• 대한토목학회논문집
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• 제8권3호
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• pp.119-128
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• 1988

본 연구의 목적은 불포화 토양내 유기독성물질의 삼계평형분포에 미치는 함수율(0.3~1.255%)과 온도 ($4{\sim}40^{\circ}C$)의 영향을 정량화 하는데 있다. 본 실험에 사용한 토양은 한국토양의 주종을 이루고 있는 마사토이며, 유기독성물질로써는 Dichlolomethane과 1, 1, 1-Trichloloethane을 사용하였다. 토양내 수분이 분포하는 모양에 따른 두가지 가정(가정 1. 토양수분이 토양입자의 표면을 완전히 둘러싸고 있다. 가정 2. 부분적으로 둘러싸고 있다.)에 기초하여 구한 두 모델과 실험결과를 비교하였다. 이 실험의 결과 함수율이 증가함에 따라 $K_{eff}$ 값은 급격히 감소하는 것을 알았다. 또한 온도가 증가함에 따라 $K_{eff}$ 값은 감소하였는데, 함수율이 낮을수록 이러한 온도의 영향은 더욱 크게 나타났다. $K_{eff}$ 값은, 모델II를 이용하여 구한 예측치와 더 잘 일치하였다. 이 결과로부터 토양의 함수율이 매우 낮을 경우, 토양수분은 부분적으로 토양입자를 둘려싸고 있다는 가정이 타당함을 실험적으로 증명할 수 있게 되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.851-858
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• 2002

This study was conducted to determine effects of whole (intact), coarsely-ground (4 mm), finely-ground (1 mm), steam-flaked and steam-flaked-ground (1 mm) corns on in vitro and in situ DM digestibilities and also in vitro fermentation characteristics. After 48 h incubation, in vitro dry matter digestibilities of whole, steam-flaked, coarsely-ground, steam-flaked-ground, and finely-ground corns were 6.79, 61.68, 76.48, 85.72 and 90.31%, respectively. Steam-flaked-ground corn showed the highest digestibility until 24 h incubation (p<0.01). After 48 h incubation, pH of whole corn decreased with a small range. However the values of pH of other media significantly decreased (p<0.01). The gas productions of finely-ground and steam-flaked-ground corns were higher than those of the other corns (p<0.01). After 24 h incubation, $NH_3$-N concentration of finely-ground and steam-flaked-ground corns increased rapidly. Total VFA was the highest in finely-ground corn, followed by steam-flaked-ground, steam-flaked, coarsely-ground and whole corns. Incorporating steam-flaked corn resulted in the highest propionate concentration (p<0.01) and the lowest acetate : propionate value (p<0.05). Finely-ground corn showed the highest in situ DM digestibility throughout the incubation period (p<0.01), followed by coarsely-ground, steam-flaked and whole corns, respectively. Overall, DM of whole corn was merely digested in vitro as well as in situ.

• 한국농공학회지
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• 제9권2호
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• pp.1301-1305
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• 1967

Ground water flow can be studied with model test. Model test of ground water works are necessary for economic and safe design of the works. Also influence of the ground water flow to the durability and safety of hydraulic structures can be studied with this model. a. Sand model ; Water flow through porous media is the principle of sand model. Darcy's formula is the basic equation, $q=k{\frac{dh}{ds}}^{\circ}. The effect of the ground water flow on the grain system itself is represented with this model only. b. Hele-Shaw model ; In this model use is made of the viscous flow analogy. Viscous fluid such as glycerine flowing through two parallel plates depends on Poiseuille law, $q=-c{\frac{dh}{ds}}$. The analogue can be used vertically and horizontally. c. Heat model ; This is based on the analogy of the Fourier's law for heat conduction and Darcy's law for ground water flow. Especially unsteady problem can be studied with this model. A difficulty of the construction of this model is the isolation, which has to prevent losses of the heat. d. Electirc model ; Ohm's law for electric current is analogous to Darcy's law. Resistance material such as metal foil, graphite block, water with salt added, gelatine with salt added, ete. is connected to electric sources and resistor, and equi-voltage line is detected with galvanometer, $N_aCl$, $CuSo_4$, etc. are used as salt in the model. e. Membrane model ; This model is based on the facts that the deflection of a thin membrane obeys Laplace's equation if there is no load in the direction perpendicular to the membrane, and if the dellection is small.

