bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation therapists’ perspectives of the role of reflection in clinical practice
Authors: Cashell Angela
Published: September 2010

A recurring theme from the literature is that the definition of reflection is nebulous and/or complex. Many authors have suggested that more research needs to be conducted to better understand an individual’s perception of reflection and reflective practice, and how these concepts affect their clinical practice as well as their personal growth and development. This paper offers the findings of a qualitative study of radiation therapists in Canada. The aim of the study was to explore radiation therapist’s understanding of the concept of reflection, and to understand how they incorporated it into their daily practice. Secondary objectives were to examine some of the perceived barriers to its use, and the possible challenges of implementing reflective writing. Two focus groups were initially conducted, and a follow-up questionnaire was developed using the themes generated from the focus groups. The questionnaire was distributed to radiation therapists at two large cancer centres in Toronto, Canada. Most participants indicated that it is an integral part of their practice and professional lives, and that they use a variety of different methods for engaging in reflection. It is not without its barriers, but many of these can be overcome by providing time, coaching and a supportive work environment. Respondents were divided as to whether they would benefit from being taught reflection; however, small group teaching would be the favoured method. Further study is suggested to determine whether there are any improvements to patient care and in particular patient outcomes.
ON THE SYNTAX OF LOGIC AND SET THEORY
Authors: SCHOENBAUM LUCIUS T.
Published: September 2010

We introduce an extension of the propositional calculus to include abstracts of predicates and quantifiers, employing a single rule along with a novel comprehension schema and a principle of extensionality, which are substituted for the Bernays postulates for quantifiers and the comprehension schemata of ZF and other set theories. We prove that it is consistent in any finite Boolean subset lattice. We investigate the antinomies of Russell, Cantor, Burali-Forti, and others, and discuss the relationship of the system to other set-theoretic systems ZF, NBG, and NF. We discuss two methods of axiomatizing higher order quantification and abstraction, and then very briefly discuss the application of one of these methods to areas of mathematics outside of logic.
Forty years of European microwaves. What about the future?
Authors: Vorst André Vander , Brazil Thomas J. , Clarricoats Peter J.B. , Gardiol Fred E. , Ligthart Leo P. , Marriott Roger , Sorrentino Roberto , Wilson Andrew F.
Published: September 2010

This paper describes some key points in the history and development of the European Microwave Conference, the European Microwave Week, and the European Microwave Association, starting from 1969. It captures the way in which the conference since the earliest days has sought to create a successful blend of scientific and industry interests and has adapted itself to and indeed shaped the many existing technical changes that have characterized and continue to be at the core of the field of microwave engineering.
Baclofen zur Behandlung der Alkoholabhängigkeit
Authors: Müller Christian A. , Volkmar Katharina , Hein Jakob , Heinz Andreas
Published: September 2010

Fragestellung: Ziel dieser Arbeit ist die zusammenfassende Darstellung des aktuellen Kenntnisstandes zur Behandlung der Alkoholabhängigkeit mit Baclofen unter Berücksichtigung präklinischer und klinischer Befunde. Methodik: Es wurde eine systematische Literaturrecherche in der medizinischen Datenbank PubMed durchgeführt. Folgende Schlüsselbegriffe wurden dabei verwendet: baclofen, alcohol dependence, craving, treatment, pharmacotherapy, relapse prevention. Ergebnisse: Sowohl in präklinischen als auch in ersten klinischen Studien fanden sich Hinweise auf die Wirksamkeit des GABAB-Rezeptor-Agonisten Baclofen bei der Behandlung der Alkoholabhängigkeit. Im Rahmen offener und einfach-verblindeter Studien konnte Baclofen bei alkoholabhängigen Patienten die Symptomatik des Alkoholentzugssyndroms bei guter Verträglichkeit abmildern. Darüber hinaus zeigen die Befunde mehrerer offener sowie zweier randomisierter, kontrollierter Studien, dass die Anwendung von Baclofen als medikamentöse Rückfallprophylaxe effektiv und sicher ist. Zudem führte Baclofen zur Reduktion einer bestehenden Angstsymptomatik bei alkoholabhängigen Patienten. Allerdings konnten diese vorläufigen Ergebnisse in einer größeren kontrollierten Studie in den USA nicht bestätigt werden, sodass die Durchführung weiterer Studien dringend erforderlich ist. Schlussfolgerungen: Baclofen stellt eine vielversprechende Substanz zur Erweiterung der aktuell verfügbaren medikamentösen Behandlungsoptionen bei alkoholabhängigen Patienten dar. Allerdings müssen den bislang vorliegenden Ergebnissen weitere Studien folgen, um wichtige Fragen bezüglich der Wirksamkeit und Verträglichkeit, der Dosierung mit dem günstigsten Nutzen-Risiko-Profil sowie des vorrangig respondierenden Patientensubtyps zu klären.
Statistical properties and geoefficiency of interplanetary coronal mass ejections and their sheaths during intense geomagnetic storms
Authors: Guo Jianpeng , Feng Xueshang , Zhang Jie , Zuo Pingbing , Xiang Changqing
Published: September 2010

