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        검색결과 458

        1.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, fire extinguisher system to which form fire extinguisher agents were adopted was applied to the combat vehicle crew room to apply fire extinguishing performance and acid gas safety that meet the national defense standards. As a result of evaluation and verification, the following conclusions were drawn. For standard fire sizes in the combat vehicle crew's standard model, we ignited using a mixture of Novec 1230 and Halon 1301 form extinguisher agent and released form extinguisher agent after 30 seconds to determine the fire extinguishing time. The amount of acid gas generated met the criteria in all cases. When the fire size was increased to 0.12m2 and a 2.0mm nozzle was used, all of the extinguishing time, the amount of acid gas generated, and the concentration of Novec 1230 met the criteria. Despite the more difficult conditions to extinguish the fire by making the fire larger, it was possible to confirm the extinguishing performance of the Novec 1230 form extinguisher agent and its safety against acid gas.
        4,000원
        2.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 유기계 산화 방지제인 가려진 페놀이 그래프팅된 산화 그래핀(hindered phenol-grafted graphene oxide, HP-GO)을 합성하였고, 이를 도입한 나피온(Nafion) 기반의 복합 막을 제조하여 고분자 전해질 막 연료전지에 응용하 였다. HP-GO는 3,5-디-tert-뷰틸-4-히드록시페닐프로피오닐 클로라이드에 존재하는 염화 카보닐기(carbonyl chloride)와 GO에 존재하는 히드록시간의 치환 반응을 통해 합성되었으며, 합성된 HP-GO를 고분자 기지체 대비 0.01~0.5 wt%까지 포함하는 복합 막을 제조하여 순수 Nafion과의 물성 차이를 비교하였다. 특정 함량의 HP-GO가 첨가된 복합 막은 순수 Nafion에 비해 우수한 인장강도와 수분 흡수율 및 치수안정성을 나타내었다. 특히 HP-GO의 산화 방지 특성으로 인해 HP-GO가 첨가된 복 합 막은 장시간의 펜톤 평가(Fenton’s test) 이후 순수 Nafion 대비 높은 산화 안정성을 나타내었다. 또한 HP-GO에 의한 향상 된 수분 흡수율에 의해 복합 막은 전 습도 구간에서 순수 Nafion 대비 우수한 수소 이온 전도도를 나타내었다.
        4,500원
        10.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of revolution speed and ball size in planetary milling on the microstructure and dehydrogenation behavior of TiH2 powder. The particle size analysis showed that the large particles present in the raw powder were effectively refined as the revolution speed increased, and when milled at 500 rpm, the median particle size was 1.47 μm. Milling with a mixture of balls of two or three sizes was more effective in refining the raw powder than milling with balls of a single size. A mixture of 3 mm and 5 mm diameter balls was the optimal condition for particle refinement, and the measured median particle size was 0.71 μm. The dependence of particle size on revolution speed and ball size was explained by changes in input energy and the number of contact points of the balls. In the milled powder, the endothermic peak measured using differential thermal analysis was observed at a relatively low temperature. This finding was interpreted as the activation of a dehydrogenation reaction, mainly due to the increase in the specific surface area and the concentration of lattice defects.
        4,000원
        11.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Carbon dioxide (CO2) is a cheaper and easier to installer fire suppressant than other extinguishing gases and is easy to install, but extinguishes fires by is suffocation. As a result, suffocation accidents continue to occur in facilities equipped with CO2 fire-extinguishing facilities, Emission standards have yet to be established. This study aims to address the issue. METHODS : To effectively remove CO2 emitted from installed systems, we reviewed and analyzed previous related research and existing international standards. RESULTS : In protected areas where CO2 fire-extinguishing systems are installed, emission facilities should discharge the emitted CO2 before it enters the protected spaces. CO2 sensors can determine whether safe entry is possible or whether respirators are required. CONCLUSIONS : This study presented a specific installation method for emission facilities capable of actively discharging CO2. Applying this method is expected to contribute to improving safety in facilities equipped with CO2 fire-extinguishing facilities.
