• 보존과학연구
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• s.22
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• pp.41-52
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• 2001

The wooden building is mainly damaged by the termite which have an effect of the structure by making emptied inner part of wood. One class, Japanese termite, inhabits throughout Korea and is often detected. So the deterioration by termite attacking the wooden building needs to be controlled. Termites are over 2,800 species in the world, usually they inhabit in the tropical or subtropical region and don’t over winter in dormant condition. So their activity and distribution are chiefly restricted by temperature and humidity. The termite inhabiting in Korea is Reticulitermes speratus kyushuensis Morimoto, which known to have an optimal temperature range at $12~30^{\circ}C$ and minimum temperature at $6^{\circ}C$ for activation. These temperatures correspond to the mean temperature($5.6^{\circ}C$~$25.8^{\circ}C$) from March to November and the activity time of termitein Seoul. In addition, as a result of environmental pollution by industrial development, the climate of Korea is getting warm. The increase of mean temperature in Korea has been $1.1^{\circ}C$ for the past seventy five years, so it is expected that the damage of wooden building by termite will increase gradually. Therefore, in order to protect wooden building from damages by termite, it needs not only development of new pest control methods, but also studies on the control of environmental factors having an effect on the activity and growth of termite. For the conservation of the large cultural properties such as the wooden building in the open air, it would be effective to use the methods of fumigation, insecticidal and antiseptic chemical treatment of wood materials, soil termiticideinjection treatment, and termite colony elimination system.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.333-337
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• 2001

This study investigated the effects of fermented product from Bacillus subtilis (FPBS) on feed conversion efficiency, fat accumulation and ammonia production in broiler chicks. Sixty female broilers (strain Chunky, 7-day old) were divided into four groups and raised in individual cages. One group was fed a commercial diet without supplementation of FPBS as the control and the other three groups were fed commercial diets containing FPBS, either 0.5, 1.0 or 2.0%, for 21 days from 7 to 28 days of age. Water and feed were given ad libitum. Feed conversion efficiency was significantly improved in chicks supplemented with 0.5 or 1.0% of FPBS as compared with the control (p<0.05). The activities of hepatic acetyl-CoA carboxylase and fatty acid synthetase, and contents of triglyceride and cholesterol in the liver were significantly decreased in treatment groups (p<0.05) as compared with the control group. FPBS had no effect on the concentration of plasma triglyceride, phospholipids and cholesterol. Feeding FPBS at 1 % or 2% levels reduced ammonia gas release (p<0.05). The inclusion of FPBS at 1 % level may be recommended both to improve production efficiency and to reduce air pollution caused by ammonia gas release. For production efficiency to reach maximal profit, the inclusion of FPBS at 0.5% level can be recommended. Feeding FPBS reduced fat accumulation in the liver.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.378-387
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• 2004

This study was carried to investigate the emission characteristics of mercury from domestic and industrial MSW (municipal solid waste) incinerator stacks. The mercury concentration levels of flue gas from 32 MSW incinerators stacks selected were above the criteria level ($5{\mu}g/S\;m^3$). MSWI facilities exceeding the criteria levels in Korea are due to the poor units comparison of combustion chamber(CC)-cyclone(CY)-stack. So, the mercury from MSW incinerators stack were suspected to contaminate the natural system unless the MSW incinerators were properly controlled. Mean-while, the relationship between mercury concentration and temperature of flue gas in MSW incinerator stacks were examined at two temperature ranges (Group A : $29.85{\sim}327.63^{\circ}C$, Group B : $446.9{\sim}848.15^{\circ}C$). The mercury concentration in flue gas with high temperature range was higher than that of flue gas with low temperature rage. This mean that the temperature of flue gas plays an important role in mercury control in MSW incinerator. The emission characteristics oi mercury was also evaluated by using the correlation matrix between the mercury and NOx, $PM_{10}$, moisture (MO.) at both low temperature and high temperature flue gas ranges. The mercury concentration was mainly affected by NOx, $PM_{10}$. moisture (MO.) at low temperature range, while the mercury concentration at high temperature flue gas was mainly affected by NOx, moisture (MO.). From these results, it was suggested that the temperature of cooling system and the air pollution control device should be properly regulated in order to control mercury of flue gas in MSWI incinerator.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.88-96
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• 2008

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. This study used a split injection method at a 4 cylinder common-rail direct injection diesel engine in order to apply the partially premixed charge compression ignition combustion method without significantly altering engine specifications And it is investigated that the effects of the injection ratio and SCV(swirl control valve) to emission characteristics. From these tests, soot(g) and NOx(g) emission could be reduced to 40% and 92% compared to base engine performance at specified engine driving conditions(6 points with weight factors) according to application of split injection and SCV(swirl control valve).

