Sequentially evaporated thin Y-Ba-Co-O superconducting films on microwave substrates

The development of high T sub c superconducting thin films on various microwave substrates is of major interest in space electronic systems. Thin films of YBa2Cu3O(7-Delta) were formed on SrTiO3, MgO, ZrO2 coated Al2O3, and LaAlO3 substrates by multi-layer sequential evaporation and subsequent annealing in oxygen. The technique allows controlled deposition of Cu, BaF2 and Y layers, as well as the ZrO buffer layers, to achieve reproducibility for microwave circuit fabrication. The three layer structure of Cu/BaF2/Y is repeated a minimum of four times. The films were annealed in an ambient of oxygen bubbled through water at temperatures between 850 C and 900 C followed by slow cooling (-2 C/minute) to 450 C, a low temperature anneal, and slow cooling to room temperature. Annealing times ranged from 15 minutes to 5 hrs. at high temperature and 0 to 6 hr. at 450 C. Silver contacts for four probe electrical measurements were formed by evaporation followed with an anneal at 500 C. The films were characterized by resistance-temperature measurements, energy dispersive X-ray spectroscopy, X-ray diffraction, and scanning electron microscopy. Critical transition temperatures ranged from 30 K to 87 K as a function of the substrate, composition of the film, thicknesses of the layers, and annealing conditions. Microwave ring resonator circuits were also patterned on these MgO and LaAlO3 substrates

In silico target prediction: identification of on- and off-targets for crop protection agents

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Comparing The Effect Of Overspeed Training On NCAA Division III Lacrosse Athletes

Please view abstract in the attached PDF file

Minimizing magnetic fields for precision experiments

An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State of the art magnetically shielded rooms (MSRs) consist of up to seven layers of high permeability materials in combination with highly conductive shields. Proper magnetic equilibration is crucial to obtain such low magnetic fields with small gradients in any MSR. Here we report on a scheme to magnetically equilibrate MSRs with a 10 times reduced duration of the magnetic equilibration sequence and a significantly lower magnetic field with improved homogeneity. For the search of the neutron's electric dipole moment, our finding corresponds to a linear improvement in the systematic reach and a 40 % improvement of the statistical reach of the measurement. However, this versatile procedure can improve the performance of any MSR for any application.Comment: 5 pages, 4 figure

The association of leadership styles and empowerment with nurses' organizational commitment in an acute health care setting: A cross-sectional study

Background: The current challenges facing healthcare systems, in relation to the shortage of health professionals, necessitates mangers and leaders to learn from different leadership styles and staff empowerment strategies, so as to create a work environment that encourages nursing staff commitment to patients and their organization. This study intends to measure the effects of nurses' overall perception of the leadership style of their managers, and psychological empowerment on their organizational commitment in acute care units, in National Guard Health Affairs, Riyadh City, Saudi Arabia. Methods: This was a cross-sectional survey, where the data was obtained from nurses at King Abdulaziz Medical City. Hard copy questionnaires were distributed to 350 randomly selected nurses. Three hundred and thirty two (332) were completed, representing a response rate of 95 %. Three validated survey instruments were used to obtain the data: (1) The Multifactor Leadership Questionnaire (MLQ), formulated by Bass and Avolio (1997), (2) The Psychological Empowerment Scale developed by Spreitzer (1995) and (3) The Three-Component Model of Employee Commitment developed by Meyer and Allen (1997). A theoretical model that conceptually links leadership, empowerment, and organizational commitment was used. The SPSS program version 19 was employed to perform descriptive and inferential statistics including correlation and stepwise multiple regression analysis. Results: Overall most nurses perceived their immediate nursing managers as not displaying the ideal level of transformational leadership (TFL) behaviors. Nurses' commitment appeared to be negatively correlated with TFL style and perceived psychological empowerment. However, commitment was positively correlated with the Transactional Leadership (TAL) style. Analysis, also, showed that commitment is significantly associated with the nurse's nationality by region: North American (P = 0.001) and Arab (p = 0.027). The other important predictors of commitment include TAL (P = 0.027), Laissez-faire Leadership (LFL (P = 0.012), and autonomy (P = 0.016). The linear combination of these predictors explained 20 % of the variability of the nurses' commitment. Conclusion: The study findings suggest that leadership styles and employee empowerment could play an instrumental role in promoting organizational commitment of nurses working in acute health care settings, at least in the Saudi Arabian context

Eignung des Anbaues von Körnerleguminosen zur Humanernährung im Alpenvorland

Die Anbaueignung sechs verschiedener traditioneller Speisekörnerleguminosen (Alblinse, Berglinse, Rotholzer Trockenbohne, Black Turtle Buschbohne, Palerbse und blaue Lupine) im Alpenvorland wurde in diesem Versuch getestet. Die Versuchsfragen waren Anbaueignung, Unterschiede im Saatsystem (Breitsaat und Reihensaat) sowie Deckungsbeiträge. Unter allen Speisekörnerleguminosen erzielten die Bohnen die höchsten Erträge (1028 und 1628 kg/ha), gefolgt von der Palerbse (766 kg/ha) und den Linsen (457 und 537 kg/ha). Zwischen den beiden Saatsystemen zeigten sich keine signifikanten Unterschiede

