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        검색결과 4,677

        2121.
        2010.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to aid in the development of the optimal recipe for chocolate with fermented and aged garlic extract (Allium sativum var. pekinense). We added garlic extract in order to increase the nutritional value of the chocolate. The optimal sensory composite recipe was determined, following Central Composites for chocolate with different levels of fermented and aged garlic extract (A) and cream (B), while analysis was performed by Response Surface Methodology, from the date that the sensory evaluation was performed. Ten experimental recipes, including 2 reference points in the composition, were selected. The compositional and functional properties were measured, and physical and sensory values were applied to the mathematical models. Perturbation plots showed the influence of each ingredient on the final product. Measurements showed significant values in lightness, sweetness, pH, hardness and cohesiveness, while sensory measurements showed significant values in color, texture, sourness, bitterness and overall quality. The optimum formulations were calculated by numerical and graphical methods, as being 34.61g fermented and aged garlic extract and 72.68g cream for each 200g chocolate. As well it was revealed that the aptitude of chocolate was more influenced by fermented garlic extract than it was by cream.
        4,000원
        2122.
        2010.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Since it was developed by Joseph Aspdin, cement has been a common construction materials up to the present time.However, there are trace constituents in cement clinker. One of the trace constituents included in cement clinker, chromium,has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects thehuman body negatively. The aim of the present study was to investigate the concentration of water-soluble hexavalent chromiumin cement clinker by using industrial by-products. For that reason, raw materials were prepared to add different SiO2 , Al2O3,and Fe2O3 sources. After the raw materials such as the limestone, the sand and the clay, iron ore was pulverized and mixed,and the raw meal was burnt at about 1450oC in a furnace with an oxidizing atmosphere. The part in the raw materials of theclinker was substituted with slag, sludge, etc. and this was used to manufacturing cement clinker. To investigate the water-soluble hexavalent chromium content in clinker, raw meal was prepared by changing the modulus, the type, and the contentof clinker materials and tested concentrations of hexavalent chromium in the clinkers. To determine Cr+6 formation of theclinker, tests were done with raw meals adding chromium by using different industrial by-products. Consequently because thechromium was to be included in the raw materials of the clinker, production of Portland cement clinker was included with thechromium. Also, the chromium was converted into hexavalent chromium in the burning process.
        4,000원
        2123.
        2010.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        마늘 분말을 첨가한 요구르트의 품질특성 평가를 위하여 탈지분유에 0.1~0.5%(w/v) 마늘 분말을 혼합하고 Streptococcus thermophilus와 Lactobacillus delbrueckii subsp. bulgaricus의 혼합균주를 접종하여 42℃ 에서 24시간 배양하였다. 마늘 분말 첨가량에 따른 유산균의 생육정도, 요구르트의 이화학적 및 관능적 특성 을 검토하였다. 마늘 분말이 첨가된 요구르트의 적정산도는 0.78~0.81%로 마늘 분말이 첨가되지 않은 대조 군(0.73%)보다 높았다. 마늘 분말을 첨가한 요구르트의 생균수는 0.3% 첨가군에서만 상대적으로 낮았고 여 타 실험군은 대조군과 유의적인 차이가 없었다. 마늘분말의 첨가량이 증가함에 따라 요구르트의 점도도 상승 하여 0.5% 마늘 분말이 첨가된 요구르트의 점도가 가장 높았으며, 색도는 대조군과 마늘 분말 첨가 요구르트 사이에 유의적인 차이가 없었다. 관능적 특성을 조사한 결과 마늘 분말의 첨가에 따라 색은 더 높은 선호도를 보였고, 마늘 맛이나 향은 마늘 분말의 첨가량에 비례적으로 증가하였으며, 전반적인 기호도는 0.1%와 0.3% 첨가시는 대조군과 유의차가 없었다. 이상의 결과를 종합하여 볼 때 요구르트 고유의 품질특성이나 유산균의 생육 및 관능적 특성에 영향을 미치지 않는 범위에서 첨가 가능한 마늘 분말의 적정 수준은 0.3% 미만으로 판단된다.
        4,000원
        2124.
        2010.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon-nanotube-embedded bismuth telluride (CNT/) matrix composites were fabricated by a powder metallurgy process. Composite powders, whereby 5 vol.% of functionalized CNTs were homogeneously mixed with alloying powders, were successfully synthesized by using high-energy ball milling process. The powders were consolidated into bulk CNT/ composites by spark plasma sintering process at for 10 min. The fabricated composites showed the uniform mixing and homogeneous dispersion of CNTs in the matrix. Seebeck coefficient of CNT/ composites reveals that the composite has n-type semiconducting characteristics with values ranging to with increasing temperature. Furthermore, the significant reduction in thermal conductivity has been clearly observed in the composites. The results showed that CNT addition to thermoelectric materials could be useful method to obtain high thermoelectric performance.
