• Korean Journal of Environment and Ecology
• /
• v.5 no.1
• /
• pp.25-31
• /
• 1991

To investigate the structure and the conservation of Abies koreana forest at Banyabong area in Chirisan, 38 plots(100$m^2$) set up with random sampling method. Dead individuals of Abies koreana were 12.81%. were observed mainly upper-layer trees. A few seedlings of Abies koreana were observed. Three groups were classified by cluster analysis. High positive correlations was proved between Abies koreana and Rhododendron mucrolunulatum var. ciliatum, and High negative correlations was proved between Abies koreana and Fraxinus sieboliana, Carpinus cordata, Sasa purpurascens and Cornus controversa. Species diversity(H') of investigated area was calculated 1.9796-2.7509. To conserve Abies koreana forest at Banyabong area in Chirisan. Research and prescription on the declining of Abies koreana was needed and Quercus mongolica, Acer pseudo-sieboldianum, Fraxinus sieboliana, Carpinus cordata, Sasa purpurascens and Cornus controversa in the Abies koreana forest should be cleared out.

• Carbon letters
• /
• v.8 no.4
• /
• pp.274-279
• /
• 2007

In order to understand the breakthrough behaviour of iodine vapours on impregnated carbon systems, an active carbon, 80 CTC grade, $12{\times}30$ BSS particle size and $1104\;m^2/g$ surface area, was impregnated with metal salts such Cu, Cr, Ag, Mo and Zn, and an organic compound Triethylene diamine (TEDA) to prepare different carbon systems such as whetlerite, whetlerite/TEDA, whetlerite/KI/KOH and ASZMT. The prepared adsorbents along with active carbon were characterized for surface area and pore volume by $N_2$ adsorption at liquid nitrogen temperature. These carbon systems were compared for their CT (concentration X time) values at 12.73 to 53.05 cm/sec space velocities and 2 to 5 cm carbon column bed heights. The carbon column of 5.0 cm bed height and 1.0 cm diameter was found to be providing protection against iodine vapours up to 5.5 h at 3.712 mg/L iodine vapour concentration and 12.73 cm/sec space velocity. The study clearly indicated the adsorption capacities of carbon systems to be directly proportional to their surface area values. Dead layer with all the prepared carbon systems was found to be less than 2.0 cm indicating it to be minimum bed height to have protection against $I_2$ vapours. Effect of carbon bed height and flow rate was also studied. The active carbon showed maximum protection at all bed heights and flow rates in comparison to all other impregnated carbon systems, showing that only physical adsorption is responsible for the removal of iodine vapours.

• Journal of Biosystems Engineering
• /
• v.31 no.5 s.118
• /
• pp.436-442
• /
• 2006

This research was conducted to design and develop a wired monitoring system for judging if sick or dead layers (SDL) exist in multi-tier layers battery (MLB) by machine vision, and to analyze its performance. In this study, 20 Brown Leghorn (Hi-Brown) layers aged 37 weeks old, were used as the experimental animals. The intensity of concern paid by layers on feed was over 90% during 5 minutes and 30 seconds after providing feed, and normal layers (NL) had been standing to take feed for that period. Therefore, in this study, the optimal judging time was set by this test result. The wired monitoring system developed was consisted of a driving device for carrying machine vision systems, a control program, a RS232 to RS485 convertor, an automatic positioning system, and an image capture system. An image processing algorithm was developed to find SDL in MLB by the processes of binary processing, erosion, expansion, labeling, and reckoning central coordinate of the captured images. The optimal velocity for driving unit was set up as 0.13 m/s by the test results for wired monitoring system, and the proximity switch was controlled not to be operated for 1.0 second after first image captured. The wired monitoring system developed was tested to evaluate the remote monitoring performance at lab-scale laying hen house. Results showed that its judgement success.ate on normal cage (without SDL) was 87% and that on abnormal cage (with SDL) was 90%, respectively. Therefore, it would be concluded that the wired monitoring system developed in this study was well suited to the purpose of this study.