In this paper, we examine and compare the statistical properties of interplanetary coronal mass ejections (ICMEs) and their sheath regions in the near‐Earth space, mainly focusing on the distributions of various physical parameters and their geoefficiency. The 53 events studied are a subset of events responsible for intense (Dst ≤ −100 nT) geomagnetic storms during the time period from 1996 to 2005. These events all fall into the single‐type category in which each of the geomagnetic storms was caused by a well‐isolated single ICME, free of the complexity of the interaction of multiple ICMEs. For both sheaths and ICMEs, we find that the distributions of the magnetic field strength, the solar‐wind speed, the density, the proton temperature, the dynamic pressure, the plasma beta, and the Alfvén Mach number are approximately lognormal, while those of the Bz component and the Y component of the electric field are approximately Gaussian. On the average, the magnetic field strengths, the Bz components, the speeds, the densities, the proton temperatures, the dynamic pressures, the plasma betas, and the Mach numbers for the sheaths are 15, 80, 4, 60, 70, 62, 67, and 30% higher than the corresponding values for ICMEs, respectively, whereas the Y component of the electric field for the sheaths is almost 1 s of that for ICMEs. The two structures have almost equal energy transfer efficiency and comparable Newell functions, whereas they show statistically meaningful differences in the dayside reconnection rate, according to the Borovsky function.
Application of wave‐induced vertical mixing to the K profile parameterization scheme
Authors: Wang Yonggang , Qiao Fangli , Fang Guohong , Wei Zexun
Published: September 2010

Surface‐wave‐induced vertical mixing is incorporated to modify the K profile parameterization (KPP) scheme. The effects of this modified KPP scheme on a quasi‐global oceanic general circulation model are examined by carrying out four test cases. To evaluate simulated upper layer temperature and surface mixed‐layer depth (MLD), the model seasonal cycle of temperature and MLD are compared with those from Levitus climatology. In this study, the MLD is defined as the depth that the temperature has changed 0.8°C from the reference depth of 10 m. Statistic analysis shows that test cases with the addition of wave‐induced vertical mixing can reduce the root‐mean‐square difference of upper layer temperature and increase the correlation with Levitus climatology. On the basis of the comparison with Levitus climatology, the surface‐wave‐induced mixing improves the simulation of MLD in summertime for both hemispheres. Comparing the MLD in different seasons, the wave‐induced mixing improves MLD in both hemispheres in summer more than in other seasons. The simulation results are sensitive to weighting coefficients of the wave‐induced mixing, suggesting that a preferred weighting coefficient be between 0.1 and 0.3 in the modified KPP scheme.
On the connection between Benguela and equatorial Atlantic Niños and the role of the South Atlantic Anticyclone
Authors: Lübbecke Joke F. , Böning Claus W. , Keenlyside Noel S. , Xie Shang‐Ping
Published: September 2010

For the eastern tropical Atlantic two recurring El Niño‐like phenomena with high interannual SST anomalies have been described, one centered in the equatorial region as part of the Atlantic zonal mode and one off Angola referred to as Benguela Niño. Both events are supposed to be generated not locally but by a relaxation of the trade winds in the western equatorial Atlantic. Here the connection between SST variations in the two regions is investigated with observational data sets as well as ocean model simulations. They are correlated to such an extent that joint events should rather be viewed as one Atlantic Niño. An intriguing feature, counterintuitive in view of the remote forcing mechanism, is that SST anomalies off Angola precede those in the equatorial Atlantic. We show this behavior to be related to the difference in thermocline depths and a different seasonality of interannual SST variability in the two regions. While Benguela Niños peak in austral fall due to the Angola Benguela Front being located furthest to the south and high interannual variability in coastal Kelvin wave activity, warm events at the equator are phase‐locked to austral winter when the thermocline is shallow. Perturbation experiments confirm the importance of remote forcing from the equator for SST variability off Angola and demonstrate the leading role of wind stress in the generation of SST anomalies in the eastern tropical Atlantic. These wind stress variations are shown to be linked to fluctuations in the strength of the South Atlantic Anticyclone, a connection that might be important with respect to the predictability of Atlantic Niños.
An algorithm for estimating downward shortwave radiation from GMS 5 visible imagery and its evaluation over China
Authors: Lu Ning , Liu Ronggao , Liu Jiyuan , Liang Shunlin
Published: September 2010

This paper presents an operational scheme to estimate downward shortwave radiation (DSR) over China from the visible‐band top‐of‐atmosphere reflectance of the Geostationary Meteorological Satellite (GMS) 5 imagery. The proposed algorithm retrieves surface reflectance and atmospheric parameters directly from GMS 5 images by searching lookup tables, which are created by the radiative transfer model SBDART and consider the effects of water vapor absorption and surface altitude variations. Experiments show that the DSR retrieval is more sensitive to the selection of aerosol type and less to that of the cloud type. Uncertainty in the reflectance of a bright surface leads to a considerable DSR retrieval error (±(6–9%)). The instantaneous retrieved DSR is evaluated by field measurements on the Tibetan Plateau, and the daily retrieved DSR is compared with one year's ground‐based measurements at 96 stations in China. The results show that the estimated DSR is in good agreement with ground measurements with a correlation coefficient of ∼0.9 and a bias of 1.5%. Root‐mean square differences in the daily DSR are 17.7% for all‐sky and 13.1% for clear‐sky conditions. These results suggest that the proposed method applied to the GMS 5 satellite data can accurately estimate temporally and spatially continuous instantaneous and daily DSR. These DSR data sets will be useful for a wide range of applications.
Climate Change: Past, Present, and Future
Authors: Chapman David S. , Davis Michael G.
Published: September 2010

Questions about global warming concern climate scientists and the general public alike. Specifically, what are the reliable surface temperature reconstructions over the past few centuries? And what are the best predictions of global temperature change the Earth might expect for the next century?

