Performance analysis of an efficient finite element solver for solidification simulation of continuous casting of steel billets

The Gauss-Seidel iterative technique of solving a set of linear algebraic equations was applied for solving the system matrices in the Finite Element Analysis of 2-D dynamic heat diffusion problems encountered in the solid-ification analysis of continuous casting of steel,billets. An efficient algorithm for storing. and manipulating only the non-zero terms of the system matrices was developed. The CPU time per iteration for solving the system matrix was independent of bandwidth. The oscillatory character-istics of the algorithm with respect to different one-step recurrence schemes, the number of iterations for solution convergency and error propagation with respect to over-relaxation factor and convergence limit were studied for a standard problem and compared with analytical solution. The accuracy of the iterative solution was compared with the standard method of direct reduction based on Gauss elimination (active column reduction method). The itera-tive technique performed better than the direct method with respect to memory requirement and CPU time, achieving acceptable actuary limits. The solver was applied for the solidification simulation of continuously cast billets at Tata Steel. The 1-D heat flux formulation of the type q = A - B Alt applicable for the C.C. mould region was modi-fied to account for the lower heat flux at the billet corners. The midface shell thickness obtained by simulat-ion at mould exit was compared with the measured thickn-esses obtained from a breakout strand. The heat transfer coefficient in the spray cooling zone was adjusted to get an acceptable match between the measured and simulated shell thicknesses in the secondary cooling zone. The pro-gram was run on IBM PC AT computer with Intel 80486 CPU (33 MHz). The present implementation of the iterative techni-que for solving the system equations reduces the matrix solution time to (1/18) and the overall time for each time step to 1/8 the times required under direct methods, for the parameters considered. There was no appreciable error in the estimated shell thickness within the CC mould. However, the error in the •secondary cooling and the radi-ation zone ranged from 2 to -5%. The second norm of tempe-rature distribution across the billet- cross section varied from 0.001 to 0.005 for the entire strand

Drinking Water in an Urban Area of South India

BackgroundGlobally, 1.1 billion people lack access to improved drinking water supply and drink water that is grossly contaminated. Hence, study of water treatment assumes utmost importance in order to ensure the safety of the water consumed especially in fast developing cities. This study would provide information of drinking water management practices in the study area. We studied the sources, the treatment and storage facilities of drinking water in households and assessed the free chlorine levels in the drinking water.Method  This community based cross sectional study was conducted in Mangalore - a city of Karnataka State in South India. Using convenience sampling, 100 households were visited in the area of Boloor. Information was collected regarding demographic profile, household drinking water sources, treatment and storage practices followed by testing for free chlorine in the drinking water using O-Toluidine.ResultsStudy population had high literacy rate and 83% had their main source of drinking water from municipality, 17% had private water source. Among these 6% households had bore wells, 10% had protected dug well. Overall 99% had improved source of drinking water. Sumps were present in 32% of the households.  Of these 34.4 % cleaned it once a month. Boiling was found to be the preferred choice of water treatment; but 5% of the population (lower socio economic status) did not use any method to treat water in their households. Overall, 43% households drank water by pouring to glass from storage vessel, 34% dipped glass into vessel using hands, 23% had tap system and 84.2% of the households cleaned their storage vessel daily. O-Toluidine test showed no free chlorine in drinking water in any of the homes.ConclusionStudy population had access to improved water. However households lacked appropriate storage and handling practices of drinking water which needs to be evaluated further

Breeding tomato (Solanum lycopersicum L.) for resistance to biotic and abiotic stresses

Tomato (Solanum lycopersicum L.) is an important vegetable crop cultivated in the tropical and sub-tropical regions of the world. Low productivity in India is due to occurrence of both biotic and abiotic stresses. Among the biotic stresses, tomato leaf curl disease, bacterial wilt, early blight and Groundnut Bud Necrosis Virus disease have become serious production constraints causing considerable yield loss in the major tomato growing areas of the country. Adoption of multiple disease resistant varieties or F1 hybrids would be the most appropriate way to address these diseases. At ICAR-IIHR, Bengaluru systematic breeding strategies were employed to pyramid genes for resistance to early blight, bacterial wilt and tomato leaf curl diseases and to develop advanced breeding lines& F1 hybrids with triple disease resistance. Stable source of resistance to early blight and bi-partite begomo-virus (Tomato Leaf Curl New Delhi Virus) has been identified in Solanum habrochaites LA-1777. Validation with molecular markers linked to tomato leaf curl virus resistance revealed that LA-1777 carryTy2 and other putative resistant genes. Several high yielding dual purpose hybrids were also developed for fresh market and processing with high level of resistance to multiple diseases. Cherry tomato lines have also been bred for high TSS, total carotenoids, total phenols, flavonoids, vitamin C, acidity and lycopene content. IIHR-249-1, IIHR-2101 (Solanum habrochaites LA-1777), IIHR- 2866 and IIHR-2864 recorded high values for quality parameters like total carotenoids, lycopene, vitamin C, total phenols, flavonoids and TSS. Drought tolerant root stock has been developed by an interspecific cross between S. habrochaites LA-1777 and S. lycopersicum (15 SB SB). Resistant sources have also been identified against Tuta absoluta, a serious insect pest reported from major tomato growing areas in the country in recent time. High temperature tolerant breeding lines are in pipe line

