• 제목/요약/키워드: Double-Negative

검색결과 414건 처리시간 0.029초

하수고도처리에서 층상이중수화물을 이용한 인산 이온교환 특성 (Characteristics of Ion Exchange of Phosphate using Layered Double Hydroxides in Advanced Wastewater Treatment)

  • 송지현;신승규;이상협;박기영
    • 한국물환경학회지
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    • 제22권6호
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    • pp.991-995
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    • 2006
  • The layered double hydroxide with the insertion of chloride ions (LDH-Cl), which was synthesized by the co-precipitation method, was applied to investigate the fundamental aspects of the absorptive agent for phosphate removal from wastewater. The adsorption capacity was best described by the Langmuir-FreundIich isotherm, and the estimated isotherm parameters indicate that the LDH-CI capacity for the phosphate removal is much higher than that observed using a natural adsorbent material such iron oxide tailing. The kinetic experiment also showed that the LDH-Cl adsorption reaction rapidly at the adsorptive rate of 0.55 mg-P/g-LDH/min, implying that this adsorbent can be of use in the full-scale applications. The pH had a minimal effect on the LDH adsorption capacity in the range of 5 to 11, although the capacity dropped at the low pHs because of the change in LDH surface properties. Furthermore, other anions such as $Cl^-$ and $NO_3{^-}$ commonly found in the wastewater streams insignificantly affected the phosphate removal efficiencies, while $HCO_3{^-}$ ions had a negative effect on the LDH adsorption capacity due to its high selectivity. The phosphate removal experiment using the actual secondary effluent from a wastewater treatment plant showed the similar decrease in adsorption capacity, indicating that the bicarbonate ions in the wastewater were competing with phosphate for the adsorptive site in the surface of the LDH-Cl. Overall, the synthetic adsorbent material, LDH-Cl, can be a feasible alternative over other conventional chemical agents, since the LDH-Cl exhibits the high phosphate removal capacity with the low sensitivity to other environmental conditions.

Rhodobacter sphaeroides의 질소고정효소에 미치는 암모니움 이온 효과 제거를 통한 수소생성 증진 (Improvement of Photoheterotrophic $H_2$ production of Rhodobacter sphaeroides by Removing Ammonium Ion Effect Exerted on Nitrogenase)

  • 진상훈;김미선;이정국
    • KSBB Journal
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    • 제20권6호
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    • pp.418-424
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    • 2005
  • Rhodobacter sphaeroides는 photoheterotrophic 조건에서 성장을 하면서 질소고정효소인 nitrogenase에 의해 수소를 발생시킨다. 이 nitrogenase는 ammonium ion이 존재할 때, PII 계열 단백질인 GlnB와 GlnK에 의해 negative regulation을 받게 된다. 본 연구에서는 glnB와 glnK 유전자를 interruption하여 수소생성의 증진을 꾀하였다. 그 결과, parental strain이나 glnB 혹은 glnK 유전자 하나만을 interruption 시켰을 경우, 암모니움 이온에 의해 nitrogenase 활성이 저해를 받고 있었으나, glnB, glnK 모두를 interruption 시켰을 때, 암모니움 이온에 의한 저해 효과가 줄어드는 것을 볼 수 있었다. 또한 이러한 glnB-glnK double mutant에 nifDK gene을 in trans로 넣어 nitrogenase의 dosage를 높였을 경우, 수소 생성이 약 30% 가량 증진되었다는 것을 볼 수 있었다.

유채 품질 평가 현황과 전망 (Prospect and Situation of Quality Improvement in Oilseed rape)