Recent publications [National Research Council (NRC), 2006; Intergovernmental Panel on Climate Change (IPCC), 2007] permit these questions to be answered in a single informative illustration by assembling temperature reconstructions of the past thousand years with predictions for the next century. The result, shown in Figure 1, illustrates present and future warming in the context of natural variations in the past [see also Oldfield and Alverson, 2003]. To quote a Chinese proverb, “A picture's meaning can express ten thousand words.” Because it succinctly captures past inferences and future projections of climate, the illustration should be of interest to scientists, educators, policy makers, and the public.
Desertification awareness decade
Authors: Ofori Leslie , Showstack Randy
Published: September 2010

In an effort to raise awareness about desertification and better protect and manage the world's drylands, the United Nations (U.N.) launched the Decade for Deserts and the Fight Against Desertification in mid‐August. Five U.N. agencies—including the U.N. Environment Programme and the U.N. Development Programme—will spearhead activities related to desertification. The degradation of drylands affects 25% of the Earth's landmass and more than 2.1 billion people, most of whom are from developing counties, according to the U.N. Each year, 12 million hectares of land are lost to desertification, an area that could produce 20 million tons of grain.
Clean water strategy
Authors: Ofori Leslie , Showstack Randy
Published: September 2010

The U.S. Environmental Protection Agency (EPA) is inviting the public to comment on a draft strategy to protect and restore lakes, streams, and coastal waters. The document, “Coming together for clean water: EPA's strategy for achieving clean water,” outlines the agency's plans to address the United States' critical water stressors, sources, and threats.

The document outlines several approaches the agency has identified, including systematically assessing the nation's waters to provide a baseline for tracking progress; increasing the focus on protecting healthy waters; enhancing EPA's ability to restore degraded waters and ecosystems; and reducing pollution. Specific EPA actions include completing national aquatic resource surveys; developing metrics to create a national list of healthy watersheds; strengthening the National Pollutant Discharge Elimination System; and encouraging integrated water management approaches and green infrastructure.
Noninvasive and Localized Blood—Brain Barrier Disruption using Focused Ultrasound can be Achieved at Short Pulse Lengths and Low Pulse Repetition Frequencies
Authors: Choi James J , Selert Kirsten , Gao Zimeng , Samiotaki Gesthimani , Baseri Babak , Konofagou Elisa E
Published: September 2010

Ultrasound methods in conjunction with microbubbles have been used for brain drug delivery, treatment of stroke, and imaging of cerebral blood flow. Despite advances in these areas, questions remain regarding the range of ultrasound parameters that disrupt the blood–brain barrier (BBB). In this study, several conditions were investigated to either enhance or reduce the likelihood of BBB disruption. Pulsed focused ultrasound (frequency: 1.5 MHz, pressure: 0.46 MPa, pulse repetition frequency (PRF): 0.1 to 25 Hz, pulse length (PL): 0.03 to 30 milliseconds) was noninvasively and locally administered to a predetermined region in the left hemisphere in the presence of circulating preformed microbubbles (Definity, Lantheus Medical Imaging, N. Billerica, MA, USA; 0.01, 0.05, 0.25 μL/g). Trans-BBB delivery of 3-kDa dextran was observed at PRFs as low as 1 Hz, whereas consistent delivery was observed at 5 Hz and above. Delivery was demonstrated at a PL as low as 33 microseconds. Although the delivered dextran concentration increased with the PL, this also increased the heterogeneity of the resulting distribution. In conclusion, key parameters that disrupt the BBB were identified out of a wide range of conditions. Reducing the total number of emitted acoustic cycles by shortening the PL, or decreasing the PRF, was also found to facilitate a more spatially uniform distribution of delivered dextran.
Epigenetic changes and alteration ofFbn1andCol3A1gene expression under hyperglycaemic and hyperinsulinaemic conditions
Authors: Gaikwad Anil B. , Gupta Jeena , Tikoo Kulbhushan
Published: September 2010

Little is known regarding the role of hyperglycaemia on histone H3 modifications and, in turn, altering the expression of genes during the development of diabetes-associated complications. In the present study, we have investigated the hyperinsulinaemia/hyperglycaemia-induced epigenetic changes and alteration of Fbn1 (fibrillin 1) and Col3A1 (collagen type III α1) gene expression. Insulin resistance and Type 2 diabetes in male Sprague–Dawley rats was developed by feeding rats an HFD (high-fat diet) and administering a low dose of STZ (streptozotocin). Hyperglycaemia induced deacetylation and dephosphorylation of histone H3 in the heart and kidneys of diabetic rats. Furthermore, mRNA expression of Fbn1 and Col3A1 increased in the kidneys and decreased in the heart under hyperglycaemic/hyperinsulinaemic conditions. Similar to mRNA expression, chromatin immunoprecipitation also showed an increase in the level of histone H3 acetylation of the Fbn1 gene, but not of the Col3A1 gene. Our present findings suggests that the change in expression of the Fbn1 gene is epigenetically regulated, but the expression of the Col3A1 gene may either be independent of epigenetic regulation or may involve other histone modifications. We provide the first evidence regarding the role of hyperglycaemia/hyperinsulinaemia in altering histone H3 modifications, which may result in the alteration of extracellular matrix gene expression.
Enhanced boundary-scattering of electrons and phonons in nanograined zinc oxide
Authors: Kinemuchi Yoshiaki , Nakano Hiromi , Mikami Masashi , Kobayashi Keizo , Watari Koji , Hotta Yuji
Published: September 2010

