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        검색결과 3,224

        701.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This Study is carried out to stabilize the system according to the change of superheat and subcooling in binary refrigeration system by applying cascade system. When the system on 1 st stage was started and the system on the other side was operated, a temperature reversal phenomenon occurred in which the temperature of the 1 st cascade outlet was temporarily lowered. This means that the condensate heat exchange on the 2 nd is not good, which can cause the compressor to overheated. In order to maintain stable system operation, the opening degree of the expansion valve is controlled to increase the refrigerant circulation amount, thereby facilitating the condensation heat exchange on the 2 nd stage system. We have found that the most suitable refrigerant circulation amount is found by stabilizing the operation of the system while lowerning the super low temperature from -65℃ to -70℃ and increasing again to -60℃.
        4,000원
        702.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study aimed to evaluate the performance of a model developed for road surface temperature change pattern in reflecting specific road characteristics. Three types of road sections were considered, namely, basic, tunnel, and soundproof tunnel. METHODS: A thermal mapping system was employed to collect actual road surface temperature and locational data of the survey vehicle. Data collection was conducted 12 times from 05:30 am to 06:30 am on the test route, which is an uninterrupted flow facility. A total of 9010 road surface temperature data were collected, and half of these were selected based on a random selection process. The other half was used to evaluate the performance of the model. The model used herein is based on machine learning algorithms. The mean absolute error (MAE) was used to evaluate the accuracy of the estimation performance of the model. RESULTS: The MAE was calculated to determine the difference between the estimated and the actual road surface temperature. A MAE of 0.48℃ was generated for the overall test route. The basic section obtained the smallest error whereas that of the tunnel was relatively high. CONCLUSIONS: The road surface temperature change is closely related to the air temperature. The process of data pre-processing is very important to improve the estimation accuracy of the model. Lastly, it was difficult to determine the influence of the data collection date on the estimation of the road surface temperature change pattern due to the same weather conditions.
        4,000원
        703.
        2018.10 구독 인증기관·개인회원 무료
        이 연구는 떡갈나무(Quercus dentata Thunb. ex Murray) 유식물을 대상으로 대기 중의 CO2농도와 기온이 상승하였을 때 광(L), 수분(M), 유기물(N) 그리고 토성(S)의 변화에 따라 생육이 어떻게 변하는지 알아본 것이다. 떡갈나무는 낙엽활엽교목으로 전국 표고 800m이하의 산기슭, 산중턱 뿐 아니라 해변가의 야산이나 섬에도 잘 생육하며, 건조한 석회암 지역에서 우점종으로 분포하고 있다. CO2농도와 기온을 상승시킨 온난화처리구와 대기 중의 상태를 그대로 둔 대조구에서 광, 수분, 유기물 그리고 토성을 각각 4구배(1, 2, 3, 4)로 처리하였다. 각 구배 당 24개체씩 파종하여 2017년 3월부터 10월까지 8개월간 생육시킨 후 잎 수, 지하 부/지상부 길이 및 무게, 잎자루/잎몸/잎폭 길이 및 무게 그리고 비엽면적 등 20가지 형질을 측정하였다. 측정한 20가지 형질은 온난화, 광, 수분, 유기물 그리고 토성 환경에 의한 생육반응에서 통계적인 차이가 있었다. 특히 지하부의 반응은 수분이나 토성 보다 광조건에서 차이가 컸고, 이에 따라 식물체 무게와 지하부/지상부 비에도 영향을 주었다. 또한 잎면적은 모든 구배에서 대조구보다 처리구에서 높아지는 경향을 보였으며 특히 유기물을 처리하였을 때 대조구와 처리구 간의 통계적인 차이가 있었다. 이는 유식물이 지구온난화가 진행됨에 따라 광합성을 증가시키기 위한 적응으로 해석된다. 이 성과는 2018년 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임 (No. NRF-2018R1A2B5A01021358)
