검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 4,677

        1781.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1782.
        2013.02 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1783.
        2013.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1784.
        2013.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1785.
        2013.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1786.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1787.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        (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.
        4,000원
        1788.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1789.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1790.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        1791.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,200원
        1792.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It seems most important for a manufacturing company to be well aware of its relationship with suppliers. This is why it is essential to analyze and control the structural relationship among CEO's characteristics, relations between suppliers and manufacturers and new product development performances affected by such relations. The present study may be summed up as follows: First, from the analysis of characteristics of manufacturing company's CEO and relations between suppliers and manufacturers, it could be verified that CEO's characteristics exercised influence upon sharing of product development process and upon cooperation for technical manpower, but not upon sharing of core technologies, signifying the fact that nothing could be more important than the role of CEO who has strong will to improve his or her relations with suppliers; and Second, from the analysis of relations between suppliers and manufacturers as well as relations between management and new product development performances, it became evident that both management performance and product development performance were affected by sharing of product development process. It was also known that cooperation for technical development process had influence upon the product development performance but not upon the management performance. Furthermore, the analysis showed that both management performance as well as product development performance were affected by sharing of core technologies.
        4,300원
        1793.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According to result of this paper, shipping companies tend to choose a third party logistics company that is able to provide consulting services that is the core of the administration of distribution. Shipping companies expect that the consulting services would be able to increase the efficiency through utilizing not logistics functions of shipping, unloading, storage, and information but performance indices of logistics activities. Because shipping companies generally regard that third party logistics not only has no expertise but also is small, in order to activate third-party logistics industry, the consulting services should be improved.
        4,000원
        1794.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed in order to determine the processing conditions (pre-drying at room temperature for 0 or 30 min, frying at 160℃ for 1 min or at 180℃ for 40 sec, and soaking for 0~24 h) of Sasambeong recorded in the “Sumunsasul”. The Sasambeong was evaluated for crude lipid content, hardness, Hunter’s color values, and sensory characteristics. After pre-drying at room temperature for 30 min, the crude lipid contents and hardness of Sasambeong were significantly increased. In addition, the crude lipid content and hardness of Sasambeong did not differ significantly according to the frying conditions. After pre-drying, the sensory characteristics of Sasambeong showed more improvement. The crude lipid content, hardness, Hunter’s color values, and sensory characteristics of Sasambeong, which were prepared according to different soaking times (0, 6, 12, or 24 hr) were investigated. As soaking time increased, the crude lipid content and hardness of Sasambeong decreased with a range of 25.43~24.31% and 525.90~388.98 g, respectively. The sensory characteristics of Sasambeong showed no significant difference according to the soaking time. Overall, we think that the best processing conditions of Sasambeong were pre-drying at room temperature for 30 min and then frying at 160℃ for 1 min.
        4,000원
        1795.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to produce Hongkuk-ju, the production and characterization of Hongkuk (Monascus red koji) by Monascus anka KCTC 6121 were investigated. The optimum cultural conditions for the production of enzyme (α-amylase and glucoamylase) and pigment (yellow and red) from this strain on solid culture (steamed rice) were examined. The results showed that the production of α-amylase and glucoamylase reached the highest for 9 days and 8 days, respectively. Since then, the productions decreased slightly. The production of yellow and red pigments reached the highest for 8 days, decreasing slightly soon after. The optimal content of the initial moisture equally presented 30% in the enzyme and pigment production. After that, the enzyme production decreased slowly, whereas pigment production decreased sharply. The optimal temperature of the culture also showed 30℃ in the production of enzyme and pigment. It was found that the initial inoculum size in enzyme and pigment production was 10% and 20%, respectively. Under these optimal conditions, the production of monacolin K and citrinin was 74.35 ㎎/㎏ and 5 ㎎/㎏ for 12 days, respectively.
