• Journal of the Korean Chemical Society
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• v.39 no.2
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• pp.87-93
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• 1995

The amount of Cr(Ⅲ) and Cr(Ⅵ) in a chromium plating solution could be determined simultaneously within five minutes using UV/VIS spectrophotometer coupled with a flow-through analysis(FTA) setup. The λmax's at 580 nm and 440 nm which correspond to Cr(Ⅲ) and Cr(Ⅵ), respectively, well obey the Beer-Lambert law in the range over 0.05 g/L for Cr(Ⅲ) and 0.005 g/L for Cr(Ⅵ). when the pH of the sample is less than 4.0, the absorption extinction coefficients of those peaks are not much dependent on the proton concentration. The amount of Cr(Ⅲ) and Cr(Ⅵ), and the total chromium in post treatment chromium plating solution, which normally has few g/L of Cr concentration, could be easily measured using UV/VIS spectrophotometry after the sample had been diluted with sulfuric acid of pH=1.0 in the flow-through analysis setup; this method is far more convenient and faster than the common redox titration (which requires at least 40 min/sample) method, while the accuracy of the method is highly comparable to conventional titrimetric method. Since the implementation of an PTA-UV/VIS setup in any plating industry is cost effective and easy to operate, the analytic method described in this paper may be applied directly for in situ analysis of plating solutions.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.73-79
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• 2017

It is difficult to detect the adult hearing loss after the language acquisition because of its slow progression, which can be evaluated voluntarily and actively when the appropriate tools are provided. Smartphones are one of useful tools, and they can utilize surveys and/or applications for hearing screening. This study aims to verify the possibility as a tool discovering delayed acquired hearing losses by comparing the pure tone screening application (app_PTS) which was recently developed by our research team and hearing handciap inventory (HHI). The subjects were 22 people whose age ranges from 10s to 80s. For pure tone averages (PTAs), hearing threshold level was selected the best one in same frequency, in both ears. Sensitivity and specificity of HHI were confirmed based on self awareness of hearing loss and PTAs at 1, 2, 4 kHz. Comparisons of two tests were measured by analyzing simple regression of correlation between PTAs of App_PTS and HHI scores. Sensitivity and specificity were 1.000 in both criteria. There was a statistically significant relationship between the PTAs_4 kHz and HHI (R-square = .951, p = .000). Hearing screening by questionnaire showed high correlation with smart phones based on application. Therefore, it can be useful as a hearing screening tool for individual life cycle using an user-friendly tool.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.167-171
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• 1992

Background:In the management of patients whose primary chemotherapy has failed, very careful assessment is essential. It is important to find out as accurate a chemotherapy history as possible. Preferably it should contain the drugs which has never used before. The present report concerns the results of retreatment of pulmonary tuberculosis patients treated at National Kongju Tuberculosis Hospital. Method: A retrospective study was made through the regular follow-up of 112 smear positive cases, who were treated by four-drug regimen between July 1985 and June 1990. Four drugs were, namely prothionamide, cycloserine, para-aminosalicylic acid, and streptomycin (kanamycin or tuber-actinomycin). The duration of follow-up was over one year. Results: 1) Out of 112 cases with positive sputum AFB smear, 72 (64%) achieved the negative conversion. 2) Among the 72 patients, 85% achieved negative conversion within 3 months after treatment. 3) When the duration of patient's illness was less than 2 years, 2 to 4 years and more than 5 years, the favourable response to retreatment was 86%, 62% and 54%, respectively. 4) When the number of sensitive drugs was 4,3,2 and 1, the favourable response rate was 74%, 68%, 39% and 0%, respectively. Conclusion: The shorter the duration of patient's illness was, the larger the number of sensitive drugs was. And the larger the number of sensitive drugs was, the better the result of treatment was. Thus it is very crucial to successfully treat newly discovered patients with adequate regimens and proper case-holding.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.148-152
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• 2013

An ultraviolet (UV) sterilization system was developed to decrease the number of microorganisms in filtered Acer mono sap (FAS). The Acer mono sap (AS) was passed through 18 strips of PTA fluoroplastic tubing with 30 UV lamps (total 1,170 W). During passage, the AS was effectively exposed to the UV rays. The total bacteria, coliform group and fungi were sterilized at a flow rate ranging from 852 to 1,358 mL/min and a UV power higher than 156 W. Although the sensory score of the UV-sterilized AS was significantly lower than that of the untreated AS, the sensory score was better under the condition of 390 W and 852~1,358 mL/min than under the other conditions examined. ANOVA did not reveal a significant difference in pH, total acidity, sugar content and color characteristic under all conditions tested (p<0.05). Considering the overall attributes of the AS quality, the optimum sterilization condition was determined to be 390 W and 852~1,358 mL/min.

