bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigação dos efeitos da hidroginástica sobre a qualidade de vida, a força de membros inferiores e a flexibilidade de idosas: um estudo no Serviço Social do Comércio - Fortaleza
Authors: Aguiar Jaina Bezerra de , Gurgel Luilma Albuquerque
Published: November 2011

Este trabalho, realizado no Serviço Social do Comércio, Fortaleza, CE, Brasil, teve como propósito verificar a influência da hidroginástica sobre a qualidade de vida, a força de membros inferiores e a flexibilidade de idosas. Foram avaliadas 26 mulheres com idade de 60 a 80 anos, que foram divididas em dois grupos: sedentário (n=13) e praticante de hidroginástica há pelo menos seis meses (n=13). Foram utilizados para coleta de dados o Instrumento Abreviado de Avaliação da Qualidade de Vida proposto pela Organização Mundial de Saúde, o teste de impulsão vertical para a avaliação indireta da força muscular de membros inferiores e o teste de sentar e alcançar para avaliação da flexibilidade. O grupo praticante de hidroginástica apresentou média de escores do domínio físico da qualidade de vida (4,5 ± 0,4 u.a.) significativamente (p < 0,05) maior que o grupo sedentário (3,8 ± 0,7 u.a.), bem como para impulsão vertical (13,8 ± 3,7 cm e 10,5 ± 2,7 cm, respectivamente; p < 0,05) e flexibilidade (41,3 ± 9,2 cm e 32,7 ± 4,6 cm, respectivamente; p < 0,05). Conclui-se que a prática regular de hidroginástica por mulheres na terceira idade contribui positivamente com a qualidade de vida, por influenciar o domínio físico desta, além de melhorar a força e a flexibilidade nesta etapa da vida.
Sistematização do conhecimento declarativo em educação física escolar de 5ª à 8ª séries do ensino fundamental
Authors: Antunes Fabia Helena Chiorboli , Dantas Luiz
Published: November 2011

O presente estudo objetivou selecionar, sistematizar e validar o conhecimento declarativo sobre o movimento a ser ensinado no componente curricular Educação Física, de 5ª a 8ª séries do Ensino Fundamental. O conhecimento declarativo sobre o movimento humano foi selecionado com base em livros didáticos de Educação Física e, sua pertinência para a educação física escolar, sendo avaliada por 11 docentes de ensino superior envolvidos com Licenciatura em suas instituições. A sistematização do conhecimento foi realizada com base nos temas selecionados pelos docentes e iniciada com a definição dos comportamentos de saída esperados ao final do quarto ciclo do Ensino Fundamental. Nesse processo, foi considerado o nível de letramento dos alunos (de acordo com indicadores do Ministério da Educação) e os objetivos dos outros componentes curriculares. A validação da proposta foi realizada por 167 professores de Educação Física e 75 assistentes técnico pedagógicos (ATP) da rede Estadual de Ensino. A escala utilizada para avaliação de cada comportamento por série foi a do tipo Likert, que tem como objetivo avaliar o grau de concordância ou discordância de determinadas afirmações. A maioria dos comportamentos esperados por séries recebeu uma aceitação maior que 80% por parte dos professores. Valores menores que esse percentual não apresentaram concordância para uma determinada série. Houve quatro comportamentos (referentes a dimensões biodinâmica e comportamental) que apresentaram unanimidade na aceitação para a 8ª série
Erros de medicação: análise do conhecimento da equipe de enfermagem de uma instituição hospitalar
Authors: Telles Filho Paulo Celso Prado , Praxedes Marcus Fernando da Silva , Pinheiro Marcos Luciano Pimenta
Published: November 2011

Objetivou-se verificar e analisar junto à equipe de enfermagem o conhecimento sobre em que consiste um erro de medicação, sua necessidade de notificação e o conteúdo da mesma. Trata-se de pesquisa de caráter quantitativo descritivo, desenvolvida em uma instituição hospitalar, da qual fizeram parte 72 profissionais. Em relação à definição de erros de medicação, constatou-se que 49 (68%) possuem conceito semelhante ao adotado nesse estudo. Quanto à necessidade de notificação, 67 (93%) afirmaram sua necessidade. Referente ao conteúdo da notificação, 63 (85%) possuem conceito semelhante ao adotado no estudo. Evidencia-se a necessidade de aprofundamento em relação aos aspectos referentes aos erros de medicação.
Ateliê de projetos físicos: estratégia para aprendizagem de administração de recursos físicos em enfermagem
Authors: Draganov Patricia Bover , Sanna Maria Cristina
Published: November 2011

O sucesso da aprendizagem envolve estratégias adequadas. Aquelas inspiradas na Andragogia, que é a arte e a ciência de ensinar adultos, parecem ser ideais para o ensino do tema projetos, conteúdo de administração de recursos físicos ministrado na graduação em enfermagem. O objetivo é relatar estratégia de ensino que estimula a aquisição de competências que tornem o enfermeiro capaz de dialogar, com a equipe multiprofissional, sobre projetos. A estratégia envolveu oficina composta por quatro etapas: leitura de projetos, atribuições do estabelecimento assistencial de saúde (EAS), noções de dimensionamento físico e elaboração de glossário de termos. A estratégia, proposta por aluna de disciplina de prática educacional de programa de pós-graduação senso estrito, foi testada, avaliada e aprovada em oficina por alunos e professores. As condições para aplicação dessa estratégia envolvem trabalho com poucos alunos, salas próprias, equipamentos disponíveis e parcerias com EAS.
Aparelho expansor GCS: aparelho expansor fixo removível
Authors: Goulart Carlos Sechi , Thiesen Guilherme , Nuernberg Nivaldo José Nicodemos
Published: November 2011

