Search

Your search keyword '"Lüdemann, Hans-Dietrich"' showing total 143 results
Start Over Author "Lüdemann, Hans-Dietrich"
143 results on '"Lüdemann, Hans-Dietrich"'

12. Search for hyperhermophilic microorganisms in fluids obtained from the KTB pump test

Author

Huber, Harald, Huber, Robert, Lüdemann, Hans-Dietrich, and Stetter, Karl Otto

Subjects
570 Biowissenschaften, Biologie, ddc:570
Abstract

Fluids from the KTB pilot hole were examined for the presence of possibly existing hyperthermophiiic microorganisms. Due to the expected low cell concentrations in the fluids, all particles (including organisms) were concentrated about a factor of 10000 by ccntrifugation. From these samples, enrichments of hypcrthermophiles were attempted at incubation temperatures between 85 and 120 °C at low (300 kPa) and high (25000 kPa) pressure. However, no hyperthermophilic microorganisms could be enriched from the concentrated samples.

Published
1994

14. The self-diffusion and hydrogen bond interaction in neat liquid alkanols: a molecular dynamic simulation study.

Author

Feng, Huajie, Gao, Wei, Sun, Zhenfan, Chen, Liuping, Lüdemann, Hans-Dietrich, Lei, Bingxin, and Li, Gaonan

Subjects
HYDROGEN bonding, ALCOHOLS (Chemical class), SELF-diffusion (Solid state physics), MOLECULAR dynamics, MOLECULAR interactions, TEMPERATURE effect, METHANOL
Abstract

Self-diffusion of methanol, ethanol, 1-propanol and 2-propanol has been studied by molecular dynamics simulation in the temperature range between the melting pressure curve and 478 K at pressures up to 300 MPa. The simulation results on self-diffusion of methanol, ethanol and 2-propanol (for 2-propanol, at high temperatures) agree well with experiment, which suggests that the simulation method is a powerful tool to obtain self-diffusion coefficients over wide range of temperature and pressure, under which it is rather difficult for experiments. The local structures of methanol, ethanol and 2-propanol are investigated by calculating the radial distribution functions, H-bond numbers, coordination numbers and the ratios of H-bond number divided by coordination number. The correlation between self-diffusion and structural properties, and the influence of temperature and pressure on them are discussed. The degree of forming H-bond space network in methanol, ethanol and water is higher than that in 2-propanol, and they are all higher than those in ammonia and methylamine. The simulation results demonstrate that the effect of hydrogen bonding on the translational dynamics in methanol and ethanol is more pronounced than that in 2-propanol. [ABSTRACT FROM PUBLISHER]

Published
2014
Full Text
View/download PDF

16. Proton spin–lattice relaxation rate in supercooled H₂O and H₂¹⁷O under high pressure

Author

Lang, Elmar, Girlich, D., Lüdemann, Hans-Dietrich, Piculell, L., and Müller, D.

Subjects
570 Biowissenschaften, Biologie, ddc:570, Physics::Chemical Physics
Abstract

The proton spin–lattice relaxation rate has been investigated as a function of pressure (p≤250 MPa), temperature (180 K≤T≤300 K), and oxygen‐17 enrichment (25.7 atom‐%, 50.7 atom‐%) in metastable water. Intramolecular proton–oxygen 17 dipolar interactions in light water in relation to deuterium electric quadrupole interactions in heavy water carry similar dynamic information and allow the complicated dynamic isotope effect in liquid water to be investigated in the whole metastable range. Under hydrostatic pressure the proton relaxation rate curve R1 (T, p, ωH) has been investigated at five different Larmor frequencies (100 MHz≤ω≤500 MHz). These experiments unequivocally prove the isotropy of reorientational motions of water molecules on a nanosecond time scale and demonstrate the necessity to include fast quasilattice vibrations into a consistent interpretation of the relaxation rates in the dispersion regime.

Published
1990

20. 13C-NMR OF FOREST SOIL LIPIDS

Author

Almendros, Gonzalo, primary, Tinoco, Pilar, additional, González-Vila, Francisco Javier, additional, Lüdemann, Hans-Dietrich, additional, Sanz, Jesús, additional, and Velasco, Francisco, additional

Published
2001
Full Text
View/download PDF

38. Front Matter.

Author

Frimmel, Fritz H., Abbt-Braun, Gudrun, Heumann, Klaus G., Hock, Berthold, Lüdemann, Hans-Dietrich, and Spiteller, Michael

Published
2002
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results