bluuebunny/crossref_metadata_2025 huggingface dataset:
Production planning with resources subject to congestion
Authors: Asmundsson Jakob , Rardin Ronald L. , Turkseven Can Hulusi , Uzsoy Reha
Published: January 2009

A fundamental difficulty in developing effective production planning models has been accurately reflecting the nonlinear dependency between workload and lead times. We develop a mathematical programming model for production planning in multiproduct, single stage systems that captures the nonlinear dependency between workload and lead times. We then use outer linearization of this nonlinear model to obtain a linear programming formulation and extend it to multistage systems. Extensive computational experiments validate the approach and compare its results to conventional models that assume workload‐independent planning lead times. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009
Approximating the nondominated frontiers of multi‐objective combinatorial optimization problems
Authors: Köksalan Murat , Lokman Banu
Published: January 2009

Finding all nondominated vectors for multi‐objective combinatorial optimization (MOCO) problems is computationally very hard in general. We approximate the nondominated frontiers of MOCO problems by fitting smooth hypersurfaces. For a given problem, we fit the hypersurface using a single nondominated reference vector. We experiment with different types of MOCO problems and demonstrate that in all cases the fitted hypersurfaces approximate all nondominated vectors well. We discuss that such an approximation is useful to find the neighborhood of preferred regions of the nondominated vectors with very little computational effort. Further computational effort can then be spent in the identified region to find the actual nondominated vectors the decision maker will prefer. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009
A cooperative game in search theory
Authors: Hohzaki Ryusuke
Published: January 2009

Search theory originates from the military research efforts of WWII. Most researchers of that period modeled their search games in noncooperative games, where players are enemies or compete against each other. In this article, we deal with a cooperative search game, where multiple searchers behave cooperatively. First we describe several search problems and discuss the possibility of a coalition or cooperation among searchers. For the cooperative search game, we define a function named quasi‐characteristic function, which gives us a criterion similar to the so‐called characteristic function in the general coalition game with transferable utility. The search operation includes a kind of randomness with respect to whether the searchers can detect a target and get the value of the target. We also propose a methodology to divide the obtained target value among members of the coalition taking account of the randomness. As a concrete problem of the cooperative search game, we take the so‐called search allocation game, where searchers distribute their searching resources to detect a target in a cooperative way and the target moves in a search space to evade the searchers. Lastly, we discuss the core of the cooperative search allocation game. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009
A model to design recreational boat mooring fields
Authors: Giachetti Ronald E. , Sanchez Jean Carlo
Published: January 2009

This article develops a mathematical model and heuristic algorithm to design recreational boating mooring fields. The boating industry is important to the Florida economy, and boat storage is becoming a concern among those in the industry. The mooring field design problem is formulated to maximize the total number of boat feet moored in the mooring field. In the model, we allow two adjacent moorings to overlap, which introduces a risk that under certain conditions the boats on these moorings could contact each other. We identify the conditions when contact is possible and quantify the probability of contact. The mooring field design problem is formulated as a nonlinear mixed‐integer programming problem. To solve the problem, we decompose it into two separate models, a mooring radii assignment model and a mooring layout model, which are solved sequentially. The first is solved via exhaustive enumeration and the second via a depth‐first search algorithm. Two actual mooring fields are evaluated, and in both cases our model leads to better layouts than ones experts developed manually. The mooring field design model rationalizes the mooring field design and shows that in one case by increasing the risk from 0 to 1%, the mooring efficiency increases from 74.8% to 96.2%. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009
In vivo quantification of blood velocity in mouse carotid and pulmonary arteries by ECG‐triggered 3D time‐resolved magnetic resonance angiography
Authors: Parzy Elodie , Miraux Sylvain , Jean‐Michel Franconi , Thiaudière Eric
Published: January 2009

Blood flow velocity is a functional parameter of fundamental importance in diagnosis and follow‐up of various vascular diseases. Vascular pathologies can be efficiently studied in animal models, especially in small rodents. ECG‐gated magnetic resonance imaging (MRI) assessment of blood velocity in small animals is a challenge because of limited spatial resolution and high‐frequency physiological parameters. Here it is shown that a bright‐blood cine‐3D‐MRI method can be used to measure blood velocity at specific times of the cardiac cycle in mouse pulmonary and carotid arteries. The method used a series of time‐of‐flight (TOF) acquisitions in a volume of interest at different times after signal cancellation in the same volume. This scheme was repeated at different periods of the cardiac cycle by varying the delay between the ECG R‐wave peak and signal cancellation. Velocity values in mouse pulmonary artery varied from 35 cm/s in systole to 0–10 cm/s in diastole. A similar pattern was displayed in carotid arteries (18 and 2.5 cm/s, in systole and diastole, respectively). Results are discussed in terms of efficiency, limitation, and comparison with other methods. Copyright © 2009 John Wiley & Sons, Ltd.
Analytical solution of time‐fractional Navier–Stokes equation in polar coordinate by homotopy perturbation method
Authors: Ganji Z.Z. , Ganji D.D. , Ganji Ammar D. , Rostamian M.
Published: January 2009

In this letter, we implement a relatively new analytical technique, the homotopy perturbation method (HPM), for solving linear partial differential equations of fractional order arising in fluid mechanics. The fractional derivatives are described in Caputo derivatives.

