Bhupendra Gandhi - Academia.edu (original) (raw)

Papers by Bhupendra Gandhi

Wear, 2005

A pot tester is normally used to study the relative erosion behavior of different materials at mo... more A pot tester is normally used to study the relative erosion behavior of different materials at moderate solid concentrations. Uniform distribution of solids and turbulence inside the pot are generally the problems with the pot tester and thus the data generated have limited application for quantitative analysis. In the present work, investigations have been carried out in a transparent cylindrical pot to determine the minimum speed of a propeller required for uniform distribution of solid particles and the observations are used to develop a slurry pot tester. It is observed that a 45 • pitched four bladed propeller in down-pumping mode gives a better distribution of solids. A pot tester is then fabricated by inserting the propeller from the bottom of the cylinder and is rotated at the speed required for uniform distribution. The test specimens are then mounted at a different shaft inserted from the top of the pot and is rotated at desired test speeds. The results were obtained for ductile material and are found in good agreement with the literature.

Journal of Tribology, 2011

Material loss due to erosion is a serious problem associated with the flow of solid-liquid mixtur... more Material loss due to erosion is a serious problem associated with the flow of solid-liquid mixtures. In the present work, erosion wear tests have been carried out in a slurry pot tester for seven different ductile type materials namely aluminum alloy (AA6063), copper, brass, mild steel, AISI 304L stainless steel, AISI 316L stainless steel, and turbine blade grade steel using three different erodents namely, quartz, alumina, and silicon carbide. Experiments have been performed at different orientation angles of target material at the velocities of 3, 6, and 8.33 m/s for solid concentrations of 10%, 20%, and 30% (by weight) and particle sizes of 363, 550, and 655 μm. The contribution of cutting wear in the total wear of ductile material at various orientation angles has been determined. It is observed that the maximum cutting wear angle for the ductile material depends on its hardness and a correlation is developed for its prediction. Also a methodology is proposed for estimation of t...

Indian Journal of Transplantation, 2019

Expanding use of ABO-incompatible kidney transplant (ABOiKT) globally and in India demands harmon... more Expanding use of ABO-incompatible kidney transplant (ABOiKT) globally and in India demands harmonized protocols. With an aim to provide unified and standardized consensus for ABOiKT in Indian setting, a 14-member working group formulated this document on key critical areas to guide ABOiKT. The recommendations include the following: (i) Gel column agglutination test is a method of choice for antibody (Ab) titer assessment with tube method as acceptable alternative. Immunoglobulin G measurement is advised for clinical decision making. (ii) Assessment of one Ab titer before subjecting patient to Ab removal is recommended. Postplasmapheresis (PP) titers to be monitored anywhere between 2 and 12 h. (iii) Target Ab titer recommended is ≤1:16 irrespective of the method used for titer assessment. (iv) If cost and availability are not a concern, immunoadsorption (IA) should be preferred. (vi) Choice of replacement fluid depends on the method employed for Ab removal. (vii) Donor or AB-positive plasma transfusion can be considered to avoid coagulopathy and bleeding in posttransplant period. It also decreases the risk of coagulopathy associated with greater number of PP cycles performed during and after transplant. (viii) IA column can be reused if cleaned, sterilized and stored properly. (ix) Intravenous immunoglobulin (IVIG) is optional for use in ABOiKT. Choose IVIG batch with lowest ABO- Ab titers and use in low dose (~ 100 mg/kg). (x) Rituximab in a low dose of 100–200 mg is effective and its use (at-least 2 weeks prior to transplant) is at the discretion of treating renal transplant physician. (xi) Avoid, if possible, the combined used of antithymocyte globulin and rituximab as it increases risk of infections significantly. (xii) Posttransplant PP is needed if there is Ab mediated rejection with increasing titers. (xiii) Standard immunosuppression should be followed. These recommendations are first of a kind that aims to standardize the practice of ABOiKT, serve as a guiding tool to the transplant physicians in India.

