• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.275-283
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• 2007

This study was carried out to: (1) analyze structural stability of representative rain-sheltering greenhouses for large-grain grapevine cultivation with widths of 3.6 m and 5 m in case of using the existing pipe for agriculture; (2) present the optimum specification of pipes in the greenhouse with a width of 5 m under the condition of using the pipe of which ultimate strength has been above $400N{\cdot}mm^{-2}$; (3) evaluate stability and also present the optimum specification of pipes as eaves height was augmented. The above analyses were done for greenhouses with roof vents and also with a main-column interval of 3 m and a rafter interval of 60 cm. First, the existing 3.6 m greenhouse with a rafter of ${\Phi}25.4{\times}1.5t@600$ was stable far a snow-depth of 35 cm but unstable for a wind velocity of $35m{\cdot}s^{-1}$. Meanwhile the existing 5 m greenhouse with the same rafter was not stable for a wind velocity of $335m{\cdot}s^{-1}$ as well as a snow-depth of 35 cm. This meant that existing greenhouses had to be reinforced to secure stability. Second, the specification of pipes, especially rafter, could be classified as two cases. One had a structural stability at a safe wind velocity of $35m{\cdot}s^{-1}$ and a safe snow-depth of 40 cm for which stability the rafter had to be ${\Phi}31.8{\times}1.5t@600$, and the other had a stability at $30m{\cdot}s^{-1}-35cm$ at the specification of rafter ${\Phi}25.4{\times}1.5t@600$. Finally, eaves height had a significant effect on safe wind velocity. But it had little influence on safe snow-depth. The results showed that the specification of side-wall pipes had to be reinforced for the safe side velocity accord-ing to the increment of eaves height and similarly the specification of fore-end post far the safe fore-end velocity.

• Journal of Animal Environmental Science
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• v.14 no.1
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• pp.31-38
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• 2008

Ammonia gas is one of the malodorous gases from swine production facilities, such as manure storage tank, manure fermentation facilities, and livestock houses, etc. Ammonia gas from swine house is being emitted at relatively low concentrations throughout the year. Therefore, livestock facilities were continuously ventilated to supply fresh air for respiration of the animals internal the livestock facilities. The swine facilities need very high ventilation rate to control the inside environmental conditions. The deodorization system of the livestock facilities must be developed considering the ventilation rates. The odor abatement system was installed in order to improve the internal environment of the naturally ventilated growing-finishing pig house. The system which distributes the deodorized air into inner space of the swine house by using plastic duct was installed. Since the internal environment, effected by the operation of the odor abatement system, is monitored by closing the winch curtain installed on the side wall of the pig house, the experiment was practiced at the season when the internal environment becomes aggravated, winter. The effects on the improvement in the internal environment of swine house by operating the odor abatement system are as follows ; 1. By re-distributing the air which was deodorized by the odor abatement system installed in the pig house, the result showed that the concentration of ammonia gas is decreased approximately 33.3% compared with that before operating odor abatement system. 2. The effect on the pig house's ammonia gas reduction was found that the ventilation rate was less than $0.5m^3$/min head. The effect of the operation of the odor abatement system showed to be scarce when the ventilation rate increases because of the influx of external fresh air makes the quantity of diluted air more than those of the odor abatement system. 3. The perishment rate of the pigs which were brooded until slaughtering decreased about 3.8% by operating the odor abatement system in the growing-finishing pig house. Also, after operating the odor abatement system, the stinging of the eyes, suspension dust, etc were decreased when going into swine house for management.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.318-332
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• 2000

The purpose of this study was to investigate the effects of demineralized freeze-dried bone (DFDB) on mechanically exposed pulp of dog by evaluating the pulpal inflammation and healing process, formation of dental hard tissue, and structural changes of fibroblasts of the remaining pulp tissue. Teeth of 4 dogs, weighing 10kg, were used in this study. Class V cavities were prepared followed by exposed the pulp tissue mechanically by sterilized round bur. In control group, exposed pulps were capped with calcium hydroxide paste followed by sealed with IRM. In experimental groups, the exposed pulps of one group were capped with the collagen and those of the other group were capped with DFDB. All cavities were sealed with same manor as control group. The animals were sacrificed at the intervals of 3, 7, 14, and 28 days for histopathlogic evaluation. The specimens were observed by the light microscope and trans-electron microscope. The results were as follows: 1. Pulp necrosis was not observed in all groups. Inflammatory response was disappeared from 1 week in control group and group 2. But it was not disappeared until 2 weeks and also irregular arrangement of odontoblasts was showed at the lateral walls of root canal just beneath the amputated site of the pulp in group 1. 2. Dentinal bridge was formed incompletely at 2 weeks but it was formed completely at 4 weeks in control group. Odontoid tissue was also found in control group at 4 weeks from treatment. Amputated site of pulp was encapsulated with fibrous tissue and odontoblast and dentinal bridge was not found in group 1. Preodontoid tissue and reparative dentin which were formed by odontoblast differentiated around DFDB were found, but dentinal bridge was not found in group 2. 3. Cell with large basophillic-stained nuclei infiltrated to amputated site and DFDB at 1 week from treatment in control group and group 2. They were found more in group 2 than in control group. Odontoblasts arranged more regularly and reparative dentin was found more as time elapsed. 4. Dentin-formative odontoblasts which showed ultramicrostructure of cytoplasm with polarized nucleus, rEM, Golgi complex, secretory granules, secretion of organic matrix in control of group and group 2. In regards to above results, the demineralized freeze-dried bone(DFDB) induce odontoblastic differentiation and further come up to the dentin formation in amputated pulp.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.74-80
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• 2001

