Free A*-algebras

In this paper we studied the free A*-algebras, the sub A*-algebra generated by a subset and its characterization, an A*-algebra freely generated by a subset and introduced the concept of A*-field of sets. Also we established some theorems on making A*-field of sets into A*-algebras

Agglomeration and Prereduction of Ores

The success of metallurgical processes greatly depends on the particle size of raw materials used. The size requi-rements differ from process to process and the desired sizes may range from tenths of millimeters to tens of centimeters. The desired size can be obtained by crush- ing or grinding if the input material is too coarse, or agglomeration if the input material is much finer. Agglo-meration is a process of size ,enlargement; btiquetteing, sintering and pelletising being the three common processes used in the metallurgical industries. The requirement of particle size for sintering is much coarser (generally upto 10 mm) against that of pelletising which is generally below 0.1 mm. The briquetting process can accommodate the size range of both sintering and pelletising

Experimental studies in Ultrasonic Pulse Velocity of roller compacted concrete pavement containing fly ash and M-sand

AbstractThis paper presents the experimental investigation results of Ultrasonic Pulse Velocity (UPV) tests conducted on roller compacted concrete pavement (RCCP) material containing Class F fly ash of as mineral admixture. River sand, M-sand and combination of M-sand and River sand are used as fine aggregate in this experimental work. Three types of fly ash roller compacted concrete mixes are prepared using above three types of fine aggregates and they are designated as Series A (River sand), Series B (manufactured sand) and Series C (combination of River sand and M-sand). In each series the fly ash content in place of cement is varied from 0% to 60%. In each series and for different ages of curing (i.e 3, 7, 28 and 90days) forty two cube specimens are cast and tested for compressive strength and UPV. The UPV results of fly ash containing roller compacted concrete pavement (FRCCP) show lower values at all ages from 3days to 90days in comparison with control mix concrete (0% fly ash) in all mixes. However, it is also observed that Series B and C mixes containing fly ash show better results in UPV values, compressive strength and Dynamic Elastic Modulus in comparison to Series A mixes with fly ash. Relationships between compressive strength of FRCCP and UPV and Dynamic Elastic Modulus are proposed for all series mixes. A new empirical equation is proposed to determine the Dynamic Elastic Modulus of FRCCP

The local power of the gradient test

The asymptotic expansion of the distribution of the gradient test statistic is derived for a composite hypothesis under a sequence of Pitman alternative hypotheses converging to the null hypothesis at rate $n^{-1/2}$, $n$ being the sample size. Comparisons of the local powers of the gradient, likelihood ratio, Wald and score tests reveal no uniform superiority property. The power performance of all four criteria in one-parameter exponential family is examined.Comment: To appear in the Annals of the Institute of Statistical Mathematics, this http://www.ism.ac.jp/editsec/aism-e.htm

Fungal Contamination of Locally Processed Nigerian Food (Okpa): A Threat to Public Health

Aim: The aim of this study is to determine the level of contamination associated with locally processed Vignea subterranea (okpa) flour in Nigeria. Study Design: The completely randomized experimental design was adopted for this study. Place and Duration of Study: The staff laboratory in University of Calabar Cross River State Nigeria was used for this research, within the space of two months. Methodology: Standard microbiological research methods were adopted for the culture, isolation and identification of fungi. Spore heads and hyphae growth were compared with standard mycological atlas. Results: Locally processed Vigna subterranea from South Eastern Nigeria markets and mills were analyzed for level of fungal contamination. Aspergillus niger, Trychophyton spp, Penicillium spp, Rhizopus nigrican, Chrysosporium spp, Geotrichum spp, Mucor spp and Syncephalastrum spp were identified at a percentage occurrence of 20.6, 5.6, 17.7, 20.6, 8.8, 2.9, 20.6 and 2.9 respectively. The Mean (x) percentage growth of fungal species was 12.46, a standard deviation (δ) of 8.19 and Variance (S.D)² of 67.08. Conclusion: Locally processed V. subterranea in Nigeria can pose harm to the consumers of the food due to poor hygienic practice, unethical conduct and production inefficiency by food processors and handlers. Deliberate efforts must be made to curb the chances of contamination by microorganism especially fungi that may likely pose some level of resistance to heat