        4,000원
        2125.
        2010.04 구독 인증기관 무료, 개인회원 유료
        Remarkably improvements have occurred recently in the maintenance management of physical assets and productive systems, so that less wastages of energy and resources occur. The technology of maintenance is about finding and applying cost-effective ways of avoiding or overcoming performance deterioration. Maintenance is thus a vital support function in business, especially as increasingly large investments are being required in physical assets. TPM(Total Productive Maintenance) focuses on optimizing planning scheduling. Availability, performance and quality rate are other factors that affect productivity. Especially there are some losses that affect the overall equipment effectiveness(OEE). These losses lead to low values of OEE, which provides an indication of how effective the production precess is. This study explores the ways in which Korean small and medium manufacturing industries can improve OEE.
        4,300원
        2128.
        2010.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, Ti powders were fabricated from Ti scrap by the Hydrogenation-Dehydrogenation (HDH) method.The Ti powders were prepared from the spark plasma sintering (SPS) and their microstructure was investigated.Hydrogenation reactions of Ti scrap occurred at near 450oC with a sudden increase in the reaction temperature and thedecreasing pressure of hydrogen gas during the hydrogenation process in the furnace. The dehydrogenation process was alsocarried out at 750oC for 2 hrs in a vacuum of 10-4torr. After the HDH process, deoxidation treatment was carried out withthe Ca (purity: 99.5%) at 700oC for 2 hrs in the vacuum system. It was found that the oxidation content of Ti powder thatwas deoxidized with Ca showed noticeably lower values, compared to the content obtained by the HDH process. In orderto fabricate the Ti compacts, Ti powder was sintered under an applied uniaxial punch pressure of 40 MPa in the range of900-1200oC for 5 min under a vacuum of 10-4torr. The relative density of the compact was 99.5% at 1100oC and the tensilestrength decreased with increasing sintering temperature. After sintering, all of the Ti compacts showed brittle fracturebehavior, which occurred in an elastic range with short plastic yielding up to a peak stress. Ti improved the corrosionresistance of the Ti compacts, and the Pd powders were mixed with the HDH Ti powders.
        4,000원
        2129.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Unknowingly, the relationship between IT departments and their internal customers becomes that of client-supplier based on the mechanisms of marketing and competition. In addition, due to enhanced focus on the customer in the planning, development, and delivery of information service, IT service management(ITSM) has become increasingly important. These days IT management is focusing particularly on the 'de-facto' standard ITIL (IT Infrastructure Library) for implementing ITSM. It is linked as a part of CobiT’s 'deliver and support' domain, which is a framework of IT governance, and ISO/IEC 20000 is a unique international certification standards on the ITSM. This paper proposes the strategy and procedure for ITSM implementation based on ITIL with consideration of IT governance structure for manufacturing industries. It also presents a case study to share the lessons learned and results of an ITSM project.
        4,200원
        2130.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 비용매 첨가제 BE와 습도 및 노출 시간이 정밀여과막의 구조, 투과특성에 미치는 영향을 살펴보았다. 멤브레인은 PES/DMF/TSA/PVP/BE 혼합 용액을 물에 침지하여 제조하였다. 다양한 농도의 BE가 첨가된 캐스팅 용액들을 공기 중의 수분이 흡착될 수 있도록 상대습도 60%와 80%로 달리하여 40초와 90초 동안 노출시켰으며, 그 결과로 만들어진 멤브레인 투과 성능과 표변 및 단면 구조와의 연관성을 조사하였다. 멤브레인의 특성은 capillary flow porometer, FE-SEM 및 순수 투과 장치를 이용하여 이루어졌다. PES 멤브레인의 표면 구조는 상대 및 노출 시간에 의해 크게 영향을 받는다. 또한 BE의 첨가는 특정한 습도와 노출 시간에서 표면 및 내부의 구조의 조절이 용이함을 확인할 수 있었다.
        4,200원
        2131.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to determine the influence of culture conditions such as temperature, time, water content, koji-thickness and agitation on the production of organic acid by Rhizopus sp. ZB9 isolated from Korean Nuruk during the preparation of rice koji, which is used in brewing the Korean rice wines, Takju and Yakju. Rice koji was made under different culture conditions, and the acidity of each koji was tested. The temperature range suitable for the production of organic acid was 28~32℃, and 36~48 hours of cultivation at that temperature range seemed to produce the optimum results. The production of organic acid increased in proportion to the increase in water content of steamed rice from 25% to 60%. An increase in koji-thickness induced no adverse effects on the production of organic acid, and agitation-work during cultivation showed very beneficial effects.