This method can be used as an alternative to obtain analytic and approximate solutions of different types of fractional differential equations applied in engineering mathematics. The corresponding solutions of the integer order equations are found to follow as special cases of those of fractional order equations. Some numerical examples are presented to illustrate the efficiency and reliability of HPM.

He's HPM, which does not need small parameter is implemented for solving the differential equations. In this method, a homotopy is introduced to be constructed for the equation. The initial approximations can be freely chosen with possible unknown constants that can be determined by imposing the boundary and initial conditions. It is predicted that HPM can be found widely applicable in engineering. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Clean air in urban China: The case of inter‐agency coordination in Chongqing's Blue Sky Program
Authors: Li W. , Chan Hon S.
Published: January 2009

Air pollution in urban China is increasingly attributed to dispersed sources such as motor vehicles and construction sites, over which environmental protection bureaus (EPBs) share jurisdiction with other government line agencies. The problem of multiple oversight bodies, with sometimes divergent goals, challenges EPBs regarding the achievement of environmental results. To do this, they need to be empowered with capacities as both green ambassadors and stringent enforcers, besides being intelligent planners and vigilant monitors. Across the country, the supply of institutional capacity for tackling air pollution does not match the demand. However, the article finds that setting up inter‐agency coordinating mechanisms enhanced the management and enforcement capacities of Chongqing's EPB in implementing Chongqing's Blue Sky Program and thus builds hope that similar measures will help bring clean air to all of urban China. Copyright © 2009 John Wiley & Sons, Ltd.
Decision‐making in Chinese local administrative reform: Path dependence, agency and implementation
Authors: Li Linda Chelan
Published: January 2009

How do policy makers make up their minds? What goes into their calculations when deciding whether a proposed policy or reform measure should or should not be adopted? This article looks into these important, if mundane, questions by considering the case of recent decisions taken in relation to Chinese township reforms. It argues that, in this case, policy makers were inclined to focus on costs, and neglected the potential benefits of reform due to the past reform trajectory whereby most previous township reforms have failed. Furthermore, policy makers were predisposed to perceive most stakeholders as ‘resisters’ of change or passive beneficiaries. This article contemplates the possibility of improving decision‐making capacity by recognising the agency role of ‘reform targets’. Copyright © 2009 John Wiley & Sons, Ltd.
State capacity building in China: An introduction
Authors: Collins Paul , Chan Hon S.
Published: January 2009

State capacity worldwide, often eroded by the effects of NPM type reforms, confronts unprecedented public policy challenges—vis‐a‐vis environment, security and health, amongst others. The state in China faces many of these—with unwelcome recent extras such as natural disasters. Whilst China has experienced phenomenal recent growth, it has also had to balance this with the need for stability. A paradox arises in which China seeks to regulate its rapid economic development whilst at the same time reforming the state itself. The collection of essays in this Special Issue will explore China's state capacity building challenges in a number of key systemic areas—budgeting, performance management, audit and state enterprise reform as well as specific public policy issue areas—environmental protection, land and security, local administrative and governance reform. In doing so, it will draw lessons about the applicability of governance models to specific country contexts and likely future paths as China seeks to deepen institutional and structural change. As in recent months the world has seen the near collapse of the US economy and further discrediting of the free market capitalist model of development, the interest in alternative development models is on the increase. Copyright © 2009 John Wiley & Sons, Ltd.
A case of natural killer cell lymphoma presenting with bilateral pleural effusions and hemophagocytic lymphohistocytosis
Authors: Tai Chun‐Fu , Chang Luan Yin , Lin Dong‐Tsamn , Lin Kai‐Hsin , Jou Shiann‐Tarng , Yang Yung‐Li
Published: January 2009

Natural killer (NK) cell lymphoma of lung is very rare. We report a case of NK cell lymphoma presented in a 17‐year‐old male with bilateral pleural effusions and hemophagocytic lymphohistocytosis. Morphologic and immunohistochemical tests revealed an association of NK cell lymphoma with Epstein–Barr virus. A literature review helped identify other cases of patients with NK cell lymphoma, their treatment and outcomes. Pediatr Blood Cancer 2009;52:666–669. © 2009 Wiley‐Liss, Inc.
Sialoblastoma and hepatoblastoma in a newborn infant
Authors: Stones D.K. , Jansen J.C. , Griessel D.
Published: January 2009

We report a case of a newborn infant who had simultaneous sialoblastoma and hepatoblastoma tumours at birth. The diagnoses were made on post mortem examination. Both of these are rare tumours in the neonatal period. Pediatr Blood Cancer 2009;52:883–885. © 2009 Wiley‐Liss, Inc.
Predictors of non‐participation in a randomized intervention trial to reduce environmental tobacco smoke (ETS) exposure in pediatric cancer patients
Authors: Klosky James L. , Tyc Vida L. , Lawford Joanne , Ashford Jason , Lensing Shelly , Buscemi Joanna
Published: January 2009

Background

Exposure to environmental tobacco smoke (ETS) is associated with the development of serious health consequences in children with cancer due to preexisting disease and treatment‐related vulnerabilities. The purpose of the current investigation was to identify predictors of non‐participation in a randomized intervention trial to reduce ETS exposure among pediatric cancer patients.

