• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.451-458
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• 2005

For the storaging and frying stability in soybean oil, the kind of treating antioxidants were mixed tocopherol and phosphatidyl choline(PC), phosphatidyl ethanolamine(PE), phosphatidyl inpsitol(PI), phosphatidyl serine(PS), phosphatidic acid(PA), phosphatidyl glycerol(PG), treating amounts were 0.03%, 0.05%(w/w), respectively. Acid value(AV), peroxide value(POV) and oxidative stability index(OSI) were determined during storage period at $50^{\circ}C$ in soybean oil. Antioxidation effect at frying condition was determined through changes of smoke point. The antioxidation effect according to AV change was $PA>PC>PI{\geq}PG>PS{\geq}PE$, preventing effect about POV change was PA>PG>PC>PS>PE>PI and preventing effect about OSI decreasing was PI>PC>PA>PG>PS>PE. At the result, antioxidation effect of individual phospholipid components in soybean oil was appeared different result according to determination code. Determination result of preventing effect of SP decreasing according to frying at $180^{\circ}C$ during 20 hours was PA>PC>PG>PE>PI>PS. But treating effect of mixed tocopherol in preventing effect about AV, POV was not. In the case of storage at $50^{\circ}C$ in soybean oil, mixed tocopherol was affected as a kind of pro-oxidant. In OSI had some antioxidation effect, preventing effect of SP decreasing had not. Treatment of mixed tocopherol in soybean oil was undesirable as frying oil.

• Macromolecular Research
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• v.16 no.8
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• pp.686-694
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• 2008

We studied the molecular shapes and structural characteristics of a 33-armed, star polystyrene (PS-33A) and two $3^{rd}$-generation, dendrimer-like, star-branched poly(methyl methacrylate)s with different architectures (pMMA-G3a and PMMA-3Gb) and 32 end-branches under good solvent and theta ($\Theta$) solvent conditions by using synchrotron small angle X-ray scattering (SAXS). The SAXS analyses were used to determine the structural details of the star PS and dendrimer-like, star-branched PMMA polymers. PS-33A had a fuzzy-spherical shape, whereas PMMA-G3a and PMMA-G3b had fuzzy-ellipsoidal shapes of similar size, despite their different chemical architectures. The star PS polymer's arms were more extended than those of linear polystyrene. Furthermore, the branches of the dendrimer-like, star-branched polymers were more extended than those of the star PS polymer, despite having almost the same number of branches as PS-33A. The differences between the internal chain structures of these materials was attributed to their different chemical architectures.

• Proceedings of the Korean Printing Society Conference
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• 2007.11a
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• pp.13-28
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• 2007

Producing printing plate is essential progress to do offset printing. In this Film-less period, the more PS plate becomes extinct, the more the age of the Plate-Making of Exposure declines the place to stand. To do offset printing, the CTP (Computer to Plate) is taking a place of PS plate that covers speed, quality and economical problems. The biggest advantage of using CTP is that laser directly goes to the plate, thus there are no dust from the Plate-Making of Exposure. It is also theoretically able to print 200lpi${\sim}$300lpi as well as print 1751pi, because it has over 2400dpi resolution. The high quality printing could be available inside of the country, if printing machine keeps the optimum condition in offset printing. The CTP has many advantages, however there is a difficulty for the operators to preserve the equipment. The actual circumstance is that they cannot make a decision about how many dots need to be generated, and also it is necessary to know how to establish the setup at RIP on CTP to make the optimum condition output. If offset printing machine keeps the optimum condition, it would be able to print up to high quality printing however it is hard to comment what is the optimum condition for the printing machine. Anyone could say easy subjectively that machine is in the optimum condition, however it is objectively hard to estimate by number. In this research GATF / Plate Test target used to analyze the image and to make numerical value of the optimum condition of the CTP. It also used GATF / The sheep fed test printing 5.0 to know the density of the color representation, dot gain and gray balance for the optimum condition of the print machine. The purpose of this research is to represent the ISO 12647-2 which is the international standard with domestic printing equipments.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.2
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• pp.69-84
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• 2007

