• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.526-531
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• 2020

Manganese ions contained in water phase are acting as a toxic substance in the human body and also known to affect the nervous system. In particular, effective treatment technology is required since manganese removal is difficult due to its high solubility in a wide pH range. In this study, Prinus densiflora bark was chemically modified with hydrogen peroxide, and the modified adsorbent was used for removing manganese ions in an aqueous solution. The modified adsorbent showed high removal capacity of 82.1 and 56.2%, respectively, at conditions of 5 and 10 mg/L manganese ions. Also, the adsorption isotherm from the data was applied to the theoretical equation. As a result, the adsorption behavior of manganese ions was better suited to the Langmuir than Freundlich model, and it was also found from kinematics that the pseudo-second order kinetic model was more suitable. In addition, the changes of Gibbs free energy indicated that the adsorption reaction became more spontaneously with increasing temperature. Consequently, these experimental results may be used as a water treatment technology which can efficiently treat manganese ions contained in water.

• Korean Journal of Construction Engineering and Management
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• v.8 no.2
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• pp.118-126
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• 2007

Environmentally Sound and Sustainable Development (ESSD)" is a key word in recent years. The construction industry, have put a great influence on ergonomic and sustainable environment. Recently, "green building certifications", such as Indoor Air Quality (IAQ) and eco-friendly material regulation have been established. With this regard, new construction and aged-housing remodeling projects are required to meet these certification criteria. Apartment residents have great concern on eco-product, since many cases are reported that Sick Building Syndrome is caused by toxic substance from building materials. Aged-housing remodeling construction has a unique characteristic in that the residents are already determined prior to construction execution. Therefore, the analysis of resident's need for building materials in aged-housing remodeling is relatively easy compared to new building construction. As such, it is very important to analyze their preferences for eco-friendly materials prior to project execution. The purpose of this study is to find the needs of residents and priority of their needs. Based on their needs and priority, this paper provides a new strategy in using environment-friendly materials and maximizing their satisfaction level when aged housing remodeling is constructed. In addition, this paper provide new criteria in selecting new developed environmental materials in remodeling projects for the purpose of improving the safety and health level in construction industry.

• Laboraroty Animal Research
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• v.33 no.2
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• pp.57-67
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• 2017

The inhibitory effects of Asparagus cochinchinensis against inflammatory response induced by lipopolysaccharide (LPS), substance P and phthalic anhydride (PA) treatment were recently reported for some cell lines and animal models. To evaluate the hepatotoxicity and nephrotoxicity of A. cochinchinensis toward the livers and kidneys of ICR mice, alterations in related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed in male and female ICR mice after oral administration of 150, 300 and 600 mg/kg body weight/day saponin-enriched extract of A. cochinchinensis (SEAC) for 14 days. The saponin, total flavonoid and total phenol levels were found to be 57.2, 88.5 and 102.1 mg/g in SEAC, respectively, and the scavenging activity of SEAC gradually increased in a dose-dependent manner. Moreover, body and organ weight, clinical phenotypes, urine parameters and mice mortality did not differ between the vehicle and SEAC treated group. Furthermore, no significant alterations were measured in alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), blood urea nitrogen (BUN) and the serum creatinine (Cr) in the SEAC treated group relative to the vehicle treated group. Moreover, the specific pathological features induced by most toxic compounds were not observed upon liver and kidney histological analysis. Overall, the results of the present study suggest that SEAC does not induce any specific toxicity in the livers and kidneys of male and female ICR mice at doses of 600 mg/kg body weight/day.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.649-657
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• 2019

Hydrazine, which is used as a representative monopropellant, is an extremely poisonous substance and has a disadvantage that it is harmful to the human body and is very difficult to handle. In recent years, research on the development of non-toxic and environmentally friendly propellants has attracted much attention. Ammonium dinitramide(ADN) based propellant developed by Swedish Space Corporation has superior performance to hydrazine and has been commercialized through performance verification in space environment. On the other hand, the exhaust gas from a thruster nozzle collides with a satellite while it is spreading in the vacuum space, thermal load and surface contamination may occur and may reduce the performance and lifetime of the satellite. However, a study on the effect of the exhaust gas of the green propellant thruster on the satellite has not been conducted in earnest yet. Therefore, the exhaust gas behavior in space was analyzed in this study for the ADN based green monopropellant using Navier-Stokes equations and the DSMC method. As a result, it can be expected to be used as design validation data in the development of satellite when using the ADN based green monopropellant.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.306-313
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• 2022

Purpose: The purpose of this study is suggested to improve upon current existing methods of ammonia chemical accident prevention and damage reduction. Method: Ammonia is one of the most common toxic substances that causes frequent chemical accidents. And it was selected as leakage materials according to statistics on chemical accident. Based on actual cases of chemical accidents, CARIS modeling was used to compare the damage impact range of Ammonia and HCl and Cl. Also, find out problems with the current systems. Result: As a result of find out the range of accident influence that spreads to the surroundings when an ammonia chemical accident, it was longer than the range of influence of hydrochloric acid and shorter than that of chlorine. In addition, it was found that when chemical accident by ammonia, hydrochloric acid, or chlorine, there are apartments and schools, which can have an effect. Conclusion: It is decided that it is necessary to determine whether or not chemical accident prevention management plans and statistical investigations are submitted for workplaces dealing with ammonia, and detailed guidelines and reviews are necessary. In addition, it is judged that it is necessary to establish a DB for ammonia handling plants, and it is considered that information sharing and joint inspection among related organizations should be pursued.

