• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.453-457
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• 2017

The proximate, fatty acid and dimethyl acetal (DMA) composition, and mineral and total amino acid content of limpets Cellana spp. were studied. Limpets contained 17.6% protein, 1.82% lipids, and 1.28% ash. The most prominent fatty acids in limpets were 20:4n-6, 20:5n-3, 18:1n-9, 16:0, 18:0, and 22:2 nonmethylene-interrupted diene (7,13). Limpets contained significant amounts of 18:0DMA (7.79%) and 20:0DMA (2.45%) derived from plasmalogen. They also contained large amounts of calcium (192.4 mg/100 g) and iron (9.4 mg/100 g), which are components of limpet teeth. The most prominent total amino acids were glutamic acid, arginine, aspartic acid, leucine, lysine, and glycine. These results suggest that limpets are a good source of n-3 and n-6 fatty acids, plasmalogen, calcium iron, and arginine.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.2
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• pp.1-8
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• 1999

The state of compatability of poly(vinyl alcohol)(PVA) and methyl cellulose(MC), prepared by an aqueous solution casting, were investigated over the entire compositions by dynamical mechanical analyzer(DMA) and differential scanning calorimetry(DSC). The glass transition temperatures of the blends, estimated by DMA, indicate that the blends of PVA and MC showed a definite degree of partial miscibility by showing two glass transition temperatures below 80 wt % MC contents in the blends and one glass transition temperature above 80 wt % of MC contents. The DSC results show a depression of melting point and crystallization temperature of PVA in the blends containing more than 80 wt % MC. This indicates that a considerable compatibility in the blend above 80 wt % MC contents may be attribute to the presence of interaction of hydroxyl groups of component polymers through hydrogen bonding. The DMA study of the effect of plasticizer on the polymers showed that water was a good plasticizer for PVA and PEG400 for MC. The addition of water and PEG400 in the blends showed a synergic plasticizing effect on these blends, which resulted in the large extent of the improvement of the compatibility. The elongation of PVA, MC and blonds was found to increase with addition of PEG400 in the blends, but the tensile strength to decrease with addition of plasticizer.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.443-448
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• 2005

To measure modulus, damping properties and smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[kg/cm$^{2}$]. The content of conductive carbon black was the variable, and their contents were 20, 30 and 40[wt$\%$], respectively. The modulus and tans were measured by DMA 2980. The ranges of measurement temperature were from -50[$^{\circ}C$] to 100[$^{\circ}C$] and measurement frequency was 1[Hz3. The modulus of specimens was increased according to a increment of a carbon black content. And modulus was rapidly decreased at the glass transition temperature. The tans of specimens was decreased according to a increment of a carbon black content. The smoothness was measured by JSM-6400. EEA resin from SEM measurement was best the dispersion of carbon back in base resin.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.1-11
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• 2006

Arsenic is a ubiquitous element found in several forms in environment. Although certain foods, such as marine fish, contain substantial levels of organic arsenic forms, they are relatively low in toxicity compared to inorganic forms. In contrast, arsenic in drinking water is predominantly inorganic and very toxic. Chronic ingestion of arsenic-contaminated drinking water is therefore the major pathway posing potential risk to human health. World populations are exposed to low to moderate levels of arsenic of parts per billion (ppb) to thousands of ppb. When exposed to human, it could metabolize into monomethylarsonous acid ($MMA^{III}$) and dimethylarsinous acid ($DMA^{III}$) which are highly toxic. Lots of stuides have been recently focused how $MMA^{III}\;and\;DMA^{III}$ induce toxic insults in various target tissues. Epidemiological studies revealed that chronic arsenic exposure caused cancer, cardiovascular diseases, and diabetes etc. In this review, the current understanding of arsenic on health effects will be discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.213-214
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• 2005

To measure modulus and damping of semiconductive materials in power cable, we have investigated the modulus and damping of semiconductive materials showed by changing the content of carbon black. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[$kg/cm^2$]. The content of conduct ive carbon black was the vailable, and their contents were 20, 30 and 40[wt%], respectively. The modulus and $Tan\delta$ experiments were measured by DMA 2980. Ranges of measurement temperature from -50[$^{\circ}C$] to 100[$^{\circ}C$] and measurement frequency is 1[Hz]. The modulus of specimens was increased according to a increment of a carbon black content. And modulus was rapidly decreased at the glass transition temperature. The $Tan\delta$ of specimens was decreased according to a increment of a carbon black content.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.7 no.1
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• pp.9-15
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• 2001