Este artigo apresenta um novo sistema de fixação para aparelhos removíveis que dispensa a confecção de grampos, sendo especialmente indicado para pacientes que apresentem dentes com pouca ou nenhuma retenção. Esse sistema de fixação, chamado GCS, utiliza attachments, fabricados a partir de botões ortodônticos, que são colados aos dentes, proporcionando excelente retenção mecânica e permitindo que os aparelhos removíveis, nesse caso um expansor, possam ser ativados como se fossem aparelhos fixos cimentados ou colados aos dentes, com a vantagem adicional de poderem ser removidos para higienização e para eventuais consertos. Também é apresentado um aparelho de contenção GCS que se encaixa aos attachments, trava o aparelho em posição e dispensa o uso de grampos, e que pode ser utilizado em praticamente todos os dispositivos ortodônticos ativos ou de contenção, aliando alta eficiência retentiva com simplicidade de construção.
Prestige and the University Press
Authors: Gump Steven
Published: November 2011

The rhetoric of prestige vis-à-vis university presses has taken many forms in the pages of this journal over the last thirty-six years. Two main types of prestige by association are identified in this article: institutional prestige (to host universities) and individual prestige (to authors and administrators at the host institutions). Although ‘manipulating’ prestige may be difficult, holding dear the original mission of university presses may help to strengthen the status and image of university presses, even in times of financial hardship.
Sleep problems and risk of fibromyalgia: Longitudinal data on an adult female population in Norway
Authors: Mork Paul J. , Nilsen Tom I. L.
Published: November 2011

Objective

Sleep problems are common among patients with fibromyalgia (FM). However, it is not known whether poor sleep is a contributing factor in FM or a consequence of the illness. The aim of the current study was to prospectively investigate the association between self‐reported sleep problems and risk of FM among adult women.

Methods

We longitudinally studied 12,350 women who did not have FM, musculoskeletal pain, or physical impairments at baseline (1984–1986). A generalized linear model was used to calculate the adjusted relative risk (RR) of FM at followup in 1995–1997.

Results

Incident FM was reported by 327 women at followup. A dose‐dependent association was found between sleep problems and risk of FM (P for trend < 0.001), with an adjusted RR of 3.43 (95% confidence interval [95% CI] 2.26–5.19) among women who reported having sleep problems often or always, compared to women who never experienced sleep problems. Age‐stratified analysis showed that women age ≥45 years who reported having sleep problems often or always had an adjusted RR of 5.41 (95% CI 2.65–11.05), whereas the corresponding RR for women ages 20–44 years who reported having sleep problems often or always was 2.98 (95% CI 1.76–5.05).

Conclusion

These prospective data indicate a strong dose‐dependent association between sleep problems and risk of FM. The association is somewhat, although not significantly, stronger in middle‐aged and older women than in younger women.
Comparing the effects of insulin glargine and thiazolidinediones on plasma lipids in type 2 diabetes: a patient‐level pooled analysis
Authors: Chaudhuri Ajay , Rosenstock Julio , DiGenio Andres , Meneghini Luigi , Hollander Priscilla , McGill Janet B. , Dandona Paresh , Ilgenfritz John , Riddle Matthew
Published: November 2011

Background

The prevalence of dyslipidaemia and the risk of cardiovascular disease are elevated in patients with type 2 diabetes. This analysis compared the effects of insulin glargine versus thiazolidinediones (TZDs) on lipid profiles.

Methods

Patient‐level data were pooled from two randomized clinical studies. The population included 552 men and women aged >18 years, diagnosed with type 2 diabetes for at least 6 months, on metformin and/or sulphonylurea, and with A1C ≥7.5% and <12.0% at screening. Lipid outcome measures included change from baseline in lipid levels [low‐density lipoprotein cholesterol (LDL‐C), high‐density lipoprotein cholesterol (HDL‐C), non‐high‐density lipoprotein cholesterol (non‐HDL‐C), total cholesterol, triglycerides, and free fatty acids] and attainment of lipid goals for LDL‐C, non‐HDL‐C, and triglycerides.

Results

Both insulin glargine and TZDs improved lipid profiles from baseline values. Compared with TZDs, treatment with insulin glargine led to 7.9% greater reduction in LDL‐C (p < 0.0003), 7.5% greater reduction in non‐HDL‐C (p < 0.0001), and 7.8% greater reduction in total cholesterol (p < 0.0001), whereas the HDL‐C increase with TZD was 7.6% greater than that with insulin glargine (p < 0.0001). The percentage of patients attaining the lipid goals was comparable between insulin glargine and pioglitazone, but lower for rosiglitazone. Insulin glargine improved glycaemic control more than TZDs; however, insulin glargine caused more hypoglycaemia. Treatment with TZDs caused more weight gain and peripheral oedema.

