bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking National Contexts with Intellectual Capital: A Comparison between Spain and Morocco
Authors: Cegarra-Navarro Juan-Gabriel , Sánchez-Polo Maria Teresa
Published: March 2013

The ‘national environment’, which includes belief and value systems, shapes the way individuals, groups and organisations perceive the world around them and determines how they react to ongoing changes. This paper analyses the role of different context's effects on intellectual capital by means of an empirical investigation of 112 Small to Medium sized Enterprises (SMEs) in the Spanish and Moroccan telecommunication industries. Within the investigation, repeated ANOVA were used, which were validated by factor analysis. Results support that Spanish SMEs are more positively associated with higher levels of human, structural and relational capital. The meaningful differences are clearly found in the ‘structural capital’. Our findings open avenues for further research to explore how governments can facilitate learning and unlearning environments in SME communities. These findings have important implications for general intellectual capital theories, as they suggest that there is no guarantee that intellectual capital theories developed within the cultural context of one particular country can be applied in another with good effect. National contexts provide the environment for learning, which in turn may have the effect of adequately improving intellectual capital.
Differences and Similarities among Volunteers who Drop out During the first Year and Volunteers who Continue after eight Years
Authors: Jiménez María Luisa Vecina , Fuertes Fernando Chacón , Abad Manuel J. Sueiro
Published: March 2013

Differences and similarities between 130 volunteers who remain for more than eight years in the same non-profit organization and 110 volunteers who quit during the first year were analyzed in this paper. Both groups were chosen from a sample of 851 volunteers that were working as volunteers when we assessed the independent variables (Time 1). After a 12-month follow-up (Time 2), 209 (25%) of them had dropped out and 642 (75%) continued in the same organization. Using the previous time, we formed two groups made up of those who dropped out and had been in the organization less than a year and those who continued and had been in the organization more than 8 years. Results show that differences and similarities between both groups are coherent with the three-stage model of volunteer's duration (Chacón, Vecina, & Dávila, 2007). This model includes the functional approach of volunteers' motivations (Clary & Snyder, 1991), and the role identity approach (Callero, 1985), and indicates that people will remain as volunteers insofar as this satisfies the motivations that are relevant for them at the first stage, they develop organizational commitment at the second stage, and they develop role identity as volunteers at the third stage. More specifically, results show that it is possible to predict 85% of the cases correctly using seven variables. Volunteers who remain after eight years feel a higher level of emotional exhaustion, a higher level of organizational commitment, and a strong role identity as volunteers. They are also highly satisfied with the friendships in the organization and have a stronger intention to remain at the long term (2 years).
Associated Factors of Unhealthy Eating Patterns among Spanish University Students by Gender
Authors: Sepulveda Ana , Carrobles José Antonio , Gandarillas Ana M.
Published: March 2013

This study has examined bio-socio-demographic and psychopathological factors probably associated with unhealthy eating patterns among university students and to estimate a multifactorial model following the associated factors by gender. Adjusted odds ratios were calculated to describe associations on basis of Eating Disorder Inventory (EDI) stratified by gender in a representative sample of Spanish university students (n = 2551). The high EDI scorers for both sexes presented higher prevalence of dieting, body dissatisfaction, levels of psychopathology and lower self-esteem than the low EDI scorers. The results suggest that older students and higher self-esteem scores present lower scores in the EDI. In the female population, depression, paranoid dimension, dieting and body dissatisfaction were associated with population with unhealthy eating patterns. In the male sample, dieting, body dissatisfaction and interpersonal sensibility were also associated with unhealthy eating patterns. The results corroborate that abnormal eating patterns tend to affect specific vulnerable groups. We do not know the precise mechanisms through which these risk behaviors and attitudes, such as dieting or body dissatisfaction, may facilitate the later development of an eating disorder.
Dysfunctional Belief Domains Related to Obsessive-Compulsive Disorder: A Further Examination of their Dimensionality and Specificity
Authors: Belloch Amparo , Morillo Carmen , Luciano Juan V. , García-Soriano Gemma , Cabedo Elena , Carrió Carmen
Published: March 2013

International consensus has been achieved on the existence of several dysfunctional beliefs underlying the development and/or maintenance of the Obsessive-Compulsive Disorder (OCD). Nevertheless, questions such as the dimensionality of the belief domains and the existence of OCD-specific dysfunctional beliefs still remain inconclusive. The present paper addresses these topics through two different studies. Study 1: A series of confirmatory factor analyses (N= 573 non-clinical subjects) were carried out on the Obsessive Beliefs Spanish Inventory-Revised (OBSI-R), designed to assess dysfunctional beliefs hypothetically related to OCD. An eight-factor model emerged as the best factorial solution: responsibility, over-importance of thoughts, thought-action fusion-likelihood, thought action fusion-morality, importance of thought control, overestimation of threat, intolerance of uncertainty and perfectionism. Study 2: The OBSI-R and other symptom measures were administered to 75 OCD patients, 22 depressed patients, and 25 non-OCD anxious patients. Results indicated that, although OCD patients differed from their non-clinical counterparts on all of the OBSI-R subscales, no evidence of OCD-specificity emerged for any of the belief domains measured, as the OCD subjects did not differ from the other two clinical groups of patients.
Psychometric Properties and Latent Structure of the Portuguese Version of the Penn State Worry Questionnaire
Authors: Castillo Cristian , Macrini Leonardo , Cheniaux Elie , Landeira-Fernandez Jesús
Published: March 2013

