• 제목/요약/키워드: Hwe

검색결과 397건 처리시간 0.031초

Growth of high quality ZnTe epilayers used for an far-infrared sensor and radiation detector

  • Kim, B. J.
    • 한국공작기계학회논문집
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    • 제11권6호
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    • pp.105-110
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    • 2002
  • ZnTe epilayers have been successfully grown on (100) CaAs substrate by hot wall epitaxy (HWE) with Zn reservoir. Optimum growth condition has been determined by a four-crystal rocking curve (FCRC). It was found that Zn partial pressure from h reservoir has a strong influence on the quality of grown films. Under the determined optimum growth condition, ZnTe epitaxial films with thickness of 0.72~24.8${\mu}m$ were grown for studying the effect of the thickness on crystalline quality. The FCRC results indicated that the quality of ZnTe films becomes higher rapidly with increase of thickness up to 6${\mu}{\textrm}{m}$. The best value of the FWHM of the few crystal rocking curve, 66 arcsec, was obtained on the film with $12{\mu}m$ in thickness. Until now, this result shows the best quality of ZnTe/GaAs films in reported.

Growth of High Quality $Cd_{0.96} Zn_{0.04} Te$ Epilayers Used for an Far-infrared Sensor and Radiation Detector

  • Kim, B. J.
    • 한국공작기계학회논문집
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    • 제11권6호
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    • pp.111-117
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    • 2002
  • The high quality and a nearly stoichometric growth of $Cd_{1-y} Zn_y$/Te(y=0.04) epilayers have been successfully grown on GaAs substrate by hot wall epitaxy (HWE) by optimizing the growth condition including the preheating treatment and Cd reservoir temperature. The relationship between quality and thickness was examined and best value of FWHM from X-ray rocking curve of 121 arcsec are obtained. Also, emission peaks related to the recombination of free excitons such as the ground state and the first excited state were observed in the PL spectrum at 4.2K. The ($A^0$, X) emission related to Cd vacancy and deep level emission was not measured. These results indicated that the grown CZT/GaAs epilayer was high qualify and purity.

각목 색상 배치에 의한 문양막대의 횡절단 무늬편을 이용한 문양구성 연구 (A Study on Patterning Techniques by sliced unit with square woods's color bars)

  • 김지건
    • 한국가구학회지
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    • 제20권5호
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    • pp.431-439
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    • 2009
  • When we look at the pattern techniques of wooden furniture in the 19th century Joeson Dynasty, we see that furniture patterns in the main living room were showy and colorful while furniture patterns in the library room, where noble men used to study, were natural and moderate, retaining the actual color of the material without any artificial coloring. Even the serial patterns in the Hwe-Jang technique, Which were used rarely, used moderate techniques. such as weaving in patterns with colorless woods - willow and black persimmon ets. - rather than using excessive techniques. However, considering the marquetry&intarsia technique of ceramic and the silver string intarsia technique of metal then current, wood work must also have been technically advanced. Korean modern wood furniture needs remedies to improve the standard of sound wood work techniques. This study shows that pattern unit production, composition techniques, and color effects etc. Using colored patterns bars, by improving the pattern composition techniques of Marquetry&Intarsia, can be substituted for the production logic of modern manufactured furniture.

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황기, 당귀 추출물의 추출조건이 추출물의 수율 및 품질에 미치는 영향 (Effect of Extraction Conditions on Yield and Quality of Extracts in Astragalas manbranaceus Bunge, Angelica gigas Nakai)