Methods

One hundred fifty‐three families of pediatric cancer patients met study eligibility criteria. Parents of 117 (76%) patients agreed to study participation, whereas 36 (24%) parents declined (non‐participants). Data were collected with respect to participant sociodemographic, medical, and treatment‐related characteristics.

Results

Univariate analyses indicated that families whose primary caregivers were females or smokers were more likely to be non‐participants in the ETS reduction trial (P = 0.045 and P = 0.009, respectively). Medical features that significantly associated with study non‐participation included CNS tumor diagnosis (P = 0.030), no history of chemotherapy (P = 0.012), history of surgery prior to study recruitment (P = 0.036), and having future radiation therapy planned post study recruitment (P = 0.009). Multivariable logistic regression modeling revealed that study non‐participation was associated with the primary caregiver being a smoker (OR = 6.48, P = 0.002) or female (OR = 8.56, P = 0.023), and patient CNS tumor diagnosis (OR = 4.63, P = 0.021).

Conclusions

Although a large percentage of eligible participants enrolled in the ETS reduction trial, findings suggest that future recruitment strategies of families should be tailored to parental smoking status and gender, as well as child diagnosis and treatment. Pediatr Blood Cancer 2009;52:644–649. © 2009 Wiley‐Liss, Inc.
Binder phenotype: clinical and etiological heterogeneity of the so‐called Binder maxillonasal dysplasia in prenatally diagnosed cases, and review of the literature
Authors: Levaillant J. M. , Moeglin D. , Zouiten K. , Bucourt M. , Burglen L. , Soupre V. , Baumann C. , Jaquemont M. L. , Touraine R. , Picard A. , Vuillard E. , Belarbi N. , Oury J. F. , Verloes A. , Vazquez M. P. , Labrune P. , Delezoide A. L. , Gérard‐Blanluet M.
Published: January 2009

Objective

Prenatal Binder profile is a well known clinical phenotype, defined by a flat profile without nasal eminence, contrasting with nasal bones of normal length. Binder profile results of a hypoplasia of the nasal pyramid (sometimes referred to as maxillonasal dysplasia). We report 8 fetuses prenatally diagnosed as Binder phenotype, and discuss their postnatal diagnoses.

Methods

Ultrasonographic detailed measurements in 2D and 3D were done on the 8 fetuses with Binder profile, and were compared with postnatal phenotype.

Results

All fetuses have an association of verticalized nasal bones, abnormal convexity of the maxilla, and some degree of chondrodysplasia punctata. The final diagnoses included fetal warfarin syndrome (one patient), infantile sialic acid storage (one patient), probable Keutel syndrome (one patient), and five unclassifiable types of chondrodysplasia punctata.

Conclusion

This series demonstrates the heterogeneity of prenatally diagnosed Binder phenotype, and the presence of chondrodysplasia punctata in all cases. An anomaly of vitamin K metabolism, possibly due to environmental factors, is suspected in these mild chondrodysplasia punctata. We recommend considering early prophylactic vitamin K supplementation in every suspected acquired vitamin K deficiency including incoercible vomiting of the pregnancy. Copyright © 2009 John Wiley & Sons, Ltd.
Endoscopic laser coagulation of feeding vessels in large placental chorioangiomas: report of three cases and review of invasive treatment options
Authors: Sepulveda Waldo , Wong Amy E. , Herrera Luis , Dezerega Victor , Devoto Juan C.
Published: January 2009

Objective

To report three cases of large placental chorioangiomas managed with endoscopic laser coagulation of the feeding vessels, and review the literature regarding cases of chorioangioma treated with invasive techniques.

Methods

Intrauterine endoscopic surgery was performed using a 2.5‐mm fetoscope under epidural anesthesia. Coagulation of the feeding vessels was attempted with laser energy, and the operation was completed with amniodrainage.

Results

The feeding vessels were successfully coagulated in one case, resulting in a term delivery. Histopathologic examination of the placenta confirmed a capillary chorioangioma with extensive necrosis. There were intraoperative complications in the other two cases, including bleeding at the site of coagulation requiring intrauterine transfusion in one, and incomplete vascular ablation in the other. In the former case the infant was born prematurely and developed chronic renal insufficiency. In the latter, the fetus died within the first week of the surgery.

Conclusions

There are limited interventions available for the management of large, symptomatic placental chorioangiomas. Although they can be treated with endoscopic laser coagulation of the feeding vessels, fetal bleeding, exsanguination, and death are potential complications of the procedure; therefore, this technique should be used with caution. The role of this treatment modality in the early devascularization of placental chorioangiomas prior to the development of significant complications warrants consideration. Copyright © 2009 John Wiley & Sons, Ltd.
Long‐term cancer survivors experience work changes after diagnosis: results of a population‐based study
Authors: Mols Floortje , Thong Melissa S.Y. , Vreugdenhil Gerard , van de Poll‐Franse Lonneke V.
Published: January 2009

Background: Although cancer survivorship is increasing with improved diagnosis and treatments, few studies have explored employment changes and the factors related to this change among cancer survivors. Therefore, we aim to explore the prevalence of employment problems in long‐term cancer survivors. In addition, we explored what patient or tumour characteristics predicted employment changes.

