• Journal of Embryo Transfer
• /
• v.12 no.1
• /
• pp.27-36
• /
• 1997

The studies were carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular cocytes and to determine the optimum thawing temperature and equilibration time on in vitro developmental rate of frozen bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TGM-199 medium containing 10 IU /ml의 PM SG, 10 IU /ml의 hCG, ip g/ml의 $\beta$-estradiol and 10% FCS for 24~48 hrs in incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquld nitrogen and thawed in 3$0^{\circ}C$ water. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are sunanarized as followes :1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM499 medium were 75.0~76.8% and 17.3~27.6%, respect-ively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%)were significantly(p<0.05) higher than cumulus-denuded oocytes (23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with l$\times$ l04cells /ml, 1 x l06cells /ml, lx l08cells /ml and 1 x l015cells /ml oviduct epithelial cells in TCM-199 medium were 74.5~77.8% and 15.7~21.20 respectively.3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes cocultured in '1CM-199 media containing PMSG, hCG, PMSG+hCG. PMSG+$\beta$-estradiol, hCG+$\beta$-estradiol 0 to 40 hrs after insemination were 74.0~77.4% and l8.9~23.l%, re-spectiv ely.4.The survival rates of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol,DMSO and propanediol were 23.5~31.4% and 20.6~34.l%, respectively. 5. The temperature thawed at 3$0^{\circ}C$ after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 2$0^{\circ}C$ and 35$^{\circ}C$.6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20min.). (Key words : bovine embryos, co-culture, freezing, in vitro development)

• Korean Journal of Environmental Biology
• /
• v.27 no.1
• /
• pp.20-30
• /
• 2009

To study reproductive dynamics of a Gold-spotted pond frog (Rana chosenica) population located at Gangnae, Cheongwon, Chungbuk, Korea, we monitored the population over 207 days between April 17$^{th}$ 2007 and December 18$^{th}$ 2008 using a drift fence accompanied with 20 pitfall traps. The population was located in an agricultural wetland, compromising three small ponds. Gold-spotted pond frogs immigrated into the wetland between April 16$^{th}$ and June 17$^{th}$ and emigrated from the wetland between September 21$^{st}$ and November 12$^{th}$. Precipitation showed a positive correlation with the number of migrated frogs in Autumn 2007 and Spring 2008, but other environmental factors such as air and water temperatures and relative humidity did not show any significant relationships. In general, small frogs first migrated into and from the wetland, but the trend was not strong. Female gold-spotted pond frogs were bigger than males. During the autumn migration, small frogs of which snout-vent length was smaller than 20 mm were found, indicating that successful breeding occurred in the population. Our results could be useful to conserve this endangered species in Korea.

• Restorative Dentistry and Endodontics
• /
• v.20 no.2
• /
• pp.399-422
• /
• 1995

The purpose of this study was to investigate a fragment of possibility of pulpotomy with the Nd-YAG laser by the observation of pulpal healing process and the fine structural changes of the fibroblasts of the remaining pulpal tissues. Class V cavities on !55 teeth from 4 adult dogs were prepared and the pulp chambers were opened with a sterilized round bur. In the control group(19 teeth), the exposed coronal pulps were excised by a sharp excarvator. After bleeding was controlled with the sterilized cotton pellets, calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 1 : the pulpotomy with laser-calcium hydroxide powder application group(l9 teeth), the exposed coronal pulps were excised by Nd-YAG laser(10 watts power, 2 psi water, 20 psi air) for 2 or 3 seconds and calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 2 : the pulpotomy with laser-no calcium hydroxide powder application group(17 teeth), after amputating the coronal pulps with Nd-YAG laser as the experimental group 1, the remaining pulpal tissues were covered with stenilized aluminum foil and the cavities were filled with Z.O.E. The animals were sacrificed at the intervals of 1, 2, 3 and 4 weeks. All the teeth were rouutinely processed and the remaining pulpal tissues were observed by the light microscope and electron microscope. The results were as follows : 1. In light microscopic findings, there was no significant difference of the inflammatory response in the remaining pulpal tissues between the control group and the experimental groups. In both of the experimental group 1 : pulpotomy with laser-calcium hydroxide powder application group and the control group, the dentin bridges were observed after 2 weeks and the structure of the dentin bridge was almost same. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the fibrous layers instead of dentin bridge were observed on the superficial portion of the remaining pulpal tissues after 2 weeks and they were consisted with densely crowded active fibroblasts. 2. In the electronmicroscopic findings, the active fibroblasts in the experimental groups were more frequently observed than in the control group at 1 week. But active fibroblasts were found with same frequency after 2 weeks in all of the control group and the experimental groups. 3. General distortions of the cell such as loss of the cell membrane, vaculoization of the cell etc. were observed at the suberficial layer of the remaining pulpal tissues and the carbonization was found in the dentinal wall in 1 week of the experimental groups. 4. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the activity and the density of the fibroblasts in the fibrous layer were more than those in the deep portion of the remaining pulpal tissues after 2 weeks. 5. In the control group, bacteria such as cocci and bacilli were observed frequently, but in the experimntal groups, they could not be observed.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.2
• /
• pp.71-78
• /
• 2012

