104 research outputs found

    Two-Dimensional Supersonic Flow with Perpendicular Injection of the Gas

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    The basic requirements for the profession of «teacher of vocational training»

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    В статье рассмотрены основные общие требования, которые должны предъявляться педагогу профессионального обучения в условиях современного образования, и закрепленных в Профессиональном стандарте педагога.The article accounts the basic general requirements for the teacher of Professional training in the conditions of contemporary education fixed in the Professional standard of the teacher

    Thermal Response Measurement and Performance Evaluation of Borehole Heat Exchangers: A Case Study in Kazakhstan

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    The purpose of the present work was to determine the thermal performance of borehole heat exchangers, considering the influences of their geometric configurations and the thermophysical properties of the soil, grout and pipe wall material. A three-dimensional model was developed for the heat and mass transfer in soil (a porous medium) and grout, together with one-dimensional conductive heat transfer through the pipe walls and one-dimensional convective heat transfer of the heat transfer fluid circulating in the pipes. An algorithm was developed to solve the mathematical equations of the model. The COMSOL Multiphysics software was used to implement the algorithm and perform the numerical simulations. An apparatus was designed, installed and tested to implement the thermal response test (TRT) method. Two wells of depth 50 m were drilled in the Almaty region in Kazakhstan. Gravel and till/loam were mainly found, which are in accordance with the stratigraphic map of the local geological data. In each well, two borehole heat exchangers were installed, which were an integral part of the ground source heat pump. The TRT measurements were conducted using one borehole heat exchanger in one well and the data were obtained. The present TRT data were found to be in good agreement with those available in literature. The numerical results of the model agreed well with the present TRT data, with the root-mean-square-deviation within 0.184 °C. The TRT data, together with the predictions of the line-source analytical model, were utilized to determine the soil thermal conductivity (λg = 2.35 W/m K) and the thermal resistance of the borehole heat exchanger from the heat transfer fluid to the soil (Rb = 0.20 m K/W). The model was then used to predict the efficiencies of the borehole heat exchangers with various geometric configurations and dimensions. The simulation results show that the spiral borehole heat exchanger extracts the highest amount of heat, followed by the multi-tube, double U-type parallel, double U-type cross and single U-type. It is also found that the spiral configuration can save 34.6% drilling depth compared with the conventional single U-type one, suggesting that the spiral configuration is the best one in terms of the depth and the maximum heat extracted. The simulation results showed that (i) more heat was extracted with a higher thermal conductivity of grout material, in the range of 0.5–3.3 W/m K; (ii) the extracted heat remained unchanged for a thermal conductivity of pipe material higher than 2.0 W/m K (experiments in the range of 0.24–0.42 W/m K); (iii) the extracted heat remained unchanged for a volumetric flow rate of water higher than 1.0 m3/h (experimental flow rate 0.6 m3/h); and (iv) the heat extracted by the borehole heat exchanger increased with an increase in the thermal conductivity of the soil (experiments in the range of 0.4–6.0 W/m K). The numerical tool developed, the TRT data and simulation results obtained from the present work are of great value for design and optimization of borehole heat exchangers as well as studying other important factors such as the heat transfer performance during charging/discharging, freezing factor and thermal interference

    ПОРІВНЯЛЬНА ОЦІНКА ЕФЕКТИВНОСТІ ВИКОРИСТАННЯ КОМПОЗИЦІЇ НА ОСНОВІ НАНОДИСПЕРСНОГО КРЕМНЕЗЕМУ З АНТИМІКРОБНИМИ ВЛАСТИВОСТЯМИ ДЛЯ МІСЦЕВОГО ЛІКУВАННЯ ГНІЙНО-ЗАПАЛЬНИХ ПРОЦЕСІВ

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    Проведена порівняльна оцінка результатів місцевого лікування гнійно-запальних захворювань м’яких тканин з використанням стандартних методів та композиції з сорбційними та антимікробними властивостями на основі нанодисперсного кремнезему. Застосування композиції в комплексі лікування хворих сприяло більш швидкому очищенню ран від некротизованих тканин та мікроорганізмів, швидкій появі грануляцій, зменшенню тяжкості інтоксикації, тривалості І фази ранового процесу, що дозволяло на 6 – 7-му добу після операції накладати на рани вторинні шви, в цілому тривалості лікування хворих у стаціонарі на 3,7 дня

    ПУНКЦИОННАЯ КРИОДЕСТРУКЦИЯ ПОД УЛЬТРАЗВУКОВЫМ НАБЛЮДЕНИЕМ В ЛЕЧЕНИИ РЕЦИДИВНЫХ БАЗАЛИОМ ЛИЦА

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    Basal cell carcinoma is the most frequent human skin malignant tumor. The risk of recurrence exists regardless of the treatment method. The ultrasound assisted treatment in patients with face and neck skin basalioma is analyzed in this study. It was shown that the ultrasound assisted method with usage of modern domestic equipment allowedincreasing the treatment effi cacy of recurrent basal cell skin cancer.Базально-клеточная карцинома — это наиболее часто встречающаяся y человека раковая опухоль кожи. Опасность рецидивирования заболевания сохраняется вне зависимости от способов лечения. В данной работе проведен анализ лечения больных с базалиомой кожи лица и шеи под УЗ-наведением с целью улучшения результатов лечения. Исследование показало, что использование ультразвукового метода и нового отечественного оборудования позволяет повысить эффективность лечения при рецидивирующем течении базально-клеточного рака кожи

