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Column leaching of lanthanides from Abu Tartur phosphate ore with kinetic study

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Journal of Rare Earths 2010年第4期28卷 576-580页

作者： A.T. Kandil m.m. Aly E.m. moussa A.m. Kamel m.m. Gouda m.N. Kouraim Chemistry Department Faculty of Science Helwan University Nuclear materials Authority P.O. Box 530 El Maadi Cairo Egypt

The dynamic leaching of lanthanides from a west desert phosphate ore, Egypt (Abu Tartur) by hydrochloric acid, nitric acid and sulfuric acid solutions was investigated in this study as a function of acid concentration, flow rate and the presence of some additives such as boric acid. Also the kinetics of leaching of lanthanides was investigated as a function of temperature. It was found that the leaching process could be described by a shrinking-core model, with activation energy about 5.9, 13.8 and 21.9 kJ/...

关键词： column leaching lanthanides Abu Tartur hydrochloric acid nitric acid sulfuric acid kinetics rare earths

microstructural evolution during ultra-rapid annealing of severely deformed low-carbon steel: strain, temperature, and heating rate effects

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International Journal of minerals,metallurgy and materials 2016年第7期23卷 779-792页

作者： m.A.mostafaei m.Kazeminezhad Department of materials Science and Engineering Sharif University of Technology

An interaction between ferrite recrystallization and austenite transformation in low-carbon steel occurs when recrystallization is delayed until the intercritical temperature range by employing high heating rate. The kinetics of recrystallization and transformation is affected by high heating rate and such an interaction. In this study, different levels of strain are applied to low-carbon steel using a severe plastic deformation method. Then, ultra-rapid annealing is performed at different heating rates of 200–1100°C/s and peak temperatures of near critical temperature. Five regimes are proposed to investigate the effects of heating rate, strain, and temperature on the interaction between recrystallization and transformation. The microstructural evolution of severely deformed low-carbon steel after ultra-rapid annealing is investigated based on the proposed regimes. Regarding the intensity and start temperature of the interaction, different microstructures consisting of ferrite and pearlite/martensite are formed. It is found that when the interaction is strong, the microstructure is refined because of the high kinetics of transformation and recrystallization. moreover, strain shifts an interaction zone to a relatively higher heating rate. Therefore, severely deformed steel should be heated at relatively higher heating rates for it to undergo a strong interaction.

关键词： low-carbon steel annealing microstructural evolution recrystallization phase transformation plastic deformation

Phase diagrams and magnetic properties of the mixed spin-1 and spin-3/2 Ising ferromagnetic thin film: monte Carlo treatment

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Chinese Physics B 2019年第2期28卷 414-419页

作者： B Boughazi m Boughrara m Kerouad Laboratoire Physique des matériaux et modélisation des Systémes(LP2mS) UnitéAssociée au CNRST-URAC:08Faculty of SciencesUniversity Moulay Ismail

Phase diagrams and magnetic properties of the mixed spin-1 and spin-3/2 Ising film with different single-ion anisotropies are investigated, by the use of monte Carlo simulation based on heat bath algorithms. The effects of the crystal-fields and the surface coupling on the phase diagrams are investigated in detail and the obtained phase diagrams are presented. Depending on the Hamiltonian parameters, the system exhibits both second-and first-order phase transitions besides tricritical point, triple point, and isolated critical end point.

关键词： monte Carlo simulation thin film phase diagrams magnetic properties

Thomson effect with hyperbolic two-temperature on magneto-thermo-visco-elasticity

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Applied mathematics and mechanics(English Edition) 2021年第9期42卷 1311-1326页

作者： A.m.ALHARBI m.I.A.OTHmAN H.m.ATEF Department of mathematics College of ScienceTaif UniveristyTaif 21944Saudi Arabia Department of mathematics Faculty of ScienceZagazig UniversityZagazig 44519Egypt Department of mathematics Faculty of ScienceDamanhur UniversityDamanhur 22511Egypt

The study considers a homogeneous isotropic thermo-visco-elastic solid with hyperbolic two-temperature to cope up with its two-dimensional(2 D)*** heat conduction equation is influenced by the Thomson ***-Shulman’s theory is used to modify the basic governing equations.A method called"normal mode analysis"is utilized to attain the magnetic field,stress,conductive and thermodynamic temperature,and displacement ***,a number of numerical calculations are performed and discussed to understand the impact of hyperbolic two-temperatures,Thomson parameter,and viscosity on the material mentioned above.

关键词： thermo-visco-elasticity magnetic field hyperbolic two-temperature Lord-Shulman’s theory Thomson coefficient normal mode analysis

Fatigue crack propagation in a helicopter component subjected to impact damage

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Defence Technology（防务技术） 2021年第2期17卷 416-428页

作者： m.Fossati m.Pagani m.Giglio A.manes Politecnico di milano Dipartimento di Meccanicavia la Masa 1MilanoItaly

Damage tolerant methodology is increasingly used in aeronautical components,especially due the fact that the Aviation Regulation requires such an assessment in case an accidental damage *** present,there is a strong and actual interest in applying such procedures to helicopter components that are subjected to high frequency cyclic *** this paper,an investigation on a damaged transmission shaft for a tail rotor transmission of an actual helicopter has been carried out focusing on the fatigue crack propagation.A complete sequence of experimental tests was performed in order to create an actual ballistic damage and to subsequently check the damage tolerant *** shaft was damaged by oblique ballistic impact and was subsequently subjected to torsional fatigue *** the fatigue cycles several cracks propagated from the ballistic *** of these steps(impact and fatigue loading)were also simulated by a complex modelling approach based on Finite Element models and fracture mechanics *** comparison between the experimental and numerical results shows a good agreement but it underlines the need for a very refined modelling technique capable to replicate all the features associated with the damage in order to reliably simulate the subsequent propagation phase.

