• Journal of Microbiology and Biotechnology
• /
• v.18 no.3
• /
• pp.560-567
• /
• 2008

An efficient method to produce water-soluble polysaccharides from Lentinus lepideus is described. The productivity of both endopolysaccharides (PPS) and exopolysaccharides (EPS) was compared under various culture conditions. The effect of treating their own PPS and EPS on immune cytokine production was also studied in relation to culture factors. High yield production of EPS required a moderate culture temperature $(25^{\circ}C)$ as well as long culture period (16-20 days). In contrast, PPS production required a high culture temperature $(30^{\circ}C)$ and short culture period (8 days). Most of the carbon sources did not affect polysaccharides and mycelial production except for sucrose. Immune cytokine levels in the EPS treatment varied among carbon sources or culture periods. PPS did not appear to affect much on the production of cytokines, regardless of the culturing factors, except for the culture period. These results suggest that the optimal culture conditions for L. lepideus vary according to culture purposes, and different culture conditions should be used for different targets including mycelial biomass, EPS, and PPS. Whereas the immunomodulating activitiy of EPS appeared to be affected by culture conditions in L. lepideus, that of PPS did not.

• Applied Biological Chemistry
• /
• v.9
• /
• pp.35-39
• /
• 1968

Addition of one percent cucumber, as a Kimchi component, showed the stimulation of lactic acid fermentation, by reducing the lagphase, and resulted the early matured Kimchi. Alcohol-soluble fraction from cucumber serum accerelated the growth of Lactobacillus plantarum, p-1, p-2 newly isolated strains from cucumber pickle, but had no effect on the growth rate of Streptococus faecalis. The growth promoting activity was inactivated by dialysis against water and heat treatment at $120^{\circ}C$ for 10 minutes. Softness of cucumber tissues enables to extract easily out a substance, which is thought one of the important factors for the stimulation of me growth of Lactic acid bacteria.

• Journal of Environmental Science International
• /
• v.25 no.7
• /
• pp.989-998
• /
• 2016

In this study, we analyzed the content and compensation factors of 337 cases of national environmental disputes from five recent years (2000~2014). Causes of damage were noise-vibration in 234 cases (69%), sunlight in 48 cases (14%), air pollution in 19 cases (6%), water pollution in 15 cases (4%), odor in 13 cases (4%), and others factors in 8 cases (3%). Sources of damage were construction in 224 cases (66%), structures in 36 cases (11%), vehicle on road in 31 cases (9%), industry in 18 cases (5%), environmental facility in 11 cases (3%), livestock facility in 6 cases (2%), and other sources in 11 cases (3%). From the results of logistic regression analysis, important factors associated with compensation were found to be damage amount, damage distance, zoning districts, source, and administrative disposition.

• Clean Technology
• /
• v.9 no.1
• /
• pp.37-42
• /
• 2003

Biofiltration was successfully applied to treat a mixture of volatile organic compounds(benzene, xylene) from contaminated air stream. Immobilized Ps. oleovorans biofilter was evaluated for its value in simultaneous removal of benzene and xylene from waste air stream. The variety of operating conditions were tested to evaluate important factors such as space velocity, pH, water content, etc.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.59 no.4
• /
• pp.411-416
• /
• 2010

Interest in application of ultraviolet light technology for primary disinfection of potable water in drinking water treatment plants has increased significantly in recent years. The efficacy of disinfection processes in water purification systems is governed by several key factors, including reactor hydraulics, disinfectant chemistry, and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics(CFD) model to predict velocity fields, mass transport, chlorine decay, and microbial inactivation in a continuous flow reactor. In this paper, It describe the how to design optimal UV disinfection device for ground water, BWT and rainwater. Spring shape instrument silver coated located in inner side of disinfection chamber. It make lead the active flowing movement target water and maximize disinfection performance. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method, performed simulation and proved satisfied performance.

• Advances in nano research
• /
• v.15 no.6
• /
• pp.541-550
• /
• 2023

The escalating growth of industrial sectors has led to a pervasive global problem—oil pollution, particularly in industrial areas. The release of substantial volumes of oil and its by-products into the environment has resulted in extensive contamination. Multiple factors contribute to the entry of these substances into water bodies and soils, thereby inflicting irreparable consequences on ecosystems, natural resources, and human health. Consequently, it becomes imperative to comprehend the characteristics and behavior of oil pollution, anticipate its impacts, and develop effective mitigation strategies. Understanding this intricate issue requires considering the physicochemical properties of the environment, the interactions between oil and sediments, and biological factors such as evaporation and dissolution. Although the oil industry has brought about remarkable advancements, its activities have raised significant concerns regarding pollution from extraction and production processes. Oil-rich nations face a particularly challenging predicament of soil pollution caused by petroleum compounds. The areas surrounding oil exploration mines and refineries often endure contamination due to oil leakages from storage tanks and transmission lines resulting from deterioration and damage. Investigating the dispersion of such pollutants and devising methods to remediate petroleum-contaminated soil represent crucial and intricate issues within the realm of environmental geotechnics.

