bluuebunny/crossref_metadata_2025 huggingface dataset:
New Preparation Methods for Composite Membranes for Medium Temperature Fuel Cells Based on Precursor Solutions of Insoluble Inorganic Compounds
Authors: Alberti G. , Casciola M. , Pica M. , Tarpanelli T. , Sganappa M.
Published: April 2005

Current PEMFCs, using perfluorinated membranes, can only operate at temperatures no higher than 70–80 °C, since their performance is dramatically reduced at higher temperatures. Encouraging results, for avoiding the reduction in performance, can be obtained by filling Nafion® membranes with inorganic nano‐particles (composite membranes) and/or by adding inorganic nano‐particles at the membrane/electrode interfaces. However, the efficient insertion of nano‐particles, other than metal oxides, inside a polymeric matrix is often very complicated or not possible. Therefore, it was of interest to find simpler methods for the insertion. In this paper, the preparation of organic precursor solutions of the insoluble compound Zr(O3P‐OH)(O3P‐C6H4SO3H), a proton conductor exhibiting very high conductivity (10–1 S cm–1 at 100 °C and 90 %RH) is reported. It was found that these precursor solutions are more stable the higher the Kb of the solvent and the lower the temperature. Precursor solutions, stable for many days at room temperature, were found by using proton acceptor solvents, such as alkanols, N,N‐dimethyl formamide (DMF), and N‐methyl pyrrolidone (NMP). The particularity of these solutions is that insoluble phosphonate particles are formed when the solvent is evaporated. They are therefore very suitable for filling porous membranes, for the preparation of composite proton conducting membranes, and for the preparation of composite electrodes. Some examples of preparation and use are reported and discussed.
Modelling and Analysis of Electro‐chemical, Thermal, and Reactant Flow Dynamics for a PEM Fuel Cell System
Authors: Khan M. J. , Iqbal M. T.
Published: April 2005

In this paper an approach for the dynamic modelling of polymer electrolyte membrane fuel cells is presented. A mathematical formulation based on empirical equations is discussed and several features, exhibiting dynamic phenomena, are investigated. A generalized steady state fuel cell model is extended for the development of a method for dynamic electrochemical analysis. Energy balance and reactant flow dynamics are also explained through physical and empirical relationships. A well‐researched system (Ballard MK5‐E stack based PGS‐105B system) is considered in order to understand the operation of a practical fuel cell unit. Matlab‐SIMULINKTMhas been used in simulating the models. The proposed method appears to be relatively simple and consequently requires less computation time. Simulation results are compared with available experimental findings and a good match has been observed.
Multidimensional Modelling of Polymer Electrolyte Fuel Cells under a Current Density Boundary Condition
Authors: Meng H. , Wang C.‐Y.
Published: April 2005

A three‐dimensional numerical model of the polymer electrolyte fuel cell (PEFC) is applied to study current distribution and cell performance under a current density boundary condition. Since the electronic resistance in the along‐channel direction in the current collector plate is much larger than in the other two directions, i.e., 50 mΩ cm2 vs. 0.5 mΩ cm2, it significantly affects current flow, and current and cell voltage distributions in a PEFC. An identical polarization curve results with two different boundary conditions, constant cell voltage and constant current density, however, the current density profiles in the along‐channel direction differ significantly; it is much flatter for the constant current boundary condition. Increasing the electronic conductivity of the bipolar plate diminishes the difference in the current density distribution under the two boundary conditions. The results also point out that an experimental validation of a PEFC model based on the polarization curve alone is insufficient, and that detailed current density distribution data in the along‐channel direction is essential.
Occupation, exposure to polycyclic aromatic hydrocarbons and laryngeal cancer risk
Authors: Becher Heiko , Ramroth Heribert , Ahrens Wolfgang , Risch Angela , Schmezer Peter , Dietz Andreas
Published: April 2005

Primary risk factors for laryngeal cancer are smoking and alcohol. The relevance of occupational exposures in the etiology of laryngeal cancer is not yet clarified. Some studies have suggested various occupational agents as additional causal risk factors. A population‐based case–control study 1:3 frequency matched by age and gender on laryngeal cancer was carried out in southwest Germany with 257 cases (236 males and 21 females between the ages of 37–80, histologically confirmed and diagnosed between January 5, 1998 and December 31, 2000) and 769 population controls (702 males, 67 females). Occupational exposures and other risk factors were obtained with face‐to‐face interviews using a detailed standardized questionnaire. The complete individual work history was assessed. A detailed assessment of work conditions was obtained by job‐specific questionnaires for selected jobs known to be associated with exposure to potential carcinogens. A specific substance list was used as second method for exposure assessment. Blood samples were taken from all individuals for genotype analysis. A strong effect of polycyclic aromatic hydrocarbons exposure on laryngeal cancer risk after adjustment for smoking and alcohol (odds ratio [OR] = 5.2, 95% confidence interval [CI] = 1.6–17.1) was observed for concordant exposure classified with both methods, and a clear dose‐response (p < 0.01 for linear trend) for exposure duration. Our findings are supported by risks associated with occupational groups in which this exposure is a priori considered likely. A differential effect by glutathione‐S‐transferases‐M1 genotype was found, however, small numbers do not allow firm conclusions on effect modification. Our study contributes to classifying polycyclic aromatic hydrocarbons as a risk factor for laryngeal cancer. © 2005 Wiley‐Liss, Inc.
The Coulomb-repulsion compensation between the ions of the beam in the presence of a strong pulsed laser field
Authors: Starodub S S , Roshchupkin S P
Published: April 2005

