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      검색결과 641

      1.
      2025.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
      The swallowing reflex is modulated by multiple sensory inputs, such as bolus volume, viscosity, and taste. The interactions among different types of sensory information have been extensively studied. However, the influence of oral temperature on bolus volume perception has not been investigated. The aim of this study was to assess the effect of temperature on volume perception sensitivity in healthy individuals. Five volumes (5, 10, 15, 20, and 25 mL) of distilled water were estimated at three different temperatures, 4℃ (cold), 21℃ (room temperature), and 45℃ (warm), using a visual analogue scale. There were no significant differences in the sensitivity of oral volume perception across temperatures. These findings suggest that the ability to perceive bolus volume remains stable under temperature variation.
      4,000원
      2.
      2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
      To analyze the effect of fire in electric-vehicle battery on concrete cement structure. A scenario evaluation was conducted for fire occurrence due to external influences on lithium battery cells used in electric vehicles. Visual inspection was conducted at each stage of the battery fire, and the fire duration and temperature were measured. The battery temperature rise curve and temperature during fire have been examined previously. The stability of a cement structure was evaluated via X-ray diffraction and SEM analyses of the reaction-product changes with respect to temperature. The battery temperature rise curve shows that the battery begins to change at 200 °C–300 °C. However, the general stage of battery damage cannot be readily confirmed from the literature. The current experiment and literature review indicate that battery fire can cause the fire temperature to increase beyond 1000 °C within a few seconds. The reaction product changes structurally in cement from 300 °C or higher. Many voids are generated owing to the decomposition of Ca(OH)2 and C-S-H gel. The temperature of an electric-vehicle fire increases rapidly to 1000 °C or higher within a few seconds. High temperatures change the reaction products in cement structures, thus creating internal voids and cracks and reducing the stability of the structure; therefore, the appropriate countermeasures must be identified.
      4,000원
      3.
      2025.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
      본 연구에서는 저온 스트레스에서 살리실산(SA, salicylic acid)의 경엽처리가 배추의 광합성, 생리활성 및 생육에 미치는 영향을 구명하고자 하였다. SA을 각각 0.25, 0.5 및 1mM 농도로 주당 100mL을 4일 간격으로 3회 엽면 살포하였고, 7일간 저온 스트레스를 처리하였다. SA 처리 시 광합성 속도, 기공전도도, 세포 내 CO2 농도 및 증산 속도는 무처리 대비 증 가하였고, 2회 처리 후 가장 높았다. MDA 함량은 무처리 대 비 유의한 차이를 보이며 감소하였다. APX, CAT, POD 및 SOD 활성은 무처리 대비 현저하게 증가하였으며, 각각 최대 62, 81, 55 및 26% 증가하였다. 배추의 생육 특성은 무처리와 유의한 차이를 보이지 않았으나, 수량 지수는 2-6% 정도 증 가하였다. 따라서 SA의 경엽처리는 배추의 생육, 광합성 특성 및 항산화 효소 활성을 증대시켜 저온 스트레스를 완화 하였 고, 적정농도는 0.5-1mM이라 판단된다.
      4,000원
      4.
      2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
      This study investigated whether calcium (Ca) addition improved the recovery of neodymium (Nd) and dysprosium (Dy) from Nd-Fe-B magnet scrap using magnesium (Mg)-based liquid metal extraction (LME). Traditional LME processes are limited to temperatures up to 850 °C due to oxidation issues, reducing the efficiency of rare earth element (REE) recovery, especially for Dy. By adding 10 wt.% Ca to Mg and increasing the processing temperature to 1,000 °C, we achieved nearly 100% Nd and approximately 38% Dy recovery, compared to 91% and 28%, respectively, with pure Mg at 850 °C. However, excessive Ca addition (20 wt.%) decreased the recovery efficiency due to the formation of stable intermetallic compounds. These results highlight the critical role of Ca in optimizing REE recycling from Nd-Fe-B magnet scrap.
      4,000원
      5.
