Effect of Mechanical Alloying and Sintering Environment on the Crystallographic Evolution, Microstructure, Mechanical and Corrosion Properties of Porous Ti4Al4Co Alloy

Pradeep Singh,Vikas Shrivastava,I. B. Singh,D. P. Mondal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Three group of porous Ti4Al4Co samples made of (i) unmilled powder and vacuum sintered (S1), (ii) milled powder andvacuum sintered (S2), and (iii) milled powder sintered in open atmosphere (S3) were prepared. Phase change, crystallite sizeand lattice strain variations due to powder milling and sintering were examined by SEM and XRD. To evaluate mechanicalproperty, alloy samples were subjected to the uniaxial compression test. For corrosion analysis, Tafel plot was plotted usingelectrochemical corrosion system in simulated body fluid (SBF) as electrolytic medium. From the obtained results, it wasfound that significant microstructural transformation takes place due to milling and change in sintering atmosphere. SampleS1possessed 139 MPa compressive strength, which was about 48% and 76% higher than samples S2and S3respectively. Corrosion current density for S3was found as 5.5 ± 0.3 μA/cm2 which is 7 and 12 times lower than S2and S1samples.

Phenolic constituents and biological activities of leaf extracts of traditional medicinal plant Plectranthus amboinicus Benth (Lamiaceae)

Pradeep Singh Negi,Sandeep Kumar Gupta,Praveena Bhatt,Gilbert Stanley Joseph,Mandyam Chakravarthy Varadaraj 셀메드 세포교정의약학회 2013 TANG Vol.3 No.4

Plectranthus amboinicus Benth (Lamiaceae) is a medicinal plant native to India, and its leaves are widely used in several traditional medicinal preparations. The purpose of this study was to detect and quantify phenolics present in ethyl acetate and acetone extracts of P. amboinicus leaves, and evaluate their antioxidant, antibacterial, antimutagenic and anticancer activities. The HPLC chromatograms of crude leaf extracts indicated the presence of phenolics like caffeic acid, coumaric acid, rutin, quercetin and gallic acid, which were present in the range of 0.01 - 1.41 mg/g in ethyl acetate and 0.03 - 1.93 mg/g in the acetone extract. The acetone extract showed statistically (p < 0.05) higher antioxidant activity (IC50, 99.59 µg/ml) than ethyl acetate extract (IC50, 149.96 µg/ml). Statistically (p < 0.05) higher antimutagenicity was shown by acetone extract (46.16%) as compare to ethyl acetate extract (12.16%) at 500 µg/plate concentration. The acetone extract showed higher antibacterial activity than ethyl acetate extract, and both the extracts showed highest activity against B. cereus (375 and 625 µg/ml, respectively) and lowest activity against Y. enterocolitica (1000 and 1125 µg/ml, respectively). Both the extracts also showed inhibitory effect on cancer cell lines HCT-15 and MCF-7. These results suggest that the leaves of P. amboinicus possess various biological activities, and validate the traditional use of the leaves of P. amboinicus against cold, infection and ulceration.

Software Fault Prediction at Design Phase

Pradeep Singh,Shrish Verma,O. P Vyas 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

Prediction of fault-prone modules continues to attract researcher’s interest due to its significant impact on software development cost. The most important goal of such techniques is to correctly identify the modules where faults are most likely to present in early phases of software development lifecycle. Various software metrics related to modules level fault data have been successfully used for prediction of fault-prone modules. Goal of this research is to predict the faulty modules at design phase using design metrics of modules and faults related to modules. We have analyzed the effect of pre-processing and different machine learning schemes on eleven projects from NASA Metrics Data Program which offers design metrics and its related faults. Using seven machine learning and four preprocessing techniques we confirmed that models built from design metrics are surprisingly good at fault proneness prediction. The result shows that we should choose Naive Bayes or Voting feature intervals with discretization for different data sets as they outperformed out of 28 schemes. Naive Bayes and Voting feature intervals has performed AUC > 0.7 on average of eleven projects. Our proposed framework is effective and can predict an acceptable level of fault at design phases.

