간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제25권 제4호 (2016년 4월) 14건
ORIGINAL ARTICLE
1.
2016.04
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We assessed the distribution of benthic macroinvertebrate at four surveying sites in Upo Wetland, a Ramsar site and the largest wetland in Korea, from February 2006 to November 2013. A long-term ecological monitoring was done monthly by using quantitative sampling method with dip net for analyzing the community change and correlation between the biodiversity and the environmental factors because environmental factors have a decisive effect on the community structure of the benthic macroinvertebrates. Total samples from the Upo Wetland area were classified into 3 phyla, 6 classes, 17 orders, 68 families, 176 species, and 25,720 individuals. Among the 176 species, 62 of the species had not been previously reported in this area. Asellus sp., Diplonychus esakii, and Gyraulus chinensis were the most common species in Upo Wetland. The change patterns of annual species diversity and species richness were calculated by using the average number of monthly occurring species and individuals. Diversity index increased from March to May and decreased after that showing lower diversity indices in July and August. It increased again in September and in October. Richness index showed similar tendency and fell around February and July, followed by a rising tendency around May and October. Correlation and regression analyses were performed with the change of biodiversity and each environmental factor. We found that water temperature have very significant positive correlation with species diversity in spring, and have significant indices in autumn and winter. On the other hand, precipitation showed a significantly negative correlation value in summer and autumn suggesting it has an effect on the community structure of benthic macroinvertebrates.
2.
2016.04
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We examined the effects of ocean acidification (OA) and eutrophication on the physiology of a red alga, Gracilariopsis chorda, using specimens collected at Wando Island, Korea, in July of 2015. The samples were transported to a laboratory and placed on growth media for treatments involving low or high levels of ammonium (4 μM or 60 μM NH4 +) and low or high pH (7.5 or 8.2). The control treatment used filtered seawater (pH 8.2 and 4 μM NH4 +). All experiments were conducted at 20°C and under a lighting intensity of 80 μmol photons m-2 s-1, with or without an injection of CO2 (pH 7.5). In addition, we calculated rates of respiration under darkness, at a pH of 7.5 and 60 μM NH4 +. Fluctuations in pH as well as the evolution of photosynthetic oxygen and NH4 + uptake rates were monitored for 6 h. The greatest increase in pH levels, from 7.50 to 8.65, occurred in response to 60 μM NH4 +, whereas the largest decrease, from 7.50 to 7.42, was associated with elevated respiration rates. At a pH of 7.5, rates of oxygen evolution were higher (236% saturation) for samples treated with 60 μM NH4 + than for the control (121% saturation). Ammonium uptake was highest at pH 7.5 and 60 μM NH4 +, with a rate of 0.526±0.002 μmol g-1 FW h-1, followed in order by the treatments of pH 8.2/60 μM NH4 +, pH 7.5/4 μM NH4 +, and the control (pH 8.2/4 μM NH4 +). We speculated that the rates of photosynthesis and NH4 + uptake could be enhanced at a higher ammonium concentration and lower pH because CO2 concentrations were increased through greater photosynthetic activity. Therefore, these findings suggest that the physiology of G. chorda populations can be improved by the interaction of optimized CO2 concentrations and an adequate supply of essential nutrients such as ammonium.
3.
2016.04
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On the basis of conducting a comprehensive investigation to agricultural sightseeing garden landscape resources, we established a evaluation index system of agricultural sightseeing garden landscape resources. From the perspective of experts, comparing the importance of all levels indicators, we obtained the weights of landscape resources evaluation index through using the Analytic Hierarchy Process. The result showed that the descending order of the weights of influence of agricultural sightseeing garden nineteen evaluation index is: reach ability (0.128), safety (0.083), location (0.078), participatory (0.076), cultural value (0.058), ecological conditions (0.057), scenic beauty (0.0505), environmental quality (0.051), featured properties (0.0501), environmental tolerance (0.048), reputation (0.047), environmental capacity (0.045), humanize (0.041), spots configuration (0.034), applicable travel period (0.033), scientific value (0.032), art value (0.031), holistic (0.03), suitability (0.027), it can provide a framework and basis for the planning, management, protection and exploitation of agricultural sightseeing garden landscape resources.
4.
2016.04
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This study, examines the flow characteristics of upstream channel depending on water gate operation of Nakdan Multi-fuctional weir. The specific purpose of this study are to simulate the variation of flow velocity depending on the operation of the weir using 1-dimensional hydraulic model, HEC-RAS, and compare it with observed velocity. For discharge conditions from 50 ㎥/s to 3,500 ㎥/s, it is observed that the velocity of upstream channel is almost constant, whereas for probability flood discharge, the velocity and froude number are increased as the discharge values are increased. The velocity values for downstream boundary condition EL, 40.0 m are more decreased than those for EL. 40.5m. From comparison on the variation of water stage depending on water gate operation, it is observed that the stage values are almost constant for discharges below 300 ㎥/s, whereas 5 cm to 20 cm for discharges over 700 ㎥/s. Flow velocity at streamflow gauging station. Nakdong, is decreased by more than 875% after installing the weir. The results obtained from this study indicate that the velocity of upstream channel is decreased and the discharge and velocity of downstream channel are significantly varied after installing the weir.
