Glass Balls Research Articles

Sustainable removal of nano/microplastics in water by solar energy

Plastic pollution in water is of increasing scientific and public concern due to the increasing plastic production, slow degradation rate and low recycling efficiency. However, the present methods for the removal of plastic particles in water are either inefficient or expensive, which limit their wide application. In this work, we propose a new strategy for the efficient removal of plastic particles in water that is driven by solar energy. Sunlight was focused through a glass ball with high power density, which could induce convection and form a microbubble at the interface. The plastic particles were driven into the bubble by convection and subsequently fused in the microbubble, as the temperature in the bubble was much higher than that in the solution due to the significantly different densities. Such a hot microbubble acts as a ‘furnace’, which can collect and fuse plastic particles into large bulks in the microbubble, facilitating the sustainable removal of plastic particles in water without the use of any chemical or biological reagents or filters. Moreover, this method is quite simple and can effectively utilize free sunlight without requiring extra energy or causing secondary pollution, implying its promising application in dealing with plastic pollution in aquatic ecosystems.

Analysis of the entropy due to radiative flow of nano–encapsulated phase change materials within inclined porous prismatic enclosures: Finite element simulation

The heat transfer and fluid flow due to the interaction between the radiation and convective modes is examined. Also, the irreversibility processes within the considered system is calculated based on the second law of the thermodynamic. The Nano–Encapsulated Phase Change Materials (NEPCM) in which their core is nonadecane and their shell is polyurethane are used to formulate the worked suspension. The flow domains are prismatic enclosures and two designs (D1 and D2) based on the aspect ratio of the enclosures walls are carried out. The geometry is filled by glass balls as an isotropic porous medium. The solution methodology is based on the finite element method and a semi implicit technique is applied for the velocities. The main outcomes disclosed that the alteration of the radiation parameter reduces the melting/solidification processes. Also, using NEPCM's gives a clear improvement in the heat transfer.

Characteristics of 2D ZnO-based piezoelectric nanogenerator and its application in non-destructive material discrimination

The present report aims at the application of piezoelectric nanogenerators for non-destructive material discrimination. The detailed characteristics of zinc oxide (ZnO) nanosheet-based piezoelectric nanogenerator and its applications in mechanical energy harvesting and sensing are considered as major objectives of the present study. The nanogenerator is fabricated with ZnO nanosheet film prepared by hydrothermal method with necessary electrodes. The nanogenerator response as a function of different load resistances, different finger-tapping frequencies, different finger-tapping pressures, bending and twisting movements are recorded. The maximum output power of 18 nW is observed at the load resistance of 200 KΩ with 60 mV output voltage. The output voltages of ∼150 mV, 350 mV, and 200 mV are observed for finger-tapping, bending, and twisting movements, respectively. The output voltages of ∼76 mV, 100 mV, and 145 mV are observed for low, medium, and high pressures applied by the finger. Nanogenerator is also tested for its stability of the output at different points of time after the device fabrication and found stable over for one year. Further, the nanogenerator is used as an impact sensor for non-destructive material discrimination application. The output voltages of 176 mV, 225 mV, 272 mV, and 300 mV were observed for acrylic, ceramic, marble, glass balls of uniform diameter but with a different mass. The fabricated nanogenerator can discriminate the equal size materials of different densities. Further, ZnO nanosheet-based nanogenerator has potential applications in mechanical sensors due to the high flexibility and mechanical reliability of the ZnO nanosheets.

