• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.668-668
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• 2013

CIGS 박막태양전지는 다른 박막태양전지에 비해 높은 에너지 변환효율을 보이고 있으며, 광범위한 기술 응용분야를 가지고 있다. CIGS를 광흡수층으로 하는 태양전지의 구조는 5개의 단위박막(배면전극, 광흡수층, 버퍼층, 앞면 투명전극, 반사방지막)을 순차적으로 형성시켜 만든다. 단위박막별로 다양한 종류의 재료와 조성, 또한 제조방법에서는 갖가지 물리적, 화학적 박막 제조방법이 사용된다. 현재 광흡수층인 CIGS층의 경우 동시증발법과 스퍼터링법이 높은 효율을 보이고 있다. 본 연구에서는 CIGS층을 3-stage process를 적용한 동시증발법을 사용하였고, Fluxmeter와 기판후면 온도 모니터링을 이용하여 제조하였으며, 버퍼층은 moving 스퍼터링 법으로 ZnS를 증착하였고, 투명전극층은 PLD (Pulsed Laser Deposition)를 이용하여 제조하였다. 가장 높은 광변환효율을 보인 Al/ZnO/CdS/Mo/SLG박막시료는 유효면적 0.45 $cm^2$에 광변환효율 15.71%, Jsc: 33.64 mA/$cm^2$, Voc: 0.64 V, FF: 73.18%를 얻을 수 있었으며, CdS를 ZnS로 대체한 Al/ZnO/ZnS/Mo/SLG 박막시료는 유효면적 0.45 $cm^2$에 광변환효율 12.13%, Jsc: 33.22 mA/$cm^2$, Voc: 0.60 V, FF: 62.85%를 얻을 수 있었다.

• Journal of Environmental Science International
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• v.14 no.7
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• pp.691-697
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• 2005

Waste sludge may be used to recovery wastewater contaminated with heavy metals. The waste sludge is an inexpensive readily available source of biomass for biosorption with metal-bearing wastewater. The biosorption of heavy metals such as Pb(II), Cu(II), Cr(II), and Cd(II) onto waste sludge was investigated in batch ex­periments and waste sludge loaded heavy metals was separated by dissolved air flotation. The biosorption equi­bria of heavy metals could be described by Langmuir and Freundich isotherms. The adsorption capacity for waste sludge was in the sequence of Pb(II)>Cr(II)>Cu(II)>Cd(II). The system attained equilibrium about 20 min. The Langmuir and Freundlich adsorption model effectively described the biosorption equilibrium of Cu(II) and Cr(II) ions on waste sludge. Maximum adsorption capacity of Cu(II) and Cr(II) were 196.08 and 158.73 mg/g, respectively. Solid-liquid separation efficiencies were kept above $95\%$ on waste sludge loaded heavy metals, and were decreased with pH increasing.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2267-2270
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• 2013

A series of blue fluorescent emitters based on triphenylene derivatives were synthesized via the Diels-Alder reaction in moderate yields. The electronic absorption and emission characteristics of the new functional materials were affected by the nature of the substituent on the triphenylene nucleus. Multilayered OLEDs were fabricated with a device structure of: ITO/NPB (50 nm)/EML (30 nm)/Bphen (30 nm)/Liq (2.0 nm)/Al (100 nm). All devices showed efficient blue emissions. Among those, a device using 1 gives the best performances with a high brightness (978 cd $m^{-2}$ at 8.0 V) and high efficiencies (a luminous efficiency of 0.80 cd/A, a power efficiency of 0.34 lm/W and an external quantum efficiency of 0.73% at 20 $mA/cm^2$). The peak wavelength of the electroluminescence was 455 nm with CIEx,y coordinates of (0.17, 0.14) at 8.0 V.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.1
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• pp.37-42
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• 2013

Double pipe system in which PB pipe is inserted in CD pipe buried in the concrete slab is widely used for cold and hot water supplies in apartment housings. The system, however becomes complicated and the overlaying pipes in the concrete slab weaken the compressive strength of the slab. Also, insufficient insulation increases energy loss. In this work, the problems of the double pipe system are studied and plans A, B, and C are suggested for improvement. In terms of compressive strength of the concrete slab, plan A(total pipe length 73 m) was the weakest and plan B(2 m) was the strongest. Energy loss of plan A was the largest with 558.9 W and plan B was the lowest with 220.7 W. However, considering the combined effect of strength and heat loss, plan C becomes the best choice, which retains the advantage of the double pipe system.

• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.16-29
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• 2019

Background: Sex influences is important to understand behavioral manifestations in a large number of neuropsychiatric disorders. We found electrophysiological differences specifically related to the influence of sex on psychopathic traits. Methods: The resting electroencephalography (EEG) activity and low-resolution brain electromagnetic tomography (LORETA) for the EEG spectral bands were evaluated in 38 teenagers with conduct disorder (CD). The 25 male and 13 female subjects had psychopathic traits as diagnosed using the Antisocial Process Screening Device. All of the included adolescents were assessed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria. The visually inspected EEG characteristics and the use of frequency-domain quantitative analysis techniques are described. Results: Quantitative EEG (QEEG) analysis showed that the slow-wave activities in the right frontal and left central regions were higher and the alpha-band powers in the left central and bitemporal regions were lower in the male than the female psychopathic traits group. The current source density showed increases in paralimbic areas at 2.73 Hz and decreases in the frontoparietal area at 9.37 Hz in male psychopathics relative to female psychopathics. Conclusions: These findings indicate that QEEG analysis and techniques of source localization can reveal sex differences in brain electrical activity between teenagers with CD and psychopathic traits that are not obvious in visual inspections.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.227-233
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• 1994

To get a fundamental data fur management of security, validity, Quality, of Paeonia suffruficosa roots as medicinal herb, the content of paeonol, ash, and inorganic components in Moutan Radicis Cortex produced in 8 regions of Korea was investigated from Oct. 1990 to May 1991. The results are summarized as follows: The average content of paeonol was 0.65%. The content of ash was 3.53%, acid-insoluble ash 0.77% in average, both of them were suitable to the standard value as Korean medical herbs. Total nitrogen content was 1.03%, phosphate 0.55%, potassium 0.82%, and calcium 1.50% in average. The content of MgO was 0.21ppm, 325.83ppm in Fe, 1.82ppm in Cr, 3.73ppm in Cu, 18.93ppm in Zn and Mn 21.27ppm, respectively. Especially Hg was not detected in the products of all regions. The average content of Cd was 0.25ppm, Pb 3.09ppm in Moutan Radicis Cortex, so they were estimated suitably to use as medicinal herb.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.179-187
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• 1996

This study was conducted to investigate the possibility of composting of household garbage. The composter with the double layer walls was operated for 60 days in each season. The following results were obtained at the end of the experiment, if the time was not specified. 1) The maximum temperature was $31^{\circ}C$ in spring, $36^{\circ}C$ in summer and $50^{\circ}C$ in winter. 2) The mass was reduced to an average of 58.5%. 3) pH values of the compost were 8.21 in spring, 8.29 in summer and 7.94 in winter. 4) The ash contents were 55.8% in spring, 57% in summer and 73.8% in winter. 5) The nitrogen contents were in the range of $0.2{\sim}5.8%$. Its values were the highest in winter and the lowest in summer. 6) Inorganic contents of the compost were in the range of : $P_2O_5$ ; $1.5{\sim}4.41%$, $K_2O$ ; $0.02{\sim}1.31%$, CaO $0.13{\sim}1.68%$ and MgO $0.05{\sim}1.22%$. 7) Heavy metal contents of the compost were in the range of : Zn ; $13{\sim}89mg/kg$, Cu ; $4{\sim}62mg/kg$, Cd ; $1{\sim}21mg/kg$, Pb ; $N.D.{\sim}97mg/kg$, Cr ; $N.D.{\sim}37$ and Hg ; $N.D.{\sim}1.38mg/kg$.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.812-817
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• 2003

