Hydroxyapatite (HA) is well known as a biocompatible and bioactive material. HA has been practically applied as bone graft materials in a range of medical and dental fields. In this study, two types of dense hydroxyapatite ceramics were prepared from natural bones and synthetic materials. The biocompatibility of HA ceramics for supporting osteoblast cell growth and cytotoxicity using an in vitro MG-63 cell line model were respectively evaluated. Artificial hydroxyapatite shows relative density of 93% with 1-2 μm after sintering, but a hydroxyapatite compact derived from bovine bone has low sintered density of 85% with a small content of MgO. Irrespective of the starting raw materials, both types of sintered hydroxyapatite displayed similar biocompatibility in the tests. FE-SEM observations showed that most MG-63 cells had a stellar shape and formed an intercellular matrix containing fibers on sintered HA. The cells were well attached and grown over the HA surface, indicating that there was no toxicity.

Bismuth antimony telluride (BiSbTe) thermoelectric materials were successfully prepared by a spark plasma sintering process. Crystalline BiSbTe ingots were crushed into small pieces and then attrition milled into fine powders of about 300 nm ~ 2μm size under argon gas. Spark plasma sintering was applied on the BiSbTe powders at 240, 320, and 380˚C, respectively, under a pressure of 40 MPa in vacuum. The heating rate was 50˚C/min and the holding time at the sintering temperature was 10 min. At all sintering temperatures, high density bulk BiSbTe was successfully obtained. The XRD patterns verify that all samples were well matched with the Bi0.5Sb1.5Te3. Seebeck coefficient (S), electric conductivity (σ) and thermal conductivity (k) were evaluated in a temperature range of 25~300˚C. The thermoelectric properties of BiSbTe were evaluated by the thermoelectric figure of merit, ZT (ZT = S2σT/k). The grain size and electric conductivity of sintered BiSbTe increased as the sintering temperature increased but the thermal conductivity was similar at all sintering temperatures. Grain growth reduced the carrier concentration, because grain growth reduced the grain boundaries, which serve as acceptors. Meanwhile, the carrier mobility was greatly increased and the electric conductivity was also improved. Consequentially, the grains grew with increasing sintering temperature and the figure of merit was improved.

This paper analyzed twenty-six production-related KPI(Key Performance indicator) factors of business diagnosis, such as personnel, equipment, materials, operations and quality affecting company business competition to 186 small machinery manufacturers in 2010. Also, we explained the concept of Business Positioning and divided research subjects into four Business Positioning Groups formed break-even point ratio & fixed cost ratio to sales and then we compared between the 4 groups using Logistic Regression analysis by SAS statistical software package. The objective of this study is two-fold. The first is to find out production-related KPI factor of superior Business Positioning Group. The second is to suggest improvement ways for small manufacturers in order to get better profitable Business Positioning.

PVA와 PAA블랜드의 용액주조법을 통하여 겔 고분자 전해질막이 제조되었다. 블랜드 내의 PAA함량은 30에서 80 wt% 사이 범위에서 조절되었다. 겔 고분자 전해질을 이용하여 아연공기전지를 제작하였다. 제조된 겔 고분자 전해질의 기계적, 전기적 특성을 인장실험과 임피던스 실험을 통하여 측정하였다. 아연공기전지의 성능은 current interrupt method와 정전류 방전실험을 통하여 측정하였다. 겔 고분자 전해질 내의 PAA함량이 증가함에 따라 인장강도 및 인장탄성계수가 감소하였다. 반면, PAA함량의 증가에 따라 겔 고분자 전해질막의 이온전도도는 증가하였다. 이와 같은 이온전도도의 증가의 아연공기전지 내에서의 효과는 current interrupt method와 정전류 방전실험에서 확인되었다. PAA함량이 높은 겔 전해질막으로 제조된 전지는 낮은 IR손실과 높은 방전용량을 보였다.

This paper deals with an empirical analysis of the structural relationship among the factors such as quality management activities, organizational learning and firm performance of manufacturing corporations. The findings of the analysis are expected to make lots of contribution to manufacturing corporations establishing strategies for quality management activities and organizational learning. From the analysis, following conclusions and suggestions could be drawn: First, an analysis of the relationship between quality management activities and organizational learning showed that most activities of quality management turned out to exercise great influence upon the factors of organizational learning. This means that the activities of quality management will prompt the members of an organization to actively engage in learning activities individually, by team and organizationally, motivating them to spread such activities across the whole organization, leading ultimately to fundamental renovation of the very organization. Second, from an analysis of the relationship between organizational learning and firm performance, that is, financial and non-financial performances of a company, it was found that most factors of organizational learning have tremendous impact upon financial and non-financial performances of the company. Such result implies that decision and management of the things to be performed in the process of organizational performances are essential to determining firm performance because firm performance depend largely on the outcomes of organizational learning.

