Inclusions Of Different Sizes Research Articles

Estimation of thermal and mass diffusivity in a porous medium of complex structure using a lattice Boltzmann method

The thermal and mass diffusivity in a porous medium of complex structure is studied by using the lattice Boltzmann method. The media under consideration include two-dimensional medium with an array of periodically distributed circular and square cylinders, three-dimensional granular medium of overlapping or non-overlapping spherical and cubical inclusions of different size, and randomly generated fibrous medium. The calculated effective diffusivities are in good agreement with existing analytical and numerical results when the inclusions, regardless of their shapes, are not overlapped. For the medium of overlapping inclusions, the effective diffusivity deviates from existing correlations as the inclusion fraction increases. In particular, the deviation increases dramatically if the thermal diffusivity of the inclusion is greater than that of the fluid in the medium for enhanced thermal conduction. A new empirical correlation between the effective diffusivity and the volume fraction for the medium of overlapping inclusions is proposed.

SERCA1 and calsequestrin storage myopathy: a new surplus protein myopathy

We describe four patients, from four different families, affected by a mild myopathy or asymptomatic elevated serum creatine kinase levels, in whom toluidine blue-stained semithin sections of muscle specimens revealed inclusions of different size and shape. The inclusions did not stain by routine histochemical studies. The sarcoplasmic or endoplasmic reticulum calcium 1 (SERCA1) ATPase and/or calsequestrin reactivity of inclusions, by immunohistochemistry, and the SERCA1- and calsequestrin-increased expression, by immunoblot, suggested that inclusions were constituted by an excess of proteins normally present in the terminal cisternae of sarcoplasmic reticulum. Our cases, both sporadic and familial, represent a new type of surplus protein myopathy.

Modelling the optical properties of composite and porous interstellar grains

There are indications that interstellar and interplanetary dust grains have an inhomogeneous and fluffy structure. We investigate different methods to describe light scattering by such composite particles. Both a model of layered particles and discrete dipole calculations for particles with Rayleigh and non-Rayleigh inclusions are used. The calculations demonstrate that porosity is a key parameter for determining light scattering. We find that the optical properties of the layered particles depend on the number and position of layers if the number of layers is small ($\la 15$). For a larger number of layers the scattering characteristics become independent of the layer sequence. The optical properties of particles with inclusions depend on the size of inclusions provided the porosity is large. The scattering characteristics of very porous particles with inclusions of different sizes are found to be close to those of multi-layered spheres. We compare the results of these calculations with the predictions of the effective medium theories (EMT) which are often used in astronomy as a tool to calculate the optical properties of composite particles. The results of our analysis show that the internal structure of grains (layers versus inclusions) only slightly affects the optics of particles provided the porosity does not exceed 50%. It is also demonstrated that in this case the optical properties of composite grains calculated with EMT agree with the results of the exact method for layered particles. For larger porosity, the standard EMT rules (i.e., Garnett and Bruggeman rules) give reliable results for particles with Rayleigh inclusions only.

Modelling of partial discharge inception and extinction voltages of sheet samples of solid insulating materials using an artificial neural network

This work attempts an estimation of partial discharge inception and extinction voltages (PDIV and PDEV) of sheet samples of solid dielectrics due to void inclusions of different sizes using an ANN. The effect of void dimensions and also the dielectric thickness of three common insulating materials, namely, Leatherite paper, polyethylene film and Perspex sheets on PDIVs and PDEVs are examined. Further, the effect of the permittivity of the insulating materials is also examined.

