14,995 research outputs found

    Creep studies on oriented thermoplastics

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    The enhancement of many of the mechanical properties of thermoplastics which may be achieved by orienting the molecules has been known for some time. It has been exploited in the production of textile fibres end oriented films. Molecular orientation also occurs during processes such as extrusion, moulding or forming. Here, unless carefully controlled, it may well cause a deterioration in the properties of the finished article. In view of this a systematic study on the anisotropy of the mechanical properties of thermoplastics, resulting from molecular orientation, is being carried out at present in these laboratories … [cont.]

    An apparatus for the measurement of tensile creep and contraction ratios in small non-rigid specimens

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    An apparatus is described for precise measurement of creep properties in specimens with gauge lengths down to 1.2 cm. An extensometer has been developed which is supported independently of the specimen and exerts a load on the specimen of less than 5 grams. It can thus be used with small non-rigid specimens. The extensometer will detect strains down to 2 x 10-6. The stability is excellent. An adaptation of the system which allows simultaneous measurement of tensile strain and lateral strain during creep is also described. The apparatus was designed for the measurement of anisotropy of creep properties in oriented thermoplastics and reference to such measurements is given. It is however entirely suitable for general application to small specimens

    Post-inpatient Attrition from Care “As Usual” in Veterans with Multiple Psychiatric Admissions

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    Disengagement from outpatient care following psychiatric hospitalization is common in high-utilizing psychiatric patients and contributes to intensive care utilization. To investigate variables related to treatment attrition, a range of demographic, diagnostic, cognitive, social, and behavioral variables were collected from 233 veterans receiving inpatient psychiatric services who were then monitored over the following 2 years. During the follow-up period, 88.0 % (n = 202) of patients disengaged from post-inpatient care. Attrition was associated with male gender, younger age, increased expectations of stigma, less short-term participation in group therapy, and poorer medication adherence. Of those who left care, earlier attrition was predicted by fewer prior-year inpatient psychiatric days, fewer lifetime psychiatric hospitalizations, increased perceived treatment support from family, and less short-term attendance at psychiatrist appointments. Survival analyses were used to analyze the rate of attrition of the entire sample as well as the sample split by short-term group therapy attendance. Implications are discussed

    Hybrid receiver study

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    The results are presented of a 4 month study to design a hybrid analog/digital receiver for outer planet mission probe communication links. The scope of this study includes functional design of the receiver; comparisons between analog and digital processing; hardware tradeoffs for key components including frequency generators, A/D converters, and digital processors; development and simulation of the processing algorithms for acquisition, tracking, and demodulation; and detailed design of the receiver in order to determine its size, weight, power, reliability, and radiation hardness. In addition, an evaluation was made of the receiver's capabilities to perform accurate measurement of signal strength and frequency for radio science missions

    Solid phase adhesion of tungsten and silver

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    Metallic adhesion strength of silver and tungsten junctio

    Economic impacts on New Zealand of GM crops : result from partial equilibrium modelling

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    This paper reports findings from economic modelling of the impacts on New Zealand agricultural producer returns from the commercial use of genetically modified (GM) food crops. Several possibilities are considered in the modelling, including different rates of GM crop adoption, positive and negative consumer responses, increases in productivity, first- and second-generation GM crops, and control of the intellectual property. The results are consistent with theory, other studies and expectations. Thus, it is not surprising that New Zealand producers increase their revenue the most when they concentrate on products that have a premium in the market because consumers prefer them. If consumers prefer non-GM products, New Zealand producers gain by focusing on those crops. If consumers prefer second-generation GM products, producers increase their returns by growing those crops. Secondly, it is also consistent with theory, experience and expectations that an increase in productivity does not necessarily lead to increased returns. This is dependent upon whether NZ has sole access to the technology or whether it is or becomes available overseas. Thus, even where a product has a consumer preference, producer returns can fall when productivity increases. Thirdly, controlling access to preferred products or to productive technology has beneficial effects for New Zealand commodity producers

    New Zealand Agribusiness Success: An Approach to exploring the role of strategy, structure and conduct on firm performance

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    This paper presents a framework to explore agribusiness success in New Zealand. The framework provides the basis for historical analysis. It draws on existing theory based on the structure-conduct-performance paradigm but expanded to take account of firm strategy and the analysis of value chains.Agribusiness, structure, conduct, performance, history, Agribusiness,

    Approaching finite-temperature phase diagrams of strongly correlated materials: a case study for V2O3

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    Examining phase stabilities and phase equilibria in strongly correlated materials asks for a next level in the many-body extensions to the local-density approximation (LDA) beyond mainly spectroscopic assessments. Here we put the charge-self-consistent LDA+dynamical mean-field theory (DMFT) methodology based on projected local orbitals for the LDA+DMFT interface and a tailored pseudopotential framework into action in order to address such thermodynamics of realistic strongly correlated systems. Namely a case study for the electronic phase diagram of the well-known prototype Mott-phenomena system V2_2O3_3 at higher temperatures is presented. We are able to describe the first-order metal-to-insulator transitions with negative pressure and temperature from the self-consistent computation of the correlated total energy in line with experimental findings.Comment: 12 pages, 15 figures, new data adde

    An Empirically Based Calculation of the Extragalactic Infrared Background

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    Using the excellent observed correlations among various infrared wavebands with 12 and 60 micron luminosities, we calculate the 2-300 micron spectra of galaxies as a function of luminosity. We then use 12 micron and 60 micron galaxy luminosity functions derived from IRAS data, together with recent data on the redshift evolution of galaxy emissivity, to derive a new, empirically based IR background spectrum from stellar and dust emission in galaxies. Our best estimate for the IR background is of order 2-3 nW/m^2/sr with a peak around 200 microns reaching 6-8 nW/m^2/sr. Our empirically derived background spectrum is fairly flat in the mid-IR, as opposed to spectra based on modeling with discrete temperatures which exhibit a "valley" in the mid-IR. We also derive a conservative lower limit to the IR background which is more than a factor of 2 lower than our derived flux.Comment: 14 pages AASTeX, 2 .ps figures, the Astrophysical Journal, in pres

    Anisotropic domain walls

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    We find an anisotropic, non-supersymmetric generalization of the extreme supersymmetric domain walls of simple non-dilatonic supergravity theory. As opposed to the isotropic non- and ultra-extreme domain walls, the anisotropic non-extreme wall has the \emph{same} spatial topology as the extreme wall. The solution has naked singularities which vanish in the extreme limit. Since the Hawking temperature on the two sides is different, the generic solution is unstable to Hawking decay.Comment: 11 pages, LaTeX, 3 PostScript figures, uses amstex and epsfi
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