Nanoscale constituents in bulk materials can promote enhanced boundary-scattering in the transport of phonons as well as electrons, which is considered a key design factor for enhancing thermoelectric properties. Here, we demonstrate a method for synthesizing zinc oxide bulk materials from nanoparticles without significant grain growth by means of pressure-induced deformation at 200 °C. This allows us to comprehensively analyze the grain size dependence of thermoelectric properties in the nanoscale range above 30 nm, the size of a nanoparticle. Grain size was found to largely influence thermal conductivity as well as electrical conductivity. The observed thermal conductivity agreed with the Callaway model, indicating that enhanced phonon boundary-scattering was responsible for the variation. On the contrary, Seebeck coefficient was mostly governed by effective mass and carrier concentration, and was independent of the grain size. The dimensionless figure of merit systematically increased with grain size, which challenged the effect of nanograin on this system.
The existence of self-dual vortices in a non-Abelian Φ2 Chern–Simons theory
Authors: Chen Shouxin , Wang Ying
Published: September 2010

Applying the dynamic shooting method, we proved the existence of nontopological radially symmetric n-vortex solutions to the self-dual equation in non-Abelian Chern–Simons gauge theory with a Φ2-type potential. Moreover, we obtained all possible radially symmetric nontopological bare (or 0-vortex) solutions in the non-Abelian Chern–Simons model. Meanwhile, we established the asymptotic behavior for the solutions as |x|→∞.
Tensile-relaxation behavior of electrodeposited nanocrystalline Ni
Authors: Shen Xixun , Gu Changdong , Lian Jianshe , Jiang Qing , Jiang Zhonghao , Qin Liyuan
Published: September 2010

The electrodeposited nanocrystalline (nc) Ni with an average grain size of 27 nm by the tensile-relaxation tests shows substantial increase in ductility up to 10.7%–11.8% at all tested strain rates (from 4.17×10−5 to 4.17 s−1), which is evidently higher than those (6%–10%) attained in the routine continuous tensile tests; while the ductility of the compared coarse-grained (CG) Ni almost keep invariable under the same two kinds of tension mode. Additionally, the notable stress softening and the subsequently parabola of convergence increase in flow stress (i.e., new strain hardening behavior) upon reloading was only observed in nc Ni during the tensile-relaxation tests, which illuminates that nc Ni lacks a permanent dislocation network like that in CG Ni during deformation process.
Decay of excited surface electron states in liquid helium and related relaxation phenomena induced by short-wavelength ripplons
Authors: Monarkha Yu. P. , Sokolov S. S. , Smorodin A. V. , Studart Nelson
Published: September 2010

Decay rates of excited surface electron states on liquid helium are theoretically studied for different electron confinement potentials and in the presence of quantizing magnetic field. Contributions of both one-ripplon and two-ripplon scattering processes are analyzed. Regarding the decay rate of the first excited surface level (l=2), two-ripplon emission of short wavelength capillary waves is shown to dominate the conventional one-ripplon scattering in two distinct cases: the ambient temperature is low enough or the surface state excitation energy Δ2−Δ1 does not match an excitation energy of the in-plane motion quantized under a strong magnetic field or in a quantum dot. In these cases magnetic field and confinement cannot essentially reduce the decay rate which is of order of 106s−1 and does not depend on temperature. The importance of these findings for a microwave resonance experiment is discussed.
Effect of γ irradiation on the parameters of localized states in p-InSe and n-InSe⟨Sn⟩ single crystals
Authors: Mustafaeva S. N. , Ismaĭlov A. A. , Asadov M. M.
Published: September 2010

It is found that γ irradiation of p-InSe and n-InSe⟨Sn⟩ (0.2 and 0.4mol.% Sn) with dose Dγ=100krad results in a considerable change of the parameters of states localized in the band gap: an increase of the density of states localized near the Fermi level and their energy densification, a decrease of the average hopping distance, and an increase of the concentration of deep traps responsible for hopping conductivity. The concentrations of radiation defects in p-InSe and n-InSe⟨Sn⟩ single crystals are determined as 5.18⋅1017cm−3 and 2.48⋅1017–2.71⋅10-18-cm−3, respectively.
Role of wall deformability on interfacial instabilities in gravity-driven two-layer flow with a free surface
Authors: Gaurav  , Shankar V.
Published: September 2010

