• 제목/요약/키워드: Property ($C_k$)

검색결과 3,020건 처리시간 0.055초

토양의 형태 및 물리적 특성을 고려한 고추재배 적지 기준 설정 (Suitability Class Criteria for Red Pepper with Respect to Soil Morphology and Physical Properties)

  • 정석재;박병식;장갑수;현병근;임상규
    • 한국토양비료학회지
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    • 제37권5호
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    • pp.336-340
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    • 2004
  • 고추 주산단지인 충북 제천, 괴산, 경북 의성, 안동 전남 고창 및 강원 평창 등 6개 지역 119 농가포장을 중심으로 실시한 세부정밀토양조사 결과에 의해 밝혀진 토성, 배수 등급, 경사, 석력함량, 유효토심 등의 토양특성과 고추 수량을 비교하여 고추 재배지의 적지기준을 설정하였다. 고추재배지의 토양물리성과 고추수량을 비교하여보면 사양질의 토성, 양호한 배수, 7-15%의 경사, 석력함량 10-20%, 유효토심 100 cm 이상, 경반층 깊이가 100 cm 이상이며 암반노출이 없는 토양에서 수량이 가장 높았다. 고추의 역병 발병율은 점토함량이 많고, 배수가 불량하고. 포장의 경사가 완만하며 석력함량이 적을수록 높아지는 경향이었다. 충북 진천군에 고추 재배적지 기준을 적용한 결과 최적지 22.5,% 적지 21.3%, 가능지 16.0%, 저위생산지 40.2%로 나타났으며 타 지역도 적용할 수 있는 지리정보기반을 구축하였다.

생불활성 질화물 이온도금된 티타늄 임프란트의 표면특성 및 생체적합성 (Surface characteristics and biocompatibility of bioinert nitrides ion plated titanium implant)

  • 장갑성;김흥중;박주철;김병옥;한경윤
    • Journal of Periodontal and Implant Science
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    • 제29권1호
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    • pp.209-231
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    • 1999
  • Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer, Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and biocompatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti, Button type specimens(14mm in diameter, 2.32rrun in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens .of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN/Ti, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing 10kg-13kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrified for the removal torque test of the implant') after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-1000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti, In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1), In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion, The removal torque force of Tilv/Ti showed significantly higher than that of Ti(p(O,05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant(p>0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.

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MC-50 싸이클로트론을 이용한 $^{123}I$ 제법 연구 (The Development of Iodine-123 with MC-50 Cyclotron)

  • 서용섭;양승대;전권수;이종두;한현수
    • 대한핵의학회지
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    • 제25권2호
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    • pp.286-293
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    • 1991
  • $^{123}I$, which is applied for the thyroid and other in vivo kinetic study, has a special role in life sciences. The 159 KeV $\gamma-ray$ from $^{123}I$ is almost ideally appropriate for the current imaging instrumentation. Its decay mode (electron capture) and short half-life (13.3 hr) reduced the burden of radiation dose to the patients, and its chemical property makes it easy to synthesize the labelling compounds. In this experiment, the production of $^{123}I$ via the nuclear reaction $^{124}Te(p,2n)^{123}I$ with 28 MeV protons was sutdied. $TeO_2$ is used as a target material, because it has good physical properties. The target was prepared with $TeO_2$ powder and was molten into a ellipsoidal cavity (a=14 mm, b=10 mm, $270.8mg/cm^2$ thick) of pure platinum. The irradiation was carried out in the external proton beam with incident energies range from 28 MeV to 22 MeV, and current was $30{\mu}A$. The loss of $TeO_2$ target was significantly reduced by using $4\pi-cooling$ system in irradiation. The dry distillation method was adopted for the separation of $^{123}I$ from irradiated target, and when it was kept 5 minutes at $780^{\circ}C$, its result was quantitative. The loss of the target material $(TeO_2)$ was below 0.2% for each production run and $^{123}I$ from the dry distillation apparatus was captured with 0.01 N NaOH in $Na^{123}I$ form, then the pH of the solution was adjusted to $7.5\sim9.0$ with HC1/NaOH. The $Na^{123}I$ solution was passed through $0.2{\mu}m$ membrane filter, and sterilized under high pressure and temperature for 30 minutes. The production of $^{123}I$ is acceptable for clinical application based on the quality of USP XXI.