Unsteady three dimensional radiative-convective flow and heat transfer of dusty nanofluid within porous cubic enclosures

Study of the convective transport of the dusty nanofluid is germane to dust ladder air, fluidization, gas cooling systems to enhance heat transfer process, environmental pollution, dust collection, sedimentation, and petroleum industry. Therefore, we aim in this article to deal with the transient three dimensional (3 D) radiative-convective flows and heat transfer of dusty nanofluid within porous cubic enclosures. Two systems of the differential equations are formulated for the nanofluid and dusty phases and two SIMPLE (Semi Implicit Method for Pressure Linked Equation) techniques are carried out for the distributions of the nanofluid and dusty pressures. The porous elements are the glass balls and the non-Darcy model is applied for the porous medium. All the porous properties are constants and taken into account during all the computations. The radiation flux is assumed in the normal direction and components of the system are in the thermal equilibrium state. The mixture is consisting of water as a host fluid and alumina as nanoparticles. The main findings revealed that the dusty parameters have significantly impacts on the heat transfer and hence they are important factors in such types of flows. Also, the increase in the nanoparticles volume fraction from 0% to 10% gives an enhancement in the average Nusselt number up to 12.88%.

Large-Size Honeycomb-Shaped and Iris-Like Liquid Crystal Elastomer Actuators

Large-Size Honeycomb-Shaped and Iris-Like Liquid Crystal Elastomer Actuators

Glass-like protein condensate for the long-term storage of proteins

Long-term storage of proteins at ambient temperature is required for applications in pharmaceutics and biotechnology. Lyophilization is a versatile approach for stabilizing proteins at ambient temperature, although its freezing and drying processes negatively affect the protein structure. In this study, we show a glass-like protein condensate (GLPC) as a new method for protein stabilization at ambient temperature. Various protein types, including immunoglobulin G, gamma globulin, albumin, and chymotrypsin, formed a glassy state during ultracentrifugation and natural drying, while proteins that tend to crystalize, such as hen egg-white lysozyme, did not. The GLPCs were characterized by a transparent solid state, similar to a dry glass ball. Importantly, the GLPCs were dissolved easily in saline solution at a physiological concentration, thereby retaining their native structures and functions. The GLPCs preserved their native structures even after 1 year of incubation at ambient temperature. These results provide a framework for the development of protein preservation methods at ambient temperature other than lyophilization.

Micro-abrasion/Corrosion Behavior of Pack-Borided AISI 316L Steel and ASTM F1537 CoCrMo Alloy in Ceramic-on-Ceramic Couplings

This study aims to investigate the effect of the presence of a simulated corrosive body fluid (Hank’s solution) on the micro-abrasion and corrosion resistance of two borided biomedical alloys (AISI 316L stainless steel and ASTM F1537 CoCrMo alloy) when in sliding contact with a ceramic countersurface. The materials were subjected to a powder-pack boriding treatment. The modified surfaces were characterized mechanically and physico-chemically. The changes of wear resistance of both borided alloys were determined by means of micro-abrasion tests using a slurry made of the corrosive solution with F-1200 SiC abrasive particles. 25-mm-diameter dielectric glass balls were used as countersurface in the wear tests with the twofold purpose of replicating a ceramic-on-ceramic biomedical contact and avoiding the effect of galvanic corrosion with the metallic samples to be tested. The tests were run in triplicated at 0.1, 0.2 and 0.5N of applied load at constant sliding distance and speed. The wear volumes and wear scar examination were carried out by optical profilometry and microscopy. On the other hand, the corrosion resistance of the materials (before and after boriding treatment) was characterized by potentiodynamic polarization measurements in a closed three-electrode cell using the corrosive fluid. According to the results found, the hardness of the alloys increased significantly between 300 and 400% by boriding. However, the micro-abrasion/corrosion situation was detrimental for both alloys under sliding with the ceramic countersurface in the presence of Hank’s solution, which is opposite to that reported in literature for other abrasion–corrosion conditions investigated.

