WorldWideScience

Sample records for obliquus mittels 13c-isotopenmarkierung

  1. LEXIKALISCHE MITTEL IN DER HOTELWERBUNG

    OpenAIRE

    Blažević, Nevenka

    2003-01-01

    Werbung ist das wichtigste Marketinginstrument in der Hotellerie. Bei jeder Werbekampagne ist die sprachliche Seite von großer Bedeutung. In diesem Beitrag wird die lexikalische Ebene der Prospekttexte analysiert. Es wird auf allgemeine sprachliche Merkmale dieser Textsorte verwiesen. In Hotelprospekten lassen sich zwei Funktionen erkennen: die Informationsfunktion und die Appellfunktion. Die Appellfunktion wird meistens durch Adjektive ausgedrückt. Bei der Auswahl der lexikalischen Mittel...

  2. Grazer-induced defense in Scenedesmus obliquus (Chlorophyceae)

    NARCIS (Netherlands)

    Lürling, M.

    2000-01-01

    The non-spiny Scenedesmus obliquus may express considerable phenotypic plasticity in response to changes in their environment. When exposed to chemicals released from the grazer Ceriodaphnia, unicellular S. obliquus populations were rapidly transformed into colonial ones. The morphological response

  3. Antitumor and immunomodulatory activity of Inonotus obliquus

    Directory of Open Access Journals (Sweden)

    Staniszewska Justyna

    2017-06-01

    Full Text Available The article presents the antitumor and immunomodulatory activity of compounds and extracts from Inonotus obliquus. Polysaccharides isolated from sclerotium have a direct antitumor effect due to protein synthesis inhibition in tumor cells. Polysaccharides derived from the mycelium function by activating the immune system. Due to the limited toxicity of these substances, both extracts as well as isolated and purified chemicals may be a good alternative to current chemotherapy and play a role in cancer prevention. In vitro experiments have shown the inhibition of inflammation with the influence of action of I. obliquus extracts; however, in vivo experiments on animals implanted with tumor cells of different types have shown the activation of the host immune system. This led to decrease in tumor mass and prolonged survival. The immunomodulatory mechanism of action is complex and it seems that stimulation of macrophages and induction of apoptosis in cancer cells is of great importance.

  4. Phytochemical analysis of Cyrtanthus obliquus bulbs from the ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    dihydroxy-lanosta-8-ene was also isolated from the bulbs. The ... Fresh bulbs from C. obliquus were purchased at the Berea market in Durban and identified by a curator from the School of Biological and. Conservation Sciences, UKZN, Westville ...

  5. Uptake of tritiated lysine by fresh water alga, Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Gogate, S.S.; Krishnamoorthy, T.M.

    1983-01-01

    Tritium uptake by fresh water alga. S.obliquus was studied using tritium labelled lysine, and a sequential solvent extraction procedure was used to study the distribution of tritium in different organic constituents of the algal cells. The accumulation of tritium in the algal cells was found to be 3-4 orders of magnitude more than that obtained for tritiated water. (author)

  6. Plutonium uptake by Scenedesmus obliquus as a function of isotope and oxidation state

    International Nuclear Information System (INIS)

    Tkacik, M.F.; Giesy, J.P.; Wilhite, E.L.; Corey, J.C.

    1979-01-01

    Uptake of 238 Pu 4+ , 238 Pu 6+ , 239 Pu 4+ and 239 Pu 6+ by the green alga Scenedesmus obliquus (Turp) Kutz was studied to determine whether isotope or oxidation state differences affect Pu uptake from aqueous medium by algal cells. At equivalent 238 Pu and 239 PU concentrations, even when initial oxidation states differed, accumulations of these isotopes by S.obliquus were not significantly (p>0.05) different. Plutonium accumulation by S.obliquus was log-linear. (author)

  7. Herbicides interfere with antigrazer defenses in Scenedesmus obliquus.

    Science.gov (United States)

    Zhu, Xuexia; Sun, Yunfei; Zhang, Xingxing; Heng, Hailu; Nan, Haihong; Zhang, Lu; Huang, Yuan; Yang, Zhou

    2016-11-01

    The extensive application of herbicides has led to a serious threat of herbicide contamination to aquatic ecosystem. Herbicide exposure affects aquatic communities not only by exerting toxicity on single species but also by changing interspecific interactions. This study investigated the antigrazer defenses of the common green alga Scenedesmus obliquus against different herbicides [glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine] at various concentrations (0-2.0 mg L(-1)). In the presence of grazer (Daphnia)-derived cues, S. obliquus populations without herbicides formed high proportions of multicelled (e.g., four- and eight-celled) colonies. This result confirms that S. obliquus exhibits a morphological defense against grazing risk. At the low concentration range of 0.002-0.02 mg L(-1), the three herbicides exerted no influence on the growth and photosynthetic efficiency of S. obliquus, and multicelled colonies showed constant proportions. At the high concentration range of 0.20-2.0 mg L(-1), atrazine significantly inhibited the algal growth and photosynthesis whereas glyphosate or 2,4-D did not. Nonetheless, these levels of glyphosate or 2,4-D remarkably decreased the proportion of multicelled colonies, with reduced numbers of cells per particle in Daphnia filtrate-treated population. No eight-celled colony was formed after treatment with atrazine at 0.20-2.0 mg L(-1) despite the addition of Daphnia filtrate. These results suggest that herbicide exposure impairs antigrazer colonial morphs in phytoplankton although it is not sufficient to hamper algal growth. This phenomenon can increase the risk of predation by herbivores, thereby disrupting the inducible phytoplankton community. Furthermore, the predator-prey interactions between herbivores and phytoplankton can be potentially changed more seriously than previously considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Chemical characterization and biological activity of Chaga (Inonotus obliquus) a medicinal "mushroom"

    NARCIS (Netherlands)

    Glamoclija, J.; Ciric, A.; Nikolic, M.; Fernandes, A.; Barros, L.; Calhelha, R.C.; Ferreira, I.C.F.R.; Sokovic, M.; Griensven, van L.J.L.D.

    2015-01-01

    ETHNOPHARMACOLOGICAL RELEVANCE: In Russian traditional medicine, an extract from the mushroom Inonotus obliquus (Fr.) Pil´at is used as an anti-tumor medicine and diuretic. It has been reported that Inonotus obliquus has therapeutic effects, such as anti-inflammatory, immuno-modulatory and

  9. Untersuchungen zur Rauchgasentstickung mittels Schwefelwasserstoff in Tri-n-butylphosphat

    OpenAIRE

    Homann, Jörg

    2000-01-01

    In der vorliegenden Arbeit wurde die Reaktion von Stickstoffmonoxid (NO) mit Schwefelwassersoff (H2S) in Tri-n-butylphosphat (TBP) im Hinblick auf ein alternatives Verfahren zur Entstickung von Rauchgasen untersucht. Mittels einer gasvolumetrischen Absorptionsapparatur wurden zuerst Daten zur physikalischen Löslichkeit in TBP ermittelt, die für den Erhalt kinetischer Daten der stofftransportüberlagerten Reaktionen in TBP relevant sind. Es sind dies die Henrykoeffizienten von NO, H2S und die d...

  10. Plutonium sorption by the green algae Scenedesmus obliquus (Tuerp) Kuetz

    International Nuclear Information System (INIS)

    Tkacik, M.F.; Giesy, J.P.; Corey, J.C.

    1978-01-01

    As part of the continuing study of the possible impact of released radioisotopes to the Savannah River Plant (SRP) environment, the interaction between a biological system and plutonium was investigated. Specifically, an algal culture, Scenedesmus obliquus, was exposed to the +4 and +6 oxidation states of 238 Pu and 239-240 Pu at three plutonium concentration levels. There was no significant different (p 3) 0.05) between 238 Pu and 239-240 Pu accumulation by the algae at equivalent concentrations or at different oxidation states

  11. Microalga Scenedesmus obliquus as a potential source for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Shovon; Mallick, Nirupama [Indian Inst. of Technology, Kharagpur, West Bengal (India). Agricultural and Food Engineering Dept.

    2009-08-15

    Biodiesel from microalgae seems to be the only renewable biofuel that has the potential to completely replace the petroleum-derived transport fuels. Therefore, improving lipid content of microalgal strains could be a cost-effective second generation feedstock for biodiesel production. Lipid accumulation in Scenedesmus obliquus was studied under various culture conditions. The most significant increase in lipid reached 43% of dry cell weight (dcw), which was recorded under N-deficiency (against 12.7% under control condition). Under P-deficiency and thiosulphate supplementation the lipid content also increased up to 30% (dcw). Application of response surface methodology in combination with central composite rotary design (CCRD) resulted in a lipid yield of 61.3% (against 58.3% obtained experimentally) at 0.04, 0.03, and 1.0 g l{sup -1} of nitrate, phosphate, and sodium thiosulphate, respectively for time culture of 8 days. Scenedesmus cells pre-grown in glucose (1.5%)-supplemented N 11 medium when subjected to the above optimized condition, the lipid accumulation was boosted up to 2.16 g l{sup -1}, the value {proportional_to}40-fold higher with respect to the control condition. The presence of palmitate and oleate as the major constituents makes S. obliquus biomass a suitable feedstock for biodiesel production. (orig.)

  12. Acute and chronic toxic effects of chloramphenicol on Scenedesmus obliquus and Chlorella pyrenoidosa.

    Science.gov (United States)

    Zhang, Wei; Sun, Wenfang; An, Shuai; Xiong, Bang; Lin, Kuangfei; Cui, Xinhong; Guo, Meijin

    2013-08-01

    The acute and chronic toxicological effects of Chloramphenicol (CAP) on Scenedesmus obliquus and Chlorella pyrenoidosa are not well understood. The indoor experiments were carried to observe and analyze the CAP induced changes. Results of the observations have showed that CAP exposure could significantly inhibit the growth of Scenedesmus obliquus in almost all the treated groups, while Chlorella pyrenoidosa exhibited less sensitivity. Chlorophyll-a syntheses of Scenedesmus obliquus were all inhibited by CAP exposure, while Chlorella pyrenoidosa displayed obvious stimulation effect. Catalase (CAT) and Superoxide dismutase (SOD) activities of both algae were promoted in all the treatments. The experimental results indicated that the growth and Chlorophyll-a syntheses of Scenedesmus obliquus were more sensitive in response to CAP exposure than that of Chlorella pyrenoidosa. While for CAT and SOD activities, Chlorella pyrenoidosa showed more susceptible. This research provides a basic understanding of CAP toxicity to aquatic organisms.

  13. Pilot cultivation of the chlorophyte microalga Scenedesmus obliquus as a promising feedstock for biofuel

    International Nuclear Information System (INIS)

    Abomohra, Abd El-Fatah; El-Sheekh, Mostafa; Hanelt, Dieter

    2014-01-01

    Scenedesmus obliquus was discussed by phycologists as a promising microalga for biofuel production based on its biomass and fatty acid productivity. In the present study, S. obliquus was pilot cultivated for large scale production in a semicontinuous culture for 3 months using polyethylene transparent bags. Cultivation of S. obliquus resulted in a maximum biomass productivity of 0.14 g L −1  d −1 and maximum esterified fatty acid productivity of 17.37 mg L −1  d −1 at light intensity of 130 μmol m −2  s −1 . Using of different flocculants for biomass harvest showed maximum flocculation efficiency of 82% using 250 mg L −1 of NaOH for 2 h. Drying of the harvested biomass showed significant increase of esterified fatty acid content by 5 and 7% with respect to control at 75 and 100 °C, respectively. In addition, fatty acid profile and iodine number of S. obliquus oil meet biodiesel standard specifications which make the fatty acid of S. obliquus eligible for further research to be used as a feedstock for biofuel production. Furthermore, the present investigation showed that after oil extraction, the residual algal biomass increased survival and fresh weight of Artemia (brine shrimp) which confirms that the residual algal biomass can be significantly used as food additives for animal feeding. - Highlights: • Scenedesmus obliquus was cultivated in plastic bags in a semicontinuous culture for high biomass production. • Different flocculants were used for harvesting of S. obliquus and the oil was chemically extracted. • The residual algal biomass was used for feeding of Artemia. • The annual productivity of EFA from S. obliquus would be nearly 5 times higher than Jatropha. • The residual algal biomass increased survival and fresh weight of Artemia

  14. 60Co retention by a freshwater planktonic alga Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Nucho, R.; Baudin, J.P.

    1989-01-01

    This paper presents the results of various decontamination experiments aimed at evaluating 60 Co retention by Scenedesmus obliquus, and the respective role played by absorption and adsorption in the contamination of the alga by this radionuclide. The physiological condition of cells is not involved in radiocobalt desorption, which seems to indicate that the phenomenon is of a passive nature. When the precontamination time is extended, the proportion of adsorbed 60 Co decreases, and the final percentage of radionuclide retained increases. These results are confirmed by bringing cells into contact with a strong chelating agent. The elimination of 60 Co in the presence of EDTA undergoes a sharp decrease which is correlated with the increase in the duration of the precontamination phase. The use of a weaker complexing agent, such as NaCl, leads to the hypothesis of there being 2 types of 60 Co receptor on cell membranes. (author)

  15. Supercritical fluid extraction and characterization of lipids from algae Scenedesmus obliquus

    Science.gov (United States)

    Choi, K. J.; Nakhost, Z.; Krukonis, V. J.; Karel, M.

    1987-01-01

    Lipids were extracted from a protein concentrate of green algae (Scenedesmus obliquus), using a one-step supercritical carbon dioxide extraction procedure in presence of ethanol as an entrainer, and were characterized. The compositions of neutral lipids, glycolipids, and phospholipids, separated into individual components by column, thin-layer, and gas-liquid chromatography procedures, are presented. Fatty acid composition patterns indicated that the major fatty acids were 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2, and 18:3. The lipids of S. obliquus were found to contain relatively high concentrations of polyunsaturated fatty acids and essential fatty acids.

  16. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    Science.gov (United States)

    Papazi, Aikaterini; Kotzabasis, Kiriakos

    2013-01-01

    The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most energetically

  17. Structural characterization of bioactive heteropolysaccharides from the medicinal fungus Inonotus obliquus (Chaga)

    DEFF Research Database (Denmark)

    Wold, Christian Winther; Kjeldsen, Christian; Corthay, Alexandre

    2018-01-01

    The aim of this paper was to perform a comprehensive characterization of polysaccharides isolated from the interior (IOI) and exterior (IOE) parts of the fungus Inonotus obliquus. Pre-extraction with DCM and MeOH, followed by water and alkali extraction and ethanol precipitation gave two water ex...

  18. Biodegradation of phenanthrene by the green alga scenedesmus obliquus ES-55

    Energy Technology Data Exchange (ETDEWEB)

    Safonova, E.; Kvitko, K. [Biological Institute of St. Petersburg State University, Oranienbaum Chaussee 2, Old Peterhof, 198504 St. Petersburg (Russian Federation); Kuschk, P.; Moeder, M. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Permoserstrasse 15, Leipzig (Germany); Reisser, W. [Universitaet Leipzig, Botanisches Institut, Johannisallee 21-23, D-04103 Leipzig (Germany)

    2005-06-01

    While the degradation of polycyclic aromatic hydrocarbons by bacteria and fungi has been broadly investigated, less is known about the metabolism of these compounds by algae. The goal of the experiments was to test the degradability of phenanthrene by the green alga Scenedesmus obliquus ES-55 (Chlorophyceae) and to identify the metabolites. It was shown that S. obliquus ES-55 metabolized phenanthrene. Under light conditions, phenanthrene (14 mg/L) inhibits cell division by more than twice. However, the metabolic processes in the cells affected by phenanthrene continued because the content of chlorophyll increased. In the exponential phase under phototrophic conditions the alga degraded phenanthrene. Phenanthrene was removed by algae up to 42 % in BBM medium and up to 24 % in Kuhl medium. Dihydroxy-dihydro-phenanthrene, a degradation metabolite in fungi, bacteria and cyanobacteria, could also be detected as a transformation product of S. obliquus ES-55. Further detected common metabolites foster the assumption that both phototrophic and non-photothrophic organisms metabolize phenanthrene via a similar pathway. The present study is the first evidence of the ability of an axenic culture of the green alga S. obliquus to biotransform phenanthrene into other metabolites. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  19. Biodiesel Production by the Green Microalga Scenedesmus obliquus in a Recirculatory Aquaculture System

    Science.gov (United States)

    Mandal, Shovon

    2012-01-01

    Biodiesel production was examined with Scenedesmus obliquus in a recirculatory aquaculture system with fish pond discharge and poultry litter to couple with waste treatment. Lipid productivity of 14,400 liter ha−1 year−1 was projected with 11 cultivation cycles per year. The fuel properties of the biodiesel produced adhered to Indian and international standards. PMID:22660702

  20. Grazer-induced morphological defense in Scenedesmus obliquus is affected by competition against Microcystis aeruginosa.

    Science.gov (United States)

    Zhu, Xuexia; Wang, Jun; Lu, Yichun; Chen, Qinwen; Yang, Zhou

    2015-07-30

    The green alga Scenedesmus is known for its phenotypic plasticity in response to grazing risk. However, the benefits of colony formation induced by infochemicals from zooplankton should come with costs. That is, a tradeoff in benefit-to-cost ratios is likely under complex environmental conditions. In this study, we hypothesized that the coexistence of Scenedesmus and its competitors decreases the formation of anti-grazer colonies in Scenedesmus. Results demonstrated that the presence of a competitor Microcystis aeruginosa inhibited inducible defensive colony formation of Scenedesmus obliquus, and the established defensive colonies negatively affected the competitive ability of S. obliquus. The proportion of induced defensive colonies in cultures was dependent on the relative abundance of competitors. Under low competition intensity, large amount of eight-celled colonies were formed but at the cost of decreased competitive inhibition on M. aeruginosa. By contrast, defensive colony formation of S. obliquus slacked in the presence of high competition intensity to maintain a high displacement rate (competitive ability). In conclusion, S. obliquus exhibited different responses to potential grazing pressure under different intensities of competition, i.e., Scenedesmus morphological response to grazing infochemicals was affected by competition against Microcystis.

  1. Acute and chronic toxic effects of bisphenol A on Chlorella pyrenoidosa and Scenedesmus obliquus.

    Science.gov (United States)

    Zhang, Wei; Xiong, Bang; Sun, Wen-Fang; An, Shuai; Lin, Kuang-Fei; Guo, Mei-Jin; Cui, Xin-Hong

    2014-06-01

    The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa) and Scenedesmus obliquus (S. obliquus) were not well understood. The indoor experiments were carried out to observe and analyze the BPA-induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short-term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose-dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa, whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms. Copyright © 2012 Wiley Periodicals, Inc.

  2. Patellar stabilization: a quantitative evaluation of the vastus medialis obliquus muscle

    NARCIS (Netherlands)

    Raimondo, R. A.; Ahmad, C. S.; Blankevoort, L.; April, E. W.; Grelsamer, R. P.; Henry, J. H.

    1998-01-01

    Twenty-one cadaveric knees were dissected to analyze the functional anatomy of the vastus medialis complex (VMC), which is composed of the vastus medialis obliquus (VMO) and the vastus medialis longus (VML) muscles. The physiologic cross-sectional area of the VMO for 20 of the knees was 29% of the

  3. Evaluation of anaerobic digestates from different feedstocks as growth media for Tetradesmus obliquus, Botryococcus braunii, Phaeodactylum tricornutum and Arthrospira maxima

    NARCIS (Netherlands)

    Massa, Marina; Buono, Silvia; Langellotti, Antonio Luca; Castaldo, Luigi; Martello, Anna; Paduano, Antonello; Sacchi, Raffaele; Fogliano, Vincenzo

    2017-01-01

    In this paper, two freshwater microalgae (Tetradesmus obliquus and Botryococcus braunii), a marine diatom (Phaeodactylum tricornutum) and a photosynthetic cyanobacterium (Arthrospira maxima) were investigated for their ability to grow on liquid digestates (LDs). Three LDs were obtained from

  4. Effects of naturally occurring aquatic organic fractions on 241Am uptake by Scenedesmus obliquus (Chlorophyceae) and Aeromonas hydrophila (Pseudomonadaceae)

    International Nuclear Information System (INIS)

    Giesy, J.P. Jr.; Paine, D.

    1977-01-01

    Naturally occurring organics were extracted from water collected from Skinface Pond near Aiken, S.C. Organics were separated into four nominal diameter size fractions (I, greater than 0.0183; II, 0.0183 to 0.0032; III, 0.0032 to 0.0009; IV, less than 0.0009 μm) by membrane ultrafiltration and introduced into Scenedesmus obliquus and Aeromonas hydrophila cultures to determine their effects on 241 Am availability for uptake. Effects on 241 Am uptake were determined in actively growing S. obliquus cultures after 96 h of growth and in dense cultures of nongrowing cells after 4 h. Uptake by A. hydrophila was determined after 4 and 24 h in actively growing cultures. All organic fractions stimulated S. obliquus growth, with the most pronounced effects due to larger organic fractions, whereas no apparent growth stimulation of A. hydrophila was observed for any organic fraction. For both long-term and short-term studies, cellular 241 Am concentration (picocuries/cell) increased with increasing 241 Am concentration for S. obliquus and A. hydrophila. Fraction IV increased 241 Am uptake by both S. obliquus and A. hydrophila during 4-h incubations. During 96-h incubations fraction I was flocculated and cosedimented, with S. obliquus and A. hydrophila cells causing an apparent increase in 241 Am uptake. Fractions II and III reduced apparent 241 Am uptake by S. obliquus as a result of biological dilution caused by increased algal growth due to the organics. Fraction IV caused a reduction in 241 Am uptake by S. obliquus not attributable to biological dilution. Organics increased 241 Am uptake by A. hydrophila during 4- and 24-h incubations. A. hydrophila also caused flocculation of fraction I during 96-h incubations

  5. Low temperature and Daphnia-associated infochemicals promote colony formation of Scenedesmus obliquus and its harvesting.

    Science.gov (United States)

    Zhu, Xuexia; Yang, Jingwen; Zhang, Xingxing; Zhang, Lu; Wang, Xiaojun; Huang, Yuan; Yang, Zhou

    2017-01-01

    To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass. A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced-colony formation of Scenedesmus. The maximum colony size at 15-25 °C was significantly larger than those at 30-35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass. Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15-25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.

  6. Comparison of different physiological parameter responses in Lemna minor and Scenedesmus obliquus exposed to herbicide flumioxazin

    Energy Technology Data Exchange (ETDEWEB)

    Geoffroy, Laure; Frankart, Cecile; Eullaffroy, Philippe

    2004-09-01

    The sensitivity of different physiological parameters in Scenedesmus obliquus and Lemna minor exposed to herbicide (flumioxazin) was investigated to indicate the most convenient and sensitive parameter. To assess toxicity of flumioxazin, we used a panel of biomarkers: pigment contents, chlorophyll fluorescence parameters and antioxidative enzyme activities. Algae and duckweed were exposed to 48-h IC{sub 50} for growth rate. In L. minor, the sensitivity of the parameters was as follows: Q{sub N}>Oxygen emission>PHIs{sub PSII}>Q{sub P}>PHI{sub PSII}>CAT, GR>Pigment>APO>Growth. For S. obliquus, this ranking was as follows: CAT>Oxygen emission>Q{sub P}>APO>GR>Pigment>PHIs{sub PSII}>Growth>PHI{sub PSII}>Q{sub N} (from the greatest to the least sensitive). The results demonstrated that the observed toxicity is related not only to interspecific variations but also to the selected parameter.

  7. Comparison of different physiological parameter responses in Lemna minor and Scenedesmus obliquus exposed to herbicide flumioxazin

    International Nuclear Information System (INIS)

    Geoffroy, Laure; Frankart, Cecile; Eullaffroy, Philippe

    2004-01-01

    The sensitivity of different physiological parameters in Scenedesmus obliquus and Lemna minor exposed to herbicide (flumioxazin) was investigated to indicate the most convenient and sensitive parameter. To assess toxicity of flumioxazin, we used a panel of biomarkers: pigment contents, chlorophyll fluorescence parameters and antioxidative enzyme activities. Algae and duckweed were exposed to 48-h IC 50 for growth rate. In L. minor, the sensitivity of the parameters was as follows: Q N >Oxygen emission>PHIs PSII >Q P >PHI PSII >CAT, GR>Pigment>APO>Growth. For S. obliquus, this ranking was as follows: CAT>Oxygen emission>Q P >APO>GR>Pigment>PHIs PSII >Growth>PHI PSII >Q N (from the greatest to the least sensitive). The results demonstrated that the observed toxicity is related not only to interspecific variations but also to the selected parameter

  8. Effects of artificial sweeteners on metal bioconcentration and toxicity on a green algae Scenedesmus obliquus.

    Science.gov (United States)

    Hu, Hongwei; Deng, Yuanyuan; Fan, Yunfei; Zhang, Pengfei; Sun, Hongwen; Gan, Zhiwei; Zhu, Hongkai; Yao, Yiming

    2016-05-01

    The ecotoxicity of heavy metals depends much on their speciation, which is influenced by other co-existing substances having chelating capacity. In the present study, the toxic effects of Cd(2+) and Cu(2+) on a green algae Scenedesmus obliquus were examined in the presence of two artificial sweeteners (ASs), acesulfame (ACE) and sucralose (SUC) by comparing the cell specific growth rate μ and pulse-amplitude-modulated (PAM) parameters (maximal photosystem II photochemical efficiency Fv/Fm, actual photochemical efficiency Yield, and non-photochemical quenching NPQ) of the algae over a 96-h period. Simultaneously, the bioconcentration of the metals by the algal cells in the presence of the ASs was measured. The presence of ACE enhanced the growth of S. obliquus and promoted the bioconcentration of Cd(2+) in S. obliquus, while the impacts of SUC were not significant. Meanwhile, EC50 values of Cd(2+) on the growth of S. obliquus increased from 0.42 mg/L to 0.54 mg/L and 0.48 mg/L with the addition of 1.0 mg/L ACE and SUC, respectively. As for Cu(2+), EC50 values increased from 0.13 mg/L to 0.17 mg/L and 0.15 mg/L with the addition of 1.0 mg/L ACE and SUC, respectively. In summary, the two ASs reduced the toxicity of the metals on the algae, with ACE showing greater effect than SUC. Although not as sensitive as the cell specific growth rate, PAM parameters could disclose the mechanisms involved in metal toxicity at subcellular levels. This study provides the first evidence for the possible impact of ASs on the ecotoxicity of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Effect of salinity stress on growth, lipid productivity, fatty acid composition, and biodiesel properties in Acutodesmus obliquus and Chlorella vulgaris.

    Science.gov (United States)

    Pandit, Priti Raj; Fulekar, Madhusudan H; Karuna, Mallampalli Sri Lakshmi

    2017-05-01

    Two microalgae strains including Chlorella vulgaris and Acutodesmus obliquus were grown on BG11 medium with salinity stress ranging from 0.06 to 0.4 M NaCl. Highest lipid content in C. vulgaris and A. obliquus was 49 and 43% in BG11 amended with 0.4 M NaCl. The microalgal strains C. vulgaris and A. obliquus grow better at 0.06 M NaCl concentration than control condition. At 0.06 M NaCl, improved dry biomass content in C. vulgaris and A. obliquus was 0.92 and 0.68 gL -1 , respectively. Stress biomarkers like reactive oxygen species, antioxidant enzyme catalase, and ascorbate peroxidase were also lowest at 0.06 M NaCl concentration revealing that both the microalgal strains are well acclimatized at 0.06 M NaCl concentration. The fatty acid composition of the investigated microalgal strains was also improved by increased NaCl concentration. At 0.4 M NaCl, palmitic acid (37%), oleic acid (15.5%), and linoleic acid (20%) were the dominant fatty acids in C. vulgaris while palmitic acid (54%) and stearic acid (26.6%) were major fatty acids found in A. obliquus. Fatty acid profiling of C. vulgaris and A. obliquus significantly varied with salinity concentration. Therefore, the study showed that salt stress is an effective stress that could increase not only the lipid content but also improved the fatty acid composition which could make C. vulgaris and A. obliquus potential strains for biodiesel production.

  10. Expression of type 2 diacylglycerol acyltransferse gene DGTT1 from Chlamydomonas reinhardtii enhances lipid production in Scenedesmus obliquus.

    Science.gov (United States)

    Chen, Chun-Yen; Kao, Ai-Ling; Tsai, Zheng-Chia; Chow, Te-Jin; Chang, Hsin-Yueh; Zhao, Xin-Qing; Chen, Po-Ting; Su, Hsiang-Yen; Chang, Jo-Shu

    2016-03-01

    Microalgal strains of Scenedesmus obliquus have the great potential for the production of biofuels, CO2 fixation, and bioremediation. However, metabolic engineering of S. obliquus to improve their useful phenotypes are still not fully developed. In this study, S. obliquus strain CPC2 was genetically engineered to promote the autotrophic growth and lipid productivity. The overexpression plasmid containing the type 2 diacylglycerol acyltransferse (DGAT) gene DGTT1 from Chlamydomonas reinhardtii was constructed and transformed into S. obliquus CPC2, and the positive transformants were obtained. The expression of DGTT1 gene was confirmed by reverse transcription PCR analysis. Enhanced lipid content of the transformant S. obliquus CPC2-G1 by nearly two-fold was observed. The biomass concentration of the recombinant strains was also 29% higher than that of the wild-type strain. Furthermore, the recombinant strain CPC2-G1 was successfully grown in 40 L tubular type photobioreactor and open pond system in an outdoor environment. The lipid content, biomass concentration, and biomass productivity obtained from 40 L tubular PBR were 127.8% 20.0%, and 232.6% higher than those obtained from the wild-type strain. The major aim of this work is to develop a tool to genetically engineer an isolated S. obliquus strain for the desired purpose. This is the first report that genetic engineering of S. obliquus has been successful employed to improve both the microalgal cell growth and the lipid production. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Utilization of xylose as a carbon source for mixotrophic growth of Scenedesmus obliquus.

    Science.gov (United States)

    Yang, Suling; Liu, Guijun; Meng, Youting; Wang, Ping; Zhou, Sijing; Shang, Hongzhong

    2014-11-01

    Mixotrophic cultivation is one potential mode for microalgae production, and an economically acceptable and environmentally sustainable organic carbon source is essential. The potential use of xylose for culturing Scenedesmus obliquus in a mixotrophic mode and physiological features of xylose-grown S. obliquus were studied. S. obliquus had a certain xylose tolerance, and was capable of utilizing xylose for growth. At a xylose concentration of 4gL(-1), the maximal cell density was 2.2gL(-1), being 2.9-fold of that under photoautotrophic condition and arriving to the level of mixotrophic growth using 4gL(-1) glucose. No changes in cellular morphology of the cells grown with or without xylose were detected. Fluorescence emission from photosystem II (PS II) relative to photosystem I (PS I) was decreased in mixotrophic cells, implying that the PSII activity was decreased. The biomass lipid content was enhanced and carbohydrate concentration was decreased, in relation to photoautotrophic controls. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Effect of food wastewater on biomass production by a green microalga Scenedesmus obliquus for bioenergy generation.

    Science.gov (United States)

    Ji, Min-Kyu; Yun, Hyun-Shik; Park, Sanghyun; Lee, Hongkyun; Park, Young-Tae; Bae, Sunyoung; Ham, Jungyeob; Choi, Jaeyoung

    2015-03-01

    Effect of food wastewater (FW) on the biomass, lipid and carbohydrate production by a green microalga Scenedesmus obliquus cultivated in Bold's Basal Medium (BBM) was investigated. Different dilution ratios (0.5-10%) of BBM either with FW or salt solution (NaCl) or sea water (SW) were evaluated. S. obliquus showed the highest growth (0.41 g L(-1)), lipid productivity (13.3 mg L(-1) day L(-1)), carbohydrate productivity (14.7 mg L(-1) day L(-1)) and nutrient removal (38.9 mg TN L(-1) and 12.1 mg TP L(-1)) with 1% FW after 6 days of cultivation. The FW promoted algal autoflocculation due to formation of inorganic precipitates at an alkali pH. Fatty acid methyl ester analysis revealed that the palmitic and oleic acid contents were increased up to 8% with FW. Application of FW improved the growth, lipid/carbohydrate productivity and biomass recovery efficiency of S. obliquus, which can be exploited for cost effective production of microalgae biomass. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Optimization of aeration for biodiesel production by Scenedesmus obliquus grown in municipal wastewater.

    Science.gov (United States)

    Han, Song-Fang; Jin, Wenbiao; Tu, Renjie; Abomohra, Abd El-Fatah; Wang, Zhi-Han

    2016-07-01

    Despite the significant breakthroughs in research on microalgae as a feedstock for biodiesel, its production cost is still much higher than that of fossil diesel. One possible solution to overcome this problem is to optimize algal growth and lipid production in wastewater. The present study examines the optimization of pretreatment of municipal wastewater and aeration conditions in order to enhance the lipid productivity of Scenedesmus obliquus. Results showed that no significant differences were recorded in lipid productivity of S. obliquus grown in primary settled or sterilized municipal wastewater; however, ultrasound pretreatment of wastewater significantly decreased the lipid production. Whereas, aeration rates of 0.2 vvm significantly increased lipid content by 51 %, with respect to the non-aerated culture, which resulted in maximum lipid productivity (32.5 mg L(-1) day(-1)). Furthermore, aeration enrichment by 2 % CO2 resulted in increase of lipid productivity by 46 % over the CO2 non-enriched aerated culture. Fatty acid profile showed that optimized aeration significantly enhanced monounsaturated fatty acid production, composed mainly of C18:1, by 1.8 times over the non-aerated S. obliquus culture with insignificant changes in polyunsaturated fatty acid proportion; suggesting better biodiesel characteristics for the optimized culture.

  14. Wastewater treatment and biodiesel production by Scenedesmus obliquus in a two-stage cultivation process.

    Science.gov (United States)

    Álvarez-Díaz, P D; Ruiz, J; Arbib, Z; Barragán, J; Garrido-Pérez, M C; Perales, J A

    2015-04-01

    The microalga Scenedesmus obliquus was cultured in two cultivation stages: (1) in batch with real wastewater; (2) maintaining the stationary phase with different conditions of CO2, light and salinity according to a factorial design in order to improve the lipid content. The presence of the three factors increased lipid content from 35.8% to 49% at the end of the second stage; CO2 presence presented the highest direct effect increasing lipid content followed by light presence and salt presence. The ω-3 fatty acids content increased with CO2 and light presence acting in isolation, nevertheless, when both factors acted together the interaction effect was negative. The ω-3 eicosapentaenoic acid content of the oil from S. obliquus slightly exceeded the 1% maximum to be used as biodiesel source (EU normative). Therefore, it is suggested the blend with other oils or the selective extraction of the ω-3 fatty acids from S. obliquus oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effect of chemicals on production, composition and antioxidant activity of polysaccharides of Inonotus obliquus.

    Science.gov (United States)

    Xu, Xiangqun; Quan, Lili; Shen, Mengwei

    2015-01-01

    Polysaccharides are important secondary metabolites from the medicinal mushroom Inonotus obliquus. Various fatty acids, surfactants and organic solvents as cell membrane-reorganizing chemicals were investigated for their stimulatory effects on the growth of fungal mycelium and production of exopolysaccharides (EPS) and endopolysaccharides (IPS) by submerged fermentation of I. obliquus. After evaluation of 14 chemicals, oleic acid, Tween 80, and TritonX-100 were chosen for optimization of addition concentration and addition time. Among the three chemicals, 0.1% (v/v) Tween 80 gave maximum production of mycelial biomass, EPS, IPS1, and IPS2 with a increase of 16.6, 81.6, 37.7 and 18.1%, respectively, when supplemented at the early growth phase (24h after inoculation). These EPS, IPS1, and IPS2 had significantly (pmonosaccharide compositions than those from the control. The simultaneously enhanced accumulation of bioactive EPS and IPS of cultured I. obliquus supplemented with Tween 80 was evident. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The kinetics of Scenedesmus obliquus microalgae growth utilizing carbon dioxide gas from biogas

    International Nuclear Information System (INIS)

    Thiansathit, Worrarat; Keener, Tim C.; Khang, Soon-Jai; Ratpukdi, Thunyalux; Hovichitr, Patcharee

    2015-01-01

    Microalgae Scenedesmus obliquus was cultured in a laboratory photobioreactor to determine the efficacy of using biogas as a carbon source for the microalgae's growth. The biogas contained ∼60% CH 4 and ∼40% CO 2 , and was derived from an anaerobic digester operating from animal wastes, and an anaerobic reactor utilizing high strength wastewater. The results showed that biogas is a viable carbon source for microalgae growth and that significant portions of the biogas' CO 2 can be utilized for algae growth, resulting in a biogas having a high concentration of methane. This paper develops the kinetic expressions for the algae's growth by assuming an autocatalytic reaction between carbon substrate and microalgae. The maximum specific growth rate and biomass productivity of S. obliquus were 0.56 d −1 and 0.145 g L −1 d −1 respectively. The biomass contained 51.8% carbon and higher heating value (HHV) was 22.9 MJ kg −1 . - Highlights: • Biogas is a viable carbon source for microalgae growth. • Biomass production rate and characteristics were assessed. • Scenedesmus obliquus can adjust to grow with high concentration of CO 2 in the carbon source

  17. Anaerobic digestibility of Scenedesmus obliquus and Phaeodactylum tricornutum under mesophilic and thermophilic conditions

    International Nuclear Information System (INIS)

    Zamalloa, Carlos; Boon, Nico; Verstraete, Willy

    2012-01-01

    Highlights: ► We investigate the digestion of two algae biomasses in hybrid flow-through reactors. ► We determine the bio-methane potential of these biomasses through batch assays. ► Conversion efficiencies of 20–50% with an HRT of 2.2 days are possible. ► We valorise microalgae biomass by anaerobic digestion in a high rate reactor. -- Abstract: Two types of non-axenic algal cultures, one dominated by the freshwater microalgae Scenedesmus obliquus and the other by the marine microalgae Phaeodactylum tricornutum, were cultivated in two types of simple photobioreactor systems. The production rates, expressed on dry matter (DM) basis, were in the order of 0.12 and 0.18 g DM L −1 d −1 for S. obliquus and P. tricornutum respectively. The biogas potential of algal biomass was assessed by performing standardized batch digestion as well as digestion in a hybrid flow-through reactor (combining a sludge blanket and a carrier bed), the latter under mesophilic and thermophilic conditions. Biomethane potential assays revealed the ultimate methane yield (B 0 ) of P. tricornutum biomass to be about a factor of 1.5 higher than that of S. obliquus biomass, i.e. 0.36 and 0.24 L CH 4 g −1 volatile solids (VS) added respectively. For S. obliquus biomass, the hybrid flow-through reactor tests operated at volumetric organic loading rate (Bv) of 2.8 gVS L −1 d −1 indicated low conversion efficiencies ranging between 26–31% at a hydraulic retention time (HRT) of 2.2 days for mesophilic and thermophilic conditions respectively. When digesting P. tricornutum at a Bv of 1.9 gVS L −1 d −1 at either mesophilic or thermophilic conditions and at an HRT of 2.2 days, an overall conversion efficiency of about 50% was obtained. This work indicated that the hydrolysis of the algae cells is limiting the anaerobic processing of intensively grown S. obliquus and P. tricornutum biomass.

  18. Objektverfolgung bei einer vollständigen Fahrzeugumfeldüberwachung mittels Radar

    Science.gov (United States)

    Schuster, M.; Pech, T.; Reuter, J.; Wanielik, G.

    2014-11-01

    Für modernste Fahrerassistenzsysteme ist zunehmend eine vollständige Rundumüberwachung des fließenden Verkehrs erforderlich. In diesem Artikel wird ein Ansatz zur Überwachung des gesamten umliegenden Verkehrs mittels Radarsystemen präsentiert. Hierfür wurde ein Versuchsfahrzeug mit insgesamt sechs Radarsensoren ausgerüstet, um eine möglichst hohe Umfeld-Überwachung zu ermöglichen. Für diese Konfiguration wird ein auf GPDA basierendes Trackingsystem vorgestellt. Es wird auf das Problem ausgedehnter Ziele eingegangen, welches auftritt wenn sich ein Fremdfahrzeug neben dem Versuchsfahrzeug befindet, da hier Reflektionen von verschiedenen Reflektionszentren des Ziels aufgefangen werden. Dieser Effekt wird ausgenutzt, um mittels einer Track-zu-Track Fusion eine Längenschätzung des vorbeifahrenden Fahrzeugs zu ermöglichen.

  19. Using microalgae scenedesmus obliquus in the removal of chromium present in plating wastewaters; Empleo de microalga scenedesmus obliquus en la eliminaciond e cromo presente en aguas residuales galvanicas

    Energy Technology Data Exchange (ETDEWEB)

    Pellon, A.; Benitez, F.; Frades, J.; Garcia, L.; Cerpa, A.; Alguacil, F. J.

    2003-07-01

    Dumping wastewaters from plating industry with a high content in chromium is a potential hazard for people and environment. It is known that some metals, including the heavy metals, at low concentrations participate in different metabolic routes, but at high concentration are toxic for many living organisms. Some microorganism taking the heavy metals from the environment are capable of concentrating and accumulating large quantities of them in different citiplasmatic structures with no-toxic effects. Microalgaehave affinity by the polyvalent metals making possible their use as depollutant agent in waters that contains dissolved metallic ions as alternative methods when others methods of recycle are unusable. In this report a chromium removal study from a plating wastewater, using scenedesmus obliquus culture was made. The removal efficiency of Cr (VI) was 12% and Cr (III) was 27% and for condition of algae's immobilization removal of Cr (III) was 95%. (Author) 19 refs.

  20. Sentinel-Lymphknoten-Biopsie des Melanoms mittels Indocyaningrün und "FOVIS"-System.

    Science.gov (United States)

    Göppner, Daniela; Nekwasil, Stephan; Jellestad, Anne; Sachse, Alexander; Schönborn, Karl-Heinz; Gollnick, Harald

    2017-02-01

    Der Nachweis metastatischer Infiltrate im Sentinel-Lymphkoten (SLN) gilt als wesentlicher prognostischer Faktor des Melanoms. Alternativ zur Farbstoffmethode mit Patentblau zum Goldstandard der SLN-Biopsie (SLNB) mittels Radiokolloid wird die fluoreszenzoptische Darstellung mit Hilfe von Indocyaningrün (ICG) und Nahinfrarot (NIR)-Kamerasystem kommuniziert. Im Vergleich zur konventionellen Methode wurde die Wertigkeit des ICG-/NIR-Verfahrens in Abhängigkeit vom Body-Mass-Index (BMI) des Patienten und der Konzentration von ICG bezüglich der Visualisierung des Lymphabstroms und des SLNs untersucht. An zehn Patienten wurde die SLNB mittels Technetium-99m, Patentblau und ICG durchgeführt. Die Fluoreszenz-Darstellung von Lymphbahnen und SLN erfolgte in Echtzeit mittels der NIR-Kameratechnik "FOVIS". Je nach erzielter Bildqualität wurde ICG in einer Dosis von 0,25 mg bis 2,5 mg intrakutan appliziert. Neun der zehn SLN wurden fluoreszenzoptisch identifiziert (90 %), alle zehn radioaktiv (100 %), nur acht (80 %) mittels ICG-Grünfärbung bzw. Patenblau-Markierung. Transdermal wurde ein SLN dargestellt (10 %). In Korrelation zum BMI waren höhere ICG-Mengen, bis zu 2,5 mg intrakutan absolut, in der Darstellung der Lymphbahnen von Vorteil. Die SLN-Fluoreszenzmarkierung mit dem ICG/NIR-Kamera-System "FOVIS" stellt eine sichere Alternative zur Farbstoffmethode mit Patentblau ergänzend zur Radiokolloidmethode mit Technetium-99m dar. Weitere Studien zur optimalen Dosierung von ICG und transdermalen Bildgebung in Relation zum BMI sind notwendig. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  1. Evaluation of anaerobic digestates from different feedstocks as growth media for Tetradesmus obliquus, Botryococcus braunii, Phaeodactylum tricornutum and Arthrospira maxima.

    Science.gov (United States)

    Massa, Marina; Buono, Silvia; Langellotti, Antonio Luca; Castaldo, Luigi; Martello, Anna; Paduano, Antonello; Sacchi, Raffaele; Fogliano, Vincenzo

    2017-05-25

    In this paper, two freshwater microalgae (Tetradesmus obliquus and Botryococcus braunii), a marine diatom (Phaeodactylum tricornutum) and a photosynthetic cyanobacterium (Arthrospira maxima) were investigated for their ability to grow on liquid digestates (LDs). Three LDs were obtained from anaerobic digestion of different organic wastes: zootechnical (ZW LD), vegetable biomass (VW LD) and the organic fraction of municipal solid wastes (MW LD). All the strains showed the same growth performance on VW LD as on the respective standard media (SM), while ZW LD was efficient only for growth of T. obliquus and B. braunii. MW LD was the poorest growth medium for all the strains. Data on nutrient removal efficiency showed that A. maxima and T. obliquus made the best use of NH 4 + -N with removal values ranging between 98.9-99.8%, while P. tricornutum and B. braunii showed values of 79.0 and 88.5% respectively. Applying repeated batch cultivation in photobioreactors, the biochemical composition of A. maxima and T. obliquus biomass grown on ZW LD and VW LD, showed an increase of lipid, carbohydrates and ash in both microalgae. Biomass biochemical profiles suggest possible applications in feed, chemicals and energy sectors. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Extractable substances (anionic surfactants) from membrane filters induce morphological changes in the green alga Scenedesmus obliquus (Chlorophyceae)

    NARCIS (Netherlands)

    Lürling, M.; Beekman, W.

    2002-01-01

    The effect of filtration of medium through different kinds of filters (glass fiber, mixed esters of cellulose and nitrocellulose) on the morphology in the green alga Scenedesmus obliquus was examined. Several compounds potentially released from membrane filters were further investigated, and among

  3. Optimization of hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology

    NARCIS (Netherlands)

    Chen, H.; Xu, X.; Zhu, Y.

    2010-01-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different

  4. Effect of nutrients on total lipid content and fatty acids profile of Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    Behrouz Zarei Darki

    2017-05-01

    Full Text Available ABSTRACT The effect of nutrients on the total lipid content and fatty acid profile of Scenedesmus obliquus isolated from the south coast of the Caspian Sea was evaluated. The nutritional compositions of the media impacted the growth rate and biomass of S. obliquus that ranged from 0.175 day-1 to 0.209 day-1and 0.92 gr·l-1 to 1.79 gr·l-1, respectively. The alga grew better in the medium which was characterized by higher levels of sodium and trace elements such as Fe, Mn, Mo, and Co and poor in N and P as compared with the other media. The highest level of the total lipid (32% and the highest values of saturated fatty acids, in particular palmitic acid also were positively correlated with these nutrients. Peaks in polyunsaturated fatty acids (43.7 %, especially α-linolenic acid (28.4% were related to N and P, but its correlation with K and Mg was more evident. The most important factors correlated with high amount of monounsaturated fatty acids were also N and P, followed by K and Mg to a lesser extent. This study demonstrated that the same algal strain may be a source of different amount of fatty acids, depending on the composition of the culture medium.

  5. Enhancing lutein productivity of an indigenous microalga Scenedesmus obliquus FSP-3 using light-related strategies.

    Science.gov (United States)

    Ho, Shih-Hsin; Chan, Ming-Chang; Liu, Chen-Chun; Chen, Chun-Yen; Lee, Wen-Lung; Lee, Duu-Jong; Chang, Jo-Shu

    2014-01-01

    Lutein, one of the main photosynthetic pigments, is a promising natural product with both nutritional and pharmaceutical applications. In this study, light-related strategies were applied to enhance the cell growth and lutein production of a lutein-rich microalga Scenedesmus obliquus FSP-3. The results demonstrate that using white LED resulted in better lutein production efficiency when compared to the other three monochromatic LEDs (red, blue, and green). The lutein productivity of S. obliquus FSP-3 was further improved by adjusting the type of light source and light intensity. The optimal lutein productivity of 4.08 mg/L/d was obtained when using a TL5 fluorescent lamp at a light intensity of 300 μmol/m(2)/s, and this performance is better than that reported in most related studies. Moreover, the time-course profile of lutein accumulation in the microalga shows that the maximal lutein content and productivity were obtained at the onset of nitrogen depletion. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Biological effect of aqueous C60 aggregates on Scenedesmus obliquus revealed by transcriptomics and non-targeted metabolomics.

    Science.gov (United States)

    Du, Chunlei; Zhang, Bo; He, Yiliang; Hu, Chaoyang; Ng, Qin Xiang; Zhang, Hui; Ong, Choon Nam; ZhifenLin

    2017-02-15

    This work evaluated biological effect of nC 60 on Scenedesmus obliquus. The cells were exposed to various concentrations of nC 60 for 7days. Low-dose of nC 60 was found to have a minor growth inhibitory effect. The transcriptomics and metabolomics were integrated to examine intricate molecular and cellular effects of nC 60 on Scenedesmus obliquus. We found that Scenedesmus obliquus cells exposed to nC 60 had several significant alterations in cellular transcription and biochemical processes. During the 7-day exposure to nC 60 , 2234 and 2,448 unigenes were differentially expressed by 0.1mg/L and 1mg/L nC 60 -treated groups compared with the control, including 2085 or 2247 up-regulated genes and 149 or 201 down-regulated genes, respectively. We successfully identified 22 metabolites, including 6 significantly changed metabolites, such as sucrose, d-glucose, and malic acid. The citrate cycle (TCA cycle) (ko00020) was the main target of both differentially expressed genes and metabolic change. However, accumulation of sucrose (end-product) could have induced feedback inhibition of photosynthesis in Scenedesmus obliquus, explaining the slight growth inhibition observed. The results provided a mechanistic understanding of the growth inhibition of nC 60 toxicity. These genes and metabolites are useful biomarkers for future studies and offer new insights into the early detectable changes in Scenedesmus obliquus with nC 60 exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The effect of hip abduction on the EMG activity of vastus medialis obliquus, vastus lateralis longus and vastus lateralis obliquus in healthy subjects

    Directory of Open Access Journals (Sweden)

    Arakaki Juliano

    2006-07-01

    Full Text Available Abstract Study design Controlled laboratory study. Objectives The purposes of this paper were to investigate (d whether vastus medialis obliquus (VMO, vastus lateralis longus (VLL and vastus lateralis obliquus (VLO EMG activity can be influenced by hip abduction performed by healthy subjects. Background Some clinicians contraindicate hip abduction for patellofemoral patients (with based on the premise that hip abduction could facilitate the VLL muscle activation leading to a VLL and VMO imbalance Methods and measures Twenty-one clinically healthy subjects were involved in the study, 10 women and 11 men (aged X = 23.3 ± 2.9. The EMG signals were collected using a computerized EMG VIKING II, with 8 channels and three pairs of surface electrodes. EMG activity was obtained from MVIC knee extension at 90° of flexion in a seated position and MVIC hip abduction at 0° and 30° with patients in side-lying position with the knee in full extension. The data were normalized in the MVIC knee extension at 50° of flexion in a seated position, and were submitted to ANOVA test with subsequent application of the Bonferroni multiple comparisons analysis test. The level of significance was defined as p ≤ 0.05. Results The VLO muscle demonstrated a similar pattern to the VMO muscle showing higher EMG activity in MVIC knee extension at 90° of flexion compared with MVIC hip abduction at 0° and 30° of abduction for male (p Conclusion The results showed that no selective EMG activation was observed when comparison was made between the VMO, VLL and VLO muscles while performing MVIC hip abduction at 0° and 30° of abduction and MVIC knee extension at 90° of flexion in both male and female subjects. Our findings demonstrate that hip abduction do not facilitated VLL and VLO activity in relation to the VMO, however, this study included only healthy subjects performing maximum voluntary isometric contraction contractions, therefore much remains to be discovered by

  8. Typisierung von HLA-Klasse-II-Merkmalen mittels des TaqMan-Verfahrens

    OpenAIRE

    Tremmel, Matthias

    2001-01-01

    In Anlehnung an die konventionelle SSP-PCR-Methode wurde ein Low-Resolution-Panel mittels des TaqMan-Prinzips entwickelt und es wurde exemplarisch für DR4 und DR15/16 gezeigt, daß die auf dem 5 Nuklease-Assay beruhende Methode fähig ist, auch einzelne Punktmutationen voneinander zu unterscheiden. Das Grundprinzip dieser Methode basiert ähnlich dem der PCR-SSP auf dem Verfahren der PCR und auf dem Ausnutzen genetischer Unterschiede. So kommt es nur zu einer Amplifizierung wenn beide Primer spe...

  9. Enhancement of lipid extraction for improved biodiesel recovery from the biodiesel promising microalga Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Abomohra, Abd El-Fatah; Jin, Wenbiao; El-Sheekh, Mostafa

    2016-01-01

    Highlights: • Chloroform:methanol 2:1 showed the highest lipid extraction efficiency. • Prolongation of extraction time over 2 h showed insignificant effect on EFAs yield and significantly increased FFAs. • Cell-disruption is not essential for lipid extraction from S. obliquus cells. • Hot-water treatment for 5 min showed significant increase in EFAs yield. - Abstract: During the transesterification of oil feedstock for biodiesel production, the reaction primarily happens at the ester bonds where the fatty acid chains meet the glycerol. Therefore, only esterified fatty acids (EFAs) are able to be turned directly into biodiesel by transesterification. In this study, an optimized procedure for EFAs recovery from the biodiesel promising microalga Scenedesmus obliquus was studied. The effect of different solvent mixtures (ratios), extraction times, pretreatments and cell-disruption methods on intracellular EFAs and free fatty acids (FFAs) yield was examined. Using of chloroform:methanol (C:M) 2:1 for 2 h was shown to be the best solvent mixture for lipid extraction which resulted in the highest EFAs yield. Furthermore, testing of different cell-disruption methods showed that cell-disruption is not essential for lipid extraction from S. obliquus cells. Although, microwave pretreatment showed significant increase in EFAs yield with respect to overnight oven drying at 80 °C, all showed insignificant differences to the control. Moreover, overnight cell freezing showed 7.7% significant reduction in EFAs yield with respect to the control, while hot-water treatment for 5 min showed significant increase by 13.7%. On the other hand, overnight cell incubation, in oven or freezing, resulted in significant increase in FFAs up to 7.44 and 12.47 mg g"−"1 of the dry weight, respectively. In addition, the present study showed that no pretreatment with isopropanol to inactivate the lipases is needed when hot-water pretreatment is performed. This study suggested that hot

  10. Fungi & Health: can polysaccharides from the fungus inonotus obliquus (CHAGA) inhibit tumor growth?

    DEFF Research Database (Denmark)

    Wold, C. W.; Corthay, A.; Kjeldsen, Christian

    Inonotus obliquus (Chaga) – a white rot fungus found on birch trees in the northern hemisphere –has been used in traditional medicine in Europe and Asia for centuries. Native peoples have made use of Chaga by brewing it as a tea to treat gastro-intestinal problems, to heal wounds and even to treat...... cancer. The last few decades, studies have found Chaga to contain biologically active substances such as polysaccharides, triterpenoids, polyphenols and melanin. In vivo effects such as tumor growth inhibition have been observed in mice receiving various Chaga extracts. The main hypothesis behind...... the tumor inhibiting effect is two-fold: i) fungal polysaccharides may inhibit tumor growth indirectly by activating certain immune cells such as macrophages and ii) triterpenoids and other steroids from Chaga may give a direct cytotoxic effect against cancer cells. While triterpenoids from Chaga have been...

  11. Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

    Science.gov (United States)

    Oukarroum, Abdallah

    2016-06-01

    Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test.

  12. Accumulation of dieldrin in an alga (Scenedesmus obliquus), Daphnia magna, and the guppy (Poecilia reticulata)

    Science.gov (United States)

    Reinert, Robert E.

    1972-01-01

    Scenedesmus obliquus, Daphnia magna, and Poecilia reticulata accumulated dieldrin directly from water; average concentration factors (concentration in organism, dry weight, divided by concentration in water) were 1282 for the alga, 13,954 for D. magna, and 49,307 (estimated) for the guppy. The amount accumulated by each species at equilibrium (after about 1.5, 3-4, and 18 days, respectively) was directly proportional to the concentration of dieldrin in the water. Daphnia magna and guppies accumulated more dieldrin from water than from food that had been exposed to similar concentrations in water. When guppies were fed equal daily rations of D. magna containing different concentrations of insecticide, the amounts of dieldrin accumulated by the fish were directly proportional to the concentration in D. magna; when two lots of guppies were fed different quantities of D. magna (10 and 20 organisms per day) containing identical concentrations of dieldrin, however, the amounts accumulated did not differ substantially.

  13. Using microalgae scenedesmus obliquus in the removal of chromium present in plating wastewaters

    International Nuclear Information System (INIS)

    Pellon, A.; Benitez, F.; Frades, J.; Garcia, L.; Cerpa, A.; Alguacil, F.

    2003-01-01

    Dumping wastewaters from plating industry with a high content in chromium is a potential hazard for people and environment. It is known that some metals, including the heavy metals, at low concentrations participate in different metabolic routes, but at high concentration are toxic for many living organisms. Some microorganism taking the heavy metals from the environment are capable of concentrating and accumulating large quantities of them in different citiplasmatic structures with no-toxic effects. Microalgaehave affinity by the polyvalent metals making possible their use as depollutant agent in waters that contains dissolved metallic ions as alternative methods when others methods of recycle are unusable. In this report a chromium removal study from a plating wastewater, using scenedesmus obliquus culture was made. The removal efficiency of Cr (VI) was 12% and Cr (III) was 27% and for condition of algae's immobilization removal of Cr (III) was 95%. (Author) 19 refs

  14. Bioaccumulation and effects of novel chlorinated polyfluorinated ether sulfonate in freshwater alga Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Wei; Li, Jingwen; Gao, Lichen; Zhang, Zhou; Zhao, Jing; He, Xin; Zhang, Xin

    2018-02-01

    Chlorinated polyfluorinated ether sulfonate (Cl-PFESA) is a novel alternative compound for perfluorooctane sulfonate (PFOS), with its environmental risk not well known. The bioaccumulation and toxic effects of Cl-PFESA in the freshwater alga is crucial for the understanding of its potential hazards to the aquatic environment. Scenedesmus obliquus was exposed to Cl-PFESA at ng L -1 to mg L -1 , with the exposure regime beginning at the environmentally relevant level. The total log BAF of Cl-PFESA in S. obliquus was 4.66, higher than the reported log BAF of PFOS in the freshwater plankton (2.2-3.2). Cl-PFESA adsorbed to the cell surface accounted for 33.5-68.3% of the total concentrations. The IC50 of Cl-PFESA to algal growth was estimated to be 40.3 mg L -1 . Significant changes in algal growth rate and chlorophyll a/b contents were observed at 11.6 mg L -1 and 13.4 mg L -1 of Cl-PFESA, respectively. The sample cell membrane permeability, measured by the fluorescein diacetate hydrolyzation, was increased by Cl-PFESA at 5.42 mg L -1 . The mitochondrial membrane potential, measured by Rh123 staining, was also increased, indicating the hyperpolarization induced by Cl-PFESA. The increasing ROS and MDA contents, along with the enhanced SOD, CAT activity, and GSH contents, suggested that Cl-PFESA caused oxidative damage in the algal cells. It is less possible that current Cl-PFESA pollution in surface water posed obvious toxic effects on the green algae. However, the bioaccumulation of Cl-PFESA in algae would contribute to its biomagnification in the aquatic food chain and its effects on membrane property could potentially increase the accessibility and toxicity of other coexisting pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Enantioselective toxicities of chiral ionic liquids 1-alkyl-3-methyl imidazolium tartrate on Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Huijun; Zhang, Xiaoqiang; Dong, Ying; Chen, Caidong; Zhu, Shimin; Ma, Xiangjuan

    2015-12-01

    Ionic liquids (ILs) are being used in various industries during the last few decades, while the good solubility and high stability of ILs may pose a potential threat to the aquatic environment. Effect of chiral ionic liquids (CILs) 1-alkyl-3-methyl imidazolium tartrate (RMIM T) on Scenedesmus obliquus (S.obliquus) was studied. The growth rate inhibition and cell membrane permeability increased with increasing RMIM T concentration and increasing alkyl chain lengths. The IC50 values of D-(-)-tartrate 1-hexyl-3-methyl imidazolium (D-(-)-HMIM T) were 28.30, 12.23,10.15 and 14.41 mg/L, respectively, at 24, 48, 72 and 96h. While that of L-(+)-tartrate 1-hexyl-3-methyl imidazolium (L-(+)-HMIM T) were 15.97, 7.91, 9.43 and 12.04 mg/L respectively. The concentration of chl a, chl b and chl (a+b) decreased with increasing RMIM T concentration. The chlorophyll fluorescence parameters (F0, Fv/Fm, Fv/F0, Y(II), ETR and NPQ) were affected by RMIM T, indicating that the RMIM T will damage the PSII, inhibit the transmission of excitation energy, decrease the efficiency of photosynthesis. The results showed that there were enantioselective toxicity of RMIM T to algae, and the toxicity of L-(+)-RMIM T was greater than that of D-(-)-RMIM T, but the enantioselective difference becomes smaller with increasing exposure time, and with the increasing carbon chain length of cation, indicating that cation properties may have a larger effect on toxicity than anion properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Mechanisms of60Co uptake and loss by Scenedesmus obliquus and transfer to two benthic organisms

    International Nuclear Information System (INIS)

    Nucho, R.

    1989-10-01

    The affinity of Scenedesmus obliquus for 60 Co has been confirmed under various experimental conditions allowing for the age of cultures, the physiological state of the cells, the radioactivity level and stable cobalt concentration in the medium, and the acute or periodic nature of the contamination. The dry weight 60 Co concentration factor may reach 4x10 4 in LCO culture medium and is about 10 4 in natural water. 60 Co uptake by algae is a 95% passive phenomenon, initiated by radionuclide absorption on the cell walls and followed by intracellular diffusion in accordance with Fick's law. From the initial cationic form, radiocobalt develops anion forms at a rate proportional to the algal biomass, resulting in lower contamination of old and dense cultures. After transfer in natural or artificial nonradioctive medium, 60 Co is eliminated by Scenedesmus obliquus, mainly as Co 2+ ions, according to a two-phase exponential process with two biological half-lives. The study of radioactive cobalt transfer from algae to gammarids and to midge larvae reveals the extend to which phytoplankton predominate over water and sediment in contaminating these two organisms. The total 60 Co uptake depends significantly on whether the cells are incorporated in or deposited on the sediment. No biomagnification phenomenon of the radionuclide was found in any case, as the transfer factor was less than 1. Depuration of 60 Co by organisms involved a two-phase exponential process regardless of whether uptake occured directly or from food. The presence of sediment appears to reduce the 60 Co desorption rate, but from 85 to 95% of the initial quantity is eliminated. This percentage does not depend on the transfer pathway or the presence of organic matter, and indicates very slight assimilation of radiocobalt ingested with algal cells [fr

  17. Konferenz Stadtmusikgeschichte in Mittel- und Osteuropa. Die Musik der Religionsgemeinschaften um 1900. Lipsko, 5.-6. listopadu 2004

    Czech Academy of Sciences Publication Activity Database

    Freemanová, Michaela

    2004-01-01

    Roč. 30, č. 4 (2004), s. 647-648 ISSN 1335-2458. [Konferenz Stadtmusikgeschichte in Mittel- und Osteuropa. Die Musik der Religionsgemeinschaften um 1900. Leipzig, 04.11.05-04.11.06] Institutional research plan: CEZ:AV0Z9058907 Keywords : music * religious community * 19th century Subject RIV: AL - Art, Architecture, Cultural Heritage

  18. Enantioselective oxidative stress and oxidative damage caused by Rac- and S-metolachlor to Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Huijun; Xia, YiLu; Cai, Weidan; Zhang, Yina; Zhang, Xiaoqiang; Du, Shaoting

    2017-04-01

    The rational use and environmental security of chiral pesticides has gained the interest of many researchers. The enantioselective effects of Rac- and S-metolachlor on oxidative stress in Scenedesmus obliquus were determined in this study. Stronger green fluorescence was observed in response to S-metolachlor treatment than to Rac-metolachlor treatment, suggesting that more reactive oxygen species (ROS) were stimulated by S-metolachlor. ROS levels following S-metolachlor treatment were 1.92-, 8.31-, and 1.08-times higher than those observed following Rac-metolachlor treatment at 0.1, 0.2, and 0.3 mg/L, respectively. Superoxide dismutase (SOD) and catalase (CAT) were stimulated with increasing herbicide concentrations, with S-metolachlor exhibiting a greater effect. Oxidative damage in terms of chlorophyll (Chl) content, cellular membrane permeability, and cellular ultrastructures of S. obliquus were investigated. Chla and Chlb contents in algae treated with Rac-metolachlor were 2-6-fold higher than those in algae treated with S-metolachlor at 0.1, 0.2, and 0.3 mg/L. The cellular membrane permeability of algae exposed to 0.3 mg/L Rac- and S-metolachlor was 6.19- and 42.5-times that of the control. Correlation analysis implied that ROS are the major factor responsible for the oxidative damage caused by Rac- and S-metolachlor. Damage to the chloroplasts and cell membrane of S. obliquus, low production of starch granules, and an increased number of vacuoles were observed upon ultrastructural morphology analysis by transmission electron microscope. These results indicate that S-metolachlor has a greater effect on S. obliquus than Rac-metolachlor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Contamination of a green algae (Scenedesmus obliquus) from fresh water by radionuclides typical of PWR effluents: culture in a turbidostat

    International Nuclear Information System (INIS)

    Sombre, L.; Carraro, S.; Myttenaere, C.

    1987-01-01

    The fixation of radioactive polluents, typical for PWR effluents, by the green soft water algae Scenedesmus obliquus is studied by means of a continuous culture method and in controlled conditions (turbidostat). Transfer factors are obtained. The elimination of radiocesium occurs in two distinct phases characterized respectively by a short biological period of less than one hour and a long period of the order of one day. The photosynthetic metabolism of the algae accounts for 25% of the decorporation. (Author)

  20. Effect of Nano-Al2O3 on the Toxicity and Oxidative Stress of Copper towards Scenedesmus obliquus

    Science.gov (United States)

    Li, Xiaomin; Zhou, Suyang; Fan, Wenhong

    2016-01-01

    Nano-Al2O3 has been widely used in various industries; unfortunately, it can be released into the aquatic environment. Although nano-Al2O3 is believed to be of low toxicity, it can interact with other pollutants in water, such as heavy metals. However, the interactions between nano-Al2O3 and heavy metals as well as the effect of nano-Al2O3 on the toxicity of the metals have been rarely investigated. The current study investigated copper toxicity in the presence of nano-Al2O3 towards Scenedesmus obliquus. Superoxide dismutase activity and concentration of glutathione and malondialdehyde in cells were determined in order to quantify oxidative stress in this study. Results showed that the presence of nano-Al2O3 reduced the toxicity of Cu towards S. obliquus. The existence of nano-Al2O3 decreased the growth inhibition of S. obliquus. The accumulation of copper and the level of oxidative stress in algae were reduced in the presence of nano-Al2O3. Furthermore, lower copper accumulation was the main factor that mitigated copper toxicity with the addition of nano-Al2O3. The decreased copper uptake could be attributed to the adsorption of copper onto nanoparticles and the subsequent decrease of available copper in water. PMID:27294942

  1. Growth and lipid accumulation characteristics of Scenedesmus obliquus in semi-continuous cultivation outdoors for biodiesel feedstock production.

    Science.gov (United States)

    Feng, Pingzhong; Yang, Kang; Xu, Zhongbin; Wang, Zhongming; Fan, Lu; Qin, Lei; Zhu, Shunni; Shang, Changhua; Chai, Peng; Yuan, Zhenhong; Hu, Lei

    2014-12-01

    In an effort to identify suitable microalgal species for biodiesel production, seven species were isolated from various habitats and their growth characteristics were compared. The results demonstrated that a green alga Scenedesmus obliquus could grow more rapidly and synthesize more lipids than other six microalgal strains. S. obliquus grew well both indoors and outdoors, and reached higher μmax indoors than that outdoors. However, the cells achieved higher dry weight (4.36 g L(-1)), lipid content (49.6%) and productivity (183 mg L(-1) day(-1)) outdoors than in indoor cultures. During the 61 days semi-continuous cultivation outdoors, high biomass productivities (450-550 mg L(-1) day(-1)) and μmax (1.05-1.44 day(-1)) were obtained. The cells could also achieve high lipid productivities (151-193 mg L(-1) day(-1)). These results indicated that S. obliquus was promising for lipids production in semi-continuous cultivation outdoors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Biodegradation of carbamazepine using freshwater microalgae Chlamydomonas mexicana and Scenedesmus obliquus and the determination of its metabolic fate.

    Science.gov (United States)

    Xiong, Jiu-Qiang; Kurade, Mayur B; Abou-Shanab, Reda A I; Ji, Min-Kyu; Choi, Jaeyoung; Kim, Jong Oh; Jeon, Byong-Hun

    2016-04-01

    This study evaluated the toxicity and cellular stresses of carbamazepine (CBZ) on Chlamydomonas mexicana and Scenedesmus obliquus, and its biodegradation by both microalgal species. The growth of both microalgal species decreased with increase of CBZ concentration. The growth of S. obliquus was significantly inhibited (97%) at 200 mg CBZ L(-1), as compared to the control after 10days; whereas, C. mexicana showed 30% inhibition at the same experimental conditions. Biochemical characteristics including total chlorophyll, carotenoid contents and enzyme activities (SOD and CAT) for both species were affected by CBZ at relatively high concentration. C. mexicana and S. obliquus could achieve a maximum of 35% and 28% biodegradation of CBZ, respectively. Two metabolites (10,11-dihydro-10,11-expoxycarbamazepine and n-hydroxy-CBZ) were identified by UPLC-MS, as a result of CBZ biodegradation by C. mexicana. This study demonstrated that C. mexicana was more tolerant to CBZ and could be used for treatment of CBZ contaminated wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of Nano-Al₂O₃ on the Toxicity and Oxidative Stress of Copper towards Scenedesmus obliquus.

    Science.gov (United States)

    Li, Xiaomin; Zhou, Suyang; Fan, Wenhong

    2016-06-09

    Nano-Al₂O₃ has been widely used in various industries; unfortunately, it can be released into the aquatic environment. Although nano-Al₂O₃ is believed to be of low toxicity, it can interact with other pollutants in water, such as heavy metals. However, the interactions between nano-Al₂O₃ and heavy metals as well as the effect of nano-Al₂O₃ on the toxicity of the metals have been rarely investigated. The current study investigated copper toxicity in the presence of nano-Al₂O₃ towards Scenedesmus obliquus. Superoxide dismutase activity and concentration of glutathione and malondialdehyde in cells were determined in order to quantify oxidative stress in this study. Results showed that the presence of nano-Al₂O₃ reduced the toxicity of Cu towards S. obliquus. The existence of nano-Al₂O₃ decreased the growth inhibition of S. obliquus. The accumulation of copper and the level of oxidative stress in algae were reduced in the presence of nano-Al₂O₃. Furthermore, lower copper accumulation was the main factor that mitigated copper toxicity with the addition of nano-Al₂O₃. The decreased copper uptake could be attributed to the adsorption of copper onto nanoparticles and the subsequent decrease of available copper in water.

  4. Metagenome changes in the mesophilic biogas-producing community during fermentation of the green alga Scenedesmus obliquus.

    Science.gov (United States)

    Wirth, Roland; Lakatos, Gergely; Böjti, Tamás; Maróti, Gergely; Bagi, Zoltán; Kis, Mihály; Kovács, Attila; Ács, Norbert; Rákhely, Gábor; Kovács, Kornél L

    2015-12-10

    A microalgal biomass offers a potential alternative to the maize silage commonly used in biogas technology. In this study, photoautotrophically grown Scenedesmus obliquus was used as biogas substrate. This microalga has a low C/N ratio of 8.5 relative to the optimum 20-30. A significant increase in the ammonium ion content was not observed. The methane content of the biogas generated from Sc. obliquus proved to be higher than that from maize silage, but the specific biogas yield was lower. Semi-continuous steady biogas production lasted for 2 months. Because of the thick cell wall of Sc. obliquus, the biomass-degrading microorganisms require additional time to digest its biomass. The methane concentration in the biogas was also high, in co-digestion (i.e., 52-56%) as in alga-fed anaerobic digestion (i.e., 55-62%). These results may be related to the relative predominance of the order Clostridiales in co-digestion and to the more balanced C/N ratio of the mixed algal-maize biomass. Predominance of the order Methanosarcinales was observed in the domain Archaea, which supported the diversity of metabolic pathways in the process. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Grundwassermodellbildung – Hydrostratigraphische Bewertungen mittels GCI-PetroKf, Datenbank- und Geoinformationssystemen

    DEFF Research Database (Denmark)

    Koch, Alexander; Fuchs, Sven; Göbel, Patricia

    reimportiert und für die Verwendung in Geoinformationssystemen (i.e. ArcGIS) weiter aufbereitet. Über Interpolationsverfahren konnte innerhalb des Programmes ArcGIS ein lateraler Bezug zwischen den verschiedenen Mächtigkeiten hergestellt werden, um so auf weitere Inhomogenitäten im Aufbau des Grundwasserleiter......-Systems schließen zu können. Anschließend wurden mittels ArcGIS die Quartärbasis des Modellraums konstruiert, sowie Grundwasserisolinien- und Grundwasserdifferenzenkarten berechnet. Die Grundwasserdifferenzenkarten reproduzieren gut die Grundwasserabsenkungen im Bereich von lokalen Tagebauen. Insgesamt zeigen sich...... gute Übereinstimmungen mit früheren hydrogeologischen Untersuchungen im Projektgebiet. Die Kombination des PetroKf-Algorithmus mit der Aufbereitung in einer Datenbank, sowie der Weiterverarbeitung in ArcGIS, zeigt einen praktikablen Weg zur Entwicklung und Parametrisierung eines hydrogeologischen...

  6. Validation of photosynthetic-fluorescence parameters as biomarkers for isoproturon toxic effect on alga Scenedesmus obliquus

    Energy Technology Data Exchange (ETDEWEB)

    Dewez, David; Didur, Olivier; Vincent-Heroux, Jonathan [University of Quebec in Montreal, Department of Chemistry, Environmental Toxicology Research Center - TOXEN, 2101, Jeanne-Mance, Montreal, Quebec H2X 2J6 (Canada); Popovic, Radovan [University of Quebec in Montreal, Department of Chemistry, Environmental Toxicology Research Center - TOXEN, 2101, Jeanne-Mance, Montreal, Quebec H2X 2J6 (Canada)], E-mail: popovic.radovan@uqam.ca

    2008-01-15

    Photosynthetic-fluorescence parameters were investigated to be used as valid biomarkers of toxicity when alga Scenedesmus obliquus was exposed to isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] effect. Chlorophyll fluorescence induction of algal cells treated with isoproturon showed inactivation of photosystem II (PSII) reaction centers and strong inhibition of PSII electron transport. A linear correlation was found (R{sup 2} {>=} 0.861) between the change of cells density affected by isoproturon and the change of effective PSII quantum yield ({phi}{sub M'}), photochemical quenching (q{sub P}) and relative photochemical quenching (q{sub P(rel)}) values. The cells density was also linearly dependent (R{sup 2} = 0.838) on the relative unquenched fluorescence parameter (UQF{sub (rel)}). Non-linear correlation was found (R{sup 2} = 0.937) only between cells density and the energy transfer efficiency from absorbed light to PSII reaction center (ABS/RC). The order of sensitivity determined by the EC-50% was: UQF{sub (rel)} > {phi}{sub M'} > q{sub P} > q{sub P(rel)} > ABS/RC. Correlations between cells density and those photosynthetic-fluorescence parameters provide supporting evidence to use them as biomarkers of toxicity for environmental pollutants. - Photosynthetic-fluorescence parameters are reliable biomarkers of isoproturon toxicity.

  7. Validation of photosynthetic-fluorescence parameters as biomarkers for isoproturon toxic effect on alga Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Dewez, David; Didur, Olivier; Vincent-Heroux, Jonathan; Popovic, Radovan

    2008-01-01

    Photosynthetic-fluorescence parameters were investigated to be used as valid biomarkers of toxicity when alga Scenedesmus obliquus was exposed to isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] effect. Chlorophyll fluorescence induction of algal cells treated with isoproturon showed inactivation of photosystem II (PSII) reaction centers and strong inhibition of PSII electron transport. A linear correlation was found (R 2 ≥ 0.861) between the change of cells density affected by isoproturon and the change of effective PSII quantum yield (Φ M' ), photochemical quenching (q P ) and relative photochemical quenching (q P(rel) ) values. The cells density was also linearly dependent (R 2 = 0.838) on the relative unquenched fluorescence parameter (UQF (rel) ). Non-linear correlation was found (R 2 = 0.937) only between cells density and the energy transfer efficiency from absorbed light to PSII reaction center (ABS/RC). The order of sensitivity determined by the EC-50% was: UQF (rel) > Φ M' > q P > q P(rel) > ABS/RC. Correlations between cells density and those photosynthetic-fluorescence parameters provide supporting evidence to use them as biomarkers of toxicity for environmental pollutants. - Photosynthetic-fluorescence parameters are reliable biomarkers of isoproturon toxicity

  8. Effect of static magnetic field on the oxygen production of Scenedesmus obliquus cultivated in municipal wastewater.

    Science.gov (United States)

    Tu, Renjie; Jin, Wenbiao; Xi, Tingting; Yang, Qian; Han, Song-Fang; Abomohra, Abd El-Fatah

    2015-12-01

    Algal-bacterial symbiotic system, with biological synergism of physiological functions of both algae and bacteria, has been proposed for cultivation of microalgae in municipal wastewater for biomass production and wastewater treatment. The algal-bacterial symbiotic system can enhance dissolved oxygen production which enhances bacterial growth and catabolism of pollutants in wastewater. Therefore, the oxygen production efficiency of microalgae in algal-bacterial systems is considered as the key factor influencing the wastewater treatment efficiency. In the present study, we have proposed a novel approach which uses static magnetic field to enhance algal growth and oxygen production rate with low operational cost and non-toxic secondary pollution. The performance of oxygen production with the magnetic field was evaluated using Scenedesmus obliquus grown in municipal wastewater and was calculated based on the change in dissolved oxygen concentration. Results indicated that magnetic treatment stimulates both algal growth and oxygen production. Application of 1000 GS of magnetic field once at logarithmic growth phase for 0.5 h increased the chlorophyll-a content by 11.5% over the control after 6 days of growth. In addition, magnetization enhanced the oxygen production rate by 24.6% over the control. Results of the study confirmed that application of a proper magnetic field could reduce the energy consumption required for aeration during the degradation of organic matter in municipal wastewater in algal-bacterial symbiotic systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Reduced graphene oxide induces cytotoxicity and inhibits photosynthetic performance of the green alga Scenedesmus obliquus.

    Science.gov (United States)

    Du, Shaoting; Zhang, Peng; Zhang, Ranran; Lu, Qi; Liu, Lin; Bao, Xiaowei; Liu, Huijun

    2016-12-01

    Increased use of graphene materials might ultimately lead to their release into the environment. However, only a few studies have investigated the impact of graphene-based materials on green plants. In this study, the impact of reduced graphene oxide (RGO) on the microalgae Scenedesmus obliquus was evaluated to determine its phytotoxicity. Treatment with RGO suppressed the growth of the microalgae. The 72-h IC 50 values of RGO evaluated using the logistic and Gompertz models were 148 and 151 mg L -1 , respectively. RGO significantly inhibited Chl a and Chl a/b levels in the algal cells. Chlorophyll a fluorescence analysis showed that RGO significantly down-regulated photosystem II activity. The mechanism of how RGO inhibited algal growth and photosynthetic performance was determined by analyzing the alterations in ultrastructural morphology. RGO adhered to the algal cell surface as a semitranslucent coating. Cell wall damage and membrane integrity loss occurred in the treated cells. Moreover, nuclear chromatin clumping and starch grain number increase were noted. These changes might be attributed to the increase in malondialdehyde and reactive oxygen species levels, which might have exceeded the scavenging ability of antioxidant enzymes (including peroxidase and superoxide dismutase). RGO impaired the extra- and intra-cellular morphology and increased oxidative stress and thus inhibited algal growth and photosynthesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Bioenergetic Strategy for the Biodegradation of p-Cresol by the Unicellular Green Alga Scenedesmus obliquus

    Science.gov (United States)

    Papazi, Aikaterini; Assimakopoulos, Konstantinos; Kotzabasis, Kiriakos

    2012-01-01

    Cultures from the unicellular green alga Scenedesmus obliquus biodegrade the toxic p-cresol (4-methylphenol) and use it as alternative carbon/energy source. The biodegradation procedure of p-cresol seems to be a two-step process. HPLC analyses indicate that the split of the methyl group (first step) that is possibly converted to methanol (increased methanol concentration in the growth medium), leading, according to our previous work, to changes in the molecular structure and function of the photosynthetic apparatus and therefore to microalgal biomass increase. The second step is the fission of the intermediately produced phenol. A higher p-cresol concentration results in a higher p-cresol biodegradation rate and a lower total p-cresol biodegradability. The first biodegradation step seems to be the most decisive for the effectiveness of the process, because methanol offers energy for the further biodegradation reactions. The absence of LHCII from the Scenedesmus mutant wt-lhc stopped the methanol effect and significantly reduced the p-cresol biodegradation (only 9%). The present contribution deals with an energy distribution between microalgal growth and p-cresol biodegradation, activated by p-cresol concentration. The simultaneous biomass increase with the detoxification of a toxic phenolic compound (p-cresol) could be a significant biotechnological aspect for further applications. PMID:23251641

  11. Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

    Science.gov (United States)

    Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

    2012-11-30

    This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Effects of imidazolium chloride ionic liquids and their toxicity to Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Huijun; Zhang, Xiaoqiang; Chen, Caidong; Du, Shaoting; Dong, Ying

    2015-12-01

    The low volatility of ionic liquids effectively eliminates a major pathway for environmental release and contamination; however, the good solubility, low degree of environmental degradation and biodegradation of ILs may pose a potential threat to the aquatic environment. The growth inhibition of the green alga Scenedesmus obliquus by five 1-alkyl-3-methylimidazolium chloride ionic liquids (ILs) ([Cnmim]Cl, n=6, 8, 10, 12, 16) was investigated, and the effect on cellular membrane permeability and the ultrastructural morphology by ILs ([Cnmim]Cl, n=8, 12, 16) were studied. The results showed that the growth inhibition rate increased with increasing IL concentration and increasing alkyl chain lengths. The relative toxicity was determined to be [C6mim]Cl<[C8mim]Cl<[C10mim]Cl<[C12mim]Cl<[C16mim]Cl. The algae were most sensitive to imidazolium chloride ILs at 48 h according to the results from the growth inhibition rate and cellular membrane permeability tests. The ultrastructural morphology showed that the ILs had negative effects on the cellular morphology and structure of the algae. The cell wall of treated algae became wavy and separated from the cell membrane. Chloroplast grana lamellae became obscure and loose, osmiophilic material was deposited in the chloroplast, and mitochondria and their cristae swelled. Additionally, electron-dense deposits were observed in the vacuoles. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. The ghost of herbivory past: slow defence relaxation in the chlorophyte Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    Jacobus VIJVERBERG

    2009-08-01

    Full Text Available The freshwater chlorophyte Scenedesmus obliquus (Turpin Kützing produces colonies as an inducible defence against herbivores. We investigated the dynamics of Scenedesmus colony formation and disintegration in response to the density of the herbivorous rotifer Brachionus calyciflorus in large-scale mesocosms. Additional bioassays were performed to investigate Scenedesmus colony disintegration under different light regimes. In the mesocosm experiment, colony formation took place rapidly, but relaxation towards the initial size took relatively long (>10 d after cessation of herbivory. In the bioassays, in the absence of infochemicals, colonies disintegrated almost immediately in the dark (1-1.5 d, within 4 d under a photoperiod of 16:8 (L:D and between 8 and 12 days under full light. Colony disintegration times in the mesocosm experiment were substantially longer as compared to treatments with the same photoperiod (L:D 16:8 in the bioassays. So after a peak of herbivory, the 'ghost of herbivory past', i.e. the remaining infochemicals, may continue to induce colony formation, causing an additional lengthening of colony disintegration times and associated fitness costs (higher sedimentation loss rates. This indicates that costs of colony formation are not only important during the induction phase, but may be even more important during the relaxation phase. We compared these sedimentation costs to the costs of herbivory for differently sized Scenedesmus, and found a clear trade-off pattern for these costs.

