• 한국대기환경학회지
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• 제15권6호
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• pp.747-755
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• 1999

Effects of precipitation and cloud cover on high ozone days are examined by investigating the precipitation and average cloud cover before the ozone peak time within a day. High ozone days above 100 ppb in the Greater Seoul Area(GSA) for the ozone season from May to September are chosen for the analyses in terms of the surface meteorological data during 1990~1997. The result shows that the effect of precipitation on the rise of ozone concentration is definitely negative so that ozone concentration could not rise above 100ppb immediately after precipitation. But, the effect of cloud cover is associated with the variations of other meteorological parameters. The number of high ozone days with "zero" cloud cover is rather less than that with cloud cover of 1 to 4 since temperature is usually lower in "zero" cloud cover days. Furthermore, ozone concentration can rise above 100ppb even with full cloud cover when the wind is weak and the temperature is high.temperature is high.

• 환경영향평가
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• 제15권3호
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• pp.207-215
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• 2006

The purpose of this paper is to analyze the spatial distribution and change of the frequency of Yellow Sand days and to examine their relationship with atmospheric circular characteristics at the surroundings of the Korean peninsula. Yellow Sand days data are used by intensity, Siberian High Index and monthly mean temperature of the Northern Hemisphere. In the Middle-western region, the occurrence frequency of Yellow Sand days was higher during the study period (1973-2004). Also, the occurrence frequency of Yellow Sand days increased to latter half 16 years compared with the first half 16 years, and be clearer in Middlewest regions. Yellow Sand days frequency increased, and the trend was distinct in the Jungbu region during the study period. Increasing trend of Yellow Sand days frequency was significant for the recent 22 years. Yellow Sand days had a negative relationship with Siberian High Index in February and March. Therefore, Siberian High Index became weaker in the spring, and possibility for the occurrence of Yellow Sand days was generating larger. Yellow Sand days had a positive relationship in monthly mean temperature of the Northern Hemisphere. Especially, the case of the strong Yellow Sand days is significant. Recently, global warming might be affecting the occurrence of strong Yellow Sand days.

• 한국토양비료학회지
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• 제50권1호
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• pp.1-11
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• 2017

In order to assess risk of high temperature damages about corn during reproduction stages in the future, we carried out analysis of climate change scenarios RCP (Representative Concentration Pathway) 4.5 and RCP8.5 distributed by KMA (Korea Meteorological Administration) in 2012. We established two indexes such as average of annual risk days of high temperature damage which express frequency and strengthen index of high temperature damage. As results of producing maps for 157 cities and counties about average of annual risk days of high temperature damage during total periods of scenarios, the risk of high temperature in RCP8.5 was evaluated to increase at all over nation except inland area of Gangwon province, while RCP4.5 showed similar to present, or little higher. The maps of annual risk days of high temperature damage with 10 years interval in RCP8.5 prospected that the risk for damaging corn growth would increase rapidly from 2030's. The largest risk of high temperature damage in the future of RCP8.5 was analyzed at Changnyeong county located east-south inland area in Kyeongnam province, while the smallest of risk counties were Pyeongchang, Taebaek, Inje, and Jeongseon. The prospect at 12 counties which is large to produce corn at present and contains large plains have been showed that there will be only a little increase of risk of high temperature at Goesan, Yangpyeong, Hongcheon, Seosan, and Mooju until 2060's. But considering strengthen index of high temperature damage, most regions analyzed would be prospected to increase rapidly after 2030's. To cope with high temperature damage of corn in the future, we should develop various practical technologies including breeding adapted varieties and controlling cultivation periods.

