• 전자공학회논문지A
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• 제32A권9호
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• pp.121-127
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• 1995

We have analyzed the double insulating layer consisting of anodic oxide and ZnS through TEM experiments. The use of double insulating layer for HgCdTe surface passivation is one of the promising passivation method which has been recently studied deeply and the double insulating layer is formed by the evaporation of ZnS on the top of anodic oxide layer grown in H$_{2}$O$_{2}$ electrolyte. The structure of anodic oxide layer on HgCdTe is amorphous but the structure of oxide layer after the evaporation of ZnS has been changed to micro-crystalline. The interface layer of 150.angs. thickness has been found between ZnS and anodic oxide layer and is estimated to be ZnO layer. The results of analysis on the chemical components of ZnS, the interface layer and anodic oxide layer have showed that Zn has diffused into the anodic oxide layer deeply while Hg has been significantly decreased from HgCdTe bulk to the top of oxide layer. The formation of ZnO interface layer and the change of structure of anodic oxide layer after the evaporation of ZnS are estimated to be defects or to induce the defects which might possibly affect the increase of the positive fixed charges shown in C-V measurements of HgCdTe MIS.

• 한국환경과학회지
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• 제22권6호
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• pp.705-715
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• 2013

The response of the freshwater microalga Chlorella vulgaris to mercuric ion ($Hg^{2+}$) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing $Hg^{2+}$ concentration. The maximum photochemical efficiency of photosystem II(Fv/Fm) changed remarkably with increasing $Hg^{2+}$ concentration and treatment time. In particular, above $200{\mu}M\;Hg^{2+}$, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by $Hg^{2+}$; the fluorescence emission decreased considerably in steps J, I, and P with an increase in $Hg^{2+}$ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ${\Phi}_{PO}$, ${\Psi}_O$ and ${\Phi}_{EO}$) decreased with increasing $Hg^{2+}$ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ${\Phi}_{PO}$, ${\Psi}_O$, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

• 한국방사선학회논문지
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• 제8권7호
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• pp.429-433
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• 2014

본 연구에서는 입자 침전법으로 제작된 HgO와 PbO 기반 영상 센서의 유방촬영 영역에서의 적용 가능성을 조사하였다. 이를 위하여, 다양한 두께에 따른 HgO와 PbO 필름의 물리적 특성과 x선에 대한 양자 효율을 측정하였으며, 몬테카를로 시뮬레이션 결과와 비교 평가하였다. 또한, 입자 침강법을 이용하여 인듐 주석 산화물로 코팅 된 투명 유리기판 위에 대면적 다결정 박막을 제작하였다. 본 연구에서는 단결정의 효율과 비슷한 양자 효율을 얻기 위하여 필름의 두께와 제작 조건을 변화시켜 최적화 하였다. 본 연구의 결과를 기반으로 차후 대면적 a-Si:H 패널에 적합한 대면적 필름의 제작 기술과 최적화 연구가 가능할 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3767-3770
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• 2013

Potassium methylselenite ($KSeO_2(OCH_3)$) was reduced to elemental selenium, Se(0), and then doped onto montmorillonite K 10 (MK10) clay to examine the interaction between elemental mercury (Hg(0)) vapor and Se(0) in an effort to understand the possible heterogeneous reaction of Hg(0) vapor and Se(0) solid. The clay was used as a cost-effective support material for uniform dispersion of Se(0). The Se(0)-doped MK10 showed an excellent reaction performance with Hg(0) under an inert nitrogen gas at 70 and $140^{\circ}C$ in our lab-scale fixed-bed system. However, the precursor, $KSeO_2(OCH_3)$-doped MK10 showed a negligible reaction performance with Hg(0), suggesting that the oxidation state of selenium plays a key role in the reaction of Hg(0) vapor and selenium compounds.

• Journal of Preventive Medicine and Public Health
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• 제25권1호
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• pp.13-25
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• 1992