  • 장영석
    • 한국작물학회지
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    • 제47권
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    • pp.175-185
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    • 2002
  • Rapeseed(Brassica napus L.) is an important oil crop as a vegetable oil, concentrated feed and industrial materials. The name "canola" was registered in 1979 by the Western Canadian Oilseed Crushers Association to describe "double-low" varieties. Double low indicates that the processed oil contains less than 2% erucic-acid and the meal less than 3mg/g of glucosinolates. Today annual worldwide production of rapeseed is approximately 35 million tons on 24 million hectares. China accounts for 33% of the world production and the European Economic Community for nearly 32%. Canola ranks 3rd in production among the world's oilseed crops following soybeans, sunflowers, peanuts and cottonseed. The recent advances in genomics and in gene function studies has allowed us to understand the detailed genetic basis of many complex traits, such as flowering time, height, and disease resistance. The manipulation of seed oil content via transgene insertion has been one of the earliest successful applications of modern biotechnology in agriculture. For example, the first transgenic crop with a modified seed composition to be approved for unrestricted commercial cultivation in the US was a lauric oil, rape-seed, grown in 1995. There were also some significant early successes, mostly notably the achievement of 40% to 60% lauric acid content in rapeseed oil, which normally accumulates little or no lauric acid. The name "$\textrm{Laurical}^{TM}$" was registered in 1995 by Calgene Inc. Nevertheless, attempts to achieve high levels of other novel fatty acids in seed oils have met with much less success and there have been several reports that the presence of novel fatty acids in transgenic plants can sometimes lead to the induction of catabolic pathways which break down the novel fatty acid, i.e. the plant recognizes the "strange" fatty acid and, far from tolerating it, may even actively eliminate it from the seed oil. It is likely that, in the future, transgenic oil crops and newly domesticated oil crops will both be developed in order to provide the increased amount and diversity of oils which will be required for both edible and industrial use. It is important that we recognize that both approaches have both positive and negative points. It will be a combination of these two strategies that is most likely to supply the increasing demands for plant oils in the 21st century and beyond.ant oils in the 21st century and beyond.

척추 측만증 환자에서의 척추 만곡과 경추 및 요추 전만각, Ferguson각의 상관관계에 대한 고찰 (A Study on the Relationship Scoliotic Curve and Cervical Lordosis, Lumar Lordosis and Ferguson Angle in Spinal Scoliosis Patient)

  • 김석;윤현석;반효정;정해찬;염선규;진은석;김한겸
    • 척추신경추나의학회지
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    • 제5권2호
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    • pp.33-41
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    • 2010
  • Objectives : This study is designed to find out the relationship of scoliotic curve, cervical lordosis, lumbar lordosis and Ferguson's angle. Method : The study was composed of 46 scoliosis patients who had single curvature(Group I) on their lumbar spine(Group I-A) or thoracic spine(Group I-B) and 38 patients who had double curvature(Group II) on their lumbar and thoracic spine. The patients were evaluated with X-ray findings of full spine AP and Lateral views and statistically analyzed. Results : 1. Group II showed a significant increase in scoliotic curve angle as compared with Group I(P<0.05). 2. Scoliotic curve has a negative relationship with cervical lordosis in group II. Conclusion : 1. The patients who has double curvature of spine had higher scoliotic curve angle compared with who has single curvature. 2. The Scoliotic curve and cervical lordosis was statistically concerned on patients who has double curvature of spine.

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아동기 외상, 거부민감성, 정서인식명확성이 전위공격성에 미치는 영향 (The Influences of Childhood Trauma, Rejection Sensitivity, Emotional Recognition Clarity on Displaced Aggression)

  • 이자영
    • 디지털융복합연구
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    • 제19권9호
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    • pp.385-392
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    • 2021
  • 본 연구의 목적은 아동기 외상, 거부민감성, 정서인식명확성이 전위공격성에 미치는 영향을 알아보는 것이다. 이를 위해 H 사이버대학교 성인 208명을 대상으로 온라인 설문조사를 하였다. 분석은 SPSS Win 25와 SPSS Process Macro를 통해 상관관계분석과 이중매개효과분석이 실시되었으며, 그 결과는 다음과 같다. 첫째, 아동기 외상, 거부민감성은 전위공격성에 정적 상관을 보였으며, 정서인식명확성은 부적 상관을 나타냈다. 둘째, 아동기 외상과 전위공격성과의 관계에서 거부민감성은 간접매개하는 것으로 나타났으나 정서인식명확성은 매개하지 않는 것으로 나타났다. 셋째, 아동기 외상과 전위공격성과의 관계에서 거부민감성과 정서인식명확성은 이중매개하는 것으로 나타났다. 이러한 결과는 아동기 외상을 경험한 사람들의 전위공격성을 감소시키기 위한 기초자료로 활용할 수 있을 것으로 보인다.

