Prediction of weld zone shape with effect of tool pin profile in friction stir welding process

Prashant Prakash,Ravi Shankar Anand,Sanjay Kumar Jha 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

This article investigates the effect of tool pin profile on weld zone shape using computational fluid dynamics techniques in friction stir welding process. The effect of tool pin profile on weld zone shape was investigated by four different pin profile tools: Cylindrical, conical, cylindrical-conical and stepped-conical. In the numerical simulation process, workpiece material and tool are considered as non-Newtonian fluids and solid material, respectively. And simulation is carried out under transient state condition. Temperature distribution and material flow profile developed by the tool pin profile are analyzed for the understanding of viscosity profile of the weld zone region. Critical iso-viscosity surface is developed from the viscosity profile to determine the difference between deformed and undeformed material, which is finally used to determine the weld zone shape. The simulation result shows that maximum temperature and material flow velocity are produced by stepped-conical pin profile tool with respect to all other tools. It is observed from the iso-viscosity surface analysis that a vaseshaped geometry developed around the contact region of the tool and workpiece. The weld zone shape produced by stepped-conical pin profile tool is cylinder dominant vase shape, and weld zone shape of all other tools is basin dominant vase shape. Numerical model was also validated with experimental results of temperature distribution and weld zone shape thickness which showed good agreement.

Altering Conidial Dispersal of Alternaria solani by Modifying Microclimate in Tomato Crop Canopy

Prashant Prakash Jambhulkar,Nitiprasad Jambhulkar,Madanlal Meghwal,Gauri Shankar Ameta 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.6

Early blight of tomato caused by Alternaria solani, isresponsible for severe yield losses in tomato. The conidiasurvive on soil surface and old dry lower leavesof the plant and spread when suitable climatic conditionsare available. Macroclimatic study reveals thathighest inoculum concentration of Alternaria sporesappeared in May 2012 to 2013 and lowest concentrationduring January 2012 to 2013. High night temperaturepositively correlated and significantly (P <0.01) involved in conidial spore dispersal and low relativehumidity (RH) displayed significant (P < 0.05)but negative correlation with conidial dispersal. Theobjective of the study was to modify microclimaticconditions of tomato crop canopy which may hamperconidial dispersal and reduce disease severity. Weevaluated effect of marigold intercropping and plasticmulching singly and in consortia on A. solani conidialdensity, tomato leaf damage and microclimatic parametersas compar to tomato alone (T). Tomato-marigoldintercropping–plastic mulching treatment (T + M +P) showed 35–39% reduction in disease intensity ascompared to tomato alone. When intercropped withtomato, marigold served as barrier to conidial movementand plastic mulching prevented evapotranspirationand reduced the canopy RH that resulted in lessgermination of A. solani spores. Marigold intercroppingand plastic mulching served successfully as physicalbarrier against conidial dissemination to diminishsignificantly the tomato foliar damage produced by A. solani.

Altering Conidial Dispersal of Alternaria solani by Modifying Microclimate in Tomato Crop Canopy

Jambhulkar, Prashant Prakash,Jambhulkar, Nitiprasad,Meghwal, Madanlal,Ameta, Gauri Shankar The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.6

Early blight of tomato caused by Alternaria solani, is responsible for severe yield losses in tomato. The conidia survive on soil surface and old dry lower leaves of the plant and spread when suitable climatic conditions are available. Macroclimatic study reveals that highest inoculum concentration of Alternaria spores appeared in May 2012 to 2013 and lowest concentration during January 2012 to 2013. High night temperature positively correlated and significantly (P < 0.01) involved in conidial spore dispersal and low relative humidity (RH) displayed significant (P < 0.05) but negative correlation with conidial dispersal. The objective of the study was to modify microclimatic conditions of tomato crop canopy which may hamper conidial dispersal and reduce disease severity. We evaluated effect of marigold intercropping and plastic mulching singly and in consortia on A. solani conidial density, tomato leaf damage and microclimatic parameters as compar to tomato alone (T). Tomato-marigold intercropping-plastic mulching treatment (T + M + P) showed 35-39% reduction in disease intensity as compared to tomato alone. When intercropped with tomato, marigold served as barrier to conidial movement and plastic mulching prevented evapotranspiration and reduced the canopy RH that resulted in less germination of A. solani spores. Marigold intercropping and plastic mulching served successfully as physical barrier against conidial dissemination to diminish significantly the tomato foliar damage produced by A. solani.

Biological activities of Cuminum cyminum seed oil and its major components against Callosobruchus chinensis and Sitophilus oryzae

Akash Kedia,Prashant Kumar Mishra,Abhishek Kumar Dwivedy,Nawal Kishore Dubey,Bhanu Prakash 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

The study reports the fumigant, repellent, oviposition deterrent, ovicidal, larvicidal and pupaecidal activities of Cuminum cyminum seed essential oil and its 4 main components (cymene, γ-terpinene, cuminaldehyde and (−)- β-pinene) against Callosobruchus chinensis and Sitophilus oryzae. The essential oil, γ-terpinene and (−)-β-pinene showed pronounced activity in all parameters against both the insects. However, the susceptibility of C. chinensis wasmuch higher than S. oryzae. Cymene and cuminaldehyde showed poormortality to insects but causedmoderate repellency and oviposition deterrency at 100 μl/L air. The essential oil when tested for practical application in protection of food commodities from insect infestation in storage containers, exhibited 100% and 97% feeding deterrent index at 100 μl/L air concentration against C. chinensis and S. oryzae damage respectively without affecting viability of chickpea and wheat. C. cyminum seed essential oil may thus be recommended as eco-friendly and biorational alternatives of synthetic pesticides for management of insect infestation of food commodities.