Characterization of Macerals in Coal Fines using Image Analysis Technique

Coal is an aggregate of heterogeneous substance consisting of various or aiiic cemsti-tnents so called nuacerals along with inorganic matter. These inacerals have been broadly classified into three major maceral groups i.e. vitrinite, exinite (liptinite) and inertinite. Coal-fines of size less than 0.5 mm, collected from Moonidih coal washery, was used in the present stud. These coal fines were subjected to size analysis and sink-float analysis. The products obtained at different size and density fractions were mounted in resin + hardener mixture using standard sample preparation technique and polished- The polished samples were examined tender- microscope inte-rfaced with image analyzer: Results indicate that size and density fractions have a significant influence on the changes in the maceral concentrations. The same has been discussed in terms of physical coal cleaning, process

Radio halos in merging clusters of galaxies

We present the preliminary results of 235 MHz, 327 MHz and 610 MHz observations of the galaxy cluster A3562 in the core of the Shapley Concentration. The purpose of these observations, carried out with the Giant Metrewave Radio Telescope (GMRT, Pune, India) was to study the radio halo located at the centre of A3562 and determine the shape of its radio spectrum at low frequencies, in order to understand the origin of this source. In the framework of the re--acceleration model, the preliminary analysis of the halo spectrum suggests that we are observing a young source (few $10^8$ yrs) at the beginning of the re--acceleration phase.Comment: 3 pages, 2 figures. Proceedings of IAU Colloquium 195 - Outskirts of Galaxy Clusters: intense life in the suburb

Hot Core, Outflows and Magnetic Fields in W43-MM1 (G30.79 FIR 10)

We present submillimeter spectral line and dust continuum polarization observations of a remarkable hot core and multiple outflows in the high-mass star-forming region W43-MM1 (G30.79 FIR 10), obtained using the Submillimeter Array (SMA). A temperature of $\sim$ 400 K is estimated for the hot-core using CH$_3$CN (J=19-18) lines, with detections of 11 K-ladder components. The high temperature and the mass estimates for the outflows indicate high-mass star-formation. The continuum polarization pattern shows an ordered distribution, and its orientation over the main outflow appears aligned to the outflow. The derived magnetic field indicates slightly super-critical conditions. While the magnetic and outflow energies are comparable, the B-field orientation appears to have changed from parsec scales to $\sim$ 0.1 pc scales during the core/star-formation process.Comment: accepted, ApJ Letter

Magnetic and electron transport properties of the rare-earth cobaltates, La0.7-xLnxCa0.3CoO3 (Ln = Pr, Nd, Gd and Dy) : A case of phase separation

Magnetic and electrical properties of four series of rare earth cobaltates of the formula La0.7-xLnxCa0.3CoO3 with Ln = Pr, Nd, Gd and Dy have been investigated. Compositions close to x = 0.0 contain large ferromagnetic clusters or domains, and show Brillouin-like behaviour of the field-cooled DC magnetization data with fairly high ferromagnetic Tc values, besides low electrical resistivities with near-zero temperature coefficients. The zero-field-cooled data generally show a non-monotonic behaviour with a peak at a temperatures slightly lower than Tc. The near x = 0.0 compositions show a prominent peak corresponding to the Tc in the AC-susceptibility data. The ferromagnetic Tc varies linearly with x or the average radius of the A-site cations, (rA). With increase in x or decrease in (rA), the magnetization value at any given temperature decreases markedly and the AC-susceptibility measurements show a prominent transition arising from small magnetic clusters with some characteristics of a spin-glass. Electrical resistivity increases with increase in x, showed a significant increase around a critical value of x or (rA), at which composition the small clusters also begin to dominate. These properties can be understood in terms of a phase separation scenario wherein large magnetic clusters give way to smaller ones with increase in x, with both types of clusters being present in certain compositions. The changes in magnetic and electrical properties occur parallely since the large ferromagnetic clusters are hole-rich and the small clusters are hole-poor. Variable-range hopping seems to occur at low temperatures in these cobaltates.Comment: 23 pages including figure