Conclusion

These findings suggest that the favourable effects of insulin glargine on plasma lipid profiles should be considered among the advantages of treatment with insulin glargine as they are for TZDs. Copyright © 2011 John Wiley & Sons, Ltd.
FLI1 is a novel ETS transcription factor involved in gene fusions in prostate cancer
Authors: Paulo Paula , Barros‐Silva João D. , Ribeiro Franclim R. , Ramalho‐Carvalho João , Jerónimo Carmen , Henrique Rui , Lind Guro E. , Skotheim Rolf I. , Lothe Ragnhild A. , Teixeira Manuel R.
Published: November 2011

To characterize the pattern of ETS rearrangements and to uncover novel ETS fusion genes, we analyzed 200 prostate carcinomas (PCa) with TaqMan low‐density arrays (TLDAs), followed by selective analyses with fluorescence in situ hybridization (FISH), RT‐PCR, and sequencing. Besides confirming the recurrent presence of ERG, ETV1, ETV4, and ETV5 rearrangements, we here report FLI1 as the fifth ETS transcription factor involved in fusion genes in prostate cancer. Outlier expression of the FLI1 gene was detected by TLDAs in one PCa that showed relative overexpression of FLI1 exons 4:5 as compared with FLI1 exons 2:3. A structural rearrangement was found using FISH probes flanking the FLI1 gene and RT‐PCR and sequencing analyses showed fusion of SLC45A3 exon 1 with FLI1 exon 3. Interestingly, we found four cases with two different ETS rearrangements in the index tumor, thus revealing intratumor genetic heterogeneity. Correlation analysis with clinico‐pathological data showed association of ERG rearrangements with locally advanced disease (pT3, P = 0.007) and MYC overexpression (P = 0.001), and association of ETV1 rearrangements with PTEN downregulation (P = 0.015). We report that FLI1 is a novel ETS transcription factor involved in gene fusions in prostate cancer and that intratumor genetic heterogeneity of ETS rearrangements can occasionally be found in index primary tumors. © 2011 Wiley Periodicals, Inc.
Perception of Hand Force in Power Grip for Females
Authors: Li Kai Way , Yu Ruifeng , Zhang Wei
Published: November 2011

Borg's rating of perceived exertion (RPE) and category ratio (CR‐10) scales are commonly used to quantify perceived muscular exertion for body segments. Twenty females participated in an experiment to study the power grip force at four perceived exertion levels using either dominant or nondominant hand under two posture conditions. It was found that the subjects tended to apply a higher power grip force (100% of perceived maximum voluntary contraction) than the levels they were requested to apply. The power grip forces between dominant and nondominant hands at low hand exertion levels were negligible. The grip forces between the two hands were significantly different when the exertion level was nearly maximal. Linear regression models were established for the subjects to link the relationship between the perceived hand exertion and measured grip force, hand used, and hand/arm posture. All the models were statistically significant (p < 0.0001) with R2 values 0.97 or higher. These models provided better estimates in perceived hand exertion for dominant hand than for nondominant hand. A follow‐up experiment was conducted to measure the subjective rating of both the CR‐10 and RPE when a 98 N grip force was applied. It was found that the subjects reported higher exertion levels when they were using the CR‐10 scale than when they were using the RPE scale. © 2011 Wiley Periodicals, Inc.
Modelling of stormwater biofilters under random hydrologic variability: a case study of a car park at Monash University, Victoria (Australia)
Authors: Daly E. , Deletic A. , Hatt B. E. , Fletcher T. D.
Published: November 2011

Biofiltration systems represent an effective technology for the management of urban stormwater runoff volumes and quality. The performance of these systems, although largely dependent on their physical characteristics, is also strongly affected by the natural variability of runoff occurrence and volumes. This article presents a model that describes the statistical behaviour of the main variables involved in the water balance of a biofiltration system, given its main physical properties (filter media and vegetation types) and accounting for the natural inflow variability in terms of occurrence and water volumes. The model permits the analytical derivation of the long‐term (e.g. annual) probability density function of the soil water content in the filter media and the estimation of the main statistics of water fluxes, that is, outflow, evapotranspiration and overflow. By relating the soil water content in the filter media before inflow events to the outflow total nitrogen concentrations, the model also gives estimates of the statistics of nitrogen removal performance as a function of inflow variability. The model was tested against field data collected at a stormwater biofiltration system in Melbourne, Australia. The model could be used to rapidly assess the hydrologic and nitrogen treatment performance of alternative applications of biofiltration for stormwater management across a range of climates. Copyright © 2011 John Wiley & Sons, Ltd.
Modelling rainfall partitioning with sparse Gash and Rutter models in a downy oak stand in leafed and leafless periods
Authors: Mużyło A. , Valente F. , Domingo F. , Llorens P.
Published: November 2011

Application of models for estimating rainfall partitioning in deciduous forests may be considered time consuming and laborious given the need for two different parameter sets to describe leafed and leafless periods. This paper reports how rainfall partitioning modelling was done for a downy oak forest plot (Eastern Pyrenees Mountains, NE Spain) using sparse Rutter and Gash interception loss models and their suitability for such studies. Moreover, variability in model sensitivity is evaluated, and an attempt to simplify their application is also presented.

