Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed...Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.展开更多
The abrasive and erosive-corrosive properties of eutectic Al-Si （LM6） alloy were studied. Microstructural features of the alloy were altered by controlling the T6 heat treatment parameter, and their influence on har...The abrasive and erosive-corrosive properties of eutectic Al-Si （LM6） alloy were studied. Microstructural features of the alloy were altered by controlling the T6 heat treatment parameter, and their influence on hardness, strength and elongation, and response of the samples in erosion-corrosion and abrasion conditions were studied. Characteristics of the Al-Si alloy samples were compared with those of Al conventionally used in agricultural machineries. Fabrication of a typical component using the Al-Si alloy was also explored in order to understand the feasibility of using the alloy system for the envisaged applications. The study suggests the response of the samples in different conditions to be greatly influenced by parameters like chemical composition, microstructural features and applied load, traversal distance and test environment. The performance of even the as cast Al-Si alloy is far superior to that of the conventional Al samples, while the T6 heat treated Al-Si alloy shows improved performance. Accordingly, the as-cast as well as T6 heat treated Al-Si alloy has potential for applications in agriculture as a replacement for the conventionally used Al.展开更多
Radiation effect on the natural convection flow of an optically thin viscous incompressible fluid near a vertical plate with ramped wall temperature in a porous medium has been studied. The exact solution of momentum ...Radiation effect on the natural convection flow of an optically thin viscous incompressible fluid near a vertical plate with ramped wall temperature in a porous medium has been studied. The exact solution of momentum and energy equations is obtained by the use of Laplace transform technique. The variations in fluid velocity and temperature are shown graphically whereas the numerical values of shear stress and the rate of heat transfer at the wall are presented in tabular form for various values of flow parameters. The results show that the fluid velocity increases with increase in Grashof number, Darcy number and time parameters whereas the fluid velocity decreases with increase in the radiation parameter and Prandtl number for ramped temperature as well as isothermal wall temperature. It is found that an increase in radiation parameter leads to rise the temperature for both ramped wall temperature as well as isothermal wall temperature. Further, it is found that an increase in Prandtl number leads to fall the temperature for both ramped wall temperature as well as isothermal wall temperature. The shear stress at the wall decreases with increases in either Prandtl number or porosity parameter while the result shows reverse in the case of radiation parameter. Finally, the rate of heat transfer is increased with increases in the radiation parameter for both ramped wall temperature as well as isothermal wall temperature.展开更多
In the present paper, the aluminum alloy i.e. LM6 based composites reinforced with different weight fraction of SiC particles was produced by stir cast technique and the effect of reinforced ratios on the forgeability...In the present paper, the aluminum alloy i.e. LM6 based composites reinforced with different weight fraction of SiC particles was produced by stir cast technique and the effect of reinforced ratios on the forgeability and the machinability was examined. The test results show that the increment in weight fraction of reinforcement particles in the matrix metal produced better mechanical property like hardness but the forgeability of the cast MMCs decreases. The forgeability of the as cast MMCs were also varied with the change in thickness of the casting. The results show that the forgeability of cast metal matrix composites at the mid section of the casting is minimum compared to both end section of a three-step casting. The effect of machining parameters, e.g. cutting speed and depth of cut on the surface roughness and cutting forces at constant feed rate was investigated during experimentation. The results show that higher weight percentage of SiCp reinforcement produced a higher surface roughness and needs higher cutting forces during machining operation. It has also observed that the depth of cut and the cutting speed at constant feed rate affected the surface roughness and the cutting forces. This practical research analysis and test results on the forgeability and machinability of Al/SiC-MMC will provide useful guidelines to the present day manufacturing engineers.展开更多