关键词： Ballistic impact Damage Fatigue Crack propagation

Effect of Friction Stir Processing on Pitting Corrosion and Intergranular Attack of 7075 Aluminum Alloy

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Journal of materials Science & Technology 2017年第2期33卷 155-165页

作者： m. Navaser m. Atapour Department of materials Engineering Isfahan University of Technology Isfahan 84156-83111 Iran

The effect of friction stir processing （FSP） on the pitting corrosion and the intergranular attack of 7075 aluminum alloy was investigated. Three friction stir processed samples were produced by employing a constant tool travel speed of 100 mm/min at the rotating speeds of 630, 1000 and 1600 rpm. It was dem- onstrated that the processed samples suffered from both pitting and intergranular corrosion. Also, the sample processed at 1600 rpm exhibited the best pitting corrosion resistance. For all FS processed samples, the corrosion attack in the heat affected zone was pitting corrosion, whereas no intergranular corrosion was detected in this area.

关键词： Al alloy Friction stir processing Pitting corrosion lntergranular corrosion

Failure pattern in ceramic metallic target under ballistic impact

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Defence Technology（防务技术） 2024年第10期40卷 173-190页

作者： m.A.Iqbal m.K.Khan Department of Civil Engineering Indian Institute of Technology RoorkeeRoorkee 247667India Department of Civil Engineering Aligarh Muslim UniversityAligarh202002India

The ballistic resistance and failure pattern of a bi-layer alumina 99.5%-aluminium alloy 1100-H12 target against steel 4340 ogival nosed projectile has been explored in the present experimental cum numerical *** the experimental investigation,damage induced in the ceramic layer has been quantified in terms of number of cracks developed and failure zone *** resultant damage in the backing layer has been studied with variation in the bulge and perforation hole in the backing layer with the varying incidence *** discussion of the experimental results has been further followed by three dimensional finite element computations using ABAQUS/Explicit finite code to investigate the behaviour of different types of bi-layer targets under multi-hit projectile *** JH-2 constitutive model has been used to reproduce the behaviour of alumina 99.5%and JC constitutive model has been used for steel 4340 and aluminium alloy *** total energy dissipation has been noted to be of lesser magnitude in case of sub-sequential impact in comparison to simultaneous impact of two *** distance between the impact points of two projectiles also effected the ballistic resistance of bi-layer *** ballistic resistance of single tile ceramic front layer and four tile ceramic of equivalent area found to be dependent upon the boundary conditions provided to the target.

关键词： Ballistic resistance Bi-layer target Ceramic metal armour multi-hit impact Finite element modelling

Designing Uniform Computer Sequential Experiments with mixture Levels Using Lee Discrepancy

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Journal of Systems Science & Complexity 2019年第2期32卷 681-708页

作者： ELSAWAH A m Department of mathematics Faculty of Science Zagazig University Division of Science and Technology BNU-HKBU United International College

Computer experiments are constructed to simulate the behavior of complex physical systems. Uniform designs have good performance in computer experiments from several aspects. In practical use, the experimenter needs to choose a small size uniform design at the beginning of an experiment due to a limit of time, budget, resources, and so on, and later conduct a follow up experiment to obtain precious information about the system, that is, a sequential experiment. The Lee distance has been widely used in coding theory and its corresponding discrepancy is an important measure for constructing uniform designs. This paper proves that all the follow up designs of a uniform design are uniform and at least two of them can be used as optimal follow up experimental designs. Thus, it is not necessary that the union of any two uniform designs yields a uniform sequential design. Therefore, this article presents a theoretical justification for choosing the best follow up design of a uniform design to construct a uniform sequential design that involves a mixture of ω≥ 1 factors with β_k ≥ 2, 1 ≤ k ≤ωlevels. For illustration of the usage of the proposed results, a closer look is given at using these results for the most extensively used six particular cases, three symmetric and three asymmetric designs, which are often met in practice.

关键词： Computer experiment Lee discrepancy Lee distance lower bound sequential design uniform design

Pollution of water resources due to industrialization in arid zone of Rajasthan, India

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Journal of Environmental Sciences 2001年第2期13卷 218-223页

作者： m A Khan Central Arid Zone Research Institute Jodhpur-342003 India.

In arid zone of Rajasthan, India, nearly 21,900 hm2 area along Bandi River has been affected by industrial effluent discharge into the river bed. Analysis of groundwater samples collected from these sites revealed that area at the vicinity of the river is most affected. The effluent water in the river is the main source of contamination of ground water. Concentration of sodium and chloride has been higher with proportional increase in TDS and EC value in the area within zone A (river water), zone B (0-100 m), zone C (101-250 m), zone D (251-500 m) and zone E (501-1000 m). There is decreasing trend in ion concentration from zone A to zone E and F, reflecting reduced effect of effluents. The pollution of water resources has resulted in the degradation of other natural resources such as land, soil and vegetation. Nearly 4463 hm2 (20.38%) area has been very severely affected. EC value at places exceeds 20 dS/m. Soil and land have become hard, compact and saline. Cropping intensity has declined. In the area (3633 hm2) affected severely, the EC value of water varies from 10-20 dS/m. Irrigation with such water has created problem of salinity, sodicity in soils. Herbal biomass declined considerably. Double cropping has almost stopped. Almost 8494 hm2 area is affected moderately. EC of ground water varies from 5 to 10 dS/m. Fragile surface crust, declining trend of phosphorous and potassium in the soil, poor density of natural vegetation are significant manifestations. Apart from this, 5305 hm2 area is slightly affected.

关键词： India Pollution of water resources due to industrialization in arid zone of Rajasthan