The estimation error for interception loss in the leafed period was −26.3% and −4.2% with the Rutter model and the Gash model applied with Penman–Monteith‐based evaporation rate, respectively. The estimate for the leafless period was less accurate in both models, suggesting that modelling in the leafless period is more susceptible to error. Nevertheless, with the Gash model, the result was well below the expected measurement error. Models proved to be highly sensitive to change in canopy cover in all periods tested. The Rutter model was especially sensitive to zero plane displacement changes in the leafed period, while the Gash model showed high linear sensitivity to evaporation rate. In addition, a decrease in rainfall rate affects the estimation of interception loss more than an increase in it. Regardless of its high sensitivity to these parameters, the Gash model yielded a good estimate of rainfall partitioning for the total period, when only one set of parameters was used, although event‐based error compensation occurred, and some periods were over or underestimated. Copyright © 2011 John Wiley & Sons, Ltd.
Assessing the relationships between elevation and extreme precipitation with various durations in southern Taiwan using spatial regression models
Authors: Chu Hone‐Jay
Published: November 2011

A spatially autocorrelated effect exists in precipitation of a mountainous basin. This study examines the relationship between maximum annual rainfall and elevation in the Kaoping River Basin of southern Taiwan using spatial regression models (i.e. geographically weighted regression (GWR), simultaneous autoregression (SAR), and conditional autoregression (CAR)).

Results show that the GWR, SAR, and CAR models can improve spatial data fitting and provide an enhanced estimation for the rainfall–elevation relationship than the ordinary least squares approach. In particular, GWR achieves the most accurate estimation, and SAR and CAR achieve similar performance in terms of the Akaike information criterion. The relationship between extreme rainfall and elevation for longer duration is more concise than that for short durations. Results show that the spatial distribution of precipitation depends on elevation and that rainfall patterns in study area are heterogeneous between the southwestern plain and the eastern mountain area. Copyright © 2011 John Wiley & Sons, Ltd.
Oxidative transformations of 4‐methylcoumarins using dimethyldioxirane
Authors: Ćavar Sanja , Kovač Franci
Published: November 2011

Efficient regioselective oxidation of the double CC bond of 4‐methylcoumarins with isolated dimethyldioxirane was performed, and related hydroxy and epoxy derivatives were obtained in good yields. All of obtained epoxides and most of hydroxy derivatives are novel compounds. The position of different electron‐donating groups attached at the aromatic part of molecule shows significant influence on kinetics and course of the reaction. J. Heterocyclic Chem., (2011).
Synthesis and antitumor activity of some novel hydrazide, 1,2‐dihydropyridine, chromene, and benzochromene derivatives
Authors: Ghorab Mostafa M. , Al‐Said Mansour S.
Published: November 2011

2‐Cyano‐N′‐[1‐(substitutedphenyl)ethylidene]acetohydrazide 2a, 2b, 2c were obtained via reaction of acetophenone derivatives 1a, 1b, 1c with cyanoacetic acid hydrazide. The hydrazidehydrazone derivative 2a underwent a novel series of heterocyclization reactions via its reaction with aromatic aldehydes and/or arylidenemalononitriles to produce arylidene and dihydropyridine derivatives 3 5l, respectively. Structures of the newly synthesized compounds were confirmed by elemental analyses, IR, 13C‐NMR, 1H‐NMR and mass spectral data. All the newly synthesized compounds were evaluated for their in‐vitro antitumor activity against Ehrlich Ascities Carcinoma (EAC) cells. Some of them showed interesting cytotoxic activity compared with Doxorubicin (CAS 23214‐92‐8) as a reference drug. J. Heterocyclic Chem., (2011).
When parents’ affection depends on child's achievement: Parental conditional positive regard, self‐aggrandizement, shame and coping in adolescents☆
Authors: Assor Avi , Tal Karen
Published: November 2011

We examined the idea that adolescents’ perceptions of their mothers as using parental conditional positive regard (PCPR) to promote academic achievement are associated with maladaptive self feelings and coping. A study of 153 adolescents supported the hypothesis that PCPR predicts self‐aggrandizement following success and self devaluation and shame following failure, which then predict compulsive over‐investment. PCPR functioned as a unique predictor of maladaptive self feelings and coping also when the effects of perceived parental conditional negative regard or psychological control were controlled for. The findings suggest that the experience of one's mother as using conditional positive regard to promote achievement leads to a non‐optimal self‐esteem dynamics, in which people vacillate between feelings of grandiosity following success and self‐derogation and shame following failure, which in turn promote a rigid and stressful mode of coping. Thus, the practice of PCPR, although seemingly benign, appears to carry significant emotional and coping costs for adolescents.
III-V Nitride based piezoresistive microcantilever for sensing applications
Authors: Qazi Muhammad , DeRoller Nicholas , Talukdar Abdul , Koley Goutam
Published: November 2011

