• 한국농공학회논문집
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• 제47권6호
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• pp.73-82
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• 2005

This study was performed to evaluate the need for heating wastewater to enhance treatment efficiency of organic matter (BOD, SS) during cold winter in newly developed Absorbent Biofilter System (ABS) which was established in the Suwon Campus of the Seoul National University. Treatments consisted of non-heating (2000 year) and heating(2001, 2002 year), and sampled data were analyzed during cold winter period as well as post winter period to investigate the influence of heating after winter season. Even the average air temperature showed only $0.4^{\circ}C$ difference between two experimental years, the difference in the average effluent temperature during cold winter period between heating and non-heating experiment was approximately $11^{\circ}C$. The average effluent concentration of organic matter in non-heating treatment exceeded the Korean standards for water quality of discharged effluent in riparian area (BOD and SS 10 mg/L); however, the standards were met in case of heating treatment during both winter and post winter period. Therefore, the need fur heating wastewater during cold winter season in ABS was justified. On the other hand, there was no improvement of treatment efficiency in T-N and T-p, but we observed the more activated nitrification as increasing the wastewater temperature. Because the average underground temperature was $5^{\circ}C$ higher than the average air temperature during cold winter period, we recommend that the ABS can be established in the underground rather than on-ground for saving the heating cost.

• 한국자동차공학회논문집
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• 제18권6호
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• pp.46-52
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• 2010

In this paper, emission analysis during cold start period of CVS-75 mode in LPG vehicle was performed to find out proper operating conditions of SAI(Secondary Air Injection) system. In order to meet SULEV target, the simulated emission system had a SAI system as well as a MCC(Manifold Catalytic Converter) and a UCC(Under body Catalytic Converter). Using commercial 1-D code AMESIM, in which 7 step global surface chemical reactions of Langmuir-Hinshelwood type were adopted, transient emission analysis in the exhaust system during cold start period of CVS-75 mode were carried out to figure out the effects of flow rate, duration of supply air on HC, CO, NO emission.

• 한국식품저장유통학회지
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• 제18권4호
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• pp.436-441
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• 2011

'캠벨' 포도주스의 이화학적 및 관능적 품질특성에 저온 안정화 처리기간이 미치는 영향을 조사하기 위하여, 포도 과실로 압착 주스를 제조하여 $-5^{\circ}C$에서 30일간 보관하면서 주스의 각종 품질특성 변화를 조사하였다. 주스의 당/산비와 pH는 증가하였으나 적정산도와 가용성 고형분 함량은 경시적으로 감소함을 보였다. 주스의 명도($L^*$ 값)와 황색도($b^*$ 값)는 증가하는 경향을 보였으며 적색도($a^*$ 값)는 감소하는 경향을 각각 나타내었다. 주스의 총페놀, 안토시아닌, 플라보노이드 함량과 유리기 소거능 및 관능적 기호도는 안정화처리 기간이 길어질수록 점차적으로 감소하였다. 이로써 저온 안정화 처리기간은 포도주스의 품질 변화에 영향을 미치며 장기간 처리는 품질을 오히려 저하시키는 것으로 확인되었다.

• 한국의사학회지
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• 제32권1호
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• pp.77-86
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• 2019

The Diary of Muk-Jae is a historical record that describes many social aspects of the Joseon period in the 16th century. It records many scenes of its author, Lee Mun-Geon, treating patients. This paper uses The Diary of Muk-Jae to examine changes in the perception of the concept of cold damage and the text of the Shanghanlun (Treatise on Cold Damage) in the Joseon period in the 16th century. In The Diary of Muk-Jae, cold damage is understood in connection with two categories: 'dangerous disease' and 'disease caused by cold'. The Diary of Muk-Jae also presents the Shanghanlun not as a work limited to the concept of cold damage, but as a medical text that could be widely used for many different diseases. Thus, The Diary of Muk-Jae may represent a point of transition between in the perception of cold damage as seen in the Uibang Yuchui (The Collection of Medical Procedures) of the 15th century and the Donguibogam of the 17th century.

• 한국건축시공학회지
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• 제17권1호
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• pp.73-81
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• 2017

본 연구는 기상자료를 토대로 우리나라 각 지역별 한중 콘크리트 적용기간을 KCI 및 AIJ 규정에 의한 방법으로 각각 산정하고 초기동해 위험일을 각 지역 및 온도 단계별로 제안하고자 하였다. 한중 콘크리트 적용기간의 경우 최근 5년간의 기상자료를 토대로 조사한 결과와 종전의 연구결과를 비교하였다. 연구결과에 따르면 국내 91개 지역의 한중 콘크리트 적용기간은 평균 98일로 조사되었고, 고위도 지역일수록, 산악 및 내륙지역일수록 적용기간은 증가되는 것으로 나타났으며, 종전 연구 대비 본 연구의 적용기간이 1~2일 정도 감소되는 것으로 나타났다. 지구온난화, 도시화 등의 영향으로 판단된다. 초기동해 위험일의 경우 $-5^{\circ}C$, $-2^{\circ}C$ 및 $0^{\circ}C$ 단계별로 시작일 및 종료일을 제시하였으며, 이를 토대로 $0^{\circ}C$ 이하 출현일 수, 출현일 및 평균 추위도를 제시하였다. 본 연구 범위에서 제시된 초기동해 위험일은 KCI에 의한 한중콘크리트 적용기간보다 길게 나타난 지역이 다수 존재하여 한중콘크리트 적용기간 이외에도 초기동해 위험이 있음을 확인할 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.261-264
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• 2003