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$M{\ddot{o}}ssbauer$ 분광법에 의한 원자로 용기재료의 비파괴적 중성자 조사평가에 대한 연구 (Study of the Nondestructive Test Method for the Embrittlement Evaluation of Nuclear Reactor Vessel Material by $M{\ddot{o}}ssbauer$ Spectroscopy)

  • 정명모;장기상;유근배;김길무;윤인섭;홍치유
    • 비파괴검사학회지
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    • 제20권3호
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    • pp.183-190
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    • 2000
  • 본 연구에서는 고속 중성자가 조사된 원자로 용기 재료의 자기적 성질 변화를 $M{\ddot{o}}ssbauer$ 분광법을 이용하여 측정하였으며, X-선 회절실험을 이용하여 중성자 조사재료의 결정성 변화를 평가하였다. 시편은 크기가 $23mm{\times}18mm{\times}70{\mu}m$로 제작되었으며, 343K에서 $10^{12}n/cm^2{\sim}10^{18}n/cm^2$의 범위에서 중성자 조사를 하였다. X-선 회절실험 결과로부터, $10^{16}n/cm^2$의 중성자가 조사된 시료에서부터 결정성이 변화가 시작되고, $10^{17}n/cm^2$ 이상의 중성자가 조사된 시료에서 결정성이 심각하게 손상되는 것이 관찰되었다. 또한 $M{\ddot{o}}ssbauer$ 분광실험으로부터 중성자 조사량이 $10^{16}n/cm^2$ 이하인 시료에서는 자기적성질의 변화가 관찰되지 않았으나, $10^{17}n/cm^2$ 이상의 중성자가 조사된 시료에서 자기완화 현상이 일어나는 것이 관찰되었다. 따라서 두 실험 모두 비파괴적 실험방법에 따른 중성자 조사취화 평가로 활용이 가능한 것으로 평가되었다.

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마이크로역학에 의하여 설계된 ECC (Engineered Cementitious Composite)의 역학적 특성 (Mechanical Properties of an ECC(Engineered Cementitious Composite) Designed Based on Micromechanical Principle)

  • 김윤용;김정수;김희신;하기주;김진근
    • 콘크리트학회논문집
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    • 제17권5호
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    • pp.709-716
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    • 2005
  • 이 연구는 국내에서 상용 중인 재료를 이용하여 고인성 섬유복합 모르타르를 개발하고자 함에 목적이 있으며, 고인성 섬유복합 모르타르를 개발하기 위해서는 모르타르 매트릭스의 파괴역학(fracture mechanics)적 특성과 섬유-모르타르 경계 면의 마이크로역학(micromechanics)적 특성을 파악하여야 한다. 특히 시멘트계 재료(cementitious materials)의 역학적 특성에 가장 큰 영향을 미치는 물-시멘트비(water cement ratio)에 대한 연구에 초점을 맞추었으며, 3가지의 물-시멘트비에 대하여 섬유의 인발실험(fiber pullout test)과 모르타르의 쐐기쪼갬실험(wedge splitting test)을 수행하였고 이를 통하여 모르타르 매트릭스와 섬유-매트릭스 경계면(interface)의 역학적인 특성을 파악하였다. 이러한 연구에 의하여 결정된 섬유-매트릭스 경계면의 마이크로역학적 특성과 모르타르의 역학적 특성을 이용하여 물-시멘트비 범위 및 재료의 기본 배합을 제시하였고 또한 마이크로역학과 안정상태 균열이론(steady-state cracking theory)을 배경으로 하여 1축인장 하에서 인장변형률 경화거동을 나타내는 고인성 섬유복합 모르타르를 개발하였다. 개발된 재료는 1축인장 하에서 변형률 경화거동을 나타내었으며, 변형능력은 최대 2.2% 이었다. 이와 같은 높은 변형 능력은 일반 콘크리트(또는 모르타르)의 약 100배에 해당된다. 또한 압축하에서는 압축강도 이후 응력-변형률 곡선이 완만하게 감소하는 연성파괴의 형태를 나타내었으며 28일의 압축강도는 보통강도 콘크리트의 강도에 해당되는 26MPa, 34MPa인 것으로 측정되었다.

