Papers by Keyword: Suspension

Abstract: The subject under study is relevant as the enterprises in different industries are really interested in disperse systems in the form of suspensions. Suspensions are being widely used in many fields. At the same time the problems of improving their quality and increasing the productivity and energy efficiency of machines still exist. In this context, this study aims at getting finely divided suspensions of metals through the erosion of metal plates in the cavitation flow reactor. The construction of the reactor provides for a technically and technologically simple high-capacity process. The leading method of the research is a laboratory experiment and a qualitative and quantitative assessment of the erosion of the metal surface in the region of maximum developed cavitation. The article presents the results of the research into the nature the metal surface damage under cavitation. The sampling materials are copper and fine silver. The experiment shows quite a strong growth of numerous erosions and states that in the beginning in the region of maximum cavitation the net of cavities appears. Then, the cavities fuse and grow in size. Around single caves the areas of plastic deformation with typical metal flows are detected. The minimal sizes of particles, torn away from the surface, are 2-3 mcm. The study is of high practical value for researchers and specialists in nanotechnologies, solid dispersion, sedimentary analysis, flow detection, biomedicine, production of fuel, lubricants, emulsifiers, catalysts, and semiconductors.

Abstract: Due to the restriction of passive layers containing Cr⁶⁺ [1], which were characterized by excellent corrosion protection due to their self-healing effect for scratches on metal surfaces, current corrosion protection systems consist of chromium (III) -containing thick layer passivation. Due to their lower hardness, current corrosion protection systems are susceptible to mechanical stress. This is particularly critical at barrel plating of screws, rivets etc. where the manufacturing process leads to damages of the corrosion protection layer and consequently to reduced corrosion resistance.To counter this problem, we point out one approach to install hard particles into the passivation layer. The entrapment of the hard particles into the passivation is detected by Glow Discharge Optical Emission Spectrometry. Comparative investigations in the corrosion chamber prove the improvement of the corrosion protection of steel parts with passivation layers containing hard particles.

Abstract: In automobile application, suspensions are used for various purposes. To improve the stability and to withstand maximum load we are trying to add additional source which is called suspension. These suspensions are made attached along with the ordinary suspension. This is manufactured using magnetic fluid called ferrofluid. Here the complete preparation of ferrofluid was done and their characteristics were studied. In this, the experimental setup of suspension has been studied and working was analyzed. The fluid was prepared and compared the viscosity with ordinary fork oil. This liquid substance which acts as a source of suspension, which has maximum efficiency when compared to ordinary fluid. These can be varied to different shapes depending on the application and needs.

Abstract: Experimental results for nanosecond electromagnetic impulses (NEMI) impact on precious metals leaching process from sulphidic ores are presented. A possibility of an intensification of leaching process of Au, Ag, Cu is established. The extraction of silver increases by 70 %, gold – by 40 %. The samples of sulphidic ores from the pit of JSC NPF "Bashkir gold mining company" are taken as objects of research. The use of economic electronic generators is suggested herein. They create impulses of 1 nanosecond, the front of 0.1 nanoseconds, amplitude of 6-15 kV impulses, 1 kHz frequency of repetition, consumed power from an electric network is less than 100 W. Energy in one impulse is 10^–3 J. The pulse field changes the valence of metals of impurity towards decrease. It changes the current of chemical reactions in a mineral matrix. The local heating of the precious metals interspersed particles and destruction of a mineral matrix are also possible.

