• 설비공학논문집
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• 제16권1호
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• pp.8-15
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• 2004

Since the vehicle is regarded as the third living space, the comfortable conditions are required in the passenger compartment. For this reason, customers are concerned about the filtering performances and the importance of filter media has been greatly placed. Therefore the dust holding capacity, the efficiency of these filter media (dry paper, wet paper, non-woven) and the configuration of air filter for vehicle were measured in this study. The following results were obtained on the basis of air filter test. It shows that the thickness and poresize of filter media should be lower for the higher efficiency. The measurement result shows that the performance of round shape filters are higher than the square shape filters. The dust holding capacity of the wet paper and the non-woven paper is higher than the dry paper. As a result, this research can provide an important design parameter and product guidance of the intake air filter for vehicular engine.

• Environmental Engineering Research
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• 제25권3호
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• pp.409-417
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• 2020

Investigation was carried out to assess the effect of cement dust deposition on the physico-chemical properties of soil near some cement plants in Jaintia Hills, Meghalaya. Soil samples were collected and analysed and compared with the control site. Comparison of various soil physico-chemical parameters revealed that cement dust emanating from cement plants has changed the soil quality in the surrounding areas of cement plants. The normal soil pH in the area is generally acidic. However, due to the continuous deposition of cement dust soil pH was found slightly alkaline near the cement plants. The higher values of soil parameters such as electrical conductivity and bulk density were also noticed near the cement plants. However, lower values of water holding capacity, soil moisture content, soil organic carbon and total nitrogen content were found compared to the control sites. The effect of cement dust deposition on soil is more in areas nearer to the cement plants. At present the changes may not be so serious but if this trend continues, soil properties of a vast area around the cement plants are likely to change leading to multiple effects on flora, fauna and socio-economy of the area.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.159-170
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• 2009

A depth filter medium was newly designed in order to achieve high collection of dust and low pressure drop in this work. Multilayer depth filter media consist of an upstream layer of highly porous structure which allows particles to pass through and to follow by one or more downstream layers to hold the particles inside the media. For each filter media, flat sheet and pleated module were made of newly developed depth filter media and filter media of commercial products. Commercial depth filter cartridge for gas turbine air intake cleaning were used as reference for filtration area and pleat geometry of pleated modules. This work attempts to evaluate and compare the newly developed depth filter medium and two commercial filter media in terms of filtration parameters such as air permeability, initial pressure drop, particle retention and pressure drop variation with dust loading. According to the close examination the newly developed depth filter showed better performance compared to the commercial depth filter media.

• 농업과학연구
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• 제37권2호
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• pp.199-207
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• 2010

This research was conducted to determine the influence of physiological and chemical properties of root substrates on the growth of the daughter plants of 'Maehyang' strawberry produced by bag culture. The daughter plants produced by stock plants during bag culture were individually separated and grown in 10-cm diameter plastic pots containing six different formulations of root substrates: a) 50% peatmoss plus 50% vermiculite (5:5 by volume, A), b) 70% peatmoss plus 30% perlite (7:3, B), c) 70% coir dust plus 30% perlite (7:3, C), d) mixture of 35% coir dust, 35% peatmoss, and 30% perlite (3.5:3.5:3.0, D), e) mixture of 20% rice hull, 70% coir dust, and 10% perlite (2:7:1, E), and f) 30% rice hull plus 70% coir dust (30:70, F). The container capacity and air filled porosity of the growing medium varied greatly among the six substrate formulations evaluated. The substrates E and F had less container capacity and higher air-holding spaces than the rest of the formulations. Therefore, these two formulations (E and F) may cause a problem in water management during the production of healthy daughter plants. The substrate formulations A, B, and D retained higher nitrogen (N) concentrations than other formulations containing coir dust or rice hull. The substrate formulations E and F which contained rice hull had lower N, phosphorus (P), and potassium(K) concentrations than other substrate formulations containing coir. The quality of the daughter plants grown in all six different substrate formulations was good with the crown diameters at around 10 mm. Fresh weights of the daughter plants grown in substrate formulations A, C, and D were higher than those obtained from B, E, and F. Dry weights of the daughter plants showed a similar trend. The daughter plants having high fresh and dry weights and increased crown diameter are in demand by the industry. For this reason, the substrate formulations A, C and D can readily be used as potting mixes during the production of 'Maehyang' strawberry transplants utilizing the bag culture system.

