• Title/Summary/Keyword: PH effect

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Research Productivity of Graduate Students in GPF program of Korea

  • Kim, Ki-Hyoung
    • Asian Journal of Innovation and Policy
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    • v.3 no.1
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    • pp.72-93
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    • 2014
  • This study analyzed the factors that influence the research productivity of 236 graduate students who are funded by the Global Ph.D. Fellowship Program of the National Research Foundation of Korea. Research productivity was measured by the number of SCI publications, and the explanatory factors are the demographic factor, the financial factor, the reputation of institutions and the supervisor factor. This study included 2 indices such as the reputation of institutions and the research productivity of supervisors to check the halo effect unlike other studies. Results are as follows: 1) no gender difference, 2) better performance by younger age group, 3) no difference even if the students are additionally funded by other research support programs, 4) no halo effect by the reputation of institution but rather better performance from low ranked universities, 5) and a positive halo effect by supervisors.

A Case of Aluminum Phosphide Poisoning (알루미늄 포스파이드 중독 1례)

  • Jung, Hyun-Min;Kim, Ji-Hye;Paik, Jin-Hui;Kim, Jun-Sig;Kim, Jung-Hun;Han, Seung-Baik
    • Journal of The Korean Society of Clinical Toxicology
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    • v.9 no.2
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    • pp.109-112
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    • 2011
  • Aluminum phosphide is commonly used as a rodenticidal agent in agricultural workplaces. However, reported cases of aluminum phosphide poisoning in Korea are rare. Upon contact with moisture in the air, aluminum phosphide releases highly toxic phosphine gas ($PH_3$). $PH_3$ is readily absorbed through lung epithelium and into the bloodstream. Phosphine may cause denaturing of oxyhemoglobin and enzymes important to respiration and metabolism, and also may effect cellular membranes. There are numerous complications associated with acute aluminum phosphide poisoning including gastrointestinal, respiratory, and cardiac toxicities. We report the case of a 46-year-old man who suffered from respiratory and cardiac toxicities after unintentional aluminum phosphide exposure. More intensive education for prevention is recommended.

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Effect of Electrolytes on Electrochemical Properties of Magnesium Electrodes

  • Ha, Se-Young;Ryu, Anna;Cho, Woosuk;Woo, Sang-Gil;Kim, Jae-Hun;Lee, Kyu Tae;Kim, Jeom-Soo;Choi, Nam-Soon
    • Journal of Electrochemical Science and Technology
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    • v.3 no.4
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    • pp.159-164
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    • 2012
  • Magnesium (Mg) deposition and dissolution behaviors of 0.2 M $MgBu_2-(AlCl_2Et)_2$, 0.5 M $Mg(ClO_4)_2$, and 0.4M $(PhMgCl)_2-AlCl_3$-based electrolytes with and without tris(pentafluorophenyl) borane (TPFPB) are investigated by ex situ scanning electron microscopy (SEM) and galvanostatic cycling of Mg/copper (Cu) cells. To ascertain the factors responsible for the anodic stability of the electrolytes, linear sweep voltammogrametry (LSV) experiments for various electrolytes and solvents are conducted. The effects of TPFPB as an additive on the anodic stability of 0.4M ($(PhMgCl)_2-AlCl_3$/THF electrolyte are also discussed.

The Effect of PH and Salinity on Egg Development of Urechis unicinctus (von Drasche) in Southern Korea. (한국산 개불, Urechis unicinctus (von Drasche)의 난 발생에 미치는 pH와 염분의 영향)

  • 최상덕;김호진;라성주;홍성윤;이원교;이우범
    • Journal of Aquaculture
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    • v.12 no.2
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    • pp.155-161
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    • 1999
  • In order to obtain the basic information for seeding production of Echiuroid worm, Urechis unicinctus, the influence of pH and salinity on egg development was investigated. Mature adult of U. unicinctus were collected at the Diving Cooperation of Yosu in Korea and reared during 5 weeks. We carried out the artificial insemination in the laboratory on Dec. 29, 1998, and reared the embryo under different pH and salinity. Treatments were carried out with different pH(4~10) and salinity($0~45\textperthousand$). Embryos in pH 4, salinity $0\textperthousand$, $10\textperthousand$, $40\textperthousand$ and $45\textperthousand$ tanks did not develope after fertilization and became deformed or dead, before swimming embryo. In these pH and salinity conditions, deformation rate of embryo was high at 8-cell stage and 16-cell stage. But embryos in pH 5~10, salinity $20~35\textperthousand$ tanks developed into swimming embryo stage. These result indicate that an echiuran inhabits in both intertidal and subtidal mudflates. After fertilization, sixteen-cell stage took 5.3~5.6 hours in pH 5~10 tanks, and 5.1~5.8 hours in $20~35\textperthousand$ tanks. And swimming embryo took 13.3~ 14.1 hours in all conditions. The desirable pH and salinity for egg development were 7~8 and $30\textperthousand$, respectively.

