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        검색결과 69

        21.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        물리화학적 처리에 의한 양돈장 악취저감 효과를 분석 하기 위하여 물리적 처리 방법인 커튼과 화학적 처리 방법 인 오존수 분무를 병합처리 하는 오존수커튼 시스템을 상 업적인 양돈장에 설치하고 처리 및 설치 전․후의 악취발생 특성과 악취저감 효과를 조사한 결과를 요약하면 다음과 같다. 오존수커튼 시스템은 돈사내부의 악취물질과 먼지를 배기구를 통해 커튼 내부로 포집 후 오존수의 강력한 산화 력으로 악취를 제거하는 안정적인 물리화학적 처리 방법 임을 확인하였다. 오존수커튼 시스템 설치 후 돈사 내부의 암모니아, 황화수소, 트리메틸아민, 휘발성 유기화합물 및 복합악취 농도가 높은 반면, 커튼 외부와 부지경계선에서 는 현저하게 감소되었으며, 악취발생량 또한 크게 감소되 었다(p<0.01). 측정위치별 악취물질농도와 악취발생량은 암모니아, 황화수소, 트리메틸아민, 휘발성 유기화합물 및 복합악취 모두 계절에 관계없이 돈사 내부, 커튼 외부 및 부지경계선 순으로 높았다(p<0.01). 돈사 내부의 악취물질 농도는 환기량이 적은 봄과 겨울에 높고 환기량이 많은 여 름과 가을에 낮았으나, 돈사 외부와 부지경계선에서의 악 취물질농도는 돈사 내부와 상반되는 결과를 나타내었다. 이상의 결과를 요약하면, 양돈장에서 배출되는 악취물질은 오존수커튼 시스템에 의한 물리화학적 처리로 90% 이상 저감 가능한 것으로 판단되며, 양돈장 외부로의 악취물질 확산을 효과적으로 차단함으로써 악취민원 제거를 위한 효율적인 악취저감시설로 활용 가능성은 충분한 것으로 사료된다.
        4,000원
        23.
        2016.10 구독 인증기관·개인회원 무료
        CRISPRs(clustered regularly interspaced short palindromic repeats) / CRISPR - associated(CAS) system has been used genome editing technology. Genome stage modification using CRISPR/CAS9 system can be used to wide research for the gene functional study and therapeutics. However, improving of CRISPR/CAS9 system in efficiency is essential for application in various fields. Here, we treated various chemicals during the procine early embryo development to increase the mutation of target site by NHEJ(non-homologous end joining). Firstly, we confirmed the chemical toxicity after parthenogenetic activation and then check embryo puality using by counting of total cell number and TUNEL Assay in blastocyst satge. To check any improvement on mutation rate by NHEJ pathway. AZT(3′-Azido-3′-deoxythymidine, antiretroviral drug – 0.1 μM) was treated after injection of cas9 and sgRNA target to OCT4 exon 5 during the zygote stage, followed by PCR sequencing. As a result, AZT treated group shows a significantly increased in knock-out efficiency as a consequence of NHEJ. Nocodazole(anti-neoplastic agent – 200ng/ml), RO-3306 (specific inhibitor of CDK1 - 10 μM) and NU-7026(PKC signalling inhibitor - 50 μM) was treated after injection of cas9 and sgRNA with eGFP vector during the zygote stage(hpa8~hpa20) and checked a efficiency of knock-in by PCR sequencing. Interestingly, nocodazole treatment groups increased of insertion of eGFP sequence in blastocyst stage compared with non-treat group(control : 8.33%, nocodazole treatment : 16.67%). However, RO-3306 and NU-7026 made a no impact. In summary, CRISPR/CAS9 system with treatment of chemicals during porcine embryogenesis can be improving of site-specific mutation and enhancement of CRISPR genome editing.
        25.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the thermal treatment yam (Dioscorea batatas DECNE.) was analyzed for its proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids. Thermal treatment yam is mainly consisted of carbohydrate (70.3%) with small amounts of crude protein (15.8%), crude ash (5.1%) and crude fat (1.6%). It was found to be a good source of essential minerals such as K (1100.2 mg/100 g), Mg (99.4 mg/100 g), Ca (54.8 mg/100 g) and Na (44.9 mg/100 g) but Zn (4.8 mg/100 g) and Fe (0.2 mg/100 g) content was low. Little amounts of vitamin E (8.3 mg/100 g), vitamin C (3.5 mg/100 g) and vitamin B1 (2.1 mg/100 g) could be found. The amino acid analysis revealed that the yam was superior with respect to serine (1454.2 mg%), lysine (684.6 mg%) and histidine (684.6 mg%). Essential amino acids were calculated to be 2849.3 mg%. The amino acid profiles showed that thermal treatment yam is limiting in isoleucine and phenylaline. Linoleic acid was the most predominant fatty acids with the value of 47.3% followed by palmitic acid (24.7%) and oleic acid (12.7%). And the unsaturated fatty acids including oleic acid and linoleic acid were present in big quantities in thermal treatment yam.
