Aluminum Ball Research Articles

Enhancing conical solar stills with aluminum ball energy storage: Optimal distance for improved performance

The aim of this investigation is to ascertain the optimal arrangement of aluminum spheres, each with a consistent diameter of 2 cm, to serve as a cost-efficient means of energy storage for augmenting the efficacy of conical solar distillation apparatus. For this purpose, three identical conical stills were manufactured. Experimental procedures were conducted over a two-day timeframe. Initially, on the first day, the first distiller operated without any aluminum spheres, while the second and third distillers were equipped with aluminum spheres positioned at intervals of 3 cm and 4 cm, respectively. Subsequently, on the second day, the initial distillation process did not involve the presence of aluminum spheres. Nevertheless, in subsequent distillations, aluminum spheres were introduced near the base of the vessel, with respective spacings of 5 cm and 6 cm for the second and third distillations. Throughout the experiment, the brine within the vessels maintained a depth of 2 cm. The investigation revealed that the highest distillation productivity, measured at 8400 g/m^2, was attained when employing aluminum spheres with a diameter of 2 cm and spaced 3 cm apart. In contrast, distillation yields were diminished when aluminum spheres were spaced at intervals of 4, 5, and 6 cm, as well as in the absence of aluminum spheres, resulting in yields of 7750, 7200, 6700, and 5750 g/m^2, respectively. The optimal separation distance between the aluminum spheres was determined to be 3 cm, resulting in a significant enhancement of 46.08 %. Ultimately, the utilization of conical solar stills coupled with aluminum spheres as an economical energy storage medium, featuring aluminum spheres with a diameter of 2 cm and spaced 3 cm apart, emerges as the most efficacious option.

Sintering and Tribological Properties of Ti3SiC2-TiSix Composite Sintered by High-Pressure High-Temperature Technology.

The Ti3SiC2TiSix ceramic composite was synthesized in situ from a mixture of 3Ti:1.5Si:1.2C powders under pressures ranging from 2 to 5 GPa and temperatures of 1150 °C to 1400 °C. At medium and high temperatures (4-5 GPa and 1400 °C), Ti3SiC2 dissolves into the cubic TiC phase. SEM analysis revealed that the high-pressure-produced multilayer structure of Ti3SiC2 remained intact. The friction properties of Ti3SiC2-TiSix composites combined with copper and aluminum were studied under both dry and lubricated conditions. After the break-in period, the Ti3SiC2-TiSix/Al combination exhibited the lowest friction coefficient: approximately 0.2. In dry-sliding conditions, the friction coefficient varies between 0.5 and 0.8. The wear mechanisms for Ti3SiC2-TiSix composites paired with aluminum primarily involve pear groove wear and adhesive wear during dry friction. Irregularly shaped aluminum balls accumulate in the pear grooves and adhere to each other. With increasing sintering pressure, the average friction coefficient of Ti3SiC2-TiSix composites against Cu ball pairs first increases and then decreases. The wear rate of the samples did not vary significantly as the sintering pressure increased, whereas the wear rate of Cu balls decreased with increasing sintering pressure. The adhesive wear of the Ti3SiC2-TiSix composite with its Cu counterpart is stronger than that of the Al counterpart. Abrasive chips of Cu balls appeared in flake form and adhered to the contact interface.

Performance optimization and comparative study of a conical solar distiller with optimized construction of aluminium balls as energy storage materials

This study seeks to find the ideal size of aluminum balls to improve the effectiveness of conical solar stills for storing energy, due to the increasing demand for drinking water and the high costs of getting portable drinking water. To achieve this, three comparable conical solar distillers were made using aluminum balls of various diameters (1 cm, 1.5 cm, 2 cm, and 2.5 cm) at a 4 cm center spacing. Two days were spent on the experiments. The first distiller had no metal balls on the first day, whereas the second and third had 41 1 cm and 1.5 cm aluminum balls uniformly dispersed at the bottom. On the second day, the first distiller had no metal balls, but the second and third had 41 2 cm and 2.5 cm balls. The water basin depth was consistently maintained at 2.5 cm. The results revealed that the distiller with 2 cm diameter aluminum balls achieved the highest productivity, yielding 840 mL/m2, compared to the distillers with aluminum balls of 1 cm, 1.5 cm, and 2.5 cm diameter, as well as the conventional distiller without any storage materials, which yielded 645 mL/m2, 695 mL/m2, 755 mL/m2, and 570 mL/m2, respectively. The ideal diameter for the aluminum balls was found to be 2 cm, leading to a significant 47.37 % enhancement in water productivity. Conical solar stills using 2 cm diameter aluminum balls as an economical energy storage material provide the best answer.

