A cell formation approach based on cluster analysis is developed for the configuration of manufacturing cells. Cell formation, which is to group machines and parts into machine cells and the associated part families, is implemented to add the flexibility and efficiency to manufacturing systems. In order to develop an efficient clustering procedure, this paper proposes a cluster analysis-based approach developed by incorporating and modifying two cluster analysis methods, a hierarchical clustering and a non-hierarchical clustering method. The objective of the proposed approach is to minimize intercellular movements and maximize the machine utilization within clusters. The proposed approach is tested on the cell formation problems and is compared with other well-known methodologies available in the literature. The result shows that the proposed approach is efficient enough to yield a good quality solution no matter what the difficulty of data sets is, ill or well-structured.

Mg3-xZnxSb2 powders with x = 0-1.2 were fabricated by mechanical alloying in a planetary ball mill with a speed of 350 rpm for 24 hrs and then hot pressed under a pressure of 70 MPa at 773 K for 2 hrs. It was found that there were systematic shifts in the X-ray diffraction peaks of Mg3Sb2 (x = 0) toward a higher angle with increasing Zn for both the powder and the bulk sample and finally the phase of Mg1.86Zn1.14Sb2 was formed at the Zn content of x = 1.2. The Mg3-xZnxSb2 compounds had nano-sized grains of 21-30 nm for the powder and 28-66 nm for the hot pressed specimens. The electrical conductivity of hot pressed Mg3-xZnxSb2 increased with increasing Zn content and temperature from 33 Sm-1 for x = 0 to 13,026 Sm-1 for x = 1.2 at 323 K. The samples for all the compositions from x = 0 to x = 1.2 had positive Seebeck coefficients, which decreased with increasing Zn content and temperature, which resulted from the increased charge carrier concentration. Most of the samples had relatively low thermal conductivities comparable to the high performance thermoelectric materials. The dimensionless figure of merit of Mg3-xZnxSb2 was directly proportional to the Zn content except for the compound with Zn = 1.2 at high temperature. The Mg3-xZnxSb2 compound with Zn = 0.8 had the largest value of ZT, 0.33 at 723 K.

The study of grinding behavior characteristics on aluminum powders and carbon nano tubes (CNTs) has recently gained scientific interest due to their useful effect in enhancing advanced nano materials and components, which significantly improves the property of new mechatronics integrated materials and components. We performed a series of dry grinding experiments using a planetary ball mill to systematically investigate the grinding behavior during Al/CNTs nano composite fabrication. This study focused on a comparative study of the various experimental conditions at several variations of rotation speeds, grinding time and with and without CNTs. The results were monitored for the particle size distribution, median diameter, crystal structure from XRD pattern and particle morphology at a given grinding time. It was observed that pure aluminum powders agglomerated with low rotation speed and completely enhanced powder agglomeration. However, Al/CNTs composites were achieved at maximum experiment conditions (350 rpm, 60 min.) of this study by a mechanical alloy process for Al/CNTs mixed powders because the grinding behavior of Al/CNTs composite powder was affected by addition of CNTs. Indeed, the powder morphology and crystal size of the composite powders changed more by an increase of grinding time and rotation speed.

Fe-TiC composite powder was fabricated via two steps. The first step was a high-energy milling of FeO and carbon powders followed by heat treatment for reduction to obtain a (Fe+C) powder mixture. The optimal condition for high-energy milling was 500 rpm for 1h, which had been determined by a series of preliminary experiment. Reduction heat-treatment was carried out at for 1h in flowing argon gas atmosphere. Reduced powder mixture was investigated by X-ray Diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM) and Laser Particle Size Analyser (LPSA). The second step was a high-energy milling of (Fe+C) powder mixture and additional powder, and subsequent in-situ synthesis of TiC particulate in Fe matrix through a reaction of carbon and Ti. High-energy milling was carried out at 500 rpm for 1 h. Heat treatment for reaction synthesis was carried out at for 1 h in flowing argon gas atmosphere. X-ray diffraction (XRD) results of the fabricated Fe-TiC composite powder showed that only TiC and Fe phases exist. Results from FE-SEM observation and Energy-Dispersive X-ray Spectros-copy (EDS) revealed that TiC phase exists uniformly dispersed in the Fe matrix in a form of particulate with a size of submicron.

