• 제목/요약/키워드: Membrane Separation

검색결과 1,432건 처리시간 0.031초

Glycine-Nitrate Process를 이용한 고온 수증기 전해용 (La, Sr)$MnO_3$ 전극의 합성 및 특성 연구 (Preparation and Characterization of (La, Sr)$MnO_3$ Electrode for High Temperature Steam Electrolysis by Glycine-Nitrate Process)

  • 최호상;김현진;류시옥;황갑진
    • 한국수소및신에너지학회논문집
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    • 제18권1호
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    • pp.46-51
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    • 2007
  • LSM powder material for an oxygen-electrode(anode) of High Temperature Steam Electrolysis (RISE) was synthesized by a Modified-Glycine nitrate process(GNP). Amount of nitric acid and its concentration was varied to find out an appropriate composition for the oxygen-electrode(anode). In order to optimize the amount of Glycine used as an oxidant of self-combustion process, the ratio of Glycine to Anion was varied. $La_{0.8}Sr_{0.2}MnO_3$, $La_{0.5}Sr_{0.5}MnO_3$, and $La_{0.2}Sr_{0.8}MnO_3$ were synthesized in this study. Those LSM were dried for overnight to remove moisture from the material at $110^{\circ}C$ and were calcined 2 hours at $650^{\circ}C$ and were sintered in a furnace for 5 hours at $1400^{\circ}C$. Their structures, surface morphologies, surface areas, and weight changes were investigated with XRD, SEM, BET, and TG/DTA. The best perovskite phase for the oxygen-electrode of HTSE was obtained with $La_{0.8}Sr_{0.2}MnO_3$ formula in which 100 ml of 3M nitric acid was used in the preparation of its formula. The optimized ratio of Glycine to Anion was 2.

돼지 간 및 정소에서 단백질 카르복실메칠화 현상 (Protein Carboxyl Ο-Methylation in Porcine Liver and Testis)

  • 조재열;김성수;이향우;홍성렬
    • 약학회지
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    • 제45권1호
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    • pp.46-54
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    • 2001
  • Protein carboxyl Ο-methylation is a kind of enzymatic reaction producing carboxyl methylester catalyzed by protein carboxyl Ο-methyltransferases at the carboxyl group of amino acid residues in polypeptide. Since the finding of carboxyl methylesterl many studies have been focused on the under-standing of biological functions in eukaryotes but still not clear except for roles in Ras attachment to membrane and protein repair. In this study, we investigated the protein carboxyl methylation in porcine liver and testis in respect of identification and characterization of carboxyl methylesters and natural proteinous substrates using pH stability of the esters and electrophoresis under acidic and basic conditions. We detected several kinds of methyl esters, 3 kinds each in cytosolic fractions from liver and testis. Under the treatment of strong acid and base, the ratio between base-stable substrates and unstable ones in liver (4 : 6) was different from the ratio obtained in testis (6 : 4). The methyl accepting capacities were affected by enzymatic proteolysis between the range of 55 to 65% in liver and of 35 to 45% in testis. Separation of the methylated proteins by acidic electrophoresis in the presence of urea and SDS revealed distinctively natural substrates of 26, 33 and 80 kD in the cytosol from liver and of 14, 25, 32 and 86 kD from testis. Most of the labelling, however were lost following electrophoresis under moderate alkaline condition, except for molecules of newly detected 7 and 17 kD in livers and 15, 29, 40 and 80 kD in testis. From these results, it was proposed that protein carboxyl Ο-methylation in each organs may be catalyzed by different classes of protein carboxyl Ο-methyltransferases. In addition, it is suggested that the protein carboxyl methylation in liver and testis may have different patterns in respect of natural substrates.