Influence of Blanching and Drying Air Temperature on Drying Kinetics of Banana Slices

Kumar Ravi,Pandey Om Prakash,Dhiman Sushil Kumar,Kumar Prashant 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.4

Purpose Drying of agro products, analternative approach to truncate the post harvesting losses which is about 40%in case of banana as reported in literatures, is conducted for banana slicesusing tray dryer. The objective was to investigate the effect of blanching and dryingtemperature on drying kinetics of banana slices for which a comparative studyof the drying kinetics of the bananaslices under blanching and without blanching conditions was conducted. Methods The samples were made circularin shape with average diameter of 30mm and 2mm thickness. Drying was done atair velocity of 3ms-1 maintained at three different temperatures of60oC, 70oC and 80oC. Blanching of banana sliceswas done in an aqueous solution of citricacid for 1 minute. Results Comprison of blanching andwithout blancing samples was done based on drying kinetics, color, energy analysis, andcost analysis to optimize the drying conditions and reduce the process cost.Two thin layer drying models werefitted to the experimental data using nonlinear regression analysis and theresults were evaluated using statistical parameter. The significant effects ofdrying temperature, drying time and blanching on moisture content of bananaslices were analyzed by ANOVA (Analysis of Variance). Conclusions The blanchingtechnique was found as cost-effective dryingprocess as compared to the without blanching technique.

Plasma cell leukemia in North India: retrospective analysis of a distinct clinicohematological entity from a tertiary care center and review of literature

Karthik Bommannan,Man Updesh Singh Sachdeva,Pankaj Malhotra,Narender Kumar,Prashant Sharma,Shano Naseem,Jasmina Ahluwalia,Reena Das,Neelam Varma,Gaurav Prakash,Alka Khadwal,Radhika Srinivasan,Subhash 대한혈액학회 2016 Blood Research Vol.51 No.1

BackgroundPlasma cell leukemia (PCL) is a rare and aggressive plasma cell neoplasm. In PCL, clonal plasma cells comprise ≥20% of the peripheral blood (PB) leukocytes and/or the absolute clonal PB plasma cell count is ≥2×109/L. Primary PCL (PPCL) originates de novo, whereas, secondary PCL (SPCL) evolves from pre-existing multiple myeloma.MethodsClinicohematological features, immunophenotypic profile, and survival of PCL patients were analyzed retrospectively.ResultsBetween January 2007 and December 2014, ten PPCL and four SPCL patients were inves-tigated (8 PPCLs and 3 SPCLs had complete clinical data). All were North Indians, sharing common geography and ethnicity. Our cohort showed less frequent renal failure, more frequent hepatomegaly, and non-secretory type disease. In contrast to western literature, flow cytometric immunophenotyping of our cohort revealed altered expression of CD138 (67%), CD56 (33%), and CD20 (0%). With novel therapeutic agents, these PPCL patients had a median overall survival of 15 months.ConclusionWe highlight that our PPCL patients from North India had distinct clinicohematological and immunophenotypic profiles. The significance of our findings must be tested in a larger patient cohort and must be supported by molecular and cytogenetic investigations to un-mask possible significant effects on pathogenesis.

Plasma cell leukemia in North India: retrospective analysis of a distinct clinicohematological entity from a tertiary care center and review of literature

Karthik Bommannan,Man Updesh Singh Sachdeva,Pankaj Malhotra,Narender Kumar,Prashant Sharma,Shano Naseem,Jasmina Ahluwalia,Reena Das,Neelam Varma,Gaurav Prakash,Alka Khadwal,Radhika Srinivasan,Subhash 대한혈액학회 2016 Blood Research Vol.51 No.1

BackgroundPlasma cell leukemia (PCL) is a rare and aggressive plasma cell neoplasm. In PCL, clonal plasma cells comprise ≥20% of the peripheral blood (PB) leukocytes and/or the absolute clonal PB plasma cell count is ≥2×109/L. Primary PCL (PPCL) originates de novo, whereas, secondary PCL (SPCL) evolves from pre-existing multiple myeloma.MethodsClinicohematological features, immunophenotypic profile, and survival of PCL patients were analyzed retrospectively.ResultsBetween January 2007 and December 2014, ten PPCL and four SPCL patients were inves-tigated (8 PPCLs and 3 SPCLs had complete clinical data). All were North Indians, sharing common geography and ethnicity. Our cohort showed less frequent renal failure, more frequent hepatomegaly, and non-secretory type disease. In contrast to western literature, flow cytometric immunophenotyping of our cohort revealed altered expression of CD138 (67%), CD56 (33%), and CD20 (0%). With novel therapeutic agents, these PPCL patients had a median overall survival of 15 months.ConclusionWe highlight that our PPCL patients from North India had distinct clinicohematological and immunophenotypic profiles. The significance of our findings must be tested in a larger patient cohort and must be supported by molecular and cytogenetic investigations to un-mask possible significant effects on pathogenesis.