• 제목/요약/키워드: equilibrium ability

검색결과 139건 처리시간 0.029초

Pseudomonas putida로 부터 분리한 cryptic플라스미드의 제한효소지도 (Restriction map of a cryptic plasmid from Pseudomonas putida)

  • 김훈규;고상균;이영록
    • 미생물학회지
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    • 제24권1호
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    • pp.7-11
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    • 1986
  • Pseudomonas의 분해계 플라스미드와 이들에 유용한 벡터를 개발하기 위해서 본 연구실에서 분리, 보존하고 있는 Pseudomonas 중에서 P.putita KU 190으로부터 하나의 플라스미드를 분리하여 그 특성을 해석코저 하였다. size marker로 RP4와 pSy343를 사용하여 플라스미드의 크기를 결정한 바 41Kb로 나타났으며, 이 플라스미드를 pKU 41라 명명하였다. 제한효소 Bglll, BamHl, Eco Rl, HindIII, Sall등으로 이 플라스미드를 소화하여 이들의 제한효소 pattern을 조사한 결과, Bg III가 1. BamHl 3, Hin dIll는 3, EcoRI은 6 그리고 SalI은 13개 이상의 절단부위를 가지고 있었다. 이 제한효소의 절단부위, 토막들의 크기로부터 BamHI, HindIII에 대한 지도를 작성하였다. 플라스미드의 생울학적 기능을 조사하기 위하여 탄화수소 자화능에 대한 큐어링 실험을 하였으나 이로부터 뚜렷한 관련성 여부를 관찰할 수 없었다.

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키틴 기반 흡착제 PEI-chitin을 이용한 반응성염료의 제거 (Removal of Reactive Dyes using Chitin-based Adsorbent PEI-chitin)

  • 김경민;왕쭈오;원성욱
    • Korean Chemical Engineering Research
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    • 제57권2호
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    • pp.232-238
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    • 2019
  • 산업폐수 속의 대표적인 색도유발물질인 염료를 효과적으로 제거하기 위한 생체흡착제로 폴리에틸렌이민을 키틴에 가교결합한 PEI-chitin을 개발하였다. 대표적인 반응성염료인 Reactive Orange 16 (RO16)을 모델염료로 사용하였고, RO16에 대한 PEI-chitin의 흡/탈착 능력을 평가하기 위해 pH의 영향, 등온흡착, 흡착속도론, 탈착 실험을 수행하였다. 그 결과, Langmuir 식에 의해 산출된 최대흡착량은 pH 2에서 266.3 mg/g이었고, 흡착평형에 도달하는 시간은 50 mg/L에서는 약 20분, 100 mg/L에서는 약 60분 그리고 200 mg/L에서는 약 240분으로 평가되었다. 탈착실험은 암모니아/에탄올 혼합용액, NaOH, $NaHCO_3$, $Na_2CO_3$를 용리액으로 이용하여 평가하였으며, 암모니아/에탄올 혼합용액에서 75.24%로 가장 높은 탈착율을 보였다.

The effect of water restriction on physiological and blood parameters in lactating dairy cows reared under Mediterranean climate

  • Benatallah, Amel;Ghozlane, Faissal;Marie, Michel
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권1호
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    • pp.152-158
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    • 2019
  • Objective: This study was conducted to evaluate the effect of water restriction (WR) on physiological and blood parameters in lactating dairy cows reared under Mediterranean climate. Methods: The trial lasted 16 days preceded by two weeks of adaptation to the experimental condition in spring 2014 on 6 dairy cows in mid-lactation. These cows were allowed water ad libitum for 4 days (W100) (hydration period), then split into 2 groups, one group has received 25% and the other 50% of water compared to their mean water consumption during the hydration period; then rehydrated for 4 days. Feed intake and physiological parameters: respiratory rate (RR), heart rate (HR), and rectal temperature (RT) were recorded twice a day. Blood was collected once a day and analyzed for serum concentration of glucose (Glc), triglycerides (TG), cholesterol (Chol), urea (Ur), creatinine (Crea), and total protein (TP) by enzymatic colorimetric method and cortisol (Cort) by radioimmunoassay. Results: Total dry matter intake (TDMI) was affected by WR. A decrease in TDMI was observed in WR groups compared to W100 group (effect, group, period, day, $group{\times}day$, $period{\times}day$: p<0.001). Also, WR resulted in a significant increase in RR, HR, RT in WR groups than in W100 group (effect, group: p<0.001). In addition, an increase in the serum concentration of Glc, TG, Chol, Ur, Crea, TP, and Cort was noted in WR groups (effect, group, period, day: p<0.001). Conclusion: This study has shown the ability of cows raised in a Mediterranean climate to cope with different levels of WR and thus reach a new equilibrium. As result, elucidates the important role of water as a limiting factor for livestock in environments with low water availability.

