The porous Mg3Sb2 based compounds with 60~70% of relative density were prepared by powder compaction at room temperature and reactive liquid phase sintering at 1023 K for 4hrs. The stoichiometric Mg3Sb2 compounds were synthesized from elemental Sb and Mg powder in the mixing range of 61~63 at% Mg. The increased scattering effect due to the micro-pores reduced the mobility of the charge carrier and the phonon, which caused the electrical conductivity and the thermal conductivity to decrease, respectively. But the scattering effect was greater for the electrical conductivity than for the thermal conductivity. Excess Mg alloyed in the Mg3Sb2 compounds decreased the electrical conductivity, but had no effect on the thermal conductivity. On the other hand, the large increase of the Seebeck coefficient was the result of a decrease in the charge carrier density due to the excess Mg. Dimensionless figure of merit of the porous Mg3Sb2 compound reached a maximum value of 0.28 at 61 at% Mg. The obtained value was similar to that of Mg3Sb2 compounds having little pores.

Fe2O3 coated plate mica(Fe2O3/mica) for infrared reflectance red pigment was prepared under hydrothermal treatment. Fe2O3 was perfectly coated on mica via the difference of surface charge between Fe2O3 and mica particles at pH 3. Fe2O3/mica was then calcined at 800 oC to stabilize the coated layer on mica. The infrare (IR) reflectance pigments were characterized by X-ray diffraction, FE-SEM, zeta potential, and a UV-Vis-NIR spectrophotometer. In particular, the CIE color coordinate and IR reflectance properties of Fe2O3/mica pigments were investigated in relation to the thickness variation of the Fe2O3 layer coated on mica of various lateral sizes. The isolation-heat red paints containing the pigments were prepared and optimized with a thinner, settling agent, and dispersant. Then, the films were made. The thermal property of isolation-heat on these films was observed through the relationship of the IR reflectance value, which was based on the variation of the Fe2O3 layer’s thickness coated on mica and mica’s lateral size as IR reflectance pigment. With an increase in IR reflectance on these films, the thermal property of isolation-heat was effectively enhanced.

This paper proposes a novel way of fabricating aligned porous Sn by freeze-drying of camphene slurry with stannic oxide (SnO2) coated Sn powders. The SnO2 coated Sn powders were prepared by surface oxidation of the initial and ball-milled Sn powders, as well as heat treatment of tin chloride coated Cu powders. Camphene slurries with 10 vol% solid powders were prepared by mixing at 50 oC with a small amount of oligomeric polyester dispersant. Freezing the slurry was done in a Teflon cylinder attached to a copper bottom plate cooled at −25 oC. Improved dispersion stability of camphene slurry and the homogeneous frozen body was achieved using the oxidized Sn powder at 670 oC in air after ball milling. The porous Sn specimen, prepared by freeze-drying of the camphene slurry with oxidized Sn powder from the heat-treated Sn/tin chloride mixture and sintering at 1100 oC for 1 h in a hydrogen atmosphere, showed large pores of about 200 μm, which were aligned parallel to the camphene growth direction, and small pores in their internal walls. However, 100 μm spherical particles were observed in the bottom part of the specimen due to the melting of the Sn powder during sintering of the green compact.

(PDDA/SiO2) thin films that consisted of positively charged poly (diallyldimethylammonium chloride) (PDDA) and negatively charged SiO2 nanoparticles were fabricated on a glass substrate by an applying voltage layer-by-layer (LBL) self-assembly method. In this study, the microstructure and optical properties of the (PDDA/SiO2) thin films coated on glass substrate were measured as a function of the applied voltage on the Pt electrodes. When 1.0 V was applied to a Pt electrode in a PDDA and SiO2 solution, the thickness of the (PDDA/SiO2)10 thin film increased from 79 nm to 166 nm. The surface roughness also increased from 15.21 nm to 33.25 nm because the adsorption volume of the oppositely charged PDDA and SiO2 solution increased. Especially, when the voltage was applied to the Pt electrode in the SiO2 solution, the thickness increase of the (PDDA/SiO2) thin film was larger than that obtained when using the PDDA solution. The refractive index of the fabricated (PDDA/SiO2) thin film was ca. n = 1.31~1.32. The transmittance of the glass substrate coated by (PDDA/SiO2)6 thin film with a thickness of 106 nm increased from ca. 91.37 to 95.74% in the visible range.

