• 한국작물학회지
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• 제27권4호
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• pp.296-313
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• 1982

At a time when world population and food supply are in a delicate balance, it is essential that we look at factors to improve this balance. We can alter the environment to better fit the plant's needs, or we can alter the plant to better fit the environment. Improved technology has allowed us to increase the yield level. For moderately detrimental weather events technology has generally decreased the yield variation, yet for major weather disasters the variation has increased. We have raised the upper level, but zero is still the bottom level. As we concentrate the production of particular crops into limited areas where the environment is closest to optimum, we may be increasing the risk of a major weather related disaster. We need to evaluate the degree of variability of different crops, and how weather and technology can interact to affect it. The natural limits of crop production are imposed by important ecological factors. Production is a function of the climate, the soil, and the crop and all activities related to them. In looking at the environment of a crop we must recognize these are individuals, populations and ecosystems. Under intensive agriculture we try to limit the competition to one desired species. The environment is made up of a complex of factors; radiation, moisture, temperature and wind, among others. Plant response to the environment is due to the interaction of all of these factors, yet in attempting to understand them we often examine each factor individually. Variation in crop yields is primarily a function of limiting environmental parameters. Various weather parameters will be discussed, with emphasis placed on how they impact on crop production. Although solar radiation is a driving force in crop production, it often shows little relationship to yield variation. Water may enter into crop production as both a limiting and excessive factor. The effects of moisture deficiency have received much more attention than moisture excess. In many areas of the world, a very significant portion of yield variation is due to variation in the moisture factor. Temperature imposes limits on where crops can be grown, and the type of crop that can be grown in an area. High temperature effects are often combined with deficient moisture effects. Cool temperatures determine the limits in which crops can be grown. Growing degree units, or heat accumulations, have often been used as a means of explaining many temperature effects. Methods for explaining chilling effects are more limited.

• 비파괴검사학회지
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• 제27권5호
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• pp.426-431
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• 2007

고에너지 초음파 여기 탄성파가 물체의 균열, 박리 등의 결함 부위를 통과할 때 서로 맞닿은 결함면은 균일하게 진동하지 않는다. 초음파 입사에 따른 결함 면 사이의 마찰(friction), 문지름 (rubbing) 또는 부딪침(clapping) 에 의해 진동 에너지가 결함 부위에서 국부적인 열로 변환된다. 이를 적외선 열 영상 카메라로 관측하면 구조물의 결함을 실시간으로 검출할 수 있다. 본 논문에서는 초음파 열 영상 검사를 이용한 인코넬 합금 박판의 브레이징 접합 결함 검출에 대해 기술한다. 2 kW 의 전력과 23 kHz 대역의 가진 주파수를 갖는 초음파 펄스를 280 ms 기간 동안 인코넬 합금의 브레이징 접합 박판에 입사시켰다. 브레이징 접합부의 결함위치 부근의 인코넬 합금 박판의 양면이 맞닿은 경계선에서 아주 밝은 국부적인 발열(핫 스팟)이 적외선 열 영상 카메라에 의해 관측되었으며 브레이징 접합 결함 위치에서도 미약한 열이 관측되었다. 배경 감산 평균 및 히스토그램 평활화 처리 등의 영상처리를 통해 브레이징 접합의 결함을 확인하였다.

• 동의생리병리학회지
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• 제18권2호
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• pp.344-348
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• 2004

