Stabilization and termination of severe accidents in LWRs

The last 20 years of research on severe accident safety for light water reactors (LWRs) has resolved a number of issues. However, the issue of melt/debris coolability is still unresolved. At stake is the stabilization and termination of a severe accident, if ever it would occur. The stabilization and termination can be established only through the coolability of the melt or the particulate debris, which are found in-vessel, or ex-vessel, depending upon the extent of the progression of a postulated accident.This paper will review the state of the art of coolability during a severe accident for the current light water reactors (LWRs). It will also review whether the accident management actions will be effective in terminating a postulated severe accident. The attention paid to the stabilization and coolability in future LWRs will be discussed and the design solutions will be evaluated.     

A decade of clinical trial developments in postmyocardial infarction, congestive heart failure, and sustained ventricular tachyarrhythmia patients: from CAST to AVID and beyond. Cardiac Arrhythmic Suppression Trial. Antiarrhythmic Versus Implantable Defibrillators

Multiple trials using antiarrhythmic drugs, pharmacologic therapy, and implantable cardioverter defibrillators have been performed in an attempt to improve survival in patients: (1) postmyocardial infarction; (2) with congestive heart failure, with and without nonsustained ventricular tachycardia; and (3) with sustained ventricular tachycardia and those who have survived an out-of-hospital cardiac arrest. This article reviews some of the key findings and limitations of completed and ongoing trials. We also make recommendations for the current treatment of such patients based on the results of these trials.     

Heterogeneity in endothelium-derived nitric oxide-mediated relaxation of different sized pulmonary arteries of newborn lambs

Extensive documentation has validated the role of UV irradiation as a tumor initiator and promoter, inducing both squamous and basal cell carcinomas. Human epidermis is a tissue which undergoes active metabolism of arachidonic acid to prostaglandins which is regulated by the action of prostaglandin H synthase (also known as cyclooxygenase). One mechanism for the promotional activity of UV light may involve its ability to induce prostaglandin formation. Work in our laboratory has demonstrated that acute exposure of human keratinocytes to UVB irradiation results in increased production of prostaglandin E2 (PGE2). When cultured human keratinocytes were examined after irradiation with 30 mJ/cm2 UVB in vitro, Western blot analysis showed a 6-fold increase in COX-2 protein which was evident at 6 h and peaked 24 h after irradiation. Furthermore, when human subjects were irradiated on sun-protected skin with up to four times their minimal erythema dosage (MED) and biopsied 24 h later, upregulation of COX-2 protein expression was observed via immunofluorescence microscopy. RNAase protection assays supported this observation, showing induction of COX-2 message which peaked at approximately 12 h following irradiation in vitro. Furthermore, human squamous cell carcinoma biopsies exhibited strongly enhanced staining for COX-2 protein via immunohistochemistry and Western analysis when compared to normal non-sun-exposed control skin. Together, these data demonstrate acute upregulation of COX-2 via UVB irradiation and suggest the need for further studies of COX-2 expression as a potential pharmacological target mediating human skin tumor development.     

On the application of CAD technology for the synthesis of spatial revolute–revolute dyads

This work presents a method based on Computer Aided Design or CAD for facilitating the synthesis of Revolute–Revolute (R–R) dyads with adjustable moving pivots. The CAD-based method presented in this work ensures that all prescribed rigid-body parameters used to synthesize the R–R dyad satisfy particular kinematic requirements of an R–R dyad. Through the application of this CAD method, five of the six general R–R dyad constraint equations are satisfied and therefore not essential for the synthesis of the R–R dyad. By reducing the number of dyad design constraints from six to one, the user can synthesize R–R links with adjustable moving pivots for multi-phase motion and path generation applications. The example included demonstrates the use of the CAD method in the synthesis of an RRSS path generator with adjustable moving pivots.     

The synthesis of symmetrical and unsymmetrical P1/P1' cyclic ureas as HIV protease inhibitors

Cyclic urea SD146, a potent HIV protease inhibitor bearing a flat resistance profile, possessed poor solubility and bioavailability, which precluded further development of the compound. In an effort to improve upon the pharmacokinetic profile of the compound, several analogs modified at the P1/P1' residues were prepared and evaluated. Several of those compounds displayed significant improvement of physical properties.     