  14. Bioethanol production from Scenedesmus obliquus sugars. The influence of photobioreactors and culture conditions on biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, J.R.; Passarinho, P.C.; Gouveia, L. [Laboratorio Nacional de Energia e Geologia (LNEG), Lisbon (Portugal). Unidade de Bioenergia

    2012-10-15

    A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L. (orig.)

  15. Bioethanol production from Scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.

    Science.gov (United States)

    Miranda, J R; Passarinho, P C; Gouveia, L

    2012-10-01

    A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L.

  16. Oxyfluorfen toxic effect on S. obliquus evaluated by different photosynthetic and enzymatic biomarkers.

    Science.gov (United States)

    Geoffroy, L; Dewez, D; Vernet, G; Popovic, R

    2003-11-01

    The effect of oxyfluorfen was investigated when alga Scenedesmus obliquus has been exposed to different concentrations (7.5, 15, and 22.5 microg x L(-1)) at 12, 24, and 48 hours of exposure. Toxicity test was done by using 13 biomarkers concerning growth rate, chlorophyll content and indicators of photosynthetic and antioxidant enzyme activities. The change of the 13 parameters showed a great variation of sensitivity indicating differences in parameters' suitability to be used as biomarkers when alga culture was exposed to oxyfluorfen toxicity. The order of sensitivity between those biomarkers was: Antenna size (ABS/RC) > Chlorophyll content > Catalase (CAT) > Operational PSII quantum yield (phiS(PSII)) > Glutathione S-transferase (GST) > Functional plastoquinone pool (Q(PQ)) > Glutathione reductase (GR) > Growth rate > Nonphotochemical quenching (QN) > Proton gradient quenching (Q(Emax)) > Ascorbate peroxidase (APX) > Photochemical quenching (Q(p)) > Maximum PSII quantum yield (Phi(PSII)). The effect of oxyfluorfen on the changes of those parameters was interpreted as a result of herbicide mode of action at molecular level of alga cellular system. This study indicated for some photosynthetic and enzymatic biomarkers to be useful indicators of toxicity effect induced in non-target alga species. Determination of biomarkers' sensitivity order may facilitate their selection to be used in environmental risk assessment of polluted water.

  17. Effect of phosphorus on biodiesel production from Scenedesmus obliquus under nitrogen-deficiency stress.

    Science.gov (United States)

    Chu, Fei-Fei; Chu, Pei-Na; Shen, Xiao-Fei; Lam, Paul K S; Zeng, Raymond J

    2014-01-01

    In order to study the effect of phosphorus on biodiesel production from Scenedesmus obliquus especially under nitrogen deficiency conditions, six types of media with combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion were investigated in this study. It was found that nitrogen starvation compared to nitrogen repletion enhanced biodiesel productivity. Moreover, biodiesel productivity was further strengthened by varying the supply level of phosphorus from depletion, limitation, through to repletion. The maximum FAMEs productivity of 24.2 mg/L/day was obtained in nitrogen depletion with phosphorus repletion, which was two times higher than that in nutrient complete medium. More phosphorus was accumulated in cells under the nitrogen starvation with sufficient phosphorus condition, but no polyphosphate was formed. This study indicated that nitrogen starvation plus sufficient P supply might be the real "lipid trigger". Furthermore, results of the current study suggest a potential application for utilizing microalgae to combine phosphorus removal from wastewater with biodiesel production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Validation of photosynthetic-fluorescence parameters as biomarkers for isoproturon toxic effect on alga Scenedesmus obliquus.

    Science.gov (United States)

    Dewez, David; Didur, Olivier; Vincent-Héroux, Jonathan; Popovic, Radovan

    2008-01-01

    Photosynthetic-fluorescence parameters were investigated to be used as valid biomarkers of toxicity when alga Scenedesmus obliquus was exposed to isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] effect. Chlorophyll fluorescence induction of algal cells treated with isoproturon showed inactivation of photosystem II (PSII) reaction centers and strong inhibition of PSII electron transport. A linear correlation was found (R2>or=0.861) between the change of cells density affected by isoproturon and the change of effective PSII quantum yield (PhiM'), photochemical quenching (qP) and relative photochemical quenching (qP(rel)) values. The cells density was also linearly dependent (R2=0.838) on the relative unquenched fluorescence parameter (UQF(rel)). Non-linear correlation was found (R2=0.937) only between cells density and the energy transfer efficiency from absorbed light to PSII reaction center (ABS/RC). The order of sensitivity determined by the EC-50% was: UQF(rel)>PhiM'>qP>qP(rel)>ABS/RC. Correlations between cells density and those photosynthetic-fluorescence parameters provide supporting evidence to use them as biomarkers of toxicity for environmental pollutants.

  19. Aneurysmatic dissection of an aberrant right subclavian artery; Disseziierendes Aneurysma einer aberranten Arteria subclavia dextra: Diagnose mittels Ultrafast-CT

    Energy Technology Data Exchange (ETDEWEB)

    Reittner, P. [Universitaetsklinik fuer Radiologie, Graz (Austria). Abt. fuer Allgemeine Radiologie; Stacher, R. [Universitaetsklinik fuer Radiologie, Graz (Austria). Abt. fuer Allgemeine Radiologie

    1996-01-01

    Diagnosis with Ultrafast-CT: An aneurysm of an aberrant right subclavian artery is a very rare cause for dysphagia. We describe such a case in a 67-year-old patient, diagnosed with Ultrafast-CT and discuss it together in concert with the embryology and the radiological findings. (orig.) [Deutsch] Eine aberrierende Arteria subclavia dextra ist eine seltene Ursache fuer Dysphagie. Anhand eines 67jaehrigen Patienten werden Embryologie und radiologische Charakteristika, diagnostiziert mittels Ultrafast-CT, diskutiert. (orig.)

  20. Effect of ionic liquids with different cations and anions on photosystem and cell structure of Scenedesmus obliquus.

    Science.gov (United States)

    Xia, Yilu; Liu, Dingdong; Dong, Ying; Chen, Jiazheng; Liu, Huijun

    2018-03-01

    The rapid increase in the production and practical application of ionic liquids (ILs) could pose potential threats to aquatic systems. In this study, we investigated the effects of four ILs with different cations and anions, including 1-hexyl-3-methylimidazolium nitrate ([HMIM]NO 3 ), 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl), N-hexyl-3-metylpyridinium chloride ([HMPy]Cl), and N-hexyl-3-metylpyridinium bromide ([HMPy]Br), on photosystem and cellular structure of Scenedesmus obliquus. The results indicated that ILs are phytotoxic to S. obliquus. The contents of chlorophyll a, chlorophyll b and total chlorophyll decreased with increasing ILs concentrations. The chlorophyll fluorescence parameters of photosynthetic system II (PSII), including minimal fluorescence yield (F 0 ), potential efficiency of PSII (F v /F o ), maximum quantum efficiency of PSII photochemistry (F v /F m ), yield of photochemical quantum [Y(II)], and non-photochemical quenching coefficient without measuring F 0 ' (NPQ), were all affected. This indicates that ILs could damage PSII, inhibit the primary reaction of photosynthesis, interdict the process of electron-transfer and lead to loss of heat-dissipating ability. ILs also increased cell membrane permeability of S. obliquus, influenced the cellular ultrastructure, changed the morphology of algae cells and destroyed the cell wall, cell membrane and organelles. The results indicated that imidazolium ILs had greater effect than pyridinium ILs, NO 3 - -IL and Br - -IL had greater effect than Cl - -IL. To minimize threats to the environment, the structure of ILs should be taken into consideration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Plutonium uptake by the green alga Scenedesmus obliquus (Turp) Kutz, as a function of isotope and oxidation state

    Energy Technology Data Exchange (ETDEWEB)

    Tkacik, M.F.

    1977-01-01

    This study was designed to determine the effect of plutonium chemical valence state on the availability of small concentrations of /sup 238/Pu and /sup 239/Pu to algae. The uptake experiments involved the green alga Scenedesmus obliquus, grown in batch cultures. Plutonium concentrations accumulated by this alga were linearly related to plutonium concentrations. There was no significant difference (rho = 0.05) in algal plutonium accumulations, on a mass basis, of either /sup 238/Pu or /sup 239/Pu in either Pu/sup +4/ or Pu/sup +6/ oxidation state at the concentrations studied.

  2. Plutonium uptake by the green alga Scenedesmus obliquus (Turp) Kutz, as a function of isotope and oxidation state

    International Nuclear Information System (INIS)

    Tkacik, M.F.

    1977-01-01

    This study was designed to determine the effect of plutonium chemical valence state on the availability of small concentrations of 238 Pu and 239 Pu to algae. The uptake experiments involved the green alga Scenedesmus obliquus, grown in batch cultures. Plutonium concentrations accumulated by this alga were linearly related to plutonium concentrations. There was no significant difference (rho = 0.05) in algal plutonium accumulations, on a mass basis, of either 238 Pu or 239 Pu in either Pu +4 or Pu +6 oxidation state at the concentrations studied

  3. Removal of pharmaceutical pollutants from synthetic wastewater using chemically modified biomass of green alga Scenedesmus obliquus.

    Science.gov (United States)

    Ali, Mohamed E M; Abd El-Aty, Azza M; Badawy, Mohamed I; Ali, Rizka K

    2018-04-30

    Pharmaceutical compounds are considered emerging environmental pollutants that have a potential harmful impact on environment and human health. In this study, the biomass of alga (Scenedesmus obliquus) was modified using alkaline solution, and used for the biosorption of tramadol (TRAM) and other pharmaceuticals. The adsorption kinetics and isotherms were investigated. The obtained results reveal high adsorption capacity of tramadol over modified algal biomass (MAB) after 45min with removal percentage of 91%. Pseudo-second order model was well fitted with the experimental data with correlation coefficient (0.999). Biosorption of tramadol on modified algal biomass proceeds with Freundlich isotherm model with correlation coefficient (0.942) that emphasized uptake of TRAM by MAB is driven by chemisorption. FTIR spectra of MAB before and after the adsorption were analyzed; some IR bands were detected with slight shift and low intensity suggesting their involving in adsorption. The tramadol biosorption by MAB is a chemical process as confirmed by Dubinin-Radushkevich. The adsorption of pharmaceutical over MAB is mainly preceded by hydrophilic interactions between amino and carbonyl groups in pharmaceutical molecules and hydroxyl and carbonyl functional groups on surface of biosorbent. It was emphasized by disappearance O-H and C-O from biomass IR spectra after adsorption. In matrix of pharmaceutical, the recorded adsorption capacities for CEFA, PARA, IBU, TRAM and CIP are 68, 58, 42, 42 and 39mg/g over MAB at natural pH and MAB dose of 0.5g/L. Furthermore, oxygen uptake by bacteria was applied for estimate the toxicity of pharmaceutical. The recorded result concluded the efficient reusability of modified algal biomass for biosorption of pharmaceuticals, as well only the adsorption efficiency decreased by 4.5% after three runs. Subsequently, the modified algal biomass is a promising reusable adsorbent for decontamination of wastewater from pharmaceuticals. Copyright

  4. Uptake and effect of highly fluorescent silver nanoclusters on Scenedesmus obliquus.

    Science.gov (United States)

    Zhang, Li; He, Yiliang; Goswami, Nirmal; Xie, Jianping; Zhang, Bo; Tao, Xianji

    2016-06-01

    The release of silver nanoparticles (Ag NPs) in aquatic environment has caused wide public concern about their effects on living organisms (e.g., algae). However, how these small NPs exert cytotoxicity in the living organisms has always been under heated debate. In this study, the uptake and toxicity effects of strongly red-emitting fluorescent silver nanoclusters (r-Ag NCs) exposed to the green algae Scenedesmus obliquus was investigated. Upon exposure to pure r-Ag NCs and r-Ag NCs containing l-cysteine, the algae growth inhibition test showed that Ag(+) ions released from r-Ag NCs played an important role in the toxicity of r-Ag NCs along with the toxicity of intact r-Ag NCs. Furthermore, no signals of intracellular reactive oxygen species (ROS) were observed indicating that r-Ag NCs or released Ag(+) ions - mediated growth inhibition of algae cells was independent of ROS production. Transmission electron microscopy (TEM) and laser scanning confocal microscopy (LSCM) were employed to study cellular uptake and cytotoxicity. Furthermore, analysis of differential expressed gene demonstrated that r-Ag NCs as well as the released Ag(+) ions can simultaneously exist inside the algae cells, and inhibit the transcriptomic process of genes by their "joint-toxicity" mechanism. Taken together, our study provides a new insight into the molecular mechanisms of r-Ag NCs and Ag(+) ions exposure to the aquatic organism and can be applied to early diagnosis of ecologic risk mediated by others metal-based NPs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Effects of an anionic surfactant (FFD-6) on the energy and information flow between a primary producer (Scenedesmus obliquus) and a consumer (Daphnia magna)

    NARCIS (Netherlands)

    Lürling, M.; de Lange, H.J.; Peeters, E.T.H.M.

    2011-01-01

    The effects of a commercially available anionic surfactant solution (FFD-6) on growth and morphology of a common green alga (Scenedesmus obliquus) and on survival and clearance rates of the water flea Daphnia magna were studied. The surfactant-solution elicited a morphological response (formation of

  6. Synthese von analogen Filtern auf einer rekonfigurierbaren Hardware-Architektur mittels eines Genetischen Algorithmus

    Directory of Open Access Journals (Sweden)

    S. Trendelenburg

    2008-05-01

    Full Text Available Rekonfigurierbare Analog-Arrays (FPAAs sind der Versuch, die Vorteile der aus der digitalen Welt bekannten FPGAs (Flexibilität, Entwurfsgeschwindigkeit auch für analoge Anwendungen verfügbar zu machen. Aufgrund der Vielfalt der analogen Schaltungstechnik ist die Abbildung von vorgegebenen Schaltungskonzepten auf eine FPAA-Architektur nicht immer einfach lösbar.

    Diese Arbeit stellt einen neuen Ansatz für die Synthese von Filtern auf einer FPAA-Architektur für zeitkontinuierliche Analogfilter mittels eines Genetischen Algorithmus (GA vor. Anhand eines Matlab-Modells des FPAA, das eine gute übereinstimmung mit Simulationen des FPAA auf Transistorebene aufweist, wurde gezeigt, dass eine große Vielzahl verschiedener Filterstrukturen auf dieser Architektur dargestellt werden kann. Daraufhin wurde ein Genetischer Algorithmus entwickelt, der es erlaubt, aus einer gegebenen Filterspezifikation Konfigurationsdatensätze zu synthetisieren, die den gewünschten Filter auf die FPAA-Architektur abbilden.

  7. Inhibitory and Acceleratory Effects of Inonotus obliquus on Tyrosinase Activity and Melanin Formation in B16 Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Zheng-Fei Yan

    2014-01-01

    Full Text Available The aim of the present study is to preliminarily investigate the antimelanogenesis effect of Inonotus obliquus extracts by cell-free mushroom tyrosinase assay. It was found that petroleum ether and n-butanol extracts might contain unknown potential tyrosinase inhibitors, while its ethyl acetate extract might contain some unknown accelerators. Six compounds were isolated and their structures were identified by interpretation of NMR data and nicotinic acid was first discovered in Inonotus obliquus. In cells testing, betulin and trametenolic acid decreased tyrosinase activity and melanin content, while inotodiol and lanosterol significantly increased tyrosinase activity and melanin content, showing an AC⁡50 of 9.74 and 8.43 μM, respectively. Nicotinie acid, 3β,22,25-trihydroxy-lanosta-8-ene, had a little or no effect on tyrosinase. Betulin exhibited a mode of noncompetitive inhibition with a KI=KIS of 0.4 μM on tyrosinase activity showing an IC50 of 5.13 μM and being more effective than kojic acid (6.43 μM, and trametenolic acid exhibited a mode of mixed inhibition with a KI of 0.9 μM, KIS of 0.5 μM, and an IC50 of 7.25 μM. We proposed betulin and trametenolic acid as a new candidate of potent tyrosinase inhibitors and inotodiol and lanosterol as accelerators that could be used as therapeutic agent.

  8. A MULTISTAGE GRADUAL NITROGENREDUCTION STRATEGY FOR INCREASED LIPID PRODUCTIVITY AND NITROGEN REMOVAL IN WASTEWATER USING Chlorella vulgaris AND Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    J. C. Robles-Heredia

    2015-06-01

    Full Text Available AbstractChlorella vulgaris and Scenedesmus obliquuswere grown in artificial-wastewater using a new nitrogen-limitation strategy aimed at increasing lipid productivity. This strategy consisted in a multi-stage process with sequential reduction of N-NH4 concentration (from 90 to 60, 40, and 20 mg.L-1 to promote a balance between cell growth and lipid accumulation. Lipid productivity was compared against a reference process consisting of nitrogen reduction in two stages, where the nitrogen concentration was suddenly reduced from 90 mg.L-1 to three different concentrations (10, 20, and 30 mg.L-1. In the multi-stage mode, only C. vulgaris exhibited a net lipid-productivity increase. Lipid content of S. obliquus did not present a significant increase, thus decreasing lipid productivity. The highest lipid productivities were observed in the two-stage mode for both S. obliquus and C. vulgaris (194.9 and 133.5 mg.L-1.d-1, respectively, and these values are among the highest reported in the literature to date.

  9. 1H NMR studies of plastocyanin from Scenedesmus obliquus: Complete sequence-specific assignment, secondary structure analysis, and global fold

    International Nuclear Information System (INIS)

    Moore, J.M.; Chazin, W.J.; Wright, P.E.; Powls, R.

    1988-01-01

    Two-dimensional 1 H NMR methods have been used to make sequence-specific resonance assignments for the 97 amino acid residues of the plastocyanin from the green alga Scenedesmus obliquus. Assignments were obtained for all backbone protons and the majority of the side-chain protons. Spin system identification relied heavily on the observation of relayed connectivities to the backbone amide proton. Sequence-specific assignments were made by using the sequential assignment procedure. During this process, an extra valine residue was identified that had not been detected in the original amino acid sequence. Elements of regular secondary structure were identified from characteristic NOE connectivities between backbone protons, coupling constant values, and the observation of slowly exchanging amide protons. The protein in solution contains eight β-strands, one short segment of helix, five reverse turns, and five loops. The β-strands may be arranged into two βsheets on the basis of extensive cross-strand NOE connectivities. The chain-folding topology determined from the NMR experiments is that of a Greek key β-barrel and is similar to that observed for French bean plastocyanin in solution and poplar plastocyanin in the crystalline state. While the overall structures are similar, several differences in local structure between the S. obliquus and higher plant plastocyanins have been identified

  10. Photosynthesis of Scenedesmus obliquus in outdoor open thin-layer cascade system in high and low CO2 in Belgium.

    Science.gov (United States)

    de Marchin, Thomas; Erpicum, Michel; Franck, Fabrice

    2015-12-10

    Two outdoor open thin-layer cascade systems operated as batch cultures with the alga Scenedesmus obliquus were used to compare the productivity and photosynthetic acclimations in control and CO2 supplemented cultures in relation with the outdoor light irradiance. We found that the culture productivity was limited by CO2 availability. In the CO2 supplemented culture, we obtained a productivity of up to 24gdwm(-2)day(-1) and found a photosynthetic efficiency (value based on the PAR solar radiation energy) of up to 5%. In the CO2 limited culture, we obtained a productivity of up to 10gdwm(-2)day(-1) while the photosynthetic efficiency was up to 3.3% and decreased to 2.1% when the integrated daily PAR increased. Fluorescence and oxygen evolution measurements showed that ETR and oxygen evolution light saturation curves, as well as light-dependent O2 uptake were similar in algal samples from both cultures when the CO2 limitation was removed. In contrast, we found that CO2 limitation conducted to a decreased PSII photochemical efficiency and an increased light-induced heat-dissipation in the control culture compared to the CO2 supplemented culture. These features are in line with a lower light use efficiency and may therefore contribute to the lower productivity observed in absence of CO2 supplementation in outdoor mass cultures of S. obliquus. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. High Yields of Hydrogen Production Induced by Meta-Substituted Dichlorophenols Biodegradation from the Green Alga Scenedesmus obliquus

    Science.gov (United States)

    Papazi, Aikaterini; Andronis, Efthimios; Ioannidis, Nikolaos E.; Chaniotakis, Nikolaos; Kotzabasis, Kiriakos

    2012-01-01

    Hydrogen is a highly promising energy source with important social and economic implications. The ability of green algae to produce photosynthetic hydrogen under anaerobic conditions has been known for years. However, until today the yield of production has been very low, limiting an industrial scale use. In the present paper, 73 years after the first report on H2-production from green algae, we present a combinational biological system where the biodegradation procedure of one meta-substituted dichlorophenol (m-dcp) is the key element for maintaining continuous and high rate H2-production (>100 times higher than previously reported) in chloroplasts and mitochondria of the green alga Scenedesmus obliquus. In particular, we report that reduced m-dcps (biodegradation intermediates) mimic endogenous electron and proton carriers in chloroplasts and mitochondria, inhibit Photosystem II (PSII) activity (and therefore O2 production) and enhance Photosystem I (PSI) and hydrogenase activity. In addition, we show that there are some indications for hydrogen production from sources other than chloroplasts in Scenedesmus obliquus. The regulation of these multistage and highly evolved redox pathways leads to high yields of hydrogen production and paves the way for an efficient application to industrial scale use, utilizing simple energy sources and one meta-substituted dichlorophenol as regulating elements. PMID:23145057

  12. Determination of photosynthetic and enzymatic biomarkers sensitivity used to evaluate toxic effects of copper and fludioxonil in alga Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Dewez, David; Geoffroy, Laure; Vernet, Guy; Popovic, Radovan

    2005-01-01

    Modulated PAM fluorometry and Plant Efficiency Analyser methods were used to investigate photosynthetic fluorescence parameters of alga Scenedesmus obliquus exposed to inhibitory effect of fungicides copper sulphate and fludioxonil (N-(4-nitrophenyl)-N'-propyl-uree). The change of those parameters were studied when alga S. obliquus have been exposed during 48 h to different concentrations of fungicides (1, 2 and 3 mg l -1 ). Under the same condition, enzymatic activities of catalase, ascorbate peroxidase, glutathione reductase and glutathione S-transferase were investigated to evaluate antioxidative response to fungicides effects. The change of sensitivity of those parameters was dependent to the mode of fungicide action, their concentration and time of exposure. For copper effects, the most indicative photosynthetic biomarkers were parameters Q N as non-photochemical fluorescence quenching, Q Emax as the proton induced fluorescence quenching and ABS/RC as the antenna size per photosystem II reaction center. Copper induced oxidative stress was indicated by increased activity of catalase serving as the most sensitive and valuable enzymatic biomarker. On the other hand, fludioxonil effect on photosynthetic parameters was very negligible and consequently not very useful as biomarkers. However, fludioxonil induced strong antioxidative activities associated with cytosol enzymes, as we found for catalase, ascorbate peroxidase and glutathione S-transferase activities. By obtained results, we may suggest for the activation of those enzymes to be sensitive and valuable biomarkers of oxidative stress induced by fludioxonil. Determination of biomarkers sensitivity may offer advantages in providing real criteria to use them for ecotoxicological diagnostic studies

  13. “Rational” Management of Dichlorophenols Biodegradation by the Microalga Scenedesmus obliquus

    Science.gov (United States)

    Papazi, Aikaterini; Kotzabasis, Kiriakos

    2013-01-01

    The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp – no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp – one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp – two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as “smart” bioenergetic “machines”, that have the ability to continuously “calculate” the energy reserves and

  14. Altheim geothermal plant. Power generation by means of an ORC turbogenerator; Geothermieanlagen Altheim. Stromerzeugung mittels Organic-Rankine-Cycle Turbogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Pernecker, G [Marktgemeindeamt Altheim (Austria)

    1997-12-01

    The report describes the project of the Austrian market town of Altheim to generate electricity by means of an ORC turbogenerator using low-temperature thermal water. The project is to improve the technical and economic situation of the existing industrial-scale geothermal project. (orig.) [Deutsch] Der Bericht beschreibt das Vorhaben der Marktgemeinde Altheim in Oberoesterreich, Strom mittels eines Organic-Rankine-Cycle-Turbogenerators unter Verwendung niedrig temperierten Thermalwassers zu produzieren. Ziel bzw. der Zweck des Projektes ist es, die technische und wirtschaftliche Situation der bestehenden Grossthermieanlage zu verbessern. (orig.)

  15. Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP on HFD/STZ-Induced Nephropathy in Mice

    Directory of Open Access Journals (Sweden)

    Yen-Jung Chou

    2016-09-01

    Full Text Available Diabetic nephropathy (DN is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM. Inonotus obliquus (IO is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP, from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg had progressively increased their sensitivity to glucose (less insulin tolerance, reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1, while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

  16. Effects of nitrogen source availability and bioreactor operating strategies on lutein production with Scenedesmus obliquus FSP-3.

    Science.gov (United States)

    Ho, Shih-Hsin; Xie, Youping; Chan, Ming-Chang; Liu, Chen-Chun; Chen, Chun-Yen; Lee, Duu-Jong; Huang, Chieh-Chen; Chang, Jo-Shu

    2015-05-01

    In this study, the effects of the type and concentration of nitrogen sources on the cell growth and lutein content of an isolated microalga Scenedesmus obliquus FSP-3 were investigated. With batch culture, the highest lutein content (4.61 mg/g) and lutein productivity (4.35 mg/L/day) were obtained when using 8.0 mM calcium nitrate as the nitrogen source. With this best nitrogen source condition, the microalgae cultivation was performed using two bioreactor strategies (namely, semi-continuous and two-stage operations) to further enhance the lutein content and productivity. Using semi-continuous operation with a 10% medium replacement ratio could obtain the highest biomass productivity (1304.8 mg/L/day) and lutein productivity (6.01 mg/L/day). This performance is better than most related studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Effect of subcellular distribution on nC₆₀ uptake and transfer efficiency from Scenedesmus obliquus to Daphnia magna.

    Science.gov (United States)

    Chen, Qiqing; Hu, Xialin; Yin, Daqiang; Wang, Rui

    2016-06-01

    The potential uptake and trophic transfer ability of nanoparticles (NPs) in aquatic organisms have not been well understood yet. There has been an increasing awareness of the subcellular fate of NPs in organisms, but how the subcellular distribution of NPs subsequently affects the trophic transfer to predator remains to be answered. In the present study, the food chain from Scenedesmus obliquus to Daphnia magna was established to simulate the trophic transfer of fullerene aqueous suspension (nC60). The nC60 contaminated algae were separated into three fractions: cell wall (CW), cell organelle (CO), and cell membrane (CM) fractions, and we investigated the nC60 uptake amounts and trophic transfer efficiency to the predator through dietary exposure to algae or algal subcellular fractions. The nC60 distribution in CW fraction of S. obliquus was the highest, following by CO and CM fractions. nC60 uptake amounts in D. magna were found to be mainly relative to the NPs' distribution in CW fraction and daphnia uptake ability from CW fraction, whereas the nC60 trophic transfer efficiency (TE) were mainly in accordance with the transfer ability of NPs from the CO fraction. CW fed group possessed the highest uptake amount, followed by CO and CM fed groups, but the presence of humic acid (HA) significantly decreased the nC60 uptake from CW fed group. The CO fed groups acquired high TE values for nC60, while CM fed groups had low TE values. Moreover, even though CW fed group had a high TE value; it decreased significantly with the presence of HA. This study contributes to the understanding of fullerene NPs' dietary exposure to aquatic organisms, suggesting that NPs in different food forms are not necessarily equally trophically available to the predator. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Determination of photosynthetic and enzymatic biomarkers sensitivity used to evaluate toxic effects of copper and fludioxonil in alga Scenedesmus obliquus

    Energy Technology Data Exchange (ETDEWEB)

    Dewez, David [Departement de Chimie et de Biochimie, Centre TOXEN, Universite du Quebec a Montreal, CP 8888, Succursale Centre-Ville, Montreal, Quebec, H3C 3P8 (Canada); Geoffroy, Laure [Laboratoire d' Eco-Toxicologie, Unite de recherche ' Vignes et Vins de Champagne' , UPRES-EA 2069, Universite de Reims Champagne-Ardenne BP 1039, F51687 REIMS CEDEX 2 (France); Vernet, Guy [Laboratoire d' Eco-Toxicologie, Unite de recherche ' Vignes et Vins de Champagne' , UPRES-EA 2069, Universite de Reims Champagne-Ardenne BP 1039, F51687 REIMS CEDEX 2 (France); Popovic, Radovan [Departement de Chimie et de Biochimie, Centre TOXEN, Universite du Quebec a Montreal, CP 8888, Succursale Centre-Ville, Montreal, Quebec, H3C 3P8 (Canada)]. E-mail: popovic.radovan@uqam.ca

    2005-08-30

    Modulated PAM fluorometry and Plant Efficiency Analyser methods were used to investigate photosynthetic fluorescence parameters of alga Scenedesmus obliquus exposed to inhibitory effect of fungicides copper sulphate and fludioxonil (N-(4-nitrophenyl)-N'-propyl-uree). The change of those parameters were studied when alga S. obliquus have been exposed during 48 h to different concentrations of fungicides (1, 2 and 3 mg l{sup -1}). Under the same condition, enzymatic activities of catalase, ascorbate peroxidase, glutathione reductase and glutathione S-transferase were investigated to evaluate antioxidative response to fungicides effects. The change of sensitivity of those parameters was dependent to the mode of fungicide action, their concentration and time of exposure. For copper effects, the most indicative photosynthetic biomarkers were parameters Q {sub N} as non-photochemical fluorescence quenching, Q {sub Emax} as the proton induced fluorescence quenching and ABS/RC as the antenna size per photosystem II reaction center. Copper induced oxidative stress was indicated by increased activity of catalase serving as the most sensitive and valuable enzymatic biomarker. On the other hand, fludioxonil effect on photosynthetic parameters was very negligible and consequently not very useful as biomarkers. However, fludioxonil induced strong antioxidative activities associated with cytosol enzymes, as we found for catalase, ascorbate peroxidase and glutathione S-transferase activities. By obtained results, we may suggest for the activation of those enzymes to be sensitive and valuable biomarkers of oxidative stress induced by fludioxonil. Determination of biomarkers sensitivity may offer advantages in providing real criteria to use them for ecotoxicological diagnostic studies.

  19. In vitro antitumor activity and structure characterization of ethanol extracts from wild and cultivated Chaga medicinal mushroom, Inonotus obliquus (Pers.:Fr.) Pilát (Aphyllophoromycetideae).

    Science.gov (United States)

    Sun, Yong; Yin, Ting; Chen, Xian-Hui; Zhang, Gong; Curtis, Rempel B; Lu, Zhan-Hui; Jiang, Ji-Hong

    2011-01-01

    Inonotus obliquus (Pers.:Fr.) Pilát has been traditionally used as a folk remedy for treatment of cancers, cardiovascular disease and diabetes in Russia, Poland, and most of the Baltic countries, but natural reserves of this fungus have nearly been exhausted. This study was designed to investigate the artificial cultivation of I. obliquus and the antitumor activity of its tissues. The ethanol extract of cultivated sclerotium had the highest cell growth inhibitory rate (74.6%) as determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 78% of the bags produced sclerotia and only 6.17 g/bag of sclerotium was obtained. Extracts of the cultivated fruiting body showed 44.2% inhibitory activity against tumor cells. However, the yield was as high as 18.24 g/bag, and 98% of the bags produced fruiting body. The results of gas chromatography-mass spectroscopy (GC-MS) showed that similar compounds were extracted from the wild and cultivated samples. The principal compounds observed were lanosterol, inotodiol, and ergosterol. Their percentages of the mass fraction were 86.1, 59.9, and 71.8% of the total, for the wild sclerotium, cultivated sclerotium, and cultivated fruiting body, respectively. Ergosterol was found to be much higher (27.32%) in cultivated fruiting body. We conclude that cultivated fruiting body of I. obliquus obtained by inoculation of the substrate with spawn mycelium of the fifth generation could serve as an ideal substitute for the wild I. obliquus.

  20. Mixotrophic cultivation of a microalga Scenedesmus obliquus in municipal wastewater supplemented with food wastewater and flue gas CO2 for biomass production.

    Science.gov (United States)

    Ji, Min-Kyu; Yun, Hyun-Shik; Park, Young-Tae; Kabra, Akhil N; Oh, In-Hwan; Choi, Jaeyoung

    2015-08-15

    The biomass and lipid/carbohydrate production by a green microalga Scenedesmus obliquus under mixotrophic condition using food wastewater and flue gas CO2 with municipal wastewater was investigated. Different dilution ratios (0.5-2%) of municipal wastewater with food wastewater were evaluated in the presence of 5, 10 and 14.1% CO2. The food wastewater (0.5-1%) with 10-14.1% CO2 supported the highest growth (0.42-0.44 g L(-1)), nutrient removal (21-22 mg TN L(-1)), lipid productivity (10-11 mg L(-1)day(-1)) and carbohydrate productivity (13-16 mg L(-1)day(-1)) by S. obliquus after 6 days of cultivation. Food wastewater increased the palmitic and oleic acid contents up to 8 and 6%, respectively. Thus, application of food wastewater and flue gas CO2 can be employed for enhancement of growth, lipid/carbohydrate productivity and wastewater treatment efficiency of S. obliquus under mixotrophic condition, which can lead to development of a cost effective strategy for microalgal biomass production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Investigation of Inonotus obliquus (Pers. Pil. Extracts and Melanins after RF-plasma Treatment of Raw Material

    Directory of Open Access Journals (Sweden)

    O.Yu. Kuznetsova

    2016-03-01

    Full Text Available High-frequency capacitive discharge (RF plasma at low pressure was used as preliminary stage for the intensification of extraction from natural medicinal raw material. RF-plasma treatment was carried out in two modes differed by the nature of plasma-forming gas. Chaga (Inonotus obliquus (Pers. Pil. known as the birch mushroom was selected as a perspective source of raw material. Extraction was carried out in two ways – remaceration and maceration. The analy-sis of chaga extracts and melanins was performed using traditional techniques including determination of physical and chemical, antioxidant and spectral characteristics. The obtained extracts and melanins were compared to the control samples and literature data. RF-plasma treatment of medicinal raw material increased the yield of extractive substances, in particular of the main active component of chaga – melanin. The antioxidant activity of chaga extracts grew, while for melanins it remained at the level similar to that of control samples. The IR spectral characteristics of the studied chaga melanins are similar and agree well with the literature data. Insignificant deviations in the position and intensity of absorption strips were observed for the samples after RF treatment. IR spectra of the studied chaga melanins are similar to those for mushroom melanins, thereby confirming the similarity in their nature. RF-plasma treatment of chaga medicinal raw materials allows to modify them partially. The structural and mechanical properties of melanins modified by RF plasma remain the same.

  2. Influence of light presence and biomass concentration on nutrient kinetic removal from urban wastewater by Scenedesmus obliquus.

    Science.gov (United States)

    Ruiz, J; Arbib, Z; Alvarez-Díaz, P D; Garrido-Pérez, C; Barragán, J; Perales, J A

    2014-05-20

    This work was aimed at studying the effect of light-darkness and high-low biomass concentrations in the feasibility of removing nitrogen and phosphorus from urban treated wastewater by the microalga Scenedesmus obliquus. Laboratory experiments were conducted in batch, where microalgae were cultured under different initial biomass concentrations (150 and 1500mgSSl(-1)) and light conditions (dark or illuminated). Nutrient uptake was more dependent on internal nutrient content of the biomass than on light presence or biomass concentration. When a maximum nitrogen or phosphorus content in the biomass was reached (around 8% and 2%, respectively), the removal of that nutrient was almost stopped. Biomass concentration affected more than light presence on the nutrient removal rate, increasing significantly with its increase. Light was only required to remove nutrients when the maximum nutrient storage capacity of the cells was reached and further growth was therefore needed. Residence times to maintain a stable biomass concentration, avoiding the washout of the reactor, were much higher than those needed to remove the nutrients from the wastewater. This ability to remove nutrients in the absence of light could lead to new configurations of reactors aimed to wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The anterior glenohumeral joint capsule: macroscopic and MRI anatomy of the fasciculus obliquus or so-called ligamentum glenohumerale spirale

    Energy Technology Data Exchange (ETDEWEB)

    Merila, M.; Eller, A.; Haviko, T. [Department of Orthopaedics, Clinic of Traumatology and Orthopaedics, University of Tartu, Puusepa 8, 51014, Tartu (Estonia); Leibecke, T.; Gehl, H.B. [Institute of Diagnostic Radiology, University of Luebeck, Ratzeburger Allee 160, 23538, Luebeck (Germany); Busch, L.C. [Institute of Anatomy, University of Luebeck, Ratzeburger Allee 160, 23538, Luebeck (Germany); Russlies, M. [Clinic of Orthopaedics, University of Luebeck, Ratzeburger Allee 160, 23538, Luebeck (Germany); Kolts, I. [Institute of Anatomy, University of Tartu, Ravila 19, Biomedicum, 50411, Tartu (Estonia)

    2004-08-01

    The purpose of this study was to demonstrate the macroscopic and MRI anatomy of the fasciculus obliquus, otherwise known as the ligamentum glenohumerale spirale or spiral GHL of the anterior shoulder joint capsule. Conventional and MR arthrography (1.5-T device Somatom Symphony, Siemens with shoulder coil) images in standard planes were compared with gross anatomic dissection findings in six fresh shoulder specimens from three cadavers. The MR imaging protocol included T1, PD and DESS 3D WI sequences. The macroscopically recognisable band - the spiral GHL - was identified by anatomic dissection and MRI in all the specimens. It was best visualised by MR arthrography on axial and oblique sagittal planes (T1; PD WI) and appeared as a low signal intensity stripe within the superficial layer of the anterior joint capsule. The absence of the variable middle glenohumeral ligament did not influence the anatomic properties and the MR imaging of the spiral GHL. Diagnostic visualisation of the normal anatomic structures is a prerequisite to distinguish between normal and pathologic conditions. Anatomy of the spiral GHL can be used by radiologists for more detailed interpretation of the anterior shoulder joint capsule ligaments on MR images. (orig.)

  4. Fixed-bed biosorption of cadmium using immobilized Scenedesmus obliquus CNW-N cells on loofa (Luffa cylindrica) sponge.

    Science.gov (United States)

    Chen, Bor-Yann; Chen, Chun-Yen; Guo, Wan-Qian; Chang, Hao-Wei; Chen, Wen-Ming; Lee, Duu-Jong; Huang, Chieh-Chen; Ren, Nan-Qi; Chang, Jo-Shu

    2014-05-01

    A continuous fixed-bed biosorption process was established for cadmium (Cd) removal by Scenedesmus obliquus CNW-N (isolated from southern Taiwan) cells immobilized onto loofa sponge. This immobilized-cell biosorption process allows better recovery and reusability of the microalgal biomass. The growth of microalgae on the matrix support with appropriate nutrient supplementation could enhance the overall metal removal activity. Major operating parameters (e.g., feeding flow rate, cycle number of medium replacement, and particle diameter of the sponge) were studied for treatability evaluation. The most promising cell growth on the sponge support was obtained at a flow rate of 0.284 bed volume (BV)/min, sponge particle diameter of 1 cm, and with one cycle of medium replacement. The performance of fixed-bed biosorption (adsorption capacity of 38.4 mg, breakthrough time at 15.5 h) was achieved at a flow rate of 5 ml/min with an influent concentration of 7.5 mg Cd/l. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Investigations on the isoprenoid biosynthesis in the green alga Scenedesmus obliquus by using the 13C-labelling technique

    International Nuclear Information System (INIS)

    Schwender, J.

    1995-01-01

    The biosynthesis of several prenyllipids (isoprenoid lipids) of the green alga Scendesmus obliquus was investigated. The aim was to verify, whether the biosynthesis of isopentenyl diphosphate (IPP) in Scenedesmus proceeds according to the classical acetate mevalonate pathway or to an alternative pathway. An alternative pathway for IPP formation has recently been detected in some eubacteria by the group of Prof. M. Rohmer. Some inhibition tests were performed with mevinolin, a specific inhibitor of HMG-CoA reductase which yields mevalonic acid. Mevinolin should block the biosynthesis of such isoprenoids which are formed via the acetate mevalonate pathway. Scenedesmus was grown heterotrophically on 13 C-labelled glucose or acetate. After isolation and purification of 13 C-labelled phytol (side chains of chlorophylls), β-carotene, lutein, plastoquinone-9 and three sterol compounds, the enrichment of 13 C at different carbon-positions of the labelled compounds was determined. This was achieved by the 13 C-NMR technique in cooperation with Miriam Seemann of the group of Prof. M. Rohmer in Mullhouse/France. (orig.) [de

  6. Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

    Science.gov (United States)

    Choi, K. J.; Nakhost, Z.; Barzana, E.; Karel, M.

    1987-01-01

    The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.

  7. 60 Co accumulation by scenedesnus obliquus. Mechanism of uptake and relative contribution of radionuclide adsorption and absorption

    International Nuclear Information System (INIS)

    Nucho, R.; Baudin, J.P.

    1989-06-01

    In this paper are presented the results of various 60 Co accumulation and depuration experiments, carried out to assess the respective contributions of passive and active processes in the radionuclide uptake by Scenedesmus obliquus. The experiments were conduced on living illuminated cells, living cells maintained in darkness and dead cells. Exposure study shows that living illuminated cells and dead cells incorporated the same amount of available 60 Co, in the order of 65%. In contrast, the radionuclide uptake by cells in darkness was very lower. Depuration experiments show that radiocobalt release by living illuminated cells and dead cells is an exponential process including two phases. The first, during which the decrease of the radioactivity was about 80%, corresponds to elimination of the 60 Co adsorbed on the cell walls. During the second phase, the slight decrease of the radioactivity results from the intracellular 60 Co desorption. The addition of EDTA in the depuration culture medium results in an almost instantaneous loss of 80% of the accumulated radionuclide. The results clearly indicate that 60 Co uptake is mainly a passive phenomenon, since adsorption accounts for 80% of the accumulation and passive diffusion for about 10%. Metabolic assimilation contributes for a weak part [fr

  8. UVΑ pre-irradiation to P25 titanium dioxide nanoparticles enhanced its toxicity towards freshwater algae Scenedesmus obliquus.

    Science.gov (United States)

    Roy, Barsha; Chandrasekaran, Hemamalini; Palamadai Krishnan, Suresh; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2018-04-02

    There has recently been an increase in the usage of TiO 2 nanoparticles (NPs). P25 TiO 2 NPs, a mixture of anatase and rutile phase in 3:1 ratio, are generally used for photocatalytic applications because both phases exhibit a synergistic effect on the photocatalytic activity of the TiO 2 NPs. In the present study, increased toxicity of UVA-pre-irradiated P25 TiO 2 NPs on freshwater algae Scenedesmus obliquus was assessed under visible light and dark exposure conditions at actual low concentrations (0.3, 3 and 35 μM of Ti). Photocatalytic property of P25 TiO 2 NPs caused disaggregation of UVA-pre-irradiated NPs, thus significantly decreasing the mean hydrodynamic diameter (MHD) (188.74 ± 0.54 nm) than that of non-irradiated NPs (232.26 ± 0.44). This decrease in diameter of UVA-pre-irradiated NPs may increase its biological activity towards algal samples. All concentrations of pre-irradiated NPs, under both light and dark conditions, showed a significantly lesser cell viability (p effects of UVA-pre-irradiated TiO 2 NPs on freshwater algae, thereby emphasising the need for ecological risk assessments of metal oxide nanoparticles in a natural experimental medium.

  9. Influence of carbon dioxide, temperature, medium kind and light intensity on the growth of algae Chlamydomonas reinhardtii and Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    Olejnik Przemysław Piotr

    2016-01-01

    Full Text Available Microalgae attracts the attention of scientists because of the possibility of using in the energy industry as one of the substrates for the production of renewable energy. So far, the greatest emphasis was put on attempts to obtain strains, and technologies of their culturing, in order to efficiently acquire fat from cells and its further conversion to biodiesel using transesterification reaction. Increasingly, algae are considered also as an efficient biomass producer, which can be used as a substrate for methane production in biogas plants. In this study the influence of different physical and chemical conditions, on the growth of two algae species: Chlamydomonasreinhardtii and Scenedesmus obliquus was investigated. Based on the literature and the data obtained for the algae growth on the standard medium and the digestate remaining after fermentation, one may suggest further investigations on the use of other liquid waste from agriculture and industry for algae breeding, including chemical. analysis and supplementation of these mediums so as to provide the best conditions for their growth.

  10. Investigations on uncertainties in patient positioning for prostate treatment with EPID; Untersuchungen zur Positionierungsgenauigkeit bei Prostatakonformationsbestrahlungen mittels Portal-Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bakai, A.; Nuesslin, F. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Medizinische Physik; Paulsen, F.; Plasswilm, L.; Bamberg, M. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Strahlentherapie

    2002-02-01

    : Konformationstechniken, wie sie heutzutage routinemaessig fuer Patienten mit Prostatakarzinom angewandt werden erlauben, durch Adaption der Bestrahlungsfelder an das Planungszielvolumen (PTV) umliegendes Normalgewebe zu schonen. Um die Vorteile dieser Techniken jedoch vollstaendig nutzen zu koennen, ist die korrekte Patientenpositionierung eine wichtige Voraussetzung. In dieser Studie wurde mittels Portal-Imaging (EPID) untersucht, welche Positionierungsgenauigkeiten im Beckenbereich unter Verwendung unterschiedlicher Lagerungshilfen moeglich sind. Patienten und Methode: Fuer die Studie wurden 15 Patienten mit Prostatakarzinom ausgewaehlt, die teils mit, teils ohne Rektumballon bzw. Beckenmaske an einem Linearbeschleuniger mit Viellamellenblenden (MLC) bestrahlt wurden. Von jedem Patienten wurden mehrfach aus orthogonalen Richtungen mittels eines Portal-Imaging-Systems Aufnahmen angefertigt und anschliessend mit den Planungs-DRRs (digitally reconstructed radiographs) sowie den Simulationsaufnahmen verglichen. Ergebnisse: Trotz unterschiedlicher Lagerungshilfen konnten fuer saemtliche Patientengruppen Gesamtpositionierungsungenauigkeiten von durchschnittlich 4,0 mm (lateral), 4,5 mm (kraniokaudal) sowie 1,7 mm (dorsoventral) festgestellt werden. Mit Beckenmaske war der laterale Positionierungsfehler zwar reduziert, gleichzeitig jedoch der kraniokaudale Positionierungsfehler verstaerkt. Der Gesamtpositionierungsfehler teilte sich dabei in einen systematischen und einen statistischen Anteil auf, fuer deren verlaessliche Abschaetzung sechs bis acht EPID-Aufnahmen erforderlich waren. Schlussfolgerungen: Mittels Portal-Imaging ist es moeglich, aus einer geringen Anzahl von Verifikationsaufnahmen fuer jeden Patienten den systematischen und statistischen Positionierungsfehler zu ermitteln. Der erfolgreiche Einsatz von Lagerungshilfen zur Patientenpositionierung erfordert jedoch - insbesondere im Hinblick auf IMRT - eine weitere Optimierung. (orig.)

  11. KOMBINASI TEKNIK MULLIGAN DAN FASILITASI VASUS MEDIALIS OBLIQUUS LEBIH EFEKTIF MENINGKATKAN AKTIVITAS FUNGSIONAL DARIPADA APLIKASI KINESIO TAPING PADA SINDROMA NYERI SENDI PATELLOFEMORAL

    Directory of Open Access Journals (Sweden)

    Atika Yulianti

    2013-11-01

    Full Text Available Patellofemoral pain syndrome is complained of knee pain by young adults who are productive oftenly, syndrome characterized by pain that is felt around the kneecap, and aggravated the activity squat and stand, up and down stairs, and change the position of the knee after a long standstill ( stand up after sitting for a long time. This is due to the weakness of the thigh muscles especially vasus medialis obliquus. Reinforcement of weak muscle in particular strengthening of the vastus medialis  oblique an appropriate treatment to increase the functional activity of the syndrome. The study was a randomized experiment with pre and post-test group design. This study aimed to compare the combining of mulligan techniques and facilitate of vasus medialis obliquus with application of kinesio taping to increase the functional activity of the lower extremities. In this study, 11 respondents were given a combination of mulligan techniques and facilitation of vastus medialis oblique for 5 weeks with a frequency of exercise 3 times a week, and 11 respondents provided application of kinesio taping for 5 weeks with 3 days and replaced with a new taping. Each treatment was measured by the Lower Extremity Fungtional Scale before and after 5 weeks. Statistical analysis parametric paired sample t-test results is the influence of a combining of mulligan techniques and facilitate of vastus medialis oblique and application of kinesio taping to increase the functional activity of the lower extremities with p<0.05. Test of different with the independent sample t-test with a result there are significant difference between the combining of techniques mulligan and facilitation of vasus medialis obliquus with application of kinesio taping values with  p <0.05. Conclusions in this study that a combining of mulligan techniques and facilitation of vasus medialis obliquus, 3 times a week for 5 weeks effectively to increase the functional activity of the lower extremities of

  12. Harvesting of freshwater microalgae Scenedesmus obliquus and Chlorella vulgaris using acid mine drainage as a cost effective flocculant for biofuel production

    International Nuclear Information System (INIS)

    Salama, El-Sayed; Jeon, Byong-Hun; Kurade, Mayur B.; Abou-Shanab, Reda A.I.; Govindwar, Sanjay P.; Lee, Sang-hun; Yang, Il-Seung; Lee, Dae Sung

    2016-01-01

    Graphical abstract: Schematic presentation of coagulation/flocculation of microalgal biomass using AMD. - Highlights: • AMDs containing high Fe"2"+/Al"3"+ improved the settling kinetics of microalgal biomass. • The highest k_2 value was 40 × 10"−"2 L mg"−"1 min"−"1 for C. vulgaris with AMD (1). • With AMD (2), k_2 was 4.0 × 10"−"2 L mg"−"1 min"−"1 for both C. vulgaris and S. obliquus. • The highest FE (93%) and CF (29) for C. vulgaris was achieved with AMD (1). • AMD (1) removed 99.80% of Fe"3"+ and 99.99% of Al"3"+ from the supernatant. - Abstract: Development of a low-cost harvesting technology could be an effective approach for making microalgal biofuel commercially feasible. The use of acid mine drainage (AMD) to coagulate/flocculate biomass is a cost-effective strategy for addressing this challenge. Here, settling kinetics, flocculation efficiency (FE), and concentration factor (CF) of two morphologically different microalgae species, Scenedesmus obliquus and Chlorella vulgaris, were investigated with respect to AMD dosage (5% and 10%) and medium pH (7 and 9). AMD was collected from two different sites, AMD (1) and AMD (2), and increasing its dosage to 10% improved the settling rate, FE, and CF of the floc. At 10% AMD (1) dosage and pH 9, the highest rate constants (k_2) for the second order equations were 6.65 × 10"−"2 and 40 × 10"−"2 L mg"−"1⋅min"−"1 for S. obliquus and C. vulgaris, respectively; at 10% AMD (2), k_2 values were 4.22 × 10"−"2 and 4.76 × 10"−"2 L mg"−"1 min"−"1, respectively. Similarly, FE/CF values were 89%/25 for S. obliquus and 93%/29 for C. vulgaris with 10% AMD (1); and 81%/17 and 79%/17, respectively, with 10% AMD (2). AMD effectively removed 99.80% of Fe"3"+, 99.99% of Al"3"+, 94% of Ca"2"+, 84% of Mg"2"+ and all of Na"+ and K"+ ions from the supernatant. The results of kinetics, EF, and CF measurements indicate that AMDs, naturally rich in iron and aluminum ions, could provide a feasible

  13. Abdominal fat-evaluation by use of single scan computed tomography; Computertomographische Bestimmung des intraabdominellen Fettvolumens mittels Einschicht-Messung

    Energy Technology Data Exchange (ETDEWEB)

    Jacobi, V. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Steinkamp, M. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Kirchner, J. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Fischer, H. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik; Diedrich, C.F. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik; Kollath, J. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik

    1997-02-01

    Purpose: Several studies emphasised the importance of the relationship between intraabdominal and total body adipose tissue as a risk factor for the development of metabolic or cardiovascular diseases. Therefore, the aim of the present study was to examine whether a single scan computed tomography is able to determine the whole intraabdominal fat volume with high accuracy and reproducibility. Materials and methods: Regions of interests (ROIs) were drawn manually for measuring intraabdominal fat in 51 unsuspicious abdominal CT. Results: The sexual differentiation of adipose tissue already described in a lot of studies could be confirmed in this study. Fat still predominates in females in lower half of the body (gynoid obesity). In men it predominates in the upper half (android obesity). Significant correlation concerning measuring the whole intraabdominal fat volume could be found in L1-level in women (r=0.992) and in L2-level in men (r=0.992). Measurement of a single scan enables us to assess whole intraabdominal fat volume due to a special formula. Conclusion: The determination of intraabdominal fat measured by a single scan computed tomography is a procedure associated with high accuracy and reproducibility. (orig.) [Deutsch] Ziel: Da in zahlreichen Studien hervorgehobene Bedeutung des intraabdominellen Fettgewebes gegenueber dem Gesamtkoerperfett als Risikofaktor fuer die Entwicklung metabolischer und kardiovaskulaerer Erkrankungen fordert ein Verfahren zur annaehernd exakten Bestimmung des intraabdominellen Fettgewebes. Ziel der vorliegenden Studie war zu pruefen, ob mit genuegender Genauigkeit die Verwendung einer Einschicht-Methode einen gezielten Einsatz der Computertomographie ermoeglicht und welche Lokalisation der zu waehlenden Schicht die aussagekraeftigste Messung ermoeglicht. Material und Methode: Anhand von 51 Computertomographien des Abdomens anderer Indikation (Normalbefunde) wurde das gesamte intraabdominelle Fettvolumen semiautomatisch mittels ROI

  14. Monitoring of lead batteries by means of optical-fibre refractometry; Ueberwachung von Bleiakkumulatoren mittels Faseroptischer Refraktometrie

    Energy Technology Data Exchange (ETDEWEB)

    Gernhold, H P; Hanitsch, R

    1994-12-31

    Electricity storage is an integral part of photovoltaic systems. At the moment, the most economical device for this is the lead battery. Battery life is determined by the charging technique applied and by the efficiency of monitoring. The optimum charging technique is selected in dependence of battery age and charge state. The authors present a method for online charge state monitoring in which the acid concentration is measured by means of optical-fibre refractometry. (orig.) [Deutsch] Ein aeusserst wichtiger Teilbereich von Photovoltaik-Anlagen ist die Speicherung von elektrischer Energie. Diesen Zweck erfuellen Bleiakkumulatoren zur Zeit am wirtschaftlichsten. Es hat sich gezeigt, dass sowohl die angewandte Ladetechnik als auch eine gute Batterieueberwachung entscheidend fuer die Lebensdauer dieser Systemkomponente sind. Die Wahl der optimalen Ladetechnik richtet sich wiederum nach dem Alter und dem Entladegrad der Batterie. Gegenstand dieser Arbeit ist es, eine Methode vorzustellen, mit der die Saeuredichte mittels faseroptischer Refraktometrie gemessen und so der Ladezustand jeder einzelnen Batteriezelle zu jedem Zeitpunkt on-line ueberwacht werden kann. (orig.)

  15. Kino filmų titrai kaip kalbų mokymosi priemonė. Untertitel als Mittel zum Fremdsprachenerwerb

    Directory of Open Access Journals (Sweden)

    Alina Baravykaitė

    2007-01-01

    Full Text Available Das in den letzten Jahren spürbare Bestreben der litauischen Gesetzgeber, Untertitelung von Fernsehfilmen zwecks Fremdsprachenerwerb gesetzlich anzuordnen, löste eine Auseinandersetzung in der Öffentlichkeit aus, die sich in der Presse sowie im Internet widerspiegelt und als Anstoß zum vorliegenden Beitrag dient. Diese Arbeit stellt den Versuch dar, die Möglichkeiten und Grenzen der Untertitelung als eines Mittels zum Fremdsprachenerwerb zu untersuchen. Auf Grund der fehlenden wissenschaftlichen Forschungen in diesem Bereich sollen dabei empirische Betrachtungen und die vergleichende Textanalyse von Original und Übersetzung als Hilfe dienen. Auch wenn die Relevanz der Untertitelung für den Fremdsprachenerwerb nicht bestreitbar ist, ist sie aber zugleich nicht zu überschätzen: Durch die lediglich für diese Form der audiovisuellen Übersetzung charakteristischen Merkmale (kurze Einblendezeit, kondensierte Sprache und begrenzte Übertragungsmöglichkeiten von Realia-Begriffen, Phraseologismen, Intertextualismen, dem Wortspiel etc. bleiben dem Zuschauer oft sprachliche Stilmittel vorenthalten und der in allen Übersetzungsbereichen vorkommende unausweichliche Sinn- und Wirkungsverlust des Originals wird erheblich verstärkt. Anbetracht der erwähnten Aspekte und der häufigen fehlerhaften Übersetzungen sollen Untertitel nur als Hilfsmittel beim Fremdsprachenerwerb angewendet werden, wobei herkömmliche Lehr- und Lernstrategien von Fremdsprachen in den Vordergrund treten müssen.

  16. Anti-diabetic effects of Inonotus obliquus polysaccharides-chromium (III) complex in type 2 diabetic mice and its sub-acute toxicity evaluation in normal mice.

    Science.gov (United States)

    Wang, Cong; Chen, Zhongqin; Pan, Yuxiang; Gao, Xudong; Chen, Haixia

    2017-10-01

    Polysaccharides are important bioactive ingredients from Inonotus obliquus. This study aimed to synthesize and characterize a novel I. obliquus polysaccharides-chromium (III) complex (UIOPC) and investigate the anti-diabetic effects in streptozotocin (STZ) induced type 2 diabetes mellitus (T2DM) mice and sub-acute toxicity in normal mice. The molecular weight of UIOPC was about 11.5 × 10 4  Da with the chromium content was 13.01% and the chromium was linked with polysaccharides through coordination bond. After treatment of UIOPC for four weeks, the body weight, fasting blood glucose (FBG) levels, plasma insulin levels of the diabetic mice were significantly reduced when compared with those of the diabetic mice (p < 0.05). The results on serum profiles and antioxidant enzymes activities revealed that UIOPC had a positive effect on hypoglycemic and antioxidant ability. Histopathology results showed that UIOPC could effectively alleviate the STZ-lesioned tissues in diabetic mice. Furthermore, high dose administration of UIOPC had no obviously influence on serum profiles levels and antioxidant ability of the normal mice and the organ tissues maintained organized and integrity in the sub-acute toxicity study. These results suggested that UIOPC might be a good candidate for the functional food or pharmaceuticals in the treatment of T2DM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1) and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Science.gov (United States)

    Amaro, Helena M.; Fernandes, Fátima; Valentão, Patrícia; Andrade, Paula B.; Sousa-Pinto, I.; Malcata, F. Xavier; Guedes, A. Catarina

    2015-01-01

    Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA), well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•)) and biological reactive species (O2•− and •NO−). A eukaryotic microalga (Scenedesmus obliquus (M2-1)) and a prokaryotic one (Gloeothece sp.) were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2) and acetone extracts of Sc. obliquus (M2-1) were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•−, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2) extracts were the most interesting ones in •NO− assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs. PMID:26492257

  18. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1 and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Directory of Open Access Journals (Sweden)

    Helena M. Amaro

    2015-10-01

    Full Text Available Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA, well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH• and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+• and biological reactive species (O2•- and •NO-. A eukaryotic microalga (Scenedesmus obliquus (M2-1 and a prokaryotic one (Gloeothece sp. were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2 and acetone extracts of Sc. obliquus (M2-1 were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•-, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2 extracts were the most interesting ones in •NO- assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs.

  19. Simulation of the beam guiding of the SAPHIR experiment by means of a differential-equation model; Simulation der Strahlfuehrung des SAPHIR-Experiments mittels eines Differentialgleichungsmodells

    Energy Technology Data Exchange (ETDEWEB)

    Greve, T.

    1991-08-01

    This paper shows the numerical simulation of a beam line by means of a model of differential equations simulating the beam line from the Bonn Electron Stretcher Accelerator ELSA to the SAPHIR spectrometer. Furthermore a method for calculating the initial values based on measurements of beam profiles is being discussed. (orig.). [Deutsch] Diese Arbeit zeigt die numerische Simulation einer Strahlfuehrung mittels eines Differentialgleichungsmodells anhand der Strahlfuehrung vom Bonner ELSA-Beschleuniger zum SAPHIR-Experiment. Weiterhin wird eine Methode zur Gewinnung der Startwerte aus Strahlprofilmessungen diskutiert. (orig.).

  20. Floating venous thrombi: diagnosis with spiral-CT-venography; Diagnose flottierender venoeser Thromben mittels Phlebo-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Gartenschlaeger, M. [Mainz Univ. (Germany). Klinik fuer Radiologie; Klose, K.J. [Univ. Marburg, Medizinisches Zentrum fuer Innere Medizin, Abt. Poliklinik (Germany); Schmidt, J.A. [Univ. Marburg, Medizinisches Zentrum fuer Radiologie, Abt. fuer Strahlendiagnostik (Germany)

    1996-05-01

    Local application of contrast agent into an ipsilateral dorsal foot vein and spiral CT were used to examine 16 consecutive cases with deep venous thrombosis proven at conventional venography; in addition, colour Doppler flow imaging was performed. At conventional venography, 8/16 thrombi appeared to be floating and the remaining 8/16 were adherent to the vessel wall. Spiral-CT showed 15/16 thrombi to be adherent to the vessel wall; the floating thrombus correlated with findings in conventional venography. At colour Doppler flow imaging 3/16 thrombi were considered floating, one of them was discordant to conventional venography. The comparison of conventional venography to spiral-CT demonstrates complete agreement for adherence to vessel wall seen in conventional venography (p=1,0) and significant discordance in cases with free-floating appearance in conventional venography. Adherence of thrombi to the wall of the vessel at conventional venography is in agreement with computed tomography. Conventional venography probably overestimates the prevalence of free floating thrombi. (orig./MG) [Deutsch] Mittels lokaler Kontrastmittelapplikation in eine ipsilaterale Fussrueckenvene und Spiral-CT wurden 16 konsekutive Faelle konventionell phlebographisch gesicherter Phlebothrombose untersucht, zusaetzlich wurde die farbkodierte Doppler-Ultraschalluntersuchung durchgefuehrt. In der konventionellen Phlebographie waren 8/16 Thromben flottierend, die uebrigen 8/16 wandadhaerent. In der Spiral-CT zeigten sich Wandadhaerenzen in 15/16 Faellen; der nachgewiesene flottierende Thrombus stimmte mit der konventionellen Phlebographie ueberein. Im farbkodierten Doppler-Ultraschall erschienen die Thromben in 3/16 Faellen flottierend, darunter ein von der konventionellen Phlebographie abweichender Befund. Der Vergleich von konventioneller und CT-Phlebographie ergab eine komplette Uebereinstimmung fuer konventionell phlebographisch nachgewiesene Wandadhaerenz und eine signifikante Abweichung

  1. Biosynthetic pathways to delta-aminolevulinic acid induced by blue light in the pigment mutant C-2A' of Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Klein, O.; Senger, H.

    1978-01-01

    The X-ray induced mutant C-2A' of Scenedesmus obliquus grows heterotrophically but forms only traces of chlorophyll in the dark. Upon illumination, delta-aminolevulinic acid (ALA) is synthesized and chlorophyll is formed. These processes are blue light dependent and ceased immediately when the cells were transferred back into darkness. Addition of levulinic acid (LA) inhibited the light-dependent formation of chlorophyll and caused accumulation of ALA by competitive inhibition of the ALA dehydratase (EC. 4.2.1.24). By feeding specifically labelled 14 C precursors to the pigment mutant, inhibiting the ALA dehydratase with LA, accumulating, extracting and analyzing the ALA, two pathways leading towards ALA could be established: glycine and succinyl CoA can be condensed to ALA and the 5 carbon skeleton of glutamate can completely be incorporated into ALA via a second pathway. The glycine-succinyl CoA pathway dominated over the glutamate pathway, but both led to chlorophyll formation. (author)

  2. Impacts of dissolved organic matter on aqueous behavior of nano/micron-titanium nitride and their induced enzymatic/non-enzymatic antioxidant activities in Scenedesmus obliquus.

    Science.gov (United States)

    Zhang, Xin; Wang, Zhuang; Wang, Se; Fang, Hao; Zhang, Fan; Wang, De-Gao

    2017-01-02

    Freshwater dispersion stability and ecotoxicological effects of titanium nitride (TiN) with particle size of 20 nm, 50 nm, and 2-10 μm in the presence of dissolved organic matter (DOM) at various concentrations were studied. The TiN particles that had a more negative zeta potential and smaller hydrodynamic size showed more stable dispersion in an aqueous medium when DOM was present than when DOM was absent. Biochemical assays indicated that relative to the control, the TiN particles in the presence of DOM alleviated to some extent the antioxidative stress enzyme activity in Scenedesmus obliquus. In addition, it was found that the TiN with a primary size of 50 nm at a high concentration presented a significant impact on non-enzymatic antioxidant defense in algal cells.

  3. 13C-nuclear magnetic resonance studies of the biosynthesis of 5-aminolevolinic acid destined for chlorophyll formation in dark-grown Scenedesmus Obliquus

    International Nuclear Information System (INIS)

    Oh-hama, Tamiko; Seto, Harvo; Miyachi, Shigetoh

    1985-01-01

    The 13 C-nuclear magnetic resonance (NMR) spectra of chlorophyll-α-formed in dark-grown Scenedesmus Obliquus (Turp.) Kutzing in the presence of (1- 13 C) glutamate, (2- 13 C) and (1- 13 C) glycine showed that the 13 C of glutamate was specifically incorporated into the eight-carbon atoms in the tetrapyrrole macrocyles derived from C-5 of 5-aminolevolinic acid (ALA), while the C-2 of glycine was only incorporated into the methyl carbon of the methoxycarbonyl group attached to the isolcyclic ring of chlorophyll a formed in the presence of (1- 13 C)-glycine. These labelling patterns provide evidence for the operation of the C 5 -pathway and against the operation of the ALA synthase pathway for chlorophyll formation in darkness. (author)

  4. [Bewusstes Erinnern und bewusstes Vergessen : der juristische Umgang mit der Vergangenheit in den Ländern Mittel- und Osteuropas / hrsg. v. Angelika Nußberger, Caroline von Gall. (Jus Internationale et Europaeum ; 52). Mohr Siebeck, Tübingen 2011.

    Index Scriptorium Estoniae

    Luts-Sootak, Marju, 1966-

    2014-01-01

    Arvustus: Bewusstes Erinnern und bewusstes Vergessen : der juristische Umgang mit der Vergangenheit in den Ländern Mittel- und Osteuropas / hrsg. v. Angelika Nußberger, Caroline von Gall (Jus Internationale et Europaeum ; 52). Mohr Siebeck, Tübingen 2011. 400 S.

  5. Natural attenuation at a former gas plant site: isotope analyses; Nachweis von Natural Attenuation mittels Isotopenuntersuchungen an einem ehemaligen Kokereistandort

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Aglaia; Strauss, Harald; Achten, Christine [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Geologie und Palaeontologie, Muenster (Germany); Stephan, Manuel [Universitaet Duisburg-Essen, Instrumentelle Analytische Chemie, Essen (Germany)

    2011-12-15

    Natural attenuation of mono- (BTEX) and polycyclic aromatic hydrocarbons (PAHs) was studied in groundwater at a former gas plant site over a distance of about 500 m. The contamination source was located within a 4-6 m thick succession of interbedded silt and sand (K{sub f} =1,4 .10{sup -7} m/s) at a depth of about 5-6 m below the surface. Groundwater flow times between source and the receiving surface waters were determined on the order of a few hundred years. The main contaminants were found to be benzene and naphthalene with concentrations up to 200,000 and 8,500 {mu}g/l, respectively. Over the past 9 years, concentrations within the contaminant plume have decreased and degradation of benzene was proven by compound specific carbon isotope analyses. In addition, sulphur isotope studies revealed that sulphate reduction has played a significant role. This was supported by ambient sulphate concentrations of 300-1,800 {mu}g/l at the site that are sufficient to sustain a long-term perspective for this process. In agreement with these physico-chemical conditions, no transfer of BTEX or PAHs from the plume into the nearby river has been observed. (orig.) [German] An einem ehemaligen Kokereistandort im Ruhrgebiet wurde das Potenzial von Natural Attenuation (natuerlicher Abbau und Rueckhalt) fuer mono- (BTEX) und polyzyklische aromatische Kohlenwasserstoffe (PAK) im Grundwasser auf einer Fliessstrecke von ca. 500 m untersucht. Das Schadenszentrum befindet sich unter eingeebnetem Bergematerial in ca. 5-6 m Tiefe unter Gelaendeoberkante innerhalb einer ca. 4-6 m maechtigen Schluff-Sand-Wechselfolge (K{sub f} =1,4 .10{sup -7} m/s). Im gesamten Aquifer resultieren Fliesszeiten von wenigen Hundert Jahren vom Schadstoffzentrum bis zur Vorflut. Hauptkontaminanten sind Benzen (bis ca. 200.000 {mu}g/l) und Naphthalen (bis ca. 8.500 {mu}g/l). An der Fahnenspitze liegen seit 9 Jahren schrumpfende Konzentrationen vor, die in Einklang mit einem mittels Kohlenstoffisotopie

  6. Preoperative assessment of asymptomatic adnexal masses by positron emission tomography and F-18-fluorodeoxyglucose; Praeoperative Dignitaetsbeurteilung asymptomatischer Adnextumoren mittels Positronen-Emissions-Tomographie und F-18-Fluordeoxyglukose

    Energy Technology Data Exchange (ETDEWEB)

    Fenchel, S.; Kotzerke, J.; Reske, S.N. [Ulm Univ. (Germany). Abt. Nuklearmedizin; Stoehr, I.; Grab, D.; Kreienberg, R. [Ulm Univ. (Germany). Frauenklinik; Nuessle, K.; Rieber, A.; Brambs, H.J. [Ulm Univ. (Germany). Abt. Radiologie 1 (Roentgendiagnostik)

    1999-08-01

    Aim: To evaluate use of F-18-FDG-PET in assessment of dignity of asymptomatic adnexal masses. Methods: 85 asymptomatic patients with suspicious, asymptomatic adnexal masses were evaluated. Static FDG-PET (Exact HR+ or ECAT 931) imaging of the abdomen was performed following application of 222-555 MBq F-18-FDG. Iterative reconstruction was applied. PET data were analysed visually, at first without and second together with MRT images. Final diagnosis was made by histopathology. Results: FDG-PET allowed correct identification of 4 of 8 malignant adnexal tumors. False negative results were obtained in 2 adenocarcinomas stage pT1a and 2 borderline-tumors. In 60 out of 77 benign adnexal masses malignancy could be excluded. False positive FDG-uptake, partly because of misinterpretation of gastrointestinal activity, was found in 3 inflammatory processes, 1 teratoma, 1 benign schwannoma, 1 dermoid cyst, 1 benign thecoma, 1 serous cyst, 1 serous cystadenoma, 2 mucinous cystadenomas, 2 corpus luteum cysts, 3 endometriosic cysts and 1 sactosalpinx. The overall sensitivity and specifity of FDG-PET alone were 50% and 78%. Evaluation together with MRT images showed a sensitivity of 50% and a specifity of 86%. (orig.) [Deutsch] Ziel: Es wurde untersucht, ob die FDG-PET zu einer Verbesserung der Dignitaetsbeurteilung asymptomatischer, sonographisch malignomsuspekter Ovarialtumoren beitragen kann. Methode: 85 Patientinnen mit malignomsuspekten, asymptomatischen Adnextumoren unterzogen sich einer FDG-PET Untersuchung. Emissionsaufnahmen des Abdomens wurden ca. 1 h nach i.v. Injektion von 222-555 MBq F-18-FDG angefertigt (Exact HR + bzw. ECAT 931). Die Bildrekonstruktion erfolgte iterativ. Die PET-Aufnahmen wurden visuell ausgewertet, zum einen ohne andere bildgebende Verfahren, zum anderen zusammen mit der Kernspintomographie. Die Validierung erfolgte mittels Histologie. Ergebnisse: Histologisch fanden sich 8 Malignome, von denen 4 mittels FDG-PET als richtig positiv erkannt wurden

  7. Cryotherapy of malignant tumors: MR imaging in comparison with pathological changes in mice; Kryotherapie maligner Tumoren: Untersuchungen mittels MRT im Tierexperiment und Vergleich mit morphologischen Veraenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Romaneehsen, B.; Anders, M.; Roehrl, B.; Hast, H.J.; Schiffer, I.; Neugebauer, B.; Teichmann, E.; Schreiber, W.G.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Hengstler, J.G. [Mainz Univ. (Germany). Inst. fuer Toxikologie

    2001-07-01

    Aim of our study was to investigate the efficacy of 7 F cryoprobes for percutaneous use morpho- and histologically, to examine the role of apoptosis after cryotherapy, and to compare contrast-enhanced MRI with histopathological findings at different time intervals in a tumor-mouse model. Methods: Percutaneous cryotherapy was performed in 15 immunocompromised nude mice with subcutaneously implanted tumors using the non-small-cell lung cancer cell line Lu 1. In group a) 7 mice were sacrificed after definite time intervals and histological examinations were done for evaluation of necrosis and apoptosis (HE; TUNEL assay); 2 mice are in long-term follow-up. In group b) in 6 mice tumor destruction and perfusion before and after freezing were investigated with native and contrast-enhanced MR imaging (T{sub 1}- and T{sub 2}-weighted spin-echo) and compared with histopathological findings. Histological control were done in 2 untreated mice. Results: We observed fast tumor-reduction within two weeks (ca. 50%). On long-term follow-up (> 6 months) no recurrence has been noticed so far. Tumors were well vascularized prior to treatment and did not-show contrast enhancement an any time after cryotherapy. A narrow contrast-enhanced zone was seen on the tumor border subcutaneously as a sign of peripheral hyperemia and central vascular stasis after cryotherapy. On histology there was evidence of both apoptosis and necrosis. (orig.) [German] Evaluierung der Durchfuehrbarkeit und Effizienz einer perkutanen Kryotherapie mittels 7-F-Kryosonde in Nacktmaeusen. Erheben des histopathologischen Befundes der Kryolaesion nach definierten Zeitintervallen und Ueberpruefung einer moeglichen Rolle der Apoptose nach Kryotherapie. Darstellung morphologischer Veraenderungen des Tumors und des angrenzenden Gewebes im Anschluss an die Kryotherapie mittels kontrastmittelunterstuetzter MRT. Methodik: Zweiminuetige Kryotherapie subkutan implantierter Tumoren eines nicht-kleinzelligen Bronchialkarzinoms

  8. Biokinetics of cadmium, selenium, and zinc in freshwater alga Scenedesmus obliquus under different phosphorus and nitrogen conditions and metal transfer to Daphnia magna

    International Nuclear Information System (INIS)

    Yu Riqing; Wang Wenxiong

    2004-01-01

    The uptake of Cd, Se(IV) and Zn by the freshwater alga Scenedesmus obliquus and the subsequent transfer and release budget in Daphnia magna were investigated under different nutrient additions and cell incubation conditions. An increase in ambient phosphate concentrations from 0.5 μmol l -1 to 50 μmol l -1 significantly increased the intracellular accumulation of Cd (by 18x) and Zn (by 5x), but decreased the accumulation of Se (by 126x) in the alga. The percentage of these metals distributing in the intracellular pool of algae also increased substantially with increasing ambient P concentrations. Nitrate addition from 5.0 to 200 μmol l -1 did not influence the uptake of any of the three metals, although a significant decrease in the intracellular Se distribution was observed. Radiolabeled algae under different nutrient manipulations (semi-continuous culture, starvation, and P-pulse treatments) were used to measure trophic transfer assimilation efficiency (AE) in Daphnia. When the algal cells were grown in a semi-continuous culture, starved for N and P, or were treated with P-pulse, the AEs of Cd and Zn were generally independent of the nutritional conditions, but the Se AE was significantly affected by different P levels. The efflux rate constants, determined during 10 d depuration following 7 days of dietary uptake, decreased significantly for Cd and Zn, but were relatively constant for Se with increasing P concentration. N-addition caused no effect on the metal efflux rate constants. P- or N-additions did not influence the release budget (including molting, neonates, excretion and feces) for all three elements in Daphnia. Our study indicated that phosphate enrichment may substantially increase metal uptake in green alga S. obliquus. Responses of trophic transfer in Daphnia to nutrient enrichment were metal specific. P-enrichment can possibly lead to considerable decrease on Se transfer from algae to zooplankton. - Phosphorous enrichment influences metal uptake

  9. Biokinetics of cadmium, selenium, and zinc in freshwater alga Scenedesmus obliquus under different phosphorus and nitrogen conditions and metal transfer to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Yu Riqing; Wang Wenxiong

    2004-06-01

    The uptake of Cd, Se(IV) and Zn by the freshwater alga Scenedesmus obliquus and the subsequent transfer and release budget in Daphnia magna were investigated under different nutrient additions and cell incubation conditions. An increase in ambient phosphate concentrations from 0.5 {mu}mol l{sup -1} to 50 {mu}mol l{sup -1} significantly increased the intracellular accumulation of Cd (by 18x) and Zn (by 5x), but decreased the accumulation of Se (by 126x) in the alga. The percentage of these metals distributing in the intracellular pool of algae also increased substantially with increasing ambient P concentrations. Nitrate addition from 5.0 to 200 {mu}mol l{sup -1} did not influence the uptake of any of the three metals, although a significant decrease in the intracellular Se distribution was observed. Radiolabeled algae under different nutrient manipulations (semi-continuous culture, starvation, and P-pulse treatments) were used to measure trophic transfer assimilation efficiency (AE) in Daphnia. When the algal cells were grown in a semi-continuous culture, starved for N and P, or were treated with P-pulse, the AEs of Cd and Zn were generally independent of the nutritional conditions, but the Se AE was significantly affected by different P levels. The efflux rate constants, determined during 10 d depuration following 7 days of dietary uptake, decreased significantly for Cd and Zn, but were relatively constant for Se with increasing P concentration. N-addition caused no effect on the metal efflux rate constants. P- or N-additions did not influence the release budget (including molting, neonates, excretion and feces) for all three elements in Daphnia. Our study indicated that phosphate enrichment may substantially increase metal uptake in green alga S. obliquus. Responses of trophic transfer in Daphnia to nutrient enrichment were metal specific. P-enrichment can possibly lead to considerable decrease on Se transfer from algae to zooplankton. - Phosphorous enrichment

  10. Enhanced CO2 sequestration by a novel microalga: Scenedesmus obliquus SA1 isolated from bio-diversity hotspot region of Assam, India.