• 한국환경교육학회지:환경교육
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• 제23권1호
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• pp.99-111
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• 2010

The purpose of this study was to investigate high school students' perceptions of biotechnology. Participants in this study were 9th and 10th grade students who were enrolled in high schools in Gyeonggi Province. The survey instrument used in this study was a 26-item questionnaire that was designed to measure students' perceptions regarding biotechnology. The study revealed that students' perceptions were positive toward the use of biotechnology on biological objects such as plant, grain and microbes. However, their perceptions were negative toward the use of biotechnology on humans and animals. Male students' perceptions were more positive than female students and there were significant differences between male and female students(p<.01). The study also revealed that male and female students had positive perceptions about the use of biotechnology in the development of beneficial products. However, male students' perceptions were more positive than female students(p<.01). Female students' perceptions were slightly more negative than males and they indicated a measure of caution in the development of beneficial products using biotechnology. Regarding the reliability of biotechnological information acquired from food companies, TV broadcasters, and entertainers, male and female students tended to be highly negative. Students perceived that environmental, religious and ethical issues did not affect the use of biotechnology when asked the effect of these factors on the use of biotechnology. They perceived that food safety and genetic factors of microbes did affect the use of biotechnology. Thus, the study findings suggest that teaching and learning strategies based on the differences of perceptions between male and female students of this study be established and the use of media, development of teaching method and materials be promoted in order to enhance student's performance in environmental education.

• 한국자기학회지
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• 제5권5호
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• pp.874-879
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• 1995

고 포화자속밀도를 갖는 Fe미세결정 박막의 자기특성 및 미세구조에 미치는 첨가원소의 영향을 조사하였다. Mo 첨가 박막의 경우, $Fe_{2}Mo$, $Fe_{4}N$, $Fe_{3-2}N$상의 생성으로 연자기 특성이 발현되지 않았다. Ta첨가 박막의 경우, 미세한 TaN, TaC 상이 석출하여 $\alpha$-Fe 결정립을 효과적으로 미세화 시켰으며 Fe 질화물의 생성도 억제되었다. 이에 따라 우수한 연자기 특성이 발현되었으며 FeTaN계 박막은 4000, FeTaC 박막은 2700의 높은 투자율을 나타내었다.

• 지구물리
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• 제3권2호
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• pp.99-112
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• 2000

전북 익산시의 쥬라기 화강암은 육안 식별이 가능한 단열이 비교적 적게 발달하고 균질하여 대형 석구조물 및 건축 재료로서 많이 사용되고 있다. 익산 쥬라기 화강암에 물리적인 힘을 가하면 어느 한 방향으로 잘 쪼개지는 결이 존재하는 것이 석공들에게 잘 알려져 있다. 이들 결은 서로 직교하며 취약한 순서에 따라 일결, 이결, 삼결이라 한다. 따라서, 익산 화강암의 물성은 사방정계적 대칭으로 표현될 수 있다. 사방정계의 탄성특성은 9 개의 독립된 탄성강성계수$(C_{1111},\;C_{2222},\;C_{3333},\;C_{2323},\;C_{1313},\;C_{1212},\;C_{1122},\;C_{2233},\;C_{1133})$로 기술된다. 익산 쥬라기 화강암의 정 및 동탄성학적 특징을 구명하기 위하여 화강암괴로부터 여섯방향의 시추공 시료를 제작하여 정탄성 실험과 동탄성 실험을 수행하였다. 정탄성 실험에서는 각 시료의 일축압축에 따른 세방향(축방향과 두 횡방향)의 변형을 측정하였고, 동탄성 실험에서는 각 시료 방향으로 진행하는 종파와 2 개의 수직방향으로 진동하는 횡파의 속도를 측정하였다. 일반 이방성 탄성지배공식으로부터 사방정계 경우를 유도한 결과를 이용하여, 실험 결과와 별도로 측정된 밀도를 사용하여 정탄성계수와 동탄성계수를 구하였다. 정탄성계수는 축응력이 증가함에 따라 탄성계수도 증가하며, 이들 중 24.5 MPa 의 축응력에 대한 정탄성계수가 상압 하에서 동탄성계수와 유사한 것으로 나타났다. 현미경관찰에서 일결, 이결, 삼결과 평행 또는 아평행한 균열들이 미세균열의 주종을 이루고 있는 것이 밝혀졌으며, 익산 쥬라기 화강암이 이방성 탄성특성을 가지는 주된 원인은 이들 미세균열로 사료된다. 이들 결과는 익산 화강암의 석재 이용 효율성을 증가시키는 데 이용되며, 석구조물의 비파괴 안전진단에 이용될 수 있다.

