• Journal of Embryo Transfer
• /
• v.19 no.1
• /
• pp.53-59
• /
• 2004

The environmental impact of nutrient waste from agriculture has become an area of concern as ways to produce more food and of offspring. In dairy cattle, as the genetic capacity for milk production has increased, decreased fertility has become a severe problem by feeding high dietary protein, resulting in high concentration of blood urea nitrogen (BUN). There are numerous reports on BUN which is associated with reduced conception rates and closely related to body condition score (BCS) in lactating cattle, but not in Korean native cattle. This study was therefore performed to investigate the relation of BUN to both BCS and conception rates in Korean cattle. A total of 400 female Korean cattle (2∼5 years) in Daewanryong were used for this experiment. Feeding condition divided into two groups depending on grazing and darn feeding period. In grazing period, the mixture of Timothy, Orchard grass and Tall fescue, and concentrates (2.5 kg/day) was fed whereas hay (6.5 kg/day) and corn silage (20 kg/day) were fed while barn feeding period. Average BUN concentration at grazing and barn feeding were 7.39$\pm$2.65 mg/㎗ and 12.36$\pm$2.92 mg/㎗, respectively. During grazing period, high rates of pregnancy showed at 4∼8 mg/㎗ BUN concentration. In barn feeding period, 66%, of cattle were in pregnant at 8∼l4 mg/㎗ BUN concentration. The BCS for obtaining high rate of pregnancy raged at 2.5∼3.5. However, BUN did not directly relate to BCS in Korean cattle.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.379-387
• /
• 1999

During the past several decades, electricity generating plant increased with remarkable rapidity in Korea. Recently the increase has been much more rapid as the rate of industrialization has accelerated. Construction of nuclear power plants in coastal areas inevitably caused the perturbation of critical coastal habitats and thus influenced marine algal species composition. Particularly, an increase in the building of nuclear power plants led the amounts of heat discharged to increase exponentially. As far as the effects of cooling water and thermal discharges are concerned, benthic marine algae are likely to be vulnerable to a discharge. Heated effluents from nuclear power plants, with the temperature rises of 7~12$^{\circ}C$ under normal operating and design conditions, are discharged through the discharge canal and into natural water bodies. It is clear that the characteristic marine algal community is developed in the area affected by the thermal discharges; i.e. low species richness and low species diversity. Nevertheless, it is worthwhile to note that elevated temperatures exert differential effects depending on the algal populations. Benthic marine algae grown at the discharge canal can be regarded as warm tolerant species. 35 species (4 blue-green, 9 green, 8 brown and 14 red algae) of marine algae occurred more than 20eye frequency at discharge canal of three nuclear power plants in the east coast during 1992 ~ 1998 and thus can be categorized as warm tolerant species in Korea. To minimize the ecological impacts of waste heat on benthic marine algae, it is recommended that, in the future, nuclear power plants will have to employ some form of closed-cycle cooling for the condensers.

• KEPCO Journal on Electric Power and Energy
• /
• v.5 no.4
• /
• pp.287-293
• /
• 2019

Domestic thermal power plant fly ash is at a situation which emissions are increasing every year. Comparing to Fly Ash, Bottom Ash is only 15 %, but it's recycling rate is low, so most of them is being buried in the ground. However, landfill site of every power plant is full, and the construction of a new landfill is difficult. To solve this problem, the best solution is to use Bottom Ash as a landfill of large-scale civil engineering projects. The purpose of this study was to investigate the compression strength behavior characteristics of weak clay and uniaxial compression test to examine the applicability of surface soil solidification method of mixed soils mixed with industrial waste coal ash and weak clay which is buried in bulk. As a result of the test, the fluidity of the Mixed soil with clay + bottom ash + cement was improved to 200 mm at the water content of 91-92 %. The uniaxial compressive strength was also good for the mixed soils (clay + bottom ash + cement) meeting the required strength of 159 kN/㎡ at 28 days. However, the other samples did not meet the required strength. In this study, the prediction equations for the compression strength behavior by cement and curing period were presented.