        4,000원
        26.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 식물구계학적 특정식물종 II급에 해당하는 난쟁이바위솔의 종자 번식법 개발을 위해 수행되었다. 종자의 형태적 특성은 크기가 1.10×0.21mm, 1,000립 중이 496.0±0.21mg인 갈색의 미립종자였다. 종자의 함수율은 24시간 만에 8.8%에서 39.8%로 급속히 증가하여최대함수율을 보였다. 온도 및 광조건에 따른 발아율은20οC, 명조건에서 가장 높았으며, GA3와 KNO3용액에 24시간 처리함으로써 발아율과 발아세가 매우 향상되었다.특히 GA3 처리구는 10~100mg•L−1의 농도에서 발아율이99.0% 이상으로 매우 우수였으며, KNO3는 5mM 처리구에서 발아율이 81.3%로 가장 높았다.
        4,000원
        27.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        복숭아의 저장성 증진을 위하여 46℃의 열풍건조기에서 0~9시간 동안 처리한 후, 저장 기간 중 화학성분들과 항산화활성이 변화하는지를 측정하였다. 복숭아 중 ascorbic acid의 함량은 13.81 ㎎%였으며, 열풍처리군은 11.73~14.16 ㎎%로 대조군과 큰 차이를 보이지 않아, 열풍처리에 의한 변화는 없는 것으로 나타났으며 저장 중 함량 변화에서는 6시간 열풍처리군을 제외하고는 대체적으로 감소하는 경향이었으며, 대조군의 변화가 가장 빠른 것으로 나타났다. Polyphenol 화합물의 함량은 대조군은 22.64 ㎎%였으며, 열풍처리군은 19.03~23.19 ㎎%로 복숭아 저장성 증진을 위한 열풍처리의 변화는 없는 것으로 나타났으며, 저장 중의 변화에서는 대조군보다는 열풍처리군에서 약간 높은 함량을 유지하는 경향이었다. Flavonoid 함량에서는 대조군 및 열풍처리군 모두 저장하는 동안 특정한 경향을 보이지는 않는 것으로 나타났다. 유리당의 변화에서는 대조군 및 열풍처리군 모두 개체 차이일 뿐 큰 차이를 보이지 않았으며, 저장 중 변화에서도 차이를 보이지는 않는 것으로 나타났다. 항산화 활성의 변화도 대조군과 열풍처리군 모두 차이를 보이지 않았다.
        4,000원
        28.
        2013.10 구독 인증기관·개인회원 무료
        This study was conducted to establish the optimized protocol for cytoplasm isolation of bee pollen. Data of biochemical parameters and amino acid profiles were obtained from acorn pollen grains treated with pulverization or lyophilization. Contents of moisture, ash, crude protein and crude fat of acorn pollen were 11.7%, 2.6%, 24.1% and 11.8%, respectively. After pulverizing, content of crude protein was decreased to 23.8% while crude fat was 22.5% which means 90% increase. Also content of crude protein was increased to 26.5% in case of the lyophilized pollen. Amino acids such as aspartic acid, glutamic acid, leucine and arginine were extensively found in acorn pollen while histidine, methionine and cystine were infrequent. The pulverized pollen was increased by 2.6% in the total amino acid percentage while the lyophilized pollen increased by 11.8% compared to the untreated pollen.
        29.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this present work, the effect of additional heat-treatment (AHT) in the range from 1800℃ to 2400℃ on the chemical composition, morphology, microstructure, tensile properties, electrical resistivity, and thermal stability of commercial polyacrylonitrile (PAN)-based carbon fibers was explored by means of elemental analysis, electron microscopy, X-ray diffraction analysis, single fiber tensile testing, two-probe electrical resistivity testing, and thermogravimetric analysis (TGA). The characterization results were in agreement with each other. The results clearly demonstrated that AHTs up to 2400℃ played a significant role in further contributing not only to the enhancement of carbon content, fiber morphology, and tensile modulus, but also to the reduction of fiber diameter, inter-graphene layer distance, and electrical resistivity of "as-received" carbon fibers without AHT. The present study suggests that key properties of commercial PAN-based carbon fibers of an intermediate grade can be further improved by proprietarily adding heat-treatment without applying tension in a batch process.
