The with various phases were prepared by simple ex-situ hydrolysis and spark plasma sintering (SPS) process of Al powder. The nano bayerite phase was derived by hydrolysis of commercial powder of Al with micrometer size, whereas the bohemite (AlO(OH)) phase was obtained by hydrolysis of nano Al powder synthesized by pulsed wire evaporation (PWE) method. Compaction as well as dehydration of both nano bayerite and bohemite was carried out simultaneously by SPS method, which is used to fabricate dense powder compacts with a rapid heating rate of per min. under the pressure of 50MPa. After compaction treatment in the temperature ranges from , the bayerite and bohemite phases change into various alumina phases depending on the compaction temperatures. The bayerite shows phase transition of sequences. On the other hand, the bohemite experiences the phase transition from AlO(OH) to It shows AlO(OH) sequences. The compacted at shows a high surface area .

This work is to present a new synthesis of metallic glass (MG)/metallic glass (MG) composites using gas atomization and spark plasma sintering (SPS) processes. The MG powders of (CuA) and (NiA) as atomized consist of fully amorphous phases and present a different thermal behavior; (glass transition temperature) and (crystallization temperature) are 716K and 765K for the Cu base powder, but 836K and 890K for the Ni base ones, respectively. SPS process was used to consolidate the mixture of each amorphous powder, being in weight. The resultant phases were Cu crystalline dispersed NiA matrix composites as well as NiA phase dispersed CuA matrix composites, depending on the SPS temperatures. Effect of the second phases embedded in the MG matrix was discussed on the micro-structure and mechanical properties.

Nanopowders of titanium dioxide incorporating the transition metal element(s) were synthesized by flame synthesis method. Single element among Fe(III), Cr(III), and Zn(II) was doped into the interior of crystal; bimetal doping of Fe and Zn was also made. The characteristics of transition-metal-doped nanopowders in the particle feature, crystallography and electronic structures were determined with various analytical tools. The chemical bond of Fe-O-Zn was confirmed to exist in the bimetal-doped nanopowders incorporating Fe-Zn. The transition element incorporated in the was attributed to affect both Ti 3d orbital and O 2p orbital by NEXAFS measurement. The bimetal-doped nanopowder showed light absorption over more wide wavelength range than the single-doped nanopowders

최근 들어 제조가 발생되는 모든 분야에서 정보의 의미론적 전달방법 및 체계를 정형화하는 작업이 표준화와 더불어 활발히 진행되고 있다. 제조시스템에서 문제가 발생하였을 때 간결하고 정확한 문제 진단에 대한 정보전달은 비용의 절감은 물론 생산성 향상을 위해서도 필수적인 요소이다. 본 연구에서는 제조시스템에서 최적화된 정보전달을 위한 상황이론적 방법론을 제시한다. 본 연구에서 제시하는 방법론의 궁극적인 목적은 실제 제조공정이나 현장에서 발생되는 복잡한 정보의 흐름, 표현, 관리를 효율적으로 할 수 있고 작업자, 관리자, 경영자 모두가 공통적으로 활용할 수 있는 정형화된 틀을 만드는데 있다. 본 연구에서 제시하는 방법론은 제조 현장에서 공정상의 문제점을 분석하고 검사할 수 있는 도구로 활용될 수 있을 것이다.

This paper considers six sigma projects for the PCB industry. This paper is divided into the following four parts. In the first part, the concept and properties of six sigma management are introduced. In the second part, some tools of six sigma project using DMAIC phases are studied for a PCB manufacturing process. In the third part, some tools of six sigma project using DMADOV phases are considered for a PCB research and development process. Finally, some tools of six sigma project for a PCB transaction process are given.

재(再) 제조란 폐기된 제품을 회수하여 신제품과 같은 품질상태로 회복시키는 과정으로, 제품의 폐기로 인하여 발생하는 경제적 손실뿐만 아니라 폐기물의 증가로 인한 환경오염의 예방에도 도움을 준다. 이러한 재 제조의 목표는 보다 많은 부품들을 재사용하는 것으로 기존의 수리와 제조 개념이 결합된 형태로서 제품의 완전 해체, 세척, 검사, 부품수리 및 조정과 교체, 제품의 재조립 등의 일련의 단계를 거치게 되며 이 과정에서 부품의 신뢰도는 매우 중요한 요소로 작용하게 된다. 따라서 이 논문에서는 크게 다음의 두 가지 내용에 대해서 다루게 된다. 첫째, 시스템의 가용도를 모델링하는 방법으로 잘 알려진 마코프 모델을 이용하여 재 제조 시스템의 가용도 분석을 위한 모델을 제시한다. 둘째, 가용도 분석을 통한 부품의 재사용 빈도와 이용시간 평가 등을 통하여 재 제조 시스템의 성능을 평가하기 위한 척도를 제시한다.

This study was conducted to develop a functional cookie with the addition of a sweet pumpkin powder on a cookie shape, that showed high preference level to all age group and that was very easily to store because of low moisture content, by substituting partially a sweet pumpkin powder for reducing content of wheat flour. This study has produced the sensory optimal composite recipe by making iced cookies, respectively, with each 5 level of Sweet pumpkin powder(X1), sugar(X2), butter(X3), by C.C.D(Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM(Response Surface Methodology). Sensory items showed very significant values in color, appearance, flavor, overall quality(p〈0.05), texture(p〈0.01), and instrumental analysis showed significant values in lightness, redness(p〈0.01), yellowness, spread ratio, hardness(p〈0.05). Also sensory optimal ratio of Sweet pumpkin cookie was calculated as sweet pumpkin powder 81.8g, sugar 116.6g, butter 210.7g, and it was revealed that the factors of influencing cookie aptitude were in order of Sweet pumpkin powder, butter, sugar.

