결과 내 재검색





        검색결과 20

        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nasopharyngeal stenosis is defined as a morphological transition of narrowing at the nasopharyngeal region. A 2-yearold, castrated male, Korean short hair cat was referred to the animal medical center, Gyeongsang National University. According to clinical signs, diagnostic imaging, and physical examination, nasopharyngeal stenosis was diagnosed. The staphylectomy was performed using a CO2 laser, and there were not any post-operative complications. The patient was discharged in two days. This report describes the case of nasopharyngeal stenosis in cat and represents that laser ablation could be a good option for surgical management of the nasopharyngeal region with a low complication rate.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultra-violet (UV) light is one of abiotic stress factors and causes oxidative stress in plants, but a suitable level of UV radiation can be used to enhance the phytochemical content of plants. The accumulation of antioxidant phenolic compounds in UV-exposed plants may vary depending on the conditions of plant (species, cultivar, age, etc.) and UV (wavelength, energy, irradiation period, etc.). To date, however, little research has been conducted on how leaf thickness affects the pattern of phytochemical accumulation. In this study, we conducted an experiment to find out how the antioxidant phenolic content of kale (Brassica oleracea var. acephala) leaves with different thicknesses react to UV-A light. Kale seedlings were grown in a controlled growth chamber for four weeks under the following conditions: 20°C temperature, 60% relative humidity, 12-hour photoperiod, light source (fluorescent lamp), and photosynthetic photon flux density of 121±10 μmol m-2 s-1. The kale plants were then transferred to two chambers with different CO2 concentrations (382±3.2 and 1,027±11.7 μmol mol-1), and grown for 10 days. After then, each group of kale plants were subjected to UV-A LED (275+285 nm at peak wavelength) light of 25.4 W m-2 for 5 days. As a result, when kale plants with thickened leaves from treatment with high CO2 were exposed to UV-A, they had lower UV sensitivity than thinner leaves. The Fv/Fm (maximum quantum yield on photosystem II) in the leaves of kale exposed to UV-A in a low-concentration CO2 environment decreased abruptly and significantly immediately after UV treatment, but not in kale leaves exposed to UV-A in a high-concentration CO2 environment. The accumulation pattern of total phenolic content, antioxidant capacity and individual phenolic compounds varied according to leaf thickness. In conclusion, this experiment suggests that the UV intensity should vary based on the leaf thickness (age etc.) during UV treatment for phytochemical enhancement.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Removing CO2 gas to address the global climate crisis is one of the most urgent agendas. To improve the CO2 adsorption ability of activated carbon, nitrogen plasma surface treatment was conducted. The effect of nitrogen plasma treatment on the surface chemistry and pore geometry of activated carbon was extensively analyzed. The porosity and surface groups of the activated carbon varied with the plasma treatment time. By plasma treatment for a few minutes, the microporosity and surface functionality could be simultaneously controlled. The changed microporosity and nitrogen groups affected the CO2 adsorption capacity and CO2 adsorption selectivity over N2. This simultaneous surface etching and functionalization effect could be achieved with a short operating time and low energy consumption.
