• Journal of Nutrition and Health
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• 제24권6호
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• pp.516-525
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• 1991

In order to investigate whether serum Cu, Zn and Cu/Zn ratio are the useful indicater for the diagnosis of cancer. serum Cu and Zn levels were determined from 35 normal subjects and 33 stomach cancer patients by Atomic absorption spectrophotometer. The following results are obtained : Serum copper levels of stomach cancer patients were significantly increased than the those of the normal controls. whereas serum Zn levels significantly decreased than those of the normal contros(P<0.01) Therefore the copper to zinc ratio revealed a significant in the serum Cu and Zn levels. The serum protein and albumin levels were significantly lower in cancer patients(P<0.01) And the correlation analysis indicated that there was no significant correlation between serum Cu/Zn ratio and protein or albumin. These data suggest that the serum Cu. Zn and Cu/Zn ratio may be used as a diagnostic test in stomach cancer patients.

• 한국표면공학회지
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• 제41권3호
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• pp.109-113
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• 2008

High strength 7xxx series Al-Zn-Mg alloy have been investigated for using light weight automotive parts especially for bump back beam. The composition of commercial 7xxx aluminum has the Zn/Mg ratio about 3 and Cu over 2 wt%, but this composition isn't adequate for appling to automotive bump back beam due to its high resistance to extrusion and bad weldability. In this study the Zn/Mg ratio was increased for better extrusion and Cu content was reduced for better welding. With this new composition we investigated the effect of composition on the resistivity against stress corrosion cracking. As the Zn/Mg ratio is increased fracture energy obtained by slow strain rate test was decreased, which means degradation of SCC resistance. While the fracture energy was increased with Cu contents although it is below 1%, which means improvement of SCC resistance. These effects of composition change on the SCC resistivity were identified by observing the fracture surface and crack propagation.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제27권1호
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• pp.53-61
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• 2024

Purpose: Although the 24-hours urinary copper excretion is useful for the diagnosis of Wilson disease (WD), there are practical difficulties in the accurate and timed collection of urine samples. The purpose of this study was to verify if the spot morning urinary Copper/Zinc (Cu/Zn) ratio could be used as a replacement parameter of 24-hours urinary copper excretion in the diagnosis of WD. Methods: A cross-sectional study was conducted at the Department of Pediatric Gastroenterology and Nutrition, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from June 2019 to May 2021 on 67 children over three years of age who presented with liver disease. Twenty-seven children who fulfilled the inclusion criteria for WD were categorized into the test group, and the remaining forty children were considered to have non-Wilsonian liver disease and were categorized into the control group. Along with other laboratory investigations, spot morning urinary samples were estimated for the urinary Cu/Zn ratio in all patients and were compared to the 24-hour urinary copper excretion. The diagnostic value of the Cu/Zn ratio was then analyzed. Results: Correlation of spot morning urinary Cu/Zn ratio with 24-hours urinary copper excretion was found to be significant (r=0.60). The area under ROC curve with 95% confidence interval of morning urinary Cu/Zn ratio measured using 24-hours urine sample was 0.84 (standard error, 0.05; p<0.001). Conclusion: Spot morning urinary Cu/Zn ratio seems to be a promising parameter for the replacement of 24-hours urinary copper excretion in the diagnosis of WD.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.236.2-236.2
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• 2015

The copper-zinc(Cu-Zn) nanofiber was prepared by electrospinning method. The Cu/PVP (polyvinylpyrrolidone) and Zn/PVP precursor solutions were prepared by dissolution of copper sulfate and zinc acetate in methanol, respectively. The PVP was used to control the viscosity of the precursor solutions. The optimized ratio for the Cu/PVP and Zn/PVP nanofibers was determined separately. Then the suitable ratio of the precursor solutions was applied for fabrication of Cu/Zn/PVP nanofiber. For the electrospinning method, the precursor solutions were filled in a syringe. The distance between metallic needle on the syringe and collector was fixed at 16 cm and the voltage was applied on the tip was 13.0 kV. And the as-spun nanofiber was heated at 353K for removal of residual solvent. Then the heated nanofibers were calcined at 973K to decompose PVP. The obtained Cu, Zn, and Cu-Zn nanofibers were investigated with X-ray photoelectron spectroscopy (XPS) for the chemical properties, scanning electron microscopy (SEM) for the morphologies, and X-ray diffraction (XRD) to characterize the crystallinity and phase of nanofibers.

• 한국분말재료학회지
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• 제11권2호
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• pp.143-148
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• 2004

In the present study, $TiO_2$ imbedded composite powders have been successfully prepared from the (Cu. Zn)/$TiO_2$ composite salt solution. The composite (Cu, Zn)/$TiO_2$ powders were formed by drying the solution at 200~$600^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting the decomposition ratio of aniline blue with UV-visible spectrophotometer(Shimazu Co., UV-1601). Phase analysis of (Cu, Zn)/$TiO_2$ composite powders was carried out by XRD and DSC, and powder size was measured with TEM. The mean particle size of composite powders was about 100mm. As the reduction temperature increases, a few zinc sulfide and oxide phases was formed and copper oxide phase was reduced. The decomposition ratio of aniline blue was about 80％ under the UV irradiation by the TiO$_2$ phase in the composite (Cu, Zn)/$TiO_2$ powders and similar decomposition ratio of 80％ was obtained at the UV lightless condition by virtue of Cu and Zn compounds.