The Coulomb-repulsion compensation of classical nonrelativistic hydrogen ions in the beam in crossover in the presence of a strong pulsed laser field with an intensity of about 1015W/cm2is theoretically studied. It is demonstrated that the average effective interaction force can fundamentally differ from the Coulomb law.
Effect of doped-fiber's spooling on performance of S-band EDFA
Authors: Ahmad H , Saat N K , Harun S W
Published: April 2005

The effect of doped-fiber's spooling on performance of
short wavelength band erbium-doped fiber amplifier (S-band EDFA)
is demonstrated. Changing the spooling diameter resulted in a
variation of gain and noise figure characteristics of this
amplifier. The optimum spooling diameter is obtained in the range
from 5 to 7 cm. Beyond this range, an inevitable degradation of
gain and noise figure characteristics is observed due to the
changes of phase matching wavelength. Therefore, maintaining the
optimum spooling diameter is the important issue for the S-band
EDFA.
Laser ice scaffolds modeling for tissue engineering
Authors: Meglinski I V , Varejka M , Woodman A C , Turner A P F , Piletsky S A
Published: April 2005

Tissue engineering is one of the most exciting and rapidly growing areas in biomedical engineering that offers vast potential for changing traditional approaches to meeting many pharmaceutics and critical health care needs. Currently the bottle-neck area in this multidisciplinary field appears to be materials and fabrication technology for the design of artificial extra-cellular matrices/scaffolds that support culturing and growth of new tissue. We have shown that stable relief structures can be created and maintained in the bulk of ice by continuous s canning with computer-guided IR CO2laser. The optimal laser beam intensity and fluence rate distribution within the ice sample, as well as the rate of scanning were estimated based on the Monte Carlo model utilized physical/optical properties of ice. The results of numerical simulation are agreed well with the observed experimental results of thermo-coupling measurements and obtained microscopic images.
Anatomical alterations of the subthalamic nucleus in relation to age: A postmortem study
Authors: den Dunnen Wilfred F.A. , Staal Michiel J.
Published: April 2005

The subthalamic nucleus (STN) is currently the preferred target for chronic electrical high‐frequency stimulation in Parkinson's disease. Anatomical determination of the exact position of the STN in the individual patient, using magnetic resonance imaging, remains cumbersome, whereas calculation of the target using a stereotactic atlas bypasses patient interindividual variations in the exact delineation of the STN. The aim of this study was to demonstrate variations in shape and position of the STN during life. In this anatomopathological study, a method was applied to localize the STN in reference to the anterior commissure–posterior commissure line (AC–PC line) in 12 postmortem brains of patients who died of non‐neurological diseases. Their age varied from 29 to 84 years. Centers and borders of the STN were macroscopically measured in three spatial orthogonal planes in relation to the AC–PC line, and verified by light microscopy. The AC–PC distance remains almost constant during life (24.4 mm; SD 3.58). With increasing age, the center of the STN tends to move 3.9 mm cranially, 2.6 mm laterally, and 0.2 mm anteriorly. This last result also differs from the position mentioned in the stereotactic brain atlases. The form of the STN also changes. During life, the STN becomes wider in the mediolateral direction and smaller in the superior–inferior and anterior–posterior direction. The shape and spatial position of the STN also change during life. These changes should be taken into account during target determination in deep brain stimulation procedures in Parkinson's disease. © 2005 Movement Disorder Society
Rimantadine in Parkinson's disease patients experiencing peripheral adverse effects from amantadine: Report of a case series
Authors: Singer Carlos , Papapetropoulos Spiridon , Gonzalez Manuel A. , Roberts Eugene L. , Lieberman Abraham
Published: April 2005

We report our experience with 7 consecutive patients with Parkinson's disease (PD) who received rimantadine (the α‐methyl derivative of amantadine) in substitution of amantadine due to peripheral side effects (lower limb edema, livedo reticularis). Mean age was 67.3 ± 5.9 years, the mean disease duration was 13 ± 6.3 years, and mean Hoehn and Yahr stage was 2.2 ± 0.4. A total of 3 patients experienced marked improvement of edema, and 1 patient experienced marked improvement of livedo reticularis. Only 1 of the 7 patients reported significant loss of motor benefit when amantadine was replaced with rimantadine. Our results demonstrate that rimantadine may be considered as an alternative to amantadine in patients experiencing amantadine‐induced peripheral side effects. © 2005 Movement Disorder Society
Time to task failure differs with load type when old adults perform a submaximal fatiguing contraction
Authors: Hunter Sandra K. , Rochette Ludovic , Critchlow Ashley , Enoka Roger M.
Published: April 2005

