•Main global resources and reserves of lithium.•Processes of lithium extraction from hard rocks.•Comparison between existing and emerging lithium extraction processes.
The increasing demand for smart ...devices and clean energy vehicles that use lithium-ion batteries has sparked a considerable interest in lithium, which is becoming a strategic element. Lithium deposits can be found in saline lacustrine environments or pegmatite hard-rocks that are located mainly in America (Argentina, Bolivia, Chile, USA, and Canada), Australia (Western Australia), and China. In this paper, we summarise the main approaches of lithium extraction from pegmatites. Well established processes such as calcination, roasting, chlorination, carbonate pressure leaching, caustic/acidic digestion and others are examined and discussed to reflect their significance to the modern lithium value chain. In addition, emerging processes that involve direct mechano-chemical activation, bioleaching, acidic or caustic leaching are evaluated and compared to proven approaches in terms of economical and environmental viability. This review indicates that while established processes are still appealing to the industry despite their excessive energy requirement, new processes may contribute significantly to modernising lithium extraction in the future.
Cast aluminium–silicon alloy, A356.0, is widely used in automotive and aerospace industries because of its outstanding mechanical, physical, and casting properties. Thermal barrier coatings can be ...applied to combustion chamber to reduce fuel consumption and pollutions and also improve fatigue life of components. The purpose of the present work is to simulate stress distribution of A356.0 under thermo-mechanical cyclic loadings, using a two-layer elastic-visco-plastic model of ABAQUS. The results of stress–strain hysteresis loop are validated by an out of phase thermo-mechanical fatigue test. Different thicknesses from 300 to 800μm of top coat and also roughness of the interfaces are simulated to get best stress gradient. Results show that increasing top coat thickness causes stress increase. The realistic interface model is useful for identifying critical areas in stress development. Two important factors having considerable effect on development of high stress in TBC, are the severity of undulations relating to amplitude and wavelength of interface waves; and the thickness of BC layer relating to mutual positioning of either interfaces. However the realistic model has some limitations including long calculation time and difficulties of generating a suitable mesh. To diminish these limitations, after recognizing critical area, in second stage of the study, a periodic unit cell is used instead . Eight models considering different mutual positioning of interfacial asperities along with different penetration in adjoining layers are simulated and compared. Results show that detachment of the thermal barrier coating system from substrate is more probable Results show that IP positioning of mutual waves produce more severe stress but contour pattern is less likely to promote crack propagation.
► Stress distribution is studied in coated A356.0 under thermo-mechanical loadings. ► Realistic interface roughness shows the critical area of tensile stress. ► Increasing TC thickness increases the stress. ► OP positioning of interface waves shows better condition for crack growth.
Deng, H.Y.; Dai, G.L., and Azadi, M.R., 2020. Fractional time-dependent merchant model for coastal soft clay. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal ...Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 825–831. Coconut Creek (Florida), ISSN 0749-0208. Soft clayey soils behave a time-dependent creep property subjected to sustained load. In order to describe the stress-strain-time property of soft clayey soil, a time-based fractional creep constitutive model is proposed based on the Caputo fractional calculus by applying the Abel dashpot in classical component model. The proposed fractional Merchant model is validated by drained creep test of coastal soft clay. The model parameters are obtained by fractional nonlinear fitting in terms of drained creep test results of coastal soft clay. Then the predicted results by the proposed fractional Merchant model and classical component models are also compared and validated with creep test results. It shows that the proposed fractional Merchant model is more approached to drained creep test results than classical component models. In particular, the proposed fractional Merchant model could well reduce the errors in the initial phase of creep compared with the classical model. It is indicated that the fractional Merchant model is superior in predicting drained creep property of coastal soft clay.
In the present study, the effect of the T6 heat treatment on high-cycle bending fatigue properties of the A380 (AlSiCu) aluminum alloy has been investigated. The fracture behavior of materials was ...also examined under stress-controlled cyclic loadings. For such an objective, standard specimens were prepared and tested by a rotating bending fatigue machine. In addition, the microstructural characterization and the fracture surface analysis were performed by the scanning electron microscopy. Using the T6 heat treatment, the solution treatment was performed at 510°C for 5 hrs and after quenching in the air, the ageing treatment was carried out at 200°C for 3 hrs. The main aim of this work is to investigate the heat treatment effect on fatigue properties of AlSiCu alloys. Moreover, the roughness influence was also studied on the fatigue lifetime. Based on experimental results, the heat treatment changed the distribution and the size of silicon phases and enhanced the microhardness. Under the highest and lowest stress levels, the heat treatment increased the high-cycle bending fatigue lifetime by 26% and 85%, respectively. Samples with low roughness had a greater fatigue lifetime than those with high roughness. The fracture surface analysis demonstrated that in both as-cast and heat-treated specimens, several microcracks occurred through intermetallic compounds. The heat-treated and as-cast materials showed a brittle fracture behavior due to cleavage planes on the fracture surface of specimens. However, some dimples and quasi-cleavages were also observed on the fracture surface of as-cast samples.
•T6 treatment increased fatigue lifetimes of A380 aluminum alloy between 26% and 85%.•Fatigue lifetimes were 124.5% and 156.2% greater in low roughness samples, respectively for T0 and T6 specimens.•Fracture surfaces demonstrated that microcracks initiated in intermetallic compounds.