Indian Journal of Transplantation, 2008

Indian Journal of Transplantation, 2008

Wear, 2005

A pot tester is normally used to study the relative erosion behavior of different materials at mo... more A pot tester is normally used to study the relative erosion behavior of different materials at moderate solid concentrations. Uniform distribution of solids and turbulence inside the pot are generally the problems with the pot tester and thus the data generated have limited application for quantitative analysis. In the present work, investigations have been carried out in a transparent cylindrical pot to determine the minimum speed of a propeller required for uniform distribution of solid particles and the observations are used to develop a slurry pot tester. It is observed that a 45 • pitched four bladed propeller in down-pumping mode gives a better distribution of solids. A pot tester is then fabricated by inserting the propeller from the bottom of the cylinder and is rotated at the speed required for uniform distribution. The test specimens are then mounted at a different shaft inserted from the top of the pot and is rotated at desired test speeds. The results were obtained for ductile material and are found in good agreement with the literature.

Journal of Tribology, 2011

Material loss due to erosion is a serious problem associated with the flow of solid-liquid mixtur... more Material loss due to erosion is a serious problem associated with the flow of solid-liquid mixtures. In the present work, erosion wear tests have been carried out in a slurry pot tester for seven different ductile type materials namely aluminum alloy (AA6063), copper, brass, mild steel, AISI 304L stainless steel, AISI 316L stainless steel, and turbine blade grade steel using three different erodents namely, quartz, alumina, and silicon carbide. Experiments have been performed at different orientation angles of target material at the velocities of 3, 6, and 8.33 m/s for solid concentrations of 10%, 20%, and 30% (by weight) and particle sizes of 363, 550, and 655 μm. The contribution of cutting wear in the total wear of ductile material at various orientation angles has been determined. It is observed that the maximum cutting wear angle for the ductile material depends on its hardness and a correlation is developed for its prediction. Also a methodology is proposed for estimation of t...

Indian Journal of Transplantation, 2019

Expanding use of ABO-incompatible kidney transplant (ABOiKT) globally and in India demands harmon... more Expanding use of ABO-incompatible kidney transplant (ABOiKT) globally and in India demands harmonized protocols. With an aim to provide unified and standardized consensus for ABOiKT in Indian setting, a 14-member working group formulated this document on key critical areas to guide ABOiKT. The recommendations include the following: (i) Gel column agglutination test is a method of choice for antibody (Ab) titer assessment with tube method as acceptable alternative. Immunoglobulin G measurement is advised for clinical decision making. (ii) Assessment of one Ab titer before subjecting patient to Ab removal is recommended. Postplasmapheresis (PP) titers to be monitored anywhere between 2 and 12 h. (iii) Target Ab titer recommended is ≤1:16 irrespective of the method used for titer assessment. (iv) If cost and availability are not a concern, immunoadsorption (IA) should be preferred. (vi) Choice of replacement fluid depends on the method employed for Ab removal. (vii) Donor or AB-positive plasma transfusion can be considered to avoid coagulopathy and bleeding in posttransplant period. It also decreases the risk of coagulopathy associated with greater number of PP cycles performed during and after transplant. (viii) IA column can be reused if cleaned, sterilized and stored properly. (ix) Intravenous immunoglobulin (IVIG) is optional for use in ABOiKT. Choose IVIG batch with lowest ABO- Ab titers and use in low dose (~ 100 mg/kg). (x) Rituximab in a low dose of 100–200 mg is effective and its use (at-least 2 weeks prior to transplant) is at the discretion of treating renal transplant physician. (xi) Avoid, if possible, the combined used of antithymocyte globulin and rituximab as it increases risk of infections significantly. (xii) Posttransplant PP is needed if there is Ab mediated rejection with increasing titers. (xiii) Standard immunosuppression should be followed. These recommendations are first of a kind that aims to standardize the practice of ABOiKT, serve as a guiding tool to the transplant physicians in India.

Indian Journal of Transplantation, 2008

Indian Journal of Transplantation, 2008