• 환경영향평가
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• 제2권2호
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• pp.1-11
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• 1993

Most developing countries are experiencing rapid urbanization and the associated growth of industry and services. Cities are currently absorbing two-thirds of the total population in the developing world. Korea has about 85 percent of urban dwellers. World population will shift from being predominantly rural to predominantly urban around the turn of the century. Although cities play a key role in development process and make more than a proportionate contribution to national economic growth, especially cities are also the main catalysts of economic growth in developing countries, they can also be unhealthy, inefficient, and inequitable places to live. Most developing countries are increasingly unable to provide basic environmental infrastructure and services, whether in the megacities or in secondary urban centers. Of particular concern is the strain on natural resources brought by the increasing number of people, cars, and factories. They are generating ever greater amounts of urban wastes and emissions. They also exceed the capacity of regulatory authorities to control them and of nature to assimilate them. The environmental consequences are translated into direct negative impacts on human health, the quality of life, the productivity of the city, and the surrounding ecosystems. Environmental degradation threatens the long tenn availability and quality of natural resources critical to economic growth. Cities, with their higher and growing per capita energy use for domestic, industrial, and transport purpose also contribute a disproportionate share of the emission leading to global warming and acid rain. An important priority is to develop strategic approaches for managing the urban environment. The design of appropriate and lasting strategic responses requires first an understanding of the underlying causes of urban environmental deterioration, it is necessary that longer tenn objectives should be set for urban area to avoid irreversible ecological damage and to ensure lasting economic development. As a means to the preventive policies against the adverse effect, environmental impact assessment (EIA) serve to identify a project's possible environmental consequences early enough to allow their being taken into consideration in the decision making process for urban planning. This paper describes some considerations of EIA for urban planning-scoping, assessment process, measurement and prediction of impacts, pollution controls and supervision, and system planning for environmental preservation.

• Advances in environmental research
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• 제2권3호
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• pp.167-177
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• 2013

We investigated that removal of aqueous U(VI) by nano-sized Zero Valent Iron (nZVI) and Fe(II) bearing minerals (controls) in this study. Iron particles showed different U(VI) removal efficiencies (Mackinawite: 99%, green rust: 95%, nZVI: 91%, magnetite: 87%, pyrite: 59%) due to their different PZC (Point of Zero Charge) values and surface areas. In addition, noticeable amount of surface Fe(II) (181 ${\mu}M$) was released from nZVI suspension in 6 h and it increased to 384 ${\mu}M$ in the presence of U(VI) due to ion-exchange of U(VI) with Fe(II) on nZVI surface. Analysis of Laser-Induced Breakdown Detection (LIBD) showed that breakdown probabilities in both filtrates by 20 and 200 nm sizes was almost 24% in nZVI suspension with U(VI), while 1% of the probabilities were observed in nZVI suspension without U(VI). It indicated that Fe(II) colloids in the range under 20 nm were generated during the interaction of U(VI) and nZVI. Our results suggest that Fe(II) colloids generated via ion-exchange process should be carefully concerned during long-term remediation site contaminated by U(VI) because U could be transported to remote area through the adsorption on Fe(II) colloids.

• 환경영향평가
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• 제15권6호
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• pp.425-433
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• 2006

Instrumental neutron activation analysis was used to measure the concentrations of 27 elements associated with respirable particulate matter (PM10) that were collected from the Third and Fourth Industrial Complex Area of Daejeon City. The distribution patterns of elements were clearly distinguished with their concentrations varying across more than four orders of magnitude. The mean for Al were recorded to be the highest value of 1,527 $ng/m^3$, while that for In showed the lowest value of 0.1 $ng/m^3$. If compared in terms of enrichment factors, it was found that certain elements (e.g., As, Br, Cl, Cr, I, In, Sb, Se, and Zn) are enriched in PM10 samples of the study site. The results of factor analysis indicated six factors with statistical significance, which may exert dominant controls on regulating the elemental concentration levels in the study area.