        4,000원
        30.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature (700℃ to 1100℃) and chemical pre-treatment (NaOH and NH4Cl) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then re-organized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.
        4,000원
        31.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        EAF dust which is contained around 30% of zinc, 15% of iron and 3% of lead individually, is chemically treated by ammonium chloride, ammonia water, ammonia gas and carbon dioxide, and also tested and identified the ratios of the recovery of In by applied the variations of particle size, pH and heating temperature as well, in order to getting optimized recovery of the In metal after performing all of those processes. Experimental results showed that the rate of Zn recovery is 97% when the mixture of 1.3 of NH4Cl/EAF is heated to the temperature of 400℃ and leached by water, and 95% recovery of In when ammonia gas and carbon dioxide is added simultaneously and adjust the 9.5 of pH to the same mixture above. For the purpose of remove the impurities in the mixed sample, which is prepared by the two samples, indicated above showing as the ratio of 95% and 97% recovery, in case of applied the cementation process to it, and also by electrolytic process, produced the In plate of 95~97%, and acquired 99-99.5% of In metal ingot finally by applied the heating process at 470~500℃.
        4,000원
        32.
        2009.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, the effects of silver treatment and activation on the physical and chemical properties of spherical activated carbon (SAC) were studied. The textural properties of SAC were characterized by BET surface area, XRD, SEM, iodine adsorption, strength intensity, pressure drop and antibacterial effects. BET surface areas of SACs decreased with an increase of the amount of PR before and after activation, and the BET surface areas of SACs were found to be about 2-3 times the size of those before activation. The XRD patterns showed their existing state as stable Ag crystals and carbon structure. The Ag particles are seaweedlike and uniform, being approximately 5-10 μm in size deposited on the surface of activated carbon. All of the samples had much more iodine adsorption capability after activation than before activation. The strength values of SACs increased with an increase of the amount of PR, and there was a smaller drop in the strength values of SACs with silver treatment than with non-silver treatment after activation. The Ag-SAC composites showed strong antibacterial activity against Escherichia coli (E. Coli).
        4,000원
        33.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 영산강유역 농공폐수처리장 방류수중의 유기오염물질 분포를 관찰하였다. 시료채취 지점은 영산강 유역에 존재하는 4지점의 농공단지 폐수처리장을 선정하였다. 본 연구에서 GC-Ion trap MS로 300종의 일반적인 화학물질을 ppt수준에서 검출할 수 있는 방법을 이용하여 분석하였다. 농공폐수처리방류수에서 검출된 주요 유기오염물질은 농약류, CH구조의 방향족, CHO구조의 프탈레이트류, 그리고 CHO(N) 구조의 아로메틱 아민류였다. 또한 diethylphthalate를 포함한 17종의 내분비계장애물질이 검출되었다. XTT assay를 이용한 세포독성 결과는 TV로 나타냈으며, 그들의 세포독성은 A지점에서 27.2, D지점에서 24.4로 가장 높게 나타났다. 한편 화학적 분석 결과와 생물학적 독성도와는 일치하지 않는 것으로 나타났다.
        4,000원
        34.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 국제 유가의 상승으로 인한 선박 운용비를 절감하기 위하여 중소형 선박에서도 저질연료유의 사용이 검토되고 있는 추세이다. 이 연구에서는 현재 중소형 선박에서 연료유로 사용중인 경유와 중유MF380을 혼합하여 소형선박에 사용이 가능하도록 제조한 혼합연료유인 MF30 연료유에 대하여 그 물리 화학적 특성을 분석하고 정제처리 및 연료유첨가제 효과에 대해 알아보았다. 연구결과 두 가지 전처리 방식인 원심식청정기와 가열 및 균질 방식(M.C.H)의 효과는 다소 미약하였지만, 유동점과 인화점은 다소 낮아졌다. 연료유첨가제로 인한 개질 효과는 뚜렷이 나타나지 않았다.
        4,000원
        35.
        2007.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Developing carbohydrate fat replacer as materials for low-calorie and low-fat food made of Korean potato, it is expected that the new demand of fat replacer will be created. Potato starch was modified by chemical modification. Observing modified starch(treated in different method) by SEM, EZ(treated by enzyme) showed shape of deformed round oval, AC(treated by acetylation,), HPR(treated by hydropropylation) showed shape similar to that of NL(N-Lite), the commercial fat replacer. In the modified starch such as AC, peak in B and C type similar to those of general starch was found, but EZ showed non-crystalline shape. Compared to other modified starch, HPR, the chemically produced denatured starch showed very peculiar peak and structure in V-form. While the order of contents of amylopectin was in the order HPR 〉 EZ 〉 AC showed extremely high contents. Measuring the degree of gelatinization per the modified method, the degree of gelatinization of HPR as much higher than others. The water binding activity of modified starch was 240% in HPR. Measuring viscosity by producing general starch and modified starch as gel of 10% concentration, the CPS showed very high viscosity of 30.30 × 103 cp. Showing viscosity of 38.60, 31.60 103 × cp, the modified starch was in the order of HPR. While the calorie of starch of GPS was measured to be 3.0 Kcal/g, very low calorie those of chemically modified starch, HPR showed 2.5 Kcal/g respectively, suggesting that calorie is decreased by modified treatment. The appropriateness of processing food was experimented by substituting the existing oil and fat containing food with saturated gel of starch and modified starch in constant rate through utilization of modified starch. Therefore, research and development for materials and related products which maintain the existing quality and reduce fat contents will be constantly performed in the future.