  • 이미숙;이근보;한명규;박상순
    • 한국식품영양학회지
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    • 제14권6호
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    • pp.543-547
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    • 2001
  • 전통 한약재인 황기. 당귀로부터 추출물의 획득은 일반적으로 열수 추출법에 의하여 행해져 왔으나 추출물의 획득수율이 낮고 추출, 농축과정에서의 심한 열처리로 인하여 고유의 향이 소실되는 등 많은 문제점을 안고 있다 이에 본 연구에서는 주정추출법을 시도하여 황기, 당귀 추출물의 획득수율을 열수 추출법의 50, 39% (w/w) 대비 각각 15, 36% 증가한 65, 75%로 향상시킬 수 있었으며, 강한 고유의 향을 포집하고 있는 전혀 새로운 타입의 추출물을 얻을 수 있었다. 추출과정에서 열수 추출법과의 차이는 추출용매를 물에서 주정으로 변경한 것과 1차 추출 후 얻어진 박을 이용하여 2차 추출을 행하였으며, 농축온도를 열수 추출의 104$^{\circ}C$에 비하여 상대적으로 낮은 9$0^{\circ}C$에서 실시하였다. 이와 같이 처리온도와 거의 무관하게 주정은 고유의 향을 포집하는 뛰어난 효과를 나타내었다. 이 추출물을 물엿, 음료 등의 제품에 적용할 경우별도의 인공향료 처리없이 천연물 그대로의 가공으로도 충분한 고유의 향미를 부여할 수 있을 것으로 기대 된다.

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Lack of Association Between LIG4 Gene Polymorphisms and the Risk of Breast Cancer: A HuGE Review and Meta-analysis

  • Zhou, Li-Ping;Luan, Hong;Dong, Xi-Hua;Jin, Guo-Jiang;Man, Dong-Liang;Shang, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3417-3422
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    • 2012
  • Objective: Non-homologous end joining (NHEJ) is one of the pathways of repair of DNA double-strand breaks. A number of genes involved in NHEJ have been implicated as breast cancer susceptibility genes such as LIG4. However, some studies have generated conflicting results. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to investigate association between LIG4 gene polymorphisms in the NHEJ pathway and breast cancer risk. Methods: Studies focusing on the relationship between LIG4 gene polymorphisms and susceptibility to breast cancer were selected from the Pubmed, Cochrane library, Embase, Web of Science, Springerlink, CNKI and CBM databases. Data were extracted by two independent reviewers and the meta-analysis was performed with Review Manager Version 5.1.6 and STATA Version 12.0 software, calculating odds ratios (ORs) with 95% confidence intervals (95%CIs). Results: According to the inclusion criteria, we final included seven studies with a total of 10,321 breast cancer cases and 10,160 healthy controls in the meta-analysis. The results showed no association between LIG4 gene polymorphisms (rs1805386 T>C, rs1805389 C>T, rs1805388 C>T and rs2232641 A>G) and breast cancer risk, suggesting that the mutant situation of these SNPs neither increased nor decreased the risk for breast cancer. In the subgroup analysis by Hardy-Weinberg equilibrium (HWE) and ethnicity, we also found no associations between the variants of LIG4 gene and breast cancer risk among HWE, non-HWE, Caucasians, Asians and Africans. Conclusion: This meta-analysis suggests that there is a lack of any association between LIG4 gene polymorphisms and the risk of breast cancer.

HWE에 의한 $Cd_{1-x}Zn_xS $박막의 성장과 광전도 특성 (Growth of $Cd_{1-x}Zn_xS $ Thin films Using Hot Wall Epitaxy Method and Their Photoconductive Characteristics)

  • 홍광준;유상하
    • 한국결정학회지
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    • 제9권1호
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    • pp.53-63
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    • 1998
  • HWE 방법에 의해 Cd1-xZnxS 박막을 (100)방향을 Si 기판 위에 성장시켰다. 증발원과 기판의 온도를 각각 600℃, 440℃로 하여 성장시킨 Cd1-xZnxS 박막의 이중 결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)값이 265 arcsec로 가장 작았다. Van der Pauw 방법으로 Hall효과를 측정하여 운반자 농도와 Hall 이동도의 온도 의존성을 조사하였다. 광전도 셀의 특성으로 spectral response, 최대 허용소비전력(MAPD), 광전류와 암전류(pc/dc)의 비 및 응답시간을 측정하였다. Cd0.53Zn0.47S광전도 셀을 Cu증기 분위기에서 열처리한 경우 감도(γ)는 0.99, pc/dc은 1.65 ×10 7 그리고 최대 허용소비전력(MAPD)은 338mW, 오름시간 (rise time)은 9.7ms, 내림시간(decay time)은 9.3ms로 가장 좋은 광전도 특성을 얻었다.

