bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple cranial neuropathy variant of guillain–barré syndrome: A case series
Authors: Wang Qingsong , Xiang Yang , Yu Ke , Li Congyang , Wang Jun , Xiao Li
Published: February 2011

Introduction:

Prompt identification of the rare cranial variant of Guillain–Barré syndrome (GBS) is crucial, but the clinical characteristics remain poorly defined.

Methods:

We conducted a retrospective review of 12 GBS patients hospitalized from 1995 to 2009 with multiple cranial nerve (CN) impairment at disease onset.

Results:

Eight patients had impairment of CN IX and X; 3 of CN VII; and 1 of CN VII, IX, and X. All patients had areflexia or hyporeflexia, 6 had Lasegue sign, and 5 required tracheostomy and mechanical ventilation. All patients had cerebrospinal fluid (CSF) albuminocytologic dissociation within 2–3 weeks after onset. Electrophysiological studies showed motor conduction velocity and F‐wave abnormalities in 10 of 12 and 10 of 11 patients, respectively. Treatment with intravenous immunoglobulin was effective.

Conclusions:

Bilateral CN IX, X, and/or VII impairment with areflexia or hyporeflexia, early abnormal F‐wave response, nerve conduction abnormalities, and CSF albuminocytologic dissociation support a diagnosis of this GBS cranial variant. Muscle Nerve, 2011
Fast truncation of mode ranks for bilinear tensor operations
Authors: Savostyanov D. V. , Tyrtyshnikov E. E. , Zamarashkin N. L.
Published: February 2011

We propose a fast algorithm for mode rank truncation of the result of a bilinear operation on 3‐tensors given in the Tucker or canonical form. If the arguments and the result have mode sizes n and mode ranks r, the computation costs (nr3 + r4). The algorithm is based on the cross approximation of Gram matrices, and the accuracy of the resulted Tucker approximation is limited by square root of the machine precision. We apply the proposed algorithms for the evaluation of the Hadamard square of the electron density and demonstrate that it outperforms previously used methods for this purpose. We also check the accuracy of the resulted Tucker approximation and show that one iteration of the Tucker‐ALS method improves it almost up to the machine precision. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient algorithm for clustered integer least squares problems
Authors: Chun Joohwan , Park Jaehyun
Published: February 2011

The integer least squares problem is known to be NP‐hard, and the algorithms such as the sphere decoding algorithm, which give the optimal solution, are usually too slow. To obtain a solution efficiently one may use one of the suboptimal algorithms such as the ordered successive interference cancellation (OSIC) algorithm or the LLL‐aided OSIC algorithm that first modifies the system of equations using the LLL algorithm due to Lenstra, Lenstra, and Lovász. However, these suboptimal algorithms still may not be fast enough depending on the applications. In this paper we present two decoupling techniques to speed‐up the LLL‐aided OSIC algorithm. Our LLL‐aided decoupled OSIC algorithm, which is applicable to clustered integer least squares problems, has the accuracy comparable to the ordinary LLL‐aided OSIC algorithm (without decoupling), but is much faster than the OSIC algorithm or the LLL‐aided OSIC algorithm. Copyright © 2011 John Wiley & Sons, Ltd.
Energy‐momentum consistent algorithms for dynamic thermomechanical problems—Application to mortar domain decomposition problems
Authors: Hesch Christian , Betsch Peter
Published: February 2011

An energy‐momentum consistent integrator for non‐linear thermoelastodynamics is newly developed and extended to domain decomposition problems. The energy‐momentum scheme is based on the first law of thermodynamics for strongly coupled, non‐linear thermoelastic problems. In contrast to staggered algorithms, a monolithic approach, which solves the mechanical as well as the thermal part simultaneously, is introduced. The approach is thermodynamically consistent in the sense that the first law of thermodynamics is fulfilled. Furthermore, a domain decomposition method for the thermoelastic system is developed based on previous developments in the context of the mortar method. The excellent performance of the new approach is illustrated in representative numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.
Relationship of health locus of control to lifestyle change programs
Authors: Jordan‐Marsh Maryalice , Neutra Raymond
Published: February 2011

The relationship of health locus of control (HLC) scores to changes in physical parameters of 339 participants in a lifestyle change program was examined. Physical parameters included weight, blood pressure, low density lipoproteins, triglycerides, and the ratio between cholesterol and high density lipoproteins. Data were collected on admission and on completion of the 24‐day residential program, and at a 6‐month followup. There were significant changes in HLC scores (p < .001) from admission to discharge. Weight changes at 6 months were positively correlated with admission HLC composite scores (p < .01) and chance dimension (p < .05) scores. There were negative correlations at 6 months between admission powerful other scores and changes in triglycerides (p < .01) and changes in the ratio of cholesterol and high density lipids (p < .01).
An approach to modifying self‐report instruments
Authors: Holm Karyn , Kavanagh Jack
Published: February 2011

The Rasch model, a simple latent trait model was applied to responses to a 21‐item self‐report instrument. Items were assigned values reflective of interval scale measurement. To modify the instrument, items below the calibrated mean were eliminated. The proposed revision contains fewer items with known scale values and only those items that are the strongest indicants of the variable in question. The present work suggests that the Rasch and similar models are useful for increasing the measurement properties of self‐report instruments.
Sensation information, self‐instruction and responses to dental surgery
Authors: Sime A. Marilyn , Libera Mary B.
Published: February 2011