        4,000원
        12.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험에서는 외인성 효소 첨가제 및 혼합 세균 배양을 통한 고상발효(Solid-state fermentation, SSF)가 채종박(Rapeseed meal, RSM)의 체외건물소화율(In vitro dry matter digestibility, IVDMD) 및 단쇄지방산(Short chain fatty acid) 생성에 미치는 영향을 조사하기 위해 수행되었다. 외인성 효소 칵테일(첨가 및 미첨가) 및 RSM에 대한 SSF(발효 및 비발효)를 나타내는 2 x 2 요인 설계가 적용되었다. 3-step 돼지 소화율 모델을 적용하여 채종박의 건물 소화율을 분석하였으며, 72시간 대장발효 후 상층액을 수집하여 단쇄지방산 생성량을 분석한 후 칼로리 단위로 변환하여 가소화에너지 소화율을 분석하였다. 소장 (IVDMDh) 및 전장 (IVDMDt) 건물소화율에서는 고상발효된 채종박이 더 높게 나타났다 (각각 p < 0.01). 마찬가지로, 외인성 효소 첨가제 처리구에서 채종박의 소장 소화율(IVDMDh)이 증가하는 경향을 나타냈다(p = 0.06). Acetic acid 및 butyric acid의 생산은 대조구에 비해 고상발효 처리 시 유의하게 더 생산되었으며 (각각 p < 0.01), 이는 총 단쇄지방산의 생산 증가 경향을 나타냈다(p = 0.09). 에너지 소화율에서는 채종박의 고상발효 및 외인성 효소제 첨가가 유의적으로 높게 나타났다 ( p < 0.01). 그러므로 채종박의 고상발효 처리는 단백질 이용성을 비롯한 영양적 가치를 향상시키는데 효과적이라고 사료된다.
        4,000원
        13.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 산화 방지 특성이 있는 가리워진 아민기를 함유한 산화 그래핀(hindered amine grafted graphene oxide, HA-GO)을 합성하여 이를 도입한 나피온(Nafion) 기반의 복합 막을 제조한 후 고분자 전해질 막 연료전지 시스템에 응용하였다. HA-GO는 4-아미노-2, 2, 6, 6-테트라메틸-4-피페리딘(4-amino-2, 2, 6, 6-tetramethyl piperidine)에 존재하는 아민 기와 GO 표면에 존재하는 에폭시기의 개환 반응을 통해 제조하였으며, 합성된 HA-GO의 함량을 달리한 복합 막을 제조하여 순수 Nafion 막과 성능 특성을 비교하였다. HA-GO가 첨가된 복합 막은 Nafion 단일 막에 비해 기계적 물성, 화학적 안정성 및 수소이온 전도 특성이 향상되었다. 특히 HA-GO의 산화 방지 특성으로 인해 HA-GO가 첨가된 복합 막은 펜톤 평가 (Fenton’s test) 이후 수소이온 전도도의 유지 특성이 Nafion 단일 막에 비해 큰 폭으로 향상된 것을 확인할 수 있었다.
        4,200원
        16.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Combat-armored vehicles were equipped with an automatic-fire-extinguishing system to ensure the safety of the crew and vehicle from fires on the vehicle. When a fire was occurred, the automatic-fire-extinguishing system automatically detects the fire through sensors and detection lines, sprays a fire extinguisher, and notifies the crew visually and audibly. Recently, there had been cases of automatic-fire-extinguishing systems malfunction on combat-armored vehicles. In this study, in order to resolve the automatic-fire-extinguisher's malfunction phenomenon, ground noise and inter-circuit noise generated from the fire detection line were identified, and the resistance connected on the circuit was revised to remove noise. As a result of resistance revision, the noises was eliminated and the electromotive force difference between input circuits was made constant, thereby improving the malfunction of the automatic-fire-extinguishing system. By applying the result, it was confirmed that the control device sensed a temperature similar to the actual temperature on actual vehicles, and it was confirmed that the automatic-fire-extinguishing system's malfunction phenomenon was not founded in the field vehicles after then.