        704.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고온다습한 하절기에 음수의 형태가 닭의 생산성, 육질, 혈액의 성상에 미치는 영향을 구명하고자 실행하였다. 8일령 로스종 360수를 4개 처리구인 수돗물, 이온수, 냉수 및 냉이온수(냉수+이온수)로 처리구당 6반복으로 평사에 수용하여 5주령까지 급수하였다. 계사내부 평균 온도와 습도는 30.9℃와 74.0%였으며, 수돗물의 평균온도는 29.5℃였다. 이온수는 정전기를 이용하여 물을 이온화하였고, 냉수는 15℃로 고정하여 급수하였다. 증체량, 사료섭취량 및 사료요구율은 주간으로 측정하였으며, 혈액과 계육 샘플은 실험 종료시에 채취하였다. 사육전기 21일령에 증체량은 수돗물 처리구에서 다른 처리구에 비하여 낮았지만 통계적 차이는 없었으며, 사육후기의 35일령에 이온수, 냉수, 냉이온수 처리구에서수돗물 처리구에 비하여 현저하게 높게 나타났다(p<0.01). 사료섭취량은 증체와 동일하게 사육전기에는 처리구간에 일관적 차이가 없었지만 사육후기에 수돗물 처리구에 비하여 다른 처리구에서 매우 개선 되는 경향을 보였다(p<0.01). 사료요구율은 사양실험 전기간에서 이온수, 냉수 및 냉이온수 처리구에서 매우 개선되었다(p<0.05). 계육의 가슴살에서 명도는 수돗물 처리구에서 높게 나타났으며, 적색도는 낮은 경향을 보였다. 황색도는 일관성이 없었지만 pH는 수돗물 처리구에서 다른 처리구에 비하여 낮게 나타났다(p<0.05). 조리감량은 이온수, 냉수 및 냉이온수 처리구에서 수돗물에 비하여 매우 낮았지만(p<0.05) 연도는 높은 경향을 보였다. 혈중 알부민과 단백질은 처리구간에 차이가 없었지만, 중성지방은 이온수, 냉수 및 냉이온수 처리구에서 낮은 경향을 보였다(p<0.05). 혈중 포도당은 처리구간에 차이가 없었지만 HDL 콜레스테롤은 이온수, 냉수, 냉이온수 처리구에서 수돗물 처리구에 비해 현저하게 높게 나타났다(p<0.05). 본 실험 결과 혹서기 육계에 냉이온수 급수는 생산성 및 육질을 개선하고 혈중HDL을 높게 하였다.
        4,000원
        705.
        2018.10 구독 인증기관·개인회원 무료
        외래해충은 자연생태계 교란과 농업환경의 파괴를 가져와 궁극적으로 우리 사회에 엄청난 사회적 비용과 경제적 손실을 유발한다. 이러한 외래해충의 국내 정착 시 대상 해충에 대한 효과적인 방제법과 천적 등의 부재로 박멸에 어려움이 있기에 검역의 역할은 매우 중요하다. 최근 붉은불개미와 금지급 과실파리류는 변화하는 기후와 국가 간교역량의 증가에 따라 최근 국내에서 발견되고 있다. 이를 위해 근연관계에 있는 일본열마디개미와 호박꽃과실파리를 대상으로 내한성을 조사하였다. 그 결과 두 종의 곤충은 저온처리(8℃에서 2시간) 후 체내빙결점의 저하가 나타났다. 또한 저온처리 후 –5℃에서 생존율은 호박꽃과실파리가 일본열마디개미 보다 높은 것으로 조사되었다.
        706.
        2018.10 구독 인증기관·개인회원 무료
        We have investigated the developmental characteristics of super mealworm on different temperatures. The test was conducted with four different temperatures of 25℃, 27℃, 30℃, and 33℃. In developmental period of 1 to 18 instars of four temperatures, 30℃ showed the shortest developmental period as 120.0±5.8 days, and 33℃ (132.6±10.7 days), 27℃ (136.5±9.2 days), 25℃ (156.7±7.5 days) in the following order. The death rate of 33℃ larvae was 2.7- 3.3 times higher than that of other temperatures. The lower temperatures tended to show the longer larval developmental period except 33℃. In the body weight, 30℃ showed the heaviest body weight and 27℃, 33℃, 25℃ in the following order. The head capsule, body capsule and body length also showed a similar tendency with body weight. The 88.8% of prepupa time of super mealworm was 16-18 instars. The longer prepupa time was accompanied by the lower temperature. In average prepupal period of 15-18 instars, 27℃ was 18.8±1.9 days, 18.8±2.3 days in 30℃, 23.0±2.4 days in 33℃, 23.1±2.9 days in 25℃. The average of pupal period of female and male in 25℃- 33℃ was 11.1±2.2 days and 11.6±2.4 days, respectively. In conclusion, the most suitable rearing temperature of super mealwarm was turned out as 30℃.