Consideration of conformational transitions and racemization during process development of recombinant glucagon-like peptide-1

This article summarizes the results of a combined analysis from two identical multicenter clinical trials that investigated the efficacy and safety of sertraline versus placebo for treating panic disorder. Patients with panic disorder who were treated with sertraline had a statistically significant reduction in the mean number of panic attacks per week (the primary efficacy measure) as compared with placebo (4.8 vs. 2.5, p < .001). Sertraline-treated patients also showed greater improvement that was statistically significant on several ratings of panic disorder symptomatology and functioning. The design characteristics, clinical rating measures, and outcome measures in these trials included most of the features deemed essential by Shear and Maser (1994) in their summary of the NIMH Consensus Conference for the development of standardized assessments for panic disorder. This suggests that the NIMH Consensus Conference played a key role in developing successful multicenter pharmacological treatment studies, such as this one that ultimately demonstrated that sertraline was an effective treatment for panic disorder.     

Production of alumina fibre through jute fibre substrate

Alumina fibre has been produced using jute fibre as substrate material at temperatures lower than 1600 C in a reducing atmosphere. Processed jute fibre was chemically pretreated by saturation with Al₂Cl₆ · 12H₂O, coked and then pyrolysed to obtain alumina fibre. Chemical pretreatment conditions have been determined by following weight loss measurements of the jute fibre at 0.1 to 0.6 N solutions of NaOH, KOH, NH₄OH, Na₂CO₃, K₂CO₃, HCl and acetic acid. The effect of heat treatment on the jute fibre and jute fibre + aluminium salt has been studied from 150 to 1600 C. Trace elements present (Fe₂O₃, SiO₂, K₂O, Na₂O, CaO, MgO, ZnO, MnO, V₂O₅, P₂O₅, CuO) on heat-treated products have been determined by atomic absorption spectrometry. Optical and scanning electron micrographs of representative samples showing growth mechanism are presented. The effect of copper, nickel and platinum catalysts and fluxing agents such as K₂O and Na₂O in fibre formation has also been examined. Particle size and surface area analyses of intermediate and final products have been carried out. Changes in 2 values are plotted for various products from X-ray diffraction studies. It is conceived that the porous surface of cellulosic fibrils in the jute fibre adsorbs the AlCl₃ molecules which decompose to oxide and are gradually shaped to the fibrous form during the course of thermal treatment in a reducing atmosphere and due to the high surface area.     

Automated construction of low-resolution, texture-mapped, class-optimal meshes

In this paper, we present a framework for the groupwise processing of a set of meshes in dense correspondence. Such sets arise when modeling 3D shape variation or tracking surface motion over time. We extend a number of mesh processing tools to operate in a groupwise manner. Specifically, we present a geodesic-based surface flattening and spectral clustering algorithm which estimates a single class-optimal flattening. We also show how to modify an iterative edge collapse algorithm to perform groupwise simplification while retaining the correspondence of the data. Finally, we show how to compute class-optimal texture coordinates for the simplified meshes. We present alternative algorithms for topologically symmetric data which yield a symmetric flattening and low-resolution mesh topology. We present flattening, simplification, and texture mapping results on three different data sets and show that our approach allows the construction of low-resolution 3D morphable models.     

Glass fiber-reinforced epoxy composites

Glass fiber-reinforced epoxy composites were prepared from the matrix resins tetraglycidyl diaminodiphenylmethane

1 Systematic name: N,N,N′,N′-Tetrakis(2,3-epoxypropyl)-4,4′-diaminodiphenylmethane.

(TGDDM) and tetraglycidyl bis(o-toluidino)-methane

2 Systematic name: N,N,N′,N′-Tetrakis(2,3-epoxypropyl)-4,4′-bis(o-toluidino)methane.

(TGMBT) using various amines like 4,4′-diaminodiphenylmethane (DDM), 4,4′-diaminodiphenylsulfone (DDS) and diethylene triamine (DETA) as curing agents. The fabricated laminates were evaluated for their mechanical and dielectrical properties and chemical resistance. The composites prepared using an epoxy fortifier (20 phr) showed significant improvement in the mechanical properties.