The linear stability of gravity-driven flow of two superposed Newtonian liquid layers down a deformable, inclined, wall is analyzed in order to examine the effect of wall deformability on the interfacial instabilities in the system. There are three distinct interfacial modes in this composite system, viz., gas-liquid (GL), liquid-liquid (LL), and liquid-solid (LS) modes. For a rigid-wall, the GL interface becomes unstable above a critical Reynolds number, while the stability of the LL interface depends on the relative placement of the liquid layers. When the more viscous liquid is adjacent to rigid surface, the LL mode becomes unstable beyond a critical Reynolds number (Re), while it becomes unstable even at Re=0 when the less viscous liquid is next to rigid-wall. Our asymptotic results show that solid deformability has a stabilizing effect on both GL and LL modes in the low-wavenumber limit when the more viscous liquid layer is near the deformable wall. Numerical results reveal that both the GL and LL interfacial instabilities can be suppressed for all wavenumbers when the solid layer becomes sufficiently deformable. With further increase in solid deformability, all three interfacial modes become unstable. However, the parameters characterizing the solid (shear modulus, thickness, and solid viscosity) can be chosen such that the GL and LL interfaces remain stable (which are otherwise unstable in flow down a rigid incline) at all wavenumbers without the destabilization of LS interface. When the thickness of the top (less viscous) liquid layer is greater, it is more difficult to obtain stable flow configuration by manipulating the solid parameters. When the less viscous liquid is adjacent to the deformable surface, solid deformability always has a destabilizing effect on LL interfacial mode, and it is not possible to simultaneously stabilize both GL and LL interfaces for this configuration.
Room temperature electron transport properties of single C60 studied using scanning tunneling microscope and break junctions
Authors: Cheng Ruihua , Carvell Jeffery , Fradin F. Y.
Published: September 2010

We report the measurements of the electron transport of an individual C60 molecule through the combination of two experimental efforts. The nanometer-sized junctions were fabricated using electromigration combined with electron beam lithography and shadow effect evaporation. We performed the scanning tunneling microscopy/spectroscopy measurements of dispersed C60 molecules which were deposited on a highly ordered pyrolytic graphite substrate. The single electron tunneling through a single C60 molecule due to the Coulomb blockage effect is observed at room temperature.
Quantum oscillations of the impedance of layered conductors with elastic scattering of electrons by short-range impurity centers
Authors: Kirichenko O. V. , Kozlov I. V.
Published: September 2010

The propagation of electromagnetic waves in layered conductors in a quantizing magnetic field B is investigated theoretically in the case where elastic scattering by short-range impurity centers is the main relaxation mechanism in the electronic system. Quantum oscillations of the impedance, including at high temperatures, are calculated under the conditions of the anomalous skin effect. The effect of spatial dispersion on the amplitude and phase of the oscillations is analyzed.
Transformations of W-type entangled states
Authors: Kıntaş S. , Turgut S.
Published: September 2010

The transformations of W-type entangled states by using local operations assisted with classical communication are investigated. For this purpose, a parametrization of the W-type states which remains invariant under local unitary transformations is proposed and a complete characterization of the local operations carried out by a single party is given. These are used for deriving the necessary and sufficient conditions for deterministic transformations. A convenient upper bound for the maximum probability of distillation of arbitrary target states is also found.
Communication: The role of the positivity N-representability conditions in natural orbital functional theory
Authors: Piris M. , Matxain J. M. , Lopez X. , Ugalde J. M.
Published: September 2010

The positivity conditions for the N-representability of the reduced density matrices are considered to propose a new natural orbital functional. The Piris reconstruction functional, which is based on an explicit form of the two-particle cumulant λ(Δ,Π) is used to reconstruct the two-particle reduced density matrix. A new approach for Π matrix, satisfying rigorously D, Q, and G necessary conditions, leads to Piris Natural Orbital Functional 4 (PNOF4). The theory is applied to the dissociation of selected diatomic molecules. The equilibrium distances, dipole moments, harmonic frequencies, anharmonicity constants, and binding energies of the considered molecules are presented. The values we have obtained are very accurate results comparing with the experimental data.
On the nature of the decay phonon spectrum in superfluid helium
Authors: Pashitskiĭ É. A. , Vil’chinskiĭ S. I. , Chumachenko A. V.
Published: September 2010

It is shown that the decay character of the phonon spectrum in superfluid helium is a consequence of the analyticity and parity of the boson self-energy as a function of energy and momentum. Previous self-consistent numerical calculations have shown that because of the strong interaction between the particles in Bose-Einstein condensate the normal and anomalous boson self-energies are analytical functions of the momentum and energy and on the mass shell, in the long-wavelength limit, they depend only on the squared momentum. It is shown on this basis that the phonon spectrum of a bose liquid is a decay spectrum in complete agreement with the experimental data on neutron scattering and the interaction of the high- and low-frequency phonons in superfluid helium.
Behaviors of InGaZnO thin film transistor under illuminated positive gate-bias stress
Authors: Chen Te-Chih , Chang Ting-Chang , Tsai Chih-Tsung , Hsieh Tien-Yu , Chen Shih-Ching , Lin Chia-Sheng , Hung Ming-Chin , Tu Chun-Hao , Chang Jiun-Jye , Chen Po-Lun
Published: September 2010

In this letter, we investigate the impact of the light illumination on the stability of indium–gallium–zinc oxide thin film transistors under positive gate-bias stress. The noticeable decrease in threshold voltage (Vt) shift more than 5.5 V under illuminated positive gate-bias stress indicates a superior reliability in contrast with the dark stress. The accelerated Vt recovery characteristic compared with dark recovery demonstrates that the charge detrapping effect was enhanced under illumination. Furthermore, the average effective energy barrier of charge trapping and detrapping was derived to verify that illumination can excite the trapped charges and accelerate the charge detrapping process.
Correlation of Mn charge state with the electrical resistivity of Mn doped indium tin oxide thin films
Authors: Kumar S. R. Sarath , Hedhili Mohamed Nejib , Alshareef H. N. , Kasiviswanathan S.
Published: September 2010