Top-to-bottom compression strength of corrugated fiberboard boxes is partly dependent on the load-carrying ability of the central panel areas. The ability of these central areas to resist bending under load will increase the stacking strength of the box. The difference of box compression strengths, among boxes which are made with identical dimensions and fabricated with same components but different flute sizes, is primarily due to difference of the flexural stiffness of the box panels. Top-to-bottom compression strength of a box is accurately predicted by flexural stiffness measurements and the edge crush test of the combined boards. This study was carried out to analyze the flexural stiffness, maximum bending force and maximum deflection for various corrugated fiberboards by experimental investigation. There were significant differences between the machine direction (MD) and the cross-machine direction (CD) of corrugated fiberboards tested. It was about 50% in SW and DW, and $62%{\sim}74%$ in dual-medium corrugated fiberboards(e.g. DM, DMA and DMB), respectively. There were no significant differences of maximum deflection in machine direction among the tested fiberboards but, in cross direction, DM showed the highest value and followed by SW, DMA, DMB and DW in order. For the corrugated fiberboards tested, flexural stiffness in machine direction is about $29%{\sim}48%$ larger than cross direction, and difference of flexural stiffness between the two direction is the lowest in DMA and DMB.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.259-261
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• 2012

The effect of high-temperature on the flexural modulus of epoxy resin were evaluated using universal testing machine with 3-point bending and dynamic mechanical analyzer. Temperatures of $30^{\circ}C$, $100^{\circ}C$, and $140^{\circ}C$ were considered for flexural test. The specimens having aspect ratio of 16, 32, and 40 were used. The results of storage modulus from DMA were similar to those from flexural test along with given temperatures. It is found that the flexural modulus increased with increasing aspect ratio and the specimen having aspect ratio of above 32 would be suitable for the evaluation of composite material properties under high temperature condition.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.606-616
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• 2003

Purpose : The purpose of this study was to research the properties of some chemically cured methacrylate polymers such as MMA, HEMA, TEG-DMA, bis-GMA, GMA. Material and Method : 5 kinds of methacrylates were selected and added 2% tertiary amine and benzoyl peroxide to make a chemically curable polymer 25 micron crushed silicas which are treated with silane were selected as filler, they were added into methacrylate monomer until the consistency did not changed by the load of 500gram. All of the experimental resins were 5 kinds, and a serial test was done with 3 kinds of items including the filler contents, the tensile strength, and the bond strength. The number of specimen were 10 for each group. Filler contents were obtained by reducing the specimens to ashes at $600^{\circ}C$ for 1 hour. The specimens with the dimension of 6mm in diameter and 3mm thick were immersed in $37{\pm}1^{\circ}C$ distilled water for 24 hours before test, and tensile strength were measured with cross-head speed 1mm/min. Shear bond strength were mea sured on the specimens attached to bovine enamel etched with 37% phosphoric acid for 1 minute. Results : 1. Maximum filler incorporation was the highest as 75.5% on MMA, and the least as 53.4% on bis- GMA(p<0.0001). 2. The tensile stregth were MMA 141.3, GMA 154.3, TEG-DMA 157.4, bis-GMA 161.4 MPa, and HEMA showed the highest value, 226.9MPa(p = 0.0004). 3. The bond strength were GMA 10.1, TEG-DMA 11.7, HEMA 12.2, bis-GMA 13.3 MPa, and MMA showed the highest value, 15.3MPa, however statistical significances were not (p =0.3838), 4. TEG-DMA and HEMA were not different on the aspect of maximum filler contents and shear bond strength(p>0.05). Conclusion : HEMA can be used as an another diluent substituting TEG-DMA with the increased strength and with the constant bond strength and the constant filler contents.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1043-1046
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• 1998

Aluminium based inorganic flocculants are extensively used in this country in the removal of fine particles present in the raw water for the production of drinking water. These inorganic flocculants, however, have potential hazard of high residual aluminium ions in the treated waters, which is known to be one of the reasons of alzheimer's disease. Inorganic flocculants alone are sometimes incapable of treating water when there are excessive turbidity in the raw water sources due to flooding. A polyamine type polymeric flocculant has long been used to treat raw water in the drinking water production in the European countries and United State of America. The optimum reaction conditions such as mole ratio of epichlorohydrin(EPI) to dimethylamine(DMA), reaction temperature and time for each stage for the pilot scale preparation of polyamine from EPI-DMA was studied in this work. The variation of intrinsic viscosity and flocculating efficiency in the water treatment of the synthesized polyamines were evaluated. The residual materials after polymerization reaction were analyzed by gas chromatography to study the effect of variation of reaction conditions.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.83-93
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• 2013

Recently, the SURF algorithm, which is conjugated for object tracking system as part of many computer vision applications, is a well-known scale- and rotation-invariant feature detection algorithm. The SURF, due to its high computational complexity, there is essential to develop a hardware accelerator in order to be used on an IP in embedded environment. However, the SURF requires a huge local memory, causing many problems that increase the chip size and decrease the value of IP in ASIC and SoC system design. In this paper, we proposed a way to design a SURF algorithm in hardware with greatly reduced local memory by partitioning the algorithms into several Sub-IPs using external memory and a DMA. To justify validity of the proposed method, we developed an example of simplified object tracking algorithm. The execution speed of the hardware IP was about 31 frame/sec, the logic size was about 74Kgate in the 30nm technology with 81Kbytes local memory in the embedded system platform consisting of ARM Cortex-M0 processor, AMBA bus(AHB-lite and APB), DMA and a SDRAM controller. Hence, it can be used to the hardware IP of SoC Chip. If the image processing algorithm akin to SURF is applied to the method proposed in this paper, it is expected that it can implement an efficient hardware design for target application.