Young adults exhibit a longer time to task failure when performing a submaximal isometric contraction by pushing against a force transducer (force task) than when supporting an equivalent inertial load (position task). The purpose of this study was to compare the time to failure for old adults when they performed a force task and a position task with the elbow flexor muscles. Eighteen old adults (72 ± 4 years) performed the force and position tasks at 20% maximal voluntary contraction (MVC) force until task failure. The time to task failure was briefer for the position task (10.6 ± 6.1 min) than the force task (22.8 ± 9.1 min, P < 0.05). The rate of increase in electromyographic (EMG) bursting activity, ratings of perceived exertion, mean arterial pressure, heart rate, and fluctuations in motor output during the fatiguing contraction were greater for the position task. However, the increase in averaged EMG for the elbow flexor muscles was greater at termination of the force task. The difference in time to failure for the two tasks was due to a higher level of central neural activity during the position task and was similar to that observed for young adults. These findings indicate that the type of load supported influences the mechanisms and time to task failure for sustained contractions in old adults, and have implications for the design of tasks for rehabilitation and for tasks that minimize fatigue. Muscle Nerve, 2005
Outsourcing warranty repairs: Dynamic allocation
Authors: Opp Michelle , Glazebrook Kevin , Kulkarni Vidyadhar G.
Published: April 2005

In this paper we consider the problem of minimizing the costs of outsourcing warranty repairs when failed items are dynamically routed to one of several service vendors. In our model, the manufacturer incurs a repair cost each time an item needs repair and also incurs a goodwill cost while an item is awaiting and undergoing repair. For a large manufacturer with annual warranty costs in the tens of millions of dollars, even a small relative cost reduction from the use of dynamic (rather than static) allocation may be practically significant. However, due to the size of the state space, the resulting dynamic programming problem is not exactly solvable in practice. Furthermore, standard routing heuristics, such as join‐the‐shortest‐queue, are simply not good enough to identify potential cost savings of any significance. We use two different approaches to develop effective, simply structured index policies for the dynamic allocation problem. The first uses dynamic programming policy improvement while the second deploys Whittle's proposal for restless bandits. The closed form indices concerned are new and the policies sufficiently close to optimal to provide cost savings over static allocation. All results of this paper are demonstrated using a simulation study. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
Chemotherapy and attentional dysfunction in survivors of childhood acute lymphoblastic leukemia: Effect of treatment intensity
Authors: Buizer Annemieke I. , de Sonneville Leo M.J. , van den Heuvel–Eibrink Marry M. , Veerman Anjo J.P.
Published: April 2005

Background

Central nervous system (CNS) directed chemotherapy is replacing prophylactic cranial irradiation in treatment protocols for childhood acute lymphoblastic leukemia (ALL), mainly to reduce long‐term neuropsychological sequelae. We evaluated the effects of chemotherapy on attentional function in survivors of ALL and examined whether possible deficits are related to treatment intensity.

Methods

In a multi‐center study, we compared attentional function in 36 children at least 1 year after finishing treatment with chemotherapy only for ALL, with a cancer control group consisting of 39 Wilms tumor patients and with 110 healthy children. We differentiated between standard‐ and intensified ALL treatment. The role of previously reported risk factors for neuropsychological deficits was also assessed.

Results

After chemotherapy, attentional deficits were detected in patients with ALL, but not in Wilms tumor patients. Children treated according to standard ALL protocols performed worse than healthy controls on only 1 of 10 outcome measures (P = 0.004), while those who had received intensified treatment performed worse on four outcome measures (0.0001 < P < 0.004). Higher treatment intensity, young age at diagnosis, and female gender were associated with worse performance.

Conclusions

CNS‐directed chemotherapy, even in the absence of cranial irradiation, is associated with attentional dysfunction in survivors of childhood ALL, particularly in case of intensified treatment protocols. These sequelae stress the importance of reducing doses of neurotoxic chemotherapy as much as possible in the design of future treatment protocols for ALL. © 2005 Wiley‐Liss, Inc.
Allogeneic graft‐versus‐hepatoblastoma effect
Authors: Inaba Hiroto , Handgretinger Rupert , Furman Wayne , Hale Gregory , Leung Wing
Published: April 2005