The interaction effects of presurgery anxiety and two intervention strategies upon adjustment during dental surgery were examined. Patients undergoing gingivectomy (N = 113) were randomly assigned to one of four information groups: sensation, self‐instruction, combined sensation and self‐instruction, or control; and separated according to level of trait and state anxiety. Results showed an interaction effect between the information conditions and state anxiety (p < .05). Compared with the control group, high state anxiety subjects reported less tension (p < .05) and distress (p < .05) after receiving sensation information; less tension (p < .005) after receiving self‐instruction information; and increased positive self‐statements (p < .05) with the combined information. Low‐state anxiety subjects showed negative treatment effects; sensation information alone (p < .001) or combined with self‐instruction (p < .01) reduced the number of reported positive self‐statements.
Effects of progressive muscle relaxation training on anxiety and health locus of control among hypertensive adults
Authors: Pender Nola J.
Published: February 2011

The effects of progressive muscle relaxation (PMR) on anxiety and perceptions of personal control over health status are evaluated in this study. After collection of baseline data, 22 hypertensive clients received relaxation training in a series of weekly group sessions followed by individual monitoring sessions over a 6‐week period. The 22 hypertensive clients in the control group received blood pressure monitoring, weight checks, and health counseling but were given no relaxation training during the study period. The group instructed in relaxation exhibited significantly lower anxiety than the control group at 4‐month followup. After training, the relaxation group also scored significantly higher than the control group on beliefs in personal control of health and lower in beliefs that chance or luck affected health outcomes. At followup, the groups did not differ significantly on perceived influence of powerful others over health status. Findings support the potential usefulness of relaxation training in modifying affective and cognitive characteristics of hypertensive clients.
Personal control interventions: Short‐ and long‐term effects on surgical patients
Authors: Johnson Jean E. , Christman Norma J. , Stitt Cathey
Published: February 2011

A randomized 2 × 3 × 2 factorial design was used to evaluate the short‐ and long‐term effects of interventions that provided different means of exerting personal control over postoperative experiences in a sample of 121 black and 47 white hysterectomy patients. One variable was the presence or absence of the description of the experience in concrete sensory terms; the second variable was instruction in a cognitive‐coping strategy, instruction in a behavior‐coping strategy, or no instruction; and the third variable was experimental or control information about the posthospital experience. There was support for the coping processes that concrete sensory information was expected to stimulate, but no significant effects on resumption of usual life activities as was expected. The behavioral‐coping technique was associated with a reduction in pain medication. The cognitive‐coping technique was associated with reports of better physical recovery during hospitalization, but longer hospitalization. Posthospitalization recovery data, collected 2, 4, and 12 weeks after discharge, showed a different pattern of effects for the interventions than observed during hospitalization.
Self‐report and psychophysiological effects of lamaze preparation: An analogue of labor pain
Authors: Professor Elizabeth Geden , Beck Niels C. , Brouder Gerald , Glaister Judy , Pohlman Susan
Published: February 2011

Eighty nulliparous college female undergraduates were cast randomly into a series of eight treatment conditions representing all possible combinations of the three major components of the Lamaze method of childbirth preparation (relaxation training, informative lectures, and breathing exercises). Assessments of the efficacy of these pain coping strategies were subsequently made in the context of a 1‐hour session involving twenty 80‐second exposures to a laboratory pain stimulus, patterned so as to resemble labor contractions. Dependent variables included self‐reported pain, systolic and diastolic blood pressure, frontalis EMG, and heart rate. Results of the study indicated that relaxation training comprises the most therapeutically active component of the Lamaze treatment regimen, with significant effects (treatments X trials) on self‐reported pain, frontalis EMG, and heart rate. The implications of these findings are discussed from the perspective of designing new, and hopefully more efficacious, methods of preparing women for labor and delivery.
Trends in public attitudes toward legal abortion, 1972–1978
Authors: Moldanado Swarnalatha A.
Published: February 2011

Trends in public attitudes toward legal abortion were analyzed for 1972 and 1978. Data were drawn from seven independent probability samples (N = 10,652) of English‐speaking persons 18 years of age or older living in noninstitutional arrangements within the continental United States. Attitudes were derived from responses to six items asking whether it should be possible for a pregnant woman to obtain a legal abortion under six different conditions. Guttman Scalogram Analysis revealed two predominant patterns; approval for all six reasons and approval only for the hard reasons (safeguarding the woman's health, preventing birth of a deformed child, or treating rape). Two major shifts were noted in the level of approval; a considerable increase in 1973 for each reason and a sharp decline in 1978 for all but woman's health and rape. These shifts paralleled the introduction of laws pertaining to abortion.
Recalled life expectancy information, phase of illness and hope in cancer patients
Authors: Stoner Martha Holt , Keampfer Suzanne Hearne
Published: February 2011