III-V Nitride based microcantilevers, with AlGaN/GaN heterostructure field effect transistor as the piezoresistive deflection transducer, have been investigated under steady state, transient, ac, and UV illuminated conditions and compared to theoretical calculations. The steady state transverse gauge factor (GFt) was found to be much larger than theoretical estimates and increased regularly with more negative gate bias. Transient GFt demonstrated opposite sign but similar gate bias dependence and was measured as high as ∼860. Measurements under ac biasing conditions and UV illumination resulted in a lower GFt of ∼13, which agrees with theoretical calculations owing to elimination of charge trapping effects.
Faraday instability in a vessel with a well: A numerical analysis
Authors: Louis E. , Miralles J. A. , Chiappe G. , Bazán A. , Adrados J. P. , Cobo P.
Published: November 2011

Simulations of the Faraday instability in a rectangular-shaped vessel with well, filled with a viscous fluid, are presented. Oscillations promoted by applying a vertical vibration of a given frequency and amplitude show the following features: (i) unstable waves become increasingly localized in the well as the amplitude of vibration increases, (ii) the threshold amplitude for an arbitrary well width is bounded by the thresholds of a vessel with no well and liquid layers thicknesses equal to those in either the plateau or in the well region, and (iii) below threshold, a weak horizontal component triggers harmonic oscillations. Experiments carried out in a vessel filled with ethanol allowed to observe wave localization and, below threshold, the harmonic wave. Below threshold, the harmonic wave had been previously observed as the only possible wave in a square vessel with an immersed concentric square well. Novel theoretical tools are developed to investigate this system: A generalized Mathieu equation is used to handle the case without well, whereas a numerical transfer matrix method is applied to the case with well.
Intense laser field effects on p – d exchange interaction in single manganese doped GaAs
Authors: Vieira Moura Fábio , Qu Fanyao , Gargano Ricardo
Published: November 2011

We have developed a comprehensive theory about optical control of p – d exchange interaction between spins of hole and Mn2+ in single-manganese doped GaAs material irradiated by a monochromatic, linearly polarized, intense pulsed laser field (PLF) under nonresonant conditions. The p – d exchange interaction leads to formation of magnetic polaron. While the PLF induces a dressed acceptor Coulomb potential, which transforms single center problem into the one with two virtual positively charged centers, resembling hydrogen molecule ion (H2+). The dichotomy of hole wave functions, determined by the laser-intensity, affects strongly the p – d exchange interaction as well as binding energy of magnetic polaron. Increasing the laser intensity reduces the magnetic polaron binding energy. At larger excitation intensity, the magnetic polaron can be completely dissolved.
Non-equilibrium Green’s function analysis of cross section and channel length dependence of phonon scattering and its impact on the performance of Si nanowire field effect transistors
Authors: Aldegunde M. , Martinez A. , Asenov A.
Published: November 2011

In this paper, we study the effect of phonon scattering in silicon nanowire field effect transistors (NWFET) using a Non-equilibrium Green’s function formalism in the effective mass approximation. The effect of electron-phonon scattering on the current voltage characteristics at high and low drain bias is investigated in detail. A wide range of cross-sections (from 2.2 × 2.2 to 6.2 × 6.2 nm2) and channel lengths (from 6 to 40 nm) are considered. The impact of phonon scattering on the electron current in different regions of the device characteristics is studied. Simulations including scattering in the whole transistor are compared with corresponding simulations in which scattering is only in the channel. Phonon limited mobility dependence on the NWFET cross-section and channel length is studied. The ballisticity coefficient, as a function of the channel length and gate voltage, is also computed for various channel cross-sections and lengths at high drain bias. The paper demonstrates that tunneling plays an important role in understanding the effect of phonon scattering at short channel lengths.
Nonlinear wake potential and stopping power for charged particles interacting with a one-dimensional electron gas
Authors: Zhang Ya , Song Yuan-Hong , Wang You-Nian
Published: November 2011

We examine the interaction of particles with a one-dimensional electron gas by employing the quantum hydrodynamic (QHD) theory, where the nonlinear wake potential and stopping power have been numerically calculated by solving the nonlinear QHD equations with flux corrected transport (FCT) numerical method. In our calculation, the nonlinear effects on the wake potential and stopping power are clearly observed and presented. In the moving coordinate, comparisons are made between the nonlinear and linear wake potentials, in which the maximum values are larger and more oscillations appear behind the projectile in a nonlinear case in contrast to that in a linear case. The nonlinear wake potentials show a clear dependence on time, that is, the FCT algorithm solves the nonlinear QHD equations by time integration starting from the initial time. It is shown that the nonlinear effects can enhance the wake potential and stopping power for particle velocities greater than a few Bohr velocities.
Excellent resistive switching in nitrogen-doped Ge2Sb2Te5 devices for field-programmable gate array configurations
Authors: Kim Seonghyun , Park Jubong , Jung Seungjae , Lee Wootae , Woo Jiyong , Cho Chunhum , Siddik Manzar , Shin Jungho , Park Sangsu , Hun Lee Byoung , Hwang Hyunsang
Published: November 2011