Although the survival rate for pediatric patients with hepatoblastoma has improved, prognosis is still poor when the disease is unresectable and refractory to chemotherapy. Therefore, novel approaches are warranted. Herein, we describe a patient with recurrent metastatic hepatoblastoma who received a nonmyeloablative hematopoietic stem cell transplantation from an HLA‐matched unrelated donor. After withdrawal of immunosuppressant and establishment of full donor T‐cell engraftment, the tumor regressed and serum α‐fetoprotein level decreased in concurrence with the onset of graft‐versus‐host disease (GVHD). Her disease recurred when GVHD resolved. This patient's clinical course provides evidence for the probable existence of allogeneic graft‐versus‐hepatoblastoma effect. Pediatr Blood Cancer 2006, 46:501–505. © 2005 Wiley‐Liss, Inc.
Accepting the gap: An introduction to the special issue on bridging research and practice
Authors: Chafouleas Sandra M. , Riley‐Tillman T. Chris
Published: April 2005

Although the gap between research and practice is certainly not a new challenge facing the field of education, it is a challenge that has yet to be successfully addressed from the perspective of both researchers and practitioners. Efforts to achieve greater harmony between the two settings can be described as slow and minimal. In this article, two of the barriers serving to widen the gap are reviewed. In addition, reasons to accept the gap between research and practice while also working to minimize a negative impact are outlined. Through the articles included within the issue, a message is reiterated regarding the importance of making better connections between the two, and suggestions are offered as to how such connections might be accomplished. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 455–458, 2005.
Reconceptualizing intervention integrity: A partnership‐based framework for linking research with practice
Authors: Power Thomas J. , Blom‐Hoffman Jessica , Clarke Angela T. , Riley‐Tillman T. Chris , Kelleher Constance , Manz Patricia H.
Published: April 2005

Prevention and intervention research studies often fail to include an assessment of program integrity, and when they do, it is often examined in a limited way. Further, despite efforts to reform the intervention research process to include community stakeholders more actively in every phase of investigation, current practice generally employs a hierarchical model of integrity that fails to be responsive to community needs and priorities. In this article, we describe the traditional, hierarchical model of integrity and contrast this framework with a partnership model of treatment integrity. The limitations of the hierarchical model are illustrated through the description of two school‐based prevention programs. Core features of the partnership model and steps for implementing this framework in research and practice are described. Although the partnership model has limitations when conducting efficacy research in clinical trials, it has clear advantages over the hierarchical model in conducting effectiveness research and research that is directly linked with practice. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 495–507, 2005.
An agile behavioral model for monitoring the effects of stimulant medication in school settings
Authors: Volpe Robert J. , Heick Patrick F. , Guerasko‐Moore David
Published: April 2005

Students are increasingly being prescribed stimulant medication to treat the symptoms of attention‐deficit/hyperactivity disorder (ADHD). Although several authors have advocated specific procedures for monitoring the effects of this medication in school settings, recent evidence suggests that these procedures are not being used adequately. In this article, we delineate the components of published medication evaluation procedures and discuss the barriers to their effective implementation in diverse settings. To address these barriers, we use a flexible model for school‐based medication evaluation, and we present a case example. In this model, an assessment of the acceptability and feasibility of evaluation components is integrated into a behavioral problem‐solving framework. We argue that to increase the quality of the evaluation of medication in children with ADHD, it is important to balance the internal validity of assessment procedures with their feasibility and acceptability. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 509–523, 2005.
Research into practice: Cattell‐Horn‐Carroll cognitive assessment in practice: Eligibility and program development issues
Authors: Fiorello Catherine A. , Primerano Diane
Published: April 2005

In this article we explore the application of Cattell‐Horn‐Carroll (CHC)‐based cognitive assessment to school psychology practice. We review the theoretical literature to address both identification practices, with a focus on learning disabilities and mental retardation eligibility, and program development, with a focus on linking assessment to intervention design. We present case studies that illustrate the application of CHC‐based cognitive assessment to identification and intervention development. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 525–536, 2005.
Bringing research into practice to intervene with young behaviorally challenging students in public school settings: Evaluation of the behavior consultation team (BCT) project
Authors: McDougal James L. , Nastasi Bonnie K. , Chafouleas Sandra M.
Published: April 2005

Increasingly, schools across the nation are encountering behaviorally challenging students entering primary grade classrooms. With this project, we sought to effectively intervene with such students within a public school setting using an empirically derived team approach adapted for use in an applied setting. The Behavioral Consultation Team (BCT) was developed utilizing the following components: (1) a prereferral intervention team approach, (2) behavioral consultation including functional behavioral assessment, (3) positive behavioral interventions, (4) frequent progress monitoring, and (5) a comprehensive method of program evaluation. Results indicated some resolution of the referral problem was achieved in 75% of the completed cases, and that successful and unsuccessful cases varied on elements related to acceptability and integrity. Further, qualitative data helped to inform program revision and identify important practical considerations in the provision of interventions for challenging students. Implications and future directions are discussed. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 537–551, 2005.
Establishing and sustaining research‐based practices at Centennial School: A descriptive case study of systemic change
Authors: Miller David N. , George Michael P. , Fogt Julie B.
Published: April 2005

