• 한국물환경학회지
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• 제27권6호
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• pp.932-937
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• 2011

Main objectives of this paper were; firstly, to explain impacts of suspended solid in the water body on the relationship between water quantity and water quality; secondly, study on the inter-relationship between organic materials, nutrients, pathogens, and suspended solids considering eco-friendly water resources. Relationship between water quality and water quantity is not easy to understand as it includes physicochemical-biological reactions and diffuse pollutions. Especially, suspended solid makes water resource management difficult. Eroded soil in the upper land transported to the downstream by water flows carrying biological and physicochemical information and sedimented in the downstream. As sediment scoured under high flow condition and environmental change, suspended solid and sediment should be emphasized for understanding the inter-relationship between water quality and water quantity. Knowledge gaps between known monitored data and management of suspended solid were identified as well for future study.

• Advances in nano research
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• 제13권2호
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• pp.121-134
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• 2022

Emerge of nanotechnology impacts all aspects of humans' life. One of important aspects of the nanotechnology and nanoparticles (NPs) is in the food production industry. The safety of such foods is not well recognized and producing safe foods using nanoparticles involves delicate experiments. In this study, we aim to incorporate intelligent computer simulation in predicting safety degree of nanofoods. In this regard, the safety concerns on the nano-foods are addressed considering cytotoxicity levels in metal oxides nanoparticles using adaptive neuro-fuzzy inference system (ANFIS) and response surface method (RSM). Three descriptors including chemical bond length, lattice energy and enthalpy of formation gaseous cation of 15 selected NPs are examined to find their influence on the cytotoxicity of NPs. The most effective descriptor is selected using RSM method and dependency of the toxicity of these NPs on the descriptors are presented in 2D and 3D graphs obtained using ANFIS technique. A comprehensive parameters study is conducted to observe effects of different descriptors on cytotoxicity of NPs. The results indicated that combinations of descriptors have the most effects on the cytotoxicity.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.228-236
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• 2004

Two varieties of alfalfa (Medicago sativa L cv. Pioneer and Beaver) and timothy (Phleum pratense L cv. Climax and Joliette), grown at different locations in Saskatchewan (Canada), were cut at three stages [1=one week before commercial cut (early bud for alfalfa; joint for timothy); 2=at commercial cut (late bud for alfalfa; pre-bloom head for timothy); 3=one week after commercial cut (early bloom for alfalfa; full head for timothy)]. The energy values of forages were determined using three approaches, including chemical (NRC 2001 formula) and biological approaches (standard in vitro and in situ assay). The objectives of this study were to determine the effects of forage variety and stage of maturity on energy values under the climate conditions of western Canada, and to investigate relationship between chemical (NRC 2001 formula) approach and biological approaches (in vitro and in situ assay) on prediction of energy values. The results showed that, in general, forage species (alfalfa vs. timothy) and cutting stage had profound impacts, but the varieties within each species (Pioneer vs. Beaver in alfalfa; Climax vs. Joliette in timothy) had minimal effects on energy values. As forage maturity increased, the energy contents behaved in a quadratic fashion, increasing at stage 2 and then significantly decreasing at stage 3. However, the prediction methods-chemical approach (NRC 2001 formula) and biological approaches (in vitro and in situ assay) had great influences on energy values. The highest predicted energy values were found by using the in situ approach, the lowest prediction value by using the NRC 2001 formula, and the intermediate values by the in vitro approach. The in situ results may be most accurate because it is closest to simulate animal condition. The energy values measured by biological approaches are not predictable by the chemical approach in this study, indicating that a refinement is needed in accurately predicting energy values.