Correlation of charge state of Mn with the increase in resistivity with Mn concentration is demonstrated in Mn-doped indium tin oxide films. Bonding analysis shows that Mn 2p3/2 core level can be deconvoluted into three components corresponding to Mn2+ and Mn4+ with binding energies 640.8 eV and 642.7 eV, respectively, and a Mn2+ satellite at ∼5.4 eV away from the Mn2+ peak. The presence of the satellite peak unambiguously proves that Mn exists in the +2 charge state. The ratio of concentration of Mn2+ to Mn4+ of ∼4:1 suggests that charge compensation occurs in the n-type films causing the resistivity increase.
Enhancement of the glass-forming ability by Zr microalloying and its influence on the magnetocaloric properties of bulk amorphous Gd–Co–Al
Authors: Fu H. , Zou M. , Mudryk Ya. , Pecharsky V. K. , Gschneidner K. A.
Published: September 2010

Microalloying with 1 at. % zirconium dramatically increases the critical size from 3 to 8 mm for Gd-based bulk metallic glasses (BMGs). The enhancement of glass-forming ability originates from the increase in the packing efficiency and high compound forming tendency between Zr and major constituent elements. The maximum magnetic entropy change (−ΔSMmax) and relative cooling power (RCP) of Gd52.5Co18.5Al29−xZrx (x=1) BMG are 9.6 J/kg K and 8.9×102 J/kg, respectively. Heat capacity data demonstrate that the broad magnetic transition arising from topological disorder is responsible for the high RCP of Gd-based amorphous magnetocaloric materials.
On the electric polarization of inhomogeneous superfluid systems
Authors: Shevchenko S. I. , Rukin A. S.
Published: September 2010

The electric polarization appearing in superfluid systems as a result of their inhomogeneity is studied. The problem is studied using the rarefied electron-hole gas model which the authors studied previously. A microscopic calculation is performed of the polarization of quantum vortices in the absence and presence of a magnetic field. It is established that in the presence of a magnetic field vortices acquire additional polarization, which results in the appearance of a quantized charge in a vortex core. It is shown that the van-der-Waals interaction of a superfluid system with a solid surface gives rise to polarization near the surface. A relation is established between the results obtained and the prediction of possible polarization of the medium in nonuniform motion.
Electronic paramagnetic resonance or rare-earth ions Yb3+, Pr3+, Dy3+, and Nd3+ in double molybdates and tungstenates
Authors: Kobets M. I. , Khats’ko E. N. , Dergachev K. G. , Kalinin P. S.
Published: September 2010

The particulars of the EPR spectrum of magnetically concentrated crystals of double molybdates and tungstenates with a crystal structure of low symmetry were studied at liquid-helium temperatures in the frequency range 15–120GHz. The directions of the principal magnetic axes were determined and the principal values of the g tensors were obtained for all experimental crystals KYb(MoO4)2, CsPr(MoO4)2, RbDy(MoO4)2, and RbNd(WO4)2. Two non-equivalent geometric centers were found in KYb(MoO4)2 and RbDy(MoO4)2 crystals; the local axes of the centers were turned in different directions relative to the crystallographic axes a and c by 34° and 25°. The dipole-dipole interaction energy was estimated as Edd∼0.1cm−1 for KYb(MoO4)2. It was shown that the lowest states of CsPr(MoO4)2 are close-lying singlets (quasidoublet) with splitting Δ∼0.2cm−1.
The vibrational behavior of silica clusters at the glass transition: Ab initio calculations and thermodynamic implications
Authors: Ottonello G. , Zuccolini M. Vetuschi , Belmonte D.
Published: September 2010

We present the results of a computational investigation with ab initio procedures of the structure-energy and vibrational properties of silica clusters in a dielectric continuum with dielectric constant ε=3.8, through density functional theory/B3LYP gas phase calculations coupled with a polarized continuum model approach [integral equation formalism applied to a polarized continuum (IEFPCM)] and those of the periodical structure D6h which leads to the α-cristobalite polymorph of silica when subjected to symmetry operations with the same functional within the linear combination of atomic orbitals (LCAO) approximation and in the framework of Bloch’s theorem. Based on the computed energies and vibrational features, an aggregate of the D6h network and the monomer locally ordered in the short-medium range and both present in the glass in a mutual arrangement lacking of spatial continuity reproduces satisfactorily the experimentally observed low T heat capacity and the deviation from the Debye T3 law. Above Tg, the experimental heat capacity of the liquid is perfectly reproduced summing to the internal modes the translational and rotational contributions to the bulk heat capacity and subtracting the (acoustic) terms arising from coherent motion (no longer existent).
Communication: The ionization and dissociation energies of HD
Authors: Sprecher Daniel , Liu Jinjun , Jungen Christian , Ubachs Wim , Merkt Frédéric
Published: September 2010

The adiabatic ionization energy [in units of hc, [Ei=124 568.485 81(36) cm−1] and the dissociation energy [D0=36 405.783 66(36) cm−1] of HD have been determined using a hybrid experimental-theoretical method. Experimentally, the wave numbers of the EF(v=0,N=0)→np[X+(v+=0 and 1, N+=0)] and EF(v=0,N=1)→np[X+(v+=0,N+=1)] transitions to singlet Rydberg states were measured by laser spectroscopy and used to validate predictions of the electron binding energies by multichannel quantum defect theory. Adding the transition energies, the electron binding energies and previously reported term energies of the EF state led to a determination of the adiabatic ionization energy of HD and of rovibrational energy spacings in HD+. Combining these measurements with highly accurate theoretical values of the ionization energies of the one-electron systems H, D, and HD+ further enabled a new determination of the dissociation energy of HD.
Probing mixed tetragonal/rhombohedral-like monoclinic phases in strained bismuth ferrite films by optical second harmonic generation
Authors: Kumar Amit , Denev Sava , Zeches Robert J. , Vlahos Eftihia , Podraza Nikolas J. , Melville Alexander , Schlom Darrell G. , Ramesh R. , Gopalan Venkatraman
Published: September 2010