There has recently been increased attention given to the widely perceived gap between research and practice in school psychology and education. The purpose of this article is to describe how Centennial School of Lehigh University, an alternative day school for students with emotional and behavioral disorders, was able to successfully implement and sustain research‐based practices. The use of such practices, in conjunction with organizational and systemic change, led to the significant reduction and eventually the virtual elimination of the use of and need for physical restraint and seclusionary time‐out in the school, as well as a substantial increase in students' prosocial behavior. Procedures for reducing the gap between research and practice at Centennial School are discussed, including the methods used by school personnel to facilitate systems change, successfully implement research‐based practices, and create a supportive organizational structure for sustaining effective practices. Possible roles for school psychologists in systems change efforts, potential barriers to the implementation of research‐based practices, and recommendations as to how these barriers may be overcome also are provided. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 553–567, 2005.
Organizational and individual factors in bringing research to practice: What we know, where we need to go
Authors: Forman Susan G. , Smallwood Diane L. , Nagle Richard J.
Published: April 2005

In this commentary, we examine the articles in this special issue in terms of a continuum of research to practice strategies currently used in school psychology. On one end of the continuum is the publish and hope approach, and at the other end is the change the organization to fit the innovation approach. We present the concept of innovation implementation as central to research to practice issues, and we review literature about organizational and individual factors that affect the success of innovation implementation. A new research‐to‐practice approach in which there is a dynamic, ongoing alliance between researchers and practitioners is suggested. Implications for researchers, practitioners, trainers, and professional organizations are described. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 569–576, 2005.
Reducing the gap between research and practice in school psychology
Authors: Kehle Thomas J. , Bray Melissa A.
Published: April 2005

We argue that the existence of the gap is perhaps a result of an overallegiance to the medical model and the lack of measurable criteria regarding the definition of an educated and psychologically healthy student. Further, an additional and equally daunting problem for school psychological practice is that it is influenced by general education that has scant evidence of accumulated scientifically based knowledge that demonstratively improves the education of children. The belief that educational practice continually increases in its effectiveness is simply not warranted. Consequently, educational practice is in constant reform and subjected to legal mandates that are most often equally ineffective and at times even detrimental. The intent of this paper is to suggest ways, within this broader milieu, to reduce the gap between science and practice. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 577–584, 2005.
Commentary: Center for promoting research to practice: Moving from findings to implementation
Authors: Shapiro Edward S.
Published: April 2005

Center for Promoting Research to Practice—Schools, Families, Communities (CPRP) at Lehigh University is described. The CPRP was designed to serve as an institutional commitment to the concept of moving empirically supported research into practice. Focused on students with or at risk for disabilities, the CPRP at Lehigh University engages faculty across disciplines and establishes partnerships with schools to provide a working laboratory for bringing research to practice. Links to the other articles in the mini‐series are included. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 585–591, 2005.
Evolution of internal friction and dielectric relaxation peaks in La2Mo2O9‐based oxide‐ion conductors assessed by a nonlinear peak‐fitting method
Authors: Fang Q. F. , Wang X. P. , Zhang G. G. , Cheng Z. J.
Published: April 2005

In this paper, a nonlinear peak‐fitting program is proposed based on the Bevington method, which would be helpful for the decomposition of relaxation peaks in the investigation of both internal friction and dielectric relaxation. Using this program, two severely overlapped relaxation peaks of internal friction and dielectric relaxation in pure and doped La2Mo2O9 oxide‐ion conductors have been successfully decomposed, and thus the peak height and peak position of both peaks exactly determined. From the fitting results the conclusion is reached that in pure La2Mo2O9 samples there are two relaxation internal friction peaks (P1 at lower temperature and P2 at higher temperature), but only one dielectric relaxation peak (Pd2). Another dielectric relaxation peak (Pd1) appears at lower temperature only in appropriately doped samples. With increasing doping content of Ca, K, and Bi, the activation energies of all peaks increase, and the height of the P2 peak decreases while that of the P1 peak increases. However, the peak heights of the Pd1 and Pd2 peaks increase at first and then decrease after passing through a maximum. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of gamma irradiation and air annealing on Yb‐doped YAlO3 single crystals
Authors: Zeng Xionghui , Zhao Guangjun , Xu Jun , Li Hongjun , He Xiaoming
Published: April 2005

The effects of gamma irradiation on as‐grown 5 at% Yb:YAlO3 (YAP) and air annealing on gamma‐irradiated 5 at% Yb:YAP have been studied by the difference in the absorption spectra before and after treatment. The gamma irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAP crystal. After air annealing, the gamma‐irradiation effects were totally removed over the wavelength range 390–800 nm and the concentrations of Fe3+ and Yb3+ were slightly increased. For the first time, the gamma‐irradiation‐induced valence changes between Yb3+ and Yb2+ ions in Yb:YAP crystals have been observed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport properties of double‐gate SiO2–Si–SiO2 quantum well
Authors: Prunnila Mika , Ahopelto Jouni , Sakaki Hiroyuki
Published: April 2005