• 생물환경조절학회지
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• 제21권4호
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• pp.362-371
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• 2012

유기 배지재료로써 국내에서 유통되는 피트모스와 코이어 더스트의 물리 화학적 특성을 분석하여 식물 공장용 혼합배지 조제를 위한 기초자료를 얻기 위하여 본 연구를 수행하였다. 연구목적을 달성하기 위해 캐나다, 리투아니아, 라트비아로부터 수입되는 피트모스 6점과 인도, 스리랑카, 베트남으로부터 수입되는 코이어 더스트 10점을 확보한 후 물리적 특성과 화학적 특성을 분석하고 비교하였다. 공극률에서 피트모스가 평균${\pm}$표준편차가 $79.6{\pm}5.04%$로써 $83.6{\pm}6.18$인 코이어 더스트 보다 낮았으며, 용기용수량은 피트모스가 평균 $69.9{\pm}10.17%$이고 코이어 더스트는 $65.9{\pm}3.46$으로 피트모스의 보수성이 코이어 더스트 보다 높았지만 종류별 차이가 컸다. 기상률은 4종류의 피트모스가 10% 이하로 측정되었지만 코이어 더스트는 12~26% 의 범위로 피트모스보다 월등히 높았다. 조사한 6종류의 피트모스는 쉽게 흡수할 수 있는 수분(easily available water, EAW)이 18~22%의 범위였던 반면 코이어 더스트는 11~16%로 측정되었고 1점을 제외한 9점이 11~13%의 범위로 측정되어 매우 낮았다. 완충수(buffering water)도 피트모스가 9~13%의 범위였지만 9점의 코이어 더스트가 5.5~7.5%로 측정되어 정확한 물 관리가 필요함을 나타내고 있다. 화학적 특성에서 피트모스는 pH가 3.46~4.17인 강산성물질이었고, 전기전도도(EC)는 분석한 6점 중 5점이 $0.137{\sim}0.254dS{\cdot}m^{-1}$로 측정되었다. 코이어 더스트의 pH는 5.31~6.48인 약산성 물질이었으며, EC는 평균${\pm}$표준편차가 $0.563{\pm}0.83dS{\cdot}m^{-1}$로 피트모스 보다 월등히 높고 종류 간 차이가 큼을 나타내고 있다. 양이온교환용량(CEC)은 코이어 더스트가 피트모스보다 약 3~4배 가량 낮았다. 코이어 더스트가 피트모스 보다 $NO_3$-N와 $P_2O_5$-P의 함량이 높았고, $NH_4$-N 함량이 낮았지만 K와 Na 함량은 월등히 높아 전기전도도가 높아진 원인이 되었다고 판단하였다. 피트모스와 코이어 더스트의 온수추출물은 각각 6.67~16.37% 및 30.0~65.1%, 알칼리 추출물은 0~38% 및 23.1~70.3%였고 생장억제물질 함량이 코이어 더스트에서 높을 수 있음을 의미하고 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1297-1301
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• 2007

The indoor air quality guideline of public transportation means was prepared recently. therefore we consider a countermeasure for the indoor air quality improvement of public transportation means. In this work, air-cleaner with roll filter system which developed alternative of indoor air quality guideline. The develpoed roll filter system is two function. the first function harmoniously circulated to heating and cooling air through HVAC system and secondary function removed PM(particluatie matters) which re-scatting to passenger's movement and suppled from outdoor air. Filter media of roll filter system select optimum electret mesh filter out of many filter media. Selected filter media was performanced tests of pressure drop, collection efficiency and dust holding capacity. Finally developed roll filter system was performanced bench test.

• 농업과학연구
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• 제37권2호
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• pp.191-197
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• 2010

The objective of this research was to determine the influence of the physical and chemical properties of root substrates used during the production of 'Maehyang' strawberry propaguleson the growth of the mother plants and the rate of daughter plant formation. Plants were cultured in plastic bags containing six different formulations of root substrates composed of: a) 50% coir dust and 50% perlite (5:5 by volume, A), b) 60% coir dust and 40% perlite (6:4, B), c) 70% coir dust and 30% perlite (7:3, C), d) 70% coir dust and 30% coconut chip (7:3 D), e) 60% coir dust and 40% coconut chip (60:40, E), or f) 50% sphagnum peat and 50% vermiculite (50:50, F). All media formulations contained a moderate level of base fertilizers. Physical and chemical properties of each formulation were determined before plant establishment and after 120 days of stock plant culture and runner production. Total porosity (TP) and container capacity (CC) of all substrate formulations were higher than 85% and 55%, respectively, allowing a suitable range of air and water holding characteristics. Formulation F provided the highest TP and CC values among the all substrate modifications evaluated. Substrate formulations A, B, C and F had higher electrical conductivity (EC) and $NO_3{^-}$-N concentrations than formulations D and E, when determined before and after plant culture. Formulations A, B, C, and F, having higher EC readings, also performed better as root substrates thanthe formulations D and E in increasing fresh and dry weights of the runners as well as the production of daughter plants per plant. The 'Maehyang' strawberry plants grown in the formulation F had the highest tissue N content, followed by those grown in substrate B, A, C, or D for 120 days after transplanting. Formulation F also facilitated accumulation of higher tissue phosphorus (P) and copper (Cu) contents compared to other treatments. Results of this experiment suggest that the chemical properties, rather than physical properties, of root substrates had a major influence on the growth of mother plants and the occurrence of healthy daughter plants during the bag-culture phase of propagation.

