검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 257

        81.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two key technologies of horizontal drilling and hydraulic fracturing are recognized to achieve the rapid growth of shale gas production, in specific, in the United States during last decade. The claims between environmentalists and oil companies have been debating in terms of water contamination. Nowadays, voluntary publication of chemicals from shale gas players are available in the website, FracFocus. This paper introduces chemicals that are currently used in hydraulic fracturing process. Among chemicals, guar gum and guar derivatives are dominantly consumed to increase the viscosity of hydrofracking fluids. The role of additional additives, such as breakers and biocides, is presented by explaining how they cut down the molecular structure of guar gum and guar derivatives. In addition, crosslinking agent, pH controller, friction reducer, and water soluble polymers are also presented
        4,000원
        82.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 전자감시의 개념과 방법, 전자감시의 효과성 및 정당성을 기반으로 전자감시제도의 현황과 그 문제점을 살펴보았다. 징역형 종료 이후의 전자장치 부착명령은 가택구금과 결합하지 않고 징역형 집행 종료자에 대한 독립적 보안처분의 성격을 가지며, 자유제한적 측면을 가지고 있어 보안처분 중 자유제한적 보호관찰과 비슷한 성격을 가지고 있다. 집행유예 대상자나 가석방(가종료)자에 대한 위치추적 전자장치 부착명령제도는 보호관찰의 유효성을 높이는 보조수단으로 보안처분의 일종으로 보는 것이 타당하다. 전자감시제도는 시설 내 구금에 비하여 더 많은 사회적응의 기회를 갖게 하며, 행동의 자유도 어느 정도 부여할 수 있다는 점에서 인간의 존엄성에 대한 침해라고까지는 할 수 없다. 전자감시제도는 보호감호제도와 거의 동일한 요건을 전제로 이미 위헌의 소지로 폐지된 보호감호제도의 전자적 부활이라는 비판과 이중처벌금지의 원칙에 반한다는 비판이 있으나, 보호감호제도와는 그 성격과 처우형태가 다르며 사후적 처분인 형벌과 구별되어 그 본질을 달리하는 것으로서 형벌에 관한 일사부재리의 원칙이 그대로 적용되지 않으므로, 이중처벌이라고 할 수는 없다. 최근 법무부는 자체 보유한 범죄자별 상세 데이터를 활용하여 범죄 징후 사전알림시스템 개발을 위한 청사진 설계(범죄자별 프로파일링 분석 기법, 시스템 구현방식 등)에 착수하여 한층 더 업그레이드된 전자감시제도의 시행을 앞두고 있어 범죄예방에 더 크게 기여 할 것으로 본다.
        6,600원
        83.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Asphaltenes are generally defined by their solubility when a light alkane, such as n-heptane or n-pentane, is mixed with crude oils or oil sand bitumen. However, this definition is nowadays not enough to understand their behaviors during oil recovery, transport, storage, and even refinery operation. Interestingly, the researches regarding asphaltenes have been vastly presented within last decade. This is because the production of heavy oils is becoming larger and asphaltenes are known to play an important role in the property changes of heavy oils. In this paper, the researches regarding molecular weight, aggregation behavior of asphaltenes are introduced and discussed. It is expected that analytical studies will be appeared continuously in the form of global collaboration in order to describe asphaltene molecules as close as possible based on their origin.
        4,000원
        84.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, leachate treatment facility (outlet, facility inside) and landfill sections (vent systems, landfill surface)of nine landfills is being buried in korea were studied emission characteristics of odor compounds. Air dilutionvalue in ventpipes of landfill section was generally highest and was more 3 times higher than emission standard(air dilution value of facilities outlet : 500) in Daejeon, Tongyeong, and Busan landfill. Outlet of leachate treatmentfacilities in Tongyeong and Daegu landfill, in case, was higher respectively 20 times, 6 times than other landfills,commonly show that a large contribution to the odor of hydrogen sulfide. In case of ordor emission rate, ammoniaand hydrogen sulfide were surveyed to comprise a high rate for odor emission rate. Odor emissions based onlandfill scale, large landfill (Sudokwon) and small landfills (Yeosu, Chuncheon, Chungju) is low in odor emissionsper unit area, whereas medium landfill (Busan, Daejeon, Daegu) was estimated to be high odor emissions. In caseof large landfill, leachate treatment facilities is management in good condition and discharged odor emission oflandfill sections was low into ambient air. In case of small landfill, decay gases and leachate is few. Thereforeodor emissions is fewer than estimated medium landfill. In case of medium landfill, management condition ofleachate treatment facility was in poor and landfill sections was under not stabilization stage. Thus, mediumlandfills was identified that needs to be intensive care.