Purpose : Irradiation cones by using backscatter electrons are made for the treatment of superficial small lesions of skin, oral cavity, and rectum where a significant dose gradient and maximum surface dose is desired. Methods and Materials : Backscatter electrons are produced from the primary electron beams from the linear accelerators. The design consists of a cylindrical cone that has a thick circular plate of high atomic number medium (Pb or Cu) attached to the distal end, and the plate can be adjusted the reflected angle. Primary electrons strike the metal plate perpendicularly and produce backscatter electrons that reflect through the lateral hole for treatment. Using film and a parallel plate ion chamber, backscatter electron dose characteristics are measured. Results : The depth dose characteristic of the backscatter electron is very similar to that of the hard x-ray beam that is commonly used for the intracavitary and superficial lesions. The basckscatter electron energy is nearly constant and effectively about 1.5 MeV from the clinical megavoltage beams. The backscatter electron dose rate of $35\~85\;cGy/min$ could be achieved from modern accelerators without any modification. and the depth in water of $50\%$ depth dose from backscatter electron located at 6mm for $45^{\circ}$ angled lead scatter. The beam flatness is dependent on the slit size and the depth of treatment, but is satisfactory to treat small lesions. Conclusions : The measured data for backscatter electron energy, depth dose flatness dose rate and absolute dose indicates that the backscatter electrons are suitable for clinical use.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.309-315
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• 2003

Background: To avoid the adverse effects of cardiopulmonary bypass and to overcome late vein graft failure we routinely peformed off-pump total arterial coronary revascularization. Material and Method: From July 2000 to August 2001, 104 consecutive patients underwent first elective off-pump total arterial coronary revascularization. Both internal mammary, radial and gastroepiploic arteries were used. Sequential and composite grafts were used to achieve complete revascularization. Perioperative adverse events and postoperative angiograms were analyzed. Result: A total of 252 arterial conduits were used with an average of 2.47 grafts per patient. A total of 326 distal anastomosis were performed with a mean of 3.13 distal anastomosis per patient. Cross over to on-pump occurred in seven patients (6.7%). Of these 4 were due to unstable hemodynamics during lateral or posterior wall stabilization as a result of cardiomegaly and 3 were due to uncontrolled bleeding during dissection of diffusely dimunitive deeply placed intramyocardial coronary arteries. There were no opeartive deaths. Two cases of perioperative myocardial infarction and transient neurologic complications occurred, respectively. Of the 312 distal anastomoses, 308 (98.7%) were compatible with Fitz-Gibboll A or B patency grading. Conclusion: Off-pump total arterial coronary revascularization was technically feasible in most elective cases with satisfactory early results. However, on-pump coronary bypass surgery should be considered in difficult circumstances, such as cardiomegaly or unfavorable anatomy of the target coronary artery.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.4
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• pp.435-444
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• 2009

Statement of problem: The clinical use of electric and electomagnetic fields for fracture healing applications began in the early 1970s. Since then, several technologies have been developed and shown to promote healing of fractures. Developments of these devices have been aided in recent years by basic research and several well controlled clinical trials not only in the medical field but in dentistry. Purpose: The purpose of this study was to compare alveolar bone reduction following immediate implantation using implants onto which magnets were attached in fresh extracted sockets. Material and methods: Four mongrel dogs were involved. Full buccal and lingual mucoperiosteal flaps were elevated and third and fourth premolars of the mandible were removed. Implants with magnets and implants without magnets were installed in the fresh extracted sockets and after 3 months of healing the animals were sacrificed. The mandibles were dissected and each implant sites were sampled and processed for histological examination. Results: The marginal gaps that were present between the implant and walls of the sockets at the implantation stage disappeared in both groups as a result of bone fill and resorption of the bone crest. The buccal bone crests were located apical of its lingual counterparts. At the 12 week interval the mean of marginal bone resorption in the control group was significantly higher than that of the magnet group. The majority of specimens in magnet group presented early bone formation and less resorption of the buccal marginal bone compared to the control group. Conclusion: Within the limitations of this study, it could be concluded that implants with magnets attached in the early stages of implantation may provide more favorable conditions for early bone formation and reduce resorption and remodeling of marginal bone.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.85-92
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• 2015

