• Title/Summary/Keyword: CD7

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Band gap energy and photocurrent splitting for CdIn2Te4 crystal by photocurrent spectroscopy ($CdIn_2Te_4$ 결정의 띠간격 에너지의 온도 의존성과 가전자대 갈라짐에 대한 연구)

  • Hong, Kwang-Joon;Kim, Do-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.121-122
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    • 2006
  • Single crystal of $CdIn_2Te_4$ were grown by the Bridgman method without using seed crystals. From photocurrent measurements, its was found that three peaks, A, B, and C, correspond to the instrinsic transition from the valence band states of ${\Gamma}_7$(A), ${\Gamma}_6$(B), and ${\Gamma}_7$(C) to the conducton band states of ${\Gamma}_6$, respectively. Crystal field splitting and spin orbit splitting were found to be at 0.2360 eV and 0.1119 eV, respectively, from found to be photocurrent spectroscopy.

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One-Pot Synthesis of CdSe Quantum Dots Using Selenium Dioxide as a Selenium Source in Aqueous Solution

  • Wang, Yilin;Yang, Hong;Xia, Zhenyi;Tong, Zhangfa;Zhou, Liya
    • Bulletin of the Korean Chemical Society
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    • v.32 no.7
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    • pp.2316-2318
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    • 2011
  • A novel technology has been developed for the synthesis of thioglycolic acid (TGA)-capped CdSe quantum dots (QDs) in aqueous medium. The reaction was carried out in air atmosphere with one-pot by using $SeO_2$ to replace Se or $Na_2Se$. The technological parameters including refluxing time, pH values and molar ratios of selenium to cadmium had significant influence on the luminescence properties of CdSe QDs. Furthermore, the obtained QDs were characterized by fluorescent spectroscopy, X-ray powder diffraction (XRD) and transmission electron microscopy (TEM), respectively. The results demonstrated that the CdSe QDs were of zinc-blended crystal structure in a sphere-like shape.

A Study on the Vibration Reduction and Performance Improvement of the CD/DVD for the Vehicles (자동차용 CD/DVD 데크의 진동 저감 및 성능 향상에 관한 연구)

  • Park Youngpil;Jung Duhan;Chung Jintai
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.7 s.238
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    • pp.1035-1041
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    • 2005
  • Dynamic characteristics of CD/DVD deck fur vehicle are analyzed in this paper. Generally CD/DVD deck for vehicle is used from inferior environment with the vibration of the vehicle, shock of outside and so on. Therefore it must have the structure which is stabilized from the vibration to prevent read error. For this purpose, vibration characteristic of the deck for vehicle should be identified. To analyze characteristic of the deck system, we perform the signal analysis and modal testing using the EFT analyzer. Also we change the design factor degrading the performance of the deck system and verify the efficiency improvement using the acceleration measurement occurring to the sound discontinuation.

Stabilization of Aspergillus sp. $\alpha$-Amylase by Modification with $IO_4$-oxidized Starch ($IO_4$-산화전분 변형에 의한 효소의 안정성 증가)

  • 안용근
    • The Korean Journal of Food And Nutrition
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    • v.12 no.3
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    • pp.265-270
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    • 1999
  • The stabilization of Aspergillus sp. $\alpha$-amylase was attained by modification with periodate-oxidized sol-uble starch. The pH stability of modified enzyme was increased at pH 3~4 and 9~11 in the presence of $\alpha$-cyclodextrin($\alpha$-CD) compared with that of native enzyme. Thermal stability of the modified enzyme was increased. After treatment at 6$0^{\circ}C$ for 30min the activity remained 20% for the enzyme modified at pH 9.7 in the presence of $\alpha$-CD and tested in the presence of $\alpha$-CD 10% for the enzyme modified at pH 9.7 in the presence of $\alpha$-CD 0% for the native enzyme. The native enzyme and modified enzyme showed one peak in HPLC. The substrate specificity of the modified enzyme was not changed in HPLC analysis of reaction product.

