Tin Layer as a Solid Lubricant for Cold Tube Drawing Processes

Mahesh Patil,Varinder Singh,Amit Kumar Gupta,Srinivasa Prakash Regalla,Tufan Chandra Bera,Bade Simhachalam,Krishna Srinivas 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

This paper reports an investigation into the deployment of a thin layer of tin as a lubricant on low carbon steel tube for tube drawing process. The layer was deposited using electro-deposition technique using a green technology of citric acid based electrolyte bath. Coating layer is characterized using SEM, EDS and 3D digital microscopy technique before and after drawing processes. Experimental trials of drawing operation were conducted and promising results were observed with respect to drawing load and surface quality. The observed drawing load is comparable to that with the conventional lubrication system thereby proving the effectiveness of the new proposed lubrication system. The use of proposed lubrication resulted in greatly improved finish as well as better corrosion resistance yielding an additional promise for better value in service life, better market potential as well as a gain on environment front as the proposed method has the potential to eliminate some after operations after drawing as the drawn tube is ready to use after drawing operation.

Antioxidant activity of Grewia tiliaefolia bark

Badami, Shrishailappa,Gupta, Mahesh Kumar,M., Ramanathan,B., Suresh Kyung Hee Oriental Medicine Research Center 2005 Oriental pharmacy and experimental medicine Vol.5 No.1

Grewia tiliaefolia is commonly used in India and several other countries for its ethnomedical properties. The antioxidant effect of 50% methanol extract of Grewia tiliaefolia bark was investigated by in-vitro and in-vivo methods. The extract exhibited $IC_{50}$ value of $51.40{\pm}3.98\;{\mu}g/ml$ in DPPH assay. In the in vivo experiments, the treatment was given at 250 and 500 mg/kg body weight doses orally for seven days and catalase, SOD, TBA-RS and ascorbic acid levels were estimated. Both the doses caused a significant increase in the levels of catalase in the liver and kidney, and SOD in the liver, kidney and blood serum. A significant decrease in the level of TBARS was also observed. These results suggest potent antioxidant nature of the extract.

Charge carrier dynamics in PffBT4T-2OD: PCBM organic solar cells

Sharma, Ramakant,Gupta, Vinay,Lee, Hyunwoo,Borse, Kunal,Datt, Ram,Sharma, Chhavi,Kumar, Mahesh,Yoo, Seunghyup,Gupta, Dipti Elsevier 2018 ORGANIC ELECTRONICS Vol.62 No.-

<P><B>Abstract</B></P> <P>We investigate the charge carrier dynamics of inverted organic solar cells (OSCs) based on PffBT4T-2OD: PCBM and PTB7: PCBM – the two leading systems among the OSCs based on polymer-fullerene bulk-heterojunction – to elucidate the origin of their performance difference. Transient absorption spectroscopy (TAS) and photo-electrochemical impedance spectroscopy (photo-EIS) were employed to unravel the photo-physics that govern the cell operation of these two highly efficient bulk heterojunction OSCs. While photo-EIS indicates that the two systems under study exhibit similar behavior in terms of recombination, TAS results reveal that PffBT4T-2OD: PCBM systems not only have higher charge generation rate but also more efficient charge transfer than PTB7: PCBM systems, leading to the power conversion efficiency of PffBT4T-2OD: PCBM-based OSCs (9.16%) that is higher than that of PTB7: PCBM-based OSCs (6.44%).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Charge carrier dynamics of PffBT4T-2OD: PCBM and PTB7: PCBM OSCs have been compared. </LI> <LI> TAS and Photo-EIS measurements along with optical simulation were carried out. </LI> <LI> Higher PCE for PffBT4T-2OD: PCBM OSCs is due to better absorption and carrier collection efficiency. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Modulation of Inula racemosa Hook Extract on Cardioprotection by Ischemic Preconditioning in Hyperlipidaemic Rats

Tiwari Arun Kumar,Gupta Pushpraj S,Prasad Mahesh,Malairajan Paraman 대한약침학회 2022 Journal of pharmacopuncture Vol.25 No.4

Objectives: Hyperlipidemia (HL) is a major cause of ischemic heart diseases. The size-limiting effect of ischemic preconditioning (IPC), a cardioprotective phenomenon, is reduced in HL, possibly because of the opening of the mitochondrial permeability transition pore (MPTP). The objective of this study is to see what effect pretreatment with Inula racemosa Hook root extract (IrA) had on IPC-mediated cardioprotection on HL Wistar rat hearts. An isolated rat heart was mounted on the Langendorff heart array, and then ischemia reperfusion (I/R) and IPC cycles were performed. Atractyloside (Atr) is an MPTP opener. Methods: The animals were divided into ten groups, each consisting of six rats (n = 6), to investigate the modulation of I. racemosa Hook extract on cardioprotection by IPC in HL hearts: Sham control, I/R Control, IPC control, I/R + HL, I/R + IrA + HL, IPC + HL, IPC + NS + HL, IPC + IrA+ HL, IPC + Atr + oxidative stress, mitochondrial function, integrity, and hemodynamic parameters are evaluated for each group. Results: The present experimental data show that pretreatment with IrA reduced the LDH, CK-MB, size of myocardial infarction, content of cardiac collagen, and ventricular fibrillation in all groups of HL rat hearts. This pretreatment also reduced the oxidative stress and mitochondrial dysfunction. Inhibition of MPTP opening by Atr diminished the effect of IrA on IPC-mediated cardioprotection in HL rats. Conclusion: The study findings indicate that pretreatment with IrA e restores IPC-mediated cardioprotection in HL rats by inhibiting the MPTP opening.