Critical Behavior of Disordered Systems with a Free Surface

The behavior of homogeneous and disordered systems with a free boundary is described on the basis of group theory in the two-loop approximation directly in three-dimensional space. The effect of the free boundary on the regime of the bulk critical behavior is revealed. It is shown that the boundedness of the system slightly affects the regime of the bulk critical behavior in the case of the ordinary transition, whereas this effect is more noticeable in the case of the special transition. Surface critical phenomena are described for homogeneous and disordered systems, and the critical exponents are calculated in the two-loop approximation. It is shown that the effect of impurities is insignificant in the special phase transition, whereas it is more noticeable in the ordinary phase transition. The derived critical exponents are compared with the computer-simulation results.Comment: 19 pages, 2 figure

Accelerator Testing of the General Antiparticle Spectrometer, a Novel Approach to Indirect Dark Matter Detection

We report on recent accelerator testing of a prototype general antiparticle spectrometer (GAPS). GAPS is a novel approach for indirect dark matter searches that exploits the antideuterons produced in neutralino-neutralino annihilations. GAPS captures these antideuterons into a target with the subsequent formation of exotic atoms. These exotic atoms decay with the emission of X-rays of precisely defined energy and a correlated pion signature from nuclear annihilation. This signature uniquely characterizes the antideuterons. Preliminary analysis of data from a prototype GAPS in an antiproton beam at the KEK accelerator in Japan has confirmed the multi-X-ray/pion star topology and indicated X-ray yields consistent with prior expectations. Moreover our success in utilizing solid rather than gas targets represents a significant simplification over our original approach and offers potential gains in sensitivity through reduced dead mass in the target area.Comment: 18 pages, 9 figures, submitted to JCA

Understanding adhesion at as-deposited interfaces from ab initio thermodynamics of deposition growth: thin-film alumina on titanium carbide

We investigate the chemical composition and adhesion of chemical vapour deposited thin-film alumina on TiC using and extending a recently proposed nonequilibrium method of ab initio thermodynamics of deposition growth (AIT-DG) [Rohrer J and Hyldgaard P 2010 Phys. Rev. B 82 045415]. A previous study of this system [Rohrer J, Ruberto C and Hyldgaard P 2010 J. Phys.: Condens. Matter 22 015004] found that use of equilibrium thermodynamics leads to predictions of a non-binding TiC/alumina interface, despite the industrial use as a wear-resistant coating. This discrepancy between equilibrium theory and experiment is resolved by the AIT-DG method which predicts interfaces with strong adhesion. The AIT-DG method combines density functional theory calculations, rate-equation modelling of the pressure evolution of the deposition environment and thermochemical data. The AIT-DG method was previously used to predict prevalent terminations of growing or as-deposited surfaces of binary materials. Here we extent the method to predict surface and interface compositions of growing or as-deposited thin films on a substrate and find that inclusion of the nonequilibrium deposition environment has important implications for the nature of buried interfaces.Comment: 8 pages, 6 figures, submitted to J. Phys.: Condens. Matte

Spin-flop transition in uniaxial antiferromagnets: magnetic phases, reorientation effects, multidomain states

The classical spin-flop is the field-driven first-order reorientation transition in easy-axis antiferromagnets. A comprehensive phenomenological theory of easy-axis antiferromagnets displaying spin-flops is developed. It is shown how the hierarchy of magnetic coupling strengths in these antiferromagnets causes a strongly pronounced two-scale character in their magnetic phase structure. In contrast to the major part of the magnetic phase diagram, these antiferromagnets near the spin-flop region are described by an effective model akin to uniaxial ferromagnets. For a consistent theoretical description both higher-order anisotropy contributions and dipolar stray-fields have to be taken into account near the spin-flop. In particular, thermodynamically stable multidomain states exist in the spin-flop region, owing to the phase coexistence at this first-order transition. For this region, equilibrium spin-configurations and parameters of the multidomain states are derived as functions of the external magnetic field. The components of the magnetic susceptibility tensor are calculated for homogeneous and multidomain states in the vicinity of the spin-flop. The remarkable anomalies in these measurable quantities provide an efficient method to investigate magnetic states and to determine materials parameters in bulk and confined antiferromagnets, as well as in nanoscale synthetic antiferromagnets. The method is demonstrated for experimental data on the magnetic properties near the spin-flop region in the orthorhombic layered antiferromagnet (C_2H_5NH_3)_2CuCl_4.Comment: (15 pages, 12 figures; 2nd version: improved notation and figures, correction of various typos