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Bharat Singh,Piyush Singhal,Kuldeep K. Saxena,Ravindra K. Saxena 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8
The present study aims to evaluate the influence of latent heat effect during phase change in a three-dimensional finite elementnumerical simulation of arc welding. A mathematical model is developed to incorporate the effect of latent heat ofphase transformation using enthalpy formulation. The accuracy of the developed model was initially validated using availableresults in the literature and found consistent prediction. The validated numerical model is used to predict the temperaturedistribution, weld width, depth of penetration, melting efficiency with and without incorporating the effect of latent heat offusion, solidification vaporization. The results obtained from a developed model incorporating the latent heat effect are ingood agreement with the experimentally measured values, whereas a considerable deviation is observed between the predictedvalues and experimental values without considering the effect of latent heat. It is found that without considering the latentheat effect in the model, the mean error is 14%, 24.6%, 22% and 29.6% for peak temperatures, weld width, depth of penetrationand melting efficiency respectively. Therefore, it can be concluded that the effect of latent heat of fusion, solidification,and vaporization is significant for analysis involving phase change and must be accounted for during numerical simulations.
Rana, Bharat Singh,Cho, Dong-Woo,Cho, Kanghee,Kim, Jong-Nam Elsevier 2018 Fuel Vol.231 No.-
<P><B>Abstract</B></P> <P>High acid crude oils contain large amount of naphthenic acids which cause serious corrosion problem in petroleum industry. Therefore, the removal of naphthenic acids becomes a great concern and challenge for oil refineries. In this study, the naphthenic acids in high TAN crude oils were removed by esterification with low consumption of methanol using a solid acid catalyst consisting of 12-tungstophosphoric acid (TPA) supported on γ-Al<SUB>2</SUB>O<SUB>3</SUB> (TPA/γ-Al<SUB>2</SUB>O<SUB>3</SUB>) in a fixed-bed up-flow reactor. The catalyst was prepared by conventional wet impregnation method, and it possessed 25 wt% TPA with high dispersion, and large pore structure. TPA leaching problem from catalyst support was not observed during the reaction. The effect of various reaction parameters such as temperature and liquid hour space velocity (LHSV), and methanol to the crude oil ratio on TAN reduction were investigated in detail to maximize TAN reduction. The results revealed that the TPA/γ-Al<SUB>2</SUB>O<SUB>3</SUB> catalyst effectively removed the naphthenic acids via esterification in high TAN crude oils. The TAN decreased with increase in methanol/oil mass ratio, reaction temperature, but it increased with increase in LHSV. In a long-term experiments (up to 100 h) running at a reaction temperature of 250 °C and LHSV of 3 h<SUP>−1</SUP> using 2 wt% methanol in acidic crude oil, the TANs of acidic crude oil reduced from 2.0 mg KOH/g to a value below 0.5 mg KOH/g which is an acceptable TAN value of crude oil to process in the refineries without material upgrades.</P>
Biological Control of Fusarium Wilt Disease of Pigeonpea
Rajesh Singh,B.K. Singh,R.S. Upadhyay,Bharat Rai,Lee, Youn-Su The Korean Society of Plant Pathology 2002 Plant Pathology Journal Vol.18 No.5
Biological control of Fusarium udum causing wilt disease of pigeonpea was studied in vitro, as well as, in vivo. Aspergilluspavus, Anergillus niger, Bacilius licheniformis (strain-2042), Gliocladium virens, Peniciliium citrimum, and Trichoderma harzianum, which were found to be the most potent ones in inhibiting the radial colony growth of the test pathogen, were used as biological control by amending their inocula at diffeyent concentrations in pots and in pathogen-infested soil in the fields. Maximum reduction of the wilt disease was observed with G. vireos both in pots and in the fields. The population of E. udum was found to be markedly reduced when the antagonists were applied in the soil. The study establishes that G. virens can be exploited for the biological control of wilt disease at field level.
Endoscopic Sleeve Gastroplasty - A New Tool to Manage Obesity
Deepanshu Jain,Bharat Singh Bhandari,Ankit Arora,Shashideep Singhal 대한소화기내시경학회 2017 Clinical Endoscopy Vol.50 No.6
Obesity is a growing pandemic across the world. Dietary restrictions and behavior modifications alone have a limited benefit. Bariatric surgery, despite being the current gold standard, has limited acceptance by patients due to cost and associated morbidity. In our review, we have discussed nine original studies describing endoscopic sleeve gastroplasty (ESG). A total of 172 subjects successfully underwent ESG. Of 65 subjects with follow up data, 95.4% (62/65) had intact gastric sleeve confirmed via esophagogastroduodenoscopy or oral contrast study at the end of study specific follow up interval (the longest being 6 months). Individual studies reported a technical success rate for intact gastric sleeve from as low as 50% to as high as 100%. A statistically significant (p<0.05) weight loss was reported in seven of the eight studies with available data. None of the patients experienced any intra-procedure complications, and approximately 2.3% (4/172) of patients experienced major post-procedure complications; however, no mortality was reported. Majority of the studies reported relatively high incidence of minor post-procedure complications, which improved with symptomatic treatment alone. Good patient tolerance with comparable clinical efficacy in achieving and sustaining desired weight loss makes ESG an attractive option to consider among other bariatric therapies.
Deepanshu Jain,Bharat Singh Bhandari,Nikhil Agrawal,Shashideep Singhal 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.5
Surgery remains the standard treatment for acute cholecystitis except in high-risk candidates where percutaneous transhepatic gallbladderdrainage (PT-GBD), endoscopic transpapillary cystic duct stenting (ET-CDS), and endoscopic ultrasound-guided gallbladder drainage(EUS-GBD) are potential choices. PT-GBD is contraindicated in patients with coagulopathy or ascites and is not preferred by patientsowing to aesthetic reasons. ET-CDS is successful only if the cystic duct can be visualized and cannulated. For 189 patients whounderwent EUS-GBD via insertion of a lumen-apposing metal stent (LAMS), the composite technical success rate was 95.2%, which increasedto 96.8% when LAMS was combined with co-axial self-expandable metal stent (SEMS). The composite clinical success rate was96.7%. We observed a small risk of recurrent cholecystitis (5.1%), gastrointestinal bleeding (2.6%) and stent migration (1.1%). Cauteryenhanced LAMS significantly decreases the stent deployment time compared to non-cautery enhanced LAMS. Prophylactic placementof a pigtail stent or SEMS through the LAMS avoids re-interventions, particularly in patients, where it is intended to remain in situ indefinitely. Limited evidence suggests that the effcacy of EUS-GBD via LAMS is comparable to that of PT-GBD with the former showingbetter results in postoperative pain, length of hospitalization, and need for antibiotics. EUS-GBD via LAMS is a safe and effcaciousoption when performed by experts.
( Gupta Anil Kumar ),( Rajiv Pathak ),( Bharat Singh ),( Hemlata Gautam ),( Ram Kumar ),( Raj Kumar ),( Rajesh Arora ),( Hemant K. Gautam ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.6
A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2- DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.