Abstract: The paper presents a complex quarter car model obtained with ADAMS software, View module, useful in the first stage of suspension dimensioning and optimization.The model is equipped with compression and rebound stopper buffer and suspension trim corrector.The proposed quarter car model with two degrees of freedom (wheel and body) performs all these goals allowing changing:Geometrical elementsPosition of equilibrium, depending on vehicle load;Trim correction;Elastic and dissipative characteristics of the suspension and tire;Suspension stroke;Road profile, assessed either by simple or summation of harmonic functions or reproducing real roadsBuffers (for stroke limitation) position and characteristics;The models developed provide information on:Vertical stability assessed by vertical movements of the body and the longitudinal and transversal stability evaluated based on adherence characterized by wheel ground contact force and frequency of soil detachment wheel.Comfort assessed on the basis of body vertical acceleration and collision forces to the stroke ends.The body-road clearanceThe trim corrector efficiencyAll above performances evaluated function the road unevenness, acceleration, deceleration, turning regime.The damping characteristic is defined by damping forces at different speed for each strokes respectively one for rebound and other for compression.The contact force road-wheel is defined based tire rigidity law.The stopper buffer forces on rebound and compression are defined based each specific rigidity characteristics.The road excitation is realized with a function generator.The software allow the model evolution visualisation in real time, also generating the diagrams of displacements, forces, accelerations, speeds, for each elements or for relative evolution between diverse elements.The simulation was realized for unloaded and fully loaded car using a road generated by a sum of harmonic functions presented in equation (8).The excitation covers the specific frequencies area, being under the body frequencies up to the wheel proper frequencies.The realized ¼ car model, have reached the goal to evaluate the suspension trim correction advantages.The simulations confirm the trim corrector increases the suspension performances, thus for the analyzed case the trim corrector increase simultaneous:Body-ground clearance (evaluated by body higher increasing) between 18.5÷55.1 %Body stability (evaluated by maximal body displacement) between 9.8÷11.4 %Body comfort (evaluated by maximal body acceleration) between 3.4÷35.5 %Adherence (evaluated by maximal and RMS wheel-groundcontact force variation) between 7.0÷12.1 %Body and axles protection (evaluated by buffer strike force) between 10.8÷38.2 %

Abstract: In this paper the authors present the results of theoretical and experimental research in order to optimize suspension rigidity in case of Daewoo Nubira vehicle. The paper presents the mathematical model obtained by assimilating car with a dynamic system with 5 rigid solids with elastic and viscous linking between them. Theoretical results obtained based on this model and the experimental results are presented, and it is presented a solution to optimize suspension in order to remove the negative effects observed driving on gravel runways or damaged runaways. Theoretical results, compared with the experimental ones, allow us to say that it is possible to optimize suspension by analyzing specific parameters equivalent mathematical model.

Abstract: The paper presents a modal analysis for the helicoidally spring from the compound of the Macpherson automotive suspension. In the first part, it is described the device used for the experimental study and then, the measurement equipment used, too. First of all, it is represented the kinematical scheme and 3D representation for the device mechanism included the helicoidally spring necessary to the dynamic analysis. After this, are made some measurements of different parameters of the helicoidally spring obtaining the experimental values which are compared finally with the simulation results.

Abstract: The emerging of bacteria/cell culturing in biological/biomedical research and industry is in demand for low cost, fast, non-invasive, and reliable alternative/approach for evaluation and measurement. Microfluidic approach is one of the promising alternatives for replacing the expensive commercial cuvvete for bacteria/cell culture and suspension for optical measurement. This study demonstrates the integration of absorbance measurement with microfluidic platform for Escherichia coli (E. coli) bacteria suspension analysis. The E. coli was cultured and prepared for suspension medium which then transferred inside the PDMS-glass based microfluidic. Then, the absorbance measurement is carried out using UV-Visible spectrophotometer. We demonstrate this method by measuring absorption of light transmitted through microfluidic chambers within the visible light range (350nm - 750nm). From the result, it had indicates that the graph pattern and growth behavior of E. coli suspension in microfluidic platform are reliable and comparable to commercial cuvvete reading. This finding

Abstract: Efficient use of adhesion between wheels and rails involves a good knowledge of this phenomenon, in order to equip the vehicle with adequate facilities and systems that protect the vehicle and the rail. The loading of the vehicle's axle with dynamic loads in vertical and horizontal planes, are to be developed in the area of contact, both normal stress and shear distributed stress, their sum giving the friction force and the moment of pivoting friction (spin). This makes the wheel-rail contact problems take the two aspects of the study, namely the problem of normal and tangential contact issue. The normal contact problem involves regular geometric shape bodies, determining the size of the resulting contact surface, the distribution of the normal contact pressures and the relationship between the proximity of the bodies and the normal contact force. Solving the problem of the tangential wheel-rail contact is about to establish the correlation between the creepage, normal contact forces and friction forces, and also the ratio between the adherent contact surface and the nominal contact surface where the creepage ocurs.

Abstract: The objective of this work is to increase the power of the two wheeler miniature engines (100cc to 250cc) by supercharging the vehicle using the suspension system. For this purpose a design is made to extract compressed air from the suspension system. It has been successfully shown that the air can be extracted from the suspension system, stored and then fed into the engine similar to supercharger or turbocharger, and the engine power can be improved using this free energy.