• 공업화학
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• 제17권2호
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• pp.163-169
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• 2006

현재 한국의 폐LIBs 소각시스템에 대한 환경적인 측면들을 규명하고, 개선시키기 위해서 전과정평가를 수행하였다. 본 연구에서는 기존의 대부분 연구에서는 생략이 되었던 소각재의 매립과 관련된 환경영향도 평가되었다. 전기 생산과정과 소각공정으로부터 배출되는 $CO_{2}$와 소각공정에서 대기와 수계로 배출되는 중금속에 의한 환경영향이 전체 환경영향의 약 90%를 차지하였다. 특히, 중금속의 배출에 의한 환경영향이 압도적인데, 이를 개선시키기 위해서는 폐LIBs 와 같이 중금속의 함량이 높은 폐기물은 일반폐기물과 분리하여 소각하는 것이 필요하다. 반면에 소각 후에 발생되는 소각재에 의한 환경영향은 미미하였다. 이는 소각재가 소각과정을 거치면서 이미 안정한 산화물을 형성한 것에 기인한다.

• 한국농공학회지
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• 제45권4호
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• pp.78-88
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• 2003

The land use changes from non-urban areas to urban areas lead to the increased impervious areas, consequently increased direct runoff and higher peak runoff. Urban areas have also been recognized as significant sources of Nonpoint Source (NPS) pollution, while agricultural activities have been known as the primary sources of NPS pollution. Many features of the L-THIA/NPS GIS, L-THIA/NPS WWW system have been enhanced to provide easy-to-use system. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed in Indiana to evaluate the accuracy of the model. The L-THIA/NPS GIS estimated yearly direct runoff values match the direct runoff separated from U.S. Geological Survey stream flow data reasonably. The $R^2$ and Nash-Sutcliffe values are 0.67 and 0.60, respectively. The L-THIA estimated runoff volume and total nitrogen loading for each land use classification in the LEC watershed were computed. The estimated runoff volume and total nitrogen loading in the LEC watershed increased by 180% and 270% for the 20 years. Urbanized areas -"Commercial", "High Density Residential", and "Low Density Residential"- of the LEC watershed made up around 68% of the 1991 total land areas, however contributed more than 92% of average annual runoff and 86% of total nitrogen loading. Therefore, it is essential to consider the impacts of land use change on hydrology and water quality in land use planning of urbanizing watershed.nning of urbanizing watershed.

• 생태와환경
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• 제37권3호통권108호
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• pp.304-312
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• 2004

수 생태계 내에서 흔히 볼 수 있는 3영양단계 먹이사슬 구조를 이루는 종들이 밀도비 의존 모델로써 구현 될 때 외부 환경에 대해서 어떻게 반응하는지를 연구하였다. 환경 요인은 주기적 요인과 일반적 노이즈 두 부분으로 나누었다. 주기적 요인이 온도로써 대표되었을 때 온도변이를 바이어스와 주기로 나누었고, 기타 복합적인 노이즈는 가우스 분포로 나타내었다. 온도변이 바이어스 ${\varepsilon}$, 온도주기 ${\Omega}$, 및 가우스 노이즈 크기 ${\'{O}}$가 서로 결합하여 3영양단계 먹이사슬에서 개체군 멸절을 포함한 다양한 개체군 동태를 보여 주었다. 변수의 적절한 값에 따라 '안정된 제한 사이클'이나 '이상한 끌개'를 보여 주었으며, 전체적으로 개체군 동태는 환경 변수에 따라 민감하게 반응하였고, 포식자 및 최상위포식자 개체군의 멸절시간이 조절되었다.

• Journal of Ecology and Environment
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• 제44권4호
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• pp.222-228
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• 2020

Background: Parthenium hysterophorus is a noxious invasive weed in tropical and subtropical regions of the world, including Nepal. Among 11 species of biological control agents released to control P. hysterophorus in Ausrtalia, winter rust Puccina abrupta var. partheniicola arrived fortuitously and has established in Kathmandu Valley, Nepal, nearly a decade back. However, the prevalence and effectiveness of this rust as a biological control agent in Kathmandu remain unknown. To address this knowledge gap, a roadside survey was done at an interval of 2 ± 0.25 km in Kathmandu Valley to assess the P. abrupta var. partheniicola incidence and its impacts on P. hysterophorus. Infested individuals of P. hysterophorus were further divided into four severity classes (very low, low, medium, and high), and rust incidence was calculated. The impact of the winter rust on the growth of P. hysterophorus was assessed by comparing biomass and seed output of infested and non-infested individuals. Results: Among 81 locations where P. hysterophorus was present in the Kathmandu Valley, winter rust infestation was observed at 98% locations. At some locations within Kathmandu Valley such as Tinkune, Kirtipur, Chabahil, Buddha Chowk, and Dhobighat, the impacts of the rust on P. hysterophorus were medium to high. Aboveground biomass and seed output of P. hysterophorus were reduced by 47% and 73%, respectively, due to winter rust infestation. The study indicates that winter rust incidence is widespread in Kathmandu Valley with very low to high levels of damages to P. hysterophorus depending on the localities. Conclusion: The rust has, therefore, a potential to reduce the growth performance of P. hysterophorus, and it can be used as a component of integrated management of P. hysterophorus by introducing to other suitable areas in Nepal.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.319-324
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• 2007