• Smart Structures and Systems
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• 제6권4호
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• pp.349-362
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• 2010

Ultrasonic Guided Waves (UGWs) are a useful tool in structural health monitoring (SHM) applications that can benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes a SHM method based on UGWs, discrete wavelet transform (DWT), and principal component analysis (PCA) able to detect and quantify the onset and propagation of fatigue cracks in structural waveguides. The method combines the advantages of guided wave signals processed through the DWT with the outcomes of selecting defect-sensitive features to perform a multivariate diagnosis of damage. This diagnosis is based on the PCA. The framework presented in this paper is applied to the detection of fatigue cracks in a steel beam. The probing hardware consists of a PXI platform that controls the generation and measurement of the ultrasonic signals by means of piezoelectric transducers made of Lead Zirconate Titanate. Although the approach is demonstrated in a beam test, it is argued that the proposed method is general and applicable to any structure that can sustain the propagation of UGWs.

• 환경위생공학
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• 제24권4호
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• pp.80-89
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• 2009

In the organic waste, food waste is the most difficult controls. In the study, food waste was treatmented to removal only the dockage. To decrease the hydrogen sulfide($H_2S$) in the produced biogas, iron chloride put in the anaerobic digester. Respectively treatment quantity of the food waste, content of the methane($CH_4S$) gas in the biogas, produced gases quantity, put in the quantity of the Iron chloride, pH, TS, Alkalinity, VFA, Ammonia. The results obtained from the experiment are as follows: 1. The produced biogases quantity/the treatment quantity of the food waste was $83.82{\sim}129.41m^3/ton$. 2. The content of the hydrogen sulfide($H_2S$) in the produced biogas is below of the 500ppm. The iron chloride put in the anaerobic digester. 200~300kg of the iron chloride put in the anaerobic digester at the steady-state. 400~850kg of the iron chloride put in the anaerobic digester at the unsteady-state. 3. Factor of the operator was the pH: 7.7~8.4, content of mathane: 55~65%. 4. TS(total solid) of the digestor sludge was 17~20%, Alkalinity was 38,500~41,750ppm, VFA(Volatile Fatty Acids) was 2,800~2,420ppm, Ammonia was 4,300~3,650ppm.

• 한국산업보건학회지
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• 제21권4호
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• pp.193-200
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• 2011

Objectives: Blood lead and hyperhomocysteinemia have been found to be associated with cardiovascular disease. The objective of the present study was to assess the relationship of lead biomarkers on plasma homocysteine and blood pressure. Methods: To evaluate the effect of lead biomarkers including blood lead on plasma homocysteine and blood pressure in retired lead workers, 66 retired lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 42 controls were recruited from same area of retired lead workers with consideration of demographic characteristics. Results: The mean levels of blood lead and ZPP of retired lead workers were significantly higher than control group. There were positive significant correlations between blood lead and plasma homocysteine, also systolic and diastolic blood pressure. The multiple linear regression analysis also reveled that plasma homocysteine was significantly associated with blood lead after adjusting for age, gender, body mass index, lead exposure, smoking and drinking. Diastolic blood pressure was significantly associated with blood lead, plasma homocysteine, and total cholesterol; whereas, systolic blood pressure was significantly associated with plasma homocysteine only. Conclusions: Blood lead showed significant association with plasma homocysteine and blood pressure even after more than mean 10 years from their retirements.