• Journal of Pharmaceutical Investigation
• /
• v.36 no.5
• /
• pp.339-342
• /
• 2006

This study was designed to prepare an animal model for partial thickness bum wound which can be employed for testing topical therapy. We first evaluated whether rabbit ear and mouse back skin wound model could differentiate the wound healing process in terms of degree of re epithelialization, required days for complete wound closure, presence of scarring. $2^{nd}$ degree wet bum were prepared on mouse back skin and rabbit ear by applying 5 mL hot water($85{\pm}0.1^{\circ}C$) for 7 see followed by 5 mL ice-cold 0.5% acrynol solution for cooling and disinfecting the inflicted area. After removing the dead epidermis layer at 24 hr, tested dressings were applied for specified time and wound progression was investigated. In mouse model, wound contraction was the primary wound closing mechanism, which is quite different from human wound healing process. In rabbit ear model, epidermal regeneration was the major wound healing process rather than wound contraction and the difference in wound healing property among tested dressings could be clearly demonstrated. A rabbit ear model could differentiate the wound progression among open, occluded and epidermal growth factor(EGF) treated wound. Four sites of circular wound(diameter: 1 cm) on the anterior part of rabbit ear could be employed for the comparative wound healing study. For obtaining reproducible bum wound, degree of bum depth and bum sites should be carefully controlled in addition, employing rabbits of same strain and weight. The result suggests that rabbit ear could be employed as a reliable and human-resembled wound model.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.590-596
• /
• 2010

To investigate and to compare the structure of Picea jezoensis forests at Chunwangbong area in the Jirisan National Park, 33 plots(400) were set up by a random sampling method. Dead individuals of Picea jezoensis trees were 15.6%, these were observed mainly in the upper-layer trees. A few seedlings of Picea jezoensis were found in this investigation area. This result indicates that Picea jezoensis might be gradually decreased in the future. Picea jezoensis stands were classified into two major groups by cluster analysis. There were strong positive correlations between Syringa reticulata and Acer pseudosieboldianum, Tripterygium regelii, Quercus serrata; Betula ermani and Lonicera maackii; Euonymus macropterus and Acer ukurunduense; Acer pseudosieboldianum and Tripterygium regelii, and relatively weak negative correlations were showed between Picea jezoensis and Abies koreana; Betula ermani and Acer ukurunduense; Acer pseudosieboldianum and Tripterygium regelii. Species diversity index(H') of investigated groups ranged from 1.0000 to 1.3010.

• Korean Journal of Veterinary Research
• /
• v.44 no.4
• /
• pp.593-605
• /
• 2004

An egg has been considered as one of the most important food sources because of it's nutritional superiority and reasonable price. With the complexity of egg flow system from production to consumption in Korea, preventive measures for egg safety have been required. Therefore, our study was carried out to analyze hazards for the egg under farm level and develope preventive measures with a purpose of obtaining egg safety. To analyze biological hazards, microbial contamination of egg(normal, dirty and cracked), water, feed, manure and equipments associated with laying were investigated. One isolate of Salmonella enteritidis and S. bardo were detected from the manure and dirty egg shell respectively. The sanitary conditions in the farm were surveyed by questionaries. Confirmation of vaccination for purchasing chicks and establishment of sanitary guidances for water and type of water suppliers ought to be preceded. Feed supplier systems including feed tanks, feed pipes and hoppers were known that their contamination might give it a chance to infect individuals and egg content and shell. The safe and rapid disposal of dead chickens and rodent were reported as more crucial factors to prevent infectious disease and manage good sanitation. Egg selector and collecting belt should be kept properly not to be contaminated from egg fluids and feces. It should be also considered that regular gathering of eggs, removal of dirty or cracked ones, storage under refrigeration and the use of disposable egg tray were continuously fulfilled. Conclusively, Our results suggested that HACCP-based system for providing fresh and safe eggs to consumers should be applied to the farm.