Nowadays, polymer parts made by additive manufacturing methods (AM) have multiple applications in various industries. Different parameters affect the print quality of the parts and subsequently their ...mechanical properties. In this study, the effect of the print direction in 3D-printing on the high-cycle bending fatigue properties of polymer parts made by the fused deposition modeling (FDM) method has been investigated. The standard samples of the fatigue test were printed in both horizontal and vertical directions and were made of two polymers, PLA and ABS. The thickness of each layer was 0.15 mm and the infill percentage of the parts was 50%. The rotary bending fatigue test was performed under conditions of fully-reversed stress-controlled loading at different stress levels. The results included the stress amplitude versus the fatigue lifetime of FDM 3D-printed PLA and ABS polymers. Besides, the scanning electron microscopy (SEM) image of the fracture surface was also depicted after fatigue testing. Results showed that PLA specimens had better fatigue lifetimes than ones of ABS samples. Moreover, the fatigue strength of 3D-printed samples in the horizontal direction was higher than that of 3D-printed specimens in the vertical direction. The print direction, the material and the stress level were found to be statistically significant factors from the analysis of variances. The SEM image demonstrated beach marks on the fracture surface of fibers (3D-printed filaments) in the PLA specimen, which proved cyclic loadings. Then, cleavage facets were the result of the brittle fracture.
This research investigated the antihypertensive effects of tamarind products and compared their potentials based on an animal model's data verified by molecular docking, multitarget interactions, and ...dynamic simulation assays. GC-MS-characterized tamarind products were administered to cholesterol-induced hypertensive albino rat models. The two-week-intervened animals were dissected to collect their serum and organs and respectively subjected to analyses of their hypertension-linked markers and tissue architectures. The lead biometabolites of tamarinds interacted with eight target receptors in the molecular docking and dynamic simulation studies and with multitarget in the network pharmacological analyses. The results show that the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), C-reactive protein (CRP), troponin I, and lipid profiles were maximally reinstated by the phenolic-enriched ripened sour tamarind extract compared to the sweet one, but the seed extracts had a smaller influence. Among the tamarind's biometabolites, ϒ-sitosterol was found to be the best ligand to interact with the guanylate cyclase receptor, displaying the best drug-likeliness with the highest binding energy, -9.3 Kcal. A multitargeted interaction-based degree algorithm and a phylogenetic tree of pathways showed that the
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,
, and
hub genes were consistently modulated by ϒ-sitosterol to reduce hypertension and related risk factors. The dynamic simulation study showed that the P-RMSD values of ϒ-sitosterol-guanylate cyclase were stable between 75.00 and 100.00 ns at the binding pocket. The findings demonstrate that ripened sour tamarind extract may be a prospective antihypertensive nutraceutical or supplement target affirmed through advanced preclinical and clinical studies.
•Image processing is employed to measure weld bead geometry and heat affected zone.•Multi-output simulation of GMAW is performed using back propagation neural networks.•Multi-criteria process ...parameters optimization is performed via combined BPNN–PSO.•Predicted results are in good agreements with those of validation experimental tests.
This research addresses multi criteria modeling and optimization procedure for Gas Metal Arc Welding (GMAW) process of API-X42 alloy. Experimental data needed for modeling are gathered as per L36 Taguchi matrix. Model inputs include work piece groove angle as well as the five main GMAW process parameters. The proposed back propagation neural network (BPNN) simultaneously predicts weld bead geometry (WBG) and heat affected zone (HAZ). Image processing technique along with Bridge Cam and AWS gauges are used to take accurate measurements of WBGs and HAZs. The adequacy of the developed BPNN is established through comparisons against measured process outputs. Measurements indicate that the BPNN model simulates GMAW process with average errors of 0.33 to 0.82%. Next, the BPNN model is implanted into a particle swarm optimization (PSO) algorithm to simultaneously optimize HAZ and WBG characteristics. The hybrid BPNN–PSO determines process parameters values and groove angle so as a desired WBG is achieved while HAZ is minimized. Verification tests demonstrate that the proposed BPNN–PSO is quite efficient for in multi-criteria modeling and optimization of GMAW.
In the present paper, mechanical properties of multilayer coatings were investigated. Titanium nitride/titanium carbide (TiN/TiC) multilayer coatings were prepared on the surface of AISI H13 hot work ...tool steel by the pulsed-DC plasma assisted chemical vapor deposition (PACVD). The microhardness, the toughness, the wear loss and the friction coefficient were measured by the Knoop and the Vickers hardness test and the pin on disk wear test. The optical microscopy was also used to examine worn surfaces and to characterize wear mechanisms. The field emission scanning electron microscopy (FE-SEM) and the grazing incidence X-ray diffraction (GIXRD) were applied to study the crystalline structure of multilayer coatings. Multilayer coatings with 10 layers exhibited lower friction coefficient (as 0.2), lower wear loss and higher toughness (17.7MPa·m1/2) than those values in other multilayer coatings. Increasing the number of layers increased the microhardness, the fracture toughness and the wear resistance with respect to single-layer coatings.
•TiN/TiC multilayer coatings were deposited by the PACVD.•We examine the composition and the structure of multilayer coatings of TiN/TiC.•This paper shows properties of TiN/TiC multilayer coatings.•TiN/TiC coatings showed highest hardness.•TiN/TiC coatings showed highest toughness.
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