496 research outputs found

    Excitonic effects in time-dependent density functional theory from zeros of the density response

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    We show that the analytic structure of the dynamical xc kernels of semiconductors and insulators can be sensed in terms of its poles which mark physically relevant frequencies of the system where the counter-phase motion of discrete collective excitations occurs: if excited, the collective modes counterbalance each other, making the system to exhibit none at all or extremely weak density response. This property can be employed to construct simple and practically relevant approximations of the dynamical xc kernel for time-dependent density functional theory (TDDFT). Such kernels have simple analytic structure, are able to reproduce dominant excitonic features of the absorption spectra of monolayer semiconductors and bulk solids, and promise high potential for future uses in efficient real-time calculations with TDDFT.Comment: 10 pages, 4 figure

    NMR — SPECTROSCOPY TECHNIQUE FOR SALMON FISH SPECIES QUALITY ASSESSMENT

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    NMR-spectroscopy was used for development of the criteria which characterize the chilled and frozen fish quality. It has been shown that 1H-NMR experiments can be used as quality factor to measure the concentration of inosine, hypoxanthine and inosine-5’-monophosphate generated during the fish storage. The quality factor is expressed by the K1 correlates well with the sensory quality of chilled Atlantic salmon (Salmo Salar), whereas, quality factor H is more sensitive for measuring the quality characteristics of frozen pink salmon (Oncorhynchus gorbuscha), chum salmon (Oncorhynchus keta), sockeye salmon (Oncorhynchus nerka).NMR-spectroscopy was used for development of the criteria which characterize the chilled and frozen fish quality. It has been shown that 1H-NMR experiments can be used as quality factor to measure the concentration of inosine, hypoxanthine and inosine-5’-monophosphate generated during the fish storage. The quality factor is expressed by the K1 correlates well with the sensory quality of chilled Atlantic salmon (Salmo Salar), whereas, quality factor H is more sensitive for measuring the quality characteristics of frozen pink salmon (Oncorhynchus gorbuscha), chum salmon (Oncorhynchus keta), sockeye salmon (Oncorhynchus nerka)

    Use of iodine and selenium enriched fodder rations for production of fortified young lamb

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    The article is devoted to preventive measures to eliminate the problem of dysmicroelementosis in order to increase the productivity of young sheep. The article presents the results of studies of the influence of feeding rations on the growth and development of young sheep of the Edilbaev breed, on the level of their meat productivity and the qualitative characteristics of biologically fortified lamb. Feed additives based on Yoddar-Zn and DAFS-25 were added to the main ration of lambs at the age of four months, once a day, being added into a fodder mixture with concentrates. For the experiment the herd of lambs was divided to four groups of 25 heads each.The changes in live weight at the age of four, five, six and seven months were analyzed, and it was found that at the age of seven months, the absolute average weight gain in the experimental groups varied from 3.45 kg to 4.49 kg, in the control group it was 3.1 kg, while the largest live weight gain was recorded in group III which received both feed additives based on Yoddar-Zn and DAFS-25.There were no significant differences in the parameters of body measurements, with the exception of group III, where the chest circumference increased by 7.2%, and the height of a lamb at the withers increased in average by 8.1%. It was found that group III had the highest meat density coefficient, equal to 3.9, and the cross-sectional area of m. Longissimus dorsi was equal to 13.61 cm2. It was noted that the amount of free amino acids of the lamb group III is 18.8% higher than the meat of the control group. The lamb obtained from the animals of the experimental groups showed a higher protein content and less fat. The ratio of water to protein in all samples was slightly higher than 3.7, which corresponds to the Federa number for meat raw materials. Enriching the rations of the Edilbaevskoy sheep with feed additives Yoddar-Zn and DAFS-25 promotes the stimulation of growth and development of animals, increases the productivity and nutritional value of lamb

    Unsettled facts: on the transformational dynamism of evidence in legal discourse

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    In this article I conduct an examination of discursive identity of a legal ‘object’ in the course of its treatment by various figures in the legal process. The need for this examination arises from a widespread concern about the effects of creating ‘records’, i.e., transforming spoken discourse by way of documentation into ‘evidence’. After a brief review of the current discussion about this phenomenon, I argue that the identity of textualized evidence is upheld by way of references to other texts, all of which create a field of signification within which an object under discussion (evidence) shows different facets without however losing its identity. In order to support my argument, I offer an analysis of ethnographic data pertaining to a specific criminal case. My objective for the analysis is to trace the status of a specific discursive identity after its enunciation during an attorney–client conference. My findings indicate that textualization should be understood not as a form of fixity for discourse, but rather as semantic pivot that provides for different ‘argumentation figures’ within the referential grid of the legal case
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