3 edition of The Application of diffusion theory to the analysis of hydrogen desorption data at 25êC found in the catalog.
The Application of diffusion theory to the analysis of hydrogen desorption data at 25êC
by National Aeronautics and Space Administration, George C. Marshall Space Flight Center, For sale by the National Technical Information Service in Marshall Space Flight Center, AL, [Springfield, Va
Written in English
|Statement||by Merlin D. Danford|
|Series||NASA technical memorandum -- 86531|
|Contributions||George C. Marshall Space Flight Center|
|The Physical Object|
We then discuss the kinetics of hydrogen adsorption and absorption, including parameters such as the activation energy, hydrogen diffusion coefficient and the apparent rates of absorption or desorption, which can be used to characterise the time-dependent sorption and desorption properties of materials. Diffusion dynamics: a review and revision of the quantitative theory of the spatial diffusion of innova Diffusion and defect data; The Application of diffusion theory to the analysis of hydrogen desorption data at 25C̊ [microform] / b The diffusion of innovations over time: A model study.
The isothermal relationships between hydrogen diffusion coefficient, DH, and hydrogen content, n (ratio of hydrogen/metal atoms) has both technological and academic interest. Completely revised and updated, this text provides an easy-to-read guide to the concept of mass spectrometry and demonstrates its potential and limitations. Written by internationally recognised experts and utilising real life examples of analyses and applications, the book presents real cases of qualitative and quantitative applications of mass spectrometry.
analysis: J #m o le s cm 2 s $! " D #d c d x $#m o le s % cm" 3 cm $ Thus: D = cm 2 /s Like chemical reactions, diffusion is a thermally activated process and the temperature dependence of diffusion appears in the diffusivity as an ÒArrhenius-typeÓ equation: D! D o e" E a &R T. Gives readers a detailed understanding of adsorption refrigeration technology, with a focus on practical applications and environmental concerns Systematically covering the technology of adsorption refrigeration, this book provides readers with a technical understanding of the topic as well as detailed information on the state-of-the-art from leading researchers in the field.
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Get this from a library. The Application of diffusion theory to the analysis of hydrogen desorption data at 25C̊. [Merlin D Danford; George C. Marshall Space Flight Center.]. THE JOURNAL OF CHEMICAL PHYSICS() Diffusion, adsorption, and desorption of molecular hydrogen on graphene and in graphite Justin Petucci,1 Carl LeBlond,2 Majid Karimi,1,a) and Gianfranco Vidali3 1Department of Physics, Indiana University of Pennsylvania, Indiana, PennsylvaniaUSA 2Department of Chemistry, Indiana University of Pennsylvania, Indiana, Pennsylvania.
5. Molecular desorption. According to Küppers et al., and Baouche et al., using a heating ramp of 1–3 K/s, molecular desorption starts around K reaching its peak at about K in agreement with earlier work on graphite ribbons with a similar setup.
At these temperatures atomic hydrogen is most likely all desorbed but the strongly bound O and P dimers are still on the by: Ono and Meshii approximated the desorption rate for a slab specimen based on the following equations:  ∂ C L ∂ t = − (π 2 d) 2 D e (C tot − C 0)  D e = D L 1 + γ C T exp (E b R T)  C tot = C L + C x = [1 + γ C T exp (E b R T)] C L where C L is the concentration of hydrogen in the normal iron lattice as defined in Eq.
2 Cited by: By solving the mass transport problem for DPSC with arbitrary diffusion coefficients of the redox species, the diffusion coefficient of hydrogen is readily determined.
Both methods yield a consistent value for the diffusion coefficient of hydrogen, D H 2, in mol dm-3 Cited by: The diffusion of molecular hydrogen (H2) on a layer of graphene and in the interlayer space between the layers of graphite is studied using molecular dynamics computer simulations.
The interatomic interactions were modeled by an Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potential. Molecular statics calculations of H2 on graphene indicate binding energies.
Application of a diffusion-desorption rate equation model in astrochemistry. He J, Vidali G. We take the experimental data of CO desorption from the MgO() surface and of D2 desorption from amorphous solid water ice as examples to show how a diffusion-desorption rate equation model explains the redistribution of adsorbate molecules among.