Anti-reflection coating films have used to increase the transmittance of displays and enhance the efficiency of solar cells. Hydrophobic anti-reflection coating films were fabricated on a glass substrate by sol-gel method. To fabricate an anti-reflection film with a high transmittance, poly ethylene glycol (PEG) was added to tetraethyl orthosilicate (TEOS) solution. The content of PEG was changed from 1 to 4 wt% in order to control the morphology, thickness, and refractive index of the SiO2 thin films. The reflectance and transmittance of both sides of the coated thin film fabricated with PEG 4 wt% solution were 0.3% and 99.4% at 500 nm wavelength. The refractive index and thickness of the thin film were n = 1.29 and d = 105 nm. Fluoro alkyl silane (FAS) was used for hydrophobic treatment on the surface of the anti-reflection thin film. The contact angle was increased from 13.2˚ to 113.7˚ after hydrophobic treatment.

본 연구에서는 농축유청단백질을 이용하여 내부젤화 방법으로 나노크기(<~200 nm)의 W1/O/W2 다중 에멀젼을 제조하고, 제조 공정요인(가교제인 CaCl2 농도, 초음파처리, 유화제)에 따른 나노다중에멀젼의 형태학적, 물리화학적(입자크기, 다분산지수, 제타전위) 특성 평가와 모델 유식품(우유, 요구르트, 치즈)을 이용한 저장 안정성을 연구하였다. 나노다중에멀젼의 형태학적 특성은 투과전자현미경을 이용하여 관찰하였으며 물리화학적 특성 및 유식품 저장 안정성 평가는 입도분석기를 이용하여 수행되었다. 실험 결과 가교제인 CaCl2을 첨가함에 따라 다중에멀젼의 크기가 유의적으로(p<0.05) 감소하였으며, 이용된 CaCl2 모든 농도(0, 4, 6, 8 mM)에서 음전하를 지닌 다중에멀젼은 다분산지수 0.2 이하의 균질의 입자 분포를 지니고 있음을 알 수 있었다. 또한 투과전자현미경을 이용하여 관찰한 결과, ~ 180 nm 크기의 내부에 오일상이 포함된 구형의 나노다중에멀젼이 성공적으로 제조되었음을 확인하였다. 초음파 처리시 다중에멀젼 크기는 유의적으로(p<0.05) 감소하였으며, 다분산지수 0.2 이하의 나노다중에멀젼이 생성됨을 확인하였다. 또한 수상 내 유화제 첨가 시 입자크기가 유의적으로(p<0.05) 감소하였고, 다분산지수 0.2 이하의 나노다중에멀젼이 생성됨을 확인하였다. 모델 유식품 저장 환경에서의 안정성 평가 결과 14일 동안 나노다중에멀젼은 물리화학적 안정성을 유지하였으며, 결과적으로 농축유청단백질 나노다중에멀젼은 유식품 적용성이 뛰어남을 확인하였다.

The purpose of this study is to present that the entrepreneurial orientation affects to management performance in the small manufacturer. In order to carry out this research, we obtained 171 survey sheets and inspected seven assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factor of entrepreneurial orientation, innovative-ness, influences on the technical innovation performance and financial performance significantly. Second, the element of entrepreneurial orientation, proactive-ness, has an important effect on the technical innovation performance and financial performance. Finally, the requisite of entrepreneurial orientation, risk taking, affects to the technical innovation performance significantly, but not the financial performance. Based on the results, the companies that achieve the technical innovation and financial performance have an atmosphere to encourage to perform the research and development works and find out innovative ideas and improvement points in processes. However, the entrepreneur is required to take careful judgement for determining the uncertain circumstance.

Optimum lot size calculation for real world manufacturing environment has been focused since last few decades. Several extensions have been made to the basic economic order and production order quantity models to realize the possible practical situations in industry. However, focus on work-in-process inventory has been ignored relatively. This paper provides a comprehensive review of the models developed for group technology based manufacturing environment focusing on work-in-process inventory. Models have been extended from a perfect manufacturing conditions to an imperfect manufacturing situation considering rework, rejection and inspection. Optimum lot size has been evaluated using a simple algebraic optimization approach. Significant parameters are highlighted using sensitivity analysis for the developed models. Numerical example is used to illustrate the utilization of such models in day-to-day production setups and the impact of significant factors’ variation on total cost and optimum lot size.

In this paper, we study the bargaining strategy of a manufacturer who sells a product through the online and offline distribution channels. To do this, we derive and analyze the equilibrium solutions for both simultaneous and sequential bargaining games. The result shows that the optimal bargaining strategy heavily depends on the size of the online distribution channel’s loyal customers and the difference between the retail prices of the online and the offline distribution channels. It is also shown that, in some cases, the online distribution channel has incentive to downsize its loyal customers and its retail price for a better bargaining outcome.

This paper is present the Technology Orientation affects to Enterprise Management Performance. In order to carry out this research, we obtained 212 survey sheets and inspected ten assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factor of Technology Orientation, research development activity, affects to all factor of Enterprise Management Performance significantly. Second, the factor of Technology Orientation, research development environment, only effect on the technology performance. Third, research development ability is affect to technology performance and new product performance that factor of Enterprise Management Performance. Finally, technology industrialization ability isn’t affects to Enterprise Management Performance significantly. Based on the results, we are recommendations for small and medium-sized manufacturing enterprises.

화장료의 UV 차단과 은폐효과를 갖는 이산화티탄을 사용하여 자기조직체 형성공법을 적용한 하이브리드 이산화티탄을 제조하고 형태, 성질, 공정의 최적조건과 자외선차단 개선을 확인하였다. 하이브리드 이산화티탄은 마이크로 이산화티탄(250~300nm)의 표면에 나노 이산화티탄(20~30nm)을 자기조직체 형성공법을 이용해 결합시킨, 이산화티탄 대 이산화티탄의 결합체를 말한다. 하이브리드 이산화티탄 제조의 최적조건을 알아내기 위해 (-)을 띄는 마이크로 이산화티탄의 표면에 양이온의 링크로써 AlCl3 를 농도별로 조정하고, 그에 따른 마이크로와 나노 이산화티탄의 투입비율을 달리하여 각각의 조건에서 만들어진 시료를 광학분석, 입도분석, 전위차분석 등을 이용해 확인하고 최적의 제조 조건을 알 수 있었다. 최적의 제조 조건에서 만들어진 하이브리드 이산화티탄의 자외선차단 상승효과를 확인하기 위하여 하이브리드 이산화티탄이 첨가된 화장료와 사용된 하이브리드 이산화티탄과 같은 비율의 마이크로와 나노 이산화티탄을 첨가한 화장료의 SPF in-vitro 를 측정하였고, 15%내지 30%의 자외선차단 상승 효과를 확인하였다.

투명 전도성 산화물로서 알루미늄과 붕소가 함께 도핑된 아연산화물(AZOB)이 900℃에서 분무 열분해법에 의해 제조되었다. 얻어진 마이크론 크기의 AZOB 분말은 알루미늄, 붕소 및 아연의 수용액으로부터 얻어진다. 분무 열분해로 얻어진 마이크론 크기의 AZOB 분말은 700℃에서 두 시간동안의 후 소성 과정과 24 시간 동안의 볼 밀링을 통해 나노 크기의 AZOB으로 변환된다. AZOB을 구성하는 일차 입자의 크기를 Debye-Scherrer 식에 의해 계산하였고 압축된 AZOB 펠렛의 표면 저항을 측정하였다.

마이크론 크기를 가지는 ITO(indium tin oxide) 입자들은 인듐과 틴의 수용성 전구체들과 유기 첨가제를 분무 열분해하여 얻었다. 유기 첨가제로서는 에틸렌글리콜과 시트르산을 이용하였다. 분무 열분해 시 에틸렌글리콜과 시트르산과 같은 유기첨가제를 첨가하지 않고 얻어진 ITO 입자들은 구형이며 속이 꽉찬 형태를 가지는데 비해 유기 첨가제를 첨가하여 분무 열분해를 하면 얻어지는 ITO 입자들은 유기 첨가제의 양이 증가 할수록 껍질이 얇고 다공성이 증대된 중공 입자가 얻어진다. 유기첨가제를 첨가하지 않고 분무 열분해를 통해 얻어지는 마이크론 크기를 가지는 ITO는 700℃에서 두 시간 동안의 후소성과 24 시간동안의 습식 볼밀링에 의해 나노 크기의 ITO로 전환되지 않으나, 유기첨가제를 첨가하고 분무 열분해를 통해 얻어지는 마이크론 크기를 가지는 ITO는 700℃에서 두 시간 동안의 후소성과 24 시간 동안의 습식 볼밀링에 의해 나노 크기의 ITO로 쉽게 전환되었다. 응집된 나노 크기의 ITO의 일차 입자의 크기를 Debye-Scherrer 식에 의해 계산하였고 ITO 입자를 압축하여 만든 펠렛의 표면저항을 측정하였다.

This study was performed to determine the optimal composition of muffins added with dropwort powder, egg and sugar. The experiment was designed based on BBD (Box-behnken design), and evaluation was carried out by means of RSM (response surface methodology), consisting of 13 experimental points with three replicates each for three independent variables dropwort powder, eggs and sugar. Using F-test, height, moisture, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity, L-value, a-value, springiness, cohesiveness, chewiness, brittleness, color, and appearance acceptability were expressed as a linear model, whereas pH, b-value, flavor, taste, and texture were expressed as a quadratic model. After swallow and overall acceptability were expressed as a 2FI model. As dropwort powder content increased, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity increased. Increasing amounts of dropwort powder led to reduction of sensory scores for color, appearance, flavor, taste, and texture quality. The optimum formulation determined by the numerical and graphical methods were similar: dropwort powder 6 g, egg 77 g, and sugar 60 g.

This study investigated the antioxidative properties of Yangha Buds (Zingiber Mioga R) and quality characteristics of Korean steamed-rice cake, Sulgidduk, prepared with Yangha Buds juice. Antioxidative activities were measured based on DPPH radical and ABTS radical scavenging activities, total phenol content, and total flavonoid content in Yangha Buds (water extract and juice). Sulgidduk was prepared by adding Yangha buds at concentrations of 0, 1, 2, 3, and 4% of juice. To analyze quality characteristics, proximate composition, color, texture profiles, and sensory evaluations were measured. As content of Yangha buds juice increased, L-value significantly decreased while a-value and b-value increased (p<0.05). For texture profiles, control group scored higher score for hardness as compared to groups added with Yangha buds juice. Springiness, chewiness, and adhesiveness were not significantly different among the groups. In the sensory evaluation, samples containing 3% Yangha buds juice showed better results for attitude. Based on these results, we suggest that Yangha buds are a good ingredient for increasing consumer acceptability and functionality of Sulgidduk.

고분자 필름의 표면에 친수성의 증가시키는 것은 그 자기 세정 및/또는 방담 특성을 가지게 하는데 중요한 접근 방법이다. 일반적으로 친수성 표면은 비이온 계면활성제를 코팅하거나 표면에너지를 증가시킴으로써 제조할 수 있다. 본 연구에서는 가격이 저렴하고 톨루엔 용제에 잘 용해될 뿐 만아니라 커플링제와 반응할 수 잇는 하이드록시기를 가지고 있는 Tween, Span 및 PEG-PPG 블록공중합체를 선택하여 실험을 수행하였다. 배합 조건에 따라 PET 필름 표면의 친수도에 큰 영향을 미침을 확인하였다. 그러나, PET 필름의 표면상에 단순히 이들 계면활성제의 도입은 수세 후에는 높은 내구성을 보여주지 않았다. 내구성을 높이기 위해 에폭시 및 이소시아네이트와 같은 두 종류의 커플링제를 사용하였다. 코팅액에 6 중량 %isophrone 디이소시아네이트 (IPDI)를 함유한 코팅액으로 코팅된 PET 필름 표면의 물에 대한 접촉각은 8.7˚까지 낮아졌으며, 이는 매우 높은 친수성에 대한 간접적인 증거이다. 또한, 코팅된 PET 필름의 광 (파장 500 nm) 투과율 값은 높은 투명 특성을 유지하면서 87%에서 85%로 약간 감소하였다. 이 PET 필름은 자기 세정 특성이 필요한 필름산업에 적합한 소제로 사용될 수 있다.

폴리스티렌계 음이온교환막은 제조가 쉽고 공정이 간단한 장점을 갖고 있으나 막의 취성이 높아 내구성이 떨어지 는 단점을 가지고 있다. 이를 보완하여 유연하고 우수한 내구성을 갖는 막을 만들기 위해 acrylonitrile-butadiene rubber를 첨 가제로 사용하여 음이온교환막을 제조하였다. 다양한 조성의 vinylbenzylchloride와 styrene, divinylbenzene, acrylonitrile- butadiene rubber 그리고 benzoyl peroxide로 이루어진 단량체 용액을 지지체인 직물 형태의 지지체인 poly(propylene)위 에 캐스팅 후 열중합 가교시킨 다음 trimethylamine과 acetone을 이용하여 음이온 교환기(-N+(CH3)3)를 함유하는 복합막을 제 조하였다. 음이온 교환막 제조시 첨가제의 함량에 따른 막의 성능을 평가하여 최적화 비율을 찾고, 단량체의 함량을 변화하여 함수율, 이온교환용량(IEC) 및 전기저항 값을 측정하였다. 그 결과 최적화 비율로 제조된 막들은 아스톰사의 상용화 음이온 교환막(AMX)보다 높은 IEC와 낮은 전기저항 값을 나타내는 동시에 유연성과 내구성이 우수한 막이 만들어진 것을 확인할 수 있었다.

