Developing Effective Roll Cooling Systems Based on Computational Simulation

In order to retrofit a roll cooling system at the JSC ‘Katur Invest’ rolling mill, computational simulation was carried out for a process of accelerated emulsion spray cooling the rolls heated during rolling. Initial and boundary conditions for the Fourier equation in the case of a body of infinite length and arbitrary cross-sectional shape were determined for the thermal state conditions of rolls in mill stands No. 1, 2, 5, 7. After model adaptation, a comparative analysis of the roll temperature field dynamics in different cooling conditions was made based on experimental data. The analysis revealed that extending the time of emulsion cooling, evenwithout any further cooling process intensification, allows to significantly reduce both the maximum temperature level in a roll and its penetration depth, which results in required roll surface temperature reduction. Based on computational simulation, cooling parameters and conditions for the retrofitted cooling system are selected. Experimental data on roll surface temperature as measured before and after retrofitting the cooling system proved its effectiveness. Keywords: rolling, rolls, accelerated cooling, temperature field, simulatio

Моделирование снегонакопления и снеготаяния в бассейне р. Кама с применением данных глобальных моделей прогноза погоды

Currently, the improvement of numerical models of weather forecasting allows using them for hydrological problems, including calculations of snow water equivalent  (SWE) or snow storage. In this paper, we discuss the applicability of daily precipitation forecasts for three global atmospheric models: GFS (USA), GEM (Canada) and PL-AV (Russia) for calculating snow storage (SWE) in the Kama river basin for the cold season of 2017–2018. As the main components of the balance of snow storages the following parameters were taken into account: precipitation (with regard for the phase); snow melting during thaws; evaporation from the surface of the snow cover; interception of solid precipitation by forest vegetation. The calculation of snow accumulation and melting was based on empirical methods and performed with the GIS technologies. The degree-day factor was used to calculate snowmelt intensity, and snow sublimation was estimated by P.P. Kuz’min formula. The accuracy of numerical precipitation forecasts was estimated by comparing the results with the data of 101 weather stations. Materials of 40 field and 27 forest snow-measuring routes were taken into account to assess the reliability of the calculation of snow storages (SWE). During the snowmelt period, the part of the snow-covered area of the basin was also calculated using satellite images of Terra/Aqua MODIS on the basis of the NDFSI index. The most important result is that under conditions of 2017/18 the mean square error of calculating the maximum snow storage by the GFS, GEM and PL-AB models was less than 25% of its measured values. It is difficult to determine which model provides the maximum accuracy of the snow storage calculation since each one has individual limitations. According to the PL-AV model, the mean square error of snow storage calculation was minimal, but there was a significant underestimation of snow accumulation in the mountainous part of the basin. According to the GEM model, snow storages were overestimated by 10–25%. When calculating with use of the GFS model data, a lot of local maximums and minimums are detected in the field of snow storages, which are not confirmed by the data of weather stations. The main sources of uncertainty in the calculation are possible systematic errors in the numerical forecasts of precipitation, as well as the empirical coefficients used in the calculation of the intensity of snowmelt and evaporation from the snow cover surface.На примере холодного периода 2017/18  г. выполнено моделирование формирования и таяния снежного покрова в бассейне р.  Кама с применением выходных данных глобальных моделей прогноза погоды GFS (США), GEM (Канада) и ПЛ-АВ (Россия). Валидация результатов проведена по данным 40 полевых и 27 лесных снегомерных маршрутов, а в весенний период – и по спутниковым снимкам MODIS. Ошибка расчёта снегозапасов по данным всех трёх моделей не превысила 25% фактических значений