Eupatilin, one of representative medical components of mugwort, can be efficiently extracted from the 'Gangwha Sajabalssuk'. The Eupatilin content may depend on environmental factors such as soil and regional climate in addition to a genetic factor and Gangwha region has a profitable environmental condition for the mugwort growth. In this study, the climatological characteristics of Gangwha was analyzed in order to find the environmental condition of mugwort containing high Eupatilin in term of atmospheric, oceanographic and land variables. The climate of Gangwha is characterized by the relatively low daily temperature and large diurnal variation with plenty of solar radiation, long sunshine duration and less cloudiness. According to our correlation analysis, the long sunshine duration and the large diurnal temperature variation are highly correlated with the Eupatilin contents. The result implies that Gangwha has the favorable conditions for the cultivation and the habitat of the high-Eupatilin concentrated mugwort. Because of the sea surrounding Gangwha Island with low salinity and moderate wind, the salt contained in sea breeze is relatively low compared to other regions. Furthermore, Gangwha has clean atmospheric environment compared to other regions because the concentrations of toxic gases harmful to crop growth such as nitrogen dioxide ($NO_2$), sulfite gas ($SO_2$) and fine dust (PM-10) are lower in the air. The ozone ($O_3$) concentration is moderate and within the level of natural production. It is also found that moderately coarse texture or fine loamy soils known as good for water drainage and for the growth and cultivation of the 'Gangwha-mugwort' are distributed throughout the areas around mountainous districts in Gangwha, coinciding with those of mugwort habitat.

• Resources Recycling
• /
• v.18 no.1
• /
• pp.22-29
• /
• 2009

To design and construct a moving bed stoker incinerator for incineration treatment of the domestic oil fly ash, operating condition and moving bed area of incinerator were determined by performing incinerate experiment of the oil fly ash in the muffle furnace which simulates moving bed stoker incinerator in all conditions. Incineration process of the oil fly ash could be divided into 3 stages, every stage needs the appropriate operating condition for effective incineration. The optimum content of water in the heavy oil fly ash was found to be 20 wt% to prevent the ash from flying and reduce the volume. Science combustion rate of oil fly ash depends on the oxygen content, the incinerator must have a equipment to control the oxygen content in the combustion air. The optimum temperature was $750{\sim}800^{\circ}C$ in order to prevent adhesion to the stocker and evaporation of metal compounds of low melting point. Uniform combustion reaction and acceleration of combustion rate required agitation during the combustion of oil fly ash. The incineration rate was $12.53kg/m^2hr$ and the working area of moving bed incinerator was found to be $60m^2$ to incinerate 18 tons of oil fly ash per day.

• International Journal of Highway Engineering
• /
• v.12 no.3
• /
• pp.87-92
• /
• 2010

As the Concept "how environmental friendly" becomes more and more important in road construction. However, so far there is no estimation method. Environmental friendly concept can be incorporated at the plan level in order to influence decision making, and support policies that affect environment. The overall goal of this study was to develop environmental friendly concept measures for the national highway and to develop a methodology to implement a more environmental friendly concept. The research identified 8 performance measures through a project analysis that could address environmental impact assessment system's ten strategic goals - Topography, Wildlife, hydrology, landuse, air quality, water quality, soil, waste, noise, landscape. The qualitatively and quantitatively evaluation approach was selected as the decision support framework and performance measure were investigated using the AHP(Analytic Hierarchy Process) and pilot corridor for a 10 section and calculate the index values. The methodology was applied to a pilot corridor comprised of a 120km section of national highway in korea. The methodology made it possible to identify the specific performance measures that need improvement to enhance the overall environmental friendly concept. It is fairly intuitive, based on readily available data, and is easy to apply. It provides a powerful tool for government to assess the relative environmental friendly conceptof their transportation corridors now and in the future. It allows for comparisons within a corridor and with other corridors and identifies the improvements needed to enhance the environmental friendly concept.