Epitaxial strain can induce the formation of morphotropic phase boundary in lead free ferroelectrics like bismuth ferrite, thereby enabling the coexistence of tetragonal and rhombohedral phases in the same film. The relative ratio of these phases is governed by the film thickness and theoretical studies suggest that there exists a monoclinic distortion of both the tetragonal as well as the rhombohedral unit cells due to imposed epitaxial strain. In this work we show that optical second harmonic generation can distinguish the tetragonal-like phase from the rhombohedral-like phase and enable detection of monoclinic distortion in only a pure tetragonal-like phase.
Global well-posedness of a dissipative system arising in electrohydrodynamics in negative-order Besov spaces
Authors: Zhao Jihong , Deng Chao , Cui Shangbin
Published: September 2010

In this paper we study the Navier–Stokes–Nernst–Planck–Poisson system arising from electrohydrodynamics. Global well-posedness of this system for small initial-data is proven in negative-order Besov spaces. As a corollary to this result, we obtain the existence of self-similar solutions to this system. Asymptotic stability of self-similar solutions as time goes to infinity is also proven.
Gas temperature dependent sticking of hydrogen on cold amorphous water ice surfaces of interstellar interest
Authors: Matar E. , Bergeron H. , Dulieu F. , Chaabouni H. , Accolla M. , Lemaire J. L.
Published: September 2010

Using the King and Wells method, we present experimental data on the dependence of the sticking of molecular hydrogen and deuterium on the beam temperature onto nonporous amorphous solid water ice surfaces of interstellar interest. A statistical model that explains the isotopic effect and the beam temperature behavior of our data is proposed. This model gives an understanding of the discrepancy between all known experimental results on the sticking of molecular hydrogen. Moreover, it is able to fit the theoretical results of Buch et al. [Astrophys. J. 379, 647 (1991)] on atomic hydrogen and deuterium. For astrophysical applications, an analytical formula for the sticking coefficients of H, D, H2, D2, and HD in the case of a gas phase at thermal equilibrium is also provided at the end of the article.
Incomplete screening by epitaxial graphene on the Si face of 6H–SiC(0001)
Authors: Sandin Andreas , Pronschinske Alex , Rowe J. E. (Jack) , Dougherty Daniel B.
Published: September 2010

A biased scanning tunneling microscope (STM) tip is used to study the ability of carriers in graphene to screen external electrostatic fields by monitoring the effect of tunneling-junction width on the position of image potential-derived surface states. These states are unusually sensitive to local electric fields due to the STM tip in both single layer and bilayer epitaxial graphene. This is attributed to the incomplete screening of applied fields in epitaxial graphene on SiC(0001). Our observations imply that charged impurity scattering is likely to be a dominant factor in the transport properties of epitaxial graphene on SiC.
Anisotropic magnetocaloric effect in all-ferromagnetic (La0.7Sr0.3MnO3/SrRuO3) superlattices
Authors: Thota S. , Zhang Q. , Guillou F. , Lüders U. , Barrier N. , Prellier W. , Wahl A. , Padhan P.
Published: September 2010

We exploit the magnetic interlayer coupling in La0.7Sr0.3MnO3/SrRuO3 superlattices to realize a crossover between inverse and conventional magnetic entropy changes. Our data reveal a strong anisotropic nature of the magnetocaloric effect due to the magnetic anisotropy of the superlattice. Therefore, artificial superlattices built from ferromagnetic materials that can be used to alter the magnetic structure as well as the magnetic anisotropy, could also be utilized for tuning the magnetocaloric properties, which may open a constructive approach for magnetic refrigeration applications.
Testing Batchelor’s similarity hypotheses for decaying two-dimensional turbulence
Authors: Lindborg Erik , Vallgren Andreas
Published: September 2010

We carry out three high resolution direct numerical simulations of the two-dimensional Navier–Stokes equation to test Batchelor’s similarity hypotheses of an equilibrium spectral range and an inertial subrange where the enstrophy wave number spectrum has the form Φ(k)=Cχ2/3k−1, where χ is the mean enstrophy dissipation rate and C is a constant. We use very different initial conditions in the three simulations and find that Batchelor’s hypotheses are well satisfied in each simulation. However, there is a small but significant difference between the equilibrium range spectrum of one of the simulations as compared to the spectra of the other two. We suggest that the difference is linked to the stronger degree of large scale variation of the enstrophy dissipation which is observed in this simulation as compared to the other two.
Mn-doped nanocrystals in light-emitting diodes: Energy-transfer to obtain electroluminescence from quantum dots
Authors: Rath Arup K. , Bhaumik Saikat , Pal Amlan J.
Published: September 2010