Methods: All 1893 long‐term survivors of prostate cancer, endometrial cancer, non‐Hodgkin's lymphoma, and Hodgkin's lymphoma diagnosed between 1989 and 1998 in the area of the Comprehensive Cancer Centre South, The Netherlands were included in a population‐based cross‐sectional survey.

Results: Response rate was 80% (n=1511). After excluding survivors without a job before diagnosis, 403 survivors remained; 197 (49%) experienced no changes in their work situation following cancer diagnosis, 69 (17%) were working fewer hours, and 137 (34%) stopped working or retired. A medium educational level was significant in reducing the risk of work changes. Being older, having more than one comorbid condition, being treated with chemotherapy, and disease progression were significant independent predictors of work changes after cancer. Experiencing work changes was associated with lower physical functioning but positively associated with social well‐being.

Discussion: Long‐term cancer survivors experience work changes after diagnosis and treatment, and clinical factors significantly predicted work change after cancer. As such, our study underscores the importance of rehabilitation programs in improving the return to work after cancer. Copyright © 2009 John Wiley & Sons, Ltd.
A network of dynamically conserved residues deciphers the motions of maltose transporter
Authors: Lukman Suryani , Grant Guy H.
Published: January 2009

The maltose transporter of Escherichia coli is a member of the ATP‐binding cassette (ABC) transporter superfamily. The crystal structures of maltose transporter MalK have been determined for distinct conformations in the presence and absence of the ligand ATP, and other interacting proteins. Using the distinct MalK structures, normal mode analysis was performed to understand the dynamics behavior of the system. A network of dynamically important residues was obtained from the normal mode analysis and the analysis of point mutation on the normal modes. Our results suggest that the intradomain rotation occurs earlier than the interdomain rotation during the maltose‐binding protein (MBP)‐driven conformational changes of MalK. We inquire if protein motion and functional‐driven evolutionary conservation are related. The sequence conservation of MalK was analyzed to derive a network of evolutionarily important residues. There are highly significant correlations between protein sequence and protein dynamics in many regions on the maltose transporter MalK, suggesting a link between the protein evolution and dynamics. The significant overlaps between the network of dynamically important residues and the network of evolutionarily important residues form a network of dynamically conserved residues. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Gene ontology functional annotations at the structural domain level
Authors: Lopez Daniel , Pazos Florencio
Published: January 2009

Most proteins are organized in domains which can be seen as independent modular units in terms of molecular function (MF). Nevertheless, current functional annotations are done on a “whole‐chain” basis without associating specific functions to the individual domains. We present here an automatic method for discerning which particular structural domain within a protein is responsible for a given MF originally attributed to the whole protein. By annotating the SCOP structural domains with gene ontology terms using this method, we obtained the first large‐scale functional annotation at the domain level. We performed a large‐scale comparison of these annotations with the ones implicit in the functional annotations of Interpro signatures, showing that the performance of this method is globally better. We also discuss in detail some particular examples. Generated automatically and available online, this resource could be the basis for future manually curated annotations. Proteins 2009. © 2009 Wiley‐Liss, Inc.
On the relation between residue flexibility and local solvent accessibility in proteins
Authors: Zhang Hua , Zhang Tuo , Chen Ke , Shen Shiyi , Ruan Jishou , Kurgan Lukasz
Published: January 2009

We investigate the relationship between the flexibility, expressed with B‐factor, and the relative solvent accessibility (RSA) in the context of local, with respect to the sequence, neighborhood and related concepts such as residue depth. We observe that the flexibility of a given residue is strongly influenced by the solvent accessibility of the adjacent neighbors. The mean normalized B‐factor of the exposed residues with two buried neighbors is smaller than that of the buried residues with two exposed neighbors. Inclusion of RSA of the neighboring residues (local RSA) significantly increases correlation with the B‐factor. Correlation between the local RSA and B‐factor is shown to be stronger than the correlation that considers local distance‐ or volume‐based residue depth. We also found that the correlation coefficients between B‐factor and RSA for the 20 amino acids, called flexibility‐exposure correlation index, are strongly correlated with the stability scale that characterizes the average contributions of each amino acid to the folding stability. Our results reveal that the predicted RSA could be used to distinguish between the disordered and ordered residues and that the inclusion of local predicted RSA values helps providing a better contrast between these two types of residues. Prediction models developed based on local actual RSA and local predicted RSA show similar or better results in the context of B‐factor and disorder predictions when compared with several existing approaches. We validate our models using three case studies, which show that this work provides useful clues for deciphering the structure–flexibility–function relation. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Free‐energy profiles for ions in the influenza M2‐TMD channel
Authors: Mustafa Morad , Henderson Douglas J. , Busath David D.
Published: January 2009