        4,000원
        2132.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        수소투과금속인 tantalum과 세라믹 지지체로 Y2O3-stabilized ZrO2 (YSZ)를 이용하여 cermet 수소분리막을 제조하였다. Ta/YSZ cermet 분리막은 헬륨분위기에서의 예비소결과 고진공 하에서의 본소결을 통해 제조하였으며, 소결 및 밀봉 과정에서 발생하는 불순물은 연마를 통해 제거 가능하였다. 이렇게 제조된 분리막은 tantalum의 연속상이 잘 발달된 치밀구조를 보였다. 수소 해리를 위해 팔라듐 코팅을 한 Ta/YSZ 분리막을 이용하여 200∼350°C의 범위에서 수소투과실험을 수행하였다. 300°C에서 분리막에 균열이 형성되었고 Pd 코팅층은 몇 곳이 박리되었다. XRD 결과는 tantalum이 수소와 반응하여 Ta2H가 생성되는 것을 보여주며, Ta2H에 인한 격자 팽창이 분리막의 결함을 초래하였다.
        4,000원
        2133.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cermet 분리막 제조를 위한 혼합 분말은 60 vol.% vanadium과 Y2O3-stabilized ZrO2 (YSZ)를 기계적으로 혼합하여 준비하였다. 혼합 분말을 원판으로 압축한 후 진공 분위기에서 1600°C로 2시간동안 소결하였다. 소결 분리막은 치밀하였고, 브레이징 필러를 이용하여 스테인레스 링에 장착되었다. V/YSZ 분리막의 수소 투과량은 100% 수소를 흘려 200∼ 350°C 범위에서 측정되었다. 350°C, 0.5 bar압력에서 분리막의 양 표면에 균열이 형성되었다. 투과실험 동안에 V/YSZ 분리막의 vanadium은 수소와 반응하여 V2H를 생성하였으며, 이로 인해 분리막이 균열되는 것을 알 수 있었다.
        4,000원
        2134.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emission characteristics of VOCs (Volatile Organic Compounds) from assembly metal product manufacturing industry (Korean standard industry classification code: 28) were studied. The sampling was carried out at 54 sites in Shiwha-Banwol industrial area with 3 M OVM (Organic Vapor Monitor) #3500 from August to October in 2008. The EPA 8020/8040 (10 chemicals) was used as a standard solution for the quantitative analysis with GC/FID. As the results, the VOCs concentration appeared to range from 0.9 ppb to 22,721.1 ppb, and the average concentration ratio of benzene : toluene : ethylbenzene : m,p-xylene : o-xylene : styrene appeared to be 0.005 : 1.000 : 0.198 : 0.096 : 0.057 : 0.110. Total VOC concentration of the "Manufacture of Structural Metal Products, Tanks, Reservoirs and Steam Generators" (KSIC code: 281) appeared to be seven times higher than that of "Manufacture of other fabricated metal products; metal working service activities" (KSIC code: 289).
        4,000원
        2135.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        볏짚 대체 배지를 개발하기 위해 밀짚 혼용 비율에 따른 볏짚 대체 효과를 구명한 결과는 다음과 같다. 후발효 배지의 화학적 성분을 분석한 결과 밀짚을 20% 혼용한 배지의 질소 함량과 C/N율은 각각 2.2%와 16.7이고, 볏짚 단용 배지는 2.0%, 17.9로 조사되었으며, 볏짚 단용 배지보다 초발이소요일수가 빠르고, 수량도 30% 증수되어 대체 효과를 기대할 수 있었다.
        3,000원
        2136.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigment concentrates with violet-red color and sweet taste were obtained from purple-fleshed sweet potato(PFSP) using ethyl alcohol and water. Extract from general potato(GP) were used as a control. The relative stability of PFSP pigment concentrate(PFSPPC) in a storage test over 15 days was confirmed in the order of dark > fluorescence > sun-light irradiation. The relative stability of GP pigment concentrate(GPPC) in a storage test over 15 days was confirmed in the order of sun-light > fluorescence > dark storage. The RRP of PFSPPC was higher than that of GPPC, but the color strength of GPPC was 1/2 that of PFSPPC. Treatment of PFSPPC with aluminum potassium sulfate(0.2~0.3%, w/w) best improved its stability. The improved RRPs of PFSPPC were 45.16~47.31% in sun light irradiation, 55.91~60.22% in fluorescence irradiation, and 76.34~75.97% in dark storage conditions. In substituting aluminum potassium sulfate for chitosan, an amount of 0.2~0.3%(w/w) was suitable, giving similar results in improving pigment stability for all concentrates tested. Also, freeze-dried PFSPPC powder was manufactured as a substitute for dextrin, and also as a substitute for chitosan to the extent of 0.25%(w/w). The results of storage stabilite for freeze-dried PFSPPC and GPPC powder over 15 days, irradiation were, PRRs of 74.47~89.36% and 61.54~76.92%, respectively. The stability improving effect of freeze dried PFSPPC powder was confirmed by the results of storage experiments at various conditions. The use of freeze-dried PFSPPC powder was therefore confirmed to be an effective treatment for general foods.