This study was conducted to estimate the contents of heavy metals in tea products (n=200) and to provide a scientific basis for standardization of heavy metals in the Korea Food Code. The contents of mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), copper (Cu), manganese (Mn), zinc (Zn), and aluminium (Al) were determined using a mercury analyzer, an AAS (atomic absorption spectrophotometer), and ICP (inductively coupled plasma spectrometer). The values of heavy metals in tea products were [minimum-maximum (mean), mg/kg] Hg: $N.D.{\sim}0.02$ (0.003), Pb: $N.D.{\sim}0.35$ (0.03), Cd: $N.D.{\sim}0.07$ (0.007), As: $N.D.{\sim}0.19$ (0.006), Cu: $N.D.{\sim}24.41$ (2.73), Mn: $N.D.{\sim}767.88$ (66.91), Zn: $N.D.{\sim}18.60$ (4.54), Al: $N.D.{\sim}1304.30$ (85.53). These results showed that metal contents in tea products in our markets were similar to those reported in other countries. The average weekly intakes of lead, cadmium, and mercury from tea products were $0.1{\sim}0.2%$ of PTWI (Provisional Tolerable Weekly Intake) that the JECFA (Joint FAO/WHO Expert Committee on Food Additives) has set to evaluate their safeties.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.623-631
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• 1998

Pyrite contained in wasted ore dumps induces a strong acid environment when it contacts oxygenated rainfall. Present research was designed to evaluate the pollution of an area that is supposedly contaminated by pyrite of ore wasted dumps form in Chonju Il Mine. Measured are the pH and selected heavy metal elements in the supposedly polluted hydrologic system. The samples include three types : those collected from the stream waters; those from the stream sediments; and those from the rice field soil scattered over the area. The dispersion path of the pollution source was also traced. The pH of the hydrologic system ranged from 3.44 to 5.46, which clearly indicates that the area is on the acid environment. The pH tends to rise as the distance from the minehead increases. The content of heavy metal elements dissolved in the stream water varies as follows; Mn=69.73~1.99ppm, Cd=0.02~0.03ppm, Zn=0.77~1.18ppm, Cu=0.04~0.13ppm, Pb=0.22~0.32ppm. The stream water in this state may induce serious heavy metal pollution to the agricultural land and the water for human life especially in the villages down the stream. The content of heavy metal elements dissolved in the stream sediment varies as follows; Mn=245.0~4685.0ppm, Cd=10.0~15.0ppm, Zn=105.0~210.0ppm, Cu=65.0~155.0ppm, Pb=90.0~150.0ppm. The content of heavy metal elements dissolved in the rice field soil varies as follows; Mn=185.0~260.0ppm, Cd=10.0~15.0ppm, Zn=135.0~180.0ppm, Cu=65.0~90.0ppm, Pb=100.0~130.0ppm. The pollution index in the stream sediment and the rice field sell is 1.36~2.03, which shows that pollution had already begun all over the area where the samples were collected.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5819-5823
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• 2014

Purpose: To investigate the expression of hypoxia-inducible factor prolyl hydroxylase 3 (HIFPH3) in non-small cell lung cancer (NSCLC) and explore the correlation of HIFPH3 expression with lymph node metastasis and microvessel density (MVD). Materials and Methods: A total of 73 cases of NSCLC specimens, 24 cases of para-cancerous tissues, and 20 normal pulmonary tissues were collected for HIFPH3 and CD31 immunohistochmical (IHC) study. Microvessel density (MVD) of the NSCLC tissues was also determined based on the expression of CD31. Results: The expression of HIFPH3 in carcinoma tissue was statistically higher than para-cancerous and normal pulmonary tissues (${\chi}^2=48.806$, p<0.05). Compared withthe negative lymph node metastasis group, the lymph node metastasis group showed significantly higher HIFPH3 expression (${\chi}^2=6.300$, p<0.05). The strong HIFPH3+group displayed a significantly higher MVD than weak HIFPH3+ and HIFPH3- groups (p<0.05). No differences in positive HIFPH3 expression were noted regarding the tumor diameter, age, smoking status, gender of NSCLC patients, tumor size, histopathology, or differentiation. Conclusions: HIFPH3 expression in human NSCLC lesions is significantly higher than that in para-cancerous and normal lung tissues and is positively associated with lymph node metastasis and MVD.