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        검색결과 3,224

        741.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 야간조명 하에서 수목이 효율적으로 생장하는 방법을 모색하고자 LED 색온도에 따른 광합성 전자전달 효 율을 검증하였다. 가로수와 조경수로 도시환경에 많이 식생하는 겹벚나무를 대상으로 White 색온도를 비춘 수목과 Warmwhite 색온도를 비춘 수목, 그리고 무처리 수목을 대상으로 건전도를 비교하였으며, 연구방법으로는 엽록소 형광 반응 (OJIP)을 활용해 LED광원 색온도 조건에 따른 광 스트레스 광생리지표 분석을 통해 광화학반응 해석과 건전성 평가를 하였다. 엽록소 형광반응 (OJIP)을 분석한 결과는 모든 처리구에서 처리 후 115일인 생육후기로 갈수록 낮아졌으며, White 광처 리구와 Warmwhite 광처리구에서 J-I구간의 전이 과정 중 생육후기의 형광량이 증가하여 광계I전자전달효율은 감소된 것을 알 수 있었다. 따라서 전자전달효율인 RE1O/CS 및 RE1o/ RC 모두 감소되었다. 이 중 White 광처리구는 Warmwhite 대비 형광량의 증가폭이 컸으며, PITOTALABS는 처리 전 무처리에 비해 가장 높은 수치였지만, 115 DAT에는 가장 낮은 수치로 감소된 것을 알 수 있었다. 본 연구를 통해 White 광을 비춘 수목은 전자전달효율 및 건전도가 낮은 것으로 판단되었으며 상대적으로 Warmwhite 광처리구의 스트레스가 더 낮은 것으로 나타났다.
        4,000원
        743.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ICT 기반 스마트 표고재배시설을 활용하여 표고재배의 과정을 후숙관리, 발이관리, 생육관리 및 휴양관리 4과정으로 나누어 6월부터 10월까지 시험을 진행하였다. 여름철 재배사 외부 25~35oC의 고온환경에서도 재배사 내부의 환경은 설정한 방향으로 제어되었다. 여름철 대표적인 재배용 품종 ‘산조701호’와 신품종 ‘산조717호’를 이용한 재배시험 결과 ‘산조701호’의 경우 353.7 g/봉, ‘산조717호’는 270.4 g/봉으로 ‘산조701호’가 높은 버섯생산성을 나타내었다. ICT 기반으로한 스마트 표고재배시설을 활용한 표고재배는 재배과정별 환경조건 설정으로 재배가 어려운 고온의 환경에서도 편리하게 재배환경 관리가 가능하였으며, 재배품종에 적합한 환경제어 범위를 연구한다면 버섯생산 안정화 및 생산성 향상에 크게 기여할 것으로 판단되었다.
        4,000원
        744.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내 분포조사가 되어 있지 않은 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레를 대상으로 3년간(2015~2017년) 281지점의 관엽식물과 666지점의 과수를 조사하였다. 관엽식물의 경우 긴꼬리가루깍지벌레는 34지점에서 발견되었고, 붉은몸긴꼬리가루깍지벌레는 87지점에서 발견되었으나 과수에서는 두 종 모두 발견되지 않았다. 분포조사를 통해 채집한 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레는 실내사육하며 온도별 발육특성을 조사하였다. 긴꼬리가루깍지벌레 암컷 약충은 14℃에서 정상적인 발육을 하지 못하였으며, 16℃에서는 361.4일로 발육 기간이 가장 길었으며 32℃에서는 39.0일로 가장 짧았다. 긴꼬리가루깍지벌레 암컷 성충수명은 28℃에서 71.7일로 가장 짧았으며, 산자수의 경우 32℃에서 177.7마리로 가장 많았다. 붉은몸긴꼬리가루깍지벌레 암컷 약충은 12℃에서 정상적인 발육을 하지 못하였으며 14℃에서 184.9일로 발육기간이 가장 길었으며, 28℃에서는 21.5일로 가장 짧았다. 붉은몸긴꼬리가루깍지벌레 암컷 성충수명은 28℃에서 51.5일로 가장 짧았으며, 산자수의 경우 28℃에서 143.8마리로 가장 많았다. 세대순증가율(R0)과 내적자연증가율(rm)은 긴꼬리가루깍지벌레는 각각 32℃에서 162.3, 0.127이며, 붉은몸긴꼬리가루깍지벌레는 각각 28℃에서 98.3, 0.139로 가장 크게 나타났다. 따라서, 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레의 최적 온도는 각각 32℃와 28℃로 판단되며 국내에서의 월동은 불가능한 것으로 보인다.