A bulk metallic glass-forming alloy, metallic glass powders was used for good commercial availability and good formability in supercooled liquid region. In this study, the Ni-based metallic glass was synthesized using by high pressure gas atomized metallic glass powders. In order to create a bulk metallic glass sample, the metallic glass powders with ball-milled Ni-based amorphous powder with 40%vol brass powder and Cu powder for 20 hours. The composite specimens were prepared by Spark Plasma Sintering for the precursor. The SPS was performed at supercooled liquid region of Ni-based metallic glass. The amorphous structure of the final sample was characterized by SEM, X-ray diffraction and DSC analysis.

The effect of carrier gases (He, ) on the properties of Ti coating layers were investigated to manufacture high-density Ti coating layers. Cold spray coating layers manufactured using He gas had denser and more homogenous structures than those using gas. The He gas coating layers showed porosity value of 0.02% and hardness value of Hv 229.1, indicating more excellent properties than the porosity and hardness of gas coating layers. Bond strengths were examined, and coating layers manufactured using He recorded a value of 74.3 MPa; those manufactured using gas had a value of 64.6 MPa. The aforementioned results were associated with the fact that, when coating layers were manufactured using He gas, the powder could be easily deposited because of its high particle impact velocity. When Ti coating layers were manufactured by the cold spray process, He carrier gas was more suitable than gas for manufacturing excellent coating layers.

In the present study, we systematically investigated the effect of Mn addition on nitrogenation behavior and magnetic properties of Sm-Fe powders produced by reduction-diffusion process. Alloy powders with only single phase were successfully produced by the reduction-diffusion process. The coercivity of powder rapidly increased during nitrogenation and reached the maximum of 637 Oe after 16 hours. After further nitrogenation, it decreased. In contrast, the coercivity of powder gradually increased during nitrogenation for 24 hours. The coercivity of powder was higher than that of powder at the same condition of nitrogenation. It was considered that the Mn addition facilitates the nitrogenation of powder and enhances the coercivity.

Yacon (Smallanthussonchifolius) is a root crop that contains high amounts of fructo-oligosaccharides (FOS). FOS has a sweet taste, is low in calories, and is known to promote intestinal tract health. In this study, various yacon concentrates were substituted for sugar in white pan bread to obtain healthy benefits from the use of FOS. The quality characteristic changes during storage of the white pan breadswith 0, 25, 50, 75 and 100% of added yacon concentrates instead of sugar were investigated. During storage, the water contents and water activities of the breads made with high amounts of yacon concentrates changed less than in those made with only sugar. The hardness and chewiness of the breads made with high amounts of yacon concentrates had lower values than those made with only sugar. Thus, bread made with yacon concentrates might exhibit increased moisture retention and decreased aging velocity. The substitution of yacon concentrates for sugar in pan bread improved the bread quality.

Fe(SO4)2, cyclohexanedione dioxime, phenylboronic acid을 이용하여 금속 템플레이트 중합을 실시한 후 메탄올로 세척하여 Fe(II) clathrochelate 화합물을 합성하였다. Fe(II) clathrochelate와 polyethersulfone을 이용한 유무기 복합 멤브레인을 제조하였다. 멤브레인 제조를 위하여 Fe(II) clathrochelate는 DMF, NMP, DMAC와 같은 멤브레인 제조에 이용되는 극성 아프로틱 용매에 잘 녹는 물질로 고안되었다. Fe(II) clathrochelate는 trifluorosactic acid와 같은 강산 존재하에서도 금속이 분리되지 않고 안정성이 유지되었다. UV-vis 분광법으로 용액 가용성을 확인하였으며 (i) 강산 및 (ii) 경쟁 킬레이트제를 이용하여 용액상의 안정성을 확인하였다. 유무기 복합막은 PES, PVP, TSA, Fe(II) clathrochelate를 DMF에 녹여 NIPS (비용매 유도 상전이) 방법으로 제조하였다. Fe(II) clathrochelate의 첨가는 표면의 기공 밀도의 향상, 평균기공 크기의 증가 및 유량 증가에 영향을 주었으며 상대적으로 비대칭 구조를 가지는 성능이 향상된 멤브레인을 얻을 수 있었다.