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pH와 완속교반 조건에 따른 중금속 수산화물 화학침전 특성 (Effects of pH and slow mixing conditions on heavy metal hydroxide precipitation)

  • 박종훈;최규진;김상현
    • 유기물자원화
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    • 제22권2호
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    • pp.50-56
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    • 2014
  • 일반적으로 도금 폐수를 비롯한 산업 폐수 내 중금속 처리에 적용되는 응집-침전은 응집제의 비용과 침전 효율의 불안정성이라는 한계가 존재한다. 본 연구에서는 수산화물 생성-분리막 공정을 전제로 하여, pH와 교반조건에 따른 수용액 상의 중금속 제거 효율과 생성된 수산화물의 입도 분포를 고찰하였다. pH별 실험 결과, pH 9-10에서 최적의 중금속 제거 효율이 확인되었으며, 무기응집제인 $FeCl_3$의 투입은 오히려 제거 효율을 저하시켰다. 완속교반 시간 및 강도는 70 rpm, 20 min 조건이 최대 효율을 보였으며 Cu, Ni, Zn 모두 청정 지역 기준 폐수 배출 기준을 만족하였다. 나타났다. 생성된 중금속 수산화물의 입도 분석을 수행한 결과, 입자의 99.9 %가 $2{\mu}m$ 이상이었다.

The Heavy Metal Tolerant Soil Bacterium Achromobacter sp. AO22 Contains a Unique Copper Homeostasis Locus and Two mer Operons

  • Ng, Shee Ping;Palombo, Enzo A.;Bhave, Mrinal
    • Journal of Microbiology and Biotechnology
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    • 제22권6호
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    • pp.742-753
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    • 2012
  • Copper-containing compounds are introduced into the environment through agricultural chemicals, mining, and metal industries and cause severe detrimental effects on ecosystems. Certain microorganisms exposed to these stressors exhibit molecular mechanisms to maintain intracellular copper homeostasis and avoid toxicity. We have previously reported that the soil bacterial isolate Achromobacter sp. AO22 is multi-heavy metal tolerant and exhibits a mer operon associated with a Tn21 type transposon. The present study reports that AO22 also hosts a unique cop locus encoding copper homeostasis determinants. The putative cop genes were amplified from the strain AO22 using degenerate primers based on reported cop and pco sequences, and a constructed 10,552 base pair contig (GenBank Accession No. GU929214). BLAST analyses of the sequence revealed a unique cop locus of 10 complete open reading frames, designated copSRABGOFCDK, with unusual separation of copCD from copAB. The promoter areas exhibit two putative cop boxes, and copRS appear to be transcribed divergently from other genes. The putative protein CopA may be a copper oxidase involved in export to the periplasm, CopB is likely extracytoplasmic, CopC may be periplasmic, CopD is cytoplasmic/inner membrane, CopF is a P-type ATPase, and CopG, CopO, and CopK are likely copper chaperones. CopA, B, C, and D exhibit several potential copper ligands and CopS and CopR exhibit features of two-component regulatory systems. Sequences flanking indicate the AO22 cop locus may be present within a genomic island. Achromobacter sp. strain AO22 is thus an ideal candidate for understanding copper homeostasis mechanisms and exploiting them for copper biosensor or biosorption systems.

Late-term healing in an augmented sinus with different ratios of biphasic calcium phosphate: a pilot study using a rabbit sinus model

  • Lim, Hyun-Chang;Hong, Ji-Youn;Lee, Jung-Seok;Jung, Ui-Won;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제46권1호
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    • pp.57-69
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    • 2016
  • Purpose: The aim of this pilot study was to determine the osteoconductivity and dimensional stability of augmented sinuses using different ratios of biphasic calcium phosphate (BCP) in a rabbit sinus model. Methods: Each sinus of New Zealand white rabbits (2.5-3.5 kg) was assigned to one of two groups: BCP with a hydroxyapatite to ${\beta}$-tricalcium phosphate (HA:${\beta}$-TCP) ratio of 70:30 (group TCP30) and BCP with an HA:${\beta}$-TCP ratio of 30:70 (group TCP70). After preparing a window in the antral wall of a sinus, the Schneiderian membrane was elevated, and the applicable material was grafted. A fluorochrome calcein green was injected five days before euthanizing the animals at four months post-surgery. The specimens were analyzed histologically, histomorphometrically, and by using micro-computed tomography (micro-CT). Results: Micro-CT analysis revealed that the total augmented volume and the new bone volume did not differ significantly between the two groups whereas the resorption of materials was greater in the TCP70 group. The trabecular thickness, number, and separation also did not differ significantly between the two groups. Histomorphometrically, the areas of total augmentation, new bone, and residual material, as well as the ratio of new-bone-material contact did not differ significantly between the groups. Histologically, the residual particles were more scattered in the TCP70 group than in the TCP30 group. The fluorescence of the calcein green did not differ notably between the two groups. Conclusions: The osteoconductivity and dimensional stability of the two BCPs with different ratios tested in this study were comparable after four months of healing. Therefore, we conclude that both BCPs show promise as a bone substitute for sinus augmentation.