        4,000원
        1796.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sulgidduk is a kind of basic steamed rice cake in Korea. Multifunctional portable grinder was used for making sulgidduk and investigated the characteristic changes of rice powder for deciding the proper particle size of rice powder. Operation times for grinding the water absorbed swelled rice were 10, 20, 30 and 40 seconds. Moisture contents of rice powder and sulgidduk showed an increasing tendency with an increase of operation times for grinding. Springiness showed significant differences according to the operation times. Cohesiveness was decreased severely after 40 seconds grinding. Chewiness showed high after 20 seconds grinding in all groups; however, decreased after 40 seconds grinding and showed similar chewiness of the control group. Fracturability also showed severe increased tendency after 20 seconds grinding and decreased after 30 seconds grinding. Strength and hardness showed significant differences; they were increased until 30 seconds and severely decreased after 40 seconds grinding. L values showed significant differences in all the groups (p≤0.05). The a and b values did not show any differences in all groups. Overall sensory evaluations, such as colors, flavors and texture, were increased with operation times for grinding and showed significant differences among the groups (p<0.05). As a result of this study, 40 seconds grinding times were the best condition for making sulgidduk, using by multifunctional grinder.
        4,000원
        1797.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the optimum mixing ratio of Opuntia humifusa powder and sugar in the preparation of muffin. The optimal sensory composite recipe was determined by following the central composites for muffin with different levels of Opuntia humifusa powder (A) and sugar (B). The analysis was performed using the response surface methodology, and the sensory evaluation was performed with the data. Ten experimental recipes, including two with reference points in the composition, were selected. The compositional and functional properties were measured, and the physical and sensory values were applied to the mathematical models. Perturbation plots showed the effects of each ingredient on the final product. Measurements showed significant values in lightness (p<0.05), sweetness (p<0.05), hardness (p<0.05), gumminess (p<0.05) and cohesiveness (p<0.01). The sensory measurements showed significant values in color (p<0.05), flavor (p<0.05), appearance (p<0.05), softness (p<0.05) and overall quality (p<0.05). Based on the numerical and graphical methods, the optimal formulation was determined to be 6.10 g of Opuntia humifusa powder and 82.61 g of sugar.
        4,200원
        1798.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of 120℃ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.
        4,000원
        1799.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This is a basic study of Cheong-song mineral water, which has high contents of Ca and Mg for making noodles as well as for general cooking. The test results of the noodles manufactured and cooked with mineral water were compared to those manufactured and cooked with distilled water and tap water. Noodles manufactured with mineral water showed higher values than others in the cooked weight, volume, water absorption ability, turbidity, lightness (L) and redness (a) on the minus scale. This means that we can manufacture cooked noodles that have high weight, high volume, high water absorption ability and high lightness (L) along with a slight green color with Cheong-song mineral water. Cooked noodles manufactured with mineral water showed significant differences in the cooked weight and volume compared to those manufactured with distilled water. Also, cooked noodles manufactured with mineral water showed significant differences in moisture absorption, turbidity, lightness (L), redness (a) and yellowness (b) compared to those manufactured with distilled water and tap water. Commercial noodles cooked in mineral water showed significant differences in the cooked weight and redness (a) compared to those cooked in distilled water and tap water. Further, commercial noodles cooked in mineral water showed significant differences in weight, volume and brightness (L) compared to those cooked in distilled water.
        4,000원
        1800.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the antioxidative effects of Opuntia humifusa and determine the optimal mixing ratio of Opuntia humifusa powder and eggs for the preparation of pasta. In regard to its antioxidant effects, Opuntia humifusa powder had a total phenolic content and DPPH free radical scavenging activity of 6.64 mg/g and 90.12%, respectively. We used response surface methodology to obtain ten experimental points (including two replicates for Opuntia humifusa powder and egg) and Opuntia humifusa pasta formulation was optimized using rheology. Yellowness (p<0.001) displayed a linear model pattern, whereas lightness (p<0.01) and redness (p<0.01) were described by a quadratic model pattern. Mechanical properties showed significant values in hardness (p<0.5), chewiness (p<0.5), gummiess (p<0.5), and cohesiveness (p<0.5). The sensory evaluation parameters showed significant differences in color (p<0.5), appearance (p<0.5), flavor (p<0.5), texture (p<0.5) and overall quality (p<0.5). The optimum formulations processed by numerical and graphical optimization were found to be 7.30 g of Opuntia humifusa powder and 31.55 g of egg.
        4,000원