• 제목/요약/키워드: $N_2-fixation$

검색결과 260건 처리시간 0.021초

바이오필터시스템을 이용한 암모니아 함유 악취폐가스 처리 (Treatment of Malodorous Waste Air Containing Ammonia Using Biofilter System)

  • 이은주;박상원;다오빈남;정찬홍;임광희
    • Korean Chemical Engineering Research
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    • 제48권3호
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    • pp.391-396
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    • 2010
  • 본 연구에서는 퇴비공장 또는 공공시설에서 발생되는 악취폐가스의 대표적인 제거대상 오염원인 암모니아의 효율적 처리를 위하여, 여러 운전 조건 하에서 동 부피의 폐타이어담체와 compost를 충전하고 반송슬러지를 고정한 바이오필터의 암모니아 제거 특성을 조사하고 바이오필터공정의 적정운전조건을 구축하였다. 암모니아를 함유한 폐가스의 처리를 위하여 바이오필터를 30일(2회/1일의 회수로 총 60회 실험) 동안 약 $30^{\circ}C$의 온도조건 하에서 암모니아부하를 $2.18g-N/m^3/h$부터 $70g-N/m^3/h$ 까지 증가시키면서 운전하였다. 바이오필터를 가동하여 I부터 IV 단계까지는 암모니아 제거율이 거의 100%로서, 암모니아부하가 $17g-N/m^3/h$에 이르기까지 거의 모든 암모니아가 제거되었으나, 바이오필터 운전 V 단계에서 암모니아부하를 약 $35g-N/m^3/h$로 증가시켰을 때에 암모니아제거율은 약 80% 정도로 급락하여 암모니아 제거용량이 약 $28g-N/m^3/h$이었다. 그러나 바이오필터 운전 VI 단계에서 암모니아부하를 약 $70g-N/m^3/h$로 두 배로 증가시켰을 때에도 암모니아제거율은 80%를 유지하여 최대암모니아 제거용량이 약 $55g-N/m^3/h$에 달하였다. 이와 같이 본 연구의 최대 암모니아 제거용량은, 분뇨슬러지를 유기담체인 rock wool에 접종하고 Kim 등에 의하여 수행된 바이오필터실험의 최대 암모니아 제거용량인 $1,200g-N/m^3/day$(i.e., $50g-N/m^3/h$)보다 다소 우월하였다. 그러나 본 연구의 암모니아 질소 임계부하는 Kim 등에 의하여 수행된 바이오필터실험의 암모니아 질소의 임계부하인 $810g-N/m^3/day$(i.e., $33.75g-N/m^3/h$)에 미치지 못하였다. 본 연구의 최대 암모니아 제거용량이 Kim 등보다 우월한 이유는 Kim 등에 의하여 사용된 미생물담체보다 본 연구에서 사용한 미생물담체인 폐타이어담체의 코코넛 활성탄분말로 도포된 표면 및 발달된 내부공극이 각각 질산화 및 탈질 미생물이 고정화되기 더욱 쉬운 환경을 제공하기 때문이라고 사료된다.

Stable Carbon and Nitrogen Isotopes of Sinking Particles in the Eastern Bransfield Strait (Antarctica)

  • Khim, Boo-Keun;Kim, Dong-Seon;Shin, Hyoung-Chul;Kim, Dong-Yup
    • Ocean Science Journal
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    • 제40권3호
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    • pp.167-176
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    • 2005
  • A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait for a complete year from December 25, 1998 to December 24, 1999. About 99% of total mass flux was trapped during an austral summer, showing distinct seasonal variation. Biogenic particles (biogenic opal, particulate organic carbon, and calcium carbonate) account for about two thirds of annual total mass flux $(49.2\;g\;m^{-2})$, among which biogenic opal flux is the most dominant (42% of the total flux). A positive relationship (except January) between biogenic opal and total organic carbon fluxes suggests that these two variables were coupled, due to the surface-water production (mainly diatoms). The relatively low $\delta^{13}C$ values of settling particles result from effects on C-fixation processes at low temperature and the high $CO_2$ availability to phytoplankton. The correspondingly low $\delta^{l5}N$ values are due to intense and steady input of nitrates into surface waters, reflecting an unlikely nitrate isotope fractionation by degree of surface-water production. The $\delta^{l5}N$ and $\delta^{l3}C$ values of sinking particles increased from the beginning to the end of a presumed phytoplankton bloom, except for anomalous $\delta^{l5}N$ values. Krill and the zooplankton fecal pellets, the most important carriers of sinking particles, may have contributed gradually to the increasing $\delta^{l3}C$ values towards the unproductive period through the biomodification of the $\delta^{l3}C$ values in the food web, respiring preferentially and selectively $^{12}C$ atoms. Correspondingly, the increasing $\delta^{l5}N$ values in the intermediate-water trap are likely associated with a switch in source from diatom aggregates to some remains of zooplankton, because organic matter dominated by diatom may be more liable and prone to remineralization, leading to greater isotopic alteration. In particular, the tendency for abnormally high $\delta^{l5}N$ values in February seems to be enigmatic. A specific species dominancy during the production may be suggested as a possible and speculative reason.