In this study two research questions were addressed: What is the relationship between recalled life expectancy information and hope in cancer patients? What effect does phase of illness have on the level of hope in cancer patients? A scale to measure hope was developed, used, and evaluated. In 55 cancer patients, an analysis of variance showed a significant main effect on hope for recalled life expectancy; difference in level of hope was found in cancer patients at different phases of illness. The findings indicated that individuals having no recollection of receiving information regarding their prognosis were more hopeful. The results have implications for determining what, how much, when, and how to communicate life expectancy information to patients who have cancer or other life‐threatening illnesses.
Effect of exercise on morning stiffness and mobility in patients with rheumatoid arthritis
Authors: Byers Patricia H.
Published: February 2011

The effects of evening exercises on arthrographic measures of elastic stiffness, subjective ratings of stiffness, and graphic goniometric measures of mobility were examined in 30 patients with rheumatoid arthritis. Measures were obtained on 2 consecutive mornings, one of which was randomly determined to be preceded by evening exercise. Each morning, elastic stiffness and mobility were measured before and after morning exercise. After the final measurements of elastic stiffness and mobility on the second day, patients compared stiffness on the 2 days. Elastic stiffness and subjective ratings of stiffness were less and mobility was greater when evening exercises were performed (p < .001). The relationships between elastic stiffness and subjective ratings of stiffness indicated that the effect of evening exercise was perceived as greater when elastic stiffness was greater, and 21 patients reported less stiffness with evening exercise (p < .05).
Inverse optimal neural control of a class of nonlinear systems with constrained inputs for trajectory tracking
Authors: Ricalde Luis J. , Sanchez Edgar N.
Published: February 2011

This paper focusses on recurrent adaptive neural control applied to unknown nonlinear systems with input constraints. A recurrent high‐order neural network is used in order to identify the unknown system and a learning law is obtained using the Lyapunov methodology. Then a control law, which stabilizes the reference tracking error dynamics, is developed using the inverse optimal control approach. Tracking error stability is established as a function of design parameters. Chaotic systems are considered to demonstrate the applicability of the approach, via simulations, as for their stabilization and synchronization. The obtained simulation results illustrates the proposed approach capabilities for trajectory tracking of unknown nonlinear systems, whose inputs are constrained. Copyright © 2011 John Wiley & Sons, Ltd.
Grafting of hyperbranched poly(amidoamine) onto waste tire rubber powder and its potential application as the curing agent for epoxy resin
Authors: Fan Ping , Lu Canhui
Published: February 2011

To realize the high‐valued application of waste tire rubber (WTR), hyperbranched poly(amidoamine) (PAMAM) were synthesized from the surface of WTR powders to endow its chemical reactivity. The hyperbranched PAMAM‐grafted WTR powders containing a large amount of amine groups on their surface were obtained through “divergent procedure.” First, methyl methacrylate‐grafted WTR powders (MMA‐g‐WTR) were prepared by ozone‐induced grafting polymerization. Afterwards, Michael reaction and subsequent amidation reactions were carried out repetitively to obtain hyperbranched PAMAM chains grafted from the surface of the MMA‐g‐WTR powders. The resulting hyperbranched PAMAM‐grafted WTR powders exhibit good dispersibility in water. Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis demonstrate the successful grafting of hyperbranched PAMAM on WTR surface. The hyperbranched PAMAM‐grafted WTR powder could be utilize as curing agent and potential toughener for epoxy resin due to abundant amine groups and elastomeric feature of WTR. Differential scanning calorimetry shows that the hyperbranched PAMAM‐grafted WTR powders can be used as effective curing agent for epoxy resin. Copyright © 2011 John Wiley & Sons, Ltd.
Ordered long‐helical conformation of isotactic polypropylene obtained in constrained environment of nanoclay
Authors: Wang Zhicheng , Fan Xi , Wang Ke , Deng Hua , Chen Feng , Fu Qiang , Na Bing
Published: February 2011

Special crystallization event of isotactic polypropylene (iPP) in a constrained environment, a layered clay network, was followed by in situ Fourier transform infrared (FTIR) spectroscopy during the cooling process. Before occurrence of nucleation/crystallization, a conformationally ordered phase, which consists of significant amounts of long 31 helices with 14 monomeric units, has been identified for the first time. More importantly, it was found that the long‐ordering helices could play a more important role than short ones for the confined crystallization. It could be tentatively explained as due to the existence of constrained regions in the proximity of the nanoclay platelets or tactoids and the heterogeneous nucleation capability of the surface of nanoclay. Copyright © 2011 John Wiley & Sons, Ltd.
Hollow microspheres with covalent‐bonded colloidal and polymeric shell by Pickering emulsion polymerization
Authors: Yin Dezhong , Zhang Qiuyu , Yin Changjie , Zhao Xingbo , Zhang Hepeng
Published: February 2011

Hollow microspheres with SiO2/polymer binary shell were fabricated from Pickering emulsion stabilized solely by methacryloxypropyltrimethoxysilane‐modified SiO2 particles, and were characterized by optical microscopy, scanning electron microscopy, Fourier transformation infrared spectrum, thermogravimetric analysis (TGA), and energy dispersive X‐ray spectroscopy. The microspheres were templated by the Pickering droplets and the inner structure was affect by the proportion of crosslinking reagent. TGA result indicated that 60.3% of polymer in the shell was connected with SiO2 by covalent bond which was formed by copolymerization of styrene and the reactive CC group on SiO2 stabilizer. Copyright © 2011 John Wiley & Sons, Ltd.
Functional copolymer/organo‐MMT nanoarchitectures. VII. Interlamellar controlled/living radical copolymerization of maleic anhydride with butyl methacrylate via preintercalated RAFT agent–organoclay complexes
Authors: Rzayev Zakir M.O. , Söylemez Ernur A. , Davarcioğlu Burhan
Published: February 2011