5.
2016.04
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Estimation of an Occupational Exposure Limit for Multi-Walled Carbon Nanotubes Manufactured in Korea
With the development of nanotechnology, nanomaterials are used in various fields. Therefore, the interest regarding the safety of nanomaterial use is increasing and much effort is diverted toward establishment of exposure assessment and management methods. Occupational exposure limits (OELs) are effectively used to protect the health of workers in various industrial workplaces. This study aimed to propose an OEL for domestic multi-walled carbon nanotubes (MWCNTs) based on animal inhalation toxicity test. Basic procedure for development of OELs was examined. For OEL estimation, epidemiological study and quantitative risk assessment are generally performed based on toxicity data. In addition, inhalation toxicity data-based no observed adverse effect level (NOAEL) and benchmark dose (BMD) are estimated to obtain the OEL. Three different estimation processes (NEDO in Japan, NIOSH in USA, and Baytubes in Germany) of OELs for carbon nanotubes (CNTs) were intensively reviewed. From the rat inhalation toxicity test for MWCNTs manufactured in Korea, a NOAEL of 0.98 mg/㎥ was derived. Using the simple equation for estimation of OEL suggested by NEDO, the OEL of 142 μg/㎥ was estimated for the MWCNT manufacturing workplace. Here, we used test rat and Korean human data and adopted 36 as an uncertainty factor. The OEL for MWCNT estimated in this work is higher than those (2-80 μg/㎥) suggested by previous investigators. It may be greatly caused by different physicochemical properties of MWCNT and their dispersion method and test rat data. For setting of regulatory OELs in CNT workplaces, further epidemiological studies in addition to animal studies are needed. More advanced technical methods such as CNT dispersion in air and liquid should be also developed.
6.
2016.04
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In order to treat groundwater containing high levels of nitrate, nitrate reduction by nano sized zero-valent iron (nZVI) was studied using batch experiments. Compared to nitrate removal efficiencies at different mass ratios of nitrate/Fe0, the removal efficiency at the mass ratio of 0.02% was the highest(54.59%). To enhance nitrate removal efficiency, surface modification of nZVI was performed using metallic catalysis such as Pd, Ni and Cu. Nitrate removal efficiency by Cu-nZVI (at catalyst/Fe0 mass ratio of 0.1%) was 66.34%. It showed that the removal efficiency of Cu-nZVI was greater than that of the other catalysts. The observed rate constant (kobs) of nitrate reduction by Cu-nZVI was estimated to 0.7501 min-1 at the Cu/Fe mass ratio of 0.1%. On the other hand, TEM images showed that the average particle sizes of synthetic nZVI and Cu-nZVI were 40~60 and 80~100 nm, respectively. The results imply that catalyst effects may be more important than particle size effects in the enhancement of nitrate reduction by nZVI.
7.
2016.04
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The biological wastewater treatment plant, which uses microbial community to remove organic matter and nutrients in wastewater, is known as its nonlinear behavior and uncertainty to operate. Therefore, operation of the biological wastewater treatment process much depends on observation and knowledge of operators. The manual inspection of human operators is essential to manage the process properly, however, it is impossible to detect a fault promptly so that the process can be exposed to improper condition not securing safe effluent quality. Among various process faults, equipment malfunction is critical to maintain normal operational state. To detect equipment faults automatically, the dynamic time warping was tested using on-line oxidation-reduction potential (ORP) and dissolved oxygen (DO) profiles in a sequencing batch reactor (SBR), which is a type of wastewater treatment process. After one cycle profiles of ORP and DO were measured and stored, they were warped to the template profiles which were prepared already and the distance result, accumulated distance (D) values were calculated. If the D values were increased significantly, some kinds of faults could be detected and an alarm could be sent to the operator. By this way, it seems to be possible to make an early detecting of process faults.
8.
2016.04
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Influence of Waterlogging Period on the Growth, Physiological Responses, and Yield of Kimchi Cabbage
This study was conducted to investigate effects of waterlogging on the growth, physiological responses, and yield of Kimchi cabbage. The growth of Kimchi cabbage with applied optimized air temperature (set to 20℃) was greater than those with high air temperature (set to 30℃) and the growth significantly decreased by severe waterlogging treatment. The net photosynthetic rate of outer leaves on one hour after waterlogging treatment was higher at 72 hours waterlogging treatment in 20℃ and lower at 24 hours of waterlogging treatment in 30℃. The root activity was decreased by the elevation of waterlogging periods in 20℃ treatment and lower by the short of waterlogging periods in 30℃ treatment. The ratio of formality with non-waterlogging treatment was approximately 64% under 20℃ air temperature and that of range was from 16 to 30% under 30℃. The yield under 20℃ showed higher than that under high air temperature. The non-waterlogging treatment in 20℃ had 4,463 kg/10a, which was the greatest among all treatments, while yields of non-waterlogging treatment at 30℃ were significantly low as 1,082 kg/10a. Results suggested that additional drainage work should be needed to overcome waterlogged conditions of open field during heavy rainfall and should be drainage as soon as possible if there are waterlogging.