We report on fabrication and low temperature transport properties of double‐gate SiO2–Si–SiO2 quantum well with a 16.5 nm thick Si layer. The device is fabricated on a silicon‐on‐insulator substrate utilizing wafer bonding, which enables us to use heavily doped back gate. Transport properties of the device are characterized by low field Hall and high field magnetotransport measurements at 4.2 K and at 0.38 K, respectively. Top (back) Si–SiO2 interface peak mobility of 1.9 m2/Vs (1.0 m2/Vs) is measured at 4.2 K. When both gates have a (large) positive bias the Hall carrier density is observed to fall below the value of the expected total carrier density, which is interpreted to arise from the occupancy of the second sub‐band in the Si well. This is confirmed by the high field magnetotransport measurements. In quantizing magnetic fields the longitudinal resistivity minima show Landau level filling factor behavior which is typical for weakly coupled bi‐layers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High power second‐order distributed feedback quantum cascade lasers
Authors: Pflügl C. , Austerer M. , Schrenk W. , Golka S. , Andrews A. M. , Strasser G.
Published: April 2005

We present high power mid‐infrared surface‐emitting single mode GaAs‐based quantum cascade lasers (QCLs). By using an air‐AlGaAs waveguide combined with second‐order distributed feedback processing, we obtained optical output, via the surface, above 3W. Surface‐normal dual‐lobe light emission exceeds the emission from one as‐cleaved facet by a factor of six. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarisation‐sensitive switch: An integrated intensity‐independent solution for 1.3 µm based on the polarisation anisotropy of ordered InGaAsP
Authors: Krämer S. , Neumann S. , Prost W. , Tegude F. J. , Malzer S. , Döhler G. H.
Published: April 2005

Ordered materials provide new possibilities for optical device applications. Through a strong polarisation anisotropy of absorption a high functional polarisation‐sensitive switch can be fabricated which in addition is nearly independent on the optical power. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of electric field on the probability of optical transitions in InGaAs/GaAs quantum wells observed by photo‐ and electroreflectance methods
Authors: Pikhtin A. N. , Komkov O. S. , Bugge F.
Published: April 2005

The influence of an electric field on the energy spectrum and the probability of optical transitions in InGaAs/GaAs single quantum wells (QWs) of different widths has been investigated with photo‐ and electroreflectance techniques. The electric field in the area of a QW is varied in a wide range and controlled by well‐defined Franz–Keldysh oscillations. A quadratic red shift of electroreflectance features concerned with interband excitonic transitions in QWs is observed. The electric field dependence of the intensity of these features and calculated data for the probability of optical transitions are compared. There are some field values when transitions that are symmetry‐forbidden in zero field are much stronger than symmetry‐allowed transitions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of site preference and lattice vibrations in Sm2Fe17–xMnx
Authors: Qian Ping , Chen Nan‐Xian , Shen Jiang
Published: April 2005

The ternary Sm2Fe17–xMnx systems in which Fe is replaced by Mn have been studied to ascertain the effect of substitution on their phase stability, site preference and lattice vibration. Calculation is based on a series of interatomic pair potentials related to the rare earth and transition metals, which are obtained by a strict lattice inversion method. Substitution of Mn for Fe make cohesive energy of Sm2Fe17–xMnx decreased markedly, indicating ternary element Mn can stabilize the Sm2Fe17–xMnx compound. And Mn atom preferentially substitutes for Fe in the 6c site and randomly substitutes in the 18h and 18f site. Besides, the phonon density of states of Sm2Fe15Mn2, the according specific heat, vibrational entropy and Debye temperature are calculated first, and a qualitative analysis with pair potentials is also carried out. The method utilized in the present investigation offers a rather easy and direct way to study the structural and vibrational properties of Sm2Fe17–xMnx. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational CI techniques for computing dispersion constants
Authors: Bendazzoli Gian Luigi
Published: April 2005

We describe the computation of dispersion constants using variational subspace methods to solve the perturbation theory equations in the tensor product space of the interacting molecules, treated separately at a (full) configuration interaction (CI) level. These new techniques are more accurate than the numerical quadrature of the Casimir Polder integral at the expense of a small additional computational cost. We also show how to compute the norm of the residual of the perturbative solution in the tensor product space to check convergence. The methods are tested on LiH and BH. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Distributed Gaussian discrete variable representation
Authors: Karabulut Hasan , Kalay Mestan
Published: April 2005

