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        검색결과 36

        1.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 합성가스 CO를 생산하기 위해 저급 석탄-CO2 촉매 가스화 실험을 수행하였 다. 제조된 CO가스 특성은 키데코 탄과 신화 탄에 KOH, K2CO3, Na2CO3 촉매들의 화학적 활성화 방 법을 이용하여 조사되었다. CO 제조공정은 석탄과 화학약품 활성화 비율, 가스 유량, CO2 전환 반응온 도와 같은 실험 변수 분석을 통해 최적화되었다. 제조된 합성 가스는 가스 크로마토그래피(GC)에 의해 분석 되었다. 실험조건 T = 950 °C, CO2 유량 100 cc/min에서, 20 wt% Na2CO3가 혼합된 키데코 탄 에 대해 98.6%, 20 wt% KOH가 혼합된 신화탄에 대한 98.9% CO2 전환율을 얻었다. 또한, 저급 석탄-촉매 가스화 반응은 동일한 공급 비와 반응 조건에서 97.8%, 98.8%의 CO 선택도를 얻었다.
        4,000원
        2.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Agriculture, Forestry and Fisheries Research Council within the Ministry of Agriculture, Forestry and Fisheries looks over the Agriculture, Forestry, and Fisheries Research and Development Project. Every five years, it revises the Agriculture, Forestry and Fisheries Research Basic Plan. Based on the information above, the following suggestions are made to implement domestic research projects. First, the strategic planning and promotion of research and development projects are needed to achieve the goals of the country and agricultural policy. Second, it is necessary to break up and diversify research assignments so that the project implementation reflects the trend of the time. Third, there is a need to develop a research partnership that strengthens cooperation among industry, academia, government, and research institutes to utilize technology seeds from fields other than agriculture. Fourth, it is necessary to improve field demonstration research projects where central and local research institutes, universities, private companies, agricultural cooperation, and farmers can participate. Fifth, follow-ups should be conducted at the end of research to advance research implementation systems. Finally, there is a need to build a new dissemination system which includes research results and policy.
        4,000원
        3.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concentration of VOCs, NO2 was measured both inside and outside residential homes surrounding an industrial complex. Measurements were performed in the area of the industrial complexes and around 10 km away from the industrial complex area. Benzene did not exceed the air quality standard value. Toluene exhibited a high value of concentration in outdoor Yeosu investigated group. The concentration of NO2 is higher than outside concentrations of houses in both inside housing research group compared with the group of Gwangyang and Yeosu. Benzene and toluene showed high correlation (p<0.001) in the housing interior in Gwangyang, It showed a high correlation (p<0.01) in the housing interior in the comparison group. In Yeosu there was a high correlation (p<0.001) between the inside and outside of the housing in the survey group. In the control group there was only high correlation (p<0.05) in the inside of the housing.
        4,000원
        4.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Japanese government, on the basis of the Food, Agriculture and Rural Areas Basic Act, announced the 4th Basic Plan for Food, Agriculture and Rural areas, at the same time the third Basic Plan for Agriculture, Forestry and Fisheries Research in March 2015. The Basic Plan is configured as improvement of food self-sufficiency rate, a stable food supply, agricultural maintenance and development, rural promotion. The new target for the calorie-based food self-sufficiency ratio has been lowered from the previous 50 percent by 2020 to 45 percent by 2025. The production target for table rice has been lowered, but production targets for rice for flour and rice for feed have been raised significantly - five times and 10 times the more than current production by 2025, respectively. The 4th Basic Plan included the important measures of 24 and the details practice challenges of 50 should be intensively promoted for the next five years. The new Research Basic Plan set 21 key targets research and development to solve problems promptly faced by producers with the aim of increasing income in agriculture and rural communities and 11 priority targets research and development to be steadily promoted under medium- to long-term strategy. In addition, it announced the necessary measures of 10 at three areas in order to promote more efficiency and effective in the Agriculture, Forestry and Fisheries Research. In Korea, it refers to the announcement contents of Japan where there is a need to formulate a development plan for Agriculture, Rural Areas and Food Industry Development Plan that meets the Korean situation.
        4,000원
        5.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 이산화탄소와 석탄을 사용하여 합성가스 CO를 생산하는 실험을 수행하였다. CO 합성특성은 KOH 촉매를 사용한 화학적 활성화 방법에 의해 조사되었으며, 제조공정은 CO2 전환 반응에서 석탄과 활성화 촉매 비율, 가스 유량과 반응온도 등과 같은 실험변수들을 분석함으로서 최적화 되었다. KOH 촉매를 사용하지 않은 경우, 반응온도 950℃와 CO2 유량 300 cc/min에서 65% CO2 전 환율을 얻었으며, 반면에 촉매를 사용한 경우 같은 반응조건에서 98.1%의 전환율을 얻었다. 석탄의 활 성화촉매 반응물의 비(석탄 : KOH = 4 : 1)가 다른 반응물 비에 대해 더 좋은 CO2 전환율과 CO 선 택도 보여줌을 알 수 있었다.
