Evaluation of uncertainties related to passive systems performance

A methodological and structured procedure to address the uncertainties related to passive safety functions is presented. The matter is treated with reference to a passive system designed for decay heat removal of advanced light water reactors, relying on natural circulation and provided with a heat exchanger immersed in a cooling pool, acting as heat sink, and connected to the pressure vessel via steam and condensate main lines. Two hazard identification used qualitative methods, as failure mode and effect analysis (FMEA) and hazard and operability study (HAZOP), are utilized and the relative results compared in order to assess the main sources of physical failure. The identification of the sources of uncertainties related to passive system performance, in terms of parameters which drive the failure mechanisms, follows. Finally the uncertainties are evaluated both for their assessment in probabilistic terms and for the determination of most contributors to the system thermal-hydraulic response.     

Two Approaches to the Philosophy of Information

Minds and Machines -     

阿维迪钢厂的技术产品优势

1992年,在克日莫那的阿维迪钢厂新建了一条以生产薄板为基础的板材紧凑式生产线,这是欧洲第一、世界第二条薄板生产线.该生产线主要生产高质量钢和特殊钢.数据表明平均每浇次浇11炉钢,56%以上的产品规格都小于2mm厚,经连轧轧成1250mm宽1mm厚的薄板材.可以生产大部分钢种,例如低、中、高碳钢(0.75%),1.2mm的高强度低合金钢,硼钢,耐候钢,合金钢,包晶钢和双相钢等.明年,准备采取措施在一座115t电炉和单流最大宽度为1300mm的生产线上达到100万t的产量.引进铁素体轧制,发展热轧来生产更薄规格的钢以及多相铁素体-马氏体、铁素体-贝氏体钢.和其它薄板生产技术相比,AST(Arvedi Steel Technology阿维迪厂技术)有如下7项优势薄板液芯压下技术,能使板坯中心晶粒细化、温度分布均匀;在线低速轧制(低拉速),从而使中间坯凸度＜1%;板坯厚度方向上的反向温度分布;感应加热炉精确、灵活的温度控制制度;稳定的终轧温度;根据最终薄带的厚度和温度来预设一个恒定的板坯精轧速度;经过克日莫那炉的无头轧制.优良的产品是经过先进的、控制精确的二次、三次冶金生产的.本文将着重陈述阿维迪钢厂的实践要点.并将叙述一些变换成本、高附加值产品及其经济结果.阿维迪有2条年产250万t的生产线,用来生产宽度接近于1600～1800mm的钢种.实践证明,AST的效益归功于它的极高的拉速以及直接无头轧制的思想.目前,AST将上一条高拉速(7.5m/min)的带有精轧的铸轧生产线.阿维迪的ECR的工艺(无头轧制)能够生产0.7mm厚的所有冷轧能生产的同种规格的产品,该工艺还能够生产IF钢(汽车板)、多相钢、薄带甚至有高延伸率和抗拉强度等特殊性能的钢,用来满足汽车工业的需要.克日莫那的阿维迪钢厂用高生产力、低成本生产各种质量的钢种,因此经济效益很好.阿维迪是这项技术的拥有者,准备以阿维迪的名义来购买掉这项技术,其中包括钢液准备、薄带制作以及薄带精整技术.     

Blood insulin values after the oral glucose tolerance test (OGTT) and the body composition in 30 obese children

The body composition and plasma insulin after OGTT were evaluated in 30 obese children, aged 6 to 14 years. The obese children higher serum insulin after OGTT. There was a relationship between plasma insulin and Body Mass Index (MBI) and between plasma insulin and Weight For Height (WFH) (p < 0.001). There is the accumulating evidence that chronic day-long hyperinsulinemia is associated with an insulin-resistance syndrome characterized by the development of hypertension, hyperlipidemia, atherosclerosis and non insulin depend diabetes.     

