• Title/Summary/Keyword: As (V)

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Application of Thermotolerant Yeast at High Temperature in Jar-fermentor Scale.

  • Sohn, Ho-Yong;Kim, Young-Ho;Rhee, In-Koo
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.316-321
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    • 1994
  • We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

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Against the Asymmetric CP- V2 Analysis of Old English

  • Yoon, Hee-Cheol
    • Korean Journal of English Language and Linguistics
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    • v.4 no.2
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    • pp.117-149
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    • 2004
  • The paper is to argue against the asymmetric CP-V2 analysis of Old English, according to which finite verbs invariably undergo movement into a clause-final T within subordinate clauses and reach the functional head C within main clauses. The asymmetric CP-V2 analysis, first of all, faces difficulty in explaining a wide range of post-verbal elements within subordinate clauses. To resolve the problem, the analysis has to abandon the obligatoriness of V-to-T movement or introduce various types of extraposition whose status is dubious as a legitimate syntactic operation. Obligatory V-to-T movement in Old English lacks conceptual justification as well. Crosslinguistic evidence reveals that morphological richness in verbal inflection cannot entail overt verb movement. Moreover, the operation is always string-vacuous under the asymmetric CP- V2 analysis and has no effect at the interfaces, in violation of the principle of economy. The distribution of Old English finite verbs in main clauses also undermines the asymmetric CP-V2 analysis. Conceptually speaking, a proper syntactic trigger cannot be confirmed to motivate obligatory verb movement to C. The operation not only gets little support from nominative Case marking, the distribution of expletives, or complementizer agreement but also requires the unconvincing stipulation that expletives as well as sentence-initial subjects result from string-vacuous topicalization. Finally, textual evidence testifies that Old English sometimes permits non-V2 ordering patterns, many of which remain unexplained under the asymmetric CP-V2 analysis.

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The Synthesis of Vanadium-Doped Forsterite by the $H_2O_2$-Assisted Sol-Gel Method, and the Growth of Single Crystals of Vanadium-Doped Forsterite by the Floating Zone Method

  • 박동곤;Mikio Higuchi;Rudiger Dieckmann;James M. Burlitch
    • Bulletin of the Korean Chemical Society
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    • v.19 no.9
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    • pp.927-933
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    • 1998
  • Polycrystalline powder of vanadium-doped forsterite (Vδ $Mg_2SiO_4$) was synthesized by the $H_2O_2$-assisted sol-gel method. The vanadium dopant, which was added as VO$(OMe)_3$ in methanol, went through several redox reactions as the sol-gel reaction proceeded. Upon adding VO$(OMe)_3$ to a mixture of $Mg(OMe)_2$ and Si$(OEt)_4$ in methanol, V(V) reduced to V(IV). As hydrolysis reaction proceeded, the V(IV) oxidized all back to V(V). Apparently, some of the V(V) reduced to V(IV) during subsequent gelation by condensation reaction. The V(IV) remained even after heat treatment of the gel in highly oxidizing atmosphere. The crystallization of the xerogel around 880 ℃ readily produced single phase forsterite without any minor phase. Using the polycrystalline powder as feeding stock, single crystals of vanadium-doped forsterite were grown by the floating zone method in oxidizing or reducing atmosphere. The doping was limited in low level because of the high partitioning of the vanadium in liquid phase during melting. The greenish single crystal absorbed visible light of 700∼1100 nm. But, no emission was obtained in near infrared range.