      2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
      In this study, Pleurotus ostreatus were grown in bottles at temperatures set to 15°C, 20°C, and 25°C inside the cultivation room. Changes in temperature, CO2 concentration, and humidity inside the bottles were measured, and growth characteristics according to the temperature conditions were evaluated. CO2 concentration increased overall as the temperature increased and was particularly stable at 20°C, suggesting that 20°C is the optimal condition for the physiological respiration of P. ostreatus . While humidity was relatively constant at 15°C, it decreased over time at 20°C and was maintained at a stable level at 25°C, suggesting that water retention capacity may occur at high temperatures. As a result of the growth investigation, the yield per bottle and individual weight were the highest at 20°C, confirming that 20°C is the most suitable temperature condition for the growth of oyster mushrooms. At 25°C, the yield per bottle was maintained but the individual weight decreased and the color tended to change. These results suggest that the interaction between CO2 concentration, humidity, and temperature has a significant effect on the growth and quality of oyster mushrooms, and that it is effective to control the cultivation room temperature to 20°C for optimal growth.
      4,000원
      6.
      2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Coal tar pitch is a raw material that can be made from various carbon materials such as activated carbon, carbon fiber, and artificial graphite through heat treatment. In particular, it is an important raw material used as a binder and impregnated pitch when manufacturing carbon composite materials. In order to improve the physical properties of such a carbon composite material, the content of β-resin is an important factor. Although β-resin plays the role of a binder, it also corresponds to fixed carbon, so it can determine the physical properties after carbonization. In this study, we compared the physical properties of coal tar pitch various temperature ramping rate, and found through Py-GC/MS analysis that intermediate materials were generated by heteroatoms such as oxygen and nitrogen. MALDI-TOF/MS analysis revealed that these intermediate materials overlapped with the molecular weight region of β-resin. Therefore, the content of β-resin is in the following order: 430–5 (12.8 wt%), 430–10 (10.2 wt%), and 430–2 (6.3 wt%), and when 430–5 is used as a binder, the highest density appeared at 1.75 g/cm3. However, such intermediate materials undergo thermal decomposition even at temperatures above 900 °C. As a result, after carbonization, 430–5 had a density of 1.60 g/cm3, which was similar or lower than that of 430–2 (1.72 → 1.63 g/ cm3) and 430–10 (1.73 → 1.61 g/cm3). From these results, it is expected that if the heteroatom content is distributed in an appropriate amount and the heating rate is well controlled, it will be possible to maintain a high density even after carbonization while ensuring a high beta-resin content.
      4,000원
      8.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      갯벌은 조석 에너지에 따른 침수와 노출이 반복되는 주기성을 가지며, 이로 인한 퇴적물의 물리적 영향과 온도 변동의 특성 을 이해하는 것은 중요하다. 태풍은 극단적인 기상 현상으로 연안 및 하구 지역에 미치는 물리적 영향이 공간적, 시간적 차이에 따라 다 르다. 태풍의 혹독한 기상 조건으로 인해 적시에 샘플링이 어려운 경우가 많아 갯벌에 온도와 압력 센서를 설치해 측정하였다. 태풍 통 과에 따른 온도 센서 데이터와 기상 요인 분석 결과, 하계의 카눈 영향에 의한 퇴적물 온도 하강 폭이 힌남노에 의한 하강 폭보다 더 컸 다. 또한, 갯벌 상부와 하부의 온도 변동은 조수에 의한 노출시간 차이에 따라 달라졌다. 이는 조위에 따른 침수의 완충 효과로 인해 하 부조간대에 미치는 영향이 상대적으로 낮다는 것을 의미한다. 전반적으로 퇴적물 온도는 태풍 유입 시기에 따라 일시적으로 영향을 받 았지만, 조위에 의한 노출 차이가 더 크게 작용한 것으로 보인다.
      4,000원
      9.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Hot section components of gas turbines are exposed to a high operating temperature environment. To protect these components, thermal barrier coatings (TBC) are applied to their surfaces. Yttria-stabilized zirconia (YSZ), which is widely used as a TBC material, faces limitations at temperatures above 1200 °C. To mitigate these issues, research has focused on adding lanthanide rare earth oxides and tetravalent oxides to prevent the phase-transformation of the monoclinic phase in zirconia. This study investigated the effects of varying TiO2 content in Nd2O3 and Yb2O3 co-doped YSZ composites. Increasing TiO2 content effectively suppressed formation of the monoclinic phase and increased the thermal degradation resistance compared to YSZ in environments over 1200 °C. These findings will aid in developing more thermally stable and efficient TBC materials for application in high-temperature environments.
      4,000원
      13.
