Search Results

You are looking at 21 - 30 of 39 items for

  • Author or Editor: E. Schmidt x
  • Refine by Access: All Content x
Clear All Modify Search
Periodica Mathematica Hungarica
Authors:
G. Grätzer
,
H. Lakser
, and
E. T. Schmidt
Restricted access

Abstract  

In the course of our work within the framework of an interdisciplinary project dealing with the absolute dating of fossil bones from Austrian caves by means of the U-series method we became interested in possible U-concentration gradients in the bone samples. A successful attempt is reported to make the U-distribution in bones directly visible by irradiating the samples with thermal neutrons and detecting the emitted fission products of235U in a plastic foil using the track etch method. This turns out to be possible also for relatively small U-concentrations of the order of 1 ppm. The uranium seems to concentrate near the surfaces which is in qualitative agreement with earlier results from the literature obtained by means of neutron activation analysis.

Restricted access
Restricted access

The control and optimization of the glass-making process is a serious problem in glass production. An EGD procedure involving high-temperature vacuum extraction and total pressure measurement allows determination of the fining state (Läuterzustand) and fining behaviour (Läuterverhalten). The fining state is characterized by the contents of CO2, N2 and other gases from the batch reactions, and gas inclusions. Oxygen evolved in a second step is characteristic for the fining behaviour.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
G. Wolf
,
J. Lerchner
,
H. Schmidt
,
H. Gamsjäger
,
E. Königsberger
, and
P. Schmidt
Restricted access
Journal of Thermal Analysis and Calorimetry
Authors:
G. Wolf
,
E. Königsberger
,
H. Schmidt
,
L.-C. Königsberger
, and
H. Gamsjäger
Restricted access

Über die Gamma-Bestrahlung von Cycliten

I. Möglichkeiten zur Dc-Trennung des Wässrigen Reaktionsgemisches: Qualitative Bestimmung der Spaltprodukte

Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Bancher
,
J. Washüttl
,
B. Schmidt
,
P. Riederer
, and
F. Wurst

Abstract  

With different TLC-methods the Rf-values of myo-inosite, myo-inosose (2), (I) epi-inosose, tetrahydroxy-p-chinon, d, 1-myo-inosose-2-phenylosazon, d,1-xylo-4,5,6-trihydroxy-2-oxo-1,3 bis(phenylhydrazono)-cyclohexan are qualitative determined.

Restricted access

Über die Gamma-Bestrahlung von Cycliten

II. Bestrahlung von Myo-Inosit in Wässriger Lösung Unter Sauerstoff

Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Bancher
,
J. Washüttl
,
B. Schmidt
,
P. Riederer
, and
F. Wurst

Abstract  

After irradiation of an aqueous 1% myo-inosite solution in presence of oxygen, following radiolysis products are qualitative demonstrable: 2,3,5/4,6-pentahydroxycyclohexanon, d,1-3,5/4,6-tetrahydroxycyclohexandion, d,1-xylo-4,5,6-trihydroxycyclohexan-1,2,3-trion, tetrahydroxy-p-benzochinon, glyoxylic acid, formic acid and carbon dioxide. The increase in the concentration of the radiolysis products is followed by a loss of myo-inosite. In dependence of radiation dosis the above mentioned radiolysis products are quantitative determined.

Restricted access

Über die Gamma-Bestrahlung von Cycliten

III. Bestrahlung von Myo-inosit in Wässriger Lösung unter Stickstoff

Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Bancher
,
J. Washüttl
,
B. Schmidt
,
P. Riederer
, and
F. Wurst

Abstract  

Irradiating myo-inosite of 1% solution under N2 atmosphere, it was established that the oxidation goes only up to monoketone (myo-inose-2) and a desoxy derivative 1,3,5/2,4-cyclohexapentite (scyllo-quercite) occurs. A new polymer was also observed which did not take place during irradiation under O2 atmosphere.

Restricted access

Radiopharmaceuticals

VIII. Preparation of 6-123I-nicotinic acid diethylamide for potential brain studies

Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Knust
,
H. Machulla
,
P. Zabel
,
Chr Astfalk
, and
U. Schmidt

Abstract  

By nucleophilic isotope exchange, 6-123I-nicotinic acid diethylamide (6-123I-NADA) was synthesized in a solution of the starting compound and catalytic amounts of CuCl in acetic acid. After purification by high pressure liquid chromatography radiochemical yields up to 97% could be obtained within 10 minutes. In mice the radioactivity was rapidly accumulated in the brain reaching the maximum (4.16%/g) 0.5 minutes after i.v. injection and eliminated by a fast and a slow phase. At the maximum of accumulation the brain/blood ratio was 1.21, decreasing to less than 0.15 already after one hour.

Restricted access