This study examined the settlement of a 1-2W type greenhouse using a timber pile, which was recently established on Gyehwa-do reclaimed land, in order to obtain base data for the construction of a greenhouse on reclaimed land. The results of this study are as follows. foundation and timber pile increased over time, irrespective of the interior and exterior of the upon investigation of the ground, it was confirmed that there was no soft rock stratum (bedrock), and that a sedimentary stratum existed under the fill deposit, which is estimated to have been reclaimed during the site renovation. It was also found that a weathered zone was located under the fill deposit and sedimentary stratum, and that the soil texture of the entire ground floor consisted of clay mixed with sand, silty clay, and granite gneiss, in that order, regardless of boreholes. In addition, the underground water level was 0.3m below ground, regardless of boreholes. Despite a slight difference, the settlement of the greenhouse or measurement sites (channels). With regard to the pillar inside the greenhouse, except in the case of CH-2, the data at a site located on the side wall of the greenhouse (wind barrier side) indicated vibrations of relatively larger amplitude. Moreover, the settlement showed a significant increase during a certain period, which was subsequently somewhat reversed. Based on these phenomena, it was verified that the settlement range of each site in the interior and exterior of the greenhouse was between 1.0 and 7.5mm at this time, except in the case of CH-1. The results of the regression analysis indicated good correlation, with the coefficient of determination by site ranging between 0.6362 and 0.9340. Furthermore, the coefficient of determination ranged between 0.6046 and 0.8822 on the exterior of the greenhouse, which is lower than inside the greenhouse, but still indicates significant correlation.

• Journal of Animal Environmental Science
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• v.16 no.1
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• pp.21-28
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• 2010

The odor problem in the livestock is increasing by 7% annually. Most importantly, the livestock odor problem in swinery accounts for the maximum ratio (54%). In this study, we reviewed the possibility of deodorizing swinery using an odor reduction device that can be used with the water washing system. First, the study confirmed that the solubility of odor gas, which was hydrogen sulfide, was very low regardless of the contact time with solvent, but the solubility of methyl mercaptan was found to increase along with the increase in time. The solubility of other odor gases, such as dimethyl sulfide, dimethyl disulfide and ammonia, was considerably high. Consequently, it is considered that if the odor reduction device for the water washing system deodorization is used in a swinery, the time during which the exhaust gas is in contact with usable water must be extended, or solvent quantity must be expanded. However, it is predicted that although hydrogen sulfide is easily generated in the anaerobic condition, it is difficult to expect high odor reduction efficiency because this gas has low solubility in water, especially in case it is used in the deodorization of the water washing system. The result of the solubility experiment using the bench-scale device practically manufactured represented the higher odor reduction ratio than expected. This result was possible because the removal efficiency of dust particles could be reached up to 93%. Therefore, it is judged that also the odor gas absorbed on dust particles could be removed by removal of dust. Consequently, it is expected that the higher order reduction ratio will be possible by structural improvement for increasing contact with water and odor gas.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.899-915
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• 2018

In this study, in order to construct an eco-friendly advanced road transportation network, the multi-layer tunnel, which is a small-sized car road, is designed to have a height of less than 60 cm. However, the shape of the tunnel is low and the height of the traffic sign is small. In order to solve these problems, traffic sign characters were designed in three dimensions, and the possibility of applying the design of the three - dimensional sign that can obtain greater visibility than the existing signs at the same distance and the possibility verification through virtual simulation were performed. The three-dimensional sign is horizontally installed on the ceiling of the multi-layer tunnel. To be seen vertically, it is enlarged by a certain ratio by the perspective, and the width and height are enlarged. Respectively. In addition, 3D simulation was performed to verify the visibility of the stereoscopic signs when the driver ran through the stereoscopic sign design specifications. As a result of the design and experimental study, it was confirmed that the stereoscopic sign could be designed through the theoretical formula and that it could provide the driver with a larger traffic sign character because there is no limitation of the facility limit compared to the existing vertical traffic sign. Also, we confirmed that it can be implemented in the side wall by using the stereoscopic sign design principle installed on the ceiling part. It was confirmed that the design of the stereoscopic sign can be designed to be smaller as the distance that the driver visually recognizes the sperm is shorter, the height of the protrusion vertically at the lower part of the stereoscopic sign becomes higher. As a result of 3D simulation running experiment based on the design information of the stereoscopic sign, it was confirmed that the stereoscopic sign is visually the same as the vertical sign at the planned distance. Although the detailed research and institutional improvement of stereoscopic signs have not been made in Korea and abroad, it is evolved into a core technology of new road traffic facilities through various studies through the possibility of designing and applying stereoscopic signs developed through this study Expect.

