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Abstract The AP1000 ® is an advanced Pressurized Water Reactor (PWR) design developed by Westinghouse which implements passive safety systems to provide core cooling in case of accident. The development of best-estimate codes produced the evolution of conservative safety analysis towards the so-called best-estimate plus uncertainty (BEPU) analysis in order to obtain more realistic results and larger safety margins. In this sense, Westinghouse used for AP1000 Large Break Loss of Coolant Accident (LBLOCA) the so-called Automated Statistical Treatment of Uncertainty Method (ASTRUM) which was developed to address this kind of BEPU analysis. This paper presents a verification of the AP1000 LBLOCA BEPU analysis by means of TRACE V5.0 patch 2 thermal–hydraulic code with the support of DAKOTA code for uncertainty calculations. The results obtained show lower values for the maximum PCT than the ones obtained by Westinghouse. In both cases the results show that AP1000 can mitigate effectively the occurrence of a postulate LBLOCA and to meet the 10CFR50.46 PCT acceptance criteria with enough margin.

Abstract To predict the time taken for the start-up process of NDDCTs with different geometric parameters and initial conditions under windless condition, dimensional analysis is used to first determine the significant variables governing the transient start-up process. Buckingham Pi theorem is subsequently adopted to identify the relationship between the air mass flow rate through the tower and the time-taken during the start-up process of NDDCTs. Then, numerical tests are carried out to investigate the start-up process of NDDCTs with different geometric parameters including the tower height H, (H = 20 m, 40 m, 60 m and 80 m) and base diameter D, (D = 8 m, 10 m and 12 m) over a range of initial condition, i.e., when the temperature difference between the heat exchanger and the ambient air ΔT, varies from = 20 K to 40 K. The numerical results demonstrate that the base diameter will not affect the time taken during the start-up process of NDDCTs in the absence of cold air inflow, i.e., when no cold air intrudes into the tower from the top. However, the time taken for the start-up process of an NDDCT rises with the increase of the tower height, but is shortened with the increase of air-heat exchanger temperature difference. Finally, an accurate mathematical model is established based on both dimensional analysis and numerical tests to predict the start-up time leading to t = α H Δ T 2 0.3 .

Abstract The residual circulation of the Ria de Muros, a large coastal embayment in NW Spain, are studied using a three-dimensional baroclinic finite-difference model. The driving forces considered by the model include the tide, winds, river inflows and density forcing at the open boundary. In situ data of current velocity and direction, water level, wind velocity and direction, river discharge, and temperature and salinity are used for model validation. Simulated and observed time series of water level and current velocity are in good agreement. Once validated, the model is applied to compute the residual circulation induced by the relevant agents of the ria hydrodynamics—the tide, an upwelling-favourable wind characteristic of spring and summer, a downwelling-favourable wind typical of winter, and freshwater inflows associated with high river runoff. The resulting residual circulation differ notably. The tide does not generate significant residual flows except in the inner ria. By contrast, winds and river discharges induce important residual flows throughout; in the middle and outer ria they generate a 3D residual circulation pattern which renders the conventional two-layer scheme of estuarine circulation too simplistic in this case. Thus, this first application of a 3D numerical model to the Ria de Muros sheds new light on its fundamental hydrodynamics.

Tire valorization by catalytic cracking of scrap tires pyrolysis oil has been investigated in a riser simulator reactor under fluid catalytic cracking (FCC) unit conditions using an equilibrated FC...

This book presents contributions on new technologies in building and construction. Buildings are complex elements that impact environment significantly. The sustainability of this sector requires a holistic and multidisciplinary approach that allows adequate strategies to be established to reduce its environmental impact. This heterogeneity is represented in these chapters, which have been developed by researchers from different countries. The book is divided into three sections: (i) analysis, (ii) design and modeling, and (iii) solutions. The book chapters together represent an advance in current knowledge about new technologies in building and construction, crucial for researchers, engineers, architects, policy makers, and stakeholders.

A one-pot, microwave-assisted protocol has been developed for the synthesis of 5,6-dihydroquinazolinones that incorporate structural fragments from chalcones, acetylacetoacetate, ammonium formate and formamide. This process generates two rings, two carbon–carbon and three carbon–nitrogen bonds and does not require the use of chromatographic purification. The dihydroquinazolinones were efficiently aromatized without the need for metal-based oxidants by a microwave-assisted halogenation–elimination sequence in the presence of N-bromosuccinimide, again in the absence of chromatographic purification.

A heuristic algorithm for solving the cluster problem is presented in this paper. The algorithm exploits both the contour tableau and the newly developed path concept, and does not require the choice of a starting node. Experimental results show that the method is competitive with other published algorithms as far as border size is concerned. Furthermore, resultant fill-in is kept small.

AbstractEthanol induces severe alterations in membrane trafficking in hepatocytes and astrocytes, the molecular basis of which is unclear. One of the main candidates is the cytoskeleton and the molecular components that regulate its organization and dynamics. Here, we examine the effect of chronic exposure to ethanol on the organization and dynamics of actin and microtubule cytoskeletons and glucose uptake in rat astrocytes. Ethanol‐treated cells cultured in either the presence or absence of fetal calf serum showed a significant increase in 2‐deoxyglucose uptake. Ethanol also caused alterations in actin organization, consisting of the dissolution of stress fibres and the appearance of circular filaments beneath the plasma membrane. When lysophosphatidic acid (LPA), which is a normal constituent of serum and a potent intercellular lipid mediator with growth factor and actin rearrangement activities, was added to ethanol‐treated astrocytes cultured without fetal calf serum, it induced the re‐appearance of actin stress fibres and the normalization of 2‐deoxyglucose uptake. Furthermore, ethanol also perturbed the microtubule dynamics, which delayed the recovery of the normal microtubule organization following removal of the microtubule‐disrupting agent nocodazole. Again, pre‐treatment with LPA prevented this alteration. Ethanol‐treated rodent fibroblast NIH3T3 cells that constitutively express an activated Rho mutant protein (GTP‐bound form) were insensitive to ethanol, as they showed no alteration either in actin stress‐fibre organization or in 2‐deoxyglucose uptake. We discuss the putative signalling targets by which ethanol could alter the cytoskeleton and hexose uptake and the cytoprotective effect of LPA against ethanol‐induced damages. The latter opens the possibility that LPA or a similar non‐hydrolysable lipid derivative could be used as a cytoprotective agent against the noxious effects of ethanol.