This study was conducted to investigate the mechanism of protective effect by sodium selenite in methylmercuric chloride neurotoxicity, increasing intracellular $Ca^{2+}$concentration of the neuron. Methylmercuric chloride of 3mg/kg of body weight was administered simultaneously with sodium selenite of 5mg/kg and pretreatment of sodium selenite via intraperitoneal injection to rats. Also, effect of methylmercuric chloride($25{\mu}M,\;50{\mu}M,\;100{\mu}M$) and sodium selenite($200{\mu}M$) on free intrasynaptosomal $Ca^{2+}$ concentration were studied using the fluorescent $Ca^{2+}$ indicator fura -2 in vitro. After the treatment, at 6, 24, and 48 hours later, mercury in the cerebral cortex, liver and kidney tissues, succlnic dehydrogenase activities, adenosin-5'-triphosphate concentration, acetylcholinesterase activities, and intracellular $Ca^{2+}$ concentration in the cerebral cortex were determined in vivo. Cerebral synaptosomes of rats were incubated with methylmercuric chloride and sodium selenite in Hepes buffer for 10 minutes and free intrasynaptosomal $Ca^{2+}$ concentration were measured with fura-2 in vitro. The results were summarized as follows ; 1. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time significantly more increased in the cerebral cortex and decreased in the liver, kidney mercury concentrations compared to the administration of $CH_3HgCl$ only. 2. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ increased more succinic dehydrogenase and acetylcholinesterase activities compared to the administration of $CH_3HgCl$ only. Particularly pretreatment of $Na_2SeO_3$ significantly more compared to the administration of $CH_3HgCl$ only. The concentration of adenosine-5'-triphosphate in $Na_2SeO_3$ treatment groups revealed a favourable effect compared to the administration of $CH_3HgCl$ only. 3. Intracellular $Ca^{2+}$ concentration in administration of $CH_3HgCl$ only was increased significantly more than control group in all test hours but was increased significantly more at 48 hours only after treatment in combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time interval more decreased significantly intracellular $Ca^{2+}$ concentration compared to the administration of $CH_3HgCl$ only. 4. Free intrasynaptosomal $Ca^{2+}$ concentration in the combined administration of $CH_3HgCl$ and $Na_2SeO_3$ was decreased ($24%{\sim}40%$) significantly more than the administration of $CH_3HgCl$ only. From the above results, the specific dosage of $Na_2SeO_3$ decreased increment of intracellular $Ca^{2+}$ concentration induced by administration of $CH_3HgCl$. These findings suggest the protective mechanism of $Na_2SeO_3$ on the neurotoxicity of $CH_3HgCl$.

• 한국재료학회지
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• 제26권11호
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• pp.604-610
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• 2016

We report on the fabrication and characterization of a novel $Cu_2O/CuO$ heterojunction structure with CuO nanorods embedded in $Cu_2O$ thin film as an efficient photocathode for photoelectrochemical (PEC) solar water splitting. A CuO nanorod array was first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method; then, a $Cu_2O$ thin film was electrodeposited onto the CuO nanorod array to form an oxide semiconductor heterostructure. The crystalline phases and morphologies of the heterojunction materials were examined using X-ray diffraction and scanning electron microscopy, as well as Raman scattering. The PEC properties of the fabricated $Cu_2O/CuO$ heterojunction photocathode were evaluated by photocurrent conversion efficiency measurements under white light illumination. From the observed PEC current density versus voltage (J-V) behavior, the $Cu_2O/CuO$ photocathode was found to exhibit negligible dark current and high photocurrent density, e.g. $-1.05mA/cm^2$ at -0.6 V vs. $Hg/HgCl_2$ in $1mM\;Na_2SO_4$ electrolyte, revealing the effective operation of the oxide heterostructure. The photocurrent conversion efficiency of the $Cu_2O/CuO$ photocathode was estimated to be 1.27% at -0.6 V vs. $Hg/HgCl_2$. Moreover, the PEC current density versus time (J-T) profile measured at -0.5 V vs. $Hg/HgCl_2$ on the $Cu_2O/CuO$ photocathode indicated a 3-fold increase in the photocurrent density compared to that of a simple $Cu_2O$ thin film photocathode. The improved PEC performance was attributed to a certain synergistic effect of the bilayer heterostructure on the light absorption and electron-hole recombination processes.

• 한국수산과학회지
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• 제38권2호
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• pp.106-111
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• 2005

We studied the cardio-respiratory properties in the Japanese amberjack (Seriola quinqueradiata) during acute hypoxia exposure. Fish were exposed to three levels of hypoxia (80, 60 or 50 mmHg) for 60 min at $25^{\circ}C$. Cardiovascular parameters (cardiac output; Q, heart rate; HR, stroke volume; SV, blood pressure; $P_{DA}$) changed little from pre-exposure values during both 80 and 60 mmHg of hypoxia. During 50 mmHg of hypoxia, the fish showed a bradycardia which significantly affected Q, whereas no change in SV. $P_{DA}$ increased transiently. Arterial oxygen partial pressure ($PaO_2$) immediately reduced along with a decrease of the water oxygen partial pressure ($P_WO_2$). Arterial $O_2$ content ($CaO_2$) decreased significantly only after 60 min of 50 mmHg of hypoxia. Arterial pH (pHa) and hematocrit value (Hct) did not change significantly. Comparing the effects of different levels of hypoxia, oxygen delivery to the tissues ($Q\;{\times}\;CaO_2$) should be maintained a constant over a broad range of $P_WO_2$, however, severely depressed below 50 mmHg of hypoxia.