    Science.gov (United States)

    Basu, Samarpita; Roy, Abhijit Sarma; Mohanty, Kaustubha; Ghoshal, Aloke K

    2013-09-01

    The present study aimed to isolate a high CO2 and temperature tolerant microalga capable of sequestering CO2 from flue gas. Microalga strain SA1 was isolated from a freshwater body of Assam and identified as Scenedesmus obliquus (KC733762). At 13.8±1.5% CO2 and 25 °C, maximum biomass (4.975±0.003 g L(-1)) and maximum CO2 fixation rate (252.883±0.361 mg L(-1) d(-1)) were obtained which were higher than most of the relevant studies. At elevated temperature (40 °C) and 13.8±1.5% CO2 maximum biomass (0.883±0.001 g L(-1)) was obtained. The carbohydrate, protein, lipid, and chlorophyll content of the CO2 treated SA1 were 30.87±0.64%, 9.48±1.65%, 33.04±0.46% and 6.03±0.19% respectively, which were higher than previous reports. Thus, SA1 could prove to be a potential candidate for CO2 sequestration from flue gas as well as for the production of value added substances. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. The synergistic effects for the co-cultivation of oleaginous yeast-Rhodotorula glutinis and microalgae-Scenedesmus obliquus on the biomass and total lipids accumulation.

    Science.gov (United States)

    Yen, Hong-Wei; Chen, Pin-Wen; Chen, Li-Juan

    2015-05-01

    In this co-culture of oleaginous yeast-Rhodotorula glutinis and microalgae-Scenedesmus obliquus, microalgae potentially acts as an oxygen generator for the growth of aerobic yeast while the yeast mutually provides CO2 to the microalgae as both carry out the production of lipids. To explore the synergistic effects of co-cultivation on the cells growth and total lipids accumulation, several co-culture process parameters including the carbon source concentration, temperature and dissolved oxygen level would be firstly investigated in the flask trials. The results of co-culture in a 5L photobioreactor revealed that about 40-50% of biomass increased and 60-70% of total lipid increased was observed as compared to the single culture batches. Besides the synergistic effects of gas utilization, the providing of trace elements to each other after the natural cells lysis was believed to be another benefit to the growth of the overall co-culture system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Mediastinal fibrosis with pulmonary artery obstruction; diagnosis and investigation with helical CT imaging including 3-dimensional reconstructions; Pulomonalarterienstenose bei aggresiver Mediastinalfibrose; Diagnostik und 3D-Darstellung mittels helikaler CT-Untersuchung

    Energy Technology Data Exchange (ETDEWEB)

    Kolbe, M. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland); Helwig, A. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland); Habicht, J.M. [Klinik fuer Herz-Torax-Chirurgie, Universitaetskliniken Basel (Switzerland); Steinbruch, W. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland)

    1997-07-01

    An aggressive mediastinal fibrosis was found in a 42-year-old female, suffering from dysphagia, stabbing pain in the chest, and an unclear weight loss. In this case, the rare combination of esophageal involvement, bronchial narrowing, and pulmonary artery obstruction could easily be demonstrated with a barium study and a helical CT examination including three-dimensional reconstructions. (orig.) [Deutsch] Wir stellen den Fall einer 42jaehrigen Patientin vor, welche zur Abklaerung einer zunehmenden Dysphagie, stechender Thoraxschmerzen und eines Gewichtsverlustes hospitalisiert wurde. Mittels klinischer und radiologischer Abklaerung konnte eine aggressive Mediastinalfibrose diagnostiziert werden. Die seltene Kombination einer Oesophaguseinengung mit Pulmonalarterienstenosen sowie einer Bronchuskompression konnte nichtinvasiv mittels Oesophagogramm und helikaler CT-Untersuchung zuverlaessig und schnell dargestellt werden. (orig.)

  13. The Complete Mitochondrial DNA Sequence of Scenedesmus obliquus Reflects an Intermediate Stage in the Evolution of the Green Algal Mitochondrial Genome

    Science.gov (United States)

    Nedelcu, Aurora M.; Lee, Robert W.; Lemieux, Claude; Gray, Michael W.; Burger, Gertraud

    2000-01-01

    Two distinct mitochondrial genome types have been described among the green algal lineages investigated to date: a reduced–derived, Chlamydomonas-like type and an ancestral, Prototheca-like type. To determine if this unexpected dichotomy is real or is due to insufficient or biased sampling and to define trends in the evolution of the green algal mitochondrial genome, we sequenced and analyzed the mitochondrial DNA (mtDNA) of Scenedesmus obliquus. This genome is 42,919 bp in size and encodes 42 conserved genes (i.e., large and small subunit rRNA genes, 27 tRNA and 13 respiratory protein-coding genes), four additional free-standing open reading frames with no known homologs, and an intronic reading frame with endonuclease/maturase similarity. No 5S rRNA or ribosomal protein-coding genes have been identified in Scenedesmus mtDNA. The standard protein-coding genes feature a deviant genetic code characterized by the use of UAG (normally a stop codon) to specify leucine, and the unprecedented use of UCA (normally a serine codon) as a signal for termination of translation. The mitochondrial genome of Scenedesmus combines features of both green algal mitochondrial genome types: the presence of a more complex set of protein-coding and tRNA genes is shared with the ancestral type, whereas the lack of 5S rRNA and ribosomal protein-coding genes as well as the presence of fragmented and scrambled rRNA genes are shared with the reduced–derived type of mitochondrial genome organization. Furthermore, the gene content and the fragmentation pattern of the rRNA genes suggest that this genome represents an intermediate stage in the evolutionary process of mitochondrial genome streamlining in green algae. [The sequence data described in this paper have been submitted to the GenBank data library under accession no. AF204057.] PMID:10854413

  14. Modulatory effects of Zn2+ ions on the toxicity of citrate- and PVP-capped gold nanoparticles towards freshwater algae, Scenedesmus obliquus.

    Science.gov (United States)

    Iswarya, V; Johnson, J B; Parashar, Abhinav; Pulimi, Mrudula; Chandrasekaran, N; Mukherjee, Amitava

    2017-02-01

    Gold nanoparticles (GNPs) are widely used for medical purposes, both in diagnostics as well as drug delivery, and hence are prone to release and distribution in the environment. Thus, we have explored the effects of GNPs with two distinct surface capping (citrate and PVP), and three different sizes (16, 27, and 37 nm) at 0.01-, 0.1-, and 1-mg L -1 concentrations on a predominant freshwater alga Scenedesmus obliquus in the sterile freshwater matrix. We have also investigated how an abundant metal ion from freshwater, i.e., Zn 2+ ions may modulate the effects of the selected GNPs (40 nm, citrate, and PVP capped). Preliminary toxicity results revealed that gold nanoparticles were highly toxic in comparison to zinc ions alone. A significant modulation in the toxicity of Zn ions was not noticed in the presence of GNPs. In contrast, zinc ions minimized the toxicity produced by GNPs (both CIT-37 and PVP-37), despite its individual toxicity. Approximately, about 42, 33, and 25% toxicity reduction was noted at 0.05-, 0.5-, and 5-mg L -1 Zn ions, respectively, for CIT-37 GNPs, while 31% (0.05 mg L -1 ), 24% (0.5 mg L -1 ), and 9% (5 mg L -1 ) of toxicity reduction were noted for PVP-37 GNPs. Maximum toxicity reduction was seen at 0.05 mg L -1 of Zn ions. Abbott modeling substantiated antagonistic effects offered by Zn 2+ ions on GNPs. Stability and sedimentation data revealed that the addition of zinc ions gradually induced the aggregation of NPs and in turn significantly reduced the toxicity of GNPs. Thus, the naturally existing ions like Zn 2+ have an ability to modulate the toxicity of GNPs in a real-world environment scenario.

  15. Effects of an anionic surfactant (FFD-6) on the energy and information flow between a primary producer (Scenedesmus obliquus) and a consumer (Daphnia magna).

    Science.gov (United States)

    Lürling, M; de Lange, H J; Peeters, E T H M

    2011-11-01

    The effects of a commercially available anionic surfactant solution (FFD-6) on growth and morphology of a common green alga (Scenedesmus obliquus) and on survival and clearance rates of the water flea Daphnia magna were studied. The surfactant-solution elicited a morphological response (formation of colonies) in Scenedesmus at concentrations of 10-100 μl l(-1) that were far below the No Observed Effect Concentration (NOEC) value of 1,000 μl l(-1) for growth inhibition. The NOEC-value of FFD-6 for colony-induction was 3 μl l(-1). Daphnia survival was strongly affected by FFD-6, yielding LC(50-24h) and LC(50-48 h) of 148 and 26 μl l(-1), respectively. In addition, clearance rates of Daphnia feeding on unicellular Scenedesmus were inhibited by FFD-6, yielding a 50% inhibition (EC(50-1.5h)) at 5.2 μl l(-1) with a NOEC of 0.5 μl l(-1). When Daphnia were offered FFD-6-induced food in which eight-celled colonies (43 × 29 μm) were most abundant, clearance rates (~0.14 ml ind.(-1) h(-1)) were only 25% the rates of animals that were offered non-induced unicellular (15 × 5 μm) Scenedesmus (~0.56 ml ind.(-1) h(-1)). As FFD-6 concentrations in the treated food used in the experiments were far below the NOEC for clearance rate inhibition, it is concluded that the feeding rate depression was caused by the altered morphology of the Scenedesmus moving them out of the feeding window of the daphnids. The surfactant evoked a response in Scenedesmus that is similar to the natural chemically induced defensive reaction against grazers and could disrupt the natural information conveyance between these plankton organisms.

  16. Operation planning for a pondage power station chain by means of linear programming and genetic optimisation; Einsatzplanung fuer eine Flusskraftwerkskette im Schwellbetrieb mittels LP und genetischer Optimierung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.; Huelsemann, M.

    1997-12-31

    This paper presents a system package which serves as a simulation and optimisation tool for daily operation planning for a hydroelectric cascade. The purpose of the planning is to maximise (the differentially weighted) production of electrical energy given a certain set of specifications and secondary conditions. Optimal operation management is achieved using a two-stage approach: first pre-optimisation by means of linear programming, followed by detail optimisation using a Genetic Algorithm based on a non-linear, dynamic model of the power station and reservoir chain. [Deutsch] Im Beitrag wird ein Systempaket als Simulations- und Optimierungswerkzeug zur taeglichen Betriebsplanung einer Wasserkraftwerkskaskade vorgestellt. Ziel der Wasserbewirtschaftung ist es, unter den gegebenen Vorgaben und Randbedingungen die (bewertete) Erzeugung elektrischer Energie zu maximieren. Das optimale Fahrplanmanagement wird durch einen zweistufigen Loesungsansatz realisiert: Mit einer Vor-Optimierung mittels Linearer Programmierung (LP), gefolgt von einer detaillierten Optimierung mit einem Genetischen Algorithmus, der auf ein nichtlineares, dynamisches Simulationsmodell fuer die Kette aus Kraftwerken und Stauraeumen zugreift. (orig./RHM)

  17. Measurement of the filling height of transient two-phase surge flows in pipelines by means of electronics; Messung der Fuellhoehe von transienten Zweiphasenschwallstroemungen in Rohrleitungen mittels Ultraschall

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, B.; Rockstroh, M. [Technische Univ. Dresden (Germany). Inst. fuer Energiemaschinen und Maschinenlabor

    1997-12-01

    The aim of the ultrasonic measurements was the determination of the time course of the level of a transient surge flow with swirl and waves in partly filled roughly horizontally laid pipelines. The running time of the ultrasonic waves from the test head to the liquid surface and back was measured for this purpose. The course of the stress was recorded digitally and was evaluated with the aid of software. Waves, swirl, turbulence of flow and introduced test bodies in the flow caused typical echoes, which had to be taken into account in the evaluation. As the test head was fitted on the outside of the pipe (clamp-on technique), the pipe wall thickness and the speed of sound in the pipe wall had to be included in the calculation of filling height by means of a correction. [Deutsch] Ziel der Ultraschallmessungen war die Bestimmung des zeitlichen Verlaufes der Fuellhoehe einer transienten, drall- und wellenbehafteten Schwallstroemung in teilgefuellten, etwa horizontal verlegten Rohrleitungen. Hierzu wurde die Laufzeit der Ultraschallwellen vom Pruefkopf zur Fluessigkeitsoberflaeche und zurueck gemessen. Die Laufzeit der Ultraschallwellen wurde auf eine quasi-analog elektrische Spannung abgebildet. Der Spannungsverlauf wurde digital aufgezeichnet und softwaregestuetzt ausgewertet. Wellen, Drall, Stroemungsturbulenzen sowie eingebrachte Pruefkoerper in der Stroemung hatten typische Echoerscheinungen zur Folge, die bei der Auswertung zu beruecksichtigen waren. Da der Pruefkopf aussen am Rohr angebracht war (clamp-on-Technik), musste die Rohrwandstaerke und die Schallgeschwindigkeit in der Rohrwandung mittels eines Korrekturgliedes in die Fuellhoehenberechnung eingezogen werden. (orig.)

  18. C-arm computed tomography for transarterial chemoperfusion and chemo-embolization of thoracic lesions; Transarterielle Chemoperfusion und -embolisation thorakaler Neoplasmen mittels C-Arm CT

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J.; Naguib, N.N.; Nour-Eldin, N.E.; Lehnert, T.; Mbalisike, E. [Klinikum der Johann-Wolfgang-Goethe-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Frankfurt am Main (Germany)

    2009-09-15

    To evaluate the role of C-arm CT for on-line fluoroscopy in regional transarterial chemoperfusion (TACP) and chemo-embolization (TPCE) of primary and secondary malignant thoracic lesions. From September 2008 to March 2009 a total of 31 patients (20 males and 11 females, average age: 61.7 years, range 22-84 years) with 53 thoracic malignant lesions from different origins (primary or secondary pulmonary carcinoma n=37, pleural mesothelioma n=16) were treated with TACP or TPCE using flat-detector CT (FD-CT). C-arm CT of the latest generation was used to localize the lesion before local chemotherapy (Artis Zeego, Siemens, Erlangen). For TACP a 220 rotation and a volume of 150 ml (ratio of 1:2 contrast/normal saline), delay 2 s and flow 12 ml/s was used. For TPCE a volume of 75 ml (ratio of 1:2 contrast/normal saline), delay 2 s and flow 3 ml/s was used. TPCE C-arm CT allowed the evaluation of the degree of perfusion of the tumor and the geographic areas of enhancement correlated with the post-interventional lipiodol uptake in MSCT. In TACP the intercostal arteries involved could be visualized and in 30% of interventions the catheter had to be repositioned for the following intervention. C-arm CT provides additional information on the vascular characteristics and perfusion of pulmonary lesions resulting in a change of interventional strategy in a relevant number of patients. (orig.) [German] Ziel der Arbeit war die Evaluation der Wertigkeit der C-Arm CT fuer die online gesteuerte regionale transarterielle Chemoperfusion (TACP) und die transpulmonale Chemoembolisation (TPCE) primaerer und sekundaerer thorakaler Neoplasmen Von September 2008 bis Maerz 2009 wurden 31 Patienten (11 Frauen/20 Maenner, Durchschnittsalter 61,7 Jahre) mit 53 unterschiedlichen thorakalen Neoplasmen (primaere oder sekundaere Lungenkarzinome [n=37], Pleuramesotheliome [n=16]) mittels TACP oder TPCE unter Einsatz der Flachdetektortechnologie (FD-CT) behandelt. Alle Behandlungen erfolgten an einem C

  19. Functional CT imaging: load-dependent visualization of the subchondral mineralization by means of CT osteoabsorptionmetry (CT-OAM); Funktionelle Computertomographie: Beanspruchungsabhaengige Darstellung der subchondralen Mineralisierung mittels CT gestuetzter Osteoabsorptiometrie (CTOAM)

    Energy Technology Data Exchange (ETDEWEB)

    Linsenmaier, U.; Schlichtenhorst, K.; Pfeifer, K.J.; Reiser, M. [Inst. fuer Klinische Radiologie, Innenstadt, Ludwig-Maximilians-Univ. Muenchen (Germany); Kersting, S.; Putz, R.; Mueller-Gerbl, M. [Anatomische Anstalt, Ludwig-Maximilians-Univ. Muenchen (Germany)

    2003-05-01

    Purpose: Functional computed tomography for visualization and quantification of subchondral bone mineralization using CT osteoabsorptiometry (CT-OAM). Materials and Methods: Tarsometatarsal (TMT) and metatarsophalangeal (MTP) joints of 46 human hallux valgus (HV) specimens were examined (sagittal 1/1/1 mm) on a single slice CT scanner SCT (Somatom Plus 4, Siemens AG). Subchondral bone pixels were segmented and assigned to 10 density value groups (triangle 100 HU, range 200 - 1200 HU) the pixels using volume rendering technique (VRT). The data analysis considered the severity of HV as determined by the radiographically measured HV-angle (a.p. projection). Results: CT-OAM could generate reproducible densitograms of the distribution pattern of the subchondral bone density for all four joint surfaces (TMT and MTP joints). The bone density localization enables the assignment to different groups, showing a characteristic HV-angle-dependent distribution of the maximum bone mineralization of the load-dependent densitogram (p < 0.001). Conclusion: CT-OAM is a functional CT technique for visualizing and quantifying the distribution of the subchondral bone density, enabling a noninvasive load-dependent assessment of the joint surfaces. Load-dependent densitograms of hallux valgus specimens show a characteristic correlation with an increase of the HV-angle. (orig.) [German] Ziel: Darstellung und Quantifizierung der subchondralen Mineralisierung in Abhaengigkeit von unterschiedlichen Beanspruchungssituationen mittels funktioneller Computertomographie als CT-Osteoabsorptiometrie (CT-OAM). Methode: An 46 humanen Praeparaten mit Hallux valgus (HV) wurden exemplarisch die TMT I (Tarsometatarsal)- und MTP I (Metatarsophalangeal)-Gelenke des ersten Strahles (sagittal 1/1/1 mm) an einem Singleslice Spiral-CT (SCT, Somatom Plus 4, Siemens AG) untersucht. Der subchondrale Knochen wurde segmentiert, den Pixel wurde mittels Volume Rendering Technik (VRT) 10 Graustufenbereiche (D100 HU

  20. Cytotoxicity of ZnO NPs towards fresh water algae Scenedesmus obliquus at low exposure concentrations in UV-C, visible and dark conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bhuvaneshwari, M.; Iswarya, V. [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Archanaa, S. [Department of Biotechnology, IIT Madras (India); Madhu, G.M. [Department of Chemical Engineering, M.S. Ramaiah Institute of Technology, Bangalore (India); Kumar, G.K. Suraish [Department of Biotechnology, IIT Madras (India); Nagarajan, R. [Department of Chemical Engineering, IIT Madras (India); Chandrasekaran, N. [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India)

    2015-05-15

    Highlights: • The cytotoxicity of ZnO NPs with two hydrodynamic sizes towards freshwater algae. • Size dependent toxicity under UV-C, dark and visible light conditions. • Cytotoxicity principally due to ZnO NPs not the released Zn{sup 2+} ions. • The internalization of ZnO NPs leads to membrane damage and ROS production. - Abstract: Continuous increase in the usage of ZnO nanoparticles in commercial products has exacerbated the risk of release of these particles into the aquatic environment with possible harmful effects on the biota. In the current study, cytotoxic effects of two types of ZnO nanoparticles, having different initial effective diameters in filtered and sterilized lake water medium [487.5 ± 2.55 nm for ZnO-1 NPs and 616.2 ± 38.5 nm for ZnO-2 NPs] were evaluated towards a dominant freshwater algal isolate Scenedesmus obliquus in UV-C, visible and dark conditions at three exposure concentrations: 0.25, 0.5 and 1 mg/L. The toxic effects were found to be strongly dependent on the initial hydrodynamic particle size in the medium, the exposure concentrations and the irradiation conditions. The loss in viability, LDH release and ROS generation were significantly enhanced in the case of the smaller sized ZnO-1 NPs than in the case of ZnO-2 NPs under comparable test conditions. The toxicity of both types of ZnO NPs was considerably elevated under UV-C irradiation in comparison to that in dark and visible light conditions, the effects being more enhanced in case of ZnO-1 NPs. The size dependent dissolution of the ZnO NPs in the test medium and possible toxicity due to the released Zn{sup 2+} ions was also noted. The surface adsorption of the nanoparticles was substantiated by scanning electron microscopy. The internalization/uptake of the NPs by the algal cells was confirmed by fluorescence microscopy, transmission electron microscopy, and elemental analyses.

  1. Cytotoxicity of ZnO NPs towards fresh water algae Scenedesmus obliquus at low exposure concentrations in UV-C, visible and dark conditions

    International Nuclear Information System (INIS)

    Bhuvaneshwari, M.; Iswarya, V.; Archanaa, S.; Madhu, G.M.; Kumar, G.K. Suraish; Nagarajan, R.; Chandrasekaran, N.; Mukherjee, Amitava

    2015-01-01

    Highlights: • The cytotoxicity of ZnO NPs with two hydrodynamic sizes towards freshwater algae. • Size dependent toxicity under UV-C, dark and visible light conditions. • Cytotoxicity principally due to ZnO NPs not the released Zn 2+ ions. • The internalization of ZnO NPs leads to membrane damage and ROS production. - Abstract: Continuous increase in the usage of ZnO nanoparticles in commercial products has exacerbated the risk of release of these particles into the aquatic environment with possible harmful effects on the biota. In the current study, cytotoxic effects of two types of ZnO nanoparticles, having different initial effective diameters in filtered and sterilized lake water medium [487.5 ± 2.55 nm for ZnO-1 NPs and 616.2 ± 38.5 nm for ZnO-2 NPs] were evaluated towards a dominant freshwater algal isolate Scenedesmus obliquus in UV-C, visible and dark conditions at three exposure concentrations: 0.25, 0.5 and 1 mg/L. The toxic effects were found to be strongly dependent on the initial hydrodynamic particle size in the medium, the exposure concentrations and the irradiation conditions. The loss in viability, LDH release and ROS generation were significantly enhanced in the case of the smaller sized ZnO-1 NPs than in the case of ZnO-2 NPs under comparable test conditions. The toxicity of both types of ZnO NPs was considerably elevated under UV-C irradiation in comparison to that in dark and visible light conditions, the effects being more enhanced in case of ZnO-1 NPs. The size dependent dissolution of the ZnO NPs in the test medium and possible toxicity due to the released Zn 2+ ions was also noted. The surface adsorption of the nanoparticles was substantiated by scanning electron microscopy. The internalization/uptake of the NPs by the algal cells was confirmed by fluorescence microscopy, transmission electron microscopy, and elemental analyses

  2. The complete chloroplast genome sequence of the chlorophycean green alga Scenedesmus obliquus reveals a compact gene organization and a biased distribution of genes on the two DNA strands

    Science.gov (United States)

    de Cambiaire, Jean-Charles; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2006-01-01

    Background The phylum Chlorophyta contains the majority of the green algae and is divided into four classes. While the basal position of the Prasinophyceae is well established, the divergence order of the Ulvophyceae, Trebouxiophyceae and Chlorophyceae (UTC) remains uncertain. The five complete chloroplast DNA (cpDNA) sequences currently available for representatives of these classes display considerable variability in overall structure, gene content, gene density, intron content and gene order. Among these genomes, that of the chlorophycean green alga Chlamydomonas reinhardtii has retained the least ancestral features. The two single-copy regions, which are separated from one another by the large inverted repeat (IR), have similar sizes, rather than unequal sizes, and differ radically in both gene contents and gene organizations relative to the single-copy regions of prasinophyte and ulvophyte cpDNAs. To gain insights into the various changes that underwent the chloroplast genome during the evolution of chlorophycean green algae, we have sequenced the cpDNA of Scenedesmus obliquus, a member of a distinct chlorophycean lineage. Results The 161,452 bp IR-containing genome of Scenedesmus features single-copy regions of similar sizes, encodes 96 genes, i.e. only two additional genes (infA and rpl12) relative to its Chlamydomonas homologue and contains seven group I and two group II introns. It is clearly more compact than the four UTC algal cpDNAs that have been examined so far, displays the lowest proportion of short repeats among these algae and shows a stronger bias in clustering of genes on the same DNA strand compared to Chlamydomonas cpDNA. Like the latter genome, Scenedesmus cpDNA displays only a few ancestral gene clusters. The two chlorophycean genomes share 11 gene clusters that are not found in previously sequenced trebouxiophyte and ulvophyte cpDNAs as well as a few genes that have an unusual structure; however, their single-copy regions differ

  3. Frauen. Kultur. Mittel- und Osteuropa oder: Über den langsamen Einzug der gender studies in die slawistischen Kulturwissenschaften Women. Culture. Middle and Eastern Europe or: On the Slow Introduction of gender studies into the Slavonic Cultural Sciences

    Directory of Open Access Journals (Sweden)

    Barbara Wurm

    2001-03-01

    Full Text Available Der vorliegende Sammelband, entstanden anläßlich einer Konferenz, die im September 1997 vom Institut für Slawistik der Universität Innsbruck in Zusammenarbeit mit der österreichischen UNESCO-Kommission veranstaltet wurde, untersucht aus soziologischer, kulturhistorischer, literatur- und filmwissenschaftlicher Perspektive verschiedenste Aspekte der Institutionalisierung und Repräsentation von „Frauen in der Kultur“ Mittel- und Osteuropas.This anthology, the result of a conference organized in September 1997 by the Institute for Slavonic studies at the University of Innsbruck in co-operation with the Austrian UNESCO commission, examines various aspects of the institutionalization and representation of women in Middle and Eastern European culture from a sociological and cultural historical perspective and from that of literary and film sciences.

  4. Vorrichtung zur Thermokoagulation mittels Laserstrahlung

    OpenAIRE

    Wehner, Martin; Aden, Mirko

    2012-01-01

    The apparatus has diode lasers (2,4) which emit laser radiation with different central wavelength. The laser radiations from diode lasers are superimposed with each other. A control device (12) is provided for controlling laser power of diode laser. The thermal coagulation process is performed with respect to simultaneous emission of laser radiation from diode laser in processing mode. The ratio of laser power of diode laser in processing mode is changed according to specific pattern and/or a...

  5. DMSA-scintigraphy in paediatrics: is the evaluation of the geometric mean necessary for the calculation of the differential renal function?; Partialfunktionsberechnung der Nieren mit DMSA in der Paediatrie: ist fuer die Bestimmung das geometrische Mittel notwendig?

    Energy Technology Data Exchange (ETDEWEB)

    Porn, U.; Alalp, S.; Fischer, S.; Dresel, S. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Rossmueller, B. [Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany)

    2001-08-01

    cases with an obvious anatomical abnormality. (orig.) [German] Bei der statischen Nierenfunktionsszintigraphie mit Tc-99m-Dimercaptobernsteinsaeure (DMSA) wird zur moeglichst exakten Bestimmung der seitengetrennten Partialfunktion (PF) die Berechnung des geometrischen Mittels aus dorsaler und ventraler Projektion empfohlen. Ziel unserer Untersuchung war es, die allein aus der dorsalen Projektion ermittelte Partialfunktion (PF{sub dors}) mit der aus dem geometrischen Mittel berechneten PF (PF{sub geom}) zu vergleichen, um die Notwendigkeit der zusaetzlichen ventralen Projektion zu ueberpruefen. Methode: Es wurden 164 DMSA-Untersuchungen von 151 Kindern (86 w, 65 m) mit einem Alter von 16 d bis 16 a (4,7 {+-} 3,9 a) ausgewertet. Die Akquisition erfolgte mit einer Doppelkopfkamera aus ventraler und dorsaler Projektion (Picker Prism 2000 XP, LEUHR, Matrix: 256 x 256, 300 kcts/view, Zoom: 1,6-2,0). Mittels ROI-Auswertung wurden die Hintergrund-korrigierten Zaehlraten der beiden Nieren von ventral und dorsal bestimmt und die dorsalen Zaehlratenverhaeltnisse mit dem geometrischen Mittel (SQR[Cts{sub dors} x Cts{sub ventr}]) verglichen. Ergebnisse: Die PF{sub dors} ergab statistisch signifikant niedrigere Werte fuer die rechte Niere (bzw. entsprechend hoehere Werte fuer die linke Niere) im Vergleich zur PF{sub geom} (p<0,01). Die mittlere Differenz zwischen der PF{sub geom} und der PF{sub dors} betrug 1,5 {+-} 1,4%. Nur in 6/164 Faellen (3,7%) ergab sich ein Unterschied von {>=}5% (5,0-9,5%). Bei 3 dieser 6 Faelle lag die mit der PF{sub dors} unterschaetzte Niere (2 x links, 1 x rechts) kaudal dystop. Die uebrigen 3 Patienten mit einer Differenz von >5% zeigten keine Lage- oder Strukturanomalie. Schlussfolgerung: Die Berechnung der Partialfunktion ausschliesslich aus den dorsalen Projektionen fuehrt im Vgl. zur Berechnung durch das geometrische Mittel zu einer Unterschaetzung der PF der rechten Niere im Vergleich zur linken Niere. Dieser Effekt fuehrt jedoch bei orthotop

  6. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette; Reduktion der Strahlendosis mittels Speicherfolienradiographie im Vergleich zum konventionellen Film-Folien-System mit Rasterkassette am Schaedelphantom

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A. [Friedrich-Schiller-Univ. Jena, Inst. fuer Diagnostische und Interventionelle Radiologie (Germany); Sehner, J. [AGFA-Deutschland, Vertriebsgesellschaft (Germany)

    1999-07-01

    mittels RK und digital (ADC-70, Agfa) a.p. geroentgt. Bei konstanter Spannung wurde das mAs-Produkt stufenweise gesenkt und dabei die Eintrittsdosis mittels Halbleiterdetektor des Dosimax (Wellhoefer) ermittelt. 5 Untersucher beurteilten die Aufnahmen nach charakteristischen Bildmerkmalen, kritischen Strukturen, Ortsaufloesung und Bildkontrast. Ergebnisse: Die Eintrittsdosis betrug bei 73 kV/22 mAs konventionell (Rasterkassette) 0,432 mGy und digital 0,435 mGy. Bis zu einer durchschnittlichen Dosis von 71% (0,308 mGy; SD 0,050) waren die Aufnahmen sehr gut und bis zu einer durchschnittlichen Dosis von 31% (0,136 mGy; SD 0,065) ausreichend beurteilbar. Die erkennbaren Linienpaare/mm auf dem Bleistrichraster reduzierten sich dabei untersucherabhaengig bis zu 2 Stufen. Der Bildkontrast war sehr gut bis ausreichend. Die Akzeptanz der nachverarbeiteten Aufnahmen war individuell verschieden und erbrachte nur in hoeheren Dosisbereichen eine verbesserte Beurteilbarkeit der Knochenstrukturen und des Kontrastes. Schlussfolgerung: Fuer die ausreichende Beurteilbarkeit einer moeglichen Fraktur/der Nasennebenhoehlen/zur Vermessung kann die Dosis auf mindestens 56% (Durchmesser 31%; SD 14,9%)/40% (Durchmesser 27%; SD 9,3%)/18% (Durchmesser 14%; SD 4,4%) gesenkt werden. Mittels digitaler Radiografie wird damit bei 73 kV ein fragestellungsbezogenes mAs-Produkt moeglich und angegeben, so z.B. zum Frakturausschluss 73 kV/12,5 mAs und zur Schaedelvermessung 73 kV/4 mAs. (orig.)

  7. Assessment of hemodynamic changes in patients with renal artery stenosis by means of the cine MR phase-contrast technique; Einstufung haemodynamischer Veraenderungen bei Nierenarterienstenosen mittels MR-Cine-Phasenkontrastflussmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberg, S.O.; Knopp, M.V.; Bock, M.; Essig, M.; Hawighorst, H.; Zuna, I.; Schad, L.; Kaick, G. van [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie; Kallinowski, F.; Allenberg, J.R. [Chirurgische Universitaetsklinik, Heidelberg (Germany). Sektion Gefaesschirurgie; Just, A. [Heidelberg Univ. (Germany). 1. Physiologisches Inst.

    1997-08-01

    Purpose: To evaluate the use of high-temporal resolution cine MR phase-contrast flow measurements for assessment of flow dynamics in renal artery stenosis (RAS). Material and methods: In a dog model, cine MR flow measurements were validated by comparing the MR flow data to an invasive transit-time ultrasound reference technique for different degrees of RAS. Cardiac-gated MR flow curves were recorded in 56 renal arteries of 28 patients with a temporal resolution of at least 32 ms. In all cases RAS was confirmed by digital subtraction angiography (DSA). Abnormalities of flow dynamics were assessed in the calculated flow curves using the MR parameters mean flow, maximum velocity, and time to systolic maximum. Results: By means of the MR blood flow paremeters high-grade stenoses (>50%, n=23) were detected with sensitivity of 100% and specificity of 94% with reference to DSA. The overall differentiation between stenoses (n=37) and non-stenosed vessels (n=19) revealed a sensitivity of 87% and a specificity of 100%. Conclusion: Analysis of cardiac-gated MR flow curves provides a non-invasive method to assess the hemodynamic significance of RAS and thus allows a functional evaluation in relation to the morphologic characteristics of the stenosis. (orig.) [Deutsch] Ziel der Untersuchung war die Beurteilung der Haemodynamik bei Nierenarterienstenosen mittels Cine-MR-Phasenkontrastflussmessungen. In einem Hundemodell wurde die Cine-MR-Flussmessung validiert, indem fuer unterschiedliche Stenosegrade Vergleichsmessungen mit einer invasiven Transitzeit-Ultraschallreferenztechnik durchgefuehrt wurden. EKG-getriggerte MR-Flusskurven wurden bei 28 Patienten in 56 Nierenarterien mit einer Zeitaufloesung von mindestens 32 ms aufgenommen. Alle Nierenarterienstenosen wurden mittels digitaler Subtraktionsangiographie gesichert. Stoerungen in der renalen Haemodynamik wurden anhand der berechneten MR-Flusskurven mit Hilfe der Parameter `Mittelfluss, `maximale Geschwindigkeit` und `Zeit

  8. Experimental determination of the electronic properties of application-relevant interfaces of organic semiconductors by means of photoelectron spectroscopy; Experimentelle Bestimmung der elektronischen Eigenschaften anwendungsrelevanter Grenzflaechen organischer Halbleiter mittels Photoelektronenspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Grobosch, Mandy

    2009-07-01

    This thesis under the titel Experimental Determination of the Electronic Properties of Application-relevant Interfaces of Organic Semiconductors by means of Photoelectron Spectroscopy was drawn up at the Leibniz Institute for Solid-State and Materials Research (IFW) Dresden at the Institute for Solid-State Research (IFF) under the maintenance of Prof. Dr. B. Buechner. To the scientific study hereby came two types of application-relevant interfaces. On the one hand the influence of the electrode preparation under normal conditions by means of ex-situ purification procedures in comparison to in-situ prepared contacts on the electronic behaviour of the organic semiconductor sexithiophene on interfaces to metallic substrates was studied. As substrate materials hereby the metals silver, palladium, gold, and platinum came to application. In a second study the interfaces of the organic semiconductors sexithiophene and copper(II)-phthalocyanine in contact to thin films of the transition-metal oxide La{sub 0.7}Sr{sub 0.3}MnO{sub 3} were studied. Also here a comparing study for ex-situ and in-situ purificated La{sub 0.7}Sr{sub 0.3}MnO{sub 3} contacts was performed. The films applied for this were fabricated in the IWF Dresden at the Institute for Metallic Materials (IMW). Also in the framework of these studies the influence of oxygen on the electronic and chemical behaviour on the interfaces held the spotlight. [German] Diese Dissertation unter dem Titel Experimentelle Bestimmung der elektronischen Eigenschaften anwendungsrelevanter Grenzflaechen organischer Halbleiter mittels Photoelektronenspektroskopie wurde am Leibniz Institut fuer Festkoerper- und Werkstoffforschung (IFW) Dresden am Institut fuer Festkoerperforschung (IFF) unter der Betreuung von Prof. Dr. B. Buechner angefertigt. Zur wissenschaftlichen Untersuchung kamen hierbei zwei Typen anwendungsrelevanter Grenzflaechen. Zum einem wurde der Einfluss einer Elektrodenpraeparation unter Normalbedingungen mittels ex

  9. Gd-DTPA-enhanced T{sub 1}-weighted excretory MR urography after low-dose diuretic injection; T{sub 1}-gewichtete MR-Ausscheidungsurographie mittels Gd-DTPA und vorheriger niedrigdosierter Gabe eines Diuretikums

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.; Buecker, A.; Adam, G.; Neuerburg, J.; Guenther, R.W. [Universitaetsklinikum der RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    1997-09-01

    Purpose: Assessment of the morphology of the urinary tract by gadolinium(Gd)-enhanced T{sub 1}-weighted MR-urography (MRU) and precontrast diuretic injection. Methods: MRU was performed in 5 patients using Gd-DTPA-enhanced coronal T{sub 1}-weighted 3D-gradient-echo sequences with different spatial resolution. Prior to contrast injection, 10 mg of furosemide were administered intravenously. Results: Secondary to the precontrast furosemide injection, the increase of the renal excretion rate allows complete visualisation of the entire collecting system within 10 minutes following Gd injection. Maximum intensity projections provide a three-dimensional overview of the ureters separate from the bladder. To achieve detailed anatomic imaging of the calices, both optimal distension and high resolution sequences are prerequisites which cannot be realized by means of survey urograms only. (orig./AJ) [Deutsch] Ziel: Darstellung der Morphologie der ableitenden Harnwege mittels T{sub 1}-gewichteter MR-Urographie (MRU) nach Gabe eines nierengaengigen Gadolinium(Gd)-Chelates und vorheriger Diuretikumapplikation. Methoden: Der Harntrakt von 5 Patienten wurde nach Injektion von Gd-DTPA mit koronaren T{sub 1}-gewichteten 3D-Gradienten-Echo-Sequenzen unterschiedlicher Ortsaufloesung untersucht. Vor der Kontrastmittelgabe wurden jeweils 10 mg Furosemid intravenoes verabreicht. Ergebnisse: Nach initialer Steigerung des Harnflusses durch Furosemidgabe wurden Uebersichtsurogramme mit vollstaendig durchzeichnenden Ureteren bereits 10 min nach Gd-Injektion erzielt. Maximumintensitaetsprojektionen ermoeglichten die Beurteilung des dreidimensionalen Verlaufes der Ureteren ohne Blasenueberlagerung. Eine genauere anatomische Darstellung der Nierenkelche erforderte neben einem guten Fuellungszustand eine moeglichst hohe Sequenzaufloesung, die mit Uebersichtsurogrammen allein nicht zu erreichen war. (orig./AJ)

  10. Development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide applying high throughput methods; Entwicklung neuer heterogener Katalysatoren zur Spaltung von Methanol in Wasserstoff und Kohlenmonoxid mittels Hochdurchsatz-Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Torsten

    2008-07-11

    The topic of this thesis has been the development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide. As an important constraint here, the content of noble metals of the catalysts should be as low as possible. High-throughput-methods were applied in some of the syntheses and experiments to accelerate the development, as, for example, the use of liquid based sol-gel syntheses and the examination of catalyst libraries by spatial resolution gas chromatography. This screening technique allowed to test up to 207 different substances during one single experiment. Then, different combinatorial strategies were applied. First, these methods led to a highly active and stable catalyst in the ternary system of Cu-Ni-Zn, which showed high conversion and selectivity comparable to an industrial reference catalyst. Its activity during an 18 hour long term run was constant in contrast to the reference. Second, an additional approach starting from a broader variety of elements led to a Ce- Ru- and to a Cr-Ru-catalyst. Both of them were highly active in short term experiments, but lost their outstanding performances during long term runs. (orig.) [German] Die vorliegende Arbeit befasste sich mit der Entwicklung neuer heterogener Katalysatoren fuer die Spaltung von Methanol zu Wasserstoff und Kohlenmonoxid, die einen moeglichst geringen Gehalt an Edelmetallen aufweisen sollten. Um diesen Prozess zu beschleunigen, wurden in einem Teil der Synthesen und Experimente Hochdurchsatzmethoden verwendet. Neben der Roboter gestuetzten Sol-Gel-Synthese umfasste dies die Untersuchung von Katalysatorbibliotheken mittels ortsaufgeloester Gaschromatographie, die es ermoeglichte, in einem Experiment bis zu 207 verschiedene Substanzen auf ihre katalytische Aktivitaet zu testen. Unter Anwendung verschiedener kombinatorischer Strategien wurde zunaechst ein sehr aktiver und stabiler Katalysator im ternaeren Cu-Ni-Zn-System entdeckt. Neben Umsaetzen und

  11. Metal recovery via geobiotechnology; Metallgewinnung mittels Geobiotechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Hedrich, Sabrina; Schippers, Axel [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany). Fachbereich Geochemie der Rohstoffe

    2017-02-15

    Specialized acidophilic bacteria and archaea are able to extract valuable metals such as copper, gold, cobalt, nickel, zinc, and uranium from sulfide ores. This process is known as bioleaching and its application in the mining industry as biomining. Laboratory studies also demonstrated bioleaching of oxide ores such as laterites and of mining residues such as mine tailings as well as metal recycling from waste (secondary mining). Metals being leached have to be recovered from acidic polymetallic solutions (mine and process waters) which is possible via biosorption or biomineralisation.

  12. Kavitationsdetektion mittels self-sensing-ultraschallwandler

    OpenAIRE

    Bornmann, Peter; Hemsel, Tobias; Sextro, Walter; Memoli, Gianluca; Hodnett, Mark; Zeqiri, Bajram; Bornmann Peter; Hemsel Tobias; Sextro Walter; Memoli Gianluca; Hodnett Mark; Zeqiri Bajram

    2015-01-01

    Many processes in chemistry can be enhanced by ultrasound assistance. In many cases ultrasound induced cavitation is the main reason for these enhancements. Therefore, it is desired to quantify cavitation activity during the process to optimize sonication for various processes and monitor cavitation activity throughout the process. One possibility to monitor cavitation activity is to measure the acoustic emissions of oscillating and collapsing cavitation bubbles by hydrophones in the liquid. ...

  13. Prediction of the pharmacological effect of octreotide in acromegaly by means of {sup 111}In-pentetreotide scintigraphy and calculation of a pituitary uptake index; Praediktion der pharmakologischen Wirkung von Octreotid bei Akromegalie mittels {sup 111}In-Pentetreotid-Szintigraphie und Berechnung eines hypophysaeren Uptake-Index

    Energy Technology Data Exchange (ETDEWEB)

    Goerges, R. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Cordes, U. [Arbeitsgemeinschaft Niedergelassener Endokrinologen, Mainz/Darmstadt (Germany); Engelbach, M. [Mainz Univ. (Germany). III. Medizinische Klinik und Poliklinik; Bartelt, K.M. [Arbeitsgemeinschaft Niedergelassener Endokrinologen, Mainz/Darmstadt (Germany); Haberern, G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Hey, O. [Mainz Univ. (Germany). Neurochirurgische Klinik und Poliklinik; Beyer, J. [Mainz Univ. (Germany). III. Medizinische Klinik und Poliklinik; Bockisch, A. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1997-06-01

    Aim: The aim of our prospective study was to optimize the determination of the pituitary somatostatin receptor status by means of 111-In-pentetreotide scintigraphy and to compare it intraindividually with the pharmacological effect of octreotide in active acromegaly. Methods: In n=22 patients with growth hormone (GH) secreting pituitary adenoma, 111-In-penetreotide scintigraphy was performed, and the specific radionuclide accumulation in the pituitary area (evaluation visually as well as semiquantitatively by means of ROI technique and calculation of various uptake indices) was correlated with the acute drop of GH after administration of 100 {mu}g octreotide s.c. (octreotide acute test). Results: The uptake index we propose (cts/pixel-ratio circular pituitary ROI: Irregular cerebrum ROI after background correction in the sagittal SPECT slice with maximum pituitary uptake 24 h p.i.) correlates best with the pharmacological effect (acute decrease of GH levels) of octreotide; its upper normal limit amounts of 3.5. Conclusion: As often the normal pituitary gland can be visualized scintigraphically, the purely visual differentiation between a normal and pathological receptor status sometimes is equivocal. A pituitary uptake index, calculated by means of a standardized ROI technique, facilitates this discrimination and so contributes to select possible responders for a treatment with octreotide. (orig.) [Deutsch] Ziel: Ziel unserer prospektiven Studie war die optimierte Bestimmung des hypophysaeren Somatostatin-Rezeptorstatus in der 111-In-Pentetreotid-Szintigraphie und der intraindividuelle Vergleich mit dem pharmakologischen Effekt von Octreotid bei florider Akromegalie. Methoden: Bei n=22 Patienten mit Wachstumshormon-(GH)-sezernierendem Hypophysenadenom wurde eine 111-In-Pentetreotid-Szintigraphie durchgefuehrt und die spezifische Nuklidakkumulation in der Hypophysenregion (Auswertung sowohl visuell als auch semiquantitativ mittels ROI-Technik und Berechnung

  14. Engineering geological and hydrogeological invstigations for storage of medium and low-activity nuclear waste at Cernavoda, Romania. Soil stabilisation using the CONSOLID system; Ingenieurgeologische und hydrogeologische Untersuchungen zur Lagerung mittel- und schwachradioaktiver Abfaelle in Cernavoda Rumaenien. Baugrundstabilisierung mit dem CONSOLID-System

    Energy Technology Data Exchange (ETDEWEB)

    Giurgea, V.; Merkler, G.P.; Hoetzl, H.; Hannich, D. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie

    1998-12-31

    In Cernavoda/Romania investigations and planning from a low and middle radioactive waste disposal site have been carried out. A multitude of hydrogeological, geological, engineering geological criteria`s and constructional security measures were examined with respect to the strict regulations for such a waste site. This studies and measures are shortly analyzed and discussed in this paper. In accordance with the selection criteria for such a hazardous waste site, several laboratory and `in situ` tests, soil-mechanic studies, numerical modeling and foundation tests for soil stabilization with the CONSOLID-System are presented. (orig.) [Deutsch] Zur Einhaltung der strengen Vorgaben, die bei einem Deponiestandort fuer mittel- und schwachradioaktive Abfaelle gestellt werden, sind in Cernavoda/Rumaenien eine Vielzahl von hydrogeologischen und ingenieurgeologischen Untersuchungen sowie bautechnischen Sicherungsmassnahmen vorgesehen, die im Rahmen dieser Publikation kurz analysiert und diskutiert werden. Im Zusammenhang mit den geologischen und hydrogeologischen Auswahlkriterien des Standortes werden eine Reihe von Labor- und `in situ` Untersuchungen, Modellrechnungen sowie Baugrundstabilisierungsmassnahmen mit dem CONSOLID-System vorgestellt. (orig.)

  15. Clinical value of FDG hybrid-PET in staging and restaging of malignant lymphoma. Compared with conventional diagnostic methods; Klinische Wertigkeit der Befunde von FDG-PET mittels Koinzidenz-Gammakamera beim Staging und Restaging maligner Lymphome. Ein Vergleich zu konventioneller Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Pichler, R.; Maschek, W.; Hatzl-Griesenhofer, M.; Huber, H. [Allgemeines Krankenhaus Linz (Austria). Inst. fuer Nuklearmedizin; Wimmer, G.; Wahl, G.; Fridrik, M. [Allgemeines Krankenhaus Linz (Austria). I. Medizinische Abt.

    2000-09-01

    Aim of the present retrospective study was to validate the clinical value of F-18-FDG PET imaging in lymphoma patients with a dual head camera modified for coincidence detection. Staging before and after oncological treatment was compared with a conservative diagnostic approach. Methods: 48 patients (28 non-Hodgkin lymphoma, 20 Hodgkin's disease) received FDG-Hybrid-PET scans. Pretherapeutic staging was realized in 28 patients, 9 of them had control studies after they had completed therapy. Totally 29 persons were examined for posttherapeutic restaging. Computed tomography imaging and lymph node sonography was performed in all cases. Results were validated by clinical follow-up, in three cases a recidive was proven by biopsy. Results: CT and ultrasound detected 77 lesions in 28 patients compared with 100 visualized by PET, but this difference in pretherapeutic staging did not reach significance at p>0.05 by Fisher's t-test. Hybrid-PET obtained a sensitivity of 93%, a specifity of 79%, a positive of 82% and a negative predictive value of 92% for detection of residual disease. The values for CT+US were 87%, 64%, 72% and 88% respectively. Conclusion: FDG Hybrid-PET is as or even more accurate than standard morphologic diagnostic methods for prestaging in malignant lymphoma. Additionally, there is a substancial benefit for therapy monitoring of residual disease using coincidence detection PET with a 3/4-inch crystal gamma camera. (orig.) [German] Ziel der vorliegenden retrospektiven Studie war die Validierung der klinischen Wertigkeit von F-18-FDG-PET mittels Doppelkopf-Koinzidenz-Gammakamera bei Lymphompatienten. Die Ergebnisse von prae- und post-therapeutischem Staging wurden mit dem konservativ bildgebender Verfahren verglichen. Methoden: 48 Patienten (28 NHL, 20 Morbus Hodgkin) erhielten FDG-DK-PET-Untersuchungen. Ein praetherapeutisches Staging wurde bei 28 Patienten durchgefuehrt, 9 von diesen hatten weitere Kontrollstudien nach abgeschlossenem

  16. Determination of left ventricular heart volume by fast MRI in breath-hold technique: how different are quantitative ventricular angiography, quantitative MRI, and visual echocardiography?; Linksventrikulaere Herzvoluminabestimmung mittels schneller MRT in Atemanhaltetechnik: Wie unterschiedlich sind quantitativer Herzkatheter, quantitativer MRT und visuelle Echokardiographie?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F. [Giessen Univ. (Germany). Diagnostische Radiologie; Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Pabst, W. [Giessen Univ. (Germany). Inst. fuer Medizinische Informatik; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Dinkel, H.P.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie

    2000-01-01

    . Ergebnisse: Der HK ueberschaetzte die EF im Vergleich zur MRT um 8,4%, Echo unterschaetzte sie im Mittel um 5,6%. Der Toleranzbereich der EF von MRT und HK betrug {+-}23,8%, vom MRT und Echo {+-}18% und von Echo und HK {+-}19,4%. Signifikante Mittelwertunterschiede zwischen HK und MRT in der Herzvoluminabestimmung ergaben sich fuer EDV, SV und HZV, nicht aber fuer ESV. Die groesste Uebereinstimmung der EF bestand in der Gruppe mit DCM, die schlechteste in der Gruppe mit KV. Schlussfolgerung: Deutliche zufaellige und systematische Abweichungen sind im Methodenvergleich von MRT, Echo und HK zu erwarten. Fuer Therapieentscheidung und Verlaufskontrolle sollten die Methoden nicht bedenkenlos ausgetauscht werden. (orig.)

  17. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study; Zerebrale Metastasendiagnostik mittels Standarddosis Gadobutrol vs. einem Hochdosisprotokoll. Intraindividuelle Evaluierung einer Phase-II-Hochdosisstudie

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Friebe, C.E. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Balzer, T. [Schering AG, Berlin (Germany); Mack, M.G. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, S. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Pegios, W. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Lanksch, W. [Neurologische Klinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Banzer, D. [Behring Krankenhaus, Berlin (Germany); Felix, R. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1995-08-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [Deutsch] In einer Phase-II-Studie wurden 20 Patienten mit zerebralen Metastasen eines Primaertumors ausserhalb des ZNS mit dem nichtionischen, paramagnetischen Kontrastmittel Gadobutrol magnetresonanztomographisch untersucht. T1- und T2-gewichtete Nativsequenzen und T1-gewichtete Postkontrastsequenzen wurden gemessen nach einer Dosis von 0,1 mmol/kg KG und nach einer additiven Dosis von 0,2 mmol/kg KG Gadobutrol 10 min nach Erstinjektion. Mittels Turbo-FLASH-Sequenzen wurde die Dynamik der Konstrastmittelanreicherung gemessen. Die klinischen und laborchemischen Untersuchungen

  18. Efeitos da eletroestimulação do músculo vasto medial oblíquo em portadores de síndrome da dor patelofemoral: uma análise eletromiográfica Effects of electrical stimulation of vastus medialis obliquus muscle in patients with patellofemoral pain syndrome: an electromyographic analysis

    Directory of Open Access Journals (Sweden)

    Fabiana R. Garcia

    2010-12-01

    Full Text Available CONTEXTUALIZAÇÃO: O uso da eletromiografia de superfície (EMG-S tem sido considerado como instrumento de avaliação quantitativa na síndrome da dor patelofemoral (SDPF. Tratamentos conservadores objetivam melhorar o alinhamento patelar, e a estimulação elétrica do músculo vasto medial oblíquo (VMO tem sido considerada por ser seletiva e não causar irritação articular. OBJETIVO: Verificar o efeito de um programa de fortalecimento muscular com estimulação elétrica do VMO na SDPF por meio da capacidade de avaliação da EMG-S. MÉTODOS: Participaram deste estudo 10 mulheres jovens (idade: 23,1±4,9 anos; massa corporal: 66,8±14,0 kg; estatura: 1,63±6,9 cm; IMC: 25,1±5,6 kg/m² com SDPF unilateral, as quais realizaram o teste funcional de subir degrau para captação da atividade eletromiográfica dos músculos VMO e vasto lateral (VL, antes e após um programa de estimulação elétrica do VMO. A eletroestimulação foi realizada três vezes por semana, durante seis semanas. Foram consideradas, para análise entre VMO e VL, as variáveis razão do tempo do início até o pico de ativação, razão da integral do sinal (teste t para amostras dependentes e diferença de início de ativação (teste de Wilcoxon, com n��vel de significância de pBACKGROUND: The use of surface electromyography (SEMG has been considered a tool for quantitative assessment of patellofemoral pain syndrome (PFPS. Conservative treatments aim to improve patellar alignment, and electrical stimulation of the vastus medialis obliquus (VMO muscle has been considered effective because it is selective and does not cause joint irritation. OBJECTIVE: This study aims to investigate the efficiency of a muscle strengthening program with electrical stimulation of the VMO muscle in PFPS by SEMG. METHODS: A group of ten young women (age: 23.1±4.9 years; body mass: 66.8±14.0 kg; height: 1.63±6.9 cm; BMI: 25.1±5.6 kg/m² with unilateral PFPS participated in the

  19. Das Gesprächsführungspraktikum im 2. Studienjahr des Modellstudiengangs HannibaL: Eine Evaluation mittels Selbsteinschätzungen der Studierenden [The communication skills course for second year medical students at Hannover Medical School: An evaluation study based on students' self-assessments

    Directory of Open Access Journals (Sweden)

    von Lengerke, Thomas

    2011-11-01

    . Regarding methods, the deployed simulated patients (2-4 per 10-student-course group in 3 of the 7 course sessions, respectively were rated the most helpful. The present evaluation calls for both further development of the doctor-patient communication curriculum at the MHH and joint activities across medical schools, which are discussed at the end of the paper. [german] Im MHH-Modellstudiengang HannibaL werden Gesprächsführungskompetenzen für Anamneseerhebung und Diagnosemitteilung durch eine Objective Structured Clinical Examination (OSCE geprüft, die Teil der dem Ersten Abschnitt der Ärztlichen Prüfung äquivalenten Prüfungen sind. Das vorbereitende Gesprächsführungspraktikum im 2. Studienjahr wurde 2009/10 evaluiert.Mittels lernzielspezifischer Fragebogen wurden der Lernbedarf erhoben, Vorher-Nachher-Vergleiche der selbsteingeschätzten Kompetenzen durchgeführt und zentrale Lehrmethoden bewertet (5-Punkt-Likertskalen, „5“=hohe Ausprägung. Zu T0 (Beginn des Praktikums nahmen 267 Studierende teil (Teilnahmerate: 93,7%, von denen 180 den T1-Fragebogen beim letzten Praktikumstermin ausfüllten (67,4%. Es wurden Varianzanalysen mit Messwiederholungsfaktor und T-Tests für verbundene Stichproben durchgeführt. Die höchsten Lernbedarfe zeigten sich bei den „to show how“-Items zu Anamneseerhebung und Diagnosemitteilung (M=4,4. Die T1-T0-Vergleiche zeigten die größten Verbesserungen bei den anamnesespezifischen Items („to know how“: Mittelwertsdifferenz=+1,7, „to show how“:+1,8, p<.0001 wie bei allen Tests und beim „to know how“-Item zur Diagnosemitteilung (+1,6, gefolgt von der Umsetzung einer Diagnosemitteilung (+1,4, partizipativer Entscheidungsfindung (+1,2, der Einschätzung eigener Stärken/Schwächen (+1,0 und dem sicheren Zugehen auf neue Patienten (+0,7. Studierende mit T0-Werten von „1“ oder „2“ auf den jeweiligen Skalen verbesserten sich über alle Items im Mittel um 2,2 Punkte, solche mit „3“ um 1,1, und mit „4“ oder

  20. Investigations on avoidance of hot cracks during laser welding of austenitic Cr-Ni steels and nickel-based alloys using temperature field tailoring. Final report; Untersuchungen zur Vermeidung von Heissrissen beim Laserstrahlschweissen von austenitischen Cr-Ni-Staehlen und Nickelbasislegierungen mittels Temperaturfeld-Tailoring. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-08

    . Zweitens wird bei rotationssymmetrischen Bauteilen, die mittels einer Axial-Rundnaht zu verschweissen sind, mit einem relativ einfachen Temperaturfeld, das durch Erwaermung des innen liegenden Fuegepartners vor und waehrend des Schweissens aufgebaut wird, ein Spannungsfeld erzeugt, das die Bildung von Heissrissen verhindert. Schliesslich konnte drittens ein heissrissfreies Laserstrahlschweissen des Stahls 1.4305 und der Nickelbasislegierung Udimet 720 bereits ohne den Einsatz zusaetzlicher Temperaturfelder erreicht werden. Die Grenzen der Einsetzbarkeit des Verfahrens bei Cr-Ni-Staehlen werden dann erreicht, wenn Quer-Heissrisse oder parallel zur Blechoberflaeche liegende Heissrisse entstehen. Die zur Vermeidung dieser Risse noetigen Druckspannungen in den Richtungen parallel zur Schweissnaht bzw. senkrecht zur Blechoberflaeche koennen mittels induktiver Erwaermung von der Blechoberseite aus nicht in der erforderlichen Groesse erzeugt werden. Ebenso stoesst das Verfahren an seine Grenzen, wenn Wiederaufschmelzungsrisse auftreten, was beim hier verwendeten Stahl 1.4435 der Fall war. Die Spannungen, die zur Verhinderung einer Rissoeffnung an den Korngrenzen der Waermeeinflusszone erforderlich waeren, konnten durch Temperaturfeld-Tailoring nicht erreicht werden. Die Moeglichkeit des heissrissfreien Schweissens des Stahls 1.4305 auch ohne Temperaturfeld-Tailoring ergibt sich hauptsaechlich aus dem primaer ferritischen Erstarrungsmodus des Stahls in der vorliegenden Legierungszusammensetzung. Ein industrieller Einsatz des Laserstrahlschweissens fuer diesen oft als nicht schweissbar klassifizierten Stahl erscheint moeglich, wenn bei der Legierungszusammensetzung auf niedrige Anteile der Austenitbildner Nickel, Kohlenstoff und Stickstoff Wert gelegt wird und damit eine stabil primaer ferritische Erstarrung erreicht wird. Fuer diesen Fall kommt es nicht zur Schwefelanreicherung an den Korngrenzen, wodurch die Bildung niedrigschmelzender Phasen und damit die Heissrissentstehung

  1. Quality characteristics of rice inoculated with Inonotus obliquus ...

    African Journals Online (AJOL)

    latif

    2013-08-14

    Aug 14, 2013 ... scavenging activity, Hunter`s color values, free amino acid content, and mineral content were investigated. ... important foods in the human diet and one of the most extended cereal crops ...... Gluten-Free Cereal Products and.

  2. The dynamics of oil accumulation in Scenedesmus obliquus

    NARCIS (Netherlands)

    Breuer, G.

    2015-01-01

    .Abstract long

    Global demands for food and biofuels increase rapidly, together with an increase of concerns for depleting fossil resources and climate change. New sustainable sources of vegetable oil, from now on referred to as triacylglycerol (TAG), are therefore highly

  3. Treatment of malignant biliary occlusion by means of transhepatic percutaneous biliary drainage with insertion of metal stents - results of an 8-year follow-up and analysis of the prognostic parameters; Behandlung der malignen Gallenwegsstenose mittels perkutaner transhepatischer Metallendoprothesenimplantation: 8 Jahres-Ergebnisse und Analyse prognostischer Faktoren

    Energy Technology Data Exchange (ETDEWEB)

    Alfke, H.; Alfke, B.; Froelich, J.J.; Klose, K.J.; Wagner, H.J. [Klinik fuer Strahlendiagnostik Philipps Univ. Marburg (Germany)

    2003-08-01

    praediktive Faktoren fuer Ueberleben und Offenheitsraten zu detektieren. Methode: In einer retrolektiven Analyse wurden 130 Patienten evaluiert. Nachsorgedaten wurden anhand der Krankenakten und eines Telephoninterviews erhoben. Verfahrensassoziierte Daten waren prospektiv in einer Datenbank erhoben worden. Univariate und multivariate Vergleiche der Ueberlebens- und Offenheitsraten wurden mittels Kaplan-Meier-Analyse mit Log-Rank-Test fuer verschiedene Tumorentitaeten durchgefuehrt. Praediktive Faktoren fuer das Ueberleben und die 30-Tages-Mortalitaet wurden durch eine schrittweise logistische Regression evaluiert. Ergebnisse: Ursachen fuer die maligne Gallenwegsobstruktion waren Cholangiokarzinome (n=50), Pankreaskarzinome (29), Lebermetastasen (27), Gallenblasenkarzinome (20) und andere (4). Die technische Erfolgsrate betrug 99%, die Komplikationsrate 27% und die 30-Tages-Mortalitaet 11%. Die primaere Stentoffenheitsrate (406 Tage, Median 207) unterschied sich nicht signifikant fuer die verschiedenen Tumorentitaeten. Die Ueberlebensrate war fuer Patienten mit Cholangiokarzinomen in der univariaten Analyse signifikant besser (p=0,03 Log-Rank-Test). Die multiple Regressionsanalyse detektierte keine praediktiven Faktoren fuer das Ueberleben und die 30-Tages-Mortalitaet. Schlussfolgerungen: Die perkutane transhepatische Metallendoprothesenimplantation bietet den Patienten eine gute kurz- und langfristige palliative Therapie des Ikterus an. Obwohl die Ueberlebenszeit fuer Patienten mit Cholangiokarzinomen signifikant laenger ist, fehlen klare praediktive Faktoren fuer ein laengeres Ueberleben und eine erhoehte 30-Tages-Mortalitaet. (orig.)

  4. Decarbonization by means of hydrogen; Dekarbonisierung mittels Wasserstoff

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Ulrich [Siemens AG, Muenchen (Germany). Research in Energy and Electronics, Corporate Technology

    2018-01-15

    Hydrogen electrolysis plays a crucial role in reducing CO{sub 2} emissions. With the help of regeneratively generated electricity, it converts water into its constituents hydrogen and oxygen without producing carbon dioxide. Experts are working on the still young PEM technology, which is particularly efficient and environmentally friendly. The holistic optimization of the plant plays an important role. [German] Wasserstoffelektrolyse spielt eine entscheidende Rolle, um CO{sub 2}-Emissionen einzudaemmen. Mit Hilfe regenerativ erzeugtem Strom wandelt sie Wasser in seine Bestandteile Wasserstoff und Sauerstoff um, ohne dass dabei Kohlenstoffdioxid entsteht. Experten arbeiten an der noch jungen PEM-Technologie, die besonders effizient und umweltvertraeglich ist. Eine wichtige Bedeutung hat dabei die ganzheitliche Optimierung der Anlage.

  5. Sliding bearing diagnosis with magnetic field measuring; Gleitlagerdiagnose mittels Magnetfeldmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Bittner, H. [HWTS Zittau (Germany). Fachgebiet Instandhaltung/Technische Diagnostik; Kluth, T. [HWTS Zittau (Germany). Fachgebiet Instandhaltung/Technische Diagnostik

    1995-09-01

    Account of their properties sliding bearings are in high demanded and important aggregats. The destruction of a bearing will be almost followed by the destruction of the aggregate. Various methods are existing for sliding bearing diagnosis. This methods often not permit the condition recognition. A new electromagnetical method will be developed. This method permits the condition recognition during working time of the aggregate. It also permits the recognition of wear. The method bases on a measuring of leak current over measuring the generated magnetic fields with Rogowski-coils. (orig.) [Deutsch] Gleitlager befinden sich wegen ihrer Eigenschaften in hoch beanspruchten und exponierten Aggregaten. Die Zerstoerung eines Gleitlagers fuehrt meist auch zur Zerstoerung des gefuehrten Aggregats. Zur Gleitlagerdiagnose existiert eine Reihe Verfahren. Ihnen wird ein elektromagnetisches Verfahren gegenuebergestellt. Damit koennen Gleitlagerzustaende waehrend des Aggregatebetriebs identifiziert werden. Das Verfahren erlaubt gleichermassen die Bestimmung des Lagerverschleisses. Es basiert auf der Ableitstrommessung, bei der sich ausbildende Magnetfelder durch Rogowskispulen ausgemessen werden. (orig.)

  6. Oberflaechenverbesserung im 3D-Druck mittels hoeherer Aufloesung

    OpenAIRE

    Ederer, Ingo

    2008-01-01

    Mit pulvergestützten 3D-Druckprozessen verbindet der Anwender bislang vor allem eine hohe Prozessgeschwindigkeiten bei mäßiger Genauigkeit und Oberflächenqualität. Dass das auch anders geht zeigt der vorliegende Artikel.

  7. Investigation of the local fracture toughness and the elastic-plastic fracture behavior of NiAl and tungsten by means of micro-cantilever tests; Untersuchung der lokalen Bruchzaehigkeit und des elastisch-plastischen Bruchverhaltens von NiAl und Wolfram mittels Mikrobiegebalkenversuchen

    Energy Technology Data Exchange (ETDEWEB)

    Ast, Johannes

    2016-07-01

    . This is linked to the thermally activated dislocation mobility which is more constrained in those samples. Investigations on plastically predeformed samples were performed in order to study the influence of the dislocation density on the fracture behavior. It was found that the fracture toughness was again not affected but that the predeformed samples failed at an earlier stage at lower J-integrals. This is due to the lower mobility of the dislocations emitted from the crack tip in consequence of the high amount of strain hardening and the higher flow stress in those samples. Experiments in ultrafine-grained tungsten revealed a fracture behavior which was more brittle than expected. A single grain at the crack front with its crystallographic orientation being prone to cleavage failure can decisively influence the fracture behavior at the micro scale. [German] Das Ziel dieser Arbeit war es, ein verbessertes Verstaendnis fuer die Groessenabhaengigkeit der Bruchzaehigkeit zu gewinnen. Hierfuer wurden mittels fokussierter Ionenstrahlen gekerbte Mikrobiegebalken in verschiedenen Groessen vom Submikrometerbereich bis hin zu einigen 10 μm in B2-NiAl und Wolfram praepariert. Diese beiden Materialien besitzen charakteristische Sproed-Duktil-Uebergange, die oberhalb der Raumtemperatur liegen. Dies erlaubte es, Bruchvorgaenge, welche von begrenzter plastischer Verformung um die Rissspitze begleitet werden, auf der Mikroskala zu untersuchen. Neue Methoden zur Beschreibung und Bestimmung des lokalen elastisch-plastischen Bruchverhaltens bzw. der Bruchzaehigkeit wurden hierfuer erarbeitet. Im Speziellen wurde das J-Integral-Konzept zur Ermittlung von Rissfortschritt ueber Steifigkeitsmessungen auf die Mikroskala uebertragen. Dies ermoeglichte eine praezise Analyse des fuer die Bruchzaehigkeit charakteristischen Uebergangs von Rissabstumpfung zu stabilem Rissfortschritt. Die Versuche an einkristallinem NiAl fuer die beiden untersuchten Risssysteme der harten und weichen Orientierung

  8. Nanoplastic affects growth of S. obliquus and reproduction of D. magna

    NARCIS (Netherlands)

    Besseling, E.; Wang, B.; Lürling, M.F.L.L.W.; Koelmans, A.A.

    2014-01-01

    The amount of nano- and microplastic in the aquatic environment rises due to the industrial production of plastic and the degradation of plastic into smaller particles. Concerns have been raised about their incorporation into food webs. Little is known about the fate and effects of nanoplastic,

  9. Cultivation of Scenedesmus obliquus in liquid hydrolysate from flash hydrolysis for nutrient recycling

    Science.gov (United States)

    Barbera, Elena; Sforza, Eleonora; Kumar, Sandeep; Morosinotto, Tomas; Bertucco, Alberto

    2016-01-01

    The production of biofuels from microalgae is associated with high demands of nutrients (nitrogen and phosphorus) required for growth. Recycling nutrients from the residual biomass is essential to obtain a sustainable production. In this work, the aqueous phase obtained from flash hydrolysis of Scenedesmus sp. was used as cultivation medium for a microalga of the same genus, to assess the feasibility of this technique for nutrient recycling purposes. Batch and continuous cultivations were carried out, to determine growth performances in this substrate compared to standard media, and verify if a stable biomass production could be obtained. In continuous experiments, the effect of hydrolysate inlet concentration and of residence time were assessed to optimize nutrient supply in relation to productivity. Results obtained show that nutrient recycling is feasible by treating biomass with flash hydrolysis, and Scenedesmus is capable of recycling large amounts of recovered nutrients. PMID:26868157

  10. Bioenergetic reprogramming plasticity under nitrogen depletion by the unicellular green alga Scenedesmus obliquus.

    Science.gov (United States)

    Papazi, Aikaterini; Korelidou, Anna; Andronis, Efthimios; Parasyri, Athina; Stamatis, Nikolaos; Kotzabasis, Kiriakos

    2018-03-01

    Simultaneous nitrogen depletion and 3,4-dichlorophenol addition induce a bioenergetic microalgal reprogramming, through strong Cyt b 6 f synthesis, that quench excess electrons from dichlorophenol's biodegradation to an overactivated photosynthetic electron flow and H 2 -productivity. Cellular energy management includes "rational" planning and operation of energy production and energy consumption units. Microalgae seem to have the ability to calculate their energy reserves and select the most profitable bioenergetic pathways. Under oxygenic mixotrophic conditions, microalgae invest the exogenously supplied carbon source (glucose) to biomass increase. If 3,4-dichlorophenol is added in the culture medium, then glucose is invested more to biodegradation rather than to growth. The biodegradation yield is enhanced in nitrogen-depleted conditions, because of an increase in the starch accumulation and a delay in the establishment of oxygen-depleted conditions in a closed system. In nitrogen-depleted conditions, starch cannot be invested in PSII-dependent and PSII-independent pathways for H 2 -production, mainly because of a strong decrease of the cytochrome b 6 f complex of the photosynthetic electron flow. For this reason, it seems more profitable for the microalga under these conditions to direct the metabolism to the synthesis of lipids as cellular energy reserves. Nitrogen-depleted conditions with exogenously supplied 3,4-dichlorophenol induce reprogramming of the microalgal bioenergetic strategy. Cytochrome b 6 f is strongly synthesized (mainly through catabolism of polyamines) to manage the electron bypass from the dichlorophenol biodegradation procedure to the photosynthetic electron flow (at the level of PQ pool) and consequently through cytochrome b 6 f and PSI to hydrogenase and H 2 -production. All the above showed that the selection of the appropriate cultivation conditions is the key for the manipulation of microalgal bioenergetic strategy that leads to different metabolic products and paves the way for a future microalgal "smart" biotechnology.

  11. Comparative study of zooid and non-zooid forming strains of Scenedesmus obliquus. Physiology and cytomorphology

    Czech Academy of Sciences Publication Activity Database

    Cepák, Vladislav; Přibyl, Pavel; Kvíderová, Jana; Lukavský, Jaromír

    2006-01-01

    Roč. 51, č. 4 (2006), s. 349-356 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA204/03/1113; GA MŠk(CZ) 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : physiology * zooids * Scenedesmus Subject RIV: EF - Botanics Impact factor: 0.963, year: 2006

  12. Individualisierender Unterricht in der Hochschullehre mittels einer IT-unterstützten Stationsarbeit

    Directory of Open Access Journals (Sweden)

    Kai Gebhardt

    2018-03-01

    Full Text Available Participants in university courses have different types of education and knowledge. In this case the didactic principle of differentiation is very important. We present the Analyzed Classroom teaching concept using an IT-system for analyze the learning progress. Students use tablets working on their exercises. The system creates a documented assessment of competence level for each student. The teacher can use the results for planning next steps into current exercise. We evaluated this concept in summer semester 2016 at Friedrich-Schiller-Universität Jena.

  13. Solar photocatalytic cleaning of polluted water. Solare Reinigung verschmutzter Waesser mittels Photokatalyse

    Energy Technology Data Exchange (ETDEWEB)

    Bockelmann, D

    1994-01-01

    Alternatively to biological, physical and chemical methods of waste water cleaning, photocatalysis can be employed. In this residue-free method, titanium dioxide particles are brought into contact with polluted water as photocatalysts. Under UV irradiation at wave-lengths below 400 nm, change carriers are generated in the semiconductor particles that act so intensely oxidizing as to completely degrade almost all organic pollutants in waste water. In this process, the ultra-violet part of the solar spectrum can be harnessed to generate oxidation equivalents. Thus, solar photocatalytic waste water cleaning is excellently suited for developing countries. (BWI)

  14. Mehrkörpersimulation eines ebenen Koppelgetriebes mittels Matlab / ADAMS -Co-Simulation

    OpenAIRE

    Gollee, Christian; Troll, Clemens

    2017-01-01

    Mit Hilfe der Matlab/ADAMS-Co-Simulation wird ein ebenes Koppelgetriebe (5- Gelenk) untersucht und anschließend die Wirkpaarung mit einem Stückgut betrachtet. Dabei werden verschiedene Modellierungsstufen angewendet und die Simulationsergebnisse Messergebnissen vom Versuchsstand gegenübergestellt. Daneben wird die grundlegende Herangehensweise beim Einsatz dieser Simulationswerkzeuge erläutert.

  15. Depths of controlled drillings by means of underground drives; Teufen von gesteuerten Bohrungen mittels Untertageantrieben

    Energy Technology Data Exchange (ETDEWEB)

    Hengevoss, Charly [Weatherford Ukraine LLC, Kiev (Ukraine); Homrighausen, Reiner [BAUER Resources GmbH, Schrobenhausen (Germany)

    2013-03-01

    Today, the most modern directional drilling technology not only is used in case of very deep drillings (deeper or longer than 2,000 meter) by means of deep-level drilling rigs, but also with small, highly mobile universal drilling rigs. Thus, drilling costs are reduced, and unconventional hydrocarbons (methane gas - oil shale and shale gas) deposits are explores economically. Furthermore, known near-surface petroleum deposits in Northern Germany as well as in other parts of the Earth (such as in Romania, the U.S.A. or in Canada) which extraction of petroleum is very low already are interesting economically. Furthermore, today it is possible to investigate with controlled drillings more economically and with more safe sites for a possibly final storage of highly radioactive wastes. Controlled drillings may give an answer to geotechnical questions on highly inaccessible on optimum points for drilling wells in order to plan underground cavities or to investigate tunnel axes geotechnical or hydrological.

  16. Light out-coupling from LEDs by means of metal nanoparticles; Lichtauskopplung aus LEDs mittels Metallnanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Goehler, Tino

    2010-12-17

    The external quantum efficiency of light-emitting diodes (LEDs) based on Al- GaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called ''Fischer pattern nanolithography'' and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data. (orig.)

  17. Bio- und Medizinethik in Ländern Mittel- und Osteuropas. Eine Hinführung

    Czech Academy of Sciences Publication Activity Database

    Bartíková, Monika; Banse, G.

    2007-01-01

    Roč. 16, č. 1 (2007), s. 5-20 ISSN 1210-0250 Institutional research plan: CEZ:AV0Z90090514 Keywords : Bioethics * Medical ethics * Middle and Eastern European Countries Subject RIV: AA - Philosophy ; Religion

  18. Funktionsintegration mittels Laserstrahlschmelzen - metallischer 3D-Druck für innovative Bauteile und Werkzeuge

    OpenAIRE

    Müller, Bernhard; Töppel, Thomas

    2017-01-01

    Laserstrahlschmelzen, ein pulverbettbasiertes additives Fertigungsverfahren, bietet zahlreiche Möglichkeiten, in Werkzeuge und Bauteile bestehende Funktionalitäten zu verbessern bzw. auch völlig neue Funktionalitäten zu integrieren. Dabei ist in drei Gruppen der Funktionalisierung zu unterscheiden: geometrische Funktionalisierung, werkstoffliche Funktionalisierung und integrative Funktionalisierung. Zur geometrischen Funktionalisierung zählen beispielsweise funktionale Hohlräume und Kanäle un...

  19. Erzeugung gleichverteilter Stichproben von Lozenge-Teilungen mittels Kopplung von Markovketten

    OpenAIRE

    Keller, Peter

    2011-01-01

    Aus dem Inhalt: 1 Einleitung 2 Eigenschaften der Lozengeteilungen 3 Coupling From The Past (CFTP) 4 Simulation von uniform verteilten Lozengeteilungen 5 Programmlisting und Diskussion der Implementierung 6 Ausblick A Anhang

  20. Engineering failure assessment methods applied to pressurized components; Bruchmechanische Bewertung druckfuehrender Komponenten mittels ingenieurmaessiger Bewertungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Zerbst, U.; Beeck, F.; Scheider, I.; Brocks, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    1998-11-01

    Under the roof of SINTAP (Structural Integrity Assessment Procedures for European Industry), a European BRITE-EURAM project, a study is being carried out into the possibility of establishing on the basis of existing models a standard European flaw assessment method. The R6 Routine and the ETM are important, existing examples in this context. The paper presents the two methods, explaining their advantages and shortcomes as well as common features. Their applicability is shown by experiments with two pressure vessels subject to internal pressure and flawed by a surface crack or a through-wall crack, respectively. Both the R6 Routine and the ETM results have been compared with results of component tests carried out in the 1980s at TWI and are found to yield acceptable conservative, i.e. sufficiently safe, lifetime predictions, as they do not give lifetime assessments which unduly underestimate the effects of flaws under operational loads. (orig./CB) [Deutsch] Gegenwaertig wird im Rahmen von SINTAP (Structural Integrity Assessment Procedures for European Industries), einem europaeischen BRITE-EURAM-Projekt geprueft, inwieweit auf der Grundlage vorhandener Modelle eine einheitliche europaeische Fehlerbewertungsmethode erstellt werden kann. Eine zentrale Stellung kommt dabei Verfahren wie der R6-Routine und dem ETM zu. In der vorliegenden Arbeit wurden beide Methoden vorgestellt, wobei ihre Vor- und Nachteile, aber auch ihre Gemeinsamkeiten herausgearbeitet wurden. Die Anwendung wurde an zwei innendruckbelasteten Behaeltern mit Oberflaechen- bzw. wanddurchdringendem Riss demonstriert. Sowohl R6-Routine als auch ETM ergaben im Vergleich mit am TWI zu Beginn der 80er Jahre durchgefuehrten Bauteilexperimenten eine vertretbare konservative Vorhersage, d.h. eine nicht allzu grosse Unterschaetzung der ertragbaren Last der Bauteile. (orig.)

  1. The visualization of pannus in rheumatoid arthritis using NMR imaging. Pannusdarstellung bei rheumatoider Arthritis mittels Kernspintomographie

    Energy Technology Data Exchange (ETDEWEB)

    Schnarkowski, P. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Bader, C. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Goldmann, A. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Friedrich, J.M. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany))

    1992-12-01

    The knee joints of 15 patients afflicted with rheumatoid arthritis were investigated using the method of nmr imaging. Parameters of investigation were the spin-echo and fast-field-echo sequences as well as the MR signal behaviour of proliferative synovial changes following intravenous administration of gadolinium dtpa. Pannus having formed on the articular surfaces or beneath the articular cartilages was distinguishable from other changes on the basis of the increased signal intensities to be observed after gadolinium dtpa had been given. (orig./GD)

  2. Untersuchungen zur oxidativen Bildung von Stickstoffmonoxid in Pflanzen sowie zur Visualisierung von Stickstoffmonoxid mittels Fluoreszenzfarbstoffen

    OpenAIRE

    Rümer, Stefan

    2013-01-01

    Stickstoffmonoxid (NO) ist ein gasförmiges, relativ stabiles Radikal, das in Pflanzen u. a. durch Reduktion aus Nitrit unter Katalyse des Enzyms Nitratreduktase gebildet wird. In tierischen Organismen wird NO dagegen über einen oxidativen Syntheseweg aus der Ami-nosäure L-Arginin katalysiert durch verschiedene Isoformen der NO-Synthasen (NOS) hergestellt. Es besitzt im tierischen System vielfältige Funktionen u. a. als Neurotransmitter sowie Blutfluss und -druck regulierendes Agens. Im Pflanz...

  3. Automation of the driving using the dynamic programming; Automatisierung des Treibens mittels diskreter dynamischer Programmierung

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zongru; Buerger, Sebastian; Lohmann, Boris [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Regelungstechnik

    2009-07-01

    Driving is a metal forming process throughout hammering in cold state. It can create almost any 2D and 3D metal sheets using universal tools. During driving, many parameters of the tools and the sheets affect the forming process, which inhibits a complete automation. In this paper, a model based control for a 2D driving process is proposed. The process of stretching L-shaped metal sheets is analytically modelled. Three phases, namely hybrid deformations, material flow as well as springback and inverse bending, describe the deformation process at one stroke. This results in a nonlinear (non-affine), time-discrete state space model. A model predictive controller (MPC) is then designed to determine the optimal control inputs at every time step. Thereby, an objective function that describes the costs from a start angle to an end condition is minimized by means of discrete dynamic programming (DDP). (orig.)

