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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1999-2011 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: At the Rijnhuizen tokamak project a double pulse multiposition Thomson scattering diagnostic has been operational since 1996. It has been installed for the study of small scale structures in electron temperature (Te) and density (ne). This diagnostic measures Te and ne with high spatial resolution (3 mm full width at half maximum, i.e., 2% of the minor radius) and high accuracy (3%–4% of Te and 2%–3% of ne in the range of 50 eV–6 keV and ne=5×1019 m−3.) In this article an extensive error analysis is performed on both statistical and systematic deviations. It is found that the instrument function of the detection branch has a smoothing effect on the noise. This reduces the statistical error on the Te and ne measurements on each spatial position, because the resolution of the instrument is oversampled. The long tail of the instrument profile of the entire diagnostic has a significant effect on the systematic deviations in the Te and ne determination. However, it does not affect the relative size of the small scale structures on Te and ne, and for this this reason does not hamper the study of these structures. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A high resolution multiposition Thomson scattering setup to measure the electron temperature (Te) and density (ne) of a hot plasma is described. The system is operational at the Rijnhuizen Tokamak Project. Light from a high power pulsed ruby laser is scattered by the free plasma electrons and relayed to a Littrow polychromator for spectral analysis. The spectrally and spatially resolved light is detected by a GaAsP photocathode. The two-dimensional image is intensified and recorded with a charge-coupled device camera.Te in the range of 50 eV–6 keV can be measured at 115 spatial elements of 2.6 mm length along the laser beam. The observation error is 〈6% at ne=2×1019 m−3 and smaller for higher ne. The high resolution and accuracy enabled the observation of small scale structures in Te and ne. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article a double pulse multiposition Thomson scattering diagnostic, under construction at RTP, is discussed. Light from a double pulsed ruby laser (pulse separation: 10–800 μs, max. 2×12.5 J) is scattered by the free electrons of the tokamak plasma and relayed to a Littrow polychromator for spectral analysis. The spectrally resolved light is recorded by two ICCD detectors. Simulations show that the system sensitivity will be such that electron temperatures in the range of 100 eV–7 keV can be determined with an accuracy as good as 2%–3% for electron densities of 1020 m−3, with a spatial resolution down to 2.6 mm. With this diagnostic the dynamics of small scale structures in the electron temperature profile will be studied. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In the Rijnhuizen tokamak project, the double pulse multiposition Thomson scattering diagnostic is in full operation. Its high spatial resolution enables the measurement of small scale structures in Te, ne, and pe. Thomson scattering profiles during an ordinary sawtooth crash show the displacement of the hot core in great detail. Measurements on off-axis sawtoothing plasmas show that a small central part remains unaffected. Filaments are observed in plasmas which show a transient central temperature rise in response to fast edge cooling. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 501-503 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Multiposition tangential Thomson scattering makes it possible to measure the profiles of the local drift velocity and current density of a tokamak plasma. To achieve a reasonably small observational error (20%) a high photon yield is required. In this paper we propose an optical system to increase the photon yield by about a factor of 7. Photons from a pulsed ruby laser are captured in a ring cavity by means of an electro-optical switch. The trapped laser beam recirculates about 14 times through the sampling volume which is part of the cavity, increasing the laser energy of 25 J to an effective energy of about 140 J. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article, the recent installed multiposition Thomson scattering (TS) of the TJ-II stellarator is presented. Light from a pulsed ruby laser is scattered by the free electrons of the plasma and led to a spectrometer for spectral analysis. The Doppler broadened spectrum of the scattered light is analyzed with a spectrometer in the Littrow configuration, detected with a GaAsP image intensifier and recorded with two intensified charged coupled device cameras. Values of the electron temperature (Te) in the range of 50 eV up to 4 keV can be measured at 160 spatial elements of 2.25 mm along a chord of 360 mm. First results show that the observational error for Te is close to the expected error of ∼10% at an electron density (ne) of 1×1019 m−3 using a laser energy of 8 J. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 2673-2679 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The local current density is one of the most important and most difficult parameters to be determined in a thermonuclear plasma. An experimental setup to measure the local electron drift velocity and thus, the current density, by means of tangential Thomson scattering, is presented. The drift velocity of the plasma causes a small wavelength shift of the scattered spectrum, which will be proportional to the local current density if toroidal ion rotation can be neglected. The ratio between the drift velocity and the mean thermal electron velocity is small, typically ∼0.05. A 20-channel high transmission polychromator has been constructed to observe the electron temperature and density within an accuracy of 1% and the drift velocity within 20% at a plasma density ne≈5×1019 m−3 and a laser energy of 7 J. A feasibility test on radial scattering shows that there is good agreement between the accuracy obtained from quantum statistics and observations, respectively. The high transmission and relatively high resolution of the polychromator enable the observation of irregularities in the velocity distribution which should be taken into account in the determination of the drift velocity. Preliminary observations in the tangential direction demonstrate the possibility to determine the drift velocity by a single laser shot. At ne ≈6×1019 m−3 and a laser energy of 3.5 J in the scattering volume a wavelength shift of −2.5±0.5 nm has been recorded corresponding to jφ≈1×107 A/m2.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1436-6215
    Keywords: pig ; dietary protein ; intestine ; bile acids ; cholesterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung In der vorliegenden Studie werden quantitative und qualitative Unterschiede im Gehalt an Gallensäuren und Cholesterin beschrieben, die im Dünndarm von Miniaturschweinen nach Diäten beobachtet wurden, die entweder Casein oder Sojaproteinisolat enthielten. Die intestinale Gesamtmenge an Gallensäuren war signifikant höher, wenn Sojaproteinisolat gefüttert worden war. Wurde das Protein als einzige Komponente verfüttert, so lagen die Werte bei 4.51±0.39 mmol, während die Caseingruppe 2.43±0.08 mmol aufwies. Wurde das Protein als Teil einer semisynthetischen Diät gegeben, waren die Werte für die Sojagruppe 6.44±1.04 mmol und für die Caseingruppe 3.95±0.39 mmol. Bei der Caseingruppe lagen die prozentualen Anteile an der Gesamtmenge der Gallensäuren im Dünndarm bei 39.6 % Hyocholsäure, 31% Hyodeoxycholsäure und 27.6% Chenodeoxycholsäure. Die Tiere, die Sojaproteinisolat bekamen, hatten in der Tendenz mehr sekundäre Gallensäuren. Das Chymusfrischgewicht im Dünndarm lag in der Sojagruppe um 63 % über dem der Caseingruppe. Unter allen experimentellen Bedingungen wurde eine enge Beziehung zwischen dem Gehalt an Chymus und Gallensäuren im Dünndarm beobachtet. Die Sojagruppe wies in der Tendenz höhere Mengen an Gallensäuren im distalen Jejunum auf. Die Soja- und Caseingruppe wiesen keine Unterschiede im Cholesteringehalt des Dünndarms auf.
    Notes: Summary This study reports quantitative and qualitative differences in intestinal bile acids and cholesterol in miniature pigs following dietary casein or soy protein isolate. The total amount of bile acids in the small intestine was significantly higher when soy protein isolate was fed in comparison to casein. The values were (mean±SEM) 4.51 ±0.39 mmol and 2.43±0.08 mmol, respectively, when the proteins were given as the sole component of the diet. When the proteins were given as part of a semipurified diet, these values were 6.44±1.04 mmol and 3.95±0.39 mmol, respectively. Hyocholic acid amounted to 39.6%, hyodeoxycholic acid to 31 %, and chenodeoxycholic acid to 27.6% of total bile acids in the small intestine when casein was fed. The soy-fed animals tended to have more secondary bile acids. The total small bowel chymus content, on a wet weight basis, was 63 % higher in the soy group. In all experimental conditions studied, there was a close correlation between small bowel chyme content and bile acid content. The distribution of bile acids in the small intestine showed that the soy fed animals tended to have more bile acids in the distal parts of the jejunum. The intestinal cholesterol contents were not significantly different between dietary groups.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 25 (1986), S. 171-179 
