• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.505-512
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• 2013

Objectives: Ultraviolet (UV) radiation may cause skin cancer, photo-ageing, erythema, and sunburn. Benzophenone (BP) is commonly used to protect skin from UV radiation. In Korea, sunscreen, sunblock, socalled 'blemish balm' (BB) and 'color correcting' (CC) creams, and foundation may contain from 0.5 to 5% benzophenone in order to protect skin from UV radiation. The purpose of this study is to understand the levels of benzophenone derivatives in urine among a group of university students and identify the contribution of cosmetics use. Methods: Forty volunteers (20 women and 20 men) were asked about skin type, frequency of use of cosmetics, and recognition of related health effects, etc. in a survey. Subjects were divided into several subgroups and were compared for concentration of benzophenone-1 (BP-1) and benzophenone-3 (BP-3). Their urine was pretreated with enzyme hydrolysis and solid phase extraction. Determinations of BP-1 and BP-3 in the urine were made with LC-MS/MS. Results: Among the study subjects, 82.5% used basic cosmetics at least once per day, and 77.5% used sunscreens at least once per day. The concentrations of BP-1 and BP-3 of the males were 4.36 ng/mL and 9.16 ng/mL, respectively. Those of the females were 3.98 ng/mL and 5.07 ng/mL, respectively. The use of cosmetics was positively related to urinary benzophenone levels. Conclusions: BP-1 and BP-3 were widely detected among the university students. Cosmetic use was identified as a potential source. Implications of such exposure deserve further investigation.

• ETRI Journal
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• v.26 no.6
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• pp.583-588
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• 2004

In this paper we investigate the effect of a shield metal line inserted between adjacent bit lines on the refresh time and noise margin in a planar DRAM cell. The DRAM cell consists of an access transistor, which is biased to 2.5V during operation, and an NMOS capacitor having the capacitance of 10fF per unit cell and a cell size of $3.63{\mu}m^2$. We designed a 1Mb DRAM with an open bit-line structure. It appears that the refresh time is increased from 4.5 ms to 12 ms when the shield metal line is inserted. Also, it appears that no failure occurs when $V_{cc}$ is increased from 2.2 V to 3 V during a bump up test, while it fails at 2.8 V without a shield metal line. Raphael simulation reveals that the coupling noise between adjacent bit lines is reduced to 1/24 when a shield metal line is inserted, while total capacitance per bit line is increased only by 10%.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.1-6
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• 2007

Leptin is the hormone product of the obese gene and is synthesized and secreted predominantly by white adipocytes and relates to the feedback system that regulates long-term body fat weight and composition. Therefore, the leptin gene could be an excellent candidate gene controlling fat deposition, carcass traits and meat quality in beef cattle. The objective of this study was to evaluate the association of 3 SNPs (A1127T and C1180T in exon 2 and C3100T in exon 3) in the bovine leptin gene with carcass and meat quality traits in Korean cattle. The C1180T SNP was associated with backfat thickness (BF) and marbling score (MS) (p<0.05). Animals with the genotype CC had higher BF than animals with TT genotype and higher MS compared with CT and TT genotypes. No significant associations were observed between the C3100T SNP and any carcass and meat quality traits analyzed. The effect of the A1127T SNP was not analyzed because the TT genotype was not detected and the AT genotype showed only 1.0% frequency. These results suggest that the C1180T SNP of the leptin gene may be useful as a genetic marker for carcass and meat quality traits in Korean cattle.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.196-200
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• 2003

A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DEGME) in spilled aviation fuels. Ethylene glycol monobutyl ether (EGBE) and ethylene glycol monoethyl ether (EGEE) were used as internal standard and surrogate, respectively. The sample preparation consists of back-extraction with 7 mL of methylene chloride after extraction of 50 mL of fuel with 2 mL of water. The extract was concentrated to dryness and dissolved with 100L of methanol and analyzed by CC-MS (SIM). The peaks had good chromatographic properties by using semi-polar column and the extraction of these compounds from fuel also gave high recoveries of 75 and 85 % with small variations for EGME and DEGME, respectively. Method detection limits were 1.3 ng/mL for EGME and 1.0 ng/mL for DEGME in spilled fuel. The method may be useful for fuel-type differentiation between kerosene and JP-8, which may originate from the storage tank.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.760-765
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• 1989