Background of the Study, Aims and Objectives: There are very few studies on histological patterns of diabetic nephropathy in our part of country. The aim of this study was to evaluate the renal involvement in patients...Background of the Study, Aims and Objectives: There are very few studies on histological patterns of diabetic nephropathy in our part of country. The aim of this study was to evaluate the renal involvement in patients with Type-2 diabetes mellitus (T2DM), assess the histopathological changes and establish a clinico-pathological correlation. Subjects, Method and Materials: Thirty two Type 2 DM patients with nephropathy, after screening consecutive hundred(100) Type 2 Diabetics admitted to the Medicine Department were evaluated for renal involvement by kidney biopsy and histopathological study. Statistical analysis was done by student’s t-test, chi-square and linear regression analysis. Results: Thirty two patients (32) with diabetic nephropathy (20 males and 12 females) formed the study group out of hundred (100) consecutive Type-2 diabetes mellitus patients (58 males and 42 females) admitted to Medicine Department of SCB Medical College Hospital, Cuttack. The frequency of occurrence of clinical diabetic nephropathy was 32%. Most of the patients were having duration of DM of 6-10 years (87.5%). Pedal edema was found in 96.87%, hypertension in 87.5% patients respectively. Regression analysis showed that durations of DM and HbA1c were the two significant risk factors (P Histopathologically, diffuse glomerulosclerosis was the most common form of renal abnormality found in 93.75% followed by nodular glomerulosclerosis in 62.50% with overlap in many patients, membranous nephropathy in 12.5% and focal necrotising glomerulonephritis in 6.25% respectively. There was no statistically significant clinicopathological correlation observed between clinical and biochemical parameters in patients harbouring the two predominant histological types of nephropathy i.e. diffuse and nodular glomerulosclerosis with respect to age, sex, duration of diabetes, body mass index, systolic blood pressure, HbA1c, 24 hour urinary protein, creatinine clearance, serum urea, serum creatinine or lipid profile. Conclusion: Durations of diabetes and HbA1c were found to be strongly associated with development of diabetic nephropathy. Diffuse glomerulosclerosis was the most common form of renal abnormality found in 93.75% followed by nodular glomerulosclerosis in 62.50% of patients.展开更多
The wide choice of materials, today’s engineers are posed with a big challenge for the right selection of a material and as well as the right selection of a manufacturing process for an application. Aluminium Metal M...The wide choice of materials, today’s engineers are posed with a big challenge for the right selection of a material and as well as the right selection of a manufacturing process for an application. Aluminium Metal Matrix Composites is a relatively new material among all the engineering materials. It has proved its position in automobile, aerospace, and many other engineering applications due its wear resistance properties and due to its substantial hardness. One of the most important criteria is forgeability by which the workability of the material can be determined. The nature of distribution of reinforcing phase in the matrix greatly influenced the properties of Aluminum Metal Matrix Composites. The forgeability of Aluminum Metal Matrix Composites, which are produced by powder metallurgy method, are greatly depends on the size and percentage of reinforcement materials, compacting load, sintering temperature and soaking time etc. In this present work, the forgeability of Aluminum Metal Matrix Composites reinforced with silicon carbide (400 meshes) has investigated. A comparison have been made with different types of Aluminum Silicon Carbide Metal Matrix Composite materials contains 0%5%,10%,15%&20% by weight of silicon carbide. The mechanical properties like hardness of the different composites have also investigated. It is observed that the forgeabilty of the composites decreases with increasing the wt% of SiC but the mechanical properties like hardness enhanced on increasing the wt% of SiC.展开更多
A single-mode laser is demonstrated using a newly developed double-clad thulium-ytterbium-doped fiber （TYDF） in a linear cavity formed by two fiber Bragg gratings （FBGs）. The YTF used is drawn from a D-shape prefo...A single-mode laser is demonstrated using a newly developed double-clad thulium-ytterbium-doped fiber （TYDF） in a linear cavity formed by two fiber Bragg gratings （FBGs）. The YTF used is drawn from a D-shape preform fabricated using the modified chemical vapor deposition and solution doping technique. The laser is operated at 1 901.6 nm via the transition of thulium ions from 3F4 to 3H6 with the assistance of ytterbium to thulium ion energy transfer. The efficiencies of the laser are 0.71% and 0.75% at 927- and 905-nm multimode pumping, respectively. The thresholds of the launched pump power for 927- and 905-nm pumping are 1 314 and 1 458 mW, respectively. A 7-mW output is obtained at a 905-nm pump power of 2 400 mW.展开更多
基金Financial support of the UGC-DAE, Center for Scientific Research, Kolkata Centre
文摘Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.