PEGDA/PETEDA dendrimer 막은 PEGDA에 5~15 wt%의 PETEDA dendrimer를 첨가하고 UV를 조사하여 제조하였다. 제조된 막의 특성은 FT-IR, 1H-NMR 그리고 DSC를 통해 분석하였다. PEGDA/PETEDA dendrimer 막의 유리전이온도(Tg)는 PETEDA dendrimer의 함량이 증가할수록 감소하였다. CH4에 대한 CO2 투과 특성은 PETEDA dendrimer의 함량과 압력을 변화시키며 조사하였다. 10 wt%의 PETEDA dendrimer를 포함하는 막의 투과도는 162.2 barrer였으나 CO2/CH4 이상분리 인자는 31.8로 가장 높게 나타났다.

H2S adsorption characteristics of adsorbent made by fallen leaves were investigated. For analyses of the manufactured adsorbent, various methods such as scanning electron microscope(SEM) and measurements of BET surface area were adopted. As major adsorption characteristics, adsorption equilibrium capacity was measured by using a batch type experimental apparatus for operating variables such as adsorption temperature(25~45℃) and adsorbent types. The experimental result showed that the H2S adsorption equilibrium capacity of adsorbent made by fallen leaves decreased with increasing adsorption temperature due to physical adsorption phenomena. It was also found that the H2S adsorption capacity of the adsorbent increased remarkably by an acid treatment with HCl solution.

Porous Al2O3 dispersed with nano-sized Cu was fabricated by freeze-drying process and solution chemistry method using Cu-nitrate. To prepare porous Al2O3, camphene was used as the sublimable vehicle. Camphene slurries with Al2O3 content of 10 vol% were prepared by milling at 50˚C with a small amount of oligomeric polyester dispersant. Freezing of the slurry was done in a Teflon cylinder attached to a copper bottom plate cooled to -25˚C while unidirectionally controlling the growth direction of the camphene. Pores were subsequently generated by sublimation of the camphene during drying in air for 48 h. The green body was sintered in a furnace at 1400˚C for 1 h. Cu particles were dispersed in porous Al2O3 by calcination and hydrogen reduction of Cu-nitrate. The sintered samples showed large pores with sizes of about 150μm; these pores were aligned parallel to the camphene growth direction. Also, the internal walls of the large pores had relatively small pores due to the traces of camphene left between the concentrated Al2O3 particles on the internal wall. EDS analysis revealed that the Cu particles were mainly dispersed on the surfaces of the large pores. These results strongly suggest that porous Al2O3 with Cu dispersion can be successfully fabricated by freeze-drying and solution chemistry routes.

Superhydrophobic SiO2 layers with a micro-nano hierarchical surface structure were prepared. SiO2 layers depositedvia an electrospray method combined with a sol-gel chemical route were rough on the microscale. Au particles were decoratedon the surface of the microscale-rough SiO2 layers by use of the photo-reduction process with different intensities (0.11-1.9 mW/cm2) and illumination times (60-240 sec) of ultraviolet light. With the aid of nanoscale Au nanoparticles, this consequentlyresulted in a micro-nano hierarchical surface structure. Subsequent fluorination treatment with a solution containingtrichloro(1H,2H,2H,2H-perfluorooctyl)silane fluorinated the hierarchical SiO2 layers. The change in surface roughness factorwas in good agreement with that observed for the water contact angle, where the surface roughness factor developed as ameasure needed to evaluate the degree of surface roughness. The resulting SiO2 layers revealed excellent repellency towardvarious liquid droplets with different surface tensions ranging from 46 to 72.3mN/m. Especially, the micro-nano hierarchicalsurface created at an illumination intensity of 0.11mW/cm2 and illumination time of 60 sec showed the largest water contactangle of 170o. Based on the Cassie-Baxter and Young-Dupre equations, the surface fraction and work of adhesion for the micro-nano hierarchical SiO2 layers were evaluated. The work of adhesion was estimated to be less than 3×10−3N/m for all the liquiddroplets. This exceptionally small work of adhesion is likely to be responsible for the strong repellency of the liquids to themicro-nano hierarchical SiO2 layers.