The nitrogen-doped Ge2Sb2Te5 (GST) programmable metallization cell is investigated to address the low switching voltage and need for a high resistance ratio, which are critical issues for the filed-programmable gate array (FPGA) configuration. Nitrogen doping of GST yields Ge–N covalent bonds, as confirmed by x-ray photoelectron spectroscopy and Raman spectroscopy; this increases the resistivity of GST. Consequently, an excellent resistance ratio (∼107) with appropriate operating voltage and stable retention properties more than for 104 s at 85 °C are achieved. The results indicate that the film is a suitable alternative candidate for the logic switch in static-random-access-memory-based FPGA technology.
Multi-scale analysis of high-speed dynamic friction
Authors: Barton P. T. , Kalweit M. , Drikakis D. , Ball G.
Published: November 2011

Friction occurring at the interface between dissimilar metallic components as a result of high velocity impact or explosive loading can have a profound effect on the subsequent motion. A comprehensive understanding of the involved processes across a wide range of initial conditions remains outstanding. Dry sliding of single crystal silver on copper at high pressure is investigated for a range of sliding speeds using a multi-scale modelling method based upon the domain decomposition approach (molecular dynamics in the near interface region and continuum mechanics elsewhere). The transient solutions reveal detailed observations of the processes that lead to phenomena such as the growth of epitaxial layers of the softer material, shifting of the sliding interface due to formation of shear-bands, development of amorphous structures, and ultimately the resultant motion of the components. Analysis of the results also links these processes to the changes in the state of the material through growth of dislocations and thermal effects.
Confinement enhancing barriers for high performance quantum dots-in-a-well infrared detectors
Authors: Barve A. V. , Sengupta S. , Kim J. O. , Sharma Y. D. , Adhikary S. , Rotter T. J. , Lee S. J. , Kim Y. H. , Krishna S.
Published: November 2011

We demonstrate the use of thin AlGaAs barrier layers in the quantum dots in a well heterostructure to enhance the quantum confinement of carriers in the excited energy level, while maintaining high escape probability. This is achieved by controlling the excited state energy between the confinement enhancing (CE) barriers and the continuum level. Responsivity of ∼0.1 A/W, detectivity of 6.5 × 1010 cmHz1/2 W−1 (77 K, 0.6 V, 7.5 µm, f/2), and a factor of 10 improvement over a control sample without the CE barriers have been measured. The effect of changing the quantum well thickness and quantum dot size is also reported.
Thermal, spectroscopic, and laser characterization of Nd:LuxY1-xVO4 series crystals
Authors: Guo Lei , Wang Zhengping , Yu Haohai , Hu Dawei , Zhuang Shidong , Chen Lijuan , Zhao Yongguang , Sun Xun , Xu Xinguang
Published: November 2011

A series of Nd:LuxY1-xVO4 (x = 0.10, 0.26, 0.41, 0.61, 0.67, 0.80) mixed laser crystals were grown and researched systematically, for the first time to our knowledge. Their thermal properties were investigated, including the specific heat, thermal expansion, thermal conductivity and the material constant. Their spectral properties were measured and their spectral parameters were calculated by J-O theory, including the absorption spectrum, emission spectrum, fluorescence lifetime and emission cross section. In CW laser operation, a maximum output power of 3.1 W was obtained from the Nd:Lu0.10Y0.90VO4 mixed crystal, corresponding to an optical conversion efficiency of 51.7 %, and a slope efficiency of 59.8 %. When Cr:YAG crystal was used as the saturable absorber, passively Q-switched pulse laser operation was achieved for Nd:LuxY1-xVO4 series crystals. The best pulse performance came from Nd:Lu0.10Y0.90VO4 crystal, with the maximum pulse energy of 169 μJ and the highest peak power of 26.4 kW.
Dendritic SNAREs add a new twist to the old neuron theory
Authors: Ovsepian Saak V. , Dolly J. Oliver
Published: November 2011

Dendritic exocytosis underpins a broad range of integrative and homeostatic synaptic functions. Emerging data highlight the essential role of SNAREs in trafficking and fusion of secretory organelles with release of peptides and neurotransmitters from dendrites. This Perspective analyzes recent evidence inferring axo-dendritic polarization of vesicular release machinery and pinpoints progress made with existing challenges in this rapidly progressing field of dendritic research. Interpreting the relation of new molecular data to physiological results on secretion from dendrites would greatly advance our understanding of this facet of neuronal mechanisms.
Investigation on blocking and deblocking isocyanates by sodium bisulphite
Authors: Zhang Yanhua , Gu Jiyou , Jiang Xiankai , Zhu Libin , Tan Haiyan
Published: November 2011

Purpose

The purpose of this paper is to study the effective procedure for blocking and deblocking isocyanate by sodium bisulphite with special cosolvent and dropwise method.

Design/methodology/approach

A number of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Thermo gravimetric analyser (TGA) were employed to assess the reactions between isocyanates and sodium bisulphite, water, cosolvent, also the deblocking temperature of blocked isocyanates.

Findings

The blocked isocyanates reacted with sodium bisulphite, water and cosolvent via a special procedure. It was found that the − NCO functional groups of the isocyanates were completely blocked by sodium bisulphite and a new method for determining the lowest deblocking temperature of the blocked isocyanates was described. It was revealed that the deblocking temperature of blocked isocyanates by sodium bisulphite was lower than others.

Practical implications

The paper provides some useful information about the blocking and deblocking of isocyanate, which would be helpful for the preparation of blocking and deblocking isocyanate, and guiding the practical applications of blocked isocyanate.

