ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Application of multiple-angle-of-incidence ellipsometry to the study of thin fluid films adsorbed on surfaces (1991)
    s.l. : American Chemical Society
    Langmuir 7 (1991), S. 2219-2229 
    Details
    ISSN: 1520-5827
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/la00058a041
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Fluids in micropores. III. Self-diffusion in a slit-pore with rough hard walls (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 5432-5436 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Self-diffusion coefficients for a model slit-pore consisting of Lennard–Jones (12,6) fluid constrained between two plane-parallel rough hard walls have been computed by standard (microcanonical) molecular dynamics. Fluid molecules collide impulsively with the walls, their speeds remaining unchanged, but the directions in which they rebound from the walls are chosen probabilistically so that the walls behave as Maxwell's "perfectly adsorbing'' walls. For comparison, fluid contained in the same thermodynamic state by a pore with smooth walls has also been simulated. The local density profiles, which are the same in both rough and smooth-walled pores, show that the pore fluid forms distinct layers parallel with the walls. The rate of transverse diffusion (parallel with walls) within a given fluid layer depends markedly on its distance from the walls and on the nature of the walls. Transverse diffusion within the layer in contact with the rough wall is slower than that within the layer in contact with the smooth wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461659
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Fluids in micropores. IV. The behavior of molecularly thin confined films in the grand isostress ensemble (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 7707-7717 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The behavior of molecularly thin prototypical confined films [Lennard-Jones (12,6) fluid constrained between two plane-parallel walls consisting of like atoms fixed in the fcc (100) configuration] is studied by Monte Carlo in a new (grand isostress) ensemble whose parameters are the thermodynamic state variables [temperature T, chemical potential μ, and normal stress (load) applied to the walls Tzz] controlled in the surface forces apparatus used to study lubrication experimentally on a molecular scale. Additional parameters of the ensemble not generally controlled in this experiment are the film–wall interfacial area A and the crystallographic alignment (registry, or shear strain α) of the walls. A multiplicity of phases is found to comport with a given choice of the parameters. The thermodynamically stable one minimizes the grand isostress potential (free energy). By means of thermodynamic integration the stable phase of the film is determined as a function of α at fixed T, μ, Tzz, and A. Solid films comprising integral numbers of layers of atoms parallel with the walls are stable when the walls are appropriately aligned. When such films are sheared (α is varied), they undergo drainage (imbibition) transitions at critical strains, whereupon the film loses (gains) whole layers. Depending on the conditions, the solid film may melt just prior to the transition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.466865
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Thermodynamics of a fluid confined to a slit pore with structured walls (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 9140-9146 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In this article we extend our previous thermodynamic analysis of films confined to slit pores with smooth walls (i.e., plane–parallel solid surfaces without molecular structure) to the situation in which the walls themselves possess structure. Structured-wall models are frequently employed to interpret experiments performed with the surface forces apparatus (SFA), in which thin films (1–10 molecular diameters thick) are subjected to shear stress by moving the walls laterally over one another at constant temperature, chemical potential, and normal stress or load. The periodic structure of the walls is reflected in a periodic variation of the shear stress with the lateral alignment (i.e., shear strain) of the walls. We demonstrate by means of a solvable two-dimensional model that the molecular length scale imposed by the structure of the walls precludes the derivation of a simple mechanical expression for the grand potential analogous to that which holds in the smooth-wall case. This conclusion is borne out by the results of a grand-canonical Monte Carlo simulation of the three-dimensional prototypal model consisting of a Lennard-Jones (12,6) fluid confined between fcc (100) walls. Criteria for the thermodynamic stability of thin films confined by structured walls are derived and applied to the SFA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.466668
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Stratification-induced order–disorder phase transitions in molecularly thin confined films (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 6865-6873 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: By means of grand canonical ensemble Monte Carlo simulations of a monatomic film confined between unstructured (i.e., molecularly smooth) rigidly fixed solid surfaces (i.e., walls), we investigate the mechanism of molecular stratification, i.e., the tendency of atoms to arrange themselves in layers parallel with the walls. Stratification is accompanied by a heretofore unnoticed order–disorder phase transition manifested as a maximum in density fluctuations at the transition point. The transition involves phases with different transverse packing characteristics, although the number of layers accommodated between the walls remains unchanged during the transition, which occurs periodically as the film thickens. However, with increasing thickness, an increasingly smaller proportion of the film is structurally affected by the transition. Thus, the associated maximum in density fluctuations diminishes rapidly with film thickness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Transient coexisting nanophases in ultrathin films confined between corrugated walls (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 