A study of the natural convection of water-AA7075 nanoliquids in low-porosity cylindrical annuli using a local thermal non-equilibrium model

Natural convection in nanoliquid-saturated porous cylindrical annuli due to uniform heat and mass influxes from the solid cylinder and effluxes from the outer hollow cylinder is investigated analytically. The Darcy model and the modified version of the Buongiorno two-phase model are used, and local thermal non-equilibrium between the phases is assumed. A nanoliquid-saturated porous medium made up of glass balls with a dilute concentration of AA7075 alloy nanoparticles well-dispersed in water is considered. Out of three types of annuli considered, shallow annuli provide the best heat transport and tall annuli show the worst performance. The presence of a dilute concentration of nanoparticles significantly enhances the heat transport in the system. Of nine nanoparticle shapes considered, lamina-shaped nanoparticles enhance heat transport the most. Heat transport is enhanced in the case of heat-and-mass-driven convection compared to the case of purely heat-driven convection. The results for a rectangular enclosure are obtained as a particular case of the present study. Two asymptotic routes that take us to the results of thermal equilibrium are shown. The vanishing limit of the concentration Rayleigh number yields the result for a single-phase model. Results for the base-liquid-saturated porous medium form a limiting case of the present study. We conclude that a shallow cylindrical annulus saturated with water-AA7075 lamina-shaped alloy nanoparticles is best suited for heat transfer due to its high effective thermal conductivity in comparison with that of other shaped nanoparticles and a tall rectangular enclosure saturated by water is best suited for heat storage applications.

Performance Improving of a Concentrating Photovoltaic System by Using a New Optical Adhesive

The objective of this present study is to manufacture a new silicone-based adhesive which is used for gluing and bonding the second optical elements (SOE) with Concentrating Photovoltaic solar cell (CPV) in order to guarantee a thickness that can provide a good silicone adherence to obtain long term stability and keeping a good solar transmittance performance, too. This new adhesive is made up of a mixture of silicone and transparent glass balls. The experimental part consists of the choice of the best size of glass balls with the suitable proportion of the glass balls weight in the mixture. For this purpose, ten samples were manufactured for every category of glass balls and weight ratio. Glass ball sizes between 100 and 1100 μm, and weight ratios between 1 and 10% were analyzed. For each category of glass balls, four proportions were mixed with the silicone. The thicknesses and transmittance of every sample were measured with appropriate instruments. The experimental results illustrate that the mixture containing balls with sizes inferior to 106 μm, is the best mixture which assures adhesive minimum thickness value necessary for an efficient mechanical bond and preserves also a good transmittance of solar irradiance.

A simple model for viscoelastic crack propagation

When a crack propagates in a viscoelastic solid, energy dissipation can occur very far from the crack tip where the stress field may be very different from the r^{-1/2} singular form expected close to the crack tip. Most theories of crack propagation focus on the near crack tip region. Remarkable, here I show that a simple theory which does not account for the nature of the stress field in the near crack tip region results in a crack propagation energy in semiquantitative agreement with a theory based on the stress field in the near crack tip region. I consider both opening and closing crack propagation and show that for closing crack propagation in viscoelastic solids, some energy dissipation processes must occur in the crack tip process zone. The theory is illustrated by new experimental results for the adhesive interaction between a silica glass ball and a silicone rubber surface.Graphic abstract

Study of unsteady thermal conductivity of a package consisting of one layer of equal-size balls

The study of unsteady heat transfer of a package consisting of the equal-size balls was performed at boundary conditions of the first kind. The package was located on a horizontal surface and was limited by the walls of a cylindrical thermostat 129 mm in diameter. The experiments were carried out using glass balls with a diameter of 8.85 mm, 16.0 mm, as well as polyoxymethylene balls with a diameter of 9.0 mm. The package was filled with water. The height of the water layer was equal to the diameter of the balls. In the experiments, the time was determined during which the ball package was heated or cooled to the temperature of the thermostat. It is shown that the time of temperature equalization between the package and the thermostat depends not only on the material and size of the balls but also on the direction of the heat flux. It is shown that the heating time of one layer of equal-size balls is much shorter than the cooling time.