Two studies evaluated the psychometric properties and the latent structure of the Portuguese version of the Penn State Worry Questionnaire (PSWQ) in a large Brazilian college student sample. Results indicated that PSWQ had an adequate internal consistency. Exploratory factor analyses yielded a two-factor solution. One factor was related to the worry presence and incorporated all the non-reversed items. The other factor was associated to worry absence and incorporated all the reversed items. Confirmatory factor analysis leaded to a three-factor solution. One factor included all the PSWQ items whereas the two other factors were linked to the reversed and non-reversed worded items. Correlations coefficients of these two reversed and non-reversed factors with the total scores of the PSWQ and the trait form of the State-Trait Anxiety Inventory suggest that PSWQ has a single meaningful construct.
Factor Structure and Invariance of the POMS Mood State Questionnaire in Spanish
Authors: Andrade Elena , Arce Constantino , Torrado Julio , Garrido Javier , De Francisco Cristina , Arce Iria
Published: March 2013

The purpose of this study was to examine the extent to which the Spanish POMS assesses the same factors as the original form of the questionnaire. We started from a version with 63 items, representing seven conceptual dimensions. This version was administered to a sample of 364 adult athletes. In the whole sample, exploratory factor analytic findings suggested a more parsimonious measurement model, with 44 items and 6 first-order factors. Then the data from said sample were randomly divided into two sets, each containing about 50% of the subjects. The fit of the first sample set (n = 166) to the proposed model was adequate. Four of the main goodness-of-fit indices exhibited the following values: CFI = .95, NNFI = .95, SRMR = .083, and RMSEA = .064. We tested the same model in the second data set (n = 198), in which the fit was also acceptable, with values of .95, .94, .088, and .066 for CFI, NNFI, SRMR, and RMSEA, respectively. In addition, we used multi-group confirmatory factor analysis to provide evidence on the invariance of the model.
Confirmatory Factorial Analysis of the Brazilian Version of the Competitive State Anxiety Inventory-2 (CSAI-2)
Authors: Coelho Eduarda Maria , Vasconcelos-Raposo José , Mahl Álvaro Cielo
Published: March 2013

The aim of this study was to assess the factorial structure of the Brazilian version of CSAI-2, using several structures suggested in previous studies. Two samples consisted of Brazilian soccer players, 266 from regional level (age 22.87 ± 4.08 years; athletic experience 11.32 ± 4.15 years) and 263 from national level (age 23.16 ± 4.37 years; athletic experience 11.11 ± 4.78 years) were used. The CSAI-2 is a 27-item inventory that measures negativism, physiological activation and self-confidence in a competitive setting. The results of CFA according to the original structure showed some inadequacy of the model. The model proposed by Cox, Martens, Russell (2003), composed of three factors (17-item), demonstrated better adjustment to the regional level sample (χ2/df = 1.871, CFI = .934, GFI = .916, RMSEA = .057), while the model suggested by Coelho, Vasconcelos-Raposo, Fernandes (2007), composed of two factors (18-item), adapted better to the national level sample (χ2/df = 1.701, CFI = .924, GFI = .914, RMSEA = .052). When we analyzed the two samples together, Coelho et al. (2007) was the better model, because it displayed greater invariance. The use of this model was suggested in the assessment of intensity of negative thoughts and the subsequent confirmation of its psychometric properties is recommended.
Convergence of Internal and External Structure for the California Child Q-set
Authors: Bimler David , Kirkland John , Fitzgerald Hiram E. , Zucker Robert A.
Published: March 2013

The language of personality traits includes single-word trait descriptors, and longer phrases or sentences. Evidence has accumulated that abstract, semantic relationships among single words have the same underlying structure as the empirical relationships when words are applied to individuals. The present study examines whether these two kinds of structure are also isomorphic for longer trait descriptors. Empirical descriptions and judgements of semantic similarity were collected among the descriptors comprising the California Child Q-set, or CCQ, and analysed with multidimensional scaling. Canonical correlation showed the solutions to be closely related to one another, and to independent sets of ratings available for the CCQ items. Informants' similarity judgements were not affected by the context in which they were made. The dominant dimensions of the solutions reproduce dimensions found previously for the single-word personality lexicon, indicating the two trait-descriptive languages to be closely parallel.
Preliminary Validation of the Spanish Version of the Multiple Stimulus Types Ambiguity Tolerance Scale (MSTAT-II)
Authors: Arquero José L. , McLain David L.
Published: March 2013

Despite widespread interest in ambiguity tolerance and other informationrelated individual differences, existing measures are conceptually dispersed and psychometrically weak. This paper presents the Spanish version of MSTAT-II, a short, stimulus-oriented, and psychometrically improved measure of an individual's orientation toward ambiguous stimuli. Results obtained reveal adequate reliability, validity, and temporal stability. These results support the use of MSTAT-II as an adequate measure of ambiguity tolerance.
A Bibliometric Analysis of Research in Psychopharmacology by Psychology Departments (1987–2007)
Authors: Portillo-Salido Enrique F.
Published: March 2013