Molecular Theory of Lipid-Protein Interaction and the Lα- HII Transition

We present a molecular-level theory for lipid-protein interaction and apply it to the study of lipid-mediated interactions between proteins and the protein-induced transition from the planar bilayer ( L α ) to the inverse-hexagonal ( H II) phase. The proteins are treated as rigid, membrane-spanning, hydrophobic inclusions of different size and shape, e.g., “cylinder-like,” “barrel-like,” or “vase-like.” We assume strong hydrophobic coupling between the protein and its neighbor lipids. This means that, if necessary, the flexible lipid chains surrounding the protein will stretch, compress, and/or tilt to bridge the hydrophobic thickness mismatch between the protein and the unperturbed bilayer. The system free energy is expressed as an integral over local molecular contributions, the latter accounting for interheadgroup repulsion, hydrocarbon-water surface energy, and chain stretching-tilting effects. We show that the molecular interaction constants are intimately related to familiar elastic (continuum) characteristics of the membrane, such as the bending rigidity and spontaneous curvature, as well as to the less familiar tilt modulus. The equilibrium configuration of the membrane is determined by minimizing the free energy functional, subject to boundary conditions dictated by the size, shape, and spatial distribution of inclusions. A similar procedure is used to calculate the free energy and structure of peptide-free and peptide-rich hexagonal phases. Two degrees of freedom are involved in the variational minimization procedure: the local length and local tilt angle of the lipid chains. The inclusion of chain tilt is particularly important for studying noncylindrical (for instance, barrel-like) inclusions and analyzing the structure of the H II lipid phase; e.g., we find that chain tilt relaxation implies strong faceting of the lipid monolayers in the hexagonal phase. Consistent with experiment, we find that only short peptides (large negative mismatch) can induce the L α → H II transition. At the transition, a peptide-poor L α phase coexists with a peptide-rich H II phase.

Effect of inclusion morphology on the densification of powder composites

To investigate the densification of powder composites, spherical lead particles have been mixed with inclusions of different sizes and morphologies and compacted either under isotropic pressure or in a rigid die at 150°C. The obtained data show in particular that angular inclusions have a more drastic effect on the densification kinetics than spherical ones. This result is confirmed by the numerical simulation of the densification of regular bidimensional arrays containing viscoelastic circular particles and rigid inclusions of miscellaneous sections. From both experimental and numerical studies, the physical mechanisms which are likely to explain the effect of inclusion morphology on the consolidation process are discussed.

Development of protein bodies in cotyledons of Fagus sylvatica

Electron microscopic analysis of cotyledons of beech (Fagus sylvatica) at different stages of seed maturation indicates that protein bodies originate by gradual subdivision of the vacuoles in which reserve proteins are deposited. The majority of protein bodies show a proteinaceous matrix and a number of globoid inclusions of different sizes. In a small number of cells, druse‐like inclusions were observed. Analysis by SDS‐PAGE of proteins extracted from isolated protein bodies shows that the majority correspond to beech seed storage globulins.

Deformation consolidation of metal powders containing steel inclusions

Uniaxial consolidation experiments have been conducted at room temperature for two deformable metal powders (1100 Al and Pb5%Sb) containing various amounts of spherical steel inclusions. The experiments illustrate that the inclusion phase offers little constraint to matrix deformation at volume fractions <0.20, but produces a rapidly increasing constraint at larger volume fractions. Two constraining mechanisms have been identified through microstructural observations: (1) the matrix must be deformed more within the composite because of the excluded volume associated with the packing of particles and inclusions of different sizes, and (2) the inclusions form a continuous touching network (predicted with site percolation theory and direct observations of deformation flats on the steel spheres) which supports a portion of the applied stress and thus, partially “shields” the deformable phase from the total applied consolidation pressure. An analysis is presented to separate the contributions of each mechanism and shows that both mechanisms contribute comparable amounts to the constraint of matrix consolidation. It is suggested that because the inclusion network supports a significant portion of the applied pressure and releases its elastic strain in a non-linear manner (as described by Hertzian theory), the matrix is placed in tension when the applied pressure is released after consolidation.

Melting behavior of fluid inclusions in laboratory-grown halite crystals in the systems NaClH 2O, NaClKClH 2O, NaClMgCl 2H 2O, and NaClCaCl 2H 2O