불소관능기인 perfluorocyclobutane (PFCB)기를 포함하는 후술폰화 poly (arylene ether sulfone) 랜덤 공중합체를 다공성 Polytetrafluoroethylene (PTFE) 막에 함침시켜 새로운 복합막을 제조하였다. 후술폰화 랜덤 공중합체는 trifluorovinyloxy 그룹을 양말단에 포함하는 biphenyl계와 sulfonyl계 단량체로부터 제조되었는데, biphenyl계와 sulfonyl계의 비율을 6 : 4와 4 : 6으로 조절 후 중부가반응 형태의 열중합과 chlorosulfonic acid (CSA)를 이용한 후술폰화 반응을 통하여 얻어졌다. 이렇게 제조된 랜덤 공중합체의 농도를 달리하면서(5~20 wt%) 다공성 PTFE 막에 함침시켜 복합막을 제조하였고, 이온 교환 능력(IEC), 함수율, 이온전도도를 측정하여 강화되지 않은 랜덤공중합체 및 Nafion과 비교하였다. 제조된 단량체 및 고분자의 구조와 순도는 각각 1H-NMR, 19F-NMR와 FT-IR를 통하여 확인하였으며, 제조된 복합막의 형태는 SEM으로 관찰하였다.

침지법 상전이 공정 방법으로 polysulfone (PSF) 분리막을 제조하였다. PSF/NMP/PVP/phosphoric acid의 캐스팅 용액과 물 침전조를 이용하여 분리막을 제조하였다. 증기 유도 상전이법과 비용매 유도 상전이법을 연속하여 적용함으로서 캐스팅 용액에 첨가된 인산의 영향이 분리막의 구조 및 투과량에 미치는 영향을 살펴보았다. 미량의 인산의 첨가로도 평균 기공의 크기, 공극률, 수투과량의 증가를 볼 수 있었다. 또한 분리막의 구조가 치밀한 스펀지 형태의 구조에서 비대칭성이 향상된 구조로 변화함을 확인할 수 있었다. PSF/NMP/PVP/phosphoric acid/BE를 함유한 캐스팅 용액을 준비한 후 동일한 조건으로 증기 유도 상전이법과 비용매 유도 상전이법을 연속하여 적용하여 분리막을 제조하였다. BE의 첨가는 평균 기공의 크기를 거의 0.1 mum 정도 향상시키는 효과를 가져왔으며 수 투과 유량 또한 10~12L/cm2·min·bar 향상시키는 결과를 나타내었다.

This study was conducted to evaluate microbial contamination levels of Korea traditional rice cakes such as Sirutteok, Garaetteok and Gyeongdan in the manufacturing process and environment. The microbial contamination levels such as total aerobic bacteria, fungi, coliforms, Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens of rice cake products were analyzed. The contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in raw materials were in the range of 2.4~4.5, ND~1.9, 1.2~2.1 and 1.0~2.1 log CFU/g, respectively. The microbial contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in manufacturing process of rice cakes were increased in the soaking and grinding steps and were decreased in steaming step. E. coli, S. aureus and C. perfringens were not detected in any manufacturing process and environment. The microbial contamination levels of raw materials and final products of rice cake were suitable for microbial safety standard in Korea. However, the manufacturing environment such as equipments and employee's sanitation were in trouble for microbial safety. The results of this study suggest that safety education for personal hygiene and safety management in processing environment are continuously required to assure safety in working environment and employee's individual hygiene.

In the manufacturing industry, fostering talented workers has become a core activity as well as an important resource leading to manufacturing enterprises’ innovative activities, which has come to the fore as one of the biggest success factors for innovat

나노 크기인 5nm 이하로 제조한 은나노제품(파이투패치)은 주요 식물병원균인 탄저병원균(Collectotrichum gloeosporioides), 잿빛곰팡이병원균(Botrytis cinerea), 균핵병원균(Sclerotinia sclerotiorum)에 대해 포자발아 및 균사생장을 억제하는 항균력이 있었다. 파이투패치 살포에 의한 고추탄저병 방제효과를 실험하기 위해 파이투패치 희석액에 포자를 침지하여 포습시킨 후 발아율을 조사한 결과 5ppm까지 희석한 처리구에서 병원균의 포자발아억제효과를 보였으며, 균사는 10ppm에서 생장억제효과가 15일간 지속되었다. 특히 파이투패치를 10ppm으로 희석하여 배지표면에 도말한 후 탄저병원균 포자를 접종하면 3일간 발아가 억제되어 식물체 감염을 효과적으로 예방하였으며, 40% 이상 발병한 시험구에 4ppm 파이투패치를 살포한 결과 21일 후 7% 이하의 발병과율로 무처리 대비 70% 방제효과가 있었다. 장마철 탄저병 발생율이 94.6%인 시험포장에서 10ppm 농도로 파이투패치를 7일간격으로 엽면살포한 결과 발병과 발생율이 5.8%로 방제효과를 확인하였으며, 수확한 홍고추를 자연건조한 후에도 발병과율이 24.2%로 건고추 수확량도 증가하였다. 장마철 고추역병(Phytophthora capsici)은 장마가 끝난 무피복시험구에서 8월 11일 15%이었으며 고온기를 지난 9월 7일에는 발병율이 74%로 수확을 포기하였으나, 파이투패치를 코팅처리한 피복재를 씌운 시험구에서는 발병주가 2.3%로 장마철 역병발생이 효과적으로 방제되었다.

