Adaptation of Radiative Properties of the End Products of Fuels Combustion within the Temperature Range of 1,000…2,000 K

The accuracy of calculating heat exchange by radiation from high-temperature gas flow produced during natural fuels combustion to a large extent depends on the accuracy and status of data on thermophysical properties of gases and the value of the radiative heat flux. The main physical load is carried by the density of the intrinsic heat flux, but all the experimental data on gas mixtures radiation are given as a total emissivity of the components and the mixture in general. That is why this study determines the emissivity factor of carbon dioxide and water vapour as the main constituents of the products of industrial fuel combustion. Dependencies are developed based on reliable experimental data and allowed to perform emissivity factor calculations for the products of combustion. The accuracy of calculated approximation is determined for experimental data in the field of two factors: optical density of gas, and its temperature. The study results are recommended to be usedfor developing heat exchange calculation programs. Keywords: emissivity factor, radiation flux, temperature, carbon dioxide, water vapou

The Heating with Gas of a Fixed Two-Component Layer with Various Initial Temperatures

We have derived the equations for the change in temperatures in a nonmoving layer consisting of two materials with various thermophysical properties and initial temperatures. An approximate method is proposed for the solution of the problem, based on the utilization of the Schumann graph data. © 1971 Consultants Bureau

Specific Features of Thermal Systems of Induration Machines for Pellet Production from Iron-ore Concentrates of Different Types

Pellets are one of the main types of iron-ore raw materials used in ferrous metallurgy. In Russia, the overall production of this iron-ore raw material is continuously growing. The analysis of pelletizing technologies over the last years has shown changes in requirements for product quality, process performance, heat and power parameters, environmental performance and production conditions of both fired and pre-reduced pellets. The article provides the analysis of technological and structural defects of conveyor-type induration machines. In order to remove these defects, we have developed an integrated technology for the production of fired pellets of various purposes. This technology made it possible to create an energy-efficient thermal system of the induration machine that has no counterparts in the world. This thermal system takes into account characteristics of the initial raw material. Its implementation at Mikhailovsky GOK in Russia provided a specific natural gas consumption within 8–9 nm3 /t of pellets and specific energy consumption less than 36 kW·h/t of pellets. These parameters were received by mathematical modelling and introduction of two-layer drying in the pellet induration process. The new induration technology has been implemented in Brazil and is now spreading at other plants in Russia. Keywords: pellets, iron-ore concentrates, induration machines, thermal systems, two-layer charging, pellet dryin

ОТДАЛЕННЫЕ РЕЗУЛЬТАТЫ ТРАНСПЛАНТАЦИИ ТРУПНОЙ ПЕЧЕНИ

Aim of the study was to evaluate patient and graft survival after liver transplantation (LT) and to determine if primary disease diagnosis, early graft dysfunction or other factors affect it. Furthermore, we analyzed the reasonsof short-term and long-term deaths or retransplantations.Materials and methods. 192 LTs from donors with brain death were performed from December 2004 until June 2014. Recipient age varied from 5 to 71 years. Most frequent diagnosis was liver cirrhosis (mainly due to hepatitis C), then hepatocellular carcinoma (HCC), liver graft dysfunction, etc.Results and discussion. 1-year patient survival is 89.5%, graft survival is 87.7%, 3-year –87% and 84.6%, respectively, and 5-year – 83.5% and 83.0%, respectively. Early mortality (in fi rst 30 days after transplantation) was 8%, long-term mortality – 5.9%. Primary non-function graft (PNF) was the reason of 66.7% early deaths. In the long term, infections and oncology were the reasons of death with the same frequency – 36.4%. Early graft dysfunction including primary non-function signifi cantly decreases short term survival (p = 0.0002). Nevertheless, in the majority of cases graft function improves and doesn’t affect survival. Donor factors play role in outcomes: early dysfunction is higher (40.6%) in extended criteria donor group than in standard donor group (р = 0.0431). PNF has the same trend – 8.5% and 0.0%, respectively, but without signifi cance (р =0.0835). 5-year survival is remarkably lower in HCC group 40.8% (p = 0.003) than in other groups.Conclusion: survival after liver transplantation in our Center is comparable with the results of the world’s centers.Цель данного исследования – изучить выживаемость больных и трансплантатов в зависимости от диагно-за первичного заболевания, наличия ранней дисфункции трансплантата, причины летальности на разныхсроках, проанализировать результаты ретрансплантаций.Материалы и методы. С декабря 2004 года по июнь 2014 года в ФНЦТИО было выполнено 192 трансплантации печени от доноров с диагнозом «смерть мозга» 186 реципиентам в возрасте от 5 лет до 71 года. В структуре показаний к трансплантации на первом месте по частоте находился цирроз печени, чаще всего в исходе гепатита С, затем гепатоцеллюлярная карцинома, дисфункция трансплантата печени и другие заболевания.Результаты и обсуждение. Однолетняя выживаемость реципиентов составляет 89,5%, трансплантатов – 87,7%, трехлетняя – 87 и 84,6%, пятилетняя – 83,5 и 83,0% соответственно. Периоперационная летальность составила 8%, отдаленная – 5,9%. Основной причиной смерти в раннем послеоперационном периоде являлись первично не функционирующие трансплантаты (ПНФТ) – 66,7% потерь, в отдаленном – одинаково часто (36,4% потерь) злокачественные новообразования и инфекции. Ранняя дисфункция трансплантата (РДТ), включая ПНФТ, статистически значимо снижает выживаемость в раннем послеоперационном периоде (p = 0,0002). Однако у большинства больных РДТ обратима и в этом случае в дальнейшем не влияет на выживаемость. При использовании трансплантата от стандартного донора частота РДТ была статистически значимо меньше – 21,2%, чем при расширении критериев – 40,6% (р = 0,0431), а частота ПНФТ составила 0,0 и 8,5%, соответственно (р = 0,0835). Пятилетняя выживаемость при трансплантации по поводу ГЦК значимо ниже, чем при наличии других показаний – 40,8% (p = 0,003).Заключение: выживаемость реципиентов после трансплантации печени в нашем центре на сроке до 10 лет сопоставима с результатами мировых регистров

Influence of base impurity distribution on the photoelectric properties of surface-barrier UV photodetectors

The article presents the study on spectral, capacitance-voltage and current-voltage characteristics of surface-barrier structures based on A2B6 composition with different carrier concentration profiles in space-charge region sensitive to ultraviolet range and perspective for ultraviolet sensor application