Simulation of industrial gravity separation processes using a general purpose simulator

Gravity separation processes have been used in the mineral industry to separate particles under the action of hydr-odynamic and gravitational forces. Although these equip-ments are extensively used for tonnage processing in coal industry, their use has been now extended to waste trea-tment such as separation of valuable metallic matter from slag. However, these processes never run at their best due to lack of understanding of the process and the under-lying principles of separation. For efficient operation it is desirable that trial runs and pilot tests are conducted but these are often time consuming and expensive. Against this background, this paper attempts to show the capabi-lities of numerical simulation to gain a better under-standing of the process with a view to improve its performance.Data from different coal washeries are colle-cted to simulate the behaviour of the plants. Results of simulation utilizing jigging for coal washing is found to be in good agreement with the plant data. The same coal is also treated in other gravity separation processes in order to decide upon a particular washing circuit

Alkoxide Complexes of Some Tri- & Tetra-valent Metals: Part I- Conductometric & Potentiometric Studies on Some Aluminium Alkoxide Complexes in Non-aqueous Solvents

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A study of knowledge beliefs and attitudes regarding aids and human sexuality among medical college, engineering college and university Undergraduates of gorakhpur.

Research Problem: i) What is the level of knowledge and altitude of undergraduates about AIDS and human sexuality? ii) What arc the preferred modes of obtaining such knowledge?. Objectives: To assess the knowledge, beliefs and attitudes of undergraduate students regarding AIDS and human sexuality. Study Design: Self administered questionnaire. Setting and Participants: 1289 undergraduates from B.R.D. Medical College., M. M. M. Engineering College and University of Gorakhpur. Study Variables: Knowledge, beliefs and attitudes regarding AIDS and sexuality. Outcome Variables: Proportion of students having correct knowledge and positive attitudes. Statistical Analysis: By proportions. Result: l.evcl of knowledge about AIDS was generally high. Most of the students obtained knowledge about it through mass media. Few students had misconceptions about transmission of 1IIV infection. Knowledge about sex was obtained mainly from friends (36%) and books (31.31%). Most of the students preferred doctors (44.15%) and friends (43.66%) for asking something about sex. and not their parents (4.37%) or teachers (4.61%). 59.13% of boys and 34.49% of girls thought that students of their age had sex. Conclusion and Recommendations: The most peculiar fact in (his study is that students have no reliable means of obtaining correct information about subjects related to sex. Medical profession contributed very little in providing such knowledge. Most of them relied on their friends for such information. So. emphasis is to be given on recommending proper education material for the youth

Creating a Soluble Binder to Endothelin-1 Based on the Natural Ligand Binding Domains of the Endothelin-1 (G-Protein-Coupled) Receptor

Since its discovery in 1989, there has been extensive research on endothelin (ET)-1 physiology, as well as pathology. Accordingly, there is considerable research on the discovery of therapeutics based around ET-1, amongst which current treatment options include endothelin receptor antagonists. These target the ET-1 receptors, which are G-protein–coupled receptors (GPCRs). We have effectively developed a soluble form of a GPCR that binds to ligands, by constructing a fusion polypeptide of different endothelin receptor ligand binding domains. Phage experiments identified strong binders to ET-1. We then constructed Fc-fusions of the top binders and further binding assays revealed a KD of 21.2 nM for the Fc-ETtr1 construct and KD of 77.3 nM for the Fc-ETtr2 construct. These constructs are soluble and have the ability to bind and potentially sequester elevated ET-1 levels that are prevalent in different diseases. These results provide a novel approach to targeting GPCR–binding ligands, and thereby to contribute to a very important class of therapeutics

Mechanically Induced Reactivity in Boehmite (y-AlOOH)

Boehmite (y- A100H) is widely used as a precursor material for the industrially important transition aluminas. Effect of mechanical activation on the thermal transformation of boehmite into other phases has been investigated and res-ults are presented in this paper. Boehmite samples, pre-pared from gibbsite by thermal decomposition, were mecha-nically activated (MA) up to 4 hours in a planetary mill. Thermal analysis (TG-DTA and DSC), XRD and FTIR were used as main techniques to study the transformations. X-ray diffraction patterns showed formation of no new phase. A steady decrease in peak intensities and broadening of peaks with increase in MA time indicated structural degradation. The changes in the FTIR, spectra with MA also supported this. The first endotherm in the DTA pattern, between 70 and 200°C, was found to correspond to the removal of physically adsorbed water. The peak temperature of this endotherm increased as a result of MA. Noticeable weight-loss in the temperature range 200-350°C, is associated with the condensation of equatorial A120H groups. As temperature is raised above 350°C the transition to y-A120-3-stArts with the condensation of other Al-OH groups. These two stages clearly manifested with different slopes in the TG profile, move towards a single event with increase in MA time. As a result of MA for four hours, boehmite to y-A1203 transition temperature decreased from 522°C to - 474°C. For samples which are MA for less than 1 hour, no thermal event occurred above 600 °C and up to 1200°C. Beyond 1 hour of MA, an exotherm began to emerge and evolved in to a fully developed one after 4 hours of milling. Its temperature of occurrence decreased from 1040°C for 90 min. milled sample to 1000 °C for 240 min. milled sample MA. DSC studies has been temperature at cutting stage by using an infrared based length system as shown in and put into practice

Fast Algorithms For Josephson Junction Arrays : Bus--bars and Defects

We critically review the fast algorithms for the numerical study of two--dimensional Josephson junction arrays and develop the analogy of such systems with electrostatics. We extend these procedures to arrays with bus--bars and defects in the form of missing bonds. The role of boundaries and of the guage choice in determing the Green's function of the system is clarified. The extension of the Green's function approach to other situations is also discussed.Comment: Uuencoded 1 Revtex file (11 Pages), 3 Figures : Postscript Uuencode

Report of CE on Semantic DS

ISO/IEC JTC1/SC29/WG11, MPEG00/M6355, 53rd meeting, Jul. 2000, Beijing, PR

Semantics of Multimedia in MPEG-7

In this paper, we present the tools standardized by MPEG-7 for describing the semantics of multimedia. In particular, we focus on the abstraction model, entities, attributes and relations of MPEG-7 semantic descriptions. MPEG-7 tools can describe the semantics of specific instances of multimedia such as one image or one video segment but can also generalize these descriptions either to multiple instances of multimedia or to a set of semantic descriptions. The key components of MPEG-7 semantic descriptions are semantic entities such as objects and events, attributes of these entities such as labels and properties, and, finally, relations of these entities such as an object being the patient of an event. The descriptive power and usability of these tools has been demonstrated in numerous experiments and applications, these make them key candidates to enable intelligent applications that deal with multimedia at human levels