Real-life time series characteristic data has significant amount of non-stationary components, especially periodic components in nature. Extracting such components has required many ad-hoc techniques with external parameters set by users in case-by-case m

Many countries are enforcing the Product Liability Act to ask the responsibility for the supply of the safe products. Thus, the safety of the product becomes one of the most important elements in modern corporate management. Diamond tool industries producing risk-high products cannot make an except to this situation. This research presents how Diamond tool manufactures in korea to respond effectively to Product Liability through construction of Product Safety Management System.

Odorous pollutants emitted from the manufacturing process of TFT-LCD were investigated to prepare the odor control plan. Odor measurements in the workplace of clean room were also carried out. The odorous pollutants detected in the organic and acid gas emission duct were acetone, acetic acid, IPA, nbutylacetate, PGMEA, cyclohexane, which were chemicals used for LCD manufacturing. Especially, acetic acid was turned out to one of the major odor substances in the acid gas emission duct because of its low odor threshold value. No odorous pollutants were detected in the toxic gas emission duct. Some organic gases detected in the clean room were due to the leakage from chemical containers or LCD devices.

Polydimethylsiloxane(PDMS) 몰드를 이용하여 Thermal Imprinting 방법을 통해 광변색 물질인Nitrospirobenzopyran(NSB)를 포함하는 Polystyrene 박막을 패터닝하였다. 패턴된 광변색 소자의 변색 및 탈색에 따른 흡광도 스펙트럼 및 회절효과를 조사된 자외선량에 따라 측정하여 자외선 조사량에따른 회절 효율 변화를 식으로 근사할 수 있었으며 회절 효율로부터 소자의 굴절률 변화량을 계산해 낼 수 있었다. 변색 전 회절효율은 6.75%, 공기와의 굴절률 차이 값은 0.078였으며, 200J/m2의 자외선량이조사된 후의 회절효율은 7.56%, 공기와의 굴절률 차이 값은 0.083로 나타났다. 광변색 패턴의 자외선에의한 회절효율의 변화는 자외선 감지에 효과적인 것으로 나타났다.

본 연구에서는 말단기에 diene 기와 dithiol 기를 갖는 두 가지 새로운 액정 단량체의 합성을 보고하며, 이를 배향 후 광경화하여 광학 위상지연 필름을 제조하는 방법에 대해 논의하였다. 특히 합성된 두 가지액정단량체의 구조를 확인하였으며, 이들의 액정특성을 연구하였다. 또한 이들을 광개시제와 혼합하여광경화형 액정조성물을 제조하고 이를 러빙 배향막이 코팅된 표면 위에서배향시킨 후 광조사하여 thiol-ene 중합에 의해 경화함으로써 광학 위상지연 필름을 제조하였다.

In this research, the coating behavior of Mg and Fe desulfurization powder fabricated by low energy and conventional planetary mill equipment was investigated as a function of milling time, which produces uniform Fe coated powders due to milling energy. Since high energy ball milling results in breaking the Fe coated Mg powders into coarse particles, low energy ball milling was considered appropriate for this study, and can be implemented in desulfurization industry widely. XRD and FE-SEM analyses were carried out to investigate the microstructure and distribution of the coating material. The thickness of the Fe coating layer reaches a maximum of 14 at 20 milling hours. The BCC structures of Fe particles are deformed due to the slip system of Fe coated Mg particles.

YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of . When the calcination temperatures were larger than , however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and to the spray solution was effective to prepare a spherical and dense structured YAG particles.

In this work, powder metallurgy and severe plastic deformation by high-pressure torsion (HPT) approaches were combined to achieve both full density and grain refinement at the same time. Pure Cu powders were mixed with 5 and 10 vol% diamonds and consolidated into disc-shaped samples at room temperature by HPT at 1.25 GPa and 1 turn, resulting in ultrafine grained metallic matrices embedded with diamonds. Neither heating nor additional sintering was required with the HPT process so that in situ consolidation was successfully achieved at ambient temperature. Significantly refined grain structures of Cu metallic matrices with increasing diamond volume fractions were observed by electron backscatter diffraction (EBSD), which enhanced the microhardness of the Cu-diamond composites.

A novel PM (powder metallurgy) steel for automotive power-train gear components was developed to reduce manufacturing cost, while meeting application requirements. The high-density PM steel was manufactured by mixing using special Cr-Mo atomized iron powders, high-pressure compaction, and sintering. Tensile strength, charpy impact, bending fatigue, and contact fatigue tests for the PM steel were carried out and compared to conventional forged steel. Pinion gears for auto-transmission were also manufactured by helical pressing, sintering, and surface densification process. In order to evaluate the durability of the PM parts, auto-transmission durability tests were performed using dynamometer tests. Results showed that the PM steel fulfilled the requirements for pinion gears indicating suitable tensile, bending fatigue, contact fatigue strengths and improved gear tooth profile. The PM gears also showed good performance during the transmission durability tests. As a result, the PM gears showed significant potential to replace the conventional forged steel gears manufactured by tooth machining (hobbing, shaving, and grinding) processes.