The purpose of this study is to identify the best firing condition for Celadon, which is one of the famous traditional pottery to represent Korean culture, by minimizing energy consumption, cutting firing time, shortening the time of processing ceramic making, in order to, save energy as well as to protect the potters' health. Most Korean potter starts their reduction from 950℃ to change kiln atmosphere. However on this study, reduction have started from 950℃ to 1200℃ by increasing 50℃ at a time. Then the results are analyzed to be compared to previous Celadon, in colors, chroma, and brightness. As a results, it is found, that the best temperature for starting reduction is 1100℃, when chroma and brightness values to meet same with previous celadon. Therefore the best condition could be made by starting the reduction on 1100℃ to fire celadon, which would have shorten 2 hours of firing process and, at the same time, it could have saved the energy by 12%.

The goal of this study is to propose the improved scheme that prevents the workers against musculoskeletal disorders at a fishcake manufacturing company, A questionnaire and an ergonomic assessment method were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an analysis of working postures and a quantitative assessment on various processes were performed to find out harmful factors of workplace. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. Suggested improvement plan was applied to the workplace step by step and it is confirmed that improvement plan can removes the injurious factors of musculoskeletal diseases effectively.

In manufacturing industry of the modem industrial society, people increasingly become concerned the awareness of safety increasingly although they have regarded production the most important factor. Even though, as people make efforts on accident preventions, the number of accidents is decreasing, fatal major industry accidents are rather thanincreasing so that the number of deaths has not decreased. Under these conditions, there is an attempt to introduce and perform the process safety management system as a means for keeping from major industry accidents. However, it leaves to be desired on the methods of measuring process safety in the general manufacturing industry, while it is available to do that in the chemistry industry. Therefore, in this paper, we analysis processes of manufacturing industry in safety point of view and suggest the technique efficiently measuring and managing each process. Proposed the technique shows that the specification on safety determines AHP weight through the managers of firms and each process is suggested by using normalized matrix.

The structural and magnetic properties of nanostructued alloy powders were investigated. Commercial alloy powders (Hoeganaes Co., USA) with purities were used to fabricate the nanostructure Fe-Si alloy powders through a high-energy ball milling process. The alloy powders were fabricated at 400 rpm for 50 h, resulting in an average grain size of 16 nm. The nanostructured powder was characterized by fcc and hcp phases and exhibited a minimum coercivity of approximately 50 Oe

In this study the nanostructured ceramics have been fabricated by the combined application of magnetic pulsed compaction (MPC) and subsequent spark plasma sintering (SPS), and their density and hardness properties were investigated. The prepared by the combined processes showed an increase by in density, approaching the value close to the true density, and an enhancement by in hardness, compared to those fabricated by MPC or static compaction method followed by sintering treatment.

In the present study, the focus is on the effect of cobalt oxide powder in the carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fine TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under flowing argon atmosphere. Changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. Titanium-cobalt-oxygen based oxide powder desalted at had a mixture of . And the one desalted at had a mixture of . In the case of the former powder, the reduction of cobalt oxide powder in the titanium-cobalt-oxygen based oxide powder occurred at lower temperature than the latter one. However, the carbothermal reduction of titanium dioxide powder in the titanium-cobalt-oxygen based oxide powder with a mixture of occurred at higher temperature than the one with a mixture of . And also, the former powder showed a lower TiC formation ability than the latter one.

Porous and porous surfaced Ti-6Al-4V implant compacts were fabricated by electro-discharge-sintering (EDS) of atomized spherical Ti-6Al-4V powders with a diameter of , The solid core formed in the center of the compact after discharge was composed of acicular Widmanstatten grains, The hardness value at the solid core was much higher than that at the particle interface or particles in the porous layer, which can be attributed to both heat treatment and work hardening effects induced from EDS, The compressive yield strength was in a range of 19 to 436 MPa which significantly depends on both input energy and capacitance, Selected porous-surfaced Ti-6Al-4V implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered Ti dental implants.

Implant prototypes with various porosities were fabricated by electro-discharge-sintering of atomized spherical Ti-6Al-4V powders. Single pulse of 0.75 to 2.0 kJ/0.7 g-powder, using 150, 300, and capacitors was applied to produce a fully porous and porous surfaced implant compact. The solid core formed in the center of the compact after discharge was composed of acicular grains and porous layer consisted of particles connected in three dimensions by necks. The solid core and neck sizes increased with an increase in input energy and capacitance. On the other hand, pore volume decreased with increased capacitance and input energy due to the formation of solid core. Capacitance and input energy are the only controllable discharge parameters even though the heat generated during a discharge is the unique parameter that determines the porosity of compact. It is known that electro-discharge-sintering of spherical Ti-6Al-4V powders can efficiently produce fully-porous and porous surfaced Ti-6Al-4V implants with various porosities in a short time less then 400 isec by manipulating the discharging condition such as input energy and capacitance including powder size.