Al2O3 has received wide attention with established use as a catalyst and growing application in structural or functional ceramic materials. On the other hand, the boehmite (AlO(OH)) obtained by sol-gel process has exhibited a decrease in surface area during phase transformation due to a decline in surface active site at high temperature. In this work, Al2O3-CuO/ZnO (ACZ) and Al2O3-CuO/CeO (ACC) composite materials were synthesized with aluminum isopropoxide, copper (II) nitrate hemi (pentahydrate), and cerium (III) nitrate hexahydrate or zinc (II) nitrate hexahydrate. Moreover, the Span 80 as the template block copolymer was added to the ACZ/ACC composition to make nano size particles and to keep increasing the surface area. The ACZ/ACC synthesized powders were characterized by Thermogravimetry-Differential Thermal analysis (TG/DTA), X-ray Diffractometer (XRD), Field-Emmision Scanning Electron Microscope (FE-SEM), Bruner-Emmett-Teller (BET) surface analysis and thermal electrical conductivity (ZEM-2:M8/L). An enhancement of surface area with the addition to Span 80 surfactant was observed in the ACZ powders from 105 m2/g to 142 m2/g, and the ACC powders from 103 m2/g to 140 m2/g, respectively.

Composites of ceramic powders and an elastomer-based matrix were prepared by mixing CaCO3 powders with polyethylene and polypropylene elastomers, and their mechanical and sound insulation properties were measured. CaCO3 powders with 0.7 μm and 35 μm particle size were added to elastomers up to 80 wt%. Scanning electron microscopy photographs showed uniform distribution of the CaCO3 powders in the matrix. While density and surface hardness increased, melt index, tensile strength and elongation of the composites decreased as the amount of added CaCO3 powders increased. As more CaCO3 powders were added sound transmission loss of the composites increased owing to the increase of density. Addition of 0.7 μm sized CaCO3 powders resulted in a slightly higher transmission loss than the addition of 35 μm sized powders because of the increased interface area between the elastomer matrix and the CaCO3 powders. Composites with a polyethylene matrix showed higher transmission loss than those with a polypropylene matrix because the tensile strength and hardness of the polyethylene-based composites were low and their elongation was high.

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 protease 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 proteolytic activity of each koji was tested. The temperature range suitable for the production of protease was 28~32℃. Based on the protease and color, 60 hours of cultivation at 28℃ was shown to produce optimum results. The production of protease increased in proportion to the increase in water content of steamed rice from 25% to 35%. An increase in koji-thickness induced no adverse effects on the production of protease, and agitation during cultivation showed beneficial effects.

Regenerated cellulose was prepared from Buckeye wood pulp V60 via dissolution in N-methylmorpholin N-oxide (NMMO) solvent system. The effect of antioxidants such as, n-propylgallate (PG), tris(nonylphenyl) phosphite (TRIS), ethylenediamine tetraacetic acid disodium salt (EDTA), and magnesium sulfate on the properties of regenerated cellulose was studied using X-ray diffraction, copper index calculation, and viscometry. Only addition of more than 0.01% of PG into NMMO solvent was effective to avoid the reduction of the degree of polymerization(DP) of regenerated cellulose during dissolution at 110℃. However, the early stage(within 0.5h of dissolution process) degradation of cellulose was not prevented eventhough up to 0.5% PG was appled to hot NMMO system. In addition, to recover the expensive NMMO after cellulose regenerating process, the washing filtrate was studied using simple techniques, such as refractive index, pH, and conductivity measurements. Through conductivity measurement result, 4-time of washing was enough to remove the NMMO completely from regenerated cellulose.

The present paper deals with an analysis of relationship among technical human resources management as a precursor, technology innovation activity and achievements of technical innovation on the basis of preceding empirical studies on technology innovation activities of manufacturing corporations. The analysis shows that First, the technical human resources management is found to have influence upon technology innovation activity in various ways, implying that the role of technical human resources management as a key to technical innovation is most important of all to enable manufacturing companies to gain edge in competition by means of technology innovation activity; and Second, technology innovation activity exercises impacts on the achievements of exploitative technology innovation as well as on the achievements of exploratory technology innovation on the part of manufacturing industry. The above findings prove that the level of technology innovation activity may be a source for superior competitiveness of manufacturing business as a result of technology innovation performance. Manufacturing corporations, thus, need to place more weight on stepping up their executive level of technology innovation activity factors than on increasing simply the level of technical investment.

