document

Knudsen self- and Fickian diffusion in rough nanoporous media

Malek, K. (author), Coppens, M.O. (author)

The effect of pore surface roughness on Knudsen diffusion in nanoporous media is investigated by dynamic Monte Carlo simulations and analytical calculations. A conceptual difference is found between the roughness dependence of the macroscopic, transport diffusivity and the microscopic, self-diffusivity, which is reminiscent of diffusion in...

journal article 2003

document

Impedance Simulation of a Li-Ion Battery with Porous Electrodes and Spherical Li+ Intercalation Particles

Huang, R.W.J.M. (author), Chung, F. (author), Kelder, E.M. (author)

We present a semimathematical model for the simulation of the impedance spectra of a rechargeable lithium batteries consisting of porous electrodes with spherical Li+ intercalation particles. The particles are considered to have two distinct homogeneous phases as a result of the intercalation and deintercalation of Li+ during charge and...

journal article 2006

document

Water diffusion through a membrane protein channel: A first passage time approach

Van Hijkoop, V.J. (author), Dammers, A.J. (author), Malek, K. (author), Coppens, M.O. (author)

Water diffusion through OmpF, a porin in the outer membrane of Escherichia coli, is studied by molecular dynamics simulation. A first passage time approach allows characterizing the diffusive properties of a well-defined region of this channel. A carbon nanotube, which is considerably more homogeneous, serves as a model to validate the...

journal article 2007

document

Collective diffusion coefficient of proteins with hydrodynamic, electrostatic, and adhesive interactions

Prinsen, P. (author), Odijk, T. (author)

A theory is presented for ?C, the coefficient of the first-order correction in the density of the collective diffusion coefficient, for protein spheres interacting by electrostatic and adhesive forces. An extensive numerical analysis of the Stokesian hydrodynamics of two moving spheres is given so as to gauge the precise impact of lubrication...

journal article 2007

document

The stress generated by non-Brownian fibers in turbulent channel flow simulations

Gillissen, J.J.J. (author), Boersma, B.J. (author), Mortensen, P.H. (author), Andersson, H.I. (author)

Turbulent fiber suspension channel flow is studied using direct numerical simulation. The effect of the fibers on the fluid mechanics is governed by a stress tensor, involving the distribution of fiber position and orientation. Properties of this function in channel flow are studied by computing the trajectories and orientations of individual...

journal article 2007

document

The Einstein relation in quantum wires of III-V, ternary, and quaternary materials in the presence of light waves: Simplified theory, relative comparison, and suggestion for experimental determination

Ghatak, K.P. (author), Bhattacharya, S. (author), Bhowmik, S. (author), Benedictus, R. (author), Choudhury, S. (author)

We study the Einstein relation for the diffusivity to mobility ratio (DMR) in quantum wires (QWs) of III-V, ternary, and quaternary materials in the presence of light waves, whose unperturbed energy band structures are defined by the three band model of Kane. It has been found, taking n-InAs, n-InSb, n-Hg1?xCdxTe, n-In1?xGaxAsyP1?y lattice...

journal article 2008

document

Brownian particles in transient polymer networks

Sprakel, J. (author), Van der Gucht, J. (author), Cohen Stuart, M.A. (author), Besseling, N.A.M. (author)

We discuss the thermal motion of colloidal particles in transient polymer networks. For particles that are physically bound to the surrounding chains, light-scattering experiments reveal that the submillisecond dynamics changes from diffusive to Rouse-like upon crossing the network formation threshold. Particles that are not bound do not show...

journal article 2008

document

An experimental study on the molecular organization and exciton diffusion in a bilayer of a porphyrin and poly(3-hexylthiophene)

Huijser, A. (author), Savenije, T.J. (author), Shalav, A. (author), Siebbeles, L.D.A. (author)

The exciton root-mean-square displacement (?D) in regioregular poly(3-hexylthiophene) (P3HT) deposited onto meso-tetrakis (n-methyl-4-pyridyl) porphyrin tetrachloride (H2TMPyP) has been determined from the photovoltaic response of a device based on these materials in a bilayer configuration. Excitons formed on illumination that reach the...

journal article 2008

document

Hydrogen vacancies facilitate hydrogen transport kinetics in sodium hydride nanocrystallites

Singh, S. (author), Eijt, S.W.H. (author)

We report ab initio calculations based on density-functional theory, of the vacancy-mediated hydrogen migration energy in bulk NaH and near the NaH(001) surface. The estimated rate of the vacancy mediated hydrogen transport, obtained within a hopping diffusion model, is consistent with the reaction rates of H-D exchange in nano-NaH at the...

journal article 2008

document

Efficient approach to nucleation and growth dynamics: Stationary diffusion flux model

Van Putten, D.S. (author), Kalikmanov, V.I. (author)

A new model describing the evolution of clusters in the processes of nucleation and growth is proposed. The diffusion flux in the nonstationary Fokker–Planck equation with an unknown distribution function is approximated by the closed form expression containing the steady-state solution of the Zeldovich–Frenkel equation. This is justified due to...

