Abstract: In the nanotechnology era, the need for products with high quality and surfaces with free-from damage has become an urgent necessity. Many components in the precision industries such as electronics, automobile, medical, and aviation require high surface finish to meet their functional requirements, such as, reducing fluid flow resistance, friction, optical losses and increase fatigue strength. However, the scale of such surface quality cannot be achieved by traditional finishing methods. To overcome these limitations, many advanced finishing processes have been developed such as abrasive flow finishing, magnetorheological fluid finishing, magnetic float polishing, and chemical mechanical polishing and magnetic abrasive finishing. Magnetic abrasive finishing (MAF) is one of advanced finishing processes which offers superior surface finish over conventional finishing processes, because of its self-adaptability to finish of different geometric shapes, its a gentle tool which does not impact workpiece surface, its capability to polish advanced engineering materials and its low cost. This article has been focused on MAF, as well as reviewing of advanced finishing processes. The recent researches and challenges of MAF have been discussed as well.
Abstract: The corrosion inhibition property of cucurbiturils has studied in 10% HCl for mild steel using gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (Tafel) and scanning electron microscopy (SEM) methods. It was found that the inhibition efficiency of inhibitors increases with increase in concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that inhibitors are of mixed type in nature. The results show that they are good inhibitors, and the adsorption of inhibitors on mild steel surface obeys Langmuir adsorption isotherm. Scanning electron microscopic (SEM) studies were used to characterize the surface morphology of uninhibited and inhibited mild steel specimens. The results obtained from experimental measurements and those from theoretical calculations are in good agreement.
Abstract: This paper presents preliminary results of modified Montmorillonite samples and the surface treatment with hydrochloric acid were investigated. The modification of this Montmorillonite surface, negatively charged and exchanged by organic cations such as alkylammoniums (Trimethylexadecyl C16 and Trimethyloctadecyl C18), yields a modified Montmorillonite (MMt). The resulting organo-mineral material acquires an organophilic character which could be used in several applications. The organically modified MMts were prepared by an ion exchange process in which sodium ions were replaced by alkylammonium ions. This material, used in the present work, is an Algerain montmorillonite obtained from MAGHNIA (West Algeria). Octadecyltrimethylammonium and hexadecyltrimethylammonium chlorides, utilized here as surfactants activators to organophilize the Montmorillonite. The microstructure of this modified Montmorillonite was characterized by XRD-diffraction with which the effects of the intercalation associated to the conformation of the long hydrocarbon chain were investigated. The results obtained showed that the amounts of hydrochloric acid added to these modified materials affect considerably the conformation of the intercalated surfactants. Their physical characteristics were determined by infrared spectrophotometer (FT-IR) and their chemical modification revealed that their thermal properties have been advantageously improved.
Abstract: A failure criterion is proposed for ductile fracture in U-notched components under mixed mode static loading. The Compact Tension Shear (CTS) is the preferred test specimen used to determine stress intensity factor in the mode I, mode II and the mixed-mode fracture. In this work, the mode I and mode II stress intensity factors were computed for different notch ratio lengths 0.1<a/W<0.7, of the inner radius of notch 0.25mm<ρ<4mm and load orientation angles 0°<α< 90° using finite element analysis. However, a review of numerical analysis results reveals that the conventional fracture criteria with only stress intensity factors (NSIFs) Kρ first term of Williams’s solution provide different description of stress field around notch zone comparing with results introduce the second and third parameter T-stress and A3.
Abstract: Nowadays, alternative fuels usage is increasing due to limited oil reserves and increasing petrol demands. There are many advantages and disadvantages of alternative fuels when used alone. In this study, alternative fuels with various specifications are mixed in different proportions to tolerate these disadvantages. Hydroxy (HHO) and hydroxy enriched compressed natural gas (HHOCNG) fuel mixtures with pilot diesel injection was used as dual-fuels on a non-modified diesel engine and investigated their performance parameters such as torque (T), power (P), brake specific fuel consumption (BSFC), indicated mean effective pressure (IMEP) and volumetric efficiency (ηv). This study conducted with AVL Boost simulation program and all graphs are plotted to compare HHO and HHOCNG fuel mixtures performance outputs, additionally all results are compared with neat diesel performance values. The general results show that, HHOCNG enrichment has the best improvement values with respect to single HHO enrichment. Overall improvements for BSFC, torque, power and IMEP values of 25 HHOCNG are 4,086%, 1.67%, 4.13% and 3.67%, respectively.
Abstract: This paper presents the conceptual design of fuel injector based on giant magnetostrictive material, with displacement amplification mechanism. The permissible emission level EURO norms become stricter in case of fuel injection technology of modern combustion engine. The magnetic circuit of the magnetostrictive fuel injector is analyzed using finite element method. Based on the structure and working principle of our magnetostrictive fuel injector (MFI), the properties of driving magnetic field are researched.
Abstract: In the article are presented results of analysis and assessment of water management in the Chirchik-Akhangaran River Basins in the middle reaches of the Syrdarya River. Big quantities of water are discharged into Syrdarya river bed towards Kazakhstan because of hydro energetic use of Chirchik river drain along with municipal sewage and drainage water within the territory of the river basin. The article describes the schemes of discharged water formation and its distribution throughout the year. It also showed the digital maps with the location of hydroelectric power stations, as well as their energy potential.
Abstract: There is an increasing demand for high quality office buildings nowadays. Occupants and developers of office buildings need to work together to create a healthy and inspiring working environment. These criteria engaged in the early stages of design can have a large impact on the performance of the finished building. This paper presents users’ perception of the general layout and adequacy of space in their office space. These features were investigated through observation and analysed data extracted from questionnaires. The aim is to investigate whether high-rise office buildings designed with a bioclimatic approach provide better working spaces than that of conventional office buildings. The assessments were made on detailed planning and the architecture of several buildings’ design approaches with the objective of consolidating perceptions on the working space and environment. The analysis shows that bioclimatic buildings are better rated than conventional buildings in terms of general layout, adequacy of space as well as flexibility of space. These factors might be connected to the size of all bioclimatic buildings, which are comparatively smaller than that of the conventional ones as well as the floor depths of all bioclimatic buildings, which are shallower than that of conventional ones. Due to these conditions, occupants in bioclimatic building are closer to the façade and might experience a better environment and space adequacy.