5,610 research outputs found
Morphological regions and oblique incidence dot formation in a model of surface sputtering
We study solid surface morphology created by off-normal ion-beam sputtering
with an atomistic, solid-on-solid model of sputter erosion. With respect to an
earlier version of the model, we extend this model with the inclusion of
lateral erosion. Using the 2-dimensional structure factor, we found an upper
bound , in the lateral straggle , for clear ripple formation.
Above this upper bound, for longitudinal straggle , we found
the possibility of dot formation (without sample rotation). Moreover, a
temporal crossover from a hole topography to ripple topography with the same
value of collision cascade parameters was found. Finally, a scaling analysis of
the roughness, using the consecutive gradient approach, yields the growth
exponents and 0.67 for two different topographic regimes.Comment: 8 pages, 14 figure
Plasma Cortisol in Men – Relationship With Atherosclerosis of Retinal Arteries
The production of cortisol increases in acute stress but the effects of chronic stress on
plasma cortisol are still controversial. Stress on the other hand plays a role in coronary
artery disease (CAD) and carotid atherosclerosis. Since there is no data about plasma
cortisol and atherosclerosis of the retinal arteries, the purpose of this study was to explore
the relationship between plasma cortisol in 101 adult males with the degree of
their retinal vessels atherosclerosis. The results were compared with those in 47
matched apparently healthy men with no retinal vessels changes. The atherosclerotic
changes of retinal vessels were determined by direct ophthalmoscopy and graded (1–4)
according to Scheie. Morning plasma cortisol levels were determined by radioimmunoassay
using commercial kits. The results were compared by using chi-square test. No association
between morning plasma cortisol concentrations and retinal vessels atherosclerosis
could be found. The results of this study do not support a role for physiological
levels of plasma cortisol in the development of atherosclerosis, at least of the retinal arteries,
in men
Investigation of the applicability of raman spectroscopy as online process control during consumer milk production
Online detection of product defects using fast spectroscopic measurements is beneficial for producers in the dairy industry since it allows readjustment of product characteristics or redirection of product streams during production. Raman spectroscopy has great potential for such application due to the fast and simple measurement. Its suitability as online sensor for process control was investigated at typical control points in consumer milk production being raw milk storage, standardization, and heat treatment. Additionally, the appropriateness of Raman spectroscopy to act as indicator for product application parameters was investigated using the example of barista foam. To assess the suitability of a pure online system, the merit of Raman spectra was evaluated by a principal component analysis (PCA). Thereby, proteolytic spoilage due to the presence of extracellular enzymes of Pseudomonas sp. was detected and samples based on the applied heat treatment (extended shelf life (ESL) and ultra-high temperature (UHT)) could be separated. A correlation of the content of free fatty acids and foam stability with spectra of the respective milk samples was found, allowing a prediction of the technofunctional quality criterion “Barista” suitability of a UHT milk. The results underlined the suitability of Raman spectroscopy for the detection of deviations from a defined product standard of consumer milk
Influence of Dilution upon Cation Exchange Equilibrium
Ion exchange equilibria in batch systems have been examined to see how the distribution of ions between the ion exchanger and the solution depends on the dilution of the solution. The exchanger was Amberlite IR-120. The following exchanges were studied· K +-H+ Mg++-Ca ++ Ca++ -H+ Ba++ -H+ Ce3 +-H+ and La3 + H+. It has been found that dilution of the system causes the ion of higher affinity to pass into the resin phase. This effect is more pronounced for the exchange of ions of unequal charge than for those of the same charge
Optical second-harmonic effect of sol-gel inorganic-organic nanocomposites
Communications: Second-order nonlinear optically (NLO) active materials have promising technical applications in optoelectronic devices. A general problem in NLO-active polymeric systems is the decay of orientational order with time. Results are presented which show that using inorganic-organic composite materials produced by the sol-gel process as a rigid matrix for oriented ÷(2) chromophores (Figure) may provide a means of overcoming this problem
The Perceptions and Determinants of Auditing and Reporting Quality in the Asia-Pacific Region
A country’s institutional environment significantly influences perceptions of auditing and reporting quality (ARQ) at the national level. Relying on a relatively unique measure of ARQ, collated by the World Economic Forum (WEF), we evaluate the influence of nine key isomorphic pressures on the ARQ in 26 Asia-Pacific countries. The results suggest that six of these (the efficacy of the corporate board, securities exchange regulations, reliance on professional management, protection of minority interests, adoption of international financial reporting and prevalence of foreign ownership) have a highly significant influence on the perception of ARQ whereas adoption of international standards on auditing is only moderately significant. However, contrary to expectations, our findings do not support the argument that the efficiency of legal frameworks and political systems significantly influence the perceptions of auditing and reporting quality in the Asia-Pacific region. These results should be of use to investors and the accounting profession in evaluating economic
environments
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Market power and long-term gas contracts: the case of Gazprom in Central and Eastern European Gas Markets
We explore a major European competition decision, the 2012-18 Gazprom case, using a global gas market simulation model. We find that access to LNG markets alone is insufficient to counterbalance Gazprom’s strategic behaviour; central and eastern Europe (CEE) needs to be well interconnected with bidirectional flow capability. ‘Swap deals’ created by the decision facilitate CEE market integration, while limiting Gazprom’s potential market power. Such deals may increase the diversity of contracted gas and number of market players, but do not improve physical supply diversity. In the next five years, swap deals could marginally impact negatively the utilization of strategic assets in CEE, but since Gazprom’s commitments expire by mid-2026, utilization of these strategic assets may fall considerably, especially if Gazprom withholds supplies. As an unintended consequence, CEE markets may disintegrate from the rest of Europe. Avoiding such outcomes will require further gas market reforms, particularly, market design for gas transportation
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Dynamics of the UK Natural Gas Industry: System Dynamics Modelling and Long-Term Energy Policy Analysis
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