• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.237-247
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• 2021

The purpose of this study is to investigate the influences on the understanding and academic achievement in general chemistry according to chemical grades in high school and College Scholatic Ability Test. We investigated the difference between the completed subjects in high school and the elective subjects in the Test, degree of understanding of the general chemistry according to the subjects completed in high school, and the effects on the academic achievement of general chemistry by dint of the chemical grades in high school and the Test, etc. By the results of the student's perception survey, most of the students choose Chemistry I at the Test. It was found that the understanding of general chemistry was greatly affected by the chemical elective subjects of high school. Chemical grades in high school and the Test were found to have a significant influence on academic achievement of general chemistry.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.222-232
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• 2009

In this study, the real site test conditions were considered and applied to suggest the improved test method for geosynthetics chemical resistance. For this, index and performance tests were done to specify and regulate the more approached test method. Accelerated model by Arrhenius equation was applied to interpretate the experimental data. Through analysis and comparison the overall experimental results, we could suggest the possibility and setup the advanced chemical resistance test method for geosynthetics.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.17.1-17.6
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• 2015

Objectives In this study, the possibility of using existing test data provided in Korea and elsewhere for the registration of chemical substances was examined. Data on 510 chemical substances that are among the first subject to registration under the "Act on the Registration and Evaluation, etc. of Chemical Substances (K-REACH)" were analyzed. Methods The possibility of using existing data from 16 reference databases was examined for 510 chemical substances notified in July 2015 as being subject to registration. Results Test data with the reliability required for the registration of chemical substances under the K-REACH constituted 48.4% of the required physicochemical characteristics, 6.5% of the required health hazards, and 9.4% of the required environmental hazards. Conclusions Some existing test data were not within the scope of this research, including data used for registration in the European Union (EU). Thus, considering that 350 of these 510 species are registered in EU Registration, Evaluation, Authorisation & Restriction of Chemicals, more test data may exist that can be utilized in addition to the data identified in this study. Furthermore, the K-REACH states that non-testing data (test results predicted through Read Across, Quantitative Structure-Activity Relationships) and the weight of evidence (test results predicted based on test data with low reliability) can also be utilized for registration data. Therefore, if methods for using such data were actively reviewed, it would be possible to reduce the cost of securing test data required for the registration of chemical substances.

• Proceedings of the Korean Reliability Society Conference
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• 2006.05a
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• pp.48-54
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• 2006

In this thesis, accelerated life test (ALT) method and procedure for rubber O-ring are applied to assure specified reliability of the products at guaranteeing the life of the products. Rubber O-ring is parts that keep intensity or make machine operation smoothly on attrition portion of machine and is used to prevent that oil is leaked. Usually. Rubber O-ring used NBR that is copolymer of acrylonitrile and butadiene. this are superior oil resistance, heat resistance, durability of abrasion, cold resistance, chemical resistance etc. The accelerated life test model for rubber O-ring are developed using the relationship between stresses and life characteristics of products. Using the accelerated life test method and the acceleration life test equipment which is developed, we performed life test, collected life data and analyzed the results of tests. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably.

• Fire Science and Engineering
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• v.24 no.2
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• pp.21-30
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• 2010

We have test chemical resistance and flame retardant properties of chemical protective clothing Fabrics by the ASTM and ISO standard methods. The flame retardant test results show that polyethylene is poor in flame resistance but fluoroelastomer add to decabrom is excellent in flame resistance. Especially, nowadays heat protective clothing for firefighters, which is aluminized film layers laminated to aramid fabric, show the excellent flame resistance. However, the chemical resistance test results show that aluminium is high corrosive in 4M NaOH solution alone. The problem of corrosion can be overcome by employing multiple barrier film. Also, based on the result of flame retardant test, duel skin of polymer barrier film add to aluminum film and single skin of fluorinated rubber with flame retardant materials seems to be fit for the chemical protective clothing. Also the thermal protection and heat transfer test results show that TPP and HTI is increased assured that the continued study on fire risk assessment & chemical resistance of chemical protective clothing fabrics will contribute to the upgrade the performances of chemical protective clothing fabrics.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.304-308
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• 1994

