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        검색결과 430

        101.
        2016.11 구독 인증기관·개인회원 무료
        역삼투막 기술은 이온을 효과적으로 제거할 수 있어 다양한 분야에 널리 활용되고 있으며, 가정용 정수기에도 사용되고 있다. 그러나 역삼투막 기술은 투과율과 회수율이 낮은 단점이 있다. 소형 가전제품에 적용하기 위해서는 이러한 단점들을 극복하는 것이 필요하다. 이를 극복할 수 있는 대체 기술의 하나로 전 기탈이온 방식을 들 수 있다. 전기탈이온 방식은 역삼투막과 중공사막의 장점을 결합한 것으로 이온교환 및 전극 소재에 전기를 걸어 높은 제거율과 풍부한 유량을 구현하는 기술이다. 또한, 전기적인 힘을 조절해 역삼투막급(순정수)와 미네랄을 함유한(청정수)를 생성할 수 있다. 본 발표에서는 전기탈이온 기술 개발 동향에 대해서 소개하고 소형 가전제품에 적용하기 위한 응용 연구사례를 소개하고자 한다.
        103.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the effect of amino acid and vitamin C supplementation on the quality attributes of top round (TR) muscle from Korean cattle (Hanwoo). Sixteen-month-old steers were divided into three different feeding groups and raised until they were 28 months old. A control group (9 heads) was fed a basal diet and rice straw, whereas two experimental groups (8 heads/group) were fed a basal diet and rice straw supplemented with rumen-protected amino acids (≥16.0% L-lysine monohydrochloride, ≥8.0% DL-methionine) and vitamin C at a dose of 100 g/head/day (AA+VC group) or only vitamin C at 100 g/head/day (VC group). After slaughter, TR muscle (M. semimembranosus) was collected from carcasses and used to measure the quality attributes. Crude fat content was significantly higher (p<0.05) in the AA+VC group than in the VC group. No significant difference was observed for water-holding capacity and shear force value between the control, AA+VC, and VC groups. Contents of the free amino acids (FAAs) glycine, aspartate, and glutamate were significantly higher (p<0.05) in the VC group than in the control group. Sensory evaluation of tenderness and flavor preference revealed significantly higher scores (p<0.05) in the AA+VC group than in the control group. These findings suggest that vitamin C supplementation increases the contents of some FAAs, and the combined supplementation of amino acids and vitamin C improves the marbling and sensory attributes of TR muscle in Hanwoo.
        4,000원
        104.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to establish the techniques of the continuous wheat production of high yield level and to standardize of quality uniformity. It was selected the experimental places which were Iksan of Jeonbuk, Gwangju metropolitan city and Hapcheon of Gyeongnam. Farmers of participating in the experiment were 13 persons with two types of advanced and lower levels of their techniques in wheat cultivation, and total numbers of fields were 22 fields. The common information on the field soils were silt loam and loam in soil textures, all most deep and some moderate in soil depth, imperfectly drained in drainage classes, coastal and interior plain with some alluvial fan or local valley in land topography. It was investigated in status of the physico-chemical properties of soils. Soil pH was 6.0 in mean values with 5.2 ~ 7.5 ranges, organic matter(OM) was 25 g/kg with 16 ~ 39 ranges, available P2O5 194mg/kg with 47 ~ 586 ranges, available SiO2 164mg/kg with 57 ~ 454 ranges, in exchangeable cations, K was 0.46 with 0.20 ~ 0.98, Ca was 6.2 with 3.6 ~ 11.7, Mg was 1.8 with 0.9 ~ 3.4 cmol(c)/kg in ranges, and these properties of soils were higher in advanced than those of lower level farmers. The amounts of fertilization in N-P2O5-K2O were 184-49-50 kg/ha in farmers application, 108-114-47 kg/ha in soil testing and 94-83-41kg/ha in standard recommendation. Fertilizer application amounts by farmers were higher than those of soil testing and standard recommendation by 76 ~ 90 kg/ha in N and 3 ~ 9 kg/ha in K2O, and less by 34 ~ 74 kg/ha in phosphate fertilizer.
        4,200원
        105.
