Исследование и совершенствование методов упрочнения нагруженных элементов многоходового переключателя скважин с целью повышения ресурса его работы

Работа направлена на построение модели узла многоходового переключателя скважин системы расчета нефти на месторождении и последующие расчеты на ее основе с целью выработки рекомендаций по упрочнению рабочих элементов клапана, подверженных интенсивному износу. Анализируя литературу по конструкции ПСМ, модернизации корпуса и других элементов, можно прейти к выводу об актуальности темы исследования. Большой ряд патентов предлагает различные модернизации корпуса ПСМ. Ряд научных статей описывает проблемы износа. ПСМ используется повсеместно на нефтегазовом промысле, выход из строя приводит к ремонту и остановке линии, а как следствие к экономическим затратам на простой, ремонт, либо замену оборудования. Из полученных с производства данных видны проблемы износа рабочих элементов корпуса.The work is aimed at building a model of the multi-pass switch node of the oil calculation system on the field and subsequent calculations based on it in order to develop recommendations for strengthening the working elements of the valve that are subject to intense wear. Analyzing the literature on the design of the PSM, the modernization of the housing and other elements, we can come to a conclusion about the relevance of the research topic. A large number of patents offer various upgrades to the PSM case. A number of scientific articles describe wear problems. PSM is used everywhere in the oil and gas field, failure leads to the repair and installation of the line, and as a result to the economic costs of downtime, repair, or replacement of equipment. From the data obtained from produc

Банковская система РФ

В данной статье изложены материалы по теме "Банковская система РФ", в которой описаны основные понятия, функции и структура, показаны рейтинг банков, сущность банковской системы РФ

Temporal muscle thickness is an independent prognostic marker in melanoma patients with newly diagnosed brain metastases.

OBJECTIVES: The purpose of this study was to evaluate the prognostic relevance of temporal muscle thickness (TMT) in melanoma patients with newly diagnosed brain metastases. METHODS: TMT was retrospectively assessed in 146 melanoma patients with newly diagnosed brain metastases on cranial magnetic resonance images. Chart review was used to retrieve clinical parameters, including disease-specific graded prognostic assessment (DS-GPA) and survival times. RESULTS: Patients with a TMT > median showed a statistically significant increase in survival time (13 months) compared to patients with a TMT < median (5 months; p < 0.001; log rank test). A Cox regression model revealed that the risk of death was increased by 27.9% with every millimeter reduction in TMT. In the multivariate analysis, TMT (HR 0.724; 95% 0.642-0.816; < 0.001) and DS-GPA (HR 1.214; 95% CI 1.023-1.439; p = 0.026) showed a statistically significant correlation with overall survival. CONCLUSION: TMT is an independent predictor of survival in melanoma patients with brain metastases. This parameter may aid in patient selection for clinical trials or to the choice of different treatment options based on the determination of frail patient populations

Low levels of taurine introgression in the current Brazilian Nelore and Gir indicine cattle populations

Background: Nelore and Gir are the two most important indicine cattle breeds for production of beef and milk in Brazil. Historical records state that these breeds were introduced in Brazil from the Indian subcontinent, crossed to local taurine cattle in order to quickly increase the population size, and then backcrossed to the original breeds to recover indicine adaptive and productive traits. Previous investigations based on sparse DNA markers detected taurine admixture in these breeds. High-density genome-wide analyses can provide high-resolution information on the genetic composition of current Nelore and Gir populations, estimate more precisely the levels and nature of taurine introgression, and shed light on their history and the strategies that were used to expand these breeds. Results: We used the high-density Illumina BovineHD BeadChip with more than 777 K single nucleotide polymorphisms (SNPs) that were reduced to 697 115 after quality control filtering to investigate the structure of Nelore and Gir populations and seven other worldwide populations for comparison. Multidimensional scaling and model-based ancestry estimation clearly separated the indicine, European taurine and African taurine ancestries. The average level of taurine introgression in the autosomal genome of Nelore and Gir breeds was less than 1% but was 9% for the Brahman breed. Analyses based on the mitochondrial SNPs present in the Illumina BovineHD BeadChip did not clearly differentiate taurine and indicine haplotype groupings. Conclusions: The low level of taurine ancestry observed for both Nelore and Gir breeds confirms the historical records of crossbreeding and supports a strong directional selection against taurine haplotypes via backcrossing. Random sampling in production herds across the country and subsequent genotyping would be useful for a more complete view of the admixture levels in the commercial Nelore and Gir populations.(VLID)90707