文摘The abrasive and erosive-corrosive properties of eutectic Al-Si （LM6） alloy were studied. Microstructural features of the alloy were altered by controlling the T6 heat treatment parameter, and their influence on hardness, strength and elongation, and response of the samples in erosion-corrosion and abrasion conditions were studied. Characteristics of the Al-Si alloy samples were compared with those of Al conventionally used in agricultural machineries. Fabrication of a typical component using the Al-Si alloy was also explored in order to understand the feasibility of using the alloy system for the envisaged applications. The study suggests the response of the samples in different conditions to be greatly influenced by parameters like chemical composition, microstructural features and applied load, traversal distance and test environment. The performance of even the as cast Al-Si alloy is far superior to that of the conventional Al samples, while the T6 heat treated Al-Si alloy shows improved performance. Accordingly, the as-cast as well as T6 heat treated Al-Si alloy has potential for applications in agriculture as a replacement for the conventionally used Al.
文摘Radiation effect on the natural convection flow of an optically thin viscous incompressible fluid near a vertical plate with ramped wall temperature in a porous medium has been studied. The exact solution of momentum and energy equations is obtained by the use of Laplace transform technique. The variations in fluid velocity and temperature are shown graphically whereas the numerical values of shear stress and the rate of heat transfer at the wall are presented in tabular form for various values of flow parameters. The results show that the fluid velocity increases with increase in Grashof number, Darcy number and time parameters whereas the fluid velocity decreases with increase in the radiation parameter and Prandtl number for ramped temperature as well as isothermal wall temperature. It is found that an increase in radiation parameter leads to rise the temperature for both ramped wall temperature as well as isothermal wall temperature. Further, it is found that an increase in Prandtl number leads to fall the temperature for both ramped wall temperature as well as isothermal wall temperature. The shear stress at the wall decreases with increases in either Prandtl number or porosity parameter while the result shows reverse in the case of radiation parameter. Finally, the rate of heat transfer is increased with increases in the radiation parameter for both ramped wall temperature as well as isothermal wall temperature.
文摘In the present paper, the aluminum alloy i.e. LM6 based composites reinforced with different weight fraction of SiC particles was produced by stir cast technique and the effect of reinforced ratios on the forgeability and the machinability was examined. The test results show that the increment in weight fraction of reinforcement particles in the matrix metal produced better mechanical property like hardness but the forgeability of the cast MMCs decreases. The forgeability of the as cast MMCs were also varied with the change in thickness of the casting. The results show that the forgeability of cast metal matrix composites at the mid section of the casting is minimum compared to both end section of a three-step casting. The effect of machining parameters, e.g. cutting speed and depth of cut on the surface roughness and cutting forces at constant feed rate was investigated during experimentation. The results show that higher weight percentage of SiCp reinforcement produced a higher surface roughness and needs higher cutting forces during machining operation. It has also observed that the depth of cut and the cutting speed at constant feed rate affected the surface roughness and the cutting forces. This practical research analysis and test results on the forgeability and machinability of Al/SiC-MMC will provide useful guidelines to the present day manufacturing engineers.
