2,962 research outputs found

    Siberian flood basalt magmatism and Mongolia-Okhotsk slab dehydration

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    Experimental data combined with numerical calculations suggest that fast subducting slabs are cold enough to carry into the deep mantle a significant portion of the water in antigorite, which transforms with increasing depth to phase A and then to phase E and/or wadsleyite by solid-solid phase transition. Clathrate hydrates and ice VII are also stable at PT conditions of cold slabs and represent other potential phases for water transport into the deep mantle. Some cold slabs are expected to deflect while crossing the 410 km and stagnate in transition zone being unable to penetrate through 660 km discontinuity. In this way slabs can move a long way beneath continents after long-lived subduction. With time, the stagnant slabs are heated to the temperature of the ambient transition zone and release free H~2~O-bearing fluid. Combining with transition zone water filter model this may cause voluminous melting of overlying upper mantle rocks. If such process operates in nature, magmas geochemically similar to island-arc magmas are expected to appear in places relatively remote from active arcs at the time of their emplacement. Dolerites of the south-eastern margin of the Siberian flood basalt province, located about 700 km from suggested trench, were probably associated with fast subduction of the Mongolia-Okhotsk slab and originated by dehydration of the stagnant slab in the transition zone. We show that influence of the subduction-related deep water cycle on Siberian flood basalt magmatism gradually reduced with increasing distance from the subduction zone

    From Free Radicals and Spin-Chemistry Over Spin-Dynamics and Hyperpolarization to Biology and Materials Science

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    This special issue of ZPC is dedicated to the 80th anniversary of Kev Salikhov, a prominent scientist who has made seminal contributions to spin chemistry, chemical kinetics, spin hyperpolarization and magnetic resonance. Altogether there are 41 scientific papers; for this reason, the guest editors have decided to publish three subsequent issues. Each issue is focused on a particular field, which is closely related to research interests of Salikhov or was even seeded by his work. As the following papers clearly demonstrate, the initial seed of Salikhov fell on a very fruitful soil and has grown to a huge and impressive scientific tree with branches ranging from fundamental science to applications in biochemistry and materials science

    Theoretical Description of Pulsed RYDMR: Refocusing Zero-Quantum and Single Quantum Coherences

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    A theoretical description of pulsed reaction yield detected magnetic resonance (RYDMR) is proposed. In RYDMR, magnetic resonance spectra of radical pairs (RPs) are indirectly detected by monitoring their recombination yield. Such a detection method is significantly more sensitive than conventional electron paramagnetic resonance (EPR), but design of appropriate pulse sequences for RYDMR requires additional effort because of a different observable. In this work various schemes for generating spin-echo like signals and detecting them by RYDMR are treated. Specifically, we consider refocusing of zero-quantum coherences (ZQCs) and single-quantum coherences (SQCs) by selective as well as by non-selective pulses and formulate a general analytical approach to pulsed RYDMR, which makes an efficient use of the product operator formalism. We anticipate that these results are of importance for RYDMR studies of elusive paramagnetic particles, notably, in organic semiconductors

    Teaching Simultaneous Interpreting with Text

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    Proceeding from the ever-growing use of simultaneous interpretation with text (SI+T) at international conferences and on the private market and the need to teach it to future interpreters, this paper touches upon the following issues: What is SI+T; types of SI+T (running texts vs. Power Point slides vs. real-time captioning, etc.); theoretical foundations of SI+T; four time-related scenarios in SI+T, i.e. (1) ideal (text given to interpreter well in advance), (2) normal (text given 10-20 minutes in advance), (3) rush (text given just before the speaker starts), and (4) crisis (text given after the speaker starts); SI with or without text: which Is easier? - Cognitive constraints and benefits in SI+T (e.g., dual input vs. increased precision); interpreting strategies in dealing with text in SI under four time-related scenarios, including (1) strategic decision on whether or not to use the text, and (2) text preparation strategies and techniques; current and recommended approaches to teaching SI+T; cognitive foundation for teaching SI+T with selected methodological recommendations; and sample progression scale for teaching SI+T

    DEVELOPMENT AND ANALYSIS OF A NEW APPROACH FOR SIMPLIFIED DETERMINATION OF THE HEATING AND THE COOLING LOADS OF LIVESTOCK BUILDINGS

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    Pig farming is a sector of animal husbandry, the development of which is great attention. The pork market occupies a large share in the trade in animal products. In the conditions of they do competition more efforts are made to improve the quality and reduce the cost of production. To achieve this goal, work is being done in several areas – development and expansion of the gene pool, improvement of the living environment in the premises for animal husbandry, reduction of energy costs. Along with the development of feeding technologies, it is necessary to create a suitable microclimate in the premises, in which the animals to realize their productive potential, which in turn is directly related to the use of heating and cooling systems. The design of these systems for both existing and new buildings is carried out according to generally accepted methodologies, which in turn require time for calculation and use of specialized software. The methodologies for determining the loads for heating and cooling of livestock buildings, in accordance with the current legislation in the Republic of Bulgaria, are compared with a new method proposed in this publication. The possibility to consider a livestock building from the point of view of the theory of heat exchange allows the use of the basic differential equations describing the dynamic interaction of the building with the environment. This description would be complete and complex to implement. Therefore, the method of dimensional analysis is used, which is based on generalized indicators, when fulfilling certain criteria of similarity. The aim of the new methodology is to shorten the design time and allow the rapid sizing of heating and cooling systems in livestock buildings. In developing the new methodology, the task was the proposed new approach to summarize the interaction of all physical parameters affecting the heat exchange between the building and the surrounding air, allowing to take into account changes in external (air temperature, wind speed, solar radiation intensity) and internal factors (heat given off by farm animals, lighting, process equipment and processes) affecting the heat exchange between the building and the ambient ai

    force adaptation in robot transmissions

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