Rheological properties of dispersion-filled thermoplastics with different types of structures at various processing temperatures

The article presents the results of a study of the rheological characteristics of dispersion-fi lled polymer composite materials (DFPCM) based on LDPE and glass balls of the ШСО-30 brand in a wide range of processing temperatures. For the fi rst time, the rheological properties of dispersion-fi lled polymer composite materials are considered from the standpoint of the formation of the dispersed phase with diff erent types of lattices, functional division of the polymer matrix (φp = Θ + В + М) and the construction of dispersed systems with diff erent types of structures (DS, LFS, MFS, HFS) in terms of generalized parameters (Θ, amid/d). This approach allows us to predict and describe the rheological properties for all DFPCMs with diff erent types of dispersed structures, using a dispersed phase (fi ller) with known geometric dimensions (d), packing density (parameter kpacking and φm) based on this polymer matrix. The infl uence of temperature on the processing technology of DFPCM with diff erent types of structures into products by injection molding has been established.

Statistical analysis and mathematical modeling of modified single slope solar still

ABSTRACT Conventional single slope solar still integrated with a parabolic trough collector in addition to packaged glass ball layer was used in water desalination. Experimental work carried and data obtained were used in modeling the influential parameters affecting water desalination using principal component analysis to reduce parameters’ numbers. These parameters were then applied in constructing a Response Surface Model (RSM). System’s Performance has been predicted in terms of temperatures; saline water temperatures (Tw), glass cover temperatures (Tg), dry bulb temperature (Tdb), and wet bulb temperature (Twb) inside the conventional solar still. Along with the above temperatures, ambient air temperature (Ta), Oil inlet temperature (Toi) and solar intensity (I). The impact of these parameters can highly effect the water desalination yield. The RSM is developed to predict the impact of these parameters. Principal Component Analysis (PCA) reduced and categorized the number of effective parameters to three components containing the parameters (Tw, Twb, and Tdb), (I, Ta, and Tg) and (Ta, Toi, and I) respectively. These combinations were then tested using the two different RSM optimized models; Modified Reduced Quadratic and Two-Factor Interaction (2FI) model. These models were tested by monitoring nine statistical indices namely: RMSE, P-value, F-value, R2, R2 adj, R2 pred, BIC, PRESS, and AICc. Results obtained for this model showed minimum RMSE value and higher values of R2, R2 adj and R2 pred as well as lowest values for BIC and AICc. Concluding supremacy of (I, Ta, and Tg) Modified Reduced 2FI model over the others.

An experimental analysis of single slope solar still integrated with parabolic trough collector and packed layer of glass balls

This research article presents an experimental performance comparison of three cases, viz (1) conventional solar still, (2) single slope solar still incorporated with parabolic trough collector, and (3) single slope solar still incorporated with parabolic trough collector and packed layer of glass balls in the basin. The resulting heat due to incident solar energy on the parabolic trough collector is transferred by means of a finned piped (steel) loop heat exchanger that is immersed in the still basin. Experimentations were carried out during the winter with saline water depth 50 mm in the still basin. The packed layer of glass balls acts as a thermal storage medium to improve the heat transfer. The analysis shows that the case (3) has the highest freshwater productivity followed by the case (2) and (1), respectively. The percentage increase in the yield of solar still is 152 for case (3) and 130 for case (2) when compared to conventional solar still. Similarly, the highest solar still efficiency is reported for case (3) which is equal to 14.96% followed by the case (2) with 13.96% and the least is for case (1) with 13.5%. An economic analysis is also carried out for all the above-mentioned cases to show the feasibility of the integration of parabolic trough collectors with a packed layer of glass balls in the still basin. Both the efficiency improvement and the economic viability show that the proposed modifications are highly promising for the water-scarce regions.

ENDOSCOPIC REMOVAL OF INTRAVESICAL RARE FOREIGN BODY USING FLEXIBLE CYSTOSCOPY: A CASE REPORT

A 50-year-old man was admitted to our hospital for urinary retention. Computed tomography revealed a spherical intravesical foreign body, measuring 1.7cm in diameter, and cystoscopy revealed glass ball in the bladder. Considering the shape of the object and the possibility of self-insertion, we used a flexible cystoscope, foreign body forceps, and a transvaginal echo probe cover to remove the intravesical foreign body. The end of the echo probe cover was grasped with the foreign body forceps, and a glass ball was inserted into the probe cover and extracted manually with a scooping action similar to using a landing net. No intraoperative hemorrhage was observed, and the glass ball was safely removed with good visual field.The patient's postoperative courses was uneventful, and he has shown no recurrence one year postoperatively.