From the very outset of scientific Psychology, psychologists have shown interest for drugs and their effects on behavior. This has given rise to numerous contributions, mostly in the form of Psychopharmacology publications. The aim of this study was to quantitatively evaluate these contributions and compare them with other academic disciplines related to Psychopharmacology. Using the PubMed database, we retrieved information about articles from 15 journals included in the Pharmacology and Pharmacy category of the Journal Citation Reports database for a 21-year period (1987 to 2007). There were 37540 articles which about 52% were represented by 3 journals. About 70% of psychology publications were represented by 2 of these journals. Psychology departments accounted for the 11% of the published papers, which places Psychology third behind Psychiatry and Pharmacology, which contributed to 22.69 and 13% respectively. Psychology contributed to the greatest number of studies in 3 journals, second in 3 and third in 8. This report represents the first effort to explore the contribution of academic Psychology to the multidisciplinary science of psychopharmacology. Although leaders of production of psychopharmacology research were from Psychiatry and Pharmacology, Psychology departments are an important source of studies and thus of knowledge in the field of Psychopharmacology
Comparison of Channeling Contrast between Ion and Electron Images
Authors: Giannuzzi L.A. , Michael J.R.
Published: March 2013

Ion channeling contrast (iCC) and electron channeling contrast (eCC) are caused by variation in signal resulting from changes in the angle of the incident beam and the crystal lattice with respect to the target. iCC is directly influenced by the incident ion range in crystalline materials. The ion range is larger for low-index crystal orientated grains, resulting in the emission of fewer secondary electrons at the surface yielding a lower signal. Ions are stopped closer to the surface for off-axis grains, resulting in the emission of many secondary electrons yielding a higher signal. Conversely, backscattered electrons (BSEs) are the primary contribution to eCC. BSEs are diffracted or channeled to form an electron channeling pattern (ECP). The BSE emission of the ECP peaks when the electron beam is normal to the surface of an on-axis grain, and therefore a bright signal is observed. Thus, iCC and eCC images yield inverse contrast behavior for on-axis oriented grains. Since there is a critical angle associated with particle channeling, accurately determining grain boundary locations require the acquisition of multiple images obtained at different tilt conditions.
High-Dose Ascorbic Acid Decreases Cholesterolemic Factors of an Atherogenic Diet in Guinea Pigs
Authors: Filis  , Anastassopoulou  , Sigala  , Theodorou  , Manouras  , Leandros  , Sigalas  , Hepp  , Bramis
Published: March 2013

Background: The study evaluates the effect of a high supplemental dose of ascorbic acid (AA) on plasma concentrations of total cholesterol (TC), triglycerides (TG), total lipids (TL), and lipoprotein fractions high-density, very-low-density-, and low-density lipoprotein (HDL, VLDL, LDL) in guinea pigs fed with atherogenic diet. Methods: Group I consisted of 5 normally fed guinea pigs plus a low dose of AA (1 mg/100 g/day), group II consisted of 7 guinea pigs fed with food enriched with 2% cholesterol plus a low dose of AA (1 mg/100 g/day), and group III consisted of 7 guinea pigs fed with food enriched with 2% cholesterol plus a high dose of AA (30 mg/100 g/day). Cholesterolemic factors concentrations were determined after nine weeks. Results: Concentrations of TC, TG, TL, LDL, and VLDL were increased in group II compared to group I (p < 0.01 for all differences). Supplementation with a high dose of AA resulted in decreased concentrations of TC (p < 0.01), TG (p < 0.01), TL (p < 0.01), and LDL (p < 0.01) in group III compared to group II. Additionally, concentration of HDL was increased in group III compared to group II (p < 0.01). Conclusion: High-dose AA supplementation to an atherogenic diet decreases concentrations of TC, TG, TL, and LDL and increases concentration of HDL compared to low-dose AA.
Dietary Protein Level and Dietary Interaction Affect Quinolinic Acid Concentration in Rats
Authors: Egashira  , Sato  , Saito  , Sanada
Published: March 2013

During tryptophan-niacin conversion, hepatic α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) [EC4.1.1.45] plays a key role in regulating NAD biosynthesis. ACMSD activity is greatly affected by many factors such as nutritional status and disease. The tryptophan catabolite quinolinic acid has been reported to be associated with the pathogenesis of various disorders and is a potential endogenous toxin. However the effects of dietary protein levels or dietary interaction between protein levels and fatty acid type to this process have not been investigated and are still unknown. In this study, we examined whether dietary protein level, fatty acid type, namely saturated fatty acid and polyunsaturated fatty acid, and their interaction affect serum quinolinic acid concentration in rats. Male Sprague-Dawley rats (4-weeks old) were fed with 20% casein + 10% stearic acid diet (20C10S), 20% casein + 10% linoleic acid diet (20C10L), 40% casein + 10%stearic acid diet (40C10S), or 40% casein + 10% linoleic acid diet (40C10L) for 8 days, and serum quinolinic acid concentration and ACMSD activity were determined. Serum quinolinic acid concentration was significantly increased in the 40C10L group compared with other three groups. There was also the negative correlation between the sum of liver and kidney ACMSD activities, and serum quinolinic acid concentration per tryptophan intake (r = 0.8209, p < 0.01). Increased serum QA concentrations are probably due to a decreased ACMSD activity.
Evaluation der Patientenzufriedenheit als qualitätssichernde Maßnahme im Krankenhaus in einer gastroenterologischen Abteilung
Authors: Eckhardt-Abdulla Regina
Published: March 2013

