• Polymer(Korea)
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• v.32 no.5
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• pp.497-500
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• 2008

Polystyrene foam (styrofoam) was treated with low-temperature oxygen plasma by means of immobilization and grafting techniques in order to modify its hydrophobic surface property to hydrophilic one using hydrophilic monomers of acrylic acid and acrylamide, and its surface chemical structure, morphology, and hydrophilicity were examined by ESCA, field emission scanning electron microscope (FESEM), and contactangle meter. The experimental evidences, such as the increases of O/C and N/C ratios in ESCA spectrum, thin film deposition, decrease in contact-angle, strongly suggested that the plasma treatments were useful methods for the preparation of hydrophilic surface. Contact angle diminished drastically from $84^{\circ}$ to $18{\sim}19^{\circ}$. Acrylamide, compared to acrylic acid, appeared to play a decisive role, and to be more powerful agent for improving its surface hydrophilicity.

• Journal of Radiation Protection and Research
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• v.4 no.1
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• pp.14-20
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• 1979

For accurate and easily shielding irregular shaped organ, its minimized penumbra region and a low melting point alloy 'Lead Y' and synchronizing instrument have been developed. The 'Lead Y' is the quaternary eutectic alloy and it is composed of Lead 30.0% Tin 11.5% Bismuth 48 5% Cadmium 10.0% The density of its at $22^{\circ}C$ is $9.8g/cm^3$ and the melting temperature has $40^{\circ}C\;to\;68^{\circ}C$. The thickness of 'Lead Y' for perfect shielding of Co-60 gamma ray and LINAC 10MeV x-ray is 6cm and 7cm respectively. The 'Lead Y' shielding block is casted directly on the styrofoam from which is cut with hot wire of synchronizer device. The special features and advantages of the Lead Y shielding block could be summarized as follows; 1. The shielding block for radiotherapy is rapidly processed only with boiling water and styrofoam. 2. It is not injure one's health and not danger of a fire, because of not generating of any metals vapor and evil smelling. 3. It is very effective to minimize secondary penumbra for the protection of healthy tissue from unnecessary ionizing radiation regardless of the magnification source to skin distance. 4. The HVL of the Lead Y is 1.2cm for Co-60 gamma ray and it's shielding effect is almost same as the pure lead block. 5. The hardness of Lead Y is 1.5 times higher than lead block. 6. It's reavailability is higher than lead block and then one block of Lead Y is reavailable about 30 to 40 times. 7. It is usefull for shielding of x-ray, gamma ray, beta-ray, electron and neutron radiation. 8. The materials for Lead Y are easy to acquire with reasonable price and tractable.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.490-496
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• 2020

A styrofoam box is used as a simple and easy freezing method to preserve animal semen as a livestock genetic source. This study optimized the methods of freezing chikso brindled cattle semen. To test the freezing box, the motility of spermatozoa was compared between two box sizes (length×width×heigh) with the dimensions of 23.5×30.5×22.5 cm and 25.5×46.5×26.5 cm. The motility of thawed sperm from brindled Korean bulls was used to confirm the efficiency of the freezing boxes. The box having a larger inner space with larger horizontal and height measurements supported better motility after thawing (60.4±5.3% vs 67.2±3.1%) with 10 min of exposure time in liquid nitrogen vapor. The optimized freezing space is estimated to be an essential element for successful freezing results and the larger box could be used for production of more than 60 frozen semen straws. These properties are also helpful to optimize the cryopreservation techniques that would control the quality and quantity of semen straws according to different animal species.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.334-341
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• 2013

Studies were carried to evaluated the influence of storage method by temperatures and fillers on yield and quality of seed rhizome in turmeric. Seed rhizome was stored at styrofoam box filled with rice hull and sand (3:1) or vermiculite for 30, 60 and 90 days at different temperatures (5, 10 and $15^{\circ}C$. compared to traditional method (rhizome only). Parameters were obtained for weight loss, cold injury, percentage of decayed in stored rhizome during storage periods. Also, the germination, growth pattern and yield from stored rhizome has been investigated. It was confirmed that storage of turmeric in stored with filled with vermiculite helps in prevention of rhizomes from microbial and fungal attack. The storage of rhizomes in styrofoam box without any filler at low temperature below $10^{\circ}C$. is not advocated due to heavy losses weight and decayed in management of postharvest for turmeric rhizome. Germination percentage, growth pattern and yield was maximum for rhizomes stored at styrofoam box filled with vermiculite for 90 days at $15^{\circ}C$. The paper outlines a brief attempt to assess the efficacy of non-chemical methods including optimal storage method (temperature and filler) of control of decay and moisture losses during storage of turmeric.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.155-165
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• 1999

