ISO 9001, quality management system, is widely known as advancing internal efficiency and productivity in various industry. As a result, the number of companies that have adopted ISO 9001’s certification have been increasing continuously year by year since ISO 9000’ family standard was published in 1987s. This fact shows that a lot of businesses are trying to get the accreditation for improving the competitiveness of quality. The purpose of this study is to present that ISO 9001’s certification motives affect to the requirement’s implementation and show that the execution of requirements influences on management performance in the small manufacturer. In order to carry out this research, we obtained 96 survey sheets and inspected twenty assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factors of certification motive influence on the requirement’s implementation except resources management. Second, the two elements of ISO 9001 requirement, resources management and product realization, have an important effect on the operational performance and financial performance considerably in the companies that choose the internal motive. Finally, the two requisites of ISO 9001 requirement, resources management and measurement, analysis and improvement, affect to the operational performance and financial performance significantly in the businesses that select the external motive. Based on the results, the companies that choose the internal motive have a good performance to execute the ISO 9001 requirements. Also, to implement the requirements of ISO 9001 is helpful for the companies to produce the operational and financial performance.
This study attempted to find an efficient method for the preparation of high-purity galactooligosaccharides (HP-GOS) using β-galactosidase and yeast fermentation. GOS prepared using Lactozym 3000L showed the greatest enhancement in total GOS of the six β-galatosidases tested. GOS alone achieved 51% conversion of initial lactose. GOS production was enhanced by fermentation with commercial yeast (Saccharomyces cerevisiae); its concentration reached 71% after 36h fermentation with 8% yeast. Component sugar analysis with HPLC indicated that HP-GOS fermented with S. cerevisiae showed significantly increased levels of 4’/6’-galactosyllactose and total GOS as well as a significantly decreased glucose level. HP-GOS facilitated the growth of Lactobacillus sp. (L. acidophilus and L. casei) and Bifidobacterium sp. (B. longum and B. bifidum). In sum, high-purity GOS has been successfully produced through both an enzymatic process and yeast fermentation. GOS encourages the growth of bacteria such as Lactobacillus and Bifidobacterium that may be beneficial to human gastrointestinal health.
본 연구에서는 이산화탄소와 석탄을 사용하여 합성가스 CO를 생산하는 실험을 수행하였다. CO 합성특성은 KOH 촉매를 사용한 화학적 활성화 방법에 의해 조사되었으며, 제조공정은 CO2 전환 반응에서 석탄과 활성화 촉매 비율, 가스 유량과 반응온도 등과 같은 실험변수들을 분석함으로서 최적화 되었다. KOH 촉매를 사용하지 않은 경우, 반응온도 950℃와 CO2 유량 300 cc/min에서 65% CO2 전 환율을 얻었으며, 반면에 촉매를 사용한 경우 같은 반응조건에서 98.1%의 전환율을 얻었다. 석탄의 활 성화촉매 반응물의 비(석탄 : KOH = 4 : 1)가 다른 반응물 비에 대해 더 좋은 CO2 전환율과 CO 선 택도 보여줌을 알 수 있었다.
본 연구는 웰빙(well-being)으로 각광받고 있는 천연물 관련 연구에 무화과 추출물의 활용 가능 성을 확인하고자 다음의 연구를 수행하였다. 무화과를 세척 건조하여 알코올추출 방법으로 추출한 후, Column chromatography, G-Mass, IR, 1H-nmr 방법에 의하여 무화과 추출물의 이화학적 성질을 분석하 였으며, 무화과 추출물을 두피 제품에 적용하기 위하여 항균, 항진균에 대한 항균성을 조사하였다. 무화과 추출물의 이화학적 분석은 열매와 잎으로 나누어 분석하였으며, 두 부분 모두 비듬과 피부병 치료 효능을 가진 항균 및 항진균 효능이 있음을 알 수 있었다. 또한 무화과 추출물에 대한 항균성은 액체배지 희석법에 의해 분석하였다. 그리고 소비자의 구매 욕구를 충족시키고, 무화과의 산업화 타당성을 검토하기 위하여 무화과 추출물 함유 수제 투명 및 고형 비누를 제조하여 타당성을 검토하였다.
본 연구에서는 높은 이산화탄소 분리성능을 가지는 폴리이미드의 제조를 위해 2,2-bis(3,4-carboxylphenyl) hexafluoropropane과 두종류의 아민인 2,3,5,6-tetramethyl-1,4-phenylenediamine, Poly(ethylene glycol) bis(3-aminopropyl) terminated을 이용하여 합성을 진행하였다. 합성된 고분자를 비용매 상전이법으로 비대칭 분리막을 제조하기 위하여 고분자의 용 해도 지수 추정 값과 비용매 상전이 계수 측정을 통해 용매를 선정하였고, 고분자 용액 점도 측정을 통해 분리막 제조를 위 한 도프용액 중의 고분자의 함량을 결정하여 질산리튬을 첨가제로 사용하여 최종적으로 분리막을 제조하였다. 제조된 평판형 비대칭 분리막은 전자주사현미경(SEM)을 통해 질산리튬과 휘발성 용매 함량에 변화에 따른 모폴로지의 변화를 확인하였으 며, 이의 변화에 따른 기체 투과도 변화를 확인하였다. 분리막 제조를 위한 도프용액 중의 휘발성 용매 함량이 작을수록 선택 도 변화가 없으면서 이산화탄소 투과도가 증가하는 것을 확인하였다.