Particle behavior and trap design for ±320 kV gas-insulated power transmission line (GIL)

The movement of metal particles in the electric field of the DC gas-insulated transmission line (GIL) may cause local electric field distortion on the surface of the spacer, which seriously affects the operation stability of the GIL. In this paper, based on a ±320 kV GIL platform, the movement characteristics of metal particles (aluminum blocks, aluminum wires, aluminum balls) inside the GIL are studied. The suppression effect of particle activity for particle trapping and surface coating are experimentally studied in DC electric field. The relationship between particle trap porosity and particle suppression effect are discussed and verified with experiments. The research results show that under negative voltage, the minimum take-off voltage of metal particles in ±320 kV GIL is −190 kV, which is far lower than the steady-state operating voltage of GIL. Once the spherical and blocky particles take off, they will continue to reciprocate rapidly between the conductors. When the block particles are close to the spacer, they might be attracted and adsorbed on the surface of the spacer. Metal wires after taking off tend to show ‘firefly’ movement near the high-voltage conductor. The coating has a significant effect on increasing the take-off electric field of metal particles. It is verified that the traditional AC GIL particle trap is not effective in inhibiting particles in DC voltage. The suppression of the DC GIL particle is positively related to the porosity of the particle trap to a certain extent. The conclusions of this paper can be reference for the development of future stable and reliable DC gas-insulated equipment.

Simulation method of debris cloud from fiber-reinforced composite shield under hypervelocity impact

A Whipple shield is a double-plate structure commonly used to protect spacecraft from space fragments. The space fragments hit the outer plate and break into a debris cloud with dispersed energy and momentum, which reduces their risk of penetrating the bulkhead. With the development of high-performance materials, for example, high-performance fiber composites, traditional Whipple shields have evolved into advanced complex shields. Using the finite element and smoothed-particle hydrodynamics adaptive method and mesoscopic modeling technology, this study aims to establish a numerical model for fiber-reinforced composite shields under hypervelocity impact. Several mesoscale models for fiber-reinforced composites for problems under hypervelocity impact have been established. These models can be meshed with high-quality elements that satisfy aerospace engineering requirements (identify hazardous fragments in the debris cloud) while retaining the main structural features of materials. We established a numerical model by combining the finite element and smoothed-particle hydrodynamics adaptive method and existent mesoscale models. Using laminates, 2D woven fiber-reinforced plastics, and 3D woven fiber-reinforced composites as examples, numerical simulations of the debris cloud generated by an aluminum ball under hypervelocity impact were conducted. The simulation results, which are highly consistent with the experimental results of the debris cloud shape, accurately reflect the failure features of laminates, that is, fiber fracture and delamination. Simulation results show that the fiber-reinforced composite has better protection than the aluminum plate at the same areal density. By comparing the debris clouds generated by the hypervelocity impact on different fiber-reinforced composite shields, it can be argued that composite knit modes strongly affect the protective effect of fiber-reinforced composites. This work shows that the simulation method combining the finite element and smoothed-particle hydrodynamics adaptive method and mesoscopic modeling is a powerful tool for simulating the Whipple shield with a fiber-reinforced composite. More importantly, this method can also be applied to other Whipple shields with complex structures and advanced materials, for example, other composite materials, metal foam materials, and multilayer board protective structures.

Design of Multiphase Metal Balls via Maskless Localized Anodization Based on Bipolar Electrochemistry

AbstractNanoporous metal‐oxide films formed on some metals and their alloys during anodization are crucial for both basic research and commercial applications. They are used as important materials for various types of device fabrication due to their distinctive solid‐state shapes, such as nanopores and nanotubes. However, preparing nanoporous films using anodization, which is a surface treatment for plate‐like specimens, requires a direct electrical connection to the workpiece. Developing new materials independent of the specimen's shape and size will vary if the need for direct energization is eliminated. Here, bipolar electrochemistry is employed to fabricate two‐phase (insulator–conductor) and three‐phase (insulator–conductor–insulator) aluminum balls by controlling the redox reaction region in an electric field. The aluminum balls are site‐selectively anodized employing a wireless and maskless operation. The multiphase aluminum balls’ versatility is demonstrated in the site‐selective electroless deposition of copper on their exposed regions. Additionally, it is demonstrated that various types of materials, including aluminum and titanium, can be oxidized simultaneously in the same cell.