벼와 옥수수 부산물로 제조한 바이오차의 NH4+ 흡착 특성 평가 (Adsorption Characteristics of NH4+ by Biochar Derived from Rice and Maize Residue)

  • 강윤구;이재한;천진혁;오택근
    • 한국환경농학회지
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    • 제40권3호
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    • pp.161-168
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    • 2021
  • BACKGROUND: Biochar has ability to reduce N loss, increase crop yield, and sequestrate carbon in the soil However, there is still limited study concerning the interactive effects of various biochars on NH3 loss and plant growth. This study, therefore, was conducted to investigate the NH4+ adsorption characteristics of biochar derived from rice and maize residues. METHODS AND RESULTS: By-products were pyrolyzed under oxygen-limited conditions at 300-700℃ for 1 hour and used for experiment of NH4+ adsorption in aqueous solution. The adsorption characteristics of biochar were studied using Langmuir isotherm. Biochar yield and hydrogen content decreased with increasing pyrolysis temperatures, whereas pH, EC, and total carbon content increased. The biochar pyrolyzed at lower temperatures was more efficient at NH4+ adsorption than those produced at higher temperatures. In addition, the RL values, indicating equilibrium coefficient were between 0 and 1, confirming that the result was suitable for Langmuir isotherm. CONCLUSION: The maize stalk biochar pyrolyzed at 300℃ was the most efficient to adsorb NH4+ from the aqueous solution. Furthermore, the adsorption results of this experiment were lower than those of other prior studies, which were ascribed to different experimental conditions such as ingredients, and pyrolysis conditions.

전기방사로 제작된 재이용 가능한 PAN/제올라이트 섬유의 암모니아 흡착 특성 (Ammonia Adsorption Characteristic of Reusable PAN/zeolite Fibers Made by Electrospinning)

  • 노연희;정우진;장순웅
    • 한국환경농학회지
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    • 제39권4호
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    • pp.281-288
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    • 2020
  • BACKGROUND: Generally, ammonia occurs from agricultural waste disposal. Ammonia is known as a harmful substance to the human body and has a bad influence such as eutrophication on the ecosystem. It is possible to remove the ammonia by ammonia adsorption method using natural zeolite, without external influence. However, due to the natural zeolite shape, it is hard to reuse. METHODS AND RESULTS: Electrospinning method can produce fiber with constant diameter. Moreover, electrospinning method has no limitation for selecting the material to make the fiber, and thus, it is valuable to reform the surface of adsorbent. In this study, reusable membrane was made by electrospinning method. The highest removal efficiency was shown from the membrane with 20% of zeolite included, and it has been verified that it is possible to reuse the membrane through chemical treatment. The highest ammonia removal efficiency was about 92.4%. CONCLUSION: In this study, ammonia adsorption characteristics of zeolite fibers were studied. Electrospinning method can produce zeolite fiber with even distribution. Ammonia can be removed efficiently from ion exchange ability of the natural zeolite. The result of adsorption isotherm indicated that both Freundlich model and Langmuir model provided the best fit for equilibrium data. And study on desorption has demonstrated that the ion exchange from zeolite was reversible when 0.01 M NaCl and KCl solution were used.