    Polyploidization as a Retraction Force in Plant Genome Evolution: Sequence Rearrangements in Triticale

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    BACKGROUND: Polyploidization is a major evolutionary process in plants where hybridization and chromosome doubling induce enormous genomic stress and can generate genetic and epigenetic modifications. However, proper evaluation of DNA sequence restructuring events and the precise characterization of sequences involved are still sparse. METHODOLOGY/PRINCIPAL FINDINGS: Inter Retrotransposons Amplified Polymorphism (IRAP), Retrotransposons Microsatellite Amplified Polymorphism (REMAP) and Inter Simple Sequence Repeat (ISSR) largely confirmed the absence of any intraspecific variation in wheat, rye and triticale. The comparative analysis of banding profiles between wheat and rye inbred lines revealed 34% of monomorphic (common to both parental species) bands for the ten different primer combinations used. The analysis of triticale plants uncovered nearly 51% of rearranged bands in the polyploid, being the majority of these modifications, due to the loss of rye bands (83%). Sequence analysis of rye fragments absent in triticale revealed for instance homology with hydroxyproline-rich glycoproteins (HRGP), a protein that belongs to a major family of inducible defence response proteins. Conversely, a wheat-specific band absent in triticale comprises a nested structure of copia-like retrotransposons elements, namely Claudia and Barbara. Sequencing of a polyploid-specific band (absent in both parents) revealed a microsatellite related sequence. Cytological studies using Fluorescent In Situ Hybridization (FISH) with REMAP products revealed a widespread distribution of retrotransposon and/or microsatellite flanking sequences on rye chromosomes, with a preferential accumulation in heterochromatic sub-telomeric domains. CONCLUSIONS/SIGNIFICANCE: Here, we used PCR-based molecular marker techniques involving retrotransposons and microsatellites to uncover polyploidization induced genetic restructuring in triticale. Sequence analysis of rearranged genomic fragments either from rye or wheat origin showed these to be retrotransposon-related as well as coding sequences. Further FISH analysis revealed possible chromosome hotspots for sequence rearrangements. The role of chromatin condensation on the origin of genomic rearrangements mediated by polyploidization in triticale is also discussed

    Contrasting patterns of the 5S and 45S rDNA evolutions in the Byblis liniflora complex (Byblidaceae)

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    To clarify the evolutionary dynamics of ribosomal RNA genes (rDNAs) in the Byblis liniflora complex (Byblidaceae), we investigated the 5S and 45S rDNA genes through (1) chromosomal physical mapping by fluorescence in situ hybridization (FISH) and (2) phylogenetic analyses using the nontranscribed spacer of 5S rDNA (5S-NTS) and the internal transcribed spacer of 45S rDNA (ITS). In addition, we performed phylogenetic analyses based on rbcL and trnK intron. The complex was divided into 2 clades: B. aquatica–B. filifolia and B. guehoi–B. liniflora–B. rorida. Although members of the complex had conservative symmetric karyotypes, they were clearly differentiated on chromosomal rDNA distribution patterns. The sequence data indicated that ITS was almost homogeneous in all taxa in which two or four 45S rDNA arrays were frequently found at distal regions of chromosomes in the somatic karyotype. ITS homogenization could have been prompted by relatively distal 45S rDNA positions. In contrast, 2–12 5S rDNA arrays were mapped onto proximal/interstitial regions of chromosomes, and some paralogous 5S-NTS were found in the genomes harboring 4 or more arrays. 5S-NTS sequence type-specific FISH analysis showed sequence heterogeneity within and between some 5S rDNA arrays. Interlocus homogenization may have been hampered by their proximal location on chromosomes. Chromosomal location may have affected the contrasting evolutionary dynamics of rDNAs in the B. liniflora complex

    Evolution of Genome Size and Complexity in Pinus

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    BACKGROUND: Genome evolution in the gymnosperm lineage of seed plants has given rise to many of the most complex and largest plant genomes, however the elements involved are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Gymny is a previously undescribed retrotransposon family in Pinus that is related to Athila elements in Arabidopsis. Gymny elements are dispersed throughout the modern Pinus genome and occupy a physical space at least the size of the Arabidopsis thaliana genome. In contrast to previously described retroelements in Pinus, the Gymny family was amplified or introduced after the divergence of pine and spruce (Picea). If retrotransposon expansions are responsible for genome size differences within the Pinaceae, as they are in angiosperms, then they have yet to be identified. In contrast, molecular divergence of Gymny retrotransposons together with other families of retrotransposons can account for the large genome complexity of pines along with protein-coding genic DNA, as revealed by massively parallel DNA sequence analysis of Cot fractionated genomic DNA. CONCLUSIONS/SIGNIFICANCE: Most of the enormous genome complexity of pines can be explained by divergence of retrotransposons, however the elements responsible for genome size variation are yet to be identified. Genomic resources for Pinus including those reported here should assist in further defining whether and how the roles of retrotransposons differ in the evolution of angiosperm and gymnosperm genomes
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