• Clean Technology
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• v.16 no.4
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• pp.277-283
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• 2010

Eosin Y is used a colorant and dye but eosin Y is harmful toxic substance. In this study, the adsorption characteristics of granular activated carbon have been investigated for the adsorption of eosin dye dissolved in water. The effects of initial dye concentration, contact time, pH and temperature on adsorption of eosin by a fixed amount of activated carbon have been studied in batch adsorber and fixed bed. The adsorptivity of activated carbon for eosin Y were largely improved by pH control. When the pH was 3 in the sample, the eosin Y could be removed 99% of initial concentration (10 mg/L). The adsorption equilibrium data are successfully fitted to the Freundlich isotherm equation in the temperature range from 293 to 333 K. The estimated values of k and ${\beta}$ are 19.56-134.62, 0.442-0.678, respectively. The effects of the operation conditions of the fixed bed on the breakthrough curve were investigated. When the inlet eosin Y concentration is increased from 10 to 30 mg/L, the corresponding adsorption breaktime appears to decrease from 470 to 268 min at bed height of 3 cm and a constant flow rate of 2 g/min. When the initial eosin Y flow rate is increased from 1 to 3 g/min, the corresponding adsorption breaktime appears to decrease from 272 to 140 min at bed height of 3 cm and inlet concentration of 10 mg/L. Also, breaktime increased with increasing bed height at flow rate of 2 g/min and inlet concentration of 10 mg/L. And length of adsorption zone showed similar patterns.

• The Journal of Korean Medicine
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• v.44 no.2
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• pp.106-118
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• 2023

Objectives: Network pharmacology is a method of constructing and analyzing a drug-compound-target network to predict potential efficacy and mechanisms related to drug targets. In that large-scale analysis can be performed in a short time, it is considered a suitable tool to explore the function and role of herbal medicine. Thus, we investigated the potential functions and pathways of Chongmyunggongjin-dan (CMGJD) on Alzheimer's disease (AD) via network pharmacology analysis. Methods: Using public databases and PubChem database, compounds of CMGJD and their target genes were collected. The putative target genes of CMGJD and known target genes of AD were compared and found the correlation. Then, the network was constructed using Cytoscape 3.9.1. and functional enrichment analysis was conducted based on the Gene Ontology (GO) Biological process and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathways to predict the mechanisms. Results: The result showed that total 104 compounds and 1157 related genes were gathered from CMGJD. The network consisted of 1157nodes and 10034 edges. 859 genes were interacted with AD gene set, suggesting that the effects of CMGJD are closely related to AD. Target genes of CMGJD are considerably associated with various pathways including 'Positive regulation of chemokine production', 'Cellular response to toxic substance', 'Arachidonic acid metabolic process', 'PI3K-Akt signaling pathway', 'Metabolic pathways', 'IL-17 signaling pathway' and 'Neuroactive ligand-receptor interaction'. Conclusion: Through a network pharmacological method, CMGJD was predicted to have high relevance with AD by regulating inflammation. This study could be used as a basis for effects of CMGJD on AD.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.334-343
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• 2023

Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.370-385
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• 2023

Cyanobacterial harmful algal blooms (Cyano-HABs) are an international environmental problem that negatively affects the ecosystem as well as the safety of water resources by discharging cyanotoxins. In particular, the discharge of microcystins (MCs), a highly toxic substance, has been studied most actively, and various water treatment methods have been proposed for this purpose. In this paper, we reviewed adsorption technology, which is recognized as the most feasible, economical, and efficient method among suggested treatment methods for removing MCs. Activated carbons (AC) are widely used adsorbents for MCs removal, and excellent MCs adsorption performance has been reported. Research on alternative adsorption materials for AC such as biochar and biosorbents has been conducted, however, their performance was lower compared to activated carbon. The impacts of adsorbent properties(characteristics of pore surface chemistry) and environmental factors (solution pH, temperature, natural organic matter, and ionic strength) on the MCs adsorption performance were also discussed. In addition, toward effective control of MCs, the possibility of the direct removal of harmful cyanobacteria as well as the removal of dissolved MCs using adsorption strategy was examined. However, to fully utilize the adsorption for the removal of MCs, the application and optimization under actual environmental conditions are still required, thereby meeting the environmental and economic standards. From this study, crucial insights could be provided for the development and selection of effective adsorbent and subsequent adsorption processes for the removal of MCs from water resources.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.258-269
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• 2022

Background and Objectives: Currently, safety pharmacological tests for the central nervous system depend on animal behavioral analysis. However, due to the subjectivity of behavioral analysis and differences between species, there is a limit to appropriate nervous system toxicity assessment, therefore a new neurotoxicity assessment that can simulate the human central nervous system is required. Methods and Results: In our study, we developed an in vitro neurotoxicity assessment focusing on neuronal function. To minimize the differences between species and fast screening, hiPSC-derived neurons and a microelectrode array (MEA) that could simultaneously measure the action potentials of the neuronal networks were used. After analyzing the molecular and electrophysiological characters of our neuronal network, we conducted a neurotoxicity assessment on neurotransmitters, neurotoxicants, illicit drugs, and new psychoactive substances (NPS). We found that most substances used in our experiments responded more sensitively to our MEA-based neurotoxicity assessment than to the conventional neurotoxicity assessment. Also, this is the first paper that evaluates various illicit drugs and NPS using MEA-based neurotoxicity assessment using hiPSC-derived neurons. Conclusions: Our study expanded the scope of application of neurotoxicity assessment using hiPSC-derived neurons to NPS, and accumulated evaluation data of various toxic substances for hiPSC-derived neurons.