교등원(交藤圓)이 백서(白鼠)의 산화유발(酸化誘發)을 방어(防禦)하는 작용(作用)에 관(關)한 연구(硏究) (Effect of JiaoTeng-Yuan(交藤圓) on Oxidation Stress Caused by D-galactose in Sprague-Dawley Rats)

  • 이송실;이상재;김광호
    • 대한예방한의학회지
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    • 제8권2호
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    • pp.141-156
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    • 2004
  • Objectives : JianTeng-Yuan(交藤圓) is said to be a prescription for preservation of health in ${\ulcorner}$HuaTuo ZhongZangJing(華陀 中藏經)${\lrcorner}$. It is known to have the effect of Bu-Shen(補腎: strengthening kidney) and Yi-Shou(益壽: prolonging the span of one's life). This study investigates whether JTY is effective on inhibition of oxidation stress. Methods : Sprague-Dawley Rats(12-week-old, weight $300{\pm}20g$) were divided into 3 groups. Normal group(n=8) was injected PBS(1ml/body, s.c) at the back neck's skin. Control group(n=8) was injected D-galactose(50mg/kg, 1ml PBS/body, s.c) to induce pathological animals. JTY group was injected the same treatment for the Control group, and fed containing JTY(10%). The whole groups were treated 1 time per day for 6 weeks. After rats were sacrificed and anti-oxidant enzyme(SOD, CAT, G-px) activity, GSH quantity of RBC and tissue(heart, liver and kidney), plasma Vit-C quantity were examined. Besides, the MDA levels of liver and kidney, lipofuscin of heart and endurance of erythrocyte membrane were measured. Results : In the JTY group, RBC's SOD activity decline was halted by 21% of the normal level, compared to the control group ; G-px activity(unit/g of Hb) increased significantly, compared to the normal group ; and the level of Vit-C in plasma increased by 16%. Heart's SOD activity was kept at the same level as that of the normal group ; and CAT activity decline was halted by 26%. Kidney's CAT and G-px activities were kept at the same level as that shown in the normal group, implying the existence of halting effect. Liver also showed a slight halting effect against the decline of anti-oxidant ability, but the effect was not significant(a=0.05). A comparison between the levels of peroxide in SD rats showed that the level of TBARS in plasma increased significantly in the control group and that it was normal in the JTY group. The livers in the JTY group, compared to those in the control group, showed 36% halting effect of the normal level while their kidney's indicated the level significantly lower than the normal level. Heart's lipofuscin increased significantly in the control group, but was alike in both the JTY and the normal groups. Endurance of erythrocyte membrane(%) decreased significantly in the control group while it was kept at the similar level in both the JTY and the normal groups, indicating the halting effect. Conclusions : This study suggests that JTY is effective to defend oxidation stress caused by D-galactose in the animals. It showed that the anti-oxidant ability was maintained and strengthened. On the other hand, it reduced the level of peroxide in animals. In sum, JTY appeared to have the equilibrium normal physiological function in SD rat.

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Glass Dissolution Rates From MCC-1 and Flow-Through Tests

  • Jeong, Seung-Young
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2004년도 학술논문집
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    • pp.257-258
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    • 2004
  • The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

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친수성 이온성 액체를 이용한 수상이성분계에서의 아크릴산 추출 평형 (Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids)

  • 이용화;이우윤;김기섭;홍연기
    • Korean Chemical Engineering Research
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    • 제52권5호
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    • pp.627-631
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    • 2014
  • 본 연구에서는 아크릴산 추출을 위한 효과적인 분리공정으로서 모폴린계 이온성 액체/$K_2HPO_4$에 의한 수상이성분계를 적용하여 수상이성분계 형성 특성 및 아크릴산 추출 효율에 대한 모폴린계 이온성 액체의 양이온 알킬사슬 길이의 영향을 고찰하였다. 실험 결과 $K_2HPO_4$ 수용액에 적정량의 모폴린계 이온성 액체를 첨가함에 따라 안정한 수상이성분계가 형성됨을 확인할 수 있었으며 이성분계 형성능력은 [HMMor][Br]>[OMMor][Br]>[BMMor][Br]> [EMMor][Br]의 순서로 나타났다. $K_2HPO_4$ 수용액을 기준으로 모폴린계 이온성 액체의 수상이성분계 형성 능력은 기존의 이미다졸계와 큰 차이가 없었으며 친수성알콜/$K_2HPO_4$와 비교했을 경우에는 적은양으로도 수상이성분계 형성이 가능하였다. 모폴린계 이온성 액체를 이용한 수상이성분계 추출에 있어 아크릴산 추출 효율은 50~90%의 범위를 가지며 이 값들은 이미다졸계와 큰 차이가 없었다. 모폴린계 이온성 액체가 이미다졸계 이온성 액체에 비해 경제적으로 생산할 수 있으므로 모폴린계 이온성 액체와 $K_2HPO_4$로 구성된 수상이성분계는 아크릴산을 포함한 각종 생물공정에 의한 제품 분리에 효과적임을 알 수 있었다.

