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Morphological and Biochemical Studies on the Effects of Cadmium on the Rat Testis
권경석 한국발생생물학회 1997 발생과 생식 Vol.1 No.2
To investigate the cadmium (Cd) toxicity on the testis, male rats were treated with 1, 2, 4 and 8 mg/kg of Cd by IP. According to histochemical studies, Cd-treated testis tissue showed death of spermatozoa, death of Sertoli cells, death of all the spermatogenic cells, and finally disappearance of basal lamina of seminiferous tubules with increasing doses, and showed decreased ground substances and Leydig cells, increased inflammatory cells and fibroblasts, and fibroblasts, and finally disappearance of ground substances and all the cells except fibroblasts within interstitial tissues with increasing doses. According to biochemical studies, two kinds of proteins, 25 and 45 kDa, were dramatically disappeared from the total protein of rat testis treated with Cd comparing to normal testis. The result of electrophoresis of total protein suggests that actin (45 kDa), presumed on its mmolecular weight and amount, in the testis-cells is the primary target of Cd poisoning. Although its exact mechanism is not clear, the disappearance of two proteins when testis is exposed to Cd should give some clues to understnad the mechanism of necrosis of testis tissue crumbling by heavy metal pollutant such as Cd.
강제 환기식 육계사 다중 입기 슬롯에서의 입기류 도달거리 분석
권경석,하태환,이인복,홍세운,서일환,Kwon, Kyeong-Seok,Ha, Tae-Hwan,Lee, In-Bok,Hong, Se-Woon,Seo, Il-Hwan,Jessie, P. Bitog 한국농공학회 2012 한국농공학회논문집 Vol.54 No.2
In the winter season, when the ventilation system is operating, the fresh cold air from the slot-type openings of broiler house which directly reached the animal zone can cause various problems such as thermal stress, decreasing of feed and water consumption, occurrence of respiratory disease, and etc. Therefore it is very important to control the trajectory of aero-flow from the slot openings to induce an efficient thermal heat change. Jet-drop distance model was proposed to predict and control the jet-trajectory. However their study was restricted due to the small scaled model and difficulties of measuring the Jet-drop distance. In this study, CFD was applied to analyze qualitatively and quantitatively the jet-drop distance in a real broiler house. The various variables were considered such as installed slot-angle, designed ventilation rate, and the outdoor ambient temperature. From the present study, two linear-regression models using the Jet-drop factor and corrected Archimedes number, and their R-squared values 0.744 and 0.736, respectively, were used. From this study, the applicability of CFD on the analysis of Jet-drop distance model was confirmed.
비육돈사 작업 종사자의 호흡기 관련 공기 중 분진 농도 측정 및 분석
권경석,이인복,황현섭,하태환,하정수,박세준,조예슬,Kwon, Kyeong-Seok,Lee, In-Bok,Hwang, Hyun-Seob,Ha, Tae-Hwan,Ha, Jung-Soo,Park, Se-Jun,Jo, Ye-Seul 한국농공학회 2013 한국농공학회논문집 Vol.55 No.5
In swine house, dust generation comes from various sources and is known to be harmful both for the animals and the farmers because the dust contains biological and gaseous matters. When farmers are constantly exposed to the dusts, they can suffer chronic or acute respiratory symptoms and have high probability of manifesting various diseases. To address this problem, understanding of the mechanism of dust generation is very important. In this paper, the dust concentration of inhalable, respirable, TSP and $PM_{10}$ were monitored and analyzed according to the pig-activity level, ventilation quantity and feeding method in fattening pig house. From the measured results, in case of the concentration of TSP, an inverse-linear relation with ventilation rate ($R^2=0.88$) and linear relation with the installation height of feed supply pipe ($R^2=0.73$) were determined. However in case of the concentration of $PM_{10}$, no particular relationship with the variables was observed. Using the concentration of inhalable and respirable dust based on the pig-activity level, multi-variate regression analysis was conducted and results have shown that the movement of pigs can contribute to the dust generation (p<0.05, $R^2=0.71$, 0.61). The relationship determined between dust generation and environmental variables investigated in this study is very significant and useful in conducting dust-reduction researches.
전산유체역학 기법을 이용한 돈사 내 습식 공기 정화기의 적정 위치 설계
권경석,이인복,황현섭,홍세운,서일환,최지선,송상현,문운경,Kwon, Kyeong-Seok,Lee, In-Bok,Hwang, Hyun-Seob,Bitog, Jessie.P.,Hong, Se-Woon,Seo, Il-Hwan,Choi, Ji-Sun,Song, Sang-Hyeon,Moon, Oun-Kyung 한국농공학회 2010 한국농공학회논문집 Vol.52 No.3
In South Korea, as the living standard has been getting higher, meat consumption is steadily increasing. To meet the country's demand, livestock houses become larger and wider with increased raising density. In larger livestock houses, pollutants such as flake of pig skin, excrement, odor, various dusts and noxious gas like ammonia are excessively accumulated inside the facility. These will cause weak immunity for the pigs, diminution of productivity and degeneration of working condition. These problems can be solved through the ventilation performance of the facility. In the winter time, ventilation must be controlled to minimum to maintain a suitable thermal condition. However, this affects the other internal environmental condition because of the minimum ventilation. The installation of "wet air cleaner" especially in the winter time can be an alternative solution. For efficient application of this machine, there is a need to understand the existing ventilation condition and analyze the interaction of existing ventilation system with the wet air cleaner considering its appropriate location. In this study, the existing ventilation system as well as the internal environmental condition negatively inside the facility with the wet air cleaner has been studied using CFD technology. The CFD simulation model was validated from the study conducted by Seo et al. (2008). Results show that the elimination rate of ammonia was 39.4 % and stability could be improved to 35.1 % (Comparing case 5 to 1 where wet air cleaner machine was not used). It can therefore be concluded that case 5 shows the optimum location of a wet air cleaner in the livestock house.
강제환기식 계사의 공기 중 분진 농도 측정 및 바닥재로부터의 분진 발생량 분석
권경석,조예슬,이인복,하태환,홍세운,Kwon, Kyeong Seok,Jo, Ye Seul,Lee, In Bok,Ha, Tae Hwan,Hong, Se Woon 한국농공학회 2014 한국농공학회논문집 Vol.56 No.6
Confined and mechanically ventilated broiler house has been recently come into wide use to increase productivity and control rearing conditions. However, high dust concentration inside facility can threaten respiratory welfare of farmers and broilers. In Korea, there is no regulation in terms of air quality control inside agricultural facilities and sufficient data is not available. To cope with these, periodic monitoring of inhalable and respirable dust concentration were conducted according to season, broiler's activity and specific events such as shipment work for broilers in mechanically ventilated broiler house. Chamber experiment was also designed to analyze mechanism of dust generation from ground beds according to water contents and surrounding wind environment. Results showed that significant increase of inhalable (p=0.002) and respirable (p=0.03) dust were observed when activity of broilers was high according to entrance of the workers. Even shipment work for matured broilers, high level of dust were observed; inhalable dust was exceeded the threshold limit over maximum 303 % and respirable dust was over maximum 1,550 %, implying that acute respiratory symptoms could be manifested for the workers. From the chamber experiment, critical water contents for interrupting of dust generation were measured; about 45 % for inhalable dust and about 50 % for respirable dust. These results can be a trigger for designing plan of dust control however it still needs consideration of various environmental conditions, hygiene problems, etc.