We have developed a new approach for the synthesis of polymer nanocomposites using a bifunctional reversible addition–fragmentation chain transfer (RAFT) agent, two types of organo‐montmorillonites (O‐MMT), such as a non‐reactive dimethyldidodecyl ammonium (DMDA)‐MMT and a reactive octadecyl amine (ODA)‐MMT organoclays, maleic anhydride (MA), and n‐butyl methacrylate (BMA) monomers and a radical initiator. This method includes the following stages: (1) synthesis of RAFT intercalated O‐MMTs by a physical or chemical interaction of the RAFT agent having two pendant carboxylic groups [S,S′‐bis(α,α′‐dimethyl‐α″‐acetic acid) trithiocarbonate] with surface alkyl amines of O‐MMT containing tertiary ammonium cation or primary amine groups through strong H‐bonding and compexing/amidization reactions, respectively, and (2) utilization of these well dispersed and intercalated RAFT…O‐MMT complexes and amide derivative of RAFT…ODA‐MMT as new modified RAFT agents in radical‐initiated interlamellar controlled/living complex‐radical copolymerization of MA‐BMA monomer pair. Nanostructure and compositions of the synthesized RAFT…O‐MMT complexes and functional copolymer/O‐MMT hybrids were confirmed by FTIR, GPC, XRD, thermal (DSC‐TGA), SEM, and TEM morphology analyses. This simple and versatile method can be applied to a wide range of monomer/comonomer systems for the preparation of completely exfoliated macromolecular nanoarchitectures. Copyright © 2011 John Wiley & Sons, Ltd.
Melt‐compounded nanocomposites of titanium dioxide atomic‐layer‐deposition‐coated polyamide and polystyrene powders
Authors: Nevalainen Katja , Isomäki Nora , Honkanen Mari , Suihkonen Reija , McNally Tony , Harkin‐Jones Eileen , Syrjälä Seppo , Vuorinen Jyrki , Järvelä Pentti
Published: February 2011

Polyamide and polystyrene particles were coated with titanium dioxide films by atomic layer deposition (ALD) and then melt‐compounded to form polymer nanocomposites. The rheological properties of the ALD‐created nanocomposite materials were characterized with a melt flow indexer, a melt flow spiral mould, and a rotational rheometer. The results suggest that the melt flow properties of polyamide nanocomposites were markedly better than those of pure polyamide and polystyrene nanocomposites. Such behavior was shown to originate in an uncontrollable decrease in the polyamide molecular weight, likely affected by a high thin‐film impurity content, as shown in gel permeation chromatography (GPC) and scanning electron microscope (SEM) equipped with an energy‐dispersive spectrometer. Transmission electron microscope image showed that a thin film grew on both studied polymer particles, and that subsequent melt‐compounding was successful, producing well dispersed ribbon‐like titanium dioxide with the titanium dioxide filler content ranging from 0.06 to 1.12 wt%. Even though we used nanofillers with a high aspect ratio, they had only a minor effect on the tensile and flexural properties of the polystyrene nanocomposites. The mechanical behavior of polyamide nanocomposites was more complex because of the molecular weight degradation. Our approach here to form polymeric nanocomposites is one way to tailor ceramic nanofillers and form homogenous polymer nanocomposites with minimal work‐related risks in handling powder form nanofillers. However, further research is needed to gauge the commercial potential of ALD‐created nanocomposite materials. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and properties of two novel silicon‐containing cycloaliphatic epoxy resins for electronic packaging application
Authors: Liu Wanshuang , Wang Zhonggang , Chen Zhuo , Li Jianfeng , Zhao Linni
Published: February 2011

In this paper, two silicon‐containing cycloaliphatic olefins were synthesized through the nucleophilic substitution reactions of cyclohex‐3‐enyl‐1‐methanol with di‐ or tri‐chlorosilane compounds. Then, after epoxidation, two new cycloaliphatic epoxy resins with different epoxy groups were successfully prepared. Their chemical structures were confirmed by 29Si NMR, 1H NMR, and Fourier‐transform infrared spectra (FTIR). The properties of cured products, including viscoelasticity, glass transition temperature (Tg), coefficient of thermal expansion, thermal stability and water absorption, were investigated. Compared to the difunctional epoxy resin, the trifunctional one exhibited a remarkably increased cross‐linking density from 0.82 to 4.08 × 10−3 mol/cm3 and Tg from 157 to 228°C. More importantly, prior to curing, they had viscosities of only 240–290 mPa sec at 25°C, which were much lower than that of ERL‐4221 (409 mPa sec), providing the possibility of easy processing. The high glass transition temperatures, good thermal stabilities, and mechanical properties as well as excellent flowability endow the silicon‐containing epoxy resins with promising potential in microelectronic packaging application. Copyright © 2011 John Wiley & Sons, Ltd.
193‐nm photodissociation of singly and multiply charged peptide anions for acidic proteome characterization
Authors: Madsen James A. , Kaoud Tamer S. , Dalby Kevin N. , Brodbelt Jennifer S.
Published: February 2011