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Hot Wall Epitaxy(HWE)법에 의한 $CdGa_2Se_4$ 단결정 박막의 광전류 연구 (Photocurrent properties for $CdGa_2Se_4$ single crystal thin film grown by using hot wall epitaxy(HWE) method)

  • 유상하;홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.124-125
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    • 2007
  • Single crystal $CdGa_2Se_4$ layers were grown on a thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with the hot wall epitaxy (HWE) system by evaporating the polycrystal source of $CdGa_2Se_4$ at $630^{\circ}C$ prepared from horizontal electric furnace. The photocurrent and the absorption spectra of $CdGa_2Se_4$/SI(Semi-Insulated) GaAs(100) are measured ranging from 293K to 10K. The temperature dependence of the energy band gap of the $CdGa_2Se_4$, obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) = 2.6400 eV - $(7.721{\times}10^{-4}\;eV/K)T^2$/(T + 399 K). Using the photocurrent spectra and the Hopfield quasicubic model, the crystal field energy$({\Delta}cr)$ and the spin-orbit splitting energy$({\Delta}so)$ for the valence band of the $CdGa_2Se_4$ have been estimated to be 106.5 meV and 418.9 meV at 10 K, respectively. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-},\;B_{1^-},\;and\;C_{11^-}$ exciton peaks.

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RAW264.7 대식세포에서 괭생이 모자반 추출물의 면역활성 증진 효과 (Immunomodulating activity of Sargassum horneri extracts in RAW264.7 macrophages)

  • 김동섭;성낙윤;박상윤;김건;엄지;유진곤;서인라;한인준;조용백;김경아
    • Journal of Nutrition and Health
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    • 제51권6호
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    • pp.507-514
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    • 2018
  • 본 연구에서는 모자반목 모자반과 갈조류인 괭생이 모자반의 3가지 서로 다른 추출물의 면역활성 가능성을 비교연구하기 위하여 RWA264.7 대식세포에 서로 다른 괭생이 모자반 추출물을 처리하여 $TNF-{\alpha}$, IL-6 및 NO 분비능과 MAPK 신호전달경로 및 $NF-{\kappa}B$ 활성화 수준을 측정하였다. 괭생이 모자반 열수추출물, 주정추출물, 그리고 초임계추출물 중 괭생이 모자반 열수추출물이 세포독성은 없는 농도 ($50{\mu}g/mL$)에서 $TNF-{\alpha}$, IL-6의 생성뿐 아니라 iNOS 활성화를 통한 NO 분비를 촉진하였다. 이러한 괭생이 모자반 열수추출물의 면역증진 효과는 MAPK 신호전달경로 및 $NF-{\kappa}B$ 활성화를 통해 이루어지고 있음을 확인하였다. 본 연구결과는 괭생이 모자반 열수추출물의 면역활성 증진 가능성을 제시하여 향후 대식세포의 활성 유도를 통한 면역증진 치료에 유용하게 사용될 수 있음을 보여주는 것이다.

생혜탕(生慧湯)이 흰쥐의 학습(學習)과 기억(記憶)에 미치는 영향(影響) (Effects of Saenghyetang on Learning and Memory Performances in Mice)