        4,300원
        85.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        조선시대 불교에 대한 이해와 연구는 불교탄압과 유교진흥이라는 편견과 선입견이 여전히 지배하고 있다. 이와 같은 인식은 조선후기 승려들의 각종 부역동원의 사실에서도 나타나고 있다. 이른바 승려 들의 산성방어와 각종 토산물의 생산과 상납이 불교계에 대한 수탈 과 착취라는 것이다. 이와 같은 평가와 인식은 조선후기 사회경제적 상황에서 살펴보면 많은 문제점을 지니고 있다. 임진왜란 이후의 조선은 인구감소, 자연 재해, 대규모 기근, 농토의 황폐화 등으로 암울한 상황이 지속되었 다. 급기야 조선정부는 백성들의 전세(田稅)·공물(貢物)·역(役)의 부담을 완화시켜 주는 조치를 취했다. 그러나 대동법이나 균역법의 시행은 백성들에게 일시적인 위안책이었다. 대동법 시행으로 백성들 의 부담을 떠안은 승려들의 곤궁함이 더해지기도 했지만, 백성들의 삶은 여전히 향상되지 못했다. 균역법의 시행 이후 승려들의 부역동 원도 점차 금지되었고 완화되었다. 요컨대 조선후기 경제상황과 수취체제의 시행은 승려들이 맹목적 인 수탈과 착취의 대상은 아니었으며, 불교탄압의 사례로 볼 수 없는 구조적인 문제였다.
        7,800원
        87.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bioenergy is classified to one of the renewable energy resources such as solar, wind, hydro and tidal energies. It should be noted that all the renewable energies contribute to the reduction of greenhouse gases emission. In some cases, energy from wastes was also categorized as a renewable energy in our country even though it has only negligible effect on the emission reduction. In this paper, we tried to identify the bioenergy in order to follow the global indices of the renewable energy. The indices evaluated here were whether a resource is renewable, iogenic, biodegradable, combustible and organic. Biogenic and combustible were selected as the indices to identify the bioenergy. It was also suggested that combustible as an index can be exchangeable to organic.
        4,000원
        88.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the sensory quality attributes for the development of soy sauce containing an extract of the fruit of Hovenia dulcis Thunb (Hutgae), also known as liver function improvement and hangover removal. Aqueous extracts of Hutgae fruit and Hutgae fruit-soy sauce were used for determining the sensory evaluation. The intensity of the sweet smell and taste was predominated in the Hutgae fruit extract (p<0.05). Various seasoning items, such as apples, pears, dried figs, Korean bramble (Bokbunja), citron (Yuza) and sun-dried hot pepper (Taeyangcho), were used to determine the suitable type of seasoned soy sauce with the Hutgae fruit extract. In the sensory analysis, the highest overall preference (acceptance score 5) was obtained from the pear extract added to soy sauce with the Hutgae fruit. The overall preference of Yuza (score 4.9) and Taeyangcho (score 4.5) extracts also very well-matched the seasoning items for soy sauce with the Hutgae fruit extract. There was no difference among the extract mixtures of multi-seasoning items added to soy sauce with the Hutgae fruit extract. As more pear extract was added, a higher overall preference was obtained. On the other hand, as the more Yuza extract was added, the higher flavor intensity without the change of the overall preference was obtained. The overall preference of soy sauce with the pear- Yuza-Taeyangcho extract mixture was not different between with or without the Hutgae fruit extract. However, the overall preference (score 5.6) was significantly higher in the pear extract added to soy sauce with the Hutgae fruit extract compared with the pear extract added to soy sauce without the Hutgae fruit extract (score 4.8). These results suggest that soy sauce with the Hutgae fruit-pear extract mixture may be useful as a functional seasoning for various salad dressings.
        4,000원
        89.