文摘Background of the Study, Aims and Objectives: There are very few studies on histological patterns of diabetic nephropathy in our part of country. The aim of this study was to evaluate the renal involvement in patients with Type-2 diabetes mellitus (T2DM), assess the histopathological changes and establish a clinico-pathological correlation. Subjects, Method and Materials: Thirty two Type 2 DM patients with nephropathy, after screening consecutive hundred(100) Type 2 Diabetics admitted to the Medicine Department were evaluated for renal involvement by kidney biopsy and histopathological study. Statistical analysis was done by student’s t-test, chi-square and linear regression analysis. Results: Thirty two patients (32) with diabetic nephropathy (20 males and 12 females) formed the study group out of hundred (100) consecutive Type-2 diabetes mellitus patients (58 males and 42 females) admitted to Medicine Department of SCB Medical College Hospital, Cuttack. The frequency of occurrence of clinical diabetic nephropathy was 32%. Most of the patients were having duration of DM of 6-10 years (87.5%). Pedal edema was found in 96.87%, hypertension in 87.5% patients respectively. Regression analysis showed that durations of DM and HbA1c were the two significant risk factors (P Histopathologically, diffuse glomerulosclerosis was the most common form of renal abnormality found in 93.75% followed by nodular glomerulosclerosis in 62.50% with overlap in many patients, membranous nephropathy in 12.5% and focal necrotising glomerulonephritis in 6.25% respectively. There was no statistically significant clinicopathological correlation observed between clinical and biochemical parameters in patients harbouring the two predominant histological types of nephropathy i.e. diffuse and nodular glomerulosclerosis with respect to age, sex, duration of diabetes, body mass index, systolic blood pressure, HbA1c, 24 hour urinary protein, creatinine clearance, serum urea, serum creatinine or lipid profile. Conclusion: Durations of diabetes and HbA1c were found to be strongly associated with development of diabetic nephropathy. Diffuse glomerulosclerosis was the most common form of renal abnormality found in 93.75% followed by nodular glomerulosclerosis in 62.50% of patients.
文摘The wide choice of materials, today’s engineers are posed with a big challenge for the right selection of a material and as well as the right selection of a manufacturing process for an application. Aluminium Metal Matrix Composites is a relatively new material among all the engineering materials. It has proved its position in automobile, aerospace, and many other engineering applications due its wear resistance properties and due to its substantial hardness. One of the most important criteria is forgeability by which the workability of the material can be determined. The nature of distribution of reinforcing phase in the matrix greatly influenced the properties of Aluminum Metal Matrix Composites. The forgeability of Aluminum Metal Matrix Composites, which are produced by powder metallurgy method, are greatly depends on the size and percentage of reinforcement materials, compacting load, sintering temperature and soaking time etc. In this present work, the forgeability of Aluminum Metal Matrix Composites reinforced with silicon carbide (400 meshes) has investigated. A comparison have been made with different types of Aluminum Silicon Carbide Metal Matrix Composite materials contains 0%5%,10%,15%&20% by weight of silicon carbide. The mechanical properties like hardness of the different composites have also investigated. It is observed that the forgeabilty of the composites decreases with increasing the wt% of SiC but the mechanical properties like hardness enhanced on increasing the wt% of SiC.
基金the Department of Science and Technology of the government of India for their financial assistanceS. W. Harun would like to thank the University of Malaya for the financial support provided under the HIR Grant No.D000009-16001
文摘A single-mode laser is demonstrated using a newly developed double-clad thulium-ytterbium-doped fiber （TYDF） in a linear cavity formed by two fiber Bragg gratings （FBGs）. The YTF used is drawn from a D-shape preform fabricated using the modified chemical vapor deposition and solution doping technique. The laser is operated at 1 901.6 nm via the transition of thulium ions from 3F4 to 3H6 with the assistance of ytterbium to thulium ion energy transfer. The efficiencies of the laser are 0.71% and 0.75% at 927- and 905-nm multimode pumping, respectively. The thresholds of the launched pump power for 927- and 905-nm pumping are 1 314 and 1 458 mW, respectively. A 7-mW output is obtained at a 905-nm pump power of 2 400 mW.