Among the new series of phenylacetamides, one of capsaicin derivatives, KR-25018 was found to have a very potent analgesic activity. Thus, the phamacological properties of KR-25018 were compared with those of morphine, capsaicin, and nonsteroidal antiinflammatory drugs (NSAIDs). The analgesic activities were evaluated in several animal models, using different stimuli, such as phenylbenzoquinone(PBQ)-induced weithing test, tail-filck test in mice and adjuvant arthritic flexion test in rat. The relationship of phamacological properties of KR-25018 to that of centrally acting opioids was assessed by the blocking test using naloxone. The analgesic potency of the KR-25018 $(MPED_{50}=0.89{\;}p.o.{\;}in{\;}PBQ-induced{\;}weithing{\;}test, {\;}MPED_{50}$=0.61$ s.c. in tail-flick test in mice0, with different action mechanism from morphine and NSAIDs, was comparable to that of morphine.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.240-241
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• 2017

In this stduy, we will references to provide reasonable basis for the test environments applicable to the chemical resistance test covered by KS F 4935 『Injection-type Sealing Materials for Water Leakage Crack of Adhesive and Flexible Rubber Asphalt』, analyze the problems with the current test methods in consideration of the features of materials. As a result, we assured more objective data in improved chemical resistance test methods.

• Particle and aerosol research
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• v.10 no.3
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• pp.109-117
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• 2014

In Korea, permeable protection clothes for chemical agent is being developed and distributed. But permeable protection clothes are vulnerable for biological agent of particle type. Therefore selective permeable membranes are being developed to protect chemical agent and biological agent simultaneously. In this study, aerosol collection efficiency test was performed to validate the protection performance of permeable clothes and selective permeable membranes. Aerosol collection efficiency test was performed by using the aerosol test equipment that could test aerosol particle diameter from $0.005{\mu}m$ to $3.0{\mu}m$. This study shows the test method and performance test results for collection efficiency by using the aerosol test equipment.

• Environmental Analysis Health and Toxicology
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• v.30 no.sup
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• pp.4.1-4.7
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• 2015

Objectives Approximately 2000 phase-in substances are subject to registration according to the Act on the Registration and Evaluation, etc. of Chemical Substances (K-REACH), and the expected testing cost is 2.06 trillion Korean won assuming all the test data required for registration are acquired. The extent to which these enormous test costs can be reduced depends on the availability of existing data that can be used to meet the requirements of the K-REACH we examined the current availability of test data that can be used for chemical substance registration. Methods We analyzed the possibility of utilizing the existing test data obtained from 16 reference databases for 369 of 518 kinds of phase-in substances subject to registration that were reported in last October 2014. Results The physical and chemical properties were available for 57.1% of substances, whereas data regarding human hazards and environmental hazards were available at considerably lower rates, 8.5% and 11.8%, respectively. Conclusions Physical and chemical properties were available for a fairly high proportion, whereas human hazards and environmental hazards were reported for considerably fewer substances.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.883-890
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• 2019

Two-phase flow near the wellbore in volatile oil reservoirs causes complications in well test analysis. In this study, the flow behavior of volatile oil reservoirs below the bubble-point pressure and the potential of radial composite model for interpretation of two-phase well test in volatile oil reservoirs was investigated. A radial composite model was used for two-phase well test analysis. A new procedure was developed to interpret well test data and estimate the radius of the two-phase region. The changes in fluid composition near the wellbore during drawdown test were found to increase the saturation pressure, which affects the saturation profile during build-up. Well test results showed that the radial composite method is a powerful tool for well test characterization and estimation of reservoir parameters. The proposed procedure was able to estimate the reservoir parameters and radius of the two-phase region with acceptable accuracy.