Numerical Study on Geometric Parameter effects of Power Generation Performances for Segmented Thermoelectric Generator

Mahesh Suresh Patil,서재형,이무연 대한설비공학회 2018 International Journal Of Air-Conditioning and Refr Vol.26 No.1

Thermoelectric generator (TEG) is a promising option in waste heat recovery with various advantages including nonmoving components, very low operating noise and overall high stability. However, low power generation efficiency of TEGs is still concerned for application in wider fields. The objective of the present study is to investigate the parameters affecting the performance and efficiency of segmented TEG. The physical parameters including length ratio, length-to-area ratio and thickness of conducting plate were considered. In addition, the effect of varying hot side temperature was analyzed. Performance of segmented TEG was compared based on the power generation and conversion efficiency. The results of the investigation showed that increasing Bi2Te3 length in the segmented TEG made up of Bi2Te3 and SiGe increased the maximum power generation and efficiency. As length-to-area ratio increased, the power generation decreased, however, efficiency increased slightly. In addition, as the hot side temperature increased from 150 ∘ ∘C to 650 ∘ ∘C, the power generation and efficiency both increased. Power generation and efficiency of segmented TEG increased when the conducting plate thickness was increased. The power generation and efficiency were 39.2% and 51.9% higher for TEG with asymmetrical element than TEG with symmetrical element showing that asymmetrical element would be better option for same thermoelectric element volume.

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.

Private Police in Emerging Markets: South Korea

Mahesh K,Nalla,Eui-Gab Hwang 아시아경찰학회 2003 아시아경찰학회 국제학술회의 Vol.2003 No.-

The Republic of Korea (South Korea) has made significant progress in the market sector in the past four decades. Relative to its neighbors in Asia, South Korea has increased its market base both in terms of production and consumption. Along with economic growth, South Korea has also experienced an increase in the employment of private security personnel. Despite large increases in the growth of the private policing industry in the last four decades in the emerging markets, we know very little about how the public perceives agents of private policing. In this paper we examine South Korean youth perceptions of private security officers. Responses were received from 172 college students. The findings suggest that respondents generally held positive attitudes toward security work and security officers.

A Straightforward Synthesis of K-7174, a GATA-Specific Inhibitor

Mahesh S. Majik,유진하,정낙신 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

K-7174, a GATA-specific inhibitor, is a putative anti-inflammatory agent that attenuates effects of inflammatory cytokines in certain cell types. An expeditious four-step synthesis of K-7174 is described in this paper. The route employs Wittig olefination and bis-alkylation of homopiperazine as the key reactions. The iodinecatalyzed isomerization of the Z-isomer results in complete conversion to the E-isomer is the highlight of our synthetic endeavors.

[국제학술회의 및 전시회 참가기]2003 IEEE AP Symposium: A Personal Experience

Mahesh P. Abegaonkar 한국전자파학회 2003 전자파기술 Vol.14 No.3

Sixteen New Records of Ascomycetes from Crop Field Soil in Korea

( Mahesh Adhikari ),( Sangwoo Kim ),( Hyun Seung Kim ),( Hyang Burm Lee ),( Youn Su Lee ) 한국균학회 2016 韓國菌學會誌 Vol.44 No.4

The present study reports 16 species of Ascomycota that were previously unknown in Korea, namely Acremonium cellulolyticus (KNU14-25), Acremonium zonatum (KNU14-15), Chaetomium madrasense (KNU14-9), Cladosporium silenes (KNU 14-18-1), Humicolopsis cephalosporioides (KNU15-3), Leptosphaerulina chartarum (KNU14-16), Paecilomyces marquandii (KNU14- 8), Paecilomyces tenuis (KNU14-18-2), Paraphaeosphaeria sporulosa (KNU15-2), Penicillium rubidurum (KNU14-12), Pochonia suchlasporia (KNU15-6), Sporothrix inflata (KNU15-8), Thielavia hyrcaniae (KNU15-1), Thielavia terricola (KNU14-23-1), Xylogone sphaerospora (KNU15-7), and Zopfiella longicaudata (KNU15-5). These fungal species were isolated from soil samples collected from various regions of Korea and identified based on their morphological characteristics and rDNA internal transcribed spacer sequence data. Full descriptions and illustrations for each species are provided.

