Journal of Mining and Mechanical Engineering

  Abstract In this study, the spoiler effect in a different angle of attacks that makes the maximum downforce is conveyed. Two different facilities are utilized to set up the experiment. A wind tunnel is used to measure the downforce and drag force, and a water tunnel is used to observe the velocity profile and flow field visualization. The result revealed that a 12° angle of attack is the optimal angle for designing the spoiler. Twelve degrees angle of attack provided the highest downforce. This downforce can improve the stability of high-speed sports car without increasing much drag. Compared to the angle of attack of 5°, the downforce of the angle of attack equal to 12° increases 233%, but the drag force only increases by 15% in wind tunnel experiments.   Read more about this article : https://lupinepublishers.com/mining-mechanical-engineerning/fulltext/experimental-investigation-of-a-spoilers-impact-on-the-flow-pattern-of-a-high-speed-sport-car.ID.000110.p...

  Abstract This Paper presents comparison of syngas compositions, for all coal ranks, as produced from different types of coal gasification processes currently in use, namely entrained flow, fluidized bed, and fixed bed gasifiers. Cold gas and carbon conversion efficiencies were investigated. The syngas composition varies with the applied gasification process. The importance of this research arises from the fact that gasifiers produce the environmentally clean fuel required to run any Integrated Gasification Combined Cycle power system. A procedure was conducted to get estimates for bituminous coal. It is important to have knowledge of the chemical reactions which take place in each gasifier and the raw syngas produced from the specific reaction involved to develop an Integrated Coal Gasification Combined Power Generation plant with CO 2 recovery in order to increase the cycle efficiency and mitigate CO 2 emission and other pollutants. The results indicate that t...

  Abstract E-waste is an emerging problem that has to be attending worldwide. The best way for E-waste management is recycling. Bioleaching is a novel method to extract metals from E-waste. In this research, bioleaching of Cu and Ni from an E-waste sample was examined using acidophil microorganisms. Different kinds of E-waste were purchased; the sample size reduced to lower than 100 microns. Acidithiobacillus ferrooxidans was adapted to the 15 g/l of the E-waste sample. Eh, pH, bacterial count, and metal recovery were followed in a period of 25 days. By using inductively coupled plasma optical emission spectroscopy (ICP-OES) identified Cu and Ni were recovered respectively 99% on 11 th day and 98% on 14 th day. The results of field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectrometer (FTIR), and X-ray diffraction before and after bioleaching emphasize the great efficiencyofbioleaching. Read more about this article :  https:...

Abstract Alkaliphilic bacteria usually grow well at pH 9, and the most extremophilic strains can grow up to values as high as pH 12-13. This group of bacteria has the ability to metabolically reduce alkalinity and are tolerant of high concentrations of ions and metals. Interest in extreme alkaliphiles has been shown as they are sources of useful, stable enzymes, and the cells themselves can be used for biotechnological and other applications at high pH values. Many industrial processes produce highly alkaline waste that is contaminated with toxic trace metals/metalloid. Thus, using alkaliphilic microorganisms is considered an attractive alternative method for treating industrial alkaline residues. Bauxite refining is one of the activities that most produces highly alkaline waste. Alumina extraction from bauxite using concentrated sodium hydroxide in the Bayer process generates a slurry and an extremely alkaline (pH of 9 to 13) by-product known as bauxite residue or r...

Abstract SiC particles with 8wt.% magnesium alloy powders as additives were mixed followed by annealing at 280 and 400 ℃ for 1 and 4 h. The particle size, phase condition, morphology and compositions distribution were analyzed using laser diffraction analyzer, X-ray diffraction (XRD), scanning electron microscopy (SEM). It was found that particles mixed homogeneously before annealing. Annealing processes have a positive effect on the decrease of magnesium alloy particle size. It has almost no effect on magnesium alloy particle size with increasing the annealing duration at 280 ℃. However, the diameter of magnesium particle decreased obviously with increasing the annealing duration at 400 ℃. Magnesium alloy particles annealed at 400 ℃ is smaller than that of the 280 ℃ ones under the same annealing duration. Si component was observed in powder annealed at both temperatures. Grain size of SiC was reduced and microstrain was improved with increase of annealing temperatu...

Abstract Field and petrological data of metakomatiite, eastern and western metabasalts and metadacite were used to propose an intraoceanic or intracontinental provenance for the Neoarchean Mundo Novo Greenstone Belt (MNGB), eastern São Francisco Craton. Despite deformation, the metakomatiite preserves the spinifex texture and the eastern metabasalt’s pillow lava structure. The metavolcanics are recovered by an ocean floor lithological association composed of chemical metasedimentary rocks and the western metabasalt hosts ocean floor hydrothermal alteration zones. The eastern metabasalt plots in the IAT and MORB fields and western metabasalt is mainly in the MORB field in the Zr vs. Zr/Y diagram, suggesting nearby oceanic settings. Heterogeneous crustal assimilation and metamorphism during the Rhyacian-Orosirian explain the mineralogical differences between the two metabasalts. The metakomatiite and metabasalts feature a vector from the MORB-OIB array to the volcanic...

Abstract In the first and second decades of the 21st century nanotechnology has given impetus to a new generation of materials namely smart materials. Having the abilities to transform in shape, to sense and correspond to external stimuli like temperature, pressure, sound, etc. and to counteract these, they excited the engineers into many new concepts like adaptive structures in aeronautics, active biomaterials and smart self-healing composite materials. This scheme was corroborated by the parallel progress in nanotechnology, as well as a real explosion in the additive manufacturing technologies, which enabled many types of sensors and smart or responsive nanomaterials to be incorporated into structural parts. This mini review paper provides an opinion on these new conceptual technologies such as 4D printing into the oncoming third decade of the century which has already been characterized as the era of nano - and bio- engineering. Introduction The be...