• Resources Recycling
• /
• v.15 no.3 s.71
• /
• pp.46-57
• /
• 2006

This study was carried out for the purpose of recovering the refined gypsum from waste phosphogypsum. The refined gypsum was recovered as a under product of 325 mesh wet screening followed by dehydration and hydration stage. The influence of dehydration temperature and time, dehydration rate, aging time, slurry density of hydration and sonication time on the yield and grade of gypsum were investigated. The refined gypsum of $94{\sim}96%$ grade is recovered in 95% yield by wet screening after selective dehydration and hydration process, from the phosphogypsum. For the better separation efficiency of gypsum, it is recommended to treat the phosphogypsum at the conditions of as follows; 6hr's dehydration at $140^{\circ}C$, hydration slury density of $3{\sim}10%$, hydration temperature of $20{\sim}30^{\circ}C$, hydration time of 2hr. In additions, addition of sodium citrate 0.005M and sonication of $5{\sim}10min.$ are effective for increase the recovery of gypsum. On the other hand, aging the dehydrated gypsum 16 hours or longer make decrease the recovery of gypsum remarkably.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.467-474
• /
• 2012

This study was carried out to evaluate effect of temperature condition on nitrogen mineralization of organic matter, distribution of microbial group by PLFA profiles, and soil microbial community structure in volcanic ash soil. Dried soil 30 g mixed well each 2 g of pellet (OFPE) organic fertilizers, pig manure compost (PMC), and food waste compost (FWC). And then had incubated at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, respectively. Nitrogen mineralization rate increased with increasing temperature and that was in the order of FWC>OFPE>PMC. Distribution ratio of microbial group by PLFA profiles were different significantly caused by incubation temperature and the type of organic matter. As incubating time passed, density of microbial group decreased gradually. The Gram-bacteria PLFA/Gram+ bacteria PLFA, Fungi PLFA/Bacteria PLFA, and Unsaturated PLFA/saturated PLFA ratios were decreased according to the increasing temperature gradually. But cy19:0/$18:1{\omega}7c$ ratio increased both FWC and PMC treatment. Principal component analysis using PLFA profiles showed that microbial community structure made up clearly at both 75 days ($10^{\circ}C$) and 270 days ($30^{\circ}C$) by temperature factor. As incubating time passed, microbial community structure shifted gradually.

• Journal of Chest Surgery
• /
• v.37 no.6
• /
• pp.499-503
• /
• 2004

Background: We investigated the longevity, thresholds of epicardial pacemaker and causes of reoperation in the pediatric patients who underwent epicardial pacemaker implantation performed during the last 13 years Material and Method: 121 operations were performed in 83 patients from January 1989 to July 2002. We analyzed the stimulation threshold, resistance, R-wave and P-wave, and sensitivity of pacemaker lead at initial implantation. Longevity and causes of reoperations were investigated. Result At implantation, epicardial ventricular mean stimula-tion threshold was 1.2$\pm$0.1 (0.1∼5) mV, mean resistance was 519.1$\pm$18.1 (319∼778) Ohm, and mean R-wave sensitivity was 8.9$\pm$0.7 (4∼20) mV, and mean P wave sensivity was 2.5$\pm$0.7 (0.4∼12) mV. The mean longe-vity of pacemaker generator was 64.7$\pm$3.7 (2∼196) months. The reoperation free rate was 94.6% for 1 year, 93.6% for 2 years, 80.8% for 5years, 63.7% for 7 years, and 45.5% for 10 years. The causes of reoperation were battery waste in 26 cases and lead malfunction in 9 cases. There was no postoperative death related to pacemaker malfunction. Conclusion: in the childrens, average longevity of epicardial pacemaker was within accep-table range. 19.1% of the patients required pacemaker related reoperation. However, recent developments, including steroid eluting lead, 6.7% of the patients required pacemaker related reoperation, look promising in expansion of pacemaker life span.