A discrete variable representation (DVR) made from distributed Gaussians gn(x) = e, (n = −∞, …, ∞) and its infinite grid limit is described. The infinite grid limit of the distributed Gaussian DVR (DGDVR) reduces to the sinc function DVR of Colbert and Miller in the limit c → 0. The numerical performance of both finite and infinite grid DGDVRs and the sinc function DVR is compared. If a small number of quadrature points are taken, the finite grid DGDVR performs much better than both infinite grid DGDVR and sinc function DVR. The infinite grid DVRs lose accuracy due to the truncation error. In contrast, the sinc function DVR is found to be superior to both finite and infinite grid DGDVRs if enough grid points are taken to eliminate the truncation error. In particular, the accuracy of DGDVRs does not get better than some limit when the distance between Gaussians d goes to zero with fixed c, whereas the accuracy of the sinc function DVR improves very quickly as d becomes smaller, and the results are exact in the limit d → 0. An analysis of the performance of distributed basis functions to represent a given function is presented in a recent publication. With this analysis, we explain why the sinc function DVR performs better than the infinite grid DGDVR. The analysis also traces the inability of Gaussians to yield exact results in the limit d → 0 to the incompleteness of this basis in this limit. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Local HSAB principle in the conjugate addition of p‐substituted thiophenols to cyclohexenone
Authors: Meza Rocío , Gordillo Bárbara , Galván Marcelo
Published: April 2005

In the formation of new bonds through the Michel‐type addition of thiolates to a α,β‐conjugate system, it is observed that the reaction takes place faster if the thio donor compound contains an electron‐rich group or the enone acceptor is highly electron deficient. In contrast, the hard–soft acid–base (HSAB) principle predicts that this reaction is favored when a soft–soft interaction between the reactants takes place. Taking into account that softness is related to a barely electronegative atom of high polarizability, we consider it of interest to analyze the effect of charge transfer of a p‐substituent on the softness of sulfur in thiophenols, as well as its impact in the conjugate addition to 2‐cyclohexen‐1‐one. Experiments‐in‐competition, net charge of X‐groups at the p‐position of the aromatic ring, the global and local softness at sulfur, and the electrophilicity, obtained by density functional theory (DFT), led to the observation that the reaction is faster for electron attractor thiophenols. The softness at sulfur increases by delocalization of charge through the aromatic ring. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Formation and physical characteristics of van der Waals molecules, cations, and anions: Estimates of complete basis set values
Authors: Zahradník Rudolf , S̆roubková Libus̆e
Published: April 2005

Complete basis set (CBS) values are sought either for highly accurate molecular characteristics of small species (e.g., pairs of rare gas atoms or the HF dimer) or for medium‐size molecules or ions (e.g., bases of nucleic acids, the benzene dimer). In the latter case, only the Møller–Plesset type 2 (MP2) procedure with DZ and TZ basis sets is feasible. In the present work, both aspects are relevant. Altogether 23 species and 7 reactions are treated, including van der Waals (vdW) molecules ((H2)2, rare gas dimers), cations (H … Rg, Rg = He, Ne, Ar, Kr), and anions associated with the CH potential energy surface (CH4 … H−, CH … H2, and the CH (D3h) Eyring activated complex). Use has been made of various extrapolation formulas. An exponential‐type formula is also reliable in instances when only small basis set data are available. By means of a formula used in our previous work (FX = F∞ + a n−1, where FX is a physical characteristics obtained with a cc‐pVXZ basis set and X is the cardinal number, F∞ a CBS value searched for, and n the total number of atomic functions in the basis set), it is possible to show that CBS ΔE values of association processes (e.g., A + B ⇋ A − B, where A and B are held together by a bond of variable strength) are essentially the same, regardless of whether simple or augmented basis sets are used when considering or neglecting corrections for the basis set superposition error (BSSE). © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Electronic structure, chemical binding, and elastic properties of M–H interactions as calculated by the Xα–DV method
Authors: Yuryeva E. I. , Pletney R. N. , Skripov A. V.
Published: April 2005

The nonempirical Xα‐discrete‐variation cluster method was used for a quantum chemistry investigation of interactions between a hydrogen atom and other atoms in systems of practical interest: M–H (MTi, V, Cr, Fe, Ni) and TaV2:H. We have calculated the parameters of chemical binding between M and H atoms: degree of ionicity (α), covalency (β), metallicity (γ), coefficient of bond elasticity (k), and reduced binding energy $\bar{E}$bin. On the basis of the results obtained for M–H (MTi, V, Cr, Fe, Ni), we have formulated the main trends of chemical binding and used these conclusions for the system TaV2:H. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A new conceptual framework integrating environment into corporate performance evaluation
Authors: Sheu Her‐Jiun , Lo Shih‐Fang
Published: April 2005

Businesses aim to make profit, but very often they fail to take environmental protection into consideration in the drive to please stakeholders. In this article, a new conceptual framework for evaluating corporate integrated development through the perspective of efficiency (looking at the company's work value created in terms of input–output) is introduced. Under the proposed framework, businesses, investors and society can conveniently understand and evaluate corporate holistic performance including its operational competence, financial health and environmental friendliness. Therefore, decisions of different levels and groups could be made with programmed consideration on this purely analytical ground. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Ireland in the new century: an opportunity to foster an ethic of sustainable enterprise
Authors: Kennelly James J. , Bradley Finbarr
Published: April 2005

