• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.263-269
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• 1992

Radish green juice was used as a dual source for the production of plant protein precipitate and Candida utilis biomass. Precipitates ranging from 10.0 to 16.5g were obtained from a liter of radish green juice by heating at 80-10$0^{\circ}C$C for 1 to 10 min or by modification of the pH of radish green juice. Crude protein content of the precipitate was between 25 and 38%. The residue remaining after protein precipitation was used in turn for the cultivation of the yeast, C. utilis, in order to produce yeast biomass. C. utilis grew well in radish green residual juice and completed growth within 24 hr at 3$0^{\circ}C$ and 200rpm in shake flask experiments. Maximum dry cell weight obtainable from a liter of radish green residual juice was 19.5g, when the yeast was grown on the juice residue diluted 3 times or more with water to make sugar content be equal to or less than about 1.0%. Supplementation of 3-fold diluted radish green residual juice with yeast extract and (NH$_4$)SO$_4$ enhanced yeast biomass production and cell protein content significantly. Total high protein material obtainable from a liter of radish green juice was 33.0g.

• Journal of the Korean Institute of Rural Architecture
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• v.18 no.1
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• pp.19-28
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• 2016

This research aimed to suggest a standard design that reflects Hanok design tendency, and present a selective design that can fulfill a building owner's intention beyond the simple function of building permit or report. In addition, this research attempted to become a standard by establishing a criterion in calculating the measurements of section design or primary framework members, in order to be a guideline for designing Hanok in different sizes and forms. The results are as follows. The building area of Hanok standard design was set to be below $85m^2$, with a straight type of $83.16m^2$ and an L-shape of $84.24m^2$. By dividing the plane into a straight type and L-shape, two straight types were suggested: 'general type' and 'large living room type.' The upper floor space, along with the main room and small room, was proposed as an option to be changed into a room where an underfloor heating is installed depending on the building owner's intention. In addition, a criterion for side design and calculation of framework measurements was suggested and applied, while a five-girder design without high pillars was suggested for material-assembling structure. Two types of pillars-circumference and square cylinder-were proposed for the building owner to choose from, and a pointed beam house and ikgong(orthogonally-projected bracket) house were suggested for pojak bracket structure so either of them could be chosen according to the building owner's taste and economic condition. Finally, the sectional size of main materials were divided according to the form of pojak bracket structure to be proposed.

• Electrical & Electronic Materials
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• v.7 no.2
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• pp.138-144
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• 1994

Electrical conduction phenomena of $C_{22}$-quinolium(TCNQ) Langmuir- Blodgett(LB) films are reported through a study of current-voltage(I-V) characteristics along a perpendicular direction. The I-V characteristics were investigated by applying a step or a pulse voltage to the specimen as well as changing temperatures in the range of 20-250[.deg. C] It show an ohmic behavior in low-electric field, and a nonohmic behavior in high-electric field. This nonohmic behavior has been interpreted in terms of a conduction mechanism of space-charge limited current and Schottky effect. When the electric field is near the strength of 10$_{6}$ V/cm, there occur anomalous phenomena similar to breakdown. When step or pulse voltage is applied, the breakdown voltage shifts to the higher one as the step or pulse time width becomes shorter. To see the influence of temperature, current was measured as a function of temperature under the several bias voltages, which are lower than that of breakdown. It shows that the current increases to about 103 times near 60-70[.deg. C], and remains constant for a while up to around 150[.deg. C] and then suddenly drops. We have also performed a DSC(differential scanning calorimetry) measurement with $C_{22}$-quinolium(TCNQ) powder in the range of 30-300[.deg. C]. These results imply that the anomalous phenomena occuring in the high electric field are caused by the electrical and internal thermal effect such as a joule heating.ating.

• Journal of the Korean Home Economics Association
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• v.47 no.7
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• pp.13-32
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• 2009

The purpose of this study was to analyze the state of housing and domestic living conditions of Vietnamese individuals in Vietnam and Korea. Using ethnographic methodologies, It was examined examined 22 Vietnamese households in Korea in relation to their usage of domestic space and also conducted the same investigation on 20 Vietnamese households in Vietnam. The following conclusion were established; 1) The majority of households in both countries preferred that the kitchen was close to the dining room and living room while a kitchen door was not deemed as necessary. 2) In Korea, washing machines are used in the bathroom space, while in Vietnam they are used outside or in a specially designated space. 3) The most uncomfortable aspect of home life in Korea was having the bathroom and toilet in the same space while in Vietnam they are separately spaced. It is recommended that house plans with separate bathroom and toilet area be made available for Vietnamese migrants. 4) Chairs were used in the sleeping area for eating, especially if guests were present, but the floor space was also used for eating. 5) Tile is a typical floor material in Vietnam while vinyl is popular in Korea. However, migrant workers were comfortable with both materials. 6) All 20 households didn't have any heating system in Vietnam but most migrants preferred a modified Ondol in Korea. 7) Most migrants took their shoes off while inside the house in Vietnam and Korea. Furthermore, the majority of households didn’t have any designated shoes space at the entrance to the house in Vietnam and most were satisfied with the same situation in korea. 8) Most households in Vietnam and Korea preferred to decorate their living room with various things or as a place of worship to their ancestors. The direction of house was an important element when deciding to buy or building houses in both countries.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.2
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• pp.145-153
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• 1984

