• Research in Plant Disease
• /
• v.23 no.2
• /
• pp.89-98
• /
• 2017

Ralstonia solanacearum species complex (RSSC) causes bacterial wilt, and it is one of the most important soil-borne plant pathogenic bacteria. RSSC has a large host range of more than 50 botanical families, which represent more than 200 plant species, including tomato. It is difficult to control bacterial wilt due to following reasons: the bacterial wilt pathogen can grow inside the plant tissue, and it can also survive in soil for a long period; moreover, it has a wide host range and biological diversity. In most previous studies, scientists have focused on developing biological control agents, such as antagonistic microorganisms and botanical materials. However, biocontrol attempts are not successful. Plant-derived metabolites and extracts have been promising candidates to environmentally friendly control bacterial wilt diseases. Therefore, we review the plant extracts, essential oils, and secondary metabolites that show potent in vivo antibacterial activities (in potted plants or in field) against tomato bacterial wilt, which is caused by RSSC.

• Smart Structures and Systems
• /
• v.23 no.6
• /
• pp.521-536
• /
• 2019

Using magnetorheological (MR) dampers in multiswitch open-loop control mode has been shown to be cost-effective for cable vibration mitigation. In this paper, a method for analyzing the damping performance of taut cables incorporating MR dampers in open-loop control mode is developed considering the effects of damping coefficient, damper stiffness, damper mass, and stiffness of the damper support. Making use of a three-element model of MR dampers and complex modal analysis, both numerical and asymptotic solutions are obtained. An analytical expression is obtained from the asymptotic solution to evaluate the equivalent damping ratio of the cable-damper system in the open-loop control mode. The individual and combined effects of the damping coefficient, damper stiffness, damper mass and stiffness of damper support on vibration control effectiveness are investigated in detail. The main thrust of the present study is to derive a general formula explicitly relating the normalized system damping ratio and the normalized damper parameters in consideration of all concerned effects, which can be easily used for the design of MR dampers to achieve optimal open-loop vibration control of taut cables.

• Analytical Science and Technology
• /
• v.26 no.6
• /
• pp.381-386
• /
• 2013

The sixty nine chemicals that are closely linked to chemical accident are designated as the substances requiring preparation for accidents and managed for public health under the Toxic Chemicals Control Act. In this study, storage stability of allyl chloride (AC) and carbon disulfide (CD), which are highly inflammable and volatile in tedlar bags, was studied for gaseous chemicals sampling. Storage stability was studied considering storage temperature ($2^{\circ}C$, $25^{\circ}C$), chemical concentration (low conc. ppm, high conc. ppm) and storage time (0, 48, 96, and 144 hr). Also, the stability of bags containing one type of chemical substance and the bags containing a mixture of chemicals was compared against each other. As a result, two chemicals showed decreasing storage stability based on storage time. Also two chemicals presented statistical significance of concentration and mixing type.

• Hwankyungkyoyuk
• /
• v.18 no.1 s.26
• /
• pp.120-133
• /
• 2005

This study investigated the changes of consciousness and ambivalent attitudes about the important environmental issues among the teachers who enrolled the environmental education training. Experimental and control groups were composed with 47 and 30 person, respectively. Environmental issues were constructions of sea-wall, nuclear power plant and dam. Cronbach alpha of the self-developed questionnaire was $0.6909{\sim}0.8992$. Score were made with 5 Likert scales for consciousness, and with semantic differential half scale for ambivalent attitudes. Almost teachers(94.0% and 97.1%) have above 10 years teaching career. Strangers in environmental program were 53.2%. After environmental training, teachers' consciousness was significantly changed to negative about the construction of sea-wall for the farm field and industry complex area(p=0.019), and about the construction of dam for disaster like flood(p=0.026), and for adverse effects of citizen by fog(p=0.042). They were also significantly changed to negative about the construction of nuclear power plant for economical energy(p=0.004)', no-emission of greenhouse gases(p=0.033)', 'alternative energy(p=0.000)', 'destruction of ecology(p=0.052)' and 'social fear(p=0.009)'. The consciousness of teachers who have the experience of environmental training, were significantly changed to negative about the construction of nuclear power plant. Scores of teachers' ambivalent attitudes were made lower in experimental than control group about the construction of sea-wall and nuclear power plant. After education training, they were made lower so much as -10.0% in control, but higher much as +4.4% in experimental, and severely higher much as 86.5% in teachers who had experienced the environmental training about construction of sea-wall. Their scores were made lower so much as -3.3% in control, but much as -6.4% in control.