        2021.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        수경재배시 양액 내 탄산정 처리를 통한 상추의 생육 및 생리활성물질 변화를 조사하기 위해 네덜란드에서 시판되는 고형 탄산정을 사용하였다. 실험은 무처리를 대조구로 하여 0.5 배, 1배, 2배 처리구로 구성하였다. 실험결과, 탄산정 처리 후 챔버내 대기 CO2 농도는 처리 직후 2배 처리구에서 472.2μL·L -1 로 가장 높은 수치를 보였으며, 양액내 pH는 2배 처리구는 pH 6.03로 가장 많이 감소하였다. 이후 시간이 경과함에 따라 CO2 농도와 pH는 처리 전 수준으로 회복하는 모습을 나타냈다. 상추의 엽폭과 엽면적은 탄산정 2배 처리시 17.1cm, 1067cm 2로 가장 큰 값을 나타내었으며 지상부 생체중, 건물 중은 0.5배 처리구에서 63.87g, 3.08g으로 가장 높게 나타났다. 상추의 근장은 대조구에서 28.4cm로 가장 길었으나 처리 구들간에 지하부의 생체중, 건물중은 유의적인 차이를 나타내지 않았다. 외관상 탄산정 처리에 의해 상추의 근장이 짧아 지고 곁뿌리가 많이 발생한 것이 관찰되었다. 또한 뿌리가 갈색으로 약간 변하는 결과가 있었지만, 지상부 생육에는 부정적인 영향을 미치지 않은 것으로 나타났다. 탄산정 처리에 의 한상추의 생리활성물질을 분석한 결과 chlorogenic acid와 quercetin 두가지 물질이 검출되었으며 이를 정량분석한 결과 1배 처리구에서 chlrogenic acid는 대조구보다 249% 증가하였지만 quercetin은 37% 감소한 결과를 나타냈다. 항산화 활 성을 나타내는 DPPH 라디컬 소거능을 비교한 결과 대조구와 0.5배 처리가 1배, 2배 처리보다 유의적으로 높은 값을 나타냈다. 이를 통해 탄산정 처리가 수경재배 상추의 생육과 생리활 성물질을 증대에 효과가 있음을 제시한다.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        느타리버섯 곤지7호의 수확 후 CO2 처리에 의한 품질 유지 효과 및 적정 처리 농도를 구명하고자 연구를 수행하였다. 수확한 버섯을 3°C에서 1일간 예냉 후에 CO2 농도 0, 30 및 50%에서 3시간 처리한 다음 20 μm 두께 OPP필름 봉지에 밀봉하여 3°C에 21일 저장하였다. 30% CO2 처리에서 대조직의 경도가 저장 21일까지 높게 유지 되었고, 대조직의 색은 명도(CIE L*값)가 30% CO2 처리 한 느타리버섯이 저장 14일, 21일에 높고 황색도(CIE b* 값)가 저장 2일, 7일에 낮게 나타났으며 외관품위가 저장 7일부터 저장기간 내내 대조구와 50% CO2 처리에 비해 높았으며 3°C 저장 중 17일까지 느타리버섯 곤지7호의 상품성을 유지하였다. 30% CO2 농도로 3시간 처리가 느타리버섯 곤지7호의 저온저장 중 품질 유지기간을 연장할 수 있는 수확 후 처리방법으로 판단되었다.
        2019.04 구독 인증기관·개인회원 무료
        In order to industrialization of the entomopathogenic nematode (EPN) isolated in Korea, it is necessary to switch to infective juveniles. Since the conversion to infective juveniles in the end of solid culture is important against the outside environment, it has a great influence on insecticidal efficacy and shelf life. We investigated whether the concentration of CO2 and NH3 at the end of the solid culture was artificially increased to affect the infective juvenile induction rate. Optimal exposure time for conversion to infective juveniles was 5 minutes for CO2 and 3 minutes for NH3. Optimal treatment time was 9 days after EPN inoculation for both CO2 and NH3. And optimum concentration was 80~90% for both CO2 and NH3 for EPN infective juveniles stage conversion.
        2018.11 구독 인증기관·개인회원 무료
        CO2 separation technology for carbon capture, which is one of the hot issues to reduce greenhouse gases from industrial flue gas, has been intensively investigated so far. Despite of several benefits, the membrane technology has some obstacles like large-scale module fabrication, membrane durability, need of pre-treatment or high pressure drive for its industrial application. Also, the power plant flue gas with normally 10~20% of CO2 content should be concentrated upto 99% for being compressed and liquefied to transportable CO2 by pipeline, indicating the need of high selective membrane process as well as high recovery. In this work, the possibility of membrane process for post-combustion treatment in terms of recent technology will be announced. The practically applicable process for CO2 capture also be suggested briefly.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sludge transporting pipes in wastewater treatment plant are easy to be clogged with struvite when the digested sludge and dehydrated filtrate are transported through the pipes, which lowers the efficiency of sludge treatment system in a WWTP. pH is one of the most important factors in struvite formation, and carbon dioxide separated from biogas can be used to control pH and struvite formation. By controlling pH, the amount of dehydrating agent can be reduced by about 10%, which saves the budget for facility maintenance. As CO2 is reused and dehydrating chemicals are saved, the approach can contribute to global warming gas reduction.