In this study, the influence on the surface passivation properties of crystalline silicon according to silicon wafer thickness, and the correlation with a-Si:H/c-Si heterojunction solar cell performances were investigated. The wafers passivated by p(n)-doped a-Si:H layers show poor passivation properties because of the doping elements, such as boron(B) and phosphorous(P), which result in a low minority carrier lifetime (MCLT). A decrease in open circuit voltage (Voc) was observed when the wafer thickness was thinned from 170μm to 50μm. On the other hand, wafers incorporating intrinsic (i) a-Si:H as a passivation layer showed high quality passivation of a-Si:H/c-Si. The implied Voc of the ITO/p a-Si:H/i a-Si:H/n c-Si wafer/i a-Si:H/n a-Si:H/ITO stacked layers was 0.715 V for 50μm c-Si substrate, and 0.704 V for 170μm c-Si. The Voc in the heterojunction solar cells increased with decreases in the substrate thickness. The high quality passivation property on the c-Si led to an increasing of Voc in the thinner wafer. Short circuit current decreased as the substrate became thinner because of the low optical absorption for long wavelength light. In this paper, we show that high quality passivation of c-Si plays a role in heterojunction solar cells and is important in the development of thinner wafer technology.

Manganese dioxide (MnO2) is one of the most important cathode materials used in both aqueous and non-aqueous batteries. The MnO2 polymorph that is used for lithium primary batteries is synthesized either by electrolytic (EMD-MnO2) or chemical methods (CMD-MnO2). Commonly, electrolytic manganese dioxide (EMD) is used as a cathode mixture material for dry-cell batteries, such as a alkaline batteries, zinc-carbon batteries, rechargeable alkaline batteries, etc. The characteristics of lithium/manganese-dioxide primary cells fabricated with EMD-MnO2 powders as cathode were compared as a function of the parameters of a manufacturing process. The flexible primary cells were prepared with EMD-MnO2, active carbon, and poly vinylidene fluoride (PVDF) binder (10 wt.%) coated on an Al foil substrate. A cathode sheet with micro-porous showed a higher discharge capacity than a cathode sheet compacted by a press process. As the amount of EMD-MnO2 increased, the electrical conductivity decreased and the electrical capacity increased. The cell subjected to heat-treatment at 200˚C for 1 hr showed a high discharge capacity. The flexible primary cell made using the optimum conditions showed a capacity and an average voltage of 220 mAh/g and 2.8 V, respectively, at 437.5μA.

(Na, K) NbO3 thick film was successfully achieved using a sol-gel coating process with the addition of polyvinylpyrrolidone (PVP) to a metal alkoxide solution. The transparent coating solution, mixed with Nb:PVP = 1:1 in a molar ration, was synthesized by evaporating the solvent to over 62.5 wt%. Additive PVP increased the viscosity of the solution so that the coating thickness could be enhanced. The thickness of the (Na, K) NbO3 film assisted by PVP was ca. 320 nm at the time of deposition; this value is four times thicker than that of the sample fabricated without PVP. Also, due to PVP binding with the OH groups of the metal alkoxide, the condensation reaction in the film was suppressed. The crystalline size of the (Na, K) NbO3 films assisted by PVP was ca. 15 nm smaller than that of the film fabricated without PVP. After the sintering process at 700˚C, the (Na, K) NbO3 films were mainly composed of randomly oriented (Na, K) NbO3 phase of perovskite crystal structure, including a somewhat secondary phase of K2Nb4O11. However, by adding PVP, the content of the secondary phase became quite smaller than that of the sample without PVP. It was thought that the addition of PVP might have the effect of restraining the loss of potassium and that PVP could hold metalloxane by strong hydrogen bonding before complete decomposition. Therefore, the film thickness of the (Na, K) NbO3 films could be considerably advanced and made more crack-free by the addition of PVP.