• Biomolecules & Therapeutics
• /
• v.17 no.2
• /
• pp.113-124
• /
• 2009

Aging is a multifaceted biological process that affects all organs and organ systems of the body. This review provides an up-to-date analysis of this highly exciting, rapidly changing field of science. The aging process is largely under genetic control but is highly responsive to diverse environmental influences. The genes that control aging are those that are involved with cell maintenance, cell damage and repair. The environmental factors that accelerate aging are those that influence either damage of cellular macromolecules, or interfere with their repair. Prominent among these are chronic inflammation, chronic infection, some metallic chemicals, ultraviolet light, and others that heighten oxidative stress. Other environment factors slow the aging process. Included among these agents are resveratrol and vitamin D. In addition, dietary restriction and exercise have been found to extend human lifespan. The various mechanisms whereby all these agents exert their influence on aging include epigenetic modification, chromatin maintenance, protection of telomeres, and anti-oxidant defense, among others. The complex process of aging remains under continued, intense investigation.

• Journal of Environmental Science International
• /
• v.20 no.7
• /
• pp.799-809
• /
• 2011

Objectives: This study is aimed at identifying the influential factors on the pulmonary function of ordinary residents in the surrounding areas of Yeosu Industrial Complex. Methods: The PFT (Pulmonary Function Test) was conducted on the target residents numbering 989 people (male 361, female 628). The exposed group (813 people) resided within the radius of 5km from Yeosu Industrial Complex and the control group (176 people) resided in the radius of more than 15 km from May 2007 to November 2007. The survey also took into account other factors including personal characteristics, life habits, respiratory diseases and allergic symptoms, medical histories, and the living environments of the residents in order to further identify influential factors on pulmonary function. Result: When comparing the PFT values of the exposure groups to the control group of the same city, values of the exposure groups were meaningfully lower with an %$FEV_1$ of 107.05% and %FVC of 100.28%. Conversely, the control group reported an %$FEV_1$ and %FVC of 107.26% and 102.85% respectively, indicating that ambient air pollutants reduce lung function. The odds ratio of asthma diagnosis history increased when a subjects residence was close to a heavily trafficked road, traffic amount was huge, a bed was used, and the family had less than four members. However the results were not statistically meaningful. The odds ratios of abnormal pulmonary function were statistically higher among those with asthma(OR=4.29, CI=1.75-10.56), wheezing (OR=2.59, CI=1.24-5.41), and nasal congestion (OR=2.87, CI=1.36-6.08) (p<0.01). The factors affecting $FEV_1$ were symptoms including asthma, passive smoking and allergic eye disease ($R^2$=0.049, p<0.001). For the FVC symptoms including asthma ($R^2$=0.014, p<0.001) were measured. The analysis showed that FVC decreased with increases in $O_3$ and CO(p<0.01). Furthermore, $FEV_1$ decreased with increases in $O_3$(p<0.01). Conclusions: These results will provide preliminary data for establishing responsive measures to protect the health of residents in industrial complexes from air pollution, and to develop lasting environmental health policies.

• The Korean Journal of Malacology
• /
• v.14 no.2
• /
• pp.167-172
• /
• 1998

As a preliminary study, effects of environmetal pollutants on propagation of freshwater microalgae, Cryptomonas ovata and feeding rate of Corbicula leana were investigated at 20${\pm}$1$^{\circ}C$, over 20 days after treatment of pollutants, glucose, complex fertilizer and NH4Cl. Number of C. ovata in control group was increased from 38${\times}$104 cell/ml to 1.910${\times}$104 cell/ml after 20 days cultivation in Sorokin-Krauss medium. Increments of cell number in experimental groups treated with glucose, complex fertilizer and NH4Cl were higher than that of control group. The higher propagation rate of C.ovata was observed when 30 mg/l of glucose treated, 120 mg/l of complex fertilizer treated, and 4 mg/l of NH4Cl treated, compared with other concentrations in each pollutant treated group. The feeding rates of large size group of C. leana which fed with a living organism, C. ovata in each experimental group were higher than small size group, and slightly reduced with the increase of pollutant concentrations. The feeding rates were not significantly different between any concentrations of the pollutant, and among experimental groups treated with glucose, complex fertilizer and NH4Cl.

• Korean Journal of Soil Science and Fertilizer
• /
• v.51 no.2
• /
• pp.128-141
• /
• 2018

Industrial complex releasing huge amounts of dusts, fumes and wastewater containing heavy metal(loid)s could be a source of heavy metal(loid)s pollution in arable soil. Heavy metal(loid)s pollution in arable soil adversely affect crops safety, subsequently human being. Hence, it is important to accurately assess the heavy metal(loid)s pollution in soil using pollution indices. The objectives of this study are 1) to compare assessment methods of heavy metal(loid)s pollution in arable soils located near industrial complex in Gyeongsang provinces and 2) to determine the relationship between concentration of plant available heavy metal(loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 10 industrial complex in Gyeongsang provinces. The average total concentration of all heavy metal(loid)s of the studied soils was higher than that of Korean arable soils but did not exceed the warning criteria established by the Soil Environmental Conservation Act of Korea. Only six sites of arable soils for the total concentration of As, Cu and Ni exceeded the warning criteria (As: $25mg\;kg^{-1}$, Cu: $150mg\;kg^{-1}$, Ni: $100mg\;kg^{-1}$). The contamination factor (CF) and geoaccumulation index ($I_{geo}$) of the heavy metal(loid)s in arable soils varied among the sampling sites, and the average values of As and Cd were relatively higher than that of other metals. Results of integrated indices of As and Cd in arable soils located near industrial complex indicated that some arable soils were moderately or heavily polluted. The plant available concentration of heavy metal(loid)s was negatively related to the soil pH and negative charge of soil. Available Cd, Pb, and Zn concentrations had relatively high correlation coefficient with pH and negative charge of soil when compared with other heavy metal(loid)s. Based on the above results, it might be a good soil management to control pH with soil amendments such as lime and compost to reduce phytoavailability of heavy metal(loid)s in arable soil located near industrial complex.

• Journal of Environmental Health Sciences
• /
• v.49 no.2
• /
• pp.108-117
• /
• 2023

Background: When particles are absorbed into the human body, they penetrate deep into the lungs and interact with the tissues of the body. Heavy metals in PM_2.5 can cause various diseases. The main source of PM_2.5 emissions in South Korea's atmosphere has been surveyed to be places of business. Objectives: The concentration of heavy metals in PM_2.5 near the Ulsan Industrial Complex was measured and a health risk assessment was performed for residents near the industrial complex for exposure to heavy metals in PM_2.5. Methods: Concentrations of heavy metals in PM_2.5 were measured at four measurement sites (Ulsan, Mipo, Onsan, Maegok) near the industrial complexes. Heavy metals were analyzed according to the Air Pollution Monitoring Network Installation and Operation Guidelines presented by the National Institute of Environmental Research. Among them, only five substances (Mn, Ni, As, Cd, Cr⁶⁺) were targeted. The risk assessment was conducted on inhalation exposure for five age groups, and the excess cancer risk and hazard quotient were calculated. Results: In the risk assessment of exposure to heavy metals in PM_2.5, As, Cd, and Cr⁶⁺ exceeded the risk tolerance standard of 10^-6 for carcinogenic hazards. The highest hazard levels were observed in Onsan and Mipo industrial complexes. In the case of non-carcinogenic hazards, Mn was identified as exceeding the hazard tolerance of 1, and it showed the highest hazard in the Ulsan Industrial Complex. Conclusions: This study presented a detailed health risk from exposure to heavy metals in PM_2.5 by industrial complexes located in Ulsan among five age groups. It is expected to be utilized as the basis for preparing damage control and industrial emission reduction measures against PM_2.5 exposure at the Ulsan Industrial Complex.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.19 no.4
• /
• pp.336-346
• /
• 2009

As a follow-up survey of A Study of Monitoring Method on Exposure Level and Biomarkers of Environmental Pollutants-Focused on Ulsan Industrial Comlpex Area, published in 2005, a close examination of the health status was conducted for selected Ulsan residents. Based on the previous study, a total number of 129 subjects were divided into two groups: the exposure group consisted of 39 residents whose blood levels of lead, mercury and/or cadmium were higher than international reference values, and 90 residents of control group with normal levels. Environmental exposure level and its association with health condition were examined by various methods such as questionnaire, analyses of lead, mercury and cadmium in blood and medical examinations. The geometric mean concentrations of lead, mercury and cadmium in blood were respectively $2.07{\mu}g/d{\ell}$ (exposure $2.54{\mu}g/d{\ell}$, control $1.90{\mu}g/d{\ell}$), $5.94{\mu}g/L$ (exposure $8.57{\mu}g/L$, control $5.07{\mu}g/L$), $1.32{\mu}g/L$ (exposure $1.30{\mu}g/L$, control $1.33{\mu}g/L$). The concentrations of the three heavy metals in blood showed lower levels than internationally recommended values except for blood mercury. Also, any abnormal or, peculiar disease, or target tissue damage related to the heavy metals was not observed among the all subjects. Therefore, it can be said that no significant difference of heavy metal concentrations and health conditions was found between the two groups.