193‐nm ultraviolet photodissociation (UVPD) was implemented to sequence singly and multiply charged peptide anions. Upon dissociation by this method, a‐/x‐type, followed by d and w side‐chain loss ions, were the most prolific and abundant sequence ions, often yielding 100% sequence coverage. The dissociation behavior of singly and multiply charged anions was significantly different with higher charged precursors yielding more sequence ions; however, all charge states investigated (1− through 3−) produced rich diagnostic information. UVPD at 193 nm was also shown to successfully differentiate and pinpoint labile phosphorylation modifications. The sequence ions were produced with high abundances, requiring limited averaging for satisfactory spectral quality. The intact, charge‐reduced radical products generated by UV photoexcitation were also subjected to collision‐induced dissociation (termed, activated‐electron photodetachment dissociation (a‐EPD)), but UVPD alone yielded more predictable and higher abundance sequence ions. With the use of a basic (pH∼11.5), piperidine‐modified mobile phase, LC‐MS/UVPD was implemented and resulted in the successful analysis of mitogen‐activated pathway kinases (MAPKs) using ultrafast activation times (5 ns).
Optical properties and size/shape dependence of α‐Sn nanocrystals by tight binding
Authors: Jensen Rasmus Vincentz S. , Garm Pedersen Thomas , Pedersen Kjeld
Published: February 2011

The semiconducting diamond structure of c‐Sn may be stabilized by embedding nanocrystals in a suitable host. Based on a very accurate tight binding parametrization we calculate electronic and optical properties of round, as well as faceted nanocrystals, under both no, tensile and compressive strain. Nanocrystals with radii up to 2.6 nm are treated and are found to cover an energy range starting at near‐zero band gap energy, with both size and also strain playing a significant role in determining the electronic properties. The HOMO‐LUMO optical transition is found to be strong even for larger crystals, making them an attractive candidate in many potential NIR applications. Furthermore, exciton effects are estimated for bulk and nanocrystals and are found to be weak (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optically active substoichiometric Si3N4 μ‐cavities
Authors: Ferrarese Lupi Federico , Navarro‐Urrios Daniel , Monserrat Josep , Dominguez Carlos , Pellegrino Paolo , Garrido Blas
Published: February 2011

We report on the morphological and emission properties of microdisk resonators with an optically active disk material made of luminescent substoichiometric Si3N4 matrix. We demonstrate the importance of optimising the material by finding a compromise between the photoluminesce properties and optical losses. A careful design of the cavities for optimising the radiative quality factors has been also performed, enabling us to produce active disks with low intrinsic losses. Subnanometer whispering gallery mode (WGM) resonances have been experimentally detected, showing quality factors as high as 1200 around the wavelength of 719 nm. These values are among the highest previously reported values in Si‐nanocluster‐based systems and are actually limited by the spectral resolution of our experimental setup. In addition, an increasing of the pumping flux is not generating a spectral widening of the resonances, thus not affecting the quality of the cavities. This is in contrast to what observed in other reports of Si‐nc based microcavities, where significant enlargements are observed associated to carrier absorption losses. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of silicon rich oxides
Authors: Summonte C. , Centurioni E. , Canino M. , Allegrezza M. , Desalvo A. , Terrasi A. , Mirabella S. , Di Marco S. , Di Stefano M.A. , Miritello M. , Lo Savio R. , Simone F. , Agosta R.
Published: February 2011

Thermally treated silicon rich oxides (SRO) used as starting material for the fabrication of silicon nanodots represent the basis of tunable bandgap nanostructured materials for optoelectronic and photonic applications. The optical modelization of such materials is of great interest, as it allows the simulation of reflectance and transmittance (R&T) spectra, which is a powerful non destructive tool in the determination of phase modifications (clustering, precipitation of new phases, crystallization) upon thermal treatments. In this paper, we study the optical properties of a variety of as‐deposited and furnace annealed SRO materials. The different phases are treated by means of the effective medium approximation. Upon annealing at low temperature, R&T spectra show the precipitation of amorphous silicon nanoparticles, while the crystallization occurring at temperatures higher than 1000 °C is also clearly identified, in agreement with structural results. The existing literature on the optical properties of the silicon nanocrystals is reviewed, with attention on the specificity of the compositional and structural characteristics of the involved material. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton Mott transition in Si studied by terahertz spectroscopy
Authors: Shimano Ryo , Suzuki Takeshi
Published: February 2011

We have investigated the exciton Mott transition in a bulk Si by optical pump and terahertz probe spectroscopy under quasi‐thermal equilibrium condition. The 1s‐2p transition energy of excitons in Si that locates around 12 meV (∼3 THz) is directly probed by the broadband terahertz pulses. The resonance energy of the 1s‐2p transition stays unchanged with increasing the photo‐excited electron‐hole (e‐h) pair density. The resonance structure sustains even above the Mott density, although broadened, in contrast to the conventional picture of the exciton Mott transition where the exciton binding energy vanishes toward the Mott density. The results indicate the existence of excitonic correlation in the metallic electron‐hole plasma phase (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intrasubband transitions in cubic AlN/GaN superlattices for detectors from near to far infrared
Authors: Mietze Christian , DeCuir E. A. , Manasreh M. O. , Lischka K. , As D. J.
Published: February 2011