This study regarded irregular life styles such as nigh-shifts as contrary to the norm advised in the rules of Yang-saeng to analyze the problems brought about in relation to the concept of 'Yin-deficiency syndrome'. Yin-deficiency survey was given to sales workers on a big shopping mall in Seoul to compare the measurements of daytime workers to those of nigh-shift workers. The measurement of complaining symptoms related to Yin-deficiency of daytime workers and night-shift workers were compared, In comparison of the daytime workers and the night-shift workers, night-shift workers showed higher measurements than the daytime workers in the item of irritable fever on the five Hearts, flushing of the zygomatic region in the afternoon, tidal fever, dizziness, insomnia, yellow and scanty urination, and constipation. Especially tidal fever, insomnia, and constipation showed statistically significant difference. The total of ten items consisting of Yin-deficiency-related symptoms showed statistically significant high score in night-shift workers than the daytime workers. 'Factors for deficiency-type Heat' consisting of irritable fever on the five Hearts, flushing of the zygomatic region in the afternoon, tidal fever, and dried mouth and throat showed statistically significant high score in night-shift workers than the daytime workers. 'Accompanying factors' consisting of night sweats, emaciation, dizziness, insomnia, yellowish and scanty urination, and constipation also showed statistically and significantly high score in night-shift workers than the daytime workers. From the above results that night-shift workers show high degree of Yin-deficiency than daytime workers, and those overworking irregularly also show high degree of Yin-deficiency than those who work for adequate amount of time regularly implies that sitting up at night for work and sleeping at daytime, excessive work, and irregular life styles all function as high-risk factor for Yin-deficiency.

• Applied Biological Chemistry
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• 제24권2호
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• pp.85-93
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• 1981

섬유소(纖維素)를 이용(利用)하기 위한 기초연구(基礎硏究)로서 섬유소분해능(纖維素分解能)이 우수(優秀)한 균주(菌株)를 분리(分離)하여 동정(同定)한 결과(結果) Trichoderma spp.로 추정하였으며 사용된 섬유소 기질(基質)은 볏짚을 용제(溶劑)로 전처리(前處理)한 것과 여기에 산, 가열처리(加熱處理)를 더 가(加)한 것을 사용(使用)하였으며 이 미생물(微生物)에 의(依)하여 전처리 및 산 가열처리(加熱處理)에서 생성되는 섬유소 분해 효소(酵素)를 시험한 결과(結果) 0.1% $H_2SO_4$, $120^{\circ}C$, 한시간동안 처리한 것을 기질(基質)로 하였을 때 효소활성(酵素活性)이 높았다. 또한 pH 5.0, 5일(日) 배양(培養)에서 효소활성(酵素活性)이 증가(增加)하였으며 요소첨가시 20%. 인산칼륨첨가시 21%, 육류추출물첨가시 25%, 감귤피첨가시 19%의 증가(增加)를 나타냈다. 48시간(時間) 효소반응(酵素反應)을 시켰을 때 전처리기질(前處理基質)보다 산(酸), 가열처리기질(加熱處理基質)이 효소활성(酵素活性)이 높았으며 24시간후(時間後)에는 활성(活性)이 완만하였다.

• The Journal of Advanced Prosthodontics
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• 제1권3호
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• pp.113-117
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• 2009

STATEMENT OF PROBLEM. Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE. The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM). MATERIAL AND METHODS. Y-TZP blocks of Vita In-Ceram YZ (Vita Zahnfabrik, Bad $S\ddot{a}ckingen$, Germany) were prepared in 40 mm (length) $\times$ 4 mm (width) $\times$ 3 mm (height) samples. Specimens were artificially aged in distilled water by heat-treatment at a temperature of 75, 100, 125, 150, 175, 200, and $225^{\circ}C$ for 10 hours, in order to induce the phase transformation at the surface. To measure the mechanical property, the specimens were subjected to a four-point bending test using a universal testing machine (Instron model 3365; Instron, Canton, Mass, USA). In addition, X-ray diffraction analysis (DMAX 2500; Rigaku, Tokyo, Japan) and SEM (Hitachi s4700; Jeol Ltd, Tokyo, Japan) were performed to estimate the phase transformation. The statistical analysis was done using SAS 9.1.3 (SAS institute, USA). The flexural strength data of the experimental groups were analyzed by one-way analysis of variance and to detect statistically significant differences ($\alpha$= .05). RESULTS. The mean flexural strength of sintered Vita In-Ceram YZ without autoclaving was 798 MPa. When applied aging temperature at below $125^{\circ}C$ for 10 hours, the flexural strength of Vita In-Ceram YZ increased up to 1,161 MPa. However, at above $150^{\circ}C$, the flexural strength started to decrease. Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION. The monoclinic phase started to appear after aging treatment above $100^{\circ}C$. With the higher aging temperature, the fraction of monoclinic phase increased. The ratio of monoclinic/tetragonal + monoclinic phase reached a plateau value, circa 75% above $175^{\circ}C$. The point of monoclinic concentration at which the flexural strength begins to decrease was between 12% and 54%.