• 한국작물학회지
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• 제60권3호
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• pp.266-272
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• 2015

등숙기 고온이 잎의 생리적 활력과 등숙에 미치는 영향을 알아보고자, 동안과 일품 두 품종을 등숙기에 고온 처리하여 등숙 형질을 분석하고, 잎의 광합성, 엽록소 함량 및 엽록소 a/b율 등을 알아보았다. 등숙기 고온($27{\pm}4^{\circ}C$)처리에서 두 품종 모두 등숙률, 완전립률, 천립중이 감소하였으나 일품은 동안에 비해 모두 감소율이 컸다. 엽록소 함량은 등숙초기 고온에서 적온보다 두 품종 모두 증가하였으며, 등숙중기이후 엽록소감소양상은 온도처리에 따른 차이가 없었다. 엽록소 a/b율은 고온에서 감소하였다가 출수후 15일 이후 증가하였으며 적온에서는 출수 이후 지속적으로 증가하였다. 잎의 단백질농도 변화는 고온에서 등숙초기 약간 높은 경향이었으나 이후 처리 간 차이없이 등숙후기까지 지속적으로 감소하였다. 최대 광합성량은 유숙기인 출수 후 14일에 고온이 적온보다 높았고 출수후 7일과, 등숙후기(출수후 34일)에는 유의한 차이가 없었다. 잎의 유리당 함량은 고온이 적온보다 낮았다. 결론적으로 등숙기 고온은 잎의 생리적 활력을 적온보다 오히려 증가 시켜 엽록소함량과 광합성율이 증가하였으므로, 고온에 의한 이삭의 등숙저하는 이삭으로의 전류나 전분축적기작 과정의 문제가 더 클 것으로 생각된다.

• 농업과학연구
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• 제35권1호
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• pp.1-9
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• 2008

메주를 만들 때 저온숙성의 경우 상온숙성보다 발효 특성과 관련이 있는 pH, 아미노산성 질소 등의 양이 낮았으며 동일한 아미노태 질소 함량에 도달하기까지 숙성기간이 약 2~3배정도 필요한 것으로 나타났고, 된장의 색상이 약 2배정도 밝은 것으로 나타났다. 그리고 숙성초기 낮은 온도로 인해 산성생균의 활동성이 낮아지고 이로 인한 유기산 생성량이 낮아져 상온숙성 된장에 비해 pH가 높고, acidity I이 낮으며, 저온숙성된장은 가수분해 효소에 의한 분해속도의 저하로 낮은 아미노산성 질소 함량을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.694-697
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• 2000

Laying hens kept in different light and dark periods of the day at high ambient temperature of maximum $35^{\circ}C$ were challenged to $38.5{\pm}0.5^{\circ}C$ acute heat 3 hours daily for 7 consecutive days. They were found to have a significant (p<0.01) acclimatization response (rectal temperature) to heat stress during the dark period compared to those exposed to the same temperature during the light period. The blood pH was not significantly different. The partial pressure of carbon dioxide ($PCO_2$) was significantly high (p<0.01) except in day 4. Similarly the blood bicarbonate ($HCO_3$) concentration was significantly high (p<0.05) except day three and day four. Acute heat exposure in the first day increased the body temperature in both groups (Light and Dark) reaching $44^{\circ}C$, followed by gradual reduction in body temperature. The dark treated birds showed rapid reduction in body temperature ($42.88^{\circ}C$) and adaptation to high temperature during days 2-4 but that this was lost to some extent in days 6-8. However this was not obvious in the light treated birds. It is concluded that darkness reduce hyperthermia and enhance acclimatization responses during acute heat stress.

• 한국잠사곤충학회지
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• 제33권2호
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• pp.68-71
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• 1991