The chemical composition of aqueous fluid inclusions in crystals of halite can be accurately determined from observed melting behaviors of ice, hydrohalite, and sylvite. Some fluid inclusion melting behaviors observed in laboratory-grown halite crystals (systems NaClH 2O, NaClKClH 2O, NaClMgCl 2 H 2O, and NaClCaCl 2H 2O) differ from predicted stable equilibrium relations. In the NaClH 2O and NaClKClH 2O systems, observed first melt temperatures are up to 15°C below the equilibrium eutectic temperatures of −21.2° and −22.9°C, respectively. The final melting temperature of ice, in the presence of hydrohalite, and the final melting temperature of hydrohalite are reproducible and match predicted melting temperatures. The limit of detection of sylvite daughter crystals in the NaClKClH 2O system is approximately 5 wt% (≈ 1 molal) KCl. Final melting temperatures of sylvite match published equilibrium data to within 0.3°C. In the NaClKClH 2O system at halite saturation, m KCl can be determined from the final sylvite dissolution temperature or from the final melting temperature of hydrohalite. Fluid inclusions in the NaClMgCl 2H 2O and NaClCaCl 2H 2O systems that form stable salt hydrates (MgCl 2 · 12H 2O and CaCl 2 · 6H 2O) during freezing first melt within 3°C of predicted eutectic temperatures (−37° and −52°C). However, fluid inclusions with MgCl 2 or CaCl 2 may also start melting at temperatures as low as −80°C. Such low first melt temperatures indicate the presence of metastable salt hydrates (presumably MgCl 2 · 8H 2O, MgCl 2 · 6H 2O or CaCl 2 · 4H 2O). The formation of metastable phases during freezing of fluid inclusions can lead to misinterpretation of the chemical composition of fluid inclusions in natural samples. This is especially true for fluid inclusions with first melt temperatures below −37°C which may be erroneously interpreted as being rich in CaCl 2. The final melting of ice in the presence of hydrohalite may vary by more than 15°C in fluid inclusions of different size but identical bulk composition, and occurs at lower temperatures than predicted in fluid inclusions from the NaClMgCl 2H 2O and NaClCaCl 2H 2O systems. However, the final melting temperature of ice in inclusions which fail to nucleate hydrohalite, and the final melting temperature of hydrohalite are reproducible to within ±0.1 ° C and can be used to determine MgCl 2 and CaCl 2 molalities.

Transmission electron microscopy of single-phase Co5Sm permanent magnets

Abstract The microstructure and magnetic domain structure of single-phase sintered Co5Sm permanent magnets has been studied by means of transmission electron microscopy. The materials contain coherent inclusions of different sizes within single-crystal Co5Sm grains. Inclusions with diameters less than 200 nm are characterized as Co7Sm2. The bordering α fringes correspond to a boundary fault vector of . Electron-diffraction analysis reveals that the large inclusions (> 300 nm) consist of a rhombohedral Co17Sm2 phase. Besides inclusions, grains with numerous fringe patterns perpendicular to the [0001] direction are also observed. These grains contain overlapping stacking faults with different crystallographic shear vectors of the type . The coercivity of the single-phase Co5Sm magnets is limited by the nucleation of reverse domains at soft magnetic inclusions. It is found that precipitates act as weak pinning centres for domain walls, and grain boundaries as strong ones.

Method for quantitative study of inclusions taking part in ductile fracture process

A technique is presented for relating the size and spatial distributions of inclusions on fracture faces produced by microvoid coalescence with those in the bulk material by considering the volumes from which inclusions of different sizes taking part in the fracture are drawn. It is demonstrated that in the simplest case, inclusions are drawn into the fracture from a distance proportional to their diameter.

Alterations of the clinically noninvolved skin in patients with malignant melanoma. An electron microscopic study before and after repeated application of BCG.

Clinically noninvolved skin of 5 patients with metastasizing malignant melanoma (MM) has been investigated under the electron microscope before and 4 weeks after repeated BCG inoculations (4 X). Increased melanin content, giant and unusual melanosomes, signs of cellular activity and some degenerative changes of the melanocytes were observed both in nontreated and in treated patients. Langerhans cells were markedly stimulated containing melanosome complexes and membrane-bound inclusions of different size and shape. Presence of amyloid, macrophage and plasma cells were also observed prior to and after repeated BCG inoculation, however, cellular infiltration was increased after this treatment and several dermal Langerhans cells appeared. These observations suggest that alterations of the melanocytes occur in MM, which are not confined to the tumor area. Moreover, BCG treatment seems to stimulate the tissue reaction against the tumor, including the activity of Langerhans cells.

大きさの異なる球型介在物が分布しているリムド軟鋼板の再結晶粒成長について

大きさの異なる球型介在物が分布しているリムド軟鋼板の再結晶粒成長について

On the phagocytosis of radiation-injured lymphocytes of the thymus

Part of the lymphocytes of the thymus were phagocytized by epithelial and mesenchymal reticular cells in rats after X-ray irradiation of the whole body. The intracellular decomposition is obviously brought about by the two cellular forms in a different way. Pearl-string-like structures — probably nucleoproteids — were found in the cytoplasma in the case of the epithelial cells. On the other hand, numerous cytoplasma inclusions of different size, which are evidently reduced lymphocytic nuclei, could be observed in the case of the mesenchymal cells.