M2 transmembrane domain channel (M2‐TMD) permeation properties are studied using molecular dynamics simulations of M2‐TMD (1NYJ) embedded in a lipid bilayer (DMPC) with 1 mol/kg NaCl or KCl saline solution. This study allows examination of spontaneous cation and anion entry into the selectivity filter. Three titration states of the M2‐TMD tetramer are modeled for which the four His37 residues, forming the selectivity filter, are net uncharged, +2 charged, or +3 charged. M2‐TMD structural properties from our simulations are compared with the properties of other models extracted from NMR and X‐ray studies. During 10 ns simulations, chloride ions occasionally occupy the positively‐charged selectivity filter region, and from umbrella sampling simulations, Cl− has a lower free‐energy barrier in the selectivity‐filter region than either Na+ or NH, and NH has a lower free‐energy barrier than Na+. For Na+ and Cl−, the free‐energy barriers are less than 5 kcal/mol, suggesting that the 1NYJ conformation would probably not be exquisitely proton selective. We also point out a rotameric configuration of Trp41 that could fully occlude the channel. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Quantum‐optical spectroscopy
Authors: Kira M. , Koch S. W.
Published: January 2009

The possibilities of quantum‐optical spectrocopy are explored theoretically on the basis of an analytically solvable Jaynes‐Cummings model. Like for semiconductors, thermal‐ and coherent‐state excitations produce drastically different mater excitation that can be characterized through the re‐radiation of light. The calculations show that matter dynamics can be sensitively monitored through distinct changes in the marginal quadrature distributions (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristics of GaN‐based light emitting diode grown on circular convex patterned sapphire substrate
Authors: Oh Tae Su , Lee Yong Seok , Jeong Hyun , Kim Jan Di , Seo Tae Hun , Suh Eun‐Kyung
Published: January 2009

We report the characteristics of GaN‐based light‐emitting diode (LED) grown on a circular convex patterned sapphire substrate (CCPSS) and conventional LEDs on a non‐patterned sapphire substrate (PSS) by metal‐organic chemical vapor deposition. A near field scanning optical microscope (NSOM) and micro Raman spectroscopy were employed to investigate the crystalline properties. In NSOM image and spectra of LED on CCPSS, an improved crystalline quality with emission fluctuation feature on the trench region was obtained. However, stress relaxation in this trench region was not achieved due to the presence of voids, indicating a stress concentration at the coalescence region. Compared to conventional LED on non‐PSS, increased internal quantum efficiency (IQE) (41.8%) and reduced leakage currents (40 nA at ‐10 V) were observed in the LED fabricated on CCPSS. The light output power of the LED on CCPSS was approximately two times higher than that of a conventional LED. This enhancement of output power is contributed to increase of IQE and the effective suppression of leakage current by reduction of dislocation density, as well as enhanced light scattering via the circular convex facets. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metallic nanoparticle array on GaN by microsphere lithography
Authors: Mak Giuseppe Y. , Fu W. Y. , Lam Edmund Y. , Choi H. W.
Published: January 2009

The optical characteristics of GaN blue‐light (peak wavelength at 440 nm) light‐emitting diode (LED) under the effect of localized surface plasmon (LSP) have been studied. Hexagonal arrays of triangular metallic nanoparticles deposited through a self‐assembled silica microsphere mask have been fabricated using vertical deposition. By comparing the PL spectra of samples coated with Au, Al and Ag nanoparticles, it is found that Ag nanoparticles offer the most pronounced PL enhancement. The resonance wavelength was determined from optical transmission and verified by theoretical calculations. These results provide a cost‐effective solution for improving the efficiency of LEDs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN‐on‐Si HEMT stress under high electric field condition
Authors: Marcon Denis , Lorenz Anne , Derluyn Joff , Das Jo , Medjdoub Farid , Cheng Kai , Degroote Stefan , Leys Maarten , Mertens Robert , Germain Marianne , Borghs Gustaaf
Published: January 2009

Nowadays, GaN‐on‐Si HEMTs (High Electron Mobility transistors) are receiving a lot of attention thanks to their impressive performance in terms of high current and voltage capabilities combined with a low production cost. Since the technology has matured, the reliability aspects have been initially investigated in order to prove the performances of these devices in the long term. In this work GaN‐on‐Si HEMTs were electrically stressed in pinched off condition while high voltages were applied on the drain side (high electric field condition). Transistors with and without in‐situ Si3N4 layer underneath the gate were tested, as well as a transistor with 1 μm field plate on each side, due to a T shaped gate.

Both type of devices with and without Si3N4 under the gate showed the same failure mode: a sudden increase of the gate and drain leakage current. This excludes, in principle, the role of Si3N4 layer on the degradation mechanism involved. Possible explanations about the failure mechanism are compared and discussed. Finally, a preliminary test on the T‐shape gate technology showed no degradation after more than 500 hours under high electric field condition of stress, which include 282 hours in pinched off condition with the drain voltage fixed as high as 60 V. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical characterization of bulk GaN substrates with c ‐, a ‐, and m ‐plane surfaces
Authors: Paskov P. P. , Monemar B. , Paskova T. , Preble E. A. , Hanser A. D. , Evans K. R.
Published: January 2009

Thick free‐standing GaN grown by hydride vapour phase epitaxy and epi‐ready substrates with c ‐, a ‐, m ‐plane surfaces are examined by variable‐temperature photoluminescence (PL), polarized PL and spatially resolved micro‐PL. Both as‐grown samples and polished substrates exhibit linewidth of the donor‐bound exciton emission below 0.7 meV at 2 K indicative of a high structural quality of the material. For as‐grown samples the relative intensity of green (2.4 eV) and red (1.8 eV) deep‐level‐defect emissions are found to decrease with increasing sample thickness. Based on plentiful two‐electron‐transition spectra measured in the samples the electronic fine structure of the donors and their bound‐exciton complexes was examined and discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigations on the SH+(X3Σ−) ion using coupled‐cluster theory in combination with the correlation‐consistent quintuple basis set augmented with diffuse functions
Authors: Shi De‐Heng , Zhang Jin‐Ping , Liu Yu‐Fang , Sun Jin‐Feng , Zhu Zun‐Lue
Published: January 2009