Die Bedeutung der Patientenzufriedenheit als eine Zielgröße der Qualität im Krankenhaus ist mittlerweile unbestritten. Ziel der vorliegenden Arbeit war es, die Patientenzufriedenheit vorwiegend gastroenterologischer Patienten der I. Medizinischen Universitätsklinik Halle-Wittenberg anhand eines vierdimensionalen Fragebogens zu ermitteln, um zu prüfen, inwieweit der Bogen geeignet ist, die Zufriedenheit bei dieser Patientengruppe genügend differenziert darzustellen, um daraus Verbesserungen ableiten zu können. Die vier Dimensionen umfassen: ärztliche Betreuung, pflegerische Betreuung, Unterbringung/Verpflegung sowie Organisation/Tagesablauf mit insgesamt 63 geschlossenen Fragen und zwei offenen Zusatzfragen. Von 319 verteilten Fragebögen wurden 60.5% zurückgegeben. 53.3% waren vollständig ausgefüllt und wurden in die Auswertung einbezogen. Die Ergebnisse zeigen, dass insbesondere die Kernleistungen (ärztliche und pflegerische Betreuung) sehr positiv bewertet wurden, andererseits aber auch Detailkritik zum Vorschein kam. Als Hauptunzufriedenheitsfaktor im ärztlichen/pflegerischen Bereich zeigte sich die mangelnde Diskretion bei Anamnese, Untersuchungen und intimen pflegerischen Verrichtungen im Patientenzimmer. Daneben gab es Kritik an langen Wartezeiten vor Untersuchungen, die häufig mit Nüchternsein verbunden waren. Grundsätzlich zeigte sich, dass die Zufriedenheitsbefragung anhand der vier Dimensionen ein brauchbarer und ökonomisch vertretbarer Weg zur Beurteilung der Patientenzufriedenheit bei gastroenterologischen Patienten darstellt und zusammen mit anderen Outcome-Parametern ein wichtiges Qualitätsmerkmal ist. Die Grenze eines derartigen Fragebogens zeigte sich jedoch, wenn Patienten außerhalb der Befragung konkrete zufriedenheitsrelevante Ereignisse schilderten, die aber im Fragebogen einschließlich der Freitextanmerkungen keine Erwähnung fanden.
Prinzipien und Methoden einer wissenschaftlich akkuraten Übersetzungspraxis von Instrumenten für Forschung und direkte Pflege
Authors: Martin Jacqueline S. , Vincenzi Christine , Spirig Rebecca
Published: March 2013

Kulturübergreifende, gültige und zuverlässige Instrumente wie Fragebogen oder Messinstrumente, die auch in der Pflege zunehmend gebraucht werden, sind aufwändig aufzubereiten. Die Übersetzung von bereits bestehenden, validierten Instrumenten aus einem Sprach- und Kulturraum in einen anderen ist die am häufigsten verwendete Methode um transkulturelle Instrumente zu entwickeln. Diese Vorgehensweise ist jedoch mit vielen Herausforderungen verbunden, da die Übersetzung und kulturelle Anpassung eines Instruments eine Vertrautheit mit den grundlegenden Problemen linguistischer Adaptation, den kulturellen Konzepten und den psychometrischen Veränderungen aufgrund des Übersetzungsprozesses verlangt. Die Qualität der Daten aus übersetzten Instrumenten ist jedoch von einem akkuraten Übersetzungsprozess abhängig. Der vorliegende Artikel hat zum Ziel, verschiedene Methoden, die für Übersetzungsprozesse von Instrumenten in andere Kultur- und Sprachräume verwendet werden, vorzustellen und anhand eines Anwendungsbeispiels zu illustrieren, sowie die Prinzipien für eine wissenschaftlich akkurate Übersetzungspraxis zu präsentieren.
Power angle control of grid‐connected doubly fed induction generator wind turbines for fault ride‐through
Authors: Bu S. Qiqi , Du Wenjuan , Wang Haifeng F. , Gao S.
Published: March 2013

This study proposes a power angle control strategy of grid‐connected doubly fed induction generators (DFIGs) to improve the transient performance during grid fault ride‐through (FRT). The proposed power angle control can efficiently restrict the rotor‐side current under a limited converter rating, support the terminal voltage of DFIGs and hence improve system stability during the fault period. In this study, the power angle of DFIGs in a multi‐machine power system is defined firstly and then the relation between the defined power angle and rotor‐side current surge and terminal voltage dip of DFIGs are analysed, respectively. Based on the analysis, control of DFIG power angle is implemented expediently on the existing flux magnitude and angle control (FMAC) scheme of DFIGs as an improved FMAC scheme. In this study, two test examples are presented to demonstrate and validate the effectiveness of improved FMAC with power angle control and to compare it with the conventional PQdq control and FMAC. Simulation results show that it can significantly enhance the FRT capability of grid‐connected DFIGs.
Expanding interconnection capacity to integrate intermittent generation in the Iberian Peninsula
Authors: Fernandes Camila , Frías Pablo , Olmos Luis
Published: March 2013

Increasing penetration of intermittent energy sources in power systems has been requiring higher operational flexibility and cross‐border transmission capacity. Intermittent generation, especially wind and solar power, has grown significantly in the Iberian Peninsula during the last decade and it will keep growing in the next year. Owing to limited interconnection capacity with the French and the Moroccan power systems, generation intermittency has been dealt with mostly within Spain and Portugal, helped by a flexible generation mix. Despite the relatively high flexibility of the Iberian system, in some situations, renewable generation output had to be curtailed. In general, renewable energy curtailment is an emergency action taken in case of network constraints or in case of generation surplus at single node. This emergency action is expected to be more common in the near future if no additional operating measures are taken. This study focuses on the expansion of interconnection capacity that would be required in order to integrate intermittent generation surplus in the Iberian Peninsula in the period 2020–2050. For this purpose, the trade‐off between transmission investment costs and the costs of renewable energy curtailment is analysed. Results for different intermittent generation levels and price scenarios are presented and discussed.
Breakdown of the Stokes-Einstein relation in two, three, and four dimensions
Authors: Sengupta Shiladitya , Karmakar Smarajit , Dasgupta Chandan , Sastry Srikanth
Published: March 2013