Software Fault Prediction at Design Phase

Singh, Pradeep,Verma, Shrish,Vyas, O.P. The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

Prediction of fault-prone modules continues to attract researcher's interest due to its significant impact on software development cost. The most important goal of such techniques is to correctly identify the modules where faults are most likely to present in early phases of software development lifecycle. Various software metrics related to modules level fault data have been successfully used for prediction of fault-prone modules. Goal of this research is to predict the faulty modules at design phase using design metrics of modules and faults related to modules. We have analyzed the effect of pre-processing and different machine learning schemes on eleven projects from NASA Metrics Data Program which offers design metrics and its related faults. Using seven machine learning and four preprocessing techniques we confirmed that models built from design metrics are surprisingly good at fault proneness prediction. The result shows that we should choose Naïve Bayes or Voting feature intervals with discretization for different data sets as they outperformed out of 28 schemes. Naive Bayes and Voting feature intervals has performed AUC > 0.7 on average of eleven projects. Our proposed framework is effective and can predict an acceptable level of fault at design phases.

Limited Laminectomy and Restorative Spinoplasty in Spinal Canal Stenosis

Sukhbir Singh Sangwan,Rakesh Garg,Paritosh Gogna,Zile Singh Kundu,Vinay Gupta,Pradeep Kamboj 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.4

Study Design: Prospective cohort study. Purpose: Evaluation of the clinico-radiological outcome and complications of limited laminectomy and restorative spinoplasty in spinal canal stenosis. Overview of Literature: It is critical to achieve adequate spinal decompression, while maintaining spinal stability. Methods: Forty-four patients with degenerative lumbar canal stenosis underwent limited laminectomy and restorative spinoplasty at our centre from July 2008 to December 2010. Four patients were lost to follow-up leaving a total of 40 patients at an average final follow-up of 32 months (range, 24–41 months). There were 26 females and 14 males. The mean±standard deviation (SD) of the age was 64.7±7.6 years (range, 55–88 years). The final outcome was assessed using the Japanese Orthopaedic Association (JOA) score. Results: At the time of the final follow-up, all patients recorded marked improvement in their symptoms, with only 2 patients complaining of occasional mild back pain and 1 patient complaining of occasional mild leg pain. The mean±SD for the preoperative claudication distance was 95.2±62.5 m, which improved to 582±147.7 m after the operation, and the preoperative anterio-posterior canal diameter as measured on the computed tomography scan was 8.3±2.1 mm, which improved to 13.2±1.8 mm postoperatively. The JOA score improved from a mean±SD of 13.3±4.1 to 22.9±4.1 at the time of the final follow-up. As for complications, dural tears occurred in 2 patients, for which repair was performed with no additional treatment needed. Conclusions: Limited laminectomy and restorative spinoplasty is an efficient surgical procedure which relieves neurogenic claudication by achieving sufficient decompression of the cord with maintenance of spinal stability.

Endoscopic Ultrasound-Guided Random Omental Fine Needle Aspiration: A Novel Technique for the Diagnosis of Peritoneal Carcinomatosis

Pradeep Kumar Siddappa,Neha Jain,Naveen K. Agarwal,Monika Jain,Gurwant Singh Lamba 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.5

Background/Aims: Diagnostic abdominal paracentesis has been described in literature to have variable sensitivity of 50%–75% forthe detection of peritoneal carcinomatosis (PC). We believe that random needle aspirates from the omentum, even in the absence ofobvious deposits by endoscopic ultrasound (EUS), could prove malignancy in patients with PC. Methods: Consecutive patients who underwent EUS for diagnosis and staging of cancer and found to have ascites were includedafter obtaining informed consent. EUS-guided fine needle aspiration (EUS-FNA) from random sites in the omentum was performedthrough the transgastric route using a linear echoendoscope. Results: Fifty-four patients underwent EUS during October 2015 to April 2017 for detection, staging, or FNA of a suspectedmalignant lesion. Ascites was seen in 17 patients and 15 patients who fulfilled the criteria were included. The procedure wassuccessful in all patients. Cytology was suggestive of malignancy in 12 (80%) but not suggestive of malignancy in 3 (20%) patients. Three patients who tested negative had hyperbilirubinemia with biliary obstruction. Their ascitic fluid analysis result was alsonegative. Conclusions: Random FNA of the omentum in patients with malignancy-related ascites is highly effective in the diagnosis of PC andcould be employed during EUS evaluation of malignancies.

Hydrogen-Atom Abstraction Reaction of CF₃CH₂OCF₃ by Hydroxyl Radical

Singh, Hari Ji,Mishra, Bhupesh Kumar,Rao, Pradeep Kumar Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

Theoretical investigations are carried out on the title reaction by means of ab-initio and DFT methods. The optimized geometries, frequencies and minimum energy path are obtained at UB3LYP/6-311G(d,p) level. Single point energy calculations are performed at MP2 and MP4 levels of theory. Energetics are further refined by calculating the energy of the species with a modified Gaussian-2 method, G2M(CC,MP2). The rate constant of the reaction is calculated using Canonical Transition State Theory (CTST) utilizing the ab-initio data obtained during the present study and is found to be $5.47{\times}10^{-12}\;cm^3\;molecule^{-1}s^{-1}$ at 298 K and 1 atm.