        2017.10 구독 인증기관·개인회원 무료
        The effects of Postharvest CO2 treatment on the quality and shelf life of oyster mushroom packaged with oriented polypropylene (OPP) film bag were investigated. On the day of harvest, the ‘Gonji-7ho’ oyster mushroom grown by bottle cultivation of Jangheung County, Korea transferred to a laboratory in Wanju County and were cooled in a cold room at 3°C for 1 day and then treated with 30% or 50% CO2 for 3 hours at 3°C. After the CO2 treatment, 400 g of oyster mushroom were sealed into 20 μm thick OPP film bag (width: 29 cm, length: 24 cm) used in the actual farmhouse. The package gas composition, hardness, color change, off-flavor index, browning index, and overall quality were evaluated during storage at room temperature (RT) for 6 days and at 3°C for 21 days. As a result, During storage at RT, the concentration of carbon dioxide in the bag of 30%, 50% CO2 were higher than untreated and shelf-life of oyster mushroom at 50% CO2 was reduced 1 day due to off-flavor while 30% CO2 or untreated was 2 days. During storage at 3°C, the concentration of carbon dioxide in the bag was kept low at 30%, 50% CO2 treatment compared to untreated, the respiration of oyster mushroom at 30, 50% CO2 were lower than untreated during initial 7 days storage at 3°C, but ethylene production were not different. The hardness of oyster mushroom at 30% CO2 was higher, the lightness (L* value) of stem surface was higher, the yellowness (b* value), browning index was lower and odor index was lower than untreated or 50% CO2. 30% CO2 treated oyster mushroom packaged with OPP film bag kept 4.2~16.2% O2 and 4.2~15.5% CO2 concentration in the bag during storage at 3°C, and showed highest overall quality index. Marketable shelf-life was assessed 10 days for untreated, 17 days for 30% CO2, and 16 days for 50% CO2, respectively.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to examine the potential of pre- and post-harvest treatment of chitosan and high pCO2 on the shelf-life of oriental melon fruit. Post-harvest dipping treatment of chitosan and high pCO2 did not bring any significant effect on the freshness of fruit in general, even at 1% of chitosan. Unlike post-harvest treatment, pre-harvest spray of chitosan significantly increased fruit firmness and firmness increase was higher in double sprays than single one. The internal quality such as soluble solid content and acidity was not altered by chitosan spray. No additional effect of high pCO2 with pre-harvest treatment of chitosan was found. Double sprays of chitosan showed significant effect on keeping visual appearance through delaying the incidence of skin browning. There was a potential of pre-harvest chitosan treatment on the shelf-life increase of oriental melon fruit and double sprays were better than single spray. However, high pCO2 seemed not to be effective on the storability of oriental melon fruit.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        큰느타리버섯은 장거리 해상운송 후 갈변 및 조직 물러 짐에 의한 품질저하가 클레임의 원인이 되는데, 수출 중 신선도 유지를 위한 전처리 기술을 개발하고자 CO2 처리 의 효과를 검증하였다. 버섯의 수확후 5 o C에서 30, 50% 농도의 CO2를 3시간 처리하고 관행적인 방법으로 필름 포장한 다음 20 o C와 5 o C에 저장하며 무처리와의 품질을 비교분석하였다. CO2 처리구는 무처리에 비해 저장 중 조 직 경도와 색도(Hunter ‘L’, ‘b’)를 유지하였고, 관능평가 에서도 품질이 급격히 저하되는 저온저장 3주차에 조직 물러짐 정도와 갈변지수가 낮아 신선도 유지에 효과가 있 었다. CO2 처리 농도 중 30% 처리구가 50%에 비해 상품 성이 높았으며 무처리에 비해서는 5 o C에서 약 1주일간 신 선도 유지기간이 연장되었다. 따라서 큰느타리버섯의 장 거리 해상운송 중 품질유지를 위한 전처리 방법으로 CO2 처리가 효과가 있는 것으로 판단되며 현장적용을 위해 효 과가 있는 CO2 처리농도의 범위 및 장해를 유발하는 한 계농도의 설정과 처리시간 등 추가적인 실험이 요구된다.