Evaluation for Optimization of CT Dose Reduction Methods in PET/CT (PET/CT 검사 시 CT 피폭선량 감소 방법들의 최적화 평가)

  • Do, Yong Ho;Lee, Hong Jae;Kim, Jin Eui
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.55-62
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    • 2015
  • Purpose Various methods for reducing radiation exposure have been continuously being developed. The aim of this study is to evaluate effectiveness of dose reduction, image quality and PET SUV changes by applying combination of automatic exposure dose(AEC), automated dose-optimized selection of X-ray tube voltage(CAREkV) and sinogram affirmed iterative reconstruction(SAFIRE) which can be controled by user. Materials and Methods Torso, AAPM CT performance and IEC body phantom images were acquired using biograph mCT64, (Siemens, Germany) PET/CT scanner. Standard CT condition was 120 kV, 40 mAs. Radiation exposure and noise were evaluated by applying AEC, CAREkV(120 kV, 40 mAs) and SAFIRE(120 kV, 25 mAs) with torso phantom compare to standard CT condition. And torso, AAPM and IEC phantom images were acquired with combination of 3 methods in condition of 120 kV, 25 mAs to evaluate radiation exposure, noise, spatial resolution and SUV changes. Results When applying AEC, CTDIvol and DLP were decreased by 50.52% and 50.62% compare to images which is not applying AEC. mAs was increased by 61.5% to compensate image quality according to decreasing 20 kV when applying CAREkV. However, CTDIvol and DLP were decreased by 6.2% and 5.5%. When reference mAs was the lower and strength was the higher, reduction of radiation exposure rate was the bigger. Mean SD and DLP were decreased by 2.2% and 38% when applying SAFIRE even though mAs was decreased by 37.5%(from 40 mAs to 25 mAs). Combination of 3 methods test, SD decreased by 5.17% and there was no significant differences in spatial resolution. And mean SD and DLP were decreased by 6.7% and 36.9% compare to 120 kV, 40 mAs with AEC. For SUV test, there was no statistical differences(P>0.05). Conclusion Combination of 3 methods shows dose reduction effect without degrading image quality and SUV changes. To reduce radiation exposure in PET/CT study, continuous effort is needed by optimizing various dose reduction methods.

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The Chemotoxonoic Relationship of Vibrio cholerae non-O1 by Fatty Acid Compositions (지방산 조성에 의한 vibrio cholerae non-O1의 화학분류학적 관계)

  • 성희경;이원재;장동성
    • Journal of Food Hygiene and Safety
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    • v.13 no.2
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    • pp.149-154
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    • 1998
  • The authors attempted utilization of fatty acid composition of vibrios as a tool for identification of the strains. Fatty acid of 49 strains of Vibrio cholerae non-O1, V. cholerae O1, V mimicus, V vulinificus and V parahaemolyticus was analyzed by gas-liquid chromatography column. According to the statistical analysis of the fatty acid data, the relationship between the Vibrio species and serotypes of the strains was discussed. Forty one kinds of fatty acid were detected from the tested strains and 35 kinds of fatty acids among the detected fatty acids were significant factors to identify the vibrios. The predominant fatty acids were 16:0, 16:1 cis 9, 18:1 trans 9/6/cis 11 and 15:0 iso 2OH/16:1 cis 9 as above about 20% in total. Fatty acid compositions of the Vibrio species were an important factor in identifying their subspecies either predominant fatty acids or minor ones. According to the analysed results by a conventional statistical processing method (UPGMA) and prepared dendrogram, V cholerae non-01 had more closer relationship with V. mimicus compared with V. cholerae 01. Moreover, the distribution of hydroxy acid was a significant factor for identifying V cholerae subspecies. Comprising all the 10 serotypes detected from V. cholerae non-01 examined such as O2, O5, O8, O10, O14, O27, O37, O39, O45 and O69, we could group them into seven subspecies by cluster analysis with the similarity value of fatty acid composition as above 92%. It means that there is a significant relationship between serotypes and fatty acid composition of V. cholerae. These results indicated that numerical analysis of fatty acid composition data of V cholerae non-01 could classifY them into subspecies, and also which may provide a useful epidemiologic information or a basis for further analysis such as PCR and DNA probe analysis.