Phialocephala lagerbergii: A New Record from Crop Field Soil in Korea

( Mahesh Adhikari ),( Sangwoo Kim ),( Dil Raj Yadav ),( Yong Hyun Um ),( Hyung Seung Kim ),( Hyang Burm Lee ),( Youn Su Lee ) 한국균학회 2016 韓國菌學會誌 Vol.44 No.3

A unrecorded hyphomycete species of Phialocephala was isolated for the first time during the investigation of fungal community in the soil samples collected from different regions of Korea. The fungal isolate was identified as Phialocephala lagerbergii, based on the morphological characteristics and phylogenetic analysis of the ribosomal DNA sequence. In addition, cultural and micro-morphological features were described in detail.

13th 2007 Symposium : Protests And Protest Policing In The U. S.: Police Organizational Culture And Responses

( Mahesh K. Nalla ),( Vincent J. Hoffman ) 한국경찰학회 2007 한국경찰학회보 Vol.9 No.1

이 논문에서는 대규모 시위의 성격과 미국에서의 특정한 사례를 들어 이러한 사건들에 대한 경찰 대응에 대하여 검증해보고자 한다 보다 구체적으로 이 논문에서는 도시 경찰력의 규모와 시위 사이의 관계, 시위의 변화하는 성격과 공공의 질서 유지, (public order maintenance)의 관계, 그리고 미국의 두 관할구역에서 이른바 `시위 대응 경찰활동(protest policing)`이라 여겨지는 것의 본질과 법집행 기관이 조직문화라는 맥락 속에서 대규모 집회와 시위를 다루는데 적용한 특수한 접근법들 사이의 관계에 대해 검증하고자 한다. In this paper, we examine the nature of mass demonstrations and police responses to these events with specific examples from the United States. More specifically, we examine the relationship between the police size of cities and protests, changing nature of protests and public order maintenance, and the nature of what is commonly referred to as `protest policing` in two jurisdictions in the U.S. and the specific approaches they have adopted to handle these mass protests and demonstrations within the context of the organizational culture of the law enforcement departments.

Fermentation Kinetics of Production of Ubiquinone-10 by Paracoccus dinitrificans NRRL B-3785: Effect of Type and Concentration of Carbon and Nitrogen Sources

Mahesh V. Bule,Rekha S. Singhal 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.3

Ubiquinone-10 (CoQ10), a vitamin-like lipophilic component of the membrane-bound electron transport system, has a wide range of therapeutic, neutraceutical, and cosmeceutical applications. The objective of this study was to optimize nutritional requirements for production of CoQ10by Paracoccus dinitrificans NRRL B-3785 fermentation. Effect of type and concentration of carbon and nitrogen source on fermentation kinetic parameters were analyzed using logistic and Luedeking-Piret equations. In submerged batch fermentation, yield of CoQ10 was 12.22 mg/L when 40 g/L glycerol was used and specific growth rate (0.056/h) as well as growth associated constant (α=0.680 mg/g)were higher as compared to other concentrations. Ammonium nitrate and proteose peptone at 5 (α=0.677 mg/g; β=0.0072 mg/g·h) and 20 g/L (α=0.806 mg/g; β=0.0074 mg/g·h), respectively, were optimal for CoQ10 production. CoQ10 formation observed to be both growth and nongrowth associated. In optimized medium CoQ10 formation increased considerably from 1.91 to 14.12 mg/L.

Dielectric Properties of Banana Fiber Filled Polypropylene Composites: Effect of Coupling Agent

Mahesh Doddashamachar,Raju Nama Vasudeva Setty,Maraluru Venkataravanappa Hemantha Reddy,Jobish Johns 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

The goal of this article is to examine the effect of MAPP (malic anhydride grafted polypropylene) used as acoupling agent on the dielectric properties of polypropylene filled banana fiber composites. Banana fiber reinforcedpolypropylene composites were prepared by using twin screw extruder and injection molding apparatus. The dielectricparameters of both coupled and uncoupled composites were calculated in the experiment with temperatures from 30 °C to150 °C in steps of 10 °C and frequencies in the 20 Hz to 10 MHz range. Composites prepared using a coupling agent andincreasing the content of the banana fiber was found to have a major change in dielectric properties. Compared to un-coupledcomposites, the dielectric constant (ε') has increased by up to 15-20 % in coupled composites. Various polarizationmechanisms can be related to boosting dielectric properties in coupled composites. Anomalous behavior in the transitionregion was shown by the dissipation factor in both composites. Low electrical conductivity has been demonstrated bycoupled composites and can therefore be used for many insulating applications. Using TGA study, degradation temperaturesof banana fiber, PP and composites were examined. Scanning electron microscopy morphological studies have shown thatMAPP integration helps to achieve proper adhesion between banana fiber and polypropylene.