        707.
        2018.10 구독 인증기관·개인회원 무료
        Diet and temperature are the two most critical environmental factors affecting life-history traits in insects, but the combined effects of these factors have been rarely investigated. In this study, various life-history traits were recorded from adult and larval Drosophila melanogaster fed on one of eight synthetic diets differing in protein:carbohydrate ratio (P:C=1:16, 1:8, 1:4, 1:2, 1:1, 2:1, 4:1, or 8:1) under one of six ambient temperatures (13, 18, 23, 28, 31, or 33oC). The patterns of adult and larval life-history traits expressed across 48 diet-by-temperature combinations were visualized using thin-plate spline technique and the presence of any significant linear, quadratic, and correlational effects of diet and temperature on trait expressions was analyzed using a second-order polynomial multiple regression. Life-history traits exhibited qualitatively different responses to variations in both diet and temperature, with the maximal expression of each trait being achieved at a completely divergent region of the diet-temperature fitness landscape. In adult females, for example, lifespan was maximized at P:C 1:16 under 13oC, but fecundity was maximized at P:C 4:1 under 28oC. These results provide empirical support for the emerging notion that environmental factors, such as diet and temperature, can mediate life-history trade-offs in insects.
        708.
        2018.10 구독 인증기관·개인회원 무료
        진딧물류의 기생성 천적인 쌍꼬리진디벌(Binozys communis)의 진딧물 밀도억제을 조사하기 위해 천적:진딧물을 1:15, 1:10, 1:5의 비율로 접종한 결과, 1:10으로 접종 시 5일차에 첫 머미가 발생하고, 진딧물의 총 개체수도 감소하기 시작하여 8일차부터 진딧물보다 머미의 수가 많아졌다. 쌍꼬리진디벌의 온도별 발육기간은 온도가 높아짐에 따라 알에서 머미까지의 발육기간은 짧아지며 20℃에서는 15.7, 25℃에서는 11.1일, 30℃에서는 10.0일이었고, 암컷 성충의 생육기간은 20℃에서는 3.1일, 25℃에서는 2.5일, 30℃에서는 1.5일이었다.
        709.
        2018.10 구독 인증기관·개인회원 무료
        To investigate the effectiveness of ventilation in bumblebee colony, we ventilated bumblebee(bombus terrestris) colonies using PC cooling fan to replace the fanning behavior of bumblebees, unventilated colonies were used as controls. The temperature of the colonies that were ventilated using the cooler fan was 3 ℃ lower than the control colonies, and the rate of fanning behavior were 9 times lower in ventilated colonies than in the control colonies. Foraging activity and survival rates of worker bees in ventilated colonies doubled compared to the control colonies. Rates of seed set per flower and number of seeds set by bees in the ventilated colonies was 12 % and –15 % and 1.1 and –1.4 times higher pollination, respectively, than for the control colonies. We conclude that installing a ventilation device on the colony box can improve the internal environment of bumblebee colonies at high temperatures through ventilation and that this is a good option to increase pollination effectiveness for the crops in high temperature greenhouse conditions.
        710.
        2018.10 구독 인증기관·개인회원 무료
        Clover cyst nematode, Heterodera trifolii have recently been identified as a serious pest to Chinese cabbage in highland area of Korea. This study was conducted to investigate the host specificity effect of H. trifolii by their inoculation density and temperature on Chinese cabbage and kale in pot in laboratory condition. H. trifolii inoculated with (1, 2, 4, 8, 16 eggs /g soil), where the number of female resulted higher in Chinese cabbage than in kale but there was no statistical differences between them. The number of cysts did not show any variation by their inoculation density in both plants. The results depicted the proliferation of H. trifolii by temperature (15, 20, 25, 30℃), where the number of females, cysts and eggs has their highest proliferation in 20℃ condition. The study thus demonstrated that, Chinese cabbage is considered a suitable host of the clover cyst nematode compared to the kale and the suitable temperature of the reproduction is estimated as 20°C.