        2016.06 구독 인증기관 무료, 개인회원 유료
        α-Amylase 및 protease 활성을 동시에 가지는 1-B-12 균주를 된장으로부터 분리하였다. 16S rRNA 유전자 염기서열 분석결과, Bacillus licheniformis로 동정되어 B. licheniformis 1-B-12 균주로 명명하였다. 효소활성 측면에서 현미(50%), 미강(30%) 및 대두(20%)의 조합이 최적의 기질 조합 조건으로 확인되었다. 기능성이 부가된 효소식품을 제조하기 위하여 Lactobacillus casei GW140 균주를 도입하였는데, B. licheniformis 1-B-12 균주와의 혼합배양 조건은 2단발효(B. licheniformis 1-B-12 접종 > 24 h 발효 > L. casei GW140 접종 > 12 h 추가 발효)가 적합한 것으로 나타났다. 이러한 최적 조건으로 생산된 효소식품을 동결건조하여 25℃에서 보관하였을 때 시험 마지막 날인 45일까지 효소의 활성이 유지되었다.
        3,000원
        108.
        2016.05 구독 인증기관·개인회원 무료
        상용화되고 있는 이온교환막의 경우 제조공정은 PVC를 분말을 paste로하여 PVC천에 함침시켜 제조하고 있다. 이러한 제조공정은 공정상의 어려움 및 제조 원가의 상승의 요인으로 지적되어 왔고, 이에 최근 PVC 비다공성 필름 지지체 가 특정 모노머에 팽윤하는 성질을 이용하여 함침 시키는 기술이 소개되고 있다. 그러나 이 또한 이온교환기를 도입하기 위해서는 슬폰화반응 및 4급 아민화 반응이 수반되어져야만 한다. 본 연구에서는 이런 이온교환기의 도입공정을 보다 단순화시키기 위한 방안의 제안 및 기초실험과정을 보고하고자 한다.
        109.
        2016.05 구독 인증기관·개인회원 무료
        In olefin/paraffin separation process, new technology such as membrane separation process has been ever demanding for both economic and environmental reasons. facilitated olefin transport membrane, containing positively charged silver nanoparticles (Ag NPs) by electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) as olefin carriers dispersed in poly(vinyl pyrrolidone) (PVP), shows extremely high separation performance for propylene/propane mixtures. However, higher permeance is always demanding for practical applications. In this study, POSSs were added to PVP/Ag NPs/TCNQ membranes. Among various kinds of POSS, trisilanolisooctyl POSS showed higher permeance with a moderate selectivity. Therefore it is concluded that mesoporous POSS is an effective additive in improving the gas permeance.
        110.
        2016.05 구독 인증기관·개인회원 무료
        Alkaline direct liquid fuel cells (ADLFCs) employing anion-exchange membranes as a fuel barrier have attracted significant attention as promising alternative energy sources. ADLFCs are allowed to use more abundant anode catalysts which are cheaper than the catalyst used in that using hydrogen fuel. In this work, novel pore-filled anion-exchange membranes (PFAEMs) were successfully fabricated by combining a highly porous poly(tetrafluoroethylene) film and cationic polyelectrolytes with structurally stable anion-exchange sites. The results of the membrane characterizations revealed that the optimization in the crosslinking degree and hydrophilicity of membranes should be considered for the successful application of the PFAEMs to ADLFCs. (KETEP)(20153030031720) and (MOTIE) (No. 10047796).
        111.
        2016.05 구독 인증기관·개인회원 무료
        고분자전해질 연료전지용 막-전극접합체 내 전극에는 삼상계면을 구성하기 위하여 이온 전도가 가능한 이오노머가 함유되어야한다. 따라서 촉매슬러리 제조를 위해 이오노머가 용매 시스템에 분산되어 있는 분산 용액 형태이어야 한다. 하지만 상용 이오노머 분산 용액의 종류가 제한되어 있으며 개발 물질로 제 조된 전해질막과의 호환성을 위해 동일 물질 기반의 분산 용액으로의 전환이 요구된다. 본 연구에서는 동결 건조 방식을 활용한 고분자 분쇄방법을 도입하여 이오노머를 분쇄하고 이를 활용한 이오노머 분쇄 용액을 제조하여 다양한 물성 및 성능을 조사하였다.