  4. Paraphrasensuche mittels word2vec und der Word Mover’s Distance im Altgriechischen

    Directory of Open Access Journals (Sweden)

    Marcus Pöckelmann

    2017-12-01

    Full Text Available To find receptions of Plato‘s work within the ancient Greek literature, automatic methods would be a useful assistance. Unfortunately, such methods are often knowledge-based and thus restricted to extensively annotated texts, which are not available to a sufficient extent for ancient Greek. In this article, we describe an approach that is based on the distributional hypotheses instead, to overcome the problem of missing annotations. This approach uses word2vec and the related Word Mover‘s Distance to determine phrases with similar meaning. Despite its experimental state, the method produces some meaningful results as shown in three examples.

  5. Enforcement of mandatory third party access based on antitrust law; Zwangsdurchleitung mittels Kartellrecht

    Energy Technology Data Exchange (ETDEWEB)

    Markert, K. [Bundeskartellamt, Berlin (Germany). 8. Beschlussabteilung

    1998-04-01

    Access of third parties to power transmission systems which up to now is governed in Germany by ownership rights will not run smoothly in future, although the general policy decision ended the dispute about the if, however leaving open aspects of the how. The problems arising in designing the how are currently displayed to the public by the disputes about conditions and model solutions reported from the telecommunications area, where deregulation is ahead of the developments in the energy sector. Obviously, the contention point is not technical feasibility of third party access, but the economic aspects and the conditions offered to competing suppliers depending on access to a transmission network. Hence it can be expected that there will be conflicts of interest that will have to be decided. The legal basis for conflict management is outlined in the recent amendment to the EnWG (German energy industry act), and jurisdiction will primarily rely on paragraph 6 of the act, referring to antitrust review. The contribution here gives an outline of the legal framework conditions governing enforcement of third party access to transmission systems in the future deregulated energy market. (orig./CB) [Deutsch] Die Oeffnung bisher geschlossener Netze fuer Drittwettbewerber verlaeuft auch dann, wenn ueber das `Ob` kein Streit mehr besteht, nicht konfliktfrei. Dies wird zur Zeit dem deutschen Publikum im Bereich der Telekommunikation mit fast taeglich neuen Varianten vorgefuehrt. Es geht dabei offensichtlich nicht um die technische Machbarkeit der Drittnutzung, sondern um die wirtschaftlichen Konditionen fuer Konkurrenten, die fuer ihr Leistungsangebot auf den Zugang zum Netz angewiesen sind. Konflikte ueber die Bedingungen dieses Zugangs sind daher vorprogrammiert, und es stellt sich die Frage, nach welchen Regeln und durch welche Gremien oder Institutionen solche Konflikte entschieden werden sollen. Der Beitrag umreisst die rechtlichen Rahmenbedingungen, die im neuen EnWG fuer den deregulierten Energiemarkt vorgesehen sind und erlaeutert speziell die Rolle des paragraph 6 EnWG als Grundlage der Durchsetzung des Zugangs Dritter zu Uebertragungsnetzen. (orig./CB)

  6. Investigation of relativistic laser-plasmas using nuclear diagnostics; Untersuchung relativistischer Laserplasmen mittels nukleardiagnostischer Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Marc M.

    2011-01-19

    The present work explores with the development of a novel nuclear diagnostic method for the investigation of the electron dynamics in relativistic laser-plasma interactions. An additional aim of this work was the determination of the real laser peak intensity via the interaction of an intense laser short-pulse with a solid target. The nuclear diagnostics is based on a photo-neutron disintegration nuclear activation method. The main constituent of the nuclear diagnostic are novel pseudoalloic activation targets as a kind of calorimeter to measure the high-energy bremsstrahlung produced by relativistic electrons. The targets are composed of several stable isotopes with different ({gamma},xn)-reaction thresholds. The activated nuclides were identified via the characteristic gamma-ray decay spectrum by using high-resolution gamma spectroscopy after the laser irradiation. Via the gamma spectroscopy the ({gamma},xn)-reaction yields were determined. The high-energy bremsstrahlung spectrum has been deconvolved using a novel analysis method based on a modified Penfold-Leiss method. This facilitates the reconstruction of the spectrum of bremsstrahlung photons without any anticipated fit procedures. Furthermore, the characterization of the corresponding bremsstrahlung electrons in the interaction zone is accessible immediately. The consolidated findings about the properties of the relativistic electrons were used to determine the real peak intensity at the laser-plasma interaction zone. In the context of this work, experiments were performed at three different laser facilities. First Experiments were carried out at the 100 TW laser facility at Laboratoire pour l'Utilisation des Lasers Intense (LULI) in France and supplementary at the Vulcan laser facility at Rutherford Appleton Laboratory (RAL) in United Kingdom. The main part of the activation experiments were performed at the PHELIX laser facility (Petawatt High Energy Laser for heavy Ion EXperiments) at GSI-Helmholtzzentrum fuer Schwerionenforschung GmbH in Germany, which were the first nuclear activation experiments at this facility. The results obtained with the novel nuclear diagnostics method have lead to an advanced understanding of high-energy electrons produced in relativistic laser-plasma interactions. Particularly, the capability of the nuclear activation-based method to determine the real laser peak intensity at the relativistic laser-plasma interaction zone was demonstrated. (orig.)

  7. Results of ultrasonic disintegration of sewage sludge in practice; Ergebnisse des Praxiseinsatzes der Schlammdesintegration mittels Ultraschall

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, E. [IWE-Ingenieurgesellschaft fuer Wasser und Entsorgung mbH, Radebeul (Germany); Friedrich, H. [Fraunhofer-Institut fuer Keramische Technologien und Sinterwerkstoffe (IKTS), Dresden (Germany); Hielscher, H. [Hielscher GmbH, Teltow (Germany)

    1999-07-01

    Using high-performance ultrasonic sludge disintegration in different stages of sewage and sludge treatment is found to be an innovative approach for reducing the accruing amounts of sewage sludge in terms of both mass and volume. By means of practical tests with sludge disintegration at sewage treatment plants, its effects are demonstrated. (orig.) [German] Der Einsatz einer Hochleistungs-Ultraschalltechnik zur Schlammdesintegration in verschiedenen Stufen der Abwasser- und Schlammbehandlung zeigt sich als innovativer Loesungsweg zur weitestgehenden massenmaessigen sowie volumenmaessigen Minimierung des Klaerschlammanfalles. An Hand von Einsatzerprobungen der Desintegration in der Klaeranlagenpraxis werden die Effekte der Desintegration vorgestellt. (orig.)

  8. Uterine cervical cancer. Preoperative staging with magnetic resonance imaging; Zervixkarzinom. Praeoperatives Staging mittels Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, F.; Hamm, B. [Charite-Universitaetsmedizin Berlin, Campus Charite Mitte, Klinik fuer Radiologie, Berlin (Germany)

    2011-07-15

    The treatment of uterine cervical carcinoma is largely dependent on the tumor stage. Despite significant inaccuracies in the clinical examination, uterine cervical cancer remains the only gynecological form of cancer still largely staged according to clinical findings. Although imaging is still not included in the staging the recently published revised FIGO (Federation International de Gynecologie et d'Obstetrique) system encourages the use of modern cross-sectional imaging (magnetic resonance imaging MRI and computed tomography CT). Due to its high soft tissue contrast MRI allows excellent non-invasive assessment of the cervix with direct tumor delineation as well as assessment of the prognosis based on morphological factors. Studies in the literature report an accuracy of 93% for MRI in the preoperative assessment of tumor size and in the differentiation of operable from advanced cervical cancer. Therefore MRI is considered to be the optimal modality for diagnostic evaluation starting from FIGO stage IB1, for radiation therapy planning, and for exclusion of recurrence in follow-up. In this paper we give an overview of the role of magnetic resonance imaging in preoperative staging of uterine cervical cancer. (orig.) [German] Die Therapieplanung beim Zervixkarzinom ist weitgehend von der Stadieneinteilung nach FIGO (Federation International de Gynecologie et d'Obstetrique) abhaengig, die trotz erheblicher Ungenauigkeiten bei der klinischen Stadieneinteilung weiterhin aufgrund klinischer Untersuchungsbefunde erfolgt. Obwohl bildgebende Verfahren nach wie vor fuer die Stadieneinteilung nicht vorgesehen sind, wird im kuerzlich erschienen revidierten Stagingsystem der FIGO zum ersten Mal die Verwendung moderner Schnittbilddiagnostik (MRT und CT) befuerwortet. Die MRT ermoeglicht dank ihres hohen Weichteilkontrasts ein ausgezeichnetes nichtinvasives Staging des Zervixkarzinoms mit direkter Tumordarstellung sowie einer Prognoseabschaetzung anhand bildmorphologischer Faktoren. Nach Ergebnissen in der Literatur betraegt die Genauigkeit der MRT bei der praeoperativen Abschaetzung der Tumorgroesse sowie der Differenzierung operabler Zervixkarzinome von fortgeschrittenen Karzinomen 93%. Sie wird daher nicht nur als das Verfahren der Wahl zur diagnostischen Beurteilung ab FIGO-Stadium IB1 angesehen, sondern auch zur Strahlentherapieplanung sowie zum Rezidivausschluss im Rahmen der Nachsorge. In der folgenden Arbeit geben wir einen Ueberblick ueber die Rolle der MRT bei der praeoperativen Stadieneinteilung des Zervixkarzinoms. (orig.)

  9. Efficient power supply using Power over Ethernet; Effiziente Stromversorgung mittels Power over Ethernet (PoE)

    Energy Technology Data Exchange (ETDEWEB)

    Huser, A.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at methods of supplying small equipment such as Internet telephones, web cams, hubs, hard discs, audio equipment, point-of-sale terminals, game consoles etc. with power via their Ethernet connections. A short comparison is presented between Power over Ethernet (PoE) and other methods of supplying power along with data, including Universal Serial Bus (USB), FireWire and Powerline systems. The advantages of PoE over the use of separate power supply units are discussed and recommendations are made to the manufacturers and users of small peripheral equipment regarding the dimensioning and loading of such power supply systems.

  10. Procedures and means for determining enzyme activities. Verfahren und Mittel zur Bestimmung von Enzymaktivitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Hunger, H; Behrendt, G; Schmidt, G

    1988-02-10

    Aim of the invention is a procedure for the determination of phosphorylating enzyme activity by using an improved means. Cellular extracts and cell lysates, resp., are contacted with surface carriers from natural and/or synthesized polymers, containing deprotonizable groups, in presence of /sup 32/P-..gamma..-ATP and, if necessary, of ATP. The phosphorylated antibiotic is evidenced by autoradiography or any other identifying procedure. Fields of application are molecular biology, genetic engineering, biotechnology and medical special fields.

  11. Institutionalisierung durch Imitation? Die Europäisierung des Parlamentarismus in Mittel- und Osteuropa / Aron Buzogany

    Index Scriptorium Estoniae

    Buzogany, Aron

    2015-01-01

    Artikli teemaks on parlamentarismi euroopastumine Kesk- ja Ida-Euroopa riikides (sh Eesti), püüdes leida vastus küsimusele, kuidas on rahvusriikide parlamendid suutnud institutsionaalselt euroopastumise väljakutsele vastata?

  12. Analyse von Kunststoffadditiven mittels Laserablation gekoppelt mit induktiv gekoppelter Plasma Massenspektrometrie

    OpenAIRE

    Börno, Fabian

    2016-01-01

    Die Laserablation gekoppelt mit der Massenspektrometrie mit induktiv gekoppeltem Plasma ist eine vielversprechende direkte Feststofftechnik, die sich jedoch bei der Analyse von Kunststoffen wegen des Mangels an matrixangepassten zertifizierten Referenzmaterialien nicht durchsetzen konnte. Vorherige Arbeiten belegen polymerabhängige Abtragsraten. Das oft als interner Standard verwendete Intensitätssignal des Kohlenstoffisotopes 13C zur Korrektur dieser Unterschiede wird in der Literatur kritis...

  13. Verfahren zum Fuegen zweier insbesondere rohrfoermiger Bauteile mittels eines wirkmedienbasierten Umformverfahrens und hiermit hergestelltes Werkstueck

    OpenAIRE

    Ortmann, S.; Unger, J.; Sterzing, A.

    2007-01-01

    DE 102005030587 A1 UPAB: 20070129 NOVELTY - In a process to joint two lengths of pipe e.g. automotive exhaust pipe, a sleeve-fit is sealed by the application of a tool exerting high internal pressure in the overlap zone forming a contiguous flush seal (3). Further claimed is a suitable tube product e.g. automotive exhaust pipe. USE - Process to join two sections of metal pipe e.g. automotive exhaust pipe. ADVANTAGE - The join zone exterior surface has an uninterrupted smooth form.

  14. Neutralisation of contaminated areas via rail; Neutralisation kontaminierter Gebiete mittels der Eisenbahn

    Energy Technology Data Exchange (ETDEWEB)

    Kunzewitsch, F.

    2007-07-01

    The problems that arose in dealing with the consequences of the Chernobyl disaster show that today we still do not have the requisite means and technology to neutralise radiation-contaminated areas effectively. Growing terrorism, ease of manufacture and the threat to use a 'dirty bomb' make it imperative to seek new ways of countering terrorism. Transport by rail offers an effective technical means for dealing with the aftermath of radiation contamination, including terrorist threats. (orig.)

  15. Musikerbriefe als Spiegel überregionaler Kulturbeziehungen in Mittel - und Osteuropa

    Directory of Open Access Journals (Sweden)

    Loos Helmut

    2002-01-01

    Full Text Available (nemački Traditionell ist die Musikgeschichtsschreibung nicht nur in Deutschland, sondern auch im östlichen Europa sehr stark nationalen Kriterien verpflichtet, und Musik wird vor allem als Nationalkultur verstanden. Dem gegenüber stehen viele Verflechtungen von Musikern, die in vergangenen Jahrhunderten häufig an vielen Orten Europas anwesend und tätig waren. Diese Verbindungen sind immer wieder einmal thematisiert, aber nur ansatzweise systematisch erforscht worden. Die überregionale Korrespondenz der Musiker im mittleren und östlichen Europa macht nicht nur europäische Verflechtungen sichtbar, sie liefert auch authentische Einschätzungen der Erfahrungen, die an verschiedenen Orten gesammelt wurden. Insgesamt ist zu erwarten, daß Europa im Spiegel der Musikerbriefe als der zusammenhängende Kulturraum im Musikleben erscheint, als der er bis weit ins 20. Jahrhundert hinein existierte.

  16. FOCJ as a Means of Regional Cooperation (FOCJ als Mittel regionaler Kooperation)

    Science.gov (United States)

    2008-03-01

    Steiner 1998. 54 ren, die sich durch regionale wie interregionale Kooperationen auszeichnen und oft komplette Wertsch6pfungsketten abdecken (Schmidt 2003...Manfred Steiner , Graz 2003 Friedrich, Peter, FOCJ: Bin neuer K6rperschaftstyp im Gesundheitswesen?, in- Li- beralisierung im Gesundheitswesen, hrsg. von...Economic Re- view,1969, Vo1. 59 (2), S. 479-487 Paptistella, Rudolf , Liquidititsoptimierung im Gemeindehaushalt. Der Einsatz der Datenverarbeitung im

  17. The effect of light color on the nucleocytoplasmic and chloroplast cycle of the green chlorococcal alga Scenedesmus obliquus

    Czech Academy of Sciences Publication Activity Database

    Cepák, Vladislav; Přibyl, Pavel; Vítová, Milada

    2006-01-01

    Roč. 51, č. 4 (2006), s. 342-348 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA204/03/1113; GA MŠk(CZ) 1M0571 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50200510 Keywords : color lights * cell cycle * Scenedesmus Subject RIV: EF - Botanics Impact factor: 0.963, year: 2006

  18. The effect of colour light on production of zooids in 10 strains of the green chlorococcal alga Scenedesmus obliquus

    Czech Academy of Sciences Publication Activity Database

    Cepák, Vladislav; Přibyl, Pavel

    2006-01-01

    Roč. 6, - (2006), s. 127-133 ISSN 1213-3434 R&D Projects: GA ČR(CZ) GA204/03/1113 Institutional research plan: CEZ:AV0Z60050516 Keywords : colour light * Scenedesmus * life cycle Subject RIV: EF - Botanics

  19. The nucleocytosolic and chloroplast cycle in the green chlorococcal alga Scenedesmus obliquus (Chlorophyceae, Chlorococcales) grown under various temperatures

    Czech Academy of Sciences Publication Activity Database

    Cepák, Vladislav; Přibyl, Pavel; Vítová, Milada; Zachleder, Vilém

    2007-01-01

    Roč. 46, č. 3 (2007), s. 263-269 ISSN 0031-8884 R&D Projects: GA MŠk ME 575; GA ČR(CZ) GA204/03/1113; GA MŠk(CZ) 1M0571 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50200510 Keywords : Scenedesmus * cell cycle * temperature Subject RIV: EF - Botanics Impact factor: 1.358, year: 2007

  20. Evaluation of the energy consumption and climate comfort by means of a complete vehicle simulation; Energieverbrauchs- und Klimakomfortbewertung mittels Gesamtfahrzeugsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Petr, Philipp [Technische Univ. Braunschweig (Germany). Inst. fuer Thermodynamik; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany); Mustafa, Rashad [Technische Univ. Braunschweig (Germany). Inst. fuer Fahrzeugtechnik; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany); Schulze, Mirko [Technische Univ. Braunschweig (Germany). Inst. fuer Verbrennungskraftmaschinen; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany)

    2012-11-01

    Intelligent thermal management for vehicles can significantly reduce energy consumption and improve the climatic comfort. This paper describes an approach of how to analyse and evaluate vehicle thermal management techniques and their combination with different test cycles in a connected vehicle environment as examples. The focus will be particularly on the methodological approach. Based on the energetic analysis of the considered drivetrain topologies conclusions can be drawn about the complex thermal and dynamic relations. The analysis in turn is based on the results of the full vehicle simulation and refers to reference driving cycles and relevant environmental conditions. The energy flow analyses derived from the simulation are used in order to develop suitable thermal management techniques, to evaluate their potential and to integrate them in the vehicle. In addition to the influence of the measures the potential resulting from an intelligent combination of techniques and their control strategies are identified. The energy consumption advantage as well as the improved heating of the passenger compartment - especially at low ambient temperatures - will be evaluated. (orig.)

  1. Positionsspezifischer Nachweis und relative Quantifizierung von Modifikationen des alpha-s1-Caseins in Milch mittels MALDI-TOF-MS

    OpenAIRE

    Vollmer, Gregor

    2013-01-01

    Milch und Milchprodukte spielen eine bedeutende Rolle in der menschlichen Ernährung. Vor der Abgabe an den Verbraucher wird Milch in den allermeisten Fällen hitzebehandelt, um mikrobielle Stabilität sicherzustellen und die Haltbarkeit zu verlängern. Allerdings kann diese Hitzebehandlung die in Milch enthaltenen Nährstoffe, unter anderem Kohlenhydrate, Lipide, Proteine und Vitamine, erheblich schädigen. Vitamine werden durch starke Erhitzung zerstört, bei den Lipiden kann es zu Abbaureaktionen...

  2. Ein empirischer Vergleich der Prozessaufzeichnungsmethoden Mouselab und Eyetracking bei Präferenzmessungen mittels Choice-based Conjoint Analyse

    DEFF Research Database (Denmark)

    Meissner, Martin; Decker, Reinhold; Pfeiffer, Jella

    2010-01-01

    , instead of eye tracking, influences the way information is acquired and processed and whether respectively how this affects the validity of CBC results. The empirical study shows that Mouselab in fact changes the information acquisition process, but this does not affect the quality of the preference......In choice-based conjoint (CBC) analysis respondents’ decisions in choice settings are used to determine relevant attributes and attribute levels of the products considered. Yet, the cognitive process preceding the choice decision is usually ignored. The eye tracking technique can be used to gain...... additional insights on how information is processed in the context of preference measurement. However, because of the technical requirements, an efficient application of eye tracking is often hard to realize in managerial practice. Therefore, the use of alternative process-tracing approaches like Mouselab...

  3. An integral IT-approach using EAI architectures; Der integrale IT-Ansatz mittels EAI-Architekturen

    Energy Technology Data Exchange (ETDEWEB)

    Zengaffinen, A.

    2003-07-01

    This article examines the question if there is any information technology (IT) on the market that meets the needs of an energy utility for an integral and comprehensive tool to control its operations. The possibilities offered by so-called 'Enterprise Application Integration' (EAI) are examined and the intelligent linking-up of various sources of data is discussed. The current and future situations in typical utilities are looked at, where the unbundling of activities threatens to make business processes that are already complex even more so. Various models for the integration of existing IT applications such those using 'peer-to-peer' architectures, data warehousing and 'middleware' applications as well as their advantages and disadvantages are discussed. An example is given of integration using a 'middleware' solution in the maintenance area. A well-tried project implementation process is described.

  4. Die Inszenierung der Toten. Italienische Kriegsgräberstätten im Alpenraum als Mittel faschistischer Propaganda

    Directory of Open Access Journals (Sweden)

    Tragbar, Klaus

    2017-07-01

    Full Text Available For the self-perception of the Kingdom of Italy, founded as late as 1861, the soldiers killed in action during WW I played a particular role. The war memorials built for them along the front between the Stelvio Pass and the Isonzo River, the frontier to the former Austro-Hungarian Empire, are a case in point. After their seizure of power in 1922, the Italian fascists radically converted the memorial culture from the mourning of the dead to their celebration as fascist martyrs. New war memorials were built, now rather driven by the ideas of heroism and sacrifice for the nation – and for future wars. These new war memorials were also erected in regions where no fighting had taken place during WW I, as in South Tyrol, at the Brenner or the Reschen Pass. This was a clear indication of their function as an instrument for political propaganda.

  5. Modeling for pipe decontamination by means of high-frequency percussive action; Modellerstellung fuer die Rohrdekontamination mittels hochfrequenter Schlagwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Aminy, Akramullah

    2014-07-30

    The formation of persistent scales in pipes causes lower flow rates and therefore represents an economic problem. The contamination of scales - which usually is the case in most industrial applications - also poses a problem with respect to the scales' environmental compatibility. The currently applied techniques for the removal of these scales involve the use of auxiliary materials which accumulate large quantities of secondary waste that is costly to be disposed of. In this research, an environmentally friendly removal method for tubing scales was developed and qualified. The analysis of the currently used technologies formed the basis for the analysis and systematic evaluation of different principles of removal action methods. Consequently, a concept for a new impact based removal method was established. The mechanism of this technique is the application of a high-frequency percussive action by a geometrically defined tool. The impact on the scales cracks their surface and causes their fracture and thus the detachment from the pipes. Compared to alternative removal methods this proposed technique works without any auxiliary material and thus prevents the production of secondary waste. The investigation of the impact process was carried out in a newly developed test rig. In this test rig, the maximum forces of the percussive tool were measured with shear force sensors on the tubing surface and the resulting stress on the tube was obtained. The evaluation of the measured values using the method of descriptive statistics demonstrated that the high dynamic stress of the tubing due to the complex tool motion is based on a normal distribution. Based on this evaluation, the effects of the influencing factors on the stress of the tubings were systematically measured and outlined in a mathematical model. This model describes the dependency of the tool and the process of related factors that influences the tubing stress. According to this model, this stress is composed of the different impact intensities and frequencies which are transmitted by the percussive tool. The stress model was then simulated and the effects of the influencing factors were demonstrated for different parameters combinations. For the investigation of the removal process through this new percussive technique, cement stone was used to simulate different types of scales inside tubings. The effects of the influencing factors of the tool and the process have finally been identified in extensive ablation studies where the effectiveness of the percussive technique for the removal of stubborn tubing scales is being demonstrated.

  6. New X-ray refractometry for nondestructive characterization of high performance composites; Charakterisierung von Hochleistungsverbundwerkstoffen mittels Roentgenrefraktion

    Energy Technology Data Exchange (ETDEWEB)

    Harbich, K W; Hentschel, M P [Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany). Labor 6.22 ` ` Zerstoerungsfreie Charakterisierung von Materialstrukturen` `

    1994-12-01

    Facing the basic relevance of single fibre bonding for the mechanical properties of composites relating testing methods are requested. These have not yet been satisfactory. A new nondestructive method provides a fast and precise tool to determine the fraction of debonded fibres by refraction of X-rays at the interface of fibres in composites. The systematic analysis of thinwalled unidirectional tapes of carbon fibres in thermoplastics results in specific characteristics of different lots. These were successfully exploited for the improvement of the processing parameters. The new method is selective for fibre orientation. The detection of specific defects in composites of orthogonal fibre orientation is performed by X-ray refraction topography. First investigations reveal clearly the detectibility and identification of impact damages and paper inserts. (orig.)

  7. Tropospheric trace gas measurement by tunable diode laser spectroscopy. Final report. Messung troposphaerischer Spurengase mittels Dioden-Laser-Spektroskopie. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, J P; Crutzen, P J; Harris, G W; Klemp, D; Johnson, T J; Perner, D; Wienhold, F G; Zenker, T

    1991-01-01

    This final report is concerned with tropospheric trace gas measurements by Tunable Diode Laser Spectroscopy (TDLAS). A TDLAS instrument was built which simultaneously measures four selected trace gases and is sufficiently sensitive for use in 'clean' air conditions. The instrument is the first of its kind to be used for measurements aboard ship platforms in clean marine air. In order to guarantee that the instrument function continuously for several weeks at a time under the difficult conditions encountered at sea, a variety of innovative technical developments were necessary. The TDLAS instrument was used to investigate boundary layer tropospheric chemistry in one engineering test and four field campaigns. Three of the field campaigns took place on board the German research vessels. The measurements on board the research vessels enabled different types of tropospheric air to be investigated: (i) clean maritime air; (ii) maritime regions influenced by continental sources of trace gases and pollutants, in particular the coastal region around the west coast of Africa was thoroughly investigated under downwind conditions. A large set of data of simultaneous measurements of key tropospheric trace gases (NO{sub 2}, CO, HCHO, H{sub 2}O{sub 2} and O{sub 3}) were obtained which help paint a more complete picture of tropospheric oxidation cycles. The first measurements of H{sub 2}O{sub 2} in the remote marine boundary layer are reported. In selected regions successful TDLAS measurements of HCl and COS were obtained, results in themselves of importance. Intercomparisons of TDLAS and other measurement techniques were successfully undertaken. (orig./BBR).

  8. Sales gas hydrocarbon dew point control with a refrigeration plant; Konditionierung des Kohlenwasserstofftaupunktes im Verkaufsgas mittels einer Kaelteanlage

    Energy Technology Data Exchange (ETDEWEB)

    Konieczny, J.; Scsepka, H. [OMV Aktiengesellschaft, Exploration and Production, Gaenserndorf (Austria)

    2004-11-01

    A new refrigeration plant was put on stream in the gas plant Aderklaa, Austria in the fall 2003. The quality criteria inherent to hydrocarbon dew point of the sales gas have already been accomplished. The contract (Allgemeinen Netzzugangsbedingungen) defines the hydrocarbon dew point at the value of 0 C with a pressure ranging 0-70 bar(g). Process facilities are a gas/gas-heat exchanger and a low-temperature-separator flanged to the chiller. A propane cycle produces the required cooling energy. The propane cycle consists of two propane compressors, one of them as back up, a condenser, an accumulator and an evaporator. About 50,000 m{sup 3} (V{sub n}) sales gas per hour are produced at a working pressure of 65 bar(g). Process gas coming from the sweetening plant Aderklaa I is lowered to a temperature of -14 C, where approx. 250 litres liquid hydrocarbons per hour are separated and saved. When the refrigeration plant was designed, attention was given to the operating costs to keep them low. This could be achieved by maximising surface area for heat transfer in the gas/gas-heat exchanger. After commissioning and start-up, full operability of the new plant was tested and documented. The pre-set project goals were accomplished, with respect to both the technical point of view and the economic aspects. (orig.)

  9. Intra-group separation of rare earths using new organic phosphorus ligands; Intragruppentrennung Seltener Erden mittels neuer phosphororganischer Liganden

    Energy Technology Data Exchange (ETDEWEB)

    Hadic, Sanela

    2017-10-01

    Rare earth elements (REE) have unique magnetic, photophysical, and chemical properties and they are therefore used in numerous high-technology applications. However, to this day, the isolation of pure rare earths from primary and secondary raw materials is very challenging. In this work, the hydrometallurgical separation of neighboring rare earths (e.g., praseodymium/ neodymium) was optimized with novel selective extraction agents. The separation of rare earths (yttrium and all lanthanides except promethium) was investigated with fourteen new organophosphorus compounds. Oxygen-bearing phosphinic acids yielded good separation results for heavy rare earths (dysprosium to lutetium). For light rare earths (lanthanum to neodymium), particularly high separation factors were realized with synergistic systems containing an aromatic dithiophosphinic acid and a co-extractant, such as tris (2-ethylhexyl) phosphate (TEHP). Optimization studies of the latter extraction system revealed an extremely high separation factor (SF) of 4.21 between praseodymium and neodymium. Another focus of this work was to understand the extraction mechanism. With the aid of nuclear magnetic resonance spectroscopy ({sup 1}H-NMR) and time-resolved laser fluorescence spectroscopy (TRLFS), the complex stoichiometry of promising extraction systems was examined. Studies revealed a dependency between the selectivity for rare earths and the coordination number of the formed complexes. In addition, temperature-dependent extraction experiments were performed and thermodynamic data (ΔG, ΔH, and ΔS) determined. These data provided additional information about the origin of selectivity for neighboring rare earths. With regard to the industrial capability of the investigated extraction systems, the chemical durability of ligands was studied under process-relevant conditions. Qualitative and quantitative analytical methods (e.g., GC-MS) were used in long-term experiments to determine the ligand degradation. After the decomposition products had been identified, reaction paths were proposed. The impact of this decomposition on the separation of rare earths was followed, in single extraction experiments, over a period of up to several months.

  10. Kommunikationsschulung mittels "Standardisierter Eltern" im Fachbereich der Pädiatrie [Communication training using "standardised parents" in paediatrics

    Directory of Open Access Journals (Sweden)

    Hoffmann, Katja

    2007-05-01

    Full Text Available [english] Introduction: Communicative competence is essential for daily medical routine. The usefulness of communication-trainings for physicians is described in various publications. However, specific trainings in paediatrics are rarely found. A characteristic for paediatric work is that the primary communication is not only with the patient – the child – but also with the parents. Beside self-assessment external assessment by parents can be used for evaluation of paediatrician’s communicative skills.Methods: 28 paediatric residents (intervention group n = 14; control group n = 14 of the University Children’s Hospital of Heidelberg took part in a communication training using standardised parents and -patients (SP, video recording and feedback by peers, SPs and supervisors. Data of self-evaluated communicative competence in contact with parents was collected from all participants before and after the training of the intervention group. In addition there was an assessment of parents’ satisfaction with the paediatricians-parents communication concerning their children’s treatment nine weeks before and nine weeks after the training (n = 248. A follow-up survey to record the transfer into clinical practice was conducted with the participants after six months.Results: After the training participants of the intervention group showed an increased feeling of communicative competence in reference to communicative situations that were explicitly practiced in the training. The external assessment by parents generally showed a positive evaluation of paediatricians’ communication skills. However, a group effect was not found. In the follow-up survey participants reported an improved self-perception and specific elements of the training that facilitated the daily clinical practice with parents and their children. Discussion: The training of specific relevant clinical situations lead to an increase in perceived communicative competence and competence in handling difficult encounters with parents. Communication trainings should be integrated not only into the medical student education but also into post-graduate education curricula. [german] Einführung: Kommunikative Kompetenzen sind wesentlich für den ärztlichen Alltag. In der Literatur wird vielfach der Nutzen von Kommunikationsschulungen für Ärzte beschrieben, über gezielte Schulungen für den Fachbereich Pädiatrie finden sich nur vereinzelt Berichte. Die Besonderheit der pädiatrischen Versorgung besteht dabei im Wesentlichen darin, dass nicht nur die Kommunikation zum Patienten – dem Kind –, sondern auch zu dessen Eltern oder Bezugspersonen eine entscheidende Rolle spielt. Zur Überprüfung kommunikativer Fähigkeiten von Pädiatern können neben Selbsteinschätzungen auch Fremdeinschätzungen durch Eltern dienen.Methode: 28 Assistenzärzte (Interventionsgruppe n = 14; Kontrollgruppe n = 14 der Universitätsklinik für Kinder- und Jugendmedizin in Heidelberg nahmen an einer Kommunikationsschulung teil. Diese beinhaltete Übungsgespräche mit standardisierten Eltern und -Patienten (SP, Videoaufzeichnungen sowie Feedback von SPs, Peers und Supervisoren. Daten zur Selbsteinschätzung der eigenen kommunikativen Kompetenz wurden vor und nach der Schulung der Interventionsgruppe von allen Teilnehmern erhoben. Weiterhin wurde neun Wochen vor und neun Wochen nach Abschluss der Schulung eine Elternbefragung bei n = 248 Eltern durchgeführt, in der die Zufriedenheit mit dem Arztkontakt hinsichtlich der Arzt-Eltern Kommunikation erfasst wurde. Nach 6 Monaten schloss sich eine Nachbefragung bei den Teilnehmern zum Transfer in den Klinikalltag an.Ergebnis: Bei den Teilnehmern der Interventionsgruppe zeigte sich im Gegensatz zur Kontrollgruppe nach Abschluss der Schulung eine signifikante Steigerung der subjektiven Kompetenzeinschätzung in Bezug auf die kommunikativen Situationen, die speziell in der Schulung trainiert wurden. Die Fremdeinschätzung durch die Eltern ergab eine generell sehr positive Bewertung der Ärzte, es ließ sich jedoch kein Gruppeneffekt nachweisen. Im Langezeitverlauf berichteten die Teilnehmer von einer verbesserten Selbstwahrnehmung und benannten konkrete Elemente der Schulung, die ihnen die tägliche klinische Arbeit im Kontakt mit Eltern erkrankter Kinder erleichterten.Diskussion: Das Training von spezifischen, für den klinischen Alltag typischen Situationen führt zu einer Verbesserung der Selbsteinschätzung kommunikativer Kompetenzen bezüglich des Umgangs mit schwierigen Situationen im Elternkontakt. Eine Integration von Kommunikationsschulungen nicht nur in das Medizinstudium, sondern auch in postgraduierte Ausbildungs-Curricula erscheint daher sinnvoll.

  11. Beschreibung des Korngrößenwachstums bei der Wirbelschicht-Sprühgranulation mittels statistischer Modelle

    OpenAIRE

    Schinzinger, Oliver

    2004-01-01

    Ein wichtiger Schritt bei der Herstellung von Tabletten ist die Aufarbeitung eines meist sehr feinen, schlecht fließfähigen Pulvers zu einem besser fließenden Granulat. Da die Granulation aus den drei Teilprozessen Mischen, Granulieren und Trocknen besteht, werden heutzutage Granulationen in der Wirbelschicht durchgeführt. Eine Wirbelschichtapparatur vereint die drei Teilprozesse in einem Gerät. Die Wirbelschichtgranulation wird durch eine große Anzahl an Parametern beeinflusst, die in Prozes...

  12. Gadolinium recovery from aqueous pharmaceutical residuals by pulsed electrical discharge; Rueckgewinnung von Gadolinium aus pharmazeutischen Abwaessern mittels gepulster elektrischer Entladung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter [TU Bergakademie Freiberg (Germany); Seifert, Martin; Jacob-Seifert, Karin [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2017-02-15

    Advanced oxidation process (AOP) is an oxidation step releasing reactive oxygen species by pulsed electrical discharge in aqueous systems. In contrast to processes generating ozone by external UV radiation this method is feasible for turbid liquids with solid particles. This method is currently used in particular in the field of purification of chemically polluted waste waters. In the present application AOP is applied for partial degradation of the organic ligand system of a gadolinium X-ray contrast agent to separate gadolinium subsequently by adding caustic soda to precipitate > 99% of gadolinium.

  13. Big Data als Informationsquelle für regionales Arbeitsmarkt-Monitoring: Online-Stellenanzeigen analysieren mittels "Jobfeed"

    OpenAIRE

    Plaimauer, Claudia

    2016-01-01

    1 Einleitung. 2 Herausforderungen bei der Interpretation von Stelleninseraten. 3 Herausforderungen im Umgang mit Big Data und semantischen Technologien. 4 Die Big-Data-Plattform "Jobfeed". 5 Ausblick. 6 Literatur.

  14. Positioning strategies for decentralized energy resources providing reactive power voltage control; Anlagenauswahl und -positionierung zur Spannungsstuetzung mittels Blindleistungsmanagement dezentraler Erzeugungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Matrose, Claas; Goedde, Markus; Cramer, Moritz; Potratz, Fabian; Pollok, Thomas; Schnettler, Armin [RWTH Aachen Univ. (Germany). Inst. fuer Hochspannungstechnik

    2012-07-01

    The integration of decentralized generation into power distribution grids in Germany has reached a level at which more and more grid reinforcement is required in order to keep voltages within the given limits. The consumption of reactive power by decentralized generation systems can reduce the voltage rise, which is caused by active power in-feed of such systems. Caused by different characteristics of overhead lines and cables, this effect significantly varies. Parameter studies of four commonly used types of lines, of different power ratings of decentralized generation systems as well as different lengths of lines can quantify the effects. It can be shown that - depending on the characteristics of a specific grid - the grid capacity for power in-feed can be increased by factors between 1.5 and 10. (orig.)

  15. Image processing. Volumetric analysis with a digital image processing system. [GAMMA]. Bildverarbeitung. Volumetrie mittels eines digitalen Bildverarbeitungssystems

    Energy Technology Data Exchange (ETDEWEB)

    Kindler, M; Radtke, F; Demel, G

    1986-01-01

    The book is arranged in seven sections, describing various applications of volumetric analysis using image processing systems, and various methods of diagnostic evaluation of images obtained by gamma scintigraphy, cardic catheterisation, and echocardiography. A dynamic ventricular phantom is explained that has been developed for checking and calibration for safe examination of patient, the phantom allowing extensive simulation of volumetric and hemodynamic conditions of the human heart: One section discusses the program development for image processing, referring to a number of different computer systems. The equipment described includes a small non-expensive PC system, as well as a standardized nuclear medical diagnostic system, and a computer system especially suited to image processing.

  16. Development and standard of batter slope monitoring by means of simple telemetering. Entwicklung und Stand von Boeschungsbeobachtungen mittels einfacher Distanzmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Duddek, H

    1990-11-01

    In the search for mainly automatic measuring techniques that furnish real-time areal data on deformations in marginal batters of opencast workings, it was decided inter alia to adopt the technique of direct linear measurement across the workings at the brown coal opencast mines in the Rhineland. The present paper describes the development of this technique from the use of instruments which initially were operated manually to the introduction of automatic measuring stations. The successful application of this technique in all the opencast workings in the Rhineland brown coal mining area is discussed. Since the accuracy obtained in electro-optical telemetering depends to a large extent on the meteorological conditions, it can hardly be increased with the instruments at present available. Hence, it is essential that two-colour telemeters which are perfected for field-work and are not refraction-prone should be developed. (orig.).

  17. Development and testing of passive autocatalytic recombiners cooled by heat pipes; Entwicklung und Erprobung mittels Heatpipe gekuehlter katalytischer Rekombinatoren

    Energy Technology Data Exchange (ETDEWEB)

    Granzow, Christoph

    2012-11-26

    A severe accident in a nuclear power plant (NPP) can lead to core damage in conjunction with the release of large amounts of hydrogen. As hydrogen mitigation measure, passive autocatalytic recombiners (PARs) are used in today's pressurized water reactors. PARs recombine hydrogen and oxygen contained in the air to steam. The heat from this exothermic reaction causes the catalyst and its surroundings to heat up. If parts of the PAR heat up above the ignition temperature of the gas mixture, a spontaneous deflagration or detonation can occur. The aim of this work is the prevention of such high temperatures by means of passive cooling of the catalyst with heat pipes. Heat pipes are completely passive heat exchanger with a very high effective thermal conductivity. For a deeper understanding of the reaction kinetics at lower temperatures, single catalytic coated heat pipes are studied in a flow reactor. The development of a modular small-scale PAR model is then based on a test series with cooled catalyst sheets. Finally, the PAR model is tested inside a pressure vessel under boundary conditions similar to a real NPP. The experiments show, that the temperatures of the cooled catalytic sheets stay significantly below the temperature of the uncooled sheets and below the ignition temperature of the gas mixture under any set boundary conditions, although no significant reduction of the conversion efficiency can be observed. As a last point, a mathematical model of the reaction kinetics of the recombination process as well as a model of the fluid dynamic and thermohydraulic processes in a heat pipe are developed with the data obtained from the experiments.

  18. Monitoring effects of river restoration on groundwater with radon; Ueberwachung der Auswirkungen von Flussaufweitungen auf das Grundwasser mittels Radon

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Eduard [Eawag, Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, Duebendorf (Switzerland)

    2007-03-15

    The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [German] Die Renaturierung des voralpinen Flusses Toess in der Schotterebene des Linsentals (suedlich Winterthur, Nordschweiz) mit einer Befreiung von seinen Uferverbauungen gab Anlass zu Traceruntersuchungen im Fluss und im Grundwasser des kiessandigen Schotters. In diesem Gebiet infiltriert der Fluss ueberall und immer natuerlicherweise ins Grundwasser, welches stark als Trinkwasser genutzt wird. Radon-Aktivitaetskonzentrationen von frisch infiltriertem Grundwasser wurden interpretiert als Radon-Grundwasseralter fuer Strecken zwischen dem Fluss und Grundwasserbeobachtungsrohren. Nach einem ersten Hochwasser bewirkten die Renaturierungsmassnahmen eine Aufweitung des Ufers und eine Verringerung der Fliessdistanz des infiltrierenden Wassers zu den Rohren. Im Vergleich mit Radonmessungen vor diesen Massnahmen, resultierten Messungen, die 16 Tage nach einem zweiten Hochwasser durchgefuehrt wurden, in einer Verringerung der Radon-Grundwasseralter auf dieser Strecke, dies als Folge der Verringerung der Fliessdistanzen. Die Zahlen von autochthonen und coliformen Bakterien stiegen bereits bei einer Messung nach der Befreiung des Ufers und dann besonders bei einer Messung einen Tag nach dem ersten Hochwasser. Damit stuetzen diese Befunde die Interpretation der Radonmessungen. Auf die Trinkwasserqualitaet wirkte sich die Flussaufweitung hingegen bislang nicht aus. Solche Untersuchungen leisten einen Beitrag zur Loesung des raumwirksamen Nutzungskonflikts zwischen Flussrenaturierung und Grundwassernutzung als Trinkwasser. (orig.)

  19. MR-based diagnosis and staging of female pelvic neoplasms; Diagnostik und Staging gynaekologischer Tumoren mittels MRT

    Energy Technology Data Exchange (ETDEWEB)

    Alt, Celine D. [Universitaetsklinik Duesseldorf (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Kubik-Huch, Rahel A. [Zuerich Univ. (Switzerland). Diagnostische Radiologie; Kantonsspital Baden AG (Switzerland). Dept. Medizinische Dienste

    2017-06-15

    Magnetic resonance imaging (MRI) is known as the cross-sectional imaging modality of choice for evaluation of the female pelvis due to an excellent soft tissue contrast and its high resolution images. It provides morphologic and functional sequences and is commonly used for evaluation of a sonographically indeterminate adnexal mass, for differentiation and characterization of pelvic organ lesions, as well as for tumor staging and therapy monitoring during/after treatment. This article gives insights into the currently valid implementation of MR-imaging, tailored to the different female pelvic organs and its special features.

  20. Thermal spraying of corrosion protection layers in biogas plants; Erzeugung von Korrosionsschutzschichten fuer Bioenergieanlagen mittels Thermischen Spritzens

    Energy Technology Data Exchange (ETDEWEB)

    Crimmann, P.; Dimaczek, G.; Faulstich, M. [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany)

    2004-07-01

    Corrosion in plants for the energetic conversion of biomass is a severe problem that often causes premature damage of components. Thermal spraying is a process for the creation of corrosion protection layer. An advantage of thermal spraying is that as well as each material can be used as layer material. First practical results demonstrated that thermal spraying has the potential to create coatings to protect components against high temperature corrosion as well as biocorrosion. Layer materials are for example nickel base alloys (high temperature corrosion) and titan alloys (biocorrosion). Further investigations are necessary in order to examine whether cost-efficient coatings also contribute to the corrosion protection (e.g. polymer materials against biocorrosion). (orig.)

  1. Procedure and means for determining aminoglucoside phosphotransferase activity. Verfahren und Mittel zur Bestimmung der Aminoglucosid-Phosphotransferaseaktivitaet

    Energy Technology Data Exchange (ETDEWEB)

    Hunger, H D; Behrendt, G; Schmidt, G; Merkel, D

    1988-02-10

    A method and means are described for determining the activity of aminoglucoside phosphotransferase. Possible applications are genetic engineering, biotechnology and medicine. Cell lysates or cell extracts are contacted with a surface carrier on cellulose basis, in the presence of a mixture of ATP and /sup 32/P-ATP, with the phosphorylated kanamycin made visible in the solid phase by autoradiography.

  2. Legal frameworks of the unconventional exploration of natural gas by means of Fracking; Rechtliche Rahmenbedingungen der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Hentschel, Anja; Polzer, Andreas

    2012-07-01

    ExxonMobile projects the exploration of natural gas from so-called unconventional deposits by means of the hydraulic fracturing procedure (Fracking). In view of the public concerns, ExxonMobile engaged a neutral group of experts to develop the 'risk study Fracting'. This risk study has to investigate the legal framework for the evaluation of the risks and impacts of an unconventional exploration of natural gas by means of Fracking. The legal instruments to control these risks and impacts also are mentioned. The legal framework for the evaluation and for the compensation for damages within the realization of these risks is described. Furthermore, the most important proposals from the legal discussion are reported. Recommendations are drawn up with respect to the improvement of the legal framework and its controlling instruments.

  3. Legal frameworks of the unconventional exploration of natural gas by means of Fracking; Rechtliche Rahmenbedingungen der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Hentschel, Anja; Polzer, Andreas

    2012-07-01

    ExxonMobile projects the exploration of natural gas from so-called unconventional deposits by means of the hydraulic fracturing procedure (Fracking). In view of the public concerns, ExxonMobile engaged a neutral group of experts to develop the 'risk study Fracting'. This risk study has to investigate the legal framework for the evaluation of the risks and impacts of an unconventional exploration of natural gas by means of Fracking. The legal instruments to control these risks and impacts also are mentioned. The legal framework for the evaluation and for the compensation for damages within the realization of these risks is described. Furthermore, the most important proposals from the legal discussion are reported. Recommendations are drawn up with respect to the improvement of the legal framework and its controlling instruments.

  4. Underground vehicle monitoring and material tracking by wireless data transmission; Untertaegige Fahrzeugueberwachung und Materialverfolgung mittels drahtloser Datenuebertragung

    Energy Technology Data Exchange (ETDEWEB)

    Huenefeld, R. [Technische Hochschule Aachen (Germany). Lehrstuhl und Inst. fuer Bergwerks- und Huettenmaschinenkunde; Kuepper, T. [XGraphic Ingenieurgesellschaft mbH, Aachen (Germany)

    2008-04-17

    Satellite-assisted navigation and position detection by GPS (Global Positioning System) are the state of the art in surface fleet management. The system cannot, of course, be used underground. With the introduction of WLAN networks, pocket PCs and WLAN Handys a technological platform, on the basis of which comparable services can be offered, has meanwhile become available also in the underground mining industry. Various applications, which were developed for the specified technological environment, are described in this contribution. They are used for communication, vehicle monitoring and position tracking, but are also suitable for complicated tasks. A typical example is the automation of monorails, in which communication with the vehicle and visualisation of the vehicle data and position are important. (orig.)

  5. Characterization of oxidation protection coatings for high temperature applications by means of nanoindentation and scanning electron microscopy methods; Charakterisierung von Oxidationsschutzschichten fuer Hochtemperaturanwendungen mittels Nanoindentierung und rasterelektronenmikroskopischen Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Webler, R.; Neumeier, S.; Goeken, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Allgemeine Werkstoffeigenschaften

    2014-10-01

    Oxidation protection coatings are required for thermally highly stressed components such as turbine blades in aircraft engines. Cyclic oxidation experiments were performed on a NiCoCrAlY protective coating of a nickel-based superalloy and hardness and modulus of elasticity (mechanical properties) were determined by nanoindentation before and after the experiments. Microstructure and chemical composition were characterized by means of scanning electron microscopy. Here, the focus is on the phase identification by combining electron backscatter diffraction and energy dispersive X-ray spectroscopy. Findings indicate that the chemical composition strongly influences the mechanical properties.

  6. Aspects of industrial production of solid electrolyte fuel cells (SOFC) by thermal spraying technology; Aspekte industrieller Fertigung von Festelektrolyt-Brennstoffzellen (SOFC) mittels thermischer Beschichtungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Weckmann, Hannes

    2010-07-01

    The present thesis deals with measures to optimize the large-volume production of Solid Oxide Fuel Cells (SOFC) based on thermal spraying technology. Based on the well-established Vacuum Plasma Spraying (VPS) at DLR the potential of alternative thermal spraying techniques as well as alternative base materials was investigated in order to deposit SOFC-anode, electrolyte and insulating layers. Production costs, reproducibility and long-term stability of the production process as well as the fuel cell performance were major target criteria. Depending on the parameter set applied when using the cost efficient Atmospheric Plasma Spraying (APS) in combination with Nickel-Graphite as base material a significant improvement of gas permeability and electrical conductivity was achieved in comparison to the VPS sprayed reference anode. The power density of a fuel cell with an APS-Nickel-Graphite anode (184 mW/cm{sup 2}) was slightly better than the performance with a VPS reference anode (159 mW/cm{sup 2}). In comparison to the VPS process, ceramic electrolyte layers of fully stabilized Zirconia (YSZ) with significantly higher gas tightness could be demonstrated when high energy processes such as Low Pressure Plasma Spraying (LPPS). Thin-film Low Pressure Plasma Spraying (LPPS-Thin-film) and High Velocity Oxy Fuel Spraying (HVOF) were applied. The power density of a fuel cell equipped with an HVOF electrolyte was significantly improved to 234 mW/cm{sup 2} as compared to 187 mW/cm{sup 2} with the VPS sprayed reference cell. Further improvement of the power density was achieved with an LPPS-electrolyte (273 mW/cm{sup 2}). HVOF and VPS sprayed layers of pure Spinel in composite with metallic active braze (equivalent to the sealing between individual layers in the fuel cell stack) could exceed the demanded charge transfer resistance of >1 k{omega}cm{sup 2} at 800 C operating temperature only in few cases. When blended base powder of Spinel and Magnesia in combination with the VPS was applied significantly higher charge transfer resistance of up to 1,7 M{omega}cm{sup 2} could be demonstrated at layer thicknesses between 20 {mu}m and 117 {mu}m. In the further course of the thesis an online controller was developed for the VPS process based on insitu process diagnostic systems in order to reproducibly produce thermal sprayed functional layers. In pretests the process diagnostic system Accuraspray appeared to be cable of identifying changes in the process by detecting particle properties in the spray torch. In order to serve as a knowledge base for the controller the plasma spraying process was successfully modelled as correlation between machine parameters, spray torch- und layer properties by using artificial neural networks (ANN). The ability for the generalization as well as the accuracy of the model was improved further by measures such as active learning (additional experiments at poorly represented regions) and the combination of several models with different network architectures as an ensemble (mixture of experts). Based on the artificial neural network model, an online process controller was developed, which manipulates major process parameters in case of a deviation in order to get back to the initial state. The ability of the prototype controller could be demonstrated successfully in most cases. (orig.)

  7. Growth of gallium nitride based devices on silicon(001) substrates by metalorganic vapor phase epitaxy; Wachstum von Galliumnitrid-basierten Bauelementen auf Silizium(001)-Substraten mittels metallorganischer Gasphasenepitaxie

    Energy Technology Data Exchange (ETDEWEB)

    Reiher, Fabian

    2009-02-25

    The main topic of this thesis is to investigate GaN-based layer systems grown by metalorganic vapor phase epitaxy on Si(001) substrates. A temperature shift up to 45 K is measured for a complete device structure on a 2-inch silicon substrate. By using a 40 nm thin LT-AlN-seed layer (680 C), the GaN crystallites on Si(001) substrates are almost oriented with their GaN(10 anti 12)-planes parallel to the Si(001)-plane. A four-fold azimuthal symmetry occurs for these layers, with the GaN[10 anti 11]-direction is aligned parallel to one of the four equivalent left angle 110 right angle -directions, respectively. However, a mono-crystalline and fully coalesced GaN-layer with this crystallographic orientation could not yet been obtained. If a deposition temperature of more than 1100 C is used for the AlN-seed layer, solely the GaN[0001]- growth direction of crystallites occurs in the main GaN layer on Si(001) substrates. These c-axis oriented GaN columns feature two opposite azimuthal alignments that are rotated by 90 with respect to each other and with GaN[11 anti 20] parallel Si[110] and GaN[10 anti 10] parallel Si[110], respectively. By using 4 off-oriented substrates towards the Si[110]-direction, one certain azimuthal texture component can be selected. The critical value of the miscut angle corresponds to theoretical calculations predicting the occurrence of atomic double steps on the Si(001) surface. The achieved crystallographic quality of the GaN layers on Si(001) is characterized by having a tilt of FWHM=0.27 and a twist of FWHM=0.8 of the crystallites, determined by X-ray diffraction. A completely crack-free, up to 2.5 {mu}m thick, and mono-crystalline GaN-template can be realized on Si(001), integrating 4 or 5 LT-AlN-interlayers in the GaN buffer structure. Based on this structure, the first successful implementation of an (InGaN/GaN)-LED on Si(001) is achieved. Furthermore, the possible fabrication of GaN-based FET-structures is demonstrated with a fully processed and operating device on Si(001). Moreover, the developed approach for the MOVPE growth of GaN on Si(001) is successfully adapted to large area 150 mm Si(001) substrates, proving the possible scalability to industrial circuits. (orig.)

  8. Firedamp processing in a membrane system in the 'Alsbachschacht' mine; 'Aufbereitung von Grubengas mittels Membrananlage am Alsbachschacht'

    Energy Technology Data Exchange (ETDEWEB)

    Berwanger, R.; Dengel, A. [Evonik New Energies GmbH, Saarbruecken (Germany); Brinkmann, T. [GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht (Germany); Clemens, W. [OTS Ingenieurgesellschaft mbH, Puettlingen (Germany); Hoting, B. [Borsig Membrane Technology GmbH, Berlin (Germany)

    2009-07-01

    For safe and environment-friendly operation of refrigerators and cryotechnical facilities, knowledge of the permeation characteristics of the elastomers and fibre-reinforced materials used is of utmost importance. While elastomers are used primarily as sealing materials, fibre-reinforced materials are used increasingly in containers for supercooled liquids (LN2, LH2, LHe). Measuring apparatuses and methods of measurement were developed at Institut fuer Luft- und Kaeltetechnik Dresden (Institute of Ventilation and Refrigeration Engineering) that provide quantitative information on the permeation characteristics as a function of temperature. (orig.)

  9. Hydraulic balance by means of electromotoric HKV drives for dynamic load profiles; Hydraulischer Abgleich mittels elektromotorischer HKV-Antriebe fuer dynamische Lastprofile

    Energy Technology Data Exchange (ETDEWEB)

    Szendrei, Danny [Westsaechsische Hochschule Zwickau (Germany)

    2010-07-01

    To date, measures and concepts for saving energy become more and more important. The development of prices for conventional energy sources forces public and private households and businesses to changes in consumer behaviour and purchasing behaviour. Due to the structural infrastructure, the housing construction in communes strongly is affected by these developments. Nearly 35 % of the total energy demand in Europe account for heating of buildings generally. The most common type of heating system for heating of residential buildings is the central hot water heating in the two-tube version. It is assumed that nearly 90 % of the operated plants have a hydraulic unbalance. Additionally, balanced heating systems fulfil the desired efficiency only under certain, structural design conditions. The integration of the control of heating systems in the smart home infrastructure or KNX infrastructure enables a building-independent, tunable heat supply between buildings and consumption acquisition. The hydraulic system loads can be optimized simultaneously via the direct access to the control value. Thus, a homogeneous mass distribution over the plant can be guaranteed which is derived from the dynamic needs of the system users. These heat loads are calculated by the KNX system and the application of HeatingControl.

  10. Development of a high performance drivage by 'Bolter-Miner' technology; Entwicklung eines Hochleistungsvortriebs mittels Bolter-Miner-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Vierhaus, R. [Deutsche Steinkohle AG, Herne (Germany); Terbach, G. [Bergwerk Auguste Victoria/Blumenthal, Marl (Germany)

    2002-09-05

    The introduction of the bolter miner technic at Auguste Victoria/Blumenthal mine will be shown. This benchmarking project coming from the australian mining industry was put into practice for the first time in the german hard coal industry. It was rapidly turned out, that the demands of the roadways concerning the number and length of the required bolts and as well as the safety aspects are very different to the visited headings in Australia. The way starting with an average drivage rate of 5 m/d day in the first project up to today's performance level of 16 m/d in the third project is represented. From a view on the totality it is described, what kind of demands are required by the logistics, the infrastructure, the organization of the operation, the ergonomics and last but not least the motivation of the crew to achieve a high performance of 22 m/d. (orig.) [German] Im Beitrag wird die Einfuehrung der Bolter-Miner-Technik auf dem Bergwerk Auguste Victoria/Blumenthal aufgezeigt. Dieses Benchmarking-Projekt aus dem australischen Bergbau wurde erstmalig im deutschen Steinkohlenbergbau umgesetzt. Es zeigte sich sehr schnell, dass die Anforderungen der Strecken in bezug auf die Anzahl und Laenge der einzubauenden Anker sowie die sicherheitlichen Aspekte zu den besuchten Vortrieben in Australien stark differierten. Zudem wird der Weg von durchschnittlich 5 m/d im ersten Projekt bis zu den heutigen Leistungsdaten von 16 m/d im dritten Projekt dargestellt. In einer ganzheitlichen Betrachtung wird aufgezeigt, welche Anforderungen in der Logistik, in der Infrastruktur, in der Betriebsorganisation, in der Ergonomie und in der Motivation der Mannschaft notwendig waren, Spitzenleistungen von 22 m/d zu erreichen. (orig.)

  11. Characterization of partitioning relevant lanthanide and actinide complexes by NMR spectroscopy; Charakterisierung von partitioningrelevanten Lanthaniden- und Actinidenkomplexen mittels NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Christian

    2016-01-15

    In the present work the interaction of N-donor ligands, such as 2,6-Bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPrBTP) and 2,6-Bis(5-(2,2-dimethylpropyl)1H-pyrazol)-3-yl-pyridine (C5-BPP), with trivalent lanthanide and actinide ions was studied. Ligands of this type show a high selectivity for the separation of trivalent actinide ions over lanthanides from nitric acid solutions. However, the reason for this selectivity, which is crucial for future partitioning and transmutation strategies for radioactive wastes, is still unknown. So far, the selectivity of some N-donor ligands is supposed to be an effect of an increased covalency in the actinide-ligand bond, compared to the lanthanide compounds. NMR spectroscopy on paramagnetic metal complexes is an excellent tool for the elucidation of bonding modes. The overall paramagnetic chemical shift consists of two contributions, the Fermi Contact Shift (FCS), due to electron spin delocalisation through covalent bonds, and the Pseudo Contact Shift (PCS), which describes the dipolar coupling of the electron magnetic moment and the nuclear spin. By assessing the FCS share in the paramagnetic shift, the degree of covalency in the metal-ligand bond can be gauged. Several methods to discriminate FCS and PCS have been used on the data of the nPrBTP- and C5-BPP-complexes and were evaluated regarding their applicability on lanthanide and actinide complexes with N-donor ligands. The study comprised the synthesis of all Ln(III) complexes with the exceptions of Pm(III) and Gd(III) as well as the Am(III) complex as a representative of the actinide series with both ligands. All complexes were fully characterised ({sup 1}H, {sup 13}C and {sup 15}N spectra) using NMR spectroscopy. By isotope enrichment with the NMR-active {sup 15}N in positions 8 and 9 in both ligands, resonance signals of these nitrogen atoms were detected for all complexes. The Bleaneymethod relies on different temperature dependencies for FCS (T{sup -1}) and PCS (T{sup -2}) that occur upon description of the paramagnetic shift as a series of temperature-dependent terms. This method was applied to all nuclei in both complex series. Especially for the protons, and to a slightly lesser degree also for the heteronuclei, calculated FCS values appear unrealistically high, as they dominate the paramagnetic chemical shift. In some cases, the Bleaney method showed that spin polarisation is an important pathway for the transfer of electron spin density between metal ion and ligand. The Reilley method is a temperature-independent and well established procedure. Two theoretically determined values, the spin expectation value in z-direction of the lanthanide ion, left angle S{sub z} right angle {sub Ln}, and the so-called Bleaney parameter C{sub Ln}, are used for the calculation of FCS and PCS. For this method, there are two sets of parameters for calculations and two variants of graphical analysis available. For all variants, the Reilley method yielded plausible values for FCS and PCS. Furthermore, the behaviour of the magnetic anisotropy of the lanthanide ions was depicted correctly. An important result is that the metal-nitrogen bonding has a notable share of covalency even in the lanthanide complexes. For the protons the PCS is the dominant interaction. The carbon atoms of the aromatic rings exhibit an influence of the PCS, while the FCS is the dominant contribution and spin polarisation patterns can be identified. Without reliable methods for the exact determination of the FCS in Am(III) complexes, the quantification of the covalency in the metal-ligand bond is not possible. Nevertheless, we can qualitatively asses that there is a strong influence of effects relying on covalent bonds in the Am(III) complexes. The coordinating nitrogen atoms show a strong, localised shift of the resonance signals of more than 250 ppm upfield compared to the lanthanide complexes. This is attributed to a strong spin-orbit interaction, which is transmitted to the nitrogen atom. Like the FCS, this mechanism roots on the presence of a significant covalency in the metal-ligand bond. Therefore, this is the first spectroscopic proof of covalency in an actinide-ligand bond. With the analysis of {sup 15}N chemical shifts in Ln(III) and Am(III) complexes, new data for directly coordinating heteronuclei in organic N-donor ligands were obtained. These data are an important prerequisite for a critical assessment of the present NMR theory for paramagnetic substances and will also be useful as a benchmark for quantum chemical calculations. They are a valuable contribution to a better understanding of bonding and extraction behaviour of N-donor ligands on a molecular scale. This newly obtained knowledge is indispensable for the design of improved extraction ligands and the optimisation of extraction processes.

  12. Investigation of environmental samples from Fukushima with respect to uranium and plutonium by AMS; Untersuchung von Umweltproben aus Fukushima in Bezug auf Plutonium und Uran mittels AMS

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Stephanie

    2017-02-01

    In March 2011, the nuclear power plant Fukushima Dai-ichi was seriously damaged by a tsunami caused by an earthquake. During the accident large quantities of radionuclides, mainly of the volatile elements cesium and iodine, were released to the environment. In small amounts refractory elements such as plutonium and uranium have also been released. Plutonium and the uraniumisotope {sup 236}U have primarily been delivered by human activities in the environment. Large amounts were released during the atmospheric nuclear weapons tests. Additional sources are accidents in nuclear facilities, like Chernobyl. Every source has its own characteristic isotopic composition. It is therefore possible to determine the origin of the contamination by measuring the isotopic ratios of {sup 240}Pu/{sup 239}Pu and {sup 236}U/{sup 238}U. These ratios can be determined by using accelerator mass spectrometry. Due to its high sensitivity, it is possible to measure even small amounts of plutonium and especially of {sup 236}U. These measurements were performed using the compact 500 kV facility ''TANDY'' of ETH Zurich. In 2013 and 2015 vegetation, litter and soil drill core samples were taken in the contaminated area in Fukushima prefecture. In 2015 samples were taken as close to the sampling locations of the 2013 campaign as possible. After isolation of plutonium and uranium by chemical extraction, separate targets were prepared for the measurement. The {sup 240}Pu/{sup 239}Pu ratios indicate global fallout as the plutonium source for most samples. The plutonium of the reactors of Fukushima Dai-ichi is located in the upper layers like in vegetation or litter. From the uranium ratios alone the reactors could not unambigously be identified as the source of {sup 236}U. However, this is plausible in the cases were reactor plutonium was detected. None of the samples contained higher plutonium activity concentrations than in the rest of Japan, caused by global fallout. This holds even for the samples where the reactors were identified as the source from the isotope ratios. This and the strong localization, even for neighboring sampling sites, indicate that the overall small quantities of plutonium were most likely released as particulate matter.

  13. Production of diesel fuels from vegetable oils by means of homogenous catalysed metathesis of methyl oleate; Gewinnung von dieselartigen Kraftstoffen aus Pflanzenoelen mittels homogen katalysierter Metathese von Methyloleat

    Energy Technology Data Exchange (ETDEWEB)

    Erben, Friedrich; Paetzold, Eckhard [Rostock Univ. (Germany). Leibniz-Institut fuer Katalyse; Schuemann, Ulrike; Wichmann, Volker; Fluegge, Evelyn; Berndt, Silvia; Harndorf, Horst [Rostock Univ. (Germany). Lehrstuhl fuer Kolbenmaschinen und Verbrennungsmotoren; Kragl, Udo [Rostock Univ. (Germany). Leibniz-Institut fuer Katalyse; Rostock Univ. (Germany). Inst. fuer Chemie

    2013-10-01

    Due to the increasing shortage of fossil combustibles renewable resources like oils and fats have great potential for the production of diesel-like fuels. A key step in adapting the properties of biogenic fuels to those from fossil sources is cracking or isomerisation of linear hydrocarbon chains. This is necessary for optimal cold flow properties and a continuously rising boiling curve. The present work describes the potential of metathesis for this purpose. By formal exchange of parts of molecules of a small number of starting materials a variety of products is formed which exhibit a fuel-like composition. Ethenolysis as well as hexenolysis is examined, whereat hexenolysis owns the greater potential for production of diesel-like fuels out of unsaturated fatty acid esters. (orig.)

  14. Analysis of novel silicon and III-V solar cells by simulation and experiment; Analyse neuartiger Silizium- und III-V-Solarzellen mittels Simulation und Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hermle, Martin

    2008-11-27

    This work presents various simulation studies of silicon and III-V solar cells. For standard silicon solar cells, one of the critical parameters to obtain good performance, is the rear side recombination velocity. The optical and electrical differences of the different cell structures were determined. The optical differences and the effective recombination velocity Sback of the different rear side structures for 1 Ohmcm material were extracted. Beside standard silicon solar cells, back junction silicon solar cells were investigated. Especially the influence of the front surface field and the electrical shading due to the rear side, was investigated. In the last two chapters, III-V solar cells were analysed. For the simulation of III-V multi-junction solar cells, the simulation of the tunneldiode is the basic prerequisite. In this work, the numerical calibration of an GaAs tunneldiode was achieved by using an non-local tunnel model. Using this model, it was possible to successfully simulate a III-V tandem solar cell. The last chapter deals with an optimization of the III-V 3-junction cell for space applications. Especially the influence of the GaAs middle cell was investigated. Due to structural changes, the end-of-life efficiency was drastically increased.

  15. Utilization of surface-near geothermal energy by means of energy piles and geothermal probes; Nutzung der oberflaechennahen Geothermie mittels Energiepfaehlen und Erdwaermesonden

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaolong

    2013-05-01

    In collaboration with the Institute of Thermo-Fluid Dynamics (Hamburg, Federal Republic of Germany), a pilot plant for geothermal and sorption supported air-conditioning was built in the dockside area of Hamburg. The author of the book under consideration investigates a geothermal power plant with five energy poles and three boreholes. The economic and environmental benefits of this pilot plant were detected. The thermodynamic behavior of these energy piles was numerically simulated very well. The complex processes in the energy pile and in the soil could be mapped By means of a thermal-hydraulic-mechanical coupled simulation. The extraction capacity of a geothermal probe could be significantly increased by means of a combination of a groundwater circulation method with borehole heat exchangers.

  16. Design of modern vehicle electrical systems based on co-simulation and a model library; Entwurf moderner Bordnetze mittels Co-Simulation und Modellbibliothek

    Energy Technology Data Exchange (ETDEWEB)

    Zehetner, Josef; Lu, Di Wenpu; Watzenig, Daniel [Virtual Vehicle Research Center, Graz (Austria)

    2013-08-15

    The complexity of vehicle electrical and electronic systems, components, and functions is growing as they become increasingly networked with each other and with the internet. Vehicle electrical systems developers can manage this complexity now and in the future by employing simulation as a central tool in designing powerful and reliable vehicle electrical systems. Bosch Engineering offers a powerful simulation tool to support the design of vehicle power nets from initial requirements to final series approval, now being used also for hybrid and electric drive train development. (orig.)

  17. Innovative technologies for emitter formation of crystalline silicon solar cells using in-line diffusion; Innovative Technologien zur Emittererzeugung fuer kristalline Silizium-Solarzellen mittels Durchlaufdiffusion

    Energy Technology Data Exchange (ETDEWEB)

    Voyer, Catherine

    2009-04-20

    An in-line emitter formation process for crystalline silicon solar cells was developed. The wafers were coated at room temperature with dilute phosphoric acid (2.5 w/w% in water) using ultrasonic spraying and then heated up to temperatures around 900 C in a metal-contamination-free in-line furnace. In the first zones of the furnace, a phosphosilicate glass (PSG) is formed on the silicon surface and serves as the doping source. The PSG thickness was adjusted by varying the flow rate of dilute phosphoric acid to the spray nozzle and took on values appropriate for emitter formation, in the range of {proportional_to}40-120 nm. A surfactant mixture was added to the dilute phosphoric acid in order to obtain complete wetting of the silicon surface. The mixture, which was composed of a hydrocarbon surfactant and of a fluorosurfactant, achieved better wetting properties than would be possible when using only one of the two surfactants. The spray solution containing only the hydrocarbon surfactant achieved a faster drop flattening, while the spray solution containing only the fluorosurfactant achieved a lower static surface tension. The mixture allowed for a combination of these desired properties: The drops coalesced together sufficiently rapidly (before drying) on the silicon surface to form a complete dopant source liquid layer and this layer remains sufficiently homogeneous during the layer drying. The sprayed-on layer is thicker ({proportional_to}15 microns) than the height of the surface texture ({proportional_to}5-10 microns). The liquid strives for a state of equilibrium, a convex meniscus. The topography of the liquid surface at the time at which the increase in viscosity puts an end to the liquid flow is reflected in the topography of the PSG thickness. The corresponding variations in sheet resistance across a wafer are sufficiently small for solar cells. Furthermore, the liquid layer conforms itself, during the drying, to the surface texture on a microscopic scale, and thus the PSG thickness and the emitter essentially follow the surface texture, as seen on SEM pictures. Through dehydration of the phosphorus molecules and reaction with silicon, the layer turns into a PSG. This process produces a vapour which contains water and phosphorus compounds. A steeper heat-up curve or a higher vapour pressure leads to a thicker PSG. In this work, a high PSG thickness homogeneity was obtained through adjustment of the air supply in the furnace entrance area. It was furthermore shown that under the condition of a steep heat-up curve, the PSG formation is only completed at temperatures above 700 C. The influence of the furnace transport speed and plateau temperature and of the spray nozzle flow rate on the emitter doping profile was examined. A lower speed or a higher temperature resulted in a lower sheet resistance. Moreover, the emitter phosphorus surface concentration was increased or reduced through, respectively, an increase or a reduction of the spray nozzle flow rate. The dependence of sheet resistance on PSG thickness was found to show a non-monotonous behaviour: Sheet resistance first decreased with increasing PSG thickness, reached a minimum and then increased. The reduction is explained by the increasing amount of phosphorus available for diffusion into silicon. The increase is assumed to be due to the longer time and greater energy requirement for PSG formation from a thicker dopant source layer, which leads to a weaker phosphorus diffusion into silicon in the first zones of the furnace. A high homogeneity of sheet resistance was obtained, for example a relative standard deviation of 2.5% on a textured surface. Standard screen-printed Cz-Si solar cells were made which had high values of open-circuit voltage of up to 626 mV, of short-circuit current of up to 36 mA/cm{sup 2} and of efficiency of up to 17.5%. In addition, the doping profile was varied. Textured solar cells with in-line diffusion achieved an efficiency of up to 16.8% compared to 16.5% for the reference solar cells with tube furnace diffusion. High fill factors of up to 79.9% showed the high homogeneity of the emitters formed using in-line diffusion. Using wafers from five heights of a mc-Si column, minority carrier lifetimes were measured and solar cells were fabricated. A longer or double-sided in-line diffusion led on average to higher lifetimes than a shorter or single-sided one respectively, and a tube furnace diffusion led on average to higher lifetimes than an in-line diffusion, but these differences were small and ambiguous. A clear influence of the doping profile was however observed: The longer in-line diffusion led to the highest efficiencies of up to 15.2% on non-textured silicon.

  18. Characterization of plasma-functionalized surfaces by means of Tof-SIMS and multivariate analysis methods; Charakterisierung von plasmafunktionalisierten Oberflaechen mittels ToF-SIMS und multivariaten Analysemethoden

    Energy Technology Data Exchange (ETDEWEB)

    Gradowski, M. von

    2006-11-13

    The basic principles and opportunities of surface characterisation of selected functionalised samples via ToF-SIMS (time-of-flight secondary ion mass spectrometry) are presented. One major focus of the project was the investigation of non-cohesive surface layers which could exhibit either domain like structure or well defined single functionalised surfaces. By means of ToF-SIMS with the ability of displaying the lateral distribution of surface fragments information on the structure and surface density of specific fragments on the investigated film can be obtained. The combination of the ToF-SIMS experiment with a multivariate algorithm (partial least squares, PLS) provides an interesting opportunity to quantitatively determine surface properties such as elemental and molecular concentrations. Due to the fact that the ToF-SIMS spectrum consist of a huge amount of intensities, a single one-dimensional correlation (e.g. CF{sub 3} fragment intensity <-{yields} CF{sub 3} concentration) would disregard the rest of the spectral information. The large number of fragment intensities in the spectrum is representative for the chemical structure of the analysed surface. Therefore, it is crucial to consider this total information for the quantification of surface properties (element concentration, water contact angle etc.). Furthermore, this method allows the determination of surface properties with a lateral resolution of a few microns only. This can be used for chemically structured surfaces which for many applications show micrometer sized surface structures. Finally, a successful application of the multivariate models is presented for samples from the biological and medical area. Human fibroblasts and pancreas cells have been cultivated on plasma functionalised surfaces in order to study the influence of the functionalisation on the cell growth. The samples have been covered by TEM grids with meshes in the {mu}m range before the plasma treatment to generate structured surfaces. By applying the multivariate models onto the ToF-SIMS spectra quantitative surface properties could then be assigned to each {mu}m-sized surface area which are crucial in interpreting the cell growth on the surface. (orig.)

  19. Measurement of transvers spin effects by means of two-hadron correlations in the COMPASS experiment; Messung transversaler Spineffekte mittels zwei Hadronen Korrelation am COMPASS-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Frank Michael

    2008-06-23

    The quark structure of the nucleon can at neglection of intrinsic quark transverse momenta be completely described by two quark distribution functions. These are the unpolarized quark distribution function q(x), the helicity distribution function {delta}q(x), and the transvers quark-spin distribution function {delta}{sub T}q(x). This lastly mentioned function called transversity function, is chirallyn odd an can therefore only be measured in a combination with another chirally odd function. An access possibility to the transversity function {delta}{sub T}q(x) is the semi-inclusive two-hadron production in deep inelastic scattering on a transversely polarized target. Thereby the folding of the chirally odd two-hadron interference fragmentation function (IFF) H{sub 1} {sup angle} (z,M{sub h}{sup 2}) and the chirally odd transversity function. The IFF H{sub 1} {sup angle} (z,M{sub h}{sup 2}) is the spin-dependent part of a fragmentation function, which describes the fragmentation of a transversely polarized quark in two unpolarized hadrons. The production of the two hadrons pursues in an interference between different wave-state of the hadron pairs. Azimuthal asymmetries in the produced hadron pairs are measured. The measurements, which are described in this thesis, were performed in the COMPASS experiment at CERN in the years 2002-2004, which is a solid-state-target experiment at the SPS accelerator. After an introduction in chapter 2 the basing theoretical concepts for the measurement of the transversity function are presented. In chapter 3 the COMPASS experiment is described. Finally in chapter 4 the evaluation methods are discussed, the results of the azimuthal asymmetries shown and compared with theoretical predictions. [German] Die Quark-Struktur des Nukleons laesst sich bei Vernachlaessigung intrinsischer Quarktransversalimpulse vollstaendig durch drei Quark Verteilungsfunktionen beschreiben. Diese sind die unpolarisierte Quark Verteilungsfunktion q(x), die Helizitaets- Verteilungsfunktion {delta}q(x) und die transversale Quarkspin Verteilungsfunktion {delta}{sub T}q(x). Diese letztgenannte Funktion, genannt ''Transversity'' Funktion, ist chiral ungerade und kann deshalb nur in Kombination mit einer anderen chiral ungeraden Funktion gemessen werden. Eine Zugangsmoeglichkeit zur ''Transversity'' Funktion {delta}{sub T}q(x) ist die semi-inklusive zwei Hadronenproduktion in tief inelastischer Streuung an einem transversal polarisierten Target. Dabei misst man die Faltung der chiral ungeraden zwei Hadronen Interferenz Fragmentationsfunktion (IFF) H{sub 1} {sup angle} (z,M{sub h}{sup 2}) und der chiral ungeraden ''Transversity'' Funktion. Die IFF H{sub 1} {sup angle} (z,M{sub h}{sup 2}) ist der spinabhaengige Teil einer Fragmentationsfunktion, die die Fragmentation eines transversal polarisierten Quarks in zwei unpolarisierte Hadronen beschreibt. Die Produktion der zwei Hadronen erfolgt in einer Interferenz zwischen verschiedenen Wellenzustaenden der Hadronenpaare. Man misst azimuthale Asymmetrien in den erzeugten Hadronenpaaren. Die Messungen, die in dieser Arbeit beschrieben werden, wurden am COMPASS Experiment am CERN in den Jahren 2002-2004 durchgefuehrt, welches ein Feststoff Target Experiment am SPS Beschleuniger ist. Nach einer Einfuehrung werden in Kapitel 2 die zugrundeliegenden theoretischen Konzepte zur Messung der ''Transversity'' Funktion vorgestellt. In Kapitel 3 wird das COMPASS Experiment beschrieben. Schliesslich werden in Kapitel 4 die Auswertemethoden besprochen, die Ergebnisse der azimuthalen Asymmetrien gezeigt und mit theoretischen Vorhersagen verglichen. (orig.)

  20. Structural analysis of a flexure tilt table by using finite element method; Strukturanalyse eines Biege-Kipp-Tisches mittels Finite-Elemente-Methode

    Energy Technology Data Exchange (ETDEWEB)

    Schust, Matthias

    2012-08-15

    At the research institute DESY the synchrotron radiation source PETRA III is operated at Hamburg site. The facility is the most powerful lightsource of its kind and enables scientists to use X-ray beams with hitherto unattained brilliance. In a so-called double-crystal monochromator certain wavelengths can be selected from the light. In these systems tilt tables with flexure hinges are used. So far, a certain susceptibility of the assembly to vibration can be seen, which decreases the beam quality. The goal of this thesis is to determine the causes of the problem and to discuss the findings concerning the known behavior. First of all the functioning of the tilt table will be explained. Afterwards the theory of flexure hinges and the boundary conditions of a finite element analysis will be treated. Using a simulation program, several assembly models will be investigated and parameter studies are carried out. Beginning with the base object of investigation - the tilt table - the model of the whole assembly is systematically developed. Natural frequencies, the stress at the spring hinges and the displacement of the crystal surface can be determined. The results of the research show that the vibration behavior of the assembly is very complex and cannot be comprehensively described within the analyses carried out. The cause of the problems has not been identified yet and therefore further studies would be necessary. (orig.)

  1. Validierung der Wirksamkeitsprüfung für Clostridium tetani Impfstoffe ad usum veterinarium durch den direkten Nachweis von Tetanus-Antitoxin im Zieltier mittels ELISA

    OpenAIRE

    Roßkopf, Ute

    2007-01-01

    Die dargelegten Ergebnisse zur Validierung einer neuen Wirksamkeitsprüfung von Tetanus-Impfstoffen resultieren aus umfangreichen Feldstudien, durchgeführt mit neun unterschiedlichen Impfstoffen für das Pferd sowie acht Impfstoffen für das Schaf. Insgesamt wurden 102 Pferde und 82 Schafe entsprechend den Angaben in der Gebrauchsinformation immunisiert. Blutentnahmen fanden nach einem vorgegebenen Schema von bis zu zwei Jahren nach der ersten Impfung statt. Die Impfstoffe waren entweder monoval...

