• Title/Summary/Keyword: The Environmental Test

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Analysis of Photovoltaic module's Phenomena of aging with Acceleration Test (외부환경적 가속시혐에 의한 PV모듈의 열화성능 분석)

  • Kang, Gi-Hwan;Kim, Kyung-Soo;Park, Chi-Hong;Yu, Gwon-Jong;Ahn, Hyung-Gun;Han, Deuk-Young
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1151-1152
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    • 2006
  • In this paper, we examined 10 domestic samples of three different model using thermal, humidity freeze, thermal-endurance and damp heat test under IEC61215 photovoltaic module environmental endurance test condition. Three was almost no changes on power generation. Insulation resistance capacity was much higher than judgement standard but, showed unstable results depending on environmental test items. On external appearance test, there were two models which showed bubble, humidity penetration, seal melted frame phenomenon. From this results, the degree of aging under the external environment is a main cause that shortens photovoltaic module life time. So it is considered that the efforts for finding optimum condition of manufacturing process should be needed.

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Performance Evaluation for Bending Strength and Tensile Type Shear Strength of GFRP Reinforced Laminated Wooden Pin (GFRP보강적층목재핀의 휨강도 및 인장형 전단내력 성능평가)

  • Song, Yo-Jin;Jung, Hong-Ju;Kim, Dae-Gil;Kim, Sang-Il;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.3
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    • pp.258-265
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    • 2014
  • By replacing the previous metal connector on the joints of timber structure, the GFRP reinforced laminated wooden pin was produced using a wooden material and Glass fiber reinforced plastic(GFRP) composite laminate. In addition, using the reinforced wooden pin, the tensile type shear strength test was conducted. Based on the result of the bending strength test of the reinforced laminated wooden pin according to the GFRP arrangement, a specimen(Type-A) with a single insertion of GFRP for each layer have shown the most favorable performance. Also, it was verified that densified specimen hot pressed for an hour at the temperature of $150^{\circ}C$ and with the oppression pressure $1.96N/mm^2$ have shown the improved performance of 1.57 times than the specimen without the densification. And in the bending strength test considering the load direction, edgewise have shown a higher performance of 3.51 times than the flatwise. A shear strength test was conducted using the Type-A reinforced laminated wooden pin which have shown a moderate performance on the test. Based on the test conducted by differentiating the type of the joint plate and the connector, compared to the specimen(Type-DS) applied with the drift pin and steel plate, the specimen( Type-WL) applied with the GFRP reinforced laminated wooden pin and GFRP reinforced wooden laminated plate have shown 1.12 times higher shear strength and also have shown an excellent toughness even after the maximum load.

An Experimental Study on Strength Properties, Size Effect, and Fatigue Behaviour of Concrete under Biaxial Flexural Stress State (이방향 휨응력상태의 콘크리트 강도 특성, 크기효과 및 피로거동에 관한 실험적 연구)

  • Zi, Goangseup;Kim, Jihwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.901-907
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    • 2013
  • In this study, flexural strength properties of concrete under biaxial stress state were experimentally investigated. Tests for size effect and fatigue behaviour of concrete under biaxial stress were carried out by the ASTM C 1550 and the biaxial flexure test(BFT). The results given by the biaxial tests were compared to those by the third-point bending test. Test results showed that biaxial flexural strengths obtained from the ASTM C 1550 and the biaxial flexure test are greater than the strength by the third-point bending test. As the size increases, the uniaxial and biaxial flexural strength decreases. However, the slope of the size effect of the biaxial strength was greater than that of the uniaxial strength. Finally, the fatigue response of concrete under the biaxial stress state was similar with that for uniaxial stress state.