      2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
      This study was conducted to secure basic data for developing technologies to reduce the generation of odor substances by investigating the effects of environmental temperature on growth performance and the generation of odor substances from feces in growing pigs. A total of 16 pigs (Landrace × Yorkshire × Duroc, average body weight 56.49±0.47kg) were randomly assigned to two treatments: thermal-neutral (TN) and heat stress (HS) conditions. The experiments were conducted for two weeks, with average temperature-humidity indices of 68.91±0.09 for TN and 85.98±0.08 for HS. The results showed that HS significantly decreased average daily feed intake (ADFI, 33.3%) and average daily gain (ADG, 25.8%) compared with TN (p<0.05). Non-esterified fatty acid in serum was lower (36.2%) in HS compared with TN (p<0.05). However, protein, blood urea nitrogen, cholesterol, triglyceride, glucose, and IgG in serum showed no difference between HS and TN. Phenol (350.0%) and skatole (416.3%) were significantly higher in HS than in TN (p<0.05). The decrease in growth performance is attributed to reduction in ADFI. The increase in phenol and skatole in HS is presumed to be due to the effect of HS on the metabolism of intestinal microbial composition. Digestion rate, intestinal microbial composition, and urine emissions are known to affect odor substances. Further research on the content of odor substances in urine, nutrient digestion rate, and intestinal microbial composition is considered necessary to determine the exact associations.
      4,000원
      14.
      2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Compared with the traditional Haber Bosch process, green and pollution-free electrocatalytic nitrogen reduction (NRR) has received considerable attention in the electrocatalysis field in the last decade. To address the issue of its low reactivity as well as the existence of competitive reactions, efficient electrocatalysts are particularly important. In this paper, NiO nanomaterials were synthesized by a simple water bath reaction. The effect of different calcination temperatures on the structure of NiO catalyst and its catalytic activity was studied. Uniform NiO-600 nanoparticles (56 ± 9.3 nm) obtained at 600 ℃ showed the best electrocatalytic NRR activity with an NH3 yield of 12 μg h− 1 mg− 1 and a Faraday efficiency of 5.5% at -0.5V (vs.RHE). The small particle size of the nanoparticles provided more active sites and the oxygen-rich vacancies facilitated the adsorption and activation of N2, which improved the catalytic activity of NiO-600. This study highlights the need for calcination temperature regulation and the huge impact on catalyst structure.
      4,000원
      15.
      2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
      For the regeneration of diesel particulate filters (DPF) using non-thermal plasma (NTP), both cost-effectiveness and regeneration efficiency should be raised. This study compared and contrasted the physicochemical characteristics of carbon black and engine particulate matter (PM). After carbon black was put into the DPF, an experimental setup for the oxidation of PM using NTP was created. The findings showed that carbon black and PM samples had comparable oxidation traits, micronanostructures, and C/O elemental ratios. O3, the main active species in NTP, was susceptible to heat breakdown, and the rate of decomposition of O3 increases with increasing temperature. The removal effectiveness of carbon black first improved and subsequently declined with an increase in the NTP injection flow rate during offline DPF regeneration using NTP at room temperature. A relatively high carbon black removal efficiency of 85.1% was achieved at an NTP injection flow rate of 30 L/min.
      4,800원
      16.
      2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Pure SnO2 has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO2 with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO2 have a porous microstructure, with a porosity of > 40%. In pure SnO2, a high sintering temperature of approximately 1300°C is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO2, the compositions of the samples were Sn1-xTixO2-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO2, densification was shown to be improved when the samples were sintered at 950°C. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950°C.
      4,000원
      17.
      2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
      본 연구는 부화 온도가 맹꽁이(Kaloula borealis) 알의 부화 기간에 영향을 미치는 여부를 알아보기 위해 수행되었다. 본 연구에서 맹꽁이 알에서 올챙이가 생긴 것을 기준으로 알 부화 과정을 기록했다. 연구 결과 맹꽁이의 모든 알은 산란 후 48시간 이내에 부화하였으며, 28.1%(±10.8, n=52)가 24시간 이내에, 99.9%(±0.23, n=49)가 산란 후 48시간 이내에 부화했다. 수온의 차이에 따라 맹꽁이 알의 평균 부화율은 유의미한 차이를 나타냈다. 산란 후 15~24시간 사이의 평균 부화율은 24.1(±0.2)°C보다 21.1(±0.2)°C의 수온에서 더 높았다. 본 연구 결과는 비교적 낮은 수온에서 빠른 부화가 되는데 이는 비가 오는 계절에 일시적인 연못이나 웅덩이에 알을 낳는 번식 습성으로 웅덩이가 마르기 전에 빠른 부화가 필요하기 때문으로 추측한다. 본 연구 결과는 멸종위기종인 맹꽁이 알의 최적 부화온도를 이해하는데 도움이 된다.