        4,000원
        6.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of 1900~2500 m2/g and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.
        4,000원
        7.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon composites for flexible fiber heating element were examined to improve the electrical conductivity in this study. Carbon composites using carbon black, denka black, super-c, super-p with/without CNF or dispersant such as BCS03 and Sikament-nn were prepared. Carbon composite slurry was coated on plane film and yarns(cotton, polyester) and the performances of prepared heating materials were investigated by checking electrical surface resistance, adhesion strength. The plane heating element using carbon black under natural drying condition(25℃) had better physical properties such as surface resistance(185.3 Ohm/sq) and adhesion strength(above 90%) than those of other carbon composite heating elements. From these results, polyester heating element coated by carbon black showed better electrical line resistance(33.2 kOhm/cm) than cotton heating element. Then, it was found that polyester heating element coated by carbon black with CNF(3 wt%) and BCS03(1 wt%) appeared best properties(0.604 kOhm/cm).
        4,000원
        8.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study were to characterize the factors affecting exposure to the VOCs and NO2 in the vicinity of Gwangyang industrial complex. The VOCs and NO2 levels were measured for residents of an exposure group (industrial area within 5 km) and a control group (15 km farther), respectively using the VOCs and NO2 filter badge as a passive sampler from August to September 2006. The means of indoor, outdoor, workplace and personal exposure levels of benzene were 1.10 ppb, 0.94 ppb, 1.85 ppb and 2.35 ppb respectively in the exposure group. The means regarding toluene for the exposure group were 9.29 ppb indoor, 8.09 ppb outdoor, 14.5 ppb workplace, 14.2 ppb personal exposure. The means regarding ethylbenzene were 4.96 ppb(indoor), 4.45 ppb(outdoor), 6.84 ppb (workplace), 6.10 ppb(personal exposure), and the means regarding xylene were 0.10 ppb(indoor, outdoor), 0.18 ppb(workplace) 0.17 ppb(personal exposure). The means for the indoor, outdoor, workplace and personal exposure level of NO2 were 18.40 ppb, 18.51 ppb, 18.59 ppb, 18.80 ppb respectively in the exposure group. Correlations between personal exposures and workplace concentrations of individual VOCs and NO2 exposures, and each of the microenvironment was statistically significant.
        4,000원
        9.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Indoor pollutants seem to have a negative affect on people from vulnerable households who are considered to be weak by the department of environmental health, such as the elderly, infants, children, patients, and pregnant women. In this study, the concentrations of pollutants were measured, especially those pollutants that endanger vulnerable households such as PM10, HCHO, TVOCs, TBC and fungi. The measurements were taken from September to October of 2013 in the Chungnam area. The results were as follows: PM10 33.2 μg/m3, HCHO 20.35 μg/m3, VOCs 132.30 μg/m3, TBC 562.71 CFU/m3 and fungi 362.04 CFU/m3. In the case of TBC and fungi, there were excessive concentrations at 30.9% and 49.3% compared to the standards set by WHO. In the case of fungi, buildings built before the 1980s showed a concentration of 446.23 CFU/m3, those built in the 1980s and 1990s had a concentration of 320.21 CFU/m3 and those built in the 2000s had a concentration of 313.43 CFU/ m3 indicating that fungi concentration was higher when the building was older. The correlation analysis between indoor air pollutants and factors affecting indoor concentrations indicate that HCHO (r = 0.423), TVOCs (r = 0.329), and humidity (r = 0.359) showed a significant difference (p < 0.01). The current study focused on vulnerable households that were unable to protect themselves from indoor pollutants and where poor living circumstances prevailed such as households that do not receive much sunlight; thus, more attention and focus needs to be given to these particular households
        4,000원
        10.