나노 스케일 판의 좌굴해석을 위한 비국소 탄성 이론의 적용 (Application of nonlocal elasticity theory for buckling analysis of nano-scale plates)

  • 이원홍;한성천;박원태
    • 한국산학기술학회논문지
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    • 제13권11호
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    • pp.5542-5550
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    • 2012
  • Eringen의 비국소 탄성이론을 이용한 3차 전단변형이론을 정식화 하였고 비국소 탄성이론이 적용된 평형방정식을 유도하였다. 비국소 탄성 이론은 미소 규모 효과를 고려할 수 있고 3차원 전단변형이론은 나노 판의 두께방향으로의 전단변형률과 전단응력의 곡선변화 효과를 고려할 수 있다. 모든 변이 단순지지된 나노-스케일 판의 지배방정식을 풀기 위해 Navier 방법을 사용하였다. 비국소 변수의 효과를 나타내기 위한 나노-스케일 판의 해석적 좌굴하중을 제시하였다. 국소 탄성이론과의 관계를 수치해석 결과를 통하여 고찰하였다. 또한 (i) 나노-스케일 판의 크기, (ii) 비국소 계수, (iii) 형상비 그리고 (iv) 모드 수 등이 나노-스케일 판의 무차원 좌굴하중에 미치는 효과에 대하여 관찰하였다. 본 연구의 결과를 검증하기 위해 참고문헌의 결과들과 비교 분석하였으며 해석결과는 참고문헌의 결과들과 잘 일치함을 알 수 있었다. 비국소 이론에 의한 나노-스케일 판의 좌굴해석에 관한 연구는 향후 관련연구에 비교자료로 활용될 수 있을 것이다.

파쇄 폐타이어를 이용한 반응벽체에 관한 연구: 폐타이어 내의 MTBE(Methyl tertiary Butyl Ether)흡착 중심 (A Study of Ground Tire as a Sorption Media for the Passive Treatment Wall: Sorption of MTBE (Methyl tertiary Butyl Ether))

  • 박상현;이재영;최상일
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제8권3호
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    • pp.37-44
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    • 2003
  • MTBE(Methyl tertiary Butyl Ether)와 같은 가솔린 연료의 첨가제의 사용은 대기오염물질의 발생을 효과적으로 감소시키지만, 다른 한편으로는 지하저장 시설로부터의 누출로 인해 토양 및 지하수의 오염을 유발할 수 있다. 특히 MTBE는 높은 용해성으로 인해 지하수내에서는 지하수와 함께 광범위하게 오염을 유발할 수 있다. 본 연구에서는 MTBE를 대상 물질로 하여 폐타이어를 현장내 오염지하수 정화 공법 중 하나인 반응벽체 공법의 흡착매질로 사용을 평가하기 위해, 회분식 실험을 통해서 크기가 다른 폐타이어의 MTBE흡착 특성을 파악해 보았다. 또한 칼럼 실험을 통해서 이용 효율(Utilization Efficiency)을 구하였다. 1.18mm 이하의 폐타이어의 g당 최대 흡착량은 약 0.5 mg으로 나타났다. Freundlich 등온흡착식을 이용하여 구한 이론 흡착용량과 실제 평균 농도 측정을 한 후 계산된 MTBE의 흡착량을 비교하여 이용 효율을 계산 해본 결과, 지름이 가장 작은 폐타이어가 약 36%,나머지 두 가지 종류의 폐타이어는 각각 15.6%와 16.4%의 효율을 나타내었다. 폐타이어의 처분비용과 재생비용을 고려한다면, 폐타이어의 이용은 경제적, 환경적 측면에서 유익하리라 생각되며, 또한 Air-Sparging이나 Bioremediation과 같은 다른 현장내 공법과 복합적으로 적용된다면, 제거효율 향상과 같은 동반 상승효과(synergy effect)를 기대할 수 있을 것이라 사료된다.