한국산 수소생산 남세균 종주들의 세포주기 동조화 (Synchronization of Cell Cycle in Korean Hydrogen Producing Cyanobacterial Strains)

  • 박종우;안세희;김형섭;이원호
    • 한국수소및신에너지학회논문집
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    • 제22권5호
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    • pp.663-670
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    • 2011
  • Under a daily photoperiod of 14h light and 10h dark synchronization of cell cycle in Korean Cyanothece spp. strains and $Synechococcus$ sp. strain Miami BG043511 was analyzed as to be applicable to enhanced hydrogen production. For all strains peaks of double cell were observed during the light period of a daily cycle. Peaks of maximal cell size measured by a coulter counter appeared at the peak of double cells observed under light microscope reconfirming the synchronization of daily cell cycle. The cell cycle synchronization became weakened within two days when treated with continuous illumination. Rapid detection of the peak time of double cell percentage by coulter counters may contribute to quasi-realtime feedback control for efficient production of photobiological hydrogen by unicellular cyanobacterial strains.

Dental Plaque Streptococci가 생산하는 세포외 다당류에 관한 연구 (STUDIES ON THE EXTRACELLULAR POLYSACCHARIDES PRODUCED BY ISOLATED DENTAL PLAQUE STREPTOCOCCI)

  • 정태영
    • 대한치과의사협회지
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    • 제9권12호
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    • pp.819-822
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    • 1971
  • For this investigation, author isolated Streptococcus mitis strain SD-9 from the bacterial flora in the human dental plaque, which was incubated in brain-heart infusion media containing 5% sucrose at 37℃ for 24 hours. For the cytochemical demonstration of polysaccharide produced by this strain, a modified thiosemicarbazide osmium method (Critchley et al., 1967) was used. After fixation with this reagent, the harvested cells was suspended in 1% agar for the higher concentration of cells(Kellenberger et al., 1964). And they were dehydrated in the various concentration of ethanol, and embedded in Epon 812(Luft, 1961). Sectioning was done with the Sorvall MT-2 Porter Blum ultramicrotome by means of a glass knife, and the sections were stained with saturated uranyl acetate and lead citrate (Raynolds, 1963). All preparations were examined in a electron microscope, Hitachi HU-ll E-1 type. The morphological features of extracellular polysaccharide produced by Streptococcus mitis strain SD-9 were appeared in 3 structurally different forms, those are, electron dense fibrillar material linearly arranged adjacent to the outer surface of cell wall, highly electron dense globular material adjacent to the outer surface of cell wall, and strutureless fluffy meshwork of possible very fine filament.

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관골상악골 복합체 골절 환자에서의 안면 비대칭에 대한 임상경험 (Clinical Experiences of Facial Asymmetries in Zygomaticomaxillary Complex Bone Fracture Patients)