• Applied Biological Chemistry
• /
• v.37 no.4
• /
• pp.221-225
• /
• 1994

For producing single cell protein from the agricultural waste, heat treatment and antibiotics on the growth of Cellulomonas sp. KL-6, isolated in rotting leaf and the adjacent soil mixture, were examined. The organism was able to grow until 5 min. at $65^{\circ}C$, 1 min. at $75^{\circ}C$ and 1/4 min. at $85^{\circ}C$ in gradually rising temperatures. It can be Seen that preheating the suspension at $48^{\circ}C$ results in a marked decrease in heat resistance. On heating at temperature of $55^{\circ}C$ for 30 min., strain KL-6 was more resisted in the 0.1 M phosphate buffer when such substrates as casamino acid (1%), yeast extract (1%) or xylose (5%) were added to it whereas this organism was appeared weaker resistances in 0.1 M phosphate buffer when cysteine (0.03 M), sodium citrate (1%) or casein (1%) were in fused into it. Test strain was susceptible to penicillin-G $(1.563\;{\mu}g/ml)$ and ampicillin $(3.125\;{\mu}g/ml)$, but the organism was resisted to kanamycin $(>200\;{\mu}g/ml)$. The treatment of strain KL-6 with sodium dodecyl sulfate (SDS) resulted in the elimination of R-plasmid from the host strain and the elimination rate with SDS $(10{\sim}30\;{\mu}g/ml)$ was about $9.2{\sim}31.2%$, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.915-921
• /
• 2001

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. In order to express a high level of fungal phytase in Saccharomyces cerevisiae, various expression vectors were constructed with different combinations of promoters, translation enhancers, signal peptides, and terminator. Three different promoters fused to the phytase gene (phyA) from Aspergillus niger were tested: a galactokinase (GAL1) promoter, glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, and yeast hybrid ADH2-GPD promoter consisting of alcohol dehydrogenase II (ADH2) and a GPD promoter. The signal peptides of phytase, glucose oxidase (GO), and rice amylase 1A(RAmy1A) were included. Plus, the translation enhancers of the ${\Omega}$ sequence and UTR70 from the tobacco mosaic virus (TMV) and spinach, respectively, were also tested. Among the recombinant vectors, pGphyA06 containing the GPD promoter, the ${\Omega}$ sequence, RAmy1A, and GAL7 terminator expressed the highest phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase was also performed by inserting an endoplasmic reticulum (ER) retention signal, KDEL sequence, into the C-terminus of the phytase within the vector pHphyA-6. It appeared that the KDEL sequence directed most of the early expression of phytase into the intracellular compartment yet more than $60\%$ of the total phytase activity was still retained within the cell even after the prolonged (>3 days) incubation of the transformant. However, the intracellular enzyme activity of the transformant without a KDEL sequence was as high as that of the extracellular one, thereby strongly suggesting that the secretion of phytase in S. cerevisiae appeared to be the rate-limiting step for the expression of a large amount of extracellular recombinant phytase, when compared with other yeasts.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.1
• /
• pp.42-45
• /
• 2008

It has been reported that FRP (fiber reinforced plastic) can be recycled by separating into layers instead of crushing into powder. F-fiber obtained from roving layer separated from FRP, has bigger tensile strength than the bundle of glass fibers of which FRP was made (more than 90%). SEM image of F-fiber shows the presence of some resin. Under the proposition of usage of F-fiber in the concrete material, tensile strength is examined after soaking in a basic solution (NaOH+KOH). The reaction mechanism of strength loss may be considered as an attack of hydroxide ion ($OH^-$) on a chemical bond of Si-O-Si of glass fiber. The simulation graph of the strength loss data implies certain reaction mechanism. While in the early stage kinetically controlled reaction results in a fast drop of tensile strength, after 30 days dispersion rate of hydroxide ion plays a major role in strength loss. This result is similar to the one for the AR glass. An extrapolation of the graph would make an assumption about the lift time of F-fiber possible.

