4 research outputs found

    Wireless power transfer in magnetic resonance imaging at a higher-order mode of a birdcage coil

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    Magnetic resonance imaging (MRI) is a crucial tool for medical visualization. In many cases, performing a scanning procedure requires the use of additional equipment, which can be powered by wires as well as via wireless power transfer (WPT) or wireless energy harvesting. In this Letter, we propose a novel scheme for WPT that uses a higher-order mode of the MRI scanner's birdcage coil for energy transmission. In contrast to the existing WPT solutions, our approach does not require additional transmitting coils. Compared to the energy harvesting, the proposed method allows supplying significantly more power. We perform numerical simulations demonstrating that one can use the fundamental mode of the birdcage coil to perform a scanning procedure while transmitting the energy to the receiver at a higher-order mode without any interference with the scanning signal or violation of safety constraints, as guaranteed by the mode structure of the birdcage. Also, we evaluate the specific absorption rate along with the energy transfer efficiency and verify our numerical model by a direct comparison with an experimental setup featuring a birdcage coil of a 1.5T MRI scanner.Comment: 6 pages, 5 figures + Supplementary Material 10 pages, 7 figure

    Synthis and Phisical And Chemical; Properties of SiO[2]-B[2]O[3] and SiO[2]-P[2]O[5] Thin Film Systems and Powders

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    The SiO[2]-B[2]O[3] and SiO[2]-P[2]O[5] films were synthesized by using film forming solutions having a P[2]O[5] content of up to 30% and B[2]O[3] up to 40%. Properties of the filmforming solutions and binary oxides were examined. The physical and chemical processes occurring in the solution during the heat treatment of films were examined. The conditions for producing films of different thicknesses were determined. The kinetic parameters were calculated

    The origins and spread of domestic horses from the Western Eurasian steppes

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture
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