The breakdown of the Stokes-Einstein (SE) relation between diffusivity and viscosity at low temperatures is considered to be one of the hallmarks of glassy dynamics in liquids. Theoretical analyses relate this breakdown with the presence of heterogeneous dynamics, and by extension, with the fragility of glass formers. We perform an investigation of the breakdown of the SE relation in 2, 3, and 4 dimensions in order to understand these interrelations. Results from simulations of model glass formers show that the degree of the breakdown of the SE relation decreases with increasing spatial dimensionality. The breakdown itself can be rationalized via the difference between the activation free energies for diffusivity and viscosity (or relaxation times) in the Adam-Gibbs relation in three and four dimensions. The behavior in two dimensions also can be understood in terms of a generalized Adam-Gibbs relation that is observed in previous work. We calculate various measures of heterogeneity of dynamics and find that the degree of the SE breakdown and measures of heterogeneity of dynamics are generally well correlated but with some exceptions. The two-dimensional systems we study show deviations from the pattern of behavior of the three- and four-dimensional systems both at high and low temperatures. The fragility of the studied liquids is found to increase with spatial dimensionality, contrary to the expectation based on the association of fragility with heterogeneous dynamics.
Recovering the reptation dynamics of polymer melts in dissipative particle dynamics simulations via slip-springs
Authors: Langeloth Michael , Masubuchi Yuichi , Böhm Michael C. , Müller-Plathe Florian
Published: March 2013

We report a multi-chain approach for dissipative particle dynamics where the uncrossability constraints of polymer chains are mimicked by temporary cross-links, so-called slip-springs. The conformational statistics of the chains are not affected by the introduction of slip-springs. Dynamical properties such as mean square displacements, diffusion coefficient, and longest relaxation time are in good agreement with the results of reptation theory. According to our analysis, the present formalism is 500 times faster and requires 7 times fewer beads than conventional generic polymer models employing Newtonian dynamics and excluded-volume potentials.
On Lie systems and Kummer-Schwarz equations
Authors: de Lucas J. , Sardón C.
Published: March 2013

A Lie system is a system of first-order differential equations admitting a superposition rule, i.e., a map that expresses its general solution in terms of a generic family of particular solutions and certain constants. In this work, we use the geometric theory of Lie systems to prove that the explicit integration of second- and third-order Kummer-Schwarz equations is equivalent to obtaining a particular solution of a Lie system on \documentclass[12pt]{minimal}\begin{document}$SL(2,\mathbb {R})$\end{document}SL(2,R). This same result can be extended to Riccati, Milne-Pinney, and to the here defined generalised Kummer-Schwarz equations, which include several types of Kummer-Schwarz equations as particular cases. We demonstrate that all the above-mentioned equations related to the same Lie system on \documentclass[12pt]{minimal}\begin{document}$SL(2,\mathbb {R})$\end{document}SL(2,R) can be integrated simultaneously, which retrieves and generalizes in a unified and simpler manner previous results appearing in the literature. As a byproduct, we recover various properties of the Schwarzian derivative.
Growth of randomly oriented single-crystalline tin (IV) oxide nanobelts: Control on the predominant crystalline growth axis
Authors: Bazargan Samad , Leung K. T.
Published: March 2013

One-dimensional nanobelts of tin (IV) oxide are synthesized by using a newly introduced catalyst-assisted pulsed laser deposition method along two growth directions of [010] and [101]. An ex situ mask-induced growth gradient technique is employed to investigate the growth evolution of the nanobelts on oxidized-Si, H-terminated Si, and Al2O3(0001) substrates by helium ion microscopy, which reveals four stages of growth including catalyst detachment, horizontal nanorod growth, deflection, and the final nanobelt growth. X-ray diffraction and transmission electron microscopy studies show that in spite of the deflections and changes in the growth direction, the nanobelts have, remarkably, maintained their single-crystalline structure throughout the growth by only changing their crystalline growth axis. This has enabled us to influence the preferred growth axis by establishing a crystalline relation between the nanobelts and an appropriate substrate that pins the nanobelts in the initial growth stage. This growth control provides an important means to selectively promote growth of the predominant side planes of the nanobelts, which can then be separated for appropriate applications based on the different growth kinetics of [010] and [101] growth direction.
Atomic scattering from an adsorbed monolayer solid with a helium beam that penetrates to the substrate
Authors: Hansen F. Y. , Bruch L. W. , Dammann B.
Published: March 2013

Diffraction and one-phonon inelastic scattering of a thermal energy helium atomic beam are evaluated in the situation that the target monolayer lattice is so dilated that the atomic beam penetrates to the interlayer region between the monolayer and the substrate. The scattering is simulated by propagating a wavepacket and including the effect of a feedback of the inelastic wave onto the diffracted wave, which represents a coherent re-absorption of the created phonons. Parameters are chosen to be representative of an observed p(1 × 1) commensurate monolayer solid of H2/NaCl(001) and a conjectured p(1 × 1) commensurate monolayer solid of H2/KCl(001). For the latter, there are cases where part of the incident beam is trapped in the interlayer region for times exceeding 50 ps, depending on the spacing between the monolayer and the substrate and on the angle of incidence. The feedback effect is large for cases of strong transient trapping.
Charge carrier transport in molecularly doped polycarbonate as a test case for the dipolar glass model
Authors: Novikov S. V. , Tyutnev A. P.
Published: March 2013