• Hwankyungkyoyuk
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• v.15 no.2
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• pp.1-13
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• Hwankyungkyoyuk
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• v.15 no.1
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• pp.137-147
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily Impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene Pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• Journal of odor and indoor environment
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• v.16 no.3
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• pp.277-286
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• 2017

The objectives of this study were to investigate the effects of $PM_{10}$ and $O_3$ concentration on the symptoms of allergic diseases. The questionnaire was used to determine whether or not symptoms of allergic diseases were present from September to October 2012. The air pollution concentration data used was the corresponding point CEM (continuous emission monitoring) data. The average concentration of $PM_{10}$ was $56.09{\mu}g/m^3$ in the control area, and the concentration in the exposed area was $40.44{\mu}g/m^3$. In the two areas, concentration of $O_3$ was 28.73 ppb and 28.74 ppb, respectively. The total average concentrations of $PM_{10}$ and $O_3$ were $45.66{\mu}g/m^3$ and 28.73 ppb in the Gwangyang area. The rate of asthma diagnosis was higher in the control area (9.6%) than in the exposed area (4.1%), but the rate of allergy eye disease was higher in the exposed area (23.9%) than in the control area (16.5%). There was a significant difference in the symptoms of some allergic diseases when the relative concentration of $PM_{10}$ and $O_3$ were high and low.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.498-503
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• 2019

Electric propulsion ships are gaining widespread interest in the marine industry owing to extreme air pollution concerns. Consequently, several studies are actively being conducted for improving the power quality. Various methods have been developed that incorporate passive filters, notch filters, and active filters for reducing the harmonic content in the input current of a conventional diode front end rectifier. Among such filters, the active front end (AFE) rectifier is considered as an excellent technology. In this paper, current control for an AFE rectifier employing space vector PWM (Pulse Width Modulation) is proposed. Conventional current control methods for the AFE rectifier, hysteresis, SPWM (Sinusoidal Pulse Width Modulation), and SVPWM (Space Vector Pulse Width Modulation) were simulated by employing the PSIM software tool for analysis and comparisons. The results corroborate that SVPWM has the simplest structure and provides the best performance.

• Journal of Environmental Science International
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• v.32 no.1
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• pp.67-76
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• 2023

Under constant environmental pollution, the incidence of Atopic Dermatitis (AD) caused by air pollutants and allergens has increased. AD is an allergy inflammatory skin disease characterized by pruritus, eczema, and skin dryness. In herbal medicine, Anemarrhena asphodeloides (Anemarrhenae Rhizoma; AR) has been utilized to treat Alzheimer's disease, osteoporosis, hypertension, and inflammation. The purpose of study evaluated the effect of AR in a mouse model of 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions. After acclimatization for 5 days, the mice (6-week-old, male Balb/c) were divided into five groups (n=6/group): NC (normal control), DNCB (control), Dex (5 mg·kg-1, p.o.), AR100 (100 mg·kg-1, p.o.), and AR300 (300 mg·kg-1, p.o.). On days 1 and 3, 1% DNCB was applied to the skin and ears. After 4 days, 0.5% DNCB was applied once every 2 days for 2 weeks. Then, skin and ears eczema area and severity index (EASI); skin nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) levels; and plasma immunoglobulin E (IgE) levels were examined. The AR groups showed lower EASI, skin and ear thickness, mast cell count, and IgE levels than the control groups. Moreover, AR reduced iNOS, COX-2, and PGE2 levels. Therefore, AR possesses anti-inflammatory properties and can improve skin damage, indicating its therapeutic potential against AD.

• Corrosion Science and Technology
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• v.4 no.6
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• pp.242-249
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• 2005

A lot of parts in FGD (Flue Gas Desulfurization) systems of fossil-fuel power plants show the environments in which are highly changeable and extremely acidic corrosive medium according to time and locations, e.g. in duct works, coolers and re-heaters etc. These conditions are formed when system materials are immersed in fluid that flows on them or when exhausted gas is condensed into thin layered acidic medium to contact materials of the system walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of the condensed solution. To cathodically protect the metallic structures in extremely acidic fluid, the properties of the protective coatings on the metal surface were very important, and epoxy Novolac coating was applied in this work. On the base of acid immersion tests, hot sulfuric acid decreased the hardness of the coatings and reduced greatly the content of $Na_2O$, $Al_2O_3$, and $SiO_2$ among the main components of the coating. A special kind of CP(Cathodic Protection) system has been developed and tested in a real scale of the FGD facility. Applied coating for this CP system was peeled off and cracked in some parts of the facility. However, the exposed metal surface to extremely acidic fluid by the failure of the coatings was successfully protected by the new CP system.