Search results for "g factor"
showing 10 items of 514 documents
Effect of pseudo-gravitational acceleration on the dissolution rate of miscible drops
2017
The effect of pseudo-gravitational acceleration on the dissolution process of two phase miscible systems has been investigated at high acceleration values using a spinning drop tensiometer with three systems: 1-butanol/water, isobutyric acid/water, and triethylamine/water. We concluded that the dissolution process involves at least three different transport phenomena: diffusion, barodiffusion, and gravitational (buoyancy-driven) convection. The last two phenomena are significantly affected by the centrifugal acceleration acting at the interface between the two fluids, and the coupling with the geometry of the dissolving drop leads to a change of the mass flux during the course of the dissol…
A neutron tomography study: Probing the spontaneous crystallization of randomly packed granular assemblies
2018
We study the spontaneous crystallization of an assembly of highly monodisperse steel spheres under shaking, as it evolves from localized icosahedral ordering towards a packing reaching crystalline ordering. Towards this end, real space neutron tomography measurements on the granular assembly are carried out, as it is systematically subjected to a variation of frequency and amplitude. As expected, we see a presence of localized icosahedral ordering in the disordered initial state (packing fraction around 0.62). As the frequency is increased for both the shaking amplitudes (0.2 and 0.6 mm) studied here, there is a rise in packing fraction, accompanied by an evolution to crystallinity. The ext…
Hard sphere fluids at a soft repulsive wall: A comparative study using Monte Carlo and density functional methods
2011
Hard-sphere fluids confined between parallel plates at a distance D apart are studied for a wide range of packing fractions including also the onset of crystallization, applying Monte Carlo simulation techniques and density functional theory. The walls repel the hard spheres (of diameter σ) with a Weeks-Chandler-Andersen (WCA) potential V(WCA)(z) = 4ε[(σ(w)/z)(12) - (σ(w)/z)(6) + 1/4], with range σ(w) = σ/2. We vary the strength ε over a wide range and the case of simple hard walls is also treated for comparison. By the variation of ε one can change both the surface excess packing fraction and the wall-fluid (γ(wf)) and wall-crystal (γ(wc)) surface free energies. Several different methods t…
Splitting of the surface phonon modes in wurtzite nanowires
2013
We analyze the surface optical modes of GaN nanowires (NW) and perform a comparative study with the characteristics expected for other polar NWs. The theoretical analysis of the modes is performed within the context of the effective medium theory that takes into account the dipolar interaction between neighboring NWs (Maxwell-Garnett approximation). It is shown that deviations of the exciting light from the NWs axis, which coincides with the wurtzite c-axis, result in the anticrossing of two distinct surface phonon branches, leading to their splitting in axial and planar components and the appearance of two peaks in the Raman spectra. Additional calculations are performed that determine th…
Anticrossing of axial and planar surface-related phonon modes in Raman spectra of self-assembled GaN nanowires
2012
cited By 17; International audience; GaN columnar nanostructures usually called nanowires have been investigated by micro-Raman spectroscopy. In addition to conventional Raman scattering by confined optical phonons of a wurtzite structure (i.e., E 2h and QLO modes), an unusual two peaks band centered near 700 cm -1 is observed and analyzed as a function of several experimental parameters (polarization, filling factor, incidence angle). The surface character of these two modes is experimentally confirmed by their high sensitivity to the dielectric constant of the as-grown nanowires surrounding medium. Calculations describing the nanowires' environment by means of an effective dielectric func…
The carrying capacity for Mediterranean bivalve suspension feeders: evidence from analysis of food availability and hydrodynamics and their integrati…
2004
Abstract In order to assess the carrying capacity of two Mediterranean areas, the Incze et al. model and its modification were applied. Our measures were carried out in the Gulf of Gaeta (Central MED), where mussels ( Mytilus galloprovincialis ) are intensively cultivated (production of approximately 200 t per year) and the Gulf of Castellammare (Southern MED), where bivalve culture is not widely practised. Velocities of water current and in field filtration rates were measured in each area. Total suspended matter (TSM), suspended chlorophyll-a (CHLa), lipid, protein and carbohydrate concentrations in the particulate were measured seasonally and used as tools to evaluate the trophic status …
Gamma-Interferon Regulates Secretion of G-CSF in Human Monocytes on the Transcriptional Level
1987
The production of colony stimulating factors (CSF) for granulocytes and monocytes is integrated into a network of communicating soluble messenger molecules resulting from T-cell/monocyte interactions. We assessed the capactiy of gamma-Interferon to modulate monocyte secretion of CSF by colony assays and Northern blot analysis to hybridize monocyte RNA with cDNA probes of different CSF-types. Whereas mRNA for GM-CSF was undetectable in untreated and gamma-IFN treated peripheral blood monocytes, the constitutive expression of mRNA for G-CSF and subsequent production of a CSF with biological activities similar to G-CSF could highly be enhanced by exposure of monocytes to gamma-IFN.
DeepSRE: Identification of sterol responsive elements and nuclear transcription factors Y proximity in human DNA by Convolutional Neural Network anal…
2021
SREBP1 and 2, are cholesterol sensors able to modulate cholesterol-related gene expression responses. SREBPs binding sites are characterized by the presence of multiple target sequences as SRE, NFY and SP1, that can be arranged differently in different genes, so that it is not easy to identify the binding site on the basis of direct DNA sequence analysis. This paper presents a complete workflow based on a one-dimensional Convolutional Neural Network (CNN) model able to detect putative SREBPs binding sites irrespective of target elements arrangements. The strategy is based on the recognition of SRE linked (less than 250 bp) to NFY sequences according to chromosomal localization derived from …
Small-Angle Scattering from Phase-Separated Metallic Alloys: From Experiment to Phase Diagrams
1994
In this paper, phase-separated metallic alloys are described in terms of concentration fluctuations. As a consequence, Small Angle Scattering equations which allow to calculate the entire scattering curve by incorporating particle-particle interference effects on the basis of the Percus-Yevick formalism, are obtained. It is shown that, for Aluminium-Lithium alloys, satisfactory fits of the experimental data can be obtained if it is assumed that Li rich elliptical monodisperse precipitate particles approach each other at average distances which are larger than the sum of the hard-sphere particle radii. It is also shown that a possible ambiguity of this model, within the Percus-Yevick formali…
Virus-receptor interactions of coxsackie B viruses and their putative influence on cardiotropism
2003
Specific virus-receptor interactions are important determinants in the pathogenesis of viral infections, influencing the location and initiation of primary infection as well as the viral spread to other target organs in the postviremic phase. Coxsackieviruses of group B (CVB) specifically interact with at least two receptor proteins, the coxsackievirus-adenovirus receptor (CAR) and the decay-accelerating factor (DAF), and cause a broad spectrum of diseases, including acute and chronic myocarditis. In the human heart, CAR is predominantly expressed in intercalated discs, regions of utmost importance for the functional integrity of the heart. Since DAF is abundantly expressed in epithelial an…