To investigate the impacts of transgenic rice on freshwater organisms, we conducted two life table experiments using Daphnia magna for fifteen and twenty days, respectively. We examined life history traits such as population growth rates (r), reproductive rates ($R_0$), generation times, and survivorship. In the first experiment, we used non-drought-stressed transgenic and non-transgenic rice harvested in 2005. In the second study, we used non-transgenic and transgenic rice harvested in 2006 following drought stress. Each experiment involved three treatments in which D. magna neonates were fed with Selenastrum capricornutum (control treatment) and S. capricornutum with 5% aqueous extracts of non-transgenic rice (N-T) and transgenic rice (T). In the first experiment, D. magna showed reduced population growth rates and lowered fecundity in the N-T and T treatments. In the second experiment, D. magna receiving both transgenic and non-transgenic rice extracts showed very high mortality, low population growth rates and reproduction rates. We could not detect any significant negative effects of extracts from transgenic rice on D. magna life history traits at 95%.

• 환경생물
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• 제22권4호
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• pp.519-523
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• 2004

This study sought to investigate the ameliorating effects of a Korean medicinal herb (KMH) complex on the impacts of alcohol consumption in rat hepatocytes and in reducing the total cholesterol levels and the total lipid levels in the serum. We compared the body weight gain and ratio of the liver, the kidney to body weight, and also the serum biochemistry of the rats administered with both the alcohol and the KMH complex to the control rats treated with alcohol alone. The clinically important enzyme markers (Aspartate Aminotransferase, AST, and Alanine Aminotransferase, ALT) of rats, administered with both the alcohol and the KMH complex treatments, were compared with those in the control group. The treatment regimen (KMH complex) significantly reduced the serum AST and ALT levels, indicating the hepato-protective effects of the KMH complex. Furthermore, total cholesterol and total lipid levels were significantly reduced. These results indicate that the KMH complex may positively mediate the effects of alcohol on hepatocytes and the general liver functions.

• Water Engineering Research
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• 제7권1호
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• pp.9-20
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• 2006

The watersheds are functional geographical areas that integrate a variety of environmental and ecological processes and human impacts on landscapes. Geographical assessments using GIS recognize the relationship between interdependence of resources and ecological/environmental components in watersheds. They are useful methodology for viable long term natural resource management. This paper performs through the using hydrological analyses, landscape ecological analyses, remote sensing, and GIS. Indicators are items or measures that represent key components of the small watersheds, and they are developed to be evaluated. Some indicators are described that they represent watershed condition and trend as well as focus on physical, biological and chemical properties of small watershed. Also, ecological functions such as stability, resilience, and sensitivity are inferred from them. The model implemented in GIS allows to reflect the ecological and hydrological functioning of watershed. Methodology from image analysis, landscape ecological analysis, spatial interpolation, and numerical process modeling are integrated within GIS to provide assessment for eco-logical/environmental condition. Results are described from the small watershed of Gwynns Falls in Baltimore County and Baltimore City, Maryland, an area of about 66.5 square miles. The small watershed within Gwynns Falls watershed are subject to a number of land-use. But it is predominantly urban, with significantly lesser amounts of forest and agriculture. The increasing urbanization is ass-coiated with ecological/environmental impacts and citizen conflicts.