• 생태와환경
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• 제49권2호
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• pp.142-146
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• 2016

본 연구는 기후변화에 따라서 예측된 상제나비의 분포 지역에서 나타나는 지형적 특성을 평가하고자 한다. 이를 위해서 상제나비의 잠재적인 서식가능성이 서로 다른 분포지역에서 고도, 산지경사, 그리고 사면향 등 지형요소의 차이를 비교하였다. 고도와 지형경사에 따라서 상제나비가 서식할 가능성은 다르게 나타났고, 사면방향에 대한 영향 보다는 고도와 산지경사의 지형조건에 영향을 더 받을 것으로 나타났다. 특히 미래로 갈수록 상제나비의 서식가능성은 고도가 높은 지역에서 높게 나타났는데, 이는 상제나비가 잠재적으로 서식하기 적합한 현재의 기후환경이 미래에는 고도가 높은 지역으로 형성될 것으로 예상된다. 비록 서식가능성에 따라서 사면향의 차이는 통계적으로 유의하지 않지만, 주로 남동사면에 상제나비의 서식가능성이 다양하다는 것은 유충에서 성충으로 성장하기 위해서 더욱 따뜻한 열 환경 조건에 기인할 것으로 추측된다. 본 연구에서 유도된 결과는 기존에 구축된 다양한 생물 자원 정보를 활용하여 자연생태계분야에서 기후변화와 지형적인 조건을 고려하여 생물종의 서식지를 온전하게 보전하고 관리하는 정책을 수립하는 데 기초자료로 활용될 것으로 기대된다.

• 한국화재소방학회논문지
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• 제25권3호
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• pp.78-84
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• 2011

이 연구에서는 목구조 건축의 화재안전 성능설계기법 개발에 선행하여 목재의 연소특성 자료를 확보하고자 목재의 탄화속도를 측정하였다. $400{\times}400$ mm 단면 북미산 미송을 대상으로 목재 두께와 목리방향에 따른 가열실험결과를 요약하면 다음과 같다. 1) 동일단면에서 목재의 두께가 늘어날수록 탄화속도는 점차 감소하는 것으로 나타났다. 일정 두께 이상의 탄화층은 단열층의 역할을 하여 목재연소를 지연시키는 것으로 판단된다. 2) 목재 두께(20, 40, 80, 120 mm)를 달리하면서 최대 l 시간까지 표준화재에 노출시켜 목재 깊이 (10, 20, 30, 40 mm)별 탄화속도를 비교해본 결과 화재노출면으로부터 30mm 깊이까지는 탄화 속도가 증가하나 40mm에서는 탄화속도가 감소하는 것으로 나타났다. 따라서 단열층으로서 역할을 할 수 있는 탄화층의 최소두께는 적어도 30mm 이상인 것으로 판단된다. 3) 목재 가열면이 목리방향(방사단면)인 경우보다 목리직각방향(횡단면)인 경우 탄화속도가 더 높은 것으로 나타났다. 이는 화재에 노출되면서 목재조직의 수축으로 인한 갈라짐과 터짐 등으로 인해 생긴 틈새로 목재 내부로의 열 유입이 더 잘 일어나기 때문으로 판단된다.

• 한국세라믹학회지
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• 제41권3호
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• pp.266-271
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• 2004

