• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.36-36
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• 2023

• 한국재료학회지
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• 제33권5호
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• pp.214-221
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• 2023

As a filler metal for lowering the melting point of Ag, many alloy metal candidates have emerged, such as cadmium, with zinc, manganese, nickel, and titanium as active metals. However, since cadmium is known to be harmful to the human body, Cd-free filler metals are now mainly used. Still, no study has been conducted comparing the characteristics of joints prepared with and without cadmium. In addition, studies have yet to be conducted comparing the typical characteristics of brazing filler metals with special structures, and the joint characteristics of brazing filler metals with available frames. In this study, the characteristics of junctions of silver-based intercalation metals were compared based on the type of filler metal additives, using a special structure, a filler metal sandwich structure, to protect the internal base metal. The general filler metal was compared using the structure, and the thickness of the filler metal according to the thickness was reached. A comparison of the characteristics of the junction was conducted to identify the characteristics of an intersection of silver-based brazing filler metal and the effect on joint strength. Each filler metal's collective tensile strength was measured, and the relationship between joint characteristics and tensile joint strength was explored. The junction was estimated through micro strength measurement, contact angle measurement with the base metal when the filler metal was melted, XRD image observation, composition analysis for each phase through SEM-EDS, and microstructure phase acquisition.

• Journal of Nutrition and Health
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• 제30권7호
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• pp.770-780
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• 1997

This study was performed to investigate the effect of chitosan and NOCC from different sources and of different molecular weights on lipid metabolism. Sprague-Dawley rats were blocked into 26 groups according to body weight, and were raised for 4 weeks. Cadmium chloride was given at the level of 0 or 400 ppm in diet. Various chitosan and NOCC sources were given at the level of 0%(w/w) of diet. Total serum cholesterol and serum triglyceride concentrations were little affected by chitosan and NOCC supplements. However, HDL-cholesterol concentration and HDL : total cholesterol ratio were increased , and liver lipid, cholesterol , and triglyceride concentration were decreased by chitosan and NOCC supplements. The cholesterol and lipid lowering activity depends on fiber sources(crab and shrimp); type (chitosan and NOCC); and molecular weight(low , medium , and high). Among cadmium-free groups, chitosan-fed groups showed greater activity than NOCC -fed groups in lowering cholesterol and lipid levels, and greater fecal excretion of lipids and bile acids. Crab chitosans were more effective in cholesterol and lipid lowering activity than shrimp chitosans. The group fed high molecular weight crab chitosan showed the highest fecal excretion of lipids and bile acids. This indicated that high molecular weight crab chitosan was most effective in interfering with cholesterol and lipid absorption.

• 대한화학회지
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• 제19권6호
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• pp.428-433
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• 1975

물중에 ppb 정도로 존재하는 구리, 납, 카드뮴 및 아연을 동시에 정량하기 위하여 디티존-클로로포름 抽出法으로 농축하여 短形波폴라로그래피法으로 측정하는 방법을 검토했다.디티존鹽으로 클로로포름層에 추출된 이들 이온을 , 디티존보다 약간 과량의 수은(II)이온을 함유하는 염산으로 역추출한 후 支持電解質로서 염화칼륨을 가하고 순수한 클로로포름으로 두번 씻은 다음 短形波폴라로그램을 기록한다. 이 방법으로 구리, 납 및 카드뮴은 3ppb까지, 아연은 14ppb까지 상대오차 10%이내로 할 수 있었다.

• 한국재료학회지
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• 제12권4호
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• pp.283-289
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• 2002

The E.M.F of the galvanic cell with fused salt was measured to determine the activities of zinc at 700-820K over the entire composition range of liquid Zn-Cd alloys. The cell used was as follows: (-) W ｜ Zn(pure) $Zn^{2+}(KCI-LiCl)$ ｜ Zn(in Zn-Cd alloy) ｜ W (+) The activities of zinc in the alloys showed positive deviation from Raoult's law over the entire composition range. The activity of cadmium and some thermodynamic functions such as Gibbs free energy, enthalpy, entropy were derived from the results by the thermodynamic relationship. The comparison of the results and the literature data was made. The liquid Zn-Cd alloy is found to be close to the regular solution. The concentration fluctuations in long wavelength limit, $S_{cc}(o)$, in the liquid alloy was calculated from the results.

• 한국자원식물학회지
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• 제30권6호
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• pp.670-678
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• 2017

Persimmon seeds contain considerable amounts of minerals, amino and organic acids, natural antioxidants and phenolic compounds. The objective of this study was to investigate quality characteristics and antioxidant potential of Korean persimmon seeds. The pH (4.88-4.94), color values, contents of minerals, free amino acids, organic acids, and phenolic compounds and DPPH free radical scavenging potentials of persimmon seed extracts significantly (p < 0.05) varied with the genotypes. This study showed that the seeds could be used as a source of different mineral elements (47.14-85.07 mg/kg) without any measureable amount of heavy metals such as arsenic, cadmium, lead and mercury. Similarly, considerable amounts of organic (1550.13-2413.08 mg/kg) and essential amino (50.85-54.03 mg/kg) acids and total phenolic compounds ($1227.91-1307.78{\mu}g$ gallic acid equivalent/g) were also found in the seed extracts, indicating their potential food value as a natural antioxidant. Results of the present study imply that prethanol-A, a food preservative, can be used as an effective extraction to obtain the minerals, organic and free amino acids, and phenolic compounds from the persimmon seeds, which possess a big potential to be commercially used in food, cosmetic and pharmaceutical industries.