Originality/value

The investigation found that the sodium bisulphite was a very efficient blocking agent for isocyanates at the room temperature via the special procedure developed. On the basis of emulsion polymerisation theory, polymer isocyanates were blocked by sodium bisulphite, which realised the new breakthrough effectively by means of controlled temperature, stirring speed and optimum dropwise speed in the whole reaction system. Meanwhile, the special cosolvent could improve the intermiscibility of isocyanate in sodium bisulphite aqueous solution, reduce the side reaction of isocyanate with water and accelerate reaction rate of isocyanate with sodium bisulphite. If no cosolvent was present, the blocked system would not be homogeneous.
Effects of water immersion‐freeze‐thaw cycling on the properties of wood‐polypropylene composites containing pigments
Authors: Butylina Svetlana , Martikka Ossi , Kärki Timo
Published: November 2011

Purpose

The purpose of this paper is to study the effects of water immersion‐freeze‐thaw treatment on the physical properties, flexural strength (FS) and morphology of wood‐polypropylene composites containing pigments.

Design/methodology/approach

Wood‐polypropylene composites containing brown, green and grey pigments were compounded in a conical twin‐screw extruder. A composite manufactured without any pigment addition was used as a reference. The amount of pelletized wood, polypropylene and coupling agent (MAPP) was kept constant. The moisture content, thickness swelling (TS), FS and surface colour of the composites were measured before and after water immersion‐freeze‐thaw cycling. Scanning electron microscopy (SEM) was used to study the morphology of the composites.

Findings

FS and dimensional stability were reduced after exposure to water immersion‐freeze‐thaw cycling for all composites. The surface properties (colour and roughness) of the composites also changed after exposure to water immersion‐freeze‐thaw cycling. The degree of change depended on the presence of pigment and the type of polypropylene (neat or recycled), however.

Research limitations/implications

This study is a part of an ongoing study on weathering of wood‐polymer composites (WPC) containing different additives. The results of this study were obtained from accelerated laboratory experiments.

Practical implications

Inorganic pigments are widely used as additives in plastics, because they have an excellent UV absorption, good IR‐reflective properties and heat stability. The research revealed that metal‐containing pigments had an effect on degradation in quality of wood‐polypropylene composites exposed to water immersion‐freeze‐thaw cyclic treatment. The addition of metal‐containing pigments to composite formulation resulted in a higher susceptibility of wood‐polypropylene composites to water absorption, and as a consequence to a higher drop of FS compared to composites made without pigment. The polymer matrix plays an important role in the protection of WPC against weathering.

Originality/value

This paper will help in understanding possible problems in the durability of wood‐polypropylene composites compounded with metal‐based pigments when they are exposed to water immersion‐freeze‐thaw cyclic treatment.
CFD simulation of momentum injection control past a streamlined body
Authors: Sahu Rajesh , Patnaik B.S.V.
Published: November 2011

Purpose

The purpose of this paper is to achieve high‐performance aerofoils that enable delayed stall conditions and achieve high lift to drag ratios.

Design/methodology/approach

The unsteady Reynolds averaged Navier‐Stokes equations are employed in conjunction with a shear stress transport (κ‐ω) turbulence model. A control equation is designed and implemented to determine the temporal response of the actuator. A rotating element, in the form of an actuator disc, is embedded on the leading edge of NACA 0012 aerofoil, to inject momentum into the wake region. The actuator disc is rotated at different angular speeds, for angles of attack (α) between 00 and 240.

Findings

Phenomena such as flow separation, wake vortices, delayed stall, wake control, etc. are numerically investigated by means of streamlines, streaklines, isobars, etc. Streamwise and cross‐stream forces on the aerofoil are obtained. The influence of momentum injection parameter (ξ) on the fluid flow patterns, and hence on the forces acting on the streamlined body are determined. A synchronization‐based coupling scheme is designed and implemented to achieve annihilation of wake vortices. A delayed stall angle resulted with an attendant increase in maximum lift coefficient. Due to delay and/or prevention of separation, drag coefficient is also reduced considerably, resulting in a high‐performance lifting surface.

Research limitations/implications

The practicality of momentum injection principle requires both wide ranging and intensive further studies to move forward beyond the proof of concept stage.

Practical implications

Determination of forces and moments on an aerofoil is of vital interest in aero‐dynamic design. Perhaps, runways of the future can be shorter and/or more pay load can be carried by an aircraft, for the same stall speed.

Originality/value

The paper describes how a synchronization‐based coupling scheme is designed and implemented along with the RANS solver. Furthermore, it is tested to verify the dynamic adaptability of the wake vortex annihilation for NACA 0012 aerofoils.
Enhancing the quality of e‐learning through mobile technology
Authors: Male Galamoyo , Pattinson Colin
Published: November 2011

Purpose

This paper aims to present part of the work of an ongoing research project that is looking at socio‐ cultural and technological developments from a mobile technology convergence view; in order to show how culturally aware convergence developments in mobile technology can be adopted and employed for the betterment of society.

Design/methodology/approach

The paper presents a scenario for a mobile technology enabled learning environment in support of the conventional learning approach with a focus on enabling parental involvement and contribution to the daily learning objectives of their children and hence enhancing a quality learning experience. It further critically discusses issues of interface design – at both the device and application levels – that will have an impact on the quality of e‐learning, with a focus on mobile technology.