• Geomechanics and Engineering
• /
• v.19 no.3
• /
• pp.255-268
• /
• 2019

Taking top-coal caving mining face (TCCMF) as research object, this paper considers the combination of top-coal and immediate roof as cushion layer to build the solution model of support resistance based on the theory of elastic foundation beam. Meanwhile, the physical and mechanical properties of coal-rock combination influencing on strata behaviors is explored. The results illustrate that the subsidence of main roof in coal wall increases and the first weighting interval decreases with the increase of top-coal and immediate roof thicknesses as well as the decrease of top-coal and immediate roof elastic modulus. Moreover, the overlying strata reflecting on support has negative and positive relationship with top-coal thickness and immediate roof thickness, respectively. However, elastic modulus has limit influence on the dead weight of top-coal and immediate roof. As a result, it has similar roles on the increase of total support resistance and overlying strata reflecting on support in the limit range of roof control distance. In view of sensitive analysis causing the change of total support resistance, it can be regards as the rank of three components as immediate roof weight > overlying strata reflecting on support > top coal weight. Finally, combined with the monitoring data of support resistance in Qingdong 828, the validity of support resistance determined based on elastic foundation beam is demonstrated, and this method can be recommended to adopt for support type selecting in TCCMF.

• Journal of the Korean earth science society
• /
• v.32 no.3
• /
• pp.276-293
• /
• 2011

In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

• The Korean Journal of Mycology
• /
• v.37 no.1
• /
• pp.33-40
• /
• 2009

From 2006 to 2008, natural habitat of Sparassis crispa were surveyed for investigating ecological conditions at sixteen different sites in Korea. The investigated sites showed very wide altitudinal distribution ranged from 240 meters to 1,100 meters above the sea level. In general, S. crispa showed distinct feature of heart-rot fungi as it occurs on soils around the stems of larch (Larix kaempferi) and Korean white pine (Pinus koraiensis). But it also could be found on stems or on the stumps of dead trees, which indicated that the fungus might have several invasion routes and capabilities to grow on various ecological conditions. All of the sixteen sites were pure stands consisted with conifers such as larch or Korean white pine. The dominant tree layer showed $15.3{\sim}38.0$ meters for tree heights, thicker than twenty centimeters for the diameter at breast height (DBH), and all of them were older than thirty years. Since the stands were pure stand, species diversity of trees in the sites was extremely low. While the dominant tree layer showed only pure coniferous stand, the co-dominant tree layer, shrub layer and herbaceous layer showed more diverse features with higher Shannon-Wiener (H') indices. Soil texture of thirteen sites among sixteen investigated sites were loamy soils, and the contents of organic matter in soil were more or less higher than general forest soils in Korea with $3.79{\sim}14.32%$. The cation exchange capacity (CEC) was also relatively higher than general forest soils with $16.1{\sim}27.2$ cmol+/kg. The data indicated that the cauliflower mushroom occurring sites were relatively fertile than general forest soils. The soils were acidic with pH ranged from 4.2 to 5.2, which were typical features for conifer stands in Korea.

• Membrane Journal
• /
• v.29 no.1
• /
• pp.18-29
• /
• 2019

The dead-end ultrafiltration (UF) of BSA protein solution was performed to investigate the defouling effects of natural convection instability flow (NCIF) induced in membrane module. The permeate fluxes were measured according to the inclined angles ($0{\sim}180^{\circ}$) of membrane module with respect to gravity, and analyzed using the blocking filtration model. NCIF are more induced as the inclined angles increased from $0^{\circ}$ to $180^{\circ}$, and the induced NCIF enhances flux. Comparing the fluxes at $0^{\circ}$ inclined angle (no NCIF induction) and $180^{\circ}$ (maximum NCIF induction), the flux enhancements by NCIF induction are increased about 5 times in the short-term UF operation (2 hours) and about 17 times in the long-term operation (20 hours). As applying the blocking filtration model, it is more suitable to analyze the flux results by using the intermediate blocking model in the early times of UF operation within 15 minutes and then thereafter times by using the cake filtration model. NCIF induced at $180^{\circ}$ inclined angle reduces the intermediate blocking fouling at about 67% in the early times operation and thereafter the cake layer fouling at about 99.9%. The main defouling mechanism of NCIF induced in the membrane module is suppress the formation of protein cake layer.