  2. Fabrication of uranium-based ceramics using internal gelation for the conversion of trivalent actinides; Herstellung uranbasierter Keramiken mittel interner Gelierung zur Konversion trivalenter Actinoiden

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Henrik

    2012-07-01

    Alternative to today's direct final waste disposal strategy of long-lived radionuclides, for example the minor actinides neptunium, americium, curium and californium, is their selective separation from the radioactive wastestream with subsequent transmutation by neutron irradiation. Hereby it is possible to obtain nuclides with a lower risk-potential concerning their radiotoxicity. 1 neutron irradiation can be carried out either with neutron sources or in the next generation of nuclear reactors. Before the treatment, the minor actinides need to be converted in a suitable chemical and physical form. Internal gelation offers a route through which amorphous gel-spheres can be obtained directly from a metal-salt solution. Due to the presence of different types of metal ions as well as changing pH-values in a stock solution, a complex hydrolysis behaviour of these elements before and during gelation occurs. Therefore, investigations with uranium and neodymium as a minor actinide surrogate were carried out. As a result of suitable gelation-parameters, uraniumneodymium gel-spheres were successfully synthesised. The spheres also stayed intact during the subsequent thermal treatment. Based upon these findings, uranium-plutonium and uranium-americium gels were successfully created. For theses systems, the determined parameters for the uraniumneodymium gelation could also be applied. Additionally, investigations to reduce the acidity of uranium-based stock solutions for internal gelation were carried out. The necessary amount of urea and hexamethylenetetramine to induce gelation could hereby be decreased. This lead to a general increase of the gel quality and made it possible to carry out uranium-americium gelation in the first place. To investigate the stability of urea and hexamethylenetetramine, solutions of these chemicals were irradiated with different radiation doses. These chemicals showed a high stability against radiolysis in aqueous solutions.

  3. Fast determination of strontium-89 and strontium-90 by simultaneous Cerencov- and Proportional-Counting; Schnelle Bestimmung von Strontium-89 und Strontium-90 mittels simultaner Cerenkov- und Proportionalzaehlrohrmessung

    Energy Technology Data Exchange (ETDEWEB)

    Laerbusch, Karin; Wiezorek, Claus [Chemisches und Veterinaeruntersuchungsamt MEL, Muenster (Germany)

    2014-01-20

    The presented method for simultaneous determination of Sr 89 and Sr 90 combines the techniques of Cerencov- and Proportional-Counting. Due to the low limit of detection of the latter technique, the method is very sensitive for the total radiostrontium. The distribution among two measurement devices offers the advantage of time saving.

  4. Verification of the weak equivalence principle of supports and heavy masses using SQUIDs; Ueberpruefung des schwachen Aequivalenzprinzips von Traegern und schwerer Masse mittels Squids

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R. [Friedrich-Schiller-Universitaet Jena (Germany). Inst. fuer Festkoerperphysik; Dittus, H. [Univ. Bremen (Germany). Zentrum fuer angewandte Raumfahrttechnologie und Mikrogravitation

    2003-07-01

    The weak equivalence principle is one of the fundamental hypotheses of general relativity and one of the key elements of our physical picture of the world, but since Galileo there has been no satisfactory way of verifying it. The new SQUID technology may offer a solution. The contribution presents the experiments of Jena University. Applications are envisaged, e.g., in the STEP space mission of the NASA/ESA. [German] Das Schwache Aequivalenzprinzip ist eine der grundlegenden Hypothesen der Allgemeinen Relativitaetstheorie und damit einer der Grundpfeiler unseres physikalischen Weltbildes. Obwohl es seit den ersten Experimenten von Galileo Galilei am Schiefen Turm zu Pisa im Jahre 1638 bis heute schon zahlreiche und immer praeziser werdende Messungen zur Ueberpruefung der Aequivalenz von schwerer und traeger Masse gegeben hat, ist die strenge Gueltigkeit dieses fundamentalen Prinzips experimentell vergleichsweise unzureichend bestimmt. Neuere Methoden, wie der Einsatz SQUID-basierter Messtechnik und die Durchfuehrung von Experimenten auf Satelliten, lassen Verbesserungen schon in naher Zukunft erwarten, so dass theoretische Ueberlegungen zur Vereinigung aller uns bekannten physikalischen Wechselwirkungen, die eine Verletzung des Schwachen Aequivalenzprinzips voraussagen, experimentell eingegrenzt werden koennten. Der Beitrag gibt einen Ueberblick ueber die an der Universitaet Jena entwickelte SQUID-basierte Messtechnik zum Test des Aequivalenzprinzips und fasst die bisher bei Freifallversuchen am Fallturm Bremen erzielten experimentellen Ergebnisse zusammen. Ein Ausblick auf die geplante Raumfahrtmission STEP der NASA/ESA zum Praezisionstest des Schwachen Aequivalenzprinzips schliesst den Beitrag ab. (orig.)

  5. Methodological study of aging effects on fuel cells using X-ray synchrotron radiography and tomography; Methodische Untersuchung von Alterungseffekten an Brennstoffzellen mittels Synchrotronradiografie und -tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Tobias

    2012-04-05

    In the present work, new and advanced methods for the investigation of methanol and hydrogen powered fuel cells were analyzed. Synchrotron radiography and tomography were applied to investigate materials and transport processes in operating fuel cells ''in-situ'' and non-destructively. The corrosion of ruthenium is a key issue during aging of direct methanol fuel cells (DMFC). Therefore the influence of different aging processes on the distribution of ruthenium is of great interesting. An imaging method based on X-ray absorption spectroscopy (XAS) was applied to investigate the changes in the distribution of fuel cell catalysts three-dimensionally. Using monoenergetic synchrotron radiation it was shown that the distribution of ruthenium (Ru) in the anode catalyst changes after application of an accelerated aging procedure. A strong influence on the flowfield and the gas diffusion layer structures on the Ru distribution were found in the gas diffusion electrode at the anode side. Additionally some ruthenium moves through the membrane from the anode to the cathode. The redistribution caused by the accelerated aging procedure strongly differs from that obtained after aging under realistic stack operation (here over 1700 h) of a fuel cell in a pallet transporter. For the tomographic investigations samples were taken out from a stack operation in aged membrane electrode assembly (MEA) and were analyzed ex-situ. It was shown that the Ru redistribution can be attributed to mass transport processes (CO{sub 2} and H{sub 2}O) in the gas diffusion layer (GDL). Other high energy resolved measurements showed that the strength of the oxidation of ruthenium and platinum depends on the spatial distribution of the ruthenium. Last mentioned - also for the platinum catalyst - could be given quantitatively by means of this newly developed method. In the second part of this work high temperature polymer electrolyte fuel cells (HT-PEFC) were investigated. No liquid water can be found due to the high operation temperature of 160-200 C in this cell type. Hence conventional analysis methods are not applicable here. In especial the product water is very important for the electrical conductivity of the membrane and changes the state of the phosphoric acid inside the membrane and the electrodes. For the first time, the water balance in a HT-PEFC at different operating conditions was characterized in-situ during cell operation. The characterization was based on measured changes in the membrane transmittance and its thickness. Suitable models allowed calculating the water balance of the membrane. The influence of different operating conditions on the redistribution of the phosphoric acid between the electrodes and in the membrane was analyzed. The analysis is complemented with investigations of polarization curve recording and electrochemical impedance spectroscopy.

  6. Determination of the electromagnetic dipole strength distribution in medium-heavy atomic nuclei by means of nuclear resonance fluorescence; Bestimmung der elektromagnetischen Dipolstaerkeverteilung in mittelschweren Atomkernen mittels Kernresonanzfluoreszenz

    Energy Technology Data Exchange (ETDEWEB)

    Massarczyk, Ralph Jens

    2011-01-17

    During the last hundred years several models were developed to describe the configuration of nuclei. These models have to make predictions, which should be comparable with experiments. As a standard type of experiment the nuclear resonance fluorescence was established. A nucleus is excited by irradiation with photons. By emitting one or more photons the nucleus decays back to the ground state. With this method it is possible to measure energy levels and to determine the strength of their excitation. A continuum of unresolved peaks gives additional strength. The existing setup at the linear electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf uses bremsstrahlung, produced as a secondary beam in a thin Niobium foil. During the years 2008/09 experiments on the nuclei of {sup 86}Kr and {sup 136}Ba took place there. In this work they will be analyzed. Photon flux and efficiency determination have been done as well as simulations on detector response and non-nuclear scattered background events. For this purpose the GEANT4 package was used. Finally the resulting cross sections were corrected for branching and feeding.

  7. Reliabilitätskriterien für die Messung der Lebersteifigkeit mittels Echtzeit-2D-Shearwave-Elastografie bei verschiedenen klinischen Szenarien der chronischen Lebererkrankung

    DEFF Research Database (Denmark)

    Thiele, M; Stæhr Madsen, Bjørn; Procopet, B

    2017-01-01

    Purpose: Liver stiffness measurement by real-time 2-dimensional shear wave elastography (2D-SWE) lacks universal reliability criteria. We sought to assess whether previously published 2D-SWE reliability criteria for portal hypertension were applicable for the evaluation of liver fibrosis......-SWE measurements from 142 patients. Overall, the variability in liver stiffness within single 2D-SWE measurements was low (SD = 1.1 ± 1.5kPa; SD/mean = 12 ± 9 %). Intra-observer analysis showed almost perfect concordance (intraclass correlation coefficient = 0.95; 95 % CI 0.94 - 0.96; average difference from...

  8. Determination of W-erosion through optical spectroscopy under ITER-relevant plasma conditions; Bestimmung der Wolframerosion mittels optischer Spektroskopie unter ITER-relevanten Plasmabedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Laengner, Marko

    2016-11-21

    Tungsten (W) is used in present fusion experiments and is as well a material choice for future reactors like ITER and DEMO. However, tungsten eroded from the wall leads to high radiation losses in the plasma and the transport to the plasma center to critical plasma cooling. Therefore a detailed investigation of the interaction between eroded tungsten and the plasma is necessary. The emission of tungsten line radiation in the plasma and thus the shape of the emission profiles is characterized by excitation and ionisation. Quantitatively the ionisation can be described in terms of the ionisation rate coefficients. This knowledge is necessary for the interpretation of spectroscopic data and especially to determine tungsten fluxes into the plasma that are caused by tungsten erosion. Up to now, ionisation rate coefficients for neutral tungsten were not determined except for the plasma temperature range below 20 eV. For higher temperatures only uncertain calculated data or semi-empirical data is available. Therefore, within this thesis for the first time ionisation and emission processes of tungsten originating from tungsten erosion were investigated in the temperature range between (41±8) eV and (81±8) eV at the tokamak TEXTOR and ionisation rate coefficients were determined experimentally. Measured emission profiles of the W I(400.88 nm)-line show a typical exponential decrease that is caused by the ionisation of the neutral tungsten atoms. But moreover, at a distance of 1 to 2 mm away from the sputtered surface the emission initially increases to a maximum. By introducing a relaxation time between 0.5 and 1 μs before reaching the equilibrium of the population of the emitting energy level of this line the increase of the emission profiles can be reproduced. Simulating the emissions profiles through a Monte-Carlo-simulation that was developed in the scope of this thesis results in ionisation rate coefficients that are identical with values calculated through using the semi-empirical Lotz-formula. The necessary extension of the atomic data base regarding neutral tungsten leads to the interest in a tungsten source that can easily be used for calibration purposes. This was realised at TEXTOR through the injection of WF{sub 6}. The tungsten that was brought into the plasma via WF{sub 6}-injection was investigated regarding the comparability to tungsten originating from a sputtering process. Moreover was WF{sub 6} used for the first time to determine conversion factors - the so-called photon efficiencies - to calculate tungsten fluxes from spectroscopically measured photon fluxes. For the given combinations of temperature and density from (20±5) eV to (82±5) eV and from (2.2±1) x 10{sup 12} cm{sup -3} to (6.8±1) x 10{sup 12} cm{sup -3}, respectively, for the W I(400.88 nm)-line a constant average value of left angle E{sup WI(400.88} {sup nm)}{sub Ph} right angle =94±16 is found. To test these values sputtering yields were determined from the amount of eroded tungsten atoms. These sputtering yields are in line with experimental reference values and calculations. The prevailing investigated plasma conditions are in the range of what can be expected considering the ITER divertor during ELMs. The found experimental results are consistent and confirm the match between WF{sub 6} photon efficiencies and photon efficiencies of sputtered tungsten.

  9. MR imaging of gastric wall layers in vitro: correlation to the histologic wall structure; Experimentelle Darstellung der Schichten der Magenwand mittels MRT: Korrelation mit dem histologischen Wandaufbau

    Energy Technology Data Exchange (ETDEWEB)

    Lubienski, A.; Grenacher, L.; Schipp, A.; Duex, M. [Radiologische Klinik, Abt. Radiodiagnostik, Ruprecht-Karls-Univ. Heidelberg (Germany); Reith, W. [Abt. fuer Neuroradiologie der Radiologischen Universitaetsklinik, Univ. Saarland (Germany); Mechtersheimer, G. [Inst. fuer Allgemeine Pathologie, Ruprecht-Karls-Univ. Heidelberg (Germany)

    2002-04-01

    Purpose: To correlate gastric wall layers visible of MRI with the anatomical structure of the gastric wall. Methods: After macroscopic preparation 5 x 5 cm post-mortem tissue sections of the gastric antrum were evaluated using a 2.4 Tesla MR unit (Bruker, Ettlingen, Germany). MR imaging consisted of T2-weighted multi-spinecho sequences in longitudinal and axial directions. The specimens then were stained with hematoxylin-eosin for histological examination. After that histological correlation of the gastric wall layers visible on MRI was performed. Results: In all specimens four gastric wall layers could be clearly identified on MRI. The direct comparison of those layers to the histological findings showed the following correlation: 1. intermediate signal = mucosa, 2. hypointense signal = lamina muscularis mucosae, 3. hyperintense signal = submucosa, 4. intermediate signal = muscularis propria. Conclusions: Gastric wall layers visible on MRI were successfully correlated to the anatomic layers of the gastric wall. This allows us for the first time to classify invasion of gastric carcinoma using high spatial-resolution MR imaging. However, the subserosa and serosa are excluded from this conclusion, because so far a reliable statement concerning the value of MRI to depict these very variable layers is not possible. (orig.) [German] Ziel: Ziel der Studie war es, magnetresonanztomographisch sichtbare Schichten der Magenwand mit dem anatomischen Wandaufbau des Magens zu korrelieren. Methoden: Nach makroskopischer Skelettierung wurden 5 x 5 cm messende Stuecke des Magenantrums von fuenf Leichenmaegen in einem 2.4 Tesla MR-Geraet (Bruker, Ettlingen, Deutschland) untersucht. Es wurden T2-gewichtete Multispinechosequenzen in longitudinaler und axialer Richtung zum Praeparat angefertigt. Nach Faerbung der Magenpraeparate mit Haematoxylin-Eosin wurden die MR-Bilder mit den histologischen Schnitten in Bezug auf sichtbare Wandschichten korreliert. Ergebnisse: Regelmaessig konnten vier Magenwandschichten auf den MR-Bildern voneinander differenziert werden. Der direkte Vergleich dieser Magenwandschichten mit den korrespondierenden histologischen Schnitten ergab von lumenseitig betrachtet folgende Korrelation: 1. Schicht: intermediaeres Signal - Mukosa, 2. Schicht: hypointenses Signal - Lamina muscularis mucosae, 3. Schicht: hyperintenses Signal - Submukosa, 4. Schicht: intermediaeres Signal - Muscularis propria. Schlussfolgerungen: Magnetresonanztomographisch sichtbare Magenwandschichten wurden dem anatomischen Wandaufbau des Magens mit Erfolg zugeordnet. Damit besteht erstmals die Moeglichkeit, die Tiefeninfiltration eines Magenkarzinoms mit Hilfe hochaufgeloester MR-Aufnahmen zu beurteilen. Diese Einschaetzung gilt ausdruecklich nicht fuer die Subserosa und Serosa, da ueber die Darstellbarkeit dieser sehr variablen Wandschichten durch die MRT noch keine Aussage zu treffen ist. (orig.)

  10. Energy conservation potentials in the countries of Central and Eastern Europe - an expose of theses; Die Energiespeicherpotentiale in den Laendern Mittel- und Osteuropas - eine Darstellung der Thesen

    Energy Technology Data Exchange (ETDEWEB)

    Riesner, W. [Hochschule fuer Technik, Wirtschaft und Sozialwesen Zittau/Goerlitz FH, Zittau (Germany)

    1996-07-01

    The report compares western and eastern Europe in terms of their supply with fossil energy, the development of their primary and end-use energy consumption, and the development of their gross power generation. The technical state of energy conversion plants and electrothermal power plants, Russia`s energy conservation potential, and the efficacy of measures for enhancing electric energy efficiency in the Ukraine are described. Finally, a comparison of energy input coefficients and energy costs between the old and new federal states of Germany is made. (DG) [Deutsch] Bezueglich der Versorgung mit fossiler Energie, der Entwicklung des Primaer- und Endenergieverbrauchs und der Entwicklung der Brutto-Stromerzeugung werden West- und Osteuropa miteinander verglichen. Der technische Stand der Energieumwandlungsanlagen und der Elektrowaermeanlagen sowie das Energieeinsparungspotential in Russland und die Effektivitaet von Massnahmen zur Elektroenergieeffizienzsteigerung in der Ukraine werden dargestellt. Schliesslich erfolgt ein Vergleich der Energieintensitaets- und Energiekosten zwischen den alten und neuen Bundeslaendern der BRD. (DG)

  11. Measurement of hydrogen distributions in iron and steel by means of neutron radiography and tomography; Messung von Wasserstoffverteilungen in Eisen und Stahl mittels Neutronenradiographie und -tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Griesche, Axel; Kannengiesser, Thomas [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Kardjilov, Nikolay; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB), Berlin (Germany); Schillinger, Burkhard [Technische Univ. Muenchen, Garching (Germany)

    2015-07-01

    In recent years, the optimization of the radiography measuring stations at research reactors and in particular the development of the neutron detectors has enabled the measurement of hydrogen distributions with ever higher spatial resolution at the same time more sensitive detection limit. Compared to iron, hydrogen has a high interaction cross-section for neutrons, and thus allows simple radiographic methods of the two and three dimensional visualization of hydrogen distribution in the structure. This allowed us for the first time the measurement of hydrogen diffusion flows in centimeter-thick steel samples with a temporal resolution of 20 s and the quantitative measurement of hydrogen accumulation of crack edges in hydrogen embrittled iron samples. It was also the first gaseous hydrogen detected in the cavities of the cracks and the pressure can be determined. This new quality of information on the microstructure scale granted unprecedented insights for the investigation of damage mechanisms e.g. in the hydrogen embrittlement. By providing local in-situ information that is not accessible by conventional methods such as carrier gas hot extraction, as well as analyzes can be performed in three dimensions with a spatial resolution of 20-30 μm. This article provides examples that use the spatial and temporal resolution of the neutron radiography and tomography to visualize hydrogen distributions in and around cracks and to quantify. The measurements were conducted at the research reactors BER II of HZB in Berlin and FRM II of teh neutron source Heinz Maier-Leibnitz in Garching. (This article contains PowerPoint slides). [German] In den letzten Jahren hat die Optimierung der Radiographie-Messplaetze an Forschungsreaktoren und hier insbesondere die Weiterentwicklung der Neutronendetektoren die Messung von Wasserstoffverteilungen mit immer hoeherer Ortsaufloesung bei gleichzeitig empfindlicherer Nachweisgrenze ermoeglicht. Wasserstoff besitzt im Vergleich zu Eisen einen hohen Wechselwirkungsquerschnitt fuer Neutronen und erlaubt somit mit einfachen radiographischen Methoden die zwei- und dreidimensionale Visualisierung von Wasserstoffverteilungen im Gefuege. Dies ermoeglichte uns erstmals die Messung von Wasserstoffdiffusionsstroemen in zentimeterdicken Stahlproben mit einer zeitlichen Aufloesung von 20 s sowie die quantitative Messung von Wasserstoffansammlungen an Rissflanken in wasserstoffversproedeten Eisenproben. Dabei konnte auch erstmals gasfoermiger Wasserstoff in den Hohlraeumen der Risse nachgewiesen werden und dessen Druck bestimmt werden. Diese neue Qualitaet der Information auf der Mikrostrukturskala gewaehrt noch nie dagewesene Einblicke fuer die Aufklaerung von Schaedigungsmechanismen z. B. bei der Wasserstoffversproedung. Durch die Bereitstellung von lokalen in situ Informationen, die mit herkoemmlichen Methoden wie der Traegergas-Heissextraktion nicht zugaenglich sind, koennen so auch Analysen in drei Dimensionen mit einer Ortsaufloesung von 20-30 μm durchgefuehrt werden. In diesem Beitrag werden Beispiele gezeigt, die die Orts- und Zeitaufloesung der Neutronenradiographie und -tomographie nutzen, um Wasserstoffverteilungen in und an Rissen zu visualisieren und zu quantifizieren. Die Messungen wurden an den Forschungsreaktoren BER II des HZB in Berlin und FRM II der Neutronenquelle Heinz Maier-Leibnitz in Garching durchgefuehrt.

  12. Biogas desulfurization with a new developed doped activated carbon. 20 month pilot test; Biogasfeinentschwefelung mittels neu entwickelter dotierter Aktivkohle. 20-monatiger Praxistest

    Energy Technology Data Exchange (ETDEWEB)

    Rossow, Silvana; Deerberg, Goerge; Goetze, Toralf; Kanswohl, Norbert; Nelles, Michael [Univ. Rostock (Germany). Lehrstuhl fuer Abfall- und Stoffstromwirtschaft

    2009-05-15

    Doped activated carbon is a special developed activated carbon for the desulfurization of technical gases. Based on its special adsorption properties, it is able to bond a large amount of hydrogen sulfide. By the special manufacturing method it was possible to optimize further the performance for the desulfurization of gases. In a biogas plant with an installed electric capacity of 2 MW the functionality of the doped activated carbon was proofed in a real biogas stream in a 20 month pilot test. The activated carbon was used in a special adsorption system that was tunes on the requirement of the activated carbon and on the site of installation. Because the biogas plant was in the starting period, all the time there were variable operation conditions. In spite of the variable conditions the doped activated carbon shows a permanent complete desulfurization, as in the executed laboratory experiments. By the use of the desulfurization system the concentration of hydrogen sulfide is decreased less than 1 ppm. The prejudices with are often caused by hydrogen sulphide could not identify until now. A positive evidence of the excellent desulfurization is the doubling of the oil lifetime of the block heating station. (orig.)

  13. Maintenance planning for transmission routes with medium voltage overlines - experience within the framework of two pilot projects; Trassenpflegeplanung fuer Mittel- und Hochspannungsfreileitungen - Erfahrungen von zwei Pilotprojekten

    Energy Technology Data Exchange (ETDEWEB)

    Geiges, H. [Ingenieurbuero Geiges, Freiraum- und Landschaftsplanung, Laumersheim (Germany)

    1997-11-03

    On the basis of the `VDEW Orientation Aid for Maintenance Measures in Transmission Routes` two pilot projects were selected in a 110 kV and a 20 kV overhead transmission route. (orig.) [Deutsch] Auf der Grundlage der `VDEW-Orientierungshilfe zu Pflegemassnahmen in Leitungstrassen` wurden Pilotprojekte in einer 110-kV- und in einer 20-kV-Freileitungstrasse im suedlichen Pfaelzerwald ausgewaehlt. (orig.)

  14. Lambda quantification by laser optical measuring methods on a supercharged Otto engine with Benz indirect injection; Lambdaquantifizierung mittels laseroptischer Messmethoden am aufgeladenen Ottomotor mit Benzindirekteinspritzung

    Energy Technology Data Exchange (ETDEWEB)

    Rogler, Philipp

    2010-07-01

    For the optimization of upcoming SI engine generations it is indispensable to understand the mixture formation process in detail because it is the basis requirement for reducing emissions and fuel consumption. On this account, fuel sprays used for gasoline direct injection are investigated with advanced laser optical measurement techniques. The spatial fuel distribution of both vapor and liquid phase is measured with a new technology approach, in which the 3D-tomography is combined with the laser induced exciplex fluorescence to create a new technology. With this laser-induced exciplex fluorescence tomography (TLIEF) the vapor and liquid phase fuel distribution of annular orifice and multi hole injectors are investigated under stationary boundary conditions in an optically accessible spray vessel. The particle density inside the spray chamber is kept constant and set to resemble that of a typical stratified engine operation point during the injection phase. Pressure and temperature are varied for parameter studies. The 3D spray visualizations show a significant dependency of the spray propagation on the ambient temperature. The vaporized fuel generated by multihole injectors with nearby oriented spray plumes is elongated differently under high ambient temperatures (500 K) compared to room temperature. PIV flow field measurements revealed that the reason for this temperature dependent behavior is the spray induced air flow. The vapor phase, which is with increasing temperatures in greater distance from the injector predominantly present, with its, compared to fuel droplets, lower moment of inertia is stronger elongated by the spray induced air flow. For a more detailed understanding of the mixture formation processes, the air-fuel-ratio {lambda} is computed from the quantified TLIEF signals. Therefore the total fluorescence intensity within the spray volume at a time where the vaporization process has been completed is equalized to the known total injected mass. Thus the spatial {lambda}-distribution of gasoline direct injection sprays is known for all observation times and can be further evaluated quantitatively. For data evaluation new methods are developed, which allow quantitative statements with regard to spray homogeneity and inflammability. Thereby it is shown within the current work, that spray geometries which generate large eddies outside and small eddies within the spray homogenize fast and possess a better spray homogeneity. Mixture formation is furthermore studied on a transparent engine with a central mounting position of the injector. Investigated were two engine operation modes: spray guided stratified engine operation mode and supercharged homogeneous engine operation mode, both with adequate annular orifice and multi hole injectors. For quantitative data, the linear vibrational Raman spectroscopy is used as a 1D-measurement technology. Compared to solutions known from the literature, the laser optical setup is improved in such a way that measurements even during and shortly after the injection phase are feasible. In parallel of the 1D measurements, the fuel distribution is visualized with planar laser induced fluorescence (PLIF). For mixture formation analysis, many injection and engine parameters are varied. The results from transparent engine and spray vessel are associated with each other and correlated to known emission measurements of a metal engine with the same combustion chamber geometry. In order to assure a reliable inflammation and receive a combustion with low raw emissions in stratified engine operation mode, all injection and engine parameters have to be adjusted individually for each spray geometry. The optima differ depending on the combustion chamber geometry and the spray shape. In supercharged homogeneous engine operation mode it is shown that from a mixture formation point of view there is a conflict of interests between a homogeneous mixture and wall wetting for driven cycles' relevant engine operation points. The results of this work show that an injection spread over the complete intake phase results in a homogeneous mixture with minimum wall and piston wetting. This optimum in mixture formation can only be realized for all operation conditions of a given engine with a reduction in spray penetration and a controllable hydraulic flow rate of the GDI injector. (orig.)

  15. Visualization of ferroelectric domain structures in lithium niobate by means of confocal nonlinear microscopy; Visualisierung ferroelektrischer Domaenenstrukturen in Lithiumniobat mittels konfokaler nichtlinearer Mikroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Berth, Gerhard

    2010-07-01

    In the field of integrated optics nonlinear-optical effects play a central role. A typical example for the commercial use of such phenomena is the frequency conversion. A deciding parameter is here the phase matching, which determines the quantity of the constructive interaction range of contributing optical fields. In view of a high efficiency of such processes the dispersion of a crystal must be balanced for the contributing frequencies. In nonlinear components on the base of optical waveguides the principle of the ''quasi-phase matching'' is applied, which uses the microdomain inversion. Phase jumps occuring at the domain boundaries compensate in the mean the different phase velocities. The application range of such periodical structures depends essentially on sharpness, homogeneity, depth extent, and period of the domain structure. The nonlinear confocal laser scanning microscopy makes a mapping of this transferred ferroelectric domain structure possible. Primary aim of this thesis is the characterization and mapping of the transferred ferroelectric domain structure in lithium niobate. A modularly kept confocal microscope makes here a nonlinear analysis in reflection and transmission geometry possible. In both geometries systematic studies as function of important process parameters were performed. It was shown that because of the larger nonlinear coherence length in the transmission modus the SHG ensues above all in forward direction. By depth-resolved studies at Z-cut PPLN structured between the surface region and the volume crystal a flippling of the SHG contrast could be observed. In samples with circular pole structure additionally in the crystal a transition to a hexagonal structure took place. In the Ti:PPLN strip waveguide a strong and specific increasement of the nonlinear signal of the domain walls was discovered. Here also the usual SHG surface contrast between dhe domains and the boundaries is inverted. Also differently processed planar and ripple structures in X- and YS-cut LN with periodic microdomains were studied. Here a strong contrast in the SH signal concerning the oppositely poled domain regions resulted, which then extends over the whole depth extension. So for instance a successful poling beyond the ripple region could be detected up to a total depth of 5 {mu}m. Further studies a a cross-section analysis of the structures suggest that the cause for the increased nonlinear signal lies in a ''filamentation'' of the inverted region. Additionally the {mu}-Raman spectroscopy was applied for the examination of the domain structure in PPLN. Here it could be shown that in dependence on the chosen Raman line both the domain boundaries and the differently oriented domains themselves can be mapped.

  16. Control of nitrification and denitrification by means of oxygen measurement in activated sludge; Steuerung der Nitrifikation und Denitrifikation mittels Sauerstoffmessung im Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Svardal, K; Kroiss, H

    1998-12-31

    As the simulation results show, controlling nitrification/denitrification by means of the oxygen content is a very effective method. Its big advantage is that the concentration of O{sub 2} can be very reliably measured. In comparison with online analysis units, O{sub 2} probes demand little maintenance and are inexpensive; so, each measuring point can be supplied with its own probe. O{sub 2} measurement is indispensable also with other control strategies. It would make sense, at least at larger plants, to monitor additionally the concentration of ammonium, a parameter which makes for a higher safety margin. (orig./SR) [Deutsch] Die Simulationsergebnisse zeigen, dass die Steuerung der Nitrifikation/Denitrifikation nach dem Sauerstoffgehalt sehr gute Resultate ergibt. Der grosse Vorteil dieser Art der Steuerung besteht darin, dass die O{sub 2}-Konzentration sich sehr zuverlaessig messen laesst. O{sub 2}-Sonden sind im Vergleich zu online-Analysatoren wartungsarm und preisguenstig, so dass auch eine reduntante Ausfuehrung jeder Messstelle vertretbar ist. Auf die O{sub 2}-Messung kann auch bei anderen Steuerstrategien nicht verzichtet werden. Eine sinnvolle Ergaenzung waere zumindest bei groesseren Anlagen eine Ueberwachung der Ammoniumkonzentration wobei dieser Messwert vor allen Dingen der Sicherheit dient. (orig./SR)

  17. Experiences with the determination of Sr-89 and Sr-90 using fast methods; Erfahrungen bei der Bestimmung von {sup 89}Sr und {sup 90}Sr mittels Schnellmethoden

    Energy Technology Data Exchange (ETDEWEB)

    Kowalik, C.; Fueger, J. [Thueringer Landesanstalt fuer Umwelt und Geologie, Jena (Germany). Landesmessstelle fuer Umweltradioaktivaet

    2014-01-20

    Quick methods of the measurement of {sup 89}Sr and {sup 90}Sr have a great importance in the supervision of the environmental radioactivity. It is necessary to receive in short time dependable analytical data to be able to carry out suitable assessments or to give recommendations. The aim of the investigations was to be guaranteed the demands for these methods (test preparation, measurement and evaluation). The use of the solid phase extraction by means of commercial Sr Resin trademark columns (4.4' (5')-Di-tert-butylcyclohexanol-18-kronen-6-aether) (Triskem) to the radiochemical separation of the Sr isotopes was suitable. The measurements occurred to the FHT 770 T12 - Multi Low Level Alpha/Beta Sample Counter (Thermo Scientific). The results contain the summary activities of all available Sr isotopes, as for example {sup 89}Sr and {sup 90}Sr. The calculations of the single activities occur about the mathematical algorithm of the linear development on the basis of the works of G. Kanisch. The first results show, this method is suitable for the analysis of {sup 89}Sr and {sup 90}Sr and is used therefore in future in Thuringia.

  18. Smart Grid. Implementation of households by means of cross-linking and energy community; Smart Grid. Integration von Haushalten mittels Vernetzung und Energie-Community

    Energy Technology Data Exchange (ETDEWEB)

    Trick, U.; Steinheimer, M.; Ruhrig, P.; Toenjes, R. [Fachhochschule Frankfurt am Main (Germany); Hoelker, D. [Hochschule Osnabrueck (Germany)

    2012-07-01

    The problems arising from the increasingly volatile and decentralized power generation as well as the today's ''black box'' distribution networks are solved here by the introduction of a new concept of a peer-to-peer networked energy community. Based on the experience with communication value-added services a service management framework is introduced which allows on the one side personalized services for the smart home, especially the energy management, and includes the integration of multimedia communications. On the other side the concept provides a convenient networking of households, energy suppliers, distribution network operators and others with the objectives cost savings, avoidance of network expansion, energy saving, CO{sub 2}-reduction, etc. Initial simulations confirm the effectiveness of this new and powerful approach, most notably the benefits of battery storage in homes, but also the potential contributions of demand side integration (load shift). (orig.)

  19. Decentralized load- and feed-in-management using a market based agent system; Dezentrales Last- und Einspeisemanagement mittels eines marktbasierten Agentensystems

    Energy Technology Data Exchange (ETDEWEB)

    Linnenberg, T.; Wior, I.; Schreiber, S.; Fay, A. [Helmut-Schmidt-Univ., Hamburg (Germany). Inst. fuer Automatisierungstechnik

    2012-07-01

    As a result of the increasing amount of decentralized electricity generation classical, centralized control concepts are taken to their limits. At present, two approaches are being followed to deal with these problems: the expansion of the electricity network and the extension of reserve capacities. The ''DEcentralized MArket based POwer control System'' (DEMAPOS) approach presented in this article, illustrates ways to solve these problems by means of a decentralized, market based control. With a focus on easy expandability and the possibility to cooperate with project partners a methodic and comprehensible development process was used along with open standards and free software. The Validation of the approach was carried out simulation based on real world data. (orig.)

  20. Advances in the staging of renal cell carcinoma with high-resolution imaging; Fortschritte im Staging des Nierenzellkarzinoms mittels hochaufloesender Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M. [Abt. Radiodiagnostik, Radiologische Klinik, Univ. Heidelberg (Germany); Bartling, S. [Medizinische Physik, DKFZ Heidelberg (Germany); Pfitzenmaier, J. [Urologische Klinik, Univ. Heidelberg (Germany)

    2007-12-15

    Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

  1. Assessment of cognitive functions after prophylactic and therapeutic whole brain irradiation using neuropsychological testing; Erfassung kognitiver Funktionen nach prophylaktischer und therapeutischer Ganzhirnbestrahlung mittels neuropsychologischer Testverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Penitzka, S.; Wannenmacher, M. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Steinvorth, S. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; MIT, Cambridge, MT (United States). Dept. of Brain and Cognitive Sciences; Sehlleier, S. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Universitaetsklinikum Wuerzburg (Germany). Abt. Strahlentherapie; Fuss, M. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Texas Univ., San Antonio, TX (United States). Health Science Center; Wenz, F. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Universitaetsklinikum Mannheim (Germany). Sektion Radioonkologie

    2002-05-01

    Purpose: Aim of this study was the assessment of neuropsychological changes after whole brain irradiation. Patients and Method: 64 patients were tested before, and 29 after whole brain irradiation, including 28 patients with small cell lung cancer (SCLC) before prophylactic cranial irradiation (PCI) and 36 patients with cerebral metastases before therapeutic cranial irradiation (TCI), as well as 14 patients after PCI and 15 after TCI (Table 1). Intelligence, attention and memory were assessed applying a 90-minute test battery of standardized, neuropsychological tests (Table 3). Results: Patients with SCLC showed test results significantly below average before PCI (n=28, mean IQ=83, SD=17). Neither after PCI, nor after TCI the tested neuropsychological functions decreased significantly (Tables 4, 5). A comparison between SCLC-patients with and without cerebral metastases before whole brain irradiation showed better test-results in patients with cerebral metastases and fewer cycles of preceding chemotherapy (Table 7). Conclusion: Neuropsychological capacity in patients with SCLC was impaired even before PCI. Possible reason is the preceding chemotherapy. Whole brain irradiation did not induce a significant decline of cognitive functions in patients with PCI or TCI. A decline in a longer follow-up nevertheless seems possible. (orig.) [German] Zielsetzung: Ziel der Studie war die Erfassung moeglicher Veraenderungen der neuropsychologischen Leistungsfaehigkeit nach Ganzhirnbestrahlung. Patienten und Methode: Untersucht wurden 64 Patienten vor und 29 Patienten nach Ganzhirnbestrahlung. Es handelte sich um 28 Patienten mit kleinzelligem Bronchialkarzinom (SCLC) vor prophylaktischer Ganzhirnbestrahlung (PCI) und um 36 Patienten mit Hirnmetastasen vor therapeutischer Ganzhirnbestrahlung (TCI). Es wurden 14 Patienten nach PCI und 15 Patienten nach TCI getestet. Zur Anwendung kam eine 90-minuetige Testbatterie standardisierter, neuropsychologischer Testverfahren zur Messung von Intelligenz, Aufmerksamkeit und Gedaechtnis. Ergebnisse: In der Patientengruppe mit SCLC lagen die Testergebnisse bereits vor der PCI deutlich unter der Norm (n=28, mittlerer Intelligenzquotient=83, Standardabweichung=17). Weder nach PCI noch nach TCI zeigte sich eine signifikante Verschlechterung der kognitiven Funktionen. Der Vergleich zwischen den Patienten mit SCLC ohne Hirnmetastasen und mit Hirnmetastasen vor Bestrahlung zeigte eine bessere Leistungsfaehigkeit der Patienten mit Hirnmetastasen und weniger Zyklen vorausgegangener Chemotherapie. Schlussfolgerung: Die neuropsychologische Leistungsfaehigkeit ist bei SCLC-Patienten bereits vor PCI eingeschraenkt. Ursache koennte die vorausgegangene Chemotherapie sein. Die Ganzhirnbestrahlung fuehrt bei Patienten mit therapeutischer oder prophylaktischer Ganzhirnbestrahlung zu keiner signifikanten Verschlechterung der kognitiven Funktionen. Eine Verschlechertung im laengeren Follow-up kann jedoch nicht sicher ausgeschlossen werden. (orig.)

  2. Non-contact test of coating by means of laser-induced ultrasonic excitation and holographic sound representation. Beruehrungslose Pruefung von Beschichtungen mittels laserinduzierter Ultraschallanregung und holographischer Schallabbildung

    Energy Technology Data Exchange (ETDEWEB)

    Crostack, H A; Pohl, K Y [QZ-DO Qualitaetszentrum Dortmund GmbH und Co. KG (Germany); Radtke, U [Dortmund Univ. (Germany). Fachgebiet Qualitaetskontrolle

    1991-01-01

    In order to circumvent the problems of introducing and picking off sound, which occur in conventional ultrasonic testing, a completely non-contact test process was developed. The ultrasonic surface wave required for the test is generated without contact by absorption of laser beams. The recording of the ultrasound also occurs by a non-contact holographic interferometry technique, which permits a large scale representation of the sound. Using the example of MCrAlY and ZrO[sub 2] layers, the suitability of the process for testing thermally sprayed coatings on metal substrates is identified. The possibilities and limits of the process for the detection and description of delamination and cracks are shown. (orig.).

  3. Pathological changes of the chemosensory function in multiple sclerosis. An MRI study; Pathologische Veraenderungen der Chemosensorik mittels Kernspintomografie bei Multipler Sklerose. Eine MRT-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, F.A.; Harms, L. [Charite Campus Mitte, Berlin (Germany). Dept. of Neurology - Consultation Service for Multiple Sclerosis; Fleiner, F.; Dahlslett, B.; Goektas, Oe. [Charite Campus Mitte, Berlin (Germany). Dept. of Otolaryngology, Head and Neck Surgery; Bohner, G.; Erb, K.; Luedemann, L. [Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

    2011-06-15

    Purpose: To examine possible causes for olfactory and gustatory dysfunction in MS patients in a prospective study with MRI. Materials and Methods: 30 MS patients (21 women, 11 men, 22 - 65 years, diameter 42 years) were examined by MRI. The olfactory bulb (OB) and olfactory brain volume was correlated with the number and volume of MS lesions in the olfactory brain and the non-olfactory brain. Olfactory testing was performed using the Threshold-Discrimination-Identification Test (TDI), and gustatory function was tested using the Taste-Strips-Test (TST). Results: 33 % of the MS patients displayed olfactory dysfunction (8 % of the control group), and 17 % displayed gustatory dysfunction (5 % of the control group). There was a correlation between the olfactory brain volume and the number (r = -0.38, p < 0.05) and volume (r = -0.38, p < 0.05) of MS lesions in the olfactory brain. The olfactory brain volume correlated with the number of MS lesions in the non-olfactory brain (r = -0.48, p < 0.05). The volume of the left OB correlated with the volume of MS lesions in the olfactory brain (r = -0.42, p < 0.05), the number (r = 0.37, p < 0.05) and volume (r = 0.4, p < 0.05) of lesions in the left part of the olfactory brain and with the TST score (r = -0.45, p < 0.05). The TST score correlated with the volume of lesions in the left (r = -0.45, p < 0.05) and right part (r = -0.53, p < 0.05) of the olfactory brain. The TST score correlated with the number of lesions in the non-olfactory brain (r = -0.48, p < 0.05). Conclusion: The correlation between a higher number and volume of MS lesions in the olfactory brain with a decreased OB and olfactory brain volume could help to explain olfactory and gustatory dysfunction in MS patients. Just the left OB correlated with the number and volume of lesions in the olfactory brain. Manual segmentation was a suitable method for measuring OB and olfactory brain volume. (orig.)

  4. Manipulation of incoherent and coherent spin ensembles in diluted magnetic semiconductors via ferromagnetic fringe fields; Manipulation inkohaerenter und kohaerenter Spinensembles in verduennt-magnetischen Halbleitern mittels ferromagnetischer Streufelder

    Energy Technology Data Exchange (ETDEWEB)

    Halm, Simon

    2009-05-19

    In this thesis it is demonstrated that fringe fields of nanostructured ferromagnets provide the opportunity to manipulate both incoherent and coherent spin ensembles in a dilute magnetic semiconductor (DMS). Fringe fields of Fe/Tb ferromagnets with a remanent out-of-plane magnetization induce a local magnetization in a (Zn,Cd,Mn)Se DMS. Due to the sp-d exchange interaction, optically generated electron-hole pairs align their spin along the DMS magnetization. One obtains a local, remanent spin polarization which was probed by spatially resolved, polarization sensitive photoluminescence spectroscopy. Fringe fields from in-plane magnetized Co ferromagnets allow to locally modify the precession frequency of the Manganese magnetic moments of the DMS in an external magnetic field. This was probed by time-resolved Kerr rotation technique. The inhomogeneity of the fringe field leads to a shortening of the ensemble decoherence time and to the effect of a time-dependent ensemble precession frequency. (orig.)

  5. Gas separation of landfill gas and other biogases by pressure swing adsorption. Final report. Gastrennung fuer Deponie- und Faulgase mittels Druckwechseltechnik. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pilarczyk, E; Mellech, L

    1986-01-01

    A new PSA-process for recovery of methane with SNG-quality from biogases was developed in the laboratory and successfully tested in field trials at the German landfill Emscherbruch/Gelsenkirchen. A special carbon molecular sieve on which carbon dioxide is adsorbed much faster than methane was proved as the best suited adsorbent for biogas separation. Even part of nitrogen which is mostly contained in landfill gases from leakage air is simultaneously removed from methane together with carbon dioxide by using the carbon molecular sieve. Low quality-SNG with 88-90% by vol. methane could be processed from landfill gas containing up to 15% by vol. nitrogen at an adsorption pressure of 3-9 bar abs. The recovery of methane goes upt to 98%. High quality-SNG can be processed from N/sub 2/-free biogases like sewage gas. The capital and operational cost (not including prepurification) for recovery of low quality-SNG by PSA is estimated to about 0,12 DM/m/sup 3/ SNG. (orig.) With 13 refs., 13 tabs., 16 figs.

  6. MR thermometry for laser-induced thermotherapy at 1.5 tesla; MR-Thermometrie bei 1,5 Tesla zur thermischen Ablation mittels laserinduzierter Thermotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Meister, D.; Huebner, F.; Mack, M.; Vogl, T.J. [Frankfurt Univ. (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie

    2007-05-15

    Purpose: Evaluation of thermometry with fast MR sequences for laser-induced interstitial laser therapy (LITT) and verification of the thermometric results with a fiber-optic thermometer. Method and Materials: In vitro experiments were conducted using an agarose gel mixture and pig liver lobes. MR-guided LITT was performed using a laser power between 3 and 15?watts. Thermometry was performed using longitudinal relaxation time T1 and proton resonance frequency shift (PRF) methods under acquisition of amplitude and phase shift images. PRF was measured with a fast spoiled GRE sequence. Four different sequences were used for T1 thermometry: gradient echo (GE), TrueFISP (TRUFI), Saturation Recovery Turbo-FLASH (SRTF) and Inversion Recovery Turbo-FLASH (IRTF) sequences. The temperature was controlled using a fiber-optic Luxtron device and correlated with the MR temperature. The range of applied and monitored temperatures exceeded 80 degrees Celsius. Results: The temperature dependence showed a good linear relationship up to 60 degrees Celsius. Calibration experiments for the T1 method delivered coefficients of determination from 0.977 to 0.997 for agarose and from 0.958 to 0.995 for the pig liver samples. The IRTF sequence had the highest temperature sensitivity (agarose 0.99, liver 1.19). During LITT the TRUE-FISP sequence exhibited a strong nonlinear relationship. R{sup 2} of this sequence was 0.809 in the agarose experiments. The average temperature errors when heated up to 80 degrees Celsius were 3.86 - 11.38 degrees Celsius for Agarose gel and 5.7 - 12.16 degrees Celsius for the liver tissue. SRTF and IRTF sequences exhibited the most linear relationship with temperature but were more dependent on tissue differences. (orig.)

  7. Electrochemical incineration of C-14-containing liquid wastes. First results and outlook; Behandlung C-14-haltiger fluessiger Abfaelle mittels elektrochemischer Totaloxidation. Erste Ergebnisse und Ausblick

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Hans-Juergen [Fraunhofer-Institut fuer Keramische Technologien und Systeme (IKTS), Dresden (Germany). Aussenstelle Rossendorf; Knappik, Reinhard; Zschornack, Daniel [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany). Fachbereich Analytik und Monitoring; Mueller, Wolfgang [IUT GmbH, Berlin (Germany)

    2014-06-15

    Liquid radioactive wastes containing carbon-14 are not acceptable for radioactive waste repository. At present incineration is the only approved way of treatment in Germany. But capacities are limited and incineration by itself is known to be a technically complex and rather expansive process. Therefore within an experimental proof of concept it should be examined whether an electrochemical incineration process is also applicable for this purpose. The R and D activities mainly comprised the gathering of informations about the chemical nature and constitution of such liquid wastes from enterprises, research laboratories and a number of the state owned collecting facilities, numerous electrochemical examinations with typical organic substances and finally electrolysis tests with original carbon-14 waste solution at lab-scale. We were able to demonstrate that electrochemical oxidation permits almost quantitative mineralization of the organic waste substances. The carbon dioxide released during electrolysis was completely fixed as solid calcium carbonate which is acceptable for final repository. An estimate shows that in comparison to conventional incineration a substantial decrease in the costs of treatment and repository can be expected. With regard to technical application further steps of development are necessary. (orig.)

  8. Studies on layer growth and interfaces on Ta-base thin layers by means of XPS; Untersuchungen zu Schichtwachstum und Grenzflaechen an Ta-basierten Duennschichten mittels XPS

    Energy Technology Data Exchange (ETDEWEB)

    Zier, M.

    2007-11-02

    In this thesis studies on the growth and on the formation of the interfaces of Ta and TaN layers on Si and SiO{sub 2} were performed. In the system TaN on SiO{sub 2} no reaction on the interface could be found. As the system with the mostly disturbed interface Ta on SiO{sub 2} was proved. Here a reduction of the SiO{sub 2} at simultaneous oxidation of the Ta was to be observed. Additionally tantalum silicide was formed to be considered concerning the bonding state as Ta{sub 5}Si{sub 3}, from which a double layer of a tantalum silicide and a tantalum suboxide resulted. A whole thickness of the double layer of above 1 nm resulted. In the system Ta on Si at the deposition of the film on the interface a tantalum silicide was formed to be characterized concerning the bonding state as TaSi{sub 2}. The thickness of the interlayer growed thereby up to 0.8 nm in form of islands. Finally in the system TaN on Si a silicon nitride formation during the deposition was observed, which was attributed to the insertion of adsorbed nitrogen from the sputtering atmosphere by recoil implantation of the sputtered Ta atoms. The silicon nitride interlayer growed thereby up to a thickness of 0.8 nm.

  9. Correlations of the chemical shift on fasly rotating biological solids by means of NMR spectroscopy; Korrelationen der chemischen Verschiebung an schnell rotierenden biologischen Festkoerpern mittels NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, Christian

    2010-04-27

    The basic aim of the thesis was the development and improvement of homo- and heteronuclear feedback sequences for the generation of correlation spectra of the chemical shift. In a first step the possibility of the acquisition of {sup 13}C-{sup 13} correlation spectra of the chemical shift by means of inversion pulses with low RF power factor was studied. Furthermore it was shown that broad-band phase-modulated inversion and universal rotational pulses can be constructed by means of global optimization procedures like the genetic algorithms under regardment of the available RF field strength. By inversion, universal rotational, and 360 pulses as starting values of the optimization efficient homonuclear CN{sub n}{sup {nu}} and RN{sub n}{sup {nu}} mixing sequences as well as heteronuclear RN{sub n}{sup {nu}{sub s},{nu}{sub k}} feedback sequences were generated. The satisfactory power of the numerically optimized sequences was shown by means of the simulation as well by means of correlation experiments of the chemical shift of L-histidine, L-arginine, and the (CUG){sub 97}-RNA. This thesis deals furthermore with the possibility to acquire simultaneously different signals with several receivers. By means of numerically optimized RN{sub n}{sup {nu}{sub s},{nu}{sub k}} pulse sequences both {sup 15}N-{sup 13}C and {sup 13}C-{sup 15}N correlation spectra were simultaneously generated. Furthermore it could be shown that the simultaneous acquisition of 3D-{sup 15}N-{sup 13}C-{sup 13}C and {sup 13}C-{sup 15}N-({sup 1}H)-{sup 1}H correlation spectra is possible. By this in only one measurement process resonance assignments can be met and studies of the global folding performed. A further application of several receivers is the simultaneous acquisition of CHHC, NHHN, NHHC, as well as CHHN spectra. By such experiments it is possible to characterize the hydrogen-bonding pattern and the glycosidic torsion angle {sup {chi}} in RNA. This was demonstrated by means of the (CUG){sub 97}-RNA. The simultaneous acquisition of all relevant crossing signals of the correlation spectra leads not only to an essential time saving, but is also necessary for the quantitative determination of {sup 1}H-{sup 1}H distances.

  10. New heating system for heaters-treaters and glycol regenerators using liquid or gaseous fuel. Neues Beheizungsverfahren von Heatern-Treatern und Glykolregeneratoren mittels fluessigen oder gasfoermigen Brennstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schmidtke, G.

    1990-12-01

    A new system for the heating of heaters-treaters and glycol regnerators is described. The main difference to the customary technique is that instead of an atmospheric gas burner, which uses the injector principle for drawing in gas, a compressed-air gas bruner with a blower is used. Burners of this type can be installed directly inside the flame tubes of the plants, so that flame arrestors with be unnecessary. Apart from its low noise, this combination technology has the further advantage of permitting near-stoichiometric operation in a wide control range. This will reduce the off-gas losses to a much lower level, as is illustrated by the dramtically lower off-gas values measured in the test phase. (orig.).

  11. Screening und Quantifizierung organischer Spurenstoffe mittels UPLC-HRMS:Entwicklung von Methoden und Anwendung zur Unterscheidung historischer und aktueller Spurenstoffe in einem ehemaligen Rieselfeld

    OpenAIRE

    Wode, Florian

    2014-01-01

    Aufgrund zunehmender Wasserknappheit gewinnt die Nutzung von gereinigtem Abwasser (Klarwasser), bezeichnet als Water Reuse, weltweit an Bedeutung. Neben herkömmlichen chemischen und mikrobiologischen Parametern spielen organische Spurenstoffe zunehmend eine Rolle bei der Beurteilung der Wasserqualität, die über mögliche Nutzungsformen entscheidet. In dieser Arbeit wurde die Spurenstoffbelastung in Grund- und Oberflächenwasser eines ehemaligen Rieselfeldgebietes untersucht, in dem seit 2005 Kl...

  12. Determination of Ra-223 in human excretion samples by means of α-spectrometry; Bestimmung von {sup 223}Ra in Ausscheidungsproben mittels α-Spektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Zoriy, M.V.; Froning, M.; Hill, P. [Forschungszentrum Juelich GmbH (Germany). Geschaeftsbereich Strahlenschutz und Sicherheit

    2015-07-01

    To ensure the safety of occupationally exposed person for possible incorporation of {sup 223}Ra during the handling with Alpharadin / Xofigo {sup registered}, the determination of {sup 223}Ra activity in its excretion sample (e.g, in a stool sample) might be of great importance. To assess the {sup 223}Ra activity in human faeces samples a new analytical method was developed in our laboratory. The determination is performed by means of grid-ionization a-spectrometry. After a relatively simple sample preparation procedure (usually within max. 6 hours) and the addition of an internal standard, a direct determination of {sup 223}Ra with the grid ionization chamber (GIK) is possible. The method was optimized and successfully tested. The procedure-related LOD for {sup 223}Ra in a 24-hour faeces sample was 0.1 Bq/Probe.

  13. Modern diagnostic assessment of the upper urinary tract using multislice CT urography; Moderne Diagnostik des oberen Harntraktes mittels Mehrschicht-CT-Urographie

    Energy Technology Data Exchange (ETDEWEB)

    Kemper, J.; Adam, G.; Nolte-Ernsting, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2006-11-15

    The advent of Multislice Computed Tomography (MSCT) has made evaluation of the entire urinary tract with high-resolution sections during a single breath-hold a reality. Acquisition of multiple thin overlapping slices provides excellent two-dimensional (2D) and three-dimensional (3D) reformations of the urinary tract. The concept of 'Multislice CT Urography (MSCTU)' has emerged from this technical improvement. As a result, a wide range of pathologies inside and outside the urinary tract can be identified. During the last several years, MSCTU has challenged intravenous urography (IVU) in the evaluation of urinary tract abnormalities. Compared with IVU, MSCT(U) is more sensitive and specific in the detection and characterization of a variety of urinary tract disorders, including renal masses and urolithiasis. The main advantage of IVU has been its ability to offer excellent delineation of kidney basin cup system and ureteral anatomy and to depict subtle uroepithelial abnormalities. MSCTU has already shown promising results for overcoming this challenge. Optimal opacification and distension appear to be an essential requirement for a thorough evaluation of the collecting system. Dedicated preparation strategies have been developed to meet these technical difficulties. The biggest disadvantage of MSCTU is the significant radiation exposure. For broad routine clinical application, there is still a need for dose reduction protocols despite the ongoing technical developments in MSCTU. In this article, we outline the different concepts of technical processing for MSCTU and summarize the current role of MSCTU in the evaluation of the upper urinary tract. (orig.)

  14. Fabrication and characterization of silicon nanowires by means of molecular beam epitaxy; Herstellung und Charakterisierung von Silizium-Nanodraehten mittels Molekularstrahlepitaxie

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, Luise

    2007-06-19

    In this work, basic processes of silicon whisker growth were examined. For the first time, Si nanowhiskers were produced under UHV conditions by Molecular Beam Epitaxy (MBE) and characterized by different analysis methods afterwards. The existence of Au/Si droplets on a Si(111) substrate surface is a precondition of this growth method. Analyses of the temporal development of the Au/Si droplets during the whisker growth show a decrease of the number of small droplets resp. whiskers during the whisker growth with increasing growth time. This behaviour, i.e. the dissolution of smaller droplets/whiskers and the growth of larger ones in parallel can be explained by Ostwald ripenning. The diffusion-determined material transition of gold, which occurs during this process, is theoretically described by the Lifshitz-Slyozov-Wagner (LSW)-Theory. After this theory only whiskers grow which radii are larger than the critical radius. The whisker radii are temperature dependend whereas analogous whisker radii exist for identical growth times. Electron microscopy analysis show that all whiskers possess a hexagonal but no cylindrical habitus. The planes that form during the growth are crystallographic (111) planes. The growth of Si nanowhiskers under MBE conditions is determined by the Vapour Liquid Solid (VLS) mechanism and by surface diffusion of Si atoms. (orig.)

  15. Energy management in the low-voltage supply by decentralized decision. Concepts, algorithms, communication and simulation; Energiemanagement in der Niederspannungsversorgung mittels dezentraler Entscheidung. Konzept, Algorithmen, Kommunikation und Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, David

    2008-07-01

    In this paper we present two key concepts for a future energy market with distributed electricity generation. First, we describe the energy management of distributed generators and loads with decentralized decision by bidirectional energy management interfaces. Second, we present a market platform supporting spontaneous trading by means of automated contract conclusion, innovative business models, and optimisation and controlling procedures for the demand as well as the supply side. (orig.)

  16. Das Ziel bestimmt die Mittel. Das Wirken Östen Undéns auf dem Weg zur schwedischen Neutralitätspolitik.

    Directory of Open Access Journals (Sweden)

    Peer Krumrey

    2009-12-01

    Full Text Available The Swedish policy of non-alliance aiming at neutrality in the event of war with all its contradictions and disputes continues to have an effect on societal debate in today’s Sweden. This article advocates a more accurate differentiation between historical processes and political assessments. It argues that this can be achieved by focussing on objectives set at that time as well as political outcomes resulting from the means chosen to achieve them rather than trying to compile moral benchmarks retrospectively. In order to exemplify this the article draws on the long-time Swedish foreign minister Östen Undén whose work is considered formative for Swedens foreign and security policy during the Cold War. It is stated that by using this approach it is possible to solve some of the prevailing contradictions and to demonstrate a higher degree of continuity.

  17. Zur Morphologie der physiologischen Foveae am Augenhintergrund von Greifvögeln und Eulen mittels Optischer Kohärenztomografie (OCT)

    OpenAIRE

    Schulze, Céline

    2016-01-01

    Die Optische Kohärenztomografie (OCT) ist eine neue Methode der Bilddarstellung, welche bereits erfolgreich in der humanmedizinischen Ophthalmologie etabliert wurde. Sie bietet die Möglichkeit, den Aufbau und die Morphologie der Retina in Querschnitten darzustellen und dies nicht-invasiv, kontaktfrei und in vivo in annähernd histologischer Auflösung. In der aviären Ophthalmologie wurde die OCT bisher kaum angewendet. Das Ziel der vorliegenden Arbeit war es daher, die OCT als ein geeignete...

  18. Detection of microbial volatile organic compounds (MVOC) by means of ion mobility spectroscopy (IMS); Detektion leicht fluechtiger organischer Verbindungen mikrobiellen Ursprungs (MVOC) mittels Ionenmobilitaetsspektrometrie (IMS)

    Energy Technology Data Exchange (ETDEWEB)

    Tiebe, Carlo

    2010-07-01

    Traces of microbial volatile organic compounds (MVOCs) can indicate the growth of moulds in the indoor air. The application of ion mobility spectrometry (IMS) is a very promising method for the detection of these MVOCs due to its high sensitivity. A mobile IMS device was tested to use this analytical-chemical method for in situ indoor air diagnostics. The first part of this work describes the test gas generation of 14 MVOCs in the laboratory. The test gases were produced by preparation of permeation procedures. Due to the MVOCs test gases IMS parameters like reduced mobility (K{sub 0}), relative drift time (t{sub rd}), the concentration dependency of MVOCs signals were determined and the limit of detection (LOD) was calculated. The LODs are in the range of 2 to 192 {mu}g m{sup -3} (1 to 51 ppb{sub V}). In the second part of this manuscript seven different mould species were cultivated on nutrient media and their MVOCs emissions were explored. It was found out, that the MVOCs emissions of moulds have a dependency of species and of their cultivation time. These results are confirmed by principal component analysis (PCA). The identification of these MVOCs was performed by test-related GC-MS analysis and approved these results. The MVOCs emissions were explored in the cultivation of mould mixtures on three different building materials. The IMS-results were interpreted chemo metrically by PCA. It was possible to find different emission patterns of cultivated moulds on building materials without an identification of the MVOCs inside the emission chamber. In 27 field trials of different indoor environments (rooms) the IMS was tested to detect MVOCs. In 59 % of the cases a positive correlation is determined between visible mould-infested rooms and the detected MVOCs by IMS. (orig.)

  19. Vermittlung von Naturheilverfahren in der Veterinärmedizin mittels E-Learning [Teaching methods of alternative therapy in veterinary medicine via e-learning

    Directory of Open Access Journals (Sweden)

    Fidelak, Christian

    2008-11-01

    Full Text Available [english] The Free University’s Veterinary Clinic of Reproduction in the Department of Veterinary Medicine, Berlin, has been offering courses on alternative and complementary veterinary medicine to its students for several years. Due to time constraints and shortages in teaching staff, it has not been possible to satisfy student demand for instruction in these areas. To provide more detailed information as well as more opportunities for discussion and practica, subject area courses were modified in two steps. Initially, blended learning was implemented to include e-learning and in-class formats of instruction. Subsequently, an entire block of courses offered were transferred to e-learning format. Students may now voluntarily register for the e-learning course entitled “Introduction of alternative and complementary veterinary medicine” via the Internet and learn the basic principles of homoeopathy, herbal medicine, acupuncture and other alternative methods in veterinary medicine. After passing this basic course, blended learning courses enable advanced students to learn more about fundamentals of methods in greater detail as well as to perform practica with animal subjects. The evaluation of these courses showed that students rated e-learning to be a reasonable addendum to in-class instruction. More than two thirds of the students recommended an increased integration of e-learning into veterinary education. [german] Die Tierklinik für Fortpflanzung in Berlin bietet den Studierenden der Veterinärmedizin seit einigen Semestern Wahlpflichtkurse zu den Naturheilverfahren an. Der enormen Nachfrage seitens der Studierenden standen personelle und zeitliche Begrenzungen des Lehrpersonals gegenüber. Um den Interessenten dennoch umfangreiche Informationen zu bieten sowie Freiräume für Diskussionen und praktische Übungen zu schaffen, wurde das Ausbildungsangebot in zwei Projektphasen ausgebaut. Zunächst wurde dabei die Methode des Blended-Learning genutzt. Anschließend wurde ein Teil des Kursangebotes komplett auf E-Learning umgestellt. Der Wahlpflichtkurs „Einführung in die Naturheilverfahren“ kann seither von den Studierenden vollständig über das Internet bearbeitet werden. Dieser Kurs behandelt die theoretischen Grundlagen von Homöopathie, Phytotherapie, Akupunktur und einigen weiteren Methoden. In Aufbaukursen werden neben einer Vertiefung der Grundlagen umfangreiche praktische Übungen durchgeführt. Die Evaluationsergebnisse belegen, dass die Studierenden E-Learning als sinnvolle Ergänzung der herkömmlichen Lehrmethoden betrachten. Zudem befürworten mehr als zwei Drittel der Studierenden eine vermehrte Einbindung von E-Learning in die Ausbildung.

  20. Using solar heat to enhance waste-heat use; Solarthermische Abwaermenutzung; Aufwertung von Abwaerme mittels Solarthermie zur Erzeugung hochwertiger Prozessenergie - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [BMG Engineering AG, Schlieren (Switzerland); Luzzi, A.; Marty, H. [HSR, Hochschule fuer Technik, SPF Institut fuer Solartechnik, Rapperswil (Switzerland)

    2008-12-15

    This final report for Swiss Federal Office of Energy (SFOE) presents the work done in a project involving the use of solar heat to enhance the use of waste heat at a chemical plant in Nyon, Switzerland. On the basis of a study carried out in 2006/2007, which looked at the reduction of process energy demand of a production site where an agent is produced in batch operation, possibilities for the recovery of waste heat were identified. The relatively low temperatures of the existing waste heat flows have, however, complicated its efficient use. This reflects a problem with waste heat use in industrial processes that can often be observed. Due to the sunny location in Nyon, a concept using solar energy to increase the temperature level of this waste heat has been developed. The objective of this analysis was the technical and economical assessment of such an installation and its transferability to other sites. Variants are presented and their economic viability is discussed.

  1. 3D characterisation of the gaseous and liquid phase using laser-induced exciplex fluorescence (LIEF) tomography; Dreidimensionale Charakterisierung der Gas- und Fluessigphase mittels laserinduzierter Exciplexfluoreszenz (LIEF) Tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Rogler, P.; Grzeszik, R.; Arndt, S. [Robert Bosch GmbH, Stuttgart (Germany); Waidmann, C. [Fachhochschule Aalen (Germany); Aigner, M. [DLR, Stuttgart (Germany). Inst. fuer Verbrennungstechnik

    2007-07-01

    The quality of mixture formation in gasoline engines has a significant influence on combustion, emissions and mileage. The measurement technique used for mixture formation analysis of both liquid and vapor phase is laser induced exciplex fluorescence (LIEF), where the aromatics TMPD and naphthalene are added to a non-fluorescing model fuel free of aromatic compounds. For spatially high-resolved measurements of liquid and vapor phase this technique was extended from planar to volume information via tomography. This new approach requires fundamental studies of tracer behavior and new evaluation algorithms for reliable signal interpretation of fluid dynamics in sprays. Using this measurement technique GDI sprays are investigated at a typical stratified engine operation point at part load. For the different injector types, e.g. multi hole and annular orifice injector, an optimal illumination is crucial. With the collected data the spray volume can be calculated, mixture homogeneity can be evaluated and, using a few assumptions, the air/fuel ratio {lambda} can be computed. (orig.)

  2. A water legislation evaluation of the unconventional production of natural gas by means of fracking; Wasserrechtliche Bewertung der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Polzer, Andreas [Kassel Univ. (Germany). Kompetenzzentrum fuer Klimaschutz und Klimaanpassung (CliMA); Hentschel, Anja [Kassel Univ. (Germany). Inst. fuer Wirtschaftsrecht (IWR)

    2012-07-01

    Fracking causes underground and aboveground risks for ground water. Under this aspect, the authors of the contribution report on regulation concepts and instruments of the water protection law in order to manage the risks. The authors also describe how these regulations have to be understood in order to manage these underground and aboveground risks.

  3. Determination of polycyclic aromatic hydrocarbons in deposited waste using GC-MSD. Bestimmung von polycyclischen aromatischen Kohlenwasserstoffen in Deponiegut mittels GC-MSD

    Energy Technology Data Exchange (ETDEWEB)

    Treffert, U. (chemlab, Gesellschaft fuer Analytik und Umweltberatung mbH, Bensheim (Germany). Abt. ' ' Organische Analytik' ' ); Kolb, M. (Fachhochschule Aalen (Germany)); Stoerk, H. (chemlab, Gesellschaft fuer Analytik und Umweltberatung mbH, Bensheim (Germany))

    1999-06-01

    The articel describes an analysis method for the determination of 16 polycyclic aromatic hydrocarbons in deposited waste. The single steps are described very detailed: sample preparation by extraction, evaporation, flash-chromatography (Al[sub 2]O[sub 3]), quantitative analysis by GC-MSD. (SR)

  4. Sealing of ceramic SOFC-components with glass seals; Fuegen von keramischen Komponenten der Hochtemperatur-Brennstoffzellen mittels Glas- und Glaskeramikloten

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, Cora

    2012-07-10

    The solid oxide fuel cell (SOFC) converts chemical energy of a fuel directly into electrical energy. However, for the implementation of SOFC-technology in competition to conventional power plants costs have to be reduced. The use of an alternative tubular cell design without closed end would allow reducing costs during cell manufacturing. However, this change in design makes a gastight sealing inside the generator near the gas inlet necessary. Different ceramic materials with varying coefficients of thermal expansion have to be sealed gastight and electrical insulating at temperatures between 850 C and 1000 C to prevent the gases from mixing and an electrical shortcut between the cells. This work comprises analysis of commercially available glass and glass-ceramic systems manufactured by Schott Electronic Packaging, Areva T and D and Ferro Corporation. Additionally new developed sealing glass and glass-ceramic systems were investigated and all systems were characterized fundamentally for the use as sealing material in SOFC generators. Therefore different test assemblies and series were conducted. Essential characteristics of a suitable sealing system are a thermal expansion coefficient between 9,5 and 12 . 10{sup -6}K{sup -1}, a viscosity in the range between 10{sup 4} to 10{sup 6} dPa{sup *}s and a wetting angle smaller than 90 during the sealing process. Also unwanted chemical side reactions between the sealing partners must be prevented, because a change in the phase composition or the creation of new phases in the sealing material could endanger the stability of the seal. Heat cycles, particularly those during generator operation, cause deterioration of the sealing material and subsequent reduction in its ability to prevent mixing of the gases. Sealant leaks can drastically impact efficiency of the generator. In order to ensure optimum operation low leak rates around 2,3 . 10{sup -4} mbar l/sec/cm{sup 2} must be maintained. Especially glass and glass-ceramics of the following systems CaO-MgO-Al{sub 2}O{sub 3}-SiO{sub 2} and BaO-Al{sub 2}O{sub 3}-SiO{sub 2}-B{sub 2}O{sub 3} show promising results. Special test assemblies for the determination of electrical conductivity and leak rate are set up for characterization. Finally, different selected sealing systems are tested under operating conditions in a bench-scale stack. Inside the SOFC-generator an additional gastight seal is needed between several dense and porous Al{sub 2}O{sub 3}-ceramic parts used for the gas supply, before the gas hits the fuel cells. Twenty four dense tubes with a length of 1 m and a porous plate were sealed as proof of concept with a seal based on the following oxides Al{sub 2}O{sub 3}-SiO{sub 2}-K{sub 2}O-CaO and with a thermal expansion coefficient between 8 and 9 . 10{sup -6}K{sup -1}.

  5. Flexible injection control for fuel consumption and emission reduction in passenger cars?; Flexible Einspritzverlaufsformung: Auch bei PKW-Dieselmotoren ein wirkungsvolles Mittel zur Reduzierung von Verbrauch und Schadstoffemissionen?

    Energy Technology Data Exchange (ETDEWEB)

    Laumen, H.J.; Koerfer, T.; Lamping, M. [FEV Motorentechnik GmbH, Aachen (Germany); Pischinger, S.; Schmuecker, K.J. [RWTH Aachen (Germany). Lehrstuhl fuer Verbrennungskraftmaschinen

    2007-07-01

    In the recent decade the Diesel injection technology has been modified significantly. The old cam driven injection systems have been replaced nearly completely by modern Common Rail systems which enable a significantly higher degree of freedom especially with respect to multi-injection strategies and exhaust aftertreatment demands. Nevertheless, cam driven injection systems offered special characteristics which were favorable regarding fuel consumption and emissions. Due to the much higher nozzle opening and closing velocity, the seat throttling effects are widely reduced. Furthermore the fuel injection rate during ignition delay is smaller, compared to today's Common Rail systems. A new type of a piezoelectric Common Rail injector for passenger car engines, called FIRST (Flexible Injection Rate Shaping Tool) is described in this article, which combines both, the flexibility of modern Common Rail injectors as well as the benefits of cam driven injection systems regarding reduced seat throttling effects. Additionally flexible injection rate shaping is enabled by forming the slope of the actuator voltage. Both, the hydraulic behavior and also the engine performance with the new injector are presented in comparison to conventional injectors. The FIRST injector offers a benefit of 20% in PM and CO emission with constant NO{sub x} emission and reduced fuel consumption at part load as a result of the reduced seat throttling. By an optimization of the injection rate shape, the NO{sub x} emissions can be reduced by 40% at constant fuel consumption and PM emissions and without deterioration of NVH level. (orig.)

  6. Quantitative imaging of magnetic nanoparticles by magneto-relaxometric tomography for biomedical applications; Quantitative Bildgebung magnetischer Nanopartikel mittels magnetrelaxometrischer Tomographie fuer biomedizinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Liebl, Maik

    2016-11-18

    Current biomedical research focuses on the development of novel biomedical applications based on magnetic nanoparticles (MNPs), e.g. for local cancer treatment. These therapy approaches employ MNPs as remotely controlled drug carriers or local heat generators. Since location and quantity of MNPs determine drug enrichment and heat production, quantitative knowledge of the MNP distribution inside a body is essential for the development and success of these therapies. Magnetorelaxometry (MRX) is capable to provide such quantitative information based on the specific response of the MNPs after switching-off an applied magnetic field. Applying a uniform (homogeneous) magnetic field to a MNP distribution and measuring the MNP response by multiple sensors at different locations allows for spatially resolved MNP quantification. However, to reconstruct the MNP distribution from this spatially resolved MRX data, an ill posed inverse problem has to be solved. So far, the solution of this problem was stabilized incorporating a-priori knowledge in the forward model, e.g. by setting priors on the vertical position of the distribution using a 2D reconstruction grid or setting priors on the number and geometry of the MNP sources inside the body. MRX tomography represents a novel approach for quantitative 3D imaging of MNPs, where the inverse solution is stabilized by a series of MRX measurements. In MRX tomography, only parts of the MNP distribution are sequentially magnetized by the use of inhomogeneous magnetic fields. Each magnetizing is followed by detection of the response of the corresponding part of the distribution by multiple sensors. The 3D reconstruction of the MNP distribution is then accomplished by a common evaluation of the distinct MRX measurement series. In this thesis the first experimental setup for MRX tomography was developed for quantitative 3D imaging of biomedical MNP distributions. It is based on a multi-channel magnetizing unit which has been engineered to generate a time-multiplexed sequence of precise magnetic fields for spatially constrained magnetizing of the MNP distribution. The unit has been integrated into a sensor system containing 304 superconducting quantum interference devices (SQUIDs) used for the spatially resolved detection of the MNP responses after each magnetizing. Furthermore, for evaluation of MRX tomography MNP phantoms reflecting the MNP distribution after magnetic drug targeting therapy in animals were designed and implemented. Using these phantoms, MNP distributions with clinical MNP doses in the milligram range could be quantitatively reconstructed by MRX tomography within a field of view up to 600 cm³ and a spatial resolution of a few cubic centimeters. The deviation between the quantified and nominal MNP amount was found to be below 10%. With the present experimental setup MRX tomography measurements of a complete MNP distribution were performed within the typical anesthesia time interval of a few minutes prevailing in preclinical animal studies. By implementing advanced magnetizing sequences this measurement time of the MRX tomography setup could be reduced to below 30 s. Finally, using the same MRX tomography setup a binding state specific quantitative imaging of MNP distributions was achieved by incorporating the temporal MNP relaxation behavior into the reconstruction. Hence, MRX tomography has the potential to image the influence of the local biological environment on the physical properties of the MNPs. The presented MRX tomography setup allows for sensitive and specific spatially resolved 3D quantification of MNPs in small animals. This represents an important step towards the development of a clinical imaging tool for the control and assessment of MNP based cancer treatments. Moreover, by adjusting the excitation coils the field of view could be easily enlarged making MRX tomography quite conceivable for human application.

  7. Functional estimation of kidneys after extracorporeal shock wave therapy (ESWL) by clearance. Funktionsbeurteilung der Nieren nach extrakorporaler Stosswellenlithotripsie (ESWL) mittels Nieren-Clearance

    Energy Technology Data Exchange (ETDEWEB)

    Sydow, K.; Kirschner, P.; Brien, G.; Buchali, K.; Frenzel, R. (Humboldt-Universitaet, Berlin (Germany). Medizinische Fakultaet)

    1991-10-01

    35 patients were scintiscanned with 99m-Tc-DTPA to determine the effects of extracorporeal shock waves used to desintegrate renal concrements may have on the patients renal function. The therapy was conducted using a standard Lithostar unit (Siemens) (20 patients) and an additional overtable module (15 patients). Functional scintigraphy was performed using a gamma camera before lithotripsy, and on the first day after it. Further control investigations were performed one or two weeks later and two till six months later. In both groups most of the patients developed temporary restrictions in renal function, some of them irreversible restrictions. Functional losses were found to be less severe with the use of the overtable module than with the standard Lithostar unit. (orig.).

  8. Kurz-, mittel- und langfristige Effekte einer Schulung für Patienten mit chronisch entzündlichen Darmerkrankungen auf krankheitsbezogene Ängste und Gesundheitskompetenzen

    OpenAIRE

    Berding, Anja

    2017-01-01

    Menschen mit chronisch entzündlichen Darmerkrankungen (CED) leiden unter vielfältigen körperlichen und psychosozialen Einschränkungen. Wie auch bei anderen chronischen Erkrankungen könnten Patientenschulungen ihr psychisches Befinden verbessern (z.B. De Ridder & Schreurs, 2001; Faller, Reusch & Meng, 2011a; Küver, Becker & Ludt, 2008; Schüssler, 1998; Warsi, Wang, LaValley, Avorn & Solomon, 2004). Für CED liegen jedoch nur wenige Schulungsevaluationen vor (z.B. Bregenzer et al., 2005; Mussell...

  9. Trace analysis of actinides in the environment using resonance ionization mass spectrometry; Spurenanalyse von Aktiniden in der Umwelt mittels Resonanzionisations-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, Sebastian

    2011-04-12

    In this work the resonant ionization of neutral atoms using laser radiation was applied and optimized for ultra-trace analysis of the actinides thorium, uranium, neptunium and plutonium. The sensitive detection of these actinides is a challange for the monitoring and quantification of radioactive releases from nuclear facilities. Using resonance ionization spectroscopy combined with a newly developed quadrupole-mass-spectrometer, numerous energy levels in the atomic structure of these actinides could be identified. With this knowledge efficient excitation schemes for the mentioned actinides could be identified and characterised. The applied in-source-ionization ensures for a high detection efficiency due to the good overlap of laser radiation with the atomic beam and allows therefore for a low sample consumption which is required for the analysis of radio nuclides. The selective excitation processes in the resonant ionization method supresses unwanted contaminations and was optimized for analytical detection of ultra-trace amounts in environmental samples as well as for determination of isotopic compositions. The efficient in-source-ionization combined with high power pulsed laser radiation allows for detections efficiency up to 1%. For plutonium detection limits in the range of 10{sup 4}-10{sup 5} atoms could be demonstrated for synthetic samples as well as for first environmental samples. The usage of narrow bandwidth continuous wave lasers in combination with a transversal overlap of the laser radiation and the free propagating atomic beam enable for resolving individual isotopic shifts of the resonant transitions. This results in a high selectivity against dominant neighboring isotopes but with a significant loss in detection efficiency. For the ultra-trace isotope {sup 236}U a detection limit down to 10{sup -9} for the isotope ratio N ({sup 236}U)/N ({sup 238}U) could be determined.

  10. A numerical calculation method for flow discretisation in complex geometry with body-fitted grids; Rechenverfahren zur Diskretisierung von Stroemungen in komplexer Geometrie mittels koerperangepasster Gitter

    Energy Technology Data Exchange (ETDEWEB)

    Jin, X.

    2001-04-01

    A numerical calculation method basing on body fitted grids is developed in this work for computational fluid dynamics in complex geometry. The method solves the conservation equations in a general nonorthogonal coordinate system which matches the curvilinear boundary. The nonorthogonal, patched grid is generated by a grid generator which solves algebraic equations. By means of an interface its geometrical data can be used by this method. The conservation equations are transformed from the Cartesian system to a general curvilinear system keeping the physical Cartesian velocity components as dependent variables. Using a staggered arrangement of variables, the three Cartesian velocity components are defined on every cell surface. Thus the coupling between pressure and velocity is ensured, and numerical oscillations are avoided. The contravariant velocity for calculating mass flux on one cell surface is resulting from dependent Cartesian velocity components. After the discretisation and linear interpolation, a three dimensional 19-point pressure equation is found. Using the explicit treatment for cross-derivative terms, it reduces to the usual 7-point equation. Under the same data and process structure, this method is compatible with the code FLUTAN using Cartesian coordinates. In order to verify this method, several laminar flows are simulated in orthogonal grids at tilted space directions and in nonorthogonal grids with variations of cell angles. The simulated flow types are considered like various duct flows, transient heat conduction, natural convection in a chimney and natural convection in cavities. Their results achieve very good agreement with analytical solutions or empirical data. Convergence for highly nonorthogonal grids is obtained. After the successful validation of this method, it is applied for a reactor safety case. A transient natural convection flow for an optional sump cooling concept SUCO is simulated. The numerical result is comparable with the experiment. To improve the cooling concept, a further simulation is carried out for a modified geometry with a slightly inclined cooler. This is difficult to be done in the Cartesian coordinate system. The result gained with the new discretisation method demonstrates an increase in the convection velocities and thus an improved cooling capability for the core melt. The method significantly expands the application range of the numerical simulation from simple geometry to arbitrary geometry. (orig.) [German] Zur Loesung staendig komplizierterer Stroemungsprobleme nimmt die Anforderung an die erfassbare Rechengeometrie zu. Fuer die Darstellung einer komplexen Geometrie sind kartesische oder zylindrische Koordinatensysteme, mit denen das Rechenprogramm FLUTAN arbeitet, allein nicht mehr ausreichend. Es besteht deshalb die Notwendigkeit von Stroemungsberechnungen im allgemeinen Koordinatensystem, damit die numerische Simulation in beliebiger, zumindest jedoch krummlinig berandeter Geometrie durchgefuehrt werden kann. Im Rahmen dieser Arbeit wird ein numerisches Rechenverfahren fuer die Diskretisierung von Stroemungen in einem koerperangepassten Gitter entwickelt. Das Rechenverfahren wird durch die dreidimensionale Koordinatentransformation fuer die Impulsgleichungen, die Kontinuitaets- und Energiegleichung im versetzten nichtorthogonalen Gitter erstellt. Aufgrund der Anschaulichkeit und der leichteren Diskretisierung der transformierten Gleichungen werden kartesische Geschwindigkeitskomponenten eingesetzt. Die Definition aller drei kartesischen Geschwindigkeitskomponenten an jeder Oberflaeche eines Kontrollvolumens sichert die enge Druck-Geschwindigkeit-Kopplung auch auf stark krummlinigen Gittern. Nach der Diskretisierung und der linearen Interpolation erscheinen insgesamt 19 unbekannte Druckknoten in der transformierten Druckgleichung fuer drei Dimensionen. Durch die explizite Behandlung der querabgeleiteten Terme ergibt sich wieder der uebliche 7-Punkt-Gleichungstyp, der mit den existierenden Solvern geloest werden kann. Hierbei koennen die Randbedingungen direkt an den gekruemmten Raendern definiert werden. Das Rechenverfahren dieser Arbeit stellt einen Fortschritt dar gegenueber den bisherigen Verfahren fuer eine versetzte Anordnung. Das Rechenverfahren ist durch eine gemeinsame Daten- und Ablaufstruktur mit FLUTAN kompatibel und in diesem Programm realisiert. (orig.)