  • 유금룡;장규태;김장현
    • 대한한방소아과학회지
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    • 제15권1호
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    • pp.77-104
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    • 2001
  • The effects of the oriental herbal medicine Saenghyetang(SHT, 生慧湯), which consists of Rehmanniae Radix (熟地黃 九蒸: was made by 9th steam) 40g, Corni Fructus(山茱黃) 16g, Polygalae Radix(遠志) 8g, Zizyphi Spinosae Semen(酸棗仁) 2g, Biotae Semen(柏子仁 去油: oil ingredient was removed) 20g, Poria Cocos(茯笭) 12g, Ginseng Radix(人蔘) 12g, Acori Graminei Rhizoma(石菖蒲) 2g, Sinapis Semen(白芥子) 8g, on learning ability and memory were investigated. Hot water extract(HWE) and ethanol extract(EE) from SHT were used for the studies. Learning ability and memory are related to modifications of synaptic strength among neurons that interactive. Enhanced synaptic coincidence detection leads to improved learning ability and memory. If the NMDA receptor, a synaptic coincidence detector, acts as a graded switch for memory formations, enhanced signal detection by NMDA receptors should enhance learning ability and memory. It was shown that NR2B was increased in the forebrains of oriental medicine-administrated mice, leading to enhanced activation of NMDA receptors and facilitating synaptic potentiation in response to stimulation at 10-100 Hz. These HWE-SHT treated mice exhibited that superior ability in learning and memory when performing various behavioral tasks, showing that NR2B is enhanced by HWE-SHT treatment and also is critical in gating the age-dependent threshold for plasticity and memory formation. NMDA receptor-dependent modifications, which were mediated in part by HWE administration, of synaptic efficacy, therefore, represent a mechanism for associative learning ability and memory. Results suggest that oriental medical enhancement of NR2B contributes to increase intelligence and memory in mammals On the other hand, to examine the effects of EE-SHT on the learning ability and memory in experimental mice, EE-SHT was tested on passive and active avoidance responses. The EE-SHT ameliorated the memory retrieval deficit induced by ethanol in mice, but not other memory impairments. EE-SHT(10, 20mg/100 g, p.o.) did not affect the passive avoidance responses of normal mice in the step through and step down tests, the conditioned and unconditioned avoidance responses of normal mice in the shuttle box, lever press performance tests and the ambulatory activity of normal mice in a normal condition. However, EE-SHT at 20 mg/kg significantly decrease the spontaneous motor activity during the shuttle box test, and also to extend the sleeping time induced by pentobarbital in mice. These results suggest that SHT has an ameliorating effect on memory retrieval impairments and a weak tranquilizing action.

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순비기나무(Vitex rotundifolia) 줄기 추출물의 폴리페놀 함량과 생리활성 (Polyphenol Compound Contents and Physiological Activities in Various Extracts of the Vitex rotundifolia Stems)

  • 주은영;이양숙;김남우
    • 한국식품영양과학회지
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    • 제36권7호
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    • pp.813-818
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    • 2007
  • 순비기나무(Vitex rotundifolia)의 줄기를 새로운 천연 항산화제나 생리활성 재료로 이용하기 위하여 한류 물 추출물(WE)과 에탄을 추출물(EE) 그리고 열수 추출물(HWE)에 대하여 총 폴리페놀 함량과 전자공여능, SOD 유사활성능, 아질산염 소거능 및 xanthine oxidase와 tyrosinase 저해 활성을 측정하였다. 총 폴리페놀의 함량을 측정한 결과 122.01 mg/g${\sim}$176.34 mg/g으로 EE에서 가장 많은 폴리페놀을 함유하였다. 전자공여능은 1.0 mg/mL의 농도에서 93.46${\sim}$96.92%로 EE가 가장 높았으며 0.1 mg/mL에서도 90% 이상이었으며, SOD 유사활성능은 WE가 47.32%로 가장 높은 활성을 나타내었다. 아질산염 소거능은 pH 1.2의 조건에서 세가지 추출물이 84.61${\sim}$88.36%였으며 pH 3.0에서는 25.83${\sim}$30.24%였다. Xanthine oxidase 저해 활성을 측정한 결과 0.5 mg/mL의 농도에서 세 가지 추출물 모두 90% 이상이었으며, 1.0 mg/mL에서도 91.02${\sim}$97.51%로 EE 추출물이 가장 높은 저해 활성을 나타내었다. 미백효과와 관련이 있는 tyrosinase 저해 활성을 측정한 결과 HWE와 WE는 57.84%와 53.47%를 나타내어 EE(28.79%)보다 높은 저해 효과가 나타났다. 따라서 순비기나무 줄기 추출물은 다량의 폴리페놀을 함유하며 항산화 활성과 xanthine oxidase 및 tyrosinase 저해 활성이 우수하므로 천연 항산화제나 미백 및 기능성 식품소재로써 활용할 수 있을 것으로 기대된다.