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2119-2128
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• 2017

Citrinin (CIT) is a toxic secondary metabolite produced by fungi belonging to the Penicillium, Aspergillus, and Monascus spp. This toxin has been detected in many agricultural products. In this study, a strain Y3 with the ability to eliminate CIT was screened and identified as Cryptococcus podzolicus, based on the sequence analysis of the internal transcribed spacer region. Neither uptake of CIT by cells nor adsorption by cell wall was involved in CIT elimination by Cryptococcus podzolicus Y3. The extracellular metabolites of Cryptococcus podzolicus Y3 stimulated by CIT or not showed no degradation for CIT. It indicated that CIT elimination was attributed to the degradation of intracellular enzyme(s). The degradation of CIT by C. podzolicus Y3 was dependent on the type of media, yeast concentration, temperature, pH, and initial concentration of CIT. Most of the CIT was degraded by C. podzolicus Y3 in NYDB medium at 42 h but not in PDB medium. The degradation rate of CIT was the highest (94%) when the concentration of C. podzolicus Y3 was $1{\times}10^8cells/ml$. The quantity of CIT degradation was highest at $28^{\circ}C$, and there was no degradation observed at 3$5^{\circ}C$. The study also showed that acidic condition (pH 4.0) was the most favorable for CIT degradation by C. podzolicus Y3. The degradation rate of CIT increased to 98% as the concentration of CIT was increased to $20{\mu}g/ml$. The toxicity of CIT degradation product(s) toward HEK293 was much lower than that of CIT.

• 한국균학회지
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• 제2권1호
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• pp.7-14
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• 1974

본(本) 시험(試驗)은 양송이 복토중(覆土中) 미생물(微生物)의 Mycogone perniciosa Magn.에 대한 항균작용(抗菌作用)및 M. perniciosa 와 Agaricus bisporus (Lange) Sing. 사이의 상호관계(相互關係)를 구명(究明)하기 위하여 실시(實施)되었으며 시험(試驗)한 결과(結果), 1. In vitro test에서 M. perniciosa는 복토(覆土)에서 분리(分離)된 미동정(未同定)의 미생물(微生物)들에 의해서 생장(生長)이 억제(抑制)되었으며 재배시험(栽培試驗)에서 M. perniciosa의 포자현탁액(胞子懸濁液)을 복토표면(覆土表面)에 국소접종(局所接種)하였을 때 라병(羅病)버섯은 접종(接種)된 부분(部分)에서만 발생(發生)되었고 접종부분(接種部分) 주변(周邊)에서는 발생(發生)되지 않았다. 2. M. perniciosa와 A. bisporus사이의 길항적(拮抗的) 관계(關係)는 in vitro test에서 배양기(培養基)의 종류(種類)에 따라 다소(多少) 차이(差異)가 있었으나 A. bisporus의 균사(菌絲)는 M. perniciosa 균총(菌總) 위를 덮어서 자랐다. 재배시험(栽培試驗)에서 M. perniciosa의 포자현탁액(胞子懸濁液)을 A. bisporus의 곡립종균(穀粒種菌) 표면(表面) 혹은 복토층(覆土層)의 중간부위(中間部位)에 분무접종(噴霧接種)하였을 때에는 라병(罹病)버섯이 발생(發生)되지 않았으나, 복토표면(覆土表面)에 접종(接種)하였을 때에만 리병(罹病)버섯이 발생(發生)되었다.