        4,000원
        745.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The main purpose of this study is suggest of field bond strength evaluation method for more objective evaluation method through Evaluation of Bond Strength Properties with changing aspect ratio and temperature. METHODS : The evaluation is laboratory bond strength test. Using the core machine, the pull-off test method ; the bond strength test of interface layer the universal testing machine. RESULTS: As a result of the laboratory bond strength evaluation, it was verified that the bond strength by aspect ratio decreases linearly with increasing aspect ratio and the bond strength properties by temperature change existed at high and low temperature condition relative to odinary temperature condition. CONCLUSIONS: According to the results of laboratory bond strength evaluation, the field bond strength evaluation results suggest applying the proposed correction factor (0.8, 1.0, 1.4, 1.9) according to aspect ratio(0.5, 0.1, 1.5, 2.0), For more objective evaluation of the bond strength, it is analyzed that the evaluation value is within 6 ~ 32℃ and the result can be obtained within 5% of the coefficient of variation.
        4,000원
        749.
        2018.05 구독 인증기관·개인회원 무료
        This study was conducted to develop a heat interception permeability aggregate pavement material that resists increase of air temperature and has permeability by decreasing pavement temperature of city in summer. For this study, a heat interception polymer binder mixed with heat interception material and polyurethane binder. And the study made heat interception permeability aggregate pavement material by mixing heat interception polymer binder. Using the materials, the study conducted flexural strength test and temperature reduction effect experiment. As the result, flexural strength was 5.43MPa average and the temperature reduction effect was effective up to maximum 16 degrees Celsius compared to current asphalt concrete.
        750.
        2018.05 구독 인증기관·개인회원 무료
        The road surface condition in winter is important for road maintenance and safety. To estimate the road surface condition in winter, the RWIS(Road Weather Information System) is used. However RWIS is not measured the continuous road surface information but measured the locational road surface information. To overcome the current RWIS limitation, the thermal mapping sensor which can collect the road surface condition employed in some countries. Although the thermal mapping sensor can collect the continuous road surface information, it is difficult to collect vast data due to apply few probe car. This study suggests a specific methodology for the prediction of road surface temperature using vehicular ambient temperature sensors and collect road surface and vehicular ambient temperature data on the defined survey route in 2015 and 2016 year, respectively. To find out the correlation between road surface and ambient temperature which may affect patterns of road surface temperature variation, the various weather and topographical conditions along with the test route were considered. For modelling, all types of collected temperature data should be classified into response and predictor before applying a machine learning tool such as MATLAB. In this study, collected road surface temperature are considered as response while vehicular ambient temperatures defied as predictor. Through data learning using machine learning tool, models were developed and finally compared predicted and actual temperature based on average absolute error. According to comparison results, model enables to estimate actual road surface temperature variation pattern along the roads very well. Model III is slightly better than the rest of models in terms of estimation performance. When correlation between response and predictor is high, when plenty of historical data exists, and when a lot of predictors are available, estimation performance of would be much better.
        751.
        2018.05 구독 인증기관·개인회원 무료
        In Korea, concrete pavements were first applied to highways in 1981 and as a result of continued increase in length over the past years, 2,592 km of concrete pavement network is currently in service, of which 1,399 km(54%) of concrete pavements is 10 years or older, and 233km(9%) is 20 years or older. The length of concrete pavement sections nationwide has been steadily on the rise every year (EXTRI, 2017). Approximately 54% of current concrete pavement highway network will reach the service life limit in 2025 which means around 660 billion won is needed for future pavement repair project (EXTRI, 2017). Given that concrete pavements beyond design life still have a remaining service life, it is economically advantageous to repair them before reconstruction. Asphalt overlays are a major repair method for older concrete pavements. Depending on the concrete pavement condition, thickness and mixture of asphalt overlays are determined. Service life of asphalt overlays varies by the presence, time and size of cracks in existing concrete pavements and reflecting crack at joints. Temperature change of concrete pavement is among the major reaction parameters of reflecting crack. Reflecting crack develops when asphalt bottom-up cracking by longitudinal shrinkage and expansion due to temperature change of the concrete base layer, top-down cracking by temperature difference between top and bottom of concrete, and shear stress by traffic loading are combined (Baek, 2010). Crack and joint behaviors of concrete pavement vary between the base layer and the concrete surface of composite pavement system, and different conductivity by mixture and thickness of asphalt overlay leads to temperature change of concrete base course. This study measured temperatures of each layer of diverse composite pavements in place on site and analyzed differences in temperature change of concrete base layer depending on mixture and thickness of asphalt overlays. Overlay thickness parameters were 5cm and 10cm, two values most widely used, while mixture parameters were SMA and porous asphalt. Based on temperature change of concrete surface, this study also evaluated the difference of temperature change in concrete base layer with an asphalt overlay on top. Findings from this study are expected to be utilized for studies on mechanism and modeling of reflecting crack in old concrete pavements with asphalt overlays.