      4,000원
      18.
      2024.04 구독 인증기관·개인회원 무료
      상추는 수요가 연중 지속됨에 따라 재배면적과 생산량이 증가하고 있는데, 주로 생식으로 이용되며 수확간격 이 짧아 해충 다발생시 약제방제가 어려운 작물이다. 최근 검은무늬밤나방이 약제방제가 소홀한 포장에서 잎을 광포식하여 빠른 시간내에 직접적인 피해를 주고 있다. 본 연구에서는 검은무늬밤나방의 온도별 발육특성을 구명하여 방제를 위한 기초자료로 이용하고자 한다. 검은무늬밤나방은 시설재배 상추에 발생한 유충을 채집하 여 실내 사육 후 항온조건(15, 20, 25, 30℃)에서 발육단계별 발육기간을 조사하였다. 온도가 높아짐에 따라 각 태별 발육기간은 짧아지는 경향이었으며, 유충은 보통 4회 탈피하였다. 25℃에서 알기간은 2.5일, 유충기간 10.0 일, 전용기간 1.0일, 번데기기간 7.0일로 알에서 성충까지의 발육기간은 20.5일 이었다.
      19.
      2024.04 구독 인증기관·개인회원 무료
      겨울과 같은 환경에서 곤충은 생존과 번성을 위해 생리학적, 생화학적 및 행동적 메커니즘을 이용하고 있다. 대부분의 곤충은 생리학적 적응가운데 급속내한성(Rapid cold hardiness, RCH) 유기를 통해 기온이 급격히 낮아 지는 외부 환경에 대해 빠르게 적응하고 저온조건에서 생존율을 높인다. 열대거세미나방의 경우 행동적 메커니 즘을 통해 따뜻한 곳을 찾아 장거리 비행을 하며, 생존에 유리한 환경으로 이동한다. 본 연구에서는 열대거세미나 방의 생리적 월동능력과 RCH 능력에 관해 조사하였다. 그 결과, RCH에 의해 혈중 글리세롤의 농도가 증가와 체내빙결점이 하강하는 것을 확인할 수 있었다. 또한, RCH(-10℃, 1h)에 노출된 2령 유충기를 대상으로 4령과 5령 유충기에 단기저온(5℃, 30min)에 노출 시 글리세롤 생합성에 관여하는 유전자(glycerol kinase 1, 2)의 발현이 RCH에 노출되지 않은 대조구와 비교하여 빠르게 발현되었다. 이는, 열대거세미나방의 유전자 수준에서 저온에 대한 단기기억이 존재하는 것을 제시한다.
      20.
      2024.04 구독 인증기관·개인회원 무료
      The small brown planthopper (SBPH), Laodelphax striatellus, is a major insect pest for the rice plants. SBPH is also a known vector of rice stripe virus (RSV), which causes severe yield losses in rice crops throughout the East Asia. RSV is persistently transmitted by SBPH and can also be transmitted to offspring through transovarial transmission. SBPH is known to migrate from China to the west coast of the Republic of Korea (ROK). The study investigated the impact of temperature on the acquisition and transmission of RSV by SBPH in ROK, which is expected to experience increased migration and emergence of SBPH due to climate change. The results revealed that the acquisition and transmission rates of RSV were higher at 27°C compared to 24°C, with rates of 100% and 78.3%, respectively. However, at 30°C, the acquisition and transmission rates of RSV was decreased. The results suggests that temperature can impact the transmission of RSV by SBPH. To investigate this further, SBPH adults were fed on RSV-infected plants and infection rates were compared across various tissues, including the head, salivary glands, midgut, Malpighian tubules, ovary, and hindgut. Results showed that at 36 hours post-infection, RSV was highly detected in the Malpighian tubules, ovary, and hindgut. At 48 hours post-infection, RSV was also detected in the thorax. These results suggest that the transmission rates of RSV in SBPH increase with temperature between 24-27°C, but decrease at 30°C, indicating that the vectorial capacity of SBPH for RSV decreases above a certain threshold.
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