Search results for "Diffusion"
showing 10 items of 1615 documents
A particle method for a Lotka-Volterra system with nonlinear cross and self-diffusion
2008
Rafael l. Ninyoles: Recorregut biogràfic i intel·lectual
2020
This article presents the biography and intellectual legacy of Valencian sociologist Rafael L. Ninyoles (1943- 2019). It reviews his formative itinerary, his early contributions to the field of the sociology of language, his latest contributions to the sociology of cities and cultural spaces, and his key involvement in the promoti-on and consolidation of the sociological study of Valencian society. The article includes a note on public acknowledgements to the author, plus an annex with a selective bibliography aimed at serving the interested reader and the posthumous diffusion of Ninyoles? oeuvre.
Local disequilibrium of plagioclase in high-temperature shear zones of the Ivrea Zone, Italy
1995
Microstructural and chemical analysis of plagioclase in 20 superficially similar amphibolite facies ductile shear zones in metagabbors and amphibolites of the Ivrea Zone in Italy reveals significant differences in An and Ba contents. Plagioclase, which was deformed at P-T conditions lower than those of the wall rocks, occurs in the following four different microstructural situations with different chemical compositions: (i) relatively undeformed porphyroclasts, (ii) dynamically recrystallized grains and subgrains rimming the porphyroclasts, (iii) infill of microcracks cross-cutting the porphyroclasts and (iv) fine-grained recrystallized grains in the matrix of the shear zones. The differenc…
Interaction of oxygen with Mo(100), Mo(110), and Mo(111) surfaces. RHEED and AES analyses of the molybdenum oxide nucleation and growth
1991
Abstract A study of the nucleation and growth of MoO 3 generated by interaction of oxygen with Mo(100), Mo(110), and Mo(111) single crystalline surfaces is investigated at high oxygen pressure (10 4 Pa) and low temperature (620 to 820 K). The results of RHEED and AES analyses prove that under these oxidation conditions, MoO 3 nucleates directly from the metal without intermediate formation of MoO 2 or nonstoichiometric molybdenum oxide such as Mo 4 O 11 . The structure and orientation of MoO 3 nuclei are characterized in relation with the parent molybdenum surface. On the Mo(110) and Mo(111) surfaces, which are faceting, the nucleation and growth of MoO 3 takes place by successive structura…
Survival probability approach to the relaxation of a macroscopic system in the defect-diffusion framework
2004
Water dynamics in different biochar fractions
2015
Biochar is a carbonaceous porous material deliberately applied to soil to improve its fertility. The mechanisms through which biochar acts on fertility are still poorly understood. The effect of biochar texture size on water dynamics was investigated here in order to provide information to address future research on nutrient mobility towards plant roots as biochar is applied as soil amendment. A poplar biochar has been stainless steel fractionated in three different textured fractions (1.0–2.0 mm, 0.3–1.0 mm and <0.3 mm, respectively). Water-saturated fractions were analyzed by fast field cycling (FFC) NMR relaxometry. Results proved that 3D exchange between bound and bulk water predominant…
The adoption of photovoltaic micro production systems in Finland
2016
A sustainable supply of energy is one of the most important requirements in order to achieve sustainable development. By using renewable resources society is not dependent on depleting reserves, but instead can have an inexhaustible source of clean energy. The rapid development of photovoltaics has led to lowered prices and increased efficiency making them more attractive alternative as a source of household electricity. Although governments play a key role in setting the constraints of how renewable energy is adopted, the wide-spread adoption of distributed electricity production ultimately depends on consumer decisions to buy them. This study examined the adoption process of photovoltaic …
A Positive Definite Advection Scheme Obtained by Nonlinear Renormalization of the Advective Fluxes
1989
Abstract A new method is developed to obtain a conservative and positive definite advection scheme that produces only small numerical diffusion. Advective fluxes are computed utilizing the integrated flux form of Tremback et al. These fluxes are normalized and then limited by upper and lower values. The resulting advection equation is numerically solved by means of the usual upstream procedure. The proposed treatment is not restricted to the integrated flux form but may also be applied to other known advection algorithms which are formulated in terms of advective fluxes. Different numerical tests are presented illustrating that the proposed scheme strongly reduces numerical and diffusion an…
Mikrostruktur der Lunge: Untersuchung mittels Diffusionsmessung von hochpolarisiertem 3Helium
2006
Imaging methods to study the lung are traditionally based on x-ray or on radioactive contrast agents. Conventional magnetic resonance imaging (MRI) has only limited applications for lung imaging because of the low tissue density of protons concentration of hydrogen atoms, which are usually the basis for the imaging. The introduction of hyperpolarized noble gases as a contrast agent in MRI has opened new possibilities for lung diagnosis. The present paper describes this new technique. Diffusion-weighted MRI for assessment of the lung microstructure is presented here as an example of the new possibilities of functional imaging. Studies to determine the sensitivity of the diffusion measurement…
Water Dynamics in Neural Tissue
2013
Water dynamics in post-mortem two-years old bovine cerebral right hemisphere has been investigated through Elastic and Quasi-elastic Neutron Scattering. Experimental parameters such as stability in time of the proton dynamics, data reproducibility and changes in the tissues dynamics upon the conservation protocol, cryogenic towards formalin addition, have been carefully investigated. Results are extremely encouraging and comparisons to magnetic resonance imaging findings are discussed.