        752.
        2018.05 구독 인증기관·개인회원 무료
        Airport concrete pavement slabs show contraction and expansion behavior due to environmental factors such as temperature and humidity. Among the various environmental factors, temperature is the most influential factor in the concrete slab. However, it is inadequate to consider air temperature or surface temperature as influential factors especially for airport concrete slabs with very large thicknesses. Therefore, this study intends to utilize the equivalent linear temperature difference calculated from the data of the thermometer embedded in 5 depths(50mm, 150mm, 250mm, 350mm, 450mm) on the airport concrete slab. Equivalent linear temperature difference is the temperature difference between the uppermost and lowermost part of the concrete slab, which shows the same behavior due to actual temperature. Since the upper part of the concrete slab is more affected by air temperature than the lower part, the daily temperature range is large. Therefore, the equivalent linear temperature difference increases during the day and decreases at night, and concrete slabs show curl-down during the day and curl-up at night. This daily variation of curling behavior causes a difference in HWD experimental results. The HWD(Heavy Weight Deflectometer) test is mainly performed to investigate the condition of the pavement. And the calculated values are deflection, ISM(Impact Stiffness Modulus), LTE(Load Transfer Efficiency). The equivalent linear temperature difference represents the behavior of the concrete slab by the environmental load, and the calculated values by the HWD test represent the behavior. Therefore, the purpose of this study is to investigate the behavior of concrete slab by combined load including environmental load and traffic load through correlation analysis between these values. This study was supported by Incheon International Airport Corporation(BEX00625) and Korea Airports Corporation.
        753.
        2018.05 구독 인증기관·개인회원 무료
        Road construction and maintenance of deteriorated pavement has been continued since industrialization. Demand for aggregate with a good quality has been increasing from limited resources, but it is difficult to supply aggregates smoothly due to environmental protection regulations (Jo et al., 2015). Accordingly, efforts are being made in the road construction industry to utilize industrial products for the purpose of efficient use of resources and environmental preservation. Steel slag which contains a non-reactive CaO is used primarily as a material for embankment and soil covering depending on the expansion and environmental issues. On the other hand, steel slag shows a variety of performance improvements as including increased elasticity factors, increased indirect tensile strength, and improved plastic deformation resistance when handling the expansion issue with sufficient aging processing (Ali et al., 1991, Asi et al., 2007). In this study, the behavior characteristics of the slag asphalt concrete mixture were analyzed according to temperature to encourage the use of steel slag aggregate. Specimens with steel slag showed a higher initial strain than those with natural aggregates. But strain of specimens were nearly similar over the repeated temperature changes. The experimental results for specimens with these characteristics were less likely to cause the performance problems from temperature because the measured strains were relatively small than strain caused from other loads. In conclusion, it is necessary to design and construction process reflecting the behavior characteristics according to temperature to encourage the use of steel slag aggregate.
        754.
        2018.05 구독 인증기관·개인회원 무료
        Tunnel is the main infrastructure in transportation system especially in Gangwon province which has 90% of its area covered by mountains. Responding to the needs for evaluating the tunnel damage in this region, the temperature inside 10 tunnels, one-way and two-way, were measured in winter by using temperature sensors. The temperatures along the length of tunnel, from the entrance until the exit, were obtained from sensors placed at 2 meters above the road. The measurement results showed the distribution of the temperature along the length of the tunnels since November 2016 until March 2017. The data showed that among all the one-way tunnels, the variation of the temperature at all positions along the length of the tunnels have almost the same gradient of temperature of all months observed. There were no significant changes between the temperatures at those points along the tunnel; whereas the changes at the entrances and the exits of the tunnels were remarkable. It was also noticed that there was the different trend of temperature variation between the one-way and two-way tunnels.