  • 강낙헌;최상문;김주학;송승한;오상하
    • Archives of Plastic Surgery
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    • 제38권2호
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    • pp.161-165
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    • 2011
  • Purpose: Zygomaticomaxillary complex (ZMC) fracture is one of the most common facial injuries after facial trauma. As ZMC composes major facial buttress, it is a key element of the facial contour. So, when we treat these fractures, the operator should have a concern with the symmetry to restore normal appearance and function. But sometimes, unfavorable results may occur. The aim of this study is to analyze the unsatisfied midfacial contour after ZMC fractures reduction retrospectively and to point out the notandum. Methods: 369 patients, treated for fractures of the ZMC were included in the study. After the operation, such as open reduction and internal fixation (ORIF with titanium or absorbable materials), open reduction, and closed reduction, midfacial contour was evaluated with plain films and 3-dimensional computed tomography. And unfavorable asymmetric midfacial contours were correcterd by secondary correction and re-evaluated. Gross photographs were obtained at outpatient clinic. Results: Total of 38 patients had got a facial asymmetry and among of them 24 patients were treated secondary revisional ORIF operations for correction of unfavorable result of after primary reduction. Two of them had received tertiary operations, three patients had got osteotomy more than after one year and six patients had got minor procedures. The etiology of asymmetry were lateral displaced simple fracture of arch (n=2), lateral displaced comminuted fracture of arch (n=6), comminuted arch fracture combined posterior root fracture (n=9), and communited arch and body fracture (n=12), severely contused soft tissue (n=9). After the manipulations outcomes were acceptable. Conclusion: To prevent the asymmetry in ZMC fracture reduction, complete analysis of fracture, choice of appropriate operation technique, consider soft tissue, and secure of zygoma position are important. Especially, we should be more careful about communited fracture of zygomatic body and lateral displacement, root fracture of zygomatic arch. Because they are commom causes that make facial asymmetry. To get optimal result, ensure the definite bony reduction.

The Effects of Acetate and $CO_2$ Supplements for Cell Growth of Haematococcus pluvialis in Bubble Column Photobioreactors

  • 서문원;이철균
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.298-300
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    • 2001
  • 본 실험의 결과, H. pluvialis의 배양에 있어서 고농도의 $CO_2$를 공급함으로서 세포의 성장속도가 의미 있게 증가함을 알았고, 더불어 $CO_2$가 공급되는 경우, acatate 와 같은 유기탄소원이 오히려 세포의 성장을 저해함을 알 수 있었다.

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The Hypernodulating nts Mutation Induces Jasmonate Synthetic Pathway in Soybean Leaves

  • Seo, Hak Soo;Li, Jinjie;Lee, Sun-Young;Yu, Jae-Woong;Kim, Kil-Hyun;Lee, Suk-Ha;Lee, In-Jung;Paek, Nam-Chon
    • Molecules and Cells
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    • 제24권2호
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    • pp.185-193
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    • 2007
  • Symbiotic nitrogen fixation with nitrogen-fixing bacteria in the root nodules is a distinctly beneficial metabolic process in legume plants. Legumes control the nodule number and nodulation zone through a systemic negative regulatory system between shoot and root. Mutation in the soybean NTS gene encoding GmNARK, a CLAVATA1-like serine/threonine receptor-like kinase, causes excessive nodule development called hypernodulation. To examine the effect of nts mutation on the gene expression profile in the leaves, suppression subtractive hybridization was performed with the trifoliate leaves of nts mutant 'SS2-2' and the wild-type (WT) parent 'Sinpaldalkong2', and 75 EST clones that were highly expressed in the leaves of the SS2-2 mutant were identified. Interestingly, the expression of jasmonate (JA)-responsive genes such as vspA, vspB, and Lox2 were upregulated, whereas that of a salicylate-responsive gene PR1a was suppressed in the SS2-2 mutant. In addition, the level of JA was about two-fold higher in the leaves of the SS2-2 mutant than in those of the WT under natural growth conditions. Moreover, the JA-responsive gene expression persists in the leaves of SS2-2 mutant without rhizobia infection in the roots. Taken together, our results suggest that the nts mutation increases JA synthesis in mature leaves and consequently leads to constitutive expression of JA-responsive genes which is irrelevant to hypernodulation in the root.

Treatment modalities for Korean patients with unilateral hemifacial microsomia according to Pruzansky-Kaban types and growth stages