journal article 2009

document

The Role of Coherency Strains on Phase Stability in LixFePO4: Needle Crystallites Minimize Coherency Strain and Overpotential

Van der Ven, A. (author), Garikipati, K. (author), Kim, S. (author), Wagemaker, M. (author)

We investigate the role of coherency strains on the thermodynamics of two-phase coexistence during Li (de)intercalation of LixFePO4. We explicitly account for the anisotropy of the elastic moduli and analytically derive coupled chemical and mechanical equilibrium criteria for two-phase morphologies observed experimentally. Coherent two-phase...

journal article 2009

document

Publisher's Note: Diffusion Impedance on Nickel/Gadolinia-Doped Ceria Anodes for Solid Oxide Fuel Cells [J. Electrochem. Soc., 156, B1417 (2009)]

Aravind, P.V. (author), Ouweltjes, J.P. (author), Schoonman, J. (author)

journal article 2009

document

Thermal stability of gas phase magnesium nanoparticles

Krishnan, G. (author), Kooi, B.J. (author), Palasantzas, G. (author), Pivak, Y. (author), Dam, B. (author)

In this work we present a unique transmission electron microscopy study of the thermal stability of gas phase synthesized Mg nanoparticles, which have attracted strong interest as high capacity hydrogen storage materials. Indeed, Mg nanoparticles with a MgO shell ( ? 3?nm thick) annealed at 300?°C show evaporation, void formation, and void...

journal article 2010

document

Drivers of residual estuarine circulation in tidally energetic estuaries: Straight and irrotational channels with parabolic cross section

Burchard, H. (author), Hetland, R.D. (author), Schulz, E. (author), Schuttelaars, H.M. (author)

The generation of residual circulation in a tidally energetic estuary with constant longitudinal salinity gradient and parabolic cross section is examined by means of a two-dimensional cross-sectional numerical model, neglecting river runoff and Stokes drift. It is shown how the longitudinal and lateral residual circulation can be decomposed...

journal article 2011

document

Electron-beam-induced deposition of 3-nm-half-pitch patterns on bulk Si

Van Oven, J.C. (author), Berwald, F. (author), Berggren, K.K. (author), Kruit, P. (author), Hagen, C.W. (author)

This paper demonstrates electron-beam-induced deposition of few-nm-width dense features on bulk samples by using a scanning electron-beam lithography system. To optimize the resultant features, three steps were taken: (1) features were exposed in a repetitive sequence, so as to build up the deposited features gradually across the entire pattern,...

journal article 2011

document

Substrate-dependent kinetics in tyrosinase-based biosensing: Amperometry vs. spectrophotometry

Rassaei, L. (author), Cui, J. (author), Goluch, E.D. (author), Lemay, S.G. (author)

Despite the broad use of enzymes in electroanalytical biosensors, the influence of enzyme kinetics on the function of prototype sensors is often overlooked or neglected. In the present study, we employ amperometry as an alternative or complementary method to study the kinetics of tyrosinase, whose catalytic activity results in o-quinone products...

journal article 2012

document

Micro-imaging of transient guest profiles in nanoporous host systems of cylindrical symmetry

Binder, T. (author), Hibbe, F. (author), Chmelik, C. (author), Kärger, J. (author), Martinez-Joaristi, A. (author), Gascon, J. (author), Kapteijn, F. (author), Ruthven, D. (author)

Nanoporous host materials giving rise to transient guest profiles of cylindrical symmetry during molecular uptake and release are shown to provide particularly advantageous conditions for the study of guest diffusion by micro-imaging. Considering zeolites of structure type DDR (Deca-dodecasil 3R) as a host system and short-chain length...

journal article 2012

document

Benefits, Adoption Barriers and Myths of Open Data and Open Government

Janssen, M.F.W.H.A. (author), Charalabidis, Y. (author), Zuiderwijk, A.M.G. (author)

Although a significant number of public organizations have embraced the idea of open data, many are still reluctant to do this. One root cause is that the publicizing of data represents a shift from a closed to an open system of governance, which has a significant impact upon the relationships between public agencies and the users of open data....

journal article 2012

document

An analytical kinetic model for chemical-vapor deposition of pureB layers from diborane

Mohammadi, V. (author), De Boer, W.B. (author), Nanver, L.K. (author)

In this paper, an analytical model is established to describe the deposition kinetics and the deposition chamber characteristics that determine the deposition rates of pure boron (PureB-) layers grown by chemical-vapor deposition (CVD) from diborane (B2H6) as gas source on a non-rotating silicon wafer. The model takes into consideration the...

journal article 2012

document

Effects of slag and fly ash on reinforcement corrosion in concrete in chloride environment: Research from the Netherlands

Polder, R.B. (author)

A review is given of research on the durability performance of concrete made with blast furnace slag and fly ash related to chloride induced reinforcement corrosion, carried out in the Netherlands, where slag has been used in cement for almost a century. Results are presented from field studies on concrete in marine environment and laboratory...

journal article 2012