Mechanical characterization of high volume fraction Al7075-Al2O3 composite fabricated by semisolid powder processing

The mechanical properties and physical characteristics of aluminum alloy composites can be significantly improved by adding reinforcing phases. However, the high loading of the reinforcement phase in Al7075-Al2O3 composites has not been thoroughly studied. In this work, a combination of semisolid metal powder processing and powder metallurgy is used to process and manufacture Al7075-Al2O3 composites with a high reinforcement fraction of > 40 vol.%. The effects of processing parameters on the microstructures and mechanical properties of the composite material are discussed in detail. The loading limits of the high volume Al2O3 reinforcement in Al7075 composites are identified and linked to the processing parameters. A methodology is introduced to estimate the consolidation temperature of Al7075 alloy using compaction testing. Al2O3 particles (the average particle size of 120 µm) were mechanically milled with Al7075 powder (the average particle size of 20 µm) for 10 min and 5 h using a high-energy planetary ball mill. The mixture was then compacted in the semisolid state at 615 °C under the compaction pressures of 50 MPa and 100 MPa. By increasing the milling time from 10 min to 5 h, the deformation of aluminum powders and the fracture of Al2O3 reinforcement particles occur, restricting the loading limit of reinforcement. The milling time also shows a dominant effect on the powder morphology, microstructure, and mechanical properties of Al7075-Al2O3 composites. Increasing compaction pressure from 50 to 100 MPa significantly improved the compressive strength of the composite from 218 to 652 MPa. Al7075-Al2O3 composite with 40 vol.% of reinforcing phase exhibits the highest hardness of 198.2 HV and 96.9% relative density when it is milled for 5 h and compacted at 100 MPa. However, this composite shows the highest strength of 652 MPa when it is milled for 10 min. By increasing the reinforcing phase to 50 vol.% and 60 vol.%, the hardness, density, and compressive strength of composites decreased. The composites with 60 vol.% of reinforcing phase appeared overloaded. Results show that semisolid metal powder processing has huge potential for the fabrication of high loading Al2O3 in Al7075 matrix with near theoretical density

Religious charity as religious experience; Redefining the types of religious experience by studying the Arbaeen pilgrimage

The largest religious community of Muslims is formed every year on the occasion of the 40th Day of Ashura by walking to Karbala and during the Arbaeen procession. This pilgrimage walk, while being a wonderful manifestation of religious experience, is a diverse field of Charity services to pilgrims, as well as a clear example of "religious charity". Religious experience is usually formed during religious practices and rituals, including during pilgrimage. But this study begins specifically with the important question of whether the experience of participation and involvement in religious charity can have the characteristics of a religious experience? To answer this question, the qualitative research method has been used using interview and participatory observation techniques by recording data such as photos, videos and field notes. Iranian pilgrims as well as processions, procession holders and members of Iranian and Iraqi processions were the observation unit and the population studied in this study. The findings showed that the experience of participating in religious charitable services, as well as the use of these services in the Arbaeen walk, can be a ground for the emergence and characteristics of religious experience. By extending the results to other situations of religious practice in which religious Charity deeds are possible, it has been argued that the possibility of defining religious charity as one of the contexts of religious experience in the Arbaeen walk can be a positive answer to the possibility of this kind of definition of Religious experience should be in all situations of religious experience - in addition to pilgrimage and Arbaeen

Fabrication of AZ91D/SiCp composites by mechanical milling of magnesium alloy chips and spark plasma sintering in a semi-solid regime

In the present study, the capability of spark plasma sintering (SPS) in a semi-solid regime to produce AZ91D/SiCp composites, prepared by mechanical milling (MM), was investigated. An SPS process was used to densify AZ91D/SiCp composite powders by heating them to a semi-solid temperature of 497°C or 516°C, at a heating rate, holding time and pressure of 50 °C/min, 1 min and 40 MPa, respectively. In preparing the requisite powders, MM was used as an effective recycling method to prevent excessive consumption of energy and raw materials while converting magnesium alloy chips into powder in a planetary ball mill. The simultaneous effects of milling parameters (time and ball-to-powder weight ratio (BPRs)) on the MM powder were investigated by FESEM and PSA. Mechanical alloying (MA) of the milled powder with 40 wt% −2 µm SiC and characterization of the obtained powder by OM and PSA were also carried out. The phase compositions of the powder and sintered samples were analyzed by XRD. The microstructure, density, hardness and compressive strength of the sintered samples were also studied. The results show that composites with few porosities and good mechanical properties were prepared by SPS in a semi-solid regime

Modulation of lipolysis and glycolysis pathways in cancer stem cells changed multipotentiality and differentiation capacity toward endothelial lineage