폴리설폰막 위에 친수성 고분자를 Layer-by-Layer법으로 코팅하여 복합막을 제조하였다. FE-SEM 분석을 통하여 복합막 표면과 기공 내 코팅층을 확인하였다. 또한 100 ppm NaCl 용액에 대한 복합막의 투과성능 평가를 실시하였다. 복합 막 제조를 위한 코팅 고분자는 PVSA, PEI, PAA, PSSA, PSSA_MA를 사용하였다. 폴리설폰막 표면에 8,000 ppm PAA (이 온세기 0.35) 수용액을 3분 동안 코팅한 뒤 10,000 ppm PEI 수용액을 4분 동안 코팅하였다. 그 결과 PAA-PEI 복합막의 투과 도는 101 LMH, 제거율은 66.7%로 가장 좋은 투과성능을 나타내었다. PAA-PEI 복합막의 투과성능은 도레이케미칼의 NE 4040-70 (투과도 = 30 LMH, 염 배제율 = 40~70%) 제품과 유사한 성능을 보여주는 우수한 투과 특성을 나타내었다.
태양광 발전시스템은 태양복사에너지를 반도체의 광전효과를 이용하여 전기에너지로 직접 전환시키는 에너지변환 시스템이다. 태양전지의 내구성과 에너지변환율에 영향을 미치는 핵심소재로는 다층형 필름구조를 갖는 백시트를 들 수 있다. 대표적인 상용 백시트는 고내구성 poly(vinyl fluoride) (PVF) 필름이 중심축에 위치하고 가격저감을 위해 도입된 poly(ethylene terephthalate) (PET) 필름이 그 양쪽에 접합된 삼층구조로 구성된다. 하지만, PVF 필름의 높은 가격은 저렴한 고내구성 백시트 를 요구하는 시장상황을 반영하기 어렵게 한다. 이를 위한 해결책으로는 PVF 필름을 결정성 PET 필름으로 대체한 탄화수소계 백시트가 될 수 있다. 하지만, PET 필름의 본질적인 가수분해에 대한 취약성으로 인해, 추가적인 수분에 대한 배리어성 부여 는 필수적이다. 이를 위해 본 연구에서는 소수성 실리카 나노입자 분산기술을 활용한 수분차단성 폴리우레탄 접착제를 개발 코자 하였다. 개발된 접착제는 내부에 위치한 PET 필름으로의 수분침투를 약화시켜, 가수분해속도를 지연시킬 것이라 기대 되었다. 본 개념의 효용성을 확인하기 위해, 표준화된 온습도조건에 노출된 이후의 일반접착제와 수분차단성 접착제가 도입 된 백시트의 기계적 강도 및 시간당 태양전지성능 변화가 비교평가되었다.
상업적으로 이용되는 폴리스티렌계 이온교환막은 제조 공정이 쉽고 간단하지만 막이 가지는 취성 때문에 내구성이 약하다는 단점을 가지고 있다. 이를 보완하기 위하여 친수성 그룹인 poly(ethylene glycol)을 곁사슬로 가지고 있는 poly(ethylene glycol)methyl ether methacrylate를 공중합시켜 음이온 교환막을 합성하였다. 지지체로는 내화학성 및 기계적 강도가 우수한 다 공성 PE 지지체를 사용하였고, 여기에 다양한 조성의 vinylbenzyl chloride, styrene, poly(ethylene glycol)methyl ether methacrylate, divinylbenzene, benzoyl peroxide를 녹인 단량체 용액을 지지체 기공에 채운 뒤 열중합 가교시켜 trimethylamine을 이 용하여 음이온 교환기를 도입해 세공충전 음이온 교환막을 합성하였다. 또한 poly(ethylene glycol)methyl ether methacrylate의 곁사슬 길이와 각 단량체가 차지하는 비율의 변화가 음이온 교환막의 전기화학적 특성에 미치는 영향을 알아보았다.
Porous thick film of alumina which is fabricated by freeze tape casting using a camphene-camphor-acrylate vehicle. Alumina slurry is mixed above the melting point of the camphene-camphor solvent. Upon cooling, the camphene- camphor crystallizes from the solution as particle-free dendrites, with the Al2O3 powder and acrylate liquid in the interdendritic spaces. Subsequently, the acrylate liquid is solidified by photopolymerization to offer mechanical properties for handling. The microstructure of the porous alumina film is characterized for systems with different cooling rate around the melting temperature of camphor-camphene. The structure of the dendritic porosity is compared as a function of ratio of camphene-camphor solvent and acrylate content, and Al2O3 powder volume fraction in acrylate in terms of the dendrite arm width.