뽕나무 고조삽목에 있어서 신광뽕을 삽수로 하고 15일간 온도를 15, 20, 25 및 3$0^{\circ}C$로 달리하여 유합촉진시킨 후 3$0^{\circ}C$ 온실베드에 삽목하였을 경우 온도별 발근생장에 미치는 영향을 검토하였다. 1. 유합촉진온도가 높으면 발아가 촉진되어 25 및 3$0^{\circ}C$의 겨우 각각 삽목 6일과 4일후부터 발아하기 시작하여 15일과 10일 후에 100% 발아하였다. 그러나 15 및 2$0^{\circ}C$에서는 8일후부터 발아하기 시작하여 15일 후에 각각 85%, 92% 발아하였다. 2. 높은 온도에서는 조기에 높은 발근율을 나타내어 삽목 15일 g수에 25-3$0^{\circ}C$에서 97-100%이었고 그 이하의 낮은 온도에서는 93%로서 비교적 낮았으며 35일 후에도 같은 경향이었다. 3. 삽목 15일 후에 뿌리수 및 길이는 온도가 높은 만큼 증대하였으나 35일 후의 뿌리수 및 무게는 2$0^{\circ}C$ 이상에서 차가 없었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.115-116
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• 2013

Property of the compressive strength of high strength concrete was investigated in adiabatic temperature history considering hot-weather conditions. As a result, compressive strength of specimens subjected to high temperature history showed more than 120% at 3days of age compare to standard cured specimens. But, at 91days of age showed the incidence of strength less than 100%.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.31-45
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• 2000

Because of the high unit cement content in the concrete mix, major concrete temperature rises are observed in the initial stages of hardening in structural members with large cross-sections made of high-strength concrete. While this temperature rise in the initial stages of hardening contributes to the initial development of the concrete strength, it also causes thermal cracking and obstructs medium to long-term increases of the concrete strength. In the study reports below, investigations were made on the effects of the concrete temperature rise in the initial stages of hardening on the medium to long-term development of the strength of structural concrete between the ages of 28 and 91 days. In the study, comparisons were made, for example, between the compressive strength of a control specimen subjected to standard curing at 28 days and the compressive strength of core specimens taken from structural members, and observations were made on the methods of evaluating the concrete strength in structure, defined here as the compressive strength of core specimens at 91 days. The results obtained indicate that, when the maximum temperature of the concrete is the structure does not exceed $60^{\circ}C$, the concrete strength in structure at the age of long-term will generally be greater than the compressive strength of the standard-curing specimens at 28 days, allowing one to evaluate the strength of the structural concrete in terms of the compressive strength of the 28-days standard-curing specimens. When, on the other hand, the maximum temperature of the concrete in the structure exceeds $60^{\circ}C$, the strength in concrete structure may be smaller than the compressive strength of the 28-days standard-curing specimens, creating risks in the evaluation of the concrete strength in structure by latter.

• 한국건설순환자원학회논문집
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• 제11권1호
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• pp.62-69
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• 2023

UAE 지역에 시공되는 원전구조물의 노출환경에서 대기 중의 높은 황산염 이온 및 해안의 높은 염화물 이온에 의한 열화를 고려할 필요가 있다. 본 연구에서는 연평균 38 ℃ 이상의 높은 온도에 따른 확산성과 강도의 영향을 평가하기 위해 두가지 강도 등급(40 MPa 및 27 MPa) 및 두 가지 양생/확산 온도 조건(20 ℃ 및 50 ℃)을 고려하였다. 초기 양생 온도가 높은 경우, 7일 전 초기재령에서는 압축강도가 고온 양생에서 크게 발현하였으나, 28일 재령에서는 20 ℃ 양생 온도 조건에서 압축강도가 약간 증가하였다. 염화물 확산의 경우, 강도 평가결과와 다르게 28일 재령에서 초기 양생 온도가 높은 경우, 40 MPa 및 27 MPa 에서 모두 확산계수가 감소하였다. 91일 재령의 경우, 온도의 증가에 따른 확산성의 증가와 재령 효과에 의한 확산성의 감소가 동시에 발생하였다. 재령 28일에 20 ℃로 양생 및 확산 실험을 한 결과에 비하여, 재령 91일에 50 ℃로 양생 및 확산 실험을 한 경우, 재령의 증가에 따라 40 MPa에서는 76.2 % 수준으로, 27 MPa 에서는 85.4 % 수준으로 확산계수가 감소하였다.