• Proceedings of the KSAR Conference
• /
• 2001.03a
• /
• pp.10-10
• /
• 2001

본 연구는 정자의 기능검사와 체외수정을 실시하여 수정능력과 수태율의 예측을 위한 이들간의 상관관계를 알아보기 위하여 AI 중인 8두의 종모돈을 가지고 시도되었다. 정자의 기능검사로서 첨체상태는 spermac stain을 이용하여 관찰하였고 정자원형질막의 온전성(integrity) 검사로는 hypo-osmotic test(HOST)를 실시하였다. 그리고 정자의 첨체효소인 acrosin activity를 측정하였다. 체외수정율은 체외성숙 난포란과 실시하였다. 8마리 종모돈의 첨체형태의 정상비율은 처리전 64.7-81.9%, 처리후 21.8~48.1%로 개체간의 유의성이 있었다. Acrosin activity는 처리전 3.70-4.57 mIU/$10^{6}$ 정자, 처리후 3.23~5.53 mIU/$10^{6}$ 정자였으며 처리전 개체에서만 유의성이 있었다. HOST는 처리전 26.5~54.5%, 처리후 20.2~50.0%로서 처리전후간의 차이는 없었지만 개체간의 유의차는 있었다. 체외수정율의 범위는 61.6~8l% 였고 6일 후 배발달율(배반포율)은 11~22%로 개체간의 유의성이 있었다. Spearman ranking correlation에서 체외수정율은 첨체상태검사와는 0.45, HOST와는 0.43로서 유의성이 인정되지 않았다. 또한 수태율은 첨체상태검사와 0.89, acrosin activity와 0.86, HOST와 0.86, 체외수정과 0.51로서 유의적으로 높은 상관관계를 나타내었다. 본 결과에서 종모돈의 기능검사와 체외수정결과로 개체간의 수정능력의 차이를 알 수 있었으나 수정란의 발달율이나 수태율을 예측할 수 있을 만큼의 상관성은 얻지 못했다. 정자검사에 있어서 일반성상 검사외에 정자기능 검사의 추가 실시가 종모돈 정자의 정확한 수정능력을 예측하는데 필요할 것이다.llus kawachii등으로 담금하여 제조한 술 시료 11종류를 대상으로 하여 쓴맛, 미묘한 맛, 떫은 맛, 신맛, 좋은 맛의 정도를 5단계로 나누어 관능검사를 실시한 다음 자료를 Duncan's multiple range test로 분석한 결과 전체적으로 좋은 맛에 대한 기호도는 Aspergillus sp. SH-607 시료와 Aspergillus sp. SH-412, Rhizopus sp. SH-606, Aspergillus sp. SH-613, Rhizopus sp. SH-654, Aspergillus sp. SH-696 Aspergillus kawachii 시료가 유의성 있게 좋은 맛을 나타내 기호도가 높았으며 맛과 기호도가 가장 좋았던 것은 Aspergillus sp. SH-607 시료로 나타났다.\varepsilon}}$는 268.20 $m^2$/day, $T_{ηη}$는 28.75 $m^2$/day이고 주 텐서방향은 N7.55$^{\circ}$E이며 BH-5호공에서의 $T_{{\varepsilon}{\varepsilon}}$는 168.40 $m^2$/day, $T_{ηη}$는 66.80 $m^2$/day이고 주 텐서방향은 N76.59$^{\circ}$E로 나타났다. 이처럼 연구지역에서의 각각의 공에 대한 투수량계수텐서는 서로 다르게 나타났으며 이에 따른 주 텐서방향도 서로 다름을 알 수 있다.. Targeting a 10% recycling rate for municipal waste in 2001. EPA plans to research and develop new recycling techniques, expand t