The en-riched 58Ni powders are dissolved in acid solution and coated on a Cu target for proton irradiation at cyclotron to produce 57Co radioisotope. The condition of the plating bath and the coating process are determined using the en-riched powders. To establish the coating conditions for 57Co, non-radioactive Co ions are dissolved in an acid solution and electroplated on to a rhodium plate. The thermal diffusion of electroplated Co into a rhodium matrix was studied to apply a 57Co Mssbauer source. The diffusion depth from surface to matrix of Co is depended on the annealing temperature and time. The deposited Co atoms diffuse completely into a rhodium (Rh) matrix without substantial loss at an annealing temperature of 1200 for 4 hours.
Microstructural examination of the Nb-Si-B alloys at Nb-rich compositions is performed. The Nb-rich corner of the Nb-Si-B system is favorable in that the constituent phases are Nb (ductile and tough phase with high melting temperature) and T2 phase (very hard intermetallic compound with favorable oxidation resistance) which are good combination for high temperature structural materials. The samples containing compositions near Nb-rich corner of the Nb- Si-B ternary system are prepared by spark plasma sintering (SPS) process using T2 and Nb powders. T2 bulk phase is made in arc furnace by melting the Nb slug and the Si-B powder compact. The T2 bulk phase was subsequently ballmilled to powders. SPS is performed at 1300oC and 1400oC, depending on the composition, under 30 MPa for 600s, to produce disc-shaped specimen with 15 mm in diameter and 3 mm high. Hardness tests (Rockwell A-scale and micro Vickers) are carried out to estimate the mechanical property.
Lanthanum zirconate, La2Zr2O7, is one of the most promising candidates for next-generation thermal barrier coating (TBC) applications in high efficient gas turbines due to its low thermal conductivity and chemical stability at high temperature. In this study, bulk specimens and thermal barrier coatings are fabricated via a variety of sintering processes as well as suspension plasma spray in lanthanum zirconates with reduced rare-earth contents. The phase formation, microstructure, and thermo-physical properties of these oxide ceramics and coatings are examined. In particular, lanthanum zirconates with reduced rare-earth contents in a La2Zr2O7-4YSZ composite system exhibit a single phase of fluorite or pyrochlore after fabricated by suspension plasma spray or spark plasma sintering. The potential of lanthanum zirconate ceramics for TBC applications is also discussed.
The organic binder-free paste for dye-sensitized solar cell (DSSC) has been investigated using peroxo titanium complex. The crystal structure of TiO2 nanoparticles, morphology of TiO2 film and electrical properties are analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectra (EIS), and solar simulator. The synthesized TiO2 nanopowders by the peroxo titanium complex at 150, 300, 400˚C, and 450˚C have anatase phase and average crystal sizes are calculated to be 4.2, 13.7, 16.9, and 20.9 nm, respectively. The DSSC prepared by the peroxo titanium complex binder have higher Voc and lower Jsc values than that of the organic binder. It can be attributed to improvement of sintering properties of TCO/TiO2 and TiO2/TiO2 interface and to formation of agglomerate by the nanoparticles. As a result, we have investigated the organic binder-free paste and 3.178% conversion efficiency of the DSSC at 450˚C.
We report on the successful fabrication of ZnO nanorod (NR)/polystyrene (PS) nanosphere hybrid nanostructure by combining drop coating and hydrothermal methods. Especially, by adopting an atomic layer deposition method for seed layer formation, very uniform ZnO NR structure is grown on the complicated PS surfaces. By using zinc nitrate hexahydrate [Zn(NO3)2 ·6H2O] and hexamine [(CH2)6N4] as sources for Zn and O in hydrothermal process, hexagonal shaped single crystal ZnO NRs are synthesized without dissolution of PS in hydrothermal solution. X-ray diffraction results show that the ZnO NRs are grown along c-axis with single crystalline structure and there is no trace of impurities or unintentionally formed intermetallic compounds. Photoluminescence spectrum measured at room temperature for the ZnO NRs on flat Si and PS show typical two emission bands, which are corresponding to the band-edge and deep level emissions in ZnO crystal. Based on these structural and optical investigations, we confirm that the ZnO NRs can be grown well even on the complicated PS surface morphology to form the chestnut-shaped hybrid nanostructures for the energy generation and storage applications
This research was conducted to evaluate the physicochemical properties of semi-dried jerky made from uncastrated (U) and castrated (C) deer meat. The jerky was manufactured by mixing the ground lean meat with spices followed by drying process, packed and stored aerobically at 25℃ for 20 days. The pH of uncastrated raw meat was significantly (p<0.05) higher than that of castrated meat as well as the pH of the jerky. No effects were found on color, hardness and sensory scores of jerky. Castrated jerky had higher fat content than uncastrated jerky (p<0.05), after 20 days of storage, its TBARS (thiobarbituric acid reactive substances) value was higher than uncastrated jerky (p<0.01). These results suggest that castration contributed to higher fat content and lipid oxidation of semi-dried venison jerky than the uncastrated, without any significant effects on texture and sensory attributes. However, proper packaging should be considered to inhibit lipid oxidation.