다공성 Poly(propylene) 분리막의 지지 하에 전해질 용액 (EC/DEC 1 : 1 혼합물 내의 LiPF6 1 M 용액) 내에서 DEGDMA [Di(ethylene glycol) dimethacrylate]의 70℃ 열중합을 통하여 겔 고분자 전해질(GPE)막이 합성 되었다. 합성된 겔 고분자 전해질막의 이온전도도 및 전기화학적 안정성은 AC 임피던스법 및 CV (cyclic voltametry)법에 의하여 측정 평가하였다. 겔 고분자를 전해질로, 그리고 양극 및 음극으로는 각각 LiMi0.8Co0.2O2 및 graphite로 이용하여 리튬이온전지(LIB)도 제작하였다. 열중합을 통하여 리튬 이온전지에 적합한 이온전도도(10 -3 S/cm 이상) 및 전기화학적 안정성을 보이면서 자체적인 성상을 유지하는 겔 고분자 전해질막을 얻을 수 있었다. 단량체 함량 5%의 전구체로 제작한 겔 고분자 전지는 단량체 함량이 7.0% 및 10.0%인 경우에 비하여 우수한 고율 및 충-방전 효율을 보였다.

The blending effects of surfactants on the polystyrene emulsion polymerization were studied. The blending of Triton X-100 and SDS affects to the interfacial properties of the styrene monomer and water phases, and finally, the properties of the polystyrene latex particles. As the blending ratio of SDS/Triton X-100 increases, the interfacial tension and CMC of the blended surfactants were decreased and results in a reducing the size of the latex particles. It was found that the interfacial tension was reduced when the surfactant were blended. By increasing the SDS content, the interfacial tension was reduced, and, at a certain condition, the interfacial tension was reached to an extremely low value to form micro-emulsion and the nano-sized latex particles (80~110 nm).

본 연구의 목적은 다양한 셀룰로오스 계 고분자를 이용한 정삼투(FO) 막을 제조하고 각각의 고분자 및 첨가제에 따른 성능의 차이를 평가하는 것이다. 셀룰로오스 아세테이트(CA)와 셀룰로오스 트리아세테이트(CTA)를 기반으로 상전환법을 통하여 정삼투막을 제조하고 가압조건과 정삼투 조건하에서 투과유량 및 염제거율을 비교하였다. CA 정삼투막은 용매의 증발 및 annealing 수행 시간에 따라 막의 성능의 변화가 발생하였으며, CTA 정삼투막의 경우에는 annealing보다는 첨가제를 활용하여 성능의 향상을 이끌어낼 수 있었다. 또한 CTA 정삼투막의 정삼투 투과유량은 4.46 L/m2hr였으나 CA/CTA 정삼투막의 경우에는 8.89 L/m2hr로, 단일 고분자를 사용하기 보다는 CTA에 CA를 혼합하여 막을 제조하는 것이 정삼투 투과유량 증가에 보다 효율적이었다.

Depreciation accounting has as its main objective, the recovery of the original cost of plant investment less net salvage, over the estimated useful life of that plant. Accuracy of the whole life technique in meeting this objective depends entirely on the

당뇨병 환자의 혈당치 측정을 위하여 폴리우레탄으로 만들어진 진단막을 제조하였다. 혈액 속의 글루코우즈의 농도를 변화시켜가며 폴리우레탄 진단막을 가지고 680 nm에서의 최종흡광도를 측정하였다. 시간에 따른 흡광도 변화량(K/S)의 최종 결과치가 글루코우즈의 농도가 증가함에 따라 직선적으로 증가하였다. 헤마토크릿이 글루코우즈의 농도 측정에 미치는 영향을 조사하였다. 낮은 헤마토크릿에서는 글루코우즈의 농도와 K/S와의 기울기 값(Dose-Response Slope : DRS)이 플라즈마와 비교해 큰 차이를 보이지 않았다. 그러나 높은 헤마토크릿(40% 이상)에서는 상당히 감소함을 알 수 있었다.