We report the growth of cubic GaN/AlN superlattices by plasma‐assisted molecular beam epitaxy on 3C‐SiC substrates. The samples consist of 100 nm thick unintentionally doped GaN buffer and 20‐40 period superlattices of silicon doped GaN quantum wells embedded in undoped AlN barriers. The thickness of the AlN barriers is varied between 1.5 nm‐3.2 nm, while the thickness of the GaN well varies between 1.5 nm‐12.5 nm. The growth was controlled by in situ reflection high energy electron diffraction. The structural properties of our samples were studied by high resolution x‐ray diffraction. Two superlattice satellite peaks in the x‐ray spectra reveal a high structural perfection of the active region. Clear evidence for inter‐ and intrasubband transitions was observed in photoluminescence, absorbance and photoconductivity spectra measured at room temperature. Model calculations show the possibility to fabricate devices for the near‐ and far infrared region. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of intersubband scattering on shift currents in GaAs quantum wells
Authors: Priyadarshi Shekhar , Pierz Klaus , Siegner Uwe , Dawson Philip , Bieler Mark
Published: February 2011

We have optically induced ultrafast shift currents in GaAs quantum wells and studied their dependence on excitation photon energy. We observed a current reversal between excitation of the n=1 and the n=2 light‐hole exciton transitions. A simple theoretical model allows for the explanation of the current reversal and suggests that it is due to intersubband scattering of the holes (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of wide‐bandgap monolithic pillar microcavities with different geometries
Authors: Seyfried M. , Kalden J. , Sebald K. , Kruse C. , Figge S. , Gust A. , Tessarek C. , Dartsch H. , Hommel D. , Florian M. , Jahnke F. , Gutowski J.
Published: February 2011

A customization of the optical properties of pillar microcavities on the desired applications is essential for their future use as quantum‐optical devices. Therefore, all‐epitaxial cavities with CdSe or InGaN quantum dots embedded in pillar structures with different geometries have been realized by focused‐ion‐beam etching. The high temperature stability of the emission and the large oscillator strength of quantum dots made of these material systems are combined with small mode volume pillar microcavities to utilize the light‐matter interaction. The quality factors of circularly shaped pillar microcavities have been measured and compared to theoretical calculations. As a possibility to achieve polarized light emission, asymmetrically shaped microcavities are presented. Examples of an elliptically shaped pillar as well as of photonic molecules are investigated with respect to their photoluminescence characteristics and polarization. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
2d Fourier spectroscopy of disordered quantum wells
Authors: Erementchouk Mikhail , Leuenberger Michael N. , Li Xiaoqin
Published: February 2011

We consider the problem of coherent coupling between spatially separated exciton states in disordered quantum wells (QW) from the perspective of two‐dimensional (2d) Fourier spectroscopy, which is sensitive to interaction between excitations. We present the basic theory of spectroscopy of QW that demonstrate split exciton resonances in linear spectra, which is characteristic for long interfacial inhomogeneities.

We find that the coherent coupling is governed by the relation between the disorder correlation length rc and the characteristic length of Coulomb correlations RI. If rc ≫ RI the coherent coupling is absent and 2d spectra are simply elongated along the diagonal (inhomogeneously broadened). In the opposite limit coupling exists and manifests itself in the form of respective off‐diagonal peaks in 2d spectra (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of the Au(I)–Au(I) closed‐shell attraction on the electronic and phosphorescent properties in a series of coordination compounds: A theoretical study
Authors: Muñiz Jesús , Sansores Enrique , Reyes‐nava J. A. , Ramos‐sanchez V.‐H. , Olea Alfredo
Published: February 2011

The Au(I)–Au(I) closed‐shell or aurophilic attraction has been the subject of interest in the experimental and theoretical chemistry fields, due to the intriguing properties associated to it. The presence of phosphorescence in “aurophilic” compounds has been addressed to a wide range of applications, but it has not yet been fully understood. A theoretical study on the electronic and phosphorescent properties of the following series of dinuclear gold complexes has been performed: [Au2(dmpm) (i‐mnt)] (1), [Au2(μ‐Me‐TU) (μ‐dppm)] (2), and [Au2(μ‐G)(μ‐dmpe)] (3). Full geometry optimizations at the second‐order Møller–Plesset perturbation theory (MP2) were carried out for each of the species. These calculations made evident that, at the ground‐state geometry, the Au(I) cations allocated at the center of the ring show a short Au–Au distance below the sum of the van der Waals radii, at the range of the aurophilic attraction. An intermolecular Au(I)–Au(I) closed‐shell attraction for a pair of the systems under study is found. This attraction is comparable to that of the hydrogen bonds. The phosphorescent properties experimentally observed for this series were also characterized through ab initio techniques. The obtained results allow to fit reasonably the excitation energies with the experimental data and to identify a correlation between the strength of the Au(I)–Au(I) interaction and the phosphorescent behavior. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
A DFT/TDDFT study of porphyrazines and phthalocyanine oxo‐titanium derivatives as potential dyes in solar cells
Authors: Zarate Ximena , Schott Eduardo , Arratia‐Pérez Ramiro
Published: February 2011