        4,000원
        2137.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전도성 고분자 중 안정성이 높은 Poly(3,4-ethylenedioxythiophene) (PEDOT)을 이용하여 전기변색 박막을 제조하고 박막제조 방법에 따른 전기변색 특성을 연구하였다. PEDOT 박막은 전기중합법과 증기중합법에 의해 제조되었고, 두가지 방법 모두 도핑되지 않은 중성 상태에서 짙은 푸른색을 띠는 박막으로 제조되었다. 전기변색 특성을 평가하기 위하여 UV-Vis spectrophotometer와 Cyclic voltammetry가 사용되었으며, 산화/환원 시 표면은 AFM으로 관찰되었다. 전기 중합법으로 제조된 PEDOT 박막에 비해 증기중합에 방법에 의해 제작된 PEDOT 박막의 표면이 거칠기 50 nm 이내로 균일 하였다. 특히 증기 중합법을 이용하여 제조된 전기 변색 소재의 특성도 응답성 1.5초 이내, 49%의 투과율 차이, 402의 변색 효율을 보여 박막의 특성 향상으로 전기변색특성이 향상 된 결과를 보였다.
        4,000원
        2138.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        원자전달 라디칼 중합을 이용하여 poly(styrene sulfonic acid) 47 wt%를 가진 poly(vinylidene fluoride-co-chlorotrifluoroethylene)-g-poly(styrene sulfonic acid) (P(VDF-co-CTFE)-g-PSSA) 가지형 공중합체를 합성하였다. 티타늄 아이소프로폭사이드(TTIP)와 가지형 공중합체를 졸-겔 공정을 통하여 TiO2/가지형 공중합체 복합막을 제조하였다. TTIP는 가지형 공중합체의 친수성을 가진 PSSA 영역에만 선택적으로 결합하였으며 그곳에 TiO2 나노 입자가 형성되어 성장하였다. 이와 같은 결과를 적외선과 자외선 분광학으로 확인할 수 있다. 함수량과 이온 교환 능력 (IEC)는 TTIP의 함량에 따라 감소하였고 이것은 막이 가진 술폰산의 수가 감소하기 때문이었다. TTIP가 5 중량%일 때, 막의 기계적 강도는 증가하고 수소이온 전도도도 유지되었다.
        4,000원
        2139.
        2010.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Glass-ceramics were fabricated by heat-treatment of glass obtained by melting a coal bottom ash with Li2O addition. The main crystal grown in the glass-ceramics, containing 10 wt% Li2O, was β-spodumene solid solution, while in Li2O 20 wt% specimen was mullite, identified using XRD. The activation energy and Avrami constant for crystallization were calculated and showed that bulk crystallization behavior will be predominant, and this expectation agreed with the microstructural observations. The crystal phase grown in Li2O 10 wt% glass-ceramics had a dendrite-like shaped whereas the shape was flake-like in the 20 wt% case. The thermal expansion coefficient of the Li2O 10 wt% glass-ceramics was lower than that of the glass having the same composition, owing to the formation of a β-spodumene phase. For example, the thermal expansion coefficient of Li2O 10 wt% glass-ceramics was 20×10-7, which is enough for application in various heat-resistance fields. But above 20 wt% Li2O, the thermal coefficient expansion of glass-ceramics, on the contrary, was higher than that of the same composition glass, due to formation of mullite.
        4,000원
        2140.
        2010.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The object of this study was to investigate the effects of rice particle size on the physicochemical properties of beef-rice porridge. The pH of beef-rice porridge was decreased as compared to that of the control, while the redness of beef porridge increased according to rice particle size. The viscosity of flour in the beef-rice porridge was the highest among three porridges, at 40℃. The protein content of beef-rice porridge was increased 3-fold over that of rice porridges. The total amino acid content of the beef-rice porridge was 3071.2 mg/100 g, and that of rice porridge was 1147.5 mg/100 g. As compared to rice porridge, the maximum amounts of the amino acids Lys and Thr were increased beef-rice porridge. Sensory evaluation results showed that the beef-rice porridge with a particle size half that of rice had the highest scores in color, taste, texture, and overall preference. Based on these results, it is suggested that beef-rice porridge with a particle size half (0.7-2.5 mm) that of rice has optimal quality in terms of both physicochemical and sensory properties.
        4,000원