이온도입에 의한 염산프로카인의 경피전달 증대 -고전압전류 및 초음파 병행의 상승효과 비교- (Enhanced Transdermal Delivery of Procaine Hydrochloride by lontophoresis -Comparison of Synergic Effect of High Voltage Current and Ultrasound-)

  • 이종숙;김경원;이재형;최영욱;이재휘
    • Journal of Pharmaceutical Investigation
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    • 제36권3호
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    • pp.185-192
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    • 2006
  • The purpose of this study was to determine the effects of iontophoresis on transdermal delivery of procaine hydrochloride in healthy volunteers, as well as to the synergic effect of high voltage current or ultrasound on the efficacy of transdermal delivery of iontophoresis. Forty healthy volunteers were randomly assigned to four groups topical application group (TA), iontophoresis group (IT), pre-treatment of high voltage current stimulation with iontophoresis (HVS + IT), and pre-treatment of ultrasound application with iontophoresis (US + IT). All subjects received procaine iontophoresis on the forearm using direct current with 4 mA f3r 15 minutes. All subject was measured the duration of local anesthesia, pressure pain threshold, pain perception threshold using rectangular wave at 0.2 ms, 1 ms, 50 ms of rectangular current stimulation after procaine iontophoresis. For comparisons of the sensory characteristics and efficacy of iontophoresis between the groups, an one-way ANOVA and Kruskal-Wallis were used. The significant difference the duration of local anesthesia were found between the groups (p<0.001). The local anesthetic duration of IT, HVS+IT were significantly longer than TA. Meanwhile, the local anesthetic duration of US+IT was significantly longer than HVS+IT, IT and TA group (p<0.05). Also, the pressure pain threshold, pain perception threshold at 0.2 ms, 1 ms, 50 ms were significant difference between the groups (p<0.001). All sensory characteristics including pressure pain threshold, pain perception threshold of IT, HVS+IT was significantly increased than TA, whereas, US+1T was significantly increased HVS+1T, IT and TA (p<0.05). This study showed that the procaine iontophoresis have increase the duration of local anesthesia concomitantly pressure pain threshold and pain perception threshold of sensory nerve fibers such as $A-{\beta}$, $A-{\delta}$ and C fiber. This findings suggest that the iontophoresis enhanced the transdermal delivery of drug ions in vivo. The combination of ultrasound application and iontophoresis synergized the transdermal delivery of drug ions. It is suggests that an electric field, mechanical and heating property of ultrasound may contribute to synergic effect due to temporary changes of structure in the stratum corneum.

서방형 이산화염소 가스를 이용한 이슬송이버섯의 저장 중 품질 변화 (Quality Changes of Lentinula edodes GNA01 Mushroom by Choline Dioxide Gas Treatment during Storage)

  • 윤영태;봉소정;강한솔;윤예지;김홍길;민경훈;이경행
    • 한국식품영양학회지
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    • 제29권4호
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    • pp.499-505
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    • 2016
  • To improve the shelf-life of mushrooms, Lentinula edodes GNA01 mushrooms were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 5~10 ppm for 5 days at $20^{\circ}C$ and the weight loss rate as well as the changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples were decreased slightly, and there were no differences during the storage period. However, the weight of the control changed faster than those of the $ClO_2$ gas treated samples during storage period. The pH in the control and in the $ClO_2$ gas treated samples were decreased during storage period, but the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. On the other hand, the samples treated with 10 ppm $ClO_2$ gas showed no difference from the other treatments during 4 days, but the pH was lower than that of the control on the fifth day. The lightness of inside and outside in mushroom were decreased whereas redness and yellowness were increased during storage period. However, color changes in the $ClO_2$ gas treated samples were lower than those of the control. Especially, the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. The texture of the mushroom were decreased consistently during storage period. The texture of the control changed faster than those of the $ClO_2$ gas treatments during 5 days. Especially, the samples treated 5 ppm $ClO_2$ gas were the least changed.

Preparation of diffusion dialysis membrane for acid recovery via a phase-inversion method

  • Khan, Muhammad Imran;Wu, Liang;Hossain, Md. Masem;Pan, Jiefeng;Ran, Jin;Mondal, Abhishek N.;Xu, Tongwen
    • Membrane and Water Treatment
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    • 제6권5호
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    • pp.365-378
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    • 2015
  • Herein, the preparation of anion exchange membrane (AEM) from brominated poly(2,6-dimethyl 1,6-phenylene oxide) BPPO and dimethylaniline (DMA) by phase-inversion process is reported. Anion exchange membranes (AEMs) are prepared by varying the DMA contents. Prepared AEMs show high thermal stability, water uptake (WR) around 202% to 226%, dimensional change ratios of 1.5% to 2.6% and ion exchange capacities (IECs) of 0.34 mmol/g to 0.82 mmol/g with contact angle of $59.18^{\circ}$ to $65.15^{\circ}$. These membranes are porous in nature as confirmed by SEM observation. The porous property of membranes are important as it could reduce the resistance of transportation of ions across the membranes. They have been used in diffusion dialysis (DD) process for recovery of hydrochloric acid (HCl) from the mixture of HCl and ferrous chloride ($FeCl_2$). Presence of $-N+(CH_3)_2C_6H_5Br^-$ as a functional group in membrane matrix facilitates its applications in DD process. The dialysis coefficients of hydrochloric acid ($U_H$) of the membranes are in range of 0.0016 m/h to 0.14 m/h and the separation factors (S) are in range of 2.09 to 7.32 in the $HCl/FeCl_2$ system at room temperature. The porous membrane structure and presence of amine functional group are responsible for the mechanism of diffusion dialysis (DD).