FAMILY ENVIRONMENTAL FACTORS AFFECTING TEST ANXIETY IN ADOLESCENT (청소년의 시험 불안에 영향을 미치는 가정 환경적 요인)

  • Sung, Jong-Ho;Sohn, In-Ki;Lee, Young-Sik
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.11 no.1
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    • pp.16-26
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    • 2000
  • Objectives:This study was done as a part of investigating individual and socioenvironmental factors affecting test anxiety in adolescent. The focusing of this study was detecting specific family enviromental factors affecting worry and emotionality of test anxiety. Methods:The subjects of this study were 880 middle and high school students in Seoul, Korea. To evaluate test anxiety level, Spielberger's Test Anxiety Inventory was applied and to evaluate familial factor, Moos and Moos' Family Environmental Scale was done. Results:The results were as follows. 1) Total and worry part of test anxiety scores were negatively correlated with cohesion and independence scores. Total, worry, and emotional part of test anxiety scores were positively correlated with achievement orientation and control scores. 2) High test anxiety group showed higher achievement orientation and control scores, and lower cohesion scores than low test anxiety group. 3) The higher socioeducational level of parents were, the higher three subscale (cohesion, independence, and achievement orientation) scores were, except control score. Conclusion:In therapeutic approach of adolescent's test anxiety, the importance of education and treatment of their parents should be emphasized. Parents should set their children's appropriate achievement goal, encourage their children's independency instead of control. Cohesion of familial members are also needed.

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Determining the reuse of metal mine wastes based on leaching test and human health risk assessment

  • Ju, Won Jung;Hwang, Sun Kyung;Jho, Eun Hea;Nam, Kyoungphile
    • Environmental Engineering Research
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    • v.24 no.1
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    • pp.82-90
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    • 2019
  • Meeting the regulations based on the short-term leaching tests may not necessarily assure the environmental and human health safety of reusing mine wastes. This study investigated heavy metal leachability of four metal mine waste samples (e.g., Z, Y, H, and M) and human health risk of reusing them as construction materials. The heavy metal leachability did not depend on the total heavy metal contents. For example, the Z sample contained greater amounts of As and Fe than Zn, but the leachates contained only Zn at a detectable level. This can be attributed to the crystalline structure and heavy metal fractions of the mine wastes. The leaching test results suggested that the four mine waste samples are potentially reusable. But the Z and M samples reused in industrial areas imposed carcinogenic risks. This was largely attributed to As that is exposed via dermal contact. The Y and H samples reused in residential areas imposed carcinogenic risk. The major exposure route was the ingestion of crops grown on the mine wastes and Cr was the major concern. The two-stage assessment involving leaching tests and risk assessment can be used to promote safe reuse of mine wastes.

Rapid Bioassay Technique Based on Temperature Control of Ceriodaphnia dubia (Ceriodaphnia dubia의 온도조절에 근거한 단기급성독성 조사법)

  • PARK Jong Ho;LEE Sang Ill;CHO Young Oak;LEE Won Ho;YEON Ik Jun;CHO Kyu Seok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.3
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    • pp.209-214
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    • 2004
  • A method for rapid acute toxicity test based on temperature control of Ceriodaphnia dubia has been developed and evaluated. A new toxicity test based on temperature control (TTBTC) which are based on temperature control, was developed and compared for the adsorption of the better methodology for short-term toxicity screening. Initially, daphnid larval are exposed to toxicants and at the same time the temperature of the water bath containing media is increased to high temperature $(35.5^{\circ}C).$ After 1.25 hrs of contact time, the number of the daphnids, either living (no toxic effect) or dead (toxic effect), is counted by the naked eyes. Effect of exposure time on test sensitivity was not significantly different between 1 to 1.5 hr. Comparison of the rapid 1.25 hr acute toxicity test developed in this study and the standard 48 hr acute toxicity test using heavy metals, cyanide and pentachlorophenol indicated that the 1.25 hour test provides an acceptable level of sensitivity in toxicity test for C. dubia.

Development and Validation of Crocidolite Quality Control Samples for Proficiency Analytical Testing (청석면 분석 정도관리용 표준시료 개발 및 평가)

  • Lee, Ji-Hyun;Kim, Eun-Young;Noh, Su-Jin;Park, Yong-Jin;Jeong, Jee-Yeon
    • Journal of Environmental Health Sciences
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    • v.37 no.1
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    • pp.57-63
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    • 2011
  • Crocidolite quality control (QC) sampling created by the wet generation method has been validated by validation tests such as the accuracy, precision, and storage tests. For this study we designed and developed a manufacturing apparatus and standard operating procedure for making these QC samples. The most important step in the procedure of making QC samples was the stage eliminating static electricity in asbestos fibers. This static electricity hampers the fibers clog functioning. In accuracy and precision tests by phase contrast microscopy analysis, the difference between the reference values and the studied values was at maximum 17.8%. This satisfies the AIHA proficiency analytical test criteria for asbestos. We could confirm the nearly even distribution of crocidolite fibers on the membrane filter. Also, there was no loss of fibers in the storage test after the one month.