• Hwankyungkyoyuk
• /
• v.20 no.2
• /
• pp.93-107
• /
• 2007

Livestock agriculture plays an essential role Hongsung's economy. Unfortunately, if manure is manage properly it can contaminate water and pollute the air. The purposes of this study were to provide awareness of environmental impact and to design educational programs with sustainable agriculture. I used the specific steps of processes. First, collecting informations through survey on environmental awareness of livestock farmers in Hongsung-gun and recognizing the tendencies. Second, analyzing on educational status of livestock farmers. Third, finding objectives of environmental educational programs. At the end of processes, establishing programs which concerning on environmental education. I used two research methods to gather and analyze the data for developing an environmental education program. The first one is a general survey among 50 livestock farmers from Hongseong-gun, Chungcheongnam-do. The second one is the in-depth interviews with specialists in environmental education and government officials from the central government - the Ministry of Agriculture and Forestry - and the local government - Hongsung-gun who are in charge of livestock farming. I found the following results from this research. First, most livestock farmers replied with 'highly likely' to the five items on the recognition of the necessity of environment preservation, whereas only 38.7% answered with 'likely' to the item on the environmental pollution caused by livestock farming. This shows the tendency that they have less recognition of the reality than necessary. Second, most of the contents among 5 areas(knowledge, recognition, function, attitude, and participation) are the knowledge areas. That results are analyzed training materials for livestock farmers made by Hongsung-gun in 2004 and in 2005 by using goal categories suggested in the Tbilisi Resolution. Third, after analyzing the survey and in-depth interviews, I found that the need for education to recognize the environmental pollution, environmental protection and recycling of the livestock waste. We can summarize conclusions from this research. First, we need on educational program improve the livestock farmers' recognition of importance in environmental protection. Second, it is necessary to develop educational program with the viewpoint that livestock waste is not one of the culprits of the environmental pollution, but a recyclable resource. Third, contents of the environmental education program, should include all the educational elements, namely, knowledge, recognition, attitude, function and participation. The education for livestock farmers requires a research on the environmental education program that can be used with crop farmers who can use the resources recycled from the livestock waste from the viewpoint of recycling resources. This research is focused on the collection and analysis of the basic data for developing an environmental education program and the composition of the program. A further research on the implementation and assessment of this program is required.

• The Journal of Engineering Research
• /
• v.6 no.2
• /
• pp.23-32
• /
• 2004

Metals, ceramics and polymers are widely used as bioimplant materials. However, Ti and Ti alloys are widely used because of its high strength to weight ratio and good biocompatibility when implanted in the body. In this experiment, Ti alloys of Grade-4 (gr4), 0.2 wt % Fe, 0.5 wt % Fe and 2 wt % Fe were studied for their surface morphology and HAp forming ability on the metal substrate for different treatments. Intially, the samples were mechanically polished on silicone carbide paper (No.-2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM. The SEM studies showed network of pores in all samples. These samples were immersed in stimulated body fluids (SBF) kept at $36.5^{\circ}C$ for different periods over the length of 1 to 14 days. The apatite formation was confirmed on all Ti-alloys using EDAX.

• International Journal of Highway Engineering
• /
• v.4 no.4 s.14
• /
• pp.13-21
• /
• 2002

This study examines the importance of conditioning temperature and period before measuring fundamental properties of asphalt mixture. Marshall specimens were made and cured in the air for one day and conditioned by submerging at $60^{\circ}C$ water for 30 min before loading. It was observed that if the specimen was cured in a lower (or higher) than normal lab temperature ($25^{\circ}C$) before submerging, the measured values were not consistent. Indirect tensile strength (ITS) was also measured on the specimens cured at different temperatures. Although there is no regulation specifying how long the specimen should be conditioned before testing, it is recommended that the conditioning time be for the specimen to be at $25^{\circ}C$. Test must be conducted for the specimen cured well before conditioning for desired test. If curing temperature was lower or higher than normal, and mixture was not properly cured, then test results would not be reliable. This study showed how long the specimen should be submerged at $60^{\circ}C$ for Marshall test and conditioned at $25^{\circ}C$ for ITS test for the specimens cured in different temperature.

• Journal of the Korean Wood Science and Technology
• /
• v.9 no.3
• /
• pp.16-23
• /
• 1981

This study has been carried out to make a comparative study for the adhesive control methods specifically developed for application to formaldehyde. The method for formaldehyde determination used in this report is the improved chromo tropic acid determination. The results are summarized as follows: 1. The soaking treatment in aqueous solution of urea wok the most scavenging effect on the formaldehyde release from a plywood sample glued with a urea formaldehyde adhesive, and other removal treatment such as resorcinol, albumine-, and hardener-treatment gave significant reduction too. 2. In glue shear strength of dry test, 2% of resorcinol treatment and soaking treatment showed the highest strength and all the other treatment met the standard, but in hot water soaking test, 2% of resorcinol treatment gave the best results, on the other hand, adding the hardener showed the lowest strength and failed in meeting the standard. 3. Air dried moisture content of all treated plywood met the standard which calls for 13% or bellow. 4. In this comparative study, we can make a strong combination each other or go into the details of one treatment for the best result through the more study.