Study on flow characteristics of primary blast furnace slag

The primary slag generated in the cohesive zone of the blast furnace determines the fuel rate as well as the quality of the hot metal in terms of its silicon content. This is because in the cohesive zone the softened slag chokes the path of gas flow, interfering with the permeability of the bed. Therefore, the cohesive zone which starts with the softening of the primary slag and ends with its flow should be formed lower down the furnace and should be a narrow one with a minimum difference between the flow temperature and the softening temperature. In the present work pellets with C/S ratio ranging from 1.8 to 2.4 with a fixed MgO content of 10% are reduced in the laboratory at different temperature ranging from 1200 C – 1400 C. Synthetic slags prepared in the laboratory in line with the comparison of reduced pellets are analyzed for its flow characteristics using the heating microscope (German Standard 51730). It is observed that under the composition examined, the pellet with C/S ratio 2.0 rendered the best result with the highest softening temperature and lowest flow temperature

A novel conductometric titration approach for rapid determination of boron

21-30In laboratories dealing with radioactive samples it is important to minimize both the sample size and also the associated waste generated in an analysis. To meet this objective a rapid conductometric titration technique is developed to determine boron in the moderators of Pressurized Heavy Water Reactors (PHWR’s). Using this novel PC interfaced titration facility a minimum tenfold reduction in sample size is achieved compared to conventional conductometric titration. Determination of boron is based on the conversion of extremely weak boric acid to better conducting boron mannitol complex and titrating the complex against NaOH. Various parameters affecting the analysis, when moving from large to small sample size, are analyzed and optimized. The technique is primarily proposed for the assay of boron (≥0.5 ppm) during reactor startup. Each analysis requires less than 10 min. The detection limit is 0.5 ppm and the precision obtained at this level is 4.6% RSD. The technique is a good alternative to less sensitive carminic acid based spectrophotometric method

Polymorphism in TNP-1 gene of Murrah buffalo bulls

Transition nuclear proteins (TPs), the major proteins found in chromatin of condensing spermatids, have been reported to be important for histone displacement and chromatin condensation during mammalian spermatogenesis. In the present study, transition nuclear protein-1 (TNP-1) gene was analyzed using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique- to detect polymorphism in Murrah bulls. Analysis of TNP-1 gene sequence of Murrah buffalo revealed 3 single nucleotide polymorphisms (SNPs) at 205, 340 and 346 bp positions of intronic region. The effect of this polymorphism was explored on individual motility, mass activity and maturation of spermatozoa. Analysis of variance indicates that two variants C and D of Murrah buffalo had significant effect on spermatozoal maturation. However, their effects on individual motility and mass activity was non significant.Key words: TNP-1 gene, polymorphism, infertility, sub-fertility, sperm maturation, SNP

Flax fiber-reinforced composites: the influence of fiber surface chemical treatment on mechanical performance

Non-Peer ReviewedFlax fibers can be used as environmentally-friendly alternatives to conventional reinforcing fibers (e.g., glass fiber) in composites. Flax fibers are less dense than glass fibers, are renewable and combustible (for easy disposal of composites), and are relatively low in price. This excellent price-performance ratio at low weight in combination with the environmentally friendly character is very important for the acceptance of natural fibers in large volume engineering markets. A major restriction to the successful use of natural fibers in durable composite applications is their high moisture absorption and poor dimensional stability. In order to improve their interfacial properties, fibers were subjected to different chemical modifications such as mercerization, silane treatment, benzoylation, and peroxide treatment. Selective removal of non-cellulosic compounds constitutes the main objective of the chemical treatments of flax fibers. Chemical treatments are able to induce fiber modifications that increase their resistance when utilized in composite products. Mechanical properties of untreated and treated fibers based composites were investigated

Robust Tuning of Modern Power System Stabilizers using Bacterial Foraging Algorithm

IEEE Std 421.5, revised by the IEEE excitation system subcommittee introduced a new type of power system stabilizer model, the multiband power system stabilizers (IEEE PSS4B). Although it requires two input signals, like the widely used IEEE PSS2B, the underlying principle of the new IEEE PSS4B makes it sharply different. This paper presents a method based on Bacterial Foraging Algorithm (BFA) to simultaneously tune these modern power system stabilizers (PSSs) in multimachine power system. Simulation results of multi-machine power system validate the efficiency of this approach. the proposed method is effective for the tuning of multi-controllers in large power systems

Quintessential Phenomena in Higher Dimensional Space Time

The higher dimensional cosmology provides a natural setting to treat, at a classical level, the cosmological effects of vacuum energy. Here we discuss two situations where starting with an ordinary matter field without any equation of state we end up with a Chaplygin type of gas apparently as a consequence of extra dimensions. In the second case we study the quintessential phenomena in higher dimensional spacetime with the help of a Chaplygin type of matter field. The first case suffers from the disqualification that no dimensional reduction occurs, which is, however, rectified in the second case. Both the models show the sought after feature of occurrence of \emph{flip} in the rate of expansion. It is observed that with the increase of dimensions the occurrence of \emph{flip} is delayed for both the models, more in line with current observational demands. Interestingly we see that depending on some initial conditions our model admits QCDM, $\Lambda$CDM and also Phantom like evolution within a unified framework. Our solutions are general in nature in the sense that when the extra dimensions are switched off the known 4D model is recovered.Comment: 17 Pages, 7 figure

Spectral fluctuation characterization of random matrix ensembles through wavelets

A recently developed wavelet based approach is employed to characterize the scaling behavior of spectral fluctuations of random matrix ensembles, as well as complex atomic systems. Our study clearly reveals anti-persistent behavior and supports the Fourier power spectral analysis. It also finds evidence for multi-fractal nature in the atomic spectra. The multi-resolution and localization nature of the discrete wavelets ideally characterizes the fluctuations in these time series, some of which are not stationary.Comment: 7 pages, 2 eps figure