Effects of forging on the mechanical properties of B4Cp/Al composite with flaked Al and Al2O3 particles

Abstract To flake the pure aluminum powder, ball grinding and forging are used. The mechanical properties of the forged B4Cp/Al composite are tested. The results show that ball milling can flake the pure aluminum powder. The alumina layer of Al2O3 on the surface of aluminum powder are broken during the ball milling and can be dispersed in the matrix as reinforcement. The hardness of the forged aluminum with flaked Al is higher of 19.5% than that without flaked. The forging can increase ultimate tensile strength of the B4Cp/Al composite. Increasing B4C volume fraction, the average hardness of the forged B4C/Al composite with flaked Al powder gradually increases, relative density gradually decreases, ultimate tensile strength first increases and then decreases.

Analysis of space debris impact source localization based on PVDF piezoelectric film

As the pace of human exploration and utilization of space continues to accelerate, space debris gradually becomes an inevitable problem affecting and threatening human space activities. When space debris strikes the spacecraft bulkhead, determining the impact source location timely and accurately is the foundation of the repair damage, and is also of great importance for the safety of astronauts' life. This paper analyzed the wave propagation law in thin plates, established a lightweight sensor array using PVDF (Polyvinylidene fluoride) circular thin-film sensors, and used a two-stage light-gas gun loading system to conduct hypervelocity collision localization experiments on impacting 2A12 aluminum plates to study the effects of sensor array radius and sensor size on localization results. The results show that the smaller the radius of the PVDF sensor array is, the more accurate the positioning result is under the premise of the same size of the PVDF circular film sensor array. On the premise of the same PVDF sensor array arrangement, the larger the PVDF circular membrane sensor is, the more accurate the positioning result is. ABAQUS finite element software is used to study the stress wave propagation of aluminum ball impacting aluminum plate at high speed, simulating space debris impacting spacecraft. The stress waveform obtained from the simulation is in good agreement with the experiment, which shows the accuracy of the numerical simulation method.

Gas-solid hydrodynamics in a stator-rotor vortex chamber reactor

The gas–solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid’s kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics. A constructed fluidization flow regime map for a fixed solids loading of 100 g shows that the bed can only be fluidized for a rotation speed between 200 and 400 RPM. Below 200 RPM, particles settle down on the bottom plate and cannot form a stable bed due to inertia and friction. Above 400 RPM, the bed cannot be fluidized with superficial velocities up to 1.8 m/s (air flow rate of 90 Nm3/h). The bed thickness shows some non-uniformities, being smaller at the top of the bed than at the bottom counterpart. However by increasing the air flow rate or rotation speed the axial nonuniformity can be resolved. The bed pressure drop first increases with increasing gas flow rate and then levels off, showing similar characteristics as conventional fluidized beds. Theoretical pressure drops calculated from mathematical models such as Kao et al. model agree well with experimental measurements. Particle velocity discrepancies between the top and bottom particles reveal that the impact of gravity cannot be completely neglected. Design guidelines and possible applications for further development of STARVOC concept are proposed based on fundamental data provided in this work.

Improvement and sensitivity analysis of equivalent heat transfer model for dynamic thermal rating of overhead lines

With the rapid growth of power demand, the conductor ampacity calculation method based on the dynamic thermal rating (DTR) becomes more and more important. Based on the shortcomings of the current DTR models, a new DTR model that does not need to measure the wind speed and the operating state of conductor is proposed, which is called the equivalent heat transfer (EHT) model. However, there are still shortcomings in the accuracy of the EHT model in application. In this paper, the EHT model is improved at first according to the consideration of the effect of air physical parameters and the redetermination of the experimental parameters of the EHT equipment. Then, the operation of EHT equipment is simulated through the established experimental platform. The improved EHT model is verified by the IEEE standard. Finally, the sensitivity analysis of the improved EHT model is carried out. The results show that the improved EHT model is greatly improved on application accuracy compared to the original EHT model. Moreover, the improved EHT model can choose the steady-state temperature at any position on the surface of the aluminum ball to calculate the conductor ampacity, and the relative error does not exceed 6%. The improved EHT model is reliable and can meet the safe operation requirements of the power system in practical engineering applications.