        2013.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Activated magnetite (Fe3O4-δ) has the capability of decomposing CO2 proportional to the δ-value at comparativelylow temperature of 300oC. To enhance the CO2 decomposition capability of Fe3O4-δ, (Fe1-xCox)3O4-δ and (Fe1-xMnx)3O4-δ weresynthesized and then reacted with CO2. Fe1-xCoxC2O4·2H2O powders having Fe to Co mixing ratios of 9:1, 8:2, 7:3, 6:4, and5:5 were synthesized by co-precipitation of FeSO4·7H2O and CoSO4·7H2O solutions with a (NH4)2C2O4·H2O solution. The samemethod was used to synthesize Fe1-xMnxC2O4·2H2O powders having Fe to Mn mixing ratios of 9:1, 8:2, 7:3, 6:4, 5:5 with aMnSO4·4H2O solution. The thermal decomposition of synthesized Fe1-xCoxC2O4·2H2O and Fe1-xMnxC2O4·2H2O was analyzedin an Ar atmosphere with TG/DTA. The synthesized powders were heat-treated for 3 hours in an Ar atmosphere at 450oCto produce activated powders of (Fe1-xCox)3O4-δ and (Fe1-xMnx)3O4-δ. The activated powders were reacted with a mixed gas(Ar:85%, CO2:15%) at 300oC for 12 hours. The exhaust gas was analyzed for CO2 with a CO2 gas analyzer. The decom-position of CO2 was estimated by measuring CO2 content in the exhaust gas after the reaction with CO2. For (Fe1-xMnx)3O4-δ,the amount of Mn2+ oxidized to Mn3+ increased as x increased. The δ value and CO2 decomposition efficiency decreased asx increased. When the δ value was below 0.641, CO2 was not decomposed. For (Fe1-xCox)3O4-δ, the δ value and CO2decomposition efficiency increased as x increased. At a δ value of 0.857, an active state was maintained even after 12 hoursof reaction and the amount of decomposed CO2 was 52.844cm3 per 1g of (Fe0.5Co0.5)3O4-δ.
        4,000원
        90.
        2013.04 구독 인증기관·개인회원 무료
        The Adhesion method is general to reinforce steel structures using FRP(Fiber reinforced Plastic) material. Until recently in many studies, the adhesion method is being utilized. Most of the problem of this method have been eliminated. The bond performance is not enough due to the delaminate of epoxy between FRP and steel. In order to improve the problem, a bolt tighting, FRP sheet wrapping is to evaluation the degree of bond performance improvement in study.
        91.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to suggest developing plans for 6 beef brands in Kangwon-do. Data were collected by consumer survey on 12th August, 2010 at Daemyung Resort in Hongcheongun. A total of 658 questionnaires were distributed and collected. SAS 9.1 and Excel 2007 were used as statistical packages and ordered logit model was used as a model to analyze the data. From the results of the study the following improvement plans were suggested for the 6 beef brands in Kangwon-do. First, the 6 beef brand agents should use public relation to give information for consumers. Clean image of Kangewon-do and clear distribution process should be stressed for the public relation. Second, promotion is an important tool to discriminate the 6 beef brands with other beef brands. The discrimination by the 6 beef brands should be focused on taste of the 6 beef brands. Third, market segmentation strategies are needed. The market segmentation may be achieved by segmentation of sales places.
        4,800원
        92.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 식물생장조절물질을 활용하여 ‘캠벨얼리’ 포도의 품질향상 증진 방안을 마련하기 위하여 실시하였다. 전엽 3∼5엽기에 화방에 대한 지베렐린(GA3) 5 mg·L-1 엽면처리는 ‘캠벨얼리’ 포도의 과경, 과방중, 가용성당함량, 과피의 착색을 증진시켰다. 전엽 3∼4엽기의 화방에 대한 GA3 5 mg·L-1과 ABA 20 mg·L-1 혼용처리는 과립 비대와 과축 신장을 저해하지 않았으며 포도 과피의 안토시아닌 축적에 효과적이었다. ‘캠벨얼리’ 포도의 전엽 3∼4엽기에 화방에 대한 thidiazuron 2.5 mg·L-1과 GA3 5 mg·L-1 혼용처리는 가용성고형물 함량 증진과 산함량 감소를 촉진하여 과실 품질이 증대되었다.
        4,000원
        94.
        2012.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A general synthetic method to make Fe3O4-δ (activated magnetite) is the reduction of Fe3O4 by H2 atmosphere. However, this process has an explosion risk. Therefore, we studied the process of synthesis of Fe3O4-δ depending on heat-treatment conditions using FeC2O4·2H2O in Ar atmosphere. The thermal decomposition characteristics of FeC2O4·2H2O and the δ-value of Fe3O4-δ were analyzed with TG/DTA in Ar atmosphere. β-FeC2O4·2H2O was synthesized by precipitation method using FeSO4·7H2O and (NH4)2C2O4·H2O. The concentration of the solution was 0.1 M and the equivalent ratio was 1.0. β-FeC2O4·2H2O was decomposed to H2O and FeC2O4 from 150˚C to 200˚C. FeC2O4 was decomposed to CO, CO2, and Fe3O4 from 200˚C to 250˚C. Single phase Fe3O4 was formed by the decomposition of β-FeC2O4·2H2O in Ar atmosphere. However, Fe3C, Fe and Fe4N were formed as minor phases when β-FeC2O4·2H2O was decomposed in N2 atmosphere. Then, Fe3O4 was reduced to Fe3O4-δ by decomposion of CO. The reduction of Fe3O4 to Fe3O4-δ progressed from 320˚C to 400˚C; the reaction was exothermic. The degree of exothermal reaction was varied with heat treatment temperature, heating rate, Ar flow rate, and holding time. The δ-value of Fe3O4-δ was greatly influenced by the heat treatment temperature and the heating rate. However, Ar flow rate and holding time had a minor effect on δ-value.
