• 한국물환경학회지
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• 제21권2호
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• pp.118-124
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• 2005

The oxygen solubilized device(O.S.D) and standardized microorganism culture system is more efficient than physical and chemical purification techniques in closed water. This study was to determine how the O.S.D and standardized culture system is efficient in purification capacity in closed water based on the lab scale and pilot plant. In the batch test, inducing the quantitative results from pilot plant operation condition, removal efficiency of COD and TN were about 48.3% and 35% respectively, while SS and chlorophyll-a were 94.9% and 68.7%. The pilot plant results showed that suspended solid(SS) and chlorophyll-a removal efficiency were 60% and 59% respectively, due to coagulation characteristics by standardized culture. Total nitrogen(TN) and total phosphorus(TP)showed good effect for the purification of target pond water quality from field data. Additionally, released velocity was determined in control condition of $5.31mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $2486.8mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. Otherwise, phosphate and COD reflux in the aeration and microorganism condition was showed $-9.95mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $-397.88mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. This technology is the most effective not only removal of SS and chlorophyll-a but also control of phosphate and COD release which is very important phenomena in evaluating water quality in closed water like a reservoir and pond.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.49-58
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• 2008

Objective: The Purpose of the study was to investigate the bone morphogenic protein expression of rhBMP-2(recombinant human bone morphogenic protein-2) as singnaling molecule and ${\beta}-TCP$(Tricalcium phosphate) as a bone substitute and carrier medium of rhBMP-2. Materials and Methods: 16 rabbits divided into 2 group of each 8 rabbit. Two standardized bone defect, round bilateral defect was made in the cranium of the 8 rabbit of first group, and was grafted with $150{\sim}500{\mu}m$ diameter ${\beta}-TCP$ 0.25g in one side, which was soaked with rhBMP-2, and autogenous bone was grafted on another side as a positive control. Second group of 8 rabbit, only ${\beta}-TCP$ was grafted with same size and same manner. After 2, 4, 8, and 12 weeks, specimen was taken for microscopic immunohiostochemical and histomorphometric analysis. Result: Grafting ${\beta}-TCP$ with rhBMP show the early formation of the bone regenerative factor (BMP-4) and more quantity of new bone formation than only use of ${\beta}-TCP$ (8,12 week), even show less new bone formation than autogenous bone. Conclusion : The experimental study result that ${\beta}-TCP$ graft combination with rhBMP-2 as a delivery system is an effective with osteoinductive capacity and biodegradable properties, so that provide clinical availibility of composite use in reconstruction of bony defect.

• Membrane and Water Treatment
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• 제9권2호
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• pp.95-104
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• 2018

Copper pollution around the world has caused serious public health problems recently. The heavy metal adsorption on traditional membranes from wastewater is limited by material properties. Different adsorptive materials are embedded in the membrane matrix and act as the adsorbent for the heavy metal. The carbonized leaf powder has been proven as an effective adsorbent material in removing aqueous Cu(II) because of its relative high specific surface area and inherent beneficial groups such as amine, carboxyl and phosphate after carbonization process. Factors affecting the adsorption of Cu(II) include: adsorbent dosage, initial Cu(II) concentration, solution pH, temperature and duration. The kinetics data fit well with the pseudo-first order kinetics and the pseudo-second order kinetics model. The thermodynamic behavior reveals the endothermic and spontaneous nature of the adsorption. The adsorption isotherm curve fits Sips model well, and the adsorption capacity was determined at 61.77 mg/g. Based on D-R model, the adsorption was predominated by the form of physical adsorption under lower temperatures, while the increased temperature motivated the form of chemical adsorption such as ion-exchange reaction. According to the analysis towards the mechanism, the chemical adsorption process occurs mainly among amine, carbonate, phosphate and copper ions or other surface adsorption. This hypothesis is confirmed by FT-IR test and XRD spectra as well as the predicted parameters calculated based on D-R model.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• 한국토양비료학회지
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• 제43권6호
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• pp.782-788
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• 2010

