• 대한환경공학회지
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• 제28권5호
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• pp.558-562
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• 2006

여과공정에서 망간제거특성을 고찰하기 위하여 모래, 망간사 등의 4가지 여재를 사용한 여과실험이 실시되었다. 여과속도는 123 m/d였고, 칼럼당 유입량은 $3.9m^3/d$이었다. 실험기간은 약 1년이었으며, 실험기간 동안 여재별로 이산화망간 부착량, 탁도제거율, 망간제거율, 유기물제거율 등을 고찰하였다. 평균 망간농도 0.208 mg/L의 여과지 유입수(잔류염소 1.0 mg/L)를 사용하여 여과실험한 결과 모래+망간사 칼럼은 98.9%, 망간사칼럼은 99.2%의 망간제거율을 보였다. 기존 모래여과지를 망간제거를 위해 사용할 경우 여층의 전부를 망간사로 교체하지 않고 일부만 교체하여도 망간제거에 충분한 효과가 나타나는 것으로 조사되었다.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.52-57
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• 2012

In this study, in order to understand contents and ranges of design for the EGR Valve test system for improving quality and performance of EGR Valve, engine performance and exhaust gas characteristic of 3L-class diesel engine was analyzed. Experimental operation of engine performance test was performed with 50% engine load and 20% and 100% opening ratio of EGR Valve. From test of performance and exhaust gas characteristic of engine, torque output of engine and temperature and pressure of inlet and outlet of EGR Valve were measured. As a result, for design of EGR Valve test system, input fluid flow of EGR Valve must be set the same amount with exhaust gas flow that was below of engine speed of 2,500 rpm, and temperature of inlet of EGR Valve must be set under about $510^{\circ}C$. And the difference of temperature between inlet and outlet of EGR Valve must be over than about $200^{\circ}C$. Exhaust gas of inlet and outlet of EGR Valve were under 1 bar that was not considerable, and the difference of pressure between inlet and outlet of EGR Valve were under 1 bar that could not effect on mechanical operation of EGR Valve.

• 한국물환경학회지
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• 제40권1호
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• pp.19-35
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• 2024

The global pandemic, coronavirus disease caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to the implementation of wastewater surveillance as a means to monitor the spread of SARS-CoV-2 prevalence in the community. The challenging aspect of establishing wastewater surveillance requires a well-equipped laboratory for wastewater sample analysis. According to previous studies, RT-PCR-based molecular tests are the most widely used and popular detection method worldwide. However, this approach for the detection or quantification of SARS-CoV-2 from wastewater demands a specialized laboratory, skilled personnel, expensive instruments, and a workflow that typically takes 6 to 8 hours to provide results for a few samples. Rapid and reliable alternative detection methods are needed to enable less-well-qualified practitioners to set up and provide sensitive detection of SARS-CoV-2 within wastewater at regional laboratories. In some cases, the structural and molecular characteristics of SARS-CoV-2 are unknown, and various strategies for the correct diagnosis of COVID-19 have been proposed by research laboratories. The ongoing research and development of alternative and rapid technologies, namely RT-LAMP, ELISA, Biosensors, and GeneXpert, offer a wide range of potential options not only for SARS-CoV-2 detection but also for other viruses. This study aims to discuss the effective regional rapid detection and quantification methods in community wastewater.

• 농촌계획
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• 제30권3호
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• pp.1-8
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• 2024

This study focused on quantifying fugitive dust levels around rural village adjacent near a stone quarry, specifically examining the influence of quarry operations and gravel transport vehicles on road dust dispersion. For this purpose, fugitive dust concentration monitoring was conducted to understand the impact of gravel transport vehicles operating through the quarry area on the generation of road dust. Gravimetric analysis indicated substantial increases in Total Suspended Particulate (TSP) concentration (5.8 times), PM-10 (3.6 times), and PM-2.5 (2.0 times) during quarry operations on the quarry transport road. Real-time monitoring during dump truck operation revealed average dust concentrations of TSP 566.8 ㎍/m³, PM-10 174.8 ㎍/m³, and PM-2.5 55.3 ㎍/m. This indicates a significant increase compared to non-operation periods, with TSP concentration rising by 5.8 times, PM-10 concentration by 3.6 times, and PM-2.5 concentration by 2.0 times. Significantly elevated dust levels were observed at the village entrance road and quarry transport road during quarry operations, with PM-10 exceeding regulatory limits by 2.2 times and PM-2.5 exceeding limits by 1.9 times on the quarry transport road. Especially, particles with a diameter greater than 10 ㎛ exhibited a meaningful increase during dump truck transportation. Considering these findings, the study recommends implementing dust mitigation measures, including the introduction of dust barriers, screens, and wheel washing facilities for quarry-bound dump trucks.