Mechanical Performance of Spacecraft Protection Structure Under Hypervelocity

In order to improve the ability of the spacecraft protection system to resisted hypervelocity orbit debris, a composite double-layer honeycomb sandwich structure was proposed in the article. Four sets of models were established, through the method of controlling variables, and the SPH algorithm of the LS-DYNA finite element software was used to analysis the composite honeycomb sandwich structure. The diameter of the aluminum ball was 7mm and the velocity was 5818m/s. The results show that the residual velocity of debris cloud decreases with the increase of the cell diameter of the front-stage honeycomb. and the residual velocity of debris cloud increases with the decreases of the cell diameter of the back-stage honeycomb structure. The energy absorption effect of the composite structure was much higher than that of the traditional honeycomb structure, the remaining speed was reduced by about 64%, and the total energy absorption was increased by 77.6%.

Semi-convertible Hydrogel Enabled Photoresponsive Lubrication

Summary A semi-convertible hydrogel with reversible photoresponsive supramolecular lubricating ability is demonstrated by integrating a responsive supramolecular system of α-cyclodextrins/polyethylene glycol (α-CD/PEG) and competitive guest 1-[p-(phenylazo)benzyl]pyridinium bromide (AzoPB) within a poly(vinyl alcohol) (PVA) and polyacrylamide (PAAm) framework. The competitive host-guest interaction between α-CD/PEG supramolecular network and AzoPB after UV and visible-light irradiation enables the appearance and disappearance of the sol-state layer on the hydrogel surface while the PVA and PAAm consistently keeps the framework. This semi-convertible process realizes the reversible photoresponsive lubricating ability and variable toughness. We envision that this finding will offer a possible way for fabricating novel smart devices far beyond lubrication, leading to an emerging branch of interdisciplinary materials science that integrates supramolecular chemistry, hydrogel, and surface science.

An Equivalent Heat Transfer Model Instead of Wind Speed Measuring for Dynamic Thermal Rating of Transmission Lines

With the increase in electricity demand, the ampacity calculation based on the dynamic thermal rating (DTR) technology is increasingly significant for assessing and improving the power transfer capacity of the existing overhead conductors. However, the DTR models now available present some inadequacies in measurement techniques related to wind speed. Therefore, it is essential to propose a new model instead of wind speed measuring in DTR technology. In this paper, the influence analysis of various weather parameters on the conductor ampacity is carried out by using the real weather data. Based on the analysis, it is confirmed that the impact of wind speed is significant, especially in the case of the low wind speed. Moreover, an equivalent heat transfer (EHT) model for DTR technology is proposed instead of wind speed measuring. For this EHT model, the calculation of conductor ampacity is realized through investigating the correlation of heat losses between the heating aluminum (Al) ball and conductor. Finally, combined with the finite element method (FEM), the EHT model proposed in this paper is verified by the Institute of Electrical and Electronic Engineers (IEEE) standard. The results indicate that the error of the EHT model is less than 6% when employing the steady thermal behavior of the Al ball to calculate the ampacity. The EHT model is useful in the real-time thermal rating of overhead conductors. It can increase the utilization of overhead conductors while also avoiding the limitation of the existing measurement techniques related to wind speed.

Effect of Sintering Temperature on Properties and Microstructure of Alumina-Aluminum Cermet via Vacuum Sintering Method

In this paper, the effect on the properties of alumina/aluminum cermet by changing the sintering temperature, and comparing the advantages and disadvantages of different characterization methods and their application range, it provides a reference for selecting the characterization technology suitable for alumina/aluminum composites.Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn: the higher the vacuum sintering temperature, the more aluminum material is melted out of the body to form aluminum balls on the surface, and the green body The more severe the cracking. When the sample is sintered at a temperature of 600 °C, the density is the highest and the appearance is the best. When the molding pressure is 40 MPa and the sintering temperature is 700 °C, the microstructure of the sintered alumina/aluminum cermet is better. It can be seen from SEM and EDS analysis that the particles are continuously distributed and the larger one is metal Al, and the particles are discontinuously distributed and finer is Al2O3.