The Distribution of the Products of Powers of Generalized Dirichlet Components

Mridula Garg,Vimal Katta,Mahesh Kumar Gupta 경북대학교 자연과학대학 수학과 2002 Kyungpook mathematical journal Vol.42 No.2

In the present paper we establish a generalized Dirichlet distribution and obtain the distirbution of the products of powers of components of the generalized Dirichlet variable. Our findings unify and extend the results given earlier by Rogers and young[3], Rogers[2],Johnson and Kotz[7] and several others.

Evaluation of Somaclonal Variation for Genetic Improvement of Patchouli ($Pogostemon$ $patchouli$), an Exclusively Vegetatively Propagated Aromatic Plant

Ravindra, Nagawara Seshagirirao,Ramesh, Srinivas Iyer,Gupta, Mahesh Kumar,Jhang, Tripta,Shukla, Ashutosh Kumar,Darokar, Mahendra Pandurang,Kulkarni, Raghavendra Narayanrao 한국작물학회 2012 Journal of crop science and biotechnology Vol.15 No.1

Patchouli ($Pogostemon$ $patchouli$) is an important, exclusively vegetatively propagated aromatic plant, whose essential oil is widely used in perfumery and cosmetic products. Forty $SC_1$ generation (first generation following $in$ $vitro$ phase) somaclones selected randomly from about 400 somaclones developed from the variety Johore, were multiplied through stem cuttings and evaluated in $SC_2$ and $SC_3$ generations to study the extent of somaclonal variation generated for plant height, herb yield, essential oil content, essential oil yield, and seven constituents of the essential oil. Significant or highly significant somaclonal variation was observed for plant height, herb yield, essential oil content, essential oil yield, and contents of patchouli alcohol, ${\alpha}$-guaiene, ${\alpha}$,${\delta}$-patchoulene, and ${\alpha}$-bulnesene in the essential oil. The number of somaclones significantly superior to the parental variety for plant height, herb yield, essential oil content, and patchouli alcohol content in the essential oil ranged from 8 - 16 and the maximum superiority over the parental variety for these traits ranged from 21 - 79%. Broad-sense heritability estimates of plant height, herb yield, and essential oil content were 0.60 - 0.70 while those of essential oil yield and patchouli alcohol content were 0.44 and 0.47, respectively. Heritability estimates of other studied essential oil constituents were generally low (0.12 - 0.38). A high positive correlation was observed between essential oil yield and herb yield suggesting that selection for herb yield would be effective in improving essential oil yield. Patchouli alcohol content in the essential oil was negatively correlated with all the studied traits. Somaclonal variation, heritabilities of traits, and inter-trait correlations are reported for the first time in patchouli.

Evaluation of Somaclonal Variation for Genetic Improvement of Patchouli (Pogostemon patchouli), an Exclusively Vegetatively Propagated Aromatic Plant

Nagawara Seshagirirao Ravindra,Srinivas Iyer Ramesh,Mahesh Kumar Gupta,Tripta Jhang,Ashutosh Kumar Shukla,Mahendra Pandurang Darokar,Raghavendra Narayanrao Kulkarni 한국작물학회 2012 Journal of crop science and biotechnology Vol.15 No.1

Patchouli (Pogostemon patchouli) is an important, exclusively vegetatively propagated aromatic plant, whose essential oil is wide-ly used in perfumery and cosmetic products. Forty SC 1 generation (first generation following in vitro phase) somaclones selected ran-domly from about 400 somaclones developed from the variety Johore, were multiplied through stem cuttings and evaluated in SC 2and SC 3 generations to study the extent of somaclonal variation generated for plant height, herb yield, essential oil content, essential oil yield, and seven constituents of the essential oil. Significant or highly significant somaclonal variation was observed for plant height, herb yield, essential oil content, essential oil yield, and contents of patchouli alcohol, α-guaiene, α,δ-patchoulene, and α-bul-nesene in the essential oil. The number of somaclones significantly superior to the parental variety for plant height, herb yield, essen-tial oil content, and patchouli alcohol content in the essential oil ranged from 8 - 16 and the maximum superiority over the parental variety for these traits ranged from 21 - 79%. Broad-sense heritability estimates of plant height, herb yield, and essential oil content were 0.60 - 0.70 while those of essential oil yield and patchouli alcohol content were 0.44 and 0.47, respectively. Heritability esti-mates of other studied essential oil constituents were generally low (0.12 - 0.38). A high positive correlation was observed between essential oil yield and herb yield suggesting that selection for herb yield would be effective in improving essential oil yield. Patchouli alcohol content in the essential oil was negatively correlated with all the studied traits. Somaclonal variation, heritabilities of traits,and inter-trait correlations are reported for the first time in patchouli.