Computational Study on OH and Cl Initiated Oxidation of 2,2,2-Trifluoroethyl Trifluoroacetate (CF₃C(O)OCH₂CF₃)

Singh, Hari Ji,Tiwari, Laxmi,Rao, Pradeep Kumar Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.5

Hydrofluoroethers (HFEs) are developed as a suitable for the replacement of environmentally hazardous CFCs and are termed as third generation refrigerants. One of the major products of decomposition of HFEs in the atmosphere is a fluoroester. The present study relates to the OH and Cl initiated oxidation of $CF_3C(O)OCH_2CF_3$ formed from the oxidation of HFE-356mff. The latter is used as a solvent in the industry and reaches the atmosphere without any degradation. Kinetics of the titled molecule has been studied at MPWB1K/6-31+G(d,p) level of theory. Single point energy calculations have been made at G2(MP2) level of theory and barrier heights are determined. The rate constants are calculated using canonical transition state theory. Tunnelling correction are made using one-dimensional Eckart potential barrier. The rate constant calculated during the present study are compared with the experimental values determined using relative rate method and FTIR detection technique.

Assessment of the quality of life in maxillectomy patients : a longitudinal study

Pradeep Kumar,Habib Ahmad Alvi,Jitendra Rao,Balendra Pratap Singh,Sunit Kumar Jurel,Lakshya Kumar,Himanshi Aggarwal 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.1

PURPOSE. To longitudinally assess the quality of life in maxillectomy patients rehabilitated with obturator prosthesis. MATERIALS AND METHODS. Thirty-six subjects were enrolled in the span of 16 months, out of which six were dropouts. Subjects (age group 20-60 years) with maxillary defects, irrespective of the cause, planned for definite obturator prosthesis, were recruited. The Hindi version of European Organization for Research and Treatment of Cancer, Head and Neck version 1 of Quality of Life Questionnaire was used before surgical intervention and one month after definitive obturator. Questionnaire includes 35 questions related to the patient’ physical health, well being, psychological status, social relation and environmental conditions. The data were processed with statistical package for social science (SPSS). Probability level of P<.05 was considered statistically significant. RESULTS. The quality of life after rehabilitation with obturator prosthesis was 81.48% (±13.64) on average. On item-level, maximum mean scores were obtained for items problem with teeth (1.87 ± 0.94), pain in mouth (1.80 ± 0.92), trouble in eating (1.70 ± 0.88), trouble in talking to other people (1.60 ± 1.22), problems in swallowing solid food (1.57 ± 1.22) and bothering appearance (1.53 ± 1.04); while minimum scores were obtained for the items coughing (1.17 ± 0.38), hoarseness of voice (1.17 ± 0.53), painful throat (1.13 ± 0.43), trouble in having social contacts with friends (1.10 ± 0.40) and trouble having physical contacts with family or friends (1.10 ± 0.31). CONCLUSION. Obturator prosthesis is a highly positive and non-invasive approach to improve the quality of life of patients with maxillectomy defects.

Synergistic effect of polypyrrole/BST/RGO/Fe3O4 composite for enhanced microwave absorption and EMI shielding in X-Band

Pradeep Sambyal,S.K. Dhawan,Preeti Gairola,Sampat Singh Chauhan,S.P. Gairola 한국물리학회 2018 Current Applied Physics Vol.18 No.5

Present study focus on the designing of high performance microwave absorbing material against electromagnetic pollution. Herein we synthesize conducting polymer based composite encapsulated with Barium strontium titanate (BST), reduced graphene oxide (RGO), and Fe3O4 nanoparticles via chemical oxidative polymerization of pyrrole. The synthesized composite materials were thoroughly characterized using SEM, FTIR, XRD, TGA, and VSM techniques. The presence of filler materials in conducting polymer matrix leads to absorption dominated shielding effectiveness value of 48 dB in the frequency range of 8.2–12.4 GHz (X-band). Moreover, presence of dielectric and magnetic fillers increases the thermal and chemical stability of the composite material. The obtained shielding effectiveness value is above the recommended limit (30–40 dB) required for the commercial applications, therefore these composite material could be used as effective shield against EM pollution.