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Electrical Properties of Boron and Phosphorus Doped μc-Si:H Films using Inductively Coupled Plasma Chemical Vapor Deposition Method for Solar Cell Applications

  • Jeong, Chae-Hwan;Jeon, Min-Sung;Koichi, Kamisako
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.1
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    • pp.28-32
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    • 2008
  • Hydrogenated microcrystalline silicon(${\mu}c$-Si:H) films were prepared using inductively coupled plasma chemical vapor deposition(ICP-CVD) method, electrical and optical properties of these films were studied as a function of silane concentration. And then, effect of $PH_3\;and\;B_2H_6$ addition on their electrical properties was also investigated for solar cell application. Characterization of these films from X-ray diffraction revealed that the conductive film exists in microcrystalline phase embedded in an amorphous network. At $PH_3/SiH_4$ gas ratio of $0.9{\times}10^{-3}$, dark conductivity has a maximum value of ${\sim}18.5S/cm$ and optical bandgap also a maximum value of ${\sim}2.39eV$. Boron-doped ${\mu}c$-Si:H films, satisfied with p-layer of solar cell, could be obtained at ${\sim}10^{-2}\;of\;B_2H_6/SiH_4$.

The Deposition of Rhombohedral - Boron Phosphide at Low Temperature and its Analysis of Physical Properties (Rhombohedral - Boron Phosphide 의 저온 증착과 물성분석)

  • Hong, Kuen-Kee;Yun, Yo-Chul;Bok, Eun-Kyung;Kim, Chul-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.27-30
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    • 2002
  • Boron Phosphide films were deposited on the glass substrate at the low temperature, $550^{\circ}C$, $480^{\circ}C$, by the reaction of $B_{2}H_{6}$, with $PH_{3}$ using CVD. The reactant gas rates were 50 cc/min and 20 cc/min for $B_{2}H_{6}$, 50 cc/min and 40 cc/min for $PH_{3}$ and $1.5\ell$/min for $N_{2}$ carrier gas. The films were annealed for 1hour, 3hours in $N_{2}$ ambient at $550^{\circ}C$ and $400^{\circ}C$. The deposition rate was $1000{\AA}$/min and the refractive index of film was 2.6. From results of XRD measurement the films have the preferred orientation of (1 0 1). For as deposited the film, the data of VIS spectrophotometer show 75.49%, 76.71% for 1hr-annealed and 86.4% for 3hrs-annealed. From AFM datas the surface condition of obtained films are was shown $73{\AA}$, $88.9{\AA}$ and $220{\AA}$ for as-deposited, for 1hr-annealed and for 3hr annealed, respectively.

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A Case Study on the Improvements of Soft Ground Using PBD Method in Pusan New Port (부산신항 연약지반에 적용된 PBD공법의 지반개량 시공사례)

  • Son, Jin-Hyun;Kim, Ji-Yong;Byun, Ki-Jun;Lee, Byung-Gil;You, Seung-Kyong;Kim, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.4
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    • pp.1-10
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    • 2006
  • In This paper, the settlements of soft ground and the undrained shear strength were compared for verify the improvement effect of PBD method, completed in the Busan New Port phase 1-1 site. Through the describing of design cases with the PBD method, the effects of the improvement method with CPT data were evaluated comparing with measured results. We expect that the output from this research is useful in future for design and analysis when similar soft grounds are planned to be used.

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Separation of Nd/Sm with Karr Column : Effect of pH and asponification of PC-88A (Karr column을 이용한 Nd/Sm의 분리 : pH 및 PC-88A 비누화도가 분리도에 미치는 영향)

  • Eom, Hyoung-Choon;Lee, Jin-Young;Kim, Jun-Soo
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2005.05a
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    • pp.28-32
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    • 2005
  • 본 연구는 Karr column을 이용한 희토류원소의 분리에 대한 기초 연구로서, 수상의 초기 pH와 유기상 중 PC-88A의 비누화도에 따른 Nd, Sm의 분리특성을 파악하였다. 실험결과 pH $0.8{\sim}2.3$ 범위에서 PH가 높아짐에 따라 Nd, Sm의 추출율 및 분리계수가 증가하였으며, PC-88A 비누화도 40%인 조건에서 추출 후 수상의 초기 PH에 관계없이 평형 pH가 약 1.5 정도로 유지되는 것을 알 수 있었다. 그리고 PC-88A 비누화도가 증가함에 따라 Nd, Sm의 추출율이 크게 증가하였으며, 비누화도 40%인 조건에서 가장 높은 분리계수(${\beta}_{Sm,\;Nd}\;=\;10.8$)를 보여 주었다.

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Effect of Flexibility Variations on Ship Responses (강성변화의 선체응답에의 영향)

  • 권영섭
    • Journal of Ocean Engineering and Technology
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    • v.6 no.2
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    • pp.151-171
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    • 1992
  • 선체응답의 변화를 고찰, 계산 결과를 요약하였다. 이에 대한 계산은 유체 동력학적 해석을 이용하였으며 본 이론의 합리성을 아울러 지적하였다. 선체의 유연성을 증가시킴으로서 추격선두 굽힘 모멘트는 줄지만, 모멘컴 굽힘 모멘트는 일반적으로 증가함이 나타났다.

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