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Preliminary Study on Arsenic Speciation Changes Induced by Biodegradation of Organic Pollutants in the Soil Contaminated with Mixed Wastes (유기물분해에 따른 유류${\cdot}$중금속 복합오염토양내 비소화학종 변화의 기초연구)

  • 이상훈;천찬란;심지애
    • Economic and Environmental Geology
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    • v.36 no.5
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    • pp.349-356
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    • 2003
  • As industrial activities are growing, pollutants found in the contaminated land are getting diverse. Some contaminated areas are subject to mixed wastes containing both organic and inorganic wastes such as hydrocarbon and heavy metals. This study concerns with the influence of the degradation of organic pollutants on the coexisting heavy metals, expecially for As. As mainly exists as two different oxidation state; As(III) and As(V) and the conversion between the two chemical forms may be induced by organic degradation in the soil contaminated by mixed wastes. We operated microcosm in an anaerobic chamber for 60 days, using sandy loam. The soils in the microcosm are artificially contaminated both by tetradecane and As, with different combination of As(III) and As(V); As(III):As(V) 1:1, As(III) only and As(V) only. Although not systematic, ratio of As(III)/As(Total) increase slightly at the later stage of experiment. Considering complicated geochemical reactions involving oxidation/reduction of organic materials, Mn/Fe oxides and As, the findings in the study seem to indicate the degradation of the organics is connected with the As speciation. That is to say, the As(V) can be reduced to As(III) either by direct or indirect influence induced by the organic degradation. Although Fe and Mn are good oxidising agent for the oxidation of As(III) to As(V), organic degradation may have suppressed reductive dissolution of the Fe and Mn oxides, causing the organic pollutants to retard the oxidation of As(III) to As(V) until the organic degradation ceases. The possible influence of organic degradation on the As speciation implies that the As in mixed wastes may be have elevated toxicity and mobility by partial conversion from As(V) to As(III).

쌍끌이 중층트롤어법의 연구 ( 2 ) - 모형어구의 깊이에 관하여 - ( A Study on the Pair Midwater Trawling ( 2 ) - Working Depth of the Model Net - )

  • 이병기
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.1
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    • pp.45-53
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    • 1995
  • Working depth of the model net was determined by using of the same experimental tank and the same model net that used in the forwarded report in a series studies. The depth of the net which indicates the depth of the head rope from the water surface, was determined by the photographs taken in front of the net mouth with the combination of towing velocity, warp length and distance between paired boats. The results obtained can be summarized as follows: 1. Working depth of model nets A and B was varied in the range of 0.09~1.66$m$,and 0.04~1.34$m$(which can be converted into 2.7~40.2$m$and 1.2~49.8$m$in the full-scale net) respectively, and the depth of model net A was slightly deeper than the depth of the model net B. 2. Working depth ($D$,which is appendixed m for the model net, f for the full-scale net, A and B for the types of the model nets) can be expressed as the function of towing velocity$V_t$, as in the model net($V_t$=$m$/$sec$) $D_{mA}$=(-1.99+0.65$L_w$) $e^{-1.72V_t}$ $D_{mA]$=(-1.91+1.04 $L_w$) $e^{2.88V_t}$ in the full-scale net($V_t$=$k$'$t$ $D_{fA}$=(-29.32+0.65$L_w$)$e^{0.40 V_t}$ $D_{fB}$=(-57.60+1.04$L_w$)$e^{-0.67 V_t}$ 3. Working depth 9$D$ appendixes are as same as the former) can be expressed as the function of warp length$L_w$) in the model net, and can be converted into full-scale net as in the model net ($V_t$=$m$/$sec$) $D_{mA}$=-0.99 $e^{-1.42V_t}$+0.67$e^{-1359V_t}$$L_w$ $D_{mB}$=-.258$e^{-3.77V_t}$+1.16$e^{-3.15V_t$ $L^w$, in the full-scale net($V_t$=k't) $D_{fA}$=-29.28$e^{-0.32V_t}$+0.67$e^{-0.37V_t$$L_w$ $D_{fB}$=-69.10$e^{-0.81V_t}$+1.16$e^{-0.72V_t}$$L_w$. 4. Working depth was gradually shallowed according to the increase of the distance between paired boats.