발효쌀겨 배합사료 급여가 돈육의 육질 개선에 미치는 효과 (Effects of Fermented Rice Bran Addition on the Quality Improvement of Pork)

  • 김동엽;;최다혜;박현실;한기동
    • 한국식품과학회지
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    • 제39권6호
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    • pp.608-613
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    • 2007
  • 본 연구는 발효쌀겨의 급여(10-20%)가 돈육의 품질에 미치는 영향을 알아보고자 실시되었다. 일반성분평가결과, 발효쌀겨 20% 급여구의 돈육이 급여하지 않은 대조구 돈육에 비하여 수분함량이 높고, 지방함량이 낮은 경향이었으나 유의적 차이는 없었다. 이화학적 특성결과, 가열감량은 처리구가 대조구에 비하여 유의적으로 낮았다(p<0.01). 육질평가에서 가장 중요한 항목인 보수력은 처리구가 대조구에 비하여 높게 나타났다(p<0.01). 돈육의 연도를 측정하는 전단력(shear force)은 대조구와 처리구 사이에서는 유의적인 차이가 없는 것으로 나타났으나, 지방함량이 적고 보수력이 높은 발효쌀겨 20% 급여구에서 높은 특성을 나타내었다. 총 유리아미노산은 발효쌀겨의 첨가수준이 높을수록 그 양이 증가하였다. 육의 추출물에서 맛과 풍미에 중요한 역할을 하는 아미노산인 glutamic acid, glycine, alanine(16) 등의 함량이 발효쌀겨를 급여한 돈육에서 증가하는 경향을 나타내었다. 지방산 조성은 처리구와 대조구간 유의적인 차이가 없었으나(p>0.05) stearic acid(C18:0)에서 발효쌀겨의 급여수준에 따라 그 조성이 증가하는 경향을 보였다. 관능평가 검사 결과, 육색, 냄새, 다즙성, 맛, 전체적 기호도에서 처리구가 다소 높은 점수를 얻었으나, 모든 관능검사항목에서 처리구와 대조구 간 유의적인 차이는 없었다(p>0.05). 이상의 결과를 종합하면, 발효쌀겨급여는 돈육의 육질 개선에 효과가 있는 것으로 판단된다.

서방형 이산화염소 가스 젤팩을 이용한 닭가슴육 저장 중 품질 변화 (Quality Changes of Chicken Breast Meat by Slow-Released ClO2 Gas Gel-Pack during Storage)

  • 이경행;윤예지;권혜원;이봄;김홍길
    • 한국식품영양학회지
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    • 제31권1호
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    • pp.127-134
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    • 2018
  • To prolong the shelf-life of chicken breast meat, samples were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 7~15 ppm for eight days at $4^{\circ}C$. The microbial, physicochemical properties and sensory evaluation of the treated samples were investigated. The total number of bacteria in the control increased during storage and showed 6.78 log CFU/g on the 8th day of storage, but $ClO_2$ gas treatments showed 6.24~6.58 log CFU/g at the same time. The initial pH of chicken breast meat was 6.00 and gradually increased during storage. And $ClO_2$ gas treatments did not show any significant difference from the control during storage period, but maintained a generally lower pH than that of the control. The lightness, redness, and yellowness during storage were not significantly different between the control and the 7~10 ppm $ClO_2$ gas treatments. However, as the storage period was increased, the redness of 15 ppm $ClO_2$ gas treatment was reduced. The cooking loss and shear force were not different between the control and $ClO_2$ gas treatments during the storage period. Volatile basic nitrogen (VBN) increased in the control from the 6th day of storage and 23.80 mg% in the 8th day of storage. However, VBN of $ClO_2$ treatments showed lower than that of the control. In the change of sensory evaluation during storage, 10 ppm $ClO_2$ treatment showed the highest preference in odor, appearance and overall acceptance during storage period.