        4,000원
        36.
        2006.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자력을 이용하는 시설 및 그와 관련한 연구개발실험실로부터 각종 화학폐수가 다량으로 발생되고 있으며 이들 폐수를 화학폐수 전용처리시설로 처리하고 있으나 최종 건조 케이크내에 함유된 우라늄의 농도가 규제면제농도인 10 Bq/g을 약간 초과하므로서 방사성폐기물로 분류하여 별도로 저장하고 있다. 화학폐수 처리후 침전된 슬러지내의 우라늄 농도를 분석한 결과 우라늄이 용액상이 아닌 침전물상에 존재함을 알았으며, 이들 우라늄을 침전물로부터 용액상으로 용해하기 위하여 강질산으로 용해시켰다. 그 결과 대부분의 우라늄이 슬러지의 침전물로부터 용액상으로 용출되었으며, 용해후 얻어진 슬러지 산용해액에 대해 IRN-77과 비드형으로 새로 제조한 다이포실 수지를 실 폐액처리에 적용하기 위한 흡착실험을 수행하였다. IRN-77과 다이포실 비드를 단독, 혼합 또는 단계적으로 사용한 결과, 80%이상의 우라늄 흡착효율을 얻기 위해서는 산용해액과 동등량 또는 그 이상의 다량의 수지가 소요되었다. 한편 침전 슬러지를 압착하여 부피가 더욱 축소된 탈수케이크를 산용해한 결과, 탈수케이크 대 질산의 비율이 3:2에서 우라늄의 함량을 최대 11 mg/L을 얻었으며 슬러지 용해시보다 적은 양으로 산용해가 가능하였다. 탈수 케이크 산용해액의 방사능 농도는 6.97E-01 Bq/ml 로서 기존의 자연증발처리시설에서 처리가 가능한 수준이었으며, 건조케이크의 비방사능은 11.2 Bq/g로서 최종 폐기물로 발생될 폐증발천의 비방사능이 4.3 Bq/g으로 평가되어 우라늄 동위원소의 규제면제치인 10 Bq/g 미만이므로 자체처분이 가능한 수준이었다. 결론적으로 화학폐수를 처리한 후 부피가 최소화된 탈수케이크에서 우라늄을 산용해시키고 최종 산용해액은 기존의 자연증발시설로 증발처리하면 방사성 건조케이크의 발생 없이 또한 자연증발천도 자체처분이 가능한 최적의 방안을 도출하였다.
        4,000원
        37.
        2006.04 구독 인증기관·개인회원 무료
        is an extremely high alloyed PM material containing about 20 to 35 wt.% titanium based carbides. Such materials are designed to achieve a high wear resistance, but the high volume fraction of hard phases causes a comparable low ductility in case of tensile loading. In the present study the mechanical properties of different Ferro-Titanit grades (variations in chemical composition and in heat treatment) were investigated by means of tensile tests. The mechanical properties and the fracture behaviour will be related to the chemical composition, the heat treatment and the microstructure.
        40.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In view of recycle or treatment of swine manure, the physico-chemical characteristic including the thermal reaction curve by DSC were evaluated. After extrusion processing of swine manure, durability of the pellet and the degree of odor reduction by olfactory detection were also evaluated. Fresh swine manure solids contains more than half of 106㎛ or smaller particles, that could cause a difficulty in physical separation. Totally, 80.34% of solids were volatile solids. As the urea level is increased, the gelatinization temperature of the manure added feed mixture is decreased although the specific energy for gelatinization is increased. The level of fiber and ash did not affect the thermal modification pattern. A durability of extruded and pelleted swine manure-incorporated feed depend primarily upon processing moisture content then secondarily upon both processing temperature and addition level of swine manure. Olfactory odor intensity of swine manure decreased with extrusion of the swine manure although the post processing emission intensity of NH3, SO2, and H2S were not changed due to the processing.
        4,000원
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