Effect of aluminum balls on the productivity of solar distillate

Abstract Drinking water has become a real global problem, despite the abundance of unsaturated saltwater and colorless, which do not meet the requirements of the World Health Organization. The El Oued, in the southeastern part of Algeria, contains vast quantities of salt water and non-potable water. Solar distillation can be used as a solution to resolve this trouble. To provide drinking water, we use free sunlight to treat salt water. The traditional solar distillation device, which is one mile long (0.5×0.5 m), is designed to confirm the effectiveness of this solution. The traditional single slope solar distillation, its dimensions (0.5×0.5 m), is designed to confirm the effectiveness of this solution. Solar distillation is an environmental, economic and simple technique, but it needs some modifications to increase the distilled water production. In this work, we added aluminum balls inside the solar distillate box. In this work, we added 42 aluminum balls with a diameter of 2 cm inside a solar distillates box; positioned as follows (6 balls x 7 balls). The results showed that aluminum balls increased the distillation of distilled water by about 27.16 %.

Impact of Peak Material Volume of Polycrystalline CVD Diamond Coatings on Dry Friction Against Aluminum

For economic and environmental reasons, dry forming is of increasing interest due to the shortening of process chains, cost savings and reduction of environmental pollution. The aim of these investigations is to examine to what extent chemical vapor deposited (CVD) diamond coatings are suitable for dry forming of aluminum and to identify the surface topology requirements for a low friction coefficient and low wear. Nine different surface topologies of CVD diamond coatings were tested in an oscillating ball-on-plate tribometer test against aluminum balls with a Hertzian contact stress of 759 MPa and 99,900 cycles. It could be concluded that the peak material volume (Vmp) of the diamond coating is the most important factor for achieving a low abrasion of aluminum as well as a low friction coefficient against aluminum. The Vmp should be smaller than 0.04 ml/m2. Microcrystalline CVD diamond with a post-treated surface has great potential for dry forming of aluminum.

Combined influence of some cations on arsenic removal by an air-injection EC reactor using aluminum ball electrodes

Combined influence of some cations on arsenic removal by an air-injection EC reactor using aluminum ball electrodes

Correlation Between Power and Lifters Forces in Grinding Mills

Using a discrete element method (DEM) software, this paper develops a methodology to obtain the forces acting on each face of the lifters and on the liner plates of a grinding mill and its correlation to the mill torque and power. This analysis gives a clear view of the contribution of each lifter face to the torque and power. A pilot mill with a transparent cover charged with steel and aluminum balls is simulated in DEM, obtaining the forces in the lifters faces and the resulting torque and power. This power is compared to the power released by the DEM software and the power obtained from the strain gauge installed in the pilot mill. Results show an almost perfect matching between the power from the lifters forces and the DEM power, and a small error compared to the measured torque and power. The analysis of the shape, magnitude, and position of force pulses acting on the front and back faces of the lifters for different mill filling and speed is correlated to the power curves and gives a physical explanation of the shape and variations of the power.

The Effect of Hypervelocity Impact Loading on Explosively Welded Ti/Al/Al Plate

The aim of this paper is to investigate the ballistic properties of explosively welded Ti6Al4V/AA1050/AA2519 laminate under hypervelocity (4000 m/s) impact loading of projectile made of aluminium ball. The paper describes the influence of the projectile impact energy on the structure of the laminate components and delamination of bonds depending on its strength and presence of intermetallic phases. Observation of the failure is performed for the plate impacted for aluminium alloy side. Results revealed ductile shearing as a dominant process leading to perforation.

Removal of arsenate by electrocoagulation reactor using aluminum ball anode electrodes

Abstract The aim of this research was to remove arsenate (As(V)) from groundwater using an air-injected electrocoagulation (EC) reactor with aluminum (Al) ball anodes. The effects of seven operating variables – initial pH, applied current (i), operating time (tEC), initial As(V) concentration (Co), Al ball anode diameter (dp), reactor column height (h), and airflow rate (Qair) were investigated with a Box-Behnken statistical experimental design. ANOVA results from the quadratic model equations indicated that the model fitted very well with the experimental data for the responses, which were removal efficiency, operating cost (OC), As(V) adsorption capacity, and effluent concentration (R2 ≥ 0.87). The most effective parameters were applied current, operating time, and anode height for As(V) removal efficiency in the EC reactor, while initial pH, Al anode diameter, and air flow rate had limited effect on removal. The model predicted a residual As(V) concentration below 10 μg/L under the optimum operating conditions (pH 7.03, 0.29 A, 10.5 min, dp 7.5 mm, 613.4 μg/L, h 5.1 cm, and Qair 6.4 L/min). The maximum As(V) removal efficiency and minimum OC in the EC process were almost 99% and 0.442 $/m3, respectively.