        4,000원
        95.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the sensory quality attributes for the development of soy sauce containing Hutgae(Hovenia dulcis Thunb). Aqueous extracts of Hutgae were prepared from different parts such as trunk, twig, and fruit. These extracts were used for determining the antioxidant effect by 2, 2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity and sensory evaluation. Hutgae twig and fruit extracts had a strong DPPH scavenging effect compared to Hutgae trunk extract. In sensory analysis, high intensities of roast smell, bitter taste, and astringent taste were observed in Hutgae twig extract, whereas those of sweet smell and sweet taste were predominated within Hutgae fruit extract. Hutgae trunk and fruit extracts obtained higher overall acceptability. Various seasoning items such as anchovy, dried-pollack, katsuobushi, shiitake, radish, and kelp were used to determine the suitable type of soy sauce containing Hutgae extracts regarding the different parts. Hutgae fruit and trunk extracts were evaluated for use as a good source of seasoned soy sauce, and the dried-pollack and radish among the seasoning items were well-matched with Hutgae extracts. From these results, soy sauce containing Hutgae trunk and fruit extracts added to dried-pollack soup may be used as a functional seasoning in order to remove hangovers.
        4,000원
        96.
        2012.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Activated magnetite (Fe3O4-δ) was applied to reducing CO2 gas emissions to avoid greenhouse effects. Wet and dry methods were developed as a CO2 removal process. One of the typical dry methods is CO2 decomposition using activated magnetite (Fe3O4-δ). Generally, Fe3O4-δ is manufactured by reduction of Fe3O4 by H2 gas. This process has an explosion risk. Therefore, a non-explosive process to make Fe3O4-δ was studied using FeC2O4·2H2O and N2. FeSO4·7H2O and (NH4)2C2O4·H2O were used as starting materials. So, α-FeC2O4·2H2O was synthesized by precipitation method. During the calcination process, FeC2O4·2H2O was decomposed to Fe3O4, CO, and CO2. The specific surface area of the activated magnetite varied with the calcination temperature from 15.43 m2/g to 9.32 m2/g. The densities of FeC2O4·2H2O and Fe3O4 were 2.28 g/cm3 and 5.2 g/cm3, respectively. Also, the Fe3O4 was reduced to Fe3O4-δ by CO. From the TGA results in air of the specimen that was calcined at 450˚C for three hours in N2 atmosphere, the δ-value of Fe3O4-δ was estimated. The δ-value of Fe3O4-δ was 0.3170 when the sample was heat treated at 400˚C for 3 hours and 0.6583 when the sample was heat treated at 450˚C for 3 hours. Fe3O4-δ was oxidized to Fe3O4 when Fe3O4-δ was reacted with CO2 because CO2 is decomposed to C and O2.
        4,000원
        97.
        2012.04 구독 인증기관·개인회원 무료
        Rehabilitation of existing steel structure attached to a steel because cross-section is generally raising. But when the area of reinforcement increases, also increases the weight of steel can cause degradation of the operations. In addition, welding process cause discomfort which due to the interference of other process. To replace the existing method, there are researches and applications for civil steel structures on the outside. In this study, bond performance of FRP and Steel were tested to reinforce steel structures by using AFRP as well as CFRP.
