• Environmental Analysis Health and Toxicology
• /
• v.22 no.2 s.57
• /
• pp.171-175
• /
• 2007

Indigenous species means a species that is likely, due to historical presence, to occur at a specified site for some portion of its life span. Therefore, indigenous species can be useful as an indicator to assess environmental risk caused by hazardous chemicals in a specific site. So far a few toxicity studies using freshwater species which are indigenous to Korea have been carried out. In this study, a freshwater shrimp (Neocardina denticulata) indigenous to Korea was used for acute toxicity test of heavy metals. Neocardina denticulata were exposed to cadmium chloride $(CdCl_2)$, copper chloride $(CuCl_2)$ and zinc chloride $(ZnCl_2)$ using automatic flow-through system for 96 hours. The 96h LC50s were calculated as 0.043 $(0.042{\sim}0.045)mg\;CdCl_2/L,\;0.104(0.098{\sim}0.113)mg\; CuCl_2/L\;and\;2.021\;(1.633{\sim}2.594)mg\;ZnCl_2/L$. When compaired with some international standard species such as medaka(Oryzias latipes), Neocardina denticulata had high sensitivity. Therefore, this study suggested that Neocardina denticulata have possibilities for a sensitive test species to test heavy metal toxicity in aqua-system.

• Journal of the Korean Society of Safety
• /
• v.34 no.6
• /
• pp.22-28
• /
• 2019

In South Korea, the enact of Korean Coast Guard Act-1 manages physical and chemical oil-dispersants. Oil snare, which is made of polypropylene, is newly added to the aforementioned act, and it has advantage on the ease of recovery compare to other adsorbents. This study synthesized bunker B-oil with diesel-oil and bunker C-oil to perform an adsorption test based on three samples which were manufactured in South Korea. As a result, adsorption test revealed 5.2 g/g more adsorption than the previous results from the act. Additional toluene test revealed that all the samples satisfied 90.0%, however coloured samples could release its pigment on the marine environment. Thus, colorless samples are recommended on the risk management of marine accidents. The study on the basic direction of the calculation of the test items and the standard value for the quality control of the oil snare was also carried out.

• Membrane and Water Treatment
• /
• v.14 no.4
• /
• pp.181-189
• /
• 2023

The Covid-19 pandemic has increased demand for chlorine-based sanitizing solutions, most of which contain hypochlorous acid (HOCl) as an active agent. Free chlorine (HOCl) in these sanitizers is crucial for their efficacy. Disposable test strips are affordable and convenient tools for determining various qualitative and quantitative parameters. In this study, disposable opto-chemical test strips were developed by physically immobilizing 3,3',5,5'-tetramethylbenzidine (TMB) and o-dianisidine (o-D) reagents on chromatography and filter paper-based test strips for the visualization and detection of free chlorine in the form of HOCl. The reagents undergo a rapid color change upon reaction with chlorine through a redox reaction. The paper-based test strips showed rapid color change within a minute and a low sample volume requirement (1 ml). This portable, disposable paper-based test strip is a simple and cost-effective way to rapidly detect the presence of HOCl sanitizers for home and field applications. Both TMB and o-D successfully detected chlorine. Chromatography paper proved to be the more efficient option among the two papers used as substrates for the reagents (TMB and o-D). It exhibited high retention capacity and high performance in terms of color transformation when reacting with HOCl, even after two months of storage.

• Hwankyungkyoyuk
• /
• v.17 no.1
• /
• pp.90-100
• /
• 2004

This study has the goal to modify ‘Investigating and Evaluating Environmental Issues and Actions’(IEEIA) instruction in the sense of Korean ecological sociocultural characteristics and ‘ecology and environment' curriculum and to assess the effects of modified IEEIA instruction on responsible environmental behavior and associated variables in high school student. A modified pre- and post-test nonequivalent control group design was utilized with 4 intact classes from J-high school at Seo-cheon, Chungcheongnamdo. Pre- and post-test data were collected on the following variables: responsible environmental behavior, knowledge of and skill in using environmental actions strategies, in-depth knowledge about issues, and locus of control. Analysis of t-test was used to compare pretest with posttest means of treatment group and control group. In treatment group, statistically significant differences between pretest and posttest were found with all variables. The treatment was found to be more effective than the control in increasing the variables of responsible environmental behavior, knowledge of and skill in using environmental actions strategies, and locus of control.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.12
• /
• pp.13-18
• /
• 2010

This study was made on the fact that the environmental impact and durability of the recently developed alkali silicasol chemical grout material. The grout material used for this study was designed to understand its environmental impact and durability through the SEM, chemical resistance test, leaching test, permeability test. In order to compare with the engineering characteristics regarding alkali silicasol grout material and sodium silicate grout material. As a result of SEM, the surface and internal tissues of alkali silicasol grout material could be identified to be denser than those of sodium silicate. As a result of leaching test the adaptability was identified as grout material as it had proved to be an ecological material owing to the total amount of the element to be leached being extremely little. As a result of permeability test it is judged that it is possible to apply the silicasol to the site in the place requiring the water cut-off as the silicasol.

• Environmental Engineering Research
• /
• v.18 no.3
• /
• pp.129-137
• /
• 2013

The infiltration of rainwater into the surface soil is highly dependent on hydraulic variables, such as the infiltration rate, capillary fringe, moisture content, and unsaturated/saturated hydraulic conductivity. This study estimates the hydraulic conductivity (K) of fluvial deposits at three sites on the right and left banks of Nakdong River in Gyeongbuk Province, South Korea, including the Gumi, Waegwan, and Seongju bridge sites. The K values of 80 samples from 13 boreholes were estimated by using six grain-size methods (Hazen, Slichter, Kozeny, Beyer, Sauerbrei, and Pavchich formulae). The Beyer, Hazen, and Slichter methods showed a better relationship with K values along with an effective grain size than did the other three methods. The grain-size, pumping test, and slug test analyses resulted in different K values, but with similar K values in the grain-size analysis and pumping test. The lower K values of the slug test represent the uppermost fine sand layer.

• Environmental Analysis Health and Toxicology
• /
• v.28
• /
• pp.2.1-2.7
• /
• 2013

Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration ($LC_{50}$) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration ($EC_{50}$) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr $EC_{50}$ was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, $L(E)C_{50}$ was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.

• Journal of the Korean Home Economics Association
• /
• v.41 no.12
• /
• pp.169-186
• /
• 2003

The purpose of this study were (1) to examine the level of housewives' pro- environmental behavior, and (2) to analyze the effect of the selected variables on pro-environmental behavior 941 sample were selected from housewives living in urban area. For the analysis of data, frequencies, means, one-way ANOVA, DMR test, Chi-square test, and multiple regression analysis were used. The major findings were as follows：1. The level of housewives' pro-environmental behavior was lower than that of pro-environmental attitude. 2. The level of housewives' pro-environmental behavior was mainly affected by their environment-related variables, for example, pro-environmental attitude, and experience of environmental education. Most of socio-demographic variables and family-related variables didn't have significant effects on the level of pro-environmental behavior.

• Journal of Applied Reliability
• /
• v.18 no.3
• /
• pp.229-239
• /
• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• Journal of the Korean Statistical Society
• /
• v.9 no.2
• /
• pp.194-212
• /
• 1980

This report describes a preliminary study necessary to implement Measurement Assurance Program (MAP). The purpose of the study is to improve the measurement reliability of the laboratories which take environmental pollution measurement. We carried out the interlaboratory test or "Round-Robin" test program in which seven laboratories participated in order to obtain more reliable data about water pollution.pollution.