전산 해석을 이용한 다중연돌의 유체유발진동 (Evaluation of Wind-Induced Vibration for Multiple Stacks Using Numerical Analysis)

  • 양광혁;박재관;김현준;백송열;박순태
    • 플랜트 저널
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    • 제12권3호
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    • pp.24-31
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    • 2016
  • 풍진동(Wind-induced vibration)은 바람에 의해 구조물에 진동이 발생하는 현상으로써 세장비가 큰 열기기 Stack 설계시 고려해야 할 중요한 사항이다. 따라서, 국제 규격에는 풍진동에 대한 설계 인자와 각 범위에 대해 필요한 고려 사항을 정의하고 있다. 규격에 의한 설계 검증은 몇몇 인자를 이용하여 간단하게 확인이 가능하다는 장점이 있는 반면, 실제 풍진동에 의한 영향을 정량적으로 평가하지 않기 때문에 실제 필요한 것보다 과도한 설계를 요구할 수 있다는 단점이 있다. 또한 여러 제약조건으로 Code 상의 요구조건을 만족하지 못하는 경우 실제 시스템의 거동을 예측할 수 없다는 단점이 있다. 이러한 점을 보완하기 위해 CFD 와 FEM 등의 수치적 해석 방법을 통해 풍진동이 실제 Stack에 미치는 영향을 해석하여 설계 적정성을 검증하여 Code 상의 요구 조건과 비교하였다.

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후두 격막증의 치험 1례 (A Case of Anterior Glottic Web (Video))

  • 김기령;박인용;김광문;이원상;이경재;정태영;이명호
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1983년도 제17차 학술대회연제순서 및 초록
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    • pp.8.1-8
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    • 1983
  • 후두격막증은 이를 선천성 및 후천성 후두격막증으로 분류하며 선천성 후두격막증은 후두의 발생과정에서 특히 태아기 7 ∼ 8주경에 후두개와 양측 피열연골 융기가 서로 합쳐진 T형 초기성문 (primitive glottis)이 태아기 10 주경에 이루어져야 할 전후분리가 장해됨으로서 선천성 후두질환의 약 3 %에서 발생되며 그 중 약 75 %가 성문부에서 발생되고 나머지 약 25 %는 성문상부 및 성문하부에서 발생된다. 한편 후천성 후두격막증은 그의 대부분이 외상이나 수술후의 상흔 등에서 합병되며 선천성에 비해서 격막이 비교적 두껍고 섬유성인 경향을 보인다. 후두격막증의 증상은 그 격막의 상태에 따라서 일정하지 않으나 대체로 그 격막형성이 아주 작은 경우에는 특별한 증상이 없으나 격막이 큰 경우에는 사성이나 호흡곤란을 유발하게 된다. 본 증의 치료 원칙으로서는 격막을 절제한 후 특히 성문의 성대전연합 (Anterior Commissure)부위의 재유착을 예방하는 것인데 현재까지의 시술방법으로서는 1924년 Haslinger가 수술후의 성대전 연합 사이로 엷은 은편(silver plate)을 삽입시켰던 례와 1950년 McNaught가 갑상연골절개술로 탄타룸 편(tantalum keel)을 삽입시켰던 례가 있으며 이밖에도 테후론편 (teflon keel)등이 삽입되거나 점막이식술 등이 시도되어 왔다. 저자들은 최근에 23세 남자 환자로서 유·소아기에 수차의 후두유두종 수술후에 성대 전연합부에 발생한 격막증에 대하여 금편(gold keel)을 삽입하여 치험하였기에 이를 비데오로 소개하고자 한다.

