• 제목/요약/키워드: JISHA

검색결과 9건 처리시간 0.017초

Electrochemical characterization of supercapacitors based on carbons derived from Sorona activated by ZnCl2

  • ;;김애란;남기석;유동진
    • 에너지공학
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    • 제21권3호
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    • pp.309-314
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    • 2012
  • Carbons derived by the pyrolysis of Sorona activated by $ZnCl_2$ in the ratio of 1:20 and non-porogen Sorona carbons are used as the electrode materials in asymmetric electrochemical supercapacitors and electrochemical behavior is investigated. Scanning electron microscopy (SEM) reveals the porogen free carbons show a flake-like structure and the $ZnCl_2$-treated Sorona carbons have a loose, disjoint structure without any particular shape. Cyclic voltammetric (CV) studies show specific prolate rectangular shape and gives good capacitive properties.

Rho-dependent Transcription Termination: More Questions than Answers

  • Banerjee Sharmistha;Chalissery Jisha;Bandey Irfan;Sen Ranjan
    • Journal of Microbiology
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    • 제44권1호
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    • pp.11-22
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    • 2006
  • Escherichia coli protein Rho is required for the factor-dependent transcription termination by an RNA polymerase and is essential for the viability of the cell. It is a homohexameric protein that recognizes and binds preferably to C-rich sites in the transcribed RNA. Once bound to RNA, it utilizes RNA-dependent ATPase activity and subsequently ATPase-dependent helicase activity to unwind RNA-DNA hybrids and release RNA from a transcribing elongation complex. Studies over the past few decades have highlighted Rho as a molecule and have revealed much of its mechanistic properties. The recently solved crystal structure could explain many of its physiological functions in terms of its structure. Despite all these efforts, many of the fundamental questions pertaining to Rho recognition sites, differential ATPase activity in response to different RNAs, translocation of Rho along the nascent transcript, interactions with elongation complex and finally unwinding and release of RNA remain obscure. In the present review we have attempted to summarize 'the knowns' and 'the unknowns' of the Rho protein revealed by the recent developments in this field. An attempt has also been made to understand the physiology of Rho in the light of its phylogeny.

Lithium Insertion Behavior of Nanoscopic Co3O4 Prepared with Avian Egg Membrane as a Template

  • Christy, Maria;Jisha, M.R;Kim, Ae-Rhan;Nahm, Kee-Suk;Yoo, Dong-Jin;Suh, E.K.;Kumari, T. Sri Devi;Kumar, T. Prem;Stephan, A. Manuel
    • Bulletin of the Korean Chemical Society
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    • 제32권4호
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    • pp.1204-1208
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    • 2011
  • Nanoscopic $Co_3O_4$ particles were prepared using avian egg membrane as a template at $800^{\circ}C$. The prepared materials were subjected to XRD, SEM, TEM and Raman spectroscopic studies. Cyclic voltammetry study shows a single step oxidation and reduction process. Electrochemical lithium insertion behavior of the materials was examined in coin cells of the 2032 configuration. The material showed a discharge capacity 600mAh/g even after 20 cycles.

건설현장 추락재해 방지를 위한 해외 선진국간의 법령비교연구 (A Comparative Study on Laws and Policies of Advanced Countries to Prevent Fall Accident)

  • 오준석;이주형;전상섭;손기영
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 추계 학술논문 발표대회
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    • pp.199-200
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    • 2019
  • Although accidents in the domestic construction industry have been decreased gradually, deaths in the construction sites have been occupied 49.9 percent of the total industry and deaths from fall accident have been accounted for 59.7 percent of the construction industry. In order to prevent fall accident, Occupation Safety and Health Act(OSHA) was enacted for setting management standards and detailed regulations was designed by the Ministry of Employment and Labor. Although government has been pushed for companies and workers to comply the regulations, currently, many domestic construction sites have been violated. On the other hand, in safety-advanced countries such as the United States, Japan, and the EU, industrial accidents have been decreased due to continual application of adapted safety policies according to characteristic in each country. Therefore, it is necessary to analyze laws and polices of advanced countries and apply them to domestic construction sites in order to reduce fall accidents. Therefore, the objective of this study is to compare domestic laws related fall accident with advanced countries laws. In the future, the results of this study will be utilized as a reference to reinforce Occupation Safety and Health Act(OSHA).