Recently, to improve operating efficiency with the higher in-line rate in automated production lines, a lot of cases of grouping machines and material handling system together to form a cluster has shown frequently. This article addresses the job allocati

Desorption reaction characteristics of the used activated carbons collected from manufacture of rubber and plastics products in Shiwha/Banwal industrial complex were investigated. Desorption reactions were analyzed based on the data obtained from a thermogravimetric analyzer. Activation energies and reaction orders for desorption reaction characteristics of the used activated carbons were estimated by employing the Friedman method and the Freeman-Carroll method. It was found that the activation energies were 24.7∼41.3 kJ/㏖ in the Friedman method and 13.9∼24.4 kJ/㏖ in the Freeman-carroll method, and reaction orders were 0.3∼1.4.

The selenization process has been a promising method for low-cost and large-scale production of high quality CIGS film. However, there is the problem that most Ga in the CIGS film segregates near the Mo back contact. So the solar cell behaves like a CuInSe2 and lacks the increased open-circuit voltage. In this study we investigated the Ga distribution in CIGS films by using the Ga2Se3 layer. The Ga2Se3 layer was applied on the Cu-In-Ga metal layer to increase Ga content at the surface of CIGS films and to restrict Ga diffusion to the CIGS/Mo interface with Ga and Se bonding. The layer made by thermal evaporation was showed to an amorphous Ga2Se3 layer in the result of AES depth profile, XPS and XRD measurement. As the thickness of Ga2Se3 layer increased, a small-grained CIGS film was developed and phase seperation was showed using SEM and XRD respectively. Ga distributions in CIGS films were investigated by means of AES depth profile. As a result, the [Ga]/[In+Ga] ratio was 0.2 at the surface and 0.5 near the CIGS/Mo interface when the Ga2Se3 thickness was 220 nm, suggesting that the Ga2Se3 layer on the top of metal layer is one of the possible methods for Ga redistribution and open circuit voltage increase.

As a starting material, BCP (biphasic calcium phosphate) nano powder was synthesized by a hydrothermal microwave-assisted process. A highly porous BCP scaffold was fabricated by the sponge replica method using 60 ppi (pore per inch) of polyurethane sponge. The BCP scaffold had interconnected pores ranging from 100 μm to 1000 μm, which were similar to natural cancellous bone. To realize the antibacterial property, a microwave-assisted nano Ag spot coating process was used. The morphology and distribution of nano Ag particles were different depending on the coating conditions, such as concentration of the AgNO3 solution, microwave irradiation times, etc. With an increased microwave irradiation time, the amount of coated nano Ag particles increased. The surface of the BCP scaffold was totally covered with nano Ag particles homogeneously at 20 seconds of microwave irradiation time when 0.6 g of AgNO3 was used. With an increased amount of AgNO3 and irradiation time, the size of the coated particles increased. Antibacterial activities of the solution extracted from the Ag-coated BCP scaffold were examined against gram-negative (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). When 0.6 g of AgNO3 was used for coating the Ag-coated scaffold, it showed higher antibacterial activities than that of the Ag-coated scaffold using 0.8 g of AgNO3.

삼백초 분말의 첨가량을 0-6%로 달리하여 쿠키를 제조한 후 물리화학적 품질 및 관능적 품질특성을 측정하고 각 특성사이의 상관관계를 살펴보았다. 삼백초 분말 첨가량이 증가함에 따라 쿠키의 두께 및 밀도는 유의적으로 증가하였으나(p<0.05), 반죽의 구께 및 밀도에는 영향을 미치지 않는 것으로 나타났다(p>0.05). 반죽과 쿠키의 pH는 삼백초 분말 첨가량이 증가함에 따라 현저하게 감소하였으며, 색 특성 중 명도와 황색도 역시 현저하게 감소한 반면 적색도는 증가하는 경향을 나타내었다. 관능검사 결과, 경도를 제외한 맛, 향미, 색 등의 강도는 분말의 첨가량이 증가함에 따라 유의적으로 증가하여 6% 첨가군이 가장 높게 평가되었다(p<0.05). 한편 상관분석결과 삼백초 분말 첨가 수준은 대부분의 물리화학적 및 관능적 품질특성과 유의적인 상관관계를 나타내어, 삼백초 분말 첨가가 반죽 및 쿠키의 전반적인 품질특성에 상당한 영향을 미치는 것으로 나타났다.

