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[en] Purpose of the work is compare analysis of oxygen diffusion of thermal annealing process for samples baked on air and in vacuum. It was determined, that for samples baked in vacuum the oxygen diffusion pass with higher velocity, than for samples baked on air
[en] Since 2001 RHIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts, a reduction of the stability threshold for bunches crossing the transition energy, and possibly incoherent emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, scrubbing, and operation with long bunches
[en] Experiments show that conditions exist whereby graphite can be baked out sufficiently so that further gas evolution is not of significance. POCO, GIS, and Pyrocarb all have almost the same activation energies for release and all exhibit the property of being easier to clean up after an initial high temperature bake-out. Data presented indicate that the release rate follows a logarithmic rate law
[en] In order to reduce production costs, the ceramic tiles have been produced in ever faster firing cycles. One of the undesirable consequences of the acceleration of the firing cycles is the anticipated overfiring, when the tiles stop shrinking and start to expand before the water absorption reaches the required values. The present study evaluated, through statistical analysis (DOE), the effects of the main characteristics of the firing cycle and the green bulk density of the compacts of porcelain tiles on this phenomenon. The results showed that the main factors responsible for porcelain tiles anticipated overfiring are very short holding periods on firing and relatively low green densities. The results also suggest that these factors contribute to the expressively heterogeneous development of the microstructure of the products, which may contribute to the development of the anticipated overfiring.
[es]A fin de reducir los costos de producción, las baldosas cerámicas se han producido en ciclos de cocción cada vez más rápidos. Una de las consecuencias indeseables de la aceleración de los ciclos de cocción es la sobrecocción anticipada, cuando las baldosas dejan de retraerse y comienzan a expandirse antes de que la absorción de agua alcance los valores requeridos. El presente estudio evaluó, a través del análisis estadístico (DOE), los efectos de las principales características del ciclo de cocción y la densidad aparente en verde de los compactos de gres porcelánico en este fenómeno. Los resultados mostraron que los principales factores responsables por la sobrecocción anticipada del gres porcelánico son los tiempos muy cortos de permanencia en la temperatura máxima del ciclo de cocción y las densidades en verde relativamente bajas. Los resultados también sugieren que estos factores contribuyen al desarrollo expresivamente heterogéneo de la microestructura de los productos, lo que puede contribuir al desarrollo de la sobrecocción anticipada.
[en] Highlights: • The production state of reheating furnace is divided. • A simplified BGCI apportionment model is established. • The duration of the NPS work is the most important factor in reducing BGCI. • Initial temperature and repair time are significant factor in reducing BGCI. - Abstract: To achieve variations on billet gas consumption intensity (BGCI) of reheating furnace in different production states, a simplified BGCI apportionment model, which was based on the division of production states, was put forward in this paper. Firstly, production states were divided into four different modes according to the sequences of billet loading and unloading and billet number change in reheating furnace, namely, (i) normal production state (NPS), (ii) abnormal production state (APS), (iii) stop production state (SPS), which included preserving heat and waiting rolling state (PHWRS) and baking process state (BPS), (iv) transient production state (TPS), which included abnormal transient production state (ATPS) and stop transient production state (STPS). Secondly, a simplified BGCI apportionment model, which had better practicability, was established. Case study shown that the BGCI of APS or SPS was higher than that of NPS. And the longer the billet was in APS, the greater the BGCI was. Meanwhile, the initial temperature of billet and the repair time of reheating furnace had an important impact on BGCI. The results show that increasing the time of NPS is the most basic measurement in reducing BGCI. And elevation of initial temperature and reduction of the repair time are also effective measurement. And then, some suggestions and measures, which can achieve energy lean management of reheating furnace, are put forward.
[en] This paper presents an original procedure to determine the softening curve in concrete from a diametric Brazilian test and a three point bend test. An inverse procedure is proposed combining experimental results, numerical finite element computation and an iterative algorithm, called algorithm AMS-UPM, developed expressly for this research. The starting point of the algorithm is a bilinear softening curve, on which a successive transformations are applied decreasing the difference between the experimental and numerical results in each step. The procedure has been applied successfully to two conventional concretes. The final result is a softening curve that adjusts almost perfectly experimental data of the three point bending test.
[es]En este trabajo se presenta un procedimiento original para obtener la curva de ablandamiento en hormigón a partir de un ensayo de compresión diametral y un ensayo de flexión en tres puntos. Se trata de un método inverso que combina resultados experimentales, cálculos numéricos por elementos finitos y un algoritmo iterativo desarrollado expresamente para la presente investigación. El punto de partida del algoritmo es la curva de ablandamiento bilineal, sobre la que se aplican una serie de transformaciones sucesivas reduciendo en cada paso la diferencia entre los resultados numéricos y experimentales. El procedimiento ha sido aplicado con éxito a dos hormigones convencionales, obteniendo en ambos casos una curva de ablandamiento que ajusta de forma prácticamente perfecta los registros experimentales del ensayo de flexión en tres puntos.
[en] The report discusses condition and perspectives of theoretical and experimental research of metal powder material radiation processing influence on their caking, recrystallization and formation of metal and alloy structure obtained by powder metallurgy methods. Radiation processing of metal powders under determined modes causes forming of homogeneous fine metal structure and helps to considerably improve their running abilities (strength, endurance, corrosion resistance) and caking technological conditions
[en] The KSTAR plasma facing components (PFCs) consist of inboard limiter, poloidal limiter, divertor, passive stabilizer and neutral beam armor. The main function of the PFCs is to define boundary of operating plasma and to protect the vacuum vessel and in-vessel components such as diagnostic components, in vessel control coil and several kinds of launchers for heating and current drive systems. The divertor is designed to enhance effective particle control to keep high quality plasma with various flexibilities in the shaping control for wide range of operational regime. The passive stabilizer that is made of CuCrZr alloy is designed to passively control the vertical position and MHD instabilities during operation as well as outer boundary of the plasma. Since fabrication has been started for all of the plasma facing components from middle of 2009, the inboard limiter, the divertor, and the passive stabilizer were successfully installed in the vacuum vessel, in turn. Moreover, one set of neutral beam armor and three strings of poloidal limiters were also installed according to the heating system that newly comes in 2010. All the PFCs tiles were baked to 200 deg. C and the PFC system showed no vacuum leakage and other mechanical troubles. In this paper, key features, fabrication, results of assembly, and baking of the KSTAR PFCs are summarized in detail.