        112.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted, using 10 high-quality rice varieties, at 24 experimental sites in 2013 and 2014 to analyze the comparative relationship among head rice yield (HRY), its attributes and sub-attributes. In the data set pooled across sites, years and varieties, where regional and varietal variations were combined, HRY was associated with milled rice yield (MRY) more closely than percentage of head rice (PHR) although both MRY and HRY demonstrated significant relationship with HRY. In the PHR higher than 80%, compared to 80% or less, fitness of the regression between PHR and HRY decreased. MRY and PHR, the two attributes of HRY, were not significantly associated with each other. Regional variation of HRY was associated only with MRY while varietal variation of HRY was related to both MRY and PHR. HRY and MRY showed regional variation greater than varietal variation meanwhile PHR demonstrated regional and varietal variations in a similar range. In the data set pooled across sites, years and varieties, MRY demonstrated relationship with spikelets per square meter (SPIK) in a higher significance than percentage of grain filling (PGF) and 1000-brown rice weight (TBRW). Both regional and varietal variations of MRY showed significant relationship only with SPIK, neitherwith PGF nor TBRW. It is concluded that regional variation of HRY was affected by MRY, varietal variation by both MRY and PHR, and region-variety combined variation mainly by MRY.
        4,000원
        113.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the result of in vivo embryo collection and pregnancy rate after embryo transfer using sex-sorted sperm of Korean brindle cattle. Donor Korean brindle cattle superovulation treated by decreasing dose of FSH injection. Embryos were recovered on 7 days after the third artificial insemination. Control group semen straw used artificial insemination contained 20 million sperm. Sex-sorted semen straws contained 4 million sperm or 10 million sperm. As for the result of the recovery of the in vivo embryos derived from sex-sorted sperm, the number of transferable embryos was significantly highly recovered to be 6.20±2.28/donor from the control group and was significantly lowly recovered to be 1.57±1.72/donor from the group treated at a sperm concentration of 10×106 (p<0.05). The number of unfertilized embryo was 0.8±1.30/donor in control group which was significantly lower than the group treated at a sperm concentration of 4×106 (p<0.05). However, there was no significant difference in the number of undeveloped ova between control and treatment groups. Pregnancy rate after embryo transfer was shown to be 35.00% in control group and 12.50% in treatment group. The karyotype analysis of the calf derived from sex-sorted sperm resulted in a similar chromosomal distribution pattern (2n=60, XX) compared to those of common Korean native cattle.
        4,000원
        114.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 홀스타인 거세육우(총 18두, 생후 4개월령, 체중 160kg)의 성장단계별 농산부산물 TMR 사 료의 에너지 수준(T1, TDN 75~84%; T2, TDN 77~85%)과 출하월령(18, 20 및 22개월)별로 배치하여 각 출하월령별 등심과 우둔육의 육질 및 관능특성을 조사하였다. 등심육의 경우 근내지방함량은 처리구 1은 22개월령 그룹이, 처리구 2는 20개월 및 22개월령 그룹이 유의적으로 가장 높았다(P<0.05). 우둔 육의 경우 처리구 1과 2가 모두 22개월령 그룹이 근내지방 함량이 가장 높았다(P<0.05). 처리구 2는 18개월령 그룹이 단백질 및 수분함량이 유의적으로 가장 높았다(P<0.05). 콜라겐 함량은 처리구 모두 출하월령간에 유의적인 차이가 없었다(P>0.05). 육질특성에서 등심육은 처리구 1의 경우 보수력, 전단 력, 가열감량, 육색에 있어서 급여기간 그룹간 유의적인 차이가 없었다(P>0.05). 처리구 2에서는 보수 력만 18개월과 20개월령 그룹이 가장 높았다(P>0.05). 우둔육은 처리구 1의 경우 보수력, 전단력, 가열 감량, 육색의 백색도에 있어서 급여기간 그룹간 유의적인 차이가 없었으며 단지 육색에서 적색도와 황 색도만 22개월령이 가장 높았다(P>0.05). 처리구 2의 경우 18개월령 그룹이 보수력이 가장 높았고 전 단력은 가장 낮았으며 가열감량은 18개월과 20개월령 그룹이 낮았다(P<0.05). 관능특성에 있어서 등심 육의 경우 처리구 1은 18개월과 20개월령이 연도점수가 높았고 20개월령 처리구가 향미 및 전반적인 기호도 점수가 유의적으로 높았다(P<0.05). 처리구 2는 연도, 다즙성, 향미 및 전반적인 기호도 점수 모두 20개월과 22개월령이 유의적으로 높았다(P<0.05). 우둔육의 경우 처리구 1은 연도가 18개월과 20 개월령이 유의적으로 높았고 전반적인 기호도는 20개월령이 유의적으로 높았다. 처리구 2는 18개월령 이 연도만 유의적으로 높았다(P<0.05). 결론적으로 홀스타인 거세육우는 농산부산물 TMR 사료를 22개 월령까지 급여한 그룹이 근내지방도는 높았으나 육질 및 관능특성은 18개월령 또는 20개월령이 더 우 수하였으므로 이러한 점을 고려하여 출하하는 것이 바람직할 것으로 생각된다.