The coupled‐cluster singles‐doubles‐approximate‐triples [CCSD(T)] theory in combination with the correlation‐consistent quintuple basis set augmented with diffuse functions (aug‐cc‐pV5Z) is used to investigate the spectroscopic properties of the SH+( X3Σ−) ion. The accurate potential energy curve is calculated over the internuclear separation range from 0.09 to 2.46 nm and is fitted to the analytic Murrell‐Sorbie function, which is used to accurately determine the spectroscopic parameters such as De, ωeχe, αe, and Be. The present De, Re, ωe, ωeχe, αe, and Be values are 3.69119 eV, 0.13644 nm, 2,556.429 cm−1, 49.290 cm−1, 0.289 cm−1, and 9.2677 cm−1, respectively, which are in excellent agreement with the available measurements. With the potential obtained at the UCCSD( T)/aug‐cc‐pV5Z level of theory, a total of 21 vibrational states is predicted when J = 0 by numerically solving the radial Schrödinger equation of nuclear motion. The complete vibrational levels, classical turning points, inertial rotation, and centrifugal distortion constants are reproduced from the potential energy curve of the SH+( X3Σ−) ion when J = 0 for the first time. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Length‐dependence of electron transfer coupling matrix in polyene wires: Ab initio molecular orbital theory study
Authors: Mallick Govind , Karna Shashi P. , He Haiying , Pandey Ravindra
Published: January 2009

The electron transfer (ET) properties of π‐electron conjugated quasi‐one‐dimensional molecular wires, consisting of polyene, [>CC<]n (n = 1–11), including β‐carotene, is investigated using ab initio molecular orbital theory within Koopmans theorem (KT) approach. The ET coupling matrix element, VDA, for 1,3‐trans‐butadiene molecule calculated with the KT approach shows excellent agreement with the corresponding results obtained with two‐state model. The calculated values of VDA for the polyene oligomers exhibit exponential decrease in magnitude with increasing length of the wire. However, the decay curve exhibits three different regimes. The magnitude of the decay constant, β, decreases with the increase in length of the wire. A highly delocalized π‐electron cloud in the polyene chain appears to facilitate retention of the electronic coupling at large separations between the donor and acceptor centers. Published 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Time‐dependent density functional theory calculation of van der Waals coefficient of potassium clusters
Authors: Banerjee Arup , Chakrabarti Aparna , Ghanty Tapan K.
Published: January 2009

We employ all‐electron ab initio time‐dependent density functional theory (DFT)‐based method to calculate the long range dipole–dipole dispersion coefficient (van der Waals coefficient)C6of potassium atom clusters (Kn) containing even number of atoms,nranging from 2 to 20. The dispersion coefficients are obtained via Casimir–Polder relation. The calculations are carried out with the asymptotically correct statistical average of orbital potential and compared with the results obtained using Vosko–Wilk–Nusair representation of exchange‐correlation potential within local density approximation. We report the dispersion coefficients between clusters of sodium and potassium atoms as well. The present results have been compared with the available jellium‐based model and other DFT results in the literature. We also study the relationship between volume of the cluster and theC6for K clusters. It is observed that theC6scales as square of the volume. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Improvement of the NEMO potential by inclusion of intramolecular polarization
Authors: Holt Asbjørn , Karlström Gunnar
Published: January 2009

The intermolecular electrostatic and induction energy of a NEMO potential which includes intramolecular polarization, are compared with a regular NEMO potential and a NEMO potential with configurationally dependent local properties. It is shown that the inclusion of intramolecular polarization improves the description of the intermolecular interactions when using the NEMO potential. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The effect of donor atoms on the complexation of alkali cations with spherands: A density functional investigation
Authors: Elroby Shabaan A. K.
Published: January 2009

Spherands are highly preorganized hosts composed of methoxy 1, fluoro 2, and cyano 3 benzene units attached to one another at their 2,6‐positions. Density functional theory calculations were used to investigate the complexation between these spherands and alkali metal ions (Li+, Na+, and K+) to understand the intrinsic factors affecting cation complexation. A comparison of binding energies for these spherands shows that, this order OMe ≫ F ≫ CN. Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygen during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. The ion–dipolar moiety interactions are found to be the main factors affecting the preference of external binding in the CN‐spherands. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Study on corrosion resistance of electroplating zinc–nickel alloy coatings
Authors: Tian W. , Xie F. Q. , Wu X. Q. , Yang Z. Z.
Published: January 2009