        711.
        2018.10 구독 인증기관·개인회원 무료
        This summer, Korea had to deal with extreme heat wave. In this research, fruit flies (Drosophila) were used to analyze the behavior of insects at a high temperature. For the experiment, three male and female fruit flies were put in each of 4 media vials. One vial was incubated at 25°C, the average temperature in August. In three vials, fruit flies were incubated in each 28°C, 30°C, and 32°C for the experiment. The breeding coefficient and death rate were calculated by counting the number of imago fruit flies in each vial and how many of them died. Also, we observed various behavioral differences. The air speed velocity of fruit flies was measured to compare the difference in behavior of fruit flies. Finally, size of them were observed by dissecting microscope. From this research, we can realize the correlation between global warming and the ecosystem of insects.
        712.
        2018.10 구독 인증기관·개인회원 무료
        금지급 과실파리 침입시 대응조치(박멸프로그램) 실행과정에서 박멸프로그램의 종료는 3세대기간 동안 미포획되는 상황을 기준으로 하고 있다. 본 연구에서는 카람볼라과실파리(Bactocera carambolae), 구아바과실파리(B. correcta), 남방고추과실파리(B. latifrons), 작은퀸즐랜드과실파리(B. neohumeralis), 일본귤과실파리(B. tsuneonis) 등 5종에 대한 기존 온도발육자료를 바탕으로 세대기간 추정에 필요한 적산온도 모형을 제시하였다. 각 종의 세대기간 추정에 필요한 발육 영점온도와 적산온도는 칼람볼라과실파리 11.8℃와 384.6 Degree days(DD), 구아바과실파리 11.6℃와 454.5 DD, 남방고추과실파리 10.4℃와 517.5 DD, 작은퀸즐랜드과실파리 9.2℃와 467.8 DD로 추정되었다. 일화성인 일본귤과실파리의 경우는 월동용의 우화모형(발육영점은 11.3℃, 625 DD)을 이용하는 방법을 제안하였다.
        716.
        2018.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        이온성 액체를 이용하여 질산 용액으로부터 Am(Ⅲ)과 Eu(Ⅲ)의 추출 거동을 조사하고 이온성 액체의 활용가능성을 살펴보았다. 이온성 액체로는 1-alkyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][Tf2N])을 사용하였고, noctyl( phenyl)-N,N-diisobutyl carbamoylmethyl phosphine oxide (CMPO)와 tri-n-butylphosphate (TBP)를 추출제로 사용하여, Am(Ⅲ)과 Eu(Ⅲ)의 추출 분배계수를 질산농도, CMPO, TBP와 같은 변수들의 함수로서 측정하였다. 이온성 액체를 사용함으로써 기존의 n-doodecane (n-DD)과 비교하여 추출 효율이 현저히 증가하였다. 질산 용액의 농도가 높을수록 Am(Ⅲ)과 Eu(Ⅲ)의 추출률은 감소하였으며, Eu(Ⅲ)의 추출률은 Am(Ⅲ)보다 전반적으로 작았다. 이온성 액체를 이용한 Am(Ⅲ)과 Eu(Ⅲ)의 추출 메카니즘은 n-DD와 같은 분자성 유기용매를 사용하는 경우와는 달리 양이온 교환 메카니즘에 의해 일어나는 것으로 판명되었다. 사용한 모든 이온성 액체에 대하여 Am(Ⅲ)과 Eu(Ⅲ)의 추출 분배계수는 CMPO의 농도가 높을수록 증가 하고, CMPO 농도에 대한 추출 데이터의 직선 기울기 값은 약 3.0으로 이온성 액체를 이용한 Am(Ⅲ)과 Eu(Ⅲ)의 추출반응에서 3분자의 CMPO가 복합착물을 형성하는 것으로 나타났다.
