Pistacia lentiscus extract as a green inhibitor for copper corrosion in 0.5 M of H2SO4: electrochemical characterization and theoretical investigations

Journal of Applied Electrochemistry - The current work aims to study the effect of Pistacia lentiscus (Pil) essential oil originating from Chefchaouen city, which is located in northeastern Morocco...     

Influence of Laser Welding on the Alumina Growth on a Thin FeCrAl-RE Foil at High Temperature

We study isothermal oxidation of laser welded FeCrAl-RE samples containing specific fractions of seams in a bead-on-plate configuration at approximately 900°C using thermogravimetric analysis (TGA), field emission scanning electron microscope (FEG-SEM), transmission electron microscope (TEM), electron probe microanalysis (EPMA) techniques. An important reduction in the alumina-growth rate over the fusion zone compared to the base material occurs at 900°C, thereby, suppressing the discontinuous increase in mass gain commonly observed for alumina-forming alloys when the temperature decreases from 1000°C to 900°C. This phenomenon is mainly related to the concomitant dramatic chromium carbide precipitation at the fusion zone/oxide film interface and possible earlier injection of the rare earth elements into the oxide layer. On one hand, chromium carbide precipitation, which is linked to the laser melting-induced high free carbon, contributes to improve the effectiveness of the diffusion barrier provided by the thermally growing scale. On the other hand, due to their initial high enrichment at the fusion zone surfaces, rare earth elements can penetrate in the oxide layer and promote the elimination of detrimental phase transformation of metastable platelets (γ,θ-Al₂O₃) to α-Al₂O₃ during the initial stages of oxidation.     

Analysis of a human cDNA containing a tissue-specific alternatively spliced LIM domain

A unique clone, isolated from a human pancreatic cDNA library, was sequenced and characterized. Northern blot analysis showed that the gene is active in a number of fetal and adult tissues, and immunoblots showed expression in nuclear and cytosolic cell fractions. The gene corresponding to the clone was localized to chromosome 13 by human/rodent somatic cell hybrid panels. The largest open reading frame contains a LIM domain, and the deduced peptide from the open reading frame appears to have the characteristics of a LIM-only protein, designated LMO7. RT-PCR and genomic sequence analyses indicate that expression of this gene product is subject to tissue-specific modulation by elimination of the LIM domain by alternative splicing in neural tissues.     

Effect of Thickness Size on Magnetic Behavior of Layered Ising Nanocube Fe/Co/Fe: a Monte Carlo Simulation

Journal of Superconductivity and Novel Magnetism - The Monte Carlo simulation method is used to investigate the magnetic and thermodynamic properties of a single Ising nanocube Fe/Co/Fe system...     

Investigating the effects of grain boundary energy anisotropy and second-phase particles on grain growth using a phase-field model

A phase-field model was used to investigate the simultaneous effects of grain boundary energy anisotropy and the presence of second-phase particles on grain growth in polycrystalline materials. The system of grains with anisotropic grain boundary energies was constructed by considering models of low and high misorientation angles between adjacent grains. Systems without particles reached a steady state grain growth rate, and this rate decreased by including the grain boundary energy anisotropy. In addition, the presence of particles significantly altered the microstructures during grain growth. This study showed that for systems including particles, the critical average grain size to stop grain growth depends not only on the volume fraction and size of particles, but also on the grain boundary energy anisotropy.     

Dynamic Behavior of a Rare-Earth-Containing Mg Alloy,WE43B-T5, Plate with Comparison to Conventional Alloy,AM30-F

The dynamic behavior of Mg alloys is an area of interest for applications such as crash-sensitive automotive components and armor. The rare-earth element-containing alloy WE43B-T5 has performed well in ballistic testing, so the quasi-static (~10^?3 1/s) and dynamic (~600–5000 1/s) mechanical behaviors of two Mg alloys, rolled WE43B-T5 and extruded AM30-F, were investigated using servohydraulic and Kolsky bar testing in uniaxial tension and compression. The yield stress was surprisingly isotropic for WE43B-T5 relative to conventional Mg alloys (including extruded AM30-F). The WE43B plate was textured; however, it was not the typical basal texture of hot-rolled Mg-Al alloys. The effect of strain rate on the yield strength of WE43B-T5 is small and the strain-hardening behavior is only mildly rate sensitive (m = 0.008). The combination of high strength (~300 MPa), moderate ductility (0.07–0.20), and low density yield a material with good specific energy absorption capacity.     

A study on the structure and mechanical behavior of the Terrapene carolina carapace: A pathway to design bio-inspired synthetic composites

The multiscale structure, materials properties, and mechanical responses of the turtle shell (Terrapene carolina) were studied to understand the fundamental knowledge of naturally occurring biological penetrator-armor systems. The structure observation and chemical analysis results revealed that the turtle shell carapace comprises a multiphase sandwich composite structure of functionally graded material having exterior bone layers and a foam-like bony network of closed-cells between the two exterior bone layers. Although the morphology was quite different, the exterior bone layers and interior bony network possessed comparable hardness and elastic modulus values of ~ 1 GPa and ~ 20 GPa, respectively. Compression and flexure test results showed a typical nonlinear deformation behavior recognizant of man-made foams. The mechanical test results revealed that the interior closed-cell foam layer plays a significant role on the overall deformation behavior of the turtle shell. The finite element analysis simulation results showed comparable agreement with the actual experimental test data. This systematic study could provide fundamental understanding for structure-property phenomena and biological pathways to design bio-inspired synthetic composite materials.     

Wall friction in the compaction of pharmaceutical powders: measurement and effect on the density distribution

In this paper, the axial density profile of tablets of microcrystalline cellulose (MCC) powder compacted in nonlubricated die is investigated by finite element modelling (FEM). The Drucker-Prager/Cap model was adopted for the compaction behavior of powder. The material parameters of the model, including the die wall friction coefficient, were estimated from experimental data of die compaction where the initial density of powder is taken uniform. Changes of Young's modulus with density was measured with a four-point beam bending test. The results of the simulation of the compression and the decompression steps were used to calculate the axial density distribution. Comparison with the measured data presented in [A. Michrafy, M.S. Kadiri, J.A.D. Dodds, Wall friction and its effects on the density distri-bution in the compaction of pharmaceutical excipients, Chem. Eng. Research and Design, Vol. 81, Part A, September (2003)] is discussed.