  • Yang, Il-Hyung;Chung, Jee Hyeok;Yim, Sunjin;Cho, Il-Sik;Kim, Sukwha;Choi, Jin-Young;Lee, Jong-Ho;Kim, Myung-Jin;Baek, Seung-Hak
    • 대한치과교정학회지
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    • 제50권5호
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    • pp.336-345
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    • 2020
  • Objective: To investigate the treatment modalities (Tx-Mods) for patients with unilateral hemifacial microsomia (UHFM) according to Pruzansky-Kaban types and growth stages. Methods: The samples consisted of 82 Korean UHFM patients. Tx-Mods were defined as follows: Tx-Mod-1, growth observation due to mild facial asymmetry; Tx-Mod-2, unilateral functional appliance; Tx-Mod-3, fixed orthodontic treatment; Tx-Mod-4, growth observation due to a definite need for surgical intervention; Tx-Mod-5, unilateral mandibular or bimaxillary distraction osteogenesis (DO); Tx-Mod-6, maxillary fixation using LeFort I osteotomy and mandibular DO/sagittal split ramus osteotomy; Tx-Mod-7, orthognathic surgery; and Tx-Mod-8, costochondral grafting. The type and frequency of Tx-Mod, the number of patients who underwent surgical procedures, and the number of surgeries that each patient underwent, were investigated. Results: The degree of invasiveness and complexity of Tx-Mod increased, with an increase in treatment stage and Pruzansky-Kaban type (initial < final; [I, IIa] < [IIb, III], all p < 0.001). The percentage of patients who underwent surgical procedures increased up to 4.2 times, with an increase in the Pruzansky-Kaban type (I, 24.1%; IIa, 47.1%; IIb, 84.4%; III, 100%; p < 0.001). However, the mean number of surgical procedures that each patient underwent showed a tendency of increase according to the Pruzansky-Kaban types (I, n = 1.1; IIa, n = 1.5; IIb, n = 1.6; III, n = 2.3; p > 0.05). Conclusions: These findings might be used as basic guidelines for successful treatment planning and prognosis prediction in UHFM patients.

골반 골절의 수술적 교정을 실시한 31두 개에서의 후향연구 (Retrospective Study on Surgical Repair of 31 Canine Pelvic Fracture Cases)

  • 이승훈;박성수;강병재;김용선;김완희;권오경
    • 한국임상수의학회지
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    • 제29권1호
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    • pp.8-11
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    • 2012
  • 본 조사는 골반골절을 수술적으로 교정한 31두 개에서의 결과를 분석한 것이다. 파행과 부중의 정도가 후지의 기능개선 평가에 이용되었다. 단순골절은 천장관절과 장골에서 발생하였으며, 골반골절은 관골절구의 골절을 포함하는 것과 포함하지 않는 경우가 있었다. 관골절구의 골절은 추가적인 대퇴골 머리 및 목 절제술 또는 관골절구 둘레 고정 만을 실시하였다. 단순골절은 복합골절에 비해 초기 회복시간과 완전한 회복시간 모두 짧았다. 관골절구를 포함하지 않는 골절에서는 포함한 골절에 비해 회복시간이 유의적으로 짧았다(p < 0.05). 또한 대퇴골 머리 및 목 절제술을 추가로 실시한 경우에서 실시하지 않은 것 보다 짧은 회복시간을 보였다. 소형견에서 관골절구의 골절 발생 시 대퇴골 머리 및 목 절제술을 이용한 수술적 교정은 대체 가능한 방법으로 생각된다.

전방십자인대 재건술 환자의 운동프로그램 참여 시기에 따른 등척성 근기능 비교 (Comparison of the Isometric Myofunction on Anterior Cruciate Ligament Reconstruction Patients according to the Time of Participation in Exercise Program)

  • 배창환;조성현;황보각
    • 대한물리의학회지
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    • 제6권4호
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    • pp.455-464
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    • 2011
  • Purpose : This study is to investigate difference in the isometric muscular function of knee joints according to the time of participation in rehabilitation exercise in patients who had anterior cruciate ligament reconstruction. Methods : The subjects of this study were patients by sports injury or accident in the sports rehabilitation center of G hospital. The early exercise program group (n=7) started functional ability exercise from 2 weeks after the surgery and the late exercise program group (n=7) from 6 weeks after the surgery. Statistical analysis was used repeated measure ANOVA to test mean difference by using SPSS 18.0 for windows. Results : First, as to quadriceps femoris muscle according to the time of participation in exercise program, significant difference was observed according to interaction and time. Second, as to hamstring muscle according to the time of participation in exercise program, significant difference was observed in muscle strength according to time. Conclusion : This results suggest that if the effect of exercise program is similar between the early starting group and the late starting group, it is not necessary to have a long period of fixation as in the late exercise program group but is desirable to start functional ability exercise early in order to relieve pains in the knee joints.