• Journal of Trauma and Injury
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• v.26 no.3
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• pp.243-247
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• 2013

Introduction: Surgical treatment of subclavian artery (SA) injury is challenging because approaching the lesion directly and clamping the proximal artery is difficult. This can be overcome by using an endovascular technique. Case 1: A 37-year-old male was drawn into the concrete mixer truck. He had a right SA injury with multiple traumatic injuries: an open fracture of the right leg with posterior tibial artery (PTA) injury, a right hemothorax, and fractures of the clavicle, scapula, ribs, cervical spine and nasal bone. The injury severity score (ISS) was 27. Computed tomography (CT) showed a 30-mm-length thrombotic occlusion in the right SA, which was 15 mm distal to the vertebral artery (VA). A self-expandable stent($8mm{\times}40mm$ in size) was deployed through the right femoral artery while preserving VA flow, and the radial pulse was palpable after deployment. Other operations were performed sequentially. He had a viable right arm during a 13-month follow-up period. Case 2: A 25-year-old male was admitted to our hospital due to a motorcycle accident. The ISS was 34 because of a hemothorax and open fractures of the mandible and the left hand. Intraoperative angiography was done through a right femoral artery puncture. Contrast extravasation of the SA was detected just outside the left rib cage. After balloon catheter had been inflated just proximal to the bleeding site, direct surgical exploration was performed through infraclavicular skin incision. The transected SA was identified, and an interposition graft was performed using a saphenous vein graft. Other operations were performed sequentially. He had a viable left arm during a 15-month follow-up period. Conclusion: The challenge of repairing an SA injury can be overcome by using an endovascular approach.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.89-89
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• 1995

Surface epithelial cells isolated from hamster tracheas and grown on a thick collagen gel become a highly enriched population of mucus-secreting cells. Epithelial cells from tracheas of hamsters were collected using enzymatic procedures and cultured under various conditions. The medium used consisted of a 1:1 mixture of medium 199 and Dulbecco's modified Eagle's (DME) medium which was conditioned before use. Insulin, transferrin, hydrocortisone, epidermal growth factor, and extract from bovine hypothalamus were used as supplement. Due to relatively low basal rates of min secretion from in vitro cultures, cultures are generally radiolabeled using $^3$H-glucosamine as a metabolic precursor. The radiolabeled mucinsreleased are quantitated by precipitation with TCA/PTA. Using this cell culture system, we investigated mucin release of goblet cells by altering the media bathing the apical surface of hamster tracheal surface epithelial(HTSE) cells. Acidic media added sulfuric acid caused sigcificant increases in mucin relesse (155${\pm}$20% at pH 4 and 146${\pm}$16% at, pH 5). Ammonium hydroxide also increased mucin release at pH 9.0(156${\pm}$17%) and pH 10(295${\pm}$9%) respectively. This additional mucin release seems to be associated with cell membrane damage as indicated by release of cellular LDH. SP stimulates secretion of mucin in cultured HTSE cells(154${\pm}$16% at 1${\times}$10$\^$-6/M and 165${\pm}$25% at 1${\times}$10$\^$-5/M. PAF at 5${\times}$10$\^$-6/M and 5${\times}$10$\^$-5/M enhanced by HTSE cells in vitro 168${\pm}$34% and 259${\pm}$30% of mucin secretion, respectively. The increase in mucin release by PAF and SP was not secondary to cell damage or necrosis. SP and PAF may be in mediating mucous secretion induced by inflammation irritantion and infection.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.363-370
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• 2016