Safety assessment of the lithium target of the international fusion materials irradiation facility

This article presents the international fusion materials irradiation facility lithium target safety and thermal transient analysis, to evaluate the most important risk factors related to the system operation and to verify the fulfillment of the safety criteria. Main conclusions are that target safety is accomplished: hazards associated with lithium operation are confined within the IFMIF security boundaries and environmental impact is negligible, and the plant well answers to the simulated transients, being able to reach steady conditions in a condition of safety.     

Influence of mineral oils on polystyrene fracture

Polystyrene specimens coated with mineral oils of different viscosities were tested in tension. It was found that craze initiation and tensile fracture stresses, and also the breaking energy decreased with decreasing oil viscosity, all being lower than for specimens tested in air. Crazes formed in oil showed a lower fibril volume fraction and thicker fibrils than air crazes. The most striking difference in the fracture patterns was found in the initiation regions, where a globular morphology appears as a result of fibrils breakage at the stages of slow propagation, these globules becoming bigger with decreasing viscosity of the oil environment. Since the polymer-oil interfacial tensions are similar for the different oils, the trends in mechanical properties and craze and fracture morphologies cannot be attributed to a surface energy effect, but to plasticization because the deterioration in the polymer properties and the increasing craze fibrils thickness go along with the plasticizing ability of the oils.     

Molecular mimicry in chronic inflammatory demyelinating polyneuropathy and melanoma

Polyclonal immunoglobulin M antibodies to the monosialoganglioside GM2, sulfoglucuronyl glycolipids, and sulfatide were detected by thin-layer chromatography and enzyme-linked immunosorbent assay in the serum of a patient with melanoma and chronic inflammatory demyelinating polyneuropathy. Both the patient's serum and polyclonal antibodies against GM2 reacted strongly with a biopsy of melanomatous tissue from the patient, suggesting a process of molecular mimicry.     

Stimulation of the activity of the IAA-oxidising enzyme - system in Lens culinaris roots by dalapon and perfluidone

The activity of IAA-oxidising enzymes from Lens roots is enhanced in vitro by dalapon (2,2-dichloropropionic acid) and perfluidone (1,1,1 -trifluoro-N-[2-methyl-4-(phenylsulphonyl)phenyl]methanesulphonamide). When concentrations are greater than 10^?8 M, both these herbicides act as activators. In vivo higher levels of the enzymatic activity are obtained when seed germination is carried out in the presence of 10^?5 M perfluidone or 10^?3 M dalapon. Gas-liquid chromatography is used for IAA determination.     

Early infantile autism: A reply to ward.

Questions the conclusions of A. J. Ward (see pa, vol. 44:12960) concerning the environmental etiology of early infantile autism on the basis of an incomplete and selected coverage of the literature. More recent evidence and different viewpoints suggest a different, or at least transactional, etiology. Different treatment approaches, also not covered in ward's review, may lead toward a more clear-cut differentiation of this syndrome. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling Suspended Sediment during Construction in Great Barrier Reef World Heritage Area

A marina was constructed in the Great Barrier Reef World Heritage Area in close proximity to coral reefs that could be damaged by excess turbidity generated during construction. Since there was uncertainty about both the fate of suspended sediments and their effect on corals, initial water quality constraints were set very conservatively. In order to better understand the movement of suspended sediment during construction, a numerical model study was commissioned using three-dimensional, numerical, hydrodynamic, and Lagrangian particle tracking models. The study was successful in: (1) increasing the understanding of and reducing the uncertainty of sediment dispersal patterns under a range of common forcing conditions; (2) testing the variation in suspended sediment concentrations over sensitive areas for two different outfall locations; (3) offering evidence that a good choice in outfall locations will reduce the threat to corals; and importantly (4) presenting the results in a way that enhanced understanding by nontechnical reef managers. This final result was achieved by creating movies of sediment movement that clearly demonstrated the complex hydrodynamic processes involved with near-coastal water currents. Specific model results showed: (1) that a more seaward outfall increases effluent dispersal away from sensitive areas; (2) the highest concentrations of effluent over sensitive sites occur during no wind and neap tide conditions; and (3) prevailing southeast winds advect effluent offshore, away from sensitive sites.