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Effects of High Molecular Weight Water-Soluble Chitosan can in 7tro Fertilization and Ovulation in Mice Fed a High-Fat Diet

  • Choo, Young-Kug;Choi, Hee-Gon;Kim, Jin-Kyung;Kwak, Dong-Hoon;Cho, Jung-Ran;Kim, Ji-Yeoun;Kim, Byung-Jin;Jung, Kyu-Yong;Choi, Bong-Kyu;Shin, Min-Kyo
    • Archives of Pharmacal Research
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    • 제25권2호
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    • pp.178-183
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    • 2002
  • A high molecular ar weight water-soluble chitosan (WSC) with an average molecular weight of 300 kD and a deacethylation level of over 90% was produced using a simple multi-step-membrane separation process. It is known that WSC prevents obesity induced by a high-fat diet. Consequently, this study investigated whether or not WSC improved the ovarian dysfunction caused by obesity in mice. The mice were fed a high density protein and lipid diet for weeks, followed by the administration of WSC at 480 mg/kg body weight per day for 4 days. Thereafter, the changes in body weight, ovulation rate, in vivo and in vitro fertilization and emboryonic development were measured . WSC markedly reduced the body weight of obese mice fed with a high-fat diet, but not in mice fed with a normal diet. WSC had siginificant effects on the ovulation rate, both the in vivo and in vitro fertilization rates and embryonic development. These results indicate an improvement in the ovarian and oviduct dysfunction caused by obesity, and suggest an adjustment in the internal secretions and metabolic functions.

제주 수산가공부산물 유래 기능성 소재 탐색 (Development of Bioactive Substances from Fishery Processing by-products in Jeju)

  • 강나래;이원우;고주영;김현수;김준성;안용석;고창익;정준범;전유진
    • 한국해양바이오학회지
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    • 제6권2호
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    • pp.62-67
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    • 2014
  • In this study, we investigated the bioactive substances of the Alcalase hydrolysate obtained from fishery processing by-products in Jeju by measuring bioactivities including radical scavenging acitivty, cytoprotective activity against 2,2-azobis-(2-amidino-propane) dihydrochloride (AAPH), and ACE inhibitory activity. This study is important because of utilization of unused fishery processing by-products in Jeju. The Alcalase hydrolysate was prepared through the hot water extraction and enzymatic hydrolysis, and then further separation of the Alcalase hydrolysate was performed by ultrafiltration using 10 kDa molecular weight cut-off membrane. The Alcalase hydrolysate showed the relatively higher DPPH and peroxyl radical scavenging activity ($IC_{50}$ value; 1.30 mg/ml and 0.888 mg/ml, respectively). Also, the Alcalase hydrolysate showed the ACE inhibitory activity with 1.87 mg/ml of $IC_{50}$ value. These biological activities are increased over 1.2 or 2.5 times through the ultrafiltration of the Alcalase hydrolysate. Therefore, the Alcalase hydrolysate obtained from fishery processing by-products in Jeju and the different molecular weight fractions should be given consideration for food and cosmetics ingredient. Furthermore, this research on the utility of fishery processing by-products might be a useful tool into the industry.

Separation and Characterization of Spikelet Proteins at Young Microspore Stage in Rice

  • Woo, Sun-Hee;Kim, Tae-Seon;Cho, Seong-Woo;Ahn, Jung-Gu;Chung, Keun-Yook;Lee, Byung-Moo;Cho, Yong-Gu;Kim, Hong-Sig;Song, Beom-Heon;Lee, Chul-Won;Jong, Seung-Keun
    • 한국작물학회지
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    • 제51권1호
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    • pp.66-72
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    • 2006
  • Spikelet proteins expressed at the young microspore stage in rice were separated and analysed by two-dimensional polyacrylamide gel electrophoresis (2DE). The separated proteins were electro blotted onto a polyvinylidene difluoride (PVDF) membrane, and 50 proteins were analyzed by a gas-phase protein sequencer. The N-terminal amino acid sequences of 20 out of 50 proteins were determined. N-terminal regions of the remaining proteins could not be sequenced because of blocking. The internal amino acid sequences of proteins were determined by sequence analysis of peptides obtained by the Cleveland peptide mapping method. Results revealed the presence of the photosynthetic apparatus at rice young microspore stage. Major proteins identified in this study could be used as a marker for various studies on physiological stresses.