Producing printing plate is essential progress to do offset printing. In this Film-less period, the more PS plate becomes extinct, the more the age of the Plate-Making of Exposure declines the place to stand. To do offset printing, the CTP (Computer to Plate) is taking a place of PS plate that covers speed, quality and economical problems. The biggest advantage of using CTP is that laser directly goes to the plate, thus there are no dust from the Plate-Making of Exposure. It is also theoretically able to print $200lpi{\sim}300lpi$ as well as print 1751pi, because it has over 2400dpi resolution. The high quality printing could be available inside of the country, if printing machine keeps the optimum condition in offset printing. The CTP has many advantages, however there is a difficulty for the operators to preserve the equipment. The actual circumstance is that they cannot make a decision about how many dots need to be generated, and also it is necessary to know how to establish the setup at RIP on CTP to make the optimum condition output. If offset printing machine keeps the optimum condition, it would be able to print up to high quality printing however it is hard to comment what is the optimum condition for the printing machine. Anyone could say easy subjectively that machine is in the optimum condition, however it is objectively hard to estimate by number. In this research GATF / Plate Test target used to analyze the image and to make numerical value of the optimum condition of the CTP. It also used GATF / The sheep fed test printing 5.0 to know the density of the color representation, dot gain and gray balance for the optimum condition of the print machine. The purpose of this research is to represent the ISO 12647-2 which is the international standard with domestic printing equipments.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.113-122
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• 2010

Corrosion of prestressing tendons and wire fractures in grouted post-tensioned prestressed concrete bridges have been considered as a serious safety problem. In bridge evaluation the condition of prestressing tendons should be inspected, and if corroded tendons are found, the loss of tendon area should be included when we calculate the ultimate strength. In the previous study, it was evaluated that continuous acoustic monitoring techniques could be considered as a reliable non-destructive method for detecting wire fractures of fully grouted post-tensioned prestressing tendons. In the present study, an experimental test was performed for detecting wire fractures of post-tensioned prestressing tendons which are prestressed lower than current design level. A 10 m prestressed concrete beam was fabricated, which included two tendons prestressed 66 percentage and 40 percentage of tensile strength, respectively. The corrosion of two tendons was induced by an accelerated corrosion equipment and the test beam was monitored by using seven acoustic sensors and a continuous acoustic monitoring system. From each prestressing tendon, two acoustic signals of wire fractures were successfully detected and source locations were estimated within 20 mm error. Based on the test results, it is considered that continuous acoustic monitoring techniques can be applied to detect low-prestressed wire fracture in fully grouted post-tensioned prestressed concrete beams.

• Journal of Biosystems Engineering
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• v.6 no.2
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• pp.9-19
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• 1982

The aim of this study was to improve the startability of the diesel engine at low temperature. The specific objective was to determine the optimum type of precombustion chamber. The eight different types of precombustion chamber and two different types of the cylinder head were designed and tested by $2^7$ factorial experiments with four replications. The lowest starting temperature for first operation, the maximum output, and the specific fuel consumption at full load and overload were checked and analyzed. The results of the study are summarized as follows; 1. The lowest starting temperature was lowered as much as $2.4^{\circ}C$ and the maximum output was increased as much as 0.3 ps with respect to the difference in the relative angle of the main passageway against the piston head from 20 degree to 18 degree. 2. The lowest starting temperature and the maximum out-put were lowered as much as $3.3^{\circ}C$ and 0.3 ps respectively with respect to the difference in the angle of the cylinder head groove from 20 degree to 18 degree. 3. The lowest starting temperature and the maximum out put were lowered as much as $2^{\circ}C$ and 0.2 ps respectively with respect to the difference in the length of the precombustion chamber from 17.5 mm to 15.5mm. 4. There was no significant difference in the startability but the maximum output was increased as much as 0.2 ps with respect to the difference in the diameter of the main passageway from 4.8mm to 4.5mm. 5. The lowest starting temperature was obtained under the condition at 47 degree in the angle of the main passageway and at 18 degree in the angle of the cylinder head groove. The maximum output and the minimum specific fuel consumption was obtained under the condition at 4.5mm in the diameter of the main passageway and at 17.5mm in the length of the precombustion chamber. 6. The angle of the cylinder head groove and the main passageway appeared to the major factors affecting the startability significantly. The interaction between the diameter of the main pass ageway and the length of the precombustion chamber had an significant influence on the maximum output. So it would be recommended to study further on the interaction between two factors mentioned above by expanding their levels. 7. The optimum condition suggested by this study could lower the starting temperature by $6^{\circ}C$ compared to the conventional precombustion chambers.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.3
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• pp.319-329
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• 1996