Hydrogen diffusion data Carbon and low alloy steels. In the absence of trapping the diffusivity is that for annealed pure iron. At temperatures up to about 80 °C for which the interstitial sites are tetrahedral the diffusion coefficient (m 2 /s) is given by:  D L = × 10 − 8 exp [− × 10 3 / R T].
Hydrogen and Oxygen Diffusion in LaCr 1-x Mg x O 3 at High Temperatures Magnesium-doped lanthanum chromite is a perovskite-type materials with good electronic conductivity at high temperatures. The bulk-diffusion rates of H 2 and O 2 through LaCr 1-x Mg x O 3 at °C must be understood in terms of the effects of doping on conduction.
The Zimm-Lundberg cluster theory was used to characterise water adsorption and desorption for wood isotherms at 10, 25, 40 and degrees-C.
The analysis showed that clustering of water molecules. hydrogen diffusion assisted by stress and strain J. Toribio, D. Vergara, M. Lorenzo & V. Kharin Department of Materials Engineering, University of Salamanca, Spain Abstract This work is based on previous research on the one-dimensional (1D) analysis of the hydrogen diffusion process, and proposes a numerical approach to simulate.
Abstract. The chapter is concerned with the model of multichannel diffusion of hydrogen in a solid. The model is developed for analysis of diffusion of small, so-called natural, hydrogen concentrations, describes experiments for the model verification, and presents data on the hydrogen binding energies in a solid obtained by identifying the model parameters by means of the experimental data.
The Application of diffusion theory to the analysis of hydrogen desorption data at 25C̊ [microform] / b An electrochemical study of hydrogen uptake and elimination by bare and gold-plated waspaloy [microform] The interaction of hydrogen with metal alloys [microform] /.
This book serves two purposes: 1) to provide worked examples of using DFT to model materials properties, and 2) to provide references to more advanced treatments of these topics in the literature. It is not a definitive reference on density functional theory.
Takafumi Ishii, Takashi Kyotani, in Materials Science and Engineering of Carbon, Introduction. A temperature programmed desorption (TPD) technique has been developed especially in the field of catalysis, because the technique allows one to study the interaction of reaction gases with solid surfaces, thereby being a powerful tool for both the evaluation of active sites on catalyst.
Ramaprabhu, N. Rajalakshmi, and A. Weiss, “ Design and development of hydrogen absorption/desorption high pressure apparatus based on the pressure reduction method,” Int.
Hydrogen Energy 23(9), – (). Analysis of Hydrogen Permeation Through Sub-Micron-Thick Palladium Alloy Membranes solid-phase diffusion through the bulk material, transition to the effluent surface, desorption into the gas phase and diffusion away from the surface.
Historically, this permeation process is limited by the bulk diffusion step and therefore membrane. 4) What is the molecular weight of a gas that diffuses 4 times slower than hydrogen.
The atomic mass of hydrogen is and since hydrogen is diatomic, the molecular mass of H₂ is (mass 1). We will give hydrogen's diffusion rate a value of 4 (rate 1) and the rate of the other gas is. Analysis of hydrogen diffusion in single-walled carbon nanotube was performed with molecular dynamic simulation.
The carbon nanotube is chosen because of a well-known fact that it is an excellent adsorption material with high surface volume ratio. The developed catalytic boundary layer theory takes into account various number of species in a gas mixture, diffusion phenomena, and different recombination efficiency for oxygen and nitrogen atoms.
The present study evaluates thermal desorption spectroscopy (TDS) data measured for UNS S duplex stainless steel. Variations in the TDS spectra are obtained by electrochemical hydrogen.Such enhanced reversible hydrogen desorption properties are ascribed to the strengthened interfacial interactions between LiBH4 and FG with large surface, as well as the formation of LiHxF1−x phase.1 Chapter 5 Chapter 5: Diffusion Diffusion: the movement of particles in a solid from an area of high concentration to an area of low concentration, resulting in the uniform distribution of the substance Diffusion is process which is NOT due to the action of a force, but a result of the random movements of atoms (statistical problem)1.
Diffusivity and 2 Fick’s laws.