        4,300원
        115.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 역전기투석 응용을 위해 엔지니어링 고분자 기반의 이오노머와 다공성 폴리에틸렌 지지체를 사용 한 세공충진 이온교환막을 제조하고 이를 결합한 이오노머-세공충진 복합막을 제조하였다. 이온전도도가 높은 이오노머와 우 수한 기계적 강도를 가진 세공충진막을 결합함으로써 상용 이온교환막(AMX/CMX, Astom Corp., Japan) 대비 동등 수준의 전기화학적 특성 및 응용에 적합한 물리적 안정성을 확보할 수 있었다. 제조된 이오노머-세공충진 복합막을 이용하여 역전기 투석 성능을 평가한 결과 상용막 대비 음이온 교환막의 경우 86.4%, 양이온 교환막은 104.8% 수준의 우수한 발전성능을 나 타내었다.
        4,300원
        117.
        2015.11 구독 인증기관·개인회원 무료
        Very recently, an efficient electrochemical desalination process employing bipolar membranes with large ion-exchange area is being developed (so-called ‘electro-adsorptive deionization’). In this process, ions dissolved in a feed solution can be removed through an ion-exchange mechanism under a strong electric field (a forward bias condition). The membranes can also be regenerated without the use of additional chemicals by the water-splitting reactions which occur at the bipolar junction of membranes (a reverse bias condition). In this work, we have developed novel bipolar membranes containing iron oxide/hydroxide catalysts. In addition, the ion-exchange capacities of the bipolar membranes have been largely enlarged by embedding finely powdered ion-exchange resins. (No. 10047796) (No. 2015H1C1A1034436)
        118.
        2015.11 구독 인증기관·개인회원 무료
        Quaternary amonium salts are used as anion-exchange and also easily decomposed due to their intrinsic structural instability. These drawbacks have limited the long-term utilization of the membranes. The objectives of this study are to synthesize high performance anion-exchange membranes and to investigate their electrochemical properties The new membranes were prepared via a monomer sorption method. Their morphological and electrochemical properties have been investigated through various analyses. While the accumulated water-splitting flux of the commercial membrane containing conventional quaternary ammonium groups was shown to largely increase with time, theirs of the new membrane was shown without significant change.
        119.
        2015.11 구독 인증기관·개인회원 무료
        Reverse electrodialysis (RED) is one of the promising processes for generating electricity from the salt concentration gradient between river and sea water. A RED stack contains alternately arranged anion and cation exchange membranes which separate salt solutions of different concentrations. The power generation performance of RED significantly depends on the characteristics of ion exchange membranes. In this work, we have prepared high performance pore-filled anion-exchange membranes. In addition, the optimization of membrane design parameters has been investigated using the membranes via various electrochemical analyses in terms of the enhancement of RED performances. Finally, the membrane surface has been modified with acid-doped polypyrrole for the improvement of the membrane properties. (No. 10047796) (No. 2015H1C1A1034436)