• 농촌의학ㆍ지역보건
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• 제49권3호
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• pp.194-204
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• 2024

Objectives: This study aims to assess the current status of diabetes management among residents in 11 administrative regions (Si and Gun) of Chungcheongbuk-do, using data from the 2023 Community Health Survey, and to analyze variations according to the types of local governments. Methods: A total of 12,033 residents of Chungcheongbuk-do, aged 19 and older, were selected as study participants through the 2023 Korean Community Health Survey by Korea Centers for Disease Control and Prevention. Diabetes management indicators, including blood glucose awareness, treatment adherence, and complication prevention, were analyzed using SAS Enterprise Guide version 8.3, focusing on regional differences and patterns according to local government classifications. Results: Less than half of the residents of Chungcheongbuk-do were aware of their blood glucose levels, with considerable variation observed across regions. The overall proportion of individuals receiving appropriate diabetes management in Chungcheongbuk-do was 9.6%, but the rates differed significantly between regions. For instance, Yeongdong had the highest rate of diabetes self-management education (57.5%), while Chungju had the lowest (4.3%). The frequency of regular diabetic complication screenings, such as eye and kidney exams, remained suboptimal in most regions, with many falling below 50%. Even among regions with similar local government characteristics, substantial disparities in diabetes management were identified. Conclusions: There is a pressing need for Chungcheongbuk-do and its local governments to enhance blood glucose awareness among residents and integrate comprehensive diabetes education into local health care strategies. Tailored health initiatives must be developed at the local level to improve diabetes management outcomes and reduce regional disparities, ultimately aiming to improve the quality of life for individuals with diabetes.

• 상하수도학회지
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• 제29권4호
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• pp.493-502
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• 2015

In accordance with the Watershed Sewer System Maintenance Plan enforced on February 2, 2013, the different compliance concentration of effluent limit be applied to effluent discharged from public sewage treatment works(PSTWs) in each watershed on the basis of water quality thereof. With the introduction of watershed sewer system, it is necessary to set the compliance concentration of effluent limit for PSTWs situated in the watershed, by region and PSTW size, to achieve water quality criteria for regional watersheds or target water quality under TMDL program. Watershed Environmental Agencies establish the Watershed Sewer System Maintenance Plan and set the compliance concentrations of effluent limit for PSTWs under the plan. The agencies plan to apply tougher effluent BOD concentration limits in Class I to IV areas. Effluent BOD concentration limits will be toughened from 5~10 mg/L to 3 mg/L in class II~III areas, from 10mg/L to 5mg/L in class IV areas. Uniform application of effluent BOD concentration limits to PSTWs in the watershed sewer system need to be complemented considering type of sewage treatment technology employed and watershed characteristics. Therefore, this study presents method to determine the compliance concentration of effluent limit from PSTWs in the watershed.

• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.555-559
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• 1993

Studies at freezing point depression (FPD) for goat milk are described in this paper. The 432 samples of raw goat milk collected in a period of two years and analysed by the use of an electronic cryoscope gave a mean value of FPD: $-0.565{\pm}0.01^{\circ}C$. Statistical significant differences were found between the morning and evening milk. The evening milk showed better quality considering the lactose and others dissolved solutes. Among the Brown, Saanen and Anglo-nubian goats, the greatest increase in FPD, occurred in the Anglo-nubian breed. The statistical analysis revealed a significant breed difference (p<0.05), when climate variation was observed. The superior and inferior values found to the FPD of the caprine milk (-0.545 to $-0.585^{\circ}C$), is important in establishing regional rules, to improve the quality control criteria and legal interpretation of standards found in the pertinent legislation. The results are also important to improve herd management so that one can increase the animal production which will affect the technological composition, and the nutritional characteristics of the resultant products.

