33 research outputs found

    Кинетика восстановления железа при восстановительной плавке рудоугольных окатышей

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    Исследовано влияние интенсивности теплообмена на кинетику восстановления железа в процессе плавки рудоугольных окатышей. Показано, что с ростом интенсивности теплообмена повышается скорость восстановительных процессов. Вследствие роста коэффициента теплообмена увеличивается глубина восстановленного слоя окатыша, существенно изменяются его структура и химический состав образующейся металлической фазы.Досліджено вплив інтенсивності теплообміну на кінетику відновлення заліза в процесі плавки рудовугільних окатишів. Показано, що при зростанні інтенсивності теплообміну підвищується швидкість відновлювальних процесів. Внаслідок зростання коефіцієнту теплообміну збільшується глибина відновленого шару окатиша, суттєво змінюються його структура та хімічний склад металевої фази, що утворюється.Influence of intensity of heat exchange is investigational on kinetics reduction of iron in the process of melting ore-coal pellets. It is rotined that speed of reduction processes rises with growth of intensity of heat exchange. Because of growth of coefficient of heat exchange the depth of the recovered layer of pellet is increased, his structure and chemical composition of appearing metallic phase changes substantially

    Validity of the 3D VECTRA photogrammetric surface imaging system for cranio-maxillofacial anthropometric measurements

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    PURPOSE: The use of three-dimensional (3D) photography for anthropometric measurements is of increasing interest, especially in the cranio-maxillofacial field. Before standard implementation, accurate determination of the precision and accuracy of each system is mandatory. METHODS: A mannequin head was labelled with 52 landmarks, and 28 three-dimensional images were taken using a commercially available five-pod 3D photosystem (3D VECTRA; Canfield, Fairfield, NJ) in different head positions. Distances between the landmarks were measured manually using a conventional calliper and compared with the digitally calculated distances acquired from labelling by two independent observers. The experimental set-up accounted for clinical circumstances by varying the positioning (vertical, horizontal, sagittal) of the phantom. RESULTS: In the entire calliper measurement data set (n = 410), a significant difference (p = 0.02) between the directly measured and corresponding virtually calculated distances was found. The mean aberration between both modalities covering all data was 7.96 mm. No differences (p = 0.94) between the two groups were found using a cut-off of 10 % (leaving n = 369 distances) due to considerable errors in direct measurements and the necessary manual data translation. The mean diversity of both measurement modalities after cut-off was 1.33 mm (maximum, 6.70 mm). Inter-observer analysis of all 1,326 distances showed no difference (p = 0.99; maximal difference, 0.58 mm) in the digital measurements. CONCLUSION: The precision and accuracy of this five-pod 3D photosystem suggests its suitability for clinical applications, particularly anthropometric studies. Three-hundred-and-sixty degree surface-contour mapping of the craniofacial region within milliseconds is particularly useful in paediatric patients. Proper patient positioning is essential for high-quality imaging

    Electroweak parameters of the z0 resonance and the standard model

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    Contains fulltext : 124399.pdf (publisher's version ) (Open Access
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