• Title/Summary/Keyword: air circulation

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An Evaluation of Environmental-Control Function on Forest Using GIS (GIS를 활용한 산림녹지의 환경조절적 기능 평가)

  • Lee, Woo-Sung;Jung, Sung-Gwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.4
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    • pp.102-115
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    • 2011
  • The purpose of this study is to establish the evaluation model through the systematic process of selecting the indicators and to evaluate the environmental-control function on forest using GIS in Deagu for the sustainable forest planning. The 35 indicators as basic items were selected by literature review and those were squeezed into the 29 indicators through expert brainstorming. Also, the 8 indicators to evaluate environmental-control function were selected by the first survey and the 5 final indicators such as carbon sink, temperature decrease, wind formation, water circulation, air purification were determined by MCB analysis using the second survey. The evaluation model was established through the weight of each indicator by AHP analysis using the third survey. According to the result of evaluating the environmental-control function on forest, the functions around the top area of Mt. Ap, Mt. Biseul, Mt. Palgong had more than 66 scores. On the other hand, the functions around Mt. Waryong and forest of Chilgok in Buk-gu had less than 40 scores. It is necessary to improve the function through the sustainable restoration and management in case of forest that the environmental-control function was lower. Furthermore, these results will be able to be utilized as basic data in order to establish the preservation area and control development area at the urban, environmental, and forest planning.

Oxygen Transfer System in Biological Fluidised Bed Using the Deep Shaft as Aeration Device (생물학적(生物學的) 유동층(流動層)을 이용(利用)한 폐수처리(廢水處理)에 있어서의 심층(深層) 폭기장치(曝氣裝置)에 의한 산소전달(酸素傳達) 시스템)

  • Kim, Hwan Gi;Ahn, Song Yeob;Jeong, Tae Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.1
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    • pp.13-24
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    • 1988
  • This paper is concentrated on the development of oxygen transfer system by U-tube deep shaft in biological fluidised bed process. The depth of the shaft is 32 m, it is composed of downcomer and riser. Not only flow pattern and oxygen transfer in the deep shaft but also oxygen limitation in biofilm and oxygen utilization in biological fluidised bed are investigated. In this investigation, driving force for liquid circulation in the deep shaft is affected by air injection depth and gas hold-up in downcomer. Flow pattern of the deep shaft is revealed to plug flow. When flow velocity in the deep shaft is maintained to 0.52 m/sec, $K_La$ value is peak at 25~30 m depth in riser. The efficiency of dissolved oxygen supply which passed from the deep shaft to biological fluidised bed is estimated to 56~81 % in the organic wastewater treatment using the deep shaft and when dissolved oxygen concentration is 9.2 mg/l and over, limiting factors of flux and substrate within biofilm are organic materials. Terefore, organic loadings could be increase without decreasing of BOD removal efficiency.

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Sawdust Cultivation of Lentinula edodes Using a Detachable Plastic Bottle (분리형 용기를 이용한 표고버섯 톱밥재배 연구)

  • Jeong, Yeun Sug;Jang, Yeongseon;Ryoo, Rhim;Ka, Kang-Hyeon
    • The Korean Journal of Mycology
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    • v.47 no.4
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    • pp.385-392
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    • 2019
  • Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

Improvement of Nutrient Balance using Feed Crops for Regional Nutrient Management (지역 양분관리를 위한 조사료 단지의 양분수지 개선효과)

  • Yang, Heon-yong;Kim, Jung-Gyun;Oh, Byung Wook;Seo, Il-hwan
    • Journal of Bio-Environment Control
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    • v.29 no.1
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    • pp.89-95
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    • 2020
  • Livestock facilities in Korea are on their way of enlargement resulting in increment of livestock manure. When the livestock manure treated inappropriate way during application to the agricultural area, environmental damage can be occurred such as bad smell, water and air pollution. Therefore it is important to make a good management plan for livestock manure treatment. In order to effectively apply organic fertilizer made by livestock manure in terms of quantity and quality, the current status of nutrient in agricultural land should be calculated quantitatively by scientific way. The OECD suggest member countries to calculate the nutrient balance as an agricultural environment indicator which represents the difference between nutrient inputs and outputs of the amount of nutrients in various ways. In this paper, we calculated the nutrient balances according to three cities which have different characteristics such as urban or rural areas. To reduce the nutrient balance, we considered how to reduce the amount of chemical fertilizer by using organic fertilizer made by livestock manure. And public treatment facilities for livestock manure can be a good solution except civil complaints for location selection. Among the options, manure fertilizer application to the agricultural area for cultivation of forage crops was mainly considered to reduce the nutrient balance by decreasing input of chemical fertilizers and increasing output of crop production. Using the field monitoring data, it can be calculated that the daily nitrogen reductions by 116.5 kg/ha and the daily phosphorus increments by 2.7 kg/ha.