        4,000원
        17.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Changes in contents of free sugars, amino acids, and fatty acids of legumes were analyzed for each phase of in vitro digestion. In addition, contents of resistant starch in raw and digested pulses were compared. Soybeans, kidney beans, cowpeas, and chickpeas were analyzed. An in vitro digestion model was used to analyze contents of nutrients using LC-MS and GC-MS. Stachyose in kidneybean, cowpea, and chickpea increased as the digestion phase progressed. In four types of legumes, raffinose slightly decreased or showed no significant difference between the Oral phase and the BBMV phase. Content of glucose, a monosaccharide, increased during the BBMV phase. During the digestion phase, levels of free amino acids and free fatty acids also increased. Content of resistant starch was reduced compared to that in the raw material. It was 0.01g/100 g food in soybean, 1.06 g/100 g food in red kidney bean, 0.77g/ 100g food in cowpea, and 0.76 g/100 g food in chickpea. It was confirmed that nutrients in the in vitro digestion model were liberated at each digestion phase with changes in the content of resistant starch. These results are expected to be used as fundamental data for obtaining bioavailability of nutrients.
        4,200원
        18.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×102 mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.
        4,000원
        19.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 과체중과 정상체중의 비글견 사이에서 미네랄 소화율의 차이를 평가하기 위해 수행되었다. 중성화 된 건강한 비글견 11마리(47.7개월령 ±0.14)의 Body condition score (BCS)를 기준으로 Normal BCS 그룹(BCS≤5, n=5)과 High BCS 그룹(BCS ≥6, n=6)의 두 그룹에 배치하였다. 시험사료는 반려견의 영양소 요구량을 충족하도록 제조하여 개체 별 에너지요구량에 맞춰 일일 2회에 나누어 14일 동안 급여하였다. 미네랄의 외관상 전장 소화율은 0.5% 산화크롬(Cr2O3)을 이용한 지시제법을 이용하여 평가되었다. 사료와 분변 내 Macro 미네랄(K, Mg, P, Na, Ca)과 Micro 미네랄(Se, Fe, Zn, Cu, Mn)의 함량은 유도결합플라즈마 분광광도계를 이용하여 분석하였다. 체중과 BCS는 Normal BCS 그룹 보다 High BCS 그룹이 유의하게 높았으며(p<0.01), 시험기간 동안 두 그룹 내 각각의 체중과 BCS는 통계적으로 유의한 변화는 관찰되지 않았다(p>0.05). 미네랄 소화율을 평가한 결과, Macro 미네랄 중에서는 마그네슘, 인, 칼슘의 소화율이 High BCS 그룹에서 높은 경향으로 관찰되었으며(p<0.1), Micro 미네랄 중에서는 High BCS 그룹에서 망간의 소화율이 유의하게 높았고(p<0.05), 셀레늄과 아연의 소화율은 높은 경향(p<0.1)을 나타내었다. 또한, 통계적인 유의성과 관계없이 분석한 모든 미네랄 지표에서 High BCS 그룹이 Normal BCS 그룹보다 높은 소화율의 결과를 보여 주었다. 본 연구의 결과는 비글견에서 과체중 또는 비만이 미네랄 소화율의 변화를 유도할 잠재적 가능성을 보여주었다.
        4,000원
        20.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study established the optimal conditions of noodles by varying the amount of modified starch treated with octenyl succinic anhydride in wheat starch. It investigated the digestibility and quality characteristics of the produced noodles. The color difference of the noodles added with octenyl-succinic anhydride (OSA)-modified starch increased as the amount of OSA-modified starch added increased but decreased after cooking. The cooking characteristics of noodles added with OSA-modified starch showed increased weight, water absorption, and turbidity but reduced volume. In the extensibility of noodles, the noodles with 10 and 20% OSA-modified starch showed the most similar values to the control. The digestibility of noodles with OSA-modified starch added showed a higher RS content as the amount of OSA-modified starch added increased. However, it is considered that an optimal addition level of 20% of modified starch is suitable for the formation of noodle texture. As a result of this study, it is thought that OSA-modified starch, with its low digestibility, could be utilized not only in noodles but also as a low-calorie food ingredient that can replace wheat flour.
        4,000원
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