The Impact of Double-Skin Façades on Indoor Airflow in Naturally Ventilated Tall Office Buildings

  • Yohan, Kim;Mahjoub M. Elnimeiri;Raymond J. Clark
    • 국제초고층학회논문집
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    • 제12권2호
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    • pp.129-136
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    • 2023
  • Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

작물생육모형 기반 비료시비량 분배 알고리즘 개발 (Development of fertilizer-distributed algorithms based on crop growth models)

  • 김도윤;이예진;허태영
    • 응용통계연구
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    • 제36권6호
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    • pp.619-629
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    • 2023
  • 비료는 작물 생산성을 높이는데 중요한 역할을 하지만 작물의 양분요구량을 고려하지 않은 비료 과다 사용은 농가 경영비 부담과 환경 부하를 높힐 우려가 있다. 스마트 농업을 통해 작물의 생장 특성을 반영하여 시기별로 필요한 만큼 비료를 공급하면 비료 유실에 대한 부담을 줄이고, 경제적인 양분관리 효과를 기대할 수 있다. 본 논문에서는 다양한 재배환경에서 재배한 고추 및 대파의 정식일수별 전체 건중량을 기반으로 다양한 생장곡선(로지스틱(logistic), 곰페르츠(Gompertz), 리차드(Richards), 이중 로지스틱(double logistic curve)을 활용한 비선형 모형 기반 작물 생육 모형을 적합하고, 작물 성장률에 기반한 비료시비량 분배 알고리즘을 제안하고자 한다.

Xylanase Supplementation Improved Digestibility and Performance of Growing Pigs Fed Chinese Double-low Rapeseed Meal Inclusion Diets: In vitro and In vivo Studies

  • Fang, Z.F.;Peng, J.;Tang, T.J.;Liu, Z.L.;Dai, J.J.;Jin, L.Z.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권11호
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    • pp.1721-1728
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    • 2007
  • An in vitro and a feeding trial were conducted to investigate the effect of xylanase supplementation on the feeding value of growing pig diets containing high proportions of Chinese double-low rapeseed meals (DLRM). Seven diets were formulated to meet NRC (1998) nutrient requirements. Diet 1 based on corn-soybean meal was used as positive control 1, and diet 2, a practical diet which incorporated a conventional level of Chinese DLRM (60 g/kg diet), as positive control 2. Diet 3 contained a higher level of DLRM (100 g/kg diet) as the negative control. Diet 3 plus xylanase at 0.10, 0.25, 0.50 and 0.70 g/kg diet created diets 4, 5, 6 and 7, respectively. The seven diets were incubated in triplicate with the in vitro two-stage enzyme incubation method to predict responses of diets to xylanase in terms of digestibility of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF). In vitro, the negative control had the lowest CP and NDF digestibility. Both DM and CP digestibility were increased (p<0.05) owing to xylanase supplementation either at 0.50 or 0.70 g/kg diet, and NDF digestibility was improved following xylanase addition at all of the test levels. There was a high linear correlation ($r^2>90$, p<0.05) between the activity concentration of the enzyme when transformed into its logarithmic value and in vitro digestibility coefficients of DM, CP or NDF. In the feeding trial, 112 crossbred pigs were randomly assigned to seven dietary treatments with 16 replicate pens of one pig each. An obvious dose effect on growth rate was observed ($r^2=0.79$, p<0.05) within the inclusion levels of xylanase. Compared with the negative control, xylanase addition at 0.70 g/kg diet resulted in significantly increased ADG (878 g/d vs. 828 g/d, p<0.05), and a tendency towards improved growth rate (868 g/d vs. 828 g/d, p = 0.10) was also observed following the inclusion of xylanase at 0.50 g/kg diet. It would appear that the nutrient utilization of corn and Chinese DLRM diets by pigs could be enhanced by an appropriate amount of xylanase addition. The in vitro and in vivo results suggested that the in vitro incubation method is feasible for predicting responses of pigs to exogenous enzymes and identifying those preparations that possess potential for improvement of the nutritive values of feedstuffs.

