Comparative analysis of soil discarding by spherical disks

The article presents data on the influence of various types of spherical disks on the discarding of soil in the horizontal and vertical planes during its processing. These studies were conducted in order to optimize the selection of working bodies of disk tillage machines in terms of resistance and processing quality. Three types of disks were used in the comparative analysis. Two types of discs with cutouts and one solid spherical disc. On one type of disk, the cutouts are made in the form of circular arcs, and on the other-in the form of arcs of a logarithmic spiral. The conducted studies have shown that within the working surface of the disk, the trajectories of movement of soil particles under the influence of the three types of disks under study differ little from each other. Although it can be noted that the steeper rise of the trajectory in the vertical plane provides a solid disk, and the smallest rise of the trajectory - at the disk with cutouts in the form of a logarithmic spiral. In the horizontal plane, the longitudinal movement of the soil mass is less in disks with cutouts, especially in a disk with cutouts along the arc of a logarithmic spiral. As a result of these studies, it was revealed that the disk working bodies with cutouts on the cutting edge in the form of arcs of a logarithmic spiral showed the best quality and energy indicators.

Friction Stir Consolidation of Aluminum AA5052 Alloy Machining Wastes

The purpose of this paper is to develop aluminum AA5052 alloy solid disc from machining wastes via friction stir consolidation (FSC) process & optimize its parameters: die rotational speed, pre-compact aspect ratio and processing time for better performance characteristics. At first, the required dedicated tooling are designed and built for the specific process. Then, the solid discs are fabricated from aluminum AA5052 alloy machining chips through FSC process in which the experimental parameters considered are rotational speed (315, 400 and 500 rpm), pre-compact aspect ratio (25.4/7, 25.4/5 and 25.4/3) and processing time (30, 45 and 60 sec). Based on the experiment, the compressive strength, hardness and microstructure of the consolidated solid disc are evaluated. Taguchi’s L9 orthogonal array is used to analyze and optimize the process. The results revealed that solid disc is successfully fabricated using FSC process using dedicated tooling, and rotational speed (500 rpm), compact aspect ratio (25.4/3) and processing time (60 sec) are optimal FSC processing conditions. The microsturcture of the solid disk shows finer and fully recrystallized grains in axial cross section orientation of the disc particularly in the central region. Moreover, the results show, the compressive strength and hardness of the solid disc are comparable to that of forged or cast disc and suitable for most engineering structural applications.

Gold–Copper Film Electrode for Voltammetry Determination of Mercury in Water

Gold-copper film electrode prepared in situ on carbon paste solid disk substrate (Au–CuF/CPE) was studied as a working electrode. The factors influencing mercury stripping peak currents, such as C Au III (0.20 mg/L), C Cu II (0.05 mg/L), type of acids and their concentration (HClO4, 0.005 M), deposition potential (-800 mV) for Au–CuF/CPE, deposition time (180 s), and interferents, were investigated and optimized. The method has a low limit of detection of 0.13 μg/L and is not affected significantly by the examined ions/substance. It was applied to detect the concentration of Hg in real water samples and is promising for practical usage.

Frictional Characteristics and Electrical Conductivity of Electrical Sliding Contacts With Circular Grooved Porous Disk Under Lubricated Conditions

In this study, porous materials were applied to the surface materials of electrical sliding contacts to produce long and stable operations. The proposed sliding contacts consist of a rotating circular grooved porous disk and a stationary rider having a spherical surface. We conducted the experimental analysis from two perspectives. The first perspective was to inspect the effect of the design parameters on the electrical conductivity and the frictional characteristics; this was done by performing tests under various loads applied on the sliding contacts. The second perspective was to investigate the durability and stability of the sliding contacts by using the tests for a long operating time under a constant applied load. Our experimental results proved that the porous disk generated a lower and a more stable contact voltage and frictional force than the conventional nonporous solid disk. This effect is significant when a large curvature radius of grooves is provided on the disk surface. These results are attributable to the reduction of the hydrodynamic fluid force by the porous material and the grooves; the porous material yields lower hydrodynamic pressure due to the seepage of the lubricant oil across the interface between the oil film and the porous matrix and the grooves enhance the reduction of the hydrodynamic effect because of oil leakage to the downstream region. These factors reduce the oil film thickness between the disk and rider and facilitate the metal contact, and thereby a porous grooved disk generates higher electrical conductivity than a conventional solid disk.