During the monsoon in Bangladesh, the possibility of preserving wet ($700g\;H_2O$) straw by urea (50 g/kg straw DM) with or without polythene cover has been studied. The quality of preserved straw (PS) in terms of colour, smell and fungal infestation were recorded. Nutritive value of the PS was compared to that of a dry straw (DS) in two separate feeding trials on growing bulls (about 290 kg) without (Expt. 1) or with (Expt. 2) concentrate supplements. Over 96% of the wet straw was excellently preserved for over 5 months when covered with polythene in horizontal heaps (of appx. 4 tons). Whereas only 33% of the straw was well preserved in the uncovered (dome shaped) heaps (of approximately 9.5 tons). Each ton of wet straw costed Tk. 1413 and its preservation cost incurred Tk. 345. Urea preservation increased the crude protein content (95 vs. 50 g/kg), dry matter (DM) degradability at all (8, 16, 24, 48, 72 and 96) hours of incubation and at 48 hours, DM degradability (%) were 45 and 25 respetively for the PS and the DS. When fed alone, DM intake (75 vs. $106g/kg\;W^{0.75}/d$), total microbial N yield (27 vs. 54 g/d) and growth rate (-379 vs. 283 g/d) were higher (p < 0.01) in the PS than the DS. Supplementation of concentrate reduced the straw DM intake both in the DS ($51g/kg\;W^{0.75}/d$) and the PS ($958g/kg\;W^{0.75}/d$), but the substitution rate (SR%) was higher in the PS (42) than the DS (27). Higher substitution rate was probably responsible for the reduction in the differences between the DS and PS in their nutrient digestibilities, total microbial N yield (62 vs. 64 g/d) and growth rate(669 vs 339 g/d) when supplemented with concentrate. On 28th day of Expt. 2, feeding PS from one of the polythene covered heaps resulted nervous disorder due to unknown reason(s). Further studies on the effect of size and shape of heap on the preservation quality need to be determined.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.479-485
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• 2008

Porous $TiO_2$ nanostructured particles containing both mesopores and macropores were fabricated by utilizing an aerosol templating method from two kinds of starting materials (colloidal mixture of $TiO_2$ nanoparticles and PS particles, and that of TTIP solution and PS particles). The effects of mixing ratio of PS to $TiO_2$ and reactor temperature on the particle properties were investigated. When $TiO_2$ nanoparticles were used as starting materials, the increase of macropores number was observed by SEM and the specific surface area and total pore volume were increased from $31.6m^2/g$ to $39.1m^2/g$ and $0.068cm^3/g$ to $0.089cm^3/g$, respectively, by increasing the weight mixing ratio of $PS/TiO_2$ from 0.79 to 1.31. When TTIP was used as precursor, the specific surface area and mesopore volume of particles prepared at same condition decreased by 67% and 75%, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.3
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• pp.107-113
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• 1989

The purpose of this study is to compare the results of shear-deformation of saturated sand under the 3 dimensional stress with the results of simple torque-shear test already reported, Japaness standard sand, Toyoura sand, was chosen as test sample and the equipments of the department of soil mechancis laboratory of Nihon University were used. The conclusions obtained are as follows. 1). The friction angle of sand (${\phi}$) is proportional to the density regardless of the condition of stress-strain. This is because of the reason that the lower the cell pressure becomes, the larger the volume changes in case of the same density. 2). The value of ${\varphi}$ are variable according to the condition of stress-strain in the same density, and ${\phi}_dTS$ is larger than ${\phi}_dPS$ and ${\phi}_dTC$ when cell pressure is low. 3). ${\phi}_dPS$ is larger then ${\phi}_dTS$, under the same denstiy and same cell pressure. Thus the shear strength of sand is decided according to the condition of stress-strain 4). the relationship between the stress ratio (q/p) and strain increment ration in the plane strain test is linear regardless of the density and the cell pressure of the test sample.

• Journal of Conservation Science
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• v.31 no.2
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• pp.87-94
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• 2015

Plastic artwork can be appeared crack, change of color and whitening event by various environment conditions. A large scale plastic artwork often exhibits in outside it will be directly degraded by physical and chemical degradation factor such as strong sunlight, high humidity and rainfall. We should know degradation characteristic of plastics to prevent these damages. In this study, we studied degradation characteristic of plastics (5 types of wide use plastics; polypropylene, polystyrene, polyethylene, polyvinyl chloride, polyurethane) depending on various artificial degradation conditions such as high temperature, ultraviolet and these complex conditions (high temperature and ultraviolet). As a result, polypropylene, polystyrene and polyethylene show the most visible change especially polypropylene, polystyrene. Polypropylene didn't show a great change degree of tensile strength and contact angle, on the other hand polystyrene did. Polypropylene and polystyrene weakened by photo degradation, polyvinyl chloride and polyurethane had relatively good light stability. Also the high temperature and complex conditions were most degradation characteristic. High temperature worked for degradation catalyst because its energy can not enough worked for cut off binding energy of plastics while ultraviolet condition effected as directly degradation condition. Though following results, we expect it can be applied to investigation of degradation factor depending on plastic artwork materials and basic result of plastic artworks conservation.