Electrodeposited zinc–nickel alloy coatings have been widely adopted for surface treatment of automobile body steel sheet for high corrosion resistance. The corrosion behavior of the coatings has been related with the components of nickel, and the zinc–nickel alloy passive coatings have much higher corrosion resistance than that of zinc–nickel alloy coatings. In the present paper, the corrosion resistance behavior of the zinc–nickel alloy coatings obtained by new process and formulation has been studied by means of the electrochemistry test and neutral salt spray test. And it is discovered that the properties of corrosion resistance of zinc–nickel alloy passive coatings were better than that of zinc passive coatings, Cadmium passive coatings and alloys of electrodeposited cadmium–titanium. The components of corrosion productions, in terms of X‐ray diffraction (XRD), are mainly ZnO, ZnCl2 · 4Zn(OH)2 and small quantity of 2ZnCO3· 3Zn(OH)2. The component of zinc–nickel alloy coatings has been investigated with Glow Discharge Optical Emission Spectrometry (GDA‐750). And it is found that as the thickness of zinc–nickel alloy coatings increases, the component of zinc increases from beginning to end, but the peak value of nickel appears and an enrichment of nickel in the coatings comes into being. Because the electrodeposited zinc–nickel alloy coatings exhibit different alloy phases as a function of their alloy composition, in this paper, the crystal structure changing with the different component of nickel has been studied in terms of XRD. The result shows that electrodeposited zinc–nickel alloy has different phases: α‐phase, a solid solution of zinc in nickel with an equilibrium solubility of about more than 79% nickel; γ‐phase, an intermediate phase with a composition Ni5Zn21; η‐phase, a solid solution of nickel in zinc with less than 5% nickel; and δ‐phase (Ni3Zn22) appeared from η‐phase to α‐phase with increasing content of nickel. Copyright © 2009 John Wiley & Sons, Ltd.
Angle resolved XPS characterization of cationic polyacrylamides
Authors: Zekonyte J. , Williams R. L. , Beamson G. , Weightman P.
Published: January 2009

In many applications surfaces are modified using polymer films and the polymers used are often complex copolymers. In biomedical applications it is critical to determine the surface properties of a substrate as it is these that mediate the cellular interactions. The surface structure of copolymer films can only rarely be established from their bulk composition alone. In this study angle resolved XPS was used to build a model of the structure of copolymer films produced on glass substrates from a family of poly(acrylamide) copolymers containing cationic blocks. The thickness of the copolymer films was demonstrated to be dependent on the concentration of the polymer solution and the ratio of non‐cationic to cationic blocks in the copolymer. The data demonstrated that the cationic blocks of the copolymer preferentially segregated to the glass surface and the non‐cationic poly(acrylamide) blocks preferentially segregated to the air–vacuum interface. A low concentration of the cationic functional groups was present throughout the poly(acrylamide) layer and it was suggested that this resulted from a small fraction of the cationic blocks being pulled into the poly(acrylamide) layer at points along the polymer chain where the two blocks are connected. Evidence of a thin surface hydrocarbon contamination layer was also observed. Copyright © 2009 John Wiley & Sons, Ltd.
The oxidation‐treated interface on tribological properties of carbon fibers‐reinforced PTFE composite under oil‐lubricated condition
Authors: Li J. , Su Y. H.
Published: January 2009

The effect of air oxidation and ozone surface treatment of carbon fibers (CF) on tribological properties of CF reinforced polytetrafluoroethylene (PTFE) composites under oil‐lubricated condition was investigated. Experimental results revealed that ozone treated CF reinforced PTFE (CF–PTFE) composite had the lowest friction coefficient and wear under various applied loads and sliding speeds compared with untreated and air‐oxidated composites. X‐ray photoelectron spectroscopy (XPS) study of carbon fiber surface showed that, after ozone treatment, oxygen concentration was obviously increased, and the amount of oxygen‐containing groups on CF surfaces was largely increased. The increase in the amount of oxygen‐containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, stress could be effectively transmitted to carbon fibers; carbon fibers were strongly bonded with PTFE matrix and large scale rubbing‐off of PTFE was prevented, therefore, the tribological properties of the composite were improved. Copyright © 2009 John Wiley & Sons, Ltd.
Interfacial properties for real rough MEMS/NEMS surfaces by incorporating the electrostatic and Casimir effects–a theoretical study
Authors: Xie Guoxin , Ding Jianning , Liu Shuhai , Xue Wei , Luo Jing
Published: January 2009

This paper studied the adhesive properties of real rough micro/nano‐electromechanical systems (MEMS/NEMS) surfaces by considering the electrostatic force and the Casimir force theoretically, and an improved model has been proposed. A statistical approach for characterizing surface topography was used by taking the surface standard deviation, the asperity density and the radius of curvature into account. The effects of surface roughness on the electrostatic force and the Casimir force were analysed individually, and a comparison between the proposed model and existing models has been conducted. The whole adhesive force increases with the surface standard deviation, and the prediction by the proposed model becomes more in agreement with the one by existing models when the surface standard deviation is increased. The contribution of the Casimir force to the total adhesive force tends to vanish when the surface standard deviation is relatively large. The electrostatic force and the Casimir force contribute more to the total adhesive forces calculated based on the proposed model with the increase of the asperity density and the radius of curvature. Copyright © 2009 John Wiley & Sons, Ltd.
Marginalized random effects models for multivariate longitudinal binary data
Authors: Lee Keunbaik , Joo Yongsung , Yoo Jae Keun , Lee JungBok
Published: January 2009