BaTiO$_3$ 소결체에 국부적으로 SiO$_2$를 첨가하고 열처리하여 비정상 입성장을 유도하였다. 열처리 중에 SiO$_2$가 첨가되지 않은 부분에서는 BaTiO$_3$ 기지상 입자의 성장이 아주 느리게 일어났으나, SiO$_2$가 첨가된 부분에서는 BaTiO$_3$ 기지상 입자가 빠르게 성장하였다. 장시간 열처리 후에는 SiO$_2$가 첨가된 부분에서 비정상 입자가 생성되었고, 열처리 중에 연속적으로 성장하여 2 cm 크기 이상으로 성장하였다. 성장한 비정상 입자내부에는 (111) double twin 또는 single twin 등의 결함이 관찰되지 않아, 국부적으로 첨가된 SiO$_2$에 의하여 생성된 액상에 의하여 비정상 입자와 단결정이 성장하였다. 이러한 결과는 BaTiO$_3$계에서 액상 분포의 불균일으로 비정상 입성장이 유도될 수 있으며, 또한 비정상 입성장을 이용하여 쌍정면 결함을 포함하지 않는 cm크기의 BaTiO$_3$ 단결정을 제조할 수 있음을 보였다.

• 한국환경보건학회지
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• 제43권2호
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• pp.143-156
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• 2017

The purpose of this study was to investigate water quality through a field survey at six floor fountain sites. The floor fountain facilities were designed and operated in such a way that tap water was stored in a water tank and recycled repeatedly. The water tank was cleaned once or twice per week in the summer. The number of facility users was low during the day due to sweltering heat, but up to 40 people, mainly children, were using them around 8 pm. Since the operation time was as short as 30 minutes, it is considered necessary to extend it for at least one hour for the number of users. As a result of the water quality test of the reservoir tank prior to operation after cleaning, it was measured to be within drinking water quality standards at the six facilities. As a result of the water quality test after use, ammonia nitrogen was measured to be 1.45 mg/L at Site IV. This exceeded the drinking water quality standard of 0.5 mg/L. In the case of turbidity, two cases exceed at 7.38 and 4.52 NTU when applying 4 NTU as the water quality standard for waterscape facilities. Twenty-eight cases exceed the standard of drinking water quality. The result of microbiological tests, at five sites excepting Site I, where disinfectant was injected, was that the maximum total colony count was 180,000 CFU/mL, total coliforms was 2,100,000 CFU/100 mL, fecal coliforms was 4,600 CFU/100 mL, Escherichia coli was 170 MPN/100 mL and Enterococcus was 100 CFU/100 mL. This exceeded the water quality standards of drinking water. Children are very likely to inhale because the water spews from below and falls from above, so it is necessary to apply water quality standards for ammonia nitrogen, turbidity and microbes. Current floor fountain facilities are highly susceptible to disease caused by microbial contamination because of water cycling and reuse, so it is necessary to change the water every day, clean the water tank, and perform chlorination. Therefore, it is necessary to inject calcium hypochlorite according to the free chlorine water quality standard of swimming pools with a different water tank capacity. In addition, facilities should be improved to prevent the reuse of water by installing the water tank at a separate location.

• 대한한의학방제학회지
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• 제11권1호
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• pp.57-90
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• 2003

The result of Bibliographic studies on the pathological mechanism of the sudden coma, we got the conclusion like this. 1. The sudden coma is an acute syndrome that refers to be a sudden fainting, an unconsciousness, an aphasia or a cold clammy limb, and immediately awakes or dies, and awakes in a short time, and if we awake, it doesn't leave over and above a sequela. 2. The clinical presentation of the sudden coma can be summarized as follows : The 1st is a disease raising the sudden death due to unconsciousness accompanied by wry mouth & sudden syncope with coma. The 2nd is simply the state of cold limbs. The 3rd is the meaning of the physique and symptomes of the six meridians. The last is the ancient method of expression in contrast of the beriberi. 3. The pathological mechanism of the sudden coma consists of the toxoid from outside, Qi and Xie, fatigue, damp phegm, the damage from seven emotions and the damage from five mental elements, especially the mental disorder due to the angry energy, causes the problems when the fleming-up of liver fire and the depressed of liver qi raise the physiological disorder. 4. Therapeutic methods of sudden coma are soothing the liver and remove stasis, soothing depression and circulating of the qi, calming the liver and suppressing yang. When that is early stage, at first, we must checking upward adverse flow of the qi after promoting the circulation of qi and awakening, and then, we must regulate excessive deficiency of yin yang by therapy that is based on differentiated in symptoms according to heat & cold, deficiency & excess, and use invigorating herb medicine for supporting vigour.