Studi X-ray Diffractometry pada Struktur Coating Alumunium yang Dipreparasi Denganmetode Mechanical Alloying

X-RAY DIFFRACTOMETRY STUDY ON STUCTURE OF ALUMINUM COATING PREPARED BY A MECHANICAL ALLOYING METHOD. Aluminum (Al) coating was successfully deposited on the surface of low carbon steel by using a mechanical alloying method. After coating deposition, the aluminum coating was annealed in vacuum furnace of 5.6 Pa at elevated temperatures of 600 oC, 700 oC and 800 oC. Phase transformation and structure changes in aluminum coating at varying curing temperatures ware studied by means of X-ray diffraction (XRD). The presence of Al (111) diffraction peak from the results of XRD characterization indicates thatAl coating was deposited on the surface of low carbon steel. On the other hand, the results of XRD characterization show the phase transformation and structure changes of Al coating due to the effect of annealing temperature. It was indicated by the presence of diffraction peaks of Al3,2Fe, Fe3Al, dan Fe0,8Al0,2 after annealing.An increase in annealing temperature leads to decrease in d-spacing, lattice parameter, and lattice constant Fe0,8Al0,2(110). However, the lattice strain and dislocation density are likely to increase. Structure coating evolution occurred due to the diffusion of aluminum to the substrate of low carbon steel

Plasmodynamic synthesis of product based on aluminum in the oxygen atmosphere of a reactor-chamber

In this paper, the possibility is shown to synthesize oxide aluminum using a high-speed electro discharge plasma jet. The synthesized products were characterized by X-Ray diffractometry and transmission electron microscopy

Plasmodynamic synthesis of product based on aluminum in the oxygen atmosphere of a reactor-chamber

In this paper, the possibility is shown to synthesize oxide aluminum using a high-speed electro discharge plasma jet. The synthesized products were characterized by X-Ray diffractometry and transmission electron microscopy

Effect of oxygen concentration on phase composition of product plasmodynamic synthesis

In this paper, the possibility is shown to synthesize oxide aluminum using a high-speed electro discharge plasma jet. The synthesized products were charactirezed by X-Ray diffractometry and transmission electron microscopy

An XRD Study of Chemical Self-Discharge in Delithiated Cobalt Oxide

Changes in samples of Li1–xCoO2 were measured by X-ray diffractometry (XRD) after thermal aging treatments that cause capacity losses in electrochemical cells. Changes in lattice parameters were used to identify lithium re-intercalation into Li1–xCoO2 when it was aged in the presence of LiClO4, LiPF6, and LiAsF6 in propylene carbonate (PC). Li+ re-intercalation could account for the reversible capacity loss. Thermal aging at 75°C in pure PC or pure argon gas resulted in other changes that are attributed to the formation of spinel phase. The rate of the lithium re-intercalation increases in the following sequence: LiPF6<LiClO4<LiAsF6

Glucosamine HCl-based solid dispersions to enhance the biopharmaceutical properties of acyclovir

The objective of the work presented here was to assess the feasibility of using glucosamine HCl as a solid-dispersion (SD) carrier to enhance the biopharmaceutical properties of a BCS class III/IV drug, acyclovir (ACV). The solid-dispersions of acyclovir and glucosamine HCl were prepared by an ethanol-based solvent evaporation method. The prepared formulations characterized by photomicroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transforms infrared spectrophotometry (FTIR), powder x-ray diffractometry (PXRD) and drug content analysis. The functional characterization of ACV-SD was performed by aqueous solubility evaluation, dissolution studies, fasted versus fed state dissolution comparison, ex vivo permeability, and stability studies. Photomicroscopy and SEM analysis showed different surface morphologies for pure ACV, glucosamine HCl and ACV-SD. The physical-chemical characterization studies supported the formation of ACV-SD. A 12-fold enhancement in the aqueous solubility of ACV was observed in the prepared solid dispersions, compared to pure ACV. Results from in vitro dissolution demonstrated a significant increase in the rate and extent of ACV dissolution from the prepared ACV-SD formulations, compared to pure ACV. The rate and extent of ACV permeability across everted rat intestinal membrane were also found to be significantly increased in the ACV-SD formulations. Under fed conditions, the rate and extent of the in vitro dissolution of ACV from the formulation was appreciably greater compared to fasted conditions. Overall, the results from the study suggest the feasibility of utilizing glucosamine HCl as a solid dispersion carrier/excipient for enhancement of biopharmaceutical properties of acyclovir, and similar drugs with low solubility/permeability characteristics

О влиянии энергии плазмы на продукт плазмодинамического синтеза в системе Si-C

The paper presents results of experimental studies on the plasmodynamic synthesis of ultradispersed silicon carbide. The product was investigated by X-ray diffractometry. It was shown that management of main product characteristics (content of SiC, dispersion) is possible by the change of the input energy

Two-phase coexistence in Fe–Ni alloys synthesized by ball milling

We used mechanical alloying with a Spex 8000 mixer/mill to synthesize a series of Fe100–xNix alloys from x=0 to x=49. The Spex mill was modified so that it could also operate at a reduced milling intensity, and we compared the alloys synthesized after long times with the normal and reduced milling intensities. X-ray diffractometry and Mössbauer spectrometry were used to measure the volume fractions of the bcc and fcc phases in the alloys, and to determine the chemical compositions of the individual phases. We found that the composition ranges of the bcc and fcc single phase regions were extended well beyond their equilibrium ranges. At the higher milling intensity, we found that the bcc phase was destabilized with respect to the fcc phase, and the two-phase region shifted to lower Ni concentrations. For those alloys with coexisting bcc and fcc phases, we present evidence that the chemical compositions of the two phases are nearly the same. We explain the destabilization of the bcc with milling intensity as originating with a higher defect density in the bcc alloys than in the fcc alloys. We argue that this defect density is not homogeneous throughout the alloy, however, and the distribution of defect enthalpies can explain the two-phase coexistence in the as-milled alloys