• 대한지역사회영양학회지
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• 제3권5호
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• pp.748-758
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• 1998

The Recommended Dietary Allowances(RDAs, Nutrient standards), dietary guidelines, and food guides, each define aspects for a healthy diet in different ways. The RDA and food guide for Koreans were first established in 1962 by the Food and Nutrition Committee of the Korea FAO Association. The committee released the RDA and suggested ways to intake the recommended nutrients. Every five years, the committee has added more data and released revisions. The latest edition of the RDA is the 6th revision. In the beginning, the concept of basic food groups was emphasized as basic data for planning means based on RDA. In the 5th revision, the basic food groups and dietary guideline for public health from the Ministry of Health and Welfairs(December, 1990) suggests that, 1) Eat a variety of foods with a recommended fat intake equaling or less than 20% of total calories ; 2) Maintain ideal body weight and prevent obesity ; 3) Eat foods low in salt. Salt intake should not exceed 10g ; 4) Do not drink too much ; 5) Eat regularly and enjoy meals. After these guidelines were established, the first nutritonal education efforts guidelines were developed in 1984. Despite broad possibilities for application, they had limited use, mainly as a nutritional assessment and food balance sheet preparation. They were not well utilized in public nutritional education and nutritonal policy through the media because of the weakness of the government's food and nutriton policy. Also a lack of administrative support and dietitians in the health department and administrative organizations was partly to blame. In regard to public health and nutrition status, life expectancy has increased 10 years since the 70's and the elderly population increased threefold in 1995 compared to 1960. The common causes of death in 1996 by 19 Chapters classification, were first disease of the circulatory system ; the second, neoplasms ; the third, external causes fo mortality ; the forth, diseases of the digestive system ; and the fifth, respiratory system diseases, In food intake, grain and complex starch intake has decreased while fruit and animal foods have considerably increased. Therefore, energy from carbohydrates has decreased while energy from protein and fat has increased. Energy intakes from protein, fat and carbohydrates were respectively 12.5, 7.2 and 80.3% in 1969 but 16.1, 19.1 and 64.8% in 1995. 62.9% of the householes had the fat energy less than 20%, while 37.1% had the fat energy above 20%. The only intakes of vitamin A and calcium were below RDA levles. Therefore, nationwide attention should be focused on public nutriton education and public activities with supplementation of the RDAs, according to the food guide and the dietary guideline.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.705-710
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• 2015

The fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ℃. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp³ content in B-NCD films and mean grain size in the range of 100-250 nm. The films deposited on the glass reference samples exhibit high refractive index (n=2.05 at λ=550 nm) and low extinction coefficient. Furthermore, cyclic voltammograms (CV) were recorded to determine the electrochemical window and reaction reversibility at the B-NCD fiber-based electrode. CV measurements in aqueous media consisting of 5 mM K₃[Fe(CN)₆] in 0.5 M Na₂SO₄ demonstrated a width of the electrochemical window up to 1.03 V and relatively fast kinetics expressed by a redox peak splitting below 500 mV. Moreover, thanks to high-n B-NCD overlay, the coated fibers can be also used for enhancing the sensitivity of long-period gratings (LPGs) induced in the fiber. The LPG is capable of measuring variations in refractive index of the surrounding liquid by tracing the shift in resonance appearing in the transmitted spectrum. Possible combined CV and LPG-based measurements are discussed in this work.