  11. Control of nitrification and denitrification by means of oxygen measurement in activated sludge; Steuerung der Nitrifikation und Denitrifikation mittels Sauerstoffmessung im Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Svardal, K.; Kroiss, H.

    1997-12-31

    As the simulation results show, controlling nitrification/denitrification by means of the oxygen content is a very effective method. Its big advantage is that the concentration of O{sub 2} can be very reliably measured. In comparison with online analysis units, O{sub 2} probes demand little maintenance and are inexpensive; so, each measuring point can be supplied with its own probe. O{sub 2} measurement is indispensable also with other control strategies. It would make sense, at least at larger plants, to monitor additionally the concentration of ammonium, a parameter which makes for a higher safety margin. (orig./SR) [Deutsch] Die Simulationsergebnisse zeigen, dass die Steuerung der Nitrifikation/Denitrifikation nach dem Sauerstoffgehalt sehr gute Resultate ergibt. Der grosse Vorteil dieser Art der Steuerung besteht darin, dass die O{sub 2}-Konzentration sich sehr zuverlaessig messen laesst. O{sub 2}-Sonden sind im Vergleich zu online-Analysatoren wartungsarm und preisguenstig, so dass auch eine reduntante Ausfuehrung jeder Messstelle vertretbar ist. Auf die O{sub 2}-Messung kann auch bei anderen Steuerstrategien nicht verzichtet werden. Eine sinnvolle Ergaenzung waere zumindest bei groesseren Anlagen eine Ueberwachung der Ammoniumkonzentration wobei dieser Messwert vor allen Dingen der Sicherheit dient. (orig./SR)

  12. Recycling of rare earths from Hg-containing fluorescent lamp scraps by solid state chlorination; Rueckgewinnung Seltener Erden aus quecksilberbelasteten Leuchtstoffen mittels Feststoffchlorierung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter; Bertau, Martin [TU Bergakademie Freiberg (Germany); Golon, Katja [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2015-10-15

    Solid state chlorination with NH{sub 4}Cl comprises a method for rare earth recycling apart from pyro- or hydrometallurgical strategies. The examined partially Hg-containing fluorescent lamp scraps are rich in rare earths like La, Ce, Tb and Gd, but especially in Y and Eu. By mixing with NH{sub 4}Cl and heating up to NH{sub 4}Cl decomposition temperature in a sublimation reactor, Y and Eu could be transferred selectively into their respective metal chlorides with high yields. The yield and selectivity depend on temperature and the ratio of NH{sub 4}Cl to fluorescent lamp scraps, which were varied systematically.

  13. Future prospects of the brown coal of central and east Germany in the all-German energy industry. Perspektive der mittel- und ostdeutschen Braunkohle in der gesamtdeutschen Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Milojcic, G

    1991-04-01

    Against a background of different basic conditions the energy industry in the former German Democratic Republic during the last 30 years underwent an entirely different development to that which occurred in the former Federal Republic of Germany. In the Federal Republic, oriented to a free market system, a structural change took place from the 1960s onwards, that is to say, away from solid fuels and towards a mixed energy utilization, in which mineral oil and natural gas in particular play a significant part. The principal market for coal, especially brown coal, is the important power generation sector. The German Democratic Republik, on the other hand, in keeping with its autarchic energy policy relied on the only source of energy available in large quantities, namely brown coal. The reason for this lay in the fact that the system made it impossible to participate in an international exchange of commidities. As a result of the ton-quota ideology and inefficiency in all sectors of energy winning, conversion and utilization the consumption both of primary energy and also of electricity in the former German Democratic Republic was high compared to that in the Federal Republic, and this in spite of the fact that the per capita economic strength was less than half that of the Federal Republic. Two changes are likely to occur in future. On the one hand, a medium-term mixed energy utilization will develop in the primary energy sector, as has been the case in the Federal Republic. On the other hand, it can be assumed that simultaneously with this development consumption will tend to decrease. As in the Federal Republic, the future prospect to brown coal, which has hitherto played a dominating role, will in the first place lie in its utilization in conjunction with the power industry and only secondarily on the thermal energy market. (orig.).

  14. Potent clones. Efficiency of phytoremediation by means of willow family on the status of heavy metals; Potente Klone. Wirkung der Phytoremediation mittels Weidengewaechsen auf den Schwermetallstatus

    Energy Technology Data Exchange (ETDEWEB)

    Fibian, Kurt D. [Rostock Univ. (Germany). Fachgebiet Pflanzenernaehrung; Gombler, Willy; Gruessing, Edgar; Janssen-Weets, Sybille; Schlaak, Michael [Fachhochschule Emden-Leer, Emden (Germany). Inst. fuer Umwelttechnik-EUTEC

    2010-11-15

    The contents of cadmium, copper and zinc in a polluted substrate (harbour silt) were determined by means of fractionated extraction. In a pot attempt, four willow clones were cultivated on this substrate. After a test period of three years the changes in the individual fractions of heavy metal were determined. At the same time, the remove capacity of the test pastures being relevant for the process of phytoextraction were determined by means of the content of heavy metals of the aboveground plant organs and its dry weight. The results show that two of the examined pasture clones clearly are better suitable than poplars and corn, in order to remove in particular cadmium and zinc from the soil by means of phytoremediation.

  15. Real-time monitoring of longitudinal electron bunch parameters by intensity-integrated and spectroscopic measurements of single coherent THz pulses; Echtzeitbestimmung longitudinaler Elektronenstrahlparameter mittels absoluter Intensitaets- und Spektralmessung einzelner kohaerenter THz Strahlungspulse

    Energy Technology Data Exchange (ETDEWEB)

    Wesch, Stephan

    2012-12-15

    High-gain free-electron lasers (FELs) generate intense and monochromatic photon pulses with few tens of femtosecond duration. For this purpose, electron beams are accelerated to relativistic energies and shrunk longitudinally down to micrometer size.The diagnosis of theses compressed electron bunches is a challenge especially for MHz bunch repetition rates as provided by the FEL FLASH in Hamburg. In this thesis, coherently emitted THz radiation of single electron bunches were investigated, on which the longitudinal structure is imprinted. Two instruments were used: First, the FLASH bunch compression monitors, relying on the integrated intensity measurement of diffraction radiation, were modified to determine the overall length of every bunch behind the two bunch compressors (BC). A model was developed showing that their response is independent of the exact bunch shape for lengths below 200 {mu}m (rms). This could experimentally be verified in the range between 50 and 190 {mu}m within 7% accuracy for themonitor behind the last BC by comparison with measurements with the transverse deflecting structure (TDS). Second, a single-shot spectrometer with five staged reflective blazed gratings has been designed, build and commissioned. With its two grating sets, the wavelength ranges from 5.5 to 44 {mu}m and 45 to 440 {mu}m can be simultaneously detected by 118 fast pyroelectric elements. Measurements based on transition radiation spectra were compared with profiles recorded by the TDS.The shape of the spectra as well as the reconstructed temporal profiles (using the Kramers-Kronig relation for phase retrieval) are in excellent agreement. For bunches with a charge of 50 pC, bunch lengths down to 5 {mu}m (fhwm) could be detected.

  16. Determination of characteristic properties of low sulphur IGO (industrial gasoil) and FAME (fatty acid methyl ester) mixtures for application technology; Bestimmung anwendungstechnischer Eigenschaften von FAME (Fettsaeuremethylester) in Heizoel EL mittels einer Pruefapparatur

    Energy Technology Data Exchange (ETDEWEB)

    Liska, M.; Rheinberg, O. van [Oel-Waerme-Inst. gGmbH, Aachen (Germany); Seehack, S.; Gruen, H.; Lucka, K.; Koehne, H. [Inst. fuer wirtschaftliche Oelheizung (IWO), Hamburg (Germany)

    2008-10-15

    Hardware-in-the-loop test rigs have been assembled for the investigation of characteristic properties of mixtures of low-sulfur IGO and FAME for application technology. The aim of these test rigs is to differentiate alternative fuels regarding the operational reliability for the use in oil firing systems. Two out of three 20% (v/v) FAME mixtures proofed to be critical as malfunctions due to blockings and deposits occurred. The critical fuels furthermore showed a significant increase in water content, acid number and peroxide number. This shows interdependency between malfunction of burner components and a delectable change of fuel properties. Nonetheless the fuel analytics prior to testing could not be used to predict the fuel quality. An increase of component lifetime could be achieved by the change of the oil tube material from copper to stainless steel respectively the stabilization of the fuel by additives for those alternative fuels proven to be critical. (orig.)

  17. Process for preparation of a zeolite catalyst and its usage for the catalytic conversion of hydrocarbons. Verfahren zur Herstellung eines Zeolith-Katalysators und Verwendung des mittels dieses Verfahrens hergestellten Katalysators zur katalytischen Umwandlung von Kohlenwasserstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Kuijpers, K.G.Y.A.S.; Nanne, J M

    1972-08-25

    The selectivity of a zeolite catalyst for hydrocracking of linear hydrocarbons is markedly improved by a controlled calcining during preparation. Several active components are deposited on the zeolite so that a catalyst composition of 0.7 to 1.2 Na/sub 2/OxAl/sub 2/O/sub 3/x4.7 to 5.3 SiO/sub 2/xx H/sub 2/O with x = 3 to 9 is formed. At least during the first calcining step at end temperatures of 400 to 550/sup 0/C a fixed partial pressure of water vapor is maintained in the atmosphere around the material in dependence of its temperature.

  18. Study of the ozone depletion and global warming potentials associated with fridge recycling operations that involve the manual stripping of polyurethane insulation froam; Untersuchung des Ozonschichtzerstoerungs- und Klimaschaedigungspotenzials bei der Durchfuehrung des Kuehlgeraeterecyclings mittels Handdemontage

    Energy Technology Data Exchange (ETDEWEB)

    Dehoust, Guenter; Schueler, Doris

    2010-09-14

    In the present study, the average emissions associated with the manual disassembly of refrigeration appliances were determined solely during the manual dismantling phase. The emissions associated with the subsequent disposal phase will be determined at a later date as part of a separate expert study and assessed in a joint final report.

  19. Not the market allowing to quickly pocket money. Siemens/KWU and their commitments in Central and Eastern Europe; ``Kein Markt fuer schnelles Geld``. Das Engagement von Siemens/KWU in Mittel- und Osteuropa

    Energy Technology Data Exchange (ETDEWEB)

    Schwegmann, P.

    1997-05-01

    After the break-up of the Eastern Bloc, Siemens very soon concluded strategic alliances with the big and most qualified Russian power plant manufacturers, busy activities currently focusing on the nuclear sector with retrofitting and safety engineering work in a number of NPPs. Points of main interest are systems analysis, recurrent inspection of primary loop components, and the installation of diagnostic systems for operational monitoring, as well as the instrumentation and control systems. (Orig./RHM) [Deutsch] In Russland ist es Siemens nach der politischen Wende gelungen, mit den groessten und qualifiziertesten Kraftwerksherstellern Russlands strategisch bedeutsame Allianzen einzugehen. Sehr ruehrig ist man auf dem Nuklear-Sektor. So werden gegenwaertig die Sicherheitseinrichtungen einer Reihe von Kernkraftwerken nachgebessert. Schwerpunkte sind dabei Analysen, wiederkehrende Pruefungen an Komponenten der Primaerkreislaeufe sowie die Installation von Diagnosesystemen, Betriebs- und Leittechnik. (orig.)

  20. Development of a method for the characterization of the oxidation stability of domestic heating oil and domestic heating oil with alternative components using chemiluminescence; Entwicklung einer Analysemethode zur Charakterisierung der Oxidationsstabilitaet von Heizoel EL und Heizoel EL A mittels Chemilumineszenz

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Winfried; Lukito, Jayadi; Schloss, Heide vom [Oel-Waerme-Institut gGmbH (OWI), Aachen-Herzogenrath (Germany)

    2013-04-15

    The project's aim was to develop a process that serves to determine the oxidation stability of heating oil - FAME-/ heating oil - vegetable oil-blends clearly. Due to a directed energy input by means of the process of chemiluminescence, statements about the storage stability and the thermal stability of blends can be made. During the process the ageing of blend components and of the heating oil are taken into consideration. As a result, ageing processes and products of pure heating oil as well as biogenic components can be determined. It was shown that the process is applicable to blends up to an admixture of at least 20 % (V/V) of biogenic components, whereby blends with higher admixture shares can be analyzed as well. According to DIN SPEC 51603 - 6 'Heating Oil Alternative' the admixture of FAME is limited to 20 %(V/V) and the admixture of vegetable oil to 5 % (V/V) because of the distillation range. On the basis of these investigations it could be shown how oxidation products influence the signal process of the chemiluminescence radiation and how they can be correlated by a measurable physical value. Moreover, a new evaluation criterion has been developed. By means of this criterion a good reproducibility - regarding the determination of the oxidation stability according to the chemiluminescence methodology for non-aged fuels - can be achieved. The fuel characteristic decrease in the stability of the tested fuels can be represented only partially by the chemiluminescence process, as the measured values are subject to fluctuations. (orig.)

  1. Analysis of sea-surface radar signatures by means of wavelet-based edge detection and detection of regularities; Analyse von Radarsignaturen der Meeresoberflaeche mittels auf Wavelets basierender Kantenerkennung und Regularitaetsbestimmung

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, U. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Gewaesserphysik

    2000-07-01

    The derivation and implementation of an algorithm for edge detection in images and for the detection of the Lipschitz regularity in edge points are described. The method is based on the use of the wavelet transform for edge detection at different resolutions. The Lipschitz regularity is a measure that characterizes the edges. The description of the derivation is first performed in one dimension. The approach of Mallat is formulated consistently and proved. Subsequently, the two-dimensional case is addressed, for which the derivation, as well as the description of the algorithm, is analogous. The algorithm is applied to detect edges in nautical radar images using images collected at the island of Sylt. The edges discernible in the images and the Lipschitz values provide information about the position and nature of spatial variations in the depth of the seafloor. By comparing images from different periods of measurement, temporal changes in the bottom structures can be localized at different resolutions and interpreted. The method is suited to the monitoring of coastal areas. It is an inexpensive way to observe long-term changes in the seafloor character. Thus, the results of this technique may be used by the authorities responsible for coastal protection to decide whether measures should be taken or not. (orig.)

  2. Functional MRI in schizophrenia. Diagnostics and therapy monitoring of cognitive deficits of schizophrenic patients by functional MRI; Funktionelle MRT bei Schizophreniepatienten. Diagnostik und Therapiemonitoring kognitiver Defizite schizophrener Patienten mittels funktioneller MRT

    Energy Technology Data Exchange (ETDEWEB)

    Furtner, J.; Prayer, D. [Medizinische Universitaet Wien, Univ.-Klinik fuer Radiodiagnostik, Wien (Austria); Sachs, G. [Medizinische Universitaet Wien, Univ.-Klinik fuer Psychiatrie und Psychotherapie, Wien (Austria)

    2010-02-15

    Cognitive impairments are core psychopathological components of the symptomatic of schizophrenic patients. These dysfunctions are generally related to attention, executive functions and memory. This report provides information on the importance of using functional magnetic resonance imaging (fMRI) for the diagnostics and therapy monitoring of the different subtypes of cognitive dysfunctions. Furthermore, it describes the typical differences in the activation of individual brain regions between schizophrenic patients and healthy control persons. This information should be helpful in identifying the deficit profile of each patient and create an individual therapy plan. (orig.) [German] Kognitive Defizite sind ein zentraler Bestandteil der Symptomatik schizophrener Patienten. Diese Defizite betreffen v. a. die Aufmerksamkeit, exekutive Funktionen sowie das Gedaechtnis. Der vorliegende Beitrag zeigt den Stellenwert der funktionellen Magnetresonanztomographie (fMRT) in Hinblick auf Diagnostik und Therapiemonitoring der unterschiedlichen kognitiven Teilbereiche auf. Darueber hinaus werden die Unterschiede in Bezug auf die Aktivierung der einzelnen Gehirnareale zwischen schizophrenen Patienten und gesunden Kontrollpersonen dargestellt. Diese Informationen sollen helfen, in der Praxis ein Profil der kognitiven Leistungsreduktionen sowie ein darauf angepasstes Therapiekonzept zu erstellen. (orig.)

  3. Visualization of the dissipation of energy during the cutting process. Presentation of energy value flows by means of dual energy signatures; Energieverschwendung beim Zerspanungsprozess sichtbar machen. Darstellung von Energiewertstroemen mittels dualer Energiesignaturen

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, Rainer [Hochschule Aalen (Germany). Professur Fertigungsorganisation und Prozessmanagement; Kalhoefer, Eckehard [Hochschule Aalen (Germany). Stiftungslehrstuhl Spanende Fertigung; Stock, Timo [Hochschule Aalen (Germany). Studiengang Maschinenbau/Produktion und Management

    2012-09-15

    Lean production systems are the minimization of wastage. Therefore, process steps are divided in value-added and non-value-added process steps. Using the value stream analysis non-value-adding process shares can be identified easily.The main aim usually are the two factors processing time and inventory. By means of a cutting process, the authors of the paper under consideration report on a method which divides the process-related utilization of energy in value-adding and non-value-adding energy use. Due to the dual consideration of energy use, the energy consumption can be easily integrated in the value stream analysis.

  4. Preoperative mapping of speech-eloquent areas with functional magnetic resonance imaging (fMRI): comparison of different task designs; Praeoperatives Mapping der Sprachareale mittels funktioneller Magnetresonanztomographie (fMRT) bei Patienten mit Hirntumoren: Ein Paradigmenvergleich

    Energy Technology Data Exchange (ETDEWEB)

    Prothmann, S.; Zimmer, C. [Leipzig Univ. (Germany). Abt. fuer Neuroradiologie; Puccini, S.; Dalitz, B.; Kuehn, A.; Kahn, T. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Roedel, L. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Neurochirurgie

    2005-11-15

    Purpose: Functional magnetic resonance imaging (fMRI) is a well-established, non-invasive method for pre-operative mapping of speech-eloquent areas. This investigation tests three simple paradigms to evaluate speech lateralisation and visualisation of speech-eloquent areas. Materials and Methods: 14 healthy volunteers and 16 brain tumour patients were given three tasks: to enumerate months in the correct order (EM), to generate verbs fitting to a given noun (GV) and to generate words fitting to a given alphabetic character (GW). We used a blocked design with 80 measurements which consisted of 4 intervals of speech activation alternating with relaxation periods. The data were analysed on the basis of the general linear model using Brainvoyager {sup registered}. The activated clusters in the inferior frontal (Broca) and the posterior temporal (Wernicke) cortex were analysed and the laterality indices calculated. Results: In both groups the paradigms GV and GW activated the Broca's area very robustly. Visualisation of the Wernicke's area was best achieved by the paradigm GV. The paradigm EM did not reliably stimulate either the frontal or the temporal cortex. Frontal lateralisation was best determined by GW and GV, temporal lateralisation by GV. Conclusion: The paradigms GV and GW visualise two essential aspects of speech processing: semantic word processing and word production. In a clinical setting with brain tumour patients, both, GV and GW can be used to visualise frontal and temporal speech areas, and to determine speech dominance. (orig.)

  5. Onward treatment of irradiated liquid egg: Detection in sponge cake mixture after baking by means of LC-GC-MS. Weiterverarbeitung von bestrahltem Fluessigei: Nachweis in gebackener Biskuitmasse mittels LC-GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, H.U. von (Staatliches Lebensmitteluntersuchungsamt Oldenburg (Germany)); Schulzki, G. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Pfordt, J. (Staatliches Lebensmitteluntersuchungsamt Oldenburg (Germany)); Spiegelberg, A. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Helle, N. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Boegl, K.W. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Schreiber, G.A. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany))

    1993-09-01

    Irradiated whole liquid egg used for preparation of sponge cake could be identified using gaschromatographic/mass spectrometric detection of the radiation induced hydrocarbons for doses from 1 kGy. Separation of the hydrocarbons out of the fat was carried out by HPLC coupled on-line to the GC. That means, for the first time an irradiated component of a heat treated food could be detected. (orig.)

  6. Visualization of coronary arteries in CT as assessed by a new 16 slice technology and reduced gantry rotation time: first experiences; Darstellung der Herzkranzgefaesse im CT mittels neuer 16-Zeilen-Technologie und reduzierter Rotationszeit: erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Heuschmid, M.; Kuettner, A.; Kopp, A.F.; Claussen, C.D. [Abt. Radiologische Diagnostik, Universitaetsklinikum Tuebingen (Germany); Flohr, T.; Schaller, S.; Hartung, A.; Ohnesorge, B. [Siemens Medical Solutions, Forchheim (Germany); Wildberger, J.E. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum (RWTH) Aachen (Germany); Lell, M.; Baum, U. [Abt. Innere Medizin IV (Kardiologie), Universitaetsklinikum Tuebingen (Germany); Schroeder, S. [Inst. fuer Diagnostische Radiologie, Universitaetsklinikum Erlangen (Germany)

    2002-06-01

    Purpose: First evaluation of image quality of a new 16-slice multidetector-row computed tomography (MDCT) for the assessment of coronary artery disease and lesion detection of the coronary arteries. Materials and Methods: On a newly developed 16-slice CT scanner (SOMATOM Sensation 16, Siemens, Forchheim, Germany) a calcium score as well as a contrast-enhanced CT angiography (CTA) were performed on 4 patients with retrospective ECG-gating and a gantry rotation time of 420 ms to exclude or follow-up coronary heart disease. CTA was performed after injecting 120 ml contrast media intravenously. After medication with a {beta}-Blocker, the heart rate was between 55 and 67 bpm. Results: The scan time for calcium score was 12s, for CTA 18s (scan range 15 and 12 cm, respectively). Volume score was between 0 and 256.4. In the CT angiography the entire coronary tree could be visualized in all patients up to the very distal subsegmental branches. In two patients a complete occlusion of the RCA and the LAD were depicted, respectively. In one of these patients, a large aneurysm of the left anterior ventricular wall was also delineated. Conclusion: Considering our first experiences with the new 16-slice technology, an excellent visualization of the entire coronary tree including the very distal and side branches due to substantially increased spatial resolution seems to be achievable. In these patients the acquired image quality raises the hope for improved, non-invasive cardiac diagnostics. In larger studies, the clinical impact of this new technology needs to be further investigated. (orig.) [German] Ziel: Darstellung erster Ergebnisse zur Bildqualitaet eines neuen 16-Zeilen Multidetektor-Computertomographen (MDCT) bei der Diagnostik der koronaren Herzerkrankung (KHK) und hochgradiger Stenosen der Herzkranzgefaesse. Material und Methode: Mit einem neuen 16-Zeilen-Computertomographen (SOMATOM Sensation 16, Siemens, Forchheim) wurde bei 4 Patienten zum Ausschluss oder Nachuntersuchung einer KHK eine Koronarkalkbestimmung (Ca-Score) sowie eine CT-Angiographie (CTA) der Herzkranzgefaesse mit retrospektivem EKG-Gating und einer Rotationszeit von 420 ms durchgefuehrt. Fuer die CTA wurden 120 ml KM i.v. appliziert. Nach {beta}-Blocker-Gabe war die Herzfrequenz zwischen 55 und 67 Schlaegen/min. Ergebnisse: Die Untersuchungszeiten betrugen 12s beim Ca-Score und 18s bei der CTA (Untersuchungsbereich 15 bzw. 12 cm). Der Volume Score lag zwischen 0 und 256,4. In der CTA konnte der gesamte Koronargefaessbaum einschliesslich der distal gelegenen, subsegmentalen Aeste bei allen Patienten artefaktfrei dargestellt werden. Bei zwei Patienten wurde ein Komplettverschluss der rechten Kranzarterie (RCA) bzw. des Ramus interventricularis anterior (RIVA) diagnostiziert. Letzterer Patient wies ein grosses linksventrikulaeres Vorderwandaneurysma auf. Schlussfolgerungen: Nach unseren bisherigen ersten Erfahrungen scheint die neue 16-Zeilen-Technologie eine sehr gute Darstellung des koronaren Gefaessbaumes mit Abgrenzbarkeit auch kleiner Gefaessaeste bis in die Peripherie aufgrund einer gesteigerten raeumlichen Aufloesung zu ermoeglichen. Die bei diesen Patienten erzielte Bildqualitaet laesst die Hoffnung auf eine verbesserte, nicht-invasive Herzdiagnostik aufkommen. In groesseren Studien muss jedoch diese neue Technologie bezueglich ihres klinischen Stellenwertes bei der Kardiodiagnostik untersucht werden. (orig.)

  7. Cooling of high temperature superconductors below 60 K by means of a two-stage cryogenic mixed refrigerant cascade; Kuehlung von Hochtemperatursupraleitern unterhalb von 60 K mittels einer zweistufigen Gemischkaeltekaskade

    Energy Technology Data Exchange (ETDEWEB)

    Kochenburger, T.M. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Technische Thermodynamik und Kaeltetechnik (ITTK); Grohmann, S. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Technische Thermodynamik und Kaeltetechnik (ITTK); Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Technische Physik (ITEP)

    2015-07-01

    High temperature superconductors enable the efficient transmission of electrical energy in urban and industrial networks. It is the availability of simple, reliable and at the same time efficient cooling methods prerequisite for the application of this technology. At operating temperatures 65-80 K is the cooling currently mostly implemented by liquid nitrogen, large-scale turbo-Brayton plants or batteries of regenerative cryocooler; however, all these options for applications in the range of a few kW of required cooling capacity have thermodynamic, economic and practical limitations. In addition, a further lowering the cooling temperature below 60 K is desirable to increase the current density in the superconductors. Two-stage cryogenic mixed refrigerant cascade offer the potential for a reliable and easily scalable alternative for refrigeration in this temperature range. The first stage of the considered process consists of a classic mixture refrigeration cycle to pre-cool to 120 K. The second stage operates in the low temperature range up to 55 K with a mixture of nitrogen, oxygen and neon at high pressures. This paper compares on the basis of experimental data, the performance of combustible and non-combustible mixtures in the precooling level. The applicability of various equations of state for modeling of phase behavior of mixtures is discussed. [German] Hochtemperatursupraleiter ermoeglichen den effizienten Transport elektrischer Energie in urbanen und industriellen Netzen. Dabei ist die Verfuegbarkeit von einfachen, zuverlaessigen und gleichzeitig effizienten Kuehlmethoden Voraussetzung fuer die Anwendung dieser Technologie. Bei Betriebstemperaturen von 65 - 80 K wird die Kuehlung derzeit meist durch Fluessigstickstoff, grossskalige Turbo-Brayton-Anlagen oder Batterien regenerativer Kleinkuehler realisiert; jedoch haben alle diese Optionen fuer Anwendungen im Bereich von einigen kW an erforderlicher Kaelteleistung thermodynamische, oekonomische und praktische Einschraenkungen. Zudem ist eine weitere Erniedrigung der Kuehltemperatur unter 60 K wuenschenswert, um die Stromdichte in den Supraleitern weiter erhoehen zu koennen. Zweistufige Gemischkaeltekaskaden bieten das Potential zu einer zuverlaessigen und leicht skalierbaren Alternative fuer die Kaelteerzeugung in diesem Temperaturbereich. Die erste Stufe des betrachteten Prozesses besteht aus einem klassischen Gemischkaeltekreislauf zur Vorkuehlung auf 120 K. Die zweite Stufe operiert im Tieftemperaturbereich bis 55 K mit einer Mischung aus Stickstoff, Sauerstoff und Neon bei hohen Druecken. In diesem Beitrag wird anhand experimenteller Daten die Leistung von brennbaren und unbrennbaren Gemischen in der Vorkuehlstufe verglichen. Die Anwendbarkeit verschiedener Zustandsgleichungen zur Modellierung des Phasenverhaltens der Gemische wird diskutiert.

  8. Unresectable colorectal liver metastases. Percutaneous ablation using CT-guided high-dose-rate brachytherapy (CT-HDBRT); Nicht resektable kolorektale Lebermetastasen. Perkutane Ablation mittels CT-gesteuerter Hochdosisbrachytherapie (CT-HDBRT)

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, F.; Lutter, A.; Schnapauff, D.; Denecke, T.; Gebauer, B. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Hildebrandt, B. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Oncology; Puhl, G. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of General, Visceral and Transplantation Surgery; Wust, P. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Radiation Oncology

    2014-06-15

    Purpose: To evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) of unresectable colorectal liver metastases (CRLMs). Materials and Methods: Retrospective analysis of all consecutive patients with unresectable CRLMs treated with CT-HDRBT between January 2008 and November 2012. Treatment was performed by CT-guided catheter placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed after 6 weeks and then every 3 months post-intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). Results: 80 heavily pretreated patients with 179 metastases were available for MRI evaluation for a mean follow-up time of 16.9 months. The mean tumor diameter was 28.5 mm (range: 8 - 107 mm). No major complications were observed. A total of 23 (12.9%) local tumor progressions were observed. Lesions ≥ 4 cm in diameter showed significantly more local progression than smaller lesions (< 4 cm). 50 patients (62.5%) experienced systemic tumor progression. The median TTP was 6 months. 28 (43%) patients died during the follow-up period. The median OS after ablation was 18 months. Conclusion: CT-HDRBT is an effective technique for the treatment of unresectable CRLMs and warrants promising LTC rates compared to thermal ablative techniques. A combination with other local and systemic therapies should be evaluated in patients with lesions > 4 cm in diameter, in which higher progression rates are expected. (orig.)

  9. Use of precision measurements for the limitation of effects beyond the standard model by means of an effective-field-theoretical approach; Verwendung von Praezisionsmessungen zur Eingrenzung von Effekten jenseits des Standardmodells mittels eines effektiven feldtheoretischen Zugangs

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, A.

    2006-09-25

    The standard model of elementary particle physics (SM) is perhaps the most significant theory in physics. It describes the interacting matter and gauge fields at high prescision. Nevertheless, there are a few requirements, which are not fulfilled by the SM, for example the incorporation of gravity, neutrino oscillations and further open questions. On the way to a more comprehensive theory, one can make use of an effective power series ansatz, which describes the SM physics as well as new phenomena. We exploit this ansatz to parameterize new effects with the help of a new mass scale and a set of new coupling constants. In the lowest order, one retrieves the SM. Higher order effects describe the new physics. Requiring certain properties under symmetry transformations gives a proper number of effective operators with mass dimension six. These operators are the starting point of our considerations. First, we calculate decay rates and cross sections, respectively, for selected processes under the assumption that only one new operator contributes at a time. Assuming that the observable's additional contribution is smaller than the experimental error, we give upper limits to the new coupling constant depending on the new mass scale. For this purpose we use leptonic and certain semileptonic precision data. On the one hand, the results presented in this thesis give physicists the opportunity to decide, which experiments are good candidates to increase precision. On the other hand, they show which experiment has the most promising potential for discoveries. (orig.)

  10. Determination of intensity and position of the extracted electron beam at ELSA by means of high-frequency resonators; Bestimmung von Intensitaet und Position des extrahierten Elektronenstrahls an ELSA mittels Hochfrequenzresonatoren

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Thorsten

    2012-06-15

    The electron stretcher facility ELSA provides an electron beam of a few hundred pA used for the generation of bremsstrahlung photons probing the nucleon structure in a detector setup. For the correct interpretation of the events registered, the persistence of the beam position over time is crucial. Its continuous monitoring has been enabled by setting up a measurement system based on resonant cavities. Position signals at a frequency of 1.5 GHz and below one aW of power can be abstracted from the beam without degrading its quality. After frequency down-conversion to a few kHz, a narrow bandwidth detection performed by lock-in amplifiers separates them from noise. A maximum sample rate of 9 Hz and a resolution of one tenth of a millimeter could be achieved. The position signals have to be normalized to the beam current which is monitored by another dedicated resonator. The measurement precision down to a few pA allows for the accelerator extraction mechanism to be controlled by a feedback loop in order to obtain the respective requested current. (orig.)

  11. Development of a thermal fatigue test method for thermal barrier coatings by laser excitation using a laser thermal shock facility; Entwicklung eines Pruefverfahrens zur laserinduzierten thermischen Ermuedung thermischer Schutzschichten mittels einer Laser-Thermoschockpruefeinrichtung

    Energy Technology Data Exchange (ETDEWEB)

    Nies, Daniel

    2012-07-13

    The finite nature of fossil fuel supply and the growing environmental awareness become increasingly stronger motivations for the development of efficient gas turbines and jet engines for power generation or as engines for land-, sea- and water-based vehicles. One concept developed for this purpose are thermal barrier coatings, where the thermal load of components is reduced by applying a ceramic coating onto the components. In this work the possibility to use a laser thermal shock facility for thermo-cyclic testing of thermal barrier coatings is examined. A focused laser beam is used for heating the sample and a homogeneous temperature distribution on the sample surface is achieved by the used trajectory and radial adjusted laser power. The required improvements of the existing testing facility are explained, including the development of a new sample holder and of the testing and evaluation routines for the experiments. For the assessment of the initiation and evolution of damages, acoustic emission and thermographic methods are used. The possibilities and limits of these methods are assessed during the experiments. The work also includes an extensive temperature dependent characterisation of the ceramic material used for the thermal barrier coating. In this part, the measurement of the Young's modulus by a dynamic method is to be highlighted, as this is a rarely used technique. The characterisations show the expected values, except for a lower porosity as expected by the manufacturer and no significant phase changes during isothermal heat treatments. To reach sample surface temperatures above 1000 C, it is necessary to increase the absorption by an additional coating of magnetite. The temperature distribution on the surface is measured by an infrared camera, which is calibrated for this purpose. With the incorporated active air cooling of the sample backside, the temperature gradient can be controlled, but still leaves room for improvements. Already without cooling, experiments can be completed, where the thermal loads are highly reproducible and comparable to real operation conditions. The development and evolution of delamination damages can be observed by acoustic emission and thermographic methods. Sound location using the acoustic emission data shows the limits of the applied equipment. Good sound location results can be achieved by a time-consuming manual routine, but the results are highly dependent on the signal quality. A reduced zone location algorithm with an automatic analysis shows satisfying results. A combination of the zone location results, the analysis of the acoustic emission data and the thermographic analysis of the infrared camera data allows a very good visualisation of the damage evolution. First experiments showed delaminations located in the ceramic layer near the topcoat-bondcoatboundary, which corresponds to a failure mode induced by high cyclic loads of the samples. The use of a focused laser beam results in a local hot spot at the laser spot during heating. This adds a thermal shock component to the thermo-cyclic load during the experiments.

  12. Electronic characterization of LaAlO{sub 3}-SrTiO{sub 3} interfaces by scanning tunneling spectroscopy; Elektronische Charakterisierung von LaAlO{sub 3}-SrTiO{sub 3}-Grenzflaechen mittels Rastertunnelspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Breitschaft, Martin

    2010-10-22

    When LaAlO{sub 3} is epitaxially grown on TiO{sub 2}-terminated SrTiO{sub 3}, an electrically conducting interface is generated. In this respect, the physical properties of the interface differ substantially from those of both LaAlO{sub 3} and SrTiO{sub 3}, which are electrically insulating in bulk form. This dissertation looks into the question of the microscopic structure of the conducting two-dimensional interface electron system. Comparing the electronic density of states of LaAlO{sub 3}-SrTiO{sub 3} interfaces measured by scanning tunneling spectroscopy with results of density functional theory, the interface electron system is found to be substantially coined by the hosting transition metal lattices. The comparison yields a detailed picture of the microscopic structure of the interface electron system. (orig.)

  13. Arsenic speciation in biological environmental samples of aquatic ecosystems by using HPLC-ICP-MS; Speciation von Arsen in biologischen Umweltproben aus aquatischen Oekosystemen mittels HPLC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Falk, K.

    1999-09-01

    The physicochemical forms of arsenic (arsenic species) which are present in the environment vary significantly with respect to toxicity, bioavailability, stability and transport behaviour. Therefore, it is necessary for an assessment of the toxic potential to humans and the environment to investigate not only the total arsenic concentrations but also to differentiate the single species. By that the knowledge about ecological correlations and pathways will be increased. The present thesis reports the results of a Ph.D. study on the development and optimisation of analytical methods for arsenic speciation and their application to biological samples from different aquatic ecosystems in Germany. The method development included separation of 12 naturally occurring arsenic species by high-performance liquid chromatography (HPLC) followed by an arsenic selective detection by inductively coupled plasma-mass spectrometry (ICP-MS). The arsenic species As (III), As (V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC), trimethylarsine oxid (TMAO) and tetramethylarsonium (Tetra) were separated with ion-exchange chromatography, whereas reversed-phase chromatography was used for the separation of four arsenosugars. Because of the partly low arsenic concentration in biological samples a very good detection power was required. Therefore, an HPLC-ICP-MS system was tested with different nebulizers. Using the high efficiency nebulizer HHPN (Hydraulic High Pressure Nebulizer), detection limits in the low pg-range could be achieved. The developed analytical methods were applied to arsenic speciation in four marine matrices, which are representative of different trophic levels in the food chain. All samples originated from an ecosystem in the North Sea.

  14. Residual stress reduction in beam welded joints by means of stress redistribution using defocused electron or laser beams; Eigenspannungsreduktion in strahlgeschweissten Naehten mittels Spannungsumlagerung durch den Einsatz defokussierter Elektronen- bzw. Laserstrahlen

    Energy Technology Data Exchange (ETDEWEB)

    Toelle, Florian

    2013-08-01

    Among the multiple advantages of beam welding processes the high longitudinal residual stresses in beam welds ranging till the local yield stress are one disadvantage. These high stresses can influence the service life of the welded components. The residual stresses in other welding processes exist in an equal high level but primarily in the transverse direction to the weld. To mitigate the high residual stresses a couple of methods were developed for these welding processes in the last decades. However these methods need large contact surfaces next to the welds for the installation of matched heating and cooling elements and other additional equipment. Furthermore, the previous developed stress mitigating processes offer a low efficiency for the small beam welds. The stress reduction by using the welding source after the welding process for a remote heat treatment of the welded components afford a flexible tool for the stress mitigation in beam welds. This method does not need any additional equipment and it is applicable for complex welding and component geometries. During this post welding heat treatment the material next to the weld is heated by the defocused electron or by the defocused laser beam, respectively, to temperatures of some hundreds degree Celsius. Hereby low plastic deformations in these regions are generated. While cooling down due to the thermal shrinkage the material between the weld and the heat treated region is compressed in longitudinal direction to the weld. This intermediate material zone constrained the shrinkage of the weld while cooling down from the melting temperature and leads to the high longitudinal residual stresses in the weld. In consequence of the compression of this intermediate zones by the heat treated zones the resistance to the shrinkage of the weld is lowered and the longitudinal stresses in the weld are reduced. In the process the quantity of the stress reduction is controlled by the selection of the process parameters. The used beam radius and the travel speed of the heat treatment have a large influence in this method. However, the right selection of the transversal distance of the heat treatment to the weld is important. This distance depends on the used beam radius. For the qualitative and quantitative analyses of the reduction of the longitudinal weld stresses in this method a great many of finite element simulations were performed. The simulation results help to define the stress reduction mechanism and to analyze the parameters, which influence this method. Experimental investigations on different materials and weld geometries with the electron beam and with the laser beam verify that this method can reduce the longitudinal stresses in the weld. Depending on the used process parameters the stress reduction can lead to compressive stresses in the weld. Due to a larger stress reduction by performing the heat treatment in a separate process after the weld could cool down to ambient temperature this method is very advantageous for the laser beam application, which does not permit an in situ heat treatment while welding.

  15. Variation of crystallinity and stoichiometry in films of gallium oxide, gallium nitride and barium zirconate prepared by means of PLD; Variation von Kristallinitaet und Stoechiometrie in mittels PLD hergestellten Schichten aus Galliumoxid, Galliumnitrid und Bariumzirkonat

    Energy Technology Data Exchange (ETDEWEB)

    Brendt, Jochen

    2011-08-05

    Pulsed Laser Deposition (PLD) is an ablation technique for thin film preparation of many materials. The film properties can be well controlled by the process parameters. Therefore, in many cases a given material can be deposited with different properties by changing one or more process parameters. In this thesis thin films of gallium oxide, gallium nitride and barium zirconate were deposited with a large variation in structure and stoichiometry by means of Pulsed Laser Deposition. The characterization of the film crystallinity, phase purity and short range structural order was completed by means of X-ray diffraction and X-ray absorption spectroscopy. The stoichiometry was investigated using electron probe microanalysis. For analyzing the correlation between the structure and stoichiometry with the optical and electrical properties, optical absorption and electrical conductivity measurements were carried out. The investigation of all three material systems showed that very unique properties can be realized when combining an amorphous structure and a non-stoichiometric composition. For example, in amorphous and oxygen deficient gallium oxide an insulator-metal-transition can be induced by partial crystallization of the as prepared phase accomplished by annealing at about 400 C in argon atmosphere (as shown in literature). Furthermore, amorphous and highly non-stoichiometric barium zirconate has the ability to split water molecules to hydrogen and oxygen at room temperature. A detailed analysis of both phenomena has been performed by means of photoemission and transmission electron microscopy in the case of gallium oxide and via X-ray absorption spectroscopy and gas chromatography in the case of barium zirconate.

  16. Determination of the stagnation point in pulverized coal swirl flames by detailed analysis of laser velocity measurements; Staupunktbestimmung in Kohlenstaub-Drallflammen mittels detaillierter Analyse von LDA-Daten

    Energy Technology Data Exchange (ETDEWEB)

    Ohliger, A.; Stadler, H.; Foerster, M.; Kneer, R. [RWTH Aachen University (Germany). Lehrstuhl fuer Waerme- und Stoffuebertragung

    2009-07-01

    When Laser Doppler Anemometry (LDA) is used for experimental investigation of flow fields in pulverised coal flames, the measured coal particle velocities are usually averaged in order to determine the gas velocity. This paper shows that this approach can lead to a misinterpretation of the data. In the burner vicinity of the investigated flame, where high accelerations in the gas phase occur, a discrepancy appears between the measured velocity distribution and the expected normal distribution. Thus, a detailed analysis of the measured particle data is conducted and compared to conventional averaging. The difference can be attributed to large particles from the inner recirculation zone of the flame, which do not follow the gas flow properly. (orig.)

  17. Test of special relativity theory by means of laser spectroscopy on relativistic {sup 7}Li{sup +} ions in the ESR; Test der Speziellen Relativitaetstheorie mittels Laserspektroskopie an relativistischen {sup 7}Li{sup +}-Ionen am ESR

    Energy Technology Data Exchange (ETDEWEB)

    Botermann, Benjamin

    2012-10-31

    The invariance under Lorentz transformation of the laws of physics is a fundamental postulate of modern physics and all theories of the fundamental interactions have been stated in a covariant form. Although the theory of Special Relativity (SR) has been tested and confirmed with high accuracy in a large number of experiments, improved tests are of fundamental interest due to the far-reaching relevance of this postulate. Additionally modern attempts of a unified description of the four fundamental interactions point to possible violations of Lorentz invariance. In this context experiments of the Ives-Stilwell type for a test of time dilation play an important role. High resolution laser spectroscopy is applied on relativistic particle beams to investigate the validity of the relativistic Doppler formula - and therefore of the time dilation factor γ. In the course of this thesis an Ives-Stilwell experiment was performed with {sup 7}Li{sup +} ions at a velocity of 34 % of the speed of light, which were stored at the experimental storage ring (ESR) of the GSI Helmholtzzentrum fuer Schwerionenforschung. The techniques of Λ- as well as saturation spectroscopy were employed on the 1s2s{sup 3}S{sub 1}→1s2p{sup 3}P{sub 2} transition. By a computer based analysis of the fluorescence detection system and utilization of appropriate edge filters the signal to noise ratio was decisively improved and the application of an additional pump laser allowed for the observation of a saturation signal for the first time. The frequency stability of both laser systems was specified by means of a frequency comb to obtain the highest possible accuracy. The data from the beam times were analyzed in the frameworks of the Robertson-Mansouri-Sexl test theory (RMS) and the Standard Model Extension (SME) and the corresponding upper limits of the relevant test parameters of the assigned theories were calculated. The upper limit of the parameter α was improved by a factor of 4 compared to earlier measurements performed at a velocity of 6.4 % of the speed of light at the test storage ring (TSR) at the Max-Planck-Institut fuer Kernphysik in Heidelberg.

  18. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields ({proportional_to} 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H{sup -})=1.10{sup 17} 1/m{sup 3}, which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  19. Nanopatterning of Co/Pt-multilayers via self-assembled block-copolymer micelles; Magnetische Nanostrukturen basierend auf Co/Pt-Multilagen, hergestellt mittels selbstorganisierter Masken aus Blockcopolymer-Micellen

    Energy Technology Data Exchange (ETDEWEB)

    Stillrich, H.

    2007-07-01

    The production and characterization of magnetic nanostructures based on Co/Ptmultilayers are described in this thesis. Nanostructure arrays of Co/Pt multilayer films are generated utilizing the self-assembly of block copolymer micelles with a few 10nm diameter. For an understanding of the magnetic properties of nanostructures the properties of Co/Pt-multilayer films are examined first. The films are grown via different sputter techniques. The structural and magnetic properties are investigated depending on the deposition technique. The sources of magnetic anisotropy are discussed based on these investigations. One major topic concerning Co/Pt-multilayers is the reorientation of the easy axis of magnetization from perpendicular to in-plane as a function of the cobalt and platinum layer thicknesses. Combining averaging magnetization measurements and high resolution magnetic imaging, the canting of magnetization within the reorientation transition and a canted domain structure were found. The basis for magnetic nanostructures are Co/Pt-multilayers that were optimized for strong magnetic anisotropy. Magnetic antidot and dot arrays are generated from Co/Pt-multilayers via novel methods utilizing block copolymer micelle masks and ion milling. The generation of nanostructure arrays is proven by the morphologic and topographic properties, combined with the evolution of magneto-optic signals. Two different approaches for the generation of antidot arrays are shown. The magnetic properties of antidot arrays with perpendicular and in-plane easy magnetization are investigated. Magnetic dot arrays are produced utilizing the cores of SiO{sub 2} filled block copolymer micelles. The dot arrays consist of single domain particles. The switching field distribution of the dot arrays is analysed and described using the size distribution of the magnetic particles. Magnetic nanostructures in the region of the superparamagnetic limit are investigated. (orig.)

  20. Investigations on pretreatment of waste prior to fermentation by percolation using the ISKA {sup registered} process; Untersuchungen zur Vorbehandlung von Abfaellen vor der Vergaerung mittels Perkolation nach dem ISKA {sup registered} -Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Santen, H. [Technische Univ. Braunschweig (Germany). FG Abfallwirtschaft; Fricke, K. [Technische Univ. Braunschweig (Germany). Lehrstuhl Abfallwirtschaft; Engelhard, T.; Widmer, C. [ISKA GmbH, Ettlingen (Germany)

    2004-07-01

    Waste treatment prior to fermentation is a key aspect in achieving economic efficiency. One process is presented here in particular: percolation, in which waste is hydrolyzed aerobically, treated mechanically, and washed out with the aid of process water. The process involves a percolation stage followed by a fermentation stage. The process water burdened with organic matter is passed into a fermentation reactor in which the organic components are reacted anaerobically into biogas and bacterial mass, and the process water is recirculated into the percolation reactor. (orig.) [German] Vergaerungstechnologien zaehlen zu den etablierten Verfahren zur Gewinnung regenerativer Energien aus Biomasse. Fuer die Energieeffizienz dieser Verfahren sind die Leistung der Vergaerungsstufe, die Hoehe der Verfuegbarkeit der anaerob abzubauenden organischen Substanzen und der spezifische Energiebedarf des Behandlungsverfahrens massgeblich. Eine Schluesselstellung fuer die Optimierung beider Faktoren nimmt die Abfallaufbereitung vor der Vergaerung ein. Eine Technoloie zur Aufbereitung vor der Vergaerung basiert auf dem Verfahren der Perkolation, in der der Abfall aerob hydrolysiert,mechanisch aufgeschlossen und durch Zugabe von Prozesswasser ausgewaschen wird. Das Verfahren besteht aus einer Aufbereitung - der Perkolation - sowie einer nachgeschalteten Vergaerung. Das mit vergaerbarer Organik beladene Prozesswasser wird einem Vergaerungsreaktor zugefuehrt, in dem die organischen Komponenten anaerob zu Biogas und Bakterienmasse umgesetzt werden. Das aufbereitete Prozesswasser wird anschliessend wieder dem Perkolationsreaktor zugefuehrt. (orig.)

  1. A model-based analysis for the improvement of electrical energy supply of future offshore windparks by means of biogas technology; Modellbasierte Analyse zur Verbesserung der elektrischen Energiebereitstellung zukuenftiger Offshore-Windparks mittels Biogastechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Tigges, Martin

    2010-09-06

    Since the beginning of industrial revolution energy supply in Germany was based on fossil fuels. Climatic change, the greenhouse effect, the growth of population on the one hand and shortage on fossil fuels on the other hand and the will to be independent from importing resources from political instable countries are calling for serious changes. The primary modernisation of the current energy supply needs to target a sustainable, generation comprehensive solution. The use of renewable fuels is necessary. Wind energy usage is one of the most promising alternatives within the short-term to middle-term planning of environmental policy. As in Germany nearly all potential habitats on mainland already are tapped, significant development potential is seen at offshore habitats in North as well as Baltic Sea. Germany aims for the allotment of up to 25 GW of offshore wind energy in the North and Baltic Sea till 2025. Electricity generation by wind energy plants subjects to the conditions the volatile characteristics of the wind. Within the planned big offshore wind energy farms comprising more than 80 plants changes in wind velocity as well as directions will lead to fluctuations in energy supply. Up to now the plant resource scheduling needed to react on the users demand. The further development of wind energy and the differences between forecasted and actual wind energy feeds do and will hinder this resource scheduling. New approaches need to be found to be able to ensure the security of energy supplies in Germany. These approaches should be sustainable and therefore be based on the usage of renewable fuels. Within this dissertation possible solutions as well as constraints of the usage of biogas as a nearly CO2 neutral fuel in combination with micro gas turbines adapted to the usage with biogas plants to be able to align the differences between forecasted and actual wind energy supply for a future offshore wind energy plant park are analysed. This combination allows an energy supply that on the one hand is independent from fossil fuels and on the other hand could be easily adjusted to current demands. (orig.)

  2. Stochastic modelling of the thermal characteristics of a hot-water storage tank on the basis of Markov chains; Zur stochastischen Modellierung des thermischen Verhaltens eines Warmwasserspeichers mittels Markov`scher Ketten

    Energy Technology Data Exchange (ETDEWEB)

    Werner, U.J. [Bauhaus-Universitaet Weimar (Germany). Fakultaet Bauingenieurwesen

    1998-09-01

    In an earlier contribution, a stochastic model was presented for a hot water storage tank supplied by a solar collector. The model was characterized in that the storage tank was assumed to be an ideal stratified storage tank, and its volume was subdivided into discrete identical storage compartments, so-called states, on the basis of the energy withdrawn from the tank. This simple model is now extended by assuming a stochastic variable for energy withdrawal and by taking account of energy loss at the surface of the hot water storage tank and inside it. [Deutsch] In einem frueheren Beitrag war fuer einen thermischen Speicher, der von einem Sonnenkollektor gespeist wird, ein stochastisches mathematisches Modell derart aufgestellt worden, dass ein als idealer Schichtenspeicher konzipierter Warmwasserspeicher bezueglich seines Volumens in diskrete, an der Energieentnahme orientierte, gleiche Speichereinheiten, sogenannte Zustaende, unterteilt wurde. Das einfache Modell wird nunmehr erweitert, indem die Entnahme als eine stochastische Groesse angenommen wird und die Energieverluste am und im Warmwasserspeicher Beruecksichtigung finden. (orig.)

  3. Self-organizing neural networks for automatic detection and classification of contrast-enhancing lesions in dynamic MR-mammography; Selbstorganisierende neuronale Netze zur automatischen Detektion und Klassifikation von Kontrast(mittel)-verstaerkten Laesionen in der dynamischen MR-Mammographie

    Energy Technology Data Exchange (ETDEWEB)

    Vomweg, T.W.; Teifke, A.; Kauczor, H.U.; Achenbach, T.; Rieker, O.; Schreiber, W.G.; Heitmann, K.R.; Beier, T.; Thelen, M. [Klinik und Poliklinik fuer Radiologie, Klinikum der Univ. Mainz (Germany)

    2005-05-01

    Purpose: Investigation and statistical evaluation of 'Self-Organizing Maps', a special type of neural networks in the field of artificial intelligence, classifying contrast enhancing lesions in dynamic MR-mammography. Material and Methods: 176 investigations with proven histology after core biopsy or operation were randomly divided into two groups. Several Self-Organizing Maps were trained by investigations of the first group to detect and classify contrast enhancing lesions in dynamic MR-mammography. Each single pixel's signal/time curve of all patients within the second group was analyzed by the Self-Organizing Maps. The likelihood of malignancy was visualized by color overlays on the MR-images. At last assessment of contrast-enhancing lesions by each different network was rated visually and evaluated statistically. Results: A well balanced neural network achieved a sensitivity of 90.5% and a specificity of 72.2% in predicting malignancy of 88 enhancing lesions. Detailed analysis of false-positive results revealed that every second fibroadenoma showed a 'typical malignant' signal/time curve without any chance to differentiate between fibroadenomas and malignant tissue regarding contrast enhancement alone; but this special group of lesions was represented by a well-defined area of the Self-Organizing Map. Discussion: Self-Organizing Maps are capable of classifying a dynamic signal/time curve as 'typical benign' or 'typical malignant'. Therefore, they can be used as second opinion. In view of the now known localization of fibroadenomas enhancing like malignant tumors at the Self-Organizing Map, these lesions could be passed to further analysis by additional post-processing elements (e.g., based on T2-weighted series or morphology analysis) in the future. (orig.)

  4. Development of a method for the detection of heavy metal discharges into the sewer system. Final report. Methodenentwicklung zum einfachen Nachweis schwermetallhaltiger Einleitungen ins oeffentliche Kanalnetz mittels Sielhautuntersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Gutekunst, B.

    1988-03-01

    Very often the agricultural use of municipal sludges is inhibited due to heavy metals contents, that exceed the values of the municipal sludge decree (Klaerschlammverordnung). This sludge contamination can only be reduced, if heavy metal containing run-offs are avoided. An effective method for registration and control of the waste water run-offs is therefore necessary. The analysis of sewer slime, a biofilm, that grows on the inner surface of waste water canals is a successful method to localize heavy metal laden run-offs. In this paper the results of the biological and the chemical analysis of several sewer slimes of different origins are presented. The accumulation of Cd, Cu, Ni, Pb and Zn in sewer slimes at different chemical conditions (pH, metal and slime concentrations) is investigated. The accumulation rate may reach 90%. The affinity of the slime towards metals decreases in the following way: Pb>Cu>Cd>Zn>Ni. The attachment of the metals on the biomass is mostly irreversible. Sequentional leaching shows that more than 70% of the Cd, Cu and Pb is tightly bound. Ni and Zn also appear in more soluble species. The remobilization of heavy metals is possible at acid conditions and in the presence of chelating agents. The growth of the biofilm depends on the nutrient content of the waste water and its flow rate. (orig.) With 42 refs., 15 tabs., 18 figs.

  5. Consistent data models and security standards for power system control through their standard compliant integration via ontologies; Einheitliche Datenmodelle und Sicherheitsstandards in der Netzleittechnik durch ihre standardkonforme Integration mittels Ontologien

    Energy Technology Data Exchange (ETDEWEB)

    Uslar, Mathias; Beenken, Petra; Beer, Sebastian [OFFIS, Oldenburg (Germany)

    2009-07-01

    The ongoing integration of distributed energy recourses into the existing power grid has lead to both grown communication costs and an increased need for interoperability between the involved actors. In this context, standardized and ontology- based data models help to reduce integration costs in heterogeneous system landscapes. Using ontology-based security profiles, such models can be extended with meta-data containing information about security measures for energyrelated data in need of protection. By this approach, we achieve both a unified data model and a unified security level. (orig.)

  6. Increase in spite of slow economic development. PV association calls for self-consumption as a remedy against low progress rates in Spain; Zunehmen trotz Diaet. Photovoltaikverband propagiert Selbstverbrauch als Mittel gegen den mageren Zubau in Spanien

    Energy Technology Data Exchange (ETDEWEB)

    Franco de Saravia, Cristina; Rosell, Alejandro Diego; Schug, Andreas

    2010-01-15

    To revive the slagging Spanish PV industry, the Spanish PV association ''Asif'' proposed a new strategy involving new regulations on self-consumption and reduced rates. Without incurring additional cost, this is to ensure an additional market growth by 35 percent through 2020, with profits of 7 percent for plant operators. Not all members of the association are in agreement. (orig./AKB)

  7. Use of precision measurements for the limitation of effects beyond the standard model by means of an effective-field-theoretical approach; Verwendung von Praezisionsmessungen zur Eingrenzung von Effekten jenseits des Standardmodells mittels eines effektiven feldtheoretischen Zugangs

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, A

    2006-09-25

    The standard model of elementary particle physics (SM) is perhaps the most significant theory in physics. It describes the interacting matter and gauge fields at high prescision. Nevertheless, there are a few requirements, which are not fulfilled by the SM, for example the incorporation of gravity, neutrino oscillations and further open questions. On the way to a more comprehensive theory, one can make use of an effective power series ansatz, which describes the SM physics as well as new phenomena. We exploit this ansatz to parameterize new effects with the help of a new mass scale and a set of new coupling constants. In the lowest order, one retrieves the SM. Higher order effects describe the new physics. Requiring certain properties under symmetry transformations gives a proper number of effective operators with mass dimension six. These operators are the starting point of our considerations. First, we calculate decay rates and cross sections, respectively, for selected processes under the assumption that only one new operator contributes at a time. Assuming that the observable's additional contribution is smaller than the experimental error, we give upper limits to the new coupling constant depending on the new mass scale. For this purpose we use leptonic and certain semileptonic precision data. On the one hand, the results presented in this thesis give physicists the opportunity to decide, which experiments are good candidates to increase precision. On the other hand, they show which experiment has the most promising potential for discoveries. (orig.)

  8. Presentation of a reference material for the spatially resolved hydrogen analytics in near-surface layers by means of nuclear-reaction analysis; Darstellung eines Referenzmaterials fuer die ortsaufgeloeste Wasserstoffanalytik in oberflaechennahen Schichten mittels Kernreaktionsanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Reinholz, U.

    2005-10-03

    The object of the thesis is the presentation of the theory of the {sup 15}N-reaction analysis (NRA), the experiemental construction of the corresponding beam pipe at the ion accelerator of the BAM and the evaluation of the measurement results. The aim is the first characterization of a reference material for the H analytics on the base of amorphous silicon (aSi) on a Si[100] substrate. The homogeneity of the aSi:H layers deposited by means of CVD was studied. For this pro substrate for about 30 samples the hydrogen depth profiles were measures, folded by means of a program created within the thesis and subjected to a statistical evaluation. The result were mean value ans standard deviation of the hydrogen concentration as well as an estimator for the contribution of the inhomogeneity to the measurement uncertainty. The stability of the potential reference material was proved by the constancy of result of repeated measurements of the hydrogen concentration during the application of a large dose of {sup 15}N ions. In an international ring experiment the reproducibility of the measurement results was proved. For the characterization of the aSi:H layers beside the NRA the white-light interferometry, ellipsometry, profilometry, and X-ray reflectometry, as well as the IR and Raman spectroscopy were used. The stoichiometry of the applied standard material kapton was checked by means of NMR spectroscopy and CHN analysis.

  9. Percutaneous, radiology-assisted stent implantation by means of a novel prosthesis of the bile duct in cases of inoperable cholangioma. Perkutane radiologische Stentimplantation beim inoperablen Gallengangskarzinom mittels einer neuen Gallengangsprothese

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A; Nanko, N [Freiburg Univ. (Germany, F.R.). Abt. Roentgendiagnostik; Milic, S [Consiglio Nazionale delle Ricerche, Rome (Italy); Volk, B [Freiburg Univ. (Germany, F.R.). Abt. Innere Medizin 1 (Haematologie und Onkologie)

    1989-07-01

    In case of malignant growth causing biliary obstruction, biliary decompression can be achieved by surgery, or by means of external/internal drainage. A novel stent with an F7 outer diameter can be percutaneously introduced and positioned through an F8 sluice, assisted by radiologic and cholangioscopic control, and can be dilated to the required diameter by means of a balloon catheter. The implentation can entirely be done through the sluice.

  10. Die Erfassung von städtischen Oberflächen mittels EDV-gestützter Luftbildauswertung : ein Beitrag zur klimatologischen und luftklimatischen Bewertung von städtischen Teilflächen

    Directory of Open Access Journals (Sweden)

    M. Sandtner

    Full Text Available The article shows that the computer-aided, analogous-visual, stereometric interpretation of large-scale colour-infrared (CIR aerial photographs and subsequent data processing in a Geographical Information System (GIS can provide fundamental data necessary to describe aspects of urban ecology in a scale relevant for city-planning. This is exemplified by an evaluation of urban areas concerning their climates and airpollution using maps of urban surfaces (scale1:2500. An argumentation relying on such detailed and current basic data can stress the importance of environmental aspects in contrast to competing public and private interests in the process of city planning.

  11. Analysis of damage processes in short glass fibre reinforced polyamide under mechanical loading by X-ray refractometry, fracture mechanics and fractography; Analyse der Schaedigungsprozesse in einem kurzglasfaserverstaerkten Polyamid unter mechanischer Belastung mittels Roentgenrefraktometrie, Bruchmechanik und Fraktografie

    Energy Technology Data Exchange (ETDEWEB)

    Guenzel, Stephan

    2013-04-01

    This thesis presents an analysis of the damage behaviour in a short glass fibre reinforced polyamide. The micro cracking is investigated by X-ray refraction technique under various, mechanical in-service loadings. In this context, potentials and limits of X-ray refraction analysis for short glass fibre reinforced polyamides are compiled. In particular the influence of fibre orientation and the influence of damage mechanisms are examined according to the X-ray refraction analysis and its interpretation. The method offers a quantitative and phenomenological based characterisation of micro crack damage. For the investigated material micro crack damage emerges as fibre matrix debonding and matrix micro cracking. The state of damage correlates with a nonlinear strain portion in a linear manner and depends on the kind of loading. Absorption of moisture in the material may influence significantly the micro crack damage behaviour. Damage of micro cracking appears preferentially under tension. The macro damage due to propagation of a single crack is characterised in an automated test setup, considering the fibre orientation and content of moisture. Based on the findings an empirical assessment approach is developed. The investigations of the micro and macro damage behaviour are accompanied by fractography, in order to support the model assumptions according to damage and fracture mechanisms.

  12. Using heat from sewers for heating and cooling the IWC watch factory using a heat pump; Waermenutzung aus der Kanalisation zur Beheizung und Kuehlung der Uhrenfabrik IWC mittels Waermepumpe

    Energy Technology Data Exchange (ETDEWEB)

    Gruendler, A.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that demonstrated the feasibility of using a heat pump to provide heating energy in winter and cooling in summer using wastewater as a source of and sink for energy. The system used, including a standard refrigeration machine and a 60-metre long, 75 cm wide heat-exchanger in stainless steel is described. The main results of the project are presented in tabular form and commented on. Further work proposed is discussed, including the installation of a second machine and additional storage tanks. Costs for investments and maintenance are listed. An appendix provides photos and schematics of the equipment and installations.

  13. Ultrasound-guided image fusion with computed tomography and magnetic resonance imaging. Clinical utility for imaging and interventional diagnostics of hepatic lesions; Ultraschallgestuetzte Bildfusion mittels CT und MRT. Klinische Bedeutung fuer die bildgebende und interventionelle Diagnostik von Leberlaesionen

    Energy Technology Data Exchange (ETDEWEB)

    Clevert, D.A.; Helck, A.; Paprottka, P.M.; Trumm, C.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Zengel, P. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Klinik fuer Hals-, Nasen- und Ohrenheilkunde, Muenchen (Germany)

    2012-01-15

    Abdominal ultrasound is often the first-line imaging modality for assessing focal liver lesions. Due to various new ultrasound techniques, such as image fusion, global positioning system (GPS) tracking and needle tracking guided biopsy, abdominal ultrasound now has great potential regarding detection, characterization and treatment of focal liver lesions. Furthermore, these new techniques will help to improve the clinical management of patients before and during interventional procedures. This article presents the principle and clinical impact of recently developed techniques in the field of ultrasound, e.g. image fusion, GPS tracking and needle tracking guided biopsy and discusses the results based on a feasibility study on 20 patients with focal hepatic lesions. (orig.) [German] Bei der Bildfusion von Ultraschall mit anderen schnittbildgebenden Verfahren (CT, MRT) handelt es sich um ein relativ neuartiges Verfahren, welches unter Studienbedingungen jedoch bereits erfolgreich eingesetzt wurde. In der folgenden Machbarkeitsstudie soll der Nutzen weiterfuehrender Anwendungen der sonographischen Bildfusion, dem so genannten Global-Positioning-System- (GPS-) und Needle-Tracking, untersucht werden. Dabei handelt es sich um Instrumente, die insbesondere die Diagnostik und das Staging (GPS-Tracking) bzw. die bioptische Abklaerung (Needle-Tracking) von Patienten mit fokalen Leberlaesionen erleichtern. In diesem Artikel werden das Prinzip und die Anwendungsmoeglichkeiten dieser neuen Techniken anhand konkreter Beispiele in einem Kollektiv von 20 Patienten mit fokalen Leberlaesionen vorgestellt und erlaeutert. (orig.)

  14. Structural analysis of GaN using high-resolution X-ray diffraction at variable temperatures; Analyse struktureller Eigenschaften von GaN mittels hochaufloesender Roentgenbeugung bei variabler Messtemperatur

    Energy Technology Data Exchange (ETDEWEB)

    Roder, C.

    2007-02-26

    The main topic of this thesis was the study of stress phenomena in GaN layers by application of high-resolution X-ray diffractometry at variable measurement temperature. For this a broad spectrum of different GaN samples was studied, which extended from bulk GaN crystals as well as thick c-plane oriented HVPE-GaN layers on c-plane sapphire over laterlaly overgrown c-plane GaN Layers on Si(111) substrates toon-polar a-plnae GaN layers on r-plane sapphire. The main topic of the measurements was the determination of the lattice parameters. Supplementarily the curvature of the waver as well as the excitonic resosance energies were studied by means of photoluminescence respectively photoreflection spectroscopy. By the measurement of the temperature-dependent lattice parameters of different GaN bulk crystals for the first time a closed set of thermal-expansion coefficients of GaN was determined from 12 to 1205 K with large accuracy. Analoguously the thermal-expansion coefficents of the substrate material sapphire were determinde over a temperature range from 10 to 1166 K.

  15. A contribution for the detection of deep defects in semi-insulating GaAs by means of PICTS; Ein Beitrag zum Nachweis tiefer Stoerstellen in halbisolierendem GaAs mittels PICTS

    Energy Technology Data Exchange (ETDEWEB)

    Zychowitz, G.

    2006-02-03

    The PICTS procedure is one of the most frequently applied methods for the characterization of semi-insulating semiconductors. The methodical progresses in the determination of defect parameters by this proceudure are presented in this thesis. as practicable method for the detection of a temperature-dependent change of the occupation ratio of a trap the normation of the PICTS spectra on the emission rate of the electrons is introduced. It is shown that peaks, in which this normation fails, must not applied for the determination of the defect parameters. The studies prove that for the complete charge-alteration of the defects a suitable excitation intensity must be applied. By PICTS measurements on copper-doped samples a systematic dependence of the peak heights of copper-correlated peaks on the copper content of the samples is detected. By the studies it is proved that copper can be detected by means of PICTS up to a minimal AES copper concentration of [Cu{sub min}]approx5.10{sup 14} cm{sup -3}.

  16. The lie of climate disaster. The most giant swindle of modern times. Manipulated fear as a mean to might. 4. enl. ed.; Die Luege der Klimakatastrophe. Das gigantischste Betrugswerk der Neuzeit. Manipulierte Angst als Mittel zur Macht

    Energy Technology Data Exchange (ETDEWEB)

    Bachmann, Hartmut

    2008-07-01

    Not investigations, if a disaster is ante portas and which consequences may occur, are content of this book. There are many publications written in detail about this themes. However new is, that there is someone who care about, if the results of so-called scientists are really correct. The author discovers due to facts, that the whole construction, which should support climate disaster, is a single cock-and-bull story. Constructed by the most supreme international climatic agencies to federal states of countries. After the discovery of this facts, the author follows the question: CUI BONO? Whom does it serve? So he stumbles on criminal machinations. This book is not only an economy- or polit thriller, as also simultanously a prove for exploitation of people by unscrupulous exploiters and egoists from economy and policy to manipulate and frighten them. (GL) [German] Laut Umfrage sind 70 % aller Deutschen durch systematische Panikmache ueber eine heraufziehende Klimakatastrophe geaengstigt. Wer jedoch erkennt, dass die Basiswerte dieser angeblichen Katastrophe groesstenteils gefaelscht sind, kann seine Aengste abbauen. Dies ist der Sinn dieses Buches. Bachmann entdeckt aufgrund von Fakten, dass die gesamte Konstruktion, welche die Klimakatastrophe stuetzen soll, ein einziges Luegengebaeude ist. Aufgebaut von den obersten internationalen Klimabehoerden bis hinunter zu den Landesregierungen. Nach Dekuvrierung dieser Fakten geht der Autor der Frage nach: CUI BONO? Wem nuetzt dies? Dabei stoesst er auf kriminelle Machenschaften. Dieses Buch ist nicht nur ein Wirtschafts- und Polit-Krimi, sondern gleichzeitig ein Beleg dafuer, wie skrupellose Ausbeuter und Egoisten aus Wirtschaft und Politik Menschen manipulieren und aengstigen, um sie dann auszubeuten. (orig.)

  17. Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT); Zerstoerungsfreie praeklinische Evaluation der Wurzelkanalanatomie menschlicher Zaehne mittels Flaechendetektor-Volumen-CT (FD-VCT)

    Energy Technology Data Exchange (ETDEWEB)

    Heidrich, G.; Hassepass, F.; Dullin, C.; Grabbe, E. [Universitaetsklinikum Goettingen, Abt. Diagnostische Radiologie (Germany); Attin, T.; Hannig, C. [Universitaetsklinikum Goettingen, Abt. fuer Zahnerhaltung, Praeventive Zahnheilkunde und Paradontologie (Germany)

    2005-12-15

    Purpose: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). Materials and methods: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. Results: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as dentricles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 {mu}m. Only around 73% of the main root canals detected with FD-VCT and 87% of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. (orig.)

  18. Analysis of CO{sub 2} separation by means of monoethanolamine wash as an option for reducing the emissions in Germany; Analyse der CO{sub 2}-Abtrennung mittels Monoethanolamin-Waesche als Emissionsminderungsmassnahme in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Nazarko, Jewgeni; Riensche, Ernst; Blum, Ludger; Menzer, Reinhard; Stolten, Detlef [Forschungszentrum Juelich GmbH, Juelich (DE). Inst. fuer Energieforschung - Brennstoffzellen (IEF-3)

    2008-07-01

    In the year 2006, the utilization of fossil fuels in the power economy in Germany results in CO{sub 2} emissions of 366 million tons. This corresponds to 43.4 % of the entire CO{sub 2} emissions in Germany. In order to reduce the emissions of carbon dioxide at fossil-fuelled power stations significantly, short term retrofits of the plants are to be considered for the separation and storage of CO{sub 2}. From the perspective of the power production, the downstream absorption of CO{sub 2} with monoethanolamine has several advantages: (a) Successful employment of the amine-wash in other industrial's applications; (b) Conventional operation of the power station qualitatively remains unchanged; (c) The downstream separation is the only option for the separation of CO{sub 2} at existing power stations. However, the separation of carbon dioxide results in further material flows and energy flows by means of the absorption in monoethanolamine. In the contribution under consideration, the authors analyze the effects of the absorption of CO{sub 2} in mono ethanol amine on an individual power station as well as on the emissions of the power economy in Germany.

  19. Radiation protection of radioactively contaminated large areas by phytoremediation and subsequent utilization of the contaminated plant residues (PHYTOREST); Massnahmen zur Strahlenschutzvorsorge radioaktiv belasteter Grossflaechen durch Sanierung mittels Phytoremediation und anschliessende Verwertung der belasteten Pflanzenreststoffe (PHYTOREST)

    Energy Technology Data Exchange (ETDEWEB)

    Mirgorodsky, Daniel; Ollivier, Delphine; Merten, Dirk; Bergmann, Hans; Buechel, Georg [Jena Univ. (Germany). Inst. fuer Geowissenschaften; Willscher, Sabine; Wittig, Juliane; Jablonski, Lukasz; Werner, Peter [Technische Univ. Dresden, Pirna (Germany). Inst. fuer Abfallwirtschaft und Altlasten

    2010-12-15

    Much progress has been achieved over the past 20 years in remediating sites contaminated by heavy metal. However, very large contaminated areas have presented major problems to this day because of remediation costs. Phytoremediation is a new, emerging, sustainable technique of remediating areas with low heavy-metal contamination. One advantage of phytoremediation is the comparatively low cost of the process, which may make it usable also on large areas with low levels of contamination. Besides extracting and immobilizing metals, respectively, phytoremediation among other things also contributes to improving soil quality in terms of physics, chemistry, and ecology. Consequently, phytoremediation offers a great potential for the future. Research into phytoremediation of an area contaminated by heavy metals and radionuclides is carried out on a site in a former uranium mining district in Eastern Thuringia jointly by the Friedrich Schiller University, Jena, and the Technical University of Dresden in a project funded by the German Federal Ministry for Education and Research. The project serves to promote the introduction of soft, biocompatible methods of long-term remediation and to develop conceptual solutions to the subsequent utilization of contaminated plant residues. Optimizing area management is in the focus of phytoremediation studies. (orig.)

  20. Biological activity and toxicitiy of imported and synthetic metal ...

    African Journals Online (AJOL)

    ... of green alga Scendesmus obliquus. The toxicity of surfactants to Scendesmus obliquus are arranged in the order: imported fluid > Synthetic fluid > S+ D > I+A> S+B> I+ C> I+B > I+D > I+D >S+A > I+4. These results prove that, the toxicity of fluids depends on its chemical structure. Egyptian Journal of Biotechnology Vol.

  1. Tux fährt Bahn

    OpenAIRE

    Sontag, Ralph

    2007-01-01

    Modelleisenbahnen können Kinderspielzeug oder anspruchsvolles Hobby sein. Heute fahren viele Bahnen digital und werden mittels Digital Command Control (DCC) gesteuert. Im Vortrag sollen die Grundlagen des Protokolls erläutert und die Grundfunktionen mittels des Decoder Programmers SPROG II unter Linux ausprobiert werden.

  2. "The hidden dimension": Kulturdimensionen als Orientierung in der interkulturellen Zusammenarbeit

    OpenAIRE

    Nagy, Carolin

    2003-01-01

    Kulturdimensionen sind seit den Untersuchungen von Hall, Brislin, Hofstede und Trompenaars/ Hampden-Turner ein gängiges Mittel, vor allem in Trainings, zur Beschreibung interkultureller Kommunikationsschwierigkeiten, Missverständnisse und kultureller Differenzen überhaupt.Ob sie jedoch auch ein nützliches und taugliches Mittel dafür sind ist sehr umstritten.

  3. Dynamics of photosynthetic activity of cyanobacteria after gut ...

    African Journals Online (AJOL)

    African Journal of Biotechnology ... carp and goldfish, whereas there was a significant stimulation of photosynthetic activity of diatom and green algae following the depressed cyanobacteria during cultivation. The mainly stimulated eukaryotic algae species were Fragilariaceae and Scenedesmus obliquus by microscopy.

  4. Quantum chemistry based quantitative structure-activity relationships for modeling the (sub)acute toxicity of substituted mononitrobenzenes in aquatic systems

    NARCIS (Netherlands)

    Zvinavashe, E.; Murk, A.J.; Vervoort, J.; Soffers, A.E.M.F.; Freidig, A.; Rietjens, I.M.C.M.

    2006-01-01

    Fifteen experimental literature data sets on the acute toxicity of substituted nitrobenzenes to algae (Scenedesmus obliquus, Chlorella pyrenoidosa, C. vulgaris), daphnids (Daphnia magna, D. carinata), fish (Cyprinus carpio, Poecilia reticulata), protozoa (Tetrahymena pyriformis), bacteria

  5. Waste Utilization and Biodiesel Production by the Green Microalga Scenedesmus obliquus▿

    Science.gov (United States)

    Mandal, Shovon; Mallick, Nirupama

    2011-01-01

    Scenedesmus obliquus was cultivated in three types of waste discharges to couple waste treatment with biodiesel production. The lipid pool accumulation was boosted to 1.0 g liter−1 against 0.1 g liter−1 for the control. The waste-grown S. obliquus showed an increase in the content of the saturated fatty acid pool, which is desirable for good-quality biodiesel. PMID:21057012

  6. A new species and new records of Cryptodacus (Diptera: Tephritidae) from Colombia, Bolivia and Peru.

    Science.gov (United States)

    Rodriguez, Pedro Alexander; Rodriguez, Erick J; Norrbom, Allen L; Arévalo, Emilio

    2016-05-16

    Cryptodacus bernardoi Rodriguez & Rodriguez, new species, is described from Colombia. It was reared from fruits of Phoradendron sp. near piperoides (Kunth) Trel. New distribution records are reported for Cryptodacus ornatus Norrbom from Colombia and Peru, for Cryptodacus trinotatus Norrbom & Korytkowski from Colombia, and for Cryptodacus obliquus Hendel from Bolivia and Peru. The female abdomen and terminalia of C. obliquus is described for the first time. The Norrbom & Korytkowski (2008)`s key to species was modified to include C. bernardoi n. sp.

  7. Morphologische Qualitätsmerkmale der Mäuseeizelle und deren Zusammenhang mit einer Fehlverteilung des Chromosoms 16

    OpenAIRE

    Rogge, Sabine

    2009-01-01

    Eizellen der Maus wurden nach lichtmikroskopischen Kriterien bewertet. Mittels Fluoreszenz- in- situ- Hybridisierung wurden zudem meiotische Fehlverteilungen des Chromosom 16 der Maus 16 dargestellt. Die Korrelation zwischen morphologischen Kriterien und chromosomaler Fehlverteilung wurde untersucht.

  8. Die Bibliothek des Bezirksmuseums Josefstadt

    Directory of Open Access Journals (Sweden)

    Maria Ettl

    2015-01-01

    Josefstadt in Wien werden die Herkunft der Bibliotheksbestände und die beengte Raumsituation beschrieben. Abschließend wird auf die Erfassung der Medien mittels der Bibliothekssoftware „Biblioweb“ eingegangen.

  9. Die transkranielle Doppler-Sonographie zur Identifikation von Rechts-Links-Shunts

    OpenAIRE

    Jekentaite, R. (Ruta)

    2003-01-01

    Paradoxe Embolien über einen Rechts-Links-Shunt (RLS) stellen eine Ursache von Hirninfarkten dar. Diese Shunts werden mittels TEE oder TCD diagnostiziert. Ziele dieser Studie waren die Bestimmung des optimalen Timings des Valsalva-Manövers (VM) sowie Vergleich der zwei Kontrastmittel Echovist®-300 und Echovist®-200. 64 Patienten wurden mittels beider Methoden untersucht. Nach der KM-Injektion wurden die Mikroemboliesignale (MES) in der ACM bilateral dopplersonographisch registriert. Die Unt...

  10. Molekulargenetische Studie zur Verbreitung und Interaktion von PCV-2 bei Haus- und Wildschweinen

    OpenAIRE

    Bronnert, Bastian Balthasar Marcel

    2014-01-01

    Im Rahmen der vorliegenden Arbeit wurden Wild- und Hausschweingewebeproben aus den Jahren 2005 bis 2008 mittels nested PCR auf das Vorkommen von PCV-2 untersucht und die positiv getesteten Proben mittels Realtime PCR quantifiziert. Zusätzlich wurden die Proben im Institut für Pathologie der Justus-Liebig-Universität histologisch und immunhistologisch untersucht (Dissertation Hohloch). Ziel war es das Vorkommen von PCV-2 und die Häufigkeit von PCV-2 assoziierter Erkankungen bei Haus- und Wilds...

  11. Study of electronic excitation and diffraction effects as well as growth, structure, and magnetic properties of ultrathin 3d metal films on Cu(001) by means of grazing-incidence ion scattering; Untersuchung elektronischer Anregungs- und Beugungseffekte sowie Wachstum, Struktur und magnetischer Eigenschaften ultraduenner 3d-Metallfilme auf Cu(001) mittels streifender Ionenstreuung

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, T.