• Journal of Korean Society of Forest Science
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• v.9 no.1
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• pp.1-44
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• 1969

The important results which have been obtained in the investigation can be recapitulated as follows. 1. As demostrated by the experimental results and analyses concerning their effects in the on-ground type mushroom house, the constructions in relation to the side wall and ceiling of the experimental houses showed a sufficient heat insulation on effect to protect insides of the houses from outside climatic conditions. 2. As the effect on the solar type experimental mushroom house which was constructed in a half basement has been shown by the experimental results and analyses, it has been proved to be effective for making use of solar heat. However there were found two problems to be improved for putting solar houses to practical use in the farm mushroom growing: (1) the construction of the roof and ceiling should be the same as for the on-ground type house, and (2) the solar heat generating system should be reconstructed properly. A trial solar heat generating system is shown in Fig. 40. 3. Among several ventilation systems which have been studied in the experiments, the underground earthen pipe and ceiling ventilation, and vertical side wall and ceiling ventilation systems have been proved to be most effective for natural ventilation. 4. The experimental results have shown that ventilation systems such as the vertical side wall and underground ventilation systems are suitable to put to practical use as natural ventilation systems for farm mushroom houses. These ventilation systems can remarkably improve the temperature of fresh air which is introduced into the house by heat transfers within the ventilation passages, so as to approach to the desired temperature of the house without any cooling or heating operation. For example, if it is assuming that x is the outside temperature and y is the amount of temperature adjustment made by the influence of the ventilation system, the relationships that exist between x and y can be expressed by the following regression lines. Underground iron pipe ventilation system ${\cdots}{\cdots}$ y=0.9x-12.8 Underground earthen pipe ventilation system ${\cdots}{\cdots}$y=0.96x-15.11 Vertical side wall ventilation system${\cdots}{\cdots}$ y=0.94x-17.57 5. The experimental results have shown that the relationships existing between the admitted and expelled air and the $Co_2$ concentration can be described with experimental regression lines or an exponent equation as follows: 1) If it is assumed that x is an air speed cm/sec. and y is an expelled air speed in cm/sec. in a natural ventilation system, since the y is a function of the x, the relationships that exist between x and y can be expressed by the regression lines shown below: 2) If it is assumed that x is an admitted volume of air in $m^3/hr$ and y is an expelled volume of air in $m^3/hr$ in a natural ventilation system, since the y is a function of the x, the relationships that exist between x and y can be expressed by the regression lines shown below. 3) If it is assumed that the expelled air speed in cm/sec and replacement air speed in cm/sec. at the bed surface in a natural ventilation system are shown as x and y, respectively, since the y is a function of the x, the relationships that exist between x and y can be expressed by the following regression line: G.E. (100%)- C.V. (50%) ventilation system${\cdots}$ y=0.54X+0.84 4) If it is assumed that the replacement air speed in cm/sec. at the bed surface is shown as x, and $CO_2$ concentration which is expressed by multiplying 1000 times the actual value of $CO_2$ % is shown as y, in a natural ventilation system, since the y is a function of the x the relationships that exist between x and y can be expressed by the following regression line: G.E. (100%)- C.V. (50%) ventilation system${\cdots}{\cdots}$ y=114.53-6.42x 5) If it is assumed that the expelled volume of air is shown as x and the $CO_2$ concentration which is expressed by multiplying 1000 times the actual of $CO_2$ % is shown as y in a natural ventilation system, since the y is a function of of the x, the relationships that exist between x and y can be expressed by the following exponent equation: G.E. (100%)-C.V. (50%) ventilation system${\cdots}{\cdots}$ $$y=127.18{\times}1.0093^{-X}$$ 6. The experimental results have shown that the ratios of the crass sectional area of the G.E. and C.V. vent to the total cubic capacity of the house, required for providing an adequate amount of air in a natural ventilation system, can be estimated as follows: G.E. (admitting vent of the underground ventilation)${\cdots}{\cdots}$ 0.30-0.5% (controllable) C.V. (expelling vent of the ceiling ventilation)${\cdots}{\cdots}$ 0.8-1.0% (controllable) 7. Among several heating devices which were studied in the experiments, the hot-water boilor which was modified to be fitted both as hot-water toiler and as a pressureless steam-water was found most suitable for farm mushroom growing.