        98.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        상록활엽수인 가시나무와 낙엽활엽수인 상수리나무 낙엽의 분해율 및 분해과정에 따른 영양염류의 함량 변화를 파악하기 위해 2008년 12월 공주의 상수리나무군락에 낙엽주머니를 설치하고 2009년 3월부터 2010년 12월까지 3개월 간격으로 낙엽주머니를 수거하여 분해율, 분해상수(k), 그리고 분해과정에 따른 C/N비, C/P비의 변화와 영양염류의 동태를 조사하였다. 24개월경과 후 상수리나무 낙엽과 가시나무 낙엽의 잔존률은 각각 46.3±5.4%와 37.8±2.5%로 가시나무 낙엽의 분해가 상수리나무 낙엽의 분해보다 빠르게 진행되는 것으로 나타났다. 24개월경과 후 상수리나무 낙엽과 가시나무 낙엽의 분해상수(k)는 각각 0.38과 0.49로 가시나무 낙엽의 분해상수가 높게 나타났다. 상수리나무 낙엽의 분해과정에 따른 C/N. C/P 비율은 초기에 각각 46.8, 270.9 이었으나 24개월경과 후에는 각각 22.5와 104.2로 점차 감소하였으며, 가시나무 낙엽의 경우 초기 C/N, C/P 비율은 각각 22.4와 41.7로 나타났고, 24개월경과 후에는 각각 16.7와 89.9로 나타났다. 낙엽의 초기 N, P, K, Ca, Mg 함량은 상수리나무 낙엽에서 각각 8.31, 0.44, 4.18, 9.38, 1.37 mg/g, 가시나무 낙엽에서 각각 19.88, 2.73, 7.06, 8.24, 2.61 mg/g으로 가시나무 낙엽의 질소와 인의 함량이 상수리나무 낙엽에 비해 현저히 높았다. 24개월경과 후 N, P, K, Ca, Mg의 잔존률은 상수리나무 낙엽에서 각각 100.91, 114.75, 32.99, 50.63, 15.51% 이었고, 가시나무 낙엽에서 각각 43.22, 11.35, 12.98, 82.22, 44.23% 로 조사기간 동안에 상수리나무 낙엽에서는 질소와 인의 부동화가, 가시나무 낙엽에서는 질소와 인의 무기화가 진행되었다.
        4,000원
        99.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험은 수출과정 중 '화산' 배의 신선도를 유지하기 위한 목적으로 과실의 숙도별 적정수송온도 및 유통온도의 설정을 위하여 모의유통기간 중 과실의 품질과 생리장해 발생을 조사하였다. 만개 후 135일에 수확한 과실의 경우, 유통 30일에 조사한 과실 경도는 1℃에 수송되고 18℃에서 유통된 과실은 28.6N로 조사되었던 반면 5℃에서 수송되고 25℃에서 유통된 과실은 24.2N으로 수송 및 유통온도가 낮을수록 경도가 높게 유지되었다. 만개 후 145일에 수확한 과실의 경도는 만개 후 135일에 수확한 과실에 비하여 유통기간 중 경도가 현저하게 낮았는데 유통온도가 높을수록 과육의 경도 저하가 빠르게 진행되었다. 과실의 생리장해 발생을 측정한 결과, 수송온도와 관계없이, 25℃에서 유통된 과실이 18℃에서 유통된 과실보다 과육의 생리장해 발생 및 과실 부패율이 2배 이상 높게 측정되어 수출과정 중 과실의 신선도 유지를 위해서는 유통온도의 관리가 보다 중요한 요인으로 작용하는 것이 확인되었다. 따라서 수출과정 중 발생하는 경제적 손실을 줄이고 고품질 과실의 유통을 위해서는 유통환경을 고려한 수확시기 조절 및 수송 유통과정에서의 철저한 온도관리가 필수적으로 판단된다.
        4,000원
        100.
        2011.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of the precipitator (NaOH, NH4OH) and the amount of the precipitator (150, 200, 250, 300 ml) on the formation of Fe3(PO4)2, which is the precursor used for cathode material LiFePO4 in Li-ion rechargeable batteries was investigated by the co-precipitation method. A pure precursor of olivine LiFePO4 was successfully prepared with coprecipitation from an aqueous solution containing trivalent iron ions. The acid solution was prepared by mixing 150 ml FeSO4(1M) and 100 ml H3PO4(1M). The concentration of the NaOH and NH4OH solution was 1 M. The reaction temperature (25˚C) and reaction time (30 min) were fixed. Nitrogen gas (500 ml/min) was flowed during the reaction to prevent oxidation of Fe2+. Single phase Fe3(PO4)2 was formed when 150, 200, 250 and 300 ml NaOH solutions were added and 150, 200 ml NH4OH solutions were added. However, Fe3(PO4)2 and NH4FePO4 were formed when 250 and 300 ml NH4OH was added. The morphology of the Fe3(PO4)2 changed according to the pH. Plate-like lenticular shaped Fe3(PO4)2 formed in the acidic solution below pH 5 and plate-like rhombus shaped Fe3(PO4)2 formed around pH 9. For the NH4OH, the pH value after 30 min reaction was higher with the same amount of additions of NaOH and NH4OH. It is believed that the formation mechanism of Fe3(PO4)2 is quite different between NaOH and NH4OH. Further investigation on this mechanism is needed. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and the pH value was measured by pH-Meter.
        4,000원
        1 2 3 4 5