    2006-11-23

    H{sup +} and He{sup +} ions with an energy of 25 keV are scattered under a grazing angle of incidence from a clean and flat Cu(001) surface. For specific azimuthal orientations of the crystal surface with respect to low index directions in the surface plane we observe the ion induced emission of electrons with a conventional LEED (low energy electron diffraction) setup. By operating the instrument in an energy dispersive mode we find intensity distributions of emitted electrons which can unequivocally be ascribed to diffraction effects at the target surface. From this ion induced LEED-reflexes (IILEED) we get important information about the electron excitation- and emission effects during the scattering process. In the second part of this work we investigate the correlation between thin-film growth (Co,Fe,Mn on Cu(001)) and electron emission in the regime of grazing ion scattering. The ''rough'' surface of uncompleted layers increase the probability of binary collisions of incident ions with individual atoms at the surface. The energy spectras and the number distribution of emitted electrons are substantially influenced by these ''violent'' collisions and allow us to monitor growth of thin films via simple measurements of target current or from energy spectra of emitted electrons. The method provides excellent signals and is also applicable in the regime of poor layer growth. By making use of ion beam triangulation (IBT), direct information on the atomic structure of thin films and substrate surfaces is obtained. We discuss in the third part of this work a new variant of this method based on the detection of the number of emitted electrons. The data are analyzed via computer simulations using classical mechanics which provides a quantitative analysis with respect to projectile trajectories. This new detection scheme allows the determination of the in-plane structure of reconstructed thin films and surfaces with high precision. The impressed potential of this method is demonstrated by quantitative analysis of the structural phases of Fe and Mn on Cu(001). (orig.)

  12. Study on the uptake and distribution of gadolinium based contrast agents in biological samples using laser ablation with inductively coupled plasma mass spectroscopy; Untersuchungen zur Aufnahme und Verteilung von gadoliniumbasierten Kontrastmitteln in biologischen Proben mittels Laserablation mit induktiv gekoppelter Plasma-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Lingott, Jana

    2016-01-05

    Gadolinium based contrast agents are used for magnetic resonance imaging. After their excretion by medicated patients they reach surface water passing waste water treatment plants where they are not removed sufficiently. The behavior of the contrast agents in the environment and the interaction with organisms was investigated in this work due to the toxicity of the free Gd{sup 3+} ion and the associated risks, such as accumulation in the human food chain. In this work, the two elemental analytical imaging methods laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SRXRF) have been used to investigate the uptake, distribution, and excretion of Gd-based contrast agents by various biological systems. Both methods were analytically characterized and compared for this application. The detection limits of gadolinium were determined under optimized conditions by LA-ICP-MS and SRXRF. With calibration by remains of dried elemental standard droplets detection limits of 0.78 pg absolute amount of gadolinium (LA-ICP-MS), respectively 89 pg (SRXRF) were reached. Based on filamentous algae as water plants the uptake and the excretion of Gd-based contrast agents were revealed. The dependence on concentration of the contrast agent in the exposition solution and the independence of temporal uptake within one to seven days were studied for duckweed. By LA-ICP-MS gadolinium was quantified in a leaf of cress plant. The verification of the results was performed by SRXRF and ICP-MS after digestion. Furthermore, the uptake and distribution of Gd-based contrast agents in higher organisms (water flea) were observed. The exact location of gadolinium was resolved by three-dimensional μ-computed tomography by the comparison of an exposed with a Gd-free water flea. In all studies, gadolinium was detected in the investigated exposed model organisms. It can be concluded that the contrast agents were taken from the environment.

  13. Volume-artifact reduction modality by helical CT of the anterior, middle and posterior carnial fossae. Comparison with conventional CT; Volumen-Artefakt-Reduktionstechnik mittels Spiral-CT in der vorderen, mittleren und hinteren Schaedelgrube. Vergleich mit der konventionellen kranialen CT

    Energy Technology Data Exchange (ETDEWEB)

    Dorenbeck, U.; Finkenzeller, T.; Hill, K.; Feuerbach, S.; Link, J. [Regensburg Univ. (Germany). Inst. fuer Roentgendiagnostik

    2000-04-01

    Purpose: The object of this study was to determine the extent to which a new volume-artifact reduction (VAR) modality using helical CT was able to reduce artifacts in the anterior, middle and posterior fossae in comparison with conventional CT (sequential mode). Methods: In a prospective, randomized trial, 50 patients underwent helical CT (VAR) and 50 underwent sequential CT. The results were evaluated by three radiologists; influences on image quality where scaled between 1 (no artifact) and 4 (not assessable). Eight regions of the anterior, middle and posterior fossae were evaluated. Results: On average, artifacts were scaled at 2.5 in helical CT (VAR) and 3.1 in conventional CT. Significant differences were seen at the eyeball, anterior to the petrosol bone, at the internal occipital crest, and at the level of the transverse sinus (p<0.005). Conclusions: Helical CT with the VAR modality is superior to conventional, sequential CT in the area of the anterior, middle and posterior fossae. (orig.) [German] Ziel: Das Ziel dieser Studie war herauszufinden, inwieweit ein neuer Volumen-Artefakt-Reduktionsmodus (VAR) im Spiral-CT in der vorderen, mittleren und hinteren Schaedelgrube gegenueber der Einzelschicht-CT zu einer Artefaktverringerung beitragen kann. Methoden: In einer prospektiven randomisierten Studie wurden 50 Untersuchungen mit Spiral-CT und 50 mit Einzelschicht-CT bezueglich Artefakten verglichen. Die Auswertung erfolgte durch drei Radiologen, die Bildqualitaet wurde in einer Skala zwischen 1 (kein Artefakt) und 4 (Beurteilung der Region wegen Artefakten nicht moeglich) angegeben. Acht anatomische Regionen in der vorderen, mittleren und hinteren Schaedelgrube wurden auf Beeintraechtigung durch Artefakte untersucht. Ergebnisse: Im Durchschnitt betrug die Bewertung fuer die Artefaktbeeintraechtigung beim Spiral-CT (VAR) 2,5 gegenueber 3,1 bei der Einzelschicht-CT. Der VAR-Modus ermoeglichte in der mittleren und hinteren Schaedelgrube sowie im Balbus oculi eine Reduktion der Aufhaertungsartefakte (p<0,005). Die Variabilitaet innerhalb der Auswerter (Rangkorrelationskoeffizient nach Spearman) lag bei 0,781 (p<0,01). Schlussfolgerung: Die Spiral-CT des Schaedels erwies sich bei Volumen-Artefakt-Reduktionstechnik der Einzelschicht-CT ueberlegen: Eine signifikante Artefaktreduktion wurde in der mittleren und hinteren Schaedelgrube ermoeglicht. (orig.)

  14. Treatment of the femoropopliteal arteries with a novel rotational atherectomy system: early single-center experience with the Pathway PV trademark Atherectomy System; Behandlung von Laesionen der femoropoplitealen Arterien mittels eines neuartigen Rotationsatherektomiesystems: Erste single-center Erfahrungen mit dem Pathway PV trademark Atherectomy System

    Energy Technology Data Exchange (ETDEWEB)

    Wissgott, C.; Kamusella, P.; Richter, A.; Steinkamp, H.J. [Radiologie, DRK-Kliniken Berlin (Germany); Schink, T. [Institut fuer Biometrie, Charite Berlin (Germany); Klein-Weigel, P. [Angiologie, DRK-Kliniken Berlin (Germany)

    2008-09-15

    Purpose: The main problem when treating the superficial femoral and popliteal artery with PTA or stent implantation is the relatively high restenosis rate. Several ablative systems are available as an alternative. The purpose of this prospective study was to evaluate the safety and performance of a novel rotational and aspirating atherectomy system. Materials and Methods: From June to December 2006, we treated 23 patients, median age 70.3 years (58 - 91), with the rotational atherectomy system. All patients had de-novo lesions of the SFA or PA with a minimum stenosis of 70%. According to the Rutherford classification, 39% of the patients were in category 2 and 61% in category 3. The median lesion length was 26.3 mm (5 - 100 mm). 26% of the patients had occlusions. Results: The technical success rate was 100%. In 14 cases (61%) additional balloon dilatation was applied, in two cases stent implantation were performed. The median treatment duration with the device was 187.7 {+-} 106.1 s (59 - 391 s). The aspirated volume was 116.5 {+-} 72.0 ml. The ankle brachial index improved from preinterventional 0.60 {+-} 0.16 to postinterventional 0.85 {+-} 0.13 and after 6 month 0.80 {+-} 0.13. During follow-up, two (8%) restenosis occurred. There were two complications, one dissection and one distal embolization. Follow-up could not be performed for two patients (8%). Conclusion: Atherectomy of femoropopliteal lesions with the Pathway PV trademark Atherectomy System is very safe and effective. The low restenosis rate of 8% is promising, but there is still a lack of long-term results.

  15. [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine receptors using single photon emission computer tomography; [{sup 123}I]-3-Iodcytisin als moeglicher Radiotracer fuer die Darstellung der nikotinergen Acetylcholin Rezeptoren mittels Single-Photon-Emissions-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, Dagmar Julia

    2015-03-06

    For the synthesis of [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine (nACh) receptors using SPECT two different technologies were used: the radio-iodination with iodogen and the radio-iodination with nitric acid. The latter one showed higher efficiency. The radiotracer will allow to detect degenerative processes and other nACh-depending diseases in the brain (Alzheimer, Parkinson) and to observe the progress. The autoradiography is aimed to the imaging of the nACh receptors in the brain bypassing the brain-blood barrier. The highest activity was measured in the thalamus of mice and rat brains.

  16. On the synthesis of radiofluorinated amino acids by isotope exchange based on the example of 6-[{sup 18}F]Fluor-L-DOPA; Zur Synthese radiofluorierter aromatischer Aminosaeuren mittels Isotopenaustausch am Beispiel von 6-[{sup 18}F]Fluor-L-DOPA

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, F M

    2008-06-15

    In nuclear medical diagnosis, 6-[{sup 18}F]fluoro-L-3,4-dihydroxyphenylalanine (6-[{sup 18}F]fluoro-LDOPA), an analogue of L-DOPA, is one of the few established radiopharmaceuticals used for the in vivo investigation of the presynaptic dopaminergic metabolism and of some kind of tumours via Positron Emission Tomography (PET). The presently used method of preparation of the radiotracer by electrophilic labelling is limited to low amounts of activity at high costs. Known nucleophilic syntheses, however, result either in insufficient enantiomeric purity or the known multi-step syntheses are hard to automate, due to their complexity. During this work a novel, easy to automate alternative for the preparation of 6-[{sup 18}F]fluoro-L-DOPA, was developed and evaluated, using a direct nucleophilic {sup 18}F-fluorination of a protected amino acid derivative. The resulting product has a very high enantiomeric purity. At first, the general suitability of the (S)-BOC-BMI-derivatives for the synthesis of {sup 18}F-labelled amino acids, used in this work, was investigated using a less complex precursor, which resulted in the amino acid 6-[{sup 18}F]fluoro-L-m-tyrosin via acidic hydrolysis. The preparation of a useful precursor for the nucleophilic {sup 18}F-isotope substitution, namely the (2S,5S)-tert.-butyl- 5-(2-fluoro-5-formylbenzyl)-2-tert.-butyl-3-methyl-4-oxoimidazolidine-1-carboxylate, was investigated in three general different ways. At first it was tried to obtain this product via formylation after coupling with the BOC-BMI, secondly via {alpha},{beta}-dehydro amino acid derivatives and finally via a systematic multi-step synthesis. Only the last mentioned way resulted in a precursor with sufficient purity that could be labelled. The radiochemical yield of the isotopic exchange was about 60 %. In the next step, the presented concept was modified to synthesize a precursor for the preparation of 6-[{sup 18}F]fluoro-L-DOPA. Only a combination of the protecting groups benzyl and THP resulted in the useful precursor (2S,5S)-tert.-butyl-5-(4-benzyloxy-2-fluoro-5- formylbenzyl)-2-tert.-butyl-3-methyl-4-oxoimidazolidine-1-carboxylate. By optimisation of the isotopic exchange with [{sup 18}F]fluoride on this precursor a radiochemical yield of about 50 % was achieved. After a three step synthesis including the labelling, a Baeyer-Villiger-oxidation using mCPBA and a hydrolysis using HBr, c.a. 6-[{sup 18}F]fluoro-L-DOPA was isolated containing more than 99 % of the desired L-isomer. The complete preparation and isolation of c.a. 6-[{sup 18}F]fluoro-L-DOPA, using optimised conditions, resulted in a decay corrected yield of about 22 % after a synthesis time of 105 minutes. Thus the presented synthesis of 6-[{sup 18}F]fluoro-L-DOPA is not only more efficient than the known methods of preparation, but is furthermore fully automatable. (orig.)

  17. Accuracy of spiral CT and 3D reconstruction in the detection of acute pulmonary embolism - development of an animal model using porcine lungs and technical specimens. Development of an animal model using porcine lungs and technical specimens; Diagnostik der akuten Lungenembolie mittels Spiral-CT und 3D-Rekonstruktion. Entwicklung eines Tiermodells und technischer Probekoerper im Ex-vivo-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ries, B.G. [Klinik und Poliklinik fuer Radiologie, Univ. Mainz (Germany); Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany); Kauczor, H.U.; Thelen, M. [Klinik und Poliklinik fuer Radiologie, Univ. Mainz (Germany); Konerding, M.A. [Anatomisches Inst., Mainz Univ (Germany)

    2001-02-01

    Purpose: To develop a model for simulation the CT morphologic situation of acute pulmonary embolism, to evaluate the accuracy of spiral CT and 3D reconstruction in the detection of artificial emboli and to investigate the influence of the orientation of emboli depending on z-axis orientation. Materials and Methods: Standardized artificial emboli made of wax and of defined size and shape were positioned into the pulmonary arteries of porcine lungs. Castings of the embolized pulmonary arterial trees were made by injection of a special opaque resin. After performance of spiral CT the data sets of the emboli and the pulmonary arteries were post-processed. The 3D segmentations were compared with the anatomic preparation to evaluate the accuracy of spiral CT/3D reconstruction-technique. Technical specimens simulating CT-morphology of acute embolized vessels underwent spiral CT in six different positions with respect to the z-axis. The CT data were reconstructed using a standardized and a contrastadapted method with interactive correction. The 3D emboli were analysed under qualitative aspects, and measurements of their extent were done. Results: In nearly 91%, there was complete agreement between CT and the corresponding findings at the anatomical preparation. Measurements of the 3D reconstructed technical specimens showed discrepancies of shape and size in dependence of the size of the original preparation, orientation and reconstruction technique. Overestimation up to 4 mm and underestimation to 2,2 mm were observed. Measurements of preparations with heights from 14 to 26 mm showed variances of {+-}1,5 mm ({proportional_to}6-11%). Conclusion: The presented models are suitable to simulate CT morphology of acute pulmonary embolism under ex-vivo conditions. Accuracy in the detection of artificial emboli using spiral CT/3D reconstruction is affected by localization, size and orientation of the emboli and the reconstruction technique. (orig.) [German] Ziel: Die Entwicklung von Modellen zur Evaluierung der Spiral-CT und 3D-Rekonstruktion im Nachweis der akuten Lungenembolie (LE) im Ex-vivo-Experiment. Material und Methoden: Standardisierte kuenstliche Emboli definierter Groesse und Geometrie wurden in Schweinelungen eingebracht. Ausguesse der embolisierten Gefaessbaeume mit roentgenkontrastgebendem Kunstharz simulierten das CT-morphologische Vollbild einer Lungenembolie. Die Bilddaten wurden dreidimensional rekonstruiert und die Exaktheit der detektierten Emboluslokalisation durch Korrelation mit dem Originalpraeparat verifiziert. Messungen an technischen Probekoerpern mit eingeschlossenen Emboli definierter Groesse sollten die Messgenauigkeit der kombinierten Spiral-CT-/3D Rekonstruktion in Abhaengigkeit von deren Orientierung zur z-Achse und von der Rekonstruktionstechnik (standardisiert und kontrastadaptiert) aufzeigen. Ergebnisse: Fuer die Detektion und Lokalisation ergab sich eine Uebereinstimmung zwischen Spiral-CT-/3D-Rekonstruktion und dem Originalpraeparat von {proportional_to}91%. Die Messungen der technischen Probekoerper ergaben deutliche Abweichungen in Abhaengigkeit von der Groesse, der Orientierung zur z-Achse und der Rekonstruktionstechnik. Hierbei traten Ueberschaetzungen von bis zu 4 mm, Unterschaetzungen von bis zu 2,2 mm auf. Bei Praeparaten mit Hoehen von 14-26 mm traten Schwankungen in einer Groessenordnung von ca. {+-}1,5 mm ({proportional_to}6-11%) auf. Schlussfolgerung: Die vorgestellten Ex-vivo-Modelle sind zur Simulation der akuten Lungenembolie gut geeignet. Die Genauigkeit der Embolusdetektion wird durch Lokalisation, Groesse, Orientierung und Rekonstruktionstechnik beeinflusst. (orig.)

  18. Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering; Die computerassistierte Operationsplanung in der Abdominalchirurgie des Kindes. 3D-Visualisierung mittels ''volume rendering'' in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, P.; Holland-Cunz, S.; Waag, K.L. [Universitaetsklinikum Heidelberg (Germany). Kinderchirurgie; Troeger, J. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Schenk, J.P. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Universitaetsklinikum, Paediatrische Radiologie, Heidelberg (Germany)

    2006-08-15

    Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this. A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning. (orig.) [German] Komplexe Operationen bei ausgepraegten pathologischen Veraenderungen anatomischer Strukturen des kindlichen Abdomens benoetigen eine exakte Operationsvorbereitung. 3D-Visualisierung und computerassistierte Operationsplanung anhand von CT-Daten finden fuer schwierige chirurgische Eingriffe bei Erwachsenen in zunehmendem Masse Anwendung. Aus strahlenhygienischen Gruenden und bei besserer Weichteildifferenzierung ist jedoch neben der Sonographie die Magnetresonanztomographie (MRT) bei Kindern das Diagnostikum der Wahl. Die 3D-Visualisierung dieser MRT-Daten ist dabei jedoch aufgrund vielfaeltiger Schwierigkeiten bisher nicht durchgefuehrt worden, obwohl sich das Gebiet embryonaler Fehlbildungen und Tumoren geradezu anbietet. Vorgestellt wird eine weiterentwickelte und an die Fragestellungen der abdominellen Kinderchirurgie angepasste, sehr leistungsstarke raycastingbasierte 3D-volume-rendering-Software (VG Studio Max 1.2). Mit speziell entwickelten Bearbeitungsalgorithmen wird beispielhaft ein ausgereiftes Operationsplanungssystem demonstriert. Durch Praktikabilitaet und hohe Visualisierungsqualitaet mit ausgesprochenem Informationsgewinn hat das vorgestellte Operationsplanungssystem einen festen Stellenwert im klinischen Alltag erlangt. (orig.)

  19. Studies of volatile secondary molasses constituents with inhibitory effect on yeast fermentation. Pt. 1. Determination of molasses and yeast components by GC and HPLC; Untersuchungen ueber fluechtige Nebenbestandteile der Melasse mit inhibitorischer Wirkung auf die Hefegaerung. T. 1. Bestimmung von Melasse- und Hefeinhaltsstoffen mittels GC und HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Fattohi, N.

    1994-07-20

    Beet molasses, the principal raw material of molasses distilleries and yeast factories, have in recent times with increasing frequency shown negative effects on the fermentation and quality of baking yeast. Based on the fact that with many ``problem molasses`` the inhibitory effect on fermentation can be substantially reduced and often even totally eliminated by prior aeration of the hot acidic molasses solution, the chemical-analytical and biological investigations presented here focused on the components of such problem molasses volatilizable in water vapour. The water vapour distillates contain, in particular, low carbon acids (C1-C10), and alkanols (C6-C7), the minimum inhibitory concentrations (m.i.c.) of which for yeast fermentation were established. This showed very high m.i.c. levels for an inhibitory effect on fermentation, which in practice are not reached by the individual carbon acid and alkanol constituents of the problem molasses. However, these acids and alcohols exhibit marked synergic effects which were confirmed by determining the m.i.c. values of mixtures. The inhibitory effect on yeast fermentation is due above all to the presence in problem molasses of butyric acid + caprilic acid + hexanol and heptanol. (orig.) [Deutsch] Ruebenmelasse, der Hauptrohstoff fuer die Melassebrennereien und Hefefabriken, zeigt in letzter Zeit immer haeufiger nachteilige Wirkungen bei der Vergaerung sowie der Qualitaet des Produkts Backhefe. Aufgrund der Tatsache, dass sich bei vielen ``Problemmelassen`` der Gaerhemmeffekt durch vorangehende Belueftung der heiss-sauren Melasseloesung deutlich vermindern, haeufig sogar gaenzlich eliminieren laesst, wurde der Schwerpunkt der vorliegenden chemisch-analytischen und biologischen Untersuchungen auf die wasserdampffluechtigen Komponenten solcher Problemmelassen gelegt. Die Wasserdampfdestillate enthalten insbesondere niedere Carbonsaeuren (C1-C10) und Alkanole (C6-C7). Ihre minimalen Hemmkonzentrationen (MHK) bei der Hefegaerung wurden ermittelt. Dabei zeigte sich, dass im Fall der Inhibitorwirkung auf die Gaerung die MHK-Werte sehr hoch liegen; sie werden praktisch von den einzelnen Carbonsaeure- und Alkanolgehalten der Problemmelassen nicht erreicht. Jedoch weisen diese Saeuren und Alkohole deutliche Synergieeffekte auf, was durch Ermittlung der MHK-Werte von Gemischen belegt wurde. Vor allem die Gehalte der Problemmelassen an Buttersaeure + Kaprylsaeure + Hexanol und Heptanol sind fuer die Hemmwirkung bei der Hefegaerung verantwortlich. (orig.)

  20. Superhard carbon film deposition by means of Laser-Arco {sup registered} on the way from the laboratory into the industrial series coating; Abscheidung superharter Kohlenstoffschichten mittels Laser-Arco {sup registered} auf dem Weg vom Labor in die industrielle Serienfertigung

    Energy Technology Data Exchange (ETDEWEB)

    Scheibe, Hans-Joachim; Leonhardt, Michael; Leson, Andreas; Meyer, Carl-Friedrich; Stucky, Thomas; Weihnacht, Volker [Fraunhofer-Institut fuer Werkstoff- und Strahltechnik (IWS), Dresden (Germany)

    2008-12-15

    Diamond-like carbon films (DLC) are more and more applied as wear protection coatings for components and tools due to their unique combination of high hardness, low friction and sticking tendency to metallic counter bodies. Up to now applied DLC films are hydrogen containing (a-C:H) or metal carbon films (Me-C:H) deposited by a plasma assisted CVD process from carbon-hydrogen gas mixtures. Their wide industrial effort results from that the can be deposited with slowly modified coating machines for classical hard coating (e.g. TiN or CrN). A new generation DLC films are the hydrogen-free ta-C films (ta-C = tetrahedral bounded amorphous carbon) with a between two and three-times higher hardness and with a resulting higher wear resistance under extreme condition than classical DLC films. They have excellent emergency running properties at lubrication break down. Their industrial application is more difficult due to that they cannot deposited with modified coating machines for classical hard and DLC coating and a new technology with corresponding equipment was not available up to now. The laser controlled, pulsed arc deposition technology (Laser-Arco {sup registered}) of the Fraunhofer IWS Dresden has this potential. In kind of a Laser-Arc-Module-source the ta-C film deposition can be integrated in every industrial used deposition machine. (orig.)

  1. A comparison of porosity analysis using 2D stereology estimates and 3D serial sectioning for additively manufactured Ti 6Al 2Sn 4Zr 2Mo alloy; Vergleich der Porositaetsanalyse einer Ti 6Al 2Sn 4Zr 2Mo-Legierung aus additiver Fertigung mittels stereologischer Schaetzungen (2D) und mit Serienschnitten (3D)

    Energy Technology Data Exchange (ETDEWEB)

    Ganti, Satya R.; Velez, Michael A.; Geier, Brian A.; Hayes, Brian J.; Turner, Bryan J.; Jenkins, Elizabeth J. [UES Inc., Dayton, OH (United States)

    2017-02-15

    Porosity is a typical defect in additively manufactured (AM) parts. Such defects limit the properties and performance of AM parts, and therefore need to be characterized accurately. Current methods for characterization of defects and microstructure rely on classical stereological methods that extrapolate information from two dimensional images. The automation of serial sectioning provides an opportunity to precisely and accurately quantify porosity in three dimensions in materials. In this work, we analyzed the porosity of an additively manufactured Ti 6Al 2Sn 4Zr 2Mo sample using Robo-Met.3D {sup registered}, an automated serial sectioning system. Image processing for three dimensional reconstruction of the serial-sectioned two dimensional images was performed using open source image analysis software (Fiji/ImageJ, Dream.3D, Paraview). The results from this 3D serial sectioning analysis were then compared to classical 2D stereological methods (Saltykov stereological theory). We found that for this dataset, the classical 2D methods underestimated the porosity size and distributions of the larger pores; a critical attribute to fatigue behavior of the AM part. The results suggest that acquiring experimental data with equipment such as Robo-Met.3D {sup registered} to measure the number and size of particles such as pores in a volume irrespective of knowing their shape is a better choice.

  2. Analysis of acoustic emission signals of fatigue crack growth and corrosion processes. Investigation of the possibilities for continuous condition monitoring of transport containers by acoustic emission testing; Analyse der Schallemissionssignale aus Ermuedungsrisswachstum und Korrosionsprozessen. Untersuchung der Moeglichkeiten fuer die kontinuierliche Zustandsueberwachung von Transportbehaeltern mittels Schallemissionspruefung

    Energy Technology Data Exchange (ETDEWEB)

    Wachsmuth, Janne

    2016-05-01

    Fatigue crack growth and active corrosion processes are the main causes of structural failures of transport products like road tankers, railway tank cars and ships. To prevent those failures, preventive, time-based maintenance is performed. However, preventive inspections are costly and include the risk of not detecting a defect, which could lead to a failure within the next service period. An alternative is the idea of continuous monitoring of the whole structure by means of acoustic emission testing (AT). With AT, defects within the material shall be detected and repaired directly after their appearance. Acoustic emission testing is an online non-destructive testing method. Acoustic emission (AE) arises from changes within the material and is transported by elastic waves through the material. If the AE event generates enough energy, the elastic wave propagates to the boundaries of the component, produces a displacement in the picometre scale and can be detected by a piezoelectric sensor. The sensor produces an electrical signal. From this AE signal, AE features such as the maximum amplitude or the frequency can be extracted. Methods of signal analysis are used to investigate the time and frequency dependency of signal groups. The purpose of the signal analysis is to connect the AE signal with the originating AE source. If predefined damage mechanisms are identified, referencing the damage condition of the structure is possible. Acoustic emission from events of the actual crack propagation process can for example lead to the crack growth rate or the stress intensity factor, both specific values from fracture mechanics. A new development in the domain of acoustic emission testing is the pattern recognition of AE signals. Specific features are extracted from the AE signals to assign them to their damage mechanisms. In this thesis the AE signals from the damage mechanisms corrosion and fatigue crack growth are compared and analysed. The damage mechanisms were generated application oriented, on plates within the heat affected zone of a weld. Their AE signals were recorded with resonant sensors. On the one hand resonant sensors are very sensitive and able to detect small displacements on huge structures, which makes them applicable for condition monitoring. On the other hand, resonant sensors have a great influence on the AE signals and hinder signal analyses and pattern recognition. Pure fatigue crack growth, fatigue crack growth in a corrosive environment and pure corrosion were applied. Signal groups of the damage mechanisms were compared by their AE features. Differences between signal groups could be made after wave mode analysis, despite the spectral influence of the AE sensors. The damage condition of the test plates is investigated with the combination of AE features of the signal groups and fracture mechanic parameters. Furthermore, two methods of unsupervised pattern recognition of the AE signals are being performed: A commercial classification system, where mainly frequency based features are generated, and an AE feature based method. In the latter, classification takes place after the frequency distributions of the AE features of the signals from the examined damage mechanisms. Both methods result in an accurate classification for the AE signals, especially originating from corrosion damage mechanisms, in the correct damage class. Concluding, the detectability of AE events, the results of pattern recognition of AE signals in metal structures and the prospects and risks of condition monitoring by means of acoustic emission testing are discussed. Therefore, monitoring tests on a tank car and results from cyclic and static loading are consulted. An assessment for the selection of the monitoring method according to the cost effectiveness of dangerous goods transportation is made.

  3. Cytokinin concentrations in the foliage of spruce trees (Picea abies (L. ) Karst. ) affected to different degrees by 'recently discovered forms of forest disease' as determined in immunoenzymatic assays (ELISA). Der Cytokiningehalt in Nadeln unterschiedlich stark von 'neuartigen Waldschaeden' betroffenen Fichten (Picea abies (L. ) Karst. ), bestimmt mittels einer immunoenzymatischen Methode - ELISA

    Energy Technology Data Exchange (ETDEWEB)

    Schwartzenberg, K von

    1989-09-25

    This report attempts to find an answer to the question as to whether the cytokinin concentrations in the leaves of spruce trees showing discolouration or loss of foliage would be any different from those determined for trees, in which no such changes have occurred. Described is a specific analytical method developed for quantitative determinations of the cytokinins trans-zeatin (t-Z), trans-zeatin riboside (t-ZR), isopentenyladenine (ZiP) and isopentenyladenosine (ZiPA). In all, it was found that the levels determined for cytokinin ribosides in needles of the older age groups tested were quite consistent with the degree of discolouration and general damage observed in those trees. Fumigation experiments were additionally performed to find out which effect 8-11 weeks of exposure to an air pollutant, ozone, would have on young spruces. Initial measurements carried out in exposed and non-exposed plants do not yet permit any predictions to be made about the probable influence of ozone on the cytokinin concentrations of foliage. (KST).

  4. Technical note: subclavian artery misplacement of a 12F Shaldon catheter: percutaneous repair with a local closure device under temporary balloon tamponade; Technische Mitteilung: Entfernung eines fehlplatzierten 12F Shaldon Katheters aus der A. subclavia und Abdichtung mittels Verschlusssystem bei temporaerer Ballonblockade

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, J.E.; Katoh, M.; Guenther, R.W. [Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany); Fussen, R. [Anaesthesiologische Klinik, Medizinisches Zentrum Kreis Aachen GmbH (Germany)

    2006-06-15

    A case of subsequent percutaneous repair using a local closure device with a collagen block (VasoSeal {sup registered}) and temporary balloon tamponade after inadvertent subclavian artery misplacement of a 12F Shaldon catheter is reported. Balloon occlusion safely prevented displacement of collagen into the vascular lumen by occluding the 12F entry site. Furthermore, collagen-induced coagulation was facilitated. (orig.)

  5. Novel lanthanide doped micro- and mesoporous solids. Characterization of ion-host-interactions, species distribution and luminescence properties using time-resolved luminescence spectroscopy; Neuartige Lanthanoid-dotierte mikro- und mesoporoese Feststoffe. Charakterisierung von Ion-Wirt-Wechselwirkungen, Speziesverteilung und Lumineszenzeigenschaften mittels zeitaufgeloester Lumineszenzspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Gessner, Andre

    2010-12-15

    In this work lanthanide-doped microporous zeolites, microporous-mesoporous hybrid materials and mesoporous silicates were investigated regarding their luminescence properties and the ion-host-interactions using time-resolved luminescence spectroscopy. Thereby, time-resolved emission spectra (TRES) provide information in the wavelength and time domain. For the analysis of the TRES a broad set of analytic methods was applied and thus a corresponding ''toolbox'' developed. Fitting of the luminescence decays was performed with a discrete number of exponentials and supported by luminescence decay times distributions. Time-resolved area normalized emission spectra (TRANES), an advancement of TRES, could be used for the determination of the number of emissive lanthanide species in porous materials for the first time. Calculation of the decay-associated spectra (DAS) allowed the correlation of spectral information with luminescence decay times and thus delivered the luminescence spectra of the different europium species. For europium(III) we could use in addition the time-dependent asymmetry ratio and spectral evolution of the {sup 5}D{sub 0}-{sup 7}F{sub 0}-transition with time to obtain further information about the distribution of the lanthanide ions in the host material. Luminescence decay times and spectra allowed conclusions on the number of OH-oscillators in and the symmetry of the first coordination sphere. For the microporous and microporous-mesoporous materials were found different lanthanide species, which were characterized by the above mentioned methods. These lanthanide species can be found on different positions in the host material. One position is located deep in the pore system. Here, lanthanide ions are hardly accessible for water and mainly coordinated by framework oxygens. This results in long luminescence decay times and distorted coordination spheres. The second position can be found near or on the outer surface or in the mesopores. Lanthanide ions located here, are easily accessible for water and thus show shorter luminescence decay times and a more symmetrical coordination sphere, which is mostly made up by water molecules. Another investigated aspect was the influence of surface modifications on the luminescence behavior of the lanthanide ions inside the material. Here we could show, that surface modifications hydrophobize the material and thus are able to protect the lanthanide ions from water, which is important for the conservation of the luminescence properties. Concerning the mesoporous silicates, again a heterogeneous distribution of the lanthanide ions in the pore system was found. A part of the lanthanide ions interacts with the pore wall, while the other part is located in the aqueous phase inside the pores. Surface modification led to a interaction of the lanthanide ions with the modification. This was reflected in the luminescence properties depending on the structure of the modification and the surface loading.

  6. Structural investigation of the amorphous/crystalline interface by means of quantitative high-resolution transmission electron microscopy on the systems a-Si/c-Si and a-Ge/c-Si; Strukturelle Untersuchung der amorph/kristallinen Grenzflaeche mittels quantitativer hochaufloesender Transmissionselektronenmikroskopie an den Systemen a-Si/c-Si und a-Ge/c-Si

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, K.

    2006-11-02

    In this Thesis the interfaces between covalently bonded crystalline and amorphous materials were studied with regard to the induced ordering in the amorphous material in the interfacial region by means of high-resolution transmission electron microscopy (HREM). The interface between amorphous germanium and crystalline silicon and the interface between amorphous and crystalline silicon served as material system. In order to quantify the influence of the crystalline order on the amorphous material, the HREM images were periodically averaged along the interface. The intensity components, which are correlated with the period of the lattice image, could thus be separated from the statistical intensity fluctuations, which are characteristic for images of amorphous materials. Since amorphous materials can only be described meaningful by statistical distribution functions, for the induced order a three-dimensional distribution function {rho}{sub 3D}(r) was taken as a basis, which describes the probability to find an atom in the amorphous material, if r=0 is the position of an atom in the crystal. Its two-dimensional projection, {rho}, can be determined using iterative image matching techniques on averaged experimental and simulated interface images. For the analyzed material systems {rho} exhibits lateral ordering as well as a pronounced layering in the vicinity of the interface. In the case of the a-Si/c-Si sample the mean orientation of bonds was 70.5 , as is in the case of the undistorted diamond lattice, while for the a-Ge/c-Si sample 65 resulted. The standard deviation for the distribution of the deviations from the mean bond angle yields for the a-Ge/c-Si sample in the first atomic layer a value of 11.3 and for the a-Si/c-Si sample 1.9 . These results suggest the conclusion, that the differences in these values are to be interpreted as the reaction of the amorphous material to the volume misfit. Although for both material systems 1.4 nm was calculated for the width of the transition region, it could be shown, that there is a qualitative difference in the localization of the atom distribution in the first three atomic layers. In addition, the lateral structural differences along the interface were analyzed for the a-Ge/c-Si sample and a method presented, which makes it possible to mark differences between two distribution functions as significant. On the basis of the achieved results it could be shown, that significant structural variations along the interface do not appear up to the second atomic layer. The atom distribution of the first layer remained constant within the errors, which indicates homogenous properties for this layer on the scale of the image region ({approx}23 nm). (orig.)

  7. Spatially resolved analyses of uranium species using a coupled system made up of confocal laser-scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS); Ortsaufgeloeste Analyse von Uranspezies mittels einem Gekoppelten System aus Konfokaler Laser-Scanning Mikroskopie (CLSM) und Laser Induzierter Fluoreszenzspektroskopie (LIFS)

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, S. [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Grossmann, K.; Arnold, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V. (Germany). Inst. fuer Ressourcenoekologie

    2014-01-15

    The fluorescent properties of uranium when excited by UV light are used increasingly for spectroscope analyses of uranium species within watery samples. Here, alongside the fluorescent properties of the hexavalent oxidation phases, the tetra and pentavalent oxidation phases also play an increasingly important role. The detection of fluorescent emission spectrums on solid and biological samples using (time-resolved) laser induced fluorescence spectroscopy (TRLFS or LIFS respectively) has, however, the disadvantage that no statements regarding the spatial localisation of the uranium can be made. However, particularly in complex, biological samples, such statements on the localisation of the uranium enrichment in the sample are desired, in order to e.g. be able to distinguish between intra and extra-cellular uranium bonds. The fluorescent properties of uranium (VI) compounds and minerals can also be used to detect their localisation within complex samples. So the application of fluorescent microscopic methods represents one possibility to localise and visualise uranium precipitates and enrichments in biological samples, such as biofilms or cells. The confocal laser-scanning microscopy (CLSM) is especially well suited to this purpose. Coupling confocal laser-scanning microscopy (CLSM) with laser induced fluorescence spectroscopy (LIFS) makes it possible to localise and visualise fluorescent signals spatially and three-dimensionally, while at the same time being able to detect spatially resolved, fluorescent-spectroscopic data. This technology is characterised by relatively low detection limits from up to 1.10{sup -6} M for uranium (VI) compounds within the confocal volume. (orig.)

  8. From consumer to energy producer. Financing of decentral energy production with the participation of citizens as consumer by means of the Consumer Stock Ownership Plans (CSOP); Vom Verbraucher zum Energieproduzenten. Finanzierung dezentraler Energieproduktion unter Beteiligung von Buergern als Konsumenten mittels sog. Consumer Stock Ownership Plans (CSOPs)

    Energy Technology Data Exchange (ETDEWEB)

    Lowitzsch, Jens; Goebel, Katarzyna [Europa-Universitaet Viadrina, Frankfurt an der Oder (Germany). Osteuropaeisches Wirtschaftsrecht und Europaeische Rechtspolitik

    2013-06-15

    Sustainable growth? A paradoxical term in order to sell sustainability as a logical consequence of a continuous policy of controlled growth. In the context of sustainable energy today there is a lot of talk about growth. However, sustainability is not continuous growth, but at worst shrinkage and at best intelligent growth. The decentralization of the production of renewable energy with consumers as producers is as a way to sustainability.

  9. On the determination of the dynamic conductivity of thin metal films on the (1 0 0)-diamond surface by means of infrared spectroscopy; Ueber die Bestimmung der dynamischen Leitfaehigkeit duenner Metallfilme auf der (1 0 0)-Diamantoberflaeche mittels Infrarot-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Lovrincic, Robert

    2009-04-29

    Thin chromium and aluminum films with thicknesses in the range of a few nanometers were prepared in ultra high vacuum. During film growth their dynamic conductivity was measured in-situ in the infrared regime. For an understanding of the processes determining the conductivity, the measured spectra were interpreted with the Drude and the Drude-Smith model. By this means it is possible to distinguish between different phases in the film growth. For aluminum a Vollmer-Weber-growth was found. As expected, the film thickness at the percolation transition shows a strong temperature dependence. The behaviour of chromium must be characterised as peculiar: Below a critical thickness of 2.5 nm the IR-spectra cannot be described by the Drude-model. From the measurements at different substrate temperatures, an amorphous and an island-like growth can be excluded. The presented explanation is based on a known transition from fcc clusters to the bulk bcc phase of chromium. The spectra of the nanocrystalline fcc phase can be described by a Drude-Smith type dielectric function, and the obtained parameters further back the proposed interpretation. (orig.)

  10. Evaluation of passive cardiomyoplasty using left- and right-ventricular volume measurements by EBCT and MRI in patients with chronic congestive heart failure; Evaluierung der passiven Kardiomyoplastie mittels links- und rechtsventrikulaerer EBCT- und MRT-Volumetrie bei Patienten mit chronischer Herzinsuffizienz

    Energy Technology Data Exchange (ETDEWEB)

    Lembcke, A.; Enzweiler, C.N.H.; Wiese, T.H.; Kivelitz, D.E.; Rogalla, P.; Hamm, B. [Inst. fuer Radiologie, Universitaetsklinikum Charite, Campus Charite Mitte, Humboldt Univ. zu Berlin (Germany); Hotz, H.; Dushe, S.; Konertz, W. [Klinik fuer Kardiovaskulaere Chirurgie, Universitaetsklinikum Charite, Campus Charite Mitte, Humboldt Univ. zu Berlin (Germany)

    2003-08-01

    Purpose: To evaluate the efficacy of passive cardiomyoplasty with the determination of biventricular volumes, global systolic function as well as left-ventricular muscle mass. Materials and Methods: In 19 patients with congestive heart failure of idiopathic or ischemic origin, a polyester mesh-graft was implanted around both ventricles for stabilization and functional support. Before and three months after surgery, 15 patients underwent EBCT and 4 patients with impaired renal function underwent MRI, for the evaluation of the volume and ejection fraction of both ventricles. Results: EBCT demonstrated a decrease from 385 to 310 ml in LV-EDV, from 312 to 242 ml in LV-ESV, from 209 to 160 ml in RV-EDV and from 149 to 87 ml in RV-ESV, and an increase from 20 to 26% in LV-EF and from 37 to 50% in RV-EF as well as a reduction of LV-MM from 300 to 274 g (p < 0.05 each). Similar results were obtained by MRI. Conclusion: Following passive cardiomyoplasty, EBCT and MRI revealed an improvement of the global systolic function as well as a reduction of biventricular volumes and left-ventricular muscle mass. (orig.) [German] Ziel: Evaluierung des Therapieerfolges der passiven Kardiomyoplastie durch Bestimmung der biventrikulaeren Volumina und global systolischen Funktion sowie der linksventrikulaeren Muskelmasse. Methoden: Bei 19 Patienten mit idiopathisch und ischaemisch bedingter Herzinsuffizienz erfolgte die Implantation eines Polyesternetzes um die Ventrikel zu deren Stabilisierung und funktioneller Unterstuetzung. Praeoperativ sowie drei Monate postoperativ wurden bei 15 Patienten durch EBCT und bei 4 Patienten mit eingeschraenkter Nierenfunktion durch MRT die Volumina und Ejektionsfraktion beider Ventrikel sowie die linksventrikulaere Muskelmasse bestimmt. Ergebnisse: Die EBCT zeigte eine Abnahme des LV-EDV von 385 auf 310 ml, des LV-ESV von 312 auf 242 ml, des RV-EDV von 209 auf 160 ml und des RV-ESV von 149 auf 87 ml, eine Zunahme der LV-EF von 20 auf 26% und der RV-EF von 37 auf 50% sowie eine Abnahme der LV-MM von 300 auf 274 g (jeweils p < 0,05). Aehnliche Ergebnisse zeigte die MRT. Schlussfolgerung: EBCT und MRT zeigen nach passiver Kardiomyoplastie die Verbesserung der global systolischen Funktion beider Ventrikel sowie eine Abnahme der biventrikulaeren Volumina und linksventrikulaeren Muskelmasse. (orig.)

  11. Study of the magnetic properties of CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2} by means of neutron scattering; Untersuchung der magnetischen Eigenschaften von CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2} mittels Neutronenstreuung

    Energy Technology Data Exchange (ETDEWEB)

    Faulhaber, Enrico

    2008-07-01

    In 1979 the first heavy-fermion superconductor CeCu{sub 2}Si{sub 2} was discovered by Steglich et al. The system is near a quantum critical point (QCP), where the magnetic order is just suppressed. The distance to the QCP can be varied with hydrostatic pressure as well as by germanium substitution on the silicon site. Next to the superconductivity in CeCu{sub 2}Si{sub 2} one finds distinct magnetic phases while increasing the germanium content. CeCu{sub 2}Si{sub 2} shows a magnetic order of a spin-density-type below T{sub N}-0.8 K, whereas the heavy fermion system CeCu{sub 2}Ge{sub 2} orders below T{sub N}=4.1 K as an antiferromagnet. The focus of this thesis is on neutron-diffraction in the system CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2}. Starting with a sample with a high germanium content of x=0.45, the magnetic structures are investigated in detail. Following a step-by-step approach, samples with reduced x are investigated subsequently to figure out the properties of pure CeCu{sub 2}Si{sub 2}, which were not accessible before. Furthermore, the complex interaction between magnetism and superconductivity is investigated in detail. Using a specially designed setup, the ac-susceptibility could be recorded simultaneously during the neutron diffraction experiments. Due to the direct correlation between antiferromagnetic signals and diamagnetic features, the microscopic coexistence of superconductivity and magnetic order can be ruled out. Instead, a phase separation on the microscopic scale is found. (orig.)

  12. Measures for radiation prevention and remediation of islightly radioactive contaminated sites by phytoremediation and subsequent utilization of the loaded plant residues (PHYTOREST). Final report; Massnahmen zur Strahlenschutzvorsorge radioaktiv belasteter Grossflaechen durch Sanierung mittels Phytoremediation und anschliessende Verwertung der belasteten Pflanzenreststoffe (PHYTOREST). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Willscher, Sabine; Werner, Peter [TU Dresden, Pirna (Germany). Inst. fuer Abfallwirtschaft und Altlasten; Jablonski, Lukasz; Wittig, Juliane

    2013-12-30

    In the presented scientific research project, the radiation protection of soil surfaces impacted by former industrial utilization or mining was investigated. This radiation protection of the contaminated soil surfaces was carried out by bioremediation techniques. The soil surfaces include larger agricultural or forestry areas useful for the production of sustainable plant-based raw materials and renewable energies. The contaminated areas show a positive climatic water balance with a subsequent impact of SM/R contaminants onto the adjacent ground water. During this scientific research project, the introduction of sustainable, biosphere conserving methods for a long-term remediation of slightly to moderately HM/R- contaminated areas was investigated; these areas are characterized by a radiotoxic amplifying potential due to a continued occurrence of radionuclides and heavy metals/ metalloids. The insights into transfer processes from the soil substrate over the mediating soil water phase and by microbes into the plant roots, into the shoots and the leaves of the plants represent necessary requirements for the control of SM/R transfer into the plants and its optimization. In this research project, considerable investigations were carried out for the understanding of binding of HM/R in the different plant compartments, also depending on different soil additives. The obtained first scientific results and their practical applicability were transformed onto experimental soil areas under natural field conditions. The transfer processes could be optimized and finally bioremediation efficiency could be enhanced due to the accompanying modifications (different soil additives of the field experiments). This new remediation method, further developed to a field application, represents a new tool for the stabilization / and extraction of HM/R on the field site and improves the efficiency of bioremediation processes. A pacification of the large areas with slightly to medium contaminated geosubstrates now can be carried out within the radiation protection regulations. Hence, the project provides a substantial contribution to the radiation protection of HM/R contaminated soils. Within the research project, ways for the utilization of HM/R- contaminated plant residuals were highlighted; this gives a substantial contribution for minimization of wastes, the winning of sustainable bioenergy and the recycling of materials. Here, different ways of solutions were investigated. The research project was carried out within the scientific funding program ''Closedown and decommissioning of nuclear facilities''. The results of the project will contribute to the development of a biologically benign, sustainable technique for the remediation of large contaminated areas that originate mostly from the legacy of the former U mining. As a general result of this comprehensive research project, a phytostabilization/ phytoextraction of such SM/R contaminated sites is feasible with a protection of ground water, and the plant crop from phytoremediation of the HM/R contaminated field site can be utilized for the winning of bioenergy (gaseous/ liquid products or thermal utilization). The beneficial combination of phytoremediation and subsequent utilization of the biomass can be further developed to an innovative and sustainable remediation technology with national and international application potential.

  13. Costs and trade-offs of grazer-induced defenses in Scenedesmus under deficient resource

    Science.gov (United States)

    Zhu, Xuexia; Wang, Jun; Chen, Qinwen; Chen, Ge; Huang, Yuan; Yang, Zhou

    2016-01-01

    The green alga Scenedesmus obliquus can form inducible defensive morphs under grazing threat. Costs and trade-offs of inducible defense are expected to accompany the benefits of defensive morphs, but are hard to detect under nutrient-sufficient experimental conditions. To test the existence of costs associated with inducible defense, we cultured S. obliquus along resource availability gradients in the presence or absence of infochemical cues from Daphnia, and measured the strength of defensive colony formation and fitness characters. Under the lowest phosphorous concentration, the expression of inducible defensive colony resulted in decreased growth rate, which provides direct evidence for physiological costs. Along the gradient reduction of phosphorous concentration or light intensity, inducible defense in S. obliquus showed a decreasing trend. However, the photosynthetic efficiency of S. obliquus was barely affected by its defense responses, suggesting that the negative correlations between resource availability and colony formation of this alga may be due to resource-based trade-offs in the allocation of limited resources. Thus, our results indicated that expression of inducible defense of S. obliquus was impaired under insufficient phosphorus or light. Furthermore, under severe phosphate deficiency, obvious physiological costs of inducible defense could be detected even though defensive colony formation also decreased significantly. PMID:26932369

  14. Conteúdo lipídico e composição de ácidos graxos de microalgas expostas aos gases CO2, SO2 e NO Lipid content and fatty acids composition variation of microalgae exposed to CO2, SO2 and NO

    Directory of Open Access Journals (Sweden)

    Elisangela Martha Radmann

    2008-01-01

    Full Text Available The objective of the present work was to verify the lipid content and the fatty acid composition of the microalgae Spirulina sp., Scenedesmus obliquus, Synechococcus nidulans and Chlorella vulgaris cultivated in a medium containing CO2, SO2 and NO. The microalga Scenedesmus obliquus presented the highest lipid content (6.18%. For the other microalgae the lipid content ranged from 4.56 to 5.97%. The major monounsaturated fatty acids content was 66.01% for S. obliquus. The PUFA were obtained in major amount by the microalgae Spirulina sp. (29.37% and S. nidulans (29.54%. The palmitoleic acid was in larger amount, with 41.02% concentration (Spirulina sp..

  15. Cultivation and harvesting of microalgae in photobioreactor for biodiesel production and simultaneous nutrient removal

    International Nuclear Information System (INIS)

    Yang, Il-Seung; Salama, El-Sayed; Kim, Jong-Oh; Govindwar, Sanjay P.; Kurade, Mayur B.; Lee, Minsun; Roh, Hyun-Seog; Jeon, Byong-Hun

    2016-01-01

    Highlights: • Wastewater treatment with algal biomass production was evaluated in a bench-scale. • C. vulgaris and S. obliquus showed μ_o_p_t values of 1.39 and 1.41 day"−"1, respectively. • Complete removal (>99%) of TN and TP by both algal strains was observed. • Harvesting efficiency of M. oleifera was 81% for C. vulgaris and 92% for S. obliquus. - Abstract: Microalgae, Chlorella vulgaris and Scenedesmus obliquus were cultivated in a small scale vertical flat-plate photobioreactor (PBR) supplemented with municipal wastewater in order to achieve simultaneous wastewater treatment and biomass production for biofuel generation. Microalgal growth and nutrient removal including total nitrogen (TN), total phosphorus (TP), total inorganic carbon (TIC) and trace elements (Ca"2"+, Na"+, Mg"2"+ and Zn"2"+) were monitored during microalgae cultivation. C. vulgaris and S. obliquus showed optimal specific growth rates (μ_o_p_t) of 1.39 and 1.41 day"−"1, respectively, and the TN and TP were completely removed (>99%) from the wastewater within 8 days. Microalgal biomass in the PBR was harvested using a natural flocculant produced from Moringa oleifera seeds. The harvesting efficiency of M. oleifera was 81% for C. vulgaris and 92% for S. obliquus. The amounts of saturated, mono-unsaturated, and poly-unsaturated fatty acids in the harvested biomass accounted for 18.66%, 71.61% and 9.75% for C. vulgaris and 28.67%, 57.14% and 11.15% for S. obliquus, respectively. The accumulated fatty acids were suitable to produce high quality biodiesel with characteristics equivalent to crop seeds oil-derived biodiesel. This study demonstrates the potential of microalgae-based biodiesel production through the coupling of advanced wastewater treatment with microalgae cultivation for low-cost biomass production in a PBR.

  16. Effects of linear alkylbenzene sulfonate (LAS) on the interspecific competition between Microcystis and Scenedesmus.

    Science.gov (United States)

    Zhu, Wei; Chen, Huaimin; Guo, Lili; Li, Ming

    2016-08-01

    The widespread use of detergents increases the concentration of surfactant in lakes and reservoirs. High surfactant loads produces toxicity to algae; however, the influence of the increasing surfactant on the competition between algae is not clear. In this paper, different amounts of linear alkylbenzene sulfonate (LAS) were added to test the effects of LAS on the competition between Microcystis aeruginosa and Scenedesmus obliquus under eutrophic condition. In single culture, the growth of S. obliquus was promoted under lower LAS concentrations (1 and 20 mg L(-1)), but cell density of S. obliquus reduced when treated with higher LAS concentration (100 mg L(-1)). The growth of M. aeruginosa was inhibited markedly with 20 and 100 mg L(-1) LAS. Compared with single culture, the result was opposite in co-cultures and the cell density of S. obliquus increased significantly when treated with LAS of 1, 20, and 100 mg L(-1). The specific growth rates of S. obliquus and M. aeruginosa in both cultures were 0.4-0.5 day(-1) and 0.6-0.7 day(-1), respectively, except that the specific growth rate of M. aeruginosa in both cultures treated with 100 mg L(-1) LAS was about 0.2 day(-1). M. aeruginosa dominated over S. obliquus in the co-culture without LAS, while the competition was completely opposite with the addition of 20 mg L(-1) LAS. The growth of S. obliquus treated with 20 mg L(-1) LAS was not affected significantly in single culture but was promoted by 75 % in co-culture. Moreover, the growth of S. obliquus in co-culture treated with 100 mg L(-1) LAS was promoted by more than 97 %. These results suggested that the increasing LAS would overturn the competition of algae in freshwater ecosystems.

  17. Sequence analysis of the its-2 region: a tool to identify strains of Scenedesmus (Chlorophyceae)

    NARCIS (Netherlands)

    Van Hannen, E.J.; Lürling, M.; Van Donk, E.

    2000-01-01

    The genetic distances between several strains of Senedesmus obliquus (Turp,) Kutz,, S, acutus Hortobagyi, and S, naegelii Chod. calculated from ITS-2 sequences were found to be smaller than the genetic distances within other strains of Scenedesmus-that is, in S, acuminatus (Lagerh,) Chod, and S,

  18. Fourier transform infrared (FTIR) spectroscopy for identification of ...

    African Journals Online (AJOL)

    Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chlorella vulgaris Beijerinck 1890 and Scenedesmus obliquus (Turpin) Kützing 1833. Two cultures were grown in a chemically-defined media under photoautotrophic culture conditions isolated from eutrophic ...

  19. Effects of UV-B irradiated algae on zooplankton grazing

    NARCIS (Netherlands)

    Lange, de H.J.; Lürling, M.F.L.L.W.

    2003-01-01

    We tested the effects of UV-B stressed algae on grazing rates of zooplankton. Four algal species ( Chlamydomonas reinhardtii, Cryptomonas sp., Scenedesmus obliquus and Microcystis aeruginosa) were used as food and fed to three zooplankton species ( Daphnia galeata, Bosmina longirostris and

  20. Synergistic Effects of Different Food Species on Life-History Traits of Daphnia-Galeata

    NARCIS (Netherlands)

    Boersma, M.; Vijverberg, J.

    1995-01-01

    In this paper we describe the life history consequences of feeding Daphnia galeata with different food types in different concentrations. We fed the animals with four concentrations of two green algae Scenedesmus obliquus and Chlamydomonas globosa, given separately as well as in a 1:1 mixture.

  1. Primary evaluation of the radon situation in dwellings in Saxony by long-time integrating measurements, comparison of the results with short-time measurements and determination of the radon activity concentration in the ground of the land; Erstbewertung zur Radonsituation von Haeusern im Freistaat Sachsen mittels langzeitintegrierenden Messungen, Vergleich der Ergebnisse mit Kurzzeitmessungen und Erfassung der Radon-Aktivitaetskonzentration in der Bodenluft der Grundstuecke

    Energy Technology Data Exchange (ETDEWEB)

    Alisch-Mark, M.; Keck, D.; Preusse, W.; Taube, A.; Busch, H.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Sachsen (Germany)

    2016-07-01

    A measurement program was carried out for primary evaluation of dwellings in terms of radon situation. Short-time measurements were compared with annual averages and checked for their suitability for forecasting the annual averages. In 89% of the cases studied, the average annual values could be predicted by short-time measurements, differences were observed depending on the date of the short-time measure. In addition, radon activity concentrations were determined in the soil air in the ground and compared with the expected areas of forecasting map of Saxony. Discrepancies were found primarily in areas which are marked by a smallscale geology. The data obtained showed that the geogenic radon potential and the year of construction of the house represent factors influencing the probability of exceedance of the reference value of 300 Bq/m{sup 3}.

  2. Study of CeO{sub x}, PrO{sub x}, and Ce{sub x}Pr{sub 1-x}O{sub 2-{delta}} films on Si(111) by means of high-energetic X-ray photoelectron spectroscopy; Untersuchung von CeO{sub x}-, PrO{sub x}- und Ce{sub x}Pr{sub 1-x}O{sub 2-{delta}}- Filmen auf Si (111) mittels hochenergetischer Roentgen-Photoelektronenspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Allahgholi, Aschkan

    2013-03-15

    The intention of this work is to shed light on two much discussed topics in the study of rare earth oxides (REO) by hard x-ray photoelectron spectroscopy (HAXPES): (i) Due to the complex spectral shape of the Ce3d region, there have been many discussions on proper approaches to determine the concentration of Ce{sup 3+} and Ce{sup 4+} species in CeO{sub x} over the last decades. (ii) Recently, the true electron structure of rare earth oxides gained new attention, since ab initio calculations showed the necessity of considering additional inter atomic charge transfer to Ce5d levels. Using HAXPES and resonant HAXPES, the question of the true electronic structure of rare earth oxides is approached from the experimental side. As a third topic, the obtained results for cerium oxide and praseodymium oxide are applied in order to investigate the plasma oxidized mixed oxide Ce{sub x}Pr{sub 1-x}O{sub 2-{delta}} grown on Si(111) during thermal reduction. (orig.)

  3. Determination of the potential radiation exposure of the population close to the Asse II mine caused by deduction of radioactive substances with the discharge air in the normal operation using the ''Atmospheric Radionuclide-Transport-Model'' (ARTM); Ermittlung der potenziellen Strahlenexposition der Bevoelkerung in der Umgebung der Schachtanlage Asse II infolge Ableitung radioaktiver Stoffe mit den abwettern im bestimmungsgemaessen Betrieb mittels des ''atmospaerischen Radionuklid-Transport-Modells'' ARTM

    Energy Technology Data Exchange (ETDEWEB)

    Esch, D.; Wittwer, C. [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

    2014-01-20

    Between 1967 and 1978 125.787 packages filled with low-level and intermediate-level radioactive waste were emplaced in the mining plant Asse II. Volatile radioactive substances like H-3, C-14 and Rn-222 are released from the emplaced waste. These substances reach the ventilated parts of the mine and are released with the discharge air. The potential radiation exposure of the population caused by deduction of radioactive substances with the discharge air in the normal operation is determined by the ''Atmospheric Radionuclide-Transport-Model'' (ARTM). As result the maximal deductions of volatile radioactive substances with the discharge air in the normal operation of the Asse II mine lead to radiation exposure of the population, which is considerably lower than the permissible values of application rate.

  4. Influence of mesoscale structures on stratospheric ozone: numerical simulation and sounding by means of airplane Lidar. Pt. B: sounding of the vertical distribution of aerosols, PSCs and ozone in the arctic stratosphere by means of an aircraft-borne Lidar system (SAPOS). Final report; Der Einfluss mesoskaliger Strukturen auf das stratospaerische Ozon: Numerische Simulation und Sondierung mit dem Flugzeug-Lidar. T. B: Sondierung der Vertikalverteilung von Aerosol, PSCs und Ozon in der arktischen Stratosphaere mittels eines flugzeuggetragenen Lidar-Systems (SAPOS). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Volkert, H.; Renger, W.

    1999-09-01

    In this project a succession of tasks, partly going beyond what had originally been planned, was carried out and documented in a series of publications: (a) establishment of a mesoscale forecasting operation for measuring campaigns such as the Lidar measurements carried out in Part B (SAPOS); (b) case study calculations on PSC observations; (c) simulation of the entire month of January 1997; (d) derivation of criteria for wave activity from conventional weather data; (e) evaluation of these criteria for the last 20 winter periods. Besides this there was a lively exchange of simulation and measuring results with other groups within the OFP and from Scandinavian countries. In executing this extensive work programme the researchers profited greatly from the preliminary work done on the use of an experimental weather forecasting model (Leutbecher and Volkert, 1998), a dissertation prepared in the working group (Leutbecher, 1998), and the actual project work which was carried out by a doctor of science with extensive experience in the operation of complex meteorological models. [German] Im vorliegenden Projekt wurde eine Stufenleiter von Aufgaben erledigt, teilweise in Erweiterung der urspruenglichen Planung, und durch eine Reihe von Veroeffentlichungen dokumentiert: (a) Einrichtung eines mesoskaligen Vorhersagebetriebs fuer Messkampagnen, u.a. fuer die Lidar-Messungen aus Teil B (SAPOS); (b) Fallstudienrechnungen zu PSC Beobachtungen; (c) eine komplette Monatssimulation des Januar 1997; (d) die Ableitung von Kriterien fuer Wellenaktivitaet aus konventionellen Wetterdaten; (e) Auswertung dieser Kriterien fuer die letzten zwanzig Winterperioden. Daneben bestand ein reger Austausch an Simulations- und Messergebnissen mit anderen Gruppen innerhalb des OFP und in den skandinavischen Laendern. Das umfangreiche Arbeitspensum profitierte stark von Vorarbeiten zum Einsatz eines experimentellen Wettervorhersagemodells (Leutbecher und Volkert, 1996), einer in der Arbeitsgruppe erstellten Dissertation (Leutbecher 1998) und der eigentlichen Projektarbeit durch einen promovierten Wissenschaftler mit umfangreicher Erfahrung im Betrieb komplexer meteorologischer Modelle. (orig.)

  5. Sociography of rural energy projects. A comparative explorative research on rural and participative initiatives for the development of regional energy infra-structures using renewable energy technologies at the example of seven case studies in one German Federal Land; Soziographie laendlicher Energieprojekte. Eine vergleichende explorative Untersuchung ueber laendliche partizipative Initiativen zur Entwicklung regionaler Energie-Infrastrukturen mittels regenerativer Energien am Beispiel von sieben Kommunen in einem neuen Bundesland

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, Conrad

    2011-11-28

    The energy shift is researched in this study as a broad societal process from a sociological perspective. As cutting edge developments are found in geographical and social niches, seven advanced and ambitious ''energy-regions'' were selected in rural areas as case studies. The paradigm of energy-autonomy (or autarky) or the 100% self sustaining region was researched as a yet young developmental path by using qualitative methods. Energy autarky or autonomy is understood as the goal to supply a region completely with heat and electricity from renewable sources. This has rather seldom been completely realised due to its high requirements. This study describes the hindrances, stages of development and typical problems as well as factors which allow to resolve them. A comparision of the case studies results in a theoretical model, to explain the success of single initiatives and partially allow for predictions. The thesis is deduced that the technical and economical infra-structures of renewable energy-regions adapt on the long term to the given social structure. Furthermore the diffusion of the ''energy-region'' is caused by the level of social capital. Due to the interdependency of social and technical complexity, the energy shift means for the countryside most of all a social and organisational challenge. This study describes the different strategies of involved actors and their constellations to one another. (orig.)

  6. Der Einfluss von COMT Val158Met auf neuronale Korrelate von Delay Discounting bei adulten Patienten mit Aufmerksamkeitsdefizit/Hyperaktivitätsstörung (ADHS)

    OpenAIRE

    Gieseke, Heiner Alexander

    2013-01-01

    In dieser Studie führten 37 adulte Patienten mit einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) ein Delay Discounting (DD) - Paradigma aus, während gleichzeitig mittels Funktioneller-Nahinfrarotspektroskopie (fNIRS) die Gehirnaktivität der „Regions of Interest“ (ROIs) des Orbitofrontalen-Kortex (OFC) und des Dorsolateralen-Präfrontalen-Kortex (dlPFC) gemessen wurde. Mittels Fragebögen und eines Delay Discounting Tasks (DDT) wurden zusätzlich Verhaltensparameter erhoben und flosse...

  7. calvyn oor die leiding van die heilige gees in die verklaring van die

    African Journals Online (AJOL)

    Mittel alters, bis er zur Ruhe kommt bei den kanonischen Schriften der. Urzeit der christlichen Ära (Barth ... (ego tamen dimoveri non possum ab amore compendii, CO 10, 403). Deur die boodskap van die .... Idem ergo spiritus qui per os prophetarum loquutus est, in corda nostra penetret necesse est, ut persuadeat fideliter ...

  8. Long-term perspectives of technical and social development in Germany. Visions for research and technology policy; Langfristige Perspektiven technischer und gesellschaftlicher Entwicklung in Deutschland. Visionen fuer die Forschungs- und Technologiepolitik

    Energy Technology Data Exchange (ETDEWEB)

    Baron, W; Zweck, A

    1995-12-01

    This publication contains six contributions discussing the medium- and long-term perspectives of technical, social and economic development in Germany. (UA) [Deutsch] Die vorliegende Publikation enthaelt 6 Vortraege, die sich mit mittel- und langfristigen Perspektiven der technischen, sozialen und wirtschaftlichen Entwicklung in Deutschland befassen. (UA)

  9. Hydroaggregat

    Science.gov (United States)

    Heinen, Frank; Eberspächer, Peter

    Das Hydroaggregat/Modulator bildet die hydraulische Verbindung zwischen dem Hauptzylinder und den Radzylindern und ist damit zentrales Bauelement elektronischer Bremssysteme. Es setzt die Stellbefehle des Steuergeräts um und regelt mittels Magnetventilen die Drücke in den Radbremsen.

  10. Der Sinn der Lehre

    DEFF Research Database (Denmark)

    Beyes, Timon; Steyaert, Chris

    2015-01-01

    Anhand der Beschreibung und Reflexion einer universitären Lehrveranstaltung, die die Erkundung städtischer Affekte und Atmosphären mittels ethnographischer Praktiken zum Inhalt hat, umreißt unser Beitrag eine Pädagogik des Affekts und skizziert ihre Implikationen für den Sinnbegriff und das Theor...

  11. [Deutschland, Russland und das Baltikum] / Bogus̮aw Dyba{250}

    Index Scriptorium Estoniae

    Dyba{250}, Bogus̮aw

    2006-01-01

    Rets. rmt.: Deutschland, Russland und das Baltikum. Beiträge zu einer Geschichte wechselvoller Beziehungen. Festschrift zum 85. Geburtstag von Peter Krupnikow, hrsg. v. Florian Anton und Leonid Luks (=Schriften des Zentralinstituts für Mittel- und Osteuropastudien. Bd.7), Böhlau Verlag, Köln-Weimar-Wien, 2005

  12. Interaktion mit RFID Ausleih- und Rückgabeautomaten

    DEFF Research Database (Denmark)

    Greifeneder, Elke; Heyroth, Melanie; Klingbeil, Karin

    2011-01-01

    Der Artikel untersucht mittels Beobachtung die Interaktion zwischen RFID-Ausleih- und Rückgabeautomaten sowie Bibliotheksbenutzern in vier deutschen Bibliotheken. Die Ergebnisse belegen, dass die Interaktion grundsätzlich funktioniert. Die Benutzer zeigten Gelassenheit und Routine im Umgang mit den...

  13. Book review: Vetter, H. 2005. Terralog. Turtles of the World. Vol. 3. Central and South America

    Directory of Open Access Journals (Sweden)

    2006-12-01

    Full Text Available Book review: Vetter, H. 2005. Terralog. Turtles of the World. Vol. 3. Central and South America/Schildkröten der Welt Band 3. Mittel- und Südamerika: 1-128, color pictures 606 + 9. Edition Chimaira, Frankfurt, Germany.ISBN 3-930612-82-8; 29.7 x 20.8 cm

  14. Environmental monitoring of mercury in waters. Reagent-free and rapid determination of mercury at trace levels.; Umweltmonitoring von Quecksilber in Gewaessern. Reagenzienfreie und schnelle Bestimmung von Hg im Spurenbereich

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jessica; Leopold, Kerstin [Ulm Univ. (Germany). Inst. fuer Analytische und Bioanalytische Chemie

    2013-05-15

    With the help of nano gold collectors for the enrichment of the total mercury content of water samples can be analyzed fully automatically using atomic fluorescence spectrometry without extensive sample preparation. [German] Mit Hilfe von Nanogoldkollektoren zur Anreicherung kann der Gesamtquecksilber-Gehalt von Gewaesserproben vollautomatisiert mittels Atomfluoreszenzspektrometrie ohne aufwendige Probenvorbereitung analysiert werden.

  15. Devil-nets of clues: True Detective and the search for meaning

    DEFF Research Database (Denmark)

    Tybjerg, Casper

    2016-01-01

    of the puzzle film genre as an interpretive framework, the existence of an audience interested in assuming the attitude of what Jason Mittell has called the forensic fan, and the choice of a traditional, one-episode-per-week release schedule. Finally, the article discusses the show’s ending and the disappointed...

  16. Modernisierungsbemühungen in islamischen Gesellschaften

    Directory of Open Access Journals (Sweden)

    Regina Harzer

    2006-07-01

    Full Text Available Im Tagungsband sind Beiträge über heterogene Lebensformen von Frauen aus islamischen Kulturkreisen versammelt. Das gemeinsame Anliegen der Autorinnen ist das Bemühen um gegenseitiges Verständnis im internationalen Diskurs. Sie konkretisieren dieses Bemühen mittels kritischer und selbstkritischer Betrachtung islamischer Verhältnisse.

  17. Use of stereographic projection for worldwide numerical weather prediction with a regional nested model

    Energy Technology Data Exchange (ETDEWEB)

    Prenosil, T. [Amt fuer Wehrgeophysik, Traben-Trarbach (Germany)

    1998-01-01

    Mittels einer fiktiven Polrotation ist das Deutsche Amt fuer Wehrgeophysik in der Lage, auf der Basis eines regelmaessigen Netzmodells fuer eine stereographische Ebene fuer jeden beliebigen Punkt der Erde hochaufloesende Wettervorhersagen zu erstellen. Die horizontale Koordinatentransformation garantiert numerische Stabilitaet fuer grosse Zeitschritte zu vertretbaren Kosten. Die Modellergebnisse werden mit Hilfe des Visualisierungsprogramms Vis5D vorgestellt. (orig.)

  18. Stellenwert der Laparoskopie in Diagnostik und Therapie der Peritonealendometriose

    Directory of Open Access Journals (Sweden)

    Schweppe KW

    2008-01-01

    Full Text Available Die diagnostische Laparoskopie ist zurzeit das einzige Verfahren, eine Endometriose im kleinen Becken hinsichtlich Ausdehnung und Schweregrad zu beurteilen, mittels Biopsie zu sichern und andere Erkrankungen differenzialdiagnostisch auszuschließen. Therapeutisch ist sie bei peritonealer Endometriose der primäre Behandlungsschritt. Ihre Effektivität ist sowohl bei Schmerzpatientinnen als auch bei Kinderwunsch durch prospektiv randomisierte Studien nachgewiesen.

  19. Entwicklung einer Produktstrategie für einen Veranstaltungskalender Wirtschaftswissenschaften

    OpenAIRE

    Steinhagen, Elisabeth

    2014-01-01

    Diese Arbeit hat das Ziel, am Beispiel des ZBW-Veranstaltungskalenders zu zeigen, dass eine Produktstrategie ein wertvolles Instrument ist, um ein Informationsprodukt erfolgreich zu etablieren bzw. weiterzuentwickeln. Dafür werden in Anlehnung an Methoden der strategischen Unternehmensplanung und des Produktmanagements wichtige Einflussfaktoren für das Produkt ZBWVeranstaltungskalender systematisch identifiziert und mittels IST-Analyse, Zielgruppenanalyse sowie Wettbewerbsanalyse unters...

  20. Bioprocessos para remoção de dióxido de carbono e óxido de nitrogênio por micro-algas visando a utilização de gases gerados durante a combustão do carvão Bioprocesses for removal of carbon dioxide and nitrogen oxide by microalgae for the utilization of gas generated during coal burning

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2008-01-01

    Full Text Available The aim of this work was to study the removal of CO2 and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed µmax and Xmax (0.11 d-1, 1.11 g L-1 d-1 when treated with CO2 and NaNO3. The maximum CO2 removal was 22.97% for S. obliquus treated with KNO3 and atmospheric CO2. The S. obliquus showed maximum NO removal (21.30% when treated with NO and CO2. Coupling the cultivation of these microalgae with the removal of CO2 and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions.

  1. Occurrence of the megatoothed sharks (Lamniformes: Otodontidae in Alabama, USA

    Directory of Open Access Journals (Sweden)

    Dana J. Ehret

    2014-10-01

    Full Text Available The Otodontidae include some of the largest sharks to ever live in the world’s oceans (i.e., Carcharocles megalodon. Here we report on Paleocene and Eocene occurrences of Otodus obliquus and Carcharocles auriculatus from Alabama, USA. Teeth of Otodus are rarely encountered in the Gulf Coastal Plain and this report is one of the first records for Alabama. Carcharocles auriculatus is more common in the Eocene deposits of Alabama, but its occurrence has been largely overlooked in the literature. We also refute the occurrence of the Oligocene Carcharocles angustidens in the state. Raised awareness and increased collecting of under-sampled geologic formations in Alabama will likely increase sample sizes of O. obliquus and C. auriculatus and also might unearth other otodontids, such as C. megalodon and C. chubutensis.

  2. Potential utilization of algal protein concentrate as a food ingredient in space habitats

    Science.gov (United States)

    Nakhost, Z.; Karel, M.

    1989-01-01

    Green alga Scenedesmus obliquus was studied as one of the potential sources of macronutrients in a space habitat. Algal protein concentrate (70.5% protein) was incorporated into a variety of food products such as bran muffins, fettuccine (spinach noodle imitation) and chocolate chip cookies. Food products containing 20 to 40% of incorporated algal proteins were considered. In the sensory analysis the greenish color of the bran muffins and cookies was not found to be objectional. The mild spinachy flavor (algae flavor) was less detectable in chocolate chip cookies than in bran muffins. The color and taste of the algae noodles were found to be pleasant and compared well with commercially available spinach noodles. Commercially available spray-dried Spirulina algae was also incorporated so the products can be compared with those containing Scenedesmus obliquus concentrate. Food products containing commercial algae had a dark green color and a "burnt after taste" and were less acceptable to the panelists.

  3. Features of muscular activity at carrying out body drop by female judo-wrestlers of highly qualification

    Directory of Open Access Journals (Sweden)

    Elipkhanov S.B.

    2012-09-01

    Full Text Available The aim of this study was evaluating muscles activity at carrying out body drop, lengths of muscles and velocity of changing their lengths. Was used 2D and 3D video analysis. Three participant of Russia female national judo team (age before 23 years took part in experiment. Has been established at carrying out reception to the right side greatest changes of length are observed at left and right muscle rectus abdominis and right muscle obliquus externus abdominis, middle and lower parts of left muscle gluteus maximus, back parts of left and right muscle deltoideus. The highest velocity of contraction are noticed at muscle obliquus externus abdominis (especially at the right, middle and lower parts of left muscle gluteus maximus and middle part of left muscle deltoideus.

  4. Bioprocesses for removal of carbon dioxide and nitrogen oxide by microalgae for the utilization of gas generated during coal burning

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Michele Greque de; Costa, Jorge Alberto Vieira [Fundacao Universidade Federal do Rio Grande, Rio Grande (Brazil)

    2008-07-01

    The aim of this work was to study the removal of CO{sub 2} and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed {mu}{sub max} and X{sub max} (0.11 d{sup -1}, 1.11 g L{sup -1} d{sup -1}) when treated with CO{sub 2} and NaNO{sub 3}. The maximum CO{sub 2} removal was 22.97% for S. obliquus treated with KNO{sub 3} and atmospheric CO{sub 2}. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO{sub 2}. Coupling the cultivation of these microalgae with the removal of CO{sub 2} and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions. 19 refs., 3 figs., 2 tabs.

  5. Utilization of non-conventional systems for conversion of biomass to food components: Potential for utilization of algae in engineered foods

    Science.gov (United States)

    Karel, M.; Kamarei, A. R.; Nakhost, Z.

    1985-01-01

    The major nutritional components of the green algae (Scenedesmus obliquus) grown in a Constant Cell density Apparatus were determined. Suitable methodology to prepare proteins from which three major undesirable components of these cells (i.e., cell walls, nucleic acids, and pigments) were either removed or substantially reduced was developed. Results showed that processing of green algae to protein isolate enhances its potential nutritional and organoleptic acceptability as a diet component in a Controlled Ecological Life Support System.

  6. Medicinal properties of fungi occurring on Betula sp. trees. A review

    OpenAIRE

    Smolibowska Joanna; Szymański Marcin; Szymański Arkadiusz

    2016-01-01

    The article presents the chemical costituents and pharmacological properties of polyporoid fungi found on birch, namely Piptoporus betulinus, Inonotus obliquus, Lenzites betulina, Fomes fomentarius, and Trametes versicolor. The in vitro and in vivo studies on the effect of different extracts from above-mentioned fungi on the human organism shown anti-cancer, anti-inflammatory, antiviral, antibacterial and immunostimulant activity, conditioned by the presence of such compounds as polysaccharid...

  7. LIGHT REGULATION OF GROWTH AND MELANIN FORMATION IN Inonotus оbliquus (Pers. Pilat

    Directory of Open Access Journals (Sweden)

    N. L. Poyedinok

    2013-04-01

    Full Text Available The study aims to investigate possibilities of using different sources of low-intensity light for the regulation of mycelium growth and melanin synthesis by medicinal mushroom Inonotus obliquus (Pers. Pilat. Studies of the light’s influence on the linear growth, biomass accumulation and melanin synthesis I. obliquus were performed using experimental installations that provide both lasing (coherent light with specified parameters, as well as sources of incoherent light. It has been demonstrated that the greatest stimulating effect took place during the irradiation of mycelium with blue light. It has been found that further realization of photobiological effect is largely dependent on the method of cultivation. Irradiation with laser light within all studied wavelength ranges was more conducive to growth, biomass and melanin accumulation in the mushroom mycelium than incoherent light irradiation within the same wavelength range. Light treatment made it possible to significantly reduce the duration of fermentation. The results of studies allow considering lowintensity light in the visible part of the spectrum as a perspective growth and biosynthetic activity regulator of I. obliquus in the biotechnology of its cultivation.

  8. Eye retraction in the giant guitarfish, Rhynchobatus djiddensis (Elasmobranchii: Batoidea): a novel mechanism for eye protection in batoid fishes.

    Science.gov (United States)

    Tomita, Taketeru; Murakumo, Kiyomi; Miyamoto, Kei; Sato, Keiichi; Oka, Shin-ichiro; Kamisako, Haruka; Toda, Minoru

    2016-02-01

    Eye retraction behavior has evolved independently in some vertebrate linages such as mudskippers (fish), frogs and salamanders (amphibians), and cetaceans (mammals). In this paper, we report the eye retraction behavior of the giant guitarfish (Rhynchobatus djiddensis) for the first time, and discuss its mechanism and function. The eye retraction distance was nearly the same as the diameter of the eyeball itself, indicating that eye retraction in the giant guitarfish is probably one of the largest among vertebrates. Eye retraction is achieved by unique arrangement of the eye muscle: one of the anterior eye muscles (the obliquus inferior) is directed ventrally from the eyeball and attaches to the ventral surface of the neurocranium. Due to such muscle arrangement, the obliquus inferior can pull the eyeball ventrally. This mechanism was also confirmed by electrical stimulation of the obliquus inferior. The eye retraction ability of the giant guitarfish likely represents a novel eye protection behavior of elasmobranch fishes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  9. Magnesium Aminoclay-Fe3O4 (MgAC-Fe3O4 Hybrid Composites for Harvesting of Mixed Microalgae

    Directory of Open Access Journals (Sweden)

    Bohwa Kim

    2018-05-01

    Full Text Available In this paper, we describe the synthesis of magnesium aminoclay-iron oxide (MgAC-Fe3O4 hybrid composites for microalgae-harvesting application. MgAC-templated Fe3O4 nanoparticles (NPs were synthesized in different ratios of MgAC and Fe3O4 NPs. The uniform distribution of Fe3O4 NPs in the MgAC matrix was confirmed by transmission electron microscopy (TEM. According to obtained X-ray diffraction (XRD patterns, increased MgAC loading leads to decreased intensity of the composites’ (311 plane of Fe3O4 NPs. For harvesting of Chlorella sp. KR-1, Scenedesmus obliquus and mixed microalgae (Chlorella sp. KR-1/ Scenedesmus obliquus, the optimal pH was 4.0. At higher pHs, the microalgae-harvesting efficiencies fell. Sample #1, which had the highest MgAC concentration, showed the most stability: the harvesting efficiencies for Chlorella sp. KR-1, Scenedesmus obliquus, and mixed microalgae were reduced only to ~50% at pH = 10.0. The electrostatic interaction between MgAC and the Fe3O4 NPs in the hybrid samples by microalgae, as confirmed by zeta potential measurements, were attributed to the harvesting mechanisms. Moreover, the zeta potentials of the MgAC-Fe3O4 hybrid composites were reduced as pH was increased, thus diminishing the microalgae-harvesting efficiencies.