In the present work, a computer simulation is performed employing Hottel-Whillier-Bliss model for thermal performance of solar collectors. The major collector parameters examined in the computer simulation are: number of transparent glass covers(N), thermal emissivity of the absorbing plate surface (.epsilon.$_{P}$), absorptivity of absorber plate (.alpha.$_{p}$), flow rate per unit area of collector (G), $L_{b}$ / $k_{b}$ of insulation material, tilt angle of collector (S), and solar insolation(I). By varying numerical values of the major collector parameters around their typical values, the corresponding variations in thermal efficiency curves are examined. In addition, an experimental investigation has been carried out with a slightly modified KAIST collector test loop under a real sun condition in order to compare with the simulation results, examine the applicability of the mathematical model of the collector thermal performance, and study the effect of variation of flow rate (G) on thermal efficiency and the range of optimum flow rate.e.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.62-72
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• 2015

Interest in three-dimensional (3D) printing processes has grown significantly, and several types have been developed. These 3D printing processes are classified as Selective Laser Sintering (SLS), Stereo-Lithography Apparatus (SLA), and Fused Deposition Modeling (FDM). SLS can be applied to many materials, but because it uses a laser-based material removal process, it is expensive. SLA enables fast and precise manufacturing, but available materials are limited. FDM printing's benefits are its reasonable price and easy accessibility. However, metal printing using FDM can involve technical problems, such as suitable component supply or the thermal expansion of the heating part. Thus, FDM printing primarily uses materials with low melting points, such as acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) resin. In this study, an FDM process for enabling metal printing is suggested. Particularly, the nozzle and heatsink for this process are focused for stable printing. To design the nozzle and heatsink, multi-physical phenomena, including thermal expansion and heat transfer, had to be considered. Therefore, COMSOL Multiphysics, an FEM analysis program, was used to analyze the maximum temperature, thermal expansion, and principal stress. Finally, its performance was confirmed through an experiment.

• Journal of the Korean Chemical Society
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• v.21 no.5
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• pp.379-383
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• 1977

Since the organophilic bentonite disperses well in polymer matrix, a composite material of polymer and bentonite was studied for its mechanical properties. To increase the degree of dispersion and the bond in forces to the polymer matrix, bentonite, encapsulated by imidazoline, was used as a filler. Polyethylene powder of particle size of 100 mesh was used, and organophilic bentonite, so-called bentone, whose particle size was 250 mesh was also used in this experiment. V-type mixer was used for mixing and Banbury mixer was used for melt-blending. The sample specimen were made by heating the mixture in the plate press, and the specimen were formed as a sheet, exactly the same as the mold on the plate. Tensile strength, bending strength and compressive strength were studied specially. Tensile strength, elongation rate, bending strength and bending rate at constant pressure were decreased as the filler content increased. Compressive strength was increased as the filler content increased.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.220-221
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• 2003

Equiatomic FePt and CoPt alloy thin films have received considerable attention as possible magnetic and magneto-optic recording because of their high magnetic anisotropy energy and high coercivity. The high coercivity in these thin films is due to the presence of finely dispersed ordered FePt phase mixed with disordered FePt phase. However, a high temperature treatment, either substrate heating during deposition or post annealing, is needed to obtain the ordered L1$\_$0/ phase with high value of magneto crystalline anisotropy. Recent microstructural studies on these films suggest that the average grain size ranges from 10-50 nm and the grains are magnetically coupled between each other. On the other hand, the ultrahigh-density magnetic recording media with low media noise imposes the need of a material, which consists of magnetically isolated grains with size below 10 nm. The magnetic grain isolation can be controlled by the amount of additional non-magnetic element in the system which determines the interparticle separation and therefore the interparticle interactions. Recently, much research work has been done on various non-magnetic matrices. Preliminary studies showed that the samples prepared in B$_2$O$_3$ and Carbon matrices have shown strong perpendicular anisotropy and fine grain size down to 4nm, which suggest these nanocomposite films are very promising and may lead to the realization of a magnetic medium capable of recording densities beyond 1 Tb/in$^2$. So, in this work, the effect of Carbon doping on the magnetic properties of FePt nanoparticles were investigated.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.123-128
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• 2004

Numerous novel ingredients have been introduced for the higher functionality of whitening cosmetics. Through the preliminary research, we have found Trichosanthes kirilowii root, Prunella vulgaris leaf and Clematis chinensis root have high whitening efficacy. But they are insoluble. Moreover the discoloration of and decrease in content take place when they are exposed to light, heat or oxygen. From Trichosanthes kirilowii root, Prunella vulgaris leaf and Clematis chinensis root, efficacious ingredients were ethanol-extracted by heating to 75∼85$^{\circ}C$ for 6∼8 h. These extracts have the inhibitory activity of tyrosinase and B16 melanin formation, thus enhancing whitening effect. We made liposomes using propylene glycol (PG)/hydrogenated lecithin/middle chain triglycerides (MCT)/glycerin/water and microfuidizer to stabilize extracts. The stability against heat and light was enhanced by 3∼5 times compared with untreated extracts. Particle size analyzer, freeze fracture transmission electron microscopy (FF-TEM), chromameter and HPLC are used for the analysis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.130-139
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• 2016

The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.