20 research outputs found
Aerosol Seasonal Variations over Urban-Industrial Regions in Ukraine According to AERONET and POLDER Measurements
The paper presents an investigation of aerosol seasonal variations in several urban-industrial regions in Ukraine. Our analysis of seasonal variations of optical and physical aerosol parameters is based on the sun-photometer 2008-2013 data from two urban ground-based AERONET (AErosol RObotic NETwork) sites in Ukraine (Kyiv, Lugansk) as well as on satellite POLDER instrument data for urban-industrial areas in Ukraine. We also analyzed the data from one AERONET site in Belarus (Minsk) in order to compare with the Ukrainian sites. Aerosol amount and optical depth (AOD) values in the atmosphere columns over the large urbanized areas like Kyiv and Minsk have maximum values in the spring (April-May) and late summer (August), whereas minimum values are observed in late autumn. The results show that fine-mode particles are most frequently detected during the spring and late summer seasons. The analysis of the seasonal AOD variations over the urban-industrial areas in the eastern and central parts of Ukraine according to both ground-based and POLDER data exhibits the similar traits. The seasonal variation similarity in the regions denotes the resemblance in basic aerosol sources that are closely related to properties of aerosol particles. The behavior of basic aerosol parameters in the western part of Ukraine is different from eastern and central regions and shows an earlier appearance of the spring and summer AOD maxima. Spectral single-scattering albedo, complex refractive index and size distribution of aerosol particles in the atmosphere column over Kyiv have different behavior for warm (April-October) and cold seasons. The seasonal features of fine and coarse aerosol particle behavior over the Kyiv site were analyzed. A prevailing influence of the fine-mode particles on the optical properties of the aerosol layer over the region has been established. The back-trajectory and cluster analysis techniques were applied to study the seasonal back trajectories and prevailing directions of the arrived air mass for the Kyiv and Minsk sites
Remote sensing of aerosol in the terrestrial atmosphere from space: new missions
The distribution and properties of atmospheric aerosols on a global scale are not well known in terms of determination of their effects on climate. This mostly is due to extreme variability of aerosol concentrations, properties, sources, and types. Aerosol climate impact is comparable to the effect of greenhouse gases, but its influence is more dificult to measure, especially with respect to aerosol microphysical properties and the evaluation of anthropogenic aerosol effect. There are many satellite missions studying aerosol distribution in the terrestrial atmosphere, such as MISR/Terra, OMI/Aura, AVHHR, MODIS/Terra and Aqua, CALIOP/CALIPSO. To improve the quality of data and climate models, and to reduce aerosol climate forcing uncertainties, several new missions are planned. The gap in orbital instruments for studying aerosol microphysics has arisen after the Glory mission failed during launch in 2011. In this review paper, we describe several planned aerosol space missions, including the Ukrainian project Aerosol-UA that obtains data using a multi-channel scanning polarimeter and wide-angle polarimetric camera. The project is designed for remote sensing of the aerosol microphysics and cloud properties on a global scale
Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease
BACKGROUND:
Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes.
METHODS:
We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization.
RESULTS:
During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events.
CONCLUSIONS:
Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)
Power and technological features of steel melting in electric arc furnace and transferring eaf to operation with water-cooled roof designed in moscow state evening metallurgical institute
Сосонкин Олег Михайлович, д-р техн. наук, профессор, Московский государственный вечерний металлургический институт, г. Москва; [email protected].