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Reduction of Dissolved Fe(III) by As(V)-tolerant Bacteria Isolated from Rhizosphere Soil

  • Khanal, Anamika;Song, Yoonjin;Cho, Ahyeon;Lee, Ji-Hoon
    • Korean Journal of Environmental Agriculture
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    • v.40 no.1
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    • pp.67-72
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    • 2021
  • BACKGROUND: Biological iron redox transformation alters iron minerals, which may act as effective adsorbents for arsenate [As(V)] in the environments. In the viewpoint of alleviating arsenate, microbial Fe(III) reduction was sought under high concentration of As(V). In this study, Fe(III)-reducing bacteria were isolated from the wild plant rhizosphere soils collected at abandoned mine areas, which showed tolerance to high concentration of As(V), in pursuit of potential agents for As(V) bioremediation. METHODS AND RESULTS: Bacterial isolation was performed by a series of enrichment, transfer, and dilutions. Among the isolated strains, two strains (JSAR-1 and JSAR-3) with abilities of tolerance to 10 mM As(V) and Fe(III) reduction were selected. Phylogenetic analysis using 16S rRNA genesequences indicated the closest members of Pseudomonas stutzeri DSM 5190 and Paenibacillus selenii W126, respectively for JSAR-1 and JSAR-3. Ferric and ferrous iron concentrations were measured by ferrozine assay, and arsenic concentration was analyzed by ICP-AES, suggesting inability of As(V) reduction whereas ability of Fe(III) reduction. CONCLUSION: Fe(III)-reducing bacteria isolated from the enrichments with arsenate and ferric iron were found to be resistant to a high concentration of As(III) at 10 mM. We suppose that those kinds of microorganisms may suggest good application potentials for As(V) bioremediation, since the bacteria can transform Fe while surviving under As-contaminated environments. The isolated Fe(III)-reducing bacterial strains could contribute to transformations of iron minerals which may act as effective adsorbents for arsenate, and therefore contribute to As(V) immobilization

REGULARIZED ELSENSTELN SERIES ON METAPLECTIC GROUPS

  • Park, Young-Ho
    • Communications of the Korean Mathematical Society
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    • v.9 no.4
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    • pp.783-796
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    • 1994
  • Let V be a vector space of dimension m over Q, and let (, ) be a non-degenerate bilinear form on V. Let r be the Witt index of V, and let $V = V' + V_0 + V"$ be the Witt decomposition, where $V_0$ is anisotropic and V', V" are paired non-singularly. Let H = O(m-r, r) be the isometry group of V, (, ), viewed as an algebraic group over Q. Let G = Sp(n) be the symplectic group of rank n defined over Q.ed over Q.

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V2X Technology Trends for Next-Generation Mobility

  • Kim, Young-Hak
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.7-13
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    • 2020
  • We describes V2X technology, a connectivity-based recognition technology that is attracting attention as a key technology for implementing autonomous driving technology, and autonomous communication modules that implement ADAS technology, a sensor-based recognition technology. It also explains the trends in V2X technology standardization centered on IEEE 802.11p, which is a WAVE technology standard based on Wi-Fi/DSRC. Finally, we will discuss the market growth trend of V2X communication modules in the United States, the leading V2X technology module, and the development of technology development trends of major domestic and international companies that are leading the global technology market related to V2X communication modules. V2X and ADAS technologies will be the biggest influence on automotive purchasing decisions. In recent years, V2I mandates have been promoted beyond V2V, mainly in developed countries such as the United States. The related industry needs to focus on the development of information transmission network technology that can support high frequency high efficiency(transmission rate) and sophisticated positioning accuracy beyond conventional vehicle communication.