        2013.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        In this study, the characteristic of the facilities and indoor environment for the senior citizens nursing facilities of Kyeonggki and Seoul-total 30 facilities;10 facilities in Seoul and 20 facilities in Kyeonggki from January to December in 2007. In the result of surveying indoor and outdoor pollution degree of 30 senior citizens nursing facilities, the average geometric concentration of indoor and outdoor TVOCs were 264.11 ㎍/㎥ and 162.63 ㎍/㎥, respectively. On the other hand, the average geometric concentration of indoor and outdoor HCHO were 22.76 ㎍/㎥ and 9.55 ㎍/㎥, respectively. The concentration ratio of indoor and outdoor air pollutants were 1.21, 1.23, 1.62 and 2.38 for benzene, toluene, TVOCs and HCHO, respectively. The concentrations of toluene, TVOCs and HCHO were 31.40 ㎍/㎥, 274.30 ㎍/㎥ and 24.17 ㎍/㎥ in the building constructed after 2000. On the other hand, The concentrations of toluene, TVOCs and HCHO were 27.99 ㎍/㎥, 248.54 ㎍/㎥ and 20.48 ㎍/㎥ in the building constructed before 2000. As the constructed year was not late, low concentration was indicated. In the facilities using carpet or not, the concentration of toluene, TVOCs and HCHO were 50.50 ㎍/㎥, 342.73 ㎍/㎥ and 32.94 ㎍/㎥, respectively, in the facilities using carpet. On the other hand, the concentration of toluene, TVOCs and HCHO were 29.35 ㎍/㎥, 261.41 ㎍/㎥ and 22.40 ㎍/㎥, respectively, in the facilities using no carpet. The concentrations were presented higher in the facilities where carpet exits.
        5,100원
        11.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electrochemical performances of an asymmetric hybrid capacitor were investigated using LiFePO4 as the positive electrode and active carbon fibers(ACF) as the negative electrode. The electrochemical behaviors of a nonaqueous hybrid capacitor were characterized by constant current charge/discharge test. The specific capacitance using LiFePO4/ACF electrode turned out to be 0.87F/cm2 and the unit cell showed excellent cycling performance. This hybrid capacitor was able to deliver a specific energy as high as 178 Wh/kg at a specific power of 1,068 W/kg.
        4,000원
        12.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The autothermal reforming reaction of methane was investigated to produce hyd rogen with Ni/CeO2-ZrO2, Ni/Al2O3-MgO and Ni-Ru/Al2O3-MgO catalysts. Honeycomb metalli c monolith was applied in order to obtain high catalytic activity and stability in autothermal r eforming. The catalysts were characterized by XRD, BET and SEM. The influence of various catalysts on hydrogen production was studied for the feed ratio(O2/CH4, H2O/CH4). The O2/CH4 and H2O/CH4 ratio governed the methane conversion and temperature profile of reactor. Th e reactor temperature increased as the reaction shifted from endothermic to exothermic reactio n with increasing O2/CH4 ratio. Among the catalysts used in the experiment, the Ni-Ru/Al2O3-MgO catalyst showed the highest activity. The 60% of CH4 conversion was obtained, and th e reactor temperature was maintained 600℃ at the condition of GHSV=10000h-1 and feed ratio S/C/O=0.5/1/0.5.
        4,000원
        13.
        2011.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        We measured indoor, outdoor, and personal exposure concentrations of ozone (O3) at 54 households in Gwangyang from June to September, 2009. The results are as follows. The concentration of ozone in outdoor, 16.53±5.72 ppb, was observed two times higher than the concentration of ozone in indoor, 8.22 ± 4.60 ppb. The similar arithmetic average ozone were obtained in exposed and controlled areas, 15.16 ± 1.45 ppb and 15.25 ± 1.94 ppb, respectively. The ozone concentration of an individual smoker was 24.89 ± 7.11 ppb, which was higher than that of a non-smoker, 21.01 ± 11.79 ppb. The indoor occupant density elevated ozone concentrations. The relatively low concentration of ozone was observed in a house with air conditioner (8.59 ± 4.04 ppb) than a house without the unit(10.07 ± 6.43 ppb).
        4,300원
        14.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        UV-Curable hybrid coatings were synthesized to improve the surface properties of plastic film. Organic-inorganic coating solutions were prepared by the sol-gel method using urethane-acrylate oligomer, acrylate monomer, photo initiator and tetraethoxysilane (TEOS). Methacryloyloxypropyltrimethoxysilane(MPTMS) was used as a silane coupling agent to improve chemical interaction between inorganic phases and UV curable acrylate. In this study, the surface hardness and adhesive properties were improved with the use of inorganic component. The experimental results showed that UV-Curable hybrid films containing aliphatic urethane oligomer, hexanedioldiacrylate, trimethylolpropanetriacrylate, hydroxy dimethyl acetophenone exhibited good surface properties. Also, the optimum curing conditions were investigated.
        4,000원
        15.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electrochemical characteristics of electric double layer capacitor(EDLC) were investigated using various carbon materials. The physical properties such as specific surface area and mean pore size of activated carbon were analyzed by BET. The results of the activated carbon used for electrode material showed that the specific surface areas varied from 600 to 1500 m2/g and mean pore sizes from 1.74 to 2.88 nm. A maximum specific capacitance of 0.30 F/cm2 was obtained for the activated carbon with the highest specific surface area and ionic conductivity. Also, it was found that the electrochemical results of the cyclic charge-discharge tests were stable.