        2014.10 구독 인증기관·개인회원 무료
        Bumblebees are important pollinators of crops and wildflowers. Bumblebees generally produce one generation per year. One of the key stages for year-round rearing of bumblebees is breaking diapause. To evaluate the effects of a combination method of CO2-narcosis and cold treatment to break the diapause of B. ignitus and B. terrestris queens, we determined whether this method affected their ability to establish a colony after the diapause break. The diapause treatment regimes that were utilized were CO2(CO2– narcosis), CT-1M(cold treatment at 5°C for 1 month), CT-1M-CO2(CO2–narcosis after cold treatment for 1 month), CT-2M-CO2(CO2–narcosis after cold treatment for 2 months), CT-2M (cold treatment for 2 months), CT-2.5M-CO2(CO2–narcosis after cold treatment for 2.5 months) and CT-2.5M (cold treatment at 5°C for 2.5 months). In view of the effects on the colony developmental characteristics of B. ignitus queens, the most favorable diapause treatment was CT-1M-CO2. A combination method of CO2– narcosis and cold temperature treatment yielded better results than that of single CO2–narcosis or cold temperature treatment on the colony development of diapause-broken B. ignitus queens. In the case of B. terrestris queens, we concluded that a combination method of CO2 and cold temperature treatment yielded better results than that of a single cold-temperature(up to2 months) treatment. In conclusion, the findings of the present study indicated that the combined application of CO2 and cold temperature was a favorable method for the colony development of diapause-broken B. ignitus and B. terrestris queens compared with only CO2–narcosisorcoldtemperaturetreatments. A combination method of CO2 and cold treatment reduced the side effect of CO2–narcosis and shortened the duration of cold treatment by at least 1month.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 저온기 시설참외 재배 시 탄산가스 발생제(탄산솔)의 사용효과를 구명하기 위하여 수행하였다. 600 m2 크기 하우스에 탄산가스 발생제(100g/1봉)를 10, 20 및 30봉을 각각 매달아 무처리와 비교하였다. 그 결과 무처리구에 비해 처리구에서 탄산가스 농도가 3.0~3.2배 정도 높았다. 그리고 무처리구에 비해 처리구에서 과중이 20.2~22.0g 더 무겁고, 태좌부 당도가 1.5~2.1oBrix 더 높았으며, 색도(a값)도 우수하였다. 또한 탄산가스 발생제 처리한 것이 무처리에 비해 발효과율 및 기형과율이 각각 2.9~3.9%, 5.4~7.3% 감소하였고, 상품과율은 8.7~10.3% 증가하였다. 10a당 상품과 수량은 무처리구의 385.8kg에 비하여 탄산가스 발생제 10, 20 및 30봉 처리 한 것이 각각 10.3%, 14.8%, 16.2% 증가하였다. 이상의 결과를 보아, 저온기 참외 시설재배시 탄산가스 발생제를 시용함으로써 탄산가스 농도가 높아져 광합성이 촉진되어 품질이 향상되고 수량이 증가한 것으로 판단되었다.
        1992.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        레이저빔에 의한 철강재의 Ti 표면합금화에 미치는 C함량의 영향을 관찰하였다. 철강재상에 Ti 코팅 후 레이저빔 조사시 질소를 취입가스로 사용하면 부분적으로 TiN과 Fe2Ti가 형성된다. 저탄소강의 경우 Ti함량의 증가에 따라 임계냉각 속도의 증가로 마르텐사이트화가 억제된다. 고탄소강의 경우 Ti의 함량이 1.5%정도 임에도 훼라이트 조직이 형성되지 않고 마르텐사이트 조직이 형성되어 경화된다. 그리고 고탄소강의 Ti 표면합금층 형성에 부분적인 TiC의 석출이 있어 더욱 경도를 증가시키는 것으로 생각된다.
        2017.05 서비스 종료(열람 제한)
        유기성폐기물(음식물, 하수슬러지 등)은 2005년부터 육상 직매립이 금지되었고, 2006년에 발효된 런던협약에 따라 2013년 1월부터 해양투기 또한 금지되어 폐기물의 처리 및 재활용이 시급한 실정이다. 따라서, 이러한 유기성 폐기물의 효과적인 자원화 방법 중 하나인 혐기성소화가 각광받고 있는 실정이며, 혐기성소화조에서 발생되는 바이가스는 일반적으로 CH4 50~90%, CO2 10~50%, 소량의 H2S 및 NH4로 알려져 있다. 이러한 바이오가스의 정제방법으로는 탄소흡착법, 막분리법 등이 있으나 높은 운전비용과 공정구성의 어려움, 2차 폐기물 발생 등 많은 문제를 일으키고, CO2의 재활용이 아닌 폐기시키고 있어 자원순환적인 측면에서 바람직하지 못하다. CH4의 전환방법중 하나인 CO2 methanation반응은 1M의 CO2와 4M의 H2가 반응하여 1M의 CH4와 2M의 H2O가 생성되는 반응이다. CO2는 열역학적으로 매우 안정된 물질로, 반응에 필요한 에너지를 공급하기 위해서는 수소 등과 같은 높은 에너지의 환원제를 같이 반응에 참여시켜 주어야 한다. 그러나 열역학적 평형으로 인해 전환이 제한되는 경우가 많아, 적절한 반응속도와 선택도를 달성하기 위해 촉매가 요구되며, CO2 methanation 반응에 사용되는 촉매는 주로 Ni, Fe, Al 등 금속계 촉매가 주를 이루고 있다. 따라서 본 연구에서는 바이오가스의 정제효율을 높이기 위하여 CO2 methanation 촉매를 다양한 조건에 따라 제조하였으며 각각의 촉매별 CO2 전환율을 평가하였다.