Шишимиров Матвей Владимирович, канд. техн. наук, доцент, начальник отдела обеспечения работы научно-технического совета и учёного совета, Всероссийский научно-исследовательский институт авиационных материалов, г. Москва; [email protected]. O.M. Sosonkin, Moscow State Evening Metallurgical Institute, Moscow, Russian Federation, [email protected],
M.V. Shishimirov, All-Russian Scientific Research Institute of Aviation Materials, Moscow,
Russian Federation, [email protected]Показана необходимость и возможность замены кирпичной кладки водоохлаждаемыми элементами при возрастании вводимой в дуговую сталеплавильную печь мощности. Такая замена приводит к некоторому увеличению удельного расхода электроэнергии, в основном за счёт возрастания потерь в окислительный и восстановительный периоды плавки, что компенсируется снижением простоев печи на замену кирпичных сводов. С увеличением производительности печи удельный расход электроэнергии
уменьшается. Тепловые потери могут быть дополнительно снижены экранированием свода путём подачи в печь углеродсодержащих газов. Рассмотрены пути достижения максимальной эффективности печей
с водоохлаждаемым сводом путем повышения производительности и изменения соотношений геометрических параметров ДСП. Водоохлаждаемый свод конструкции Московского государственного вечернего металлургического института находился в эксплуатации на ДСП вместимостью от 1,5 до 200 т
включительно, а в 2004–2005 гг. введены в эксплуатацию ДСП вместимостью 175 и 320 т. Достигнуты показатели по производительности 230 и 320 т/ч при удельном расходе электроэнергии 290 и 359 кВт·ч/т. The work shows the necessity and possibility of replacement of brickwork in steelmaking electric arc furnace
roof with water-cooled elements as the power introduced to the furnace increases. Such replacement results in some increase of specific energy consumption, mainly due to increase of losses during the oxidation and reduction
periods of the melt, which is offset with reducing the furnace downtime for replacement of brickwork
roof. Specific energy consumption decreases with increasing furnace productivity. Heat losses can also be reduced by screening the roof by injection of carbon-bearing gases to the furnace. The ways to achieve the maximum effectiveness of furnaces with water-cooled roofs by increasing productivity and changing the geometrical parameters of the furnace are also considered. The water-cooled roof designed in the Moscow State Evening Metallurgical Institute was operated at EAFs with capacities ranging from 1.5 to 200 t, and new EAFs of 175 and 320 t were put into operation in 2004–2005. Productivity indices of 230 and 320 t/hour were achived, with specific electric energy consumption of 290 and 359 kWh/t
Resource saving and reserves of increasing efficiency of steelmaking in electric arc furnaces
Шишимиров Матвей Владимирович, канд. техн. наук, доцент, начальник отдела обеспечения работы научно-технического совета и учёного совета, Всероссийский научно-исследовательский институт авиационных материалов, г. Москва; [email protected].
Сосонкин Олег Михайлович, д-р техн. наук, профессор, Московский государственный вечерний металлургический институт, г. Москва; [email protected]. M.V. Shishimirov, All-Russian Scientific Research Institute of Aviation Materials, Moscow,
Russian Federation, [email protected],
O.M. Sosonkin, Moscow State Evening Metallurgical Institute, Moscow, Russian Federation, [email protected]Приведены результаты анализа тепловой работы различных дуговых сталеплавильных печей. Рассмотрены пути повышения эффективности выплавки стали в ДСП за счет специальных мероприятий, направленных на снижение угара металла, и разработки рациональных энерготехнологических режимов
ведения плавки. Снижение угара может быть достигнуто укладкой шихты в корзину с учетом насыпной плотности ее составляющих, обеспечением подачи охладителя (окатыши, шлакообразующие, мелкий
лом и т. п.) в зоны горения дуг с момента образования жидкой ванны под электродами и в зоны продувки кислородом, продувкой ванны кислородом с рассредоточением зоны протекания реакций окисления
элементов расплава в объеме ванны, принудительным перемешиванием металла, снижением температуры металла на выпуске. Рационализация режимов работы печи включает в себя увеличение вводимой
электрической мощности оптимизации токового режима, сокращение времени работы газокислородных горелок до 40–50 % от времени расплавления при соотношении кислород / природный газ 2 : 1, обеспечивающем максимальную температуру факела, установление расходов природного газа и кислорода с
учетом тепловых условий в рабочем пространстве печи, синхронную работу всех газокислородных устройств, сбалансированный расход кислорода на плавление для снижения испарения металла, применение режима дожигания отходящих газов, своевременное вдувание углеродосодержащего материала для
вспенивания шлака и др. The work presents the results of analysis of heat operation of various steelmaking arc furnaces. The ways of increasing efficiency of steelmaking in EAF by special measures decreasing the waste of metal and rational
energy and technological regimes of melting are considered. Waste of metal can be reduced by placing the charge in the basket with account for apparent density of components; supplying the coolant (pellets, slagformers, fine scrap etc.) to arc burning zone from the moment of formation of liquid bath under the electrodes and to oxygen blowing zones; blowing the bath with oxygen providing distribution of the zone of reactions of melt element oxidation throughout the bath; forced stirring of the metal; decreasing the metal temperature at tapping. Rationalization of operating regimes of the furnace includes increasing the introduced electric power; optimizing current mode; reducing the working time of gas-oxygen burners to 40–50 % of the melting time with oxygen / natural gas ratio maintained 2 : 1, which provides the maximum flame temperature; establishing ga