Density functional theory and time dependent density functional theory calculations at the level of LDA/BP86/TZ2P were performed systematically on several Ti(IV) complexes of porphyrazines and one phthalocyanine. We performed an analysis of the frontier molecular orbitals of the ground state electronic structures and also discuss in particular the good concordance of our results with the experimental data, which affords to predict the geometrical and optical properties of new complexes (3, 4, and 7). We also emphasize the characterization of the UV–vis absorption spectra and propose transitions that contribute to the Q and B bands. Some useful calculated properties in complexes 2, 3, and 7, like: high light absorption in the visible region of the spectra, transitions involved in these bands with a determined direction, charge separation, bigger highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) gaps than complexes 4 and 5, and the energy of their LUMO orbitals (that are higher than the lowest energy level of the conduction band of the TiO2) indicate that system complexes 2, 3, and 7 could act as light‐harvesting sensitizers for dye‐sensitized solar cells (DSCs). These proposals were made using a model of the previously experimentally known phthalocyanine, which was used as sensitizer in DSCs devices, comparing its electronic properties with the herein proposed sensitizers. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Potential energy curves and interpretation of electronic spectrum of the yttrium nitride
Authors: Dou Xiaotong , Han Huixian , Zhai Gaohong , Suo Bingbing
Published: February 2011

Potential energy curves of 14 electronic states of yttrium nitride (YN) are calculated by using multistate complete active space second order perturbation theory. The ground state is predicted as X1Σ+ and has the equilibrium bond length of 1.809 Å and vibrational frequency of 658 cm−1. Two low‐lying excited states, a3Σ+ and A1Σ+, locate at 2,360 and 3,670 cm−1 higher than the ground state, which are in agreement with experimental excitation energies of 2,423 and 3,700 cm−1, respectively. The high‐order singlet, the D1Π state, lies at 19,232 cm−1 above the ground state with the equilibrium bond length of 2.057 Å and vibrational frequency of 562 cm−1. The D1Π → X1Σ transition is dipole allowed and may contribute to spectra of YN in visible region. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3378–3384, 2011
Effective reproduction numbers are commonly overestimated early in a disease outbreak
Authors: Mercer G. N. , Glass K. , Becker N. G.
Published: February 2011

Reproduction numbers estimated from disease incidence data can give public health authorities valuable information about the progression and likely size of a disease outbreak. Here, we show that methods for estimating effective reproduction numbers commonly give overestimates early in an outbreak. This is due to many factors including the nature of outbreaks that are used for estimation, incorrectly accounting for imported cases and outbreaks arising in subpopulations with higher transmission rates. Awareness of this bias is necessary to correctly interpret estimates from early disease outbreak data. Copyright © 2011 John Wiley & Sons, Ltd.
Gamma irradiation of treated waste rubber powder and its composites with waste polyethylene
Authors: El‐Nemr Khaled F. , Khalil Ahmed M.
Published: February 2011

This investigation was undertaken to prepare composites of waste polyethylene (WPE) with concentrations of 5, 15, and 25 wt% of waste rubber powder (WRP) and to determine the changes in properties of these composites before and after treatment of the WRP with acrylic acid. Mechanical, physical, thermal, FTIR, and SEM investigations showed that treated and gamma‐irradiated WRPs gave better properties than untreated ones. Hence, a simple method to prepare composites based on recycled polyethylene and waste rubber powder could be achieved without using expensive treatment of the polymeric wastes. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
One step forward to a sustainable green solution for extruded foam PVC building products
Authors: Chang Hong , Abu‐Zahra Nidal
Published: February 2011

This paper is dedicated to the development of a robust and cost‐effective formulation to maximize the use of recycled poly(vinyl chloride) (PVC) back into its virgin compounds. This study concludes that a balanced stabilizer and lubricant formulation will overcome the detrimental effects of repeated heat history on the recycled/regrind PVC. The developed formulation using up to 70% of recycled/regrind PVC has been successfully implemented in the extrusion process for manufacturing high‐quality foam PVC profiles for the building industry. As a result, this study takes a huge step forward toward a green and sustainable solution for PVC applications. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Devulcanization of waste tires using a twin‐screw extruder: The effects of processing conditions
Authors: Yazdani Hamid , Karrabi Mohammad , Ghasmi Ismaeil , Azizi Hamed , Bakhshandeh Gholam Reza
Published: February 2011

During recent decades, for both economic and environmental reasons, recycling of waste tires that are based on SBR/NR has been widely considered. In this study the devulcanization process of the tread section of waste tires was carried out by using a twin‐screw extruder. The effects of barrel temperature and screw speed were investigated. Percent of devulcanization, sol fraction, and curing behavior of devulcanized samples were studied. After the addition of curing agents into the devulcanizates, the general behavior of the rheometry test for rubber compounds was observed. Percent of devulcanization and sol fraction depended on the screw speed and barrel temperature, respectively. The devulcanized samples were formulated with virgin rubber (15/85 wt% ratio) and re‐cured successfully. Tensile strength, elongation at break, compression set, hardness, and resilience were evaluated. It was found that the mechanical properties of the compound containing devulcanizates were slightly inferior to those of the virgin compound. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Analysis of a strongly coupled system of two convection‐diffusion equations with full layer interaction
Authors: Roos H.‐G. , Reibiger C.
Published: February 2011