Abstract Cancer stem cells obtain energy demand through the activation of glycolysis and lipolysis. It seems that the use of approached targeting glycolysis and lipolysis could be an effective strategy for the inhibition of cancer stem cells. In the current experiment, we studied the potential effect of glycolysis and lipolysis inhibition on cancer stem cells differentiation and mesenchymal–epithelial-transition capacity. Cancer stem cells were enriched from human ovarian cells namely SKOV3 by using MACS technique. Cells were exposed to Lonidamine, an inhibitor of glycolysis, and TOFA, a potent inhibitor of lipolysis for 7 days in endothelial differentiation medium; EGM-2 and cell viability was studied by MTT assay. At the respective time point, the transcription level of genes participating in EMT such as Zeb-1, -2, Vimentin, Snail-1, -2 and VE-cadherin were measured by real-time PCR analysis. Our data noted that the inhibition of lipolysis and glycolysis could decrease cell viability compared to the control of cancer stem cells. The inhibition of glycolysis prohibited the expression of Zeb-1, Snails, and Vimentin while increased endothelial differentiation rate indicated by the expression of VE-cadherin. In contrast, the inhibition of lipolysis increased EMT associated genes and reduced endothelial differentiation rate by suppressing the transcription of VE-cadherin. Notably, the simultaneous inhibition of glycolysis and lipolysis had moderate effects on the transcription of EMT genes. We concluded that the modulation of the metabolic pathway of glycolysis in ovarian CSCs is more effective than the inhibition of lipolysis in the control of angiogenesis potential and stemness feature

Treatment of cancer stem cells from human colon adenocarcinoma cell line HT-29 with resveratrol and sulindac induced mesenchymal-endothelial transition rate

WOS: 000468934500006PubMed ID: 30758710In the current experiment, the combined regime of resveratrol and a Wnt-3a inhibitor, sulindac, were examined on the angiogenic potential of cancer stem cells from human colon adenocarcinoma cell line HT-29 during 7days. Cancer stem cells were enriched via a magnetic-activated cell sorter technique and cultured in endothelial induction medium containing sulindac and resveratrol. Expression of endothelial markers such as the von Willebrand factor (vWF) and vascular endothelial cadherin (VE-cadherin) and genes participating in mesenchymal-to-epithelial transition was studied by real-time PCR assay. Protein levels of Wnt-3a and angiogenic factor YKL-40 were examined by western blotting. ELISA was used to determine the level of N-acetylgalactosaminyltransferase 11 (GALNT11) during mesenchymal-endothelial transition. Autophagy status was monitored by PCR array under treatment with the resveratrol plus sulindac. Results showed that resveratrol and sulindac had the potential to decrease the cell survival of HT-29 cancer cells and the clonogenic capacity of cancer stem cells compared with the control (p<0.05). The expression of VE-cadherin and vWF was induced in cancer stem cells incubated with endothelial differentiation medium enriched with resveratrol (p<0.05). Interestingly, the Wnt-3a level was increased in the presence of resveratrol and sulindac (p<0.05). YKL-40 was reduced after cell exposure to sulindac and resveratrol. The intracellular content of resistance factor GALNT11 was diminished after treatment with resveratrol (p<0.05). Resveratrol had the potential to induce the transcription of autophagy signaling genes in cancer stem cells during endothelial differentiation (p<0.05). These data show that resveratrol could increase cancer stem cell trans-differentiation toward endothelial lineage while decrease cell resistance by modulation of autophagy signaling and GALNT11 synthesis.Tabriz University of Medical SciencesThis study was supported by a grant from the Tabriz University of Medical Sciences

Reliable and Environmental Economic Dispatch in a Microgrid with Renewable Energy Sources

This paper contrasts the Genetic Algorithm (GA) strategies to solve the problem of Economic Dispatch (ED) in a Microgrid (MG). An environmental ED strategy for MG is proposed through maintaining the system reliability requirements at acceptable level. Two additional cost terms such as the CO 2 emission penalties and load curtailment charges are added to the traditional objective function of the ED problem. Also, cost and reserve supply of the network are considered. Since the load curtailment cost is highly dependent to the network reliability indices, specifically those determining network inability to supply demand, the Expected Energy Not Served (EENS) reliability index is used to calculate the curtailment costs. By illustrating the advantages of Inherit Based Genetic Algorithm (IBGA) over the other two strategies, namely Simple Genetic Algorithm (SGA) and 3-matrices Genetic Algorithm (3MGA), IBGA is used to solve the proposed Reliable, Environmental Economic Dispatch (REED) problem in a MG.©2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed