bluuebunny/crossref_metadata_2025 huggingface dataset:
Halting scale and energy equilibration in two-dimensional quasigeostrophic turbulence
Authors: Scott R. K. , Dritschel D. G.
Published: March 2013

The halting scale of the inverse energy cascade and the partition between kinetic and potential energy are considered for the case of forced quasigeostrophic turbulence in the regime of intermediate Rossby deformation length, for which the deformation length is comparable to the energy-containing scales of the flow. Phenomenological estimates for the halting scale and equilibrated energy of the forced–dissipative system with a simple representation of large-scale thermal damping are tested against numerical integrations and are found to poorly describe the numerically obtained dependence on damping coefficient; a modified scaling law is proposed that more accurately describes the dependence. The scale-selective nature of the damping leads to a large-scale spectral bottleneck that steepens the energy spectrum, consistent with previous studies of hypodiffusive dissipation. It is found that, across the parameter range considered, the blocking is largely insensitive to the ratio of deformation radius to the energy-containing scales.
Dietary glycaemic index and glycaemic load in relation to food and nutrient intake and indices of body fatness in British children and adolescents
Authors: Murakami Kentaro , McCaffrey Tracy A. , Livingstone M. Barbara E.
Published: March 2013

The diversity of the associations of dietary glycaemic index (GI) and glycaemic load (GL) with dietary intake and body fatness observed in epidemiological studies may be partly due to the differences in underlying dietary intake patterns. We examined the cross-sectional associations of dietary GI and GL with food and nutrient intakes and indices of body fatness in 818 children aged 4–10 years and 818 adolescents aged 11–18 years in Britain, based on the data from the National Diet and Nutrition Survey. Dietary intake was assessed using a 7 d weighed dietary record. Overweight was defined as BMI ≥ 85th percentile of the age- and sex-specific British growth reference data. Central obesity was defined as waist:height ratio (WHtR) ≥ 0·5 (adolescents only). Breads, breakfast cereals and potatoes were the positive predictive food groups for dietary GI, while dairy products, fruit juice, other cereals and fruit were the negative predictors. Dietary GL was closely correlated with carbohydrate intake. Dietary GI showed no associations with overweight or central obesity. Conversely, dietary GL showed an independent association with a higher risk of overweight in children and a higher risk of central obesity (but not overweight) in adolescents. However, dietary GI and GL were not associated with BMI z-score in children and adolescents or WHtR in adolescents. In conclusion, the present study showed that dietary GL was independently associated with overweight in children and with central obesity in adolescents. Nevertheless, given no associations when body fatness measures were treated as continuous variables, the results must be interpreted cautiously.
Glycaemic index, carbohydrate substitution for fat and risk of CHD in men
Authors: Similä Minna E. , Kontto Jukka P. , Männistö Satu , Valsta Liisa M. , Virtamo Jarmo
Published: March 2013

We have examined the associations between dietary glycaemic index (GI), substitutions of total, low-, medium- and high-GI carbohydrates for fat and the risk of CHD. The study consisted of 21 955 male smokers, aged 50–69 years, within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. The diet was assessed at baseline using a validated FFQ. During a 19-year follow-up, 4379 CHD cases (2377 non-fatal myocardial infarctions and 2002 CHD deaths) were identified from national registers. Relative risks (RR) and CI for CHD were analysed using Cox proportional hazards modelling, and multivariate nutrient density models were applied to examine the associations between the substitutions of macronutrients and the risk of CHD. Dietary GI was inversely associated with CHD risk: multivariate RR in the highest v. lowest quintile was 0·89 (95 % CI 0·81, 0·99). Replacement of higher-GI carbohydrates with lower-GI carbohydrates did not associate with the risk. Replacing saturated and trans-fatty acids with carbohydrates was associated with decreased CHD risk: RR for substitution of 2 % of energy intake was 0·97 (95 % CI 0·94, 0·99). On the contrary, replacing MUFA with carbohydrates was associated with an increased risk: RR for substitution of 2 % of energy intake was 1·08 (95 % CI 1·01, 1·16). We conclude that in the present study population, contrary to the hypothesis, a lower GI does not associate with a decreased risk of CHD. The associations of carbohydrates with CHD risk depend on the fatty acid composition of the diet.
Photo-ionized neon plasmas induced by radiation pulses of a laser-plasma EUV source and a free electron laser FLASH
Authors: Bartnik A. , Fedosejevs R. , Wachulak P. , Fiedorowicz H. , Serbanescu C. , Saiz E.G. , Riley D. , Toleikis S. , Neely D.
Published: March 2013

In this work, a laser-produced plasma extreme ultraviolet source and a free electron laser were used to create Ne photo-ionized plasmas. In both cases, a radiation beam was focused onto a gas stream injected into a vacuum chamber synchronously with the radiation pulse. Extreme ultraviolet radiation from the plasma spanned a wide spectral range with pronounced maximum centered at λ = 11 ± 1 nm while the free electron laser pulses were emitted at a wavelength of 32 nm. The power density of the focused plasma radiation was approximately 2 × 107 W/cm2 and was seven orders of magnitude lower compared with the focused free electron laser beam. Radiation fluences in both experimental conditions were comparable. Despite quite different spectral characteristics and extremely different power densities, emission spectra of both photo-ionized plasmas consist of the same spectral lines within a wavelength range of 20 to 50 nm, however, with different relative intensities of the corresponding lines. The dominating spectral lines originated from singly charged ions (Ne II); however, Ne III lines were also detected. Additionally, computer simulations of the emission spectra, obtained for photo-ionized plasmas, driven by the plasma extreme ultraviolet source, were performed. The corresponding measured and calculated spectra are presented. An electron temperature and ionic composition were estimated. Differences between the experimental spectra, obtained for both irradiation conditions, were analyzed. The differences were attributed mainly to different energies of driving photons.
Stiffness analysis of the 3SPS+1PS bionic parallel test platform for a hip joint simulator
Authors: Cheng Gang , Yu Jingli , Xu Peng , Liu Houguang
Published: March 2013

A novel parallel hip joint simulator, called 3SPS+1PS bionic parallel test platform, with 4 degrees of freedom including three rotations and one translation is designed to represent three-dimensional motion and compound friction movement of a human hip joint and to be a better simulator for testing the tribology performance of biomaterials for hip joint prosthesis. Stiffness is one of the most important performances of parallel manipulators, as well as for the 3SPS+1PS parallel manipulator with higher speeds. First, the differential kinematic/static model was derived based on the kinematics model. The relationship between the elastic deformation of each active leg and the variation of position/orientation deformation of the moving platform was described based on the virtual work principle. Then, a 6 × 6 global stiffness matrix of the 3SPS+1PS parallel manipulator was derived. The maximum versus minimum eigenvalues of the global stiffness matrix were obtained as its two evaluation indexes. By letting the 3SPS+1PS bionic parallel test platform represent three rotation motions and the dynamic loading of the human hip joint as described by ISO 14242 Part-1, the forces acted on each active leg and their responding elastic deformations were analyzed. The distributions for maximum and minimum stiffness in different workspace were detected. Finally, the results showed that the minimum stiffness in the whole workspace should be larger than the allowable stiffness of the 3SPS+1PS parallel manipulator.
How early do children understand gesture–speech combinations with iconic gestures?
Authors: STANFIELD CARMEN , WILLIAMSON REBECCA , ÖZÇALIŞKAN ŞEYDA
Published: March 2013

Children understand gesture+speech combinations in which a deictic gesture adds new information to the accompanying speech by age 1;6 (Morford & Goldin-Meadow, 1992; ‘push’+point at ball). This study explores how early children understand gesture+speech combinations in which an iconic gesture conveys additional information not found in the accompanying speech (e.g., ‘read’+BOOK gesture). Our analysis of two- to four-year-old children's responses in a gesture+speech comprehension task showed that children grasp the meaning of iconic co-speech gestures by age three and continue to improve their understanding with age. Overall, our study highlights the important role gesture plays in language comprehension as children learn to unpack increasingly complex communications addressed to them at the early ages.
Introduction: music, the city and the modern experience
Authors: PROKOPOVYCH MARKIAN
Published: March 2013

It is somewhat surprising that music has only recently become a serious subject for urban historians. Musicologists and music historians, urban geographers, planners and all others who deal with diverse aspects of local development, cultural industry and the built environment have fared much better in tackling the fundamental social implications of music in a particular locality. It is not an accident that, for example, the recent volume ofBuilt Environment, ‘Music and the city’, edited by an economic geographer, Robert C. Kloosterman, deals with urban spaces of creativity and the role of black music today, some of which have by now an ascribed ‘urban’ adjective in North America.1It is also only natural, however, that Kloosterman's enquiry should concentrate on music in the city of the present and rarely venture into the time periods before World War II.
Stages in the early and larval development of the African catfish Clarias gariepinus (Teleostei, Clariidae)
Authors: Olaniyi Wasiu Adekunle , Omitogun Ofelia Galman
Published: March 2013

The African catfish Clarias gariepinus Burchell 1822 is a favourite aquaculture fish in many parts of Africa and Asia because of its hardiness and fast growth rate. In this study, early, post-embryonic and larval developmental stages of C. gariepinus were examined chronologically and described. Photomicrographs of unfertilized matured oocytes from 0 min of fertilization through all cell stages to alevin, to complete yolk absorption, to free swimming larval stages are shown and documented live from lateral and top views, with the aid of a light microscope. Extruded oocytes had a mean diameter of 1 ± 0.1 mm, and possessed a thin perivitelline membrane whose space was filled with a protoplasmic layer. Heartbeat was in the range of 115–160/min prior to hatching. Hatchability rate was 85% and hatching occurred at 17 h at a controlled temperature of 28.5 ± 0.5°C, while ontogeny of the eyes and other organs were discernible. At day 4, larvae mean length was 9.3 ± 0.5 mm, exogenous feeding had commenced fully and melanophores spread cephalocaudally but were concentrated significantly on the head parts. This paper, for the first time, presents the significant chronological developmental stages of C. gariepinus embryology that will have significant implications for genetic manipulation and catfish seed production for aquaculture.
The impact of actual and perceived disease severity on pre-operative psychological well-being and illness behaviour in adult congenital heart disease patients
Authors: Callus Edward , Utens Elisabeth M. W. J. , Quadri Emilia , Ricci Cristian , Carminati Mario , Giamberti Alessandro , Chessa Massimo
Published: March 2013

Objectives: The purpose of this study was to investigate whether the objective medical parameters related to congenital heart disease and patients’ ratings of cardiac disease severity were related to psychological well-being and illness behaviour during the pre-operative period.Methods: A total of 143 patients (63 male patients; 16–73 years old) with congenital heart disease evaluated the severity of their cardiac condition using a numerical rating scale ranging from 0, indicating the least severe condition, to 100, indicating the most severe condition. Psychological well-being was assessed using the Psychological General Well-Being Index (total score ≤60 indicating severe distress) and illness behaviour using the Illness Behavior Questionnaire.Results: Pre-operative psychological well-being was not related to the objective medical parameters reflecting cardiac disease severity. In contrast, total psychological well-being scores correlated significantly with patients’ subjective ratings of disease severity (p < 0.001). When compared with the reference values from the Italian population, the mean scores of the patients on psychological well-being were similar. As regards the Illness Behavior Questionnaire, the scores on denial were higher and those on hypochondria were lower compared with other hospitalised patients.Conclusions: This study shows that the perception of cardiac disease severity, and not the medical parameters in congenital heart disease, is related to the patients’ pre-operative psychological state. Thus, more importance needs to be given to assessing the patients’ pre-operative perception and psychological state independently of cardiac severity. Targeted interventions with regard to the cardiac condition are recommended.
Stenting of the right ventricular outflow tract in symptomatic neonatal tetralogy of Fallot
Authors: Haas Nikolaus A. , Laser Thorsten K. , Moysich Axel , Blanz Ute , Sandica Eugen
Published: March 2013

There is ongoing debate regarding the initial management of symptomatic neonates with tetralogy of Fallot. Although neonatal repair can be performed with low mortality, it is associated with increased morbidity and long-term impact on right ventricular performance. Traditionally, the modified Blalock–Taussig shunt remains the palliative procedure of choice. Differential pulmonary artery flow may occur and subsequently result in underdevelopment and distortion of pulmonary vessels. Transcatheter therapy was previously limited to balloon valvulotomy when the obstruction is predominantly at the pulmonary valve level. Stenting of the right ventricular outflow tract can enable adequate forward flow; however, pulmonary regurgitation may impact on right ventricular performance and cardiac output. Stenting of the right ventricular outflow tract with valve sparing placement of the stent thus treating the underlying pathophysiology of the hypercyanotic spells provides a safe and effective management strategy, improving arterial oxygen saturation, avoiding pulmonary regurgitation and encouraging pulmonary artery growth.
Preparedness for and Impact of Tropical Cyclone Yasi in North Queensland, Australia
Authors: Usher Kim , Buettner Petra , West Caryn , Millis Jane , Woods Cindy , Mason Matt , Boon Helen , Chamberlain-Salaun Jennifer
Published: March 2013

Introduction

Tropical cyclone (TC) Yasi, thought to be the largest and most severe cyclone to cross the Queensland coast since 1918, made landfall on the southern tropical coast near Mission Beach and continued to track westward across Northern Queensland on February 3, 2011. The warning and response model (WRM) suggests that situational factors, personal characteristics, and social contextual variables influence the degree of threat perceived and protective actions taken.

Aim

The aim of this study was to examine preparation for this impending natural disaster by residents of the affected regions, and to identify the residents’ resource losses and symptoms of psychological distress following TC Yasi.

Methods

A cross-sectional survey was conducted 6-12 months after the cyclone using an adapted tool designed to measure preparedness, loss and psychosocial distress. Four hundred and thirty-three responses were received. Statistical analysis was conducted using Statistical Package for the Social Sciences (SPSS). Categorical characteristics were described using sample size and percentages.

Results

Almost all respondents perceived the cyclone warning as serious or very serious, and more than a third started preparing for the cyclone at least three days before it reached landfall. Overall, 115 (26.7%) respondents reported moderate and 59 (13.7%) reported major property damage; 72 (17.1%) reported a moderate and 49 (11.6%) reported a major change in their feeling of whether they have control over their life; 55 (13.1%) reported a major change in their motivation of getting things done; and 33 (7.9%) reported a major change in their perception of feeling valuable to others. Overall, 142 (34.1%) documented at least one of five symptoms of acute distress.

Conclusion

The findings document the experiences of Australians who have lived through tropical cyclone Yasi. The results support the WRM theory which proposes that people with previous experience take threatened disasters seriously.

UsherK,BuettnerP,WestC,MillisJ,WoodsC,MasonM,BoonH,Chamberlain-SalaunJ.Preparedness for and impact of tropical cyclone Yasi in North Queensland, Australia.Prehosp Disaster Med.2013;28(3):1-7.
The Dramaturgical and Compositional Genesis of Luigi Nono's Intolleranza 1960
Authors: DE BENEDICTIS ANGELA IDA , O'DONNELL JOHN
Published: March 2013

Intolleranza 1960, an ‘azione scenica in two parts based on an idea by Angelo Maria Ripellino, music by Luigi Nono’, was first performed on 13 April 1961 during the 24th International Contemporary Music Festival at the Teatro La Fenice in Venice. In the aftermath of the première, critics perceived a gap in the work's realization between intentions and results, a gap perceived mainly in political terms. An examination of the dramaturgical and compositional genesis of the work through the sketches suggests a gap of a very different nature. The work as originally announced was to have revolutionary potential, and the innovations were intended by Nono to affect the musical language, the staging, and the dramatic content. But many of these ideas and innovations remained unrealized in the final production, while the ambitious dramaturgical logic underpinning the compositional process – involving ‘character rows’ for each of the principal roles – was never fully implemented. Nono's first theatrical work proves to be the result of a singular compromise between intention and necessity, something quite different from the original project. Nevertheless, the compositional solutions forced on Nono, partly through pressures of time, were to prove decisive in later works, liberating the now ‘autonomous’ interval from parametric predetermination and classic serial grids. Moreover, the work, which had been envisaged as an ideal convergence of dramaturgical and technical principles, became an emblem not only of the new music theatre but of avant-garde theatre in general.
A Sign of the Times: Semiotics in Anglo-American Musicology
Authors: HOOPER GILES
Published: March 2013

This article provides a critical account of the appropriation of semiotics in Anglo-American musicology, its theoretical and discursive foundations, and its impact on the discipline in the period from the mid-1970s to the present. Starting out from the work of Jean-Jacques Nattiez and Philip Tagg in the 1970s, it traces two principal approaches in music semiotics, here termed the ‘structural–analytical’ and the ‘semantic–interpretative’, which draw in significant measure on, respectively, the Saussurean and Peircean legacies. Both differences of musicological tradition and the wider state of the discipline have a part to play in explaining why semiotics never established itself as a discrete and distinctive subfield in the English-speaking world in the way that it did in continental Europe. But with the increasing currency of, among other concerns, topic theory, theories of emotion and affect, and studies of musical gesture and metaphor, it might be argued that semiotics – or, rather, an interdisciplinary aggregation of approaches that might be termed ‘post-semiotic’ – has never had a stronger presence in anglophone musicology than at the present time.
Resituating the Icon: David Osmond-Smith's Contribution to Music Semiotics
Authors: CURRY BEN
Published: March 2013

After pursuing doctoral studies at the University of York (1968–70), David Osmond-Smith gained two consecutive scholarships, allowing him to research first with Umberto Eco in Milan (1970–71) and then with Roland Barthes in Paris (1971–3). One of the outcomes of his encounters with these highly influential thinkers was a series of articles subjecting musical phenomena to semiotic analysis. The principal concept deployed in these articles is that of the icon or iconism, itself borrowed from the American semiotician and pragmatist philosopher Charles Sanders Peirce and exhaustively examined, re-examined, and criticized by Eco. This article explains the principles of iconic signification and their use in Osmond-Smith's work. Central to this explanation is a consideration of Eco's work on iconism (Barthes's influence is less apparent) and the somewhat perplexing point that Osmond-Smith embraced iconism despite his awareness – and, at times, apparent endorsement – of Eco's thoroughgoing critique of the concept. Lastly, the recent resurgence of interest in Peircian semiotics will be invoked in order to propose ways of developing Osmond-Smith's application of iconism to music in line with pragmatist (or, to use Peirce's term, pragmaticist) rather than structuralist thought.
Straightening the Record: Morton Feldman's Return to Graph Music
Authors: CLINE DAVID
Published: March 2013

Morton Feldman composed his first works on graph paper in 1950–53, but he subsequently abandoned graph music, before taking it up again in 1958 at a time of rapidly increasing interest in musical indeterminacy and graphic notations in the United States and Europe. Feldman's return to graph music was a turning point in his career that would affect his subsequent output for almost a decade, but his principal surviving account of this change in his musical direction, which appeared in liner notes for an LP record, is misleading. This article presents a revised account that highlights a previously undocumented and atypical graph work that was used by John Cage to derive the graph now known as Ixion. In addition, it reveals links between Feldman's compositional ideas and those of Henry Cowell, explains how Robert Rauschenberg inadvertently affected the sound of Feldman's graph music for several years, and clarifies Feldman's response to problems he encountered in performances of his graph music.
Understanding Indeterminate Music through Performance: Cage's Solo for Piano
Authors: THOMAS PHILIP
Published: March 2013

This article demonstrates how performance may further understanding of – and offer new perspectives on – indeterminate music, and in particular the ways in which performers realize the indeterminate aspects of the scores. Cage's Solo for Piano (1957–8), one of the most celebrated indeterminate scores, is used as the model for such an approach. The close involvement that performers have with the score and the music over what is often a prolonged period of time leads to a particular kind of understanding, different from that of non-performers, which, when articulated, can offer valuable insights. After a brief outline of the score, the article begins by discussing the performances of other pianists, notably David Tudor. It then examines in detail the author's own approach to making a realization, discussing the implications of such an approach from both practical and aesthetic perspectives.
A new application of bagasse char as a solar energy absorption and accumulation material
Authors: Kondo Yoshikazu , Fukuzawa Yasunori , Kawamitsu Yoshinobu , Ueno Masami , Tsutsumi Junichiro , Takemoto Tetsuya , Kawasaki Shinichi
Published: March 2013

This study is concerned with the relationship between carbonisation conditions and properties of the resultant bagasse char, and the challenging proposal for the use of fine bagasse char particles as high-performance solar light collectors. Bagasse char was obtained by carbonising raw bagasse at temperatures of 200–900°C for three hours in nitrogen (N2) gas. Characterisation of the resultant bagasse char was performed by elemental analysis (EA), scanning electric microscope (SEM) observation, estimation of colour, nominal bulk density and evaluation of specific surface area and pore structure by N2 gas absorption/desorption. The most typical property of the resultant bagasse char is its unique pore structure, which is clear in SEM observation. The largest specific surface area of bagasse char in this study was about 600 m2/g, which is as large as commercial activated carbon materials. Macro-, meso- and micro-porous structures in the bagasse char induce many important characteristics, such as increased hydrophilicity, very low bulk density and excellent light absorption and accumulation. We also suggest the use of bagasse char as an excellent heat insulation material. The energy used for air conditioning in a private house or office building can be decreased by more than 50–60% by use of this insulator on the roof or walls.
Science, Politics and Transnational Regulation: Regulatory Scientific Institutions and the Dilemmas of Hybrid Authority
Authors: Ayal Adi , Hareuveny Ronen , Perez Oren
Published: March 2013

The main objective of this article is to develop a better understanding of the structure of transnational regulatory scientific institutions (RSIs). We will argue that the hybrid political-legal-epistemic nature of RSIs creates a continual tension between their hierarchical and policy-driven structure and the paradigms of objectivity, parallelism and non-centralism that characterize science. The article examines the way in which RSIs cope with the challenge of maintaining their epistemic/political authority against the tensions generated by their hybrid structure. The article focuses on three institutions: the Intergovernmental Panel on Climate Change (IPCC), the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and the International Competition Network (ICN), and examines how this challenge manifests itself in the context of these three bodies. The article links the discussion of hybrid authority with the problem of scientific uncertainty. It concludes with a discussion of the optimal design of RSIs.
Validierung einer deutschsprachigen 16-Item-Version des Inventars der Persönlichkeitsorganisation (IPO-16)
Authors: Zimmermann Johannes , Benecke Cord , Hörz Susanne , Rentrop Michael , Peham Doris , Bock Astrid , Wallner Tanja , Schauenburg Henning , Frommer Jörg , Huber Dorothea , Clarkin John F. , Dammann Gerhard
Published: March 2013

In diesem Artikel wird eine deutschsprachige Kurzskala des Inventars der Persönlichkeitsorganisation (IPO-16) vorgestellt und in drei klinischen Stichproben mit insgesamt 1300 Personen validiert. Das IPO ist ein international verbreitetes Selbsteinschätzungsinstrument, das in mehreren Versionen vorliegt und zur Erfassung von struktureller Beeinträchtigung in den Bereichen Identität, Abwehr und Realitätsprüfung eingesetzt wird. Die Kurzskala basiert auf 16 versionsübergreifenden IPO-Items und misst den Schweregrad der strukturellen Beeinträchtigung. In den Studien konnte gezeigt werden, dass das IPO-16 (1) intern konsistent ist, (2) eine modellkonforme Faktorenstruktur hat, (3) eine sehr hohe Überlappung zur IPO-Vollversion aufweist, (4) in der Selbsteinschätzung über konvergente und diskriminante Validität verfügt, (5) den Schweregrad der Persönlichkeitsstörung aus Expertensicht unabhängig vom aktuellen Leidensdruck vorhersagt und (6) eine diagnostische Effizienz erreicht, die mit anderen Screening-Instrumenten im Bereich der Persönlichkeitsstörungsdiagnostik vergleichbar ist. Mit dem IPO-16 liegt für den deutschsprachigen Raum erstmals ein ökonomisches und gut validiertes Selbsteinschätzungsinstrument zur Erfassung von struktureller Beeinträchtigung vor.
Andreev-reflection spectroscopy with superconducting indium—A case study
Authors: Gloos Kurt , Tuuli Elina
Published: March 2013

We have investigated Andreev reflection at interfaces between superconducting indium (Tc = 3.4 K) and several normal conducting nonmagnetic metals (palladium, platinum, and silver) down to T = 0.1 K as well as zinc (Tc = 0.87 K) in its normal state at T = 2.5 K. We analyzed the point-contact spectra with the modified one-dimensional BTK theory valid for ballistic transport. It includes Dynes' quasiparticle lifetime as fitting parameter Γ in addition to superconducting energy gap 2Δ and strength Z of the interface barrier. For contact areas from less than 1 nm2 to 10 000 nm2 the BTK Z-parameter was close to 0.5, corresponding to transmission coefficients of about 80%, independent of the normal metal. The very small variation of Z indicates that the interfaces have a negligible dielectric tunneling barrier. Also Fermi surface mismatch does not account for the observed Z. The extracted value Z ≈ 0.5 can be explained by assuming that practically all of our point contacts are in the diffusive regime.
Cathodic corrosion. II. Properties of nanoparticles synthesized by cathodic corrosion
Authors: Yanson A. I. , Yanson Yu. I.
Published: March 2013

We demonstrate how cathodic corrosion in concentrated aqueous solutions enables one to prepare nanoparticles of various metals and metal alloys. Using various characterization methods we show that the composition of nanoparticles remains that of the starting material, and the resulting size distribution remains rather narrow. For the case of platinum we show how the size and possibly even the shape of the nanoparticles can be easily controlled by the parameters of corrosion. Finally, we discuss the advantages of using the nanoparticles prepared by cathodic corrosion for applications in (electro-)catalysis.
Wigner function description of a qubit-oscillator system
Authors: Allen James , Zagoskin A. M.
Published: March 2013

We derive Bloch-type equations of motion for the Wigner function of a qubit nonlinearly coupled to a linear oscillator, and investigate their application to the quantum-classical transition.
Electronic structure and electrical transport in ternary Al-Mg-B films prepared by magnetron sputtering
Authors: Yan C. , Jha S. K. , Qian J. C. , Zhou Z. F. , He B. , Ng T. W. , Li K. Y. , Zhang W. J. , Bello I. , Klemberg-Sapieha J. E. , Martinu L.
Published: March 2013

Nanostructured ternary Al-Mg-B films possess high hardness and corrosion resistance. In the present work, we study their electronic structure and electrical transport. The films exhibit semiconducting characteristics with an indirect optical-bandgap of 0.50 eV, as deduced from the Tauc plots, and a semiconductor behavior with a Fermi level of ∼0.24 eV below the conduction band. Four-probe and Hall measurements indicated a high electrical conductivity and p-type carrier mobility, suggesting that the electrical transport is mainly due to hole conduction. Their electrical properties are explained in terms of the film nanocomposite microstructure consisting of an amorphous B-rich matrix containing AlMgB14 nanoparticles.
360 degree domain walls monitored by anisotropic magnetoresistance measurements
Authors: Nam Chunghee , Ross C. A.
Published: March 2013

This study investigates the electrical observation of the formation of a 360° magnetic domain wall (360DW) in an elliptical Co ring structure. Because the 360DW consists of two 180° domain walls, a decrease in resistance is observed in the switching process due to anisotropic magnetoresistance (AMR). Certain AMR measurements exhibit an increase in the resistance in the switching process, indicating that a flux-closure vortex state is formed without first forming a 360DW state. The difference between the 360DW and vortex state in the switching process reflects differences in the DW depinning mechanism from the onion state. The minor loop of the AMR measurements is also dependent on the initial magnetic configuration between the 360DW and the vortex state.
Thermal hysteresis of interface biased dipolar coupled nanoelements
Authors: Dantas Ana L. , Queiroz Idalmir , Reboucas Gustavo , Dias Maria G. , Carriço A. S.
Published: March 2013

We report a theoretical investigation of thermal hysteresis of a pair of interface biased elliptical iron nanoelements, separated by an ultrathin layer of nonmagnetic material. The thermal hysteresis originates in the strong dipolar interaction, and is tunable by the nature of the low temperature state and the eccentricity of the nanoelements. The width of the thermal hysteresis varies from 500 K to 100 K for lateral dimensions of 125 nm × 65 nm and 145 nm × 65 nm.
Comment on “The origins of pressure-induced phase transitions during the surface texturing of silicon using femtosecond laser irradiation” [J. Appl. Phys. 112, 083518 (2012)]
Authors: Munawar Chaudhri M.
Published: March 2013

Smith et al. [Appl. Phys. 112, 083518 (2012)] have reported that the irradiation of Si (100) with femtosecond laser pulses of a sufficiently high fluence, about 4 kJ m−2, results in the formation of the Si-III and Si-XII phases in the irradiated region. These authors have also suggested that the formation of the Si-III and Si-XII phases is due to the pressure-induced phase transitions in the silicon. It is argued here that Smith et al. [Appl. Phys. 112, 083518 (2012)] have incorrectly assigned the observed Raman peaks at 354 and 395 cm−1 to the Si-XII phase and that these peaks are due to the Si-III phase.
Double excitations from modified Hartree Fock subsequent minimization scheme
Authors: Tassi M. , Theophilou Iris , Thanos S.
Published: March 2013

Doubly excited states have nowadays become important in technological applications, e.g., in increasing the efficiency of solar cells and therefore, their description using ab initio methods is a great theoretical challenge as double excitations cannot be described by linear response theories based on a single Slater determinant. In the present work we extend our recently developed Hartree-Fock (HF) approximation for calculating singly excited states [M. Tassi, I. Theophilou, and S. Thanos, Int. J. Quantum Chem. 113, 690 (2013)10.1002/qua.24049] in order to allow for the calculation of doubly excited states. We describe the double excitation as two holes in the subspace spanned from the occupied HF orbitals and two particles in the subspace of virtual HF orbitals. A subsequent minimization of the energy results to the determination of the spin orbitals of both the holes and the particles in the occupied and virtual subspaces, respectively. We test our method, for various atoms, H2 and polyene molecules which are known to have excitations presenting a significant double excitation character. Importantly, our approach is computationally inexpensive.
Arrays of ordered nanostructures in Fe-Pt thin films by self-assembling of polystyrene nanospheres
Authors: Tiberto Paola , Barrera Gabriele , Boarino Luca , Celegato Federica , Coïsson Marco , De Leo Natascia , Albertini Franca , Casoli Francesca , Ranzieri Paolo
Published: March 2013

Large-area arrays of dots having diameter ranging in the interval 80–400 nm were obtained by polystyrene nanosphere (PN) lithography in L10-FePt thin films. Fe53Pt47 thin films (thickness 10 nm) were epitaxially deposited by rf sputtering on a MgO(100) substrate heated at 400 °C to promote the formation of the L10 tetragonal phase. Patterned films were obtained by assembling PN nanospheres monolayer with starting mean diameter of 100 and 500 nm on a continuous thin film; subsequently, the PNs size has been reduced by reactive ion etching, obtaining a final dots diameter of 80 and 400 nm, respectively. The patterning process resulted to disorder the tetragonal phase therefore reducing the coercive field. A post-annealing at 550 °C for 1 h resulted to be effective in re-inducing the precipitation of the ordered phase. The effect of patterning (i.e., dot diameter and mutual distance) on the magnetic properties is discussed in the light of the presence of the high-anisotropy L10 tetragonal phase, by means of both structural and magnetic characterization techniques.
Electric-field control of the magnetic anisotropy in an ultrathin (Ga,Mn)As/(Ga,Mn)(As,P) bilayer
Authors: Niazi T. , Cormier M. , Lucot D. , Largeau L. , Jeudy V. , Cibert J. , Lemaître A.
Published: March 2013

We report on the electric control of the magnetic anisotropy in an ultrathin ferromagnetic (Ga,Mn)As/(Ga,Mn)(As,P) bilayer with competing in-plane and out-of-plane anisotropies. The carrier distribution and therefore the strength of the effective anisotropy are controlled by the gate voltage of a field effect device. Anomalous Hall effect measurements confirm that a depletion of carriers in the upper (Ga,Mn)As layer results in the decrease of the in-plane anisotropy. The uniaxial anisotropy field is found to decrease by a factor ∼4 over the explored gate-voltage range so that the transition to an out-of-plane easy-axis configuration is almost reached.
Impact ionisation electroluminescence in planar GaAs-based heterostructure Gunn diodes: Spatial distribution and impact of doping non-uniformities
Authors: Montes Bajo M. , Dunn G. , Stephen A. , Khalid Ata , Cumming D. R. S. , Oxley C. H. , Glover J. , Kuball M.
Published: March 2013

When biased in the negative differential resistance regime, electroluminescence (EL) is emitted from planar GaAs heterostructure Gunn diodes. This EL is due to the recombination of electrons in the device channel with holes that are generated by impact ionisation when the Gunn domains reach the anode edge. The EL forms non-uniform patterns whose intensity shows short-range intensity variations in the direction parallel to the contacts and decreases along the device channel towards the cathode. This paper employs Monte Carlo models, in conjunction with the experimental data, to analyse these non-uniform EL patterns and to study the carrier dynamics responsible for them. It is found that the short-range lateral (i.e., parallel to the device contacts) EL patterns are probably due to non-uniformities in the doping of the anode contact, illustrating the usefulness of EL analysis on the detection of such inhomogeneities. The overall decreasing EL intensity towards the anode is also discussed in terms of the interaction of holes with the time-dependent electric field due to the transit of the Gunn domains. Due to their lower relative mobility and the low electric field outside of the Gunn domain, freshly generated holes remain close to the anode until the arrival of a new domain accelerates them towards the cathode. When the average over the transit of several Gunn domains is considered, this results in a higher hole density, and hence a higher EL intensity, next to the anode.
Suppression of low-temperature ferromagnetic phase in ultrathin FeRh films
Authors: Han G. C. , Qiu J. J. , Yap Q. J. , Luo P. , Kanbe T. , Shige T. , Laughlin D. E. , Zhu J.-G.
Published: March 2013

Highly ordered B2 FeRh films with sharp magnetic transitions from the antiferromagnetic (AF) to ferromagnetic (FM) states were prepared on thermally oxidized Si wafers with thicknesses as low as 10 nm. It is found that the transition temperature increases as the thickness decreases from 80 nm to 15 nm, and then decreases from 15 nm to 10 nm. While the ratio of the residual magnetization to the maximum magnetization keeps nearly unchanged for the film thickness of 15 nm and larger, it increases significantly when the thickness is reduced to 10 nm. This residual magnetization was suppressed by slightly increasing the Rh atomic content in 10 nm thick FeRh films. Low-pressure deposition is found to play an important role in the stabilization of the AF phase. By depositing FeRh films at an extremely low pressure of 0.057 Pa, a residual magnetization as small as 13.5 emu/cc at 100 K was observed for a film with a nominal thickness of 10 nm deposited on Si wafer. This value was further reduced to 6 emu/cc when the film is deposited on MgO substrates due to much improved FeRh crystallinity. These results are in close agreement with theoretical predictions on defect and interface induced FM stabilization.
Spin-phonon coupling probed by infrared transmission spectroscopy in the double perovskite Ba2YMoO6
Authors: Qu Zhe , Zou Youming , Zhang Shile , Ling Langsheng , Zhang Lei , Zhang Yuheng
Published: March 2013

In this work, we report a study on the infrared transmission spectroscopy of the double perovskite Ba2YMoO6. At 300 K, three bands are observed at ∼255.1 cm−1, ∼343.4 cm−1, and ∼561.5 cm−1, which are related to the motion between the cation Ba2+ and the anion YMO6−2, the Y-O stretching motion, and the stretching vibration of the MoO6 octahedron, respectively. These modes continue to harden upon cooling owing to the shrink of the lattice constant. When the temperature decreases to T≤130 K around which the spin singlet dimer begins to form, an additional phonon mode appears at ∼611 cm−1, suggesting the occurrence of local distortion of MoO6 octahedra. With further decrease of the temperature, its intensity enhances and its peak position keeps unchanged. These results indicate that the formation of the spin singlet dimers is accompanied with the occurrence of the local structure distortion of MoO6 octahedra, providing evidence for the strong spin-phonon coupling in the double perovskite Ba2YMoO6.
Recent advances in the use of density functional theory to design efficient solar energy-based renewable systems
Authors: Nashed Ramy , Ismail Yehea , Allam Nageh K.
Published: March 2013

This article reviews the use of Density Functional Theory (DFT) to study the electronic and optical properties of solar-active materials and dyes used in solar energy conversion applications (dye-sensitized solar cells and water splitting). We first give a brief overview of the DFT, its development, advantages over ab-initio methods, and the most commonly used functionals and the differences between them. We then discuss the use of DFT to design optimized dyes for dye-sensitized solar cells and compare between the accuracy of different functionals in determining the excitation energy of the dyes. Finally, we examine the application of DFT in understanding the performance of different photoanodes and how it could be used to screen different candidate materials for use in photocatalysis in general and water splitting in particular.
Guiding the migration of adherent cells by using optical micropatterns
Authors: Xiao Jian-Long , Lu De-Han , Lee Chau-Hwang
Published: March 2013

We employed static and dynamic optical patterns to guide the motion of adherent cells. With the illumination intensity of 0.2 W/cm2 and propelling patterns moving at a speed of 2.8 μm/h, nearly 70% of the tested cells could be guided along a static optical pattern. We also demonstrated the cell guidance in an L-shaped optical channel. Comparing the result with only the static optical channel and that with both the static channel and moving optical pushes, we ascertained that the optical pushes placed at the start and turning points are necessary for effective optical cell guidance.
Mechanical characterization of benign and malignant urothelial cells from voided urine
Authors: Shojaei-Baghini Ehsan , Zheng Yi , Jewett Michael A. S. , Geddie William B. , Sun Yu
Published: March 2013

This study investigates whether mechanical differences exist between benign and malignant urothelial cells in voided urine. The Young's modulus of individual cells was measured using the micropipette aspiration technique. Malignant urothelial cells showed significantly lower Young's modulus values compared to benign urothelial cells. The results indicate that Young's modulus as a biomechanical marker could possibly provide additional information to conventional urinary cytology. We hope that these preliminary results could evoke attention to mechanical characterization of urine cells and spark interest in the development of biomechanical approaches to enhance non-invasive urothelial carcinoma detection.
Generation of sub-femtoliter droplet by T-junction splitting on microfluidic chips
Authors: Yang Yu-Jun , Feng Xuan , Xu Na , Pang Dai-Wen , Zhang Zhi-Ling
Published: March 2013

In the paper, sub-femtoliter droplets were easily produced by droplet splitting at a simple T-junction with orifice, which did not need expensive equipments, complex photolithography skill, or high energy input. The volume of the daughter droplet was not limited by channel size but controlled by channel geometry and fluidic characteristic. Moreover, single bead sampling and bead quantification in different orders of magnitude of droplet volumes were investigated. The droplets split at our T-junction chip had small volume and monodispersed size and could be produced efficiently, orderly, and controllably.
Laser-induced shock process in under-liquid regime studied by time-resolved photoelasticity imaging technique
Authors: Nguyen T. T. P. , Tanabe R. , Ito Y.
Published: March 2013

Stress enhancement in laser-induced shock process by plasma-confining effect of liquid overlay was demonstrated visually and its dependence on liquid layer thickness was studied. Time-resolved photoelasticity imaging technique in bright-field mode was used to observe the stress wave in solid phase and the shock wave, plasma, and cavitation bubble in the liquid phase simultaneously. From the photoelastic images, intensity of the laser-induced stress wave (LSW) inside a solid was evaluated semi-quantitatively. We prove that LSW is weaker with thinner liquid layer. To achieve the same effect with bulk liquid, the liquid film needs to be thicker than a threshold value.
A digitally linear piezoelectric bimorph actuator in open-loop mode
Authors: Xiao Wenlei , Huan Ji , Liu Guoxi , Shi Huaduo , Dong Shuxiang
Published: March 2013

The current paper reports a digital piezoelectric bimorph actuator having segmented electrodes and producing 2 to the nth power digital bending actuation in on/off switch mode and under a fix applied voltage. Correspondingly, a simple model for predicting digital actuation under applied coding voltage is also presented. Experimental results have confirmed that the proposed actuator can produce a linear digital displacement without a hysteresis loop. The proposed method is significant for open-loop high precise actuation.
Self-modulation of ultra-fast laser pulses with 1550 nm central wavelength in VO2 thin films
Authors: Hiltunen Jussi , Puustinen Jarkko , Sitomaniemi Aila , Pearce Stuart , Charlton Martin , Lappalainen Jyrki
Published: March 2013

The possibility to use an ultra-fast laser operating at 1550 nm wavelength to induce intensity self-modulation in metal-insulator phase transition VO2 thin films was investigated. The results show that a self-modulation value upto 0.55 can be obtained by using z-scan method. In comparison, an externally triggered phase transition induced by heating the sample produced a modulation depth of 0.995 corresponding to almost complete light absorption. The results suggest that significant self-modulation can be produced by fs laser pulses, but the modulation strength is partially suppressed by incomplete transition from a transparent to an absorbing state and potentially time delay in the rise of absorbance.