        4,200원
        717.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Soil is the main nitrogen (N) provider for plants but N in soil is not all available to advanced plants. Mineralization is a critical biological process for transferring organic N to inorganic N that can be used by plants directly. To investigate the effect of different levels of soil temperature and water content to soil mineralization, a field experiment was established on three different sites (A, B and C). We measured soil temperature, moisture and electrical conductivity once daily after swine slurry application. Average soil moisture and temperature in site A is the highest among three sites (40.9% and 9.7°C, respectively). Following is in site C (37.3% and 9.6°C) and the lowest is in site B (28.0% and 9.0°C). Ammonium N (NH4+-N) and nitrate N (NO3--N) were determined on the first and fifth day after treatment. Compared with site B and C, site A always had the highest soil total N content (1.54 g N kg-1 on day one; 1.22 g N kg-1 on day five) and highest NO3-- N content (93.18 mg N kg-1 on day one; 16.22 mg N kg-1 on day five) and a significant decrease on day five. Content of NH4+-N in site B and C reduced while in site A, it increased by 6.7%. Results revealed that net N mineralization positively correlated with soil temperature (P<0.5, r=0.675*) and moisture (P<0.01, r=0.770**), suggesting that to some extent, higher soil moisture and temperature contribute more to inorganic N that can be used by plants.
        4,000원
        718.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Environmental stresses caused by climate change, such as high temperature, drought and salinity severely impact plant growth and productivity. Among these factors, high temperature stress will become more severe during summer. In this study, we examined physiological and molecular responses of maize plants to high temperature stress during summer. Highest level of H2O2 was observed in maize leaves collected July 26 compared with June 25 and July 12. Results indicated that high temperature stress triggers production of reactive oxygen species (ROS) in maize leaves. In addition, photosynthetic efficiency (Fv/Fm) sharply decreased in leaves with increasing air temperatures during the day in the field. RT-PCR analysis of maize plants exposed to high temperatures of during the day in field revealed increased accumulation of mitochondrial and chloroplastic small heat shock protein (HSP) transcripts. Results demonstrate that Fv/Fm values and organelle-localized small HSP gene could be used as physiological and molecular indicators of plants impacted by environmental stresses.
        4,000원
        719.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        포인세티아 ‘Red Pearl’은 국립원예특작과학원에서 2016년에 육성한 품종이다. 생육이 우수한 적색의 착색엽을 가진 포인세티아 ‘Freedom Red’를 모본으로, 키가 작고 밝은 적색의 결각이 깊은 착색엽을 가진 ‘Little Star’를 부본으로 2013년에 교배하여 획득한 실생 계통을 선발한 품종이다. 2014년부터 2015년까지 생육특성, 개화특성, 균일성에 대하여 1, 2차 특성 검정을 실시하였으며 2016년에 3차 특성검정을 실시하여 최종 선발하였다. ‘Red Pearl’의 잎은 계란형의 녹색이고, 초장과 엽병의 길이는 중간 정도이며, 줄기는 녹색으로 적심을 하지 않아도 분지력이 뛰어나다. 하계 고온에서도 줄기 신장이 우수하였으며, 스트레스에 의한 생리장해가 발생하지 않았다. 이 품종은 2018년 1월 24일에 국립종자원에 품종등록(제6922호)되었다.
        3,000원
        720.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to evaluate thermal performance using the ASTR method. Its findings are as follows: 1) The measured U-Values of 49A type and 59A type walls were almost the same as the theoretically calculated values. 2) One notable phenomenon for both walls was that the interior surface temperatures of the channels attached to corners were up to 10.4% lower than that of the cross of the wall, even though they consisted of the same materials. This is due to the surface temperature drop caused by the thermal bridge. 3) The surface temperatures of the thermal bridge were converted into U-Values. The U-Value of the top left corner on the 59A type house was 1.044W/m²K, and of the bottom right corner on the 49A type house was 0.959W/m²K. Therefore, the thermal performance of the thermal bridge area was decreased after construction. 4) Differences were found in the results of comparing heat transfer analysis simulation data and measured data. A maximum difference of 12.4% occurred in the top left corner on 59A type, and of 7.6% occurred in the bottom right corner on 49A type. 5) The results of a heat transfer analysis simulation showed that the temperature of both 49A type and 59A type top right corner were the lowest, but in-situ measurement results were the lowest in the bottom right corner on 49A type and in the top left corner on 59A type. These results are considered to be due to the occurrence of thermal bridges and a deterioration in the construction quality.
        4,000원