• Applied Chemistry for Engineering
• /
• v.28 no.1
• /
• pp.57-63
• /
• 2017

In this study, we identified how the water content change in various NCO index affects the static comfort of polyurethane seat foam pad for automobiles. In order to identify factors that affect the static comfort, a static load test was performed using UTM to plot a hysteresis curve. The hardness of the foam when it was modified by 25, 65%, hysteresis loop area, hysteresis loss (%), and Sag factor were also obtained. By measuring the swelling ratio, it was confirmed that, as the water content increased in a fixed NCO index, the hardness and crosslinking density increased while the restoring force decreased due to the increase of urea bond. Also the Sag factor decreased due to the increase of surface hardness. As the NCO index increased in a fixed water content, the urethane and urea bond reacted more with isocyanate, leading to an increase in hardness and decrease in restoring force.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.121-121
• /
• 2004

The groundwater in the Pocheon area occurs from both a fractured bedrock aquifer in igneous and metamorphic rocks and an alluvial aquifer with a thickness of <50 m, and forms a major source of domestic and agricultural water supply. In this study, we performed a hydrogeochemical study in order to identify the control of geochemical processes on groundwater quality. For this study, groundwater level and physicochemical parameters (EC, Eh, pH, alkalinity) were monitored once a month from a total of 150 groundwater wells between June 2003 to August 2004. A total of 153 water samples (13 surface water, 66 alluvial groundwater, 74 bedrock groundwater) were also collected and analyzed in February 2004. Groundwater chemistry in the study area is very complex, depending on a number of major factors such as geology, degree of chemical weathering, and quality of recharge water. Hydrochemical reactions such as the leaching of surficial and near-solace soil salts, dissolution of calcite, cation exchange, and weathering of silicate minerals are proposed to explain the chemistry of natural groundwater. Alluvial groundwaters locally have very high TDS concentrations, which are characterized by their chloride(nitrate)-sulfate-bicabonate facies and low Na/Cl ratio. Their grondwater levels are highly fluctuated according to rainfall event. We suggest that high nitrate content and salinity in such alluvial groundwaters originates from the local recharge of sewage effluents and/or fertilizers. Likewise, high concentrations of nitrate were also locally observed in some bedrock groundwaters, suggesting their effect of anthropogenic contamination. This is possibly due to the bypass flow taking place through macropores. Tile degree of the weathering of silicate minerals seems to be a major control of the distribution of major cations (sodium, calcium, magnesium, potassium) in bedrock groundwaters, which show a general increase with increasing depth of wells. Thermodynamic interpretation of groundwater chemistry shows that the groundwater in the study area is in chemical equilibrium with kaolinite and Na-montmorillonite, which indicates that weathering of plagioclase to those minerals is a major control of hydrochemistry of bedrock groundwater. The interpretation of the molar ratios among major ions, as well as the mass balance calculation, also indicates the role of both dissolution/precipitation of calcite and Ca-Na cationic exchange as bedrock groundwaters evolves progressively.

• Applied Chemistry for Engineering
• /
• v.33 no.6
• /
• pp.563-573
• /
• 2022

This work aimed to develop a new equation for turbidity (Turb) simulation and prediction using statistical methods based on principal component analysis (PCA) and multiple linear regression (MLR). For this purpose, water samples were collected monthly over a five year period from Cheurfa dam, an important reservoir in Northwestern Algeria, and analyzed for 12 parameters, including temperature (T°), pH, electrical conductivity (EC), turbidity (Turb), dissolved oxygen (DO), ammonium (NH₄⁺), nitrate (NO₃^-), nitrite (NO₂^-), phosphate (PO₄^3-), total suspended solids (TSS), biochemical oxygen demand (BOD₅) and chemical oxygen demand (COD). The results revealed a strong mineralization of the water and low dissolved oxygen (DO) content during the summer period. High levels of TSS and Turb were recorded during rainy periods. In addition, water was charged with phosphate (PO₄^3-) in the whole period of study. The PCA results revealed ten factors, three of which were significant (eigenvalues >1) and explained 75.5% of the total variance. The F1 and F2 factors explained 36.5% and 26.7% of the total variance, respectively and indicated anthropogenic pollution of domestic agricultural and industrial origin. The MLR turbidity simulation model exhibited a high coefficient of determination (R² = 92.20%), indicating that 92.20% of the data variability can be explained by the model. TSS, DO, EC, NO₃^-, NO₂^-, and COD were the most significant contributing parameters (p values << 0.05) in turbidity prediction. The present study can help with decision-making on the management and monitoring of the water quality of the dam, which is the primary source of drinking water in this region.

• Advances in environmental research
• /
• v.6 no.3
• /
• pp.217-227
• /
• 2017

In this study, the elimination of $Ni^{2+}$ using 13X sorbent due to an electrostatic interaction was reported. The significant factors including pH, time and 13X sorbent amount were investigated using Box-Behnken design (BBD). In the optimum experimental conditions, the linear rang and limit of detection of the proposed method were 0.1-20 and $0.102mg\;L^{-1}$, respectively. The precision as RSD% was 1.3% for concentration of $2mg\;L^{-1}$. Concerning the excellent recoveries in a short time with highly efficient sample clean-up and removal, this method may be a very powerful and innovative future sample removal technique. To the best of our knowledge, this is the first report on using BBD for optimizing the parameters affected the removal of $Ni^{2+}$ by 13X zeolite sorbent.