In completely weathered granite gneiss,8 of 40cm cast-in-situ concrete piles are constructed, and static pile load tests are executed on the piles to study the bearing behavior of rock-socketed piles. Subsurface explorations are carried out on the test site in three phases, in which 14 borehole investigations as well as the seismic investigation are performed. Rock socketd depths of the piles in the weathered rocks are varied as 3m, 6m and 9m to separate the shaft resistance from the end bearing resistance, and for a couple of piles, styrofoam of 10cm thickness is installed under the pile point to eliminate the effect of the end resistance. Strain gages are instrumented on re-bars to pick-up the transferred loads along the pile length. From the results of the pile load tests, the allowable shaft resistance and the allowable end bearing values of weathered rocks are proposed as $8.6t/m^2\;and\; 84t/m^2$, respectively. The empirical equation relating the elastic modulus of rock mass with the uniaxial compressive strength of the rock specimen is also proposed for the weathered rocks.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.287-293
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• 1998

Floating debris was recorded from a training ship, #1 Kwarnksan, of Pukyong National University with about 10 knots speed during March, May and July of 1997. The area sampled is the Southeastern Coast of Korea, divided into 40 unit segments on survey routes. Debris fabrication materials were categorized using the following ; man-made or natural wood items, paper, cardboard, nylon rope, netting, styrofoam and plastics, floating metal and glass containers. All identified items within a $100\;{\pm}\;2\;m$ wide band were recorded but ignored if beyond this boundary.The results of distribution and composition of floating debris in the area as follows:1. The quantities of debris during the duration of survey were distributed from 2~605 items per km2. The most obvious trend is the widespread distribution of all debris. 2. The highest densities of all debris were discovered in the coastal waters of Seoimal lighthouse, the southeastern part of Koje island, next near Nakdong estuaries. Especially styrofoam & plastics were observed in 77.4~87.2% of sampled area, next is wood items, 9.1~ 13.5%. And nylon netting & rope, 3.6%, was the third item of pollutant. Others are very small. 3. Compared with the East Coat of Korea, the quantities of all debus in theSoutheastern Sea are 6 times as large as the East Coast. The survey provides a basis for more detailed survey work in the South Sea. Further surveys are being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps on all sites of the Coast of Korea and contributed to the removal method, finding of sources, stationary area of debris.

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.1
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• pp.31-39
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• 1997

Floating debris was recorded from a training ship, #1 Kwanaksan, of Pukyong National University with about 10 knots speed during August 19~26, 1996. The area sampled is the East Coast of Korea, divided into 33 unit segments on survey routes. Debris fabrication materials were categorized using the following; man-made or natural wood items, paper, cardboard, nylon rope, netting, styrofoam and plastics, floating metal and glass containers. All identified items within a $100{\pm}2m$ wide band were recorded but ignored if beyond this boundary. The results of distribution and composition of floating debris in the area are as follows: 1. The quantities of debris during the summer were distributed from 1.8~52 items per $km^2$. The most obvious trend is the widespread distribution of all debris. 2. The highest densities of all debris were discovered in the vicinity of Pusan and ills an area. Especially styrofoam & plastics were observed in 81% of sampled area, next is wood items, 9.1%. Nylon netting & rope was the least widespread pollutant. 3. The relationship between distribution of debris and surface currents of the area was not apparently revealed through this survey. Further surveys are being instigated, and from this it is hoped that a much wider coverage can be achived, perhaps on all sites of Southern and Western sea of Korea and contributed to the finding of sources,stationary area of debris.

• Food Science and Preservation
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• v.11 no.2
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• pp.282-285
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• 2004

This experiment was carried out to investigate the cost reduction of rhizome through the stable storage of Jiwhang #1(Rehmannia glutinosa Libosch). The growth characteristics of Jiwhang #1 are different from those of local Rehmannia glutinosa L. varieties in Korea. Various storage methods was introduced and analyzed for 120 days. Among storage methods, changes in mean daily temperature in storage location were the least from 7.2 to 13.8$^{\circ}C$ in underground storage, while those were wide in styrofoam box filled with soil, and changes in mean daily relative humidity were the highest 98.2% in underground storage. As the storage period increased, the rhizome brix and the rate of rhizome loss and spoiled rhizome increased. The brix and loss rate of rhizome were higher in net sack filled with hull and styrofoam box filled with hull, but the rate of spoiled rhizome was the greatest in underground storage among storage methods. As the storage period increased, the hardness of rhizome epidermis increased, while that of rhizome endodermis decreased.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.125-125
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• 2003

Recirculating aquaculture systems consist of different treatment compartments that maintain water quality within the ranges of commonly recommended for fish culture. This paper presents the common considerations in designing different treatment compartments as well as the engineering criteria in designing closed recirculating aquaculture system including a circular tank for fish culture, a sedimentation basin and a foam fractionator for solids removal, two styrofoam bead filters for TAN removal, a sand filter for nitrate removal, and aerators. The main purpose is to outline a common procedure in designing of closed recirculating aquaculture system for marine fish culture.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1145-1148
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• 2007

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.