Findings

The paper shows how interface design can positively enhance the quality defining characteristics of learning in an e‐learning environment. Ways of achieving these characteristics of learning through effective e‐learning are reported. This is done by addressing requirements for quality‐learning through effective interface‐design considerations, towards meeting the overall quality requirements of learning that should be intrinsic to a holistic e‐learning environment. The value of human computer interaction and the critical factors of promoting productive interaction are addressed.

Research limitations/implications

There are several factors affecting quality of e‐learning as a tool and approach to flexible and independent learning. The advent and use of mobile technology has been investigated in this work from a socio‐cultural and technological perspectives in two continents. The limitations lie in the depth of investigations and how far the findings can be applied to the diversity of learners.

Practical implications

As the effects of cultures and the rapid technological advancements take toll on teaching and learning the findings reported in this paper have far reaching implications for learners from different cultures and also for attempts at bridging existing digital divide.

Originality/value

The approach adopted in the research is unique by virtue of new findings and ideas presented. The paper highlights the opportunities for mobile devices and technology to play a role in the development of communities through technology aided learning (e‐learning), with a focus on e‐learning systems and technology requirements for delivering a quality learning experience.
How BMW successfully practices sustainable leadership principles
Authors: Avery Gayle C. , Bergsteiner Harald
Published: November 2011

Purpose

This BMW case aims to show how many of the company's practices that accord with principles espoused in the authors' sustainable leadership model contributed to its recovery after the global financial crisis (GFC).

Design/methodology/approach

This case illustrates how BMW institutes the 23 honeybee leadership principles and practices described in the authors' 2011 article “Sustainable leadership: practices for enhancing business resilience and performance” in Strategy & Leadership.

Findings

The examples provide a glimpse into the honeybee practices that enabled one firm to emerge successfully from the GFC. Regarding the five performance outcomes on the sustainable leadership pyramid, BMW clearly exceeded expectations in 2010 on financial returns and shareholder value.

Practical implications

Clearly BMW provides long‐term value for all its stakeholders – suppliers, shareholders, employees and customers – as is expected of a sustainable enterprise. BMW's business model, innovative approach to problem‐solving and adherence to sustainable leadership practices underpin a capacity to survive crises such as the GFC.

Originality/value

This is a rare case study of corporate‐wide sustainability practices and principles in operation. Informed by the examples of best practices at BMW, managers at other companies can envision how honeybee management might be implemented at their firm.
The subprime crisis and stock index futures markets integration
Authors: Abdul Karim Bakri , Jais Mohamad , Ariffin Abdul Karim Samsul
Published: November 2011

Purpose

The purpose of this paper is to examine the effects of the current global crisis on the integration and co‐movements of selected stock index futures markets.

Design/methodology/approach

Time series techniques of cointegration and weekly data covering the period from January 2001 to December 2009 were used in this study. The period of analysis was divided into two periods, namely the pre‐crisis period (January 2001‐July 2007) and during crisis period (August 2007‐December 2009).

Findings

No evidence was found of cointegration among the stock index futures markets in both periods. Accordingly, the 2007 subprime crisis does not seem to affect the long‐run co‐movements among the stock index futures markets.

Practical implications

The stock index futures markets provide opportunity for the potential benefits from international portfolio diversification and hedging strategies even after the subprime crisis. The stock index futures significantly extended the variety of investment and risk management strategies available to investors.

Originality/value

Examining the effects of the US subprime crisis on the stock index futures markets integration, to the best of the authors' knowledge, goes clearly beyond the existing literature on the subject matter.
Measuring intangible effects of m‐coupon campaigns on non‐redeemers
Authors: Banerjee Syagnik , Poddar Amit , Yancey Scott , McDowell Danielle
Published: November 2011

Purpose

The purpose of this paper is to demonstrate how to design better awareness and memory of product information using mobile coupon campaigns among those who do not redeem the coupons.

Design/methodology/approach

The research involves two field experiments with a Mid Western mobile marketing firm where differently designed coupons were sent out to men and women customers of a fast food chain, and non‐redeemers filled out a survey revealing how much they remembered. The research also connected their subsequent purchases a week later. The data were analyzed using ANOVAs.

Findings

Factual ad claims create better recognition than descriptive ad claims in general, but among older working people when ad is viewed in leisure situations men better remember descriptive appeals, and women factual appeals. Also the memory has no effect on purchase intentions or future purchases. In contrast, among younger students, men remember factual ad claims better than descriptive, like women, and their memory has significant effects on subsequent purchase behavior.

Research limitations/implications

Selectivity hypotheses may be applied to design advertising congruity/incongruity based on tasks people are doing in different physical situations. Other limitations include some sampling error (or selectivity) and its difficulties in generalizability across industries.

Practical implications

Managers can build awareness using different types of ad claims depending on gender and situation among older working groups, and use factual appeals for younger groups. Among younger groups the memory of coupons can also drive subsequent purchase behavior.

Originality/value

The paper uncovers the value of non redeeming customers in m‐coupon campaigns, and identifies how to target and design campaigns to best extract that value.