We present the results of Monte Carlo simulations of the charge carrier transport in a disordered molecular system containing spatial and energetic disorders using the dipolar glass model. Model parameters of the material were chosen to fit a typical polar organic photoconductor polycarbonate doped with 30% of aromatic hydrazone, whose transport properties are well documented in literature. Simulated carrier mobility demonstrates a usual Poole-Frenkel field dependence and its slope is very close to the experimental value without using any adjustable parameter. At room temperature transients are universal with respect to the electric field and transport layer thickness. At the same time, carrier mobility does not depend on the layer thickness and transients develop a well-defined plateau where the current does not depend on time, thus demonstrating a non-dispersive transport regime. Tails of the transients decay as power law with the exponent close to −2. This particular feature indicates that transients are close to the boundary between dispersive and non-dispersive transport regimes. Shapes of the simulated transients are in very good agreement with the experimental ones. In summary, we provide a first verification of a self-consistency of the dipolar glass transport model, where major transport parameters, extracted from the experimental transport data, are then used in the transport simulation, and the resulting mobility field dependence and transients are in very good agreement with the initial experimental data.
Thermoelectric studies in β-Zn4Sb3—the complex interdependence between thermal stability, thermoelectric transport, and zinc content
Authors: Dasgupta T. , Stiewe C. , Sesselmann A. , Yin H. , Iversen B. B. , Mueller E.
Published: March 2013

β-Zn4Sb3 is reported to have poor thermal stability and there is a wide scatter in the thermoelectric figure of merit (ZT) measured by different groups. Here, we show that both these issues are related to the zinc concentration. Specimens of β-Zn4Sb3 having different carrier concentrations (n) have been prepared and thermoelectric property measurements carried out between room temperature and 525 K. The maximum ZT is found to vary between 0.4 and 0.85. The cause of the large variation in ZT is the strong dependence of the lattice thermal conductivity (κL) on n which make ZT sensitive to small changes in zinc concentrations. Based on analytical calculations, we show that by changing the zinc interstitial to the zinc lattice ratio, it is possible to achieve the experimental κL variation. Thermal cycling of the electrical conductivity (σ) has been performed and phase identification after each cycling is carried out from power x-ray data. Different trends are observed in the specimens depending on n with accelerated degradation occurring only in a certain range of n (∼1.2–2.5 × 1020 cm−3) corresponding to low zinc content in the matrix.
Magnetization kinetics in tension and field annealed Fe-based amorphous alloys
Authors: Hasegawa Ryusuke , Takahashi Kengo , Francoeur Bruno , Couture Pierre
Published: March 2013

Magnetization kinetics in tension-annealed and field-annealed amorphous magnetic materials indicates that strain and magnetic fields are equally effective in inducing and relaxing local structural and magnetic anisotropy changes. This observation is based on the thermomagnetic aging of the magnetic properties obtained in the materials studied.
Large electroluminescence excitation cross section and strong potential gain of erbium in ErYb silicate
Authors: Wang Bing , Guo Ruimin , Wang Xingjun , Wang Lei , Yin Bing , Zhou Zhiping
Published: March 2013

1.53 μm electroluminescence of erbium was observed in ErYb silicate metal-insulator-silicon light emitting device (MISLED). The erbium ions were excited by direct impact of hot carriers at electric field higher than 7 MV/cm. The conduction and carrier injection mechanisms were investigated. The impact excitation cross section of Er ions was measured to be 3 × 10−14 cm2, three times of Er-doped SiO2 MISLED. Rate equation modeling suggests that strong potential material's gain of more than 23 dB/cm from the ErYb silicate may be achieved by electrical pumping.
Helium at elevated pressures: Quantum liquid with non-static shear rigidity
Authors: Bolmatov D. , Brazhkin V. V. , Trachenko K.
Published: March 2013

The properties of liquid helium have always been a fascinating subject to scientists. The phonon theory of liquids, taking into account liquid non-static shear rigidity, is employed here for studying internal energy and heat capacity of compressed liquid 4He. We demonstrate the good agreement of calculated and experimental heat capacity of liquid helium at elevated pressures and supercritical temperatures. Unexpectedly, helium remains a quantum liquid at elevated pressures for a wide range of temperature supporting both longitudinal and transverse-like phonon excitations. We have found that in the very wide pressure range of 5 MPa-500 MPa, liquid helium near melting temperature is both solid-like and quantum.
Micro mold filling kinetics of metallic glasses in supercooled liquid state
Authors: Ma J. , Huo L. S. , Zhao D. Q. , Wang W. H.
Published: March 2013