On magnetized non-Newtonian rotatory fluid flow field

The current pagination is devoted to offering the untapped features of non-Newtonian rotatory magnetized fluid flow over the solid disk. The said non-Newtonian fluid model is a Powell–Eyring fluid model. The flow field is further carried with suspended nanoparticles with velocity slip effects. The strength of the article is a complex mathematical modeling subject to physical effects mentioned before, and the computational results are provided through the self-coded algorithm rather than to move on with the usual built-in scheme. To make the implementation possible, the obtained flow-narrating system is converted into a system having fewer independents. The key involved parameters are Powell–Eyring fluid, magnetic field, velocity slip, thermophoresis, and Brownian motion parameters. The dependent quantities namely axial, tangential velocities, temperature, and concentration are examined against flow-controlling parameters. The obtained outcomes in this direction are offered by means of graphical trends. It is noticed that both axial and radial velocities possess direct relation with Power–Eyring parameter ( M). The Powell–Eyring fluid temperature is an increasing function of the thermophoresis parameter. Furthermore, the Powell–Eyring concentration enhances significantly toward the higher values of the Brownian motion parameter.

Thermal Behavior of Auxetic Honeycomb Structure: An Experimental and Modeling Investigation

Recently, engineers and researchers reconsider honeycomb sandwich structures due to their vast application in industries and aviation arenas. In this study, a new honeycomb sandwich material was developed and tested. The purpose of the present work is to investigate numerically and experimentally with a comparative study on the effects of heat transfer on design parameters and geometry for different types of exotic honeycomb structures taking in account radiation within the cell and conduction in the cell walls. The numerical solution for temperature profiles for different types of exotic honeycomb structures and solid disk are performed in order to inspect the variation of heat transfer. The modeling results show a good agreement with the experimental results. The present work demonstrates that the temperature profile for reentrant is the highest one compared to splined and stiffened which reaches around 10% at temperature of the front surface Tin = 100 °C. It was found that the rib length enhances significantly heat transfer. Results showed also that stiffened honeycomb has a good insulation and metallic honeycomb core structure has a good thermal insulation characteristic for the highest instantaneous temperature, whereas reentrant honeycomb has a good heat transmission.

Wide Acoustic Bandgap Solid Disk-Shaped Phononic Crystal Anchoring Boundaries for Enhancing Quality Factor in AlN-on-Si MEMS Resonators

This paper demonstrates the four fold enhancement in quality factor (Q) of a very high frequency (VHF) band piezoelectric Aluminum Nitride (AlN) on Silicon (Si) Lamb mode resonator by applying a unique wide acoustic bandgap (ABG) phononic crystal (PnC) at the anchoring boundaries of the resonator. The PnC unit cell topology, based on a solid disk, is characterized by a wide ABG of 120 MHz around a center frequency of 144.7 MHz from the experiments. The resulting wide ABG described in this work allows for greater enhancement in Q compared to previously reported PnC cell topologies characterized by narrower ABGs. The effect of geometrical variations to the proposed PnC cells on their corresponding ABGs are described through simulations and validated by transmission measurements of fabricated delay lines that incorporate these solid disk PnCs. Experiments demonstrate that widening the ABG associated with the PnC described herein provides for higher Q.

Experimental researches of determination of degree of interaction of a working organ with the object of treatment in plant growing

The article is devoted to the main soil treatment with a combined plow. The article has a research character, which is expressed in the fact that the analysis of methods and means of mechanization for the main tillage with the turnover of a layer, as well as excerpts from the works of leading scientists on the problem, there were shown the types of patents that provided the optimal soil treatment, their shortcomings and solutions to these problems. There were determined the main trend of development of soil-processing combined machines, improvement of constructions of arable units to improve the quality of their work. Also, the form of the disk was justified, namely, there was shown the causal relationship of the presence of cuts in the disk of the tillage tool in comparison with the solid disk. There were described the principle and process of the developed combined plow. As a result of the work done, there was obtained the design of a combined plow with additional working bodies which consist of disks installed by batteries behind each body of the plow. The conclusions set out the main results achieved so far.