10824-10832 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Grand-canonical Monte Carlo and microcanonical molecular dynamics methods have been used to simulate an ultrathin monatomic film confined to a slit-pore [i.e., between solid surfaces (walls)]. Both walls comprise atoms rigidly fixed in the face centered cubic (100) configuration; one wall is smooth on a nanoscale and the other is corrugated (i.e., scored with regularly spaced rectilinear grooves one to several nanometers wide). Properties of the film have been computed as a function of the lateral alignment (registry), with the temperature, chemical potential, and distance between the walls kept constant. Changing the registry carries the film through a succession of equilibrium states, ranging from all solid at one extreme to all fluid at the other. Over a range of intermediate registries the film consists of fluid and solid portions in equilibrium, that is fluid-filled nanocapillaries separated by solid strips. The range of registries over which such fluid–solid equilibria exist depends upon the width of the grooves and the frequency of the corrugation. For grooves of width comparable to the range of the interatomic potential, fluid and solid phases cease to coexist. In the limit of very wide grooves the character of the film is similar to that of the film confined by strictly smooth walls. The rich phase behavior of the confined film due to the coupling between molecular (registry) and nano (corrugation) scales has obvious implications for boundary lubrication. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nanophase coexistence and sieving in binary mixtures confined between corrugated walls (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 2132-2139 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The grand canonical Monte Carlo method is used to study a binary mixture of Lennard-Jones atoms confined to a corrugated slit micropore which is in thermodynamic equilibrium with its bulk phase counterpart. The micropore has atomically structured walls; one of the which possesses nanoscale structure in the form of rectilinear grooves (corrugation). The grooved surface divides the confined fluid film into two strip shaped regions, that inside and that outside the grooves. Transverse solidlike order in the film gives rise to shear stress. Transverse order coupled with packing restrictions give rise to a difference between the pore and bulk fluid mixture compositions. Solidlike order may appear within the grooves only, outside the grooves only, or in both regions simultaneously. As the relative alignment of the walls is shifted the pore fluid undergoes freeze–thaw cycles in one or both regions with associated changes in the shear stress and pore fluid composition. The degree of transverse order in the film is less than would be expected in a pure Lennard-Jones film and fluid-solid phase transitions are gradual as opposed to sudden as seen in pure Lennard-Jones films. The magnitude of the shear stress is greatest when a fluid–solid phase transition occurs in both regions of the pore. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469690
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Statistical mechanics with three-dimensional particle tracking velocimetry experiments in the study of anomalous dispersion. I. Theory (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 13 (2001), S. 75-80 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Eulerian models developed to simulate dispersion in fluid mechanics often consider the flux of the contaminant species to be proportional to the concentration gradient via a constant or time-dependent dispersion coefficient. These models are crude approximations for systems with velocity fluctuations evolving over a hierarchy of scales on the scale of observation. We say a system behaves in a Fickian fashion if the dispersion coefficient is constant, it is quasi-Fickian if the dispersion coefficient is time dependent, and it is convolution-Fickian if the flux is a convolution. The fractional flux in the sense of fractional derivatives is a special case of a convolution-Fickian flux. More general forms of the flux are possible, and in any case we call all fluxes anomalous if there is not a constant coefficient of proportionality between the flux and the gradient of concentration. In paper I of this two-part sequence we present a theory with statistical mechanical origins for simulating anomalous dispersion. Under appropriate limiting conditions the theory gives rise to Fickian, quasi-Fickian, convolution-Fickian, and fractional-Fickian fluxes. The primary result is a dispersive flux of integral type which in its most general form is not a convolution on time (it is non-Markovian however), but it is always a convolution in space. The concentration is represented by the inverse Fourier transform of the self-part of the intermediate scattering function. In paper II we present an experimental procedure that uses this theory to examine if and when the Fickian limit is reached in porous media homogeneous on the Darcy-scale but heterogeneous on the pore-scale. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1328075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Keeping supercomputers under control (1986)
    [s.l.] : Nature Publishing Group
    Nature 321 (1986), S. 21-21 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR-The Purdue Water Resources Reseach Center in conjunction with the Office of Health and Environmental Research of the US Department of Energy recently co-sponsored a meeting on the current uses of, and future needs for, supercomputers in hydrology. 'Supercomputers in Hydrology: Future ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/321021a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Keeping supercomputers under control (1986)
    [s.l.] : Nature Publishing Group
    Nature 321 (1986), S. 120-120 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR-The Purdue Water Resources Reseach Center in conjunction with the Office of Health and Environmental Research of the US Department of Energy recently co-sponsored a meeting on the current uses of, and future needs for, supercomputers in hydrology. 'Supercomputers in Hydrology: Future ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/321120a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...