• 한국식품영양과학회지
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• 제25권4호
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• pp.575-580
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• 1996

식이 vitamin E 수준이 Cd 중독된 휜쥐 뇌조직 내의 지질과산화와 항산화계에 미치는 영향을 알아보기 위해 체중 $60\pm5g되는$ Spraue-Dawley종 흰쥐 숫컷을 식이내 vitamin E 함량을 0, 40, 400mg/kg of diet로 나누어 각각 2주 및 4주간 사육한 후 체중 kg당 2.5mg Cd을 하루에 한번씩 4회 투여하여, 실험 종료 후 쥐를 희생시켜 뇌조직내의 SOD, GSH-Px, GST의 항산화 효소활성 및 지질과산화가를 측정하여 다음과 같은 결과를 얻었다. 전 실험기간 동안 체중변화를 관찰한 결과 대조군에 비해 실험군들이 모두 유의적으로 감소하였고, 식이 섭취량은 2주간 사육한 대조군과 각 실험군간에 차이가 없었으나, 4주간 사육한 대조군에 비해 Cd-0E군만이 유의적으로 낮았다. 식이 효율도 2주 및 4주 모두 대조군에 비해 실험군들이 모두 낮았다. 뇌, 간장 및 신장의 무게는 대조군과 실험군 간에 유의적인 차이가 없었다. SOD의 활성을 관찰한 결과 대조군에 비해 Cd-0E군이 유의적으로 낮았으나 Cd-40E와Cd-400E군과는 차이가 없었다. GSH-Px 활성은 대조군에 비해 실험군이 Cd-400E, 40E, Cd-0E순으로 낮았다. G57 활성을 측정한 결과는 대조군에 비해 Cd-0E, Cd-40E군에서는 유의적으로 낮았으며, Cd-400E와는 차이가 없었다. 뇌조직의 지질과산화가를 측정한 결과, 대조군에 비하여 Cd-0E, Cd-40E, Cd-400E 군은 각각 2.5배, 1.8배, 1.4배 증가하였다. 그리고 Cd-40E, Cd-400E는 Cd-0E군에 비해 각각 28.8%, 44% 지질과산화가가 각각 낮았다. 2주 및 4주 동안 실험구간의 효소활성 및 과산화지질 함량은 유의적인 차이가 없었다. 결론적으로 Cd 중독된 흰쥐 뇌조직에서는 대조군에 비해 지질과산화 반응이 촉진되었으나 식이내 vitamin E의 적절한 첨가는 항산화계를 강화시킴으로써 뇌조직의 과산화적 손상을 완화시키는데 기여함을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제4권1호
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• pp.47-54
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• 2000

Transition metal ions including $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ have been thought to disturb the bone metabolism directly. However, the mechanism for the bone lesion is unknown. In this study, we demonstrated that MC3T3E1 osteoblasts, exposed to various transition metal ions; selenium, cadmium, mercury or manganese, generated massive amounts of reactive oxygen species (ROS). The released ROS were completely quenched by free radical scavengers-N-acetyl cysteine (NAC), reduced glutathione (GSH), or superoxide dismutase (SOD). First, we have observed that selenium $(10\;{\mu}M),$ cadmium $(100\;{\mu}M),$ mercury $(100\;{\mu}M)$ or manganese (1 mM) treatment induced apoptotic phenomena like DNA fragmentation, chromatin condensation and caspase-3-like cysteine protease activation in MC3T3E1 osteoblasts. Concomitant treatment of antioxidant; N-acetyl-L-cysteine (NAC), reduced-form glutathione (GSH), or superoxide dismutase (SOD), prevented apoptosis induced by each of the transition metal ions. Catalase or dimethylsulfoxide (DMSO) has less potent inhibitory effect on the apoptosis, compared with NAC, GSH or SOD. In line with the results, nitroblue tetrazolium (NBT) stain shows that each of the transition metals is a potent source of free radicals in MC3T3E1 osteoblast. Our data show that oxidative damage is associated with the induction of apoptosis in MC3T3E1 osteoblasts following $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ treatment.

• Nuclear Engineering and Technology
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• 제6권1호
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• pp.9-13
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• 1974

80$^{\circ}$K에서 카드미움설파이드 단결정에 펄스형 전자빔을 쪼였을 때 자연적으로 방출되는 빛의 스펙트럼을 파장의 함수로 측정하였다 측정된 스펙트럼으로부터 중성도너에 묶일 엑사이톤의 분리에너지가 2.0meV였으며, 계산치는 2.4-3.2meV였다. 이 중성도너에 구속된 엑사이톤과 세로방향 광학 음향양자와는 상호작용을 하지 않으며 분리된 자유엑사이톤과 상호작용을 한다는 결론을 얻었다. 그러므로 상호작용으로 구성되는 스펙트럼의 원점은 중성도너로부터 분리된 자유엑사이톤의 스펙트럼의 위치에 있게 되며 또한 스펙트럼의 분석으로부터 카드미움설파이드의 세로방향 광학음향양자 에너지는 40.SmeV로 밝혀졌다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.152-153
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• 2006

The new approach to buffer layer design for CIGS solar cells that permitted to reduce the buffer absorption losses in the short wavelength range and to overcome the disadvantages inherent to Cd-free CIGS solar cells was proposed. A chemical bath deposition method has been used to produce a high duality buffer layer that comprises thin film of CdS and Zn-based film. The double layer was grown on either ITO or CIGS substrates and its morphological, structural and optical properties were characterized. The Zn-based film was described as the ternary compound $ZnS_x(OH)_y$. The composition of the $ZnS_x(OH)_y$ layer was not uniform throughout its thickness. $ZnS_x(OH)_y$/CdS/substrate region was a highly intermixed region with gradually changing composition. The short wavelength cut-off of double layer was shifted to shorter wavelength (400nm) compared to that (520 nm) for the standard CdS by optimization of the double buffer design. The results show the way to improve the light energy collection efficiency of the nearly cadmium-free CIGS-based solar cells.