The unique thermoplastic forming ability of metallic glasses in their supercooled liquid state makes them the ideal embossing materials for miniature fabrication. However, the understanding and controlling of micro filling process that is crucial for miniature fabrication and their applications remain fundamental, yet presently unresolved issues. Here, the mold filling kinetics of a model Pd-based metallic glass in supercooled liquid state is studied using different Si micro molds with different channels. A universal kinetic equation, which can describe the filling kinetics of viscous metallic supercooled liquid in micro molds with irregular shapes, is obtained.
Ferroelectric-domain-controlled magnetic anisotropy in Co40Fe40B20/YMnO3 multiferroic heterostructure
Authors: Wang J. W. , Zhao Y. G. , Fan C. , Sun X. F. , Rizwan S. , Zhang S. , Li P. S. , Lin Z. , Yang Y. J. , Yan W. S. , Luo Z. L. , Zou L. K. , Liu H. L. , Chen Q. P. , Zhang X. , Zhu M. H. , Zhang H. Y. , Cai J. W. , Han X. F. , Cheng Z. H. , Gao C. , Xie D. , Ren T. L.
Published: March 2013

We report on the magnetic properties of Co40Fe40B20/YMnO3 multiferroic heterostructures in which Co40Fe40B20 shows an in-plane uniaxial magnetic anisotropy with the magnetic easy axis along the ferroelectric polarization direction of YMnO3. The coercive field (Hc) of Co40Fe40B20 shows an interesting non-monotonic change from the easy axis to hard axis with a maximum at a certain angle. It was demonstrated that the magnetic property of Co40Fe40B20 was dominated by the FE domain induced strain and the angular dependence of Hc can be understood by the two phase model. This work is helpful for understanding the coupling between ferromagnetic and ferroelectric materials.
Electron spin dynamics of ferromagnetic Ga1−x Mnx As across the insulator-to-metal transition
Authors: Yue Han , Zhao Chunbo , Gao Haixia , Wang Hailong , Yu Xuezhe , Zhao Jianhua , Zhang Xinhui
Published: March 2013

Electron spin dephasing dynamics of ferromagnetic Ga1−xMnxAs with Mn concentration spanning from 0.5% to 15% across the insulator-to-metal transition is systematically studied using time-resolved magneto-optical Kerr effect measurements. In the insulating Ga1−xMnxAs, the impurity scattering and s-d exchange scattering induced by the magnetic impurity Mn ions are responsible for the electron spin dephasing process. While in the metallic and near metallic regime, the electron-electron Coulomb scattering becomes dominant over the impurity scattering on the spin dephasing process with D'yakonov-Perel' mechanism. Our findings are important for better engineering of Mn impurity doping in order to achieve potential Ga1−xMnxAs-based spintronics application.
Phase-change material Ge0.61Sb2Te for application in high-speed phase change random access memory
Authors: Gu Yifeng , Song Sannian , Song Zhitang , Bai Suyuan , Cheng Yan , Zhang Zhonghua , Liu Bo , Feng Songlin
Published: March 2013

Compared with Ge2Sb2Te5, Ge0.61Sb2Te has higher crystallization temperature (∼200.5 °C), larger crystallization activation energy (∼3.28 eV), and better data retention (∼120.8 °C for 10 yr). The switching between amorphous and crystalline state could be triggered by the electric pulse of as short as 10 ns. With the resistance ratio of two orders of magnitude, the endurance test was up to 106 cycles. Ge0.61Sb2Te material is a promising candidate for the trade-off between programming speed and data retention.
Measurement of elastic properties in fluid using high bandwidth atomic force microscope probes
Authors: Vijayraghavan K. , Wang A. , Solgaard O. , Butte M. J. , Melosh N. A.
Published: March 2013

High bandwidth interdigitated probes have enabled high-speed mapping of elastic properties of various samples in air. To extend this capability to imaging in fluids, we implemented a signal processing scheme to calculate the tip-sample interaction force as well as elastic properties from high-frequency photodiode signals. Using this method, we imaged a styrene-(ethylene/butylene)-styrene copolymer sample submerged in water and obtained spatial maps of elastic properties as well as maps of higher harmonics of the motion of the tip. We observed that multiple physical quantities contribute to the contrast observed in the phase and higher harmonic images.
Efficient reduction of defects in (11

2

0) non-polar and (11

2

2) semi-polar GaN grown on nanorod templates
Authors: Bai J. , Gong Y. , Xing K. , Yu X. , Wang T.
Published: March 2013

(1120) non-polar and (1122) semi-polar GaNs with a low defect density have been achieved by means of an overgrowth on nanorod templates, where a quick coalescence with a thickness even below 1 μm occurs. On-axis and off-axis X-ray rocking curve measurements have shown a massive reduction in the linewidth for our overgrown GaN in comparison with standard GaN films grown on sapphire substrates. Transmission electron microscope observation demonstrates that the overgrowth on the nanorod templates takes advantage of an omni-directional growth around the sidewalls of the nanostructures. The dislocations redirect in basal planes during the overgrowth, leading to their annihilation and termination at voids formed due to a large lateral growth rate. In the non-polar GaN, the priority 〈0001〉 lateral growth from vertical sidewalls of nanorods allows basal plane stacking faults (BSFs) to be blocked in the nanorod gaps; while for semi-polar GaN, the propagation of BSFs starts to be impeded when the growth front is changed to be along inclined 〈0001〉 direction above the nanorods.
Electric-double-layer transistors with thin crystals of FeSe1−xTex (x = 0.9 and 1.0)
Authors: Eguchi R. , Senda M. , Uesugi E. , Goto H. , Kambe T. , Noji T. , Koike Y. , Fujiwara A. , Kubozono Y.
Published: March 2013