    ISSN: 1436-6215
    Keywords: risk ; galactose ; hydrolyzed lactose ; toxicity ; galactose-1-phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Wir haben die Wirkung einer Glukose-Galaktose-Zufuhr, wie sie bei Aufnahme von Lebensmitteln mit hydrolysierter Laktose auftreten kann, untersucht. Dazu erhielten 5 gesunde erwachsene Versuchspersonen morgens nüchtern je 32,3 g Glukose plus 32,3 g Galaktose (entsprechend 125 g eines Magermilchpulvers mit hydrolysierter Laktose). Die postprandialen erythrozytären Galaktose-1-Phosphat-(Gal-1-P-)Spiegel stiegen bei keinem der Probanden höher als 22,3 Μmol/l gepackter Erythrozyten an. Damit erreichten die Konzentrationen dieses Indikatormetaboliten lediglich 22 % der Spiegel, die sich bei galaktosämischen Kindern als sicher herausgestellt haben, was die Entstehung von Leberoder Hirnschäden bzw. Katarakten angeht. Wir schließen daraus, daß das Kriterium der erythrozytären Gal-1-P-Spiegel kein Stoffwechselrisiko beim Konsum von hydrolysierter Laktose erkennen läßt. Hingegen ist die Aufnahme von Galaktose allein ohne Glukose von 17fach höheren Plasma-Galaktosespiegeln und einer ca. 8fach höheren erythrozytären Gal-1-P-Konzentration begleitet. Die Zufuhr von Galaktose allein dürfte daher ein erheblich höheres Stoffwechselrisiko verursachen.
    Notes: Summary This study deals with the metabolic effects of hydrolyzed lactose: After an overnight fast 5 healthy adult volunteers consumed a glucose-galactose mixture equivalent to 61.4g of lactose (or 125g of a dried skim milk powder with hydrolyzed lactose). The postprandial rise of erythrocyte galactose-1-phosphate (gal-1-P) never exceeded 22.3 Μmol per liter packed red blood cells. This amounts to no more than 22 % of the levels known from galactosemic children to be safe, concerning ocular, neural or hepatic damage. We conclude that the consumption of the hydrolyzed lactose does not cause a risk for consumer's health as judged from this galactose metabolite. A considerably higher risk, however, may accompany the consumption of galactose alone which causes around 17-fold higher plasma galactose levels and around 8-fold higher erythrocyte gal-1-P concentrations for more extended time periods.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1436-6215
    Keywords: cholesterol ; triglycerides ; lipoproteins ; ω 3 fatty acids ; Cholesterol ; Triglyceride ; Lipoproteine ; ω-3-Fettsäuren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung In einem Kurzzeit-Experiment wurde an gesunden, normolipidämischen Probanden geprüft, ob durch einen mäßig hohen Fischverzehr der Gehalt an Plasma- und Lipoproteinlipiden gesenkt werden kann. 8 Teilnehmer aßen eine Woche lang täglich 100 g Makrele (entsprechend etwa 2,5–3 g ω-3-Fettsäuren). Die Triglycerid-Konzentrationen im Plasma und in den VLDL und LDL waren nach der Fischdiät um 40, 46,7 und 38,5 % niedriger als zu Beginn des Experiments. Die Plasmacholesterol-Konzentration war nur geringfügig erniedrigt, das Verhältnis HDL/Gesamt-Cholesterol aber signifikant erhöht. Die Studie zeigt, daß eine moderate Steigerung des Fischverzehrs bei gesunden, normolipidämischen Probanden innerhalb einer Woche — selbst auf der Basis einer nicht strikt kontrollierten Diät — die Lipidspiegel verändern kann.
    Notes: Summary The effect of mackerel consumption on plasma and lipoprotein lipid concentrations was studied in a seven-day experiment in eight healthy, normolipidemic subjects. Participants ate about 100 g mackerel (corresponding to about 2.5–3 g ω3 fatty acids daily. The mean triglyceride concentrations in total plasma, VLDL, and LDL were significantly reduced by 40, 46.7, and 38.5 % respectively after fish consumption. There was also a small (non-significant) reduction of plasma cholesterol and a (significant) increase of the ratio of HDL/total plasma cholesterol. These data show that a moderately increased intake of ω-3 fatty acids by fish food can change lipid characteristics in healthy normolipidemic individuals within a short-time period, even on a free diet.
    Type of Medium: Electronic Resource
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