  10. SIMULATION OF MICROALGAL GROWTH IN A CONTINUOUS PHOTOBIOREACTOR WITH SEDIMENTATION AND PARTIAL BIOMASS RECYCLING

    Directory of Open Access Journals (Sweden)

    C. E. de Farias Silva

    Full Text Available Abstract Microalgae are considered as promising feedstocks for the third generation of biofuels. They are autotrophic organisms with high growth rate and can stock an enormous quantity of lipids (about 20 - 40% of their dried cellular weight. This work was aimed at studying the cultivation of Scenedesmus obliquus in a two-stage system composed of a photobioreactor and a settler to concentrate and partially recycle the biomass as a way to enhance the microalgae cellular productivity. It was attempted to specify by simulation and experimental data a relationship between the recycling rate, kinetic parameters of microalgal growth and photobioreactor operating conditions. Scenedesmus obliquus cells were cultivated in a lab-scale flat-plate reactor, homogenized by aeration, and running in continuous flow with a residence time of 1.66 day. Experimental data for the microalgal growth were used in a semi-empirical simulation model. The best results were obtained for Fw=0.2FI, when R = 1 and kd = 0 and 0.05 day-1, with the biomass production in the reactor varying between 8 g L -1 and 14 g L-1, respectively. The mathematical model fitted to the microalgal growth experimental data was appropriate for predicting the efficiency of the reactor in producing Scenedesmus obliquus cells, establishing a relation between cellular productivity and the minimum recycling rate that must be used in the system.

  11. The Potential of Microalgae Lipids for Edible Oil Production.

    Science.gov (United States)

    Huang, Yanfei; Zhang, Dongmei; Xue, Shengzhang; Wang, Meng; Cong, Wei

    2016-10-01

    The objective of this study was to evaluate the potential of oil-rich green algae, Chlorella vulgaris, Scenedesmus obliquus, and Nannochloropsis oceanica, to produce edible oil with respect to lipid and residue properties. The results showed that C. vulgaris and N. oceanica had similarly much higher lipid recovery (about 50 %) in hexane extraction than that of S. obliquus (about 25 %), and C. vulgaris had the highest content of neutral lipids among the three algae. The fatty acid compositions of neutral lipids from C. vulgaris and S. obliquus were mainly C16 and C18, resembling that of vegetable oils. ARA and EPA were the specific valuable fatty acids in lipids of N. oceanica, but the content of which was lower in neutral lipids. Phytol was identified as the major unsaponifiable component in lipids of the three algae. Combined with the evaluation of the ratios in SFA/MUFA/PUFA, (n-6):(n-3) and content of free fatty acids, lipids obtained from C. vulgaris displayed the great potential for edible oil production. Lipids of N. oceanica showed the highest antioxidant activity, and its residue contained the largest amounts of protein as well as the amino acid compositions were greatly beneficial to the health of human beings.

  12. Effects of temperature, genetic variation and species competition on the sensitivity of algae populations to the antibiotic enrofloxacin.

    Science.gov (United States)

    Rico, Andreu; Zhao, Wenkai; Gillissen, Frits; Lürling, Miquel; Van den Brink, Paul J

    2018-02-01

    Primary producers are amongst the most sensitive organisms to antibiotic pollution in aquatic ecosystems. To date, there is little information on how different environmental conditions may affect their sensitivity to antibiotics. In this study we assessed how temperature, genetic variation and species competition may affect the sensitivity of the cyanobacterium Microcystis aeruginosa and the green-algae Scenedesmus obliquus to the antibiotic enrofloxacin. First, we performed single-species tests to assess the toxicity of enrofloxacin under different temperature conditions (20°C and 30°C) and to assess the sensitivity of different species strains using a standard temperature (20°C). Next, we investigated how enrofloxacin contamination may affect the competition between M. aeruginosa and S. obliquus. A competition experiment was performed following a full factorial design with different competition treatments, defined as density ratios (i.e. initial bio-volume of 25/75%, 10/90% and 1/99% of S. obliquus/M. aeruginosa, respectively), one 100% S. obliquus treatment and one 100% M. aeruginosa treatment, and four different enrofloxacin concentrations (i.e. control, 0.01, 0.05 and 0.10mg/L). Growth inhibition based on cell number, bio-volume, chlorophyll-a concentration as well as photosynthetic activity were used as evaluation endpoints in the single-species tests, while growth inhibition based on measured chlorophyll-a was primarily used in the competition experiment. M. aeruginosa photosynthetic activity was found to be the most sensitive endpoint to enrofloxacin (EC50-72h =0.02mg/L), followed by growth inhibition based on cell number. S. obliquus was found to be slightly more sensitive at 20°C than at 30°C (EC50-72h cell number growth inhibition of 38 and 41mg/L, respectively), whereas an opposite trend was observed for M. aeruginosa (0.047 and 0.037mg/L, respectively). Differences in EC50-72h values between algal strains of the same species were within a factor

  13. Cortical blindness after intoxication with heroin; Kortikale Blindheit nach Heroinintoxikation

    Energy Technology Data Exchange (ETDEWEB)

    Braendli, M. [Institut fuer Diagnostische Radiologie, Universitaetskliniken, Kantonspital Basel (Switzerland); Otte, A.; Mueller-Brand, J. [Institut fuer Nuklearmedizin, Universitaetskliniken, Kantonspital Basel (Switzerland)

    2000-07-01

    For the case reported, both morphological and functional diagnostic examination methods were applied, such as MRI and CT, or SPECT using ECD as a tracer. The bilateral, occipital lesion finally could be detected with the SPECT examinations, and SPECT findings were clearly better than MRI findings, whereas even restrospective analysis of the CT images failed to show the lesion. Thus the functional imaging method in this case of a discrete bilateral occipital lesion was the most sentitive method. (orig./CB) [German] In unserem Fallbeispiel wurden sowohl morphologische (MRT, CT) als auch funktionelle Bildgebung (SPECT unter Verwendung von ECD als Tracer) ad extensum zur Diagnosefindung verwendet. Die bilaterale okzipitale Defektbildung konnte schliesslich mittels SPECT-Untersuchung deutlich besser dargestellt werden als mittels MRT. In der CT gelangte der Befund - auch bei retrospektiver Betrachtung - ueberhaupt nicht zur Darstellung. Damit war die funktionelle Bildgebung im Falle dieser diskreten bilateralen okzipitalen Defektbildung die sensitivste Methode. (orig.)

  14. GPS-gestützte Beikrautregulierung im Freilandgemüsebau

    Directory of Open Access Journals (Sweden)

    Hans-Peter Schwarz

    2014-04-01

    Full Text Available Im Freilandgemüsebau sollen einerseits qualitativ hochwertige Produkte erzeugt werden, die frei von Pflanzenschutzmittelrückständen und unerwünschtem Beikrautbesatz sind, andererseits nehmen Indikationslücken bei Herbiziden zu oder die Mittel können unerwünschte Rückstände verursachen. Zunehmend werden daher mechanische Verfahren zur Beikrautregulierung verwendet. Diese sind jedoch sehr zeitaufwendig und somit kostenintensiv. Ob die moderne GPS-Technologie die mechanische Beikrautregulierung unterstützen und optimieren kann, sollte in einer Masterthesis an der Hochschule Geisenheim geklärt werden. Die praktischen Untersuchungen führten zu dem Ergebnis, dass die Beikrautregulierung mittels GPS-Steuerung der Maschinen und Geräte nicht nur schneller, sondern auch kostengünstiger und präziser durchgeführt werden kann.

  15. A fully variable, piezo-actuated research injection system as a tool in diesel engine combustion process development; Ein vollvariables, piezoaktuiertes Foschungs-Einspritzsystem als Werkzeug in der dieselmotorischen Brennverfahrensentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, S.; Stegemann, J.; Seebode, J.; Merker, G.P. [Hannover Univ. (Germany). Inst. fuer Technische Verbrennung

    2004-07-01

    The injection process is a central optimisation approach for low-cost, low-emission diesel engines. An injection system is presented which comprises a pressure modulator and a research injector with piezo-actuated direct actuation of the nozzle. The high flexibility of the system enables systematic investigations of different combustion processes. (orig.) [German] Die Einspritzverlaufsformung als Mittel zur Minimierung von Rohemissionen bleibt auch im heutigen, von Diskussionen und Partikelfilter und Entstickungstechnologien gepraegten Umfeld ein zentraler Optimierungsansatz fuer kostenguenstige und emissionsarme Dieselmotoren. Das hier vorgestellte Einspritzsystem, bestehend aus einer Druckmodulationseinheit und einem Forschungsinjektor mit piezogesteuerter Direktansteuerung der Duesennadel, dient zur Potenzialanalyse einer freien Einspritzverlaufsformung als Mittel zur innermotorischen Brennverfahrensoptimierung. Dank der hohen Flexibilitaet des Systems sind systematische Untersuchungen in Bezug auf unterschiedliche Brennverfahren moeglich. (orig.)

  16. Petrićevo tumačenje duše svijeta

    OpenAIRE

    Brida, Marija

    1984-01-01

    Seine Ergriffenheit durch die neu-entdecket Schönheit und durch die Sinnhaftigheit der Welt hat der Renaissancemensch erfolgreicher durch die Imanenz des lebendigen Bewegungsprinzips vom geistigen Ursprung erklärt, als mittels der reinen Transzendenz des aristotelischen ersten Bewegers. Die Mehrheit der philosophischen Systeme aus dieser Periode schliesst deshalb als einen von seinen ontologisch konstitutiven Faktoren die platonische Idee der Weltseele ein. Bei Cusanus und Bruno wird dieser B...

  17. Innovative Techniken und Algorithmen im Bereich Computational-Finance und Risikomanagement

    OpenAIRE

    Liang, Qian

    2012-01-01

    Diese Dissertation besteht aus zwei aktuellen Themen im Bereich Finanzmathematik, die voneinander unabhängig sind. Beim ersten Thema, "Flexible Algorithmen zur Bewertung komplexer Optionen mit mehreren Eigenschaften mittels der funktionalen Programmiersprache Haskell", handelt es sich um ein interdisziplinäres Projekt, in dem eine wissenschaftliche Brücke zwischen der Optionsbewertung und der funktionalen Programmierung geschlagen wurde. Im diesem Projekt wurde eine funktionale Biblio...

  18. Ein MapReduce-basiertes Programmiermodell für selbstwartbare Aggregatsichten

    OpenAIRE

    Schildgen, Johannes

    2014-01-01

    Hadoop ist ein beliebtes Framework für verteilte Berechnungen über große Datenmengen (Big Data) mittels MapReduce. Hadoop zu verwenden ist einfach: Der Entwickler definiert die Eingabedatenquelle und implementiert die beiden Methoden Map und Reduce. Über die verteilte Berechnung und Fehlerbehandlung muss er sich dabei keine Gedanken machen, das erledigt das Hadoop-Framework. Allerdings kann die Analyse von Big Data sehr lange dauern und da sich die Eingabedaten jede Sekunde...

  19. Der Einfluß der Ablauforganisation auf die Effizienz von Entscheidungen: Eine empirische Untersuchung am Beispiel von Bilanzanalysen

    OpenAIRE

    Gemünden, Hans Georg

    1987-01-01

    Der vorliegende Beitrag widmet sich einem in der Organisationstheorie stark vernachlässigten Problem: der Ablauforganisation von Entscheidungen. Am Beispiel von Bilanzanalysen wird empirisch geprüft, in welcher Weise eine Gliederung des Prozesses nach Verrichtungen oder Objekten die Qualität der Analyse beeinflußt. Hierzu wird ein validiertes Konzept zur Messung der Qualität von Bilanzanalysen entwickelt. Es wird gezeigt, wie man mittels prozeßbegleitender experimenteller Organisationsforschu...

  20. Neue Shandite und Parkerite. Darstellung und röntgenographische Charakterisierung

    OpenAIRE

    Anusca, Irina

    2009-01-01

    Das Ziel dieser Arbeit war es, neue Verbindungen mit Shandit- und Parkeritstruktur zu darstellen und mittels röntgenographischen Methoden (Pulverdiffraktometrie und Einkristallanalyse), das thermische Verhalten durch DTA / DSC - Messungen und Elektronenmikroskopische Untersuchungen (REM, EDX) zu charakterisieren. Die vorliegende Arbeit ist wie folgt im zwei Themen gegliedert: Shandite und Parkerite. Der ersten Teil dieser Arbeit befaßt sich mit metallreichen ternären Chalkogeniden M3A2X2, ...

  1. Konzeptionelle Entwicklung innovativer Bremssysteme

    OpenAIRE

    Schwankl, L.

    2017-01-01

    Im Rahmen des hier vorgestellten Kooperationsprojekts wurden vorhandene elektromagnetische Bremsen nach konstruktionsmethodischen Gesichtspunkten überarbeitet. Nach einer intensiven Auseinandersetzung mit dem bestehenden System wurde unter Anwendung unterschiedlichster Kreativitätstechniken eine große Anzahl von neuen Lösungsvorschlägen erarbeitet und dokumentiert. Bereits in den frühen Phasen der Produktentwicklung wurden die relevanten, produktbestimmenden Eigenschaften mittels einfacher An...

  2. Integration einer Volltextsuchmaschine in Meta-Akad

    OpenAIRE

    Tuchbreiter, Jochen

    2003-01-01

    Das Projekt Meta-Akad hat das Ziel, Lernenden und Lehrenden den möglichst einfachen, umfassenden und schnellen Zugriff auf Lehrmaterial zu ermöglichen. Dabei werden verschiedene, über die Aspekte einer reinen Internet- Suchmaschine hinausgehende Aspekte berücksichtigt: Neben dem Aufbau einer umfangreichen und repräsentativen Sammlung von Lerndokumenten sollen diese mittels bibliothekarischer Methoden erschlossen und mit umfangreichen Metadaten, wie beispielsweise einer inhaltlichen Einordnung...

  3. Die Expression des Calcitonin receptor-like receptors in humanen Gliomen

    OpenAIRE

    Kappus, Christoph

    2014-01-01

    In dieser Arbeit wurden humane Gliome vom WHO-Grad II-IV auf das Vorkommen des Calcitonin receptor-like Rezeptors untersucht. Hierzu erfolgte zunächst der Nachweis der CRLR-RNS in den humanen Gliomzellinien G 109 und G 139, welche sich eindeutig posi-tiv zeigten. Sodann wurden paraffinasservierte Schnitte aus humanen Gliomen mittels im-munhistochemischer Färbung auf das Vorkommen des CRLRs untersucht. Hierzu diente ein Antikörper ...

  4. Untersuchungen zum in vivo Differenzierungspotenzial muriner und humaner hämatopoetischer sowie muriner neuraler Stammzellen

    OpenAIRE

    Harder, Friedrich

    2003-01-01

    Zusammenfassung Im Zuge der Säugerentwicklung entsteht aus der totipotenten Eizelle ein Organismus aus mehr als 200 verschiedenen Zelltypen. Dabei wird die Entwicklung und der Erhalt des Tieres von Stammzellen gewährleistet. Während der Embryonalentwicklung gibt es nur transient vorkommende Stammzelltypen, während der adulte Körper die Homoeostase mittels permanent vorhandener somatischer Stammzellen aufrechterhält. Als kennzeichnend für die somatischen Stammzellen galt, dass sie nur die Zell...

  5. Erklärung der individuellen Existenzgründungsabsicht: Die 'theory of planned behavior' als sozialpsychologisches Modell im Gründungskontext

    OpenAIRE

    Tegtmeier, Silke

    2006-01-01

    Mittels einer empirischen Untersuchung (n=208) bei Lüneburger Studierenden wird Ajzens 'Theory of Planned Behavior' - eine einschlägige Theorie zur Erklärung spezifischen Verhaltens- auf die Erklärung der individuellen Gründungsabsicht angewendet. Im Anschluss an die Darlegung des Forschungsansatzes werden Ergebnisse der Untersuchung besprochen. Hierarchische Regressionsanalysen zeigen, dass Einstellung, sozialer Druck und wahrgenommene Verhaltenskontrolle maßgeblich zur Schätzung der Gründun...

  6. Eisengehalt von Fleisch - Ermittlung des Eisengehalts im Fleisch verschiedener Tierarten

    OpenAIRE

    Westphal, Karsten; Klose, Ralf; Golze, Manfred

    2009-01-01

    Der Bericht beinhaltet Ergebnisse von Fleischuntersuchungen auf den Eisengehalt. Untersucht wurden 308 Schweinefleischproben und etwa 300 Fleischproben der Tierarten Rind, Bison, Auerochse, Büffel, Schaf, Ziege, Kaninchen, Wildschwein, Rehwild, Rotwild und Fasan. Die sächsischen Ergebnisse bestätigen Untersuchungen anderer Bundesländer und belegen den starken Rückgang des Eisengehaltes im Schweinefleisch. Er lag im Mittel bei 4,1 mg/kg Frischmasse (FM). Vor 30 Jahren lag der Eisengehalt...

  7. Urämische Kardiomyopathie und der Einfluss der Hämodialyse

    OpenAIRE

    Valina, Ulrike Katrin

    2011-01-01

    ZIEL: Analyse von Risikofaktoren und Entstehungsmechanismen der urämischen Kardiomyopathie bei Hämodialysepatienten und Vergleich von Diagnostiken zur frühen Detektion kardialer Funktionstörungen zur Optimierung der Therapie bei terminaler Niereninsuffizienz und Senkung der hohen Mortalitätsrate. METHODEN: Einschluss von 32 Hämodialysepatienten. Messungen mittels Blutentnahme (Entzündungs-, Atherosklerose-, Anämieparameter, EPO, PTH und RAAS) und MRT (Herzfunktion, Herzmorphologie und Her...

  8. Automatische Fehlersuche in Algebraischen Spezifikationen

    OpenAIRE

    Dunets, Andriy

    2010-01-01

    Abstrakte Datentypen eignen sich sehr gut für die High-Level Spezifikation von Software. Die algebraischen Spezifikationen von abstrakten Datentypen bringen durch die Strukturierung gute Überschaubarkeit des Entwurfs und erlauben die Ausdrucksstärke der Logik der ersten Stufe. Wir haben einen Ansatz zur Fehlersuche mittels endlicher Modellsuche entworfen und auf mehreren Fallstudien evaluiert. Die entwickelte Methodik ermöglicht automatische Fehlersuche in den algebraischen Spezifikationen de...

  9. Mehrfacheffekt-Feuchtluftdestillation bei Umgebungsdruck

    OpenAIRE

    Müller-Holst, Hendrik

    2007-01-01

    Ein neuartiges Verfahren zur Feuchtluftdestillation mittels Verdunstung und Kondensation in einer einzigen Kammer wurde im Rahmen der Arbeit umfassend analysiert. Das Verfahren arbeitet bei Umgebungsdruck; der dadurch bei Temperaturen unter dem Siedepunkt verringerte Stoffübergang wird durch große Austauschflächen mit hoher Packungsdichte kompensiert. Der Transport der im Verdunster beladenen Feuchtluft zum Kondensator erfolgt innerhalb einer optimierten geometrischen Anordnung der Baueinheit...

  10. Erfolgreiche Koordination durch Kultur? : Herrschaftsmythen der Frühen Neuzeit und die Organizational-Culture-These

    OpenAIRE

    Ewert, Ulf Christian

    1998-01-01

    Herrschaftsmythen können als spezifische Gestaltungselemente einer Organisationskultur interpretiert werden. Sie waren in den frühneuzeitlichen Systemen Mittel des politischen Zusammenwirkens, gerichtet auf Integration und Definition der jeweiligen Organisation. Gegenstand der Untersuchung sind neun frühneuzeitliche Mythen, darunter der Roi Soleil, Neues Israel und Wilhelm Tell. Hinterfragt wurden wahrgenommene Ähnlichkeiten zwischen den neun Mythen, deren integrative und revolutionäre Muster...

  11. Einfluss von Flüssigkeitskontamination auf die Verbundfestigkeit von Wurzelkanalsealern (Adseal und RelyX Unicem)

    OpenAIRE

    Höfer, Margarita

    2010-01-01

    Ziel dieser Arbeit war es, eine Aussage über die Verbundfestigkeit des epoxidharz-basierten Wurzelkanalsealers Adseal und des selbstadhäsiven methacrylatbasierten Befestigungszements RelyX Unicem zum Wurzelkanaldentin in Abhängigkeit vom Verbleib der Spülflüssigkeit im Wurzelkanal zu treffen. Die Kontamination des Wurzelkanals wurde mittels dreier verschiedener Spüllösungen durchgeführt. Zu diesem Zweck wurden Scherfestigkeitsmessungen sowie lichtmikroskopische Untersuchungen der Sealer-Sprea...

  12. Feinkartierung von Loss of Heterozygosity-Intervallen auf Chromosom 11p und Untersuchungen zum Expressions- und Methylierungsstatus von FANCF beim Ovarialkarzinom

    OpenAIRE

    Schulze, Kathrin

    2011-01-01

    Um Tumorsuppressorgene beim Ovarialkarzinom zu identifizieren wurde eine Kartierung von LOH-Intervallen der Region 11p15.5 - 11p11.2 mittels 11 Mikrosatellitenmarkern an 47 Ovarialtumorproben vorgenommen. Im Bereich des ST5- und AFM255/KAI1-Locus konnten potentielle Intervalle abgegrenzt werden. Das Fanconi Anämie Gen FANCF wurde für Untersuchungen zum Expressions- und Methylierungsstatus ausgewählt, da dessen Abschaltung mit einem besseren Ansprechen auf Cisplatin bei Ovarialkarzinompatienti...

  13. Imagem, texto, sensibilização, criatividade

    Directory of Open Access Journals (Sweden)

    João Azenha Junior

    1997-11-01

    Full Text Available Ziel dieses Beitrags ist es, die dynamische Wechselbeziehung zwischen Bild und Text bei der didaktischen Bearbeitung verschiedener Textsorten im Rahmen der Fremdsprachen- bzw. Übersetzungsdidaktik zu untersuchen. Am Beispiel von Textsorten aus dem Bereich der Wissenschaft, Technik, Literatur und Sprachvermittlung wird versucht, erfolgreiche und mißlungene Anwendungen ikonischer Mittel bei der Textproduktion unter die Lupe zu nehmen und didaktische Konsequenzen daraus zu ziehen.

  14. Evaluation der Behandlungseinheit für Tinnitus, Hör- und Sinnesstörungen (BETHS)

    OpenAIRE

    Hofmeister, Alexander A. K.

    2015-01-01

    Evaluation der Behandlungseinheit für akuten und chronischen Tinnitus an der HNO-Klinik Dr. Gärtner. Mittel der Datenerhebung waren der Tinnitus-Fragebogen (Goebel & Hiller, 1998), die Allgemeine Depressionsskala (Hauzinger & Bailer, 1993), Audiogramm und Tinnitus-Anamnese. Es wurden die Daten von 141 Patienten ausgewertet und die Veränderung der tinnitusspezifischen und depressiven Belastung sowie der Einfluss von Prädiktorvariablen untersucht. Die Ergebnisse belegen eine signifikante Redukt...

  15. Untersuchungen am System NMMO/H2O/Cellulose

    OpenAIRE

    Cibik, T.

    2003-01-01

    Die vorliegende Arbeit befasst sich mit der Untersuchung des Zweistoffsystems N-Methylmorpholin-N-oxid (NMMO)/H2O und des Dreistoffsystems NMMO/H2O/Cellulose sowie mit der Herstellung und Charakterisierung von faserverstärkten Cellulosefolien. Das binäre System wird mittels Dynamischer Differenzkalorimetrie und Röntgenweitwinkel-Diffraktometrie untersucht und dadurch das Schmelzverhalten und die Phasenzusammensetzung dieses Systems im festen Zustand als Funktion des NMMO/H2O-Verhältnisses bes...

  16. M&A-Transaktionen - Fluch oder Segen der Realoptionstheorie?

    OpenAIRE

    Franke, Günter; Hopp, Christian

    2005-01-01

    Technologische und politische Veränderungen sowie komplexere Wertschöpfungsketten haben in den letzten Jahrzehnten zu einer verstärkten Unternehmensexpansion mittels Mergers and Acquisitions geführt. Unter dem Sammelbegriff "Mergers and Acquisitions" werden strategische Entscheidungen eines Unternehmens subsumiert, ein anderes Unternehmen oder einen Geschäftsbereich eines anderen Unternehmens durch Aktientausch oder Barentschädigung zu erwerben oder sich mit einem anderen Unternehmen zusammen...

  17. The Natural Product Acivicin as a Tool for ABPP and the Activity of Serine Hydrolases in Uterine Fibroids

    OpenAIRE

    Kreuzer, Johannes

    2015-01-01

    The target proteins of acivicin and structure derived probes in tumor cells were identified using activity-based protein profiling. The target proteins were further characterized and their relation to the antitumor activity of acivicin pointed out. In a further project, the activity of serine hydrolases in myoma and myometrium was examined from tissue samples. This revealed a different activity of mast cell proteases. Mittels Activity-based Protein Profiling wurde eine Identifikation der Z...

  18. Applanationstonometrie zur nichtinvasiven kontinuierlichen Blutdruckmessung:Vergleich mit der Fingerlichtplethysmographie bei der Kipptisch-Orthostase Testung und Anwendbarkeit für die ergometrische Blutdruckmessung

    OpenAIRE

    Lammers, D. (Dirk)

    2005-01-01

    Die Applanationstonometrie wird mit der Fingerlichtplethysmographie während der Kipptisch-Testung verglichen und die Nutzbarkeit für die Ergometrie geprüft. 31 Patienten wurden einem Kipptisch Orthostase Test unterzogen. Der Patient erhielt kontinuierliches Blutdruckmonitoring durch Colin CBM 7000 am einen und Ohmeda Finapres am anderen Arm. Gleichzeitig wurden Referenzmessungen mittels Oszillometrie durchgeführt. Bei 22 weiteren Patienten wurden Belastungs-EKG’s durchgeführt. Die applanatio...

  19. Anwendung der extrakorporalen Stoßwellentherapie bei kalzifizierender Periathropathia humeroscapularis, Fersensporn und Epicondylitis humeri - Erfahrungsbericht aus dem Wilhelminenspital

    Directory of Open Access Journals (Sweden)

    Feyertag J

    2004-01-01

    Full Text Available Die Stoßwellentherapie wird bei verschiedenen Indikationen, die unter konservativen Therapien schwer zu schwer zu behandeln sind, eingesetzt. Dazu zählen die kalzifizierenden Schultererkrankungen (Tendinitis calcarea, Epicondylitis humeri (EHR und die plantare Fasciitis mit/ohne plantarem Fersensporn (FSP. Berichtet werden die Ergebnisse von 147 Patienten (102 Frauen/45 Männer, mittleres Alter betrug 57,8 Jahre, die mittels einer einmaligen extrakorporalen Stoßwellentherapie (ESWT (Tend. calc. 82 %, FSP 11 % oder EHR 7 % mittels eines HMT-ReflecTron therapiert wurden. Verabreicht wurden im Mittel 1.800 Stoßwellen. Untersucht wurde die subjektive Verbesserung der Schmerzen anhand einer visuellen Analogskala vor und 6 Wochen nach der Therapie bei allen Patienten. Bei Patienten mit Tendinitis calcarea wurde auch eine Verbesserung der Funktion sowie Veränderungen der Kalzifizierungen untersucht. Bei allen Patienten konnte eine statistisch signifikante Verbesserung der Schmerzen sowie des Bewegungsumfanges beobachtet werden (p 0,0001. Röntgenaufnahmen ergaben eine partielle Verkleinerung der Kalkdepots bei ca. 80 % der Patienten. Aufgrund der geringen Zahl der Patienten fand sich für die EHR keine signifikante Verbesserung der Schmerzsymptomatik. Eine einmalige ESWT kann zu einer deutlichen Verbesserung der Schmerzsymptomatik und zu einer Verbesserung des Bewegungsumfanges führen. Bei 80 % der Patienten mit einer Tendinitis calcarea findet sich weiter eine partielle Verkleinerung der Kalkdepots 6 Wochen nach Therapie.

  20. Titanium dioxide nanoparticles enhance inorganic arsenic bioavailability and methylation in two freshwater algae species.

    Science.gov (United States)

    Luo, Zhuanxi; Wang, Zhenhong; Yan, Yameng; Li, Jinli; Yan, Changzhou; Xing, Baoshan

    2018-07-01

    The effect of titanium dioxide nanoparticles (nano-TiO 2 ) on the bioaccumulation and biotransformation of arsenic (As) remains largely unknown. In this study, we exposed two freshwater algae (Microcystis aeruginosa and Scenedesmus obliquus) to inorganic As (arsenite and arsenate) with the aim of increasing our understanding on As bioaccumulation and methylation in the presence of nano-TiO 2 . Direct evidence from transmission electron microscope (TEM) images show that nano-TiO 2 (anatase) entered exposed algae. Thus, nano-TiO 2 as carriers boosted As accumulation and methylation in these two algae species, which varied between inorganic As speciation and algae species. Specifically, nano-TiO 2 could markedly enhance arsenate (As(V)) accumulation in M. aeruginosa and arsenite (As(III)) accumulation in S. obliquus. Similarly, we found evidence of higher As methylation activity in the M. aeruginosa of As(III) 2 mg L -1 nano-TiO 2 treatment. Although this was also true for the S. obliquus (As(V)) treatment, this species exhibited higher As methylation compared to M. aeruginosa, being more sensitive to As associated with nano-TiO 2 compared to M. aeruginosa. Due to changes in pH levels inside these exposed algae, As dissociation from nano-TiO 2 inside algal cells enhanced As methylation. Accordingly, the potential influence of nanoparticles on the bioaccumulation and biotransformation of their co-contaminants deserves more attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Harvesting of freshwater microalgae biomass by Scenedesmus sp. as bioflocculant

    Science.gov (United States)

    Rinanti, A.; Purwadi, R.

    2018-01-01

    This study is particularly expected to provide information on the diversity of microalgae as the flocculant agent that gives the highest biomass yield. Bioflocculation was done by using one of the flocculating microalgae i.e. Scenedesmus obliquus to concentrate on non-flocculating microalgae Chlorella vulgaris. The freshwater microalgae S. obliquus tested it ability to harvest other non-flocculating microalgae, increased sedimentation rate in the flocculation process and increased biomass yield. The flocculation of biomass microalgae with chemical flocculant as comparison was done by adding alum (K2SO4·Al2 (SO4)3·24H2O). The addition of alum (K2SO4·Al2 (SO4)3·24H2O) as flocculant at pH 11 and S. obliquus sp. as bioflocculant caused significant alteration of nutrition of microalgae. Overall, the essential content produced by flocculation method with addition of alum or with bioflocculation (%, mg/100 mg dry weight) are lipid 31,64; 38,69, protein 30,79; 38.50%, and chlorophyll 0.6253; 0.8420). Harvesting with bioflocculation methods conducted at the end of the cultivation period increase the amount of biomass significantly and can accelerate the settling time of biomass. Harvesting microalgae cells by bioflocculation method becomes an economically competitive harvesting method compared to alum as a chemical flocculant because of the cheaper cost of flocculant, not toxic so it does not require further water treatment after harvesting due to the use of alum as chemical flocculants.

  2. Clinical Investigation Program.

    Science.gov (United States)

    1981-10-01

    0. Effect of VaStUS Medialis £1 Obliquus Strength on Chondromalacia Patella. (0) 17,󈨒 Kearney, J. 3. Human Irplantation of Intraocular q, Lenses. (C...to: . 8i I - rot rlo Sat : Te (,t- i ricl teo TI~i:I valuation of Iowor caitruiitctiral leediro (I o occpy Wie v,, I(V O V as an /’.,i~nct Lu Lori!;i...ntrations. Pht [l /, ’A ,,T-: ipididyral fat pads arc re ovcd fr . ra ;vit’ rI.1 . I -l fat cells are -repared Ly shakir c at 7 t for (f, "i. ,tcs iv

  3. Biodeuterated Materials: High-Temperature Lubricants from Algae.

    Science.gov (United States)

    1986-01-06

    to obtain significant growth in D20 media. 1. Chlorella vulgaris (UTEX 397) 2. Chlorella vulgaris (Arg) 3. Scenedesmus obliquus (Arg) 4. Scenedesmus...the other two strains, and almost half of the total fatty acids of strain 1237 was 18:1. Effect of Nitrogen-Deficient Media Chlorella vulgaris (Arg...2.3 36 18 4.5 strain 1237 D20 31 2.9 -- 46 14 5.7 Chlorella vulgaris strain 397 H20 53 9.3 -- 1.6 5.6 19 12 strain 397 D20 28 2.3 -- 6.4 30 23 9.5

  4. Medicinal properties of fungi occurring on Betula sp. trees. A review

    Directory of Open Access Journals (Sweden)

    Smolibowska Joanna

    2016-09-01

    Full Text Available The article presents the chemical costituents and pharmacological properties of polyporoid fungi found on birch, namely Piptoporus betulinus, Inonotus obliquus, Lenzites betulina, Fomes fomentarius, and Trametes versicolor. The in vitro and in vivo studies on the effect of different extracts from above-mentioned fungi on the human organism shown anti-cancer, anti-inflammatory, antiviral, antibacterial and immunostimulant activity, conditioned by the presence of such compounds as polysaccharides, polyphenols or terpenes. These fungi are commonly found in Poland and may superbly compete with Ganoderma lucidum (Reishi or Lentinula edodes (Shitake used in Asia for medicinal purposes.

  5. Urban wastewater treatment by seven species of microalgae and an algal bloom: Biomass production, N and P removal kinetics and harvestability.

    Science.gov (United States)

    Mennaa, Fatima Zahra; Arbib, Zouhayr; Perales, José Antonio

    2015-10-15

    This study evaluates the capacity of seven species and a Bloom of microalgae to grow in urban wastewater. Nutrient removal kinetics and biomass harvesting by means of centrifugation and coagulation-flocculation-sedimentation have been also tested. Results show that the best biomass productivities ranged from between 118 and 108 mgSS L(-1) d(-1) for the Bloom (Bl) and Scenedesmus obliquus (Sco). Regarding nutrient removal, microalgae were able to remove the total dissolved phosphorus and nitrogen concentrations by more than 80% and 87% respectively, depending on the species tested. The final total dissolved concentration of nitrogen and phosphorus in the culture media complies with the European Commission Directive 98/15/CE on urban wastewater treatment. Regarding harvesting, the results of coagulation-flocculation sedimentation using a 60 mg L(-1) dose of Ferric chloride were similar between species, exceeding the biomass removal efficiency by more than 90%. The results of centrifugation (time required to remove 90% of solids at 1000 rpm) were not similar between species, with the shortest time being 2.9 min for Sco, followed by the bloom (7.25 min). An overall analysis suggested that the natural bloom and Scenedesmus obliquus seem to be the best candidates to grow in pre-treated wastewater, according to their biomass production, nutrient removal capability and harvestability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Effect of perfluorooctane sulfonate on toxicity and cell uptake of other compounds with different hydrophobicity in green alga.

    Science.gov (United States)

    Liu, Wei; Zhang, Yao-Bin; Quan, Xie; Jin, Yi-He; Chen, Shuo

    2009-04-01

    Perfluorooctane sulfonate (PFOS) was evaluated alone and in binary mixtures with pentachlorophenol, atrazine and diuron, respectively to investigate the effects of interactions between PFOS and other compounds on the growth rate in Scenedesmus obliquus. Single application of PFOS showed no inhibition on the growth of S. obliquus below 40 mg L(-1), whereas PFOS acting with pentachlorophenol resulted in higher algal growth inhibition in comparison with pentachlorophenol alone. A maximum increase of 45% in the growth inhibition was observed at a pentachlorophenol concentration of 2.56 mg L(-1) together with a PFOS concentration of 40 mg L(-1). On the contrary, the algal growth inhibition of atrazine and diuron was depressed by PFOS. Furthermore, cell uptake was examined to gain some insights into the mechanisms of the effects of PFOS on the toxicity of the other compounds. Cell uptake of pentachlorophenol increased while that of atrazine and diuron was reduced in cells that have been exposed to PFOS. The effects of PFOS on the toxicity of pentachlorophenol, atrazine and diuron were possibly related to the influence of PFOS on the cell uptake of these hydrophobic compounds. Results suggested that PFOS influenced the cell uptake and toxicity of structurally different compounds in dissimilar manners and potentially increased the accessibility and toxicity of more hydrophobic compounds to algal cells.

  7. Alterations in in vivo knee joint kinematics following a femoral nerve branch block of the vastus medialis: Implications for patellofemoral pain syndrome.

    Science.gov (United States)

    Sheehan, Frances T; Borotikar, Bhushan S; Behnam, Abrahm J; Alter, Katharine E

    2012-07-01

    A potential source of patellofemoral pain, one of the most common problems of the knee, is believed to be altered patellofemoral kinematics due to a force imbalance around the knee. Although no definitive etiology for this imbalance has been found, a weak vastus medialis is considered a primary factor. Therefore, this study's purpose was to determine how the loss of vastus medialis obliquus force alters three-dimensional in vivo knee joint kinematics during a volitional extension task. Eighteen asymptomatic female subjects with no history of knee pain or pathology participated in this IRB approved study. Patellofemoral and tibiofemoral kinematics were derived from velocity data acquired using dynamic cine-phase contrast MRI. The same kinematics were then acquired immediately after administering a motor branch block to the vastus medialis obliquus using 3-5ml of 1% lidocaine. A repeated measures analysis of variance was used to test the null hypothesis that the post- and pre-injection kinematics were no different. The null hypothesis was rejected for patellofemoral lateral shift (P=0.003, max change=1.8mm, standard deviation=1.7mm), tibiofemoral lateral shift (Ppain, but could not account for the full extent of these changes. Thus, vastus medialis weakness is likely a major factor in, but not the sole source of, altered patellofemoral kinematics in such individuals. Published by Elsevier Ltd.

  8. Algal Production of Extra- and Intra-Cellular Polysaccharides as an Adaptive Response to the Toxin Crude Extract of Microcystis Aeruginosa

    Directory of Open Access Journals (Sweden)

    Mostafa Mohamed El-Sheekh

    2012-11-01

    Full Text Available This is an investigation concerned with studying the possible adaptive response of four different unicellular algae, Anabaena PCC 7120, Oscillatoria angustissima, Scendesmus obliquus and Chlorella vulgaris, to the toxin of Microcystis aeruginosa (Kützing. Theeffects of four different concentrations, 25, 50, 100 and 200 μg mL-1 of microcystins crude extract of M. aeruginosa, on both intra and extra-cellular polysaccharide levels, in log phase,of the four tested algae were studied. The obtained results showed differential increase in the production levels for both intra and extra-cellular polysaccharides by the tested algae,compared with the control. S. obliquus and C. vulgaris showed a resistance to crude toxinhigher than Anabaena PCC 7120 and O. angustissima. The highly production of polysaccharides by green algal species under this toxic stress indicated the involvement of these polysaccharides in protecting the algal cells against toxic species and, reflect thebiological behavior of particular algal species to the environmental stresses.

  9. TiO2, SiO2 and ZrO2 Nanoparticles Synergistically Provoke Cellular Oxidative Damage in Freshwater Microalgae

    Directory of Open Access Journals (Sweden)

    Yinghan Liu

    2018-02-01

    Full Text Available Metal-based nanoparticles (NPs are the most widely used engineered nanomaterials. The individual toxicities of metal-based NPs have been plentifully studied. However, the mixture toxicity of multiple NP systems (n ≥ 3 remains much less understood. Herein, the toxicity of titanium dioxide (TiO2 nanoparticles (NPs, silicon dioxide (SiO2 NPs and zirconium dioxide (ZrO2 NPs to unicellular freshwater algae Scenedesmus obliquus was investigated individually and in binary and ternary combination. Results show that the ternary combination systems of TiO2, SiO2 and ZrO2 NPs at a mixture concentration of 1 mg/L significantly enhanced mitochondrial membrane potential and intracellular reactive oxygen species level in the algae. Moreover, the ternary NP systems remarkably increased the activity of the antioxidant defense enzymes superoxide dismutase and catalase, together with an increase in lipid peroxidation products and small molecule metabolites. Furthermore, the observation of superficial structures of S. obliquus revealed obvious oxidative damage induced by the ternary mixtures. Taken together, the ternary NP systems exerted more severe oxidative stress in the algae than the individual and the binary NP systems. Thus, our findings highlight the importance of the assessment of the synergistic toxicity of multi-nanomaterial systems.

  10. Isolation and selection of microalgae from coal fired thermoelectric power plant for biofixation of carbon dioxide

    International Nuclear Information System (INIS)

    Morais, Michele Greque de; Costa, Jorge Alberto Vieira

    2007-01-01

    Global warming is thought to be caused mainly by the emission of carbon dioxide (CO 2 ), with thermoelectric power plants being responsible for about 7% of global CO 2 emissions. Microalgae can reduce CO 2 emissions from thermoelectric power plants, but for this use, they must be resistant to the mixture of gases produced by the power plants. We isolated the microalgae Scenedesmus obliquus and Chlorella kessleri from the waste treatment ponds of the Presidente Medici coal fired thermoelectric power plant in the Southernmost Brazilian state of Rio Grande do Sul and investigated their growth characteristics when exposed to different concentrations of CO 2 . When cultivated with 6% and 12% CO 2 , C. kessleri showed a high maximum specific growth rate (μ max ) of 0.267/day, with a maximum biomass productivity (P max ) of 0.087 g/L/day at 6% CO 2 . For S. obliquus, the highest maximum dry weight biomass value was 1.14 g/L with 12% CO 2 . We also found that these two microalgae also grew well when the culture medium contained up to 18% CO 2 , indicating that they have potential for biofixation of CO 2 in thermoelectric power plants

  11. [Fe]-hydrogenases in green algae: photo-fermentation and hydrogen evolution under sulfur deprivation

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, M.; Hemschemeier, A.; Happe, T. [Botanisches Institut der Universitat Bonn (Germany); Gotor, C. [CSIC y Universidad de Sevilla (Spain). Instituto de Bioquimica Vegetal y Fotosintesis; Melis, A. [University of California, Berkeley, CA (United States). Department of Plant and Microbial Biology

    2002-12-01

    Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted conditions. Biochemical analyses indicate that S. obliquus decreases almost the complete metabolic activities while maintaining a low level of respiratory activity. (author)

  12. Isolation and application of SOX and NOX resistant microalgae in biofixation of CO2 from thermoelectricity plants

    International Nuclear Information System (INIS)

    Radmann, Elisangela Martha; Vieira Camerini, Felipe; Duarte Santos, Thaisa; Vieira Costa, Jorge Alberto

    2011-01-01

    Highlights: → Microalgae can help reduce global warming. → Synechococcus nidulans and Chlorella vulgaris were isolated in a thermoelectric plant. → Microalgae were compared with Spirulina and Scenedesmus obliquus for CO 2 fixation. → Microalgae were exposed to CO 2 , SO 2 and NO, simulating a gas from coal combustion. → C. vulgaris and Spirulina sp. showed 13.43% of maximum daily fixation. - Abstract: Microalgae have been studied for their potential use in foodstuffs, agriculture, in the treatment of wastewater and, in particular, in the reduction of atmospheric carbon dioxide, the main cause of global warming. Thermoelectricity plants account for 22% of CO 2 emitted into the atmosphere and native microalgae may be more tolerant to the gases emitted from burning fossil fuels. In the study presented here, microalgae were isolated from ponds next to a Thermoelectricity Plant, located in southern Brazil, and identified as Synechococcus nidulans and Chlorella vulgaris. The isolated microalgae were grown and compared with two different strains of microalgae, Spirulina sp. and Scenedesmus obliquus, for CO 2 biofixation. The microalgae were exposed to 12% CO 2 , 60 ppm of SO 2 and 100 ppm of NO, simulating a gas from coal combustion. The C. vulgaris had similar behavior to Spirulina sp., with 13.43% of maximum daily fixation. The microalgae with the greater fixing capacity were C. vulgaris and Spirulina sp. and these can be grown in electric power plants for CO 2 biofixation of the coal combustion gas, which would help reduce global warming.

  13. Isolation and selection of microalgae from coal fired thermoelectric power plant for biofixation of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    de Morais, M.G.; Costa, J.A.V. [Federal University of Rio Grande, Rio Grande (Brazil)

    2007-07-15

    Global warming is thought to be caused mainly by the emission of carbon dioxide (CO{sub 2}), with thermoelectric power plants being responsible for about 7% of global CO{sub 2} emissions. Microalgae can reduce CO{sub 2} emissions from thermoelectric power plants, but for this use, they must be resistant to the mixture of gases produced by the power plants. We isolated the microalgae Scenedesmus obliquus and Chlorella kessleri from the waste treatment ponds of the Presidente Medici coal fired thermoelectric power plant in the Southernmost Brazilian state of Rio Grande do Sul and investigated their growth characteristics when exposed to different concentrations of CO{sub 2}. When cultivated with 6% and 12% CO{sub 2}, C. kessleri showed a high maximum specific growth rate ({lambda}{sub max}) of 0.267/day, with a maximum biomass productivity (P-max) of 0.087 g/L/day at 6% CO{sub 2}. For S. obliquus, the highest maximum dry weight biomass value was 1.14 g/L with 12% CO{sub 2}. We also found that these two microalgae also grew well when the culture medium contained up to 18% CO{sub 2}, indicating that they have potential for biofixation of CO{sub 2} in thermoelectric power plants.

  14. Isolation and selection of microalgae from coal fired thermoelectric power plant for biofixation of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Michele Greque de [Department of Chemistry, Laboratory of Biochemistry Engineering, Federal University Foundation of Rio Grande, Rio Grande, RS (Brazil); Costa, Jorge Alberto Vieira [Department of Chemistry, Laboratory of Biochemistry Engineering, Federal University Foundation of Rio Grande, Rio Grande, RS (Brazil)]. E-mail: dqmjorge@furg.br

    2007-07-15

    Global warming is thought to be caused mainly by the emission of carbon dioxide (CO{sub 2}), with thermoelectric power plants being responsible for about 7% of global CO{sub 2} emissions. Microalgae can reduce CO{sub 2} emissions from thermoelectric power plants, but for this use, they must be resistant to the mixture of gases produced by the power plants. We isolated the microalgae Scenedesmus obliquus and Chlorella kessleri from the waste treatment ponds of the Presidente Medici coal fired thermoelectric power plant in the Southernmost Brazilian state of Rio Grande do Sul and investigated their growth characteristics when exposed to different concentrations of CO{sub 2}. When cultivated with 6% and 12% CO{sub 2}, C. kessleri showed a high maximum specific growth rate ({mu} {sub max}) of 0.267/day, with a maximum biomass productivity (P {sub max}) of 0.087 g/L/day at 6% CO{sub 2}. For S. obliquus, the highest maximum dry weight biomass value was 1.14 g/L with 12% CO{sub 2}. We also found that these two microalgae also grew well when the culture medium contained up to 18% CO{sub 2}, indicating that they have potential for biofixation of CO{sub 2} in thermoelectric power plants.

  15. A Novel Miniature Culture System to Screen CO2-Sequestering Microalgae

    Directory of Open Access Journals (Sweden)

    Xiaoling Miao

    2012-11-01

    Full Text Available In this study, a novel 96-well microplate swivel system (M96SS was built for high-throughput screening of microalgal strains for CO2 fixation. Cell growth under different CO2 supply conditions (0.2, 0.4, 0.8, and 1.2 g L−1 d−1, residual nitrate, and pH value of Chlorella sp. SJTU-3, Chlorella pyrenoidosa SJTU-2, and Scenedesmus obliquus SJTU-3 were examined in the M96SS and traditional flask cultures. The dynamic data showed there was a good agreement between the systems. Two critical problems in miniature culture systems (intra-well mixing and evaporation loss were improved by sealed vertical mixing of the M96SS. A sample screen of six microalgal species (Chlorella sp. SJTU-3, Chlorella pyrenoidosa SJTU-2, Selenastrum capricornutum, Scenedesmus obliquus SJTU-3, Chlamydomonas sajao, Dunaliella primolecta was carried out in flasks and the M96SS. Chlamydomonas sajao appeared to be a robust performer (highest cell density: 1.437 g L−1 in anaerobic pond water with 0.8, and 1.2 g L−1 d−1 CO2. The reliability and efficiency of the M96SS were verified through a comparison of traditional flask culture, M96SS, Lukavský’s system, and a microplate shaker.

  16. Supersonic shear imaging provides a reliable measurement of resting muscle shear elastic modulus

    International Nuclear Information System (INIS)

    Lacourpaille, Lilian; Hug, François; Bouillard, Killian; Nordez, Antoine; Hogrel, Jean-Yves

    2012-01-01

    The aim of the present study was to assess the reliability of shear elastic modulus measurements performed using supersonic shear imaging (SSI) in nine resting muscles (i.e. gastrocnemius medialis, tibialis anterior, vastus lateralis, rectus femoris, triceps brachii, biceps brachii, brachioradialis, adductor pollicis obliquus and abductor digiti minimi) of different architectures and typologies. Thirty healthy subjects were randomly assigned to the intra-session reliability (n = 20), inter-day reliability (n = 21) and the inter-observer reliability (n = 16) experiments. Muscle shear elastic modulus ranged from 2.99 (gastrocnemius medialis) to 4.50 kPa (adductor digiti minimi and tibialis anterior). On the whole, very good reliability was observed, with a coefficient of variation (CV) ranging from 4.6% to 8%, except for the inter-operator reliability of adductor pollicis obliquus (CV = 11.5%). The intraclass correlation coefficients were good (0.871 ± 0.045 for the intra-session reliability, 0.815 ± 0.065 for the inter-day reliability and 0.709 ± 0.141 for the inter-observer reliability). Both the reliability and the ease of use of SSI make it a potentially interesting technique that would be of benefit to fundamental, applied and clinical research projects that need an accurate assessment of muscle mechanical properties. (note)

  17. Utilization of non-conventional systems for conversion of biomass to food components

    Science.gov (United States)

    Karel, M.; Nakhost, Z.

    1989-01-01

    Described here is work accomplished in investigating the potential use of micro-algae in yielding useful macronutrients for closed ecological life support systems in space habitats. Analysis of the chemical composition of the blue-green alga Synechoccus 6311 was done in the present work, and was compared to values found in previous work on the green algae Scenedesmus obliquus. Similar values were obtained for proteins, and lower values for nucleic acids and lipids. A second part of the work involved fabrication of food products containing various levels of incorporated algae (S. obliquus) proteins and/or lipids. Protein isolate was incorporated into a variety of food products such as bran muffins, fettuccine (spinach noodle imitation), and chocolate chip cookies. In the sensory analysis, the greenish color of the bran muffins and cookies was not found to be objectionable. The mild spinachy flavor was less detectable in chocolate chip cookies than in bran muffins. The color and taste of the algae noodles were found to be pleasant and compared well with commercially available spinach noodles.

  18. Abdominal crunch exercise analysis performed with maximum and submaximum loads: An electromyographic study

    Directory of Open Access Journals (Sweden)

    M.L. Moura

    2011-01-01

    Full Text Available The purpose of this study was to verify the electromyographic activity of the rectus abdominis and obliquus externus abdominis during abdominal crunch exercise performed with maximum and submaximum loads. Thirteen male and female university students participated in this investigation (18-23 years old. The subjects completed abdominal crunch exercise until exhaustion with 20, 40, 60 and 80% of the maximum load. The root-mean-square (RMS from electromyography activity of the rectus abdominis and obliquus externus muscles from the first and last three repetitions from each workload performed was analyzed. RMS for the last repetitions increased in relation to the first repetitions for the 20% workload, first two repetitions on 40% workload and first repetition on the 80% workload. There was no difference for the 60% workload. Results showed that external load on abdominal crunch exercise might be an alternative to increase intensity while performing abdominal crunch exercise, which on its turn can be a practical tool for subjects that aim to increase abdominal strength level.

  19. Molecular characterization of phytoplankton dissolved organic matter (DOM) and sulfur components using high resolution Orbitrap mass spectrometry.

    Science.gov (United States)

    Mangal, Vaughn; Stock, Naomi L; Guéguen, Celine

    2016-03-01

    Orbitrap high resolution mass spectrometry (HRMS) with electrospray ionization in both positive and negative polarity was conducted on Suwannee River fulvic acid (SRFA), Pony Lake fulvic acid (PLFA) standards, and dissolved organic matter (DOM) released by freshwater phytoplankton (Scenedesmus obliquus, Euglena mutabilis, and Euglena gracilis). Three-dimensional van Krevelen diagrams expressing various oxygenation states of sulfur molecules and abundance plots of sulfur-containing species were constructed. Orbitrap HRMS analysis of SRFA found a high density of peaks in the lignin region (77 %) and low density of protein material (6.53 %), whereas for PLFA, 25 % of the total peaks were lignin related compared to 56 % of peaks in protein regions, comparable with other HRMS studies. Phytoplankton-derived DOM of S. obliquus, E. mutabilis, and E. gracilis was dominated by protein molecules at respective percentages of 36, 46, and 49 %, and is consistent with previous experiments examining phytoplankton-derived DOM composition. The normalized percentage of SO-containing compounds was determined among the three phytoplankton to be 56 % for Scenedesmus, 54 % for E. mutabilis, and 47 % for E. gracilis, suggesting variation between sulfur content in phytoplankton-derived DOM and differences in metal binding capacities. These results suggest the level of resolution by Orbitrap mass spectrometry is sufficient for preliminary characterization of phytoplankton DOM at an affordable cost relative to other HRMS techniques.

  20. Segmental stabilization and muscular strengthening in chronic low back pain: a comparative study

    Directory of Open Access Journals (Sweden)

    Fábio Renovato França

    2010-01-01

    Full Text Available OBJECTIVE: To contrast the efficacy of two exercise programs, segmental stabilization and strengthening of abdominal and trunk muscles, on pain, functional disability, and activation of the transversus abdominis muscle (TrA, in individuals with chronic low back pain. DESIGN: Our sample consisted of 30 individuals, randomly assigned to one of two treatment groups: segmental stabilization, where exercises focused on the TrA and lumbar multifidus muscles, and superficial strengthening, where exercises focused on the rectus abdominis, abdominus obliquus internus, abdominus obliquus externus, and erector spinae. Groups were examined to discovere whether the exercises created contrasts regarding pain (visual analogical scale and McGill pain questionnaire, functional disability (Oswestry disability questionnaire, and TrA muscle activation capacity (Pressure Biofeedback Unit = PBU. The program lasted 6 weeks, and 30-minute sessions occurred twice a week. Analysis of variance was used for inter- and intra-group comparisons. The significance level was established at 5%. RESULTS: As compared to baseline, both treatments were effective in relieving pain and improving disability (p<0.001. Those in the segmental stabilization group had significant gains for all variables when compared to the ST group (p<0.001, including TrA activation, where relative gains were 48.3% and -5.1%, respectively. CONCLUSION: Both techniques lessened pain and reduced disability. Segmental stabilization is superior to superficial strengthening for all variables. Superficial strengthening does not improve TrA activation capacity.

  1. Deri Endüstrisi Atıksularından Kromun Çeşitli Alglerle Biyosorpsiyonu

    Directory of Open Access Journals (Sweden)

    T. NAKİBOĞLU

    2009-04-01

    Full Text Available Bu makalede yapılan kinetik testlerin amacı, deri endüstrisi atıksularından Cr(VI metalinin Scenedesmus obliquus ve Chlorella sp. ile biyosorpsiyonu için optimum reaksiyon süresinin ve optimum karıştırma hızının belirlenmesidir. Scenedesmus obliquus ve Chlorella sp. ile orijinal atıksu ve sentetik atıksuda yapılan Cr(VI biyosorpsiyon çalışmaları sonucunda optimum karıştırma süreleri sırasıyla 24 saat ve 6 saat olarak belirlenmiştir. Optimum karıştırma hızı her iki alg biyokütlesi için orijinal atıksu ve sentetik atıksuda 150 devir/dakika olarak belirlenmiştir. Makalede yapılan izoterm testlerinin amacı, deri endüstrisi atıksularından Cr(VI metalinin Scenedesmus obliquus ve Chlorella sp. ile biyosorpsiyonu için optimum pH, optimum sıcaklık ve optimum alg dozajını belirlemektir. Scenedesmus obliquus ve Chlorella sp. ile orijinal atıksu ve sentetik atıksuda yapılan biyosorpsiyon çalışmaları sonucunda optimum pH'lar sırasıyla 2 ve 1 olarak belirlenmiştir. Her iki alg türü için orijinal atıksu ve sentetik atıksuda optimum biyosorpsiyon sıcaklığı 250C olarak bulunmuştur. Optimum şartlarda orijinal atıksu ve sentetik atıksuda en yüksek Cr(VI giderimi yapan alg dozajları, her iki alg türü için 0.5 g/L olarak belirlenmiştir. Çalışma kapsamında, deri endüstrisi atıksularında bulunan Cr(VI ağır metal iyonlarının, Scenedesmus obliquus ve Chlorella sp. ile maksimum biyosorpsiyon kapasiteleri araştırılmış ve maksimum biyosorpsiyon kapasiteyi sağlayacak reaktör işletme koşulları (optimum karıştırma süresi, optimum karıştırma hızı, optimum pH, optimum sıcaklık, optimum alg dozajı belirlenmiştir.

  2. Optimierung der Gesichtsklassifikation bei der Erkennung von Akromegalie

    Directory of Open Access Journals (Sweden)

    Frohner R

    2013-01-01

    Full Text Available In vorausgegangenen Studien konnte gezeigt werden, dass eine Gesichtsklassifikation mittels Gesichtsphotographien zur Diagnostik von Akromegalie mit guten Ergebnissen eingesetzt werden kann. In diesem Artikel werden die grundlegende Vorgehensweise der Klassifikation mittels der Software FIDA erläutert sowie Optimierungsansätze mit dem Ziel diskutiert, diese Methode näher an den klinischen Einsatz zu bringen. Die Gesichtsklassifikation basiert auf „Knotenpunkten“, die verteilt über die jeweilige Frontal- und/oder Seitenansicht des Gesichts platziert werden und den so genannten „Graphen“ bilden. Mittels mathematischer Verfahren erfolgt eine Analyse der zugrunde liegenden Textur des Bildes sowie die Auswertung geometrischer Informationen. Untersucht wird, wie sich die Reduktion von als irrelevant eingestuften Knoten auf das Klassifikationsergebnis auswirkt. Ebenso wird untersucht, wie sich neu definierte Knoten, die die typischen morphologischen Veränderungen der akromegalen Erkrankung im Gesicht berücksichtigen, auf die Klassifizierungsergebnisse auswirken. Die interne Validierung erfolgt an einem Datenset bestehend aus 57 an Akromegalie erkrankten Probanden (29 weiblich, 28 männlich sowie 59 Kontrollen (29 weiblich, 30 männlich. Die externe Validierung wird an einer weiteren Stichprobe gemessen, die zum Zeitpunkt der Präsentation auf der Tagung der European Neuroendocrine Association 2012 in Wien 13 akromegale Patienten (7 weiblich, 6 männlich sowie 45 Kontrollen (25 weiblich, 20 männlich umfasste. Die Datenbank wird ständig durch neue Probanden aus verschiedenen Quellen erweitert. Erste Ergebnisse zeigen, dass die Verwendung von Graphen mit reduzierten Knoten und von neuen Sets von Knoten unter Einbeziehung typischer morphologischer Veränderungen des Gesichts die Klassifizierung weiter verbessert. Diese Ergebnisse ermutigen zu weiteren Untersuchungen an einer erweiterten Datenbank.

  3. Genetische Veränderungen an primären Prostatakarzinom-Biopsien in Korrelation zum klinischen Verlauf

    Directory of Open Access Journals (Sweden)

    Steiner T

    2002-01-01

    Full Text Available Die der Entstehung des Prostatakarzinoms zugrundeliegenden bzw. mit einem Progreß vergesellschafteten genetischen Veränderungen sind noch weitgehend unbekannt. Ziel der vorliegenden retrospektiven Untersuchung war die Erfassung genetischer Aberrationen an paraffineigebettetem Material primärer Prostatakarzinom-Biopsien und die Korrelation der Daten zum klinischen Verlauf. In 28 karzinomtragenden primären Prostatabiopsien wurden die Tumorareale gekennzeichnet. Nach Dissektion der Tumorzellen wurden die Proben mittels "comparative genomic hybridization" (CGH analysiert. Daten zum klinischen Verlauf der Patienten wurden erfaßt. Die mittlere Nachbeobachtungszeit betrug 36 Monate, alle Patienten wurden hormonablativ behandelt. 11 Patienten (39 % wiesen unter laufender Therapie einen Tumorprogreß auf. In 25 (88 % der 28 untersuchten Tumorareale konnten genetische Aberrationen detektiert werden, im Mittel fanden wir 4,8 Aberrationen je Tumor. Das Verhältnis Verlust / Zugewinn betrug 1,3 / 1. Folgende chromosomale Veränderungen wurden häufig festgestellt: Verluste von 6q in 40 %; von 8p in 32 %; von 16q in 21 %; von 18q in 21 %; Zugewinne von 8q in 32 %; von 17 in 43 %. In Korrelation zum klinischen Verlauf fand sich ein Zugewinn von 8q signifikant häufiger bei Patienten, welche im Beobachtungszeitraum einen Tumorprogreß entwickelten (64 % vs. 12 %; p = 0,0001. In der primären Tumorbiopsie waren bei progredienten Patienten im Mittel 5,3, bei Patienten ohne Tumorprogreß 3,8 Aberrationen je Tumor nachzuweisen. Unsere Ergebnisse zeigen, daß Veränderungen der Chromosomen 6q, 8, 16q, 17 und 18q regelmäßig beim Prostatakarzinom auftreten. Karzinome mit klinisch ungünstigem Verlauf weisen bereits in der primären Biopsie eine hohe genetische Instabilität auf.

  4. [Schosslisten...] / Juhan Kreem

    Index Scriptorium Estoniae

    Kreem, Juhan

    2004-01-01

    Rets. rmt.: Heinz von zur Mühlen. Schosslisten der Stadt Reval 1369-1372. Ein Querschnitt durch die Bewölkerungsentwicklung Revals von der Frühzeit bis zum Ende des 17. Jahrhunderts, in: Jahrbuch für die Geschichte Mittel- und Ostdeutschlands. Zeitschrift für vergleichende und preussische Landesgeschichte. Bd 48 (2002) München, 2003. S. 117-218. (Tegemist on Tallinna vanimate maksunimistute väljaandega, mida raamistab sotsiaalajalooline analüüs)

  5. Erhöht ein Opfer-Täter-Zyklus das Risiko, Sexualstraftaten als pädosexuelle Straftaten zu begehen? : Ergebnisse einer ereignisanalytischen Pilotstudie

    OpenAIRE

    Urban, Dieter; Lindhorst, Heiko

    2004-01-01

    Die Pilotstudie untersucht mittels multivariater Ereignisanalysen den Übergang vom ehemaligen Opfer pädosexuellen bzw. körperlichen Missbrauchs zum pädosexuellen Täter im Lebensverlauf verurteilter Sexualstraftäter. Zur Erklärung dieses Übergangs werden aus den wichtigsten täterorientierten Theoriemodellen drei Hypothesen abgeleitet, die empirisch getestet werden sollen. Diese Hypothesen betreffen das Risiko, nach Opfererfahrungen in der Kindheit zum Täter pädosexuellen Missbrauchs zu werden....

  6. Erhöht ein Opfer-Täter-Zyklus das Risiko, Sexualstraftaten als pädosexuelle Straftaten zu begehen? : Ergebnisse einer ereignisanalytischen Pilotstudie

    OpenAIRE

    Urban, Dieter; Lindhorst, Heiko

    2004-01-01

    "Die Pilotstudie untersucht mittels multivariater Ereignisanalysen den Übergang vom ehemaligen Opfer pädosexuellen bzw. körperlichen Missbrauchs zum pädosexuellen Täter im Lebensverlauf verurteilter Sexualstraftäter. Zur Erklärung dieses Übergangs werden aus den wichtigsten täterorientierten Theoriemodellen drei Hypothesen abgeleitet, die empirisch getestet werden sollen. Diese Hypothesen betreffen das Risiko, nach Opfererfahrungen in der Kindheit zum Täter pädosexuellen Missbrauchs zu werden...

  7. Touring Berlin

    OpenAIRE

    Farías, Ignacio

    2009-01-01

    Mittels einer Untersuchung von standardisierten Praktiken (Stadtrundgängen und Stadtrundfahrten) und Dispositiven (Stadtkarten, Reiseführer) fürs „Touren“ von Städten zeigt diese Dissertation, (1) wie die Stadt Berlin in ein virtuelles Objekt, nämlich, einen touristischen Zielort, transformiert wird, ( 2) wie diese Transformation nicht nur durch die Bewegung von Touristen im Raum und das Unterwegssein ermöglicht wird, sondern durch touristische Kommunikation über die Stadt, und (3) wie diese ...

  8. Texturierung und Visualisierung virtueller 3D-Stadtmodelle

    OpenAIRE

    Lorenz, Haik

    2011-01-01

    Im Mittelpunkt dieser Arbeit stehen virtuelle 3D-Stadtmodelle, die Objekte, Phänomene und Prozesse in urbanen Räumen in digitaler Form repräsentieren. Sie haben sich zu einem Kernthema von Geoinformationssystemen entwickelt und bilden einen zentralen Bestandteil geovirtueller 3D-Welten. Virtuelle 3D-Stadtmodelle finden nicht nur Verwendung als Mittel für Experten in Bereichen wie Stadtplanung, Funknetzplanung, oder Lärmanalyse, sondern auch für allgemeine Nutzer, die realitätsnah dargestellte...

  9. Das verfügbare Geld im Jugendalltag von 13- bis 17-jährigen Schülern und Schülerinnen: empirische Ergebnisse

    OpenAIRE

    Tully, Claus; Santen, Eric van

    2012-01-01

    "Prozesse der Bildung, Ablösung, Differenzierung und Positionierung gehören zur Verselbstständigung und zum Erwachsenwerden. Die Verfügung über Geld spielt dabei eine wichtige Rolle. Geld, als Voraussetzung für Konsum und damit Mittel, um 'im Spiel zu bleiben'. SchülerInnen verfügen über keine eigenen Einkünfte und sind auf Zuwendungen (Taschengeld und staatliche Transferleistungen wie Schüler-Bafög) oder selbst hinzu verdientes Geld angewiesen. Der Beitrag stellt empirische Ergebnisse zur Hö...

  10. Einfluss von abiotischen Faktoren auf Wuchs und Scopolamin-Biosynthese in Duboisia myoporoides.

    Directory of Open Access Journals (Sweden)

    Ullrich, Sophie Friederike

    2014-09-01

    Full Text Available Duboisia ist eine in Australien beheimatete Pflanze aus der Familie der Nachtschattengewächse, die Tropanalkaloide als sekundäre Pflanzeninhaltsstoffe enthält, deren quantitativ und ökonomisch bedeutsamstes Scopolamin ist. Um neue Erkenntnisse hinsichtlich des Einflusses abiotischer Faktoren auf Wuchs und Scopolamin-Biosynthese zu gewinnen, wurden Pflanzen der Art Duboisia myoporoides in Hydrokultur in Klimakammern unter streng kontrollierten Bedingungen angebaut (kalibrierte Einstellungen für Beleuchtungsdauer, Lichtintensität und Temperatur. Wichtige Messgrößen stellten dabei Biomasse und Alkaloidgehalt dar, letzterer gemessen mittels UHPLC und LC-MS.

  11. Empathy and the Big Five

    OpenAIRE

    Paulus, Christoph

    2016-01-01

    Del Barrio et al. (2004) haben vor mehr als 10 Jahren versucht, eine direkte Beziehung zwischen Empathie und den Big Five herzustellen. Im Mittel hatten in ihrer Stichprobe Frauen höhere Werte in der Empathie und auf den Big Five-Faktoren mit Ausnahme des Faktors Neurotizismus. Zusammenhänge zu Empathie fanden sie in den Bereichen Offenheit, Verträglichkeit, Gewissenhaftigkeit und Extraversion. In unseren Daten besitzen Frauen sowohl in der Empathie als auch den Big Five signifikant höhere We...

  12. Hochauflösende Fourier-Transform-Emissionsspektroskopie

    OpenAIRE

    Uibel, Christian

    2000-01-01

    Mittels hochauflösender Fourier-Transform-Infrarot-Emissionsspektroskopie wurden tiefliegende elektronische Anregungszustände der mittelschweren zweiatomigen Radikale As2, Sb2 und TeF untersucht. Dabei lag das Interesse vor allem bei den Emissionen nicht voll erlaubter Übergänge wie beispielsweise der 3Σ +u →  1Σ +g- bzw. (1u) →  (0+g)-Übergänge bei den Stickstoff-Homologen. Dieses besondere Interesse an der genauen Analyse der 3Σ +u-Zustände liegt in ihrem metastab...

  13. Welfare von Milchkühen in weidehaltenden Betrieben: Wie wirkt sich Weidehaltung auf das Sterblichkeitsrisiko von Kühen aus?

    DEFF Research Database (Denmark)

    Burow, Elke

    2011-01-01

    Die Strukturentwicklung in dänischen Milchviehherden führte in den letzten Jahrzehnten zu einem raschen Wachstum der Herden. Während im Jahr 1990 noch lediglich 36 Kühe je Betrieb gehalten wurden, waren es in 2000 bereits 66 im Mittel aller Betriebe (Dansk Kvæg 2009). Die derzeitige durchschnittl...... durchschnittliche Herdengröße beträgt 143 Kühe (Videncentret For Landbrug 2011). Dieser Trend ist vergleichbar mit den Entwicklungen in Deutschland und es ist zu erwarten, dass sich dieser Strukturwandel in beiden Ländern weiter fortsetzt....

  14. Nanostrukturierte Filme aus anorganisch-organischen Hybridmaterialien für die Photovoltaik

    OpenAIRE

    Perlich, Jan

    2009-01-01

    Es wurden nanostrukturierte dünne Filme aus kristallinem TiO2 für Anwendungen in der Photovoltaik untersucht. Die Herstellung der dünnen Filme basiert auf einem Hybridansatz. Das über eine Sol-Gel-Synthese bereitgestellte anorganische Metalloxid wird durch die Templateigenschaften des eingesetzten organischen Diblockcopolymers strukturiert. Über die Filmaufbringung mittels Schleuderbeschichtung wurden zunächst Hybridfilme hergestellt, die durch Kalzinierung in kristalline TiO2-Filme mit maßge...

  15. Radionuclides in corals of Costa Rica

    International Nuclear Information System (INIS)

    Loria M, L.G.; Banichevich, A.; Cortes, T.

    1998-01-01

    Using Low Level Spectrometry they have evaluated the activity (Kq/kg) of 40 K, the gamma emisor daugther of 238 U and 232 Th and the presence of arificial isotopes due to anthropogenic contamination. The probes used are coral as biodynamic captors. The results show a presence between low and mittel of natural isotopes compared to other accumulation processes like sedimentation in soil and agricultural production. The Caribbean side show a higher activity than the Pacific for 40 K and a similar for 226 Ra. Results show low activity for artificial radionuclides with short lif ( 137 Cs). (author) [es

  16. Verbesserte Visualisierung der Koronararterien in MSCT-Daten mit direkter Vergleichbarkeit zur Angiographie

    Science.gov (United States)

    Lacalli, Christina; Jähne, Marion; Wesarg, Stefan

    In diesem Beitrag stellen wir neue, automatisierte Verfahren zur Visualisierung der Koronararterien einerseits und für eine direkte Vergleichbarkeit mit konventionellen Angiogrammen andererseits vor. Unser Ansatz umfasst Methoden für die automatische Extraktion des Herzens aus kontrastverstärkten CT-Daten, sowie für die Maskierung grosser kontrastmittelgefüllter Kavitäten des Herzens, um die Sichtbarkeit der Koronararterien bei der Darstellung mittels Volumenrendering zu verbessern. Zum direkten Vergleich mit konventionellen Angiographien wurde ein Verfahren zur automatischen Generierung von Projektionsansichten aus den CT-Daten entwickelt.

  17. Die Bedeutung von Musiker- und Komponistenbriefe für die regionale und europäische Kulturgeschichte

    Directory of Open Access Journals (Sweden)

    Buschmeier Gabriele

    2002-01-01

    Full Text Available (nemački Die Entwicklung der Musikkultur insbesondere in Mittel- und Osteuropa ist von einem äußerst regen Austausch und lebendigen Beziehungen gekennzeichnet. Die Dokumente dieser Beziehungen sind zum Teil die erhaltene Briefe. Für den Musikwissenschaftler sind dabei alle Arten von Briefen sowohl privaten als auch geschäftlichen Charakters, von Interesse und zwar nicht nur Briefe von den sogenannten "Heroen" der Musikgeschichte, sondern insbesondere auch von nur lokal bekannten Musikern oder Menschen, die sich mit Musik beschäftigen.

  18. Freundschaftsbeziehungen in Zeiten sozialer Onlinenetzwerke – Die Bedeutung von Freundschaft für das Selbstkonzept Jugendlicher

    OpenAIRE

    Krafzick, Svenja; Schmidt, Esther

    2017-01-01

    Freundschaften sind und bleiben wichtig für die Persönlichkeitsentwicklung im Jugendalter, weil sie entscheidende soziale Ressourcen für das Leben darstellen. Durch soziale Medien entstehen neue Möglichkeiten aber auch Herausforderungen für die Freundschaftspflege. In der vorliegenden empirischen Arbeit werden mittels einer qualitativen Befragung von Jugend-lichen (n = 59) vier Freundschaftstypen identifiziert – die/der Traditionelle, die/der Modern-Traditionelle, die/der Onliner/in und die/d...

  19. Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

    OpenAIRE

    Heinrichs, Christina

    2013-01-01

    Durch thermische Entwässerung der Seltenerdmetall(SE)-Nitrat-Hydrate und der SE-Acetat-Hydrate im Argon-Strom/Vakuum konnten wasserfreie SE-Nitrate und SE-Nitrat-Monohydrate bzw. wasserfreie SE-Acetate erhalten werden. Es gelang zudem, SE-Oxyacetate durch thermische Zersetzung der SE-Acetate darzustellen. Des Weiteren wurde beim Erhitzen von Praseodym-Carbonat-Hydrat ein Pr-Carbonat-Hydroxid erhalten. Die Verbindungen wurden mittels Röntgenpulverdiffraktometrie und an ausgewählten Beispielen ...

  20. Experimentelle, analytische und numerische Untersuchungen des Rührreibschweißprozesses

    OpenAIRE

    Hoßfeld, Max

    2016-01-01

    Mit dem Rührreibschweißverfahren steht seit einigen Jahren eine Fügetechnologie zur Verfügung, mit der viele fügetechnische Problemstellungen speziell beim Fügen von Aluminiumlegierungen gelöst oder vermieden werden können. Mittels Rührreibschweißen können sämtliche Aluminiumlegierungen zuverlässig, hocheffizient und mit einem sehr hohen Verbindungswirkungsgrad gefügt werden. Dabei weisen rührreibgeschweißte Verbindungen bereits ohne Nachbehandlung sehr gute statische und zyklische Festigkeit...

  1. Impacts from electric railway operation on the power supply system characteristic; Einfluss des elektrischen Bahnbetriebs auf das Tagesbelastungsdiagramm der Energieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, C. [Militaerhochschule fuer Verkehr ``Todor Kableshkov``, Sofia (Bulgaria)

    1995-12-31

    Some characteristic figures are derived from daily load diagrams of electric railways, analized and compared with those of public power supply load diagram, especially with regard to sharing in base - medium - peak load and in day - night times, and optimizations are proposed. (orig.) [Deutsch] Fuer die Tagesbelastungsdiagramme elektrischer Bahnen werden einige Kennziffern gebildet, analysiert und mit denen des Tagesbelastungsdiagramms der Landesenergieversorgung verglichen, insbesondere hinsichtlich der Verteilung des Bahnenergiebedarfs auf Grund-, Mittel- und Spitzenlast sowie auf die verschiedenen Tages- und Nachtzeitzonen. Daraus werden Optimierungsvorschlaege abgeleitet. (orig.)

  2. Music and Artistic Artefacts: Symbols of Rohingya Identity and Everyday Resistance in Borderlands

    Directory of Open Access Journals (Sweden)

    Kazi Fahmida Farzana

    2011-01-01

    Full Text Available This study looks at the creation of music and art by Rohingya refugees in Bangladesh as a symbol of social resistance and identity. Ethnographic research on the Rohingyas’ use of music and art suggests that these non-conventional means play an important role in communicating their coherent identity and expressing their resistance to the discrimination and oppression experienced in their country of origin as well as in their exile in Bangladesh. This informal resistance is used to keep their memory alive, to transmit that history through verbal and visual expressions to the new generations, and to communicate information about themselves to outsiders. This article posits that these forms of expression, while suggestive of their identity and everyday resistance, occur mostly in an informal and indirect form, rather than in direct confrontation and protest. These informal means also reflect the Rohingyas’ pragmatism and coping strategies for living in the borderlands. ----- Die vorliegende Studie untersucht die Bedeutung der Musik und Kunst der Rohingya-Flüchtlinge in Bangladesch als Symbole sozialen Widerstands und Ausdruck ihrer Identität. Ethnographische Forschungen zur Rohingya-Musik und -Kunst lassen darauf schließen, dass diese nicht-konventionellen Mittel eine wichtige Rolle bei der Vermittlung ihrer kohärenten Identität spielen und ihren Widerstand gegen Diskriminierung und Unterdrückung in ihrem Herkunftsland als auch im Exil in Bangladesch ausdrücken. Der informelle Widerstand wird dazu verwendet ihre Erinnerung lebendig zu halten, ihre Geschichte mittels verbaler und visueller Ausdrucksformen weiterzugeben sowie mit der jungen Generation und Außenstehenden Informationen über sich selbst zu teilen. Der Artikel postuliert, dass diese Ausdrucksformen – wenngleich suggestiv in ihrer Identität und im alltäglichen Widerstand – meist in informeller und indirekter Form auftreten und nicht mittels direkter Konfrontation und

  3. Seminar of the expert committee ultrasonic testing. Abstracts; Seminar des Fachausschusses Ultraschallpruefung. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2017-07-01

    This seminar volume contains 13 papers focusing on the following topics: 1. Test methods in the automotive sector, 2. Characterization of metallic and non-metallic materials, 3. Industrial test approaches, 4. Fiber composite materials and structures, and 5. Defect characterization using imaging techniques. One paper was separately analyzed for this database. [German] Dieser Seminarband enthaelt 13 Beitraege mit folgenden Themenschwerpunkten: 1. Pruefansaetze im Automobilbereich, 2. Charakterisierung metallischer und nicht-metallischer Materialien, 3. Pruefansaetze im industriellen Umfeld, 4. Faserverbundwerkstoffe und -strukturen, und 5. Fehlercharakterisierung mittels bildgebender Verfahren.

  4. Big Data in kleinen und mittleren Unternehmen: Eine empirische Bestandsaufnahme

    OpenAIRE

    Vossen, Gottfried; Lechtenbörger, Jens; Fekete, David

    2015-01-01

    Dieser Bericht untersucht das Potential von Big Data in und für kleine und mittlere Unternehmen (KMU). Dafür werden mittels einer Umfrage, Fokus-Interviews und zusätzlichen Recherchen die Potentiale und Herausforderungen bei Big Data untersucht, welche für KMU zu Tragen kommen. Der Begriff Big Data selbst wird genauer betrachtet und es wird erklärt, welche Dimensionen abseits schierer Größe ebenfalls dazu zählen, wie etwa Vielfalt oder Schnelligkeit der Daten. Weiter wird mit eingängigen Prax...

  5. Die ILO-Standards zum Schutz von Arbeitnehmerrechten : ein Begründungsversuch mit Hilfe der kantischen Position von Norman E. Bowie

    OpenAIRE

    Bäumlisberger, Damian; Brink, Alexander

    2012-01-01

    "Der Beitrag ergründet die normativen Grundlagen der Standards zum Schutz der Arbeitnehmerrechte der International Labour Organization. Auf Basis der kantischen Position des US-amerikanischen Wirtschaftsethikers Norman E. Bowie zeigen die Autoren, dass sich Bowies Theorieansatz grundsätzlich dazu eignet, die vier Kernbereiche der ILO-Aktivitäten ethisch zu fundieren. Jedoch stößt Bowies Position bei der Begründung der ILO-Standards auch auf Grenzen, die nur teilweise mittels zusätzlicher, mit...

  6. Hochaufgelöste Magnetresonanz-Bildgebung der Mäuseaorta zur Bestimmung der Dynamik funktioneller Parameter durch Laufrad-Training bei ApoE-Knock-Out-Mäusen

    OpenAIRE

    Offenberger, Wolfgang

    2009-01-01

    Einführung: Atherosklerose ist eine führende Ursache von Morbidität und Mortalität weltweit. Die ApoE-Knock-Out-Maus (ApoE-/-) ist das wichtigste Tiermodell für das Studium der Atherosklerose und von Interventionen auf diese Erkrankung. Mittels hochaufgelöster Magnet-Resonanz-Bildgebung ist es möglich, eine nicht-invasive in-vivo Gefäß-Charakterisierung bei Mäusen durchzuführen. In dieser Arbeit wurden die Auswirkungen von Sport auf die Gefäßfunktion der Aorta ascendens und abdominalis bei Ap...

  7. Einfluss der Etch-and-Rinse-Technik auf Adper Easy Bond

    OpenAIRE

    Kunstmann, Thorsten

    2011-01-01

    Ziel der vorliegenden Studie war es die Auswirkungen der Etch-and-Rinse-Technik auf die Randqualität von Kompositfüllungen bei Anwendung des selbstätzenden Bondingsystems Adper Easy Bond zu untersuchen. An 64 extrahierten menschlichen Molaren wurden tiefe Klasse-II-Kavitäten präpariert, deren approximale Begrenzung unterhalb der Schmelz-Zement-Grenze lag. Diese wurden in acht Gruppen aufgeteilt, jeweils mit 8 Zähnen pro Gruppe, und mittels verschiedener Bonding-Techniken mit Kompositfüllungen...

  8. Zeitarbeit in Deutschland: Trends und Perspektiven

    OpenAIRE

    Burda, Michael C.; Kvasnicka, Michael