Detail management standard on soil conditions in 'Kyoho' grapes were not yet made. Therefore, this study was carried out to investigate the optimum soil environmental conditions on production of high fruit quality in 'Kyoho' grapes. We established using correlation between fruit quality and soil condition. These results were used to develop soil management guideline with promoting efficiency and minuteness in grape vineyard. Soil conditions were analyzed at total 80 vineyards in major grape producing areas such as Ansung, and Cheonan (40 orchards an area). The soil environmental factors affected fruit weight were soil pH of 36.6%, cultivation layer depth of 23.3%, and cation of 17.8%. The soil condition factors affected sugar content were soil hardness of 24.4%, cation of 24.1% and organic matter content of 22.1%. Cultivation layer depth, soil texture, and phosphate content were low as relative contribution. Coloring was involved with organic matter content, CEC (cation exchange capacity), and saturated hydraulic conductivity. while soil pH, cultivation layer depth, and phosphate content showed low contribution. Finally, relative contribution on fruit quality related with sugar content, fruit weight, and coloring were soil hardness of 28.0%, organic matter content of 25.0%, soil pH of 12.9%.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1104-1110
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• 1999

We condicted two experiments to evaluate the interaction among fumaric acid (FA), protected acids (PA), or no additional acid (NO) and two different levels of acid buffering capacity (BC) in diets for 14-d-old weaned pigs. BC was varied substituting mono-calcium phosphate and calcium sulfate for dicalcium phosphate and calcium carbonate. In the high BC diet plus PA, FA was also added. In Exp. 1, 48 gilts were raised for 31 days on the six diets, evaluating growth performance and fecal digestibility. In Exp. 2, 42 gilts were raised. With each diet three subjects were sacrificed after 19 days and four after 38 days. In addition, six subjects were sacrificed at weaning. Growth and carcass performance, ileal digestibility, bacterial populations and pH in the gut were assessed. The piglet performance and stomach, ileal and cecal pH, and empty body composition were not affected by the diets. Empty body composition other than ash content was affected by piglet age (p<0.01). The BC did not influence digestibility. The dietary inclusion of PA improved fecal digestibility of protein (p<0.05) compared to the addition of FA and NO. Ileal digestibility slightly increased with both acid additions (p<0.10), the groups receiving PA showing the higher values. Piglets fed diets with low BC had lower Lactobacillus and E. coli counts in the ileum (p=0.07) and higher Lactobacillus in the colon (p=0.08). Acidified diets tended to reduce E. coli counts in the ileum (p=0.10) and increased Lactobacillus in the colon (p=0.09). The addition in the diet of PA increased Lactobacillus in the ileum compared to the sole addition of free fumaric acid (p=0.07). The addition of protected acids, combined with free fumaric acid in the case of high BC diets, increased protein digestibility and Lactobacillus counts and reduced E.coli counts. Only some changes in the concentration of bacterial population can be expected with a diet of low BC.

• 대한화학회지
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• 제45권4호
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• pp.304-311
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• 2001

경수로 사용후 핵 연료에 미량 함유되어 있는 핵분열생성물을 유도 결합 플라스마 원자방출분광법(ICP-AES)으로 분석하기 위하여 우라늄으로부터 학분열생성물을 추출 크로마토그래피로 분리, 회수하는 방법을 검토하였다. 우라늄 분리 분야에서 잘 알려져 있는 tri-n-butyl phosphate(TBP)를 추출제로 사용하여 몇 가지 Amberlite XAD 다공성 수지들에 대한 침윤능을 비교한 후 TPB침윤양이 가장 큰 Amberlite XAD-16을 지지체로 선택하였다. 사용후핵연료 용해용액과 화학조성이 유사한 모의 사용후핵연료 용해용액을 사용하여 TBP 침윤수지에 대한 핵분열생성물 원소들의 흡착거동을 조사하고, 분리에 미치는 여러 변수들을 최적화 하였다. Pd 및 Ru을 제외한 대부분의 핵분열생성물 원소들을 정밀도 3.1% 이하의 범위에서 정량적으로 회수할 수 있었다.

• 한국가금학회지
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• 제16권3호
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• pp.157-167
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• 1989