The change of volatile flavor components In nutmeg (Kernels of the fruits of Myristica fragrans Houttuyn) during aging at $37^{\circ}C$ were studied by using a fused silica capillary GC & GC/MS. Volatile flavor components having the low boiling point showed a general decrease during aging, but those of the middle and high boiling point showed a reactionary tendency Myristicin and myristic acid among volatile flavor components showing the high boiling point had the amount increased considerably, and those were composed of 24.50% and 18.69% in aging for 6 months, respectively. The amount of whole volatile flavor concentrate showed the increased tendency till the aging period for 4 months, and then subsequently decreased.

• Membrane Journal
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• v.15 no.4
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• pp.297-309
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• 2005

As a number of potential endocrine disrupting compounds (EDCs) are released into the environment, recently growing attention has been drawn to them. Therefore sensitive and reliable analytical methods are essential to monitor those compounds. In this study, complementary CC-MS and LC-MS were employed to analyze the endocrine disrupters, and the results of two methods were compared for di(2-ethylhexyl)phthalate (DEHP), benzylbutylphthalate (BBP), pentachlorophenol (PCP), and 4,4'-Isopropylidenediphenol (Bisphenol-A, or BPA). The results indicate that it was possible to lower the detection limits of EDCs by LC-MS. Also, LC-MS enabled to identify the EDCs as almost intact molecules. Furthermore, this study presented a nanofiltration membrane (MWCO 250) and a ultrafiltration membrane (MWCO 1,000) filtration system as methods far removing EDCs from drinking water containing $\gamma$-BHC, p,p'-DDE, BBP, p,p'-DDT, DEHP, PCP, and BPA. Cross-flow type nanofiltrations showed $100\%$ removal of EDCs, and the result implies that MWCO 250 nanofilter was sufficient for treatment of EDCs. The ratio of permeate flux to mass transfer coefficient of nanofiltration, high flux ultrafiltration, and low flux ultrafiltration with ultrapure water were 0.67, 3.4, and 0.44, respectively. It was found that nanofiltration and low flux ultrafiltration were operated at a diffusion dominant condition, and the high flux ultrafiltration was operated at a convection dominant condition. Furthermore, a diffusion dominant process attained reasonable rejection of EDCs. The removal in the ultrafiltration was depending on the molecular weight of an EDC, and the filtration was governed by diffusion-dominant hydrodynamic conditions.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.79-85
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• 1990

Many kinds of acetosolv lignin including ricestraw and spruce lignin were pyrolyzed. and liquefied in the autoclave reactor using 50% tetralin and m-cresol solution respectively as soluble solvent and Co-Mo as catalyst. In order to promote deoxyhydrogenolysis reaction $H_2$ gas was supplied into the reactor. The ratio between lignin and the soluble solvent are lg and 10cc. The reaction conditions are $200^{\circ}-700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure and 100-500rpm of the reactor stirrer. By the deoxyhydrogenolysis liquefaction reaction, the main chemical structures of lignin which are aryl-alkyl-${\beta}$-0-4 ether, phenylcoumaran and biphenyl etc. are easily destroyed into liqufied aromatic compounds and aliphatic compunds linked with aromatic compounds. The percent yield of monomeric phenols on the weight bvase of lignin reacted reached to 12-14% by the chemical analytic GC-MS etc.