• 한국자기학회지
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• 제5권3호
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• pp.191-196
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• 1995

고상반응법에 의해 NiCuZn ferrite를 제조하였으며 소결온도 $900^{\circ}C$에서의 조성 및 공정변화에 따른 특성을 검토하였다. NiCuZn ferrite에서 Cu 치환 첨가량과 (Ni+Cu)/Zn의 조성비를 변화시킨 결과 ${(Ni_{0.2}Cu_{0.2}Zn_{0.6}O)}_{1.02}{(Fe_{2}O_{3})}_{0.98}$의 조성을 가질 때 초기투자율이 가장 높게 나타났다. NiCuZn ferrite의 Curie 온도 ($T_{c}$)는 Cu의 치환 첨가량이 증가함에 따라 점차 감소하였으며, Cu의 함량을 고정하고 Ni의 함량을 변화시킬 경우, (Ni+Cu)/Zn의 조성비가 증가할 수록 현저하게 증가하였다. ${(Ni_{0.2}Cu_{0.2}Zn_{0.6}O)}_{1-w}{(Fe_{2}O_{3})}_{1+w}$의 조성에서 분쇄시간을 20~80시간으로 변화시켰을 경우 $Fe_{2}O_{3}$ 결핍량(w)이 -0.015일 때 초기투자율이 가장 높았으며, Curie 온도 ($T_{c}$)는 $Fe_{2}O_{3}$ 결핍량(w)이 0에서 -0.025로 증가할 수록 점차 감소하였다.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.66-68
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• 2001

An experiment was conducted investigate the of supplemental Cu and Zn methionine chelates on the performance, nutrient digestibility, serum IgG level, gizzard erosion, and Cu and Zn contents in the liver and excretion of broiler chickens. One thousand hatched broiler chickens (Ross) of one day old were assigned to 4 treatments:control(T1), 100ppm of copper in the from of Cu-methionine chelate(Cu-Met, T2), 100ppm of zinc in the from of Zn-methionine chelate(Zn-Met, T3) and 100ppm of copper plus 100ppm of zinc in the from of methionine chelate(Cu-Zn-Met, T4). Each treatment had four replications of 50 bird each. Weight gain of chicks fed chelated products were significantly higher than that of chicks fed control(P＜0.05).Combination of Cu and Zn chelates(Cu-Zn-Met) tended to show the best growth rate and feed conversion ratio. Nutrient digestibilities were not affected by dietary treatments. Serum IgG level of chicks fed Cu-Zn-Met was significantly higher than that of chicks fed control(P＜0.05). Gizzard erosion index was not significantly different among treatments. Contents of Cu and Zn in liver were not significantly affected by dietary treatments, whereas excretions of these minerals were significantly affected by dietary treatments.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.528-531
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• 2000

ZnS:Cu phosphor used on powder electroluminescent device has a green emission in low frequency and a blue emission in high frequency. In this paper, to obtain the powder electroluminescent device of the blue emission in low frequency, the emission properties with mixed the ratio between phosphor and dye was investigated. The mixed ratio of the dye was from 0 to 5 weight percent. To inquire into the blue emission, the emission spectrum, the CIE coordinate system and the brightness were measured.

• 한국정보통신학회논문지
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• 제5권5호
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• pp.994-1000
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• 2001

정보통신기술의 발달과 전자기기의 사용량 증가에 따른 전자파장애의 발생이 점차 사회 문제화되면서 그 대책이 요구됨에 따라 전자파 흡수체에 대한 관심도 증가되고 있는데 본 연구에서는 전자파 흡수체로 알려진 NiCuZn 페라이트의 조성비 및 소결온도 변화에 따른 복소유전율과 복소투자율의 주파수 의존 특성을 알아보고 전자파 흡수성능에 대한 영향을 조사하였다. NiCuZn 페라이트의 조성 중 $Fe_2O_3$및 ZnO를 각각 49.0, 34.0mol%로 고정하고 NiO 및 CuO의 구성비를 변화시켜 측정한 결과 NiO의 구성비가 8.5~9.5 mol%의 범위에서, 소결온도는 $1080^{\circ}C$에서 초투자율 및 유전율이 크고 $loss tangent(=\mur"/\mur')$가 약 2 MHz~9.5 GHz 주파수 대역에서 1 이상을 보이며 전파흡수 성능이 가장 우수하게 나타났다.나타났다.

• 농업과학연구
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• 제51권1호
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• pp.53-61
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• 2024

A total of 180 21-day-old weaning pigs ([Yorkshire × Landrace] × Duroc) with an initial body weight of 6.44 ± 0.01 kg were randomly assigned to 9 treatments for evaluating the effects of replacing dietary inorganic copper (Cu) and zinc (Zn) with glycine (Gly) or methionine (Met)-chelated Cu and Zn on growth performance and nutrient digestibility. The experimental period was 35 days. There were four replicated pens per treatment, with five pigs (three males and two females) per pen. Dietary treatments consisted of a basal diet (CON), in which the sources of Cu and Zn were in inorganic form. The inorganic Cu and Zn in the basal diet were replaced by glycine-chelated (GC) and methionine-chelated (MC) Cu and Zn by 30, 50, 70, or 100% to form the GC1, GC2, GC3, GC4, or MC1, MC2, MC3, MC4 groups. The 100% replacement of dietary inorganic Cu and Zn with GC or MC increased (p < 0.05) average daily gain, average daily feed intake, and gain-to-feed ratio. The complete replacement of dietary inorganic Cu and Zn with GC or MC led to enhanced (p < 0.05) digestibility of dry matter, nitrogen, Cu and Zn. Thus, the replacement of inorganic Cu and Zn with GC or MC can improve the growth efficiency and nutrient utilization of weaning pigs.