• 한국농공학회논문집
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• 제62권6호
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• pp.43-50
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• 2020

The Doam Lake watershed is one of the non-point source management areas announced by the Ministry of Environment, and is a constant problem for the stream ecosystem dut to Storm water. In this study, a total of 48(rainfall) and 47(non-rainfall) sites were investigated for the entire watershed (Samyangcheon, Chahangcheon, Hoenggyecheon, Yongpyeongcheon, Songcheon, Lake Doam) on August 15, 2019 and on October 18, 2019 to estimate the source of turbid water in the Doam Lake watershed. Subsequently, water quality analysis was performed on Suspended Soild (SS), Turbidity, Total Phosphorus (TP), Total Nitrogen (TN), and Biochemical Oxygen Demands (BOD) and correlation among water quality parameters was analyzed based on the analyzed samples. As a result, most of the turbid water generated during rainfall was in highland fields. During rainfall, Hoengyecheon had the highest average SS concentration among all streams, and during non-rainfall, the average SS concentration was highest in Yongpyeongcheon, so the two stream were selected as vulnerable areas. However, since Yongpyeongcheon may be a temporary phenomenon due to river construction, additional continuous monitoring is required. Therefore, in the Doam Lake watershed, intensive management is required for vulnerable areas.

• 패션비즈니스
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• 제27권3호
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• pp.63-74
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• 2023

As "Made in Korea" has high branding power in the fashion industry, domestic clothing manufacturers also need to consider branding the country of origin. Therefore, the purpose of this study was to reconsider the need for a domestic certification system and suggest a direction by analyzing apparel origin certification systems operating overseas. The results of this study could be used for planning certification standards and operating methods suitable for regional characteristics and industrial environments when establishing a certification system for clothing produced in Korea. The case study subjects were Japan's J∞ Quality, USA's Made in New York, Italy's 100% Made in Italy, and France's Origin France Guarantee has been classified as certification criteria related to the country of origin include items related to the production process rate in the region and the production area for each production process/stream. Manufacturing technology and design are used for quality standards, safety, hygiene compliance, production facilities, and quality control and are applied to working environment standards. The certification system selects and operates standards according to each country's industrial environment, certification subject, and purpose. Therefore, when designing a domestic apparel certification system, a feasible promotion plan should be established that considers the current state of the domestic industry, which will serve as a driving force for the growth of the apparel manufacturing industry and an opportunity to increase the trust of global fashion consumers.

• 한국농공학회논문집
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• 제59권3호
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• pp.83-96
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• 2017

This study presented a surface water quality modeling framework considering the spatial resolution of pollutant load estimation to better represent stream water quality characteristics in the Saemangeum watershed which has been focused on keeping its water resources sustainable after the Saemangeum embankment construction. The watershed delineated into 804 sub-watersheds in total based on the administrative districts, which were units for pollutant load estimation and counted as 739 in the watershed, Digital Elevation Model (DEM), and agricultural structures such as drainage canal. The established model consists of 7 Mangyung (MG) sub-models, 7 Dongjin (DJ) sub-models, and 3 Reclaimed sub-models, and the sub-models were simulated in a sequence of upstream to downstream based on its connectivity. The hydrologic calibration and validation of the model were conducted from 14 flow stations for the period of 2009 and 2013 using an automatic calibration scheme. The model performance to the hydrologic stations for calibration and validation showed that the Nash-Sutcliffe coefficient (NSE) ranged from 0.66 to 0.97, PBIAS were -31.0~16.5 %, and $R^2$ were from 0.75 to 0.98, respectively in a monthly time step and therefore, the model showed its hydrological applicability to the watershed. The water quality calibration and validation were conducted based on the 29 stations with the water quality constituents of DO, BOD, TN, and TP during the same period with the flow. The water quality model were manually calibrated, and generally showed an applicability by resulting reasonable variability and seasonality, although some exceptional simulation results were identified in some upstream stations under low-flow conditions. The spatial subdivision in the model framework were compared with previous studies to assess the consideration of administrative boundaries for watershed delineation, and this study outperformed in flow, but showed a similar level of model performance in water quality. The framework presented here can be applicable in a regional scale watershed as well as in a need of fine-resolution simulation.