1,592 research outputs found
Extension of the Johnson-Mehl-Avrami-Kolmogorov theory incorporating anisotropic growth studied by Monte Carlo simulations
Full text linkAn analytical theory has been developed, based on Monte Carlo (MC) simulations, describing the kinetics of isothermal phase transformations proceeding by nucleation and subsequent growth for d-1 dimensional growth in d dimensional space (with d 2 or 3). This type of growth is of interest since it is generally anisotropic, leads to hard impingement, and obtains strong deviations from the traditional Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory. Within the MC simulations 1D growth can occur with equal probability in two or three different nonparallel orientations in 2D space. In 3D space 2D growth can occur with equal probability in three (or two) different orthogonal orientations. The MC simulations show that initially always a regime is present where JMAK theory prevails, but that after a well-defined critical time a transition to a blocking regime occurs. Both regimes are characterized by clearly different, but nearly constant values of the Avrami exponent which depend on the dimensionality of growth and space and on the time dependence of nucleation. The dependence of the critical time and of the extended fraction within the blocking regime (based on the concept of the extended volume of the JMAK theory) on the nucleation and growth parameters has been extensively analyzed and all results of the MC simulations have been captured within the analytical theory
Oregon serious crime survey
No full textauthor, survey administration and data processing: Stan WoodwellCaption titleThis archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposesBureau of Justice Statistics, United States Department of Justice 80-BJ-CX-K009 82-BJ-CX-0002 82-BJ-CX-0014Mode of access: Internet from the Oregon Government Publications CollectionText in Englis
BJ-TSA-9, a Novel Human Tumor-Specific Gene, Has Potential as a Biomarker of Lung Cancer
No full textAbstractUsing bioinformatics, we have identified a novel tumorspecific gene BJ-TSA-9, which has been validated by Northern blot analysis and reverse transcriptionpolymerase chain reaction (RT-PCR). BJ-TSA-9 mRNA was expressed in 52.5% (21 of 40) of human lung cancer tissues and was especially higher in lung adenocarcinoma (68.8%). To explore the potential application of BJ-TSA-9 for the detection of circulating cancer cells in lung cancer patients, nested RT-PCR was performed. The overall positive detection rate was 34.3% (24 of 70) in peripheral blood mononuclear cells (PBMCs) of patients with various types of lung cancers and was 53.6% (15 of 28) in PBMCs of lung adenocarcinoma patients. In combination with the detection of two known marker genes SCC and LUNX, the detection rate was increased to 81.4%. A follow-up study was performed in 37 patients after surgical removal of tumor mass. Among nine patients with persistent detection of two to three tumor marker transcripts in PBMCs, six patients had recurrence/metastasis. In contrast, 28 patients with transient detection of one tumor marker or without detection of any tumor marker were all in remission. Thus, BJ-TSA-9 may serve as a marker for lung cancer diagnosis and as a marker, in combination with two other tumor markers, for the prediction of the recurrence and prognosis of lung cancer patients
Bj: Physical Parts Bj
No full textComments are invited and should be directed to the author at the address listed below. Please do not reproduce in any way without the permission of the authors. A complet
Estimation of the number of periodic orbits
No full textThe main theme of this paper is to estimate, for self-maps f : X --> X of compact polyhedra, the asymptotic Nielsen number N-infinity(f) which is defined to be the growth rate of the sequence {N(f(n))} of the Nielsen numbers of the iterates of f. The asymptotic Nielsen number provides a homotopy invariant lower bound to the topological entropy h(f). To introduce our main tool, the Lefschetz zeta function, we develop the Nielsen theory of periodic orbits. Compared to the existing Nielsen theory of periodic points, it features the mapping torus approach, thus brings deeper geometric insight and simpler algebraic formulation. The important cases of homeomorphisms of surfaces and punctured surfaces are analysed. Examples show that the computation involved is straightforward and feasible. Applications to dynamics, including improvements of several results in the recent literature, demonstrate the usefulness of the asymptotic Nielsen number.MathematicsSCI(E)19ARTICLE1151-18517
Interfacial reactions in Ti-6Al-4V with laser-embedded SiC particles and the origin of intergranular corrosion susceptibility of an Al-Mg alloy
No full textIn the first part of the paper the microstructure of Ti-6Al-4V with laser embedded SiC particle is explained. The interfacial reaction between Ti and SiC is responsible for the largely improved wear resistance of the Ti alloy. In the second part the phase responsible for the intergranular corrosion susceptibility of an Al-Mg alloy when annealed above 65 degreesC is identified and possible mechanisms to solve this interfacial problem are proposed.</p
Thermodynamics and long-range order of nitrogen in gamma'-Fe4N1-x
No full textModels are given for the description of the chemical potential of nitrogen in gamma'-Fe4N1-x. In previous work, gamma'-Fe4N1-x was treated as a (sub)regular solution, thereby assuming that the N atoms are distributed randomly on the sites of their own sublattice. However, in gamma'-Fe4N1-x, long-range ordering occurs of the N atoms over the sites of their own sublattice. Then, the expression for the configurational entropy should account for the occurrence of ordering. In the present article, the descriptions adopted and tested for gamma'-Fe4N1-x are based on a Langmuir-type approach, the Wagner-Schottky (WS) approach, and the Gorsky-Bragg-Williams (GBW) approach. Application of the various models to data of nitrogen-absorption isotherms for the gamma' iron-nitride phase shows that the subregular solution concept fails to describe the experimental data satisfactorily, whereas a very good agreement between theory and experiment is obtained for the WS and GBW approaches. It is shown that, in particular, accounting for the occupation of disorder (octahedral) sites by N atoms is necessary to obtain an accurate description of the chemical potential of nitrogen in gamma'-Fe4N1-x
Mismatch and misalignment at interfaces between Ag and Mn3O4 studied with HRTEM
No full textInternal oxidation of Ag-3at.%Mn resulted in Mn3O4 precipitates with a ''parallel'' topotaxy with the metal matrix and an octahedron shape due to {111} facets. Due to the tetragonality of Mn3O4, only a few planes and directions of Ag and Mn3O4 can be actual parallel. The precipitates exhibited a preference to align {111} planes parallel with the matrix for one pair of facets and then for another pair a tilt of 7.6 degrees occurs which is relieved by ledges in Ag. The dislocation structure at these parallel and tilted (111) interfaces, originating from a 1-dimensional mismatch and including phenomena such as stand-off and dissociation of dislocations, was scrutinized.</p
In-situ TEM study of the crystallization of thin films composed of Sb3.6Te with Ge
No full textThis paper addresses the crystallization of amorphous Sb3.6Te films (40 nm thick) and 5 at.% Ge containing Sb3.6Te films (10, 20 and 40 nm thick) as studied using in-situ annealing in a Transmission Electron Microscope (TEM). These materials show growth-dominated crystallization, in contrast to Ge2Sb2Tc5 that shows nucleation-dominated crystallization. Particularly the crystal-growth velocity in these systems is measured as a function of temperature from which the activation energy for growth can be derived. The strong effect of the 5 at.% Ge addition on the total crystallization behavior is revealed: Ge increases the crystallization temperature (from 95 to 150 degreesC), increases the activation energy for growth (from 1.58 to 2.37 eV), increases the nucleation rate and decreases the growth anisotropy.</p
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