• 한국입자에어로졸학회지
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• 제8권4호
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• pp.133-141
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• 2012

A new depth filter media was designed and samples of flat sheet as well as cartridge assembly were prepared and tested to evaluate the filtration performance and compare with the commercial product. The arrangement of the depth filter media layers is important to reach the optimal filtration parameters like filter pressure drop, particle collection efficiency and dust holding capacity. Initially, both flat sheet samples of new media and commercial product have been tested using standard test units. Tests with new depth filter media cartridges of various pleat count were conducted in order to find the optimal pleat count which would represent the lowest pressure drop. These tests give an insight on how the pleat count and the assembly configuration affect the performance of the depth filter media cartridge. By comparing the samples with a commercial product we could confirm relatively high filtration performance of the sample cartridge with pleat count 150 made of new depth filter media. The cartridge with the same pleat count exhibits better performance without the outer mesh.

• 생물환경조절학회지
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• 제31권4호
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• pp.292-299
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• 2022

잎들깨 수경재배 시 적합한 고형배지를 선발하기 위하여 본 연구를 수행하였다. '남천'과 '소미랑' 2품종에 대해 코이어(chip:dust = 5:5), 펄라이트, 입상 암면, 원예용 상토(cocopeat: peatmoss:vermiculite:perlite:zeolite = 50:25:10:10:5) 등 4종의 배지에 따른 배지의 물리화학적 특성 및 생육반응을 분석하였다. 배지 간의 EC와 pH의 차이는 보이지 않았으나, 용기용수량 측정 결과 입상 암면이 가장 높고 원예용 상토와 코이어가 적절한 수준을 유지하였다. 배지의 기상률은 코이어와 펄라이트가 30% 이상으로 높은 경향을 보였으며 가비중은 코이어 배지를 제외한 모든 배지가 기준을 충족하였다. 잎의 크기는 품종 간에 배지에 따른 반응이 다르게 나타났는데 '남천' 품종은 원예용 상토에서 엽장, 엽폭이 가장 컸고 '소미랑'의 경우 코이어에서 재배하였을 때 가장 컸다. 엽중은 두 품종 모두 원예용 상토에서 재배한 것이 가장 높았고, 코이어와 펄라이트에서 재배한 것이 상대적으로 낮았다. 총 생산량을 조사한 결과 수량이 높은 원예용 상토 및 입상 암면과 수량이 낮은 코이어, 펄라이트로 두 그룹으로 구분되는 형태를 보였으며 그룹 간에 최대 28% 차이를 보였다. 따라서 근권에 충분한 수분 공급이 필요한 잎들깨를 수경재배하기 위해서는 보수력이 좋은 원예용 상토와 입상 암면을 이용하는 것이 적합할 것으로 판단한다.

• 생물환경조절학회지
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• 제14권3호
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• pp.182-189
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• 2005

본 연구는 혼합상토의 보수성 증가를 위하여 polyacrylamide 고흡수성 수지 Stocksorb C를 혼합할 경우 상토의 물리성에 미치는 영향을 밝히기 위하여 수행하였다. 네종류 혼합상토, 피트모쓰 + 버미큘라이트(1:1 , v/v; PV), 피트모쓰+부숙왕겨(1:1, v/v; PR), 피트모쓰+부숙톱밥(1:1, v/v; PS), 그리고 피트모쓰+부숙수피(1:1, v/v; PB)를 조제하는 과정에서 STSB를 혼합하고, 플라스틱 포트에 충전하였으며, 5주 후에 상토의 물리적 특성을 측정하였다. STSB의 혼합비율이 증가할수록 PV, PS 및 PB 상토의 공극률이 증가하여 $5{\%}$ 수준의 통계적인 차이가 인정되었고, 직선 또는 2차곡선회귀가 성립하여 경향을 찾을 수 있었다. STSB의 혼합비율 증가로 PS와 PB상토의 용기용수량이 뚜렷하게 증가하였으나 PV 및 PR상토에서는 STSB의 혼합비율에 따른 처리간 차이가 인정되지 않았다. 특히 STSB의 혼합은 PV PS및 PB 상토의 기상률을 뚜렷하게 증가시켜 처리간 통계적인 차이와 함께 직선 및 2차곡선회귀가 성립하여 경향이 뚜렷하였다. 고흡수성 수지의 혼합비율이 높아질수록 4.90 kPa, 9.81 kPa, 29.4 kPa및 1.5 MPa 토양 수분장력 하에서 존재하는 수분량이 많았다. 각 상토별로 29.4 kPa이나 1.5 MPa에서 존재하는 수분은 PV 혼합상토에서 적었고, PB와 PR 혼합상토에서 유사한 수준이었으며, PS 혼합상토에서 가장 많았다. 이는 고흡수성 수지의 혼합비율이 높아짐에 따라 상토가 보유하는 수분량이 증가하지만 식물이 쉽게 흡수할 수 있는 수분량이 증가하지 않음을 의미한다.