• The Research Journal of the Costume Culture
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• v.10 no.5
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• pp.555-564
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• 2002

The purpose of this research was to analysis compounds of unpleasant odor from the cotton fabrics in dehydration and drying process during washing. The cotton fabrics were treated with various commercial detergents and fabric softener or cationic surfactants such as Cetyltrimethylammonium bromide(CTAB) and Benzalkonium chloride(BC), then dehydrated and dried. The compounds of odor impregnated in fabric were detected by using CC-MS. The results are as follows: The fabrics treated with a powder-type detergent, CTAB and BC gave out compounds unpleasant odor. n-Butyraldehyde and isobutyaldehyde produced during microorganism growth were revealed as source of the compounds of the unpleasant odor. However, no aldehydes were detected from the fabrics treated with commercial fabric softener which seems to act as a deodorizer.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.627-630
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• 1995

BaM films have a lot of advantage of chemical stability and mechanical stability as compared with a metallic thin film. In this paper, (Ba.Pb)M films have been prepared by using dc magnetron sputtering system and the dependences of their crystallographic characteristics and magnetic properties on oxygen pressure($Po_{2}$) were studied. The films prepared at $Po_{2}$ of around 0.02mTorr exhibit a fine particle-like structure and ${\Delta}{\theta}_{50}$ is as small as $1^{\circ}$. $Hc_{\bot},\;Hc_{//}$ and Ms of (Ba.Pb)M films are 700-800Oe, 200Oe and 180-230emu/cc, respectively.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.87-109
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• 2020

Currently, thanks to the major stride made in developing wired and wireless communication technology, a variety of IT services are available on land. This trend is leading to an increasing demand for IT services to vessels on the water as well. And it is expected that the request for various IT services such as two-way digital data transmission, Web, APP, etc. is on the rise to the extent that they are available on land. However, while a high-speed information communication network is easily accessible on land because it is based upon a fixed infrastructure like an AP and a base station, it is not the case on the water. As a result, a radio communication network-based voice communication service is usually used at sea. To solve this problem, an additional frequency for digital data exchange was allocated, and a ship ad-hoc network (SANET) was proposed that can be utilized by using this frequency. Instead of satellite communication that costs a lot in installation and usage, SANET was developed to provide various IT services to ships based on IP in the sea. Connectivity between land base stations and ships is important in the SANET. To have this connection, a ship must be a member of the network with its IP address assigned. This paper proposes a SANET-CC protocol that allows ships to be assigned their own IP address. SANET-CC propagates several non-overlapping IP addresses through the entire network from land base stations to ships in the form of the tree. Ships allocate their own IP addresses through the exchange of simple requests and response messages with land base stations or M-ships that can allocate IP addresses. Therefore, SANET-CC can eliminate the IP collision prevention (Duplicate Address Detection) process and the process of network separation or integration caused by the movement of the ship. Various simulations were performed to verify the applicability of this protocol to SANET. The outcome of such simulations shows us the following. First, using SANET-CC, about 91% of the ships in the network were able to receive IP addresses under any circumstances. It is 6% higher than the existing studies. And it suggests that if variables are adjusted to each port's environment, it may show further improved results. Second, this work shows us that it takes all vessels an average of 10 seconds to receive IP addresses regardless of conditions. It represents a 50% decrease in time compared to the average of 20 seconds in the previous study. Also Besides, taking it into account that when existing studies were on 50 to 200 vessels, this study on 100 to 400 vessels, the efficiency can be much higher. Third, existing studies have not been able to derive optimal values according to variables. This is because it does not have a consistent pattern depending on the variable. This means that optimal variables values cannot be set for each port under diverse environments. This paper, however, shows us that the result values from the variables exhibit a consistent pattern. This is significant in that it can be applied to each port by adjusting the variable values. It was also confirmed that regardless of the number of ships, the IP allocation ratio was the most efficient at about 96 percent if the waiting time after the IP request was 75ms, and that the tree structure could maintain a stable network configuration when the number of IPs was over 30000. Fourth, this study can be used to design a network for supporting intelligent maritime control systems and services offshore, instead of satellite communication. And if LTE-M is set up, it is possible to use it for various intelligent services.