Assessment of biosafety and fillet-residues After florfenicol exposures in Trachinotus blochii to ensure safe applications in disease incidences

Trachinotus blochii is a promising mariculture fish species. Scientific data on biosafety and fillet residues of florfenicol exposure, one recommended amphenicol antimicrobial for aquaculture use, remains unknown in T. blochii, despite its criticality for prudent application. Accordingly, the paper evaluated the safety (regarding mortality, symptoms, weight gain, and histopathology) of dietary florfenicol after therapeutic (10 mg Kg-1 for ten days) and excessive (three, five, and ten times the therapeutic dose for 10, 20, and 30 days) exposures. There was no mortality in any group. The clinical abnormalities were noted only in 10X group from the 25th exposure day, which disappeared on the fourth day after withdrawal. Reduced growth was recorded at 5X and 10X groups from 20 and 30 exposure days, respectively. Histological lesion’s severity was in the liver > kidney > gill > spleen > muscle > intestine. The lesion severity relied on the quantity and duration of exposures, with maximum severity in 5X and 10X groups on the 30th day. After recommended therapeutic exposure, fillet residues were below the maximum residual limit accepted by the European Union (1000 µg Kg-1) from day three of the withdrawal, showing a minimum three-day is necessary to reach a safe, acceptable level

Region of magnetic dominance near a rotating black hole

This is a brief contribution in which a simplified criterion of the relevance of the test-particle approximation describing motion of material near a magnetized black hole is discussed. Application to processes of the dissipative collimation of astronomical jets (as proposed by de Felice and Curir, 1992) is mentioned.Comment: 11 pages, to appear in General Relativity and Gravitation, also available (with additional illustrations) at http://otokar.troja.mff.cuni.cz/user/karas/au_www/karas/papers.ht

Using ICP-OES and SEM-EDX in biosorption studies

We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution

Letter to the Editor

Background Disaster, whether man made or natural, may occur at any place or time. This study was conducted to assess the preparedness of hospitals in handling emergencies as per District Disaster Management Plan (DDMP) at Mangalore, a coastal city on the Western coast of Karnataka. Method A cross sectional study was conducted in 12 hospitals of Mangalore city, located at the Southwestern coast of India in April 2009, using a semi-structured proforma. All surveyed hospitals were included in the DDMP. The respondents were hospital administrators. Results Though all the hospitals surveyed were aware about the existence of DDMP in the district of Dakshina Kannada, 6 (50%) were unaware that their hospitals were included in the same plan. Out of 12 hospitals, 4 (33.3%) said that they had got a letter from DDMP, spelling out their responsibilities. Only 6 (50%) hospitals had a contingency plan for emergency. Mock drill was conducted only by 6 (50%) hospitals. Six (50%) hospitals had blood bank, 5 (41.6%) had trauma center and 8 (66.6%) had burns ward available for emergency. Half of them had more than 2 ambulances and 10(83.3%) had sufficient stock of medicines. Extra beds for emergency were available in 11(91.7%) hospitals with maximum number of 42 beds in one hospital. Conclusion; Most hospitals in Mangalore were not well prepared to manage emergencies in disasters. Facilities like burns ward, blood bank and ambulance services need to be enhanced

Localization of uPAR and MMP-9 in lipid rafts is critical for migration, invasion and angiogenesis in human breast cancer cells

<p>Abstract</p> <p>Background</p> <p>uPAR and MMP-9, which play critical roles in tumor cell invasion, migration and angiogenesis, have been shown to be associated with lipid rafts.</p> <p>Methods</p> <p>To investigate whether cholesterol could regulate uPAR and MMP-9 in breast carcinoma, we used MβCD (methyl beta cyclodextrin, which extracts cholesterol from lipid rafts) to disrupt lipid rafts and studied its effect on breast cancer cell migration, invasion, angiogenesis and signaling.</p> <p>Results</p> <p>Morphological evidence showed the association of uPAR with lipid rafts in breast carcinoma cells. MβCD treatment significantly reduced the colocalization of uPAR and MMP-9 with lipid raft markers and also significantly reduced uPAR and MMP-9 at both the protein and mRNA levels. Spheroid migration and invasion assays showed inhibition of breast carcinoma cell migration and invasion after MβCD treatment. <it>In vitro </it>angiogenesis studies showed a significant decrease in the angiogenic potential of cells pretreated with MβCD. MβCD treatment significantly reduced the levels of MMP-9 and uPAR in raft fractions of MDA-MB-231 and ZR 751 cells. Phosphorylated forms of Src, FAK, Cav, Akt and ERK were significantly inhibited upon MβCD treatment. Increased levels of soluble uPAR were observed upon MβCD treatment. Cholesterol supplementation restored uPAR expression to basal levels in breast carcinoma cell lines. Increased colocalization of uPAR with the lysosomal marker LAMP1 was observed in MβCD-treated cells when compared with untreated cells.</p> <p>Conclusion</p> <p>Taken together, our results suggest that cholesterol levels in lipid rafts are critical for the migration, invasion, and angiogenesis of breast carcinoma cells and could be a critical regulatory factor in these cancer cell processes mediated by uPAR and MMP-9.</p