ВЛИЯНИЕ НАПРЯЖЕННОГО СОСТОЯНИЯ НА ПРЕДЕЛЬНУЮ ПЛАСТИЧНОСТЬ МЕДНОЙ КАТАНКИ М00К

A fracture locus of copper rolled wire depending on the stressed-state coefficient (k) and Lode–Nadai coefficient (μσ) is constructed. The region of using this fracture locus to calculate the damage is limited by values k < 1,4 and –1 < μσ < 0. To construct the fracture locus, we performed twisting tests of cylindrical samples and tension tests of cylindrical and plane samples in air and in a chamber with a controlled liquid pressure, which was varied from 49 to 375 MPa. The constructed fracture locus will be further used for the calculations of damage of copper rolled wire in drawing processes, by the results of which, recommendations for lowering the wire breakage during drawing will be elaborated.Получена диаграмма пластичности медной катанки в зависимости от коэффициента напряженного состояния (k) и коэффициента Лоде–Надаи (μσ). Область использования этой диаграммы для расчетов поврежденности ограничивается значениями k < 1,4; –1 < μσ < 0. Для построения диаграммы пластичности проводились испытания на кручение цилиндрических образцов, на растяжение цилиндрических и плоских образцов на воздухе и в камере с регулируемым давлением жидкости, которые варьировалось от 49 до 375 МПа. Полученная диаграмма пластичности в дальнейшем будет служить для расчетов поврежденности медной катанки в процессах волочения, по результатам которых будут выработаны рекомендации по снижению обрывности проволоки при волочении

Оценка снегозапасов в засушливой зоне по данным глобальных численных моделей ICON и GFS/NCEP (на примере бассейна реки Селенга)

The possibility to use the global numerical (NWP) models ICON and GFS/NCEP for We consider the applicability of ICON and GFS/NCEP global numerical atmospheric model data for calculating the snow water equivalent (SWE) in the Selenga River basin located the semiarid zone. SWE was calculated for the cold periods of 2020–2022 based on the empirical methodology previously developed for the Kama River basin and adapted to the semiarid conditions. The main components of the SWE balance that are taken into account in the calculation are atmospheric precipitation (liquid or solid phase), snowmelt, sublimation from the snow surface and precipitation interception by vegetation with subsequent sublimation. The validation of the results was performed for the Russian part of the basin using the data of snow surveys carried out in the second half of the winter of 2021/22. In general, reasonable estimates of the SWE spatial distribution were obtained. While in 2021, both overestimation and underestimation by 1–15 mm (20–50%) of the calculated SWE was observed at different sites compared to the measurements, in 2022, its systematic underestimation was observed, especially significant in calculations using the ICON model data. In the steppe zone, SWE is significantly underestimated, which may be due to overestimation of the intensity of sublimation from the snow surface. The comparison of these results with the ERA5-Land reanalysis data and MODIS satellite images showed that the ERA5-Land reanalysis significantly overestimates the SWE and the snow cover area. The simulation results based on the GFS/NCEP and ICON models underestimated the snow cover area in 2022 and reproduced well in 2021, which correlates with the results of the SWE calculation.Рассматривается применимость данных глобальных численных моделей прогноза погоды ICON и GFS/NCEP для оценки снегонакопления в бассейне р. Селенги, на примере 2020–2022 гг. Валидация результатов выполнена по данным снегомерных съёмок. Получены реалистичные оценки пространственного распределения снегозапасов. Результаты сопоставлены с данными реанализа ERA5–Land и спутниковыми снимками MODIS

О связи протонного облучения и термической обработки монокристаллического кремния с его структурой