        4,000원
        16.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To investigate the toxicological effects of β-glucan, we performed basic studying on β-glucan in Sprague-Dawley (SD) rats. Standard endpoints in this study included mortality, clinical observations, changes of body weights, analysis on food consumption, ophthalmoscopic examination, hematologic examination, serum biochemistry,analysis of organ weights, gross anatomic pathology and histopathology. No clinical signs and mortality were observed in animals treated with beta-glucan throughout the experimental period. The average body weight of each treatment groups showed similar levels at end of experiment. There were no treatment-related changes in mortality,body weights changes, food consumption, ophthalmoscopic examination. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analysis, the data were in biologically normal ranges and did not show a dose-dependent manner. In the morphological change, hepatic tissue were not showed ballooning degeneration and irregular arrangement of hepatic cell in β-glucan treatment groups with control group. Also, organs weights (liver, heart, kidney and stomach) and hematological indices (WBC, RBC, Hb, Hct and Platelet) did not show statistically significant differences among the experimental groups. In summary of these results, there were no changes in mortality, mean body weight, clinical signs, food consumption. There were no changes in ophthalmological examination, hematology, blood chemistry,necropsy and histopathology. In conclusion, although further investigation of glucan should be performed in the functions registered in many ancient literatures, β-glucan is physiologically safe and may have potential as candidate food for human health.
        4,000원
        17.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electrochemical properties of electric double layer capacitor(EDLC) was studied by controlling pore size distribution and specific surface area of the activated carbon fiber(ACF). The mesoporous ACF, which was prepared by the iron exchange method, showed the tendency of increasing average pore size and decreasing total surface area. The mesoporous ACF (surface area = 2225 m2/g, pore size=1.93 nm) showed increased mesopore(pore size=1~3nm) volume from 0.055 cc/g to 0.408 cc/g compared to its raw ACF. The charging capacity of the EDLC which uses the prepared mesoporous ACF also increased from 0.39 F/cm2 to 0.55 F/cm2. From these results, it can be known that the electrochemical properties of EDLC are mainly dependent on the specific surface area, but above the surface area 2200 m2/g, it is the mesopore volume that affects the performance of the capacitor considerably. Because the increased mesopore volume results in a decreased ion mobility resistance, the charge capacitance is enhanced.
        4,000원
        18.
        2010.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study investigated the indoor air concentrations and the harmful effects on health by hazardous pollutants in the normal classrooms and special classrooms of 132 elementary, middle, and high schools located in 13 sites in Chungnam from February 2006 to June 2007. The results obtained from this investigation are as follows. As the results of the survey on the indoor air quality, volatile organic compounds were higher in normal classrooms(251.67㎍/m3) than special classrooms (181.59㎍/m3), and formaldehyde was significantly higher in special classrooms (34.22㎍/m3) than normal classrooms (24.61㎍/m3). With regards to the differences of pollutant distribution among elementary, middle, and high schools, volatile organic compounds were the highest in elementary schools (210.79㎍/m3) followed by middle schools (207.79㎍/m3) and high schools (195.96㎍/ m3), and formaldehyde was the highest in high schools (36.03㎍/m3) followed by elementary schools (29.84㎍/ m3) and middle schools (29.16㎍/m3). With regards to the mean concentration of pollutants by school building age, VOCs were the highest in less than 1 year old classrooms (410.93㎍/m3), followed by less than 3 years old classrooms (156.52㎍/m3) and less than 2 years old classrooms (120.18㎍/m3). Formaldehyde was also investigated to be significantly higher in less than 1 year old classrooms (41.37㎍/m3) than 2 or 3 years old classrooms (31.50㎍/m3, 22.21㎍/m3, respectively).
        4,000원
        19.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, much interest on mesoporous carbon has been shown in their use for both hydrogen and methane storage and as an electrode material for electric double layer capacitors. The mesoporous active carbons by ion exchange were prepared and physical properties such as specific surface area and pore structure of active carbon were investigated using BET. In this study, active carbons with mesopore fraction of 60~90% were obtained. The Fe/Ca-exchanged active carbons showed a greater mesoporosity compared with Fe-exchanged carbons. The mean mesopore size in active carbons using Ca- and Fe-exchange was about 5.5~6.0nm and was approximately 1nm higher than that of the Fe-exchanged active carbon.
        4,000원
        20.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Novolac is widely used as the primary solid component of most photoresists in semiconductor and microelectronic devices. In this study, novolac resins were prepared by condensation of 35% formaldehyde with phenolic compounds such as m-/p-cresol, 2,5-dimethylphenol and bisphenol A in the presence of oxalic acid as catalyst. The average molecular weight (Mw) of these novolac resins has been varied on the changing of mixing ratio of m-/p-cresol/2,5-dimethylphenol/bisphenol A or formaldehyde/phenolic compound. Also, thermal properties of novolac were observed by TGA.
        4,000원
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