Ireland's economy has undergone enormous change over the past decade, with rapid development accompanied by increasing pressures upon the natural environment. One element of this process has been the development of an ‘enterprise culture’ within Ireland. In this paper, we argue that Ireland is uniquely advantaged to build upon this enterprise culture, and to develop a ‘sustainable enterprise culture’ that is more consistent with the principles of sustainable development. Indeed, we see this as a unique opportunity to further the development of Ireland in an economically, ecologically and socially sustainable manner. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Assessing forest cover sustainability and deforestation risk from socioeconomic and biophysical indicators – a case study from Rampa Forests, south India
Authors: Prasad V. Krishna , Badarinath K. V. S.
Published: April 2005

Assessing socio‐economic and biophysical constraints on the deforestation process gains importance in the context of increasing pressure on tropical forests. In this study, we quantify forest change ‘hotspots’, defined as the areas where land cover changes are likely to occur in the near future, by utilizing land use/cover data, in conjunction with socio‐economic and biophysical indicators, from one of the tropical forests of south India. We assessed deforestation risk as a function of density of shifting cultivation, density of agricultural area to total area, land availability for agricultural purposes, demand of endosomatic energy and the applied power to forest ecosystem. Results suggested that, due to relatively high demand for resources and high percentage of agricultural labourers, one of the provinces had high risk of forest loss. The indicators selected were useful in addressing deforestation in the study area and have potential to establish sustainable forest management models elsewhere. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Coping with chronic and extreme risks in contemporary Athens: confrontation or resilience?
Authors: Sapountzaki Kalliopi , Chalkias Christos
Published: April 2005

The present work attempts to address the main aspects of chronic and extreme risks in contemporary Athens. It focuses on two cases of acute chronic risk bedevilling the capital region, namely road accidents and noise pollution, and one case of extreme risk, namely seismic disasters. In all cases social vulnerability, seen as the attribute of social and economic entities that can serve to increase damage from given danger, is a basic determinant of risk level. This social vulnerability might be defined in terms of three constituent elements: exposure to, resistance against and resilience to danger impacts.

The whole analysis seeks the generating causes of the relevant high risk levels; their distribution across the geographical and social space of the capital region; their impacts on citizens' lifestyle and awareness of unsustainability; the public policy actions to abate or mitigate them and the individuals' adaptive reactions or efforts to escape risks and finally the repercussions of individualized and governmental responses on future risk and vulnerability levels. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Prenatal ultrasonography and neonatal imaging of complete cleft sternum: a case report
Authors: Twomey E. L. , Moore A. M. , Ein S. , McAuliffe F. , Seaward G. , Yoo S.‐J.
Published: April 2005

The prenatal diagnosis of a complete cleft sternum was established in a fetus of a twin pregnancy at 22 weeks' gestation. We present the prenatal imaging and correlation with postnatal magnetic resonance imaging and high‐resolution ultrasonography. Thinned and depressed midline anterior chest wall transmitting the cardiac pulsation was the clue to the diagnosis, and the defective sternum could be identified on close sonographic observation. Successful surgical correction was undertaken at 2 months of age. There were no major associated abnormalities such as ectopia cordis or midline abdominal wall defects. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
The sensitivity of antenatal ultrasound for predicting renal tract surgery in early childhood
Authors: Bhide A. , Sairam S. , Farrugia M.‐K. , Boddy S.‐A. , Thilaganathan B.
Published: April 2005

Objective

To establish the sensitivity of antenatal ultrasound for identifying the need for renal tract surgery in infancy and early childhood.

Methods

A retrospective analysis of the surgical records in children under 5 years of age undergoing renal tract surgery in a regional pediatric urological surgery referral unit was carried out. All records between May 1997 and July 2002 were examined to assess the relationship between prenatal ultrasound findings and postnatal surgical pathology.

Results

A total of 106 operations had been performed. The detection rate of multicystic renal dysplasia was 100% (17/17). The equivalent detection rates for pelviureteral junction obstruction, duplex renal system and vesicoureteral reflux were 82.8, 67 and 26.1%, respectively. None of the babies with renal tumors had abnormal antenatal ultrasound findings. The diagnosis of postnatal renal surgical pathology was made on the basis of prenatal scan findings in 59.6% of cases, while recurrent urinary tract infection led to the diagnosis in 26.0%.

Conclusions

Approximately 40% of children requiring surgery for renal tract pathology will have a normal antenatal ultrasound examination. The prevalence of abnormal antenatal ultrasound findings varies depending on the type of renal tract pathology. Despite these findings, the commonest indicator for surgery remains abnormal prenatal scan findings, followed by recurrent urinary tract infections. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.