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Changes in Soil Physical Properties in Various Sizes of Container as Influenced by Packing Amount of Coir Dust Containing Root Media (다양한 규격의 포트에서 코이어더스트를 포함한 혼합상토의 충전밀도 차이에 의해 유발된 물리성 변화)

  • Park, Eun Young;Choi, Jong Myung
    • Horticultural Science & Technology
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    • v.31 no.6
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    • pp.720-725
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    • 2013
  • When highly shrinkable materials such as coir dust are major component of root media, the degrees of compaction during container filling of root media severely influences the physical properties of root media. It results in the changes in total porosity (TP), container capacity (CC) and air-filled porosity (AFP). This research was conducted to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. To achieve this, three root media were formulated by blending coir dust (CD) with expanded rice hull (CD + ERH, 8:2, v/v), carbonized rice hull (CD + CRH, 6:4) and ground and raw pine bark (CD + GRPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120 and 130% based on the weight of root media. Then the changes in TP, CC, and AFP were measured. Elevation of the packing amount of root media in all sizes of pot resulted in the decrease of TP. But the decrease was more severe in CD + ERH and CD + CRH than those in CD + GRPB. The CC also decreased gradually as the packing amounts were elevated in three root media, but the decreases were severe as the container sizes became larger. The AFP decreased drastically by the elevation of the packing amount of root media in all sizes of pot. The AFP was the highest in CD + CRH medium when pot sizes were smaller than 7 cm, but that was the highest in CD + ERH when the pot sizes were larger than 8.5 cm among the 3 root media tested. In this research, the elevation of packing amount of three root media influenced more severely the AFP rather than CC. This result indicates that the packing amount should be controlled to maintain appropriate level of AFP because AFP rather than CC influence severely crop growth. The results obtained through this study can be used to predict the changes in physical properties of root media as influenced by packing amount in various sizes of pots.

돼지고기가 생체내(生體內) 중금속(重金屬)의 축적억제(蓄積抑制)에 미치는 영향

  • Han, Chan-Gyu;Lee, Nam-Hyeong;No, Jeong-Hae;Seong, Gi-Seung;Chae, Chan-Hui
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 1999.06a
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    • pp.97-117
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    • 1999
  • This study was performed to investigate the effect of pork on the cadmium detoxification in rats. Ninety male Sprague-Dawley rats weighing $125.3{\pm}1.4g$ were divided into five groups based on cadmium treatment(0, 25, 50, 100, 250ppm) and five levels of Cd in AIN-76 purified diet had been fed for 8 weeks. Cadmium was supplemented with a form of $CdCl_2$.. During following 8 weeks of intoxication, casein was replaced by pork and the effect of pork on cadmium- detoxification was compared with casein. After 8 weeks of Cd intake had resulted in apparent cadmium intoxication; reduced growth rate, enlarged kidney and testis, decreased hematocrit value and hemoglobin content in response to the supplemented Cd levels in the diets. Discontinuing cadmium feeding, the body weights were relieved. Pork-fed groups seemed to have higher body weight than casein-fed groups. Hemoglobin content and hematocrit value became normal range at detoxification stage. The weights of liver, kidney, and testis were decreased along with cadmium intake. However, organ weight ratio was not affected by cadmium. Cadmium accumulation in liver and kidney showed a tendency to increase in the cadmium-exposed groups. The levels of metallothionein were also significantly elevated in the tissues of liver in response to the levels of Cd supplemented(p<0.05). Cadmium concentration in kidney was two times higher than that in liver. Cadmium removal rate of liver was higher than that of kidney. Cadmium accumulation of the pork-fed group was lower than that of casein. Especially, the factors which affected the cadmium contents in kidney were $Cd^{***}$ and $Cd{\times}pork^{***}$. Metallothionein(MT) was increased with cadmium, and MT was not likely to be affected by pork. Based on the findings from gross lesion, rats fed 250ppm of Cd were externally emaciated, had exposed penis and observed atrophies of kidney and testis. Histopathological observation seemed that the liver of groups feeding Cd supplemented diets showed cellular degeneration and accumulation of eosinophilic materials in the capillaries. In kidney, rats fed Cd diets had shown tubular epithelium degeneration and lesions of basophilic materials, while testis were weakened in numbers of spermatid and sporadically enlarged of giant cells. But the rats administered cadmium-detoxified diet supplemented pork for 7 weeks were shown individually decreased lesions compared with the rats supplied with casein diet.

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Neuronal Phenotypes and Gene Expression Profiles of the Human Adipose Tissue-Derived Stromal Cells in the Neuronal Induction (신경 분화 유도한 인체 지방조직 유래 간질세포의 신경 표현형과 유전자 발현)