Strong coupling of convection‐diffusion equations causes interactions between boundary layers that are not fully understood so far. Under certain assumptions, a new approach presented explains what happens.
Use of and satisfaction with support received among survivors from three Scandinavian countries after the 2004 Southeast Asian tsunami
Authors: Michel P.O. , Rosendal S. , Weisaeth L. , Heir T.
Published: February 2011

Introduction

There is limited guidance regarding effective preventions for post-disaster mental health problems and what kind of support is preferred by disaster survivors.

Aim

To describe the use of and satisfaction with support in three Scandinavian countries after the tsunami and analyzing the association between support and posttraumatic stress reactions.

Method

The sample comprises 6772 responders who returned to Scandinavia from the tsunami-struck countries of Southeast Asia in 2004.

Results

Most were satisfied with informal support on site. Support from embassies/consulates was not received well, leaving about 64% of the Danes/Norwegians and 73% of the Swedes dissatisfied. After returning home, support from close relatives rendered highest degree of satisfaction. Consultation with general practitioner (GP) was reported by 63% of Norwegians, 40% of Danes, and 16% of Swedes. Most responders (60–77%) were satisfied with their GP, although Norwegians were least satisfied. Using support was associated with higher levels of posttraumatic stress symptoms.

Conclusions

Informal support was used to a high degree and rendered considerable satisfaction in all three countries, while the use of and satisfaction with formal support varied more. Lack of satisfaction with embassies and consulates may indicate deficiencies in the authorities’ preparedness in assisting disaster stricken citizens abroad.
Tree-ring reconstructions of May–June precipitation for western Anatolia
Authors: Köse Nesibe , Akkemik Ünal , Dalfes H. Nüzhet , Özeren M. Sinan
Published: February 2011

In this study, we aim to examine past dry and wet events for the western Anatolia, performing local and spatial reconstructions. 17 new black pine site chronologies were developed, May–June precipitation time series were reconstructed for four localities, and the first spatial May–June precipitation reconstruction was achieved for western Anatolia. The long-term local May–June precipitation reconstructions contain mostly one-year and less commonly, two-year drought events. The longest consecutive dry period (AD 1925–1928) in the reconstructed time series for Kütahya lasted four years. Spatial reconstructions revealed that between AD 1786 and 1930 the extreme dry years for all of western Anatolia were AD 1887, 1893, 1794 and 1740. The driest year during the 215-year-long period under consideration was 1887. The wettest years for the entire western Anatolia were determined to be AD 1835, 1876, 1881 and 1901. There is a big overlap between agricultural famine years and dry years as determined from reconstructions. In this context, our study provides a basis for understanding agricultural drought and better management of regional water resources.
Rayleigh–Taylor instability of an inclined buoyant viscous cylinder
Authors: LISTER JOHN R. , KERR ROSS C. , RUSSELL NICK J. , CROSBY ANDREW
Published: February 2011

The Rayleigh–Taylor instability of an inclined buoyant cylinder of one very viscous fluid rising through another is examined through linear stability analysis, numerical simulation and experiment. The stability analysis represents linear eigenmodes of a given axial wavenumber as a Fourier series in the azimuthal direction, allowing the use of separable solutions to the Stokes equations in cylindrical polar coordinates. The most unstable wavenumber k∗ is long-wave if both the inclination angle α and the viscosity ratio λ (internal/external) are small; for this case, k∗ ∝ max{α, (λ ln λ−1)1/2} and thus a small angle in experiments can have a significant effect for λ ≪ 1. As α increases, the maximum growth rate decreases and the upward propagation rate of disturbances increases; all disturbances propagate without growth if the cylinder is sufficiently close to vertical, estimated as α ≳ 70°. Results from the linear stability analysis agree with numerical calculations for λ = 1 and experimental observations. A point-force numerical method is used to calculate the development of instability into a chain of individual plumes via a complex three-dimensional flow. Towed-source experiments show that nonlinear interactions between neighbouring plumes are important for α ≳ 20° and that disturbances can propagate out of the system without significant growth for α ≳ 40°.
Hollow wakes past arbitrarily shaped obstacles
Authors: TELIB H. , ZANNETTI L.
Published: February 2011

An analytical solution is presented for steady inviscid separated flows modelled by hollow vortices, that is, by closed vortex sheets bounding a region with fluid at rest. Steady flows past arbitrary obstacles protruding from an infinite wall are considered. The solution is similar to that of the vortex patch model; it depends on two free parameters that define the size of the hollow vortex and the location of the separation point. When a sharp edge constrains the separation point (Kutta condition), the solution depends on a single parameter. As with the vortex patch model, families of growing vortices exist, which represent the continuation of desingularized point vortices. Numerical results are presented for the flows past a semicircular bump, a Ringleb snow cornice and a normal flat plate. The differences from the previous results found in the literature are analysed and discussed with the present solutions for the flow past a normal flat plate.