Bacillus subtilis ATP 조해(阻害) Ribonuclease에 관한 연구 (ATP-Inhibited Ribonuclease of Bacillus subtilis)

  • 이택수
    • Applied Biological Chemistry
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    • 제18권3호
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    • pp.167-176
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    • 1975
  • ATP-저해 ribonuclease는 Bacillus subtilis와 같은 Bacillus속에서만 발견 되는 것으로서 이들 효소의 생리적 역활을 규명할 목적으로 Bacillus subtilis 균주를 사용하여 ATP저해성 negative ribonuclease변이주의 취득을 시도하고 선정된 균주가 생산하는 ribonuclease의 정제 및 몇 가지 성질에 대하여 실험한 결과는 아래와 같다. 1. Bacillus subtilis로 부터 ATP-저해 ribonuclease negative mutant의 취득을 시도한 결과 시험된 1817주의 균중에서 101균주가 변이주주로 선정 되었다. 2. 수개의 개별적인 column chromatography에 의하여 당균주가 생산하는 ATP-저해성 ribonuclease의 정제를 시도한 결과 DEAE-Sephadex A-50 column chromatography을 이용한 경우는 30배의 정제 효과와 99%의 회수율을 나타냈고 Sephadex G-75 column의 경우는 20배의 정제 효과와 98%의 회수율을 각각 나타냈다. 3. pH 5침전, 유안염석, Sephadex G-75 및 CM Sephadex를 연속적으로 통과시켜 당효소에 대한대량정제 시험을 시도한 결과 최초의 step(crude extract) 과정에 비하여 60배의 정제효과를 나타냈다. 4. 본정제 효소액에 대하여 전기영동을 실시한 결과 비정제 효소액에 비하여 매우 감소된 수의 담백 pattern을 나타냈다. 5. 당균주가 생산하는 ATP저헤 ribonuclease는 single stranded RNA를 분해하여 2',3'-cyclic AMP, 2',3'-cyclic CMP, 2',3'-cyclic GMP, 2',3'-cyclic UMP와 몇종의 미지물을 생성하였고 또한 본효소는 double stranded RNA를 분해하지 않었다.

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콘 사토시 작품에서 나타나는 양면성을 지닌 캐릭터의 페르소나 연구 - <퍼펙트 블루>, <망상대리인>, <파프리카>를 중심으로 - (A Study on Persona of Double-sided Characters Shown in Satoshi Kon's Works)

  • 추혜진
    • 만화애니메이션 연구
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    • 통권35호
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    • pp.181-208
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    • 2014
  • 콘 사토시는 양면성이란 모티브에 초점을 맞춰 인간의 근본적인 자아 정체성을 다루며 존재에 대한 성찰을 담아내는 대표적인 애니메이션감독이다. 본 연구는 그의 작품 속의 자아와 또 다른 자아의 결합 방식에 따라 캐릭터의 페르소나, 즉 인격의 가면이 어떻게 드러나며 자기실현을 이루어 나가는지 그 유형을 융의 분석 심리학적 견해를 토대로 분석하는데 그 목적이 있다. 인간의 가장 외적 인격을 의미하는 페르소나는 자신이 속한 사회 속에서 타인과 지속적인 관계를 맺기 위해 일정한 역할을 수행하는 사회적 행위와 연결된다. 사회적 요구가 많아질수록 개인은 여러 가지 인격의 가면을 쓰고 주어진 역할을 수행하며 외부 환경에 적응해 나간다. 이처럼 페르소나는 외부와 중요한 관계기능의 역할을 담당하게 되는데, 집단의 요구에 지나치게 순응하여 인격의 가면에만 몰입할 경우 의식과 무의식 간의 불균형을 야기하여 개인의 자아 정체성 형성에 부정적인 영향을 미칠 수 있다. 그러나 페르소나가 항상 부정적인 요인으로만 작용하는 것은 아니다. 원활한 사회적 역할을 수행하기 위해 적절하게 발달된 페르소나는 내면의 무의식과 외면의 의식 사이에 균형을 이뤄 건강한 자아 정체성을 확립할 수 있도록 돕는다. 이러한 관점에서 의식과 무의식의 상관관계와 결합 유형에 따라 작품 속 캐릭터를 분석함으로써 각 캐릭터의 내면에 숨어있는 가면의 욕망이 어떻게 표면화되어 긍정적 혹은 부정적으로 작용하는지 확인할 수 있다. 이와 더불어 본 연구에서 차용한 심리학적 관점의 분석 방식이 다양한 캐릭터 연구에 유용한 이론적 틀로 활용되기를 바란다.