution. Project managers can use these data to structure team integration mechanisms or to identify coordinating mechanisms for groups of concurrently scheduled PDP tasks. Functional managers and process architects can use these data to identify important or overloaded tasks. They can also evaluate whether tasks like stage gates and design reviews are acting as effective information flow regulators in the PDP. This new Systems Engineering approach provides a rigorous decision support tool for managers who must alter ideal task sequences due to specific schedule, budget, and expertise constraints encountered on their projects. © 2008 Wiley Periodicals, Inc. Syst Eng
Diversity‐oriented synthesis
Authors: Spandl Richard J. , Díaz‐Gavilán Mónica , O'Connell Kieron M. G. , Thomas Gemma L. , Spring David R. 
Published: June 2008

AbstractDiversity‐oriented synthesis (DOS), which describes the synthesis of structurally diverse collections of small molecules, was developed, in part, to address combinatorial chemistry's shortfalls. In this paper, we hope to give an indication of what can be achieved using the DOS approach to library generation. We describe some of the most successful strategies utilized in DOS, with special focus on our own area of interest; DOS from simple, pluripotent starting materials. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 129–142; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20144
Glutamate transporter blockers for elucidation of the function of excitatory neurotransmission systems
Authors: Shimamoto Keiko 
Published: June 2008

AbstractL‐Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. Termination of glutamate receptor activation and maintenance of low extracellular glutamate concentrations are mainly achieved by glutamate transporters [excitatory amino acid transporters 1–5 (EAAT1–5)] located in nerve endings and surrounding glial cells. Selective and potent inhibitors have long been required to investigate the physiological significance of transporters in the regulation of synaptic transmission and the pathogenesis of neurological diseases. Non‐transportable blockers are desirable because, unlike competitive substrates, they do not cause ion flux and heteroexchange. After a series of possible candidate molecules, we synthesizedthreo‐β‐benzyloxyaspartate (TBOA), the first non‐transportable blocker for all subtypes of EAATs. In addition, TBOA analogs with a bulky substituent on their benzene ring showed enhanced inhibition of labeled glutamate uptake. Comparing the effects of substrates and non‐transportable blockers revealed the physiological roles of EAATs. We also developed a novel binding assay system using a tritium‐labeled TBOA analog. In this review, we describe the design and synthesis of these blockers and the functions of the EAATs elucidated with them. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 182–199; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20145
Catalytic enantioselective organozinc addition toward optically active tertiary alcohol synthesis
Authors: Hatano Manabu , Ishihara Kazuaki 
Published: June 2008

AbstractA highly enantioselective organozinc (R2Zn) addition to a series of aldehydes and ketones was developed based on conjugate Lewis acid–Lewis base catalysis. Optically active secondary and tertiary alcohols were obtained in high yields with high enantioselectivities without Ti(IV) compounds. Bifunctional chiral 3,3′‐diphosphoryl‐BINOL ligands were designed and prepared through a phospho‐Fries rearrangement as a key step. On the other hand, bifunctional chiral phosphoramide ligands were designed and prepared from L‐valine. Mechanistic studies were performed by X‐ray analyses of Zn(II) cluster and chiral ligands, a 31P NMR experiment on Zn(II) complexes, and stoichiometric reactions with some chiral or achiral Zn(II) complexes to propose a transition state assembly that includes monomeric active intermediates. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 143–155; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20146
Cannabinoid CB1receptor antagonists in therapeutic and structural perspectives
Authors: Lange Jos H. M. , Kruse Chris G. 
Published: June 2008

AbstractThe observed antiobesity effect of rimonabant (1) in a pharmacological rodent model 10 years ago has led to a surge in the search for novel cannabinoid CB1antagonists as a new therapeutic target for the treatment of obesity. Rimonabant showed clinical efficacy in the treatment of obesity and also improved cardiovascular and metabolic risk factors. Cannabinoid CB1receptor antagonists have also good prospects in other therapeutic areas, including smoking and alcohol addiction as well as cognitive impairment. Solvay's research achievements in this fast‐moving field are reported in relation with the current state of the art. Several medicinal chemistry strategies have been pursued. The application of the concept of conformational constraint led to the discovery of more rigid analogs of the prototypic CB1receptor antagonist rimonabant. Replacement of the central heterocyclic pyrazole ring in rimonabant yielded imidazoles, triazoles, and thiazoles as selective CB1receptor antagonists. Dedicated medium‐throughput screening efforts delivered one 3,4‐diarylpyrazoline hit. Its poor pharmacokinetic properties were successfully optimized which led to the discovery of orally active and highly CB1/CB2receptor selective analogs in this series. Regioisomeric 1,5‐diarylpyrazolines, 1,2‐diarylimidazolines, and water‐soluble imidazoles have been designed as novel CB1receptor antagonist structure classes. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 156–168; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20147