난백으로부터 lysozyme을 효과적으로 추출하기 위하여 난백의 전처리와 이온교환수지의 선택 및 전처리 등 추출조건에 관한 연구를 실시한 결과는 다음과 같다. 난백의 점도저하를 위하여 2,000 rpm의 속도로 30분간 균질하고 45분간 초음파처리를 실시한 결과 난백의 겉보기 점도가 3 cp까지 떨어졌으나 pH의 변화에 따라서는 점도의 차이가 크지 않았다. lysozyme의 추출을 위한 이온교환수지의 선택을 위하여 Amberlite IRC-84 등 6종류의 수지에 대한 Lysozyme 흡착력을 검토한 결과 CM-Sepdex C-25＞Duolte C-464＞Amberlite C-50＞Dowex MSC-1＞Amberlite IRC-50＞Amberlite IRC-84의 순으로 lysozyme 흡착력이 높았으나 난백에의 적용시 CM-Sephadex C-25의 경우에는 난백의 유출이 용이하지 않은 것으로 나타나 Duolite C-464가 가장 적합한 것으로 나타났다. 양이온교환수지인 Duolite C-464 의 양이온형태 결정을 위하여 $Na^{＋}$, $NH_4$$^{＋}$. $K^{＋}$ form으로 만들어 lysozyme 흡착력을 검토한 결과 $Na^{＋}$ ＞ $NH_4$$^{＋}$ ＞ $K^{＋}$의 순으로 나타나 $Na^{＋}$ form으로 하는 것이 가장 효과적인 것으로 나타났다. Duolite C-464의 $Na^{＋}$form을 이용하여 lysozyme을 추출할 경우 rinse buffer는 pH6.5의 0.1M sodium phosphate buffer, eluting solution은 10% ammoniun sulfate가 효율적이었다. Lysozyme을 추출한 전, 후 난백의 가공적성을 측정한 결과 기포력은 추출전의 난백액에 대하여 85.3%로서 다소 떨어졌으나 가열한 난백겔의 경우에는 추출전, 후 색택의 변화가 크지 않았으며 조직감의 경우에도 hardness가 다소 떨어졌으나 elasticity는 오히려 13%가량 증가되었다.

• 한국철도학회논문집
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• 제18권6호
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• pp.543-551
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• 2015

급속경화궤도는 자갈궤도를 콘크리트궤도로 개량하는 공법으로서 야간 차단시간에 공사가 이루어지기 때문에 시공속도를 충분히 확보하는 것이 중요하다. 시공시간의 대부분은 자갈을 철거하고 재포설하는 과정에 소요되는데 도상자갈을 교체하지 않는 무교환방식이 적용 가능하다면, 시공시간 및 공사비를 대폭적으로 절감할 수 있다. 본 논문에서는 도상자갈 무교환방식의 급속경화궤도공법을 개발하기 위하여 침투성이 매우 높은 대체 충전재를 제시하고 재료의 공극조건을 고려하여 층별로 분리주입하는 시공방식을 도입하였다. 분리주입은 공극률이 높은 상부도상층과 공극률이 낮은 하부 혼입층에 최적화된 재료를 분리 주입하여 필요한 소요강도를 확보할 수 있다. 이를 달성하기 위하여 우선적으로 도상자갈의 크기, 분포도, 형상에 따른 공극률, 공극의 크기, 유효길이, 비틀림도, 침투성에 따른 충전재의 유동학적 해석을 통하여 최적의 충전재를 설계하고자 하였다. 하부 혼입층에 충전되는 1차 충전재료는 세립화 도상의 충전성과 부착력을 확보할 수 있는 폴리머계 재료를 도입하였으며, 상부 도상층에 충전되는 2차 충전재는 상온 반응성 마그네시아-포스페이트(MPC, Magnesium-Phosphate Ceramic)를 도입하였다. 선정재료 및 구조에 대한 역학시험 결과, 기존 급속경화궤도에 준하는 성능을 확인하였다.

• 전기화학회지
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• 제13권2호
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• pp.145-152
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• 2010

본 연구에서는 organophosphate를 기반으로 한 과불소화된 아크릴레이트 가교제를 사용하여 제조한겔 고분자 전해질의 이온 전도도 및 전기화학적 특성을 평가하였다. 과불소화된 아크릴레이트 가교제를 사용하여 만든 겔 고분자 전해질은 액체전해질의 함량이 최대 97 wt%까지 안정한 겔 상태를 유지하였다. 본 연구에서 제조한 겔 고분자 전해질의 이온전도도는 $30^{\circ}C$에서 $1.0\;{\times}\;10^{-2}\;S/cm$의 값을 가졌다. 또한 전기화학적 안정성 테스트에서도 약 4.5V로 이상까지 산화에 의한 열화가 없이 안정하였다. 합성된 겔고분자 전해질을 리튬이온 고분자 전지에 적용하여 그 활용성을 평가하였다. 양극으로는 $LiCoO_2$를 사용하였으며 음극으로는 카본을 사용하였다. 이렇게 만든 리튬이온 고분자 전지는 0.1C에서 136.11 mAh/g의 용량으로 이론용량과 거의 비슷한 값을 나타내었으며, 2C 방전에서도 초기 용량의 91%를 유지하였다. 또한 500번의 충방전 후에도 초기 용량의 70%정도의 용량을 유지하였다.