• 분석과학
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• 제15권5호
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• pp.439-444
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• 2002

이 연구는 E-O-V ICP-AES를 이용하여 As, Se, Ge에 대한 분석적 특성을 PN과 USN, 그리고 HG를 이용하여 비교 조사하였다. 특히 세 가지 원소들의 수소화물 형성을 위한 최적의 조건을 찾기 위하여 $NaBH_4$와 HCl의 농도 변화에 대한 신호세기의 영향을 면밀히 조사하여 보았다. 수소화물 발생화 장치를 이용하였을 때가 PN과 USN 이용시 보다 세 가지 원소 모두 훨씬 좋은 감도를 얻을 수 있었고, 그 검출한계는 PN 보다는 약 100배, USN 보다는 약 10배 향상시킬 수 있었다.

• Journal of Yeungnam Medical Science
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• 제10권2호
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• pp.345-359
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• 1993

대구시내 1개 국민학교 4학년 284명(남아 144명, 여아 140명)을 대상으로, 1992년 5월에 일반적인 특성을 조사하였고, 체격, 체지방 및 혈압을 측정하였으며, 혈액의 생화학적 검사를 실시하여 혈압과 관련된 요인을 분석하였다. 대상자의 평균 수축기 혈압은 103.5mmHg였으며, 남아가 104.1mmHg, 여아가 102.9mmHg로 남아가 약간 높게 나타났으며, 평균 확장기 혈압은 67.1mmHg이고, 남아가 66.6mmHg, 여아가 67.5mmHg로 여아가 약간 높았다. 수축기 및 확장기 혈압을 종속변수로 총콜레스테롤, 고밀도 지단백 콜레스테롤, 저밀도 지단백 콜레스테롤, 중성지방, 총단백질, 요산, 혈당, R$\ddot{o}$hrer지수, 체지방 비율, 체지방 무게 및 제지방체중을 독립변수로 하여 상관관계와 중회귀분석을 실시하였다. 수축기 및 확장기혈압과 독립변수들과의 상관관계를 성별에 따라 분석한 결과 남아의 수축기혈압은 신장, 체중, R$\ddot{o}$hrer지수, 제지방 체중, 체지방 무게 및 중성지방과 유의한 상관관계가 있었으며(p<0.01). 여아의 수축기혈압은 신장, 체중, 제지방체중 및 요산과 유의한 상관관계가 있었다(p<0.01). 남아의 확장기혈압은 체중, R$\ddot{o}$hrer지수 및 제지방체중과 유의한 상관관계가 있었으며(p<0.01). 여아의 확장기혈압은 체중, 제지방체중(p<0.01), 신장, 체지방무게 및 총단백질(p<0.05)과 유의한 상관관계가 있었다. 수축기 혈압을 종속변수로 한 중회귀분석에서 남아는 R$\ddot{o}$hrer지수와 sodium이 유의한 변수였고, 여아는 요산, R$\ddot{o}$hrer지수 및 체지방 비율이 유의한 변수였다. 확장기 혈압에서 남아는 R$\ddot{o}$hrer지수가 유의한 변수였고, 여아는 총단백질이 유의한 변수였다. 이상의 결과로 보아 소아의 혈압에 영향을 미치는 인자로는 R$\ddot{o}$hrer지수, sodium, 요산, 총단백질 및 체지방 비율 이었고, 그 중 R$\ddot{o}$hrer지수가 가장 중요한 요인으로 인정되었다. 따라서 고혈압 발생을 예방하기 위해서는 비만, 식이 및 이와 관련된 생활양식의 개선과 이에 대한 보건교육이 요망된다.

• 한국재료학회지
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• 제28권4호
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• pp.214-220
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• 2018

We report on the fabrication and photoelectrochemical(PEC) properties of a $Cu_2O$ thin film/ZnO nanorod array oxide p-n heterojunction structure with ZnO nanorods embedded in $Cu_2O$ thin film as an efficient photoelectrode for solar-driven water splitting. A vertically oriented n-type ZnO nanorod array was first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method and then a p-type $Cu_2O$ thin film was directly electrodeposited onto the vertically oriented ZnO nanorods array to form an oxide semiconductor heterostructure. The crystalline phases and morphologies of the heterojunction materials were characterized using X-ray diffraction and scanning electron microscopy as well as Raman scattering. The PEC properties of the fabricated $Cu_2O/ZnO$ p-n heterojunction photoelectrode were evaluated by photocurrent conversion efficiency measurements under white light illumination. From the observed PEC current density versus voltage (J-V) behavior, the $Cu_2O/ZnO$ photoelectrode was found to exhibit a negligible dark current and high photocurrent density, e.g., $0.77mA/cm^2$ at 0.5 V vs $Hg/HgCl_2$ in a $1mM\;Na_2SO_4$ electrolyte, revealing an effective operation of the oxide heterostructure. In particular, a significant PEC performance was observed even at an applied bias of 0 V vs $Hg/HgCl_2$, which made the device self-powered. The observed PEC performance was attributed to some synergistic effect of the p-n bilayer heterostructure on the formation of a built-in potential, including the light absorption and separation processes of photoinduced charge carriers.