        755.
        2018.05 구독 인증기관·개인회원 무료
        연료 전지 구동 시 전기화학적 활성은 촉매와 연료, 전해질이 만나는 삼상계면에서 일어나며 연료전지의 성능은 이 삼상계면의 수에 영향을 받는다. 인산이 도핑된 Polybenzimidazole (PA-doped PBI)을 기반으로 한 고온 고분자 전해질막 연료전지 (HT-PEMFC)의 경우 막 내의 인산이 전해질의 역할을 하며 삼상계면 및 연료전지의 성능에 영향을 끼친다. PBI 막 내의 인산은 고분자 합성 용매인 폴리인산의 가수분해에 의해 생성된다. 본 연구에서는 Sol-Gel 법(Direct casting 법)으로 제조된 PA-doped PBI 막의 가수분해 조건을 달리하여 이에 따른 연료전지의 성능을 비교하여 보았다.
        756.
        2018.05 구독 인증기관·개인회원 무료
        고온형 고분자 전해질 막 연료전지 (HT-PEMFC)는 100°C 이하의 저온 고분자전해질 운영 시스템에 비해 개선된 전극 반응 동역학, 뛰어난 물 및 열 관리, 연료 불순물에 대한 내성 및 폐열 이용과 같은 많은 이점을 제공한다. 그러나 HT-PEMFC는 구동 중 발생하는 물의 증발과 함께 분리막 내 인산이 증발하여 성능이 낮아진다는 단점이 있다. 때문에 본 연구에서는 이러한 인산의 유출에 대한 핫 프레스 유무, 전극 GDL 종류, 분리막 가수분해 조건, 셀 성능에 따른 영향을 인산의 비색정량을 통해 분석하였다. 그 결과 인산의 유출량은 주로 셀성능에 영향을 받으며 GDL이 치밀할수록 억제됨을 확인하였다.
        757.
        2018.05 구독 인증기관·개인회원 무료
        We synthesized the poly(4-vinylbenzyltributylammonium hexanesulfonate) P[VBTBA][HS] which was obtained via anion exchange with hexanesulfonate after acquiring monomer [VBTBA][Cl] by Menshutkin reaction to investigate its feasibility as draw solute for forward osmosis process. P[VBTBA][HS] shows lower critical solution temperature (LCST) property at about 21℃, while LCST property of [VBTBA][Cl] and P[VBTBA][Cl] was not confirmed. This result suggests that P[VBTBA][HS] can be recovered from solution by heating them to above LCST. In AL-FS mode with solution of 20 wt% P[VBTBA][HS] at 15℃, water flux and reverse solute flux were found to be about 6.43 LMH and 0.59 gMH. This study can provide an understanding of new way of proceeding draw solute and information for the potential design and synthesis of thermo-responsive organic material.
        758.
        2018.05 구독 인증기관·개인회원 무료
        Recently, among the water treatment technologies, the forward osmosis (FO) system has been received much attention due to the advantages in energy consumption. However, the practical application of the FO system has been limited because of the remaining obstacles such as the absence of both adequate draw solute and efficient membrane. In this study, polymers having lower critical solution temperature (LCST) and upper critical solution temperature (UCST), one of the temperature-responsive characteristics, are used as the draw solutes. These materials could be recovered easily by heating them to above their LCST and to below their UCST, respectively. Finally, we believe that our results will provide insight into the synthesis of temperature-responsive draw solutes for water treatment applications.
        760.
        2018.04 구독 인증기관·개인회원 무료
        The effects of temperature (150°C and 160°C) on physicochemical properties of extruded texturized vegetable protein with mealworm (0%, 15%) were studied. The extrusion process had a screw speed of 250 rpm, moisture content of 65%. The variation of formula was gluten content of 40% in 4 samples and none of gluten in 4 samples. As addition of mealworm increased and temperature increased, breaking strength and integrity index decreased, The nitrogen solubility index and protein digestibility increased as addition of mealworm increased and temperature decreased. DPPH radical scavenging activity significantly increased as addition of mealworm increased and temperature increased. On the contrary, the value of rancidity decreased as addition of mealworm increased even in 60 days. In conclusion, addition of mealworm became softer texture, and protein quality of the extruded texturized vegetable protein. The process promoting functionality such as improvement of antioxidant function was confirmed through this study. Also, adjusting temperature have an effect on protein content and antioxidation. The addition of gluten of 40% resulted in improving texture of TVP.