Reproductive and Developmental Toxicity Screening Test of Ethyl Hydrogen Adipate in Rats

  • Nam, Chunja;Hwang, Jae-Sik;Han, Kyoung-Goo;Jo, Eunhye;Yoo, Sun-kyoung;Eom, Ig-Chun;Kang, Jong-Koo
    • Toxicological Research
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    • v.32 no.4
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    • pp.327-335
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    • 2016
  • This study aimed to evaluate the potential toxicity and safety of ethyl hydrogen adipate (EHA) by determining its effect on the reproductive function and development of Sprague-Dawley (SD) rats at dose levels of 0 (control), 200, 400, and 800 mg/kg/day. One male and five females of the 800 mg/kg/day died. Body weight loss was observed in the males of the 800 mg/kg/day and in females of the 400 and 800 mg/kg/day. In addition, mating indices decreased and pre-implantation loss rates increased in parental animals of the 400 and 800 mg/kg/day. The gestation index decreased in the male and female rats of the 800 mg/kg/day. Moreover, the body weight of the pups from the 800 mg/kg/day group decreased on post-parturition day 4. These results indicated that the no-observed-adverse-effect level of EHA for parental males and females was 400 mg/kg/day and 200 mg/kg/day, respectively, and that for pups was 400 mg/kg/day.

Study on ZnO Nanoparticle Dispersions in Test Media Including Natural Organic Matter for Ecotoxicological Assessment (천연유기물을 포함한 산화아연 나노입자 분산배지의 생태독성평가 적용성 연구)

  • Park, Sun-Young;Kim, Kyung-tae;Shin, Yu-jin;Kim, Ji-eun;Lee, Jae-woo;Jo, Eunhye;Sung, Hwa kyung;Kim, Pil-je;Choi, Kyung-hee;Eom, Ig-chun
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.11
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    • pp.634-640
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    • 2017
  • Toxicity and fate assessment is necessary in the evaluation of the environmental, health and safety risks of engineered nanomaaterials (ENMs). Therefore, in order to ensure the reproducibility, reliability and relevance of ENMs toxicity results, stable and monomodal dispersion protocols in toxicity test media are needed. Zinc oxide nanoparticles (nZnO) are widely used in various products such as cosmetic products, paper, paints etc. In this study, nZnO dispersions in ecotoxicity test media were produced by following a series of steps of modified National Institute of Standards and Technology (NIST) Special publication 1200-5. In addition, natural organic matter (humic acid (HA)) was used as a stabilizing agent to disperse nZnO in the test media. The hydrodynamic diameters (HDD) of the nZnO in dispersion ranged between 150 and 200 nm according to the dynamic light scattering (DLS) measurement. Based on these dispersions in ecotoxicity test using ecological species (Oryzias latipes, Daphnia magna, Pseudokirchneriella subcapitata and Chironomusus riparius), dispersion protocol was found to have a considerable potential in ecotoxicity test of ENMs.

Feasibility Study of Slug Test in Unsaturated Mine Tailings Pile of the Imgi Abandoned Mine in Busan (부산임기광산 폐석적치장에서의 순간충격시험 적용성 연구)

  • Park, Hak-Yun;Ju, Jeong-Woung;Cheong, Young-Wook;Yeo, In-Wook
    • Journal of Soil and Groundwater Environment
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    • v.12 no.3
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    • pp.10-16
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    • 2007
  • The slug test by adding water to well and measuring falling head was conducted to investigate the hydrogeological property of unsaturated or partially saturated mine tailings in the Imgi abandoned mine in Busan. In case that wells were installed with a full screen through two layers with different hydraulic properties, Bouwer and Rice method was useful to estimate the hydraulic conductivity and the depth of mine tailings. In particular, when groundwater dried out in the dry season, the slug test performed by adding water into well to form artificial water table and then conducting falling head test produced the reasonable hydraulic conductivity values. The slug test using falling head test can be an alternative to investigate the hydrogeological property of abandoned mine tailings.