감태 분말의 대체량을 0-8%로 달리하여 스펀지 케이크를 제조한 후 물리화학적 및 관능적 품질특성을 측정하고 각 특성사이의 상관관계를 살펴보았다. 감태 분말의 대체비율이 증가함에 따라 반죽의 비중은 점차적으로 증가하는 경향을 나타내었고, 케이크의 비체적은 감태 분말 대체에 따라 감소하고 굽기 손실은 증가하였다. 부피지수는 감소하는 경향을 보여 감태 분말의 비율이 높아지면 케이크의 부피가 작아짐을 알 수 있다. 밝기는 나타내는 L*값은 유의적으로 감소하였으며(p<0.05), 경도는 점차적으로 증가하였다. 관능검사 결과 감태 분말대체에 따라 대부분의 관능 특성이 뚜렷하게 구분되었다(p<0.05). 한편 상관분석 결과 감태 분말의 대체수준은 a*값과 관능적 경도(firmness)를 제외하고 모든 품질특성과 유의적인 상관관계를 나타내었다(p<0.05, p<0.01 또는 p<0.001).

기존의 재래식 유탕팽화유과의 문제점을 개선하기 위하여 진공을 이용한 진공팽화기를 설계 제작하였다. 공정변수에 따른 진공팽화유과의 특성을 비교 분석하기 위하여 부피팽화율, 밀도, 절단강도, 색도, 미세구조를 측정하였다. 진공팽화기의 공정변수는 가열온도(100, 120, 140, 160, 180oC), 예열시간(0, 2, 4, 6, 8분), 진공팽화시간(5, 10, 15, 20분)이며, 가열온도 100oC, 예열시간 6분, 진공팽화시간 10분에서 진공팽화유과의 부피팽화율은 10.04로 가장 높게 측정되었고, 밀도는 0.15 g/cm3로 가장 낮게 측정되었지만, 부피팽화율 9.47, 밀도 0.16 g/cm3으로 측정된 가열온도 120oC, 예열시간 4분, 진공팽화시간 5분에서의 진공팽화유과가 유탕유과의 외관 및 조직과 가장 유사하였다. 절단강도는 가열온도 100oC, 예열시간 6분, 진공팽화시간 15분에서 140 g/cm2로 가장 낮게 측정되었다. 색도는 예열시간과 진공팽화시간이 증가함에 따라 백색도가 증가하는 경향을 보였고, 황색도는 감소하는 경향을 보였으며, 적색도는 유의적 차이가 없었다. 진공팽화유과의 백색도(L값)가 유탕팽화유과보다 25정도 높았으며, 적색도(a값)와 황색도(b값)는 유의적 차이는 보이지 않았으며, 진공팽화유과의 미세구조는 가열온도 120oC, 예열시간 4분, 진공팽화시간 5분에서 기공이 작고 균일하였다. 유탕팽화유과와 비교 시 절단강도는 유사하였으나, 부피팽화율은 낮았고, 밀도는 높았다. 셀이 균일하게 형성된 진공팽화의 미세구조와는 달리 유탕팽화유과의 미세구조는 표면과 내부층의 차이가 확인되었다. 진공팽화기의 최적 공정조건은 진공팽화유과의 품질을 고려 할 때, 가열온도 120oC, 예열시간 4분, 진공팽화시간 5분으로 판단되었다.

Recently, to improve operating efficiency with the higher in-line rate in automated production lines, a lot of cases of grouping machines and material handling system together to form a cluster has shown frequently. This article addresses the job allocation and operation method of automated material handling for cluster-type production systems. First of all, the control problems of the automated material handling systems are classified into the control problem of inter-cluster material handling system and that of intra-cluster material handling system. Then, a distributed agent-based control scheme is proposed for the former, and an operational control procedure for the latter. Simulation experiment shows that the proposed method is efficient in reducing cycle times and improving utilization of material handling vehicles.

인피섬유로 한지를 제조하고 남은 닥나무 목질부를 고부가치화 하기 위하여 닥나무 목질부로 제조된 파티클보드를 이용하여 탄화온도 변화에 따른 닥나무재료 우드세라믹을 제조하여 물성을 검토하였다. 밀 도, 휨강도성능, 브리넬 경도, 압축강도 등은 탄화온도가 증가할수록 증가하였으며 밀도와 휨강도성능, 경도, 압축강도사이에는 유의성이 인정되는 밀접한 상관관계를 나타내었다.