Field-effect transistor (FET) devices using thin crystals of FeSe1−xTex (x = 0.9 and 1.0) have been fabricated with an electric-double-layer (EDL) capacitor. Despite the presence of substantial quantities of electron and hole carriers in the bulk due to the semimetallic electronic structure of FeSe1−xTex, we have observed p-channel depletion-type FET characteristics, in contrast to the n-channel normally on FET characteristics of a Bi2Se3 EDL FET. In FeSe1−xTex, the mobile carriers, holes, are depleted in the channel region by accumulating electrons, resulting in a decrease in conductivity. This result is consistent with the experimentally observed positive Hall coefficient at room temperature.
Deep-ultraviolet lasing at 243 nm from photo-pumped AlGaN/AlN heterostructure on AlN substrate
Authors: Lochner Zachary , Kao Tsung-Ting , Liu Yuh-Shiuan , Li Xiao-Hang , Mahbub Satter Md. , Shen Shyh-Chiang , Douglas Yoder P. , Ryou Jae-Hyun , Dupuis Russell D. , Wei Yong , Xie Hongen , Fischer Alec , Ponce Fernando A.
Published: March 2013

Deep-ultraviolet lasing was achieved at 243.5 nm from an AlxGa1−xN-based multi-quantum-well structure using a pulsed excimer laser for optical pumping. The threshold pump power density at room-temperature was 427 kW/cm2 with transverse electric (TE)-polarization-dominant emission. The structure was epitaxially grown by metalorganic chemical vapor deposition on an Al-polar free-standing AlN (0001) substrate. Stimulated emission is achieved by design of the active region, optimizing the growth, and the reduction in defect density afforded by homoepitaxial growth of AlN buffer layers on AlN substrates, demonstrating the feasibility of deep-ultraviolet diode lasers on free-standing AlN.
Saliva sharing in the allied rock-wallaby, Petrogale assimilis
Authors: Davies W. G.
Published: March 2013

Prolonged licking of the mouth of one individual by another has so far been reported for two species of rock-wallaby and the red kangaroo. It may occur in other macropodids. It is suggested that the primary function of lip-licking is the transfer of saliva to the fore-stomach of the licker so as to maintain water content of digesta at a sufficient level for efficient digestive fermentation. Lip-licking may be a useful behavioural indicator that water intake from milk, vegetation or drinking water is inadequate.The occurrence of the behaviour outside the mother–young relationship is indicative of the high level of cooperation that has evolved in Petrogale assimilis.
Morphology, sex ratio and cause of death in Australian sea lion (Neophoca cinerea) pups
Authors: McIntosh Rebecca R. , Kennedy Clarence W.
Published: March 2013

During a study of the demographics of the Australian sea lion (Neophoca cinerea), the sex ratio and morphology were obtained from 128 pups at Seal Bay Conservation Park over three breeding seasons (2002–03, 2004 and 2005–06). Gross necropsies were also performed. Dead pups were small and young, averaging 8.0 and 7.0 kg in weight, and 75.2 and 71.3 cm in length, for males and females respectively, only 1.8 kg heavier and 6.7 cm longer than newborn pups. There was no sex bias in the dead pups overall or in each cause of death classification. In 49% of mortalities, cause of death could not be inferred from gross necropsy and pups appeared in good condition. In pups in which cause of death was inferred, trauma inflicted by conspecifics was the primary result in both males and females (31.6%), followed by emaciation (10.4%), stillbirth or premature birth (7.6%) and possible shark attack (1.4%). Histopathological examination of tissues and other investigations would be required to determine whether other factors, such as disease or parasitic infection, and pollutant contamination contribute to pup mortality.
Awareness and knowledge of syphilis among different populations in Guangzhou, Guangdong Province, China
Authors: Ying Liu , Shaokai Tang , Xingdong Ye , Wanping He , Jinliang Li , Qian Yang , Kexian Gao
Published: March 2013

The purpose of this study was to investigate the awareness of different populations about syphilis in Guangzhou, the capital city of Guangdong Province, China. A questionnaire survey was conducted, and awareness rates of different groups were calculated. The results suggested that the awareness rates of syphilis knowledge in the surveyed subjects were low, and targeted health education and health promotion should be strengthened.
Proactive control of sequential saccades in the human supplementary eye field
Authors: Sharika K. M. , Neggers Sebastiaan F. W. , Gutteling Tjerk P. , Van der Stigchel Stefan , Dijkerman H. Chris , Murthy Aditya
Published: March 2013

Our ability to regulate behavior based on past experience has thus far been examined using single movements. However, natural behavior typically involves a sequence of movements. Here, we examined the effect of previous trial type on the concurrent planning of sequential saccades using a unique paradigm. The task consisted of two trial types: no-shift trials, which implicitly encouraged the concurrent preparation of the second saccade in a subsequent trial; and target-shift trials, which implicitly discouraged the same in the next trial. Using the intersaccadic interval as an index of concurrent planning, we found evidence for context-based preparation of sequential saccades. We also used functional MRI-guided, single-pulse, transcranial magnetic stimulation on human subjects to test the role of the supplementary eye field (SEF) in the proactive control of sequential eye movements. Results showed that (
i
) stimulating the SEF in the previous trial disrupted the previous trial type-based preparation of the second saccade in the nonstimulated current trial, (
ii
) stimulating the SEF in the current trial rectified the disruptive effect caused by stimulation in the previous trial, and (
iii
) stimulating the SEF facilitated the preparation of second saccades based on previous trial type even when the previous trial was not stimulated. Taken together, we show how the human SEF is causally involved in proactive preparation of sequential saccades.