폴리에스터(polyester) 부직포 상에 폴리술폰(polysulfone) 고분자 지지체를 만든 후, 그 표면에 폴리아미드 복합 박 막을 형성시킴으로써 정삼투(FO) 공정에 적합한 분리막을 제조하였다. PSF 지지체는 19 중량%의 함량으로 디메틸 포름아미 드(DMF)에 균일하게 용해된 폴리술폰 용액을 상 전이 공정을 통하여 제조되었으며, 기계적 보강재로 100 μm의 두께를 가지 는 폴리에스터 부직포를 사용하였다. 19 중량%의 PSF/DMF 용액으로 제조된 PSF 지지층은 sponge-like구조를 가지는 비대칭 내부 구조를 나타내었다. 정삼투(FO) 공정에서 내부의 농도 분극을 줄이기 위하여, 20 μm의 얇은 부직포 보강층을 가지는 지 지체 상에 9~19 중량%의 PSF/DMF 용액으로 PSF 지지체를 제조하였다. 이들 얇은 부직포 보강층에서 제조된 지지층들은 공 극률이 향상된 sponge-like구조를 가지는 것을 확인할 수 있었다. 각각의 지지층들 표면에 방향족 폴리아미드 가교 반응을 통 하여 복합 박막을 얻을 수 있었다. FO 운전 결과, 12 중량%의 DMF/PSF 용액으로 제조한 지지체를 가지는 복합 박막이 가장 우수한 투과 성능을 보여 주었다. 이 경우 4.5 LMH의 유량과 3.47 GMH의 염의 역확산 속도를 가지는 역삼투 분리막에 사용 되는 두꺼운 부직포에 비해 약 2.5배 유량이 많은 24.3 LMH의 유량과 1.5 GMH의 염의 역확산 속도를 보여주고 있다. 부직포 의 두께 저하와 이에 적합한 PSF 캐스팅 용액의 최적화를 통하여 부직포와 PSF층의 경계면 공극률을 향상시킬 수 있었다.

Effect of oxygen content in the ultrafine tungsten powder fabricated by electrical explosion of wire method on the behvior of spark plasma sintering was investigated. The initial oxygen content of 6.5 wt% of as-fabricated tungsten powder was reduced to 2.3 and 0.7 wt% for the powders which were reduction-treated at 400˚C for 2 hour and at 500˚C for 1h in hydrogen atmosphere, respectively. The reduction-treated tungsten powders were spark-plasma sintered at 1200-1600˚C for 100-3600 sec. with applied pressure of 50 MPa under vacuum of 0.133 Pa. Maximun sindered density of 97% relative density was obtained under the condition of 1600˚C for 1h from the tungsten powder with 0.7 wt% oxygen. Sintering activation energy of 95.85kJ/mol-1 was obtained, which is remarkably smaller than the reported ones of 380~460kJ/mol-1 for pressureless sintering of micron-scale tungsten powders.

Silicon carbide(SiC) layer is particularly important tri-isotropic (TRISO) coating layers because it acts as a miniature pressure vessel and a diffusion barrier to gaseous and metallic fission products in the TRISO coated particle. The high temperature deposition of SiC layer normally performed at 1500-1650˚C has a negative effect on the property of IPyC layer by increasing its anisotropy. To investigate the feasibility of lower temperature SiC deposition, the influence of deposition temperature on the property of SiC layer are examined in this study. While the SiC layer coated at 1500˚C obtains nearly stoichiometric composition, the composition of the SiC layer coated at 1300-1400˚C shows discrepancy from stoichiometric ratio(1:1). 3-7μm grain size of SiC layer coated at 1500˚C is decreased to sub-micrometer (＜ 1μm) -2μm grain size when coated at 1400˚C, and further decreased to nano grain size when coated at 1300-1350˚C. Moreover, the high density of SiC layer (≥3.19g/cm3) which is easily obtained at 1500˚C coating is difficult to achieve at lower temperature owing to nano size pores. the density is remarkably decreased with decreasing SiC deposition temperature.