        2016.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to determine CO2 treatment condition to extend the shelf-life of ‘Seolhyang' strawberry. Fresh strawberries with red color on 80% of the fruit surface were harvested. The samples at two different stages (on the 1st and 3rd day after harvest) were placed in a gas-tight chamber with 0, 5, 15, or 30% CO2 concentration for 3 hours at 4℃. Then, the strawberry samples were immediately packaged in a PET tray and stored at 4℃. The carbon dioxide treatment was effective in maintaining the quality of ‘Seolhyang’ strawberries treated on the 1st day after harvest. These samples had higher firmness, lower redness, softening index, and decay rate compared to samples treated on the 3rd day after harvest. Treatment with both 15 and 30% of CO2 concentration on the 1st day after harvest induced an increase of firmness of ‘Seolhyang’ strawberry after the treatment. Samples treated with 15 and 30% CO2 the 1st day after harvest maintained quality for 10 days. However, samples treated with CO2 on the 3rd day after harvest lost marketability at 10 days of storage. At the atmosphere containing 30% CO2 on the 1st day after harvest was most effective in reducing decay rate and fruit softening, and maintaining bright red color of strawberries among different CO2 concentrations. Therefore, a 30% CO2 treatment within one day after harvest can be a practical postharvest technology to extend shelf-life of ‘Seolhyang’ strawberry.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This experiment was conducted to establish the optimum conditions for high CO2 gas treatment in combination with a proper gas-permeable packaging film to maintain the quality of fig fruit (Ficus carica L). Among the fig fruits with different high CO2 treatments, the quality change was most effectively controlled during storage in the 70%-CO2-treated fig fruit. Harvested fig fruit was packaged using microperforated oriented polypropylene (MP) film to maintain the optimum gas concentrations in the headspace of packaging for the modified-atmosphere system. MP film had an oxygen transmission rate of about 10,295 cm3/m2/day/atm at 25℃. The weight loss, firmness, soluble-solid content (SSC), acidity (pH), skin color (Hunter L, a, b), and decay ratio of the fig fruits were monitored during storage at 5 and 25℃. The results of this study showed that the OPP film, OPP film + 70% CO2, and MP film+70% CO2 were highly effective in reducing the loss rate, firmness and decay occurrence rate of fig fruits that were packaged with them during storage. In the case of using treatments with packages of OPP film and OPP film+70% CO2, however, adverse effects like package bursting or physiological injury of the fig may occur due to the gas pressure or long exposure to CO2. Therefore, the results indicated that MP film containing 70% CO2 can be used as an effective treatment to extend the freshness of fig fruits for storage at a proper low temperature.
        2009.10 KCI 등재 서비스 종료(열람 제한)
        황기의 자가불화합성 타파를 위한 노화수분 처리, NaCl 처리 및 CO2 처리에 대한 결과를 요약하면 다음과 같다. 비닐하우스에서 노화수분은 8월 하순에는 거의 수정이 되지 않았으며, 9월 상순부터 10월 상순까지는 개화 당일 부터 개화 후 2일까지 수정되었고, 9월 하순 개화 당일 수분한 것이 결협율 33.3%, 결실율 86.2%로 가장 양호하였다. 노지에서 노화수분은 대조구는 8월 하순부터 10월 상순까지 결협은 되었으나, 9월 중순과 9월 하순을 제외하고 결실이 되지 않았으며, 9월 하순의 개화 후 1일에 결협율 39%, 결실율 94.9%로 가장 양호하였다. NaCl 처리는 비닐하우스에서는 1% 농도 처리가 결협율은 10월에서 21.3%로 가장 좋았으나, 결실율은 9월 하순 66.7%로 가장 양호 하였고, 노지에서는 NaCl 농도 5%에서 결협율 7.3%, 결실율 90.9%로 가장 양호하였다. 식물생육상을 이용하여 CO2 700 ppm을 처리한 결과 무처리구와 큰 차이 없었다. 결론적으로 황기 자가불화합성 타파를 위하여 9월 중하순에 자화가 아닌 자가화를 개화당일 또는 개화 후 1일에 인공수분해주거나 NaCl 1~5%를 처리해주면 자가불화합성을 타파할 수 있다고 사료된다.