Study of metal and metal oxides in the matrix of graphite and Graphene using photoacoustic technique

2020 ◽  
Author(s):  
Archana Kumari ◽  
A. K. Chaudhary
Keyword(s):  
Metal Oxides ◽  
Photoacoustic Technique ◽  
The Matrix

scholarly journals Influence of CNTs, ZnO, Gd2O3 and SiO2 on Calcium Silicate Hydrate: A Raman spectroscopic study

2021 ◽  
Author(s):  
Muhammad Azeem
Keyword(s):  
Metal Oxides ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Weight Percent ◽  
The Other ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
The Matrix ◽  
Vibrational Bands ◽  
Strength And Durability

Abstract Raman spectra are collated from the cement paste matrices of CNTs, ZnO, Gd2O3, and SiO2. The spectra show that CNTs do not take part in hydration process and therefore concentration of calcium silicate hydrate (CSH) is unchanged in CNT-OPC matrix. The metal oxides, on the other hand, have shown significant effects on the CSH concentration. The CSH concentration increases with the increase of ZnO weight percent in the matrix whereas spectra collected from Gd2O3 matrix shows the strongest CSH vibrational bands. Moreover, vibrational bands of CaCO3 also become weak in the matrices with Gd2O3. The addition of SiO2 however had opposite effects that is by increasing the weight percent of SiO2 in the matrix, the CSH concentration is decreased. Since CSH acts a glue in a binder, the study shows that its concentration can be controlled by adding foreign elements. Such binders are expected to show improved strength and durability.

Effects of the Combination of Organic Filter and Inorganic Metal Oxides and the Matrix Formulations on UV and Blue Light Protection Efficiencies

2020 ◽  
Vol 859 ◽  
pp. 153-158
Author(s):  
Onjira Chunnawong ◽  
Tasana Pitaksutepong
Keyword(s):  
Titanium Dioxide ◽  
Metal Oxides ◽  
Iron Oxides ◽  
Blue Light ◽  
Solar Spectrum ◽  
Protection Factor ◽  
Matrix Formulation ◽  
Protection Efficiency ◽  
The Matrix ◽  
Light Protection

Other portion of solar spectrum apart from UV, particularly blue light, is currently reported to induce the damaging effects to human skin. This study was aimed to investigate the effect of the combination of tris-biphenyl triazine (TBPT) and inorganic metal oxides as well as the effect of the matrix formulations on UV and blue light protection efficiencies. The protection efficiency of various combinations against UVB, UVA and blue light was determined through sun protection factor (SPF), UVA protection factor (UVA-PF) and porphyrin protection factor (PPF), respectively. The results demonstrated that TBPT combined with nanosize titanium dioxide and blended iron oxides (TT60-IR) achieved the highest SPF and UVA-PF. On the other hand, TBPT combined with submicron-size titanium dioxide and blended iron oxides (TT300-IR) yielded the highest PPF value. The matrix formulation affected the scattering property of the filters (i.e. combined TBPT and inorganic metal oxides). Containing the same amount and types of the filters, the matrix formulation that possessed a high transparency property showed high scattering efficiency against the blue light.

scholarly journals Formation of microfibrillar structure of polypropylene/copolyamide blends in the presence of nanoparticles of metal oxides

2021 ◽  
pp. 71-78
Author(s):  
N.M. Rezanova ◽  
◽  
Yu.O. Budash ◽  
V.P. Plavan ◽  
V.I. Bessarabov
Keyword(s):  
Metal Oxides ◽  
Structural Characteristics ◽  
Average Diameter ◽  
Dispersed Phase ◽  
Polarization Microscopy ◽  
Filter Materials ◽  
The Matrix ◽  
Modifying Effect ◽  
Nanoparticles Of Metal Oxides ◽  
Microfibrillar Structure

The influence of nanoparticles made of ifferent metals oxides (ZnO, Al2O3, TiO2, and ZnO/Al2O3) on the in situ formation of microfibrils by the components of a dispersed phase was studied in a thermodynamically incompatible blend of polypropylene/copolyamide (PP/CPA). The viscosity of the melts was determined by capillary viscometry method. Elastic properties were evaluated by the degree of extrudate swelling. The morphology of the compositions was studied by optical polarization microscopy. The method of image analysis was used to quantify the structural characteristics of the blends. It was established that the introduction of 1.0 wt.% of nanoparticles of the studied oxides made from different metals allows tuning the microstructure of the melt of the PP/CPA blend, which is realized in the course of extrusion. More perfect morphology is formed in nanofilled systems: the average diameter of PP microfibrils decreases and their mass fraction increases. The modifying effect of oxide nanoparticles is manifested due to their influence on interfacial phenomena and rheological properties of nanofilled PP melt. The viscosity of the PP melts increases and their elasticity decreases in the presence of nanoparticles of the studied metal oxides. The values of the ratio of the viscoelastic characteristics of the dispersed phase and the matrix in nanofilled systems depend on the nature of oxide and indirectly correlate with the microstructure of the extrudate. As these ratios approach unity, the diameter of PP microfibrils decreases and their share increases. The efficiency of the studied oxides to improve the microfibrillar structure increases in the following series: ZnO, Al2O3, TiO2, ZnO/Al2O3. The obtained results demonstrate the possibility to create the microfiber textile and filter materials with improved consumer characteristics by adjusting the phase morphology of the blends.

Crystalloid Inclusions in Hepatocyte Mitochondria and Their Similarity to Cytoplasmic Crystalloids

1974 ◽  
Vol 32 ◽  
pp. 198-199
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo
Keyword(s):  
Liver Disease ◽  
Alcoholic Liver Disease ◽  
Special Interest ◽  
Structural Variations ◽  
Mitochondrial Alterations ◽  
The Matrix ◽  
Crystalloid Inclusions ◽  
Liver Biopsies

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.

Coherency loss in γ' precipitates in nickel-base superalloy

1983 ◽  
Vol 41 ◽  
pp. 244-245
Author(s):  
R. A. Ricks ◽  
Angus J. Porter
Keyword(s):  
Lattice Mismatch ◽  
Lattice Parameter ◽  
Nickel Base Superalloy ◽  
Large Size ◽  
The Matrix ◽  
Nimonic 80A ◽  
Interfacial Dislocations ◽  
Nickel Base ◽  
Coherency Loss ◽  
Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Organisation in the Structure of the Cytoplasmic Ground Substance

1978 ◽  
Vol 36 (3) ◽  
pp. 627-639
Author(s):  
K.R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Random Distribution ◽  
Ground Substance ◽  
The Matrix ◽  
Cell Processes ◽  
Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

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