ZnO nanorods were successfully fabricated on Zn foil by chemical bath deposition (CBD) method. The ZnO precursor concentration and immersion time affected the surface morphologies, structure, and electrical properties of the ZnO nanorods. As the precursor concentration increased, the diameter of the ZnO nanorods increased from ca. 50 nm to ca. 150 nm. The thicknesses of the ZnO nanorods were from ca. 1.98μm to ca. 2.08μm. ZnO crystalline phases of (100), (002), and (101) planes of hexagonal wurtzite structure were confirmed by XRD measurement. The fabricated ZnO nanorods showed a photoluminescene property at 380 nm. Especially, the ZnO nanorods deposited for 6 h in solution with a concentration of 0.005M showed a stronger (101) peak than they did (100) or (002) peaks. In addition, these ZnO nanorods showed a good electrical property, with the lowest resistance among the four samples, because the nanorods were densely in contact and relatively without pores. Therefore, a ZnO nanorod substrate is useful as a highly sensitive biochip substrate to detect biomolecules using an electrochemical method.

This study was conducted to monitor and evaluate microbial contamination during manufacturing process in 6 red pepper powder factories. Red pepper powder samples were taken from manufacturing facilitates, working area and workers’ hands to determine sanitary indicator bacteria (SIB) such as aerobic bacteria and coliform group as well as pathogenic indicator bacteria (PIB) such as Staphylococcus aureus, E.coli, Salmonella spp., Listeria monocytogenes, and Bacillus cereus. The results indicated that SIB in primary materials was detected as low as 3 log units and E.coil and Staphylococcus aureus of PIB were detected. After grinding process, aerobic bacteria, fungi, and coliform group increased 52% and 108%, respectively. In final products, PIB was not detected except for one found Staphylococcus aureus by which workers’ hands were contaminated. Moreover, UV detectors in all the manufacturers were not able to reduce bacteria. Thus, this data suggest that a stringent safety management be needed to prevent cross contamination, and also reconsider effectiveness of facility.

The purpose of this study was to identify control points through microbiological hazard analysis in the manufacturing processes of starch noodles. Samples were collected from the ingredients, manufacturing processes, equipment and environment. Microbiological hazard assessments were performed using aerobic plate counts (APC), Enterobacteriaceae (EB), E. coli and five pathogens including B. cereus, E. coli O157:H7, L. monocytogenes, Salmonella spp., and S. aureus. The APC levels in raw materials were from 2.12 to 3.83 log CFU/g. The contamination levels after kneading were 4.31 log CFU/g for APCs and 2.88 log CFU/g for EB counts. APCs decreased to 1.63 log CFU/g and EB were not detected after gelatinization, but their levels slightly increased upon cooling, cutting, ripening, freezing, thawing, and separating. The reuse of cooling and coating water would be a critical source of microbial increase after cooling. After drying, APCs and EB counts decreased to 5.05 log CFU/g and 2.74 log CFU/ g, respectively, and the levels were maintained to final products. These results suggest that the cooling process is a critical control point for microbiological safety, and the cooling water should be treated and controlled to prevent cross contamination by pre-requisite program.

Quality management activities are an important factor that they could be regarded as a most significant drive to prompt growth of a corporation. From this research as core strategy of the enterprise single ppm wants to emphasize the importance of the quality management activity. The Empirical results are summarized as follows, for successful Single PPM, leadership and corporate culture should be based on. As Single PPM activities factor, Customer Management significantly affects Single PPM Performance. Therefore, to the success of quality management activities, internal corporate leadership and corporate culture must be formed. And for customer management, should take advantage of a variety of the company's internal and external information strategically.