  • Shim, Su Kyung;Oh, Deuk Young;Jun, Young Joon;Lee, Paik Kwon;Ahn, Sang Tae;Rhie, Jong Won
    • Archives of Plastic Surgery
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    • v.34 no.1
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    • pp.1-7
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    • 2007
  • Purpose: Human adipose tissue-derived stromal cells(hADSCs) can be expanded in vitro and induced to differentiate into multiple mesenchymal cell types. In this study we have examined various neuronal phenotypes and gene expression profiles of the hADSCs in the neuronal induction. Methods: The hADSCs were isolated from human adipose tissue and they were characterized by the flow cytometry analysis using CD13, CD29, CD34, CD45, CD49d, CD90, CD105 and HLA-DR cell surface markers. We differentiated the hADSCs into the neuronal lineage by using chemical induction medium and observed the cells with contrast microscopy. The immunocytochemistry and western blotting were performed using the NSE, NeuN, Trk-A, Vimentin, N-CAM, S-100 and ${\beta}$-Tubulin III antibodies. Results: The hADSCs were positive for CD13($90.3{\pm}4%$), CD29($98.9{\pm}0.7%$), CD49d($13.6{\pm}6%$), CD90 ($99.4{\pm}0.1%$), CD105($96%{\pm}2.8%$) but negative for CD34, CD45 and HLA-DR. The untreated cultures of hADSCs predominately consisted of spindle shaped cells and a few large, flat cells. Three hours after the addition of induction medium, the hADSCs had changed morphology and adopted neuronal-like phenotypes. The result of immunocytochemistry and western blotting showed that NSE, NeuN, Trk-A, Vimentin, N-CAM, S-100 and ${\beta}$-Tubulin III were expressed. However, NSE, NeuN, Vimentin were weakly expressed in the control. Conclusion: Theses results indicate that hADSCs have the capabillity of differentiating into neuronal lineage in a specialized culture medium. hADSCs may be useful in the treatment of a wide variety of neurological disorders.

Growth and Characterization for $CdIn_2S_4/GaAs$ Epilayers ($CdIn_2S_4$ 에피레이어 성장과 특성)

  • Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.239-242
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    • 2004
  • A stoichiometric mixture of evaporating materials for $CdIn_2S_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CdIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by hot wall epitaxy(HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $420^{\circ}C$ respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of $CdIn_2S_4$ single crystal thin films measured from Hall effect by van der Pauw method are $9.01{\times}10^{16}\;cm^{-3}$ and $219\;cm^2/V{\cdot}s$ at 293 K, respectively. From the optical absorption measurement, the temperature dependence of energy band gap on $CdIn_2S_4$ single crystal thin films was found to be $E_g(T)\;=\;2.7116\;eV\;-\;(7.74{\times}10^{-4}\;eV)T^2/(T+434)$. After the as-grown $CdIn_2S_4$ single crystal thin films was annealed in Cd-, S-, and In-atmospheres, the origin of point defects of $CdIn_2S_4$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K.

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The Effects of Cadmium on the Growth of Mulberry Tree and Metabolic Activities in the Leaves (카드뮴의 處理가 桑樹의 生長 및 生體內 代謝에 미치는 影響)

  • Bae, Kae-Sun;Kim, Yong-Sang
    • Journal of Sericultural and Entomological Science
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    • v.25 no.1
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    • pp.27-33
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    • 1983
  • The study was carried out to examine effect of cadmium spraying on mulberry leaves on the growth and metabolism of mulberry tree.The results obtained were as follow:1. Brown spot were appeared on the leaves as the symptoms of damage and the damage was remarkable with higher concentration of cadmium.2. Higher concentration of Cd inhibited the length and diameter of mulberry branches with a significant difference (P<0.05) for the length. The growth of branch length in both 5 and 7 ppm treatment of Cd was inhibited by 31% compared with the control. 3. Cadimum concentration of mulberry barks was noticeably lower than that of leaves. 4. Cadimum concentration over 3ppm inhibited significantly chlorophyll content, activitsies of respiration, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transase (GPT) and adenocine triphosphate (APT). 5. The lowest concentration of cadmium was identified to be 3ppm to incur the inhibitory effect on the growth and metabolism of mulberry and cadmium content of mulberry leaves at the concentration was 13.86ppm.

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Flavor development in cheddar cheese (체다 치즈의 맛의 개발)

  • 정청송;유상훈
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.14 no.1
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    • pp.59-77
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    • 2003
  • This study was carried out to find a cholesterol removal rate, flavor development, and bitter amino acid productions in Cheddar cheese treated with -cyclodextrin ($\beta$-CD): l) Control (no homogenization, no $\beta$-CD), and 2) Milk treatment (1000 psi milk homogenization, 1 % $\beta$-CD). The cholesterol removal of the cheese were 79.3%. The production of short-chain free fatty acids (FF A) increased with a ripening time in both control and milk treated cheese. The releasing quantity of short-chain FFA was higher din milk treated cheese than control at 5 and 7 mo ripening. Not much difference was found in neutral volatile compounds production between samples. In bitter-tasted amino acids, milk treatment group produced much higher than control. In sensory analysis, texture score of control Cheddar cheese significantly increased, however, that in cholesterol-reduced cheese decreased dramatically with ripening time.

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