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Studies on Methanolic Extract of Lepidagathis keralensis as Green Corrosion Inhibitor for Mild Steel in 1M HCl

  • Leena, Palakkal;Zeinul Hukuman, N.H.;Biju, A.R.;Jisha, Mullapally
    • Journal of Electrochemical Science and Technology
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    • 제10권2호
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    • pp.231-243
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    • 2019
  • The methanolic extracts of the leaves and stem of the plant Lepidagathis keralensis were evaluated for anticorrosion behavior against mild steel in 1M HCl. Corrosion inhibition studies were done by gravimetric method, electrochemical impedance spectroscopy and potentiodynamic polarization methods. Surface morphology of mild steel in the presence and absence of inhibitors were studied using SEM analysis. UV-Vis studies were also done to evaluate the mechanism of inhibition. Both the extracts showed good inhibition efficiency which increased with increase in concentration of the inhibitor and decreased with increase in temperature. The mechanism of inhibition was explained by adsorption which obeyed Langmuir adsorption isotherm. Thermodynamic calculations revealed a combination of both physisorption and chemisorption of the inhibitor on the surface of mild steel. The extracts behaved as mixed type inhibitors as determined by polarization studies. Quantum chemical studies on Phenoxyethene, one of the major components in the leaf extract of the plant was also carried out to support the experimental results.

리튬이온이차전지 음극활물질로써 주석을 첨가한 열분해탄소의 합성과 특성평가 (Synthesis and Characterization of Tin-Pyrolyzed Carbon Composites as Anode Material for Lithium Ion Secondary Batteries)

  • 황윤주;박상호;김애란;;;서은경;남기석
    • 에너지공학
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    • 제19권1호
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    • pp.16-20
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    • 2010
  • 본 연구에서는 바이오매스로 커피원두를 이용하여 합성한 카본재료에 도전재로 주석을 이용하였다. 주석을 첨가하는 방법에 따라 단순 혼합, 화학적인 방법을 이용하여 혼합체를 만들어 시료를 합성하였다. 시료에 대한 XRD를 이용하여 주석과 탄소가 혼합된 구조를 가지고 있음을 확인하였고 SEM을 통한 합성된 시료구입자크기($12{\sim}85\;{\mu}m$)와 형태를 확인하였다. 충 방전 테스트를 실시하여 15사이클에서 카본블랙을 사용했을 때(105 mAh/g)보다 주석을 화학적으로 혼합을 시킨 시료의 경우(191 mAh/g)가 방전용량이 더 높게 나타나는 것을 볼 수 있었고, 주석을 단순 혼합을 실시한 경우에서는 카본블랙과 비슷한 용량(131 mAh/g)을 보였다.

Phenylbutazone의 란탄(III) 착물에 대한 합성, 스펙트럼 및 열적 연구 (Synthesis, Spectral and Thermal Studies of Lanthanide(III) Complexes of Phenylbutazone)

  • Anoop, M.R.;Binil, P.S.;Jisha, K.R.;Suma, S.;Sudarsanakumar, M.R.
    • 대한화학회지
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    • 제55권4호
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    • pp.612-619
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    • 2011
  • 1,2-diphenyl-4-butyl-3,5-pyrazolidinedione(phenylbutazone, PB)의 란탄(III) 착물을 합성하여 원소분석, 몰전기전도도 측정, IR, UV-Vis. 및 NMR 스펙트럼으로 특성을 조사하였다. 스펙트럼 데이터로부터 PB가 pyrazolidinedione 고리의 두 카르보닐 산소를 통해 이배위 및 일이온화 리간드로 배위됨을 규명하였다. 몰전기전도도 데이터로부터 이들 착물이 비전해질임을 규명하였다. 이들 착물의 열적 행동을 공기 중에서 TG 및 DTG로 연구한 결과, 탈수화, 열적 안전성 및 열분해에 관한 정보를 얻을 수 있었다. 최종 생성물은 해당 금속의 산화물로 밝혀졌다. 탈수화 및 분해 단계에 대한 열역학 및 반응속도 파라메터를 구하였다. 분해 단계에 대한 음의 엔트로피 값은 반응물보다 활성화 착물이 더 질서있는 구조를 갖는다는 것을 의미하며, 이때 반응은 정상보다 느렸다. 이러한 연구를 바탕으로 착물의 분자식이 $[Ln(PB)_3]{\cdot}5H_2O$(Ln=La 및 Ce) 그리고 $[Ln(PB)_3 (H_2O)_2]{\cdot}2H_2O$(Ln=Pr, Nd 및 Sm)임을 규명하였다.