The method of two-crystal X-ray diffractometry is used to control the quality and perfection of monocrystalline silicon obtained by implantation of hydrogen ions and subsequent thermal annealing, which is used in a number of semiconductor technologies. The principal feature of this approach is the ability to quickly obtain reliable experimental results, which was confirmed in this paper by the use of X-ray topography. The presented data provide information on the state of the disturbed layer of silicon crystals of n-type conductivity (ρ = 100 Om ⋅ cm) by orientation (111), 2 mm thick, implanted by protons with energy E = 200, 300, 100 + 200 + 300 keV, dose D = 2 ⋅ 1016cm-2 and subjected to subsequent thermal treatment in the temperature range T from 100 to 900 °С. We have established a non-monotonic dependence of the integral characteristics of the disturbed layer, namely the average effective thickness Leff and the average relative deformation ∆а/а, on annealing temperature, with the maximum level of distortion in the field of temperature ∼300 °С, using the method of integral characteristics. Obtained data allowed to assess the general condition of disturbed layer during thermal treatment.Метод двухкристальной рентгеновской дифрактометрии применен для контроля качества и совершенства монокристаллического кремния, получаемого с помощью имплантации ионов водорода и последующего термического отжига, который используется в ряде полупроводниковых технологий. Принципиальная особенность данного подхода состоит в возможности быстрого получения надежных экспериментальных результатов, что было подтверждено путем использования рентгеновской топографии. Представлены данные о состоянии нарушенного слоя кристаллов кремния n-типа проводимости (ρ = 100 Ом ⋅ см) ориентацией (111) толщиной 2 мм, имплантированных протонами с энергией Е = 200, 300 и 100 + 200 + 300 кэВ и дозой имплантации D = 2 ⋅ 1016 см-2 и подвергнутых последующей термической обработке в интервале температур Т от 100 до 900 °С. С использованием метода интегральных характеристик установлена немонотонная зависимость интегральных характеристик нарушенного слоя, а именно: средней эффективной толщины Lэфф и средней относительной деформации ∆а/а от температуры отжига, с максимальным уровнем искажений в области температуры ∼300 °С. Показано, что полученные данные позволили оценить общее состояние нарушенного слоя при термообработке

Interim results of targeted therapy of patients with metastatic kidney cancer in Moscow (for the period from June 2005 to July 2015)

The paper provides the first interim analysis of a database including information on 806 metastatic kidney cancer patients receiving targeted therapy in the cancer facilities of the Moscow Healthcare Department. It shows a comparative analysis of the periods of first-line targeted therapy with different drugs until progression is established

Промежуточные результаты таргетной терапии больных метастатическим раком почки в Москве (за период с июня 2005 г. по июль 2015 г.)

The paper provides the first interim analysis of a database including information on 806 metastatic kidney cancer patients receiving targeted therapy in the cancer facilities of the Moscow Healthcare Department. It shows a comparative analysis of the periods of first-line targeted therapy with different drugs until progression is established.В статье представлен первый промежуточный анализ базы данных, включающей информацию о 806 больных метастатическим раком почки, получавших таргетную терапию в онкологических учреждениях Департамента здравоохранения г. Москвы. Показан сравнительный анализ сроков проведения 1-й линии таргетной терапии различными препаратами до установления прогрессирования

ПЕРВЫЕ РЕЗУЛЬТАТЫ ТАРГЕТНОЙ ТЕРАПИИ ПРИ РАКЕ ПОЧКИ В МОСКВЕ

The paper provides the first interim analysis of a database including information on 427 metastatic kidney cancer patients receiving targeted therapy in the cancer facilities of the Moscow Healthcare Department. It shows a comparative analysis of the periods of first-line targeted therapy with different drugs until progression is established.В статье представлен первый промежуточный анализ базы данных, включающий информацию о 427 больных метастатическим раком почки, получавших таргетную терапию в онкологических учреждениях Департамента здравоохранения г. Москвы. Показан сравнительный анализ сроков проведения первой линии таргетной терапии различными препаратами до установления прогрессирования

The influence of properties electrotechnical copper on engine load heavy-middle drawing

In this article represented the analysis of the causes of fluctuations in engine load heavy-middle drawing mill in the production of copper wire for electrical purposes.Приведен анализ причин колебания нагрузки двигателей стана грубо-среднего волочения при производстве медной проволоки электротехнического назначения

Sclerotherapy in patients with hydrocele

This article presents the analysis of world literature about methods of treatment hydrocele. The authors describe the evolution and the results of different methods operations of hydrocele. The special attention was paid to miniinvasive method – puncture and sclerosation of hydrocele with different drugs. The best results were obtained in the treatment of patients operated via sclerosation, than traditional