Noise is unwanted sound that is the reason of the stress and hearing loss. The current study attempted to estimate whether the noise of dental laboratory affected stress and pure tone audiometry (PTA) of dental laboratory technicians (DLTs) using heart rate variability, air and bone conduction audiometry. The age, heights, and weights of DLTs were resembled control. Standard deviation of normal to normal interval such as stress resistance and normalized HF of DLTs were significantly decreased, but heart rates, normalized LF, and LF/HF ratio of DLTs were significantly increased compared with control. In air conduction audiometry of DLTs, significant increments of thresholds encountered in 125, 250, 500, 1000, 2000, 3000, 4000, and 6000 Hz in the right ears and 125, 250, 500, 1000, and 2000 Hz in the left ears. Thresholds of bone conduction audiometry in both ears were significantly increased in 250, 500, 1000, 2000, and 4000 Hz. The findings in this study provide that stress and hearing loss observed in noise-exposed DLTs at dental laboratory. Therefore, proper safety precautions should be carried out at dental laboratory.

• Polymer(Korea)
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• v.35 no.1
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• pp.52-59
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• 2011

L-PLA or D-PLA was synthesized in bulk at $140^{\circ}C$ by ring opening polymerization(ROP) of L-lactide or D-lactide as a monomer using tin(II) octoate and lauryl alcohol as a catalyst and an initiator with changing the amounts of catalyst(0.25~1.0 wt%) and initiator(0.l~0.5 wt%). And stereocomplex-PLA was prepared by L-PLA/D-PLA having a wide range of molecular weight(30000~90000 g/mol) and L-PLA/D-PLA blends having different mixing ratio ($X_D$). The melting temperature. thermal degradation temperature and thermal stability of stereocomplex-PLA were higher than those of homopolymers(L-PLA, D-PLA). We supposed that these improvements arose from a strong interaction between L-PLA and D-PLA. The improved mechanical properties and changes in morphology of LPLA/D-PLA blends were compared to those of homopolymers(L-PLA, D-PLA).

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.790-803
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• 2019

The dioctyl terephthalic acid (DOTP) process produces plastic plasticizers by esterification of terephthalic acid with powder in the form of octanol. In this study, the dust explosion characteristics of terephthalic acid directly injected into the manhole in the form of powder in the presence of flammable solvent or vapor in the reactor of this process were investigated. Dust particle size and particle size distribution dust characteristics were investigated, and pyrolysis characteristics of dust were investigated to estimate fire and explosion characteristics and ignition temperature. Also, the minimum ignition energy experiment was performed to evaluate the explosion sensitivity. As a result, the average particle size of terephthalic acid powder was $143.433{\mu}m$. From the thermal analysis carried out under these particle size and particle size distribution conditions, the ignition temperature of the dust was about $253^{\circ}C$. The lower explosive limit (LEL) of the terephthalic acid was determined to be $50g/m^3$. The minimum ignition energy (MIE) for explosion sensitivity is (10 < MIE < 300) mJ, and the estimated minimum ignition energy (Es) based on the ignition probability is 210 mJ. The maximum explosion pressure ($P_{max}$) and the maximum explosion pressure rise rate $({\frac{dP}{dt}})_{max}$ of terephthalic acid dust were 7.1 bar and 511 bar/s, respectively. The dust explosion index (Kst) was 139 mbar/s, corresponding to the dust explosion grade St 1.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.117-130
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• 2011

In a situation where worldwide free trade between countries has expanded recently, our country is being rapidly pushed FTA agreements with the financial developed countries such as United States, EU. According to the agreement, the user information of foreign financial companies in Korea is expected to be transfered overseas. In this paper, we need to define the scope and the definition about the transfer of information and analyze the relating domestic and foreign laws preparing for Cross Border Financial Information Transfer. Also, we review the expected issues about the transfer of information divided into institutional and technical sectors and arc presented the policy implication such as differentiation of regulatory information, enactment and amendment of Personal Information Protection Law(Draft) and related regulations, ensuring the safety of financial companies, raise the standard guidelines of the transfer of information. We refers to the needs for policy formulation to differentiate our privacy information from financial information to protect the privacy of users. The proposed countermeasures in this paper is expected to be helpful the measures to prepare for other institutions such as banks and supervisory authorities prepare for the future Cross Border Financial Information Transfer according to PTA.