• 한국발생생물학회지:발생과생식
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• 제21권2호
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• pp.215-221
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• 2017

Bitter melon (Momordica charantia, MC) has been used in traditional Korean medicine in treating diabetes. In addition, some reports were emerged, showing the antifertility activities of MC in mammals. We investigated the effects of ethanolic MC extract on the reproductive activity of golden hamsters whose spermatogenetic capacity is controlled by their photoperiods. The animals were divided into 4 groups: long photoperiod (LP) control, short photoperiod (SP) control, and LP animals treated with MC. The animals were orally ingested with low (0.03 g/kg) or high (0.15 g/kg) concentrations of the ethanolic extracts for 8 weeks on the daily basis. The control animals received the vehicle. The animals were then mated with age-matched females, experienced pregnancy. As results, the LP control animals showed active large testes but SP control animals displayed remarkably reduced testes. The animals treated with both concentrations of MC extracts demonstrated large testes, indicating fertile activity as animals in LP. LP control animals had litters as expected, but SP controls had no litters at all. MC extract showed the same results as LP animals in generating offsprings. These results suggest that the MC extract does not change the photoperiodic influence on reproductive activity of male golden hamsters.

• 한국물환경학회지
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• 제22권4호
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• pp.706-710
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• 2006

To evaluate impacts of the construction noise, Trionyx sinensis, inland fishers aquacultural organism, were exposed to control groups (about 55 dB) and noise groups (80 dB). The survival, growth rate and feeding efficiency of the juvenile Trionyx sinensis were measured at 10, 20 and 30 days intervals (each 9 hours/day). No significant mortality occurred during the experiments, but growth rates (1.7 times) and feeding efficiency (1.83 times) showed significant reduction in time-dependent manner. Also, serum cortisol (6.7 times) and corticosterone levels (1.37 times) in noise groups significantly increased by the noise exposure, compared to the controls, In conclusion, this study may provide the fundamental knowledge on adverse effects Trionyx sinensis and apply to assessments on the impacts of aquaculture industry by construction noise.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2003년도 학술대회지
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• pp.97-103
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• 2003

Phytochrome controls diverse aspects of plant development in response to the ambient light conditions. HFRl, a basic helix-loop-helix protein, is required for a subset of phytochrome A (phy A)-mediated photo-responses in Arabidopsis. Here, we show that overexpression of HFR1-N105, but not the one of the full-length HFR1, confers exaggerated photo-responses. The transgenic plants overexpressing HFR1- N105 exhibited light-independence in a subset of photo-responses, including germination, de-etiolation, gravitropic hypocotyl growth, and blocking of greening. Overexpression of HFR1-N105 also caused constitutive light-responses in the expression of some light-regulated genes. In addition, the HFR1-N105 overexpressor showed hypersensitive responses under R and FR light, dependently on phyB and phyA, respectively. End-of-day far-red light response and petiole elongation were suppressed in the HFR1-N105 overexpressor plants. Together these results imply that overexpression of HFR1-N105 activated a branch of light signaling, supporting the hypothesis that transcriptional regulation in the nucleus would be the primary mechanism of light signaling in Arabidopsis. We discuss the biotechnological potential of the mutant bHLH protein, HFR1-N105 in regard to suppressed shade avoidance syndrome.

• 자원환경지질
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• 제32권1호
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• pp.101-111
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• 1999

Sedimentary organic matter, exposed to continental surficial environment, reacts with oxygen supplied from the atmosphee and forms carbon-containing oxidation products. Knowledge of the rate and mechanisms of sedimentary organic matter weathering is important because it is one of the major controls on atmospheric oxygen level through geologic time. Under the abiological conditions, the oxidation rate of coal organic matter by molecular oxygen is enhanced by the increase of oxygen concentration and temperature. At ambient temperature and pressure, aqueous coal oxidation results in the formation of dissolved $CO_2$ dissolved organic carbon and solid oxidation products which are all quantitatively significant reaction products. The effects of pH, ultraviolet light, and microbial activity on the weathering of sedimentary organic matter are poorly contrained. Based on the results of geochmical and environmental studies, it is believed that the photochemical reaction should play an important role in the decomposition and oxidation of sedimentary organic matter removed from the weathering profile. At higher pH conditions, the production rate of DOC can be accelerated due to base catalysis. These high molecular weight oranic matter can react with man-made pollutants such as heavy metal ions via adsorption/desorption or ion exchange reactions. The effect of microbial activity on the oxidative weathering of sedimentary organic matter is poorly understood and remains to be studied.