Generalized linear models with random effects are often used to explain the serial dependence of longitudinal categorical data. Marginalized random effects models (MREMs) permit likelihood‐based estimations of marginal mean parameters and also explain the serial dependence of longitudinal data. In this paper, we extend the MREM to accommodate multivariate longitudinal binary data using a new covariance matrix with a Kronecker decomposition, which easily explains both the serial dependence and time‐specific response correlation. A maximum marginal likelihood estimation is proposed utilizing a quasi‐Newton algorithm with quasi‐Monte Carlo integration of the random effects. Our approach is applied to analyze metabolic syndrome data from the Korean Genomic Epidemiology Study for Korean adults. Copyright © 2009 John Wiley & Sons, Ltd.
XSLT‐based evolutions and analyses of design patterns
Authors: Dong Jing , Zhao Yajing , Sun Yongtao
Published: January 2009

Design patterns document flexible designs that may evolve over time. Design pattern evolution typically involves the addition or removal of a group of modeling elements, such as classes, attributes, operations, and relationships. However, the possible evolutions of each design pattern are often not explicitly documented. Missing part of the evolution process may result in inconsistent evolution. Pattern instances may interact with each other making the evolution of design patterns more error‐prone. Undetected design errors and inconsistencies may cause failures of systems. In this paper, we propose a service‐oriented architecture for design pattern evolution and analysis based on two‐level transformations, thus making the possible evolutions of each design pattern explicit. In addition, we automate the evolution processes as XSLT transformations that can transform the unified modeling language (UML) model of a design pattern application into the evolved UML model of the pattern. Both the original and evolved UML models are represented in the XML Metadata Interchange format to facilitate the transformations. Furthermore, we check the consistency of the evolution results using the semantic web checker based on the Java Theorem Prover. A case study on a large real‐world system is presented to illustrate and evaluate our approach. Copyright © 2009 John Wiley & Sons, Ltd.
Mono‐ and Di‐Potassium Derivatives of Benzenepentacarboxylic Acid
Authors: Turner David R. , Strachn‐Hatton Joshua , Batten Stuart R.
Published: January 2009

The synthesis and structure of the hydrated mono‐ and di‐potassium salts of benzenepentacarboxylic acid are reported – [K(H4BPC)(H2O)2]·(H2O) 1 and [K2(H3BPC)(H2O)3]·(H2O) 2 (BPC = benzenepentacarboxylate). In both instances the structures are complex coordination networks, predominantly containing η1 binding modes of the carboxylate and carboxylic acid groups, although bridging (O,O) and (O,O′) carboxylates and μ2‐H2O ligands also feature. Extensive hydrogen bonding is present through the carboxylic acid groups and both coordinated and interstitial water molecules.
On the Oxidation of Octamethylenetetrathiafulvalene by CuBr2 – Synthesis, Crystal Structure and Magnetic Properties of (OMTTF)2[Cu4Br10]
Authors: Beck Johannes , Bof de Oliveira Adriano
Published: January 2009

The reaction of octamethylenetetrathiafulvalene (OMTTF) with excess CuBr2 in tetrahydrofurane/acetonitrile yields black (OMTTF)2[Cu4Br10] (1). The crystal structure determination shows the presence of OMTTF cations and tetranuclear bromidocuprate anions. The novel anion consists of four edge and corner sharing CuBr4 tetrahedra, which are connected to a ring. The assignment of the ionic charges and oxidation states for the copper atoms is supported by the magnetic properties. 1 is antiferromagnetic with TN ≈ 30 K. The magnetic moment reaches 2.54 B.M., which indicates, together with the Curie–Weiss constant of –35 K, a coupling of the paramagnetic spins over the whole temperature region. The ionic charges of the salt‐like compound 1 are therefore (OMTTF2+)2[(Cu+)2(Cu2+)2Br10]4–. The antiferromagnetism is explained by the coupling of the spins of two Cu2+ ions in the anion with an exchange constant of J = –18 cm–1. The CuI and CuII atoms are clearly distinguishable in the mixed valent anion. The OMTTF cation is not planar but exhibits an interplanar angle between the two central C3S2 ring moieties of 15.3°, which is in accordance to the dicationic oxidation state.
A New Coordination Polymer [Pb(1,4‐BDC)]n Containing a Unique μ6‐Bridging Coordination Mode
Authors: Li Zhang‐Peng , Xing Yong‐Heng , Wang Chun‐Guang , Li Jing , Zeng Xiao‐Qing , Ge Mao‐Fa , Niu Shu‐Yun
Published: January 2009

A new coordination polymer, [Pb(1,4‐BDC)]n (1) (1,4‐H2BDC = 1,4‐benzenedicarboxylic acid), has been synthesized under solvothermal conditions. Its structure was determined with single‐crystal X‐ray diffraction studies and further characterized by inductively coupled plasma (ICP) spectrometry, elemental analysis, IR spectroscopy, thermogravimetric analysis, and X‐ray powder diffraction studies. The results revealed that complex 1 has a two‐dimensional network with (6, 3) topology observed in the [110] direction. Moreover, the layers are connected into a framework through 1,4‐BDC2− ligands. The μ6‐bridging coordination mode adopted by 1,4‐BDC2− is unprecedented in metal/1,4‐BDC2− complexes.