9.
2016.04
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Sangju, a city in the North Gyeongsang Province, is well known as “Three Whites”, representing its three main agricultural products: rice, silkworm, and dried persimmons. Therefore, development of a variety of dishes or products that can promote the consumption of dried persimmons is an urgent requirement for this region. This study was designed to provide fundamental information for revitalizing community-based specialized agriculture through scientific inquiry into medicinal foods and to develop a medicinal food menu based on the results of previous research and pre-survey. The pre-survey results and incompatibility revealed that palatability influenced people’s decision to consume dried persimmons far more than pharmacological functionality. Therefore, palatability played an important part in the development of dried persimmon puddings with acceptable texture. These dishes are in high demand as they suit the tastes of variety of consumers. The inclusion of various additives lowered the sugar content in the developed foods and made the products alkalescent (pH > 7), thereby improving functionality. Unique color and flavor additives were also important criteria that determined the selection attributes of the developed medicinal foods. In addition, the additives had a positive effect on the fragrance and texture of the foods. In conclusion, the results suggested that use of additives provides significant advantages in promoting the consumption of Sangju-dried persimmons by improving both functionality and palatability.
10.
2016.04
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In nine commercial watermelon cultivars, the effects of osmotic seed priming were evaluated for seed viability and seedling growth at different germination temperatures and field conditions. Generally, primed seeds showed improved germination rate and reduced time for emergence at different germination temperatures, as compared to untreated seeds. In particular, priming effect on seed germination was significantly high at 15℃, which is an environment normally resulting in poor germination. Depending on the watermelon cultivar, germination rate under low temperature (15℃) was improved by up to 15~66% in primed seeds, as compared to untreated seeds. However, priming effect on germination was gradually reduced as the temperature reached to its optimum level for seed germination. Seed priming tended to improve the viability, fresh weight, and dry weight of watermelon seedlings, but its effect on seedling stage was not large, as compared to untreated seeds. Primed watermelon seeds showed improved emergence rate and facilitated germination in the field, but their seedling growth after 30 days from germination was not significantly affected. Our results indicated that seed priming can greatly improve the seed germination at poor temperature conditions in the watermelon.
11.
2016.04
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The purpose of this study was to measure the antioxidant activity and bioactivity of black chokeberry (Aronia melanocarpa). The black chokeberry was known to contain many physiologically active substance, such as ascorbic acid, anthocyanin, quercetin. We extracted black chokeberry powder from four solvents such as chloroform:methanol(CM, 2:1, v/v), distilled water (DW), 70% ethanol, 70% methanol. After that, we determined anthocyanin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power, reducing power and Nitrite scavenging activity of black chokeberry extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of black chokeberry extracts was the highest in 70% methanol (p<0.05). The results suggest that black chokeberry can be used as nutraceutical foods and natural antioxidant.
12.
2016.04
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The aim of this study was to investigate and development collagen peptide materials from skate skin. Protein and fat content of collagen peptide showed about 95% and 0.1%, respectively. Average molecular weight of collagen peptide was measured as 1,015. In the analysis of amino acid, glycine and hydroxy proline content in collagen peptide was 19.32% and 16.25%, respectively, showing a typical characteristics of the collagen peptide. In obese db/db mice ingested 500 mg/day of collagen peptide for 18 days, the amounts of food and water intake were decreased considerably, contents of triglyceride, total cholesterol were decreased significantly in white adipose tissue of db/db mice. The final yield of collagen peptide was 17.23% in the optimized process for mass production. These results indicate that collagen peptide from skate skin may serve as candidates of fat reduction in adipose tissue and could be used as functional food and cosmetic ingredients.
13.
2016.04
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This study aims to analyze the priority of regional climate change policy utilizing AHP (analytic hierarchy process) at the area of Metropolitan City of Incheon. It derives four factors at first hierarchical level, at which level the analysis of pair-wise comparison indicates that industrial sector, energy sector, climate change response, and green culture policy are considered important in that order. It also ends up with sixteen factors at second level. The result of comparison analysis between all factors reveals that investment promotion in green technology R&D is considered the most significant factor of all, followed by establishment of green enterprise support system, electricity-efficiency enhancement support project and build-up of green culture policy governance. The result implies that diverse promotional policies have to incorporate business, institutional, and cultural aspects for sustainable climate change policy of regions. The contribution of this study is that it highlights the need to include regional characteristics in deciding priority among policy options for them to be effective.
14.
2016.04
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Fog may have a significant impact on road conditions. In an attempt to improve fog predictability in Jeju, we conducted machine learning with various data mining techniques such as tree models, conditional inference tree, random forest, multinomial logistic regression, neural network and support vector machine. To validate machine learning models, the results from the simulation was compared with the fog data observed over Jeju(184 ASOS site) and Gosan(185 ASOS site). Predictive rates proposed by six data mining methods are all above 92% at two regions. Additionally, we validated the performance of machine learning models with WRF (weather research and forecasting) model meteorological outputs. We found that it is still not good enough for operational fog forecast. According to the model assesment by metrics from confusion matrix, it can be seen that the fog prediction using neural network is the most effective method.