Evaluation of Privately Owned Public Spaces within Detached Housing Areas in Pangyo City - Focusing on the Mixed use Housing Areas (가구내부 공유외부공지의 조성실태에 관한 연구 - 서판교 점포주택지를 중심으로)

  • Park, Kyung Seo;Kang, Jun Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.1
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    • pp.157-167
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    • 2016
  • Detached residential housing areas are located in the west part of Pangyo City. Seven areas of them are designated for the displaced residents from their original homes by the city development, in which commercial use on the first floor is permitted. The District Plan for the areas were establishes, and one of its main goals is to secure privately owned public spaces (POPS). This research conducted a post enumeration survey on the POPS on the blocks in the seven areas, which blocks contain inner corridors between two rows of housing units. Analytical review of the survey result reveals that (1) POPS facing roads are mainly being used as parking lots or expansion-spaces for the commercial use on the first floor, (2) inner POPS forming corridors are being neglected and otherwise being used as storage areas or outdoor sub-kitchen spaces, and (3) no consideration has been taken for the continuity of the sloped corridors. Regardless of a few good practices in terms of air circulation and lighting, the POPS in the blocks prove to be limited in following the plan's original design intentions and principles.

Experimental Study of Adoption of Alternative Refrigerant for Avionic Equipment Cooling System (항공전자기기용 냉각시스템의 대체냉매 적용에 관한 실험적 연구)

  • Kang, Hoon;Jung, Jongho;Jung, Minwoo;Chi, Yongnam;Yoo, Yongseon;Choi, Heeju;Byeon, Youngman;Kim, Youngjin;Oh, Kwangyoon;Kim, Yongchan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.5
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    • pp.431-439
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    • 2013
  • A cooling system is adopted to control the thermal load from the avionic equipments in an aircraft for stable operation. In this study, an avionic cooling system was designed and manufactured by adopting a vapor compression cycle with a closed-loop air-circulation system to investigate the operating characteristics of an alternative refrigerant. The performance characteristics of a cooling system adopting R236fa as an alternative refrigerant were experimentally determined by varying the refrigerant charging amount, expansion valve opening, and compressor rotation speed. The experimental results were analyzed and compared with those of a cooling system adopting R124 as a refrigerant. The possibility of the adoption of R236fa as an alternative refrigerant was verified, and design solutions were suggested to improve the system efficiency.

Germination Rate of Zostera marina Seeds Relative to Storage Methods and Periods (저장 방법과 기간에 따른 거머리말 (Zostera marina)의 발아율)

  • Park, Jung-Im;Park, Jay Hee;Lee, Kun-Seop;Son, Min Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.2
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    • pp.164-168
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    • 2014
  • To determine the optimal storage method and longest possible storage period of Zostera marina seeds, we examined post-storage germination rates using different storage methods and periods for Z. marina seeds harvested in southern coast of Korea. Storage methods included in seawater at room temperature with air supply, seawater at $4^{\circ}C$, seawater at $30^{\circ}C$, an aquarium with continuous seawater circulation, seawater at room temperature in an airtight tank, a refrigerator at $-20^{\circ}C$, and a desiccator at room temperature. Germination rates of Z. marina seeds stored in seawater at $4^{\circ}C$ showed highest germination (52.0%), whereas those of seeds stored in seawater at room temperature and an aquarium were 27.4% and 17.7%, respectively. But the seeds stored in seawater at $30^{\circ}C$, a refrigerator, and a desiccator did not germinate. Storage periods were 10, 20, 30, 60, 180 and 240 days of storage. Z. marina seeds maintained germination rates of 46.4~52.4% until 10~60 days of storage, but showed rapidly decreasing germination rates after then and no germination after 240 days.

Experimental Studies of the Blood Gas Transport during Normothermic Hemodilution Perfusion (상온하 혈액희석 체외순환에 있어서 혈액 GAS 동태에 관한 실험적 연구)