Cold weather can lead to many problems in mixing, placing, setting time, and curing of concrete that can have harmful effects on its properties and service life. Korean Concrete Institute (KCI) defines cold weather as a period when the average daily air temperature is less $4^{\circ}C$ and recommends to cast concrete with special care such as shielding, heating and so on. The use of high early strength cements may improve the rate of hardening characteristics of concrete in cold weather by making it possible to achieve faster setting time and evolving more hydration heat than ordinary Portland cement. Higher early strength can be achieved using Type III cement especially during the first 7 days. The strength increase property of Type III cement at low temperature was studied. As a conclusion the heat or heat insulation curing period can be reduced to 50~75%. So, it can be used for cold weather concreting to reduce construction cost and extend the construction season.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.326-328
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• 2013

This study compares the periods of cold weather concrete determined by the codes regulated by KCI (Korean Concrete Institute) and AIJ (Architectural Institute of Japan). For the calculation of the periods of cold weather concrete, the climate data for last 5 years obtained from Korean weather forecast station is used. Calculated data indicated that the period of cold weather concrete by AIJ code is longer than that by KCI code. Although global warming causes the decrease of the period of winter season, the temperature differences are large in Korea. Therefore, it is required that the current KCI code should be accordingly upgraded to reflect the weather variation in Korea over time.

• International Journal of Industrial Entomology and Biomaterials
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• 제28권2호
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• pp.51-57
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• 2014

Bumblebees are important pollinators of crops and wildflowers. The Korean native bumblebee, Bombus ignitus, undergoes one generation per year, and induction of artificial hibernation is essential for year-round rearing of the bumblebee. Keeping queens under cold treatment conditions for several mo is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how the timing and duration of chilling affect the artificial hibernation of B. ignitus queens. In the timing assessment, cold treatment was instituted at 12 d, 40 d, or 100 d after eclosion under a constant temperature of $5^{\circ}C$ and 80% humidity. The queens that entered cold treatment at 12 d after emergence evidenced the highest survival rates: 86.7% at two mo, 73.3% at three mo, and 46.4% at 4 mo. Survival rates were reduced under storage conditions at 12 d, 40 d, and 100 d after emergence. When queens were subjected to chilling at 8 d, 12 d, or 16 d after eclosion with constant 80% humidity, the queens stored at 12 d after eclosion exhibited the highest survival rates, which were 84.6 at one mo, 25.0% at two mo, and 7.9% at three mo. In regards to the duration of the cold period, the queens that hibernated for at least two mo evidenced optimal colony development rates. The rates of oviposition, colony foundation, and progeny-queen production of queens hibernated for two mo were 60.0%, 30.0%, and 13.3%, respectively. These values were 6.0 to 13.3 times higher than those in the queens that hibernated for 15 d. Therefore, a cold period of at least 2 mo applied 12 d after emergence were found to be the most favorable conditions for diapause break in B. ignitus queens.

• 한국대기환경학회지
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• 제25권6호
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• pp.481-492
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• 2009

The characteristic of cold water by upwelling in the southeast of the Korean Peninsula and the effect of sea breeze in this region are investigated. The coastal upwelling around the southeast coast of the Korea Peninsula is analyzed by using Coastal Oceanographic Data statistical analyses for 5 years were carried out. The period of an cold water event, on the average, was observed southwesterly wind events. The analysis suggests that strong and persistent southwesterly winds in period of an cold water play an important role of bring the moisture to the surface, generating persistent cyclone as jangma. In order to investigate the effect of cold water on sea breeze, we considered two case. First, Exp. 1 is not occurred coastal upwelling on sea breeze. Second, Exp. 2 is occurred cold water on sea breeze. Two experiments were completed separately to the effects of cold water by upwelling. The results show the sea breeze is stronger in Exp. 2, when the cold water occurs, and weaker in Exp. 1, when there is no cold water. In order to verify the effect of the sea breeze on the cold water by upwelling, on the intensification and change of direction of the prevailing wind, the sea breeze effectively intensify cold water condition.

• The Korean Journal of Pain
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• 제13권2호
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• pp.156-163
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• 2000

Background: Peripheral nerve injury sometimes leads to chronic neuropathic pain such as causalgia. A subset of patients with causalgia have a sympathetically maintained pain which is often evoked by cooling stimuli. However, our knowledge on adrenergic receptor types responsible for cold-evoked pain that is sympathetically dependent is lacking. The present study was conducted to investigate subtypes of adrenoceptors involved in mediating cold-evoked pain that developed following peripheral nerve injury. Methods: Neuropathic surgery was performed by a unilateral ligation of L5 and L6 spinal nerves of rats. Behavioral sign of cold-evoked pain was examined for 5 min by measuring cumulative duration of time that the rat lifted its foot off a metal plate held at cold temperature ($5^{\circ}C$). Whether cold-evoked pain behavior was affected by antagonists of various subtypes of adrenoceptors, which were administered intraperitoneally before and after the ligation, was investigated. Results: After ligation, duration of foot lifting on the ligated side at cold temperature increased as compared to the pre-operative period. This increase maintained for the entire 40-day test period. Pretreatment with alpha-antagonist phentolamine produced a suppression of cold-evoked pain behavior that was not affected by beta-antagonist propranolol pretreatment. Prazosin, alpha-1 antagonist, suppressed cold- evoked pain behavior when treated either before or after nerve ligation. On the other hand, alpha-2 antagonist yohimbine was without effect on cold-evoked pain behavior whether it was treated before or after the ligation. Conclusions: The results suggest that peripheral nerve injury develops cold-evoked pain that is sympathetically dependent, and that alpha-1 adrenoreceptor plays a critical role for the generation of this type of pain in its initiation as well as maintenance.