Detection and imaging of the oxygen deficiency in single crystalline YBa2_{\text{2}}Cu3_{\text{3}}O7−δ_{\text{7}-\delta} thin films using a positron beam

Single crystalline YBa$_{\text{2}}$Cu$_{\text{3}}$O$_{\text{7}-\delta}$ (YBCO) thin films were grown by pulsed laser deposition (PLD) in order to probe the oxygen deficiency $\delta$ using a mono-energetic positron beam. The sample set covered a large range of $\delta$ (0.191<$\delta$<0.791) yielding a variation of the critical temperature $T_{\text{c}}$ between 25 and 90\,K. We found a linear correlation between the Doppler broadening of the positron electron annihilation line and $\delta$ determined by X-ray diffraction (XRD). Both, the origin of the found correlation and the influence of metallic vacancies, were examined with the aid of ab-initio calculations that allowed us (i) to exclude the presence of Y vacancies and (ii) to ensure that positrons still probe $\delta$ despite the potential presence of Ba or Cu vacancies. In addition, by scanning with the positron beam the spatial variation of $\delta$ could be analyzed. It was found to fluctuate with a standard deviation of up to $0.079(5)$ within a single YBCO film

Possible indicators for low dimensional superconductivity in the quasi-1D carbide Sc3CoC4

The transition metal carbide Sc3CoC4 consists of a quasi-one-dimensional (1D) structure with [CoC4]_{\inft} polyanionic chains embedded in a scandium matrix. At ambient temperatures Sc3CoC4 displays metallic behavior. At lower temperatures, however, charge density wave formation has been observed around 143K which is followed by a structural phase transition at 72K. Below T^onset_c = 4.5K the polycrystalline sample becomes superconductive. From Hc1(0) and Hc2(0) values we could estimate the London penetration depth ({\lambda}_L ~= 9750 Angstroem) and the Ginsburg-Landau (GL) coherence length ({\xi}_GL ~= 187 Angstroem). The resulting GL-parameter ({\kappa} ~= 52) classifies Sc3CoC4 as a type II superconductor. Here we compare the puzzling superconducting features of Sc3CoC4, such as the unusual temperature dependence i) of the specific heat anomaly and ii) of the upper critical field H_c2(T) at T_c, and iii) the magnetic hysteresis curve, with various related low dimensional superconductors: e.g., the quasi-1D superconductor (SN)_x or the 2D transition-metal dichalcogenides. Our results identify Sc3CoC4 as a new candidate for a quasi-1D superconductor.Comment: 4 pages, 5 figure

SLM Materials Development

The purpose of this project was to create a procedure to efficiently determine a “recipe” of parameter values that create a desired set of mechanical properties. Research was conducted into the laser powder bed fusion process with focus on underdeveloped materials. A design of experiment was used with a set of density correlated parameters to establish a method of producing nearly dense parts. Our methods include SLM printing, metrology, and statistical analysis. An experimental procedure for materials development was designed, but unable to be validated during the scope of this project, due to unforeseen safety issues (exposure to Chromium 6, a toxic substance). Next steps include validation of this procedure using various metal powders in a SLM 125 HL

Reporting Technical Information; Designlng Technical Reports; IBM Dictionary of Computing

Book reviews of Reporting Technical Information, by Kenneth W. Houp and Thomas E. Pearsall; and Designlng Technical Reports, by J.C Mathes and Dwight W. Stevenson; IBM Dictionary of Computing (Ninth Edition), International Business Machines Corporation

Comparative Cost Analyses of Conventional, Integrated Crop Management, and Organic Methods

Production costs have been analyzed in several studies using such normative approaches as budgeting and mathematical programming, and positive approaches as estimation of production, cost, or profit functions. This study used budgeting methods to analyze the costs and benefits of adopting integrated crop management (ICM) or organic methods versus conventional agriculture for tomatoes (Lycopersicon esculentum Mill.), sweet corn (Zea mays L. var. saccharada), and pumpkins (Cucurbita pepo L.). Data were collected using field studies conducted at the Rutgers University Snyder Research and Extension Farm, Pittstown, N.J. Time and motion study techniques were used to record machinery use and labor quantities. Records of production inputs and yields were also collected. These records were then converted to a 1.0-acre (0.4-ha) basis to constructed crop budgets. Results show that ICM systems are more profitable than conventional and organic systems. Organic systems had the lowest net returns. However, because of the organic price premium, the net returns were fairly close to those for conventional and ICM systems

Quaternion algebras with the same subfields

G. Prasad and A. Rapinchuk asked if two quaternion division F -algebras that have the same subfields are necessarily isomorphic. The answer is known to be "no" for some very large fields. We prove that the answer is "yes" if F is an extension of a global field K so that F /K is unirational and has zero unramified Brauer group. We also prove a similar result for Pfister forms and give an application to tractable fields

Entbürokratisierung der Statistik durch Flexibilisierung

Der "Masterplan Entbürokratisierung", den die Bundesregierung vorgelegt hat und nun beginnt umzusetzen, betrifft auch den Bereich der amtlichen Statistik. Dazu haben die statistischen Ämter inzwischen einen "Masterplan zur Reform der amtlichen Statistik" beschlossen. Es reicht aber nicht, Statistiken zu streichen, vielmehr muss das gesamte System der statistischen Infrastruktur in Deutschland (und in Europa) besser aufeinander abgestimmt werden. Dazu sind gesetzliche Neuregelungen nötig, um beispielsweise eindeutige Zuständigkeiten zu schaffen.

2010 EPRG Public Opinion Survey: Policy Preferences and Energy Saving Measures

This paper presents results of the 2010 Electricity Policy Research Group (EPRG) public opinion survey. The survey examines the energy policy preferences and attitudes of the British public, the potential for consumer engagement and consumer acceptance of various energy demand response activities. Wherever possible, comparisons were made to EPRG public opinion surveys from 2006 and 2008. Since the global financial crisis of 2008, energy and environmental concerns have decreased in priority, and respondents are more sceptical about government interventions in electricity markets. The share of individuals reporting that they are experiencing serious hardship due to energy prices has gone down from the 2008 level. While roughly half of the respondents would agree to have detailed metered consumption information recorded by their energy providers, they are even more wary about making data available to other entities. Local ownership is a potential motivating factor for public support for local small-scale energy plants. Energy efficiency measures had higher uptake than in previous years, but the widespread measures are typically cheaper and easiest to implement. There is scope for shifting discretionary electricity load to off-peak hours through both Time-of-Use tariffs and smart appliances that require limited user intervention.Time-of-use tariff