  • 박희철
    • Journal of Chest Surgery
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    • v.13 no.2
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    • pp.85-91
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    • 1980
  • Extracorporeal circulation by hemodilution technique has been currently used with its clinical safety and good peripheral tissue perfusion in open heart surgery. There is no doubt that $O_{2}$ carrying capacity of the blood is disturbed by decreased hemoglobin level resulting from hemodilution of the circulating blood. From the view point of the blood gas exchange, these experimental studies were undertaken to determined the sate limit of hemodilution in the condition of cardiopulmonary bypass with a constant perfusion flow rate. Twelve adult mongrel dogs weighing 10 to 13 Kg. were anesthetized with pentobarbital and then respiration was controlled with Harvard volume respirator using room air. The cardiopulmonary by pass was performed by use of Sarns heart lung machine (console 5000, 5 head and 2 roller pumps) and Travenol pediatric bubble oxygenator. The perfusion rate during bypass was maintained at a constant rate of 80 ml/min/Kg of body weight. The ratio of oxygen gas flow to blood flow was kept in 3 to 1 constantly. International hemodilution was attained by serial blood withdrawals and immediate infusion of equal volumes of diluants composed of Ringer's lactate, 5% dextrose in water and 25% mannitol solution, proportionally 60%, 30%, and 10%. Arterial and venous blood samples were obtained between 15 and 20 minutes following each hemodilution. Hematocrits and hemoglobin values, $PO_{2}$, $PCO_{2}$ and pH were measured. Oxygen and carbon dioxide contents oxygen consumption and carbon dioxide elimination were calculated groups according to different hematocrit values and the correlations were evaluated. Result were as follows. 1. the arterial $O_{2}$ tension and $O_{2}$ saturation were maintained at the physiological level irrespective of the hematocrit value. 2. The venous $O_{2}$ tension and $O_{2}$ saturation showed a tendency to decline with the decrease in hematocrit value and positive correlation between them (r = +0.49, r = +0.76), The mean values of venous $O_{2}$ tension and $O_{2}$ saturation, however, were not decreased when the hematocrit levels were lower than 20%. 3. The arterial $O_{2}$ content declined lineally in proportion to the fall of hematocrit level with a positive correlation between them (r = +0.95). 4. The venous $O_{2}$ contents were decreased gradually as the hematocrit value decreased with positive correlation between them ( r =+0.89). The trend of diminution of venous $O_{2}$ content, however, was became low according to progressive decrease of hematocrit level. 5. Systemic oxygen consumption was in higher range than $O_{2}$ requirement of basal metabolism when the hematocrit value was above 20%, but abruptly decreased when the hematocrit value became to below 20%. 6. The arterial $CO_{2}$ tension and $CO_{2}$ content showed trend of increasing with progressive decrease of hematocrit value but exhibited a rather broad range and there was no relationship between those value and the hematocrit value. 7. The venous $CO_{2}$ tension and $CO_{2}$ content have also no correlation with change of Ht. value but related directly to those value of arterial blood with positive correlation between them (r = +0.78, r = +0.95_. 8. A-V difference of $CO_{2}$ content and $CO_{2}$ elimination wasnot significantly influenced by Ht. value. From the results, we obtained that feasible limit in inteneional hemodilution is above the hematocrit value of 20% under the given experimental condition.

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Fatty and organic acids, and barbaloin in various parts of Aloe species dried at different drying temperatures (건조조건(乾燥條件)에 의(依)한 알로에의 부위별(部位別), 품종별(品種別) 지방산(脂肪酸) 유기산(有機酸) 및 Barbaloin 성분(成分) 연구(硏究))

  • Chang, Ki-Woon;Park, Joung-Sang;Jang, Gi-Chul;Nam, Yun-Gyu
    • Applied Biological Chemistry
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    • v.36 no.4
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    • pp.244-248
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    • 1993
  • The fatty and organic acids, and barbaloin in various parts of aloe species dried at different temperatures were analyzed by GC and HPLC. Seven fatty acids and six organic acids were identified and quantified. In the case of fatty acids, generally, the contents of palmitic and eicosanoic acid were abundants, and compared to the total contents of seven fatty acids, Aloe arborescence variant 1 was abundant, but Aloe saponaria was poor. And six fatty acids were distributed in the aloe species with the exception of linoleic acid. The contents of malic, citric and oxalic acids in the aloe species were higher than those of other acids, and compared to the sum of contents of six organic acids, Aloe saponaria was high, but Aloe arborescence variant 1 was low. Therefore Aloe arborescence variant 1 was abundant in total fatty acids, but poor in total organic acids. The contents of fatty and organic acids in the sample dried at $65^{\circ}C$ and $80^{\circ}C$ air circulation were almost similar. The contents of fatty and organic acids in the freeze-dried samples were lower than in the other dried samples. The contents of barbaloin in Aloe arborescence and A. arborescence variant 1 were higher than those of other various samples, and barbaloin was not detected in Aloe saponaria. As the drying temperature was increased, the contents of barbaloin in the various parts of the Aloe vera decreased.

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Control of Spinach Downy Mildew by Forced Ventilation in Greenhouse Cultivation (강제환기처리에 의한 비닐하우스재배 시금치의 노균병 발생 억제)

  • Park, Seok-Hee;Lee, Joong-Hwan;Woo, Jin-Ha;Choi, Seong-Yong;Park, So-Deuk;Moon, Yong-Sun
    • Korean Journal of Organic Agriculture
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    • v.22 no.1
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    • pp.147-154
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    • 2014
  • Spinach downy mildew caused by Peronospora spinaciae is the main reason of yield reduction in Korea as well as in worldwide. After forced ventilation or horizontal air circulation fans were installed to control growth conditions in green house, the changes of temperature, relative humidity (RH), growth and yield, and occurrence of downy mildew were examined. Althought here was no significant difference of temperature between the treatments, RH as 9.2% lower at nighttime by forced ventilation. In addition, final fresh weight was increased to 17.8g compared to control (10.1g), which as 7.7g enhancement. Downy mildew s tarted to show 20 days after sowing (DAS) and increased to 34.7% at 60 DAS on harvest time in control. In contrast downy mildew was occurred 40 DAS with 0.7% incidence rate and 4% at harvest by forced ventilation. The results indicated that reduction of only 9.2% of RH at nighttime by forced ventilation in greenhouse spinach growth was dramatically thrived over 76.2%. Additionally spinach downy mildew occurred 20 days later with extremely lower incident rate, which meant 88.5% reduction of downy mildew.