We fabricate light-emitting diodes (LEDs) based on Mn-doped ZnS nanocrystals along with hole-transporting N,N′ bis(3-methylphenyl)-N,N′-diphenyl-benzidine (TPD). With Mn-doping, ZnS nanostructures exhibit a strong photoluminescence. The LEDs exhibit electroluminescence (EL) from Mn-doped ZnS quantum dots and TPD. In order to open up channels for energy-transfer from TPD to quantum dots and to achieve EL from only the nanoparticles, we grow core-shell nanoparticles with Mn-doped ZnS in the core and CdS as the shell layer. Excitons formed in TPD can now transfer their energy directly to the shell-layer to yield EL from only the nanoparticles.
Edge dopant energy levels of graphene nanoribbons
Authors: Lu Yang , Guo Jing
Published: September 2010

Edge doping of graphene flakes and graphene nanoribbons (GNRs) was achieved in recent experiments. Atomistic self-consistent simulations are performed in this study to compute the edge dopant energy levels of GNRs. The results indicate that the energy required to ionize the edge dopant in a sub-10 nm wide GNR increases considerably as the GNR width decreases and it is sensitive to electrostatic environment such as the substrate and gate insulator materials. These unusual behaviors of dopants in a GNR are due to its quasi-one-dimensional structure and monolayer-thin body.
Increased electromechanical coupling in w−ScxAl1−xN
Authors: Wingqvist Gunilla , Tasnádi Ferenc , Zukauskaite Agne , Birch Jens , Arwin Hans , Hultman Lars
Published: September 2010

AlN is challenged as the material choice in important thin film electroacoustic devices for modern wireless communication applications. We present the promise of superior electromechanical coupling (kt2), in w−ScxAl1−xN by studying its dielectric properties. w−ScxAl1−xN (0≤x≤0.3) thin films grown by dual reactive magnetron sputtering exhibited low dielectric losses along with minor increased dielectric constant (ε). Ellipsometry measurements of the high frequency ε showed good agreement with density function perturbation calculations. Our data show that kt2 will improve from 7% to 10% by alloying AlN with up to 20 mol % ScN.
Toward remote high energy terahertz generation
Authors: Wang Tie-Jun , Yuan Shuai , Chen Yanping , Daigle Jean-François , Marceau Claude , Théberge Francis , Châteauneuf Marc , Dubois Jacques , Chin See Leang
Published: September 2010

Remote terahertz (THz) generation from a two-color femtosecond laser-induced filament in air was experimentally demonstrated. A record of remote THz emission at 16 m was achieved. THz pulse energy more than 250 nJ in the frequency range below 5.5 THz was recorded; this is two orders of magnitude stronger than that from single-color excitation. Back-scattered nitrogen (N2) fluorescence signal remotely measured with a lidar is linearly proportional to the THz emission, which would provide a more practical method to characterize the THz pulses.
Do preservation methods affect the identification of dietary components from faecal samples? A case study using a mycophagous marsupial
Authors: Zosky Kerry , Bryant Kate , Calver Michael , Wayne Adrian
Published: September 2010

We tested whether four preservation methods for faecal samples affected the identification of dietary components from the mycophagous woylie (Bettongia penicillata ogilbyi). All storage techniques identified fungi as the most abundant food type (>69%), followed by plant material (9–17%) and invertebrates (<5%). Between 8 and 13% of material from each technique was unidentifiable. Despite these general similarities in the results from the different techniques, there were small but statistically significant differences in the relative importance of the food types estimated using the different preservation techniques. Individual researchers will need to decide on a case-by-case basis whether these small differences can be disregarded given the general aims of their study or whether a correction factor is appropriate if small differences in diet are important to their objectives.
Estimating western ringtail possum (Pseudocheirus occidentalis) density using distance sampling
Authors: Finlayson G. R. , Diment A. N. , Mitrovski P. , Thompson G. G. , Thompson S. A.
Published: September 2010

A reliable estimate of population size is of paramount importance for making management decisions on species of conservation significance that may be impacted during development. The western ringtail possum (Pseudocheirus occidentalis) is regularly encountered during urban development and is the subject of numerous surveys to estimate its abundance. A variety of techniques have been used for this species with mixed results. This paper reports on a case study using distance sampling to estimate density of P. occidentalis in a small habitat remnant near Busselton, Western Australia. Density estimates obtained were within the range of previous studies of this species and we suggest that this technique should be employed in future surveys to improve the accuracy of population estimates for this species before development.
Observation of reproductive strategies of captive kultarrs (Antechinomys laniger)
Authors: Stannard Hayley J. , Old Julie M.
Published: September 2010

Captive kultarrs (Antechinomys laniger) were bred from June to February. Their gestation period was longer than 12 days, as suggested by previous research. Pouches were observed to determine whether births occurred. Individuals were capable of producing offspring in their second and third year of life, which has been suspected previously, but never demonstrated in other published studies.
Photometric Observations of the η Carinae 2009.0 Spectroscopic Event
Authors: Landes H. , Fitzgerald M.
Published: September 2010

We have observed η Carinae over 34 nights between 2009 January 4 and 2009 March 27 covering the estimated timeframe for a predicted spectroscopic event related to a suspected binary system concealed within the homunculus nebula. A photometric minimum feature was confirmed to be periodic and comparison to a previous event indicated that the period to within our error was 2022.6±1.0 d. Using the E-region standard star system, the apparent V magnitudes determined for the local comparison stars were HD 303308 8.14±0.02, HD 93205 7.77±0.03, and HD 93162 8.22±0.05. The latter star was found to be dimmer than previously reported.