Effect of adding finer particles on the transport characteristics of coarse-particle slurries in pipelines

Resistance reduction has always been a concerning problem in pipeline transportation projects. Moreover, adding fine particles has shown resistance reduction. Therefore, we studied the effect of adding finer particles on the transport characteristics of coarse-particle slurries in pipelines. The flow conditions and slurry characteristics, such as the flow velocity and particle volume concentration, and the addition of finer particles can reduce the resistance of coarse-particle slurries under certain working conditions. In this study, the changes in the transport characteristics of slurries with 0.44 mm diameter glass balls after adding an equal volume of 0.125 mm diameter glass balls under different flow velocities and volume concentrations were analysed. The effects of adding fine particles on the transport characteristics of coarse particles under different flow conditions were determined, including the distributions of the particle volume concentration, velocity, particle pressure, and wall shear stress. We observed that adding fine particles could change the flow regime of coarse particles near the critical flow velocity (from sliding bed to heterogeneous flow), thereby considerably reducing the pipeline resistance (by approximately 20%). At a high flow velocity (heterogeneous or homogeneous flow), the addition of fine particles will increase the resistance. The study results explain the mechanism and characteristics of resistance reduction on adding fine particles from the perspective of changing the flow regime. These findings can serve as a reference for further studying the resistance reduction mechanism on adding fine particles and for finding the optimal particle size distribution for slurry transport in pipelines.

Hydrogen ion induced mechanochemical wear of soda lime silica glass in acid solutions

In this study, the friction and wear behaviors of soda lime silica (SLS) glass are studied by rubbing against Pyrex glass ball in various acid solutions. The experimental results show that as the solution pH increases from 0.5 to 6, the steady-state friction coefficient and wear volume of SLS glass increase firstly and then decrease. Further analyses indicate that the hydrogen ion concentration induced surface charge effect play critical roles in the wear behavior of SLS glass in acid solutions. When the solutions pH is 2.5, substantial direct contact at sliding interface will cause the highest friction and wear. In contrast, when the solution pH is lower or higher than 2.5, the interfacial direct contact can be weakened by the surface charge effect, therefore the friction and wear of SLS glass would be lower. These results may provide deeper understanding the material removal of oxide glasses during manufacturing and serving processes.

RETRACTED: Analysis of Particle Damping Characteristics on Steel Vertical Machining Centre Column with Epoxy Reinforced Granite

Retracted paper: In high speed machining, performance is generally influenced by the dynamic behaviour of the machine tool structures. The machine tool structure is required to be rigid in order to remove the undesirable vibration and to improve the work piece quality. The most conventional material used in machine tool structure is cast iron which has both stiffness and dynamic characteristics to perform at varying speeds. The objective of this work is to improve damping capacity of vertical machining centre column. The damping capacity of column can be increased further by using passive damping method of ball packing. Damping capacity is a crucial factor which makes the dissipation of vibration happens at faster rate. As compared with cast iron established studies shows that epoxy granite a composite material improves damping capacity. Epoxy granite though could be a good choice for improving the machine tool performance at high speeds but is poor in static stiffness compared to cast iron. In this investigation it was observed that, the static stiffness of epoxy granite composite vertical machining centre column could be increased by using steel reinforcements. The final results reveal that, steel balls with epoxy granite provide faster dissipation time of 15ms at 70% packing ratio as compared to glass balls that showed dissipation time of 35ms. Also it was seen that, the steel balls offer the better damping capacity at optimum packing ratio of 50% mainly due to its specific gravity and mass of the balls.

Natural convection of water-copper nanoliquids confined in low-porosity cylindrical annuli

Natural convection in cylindrical porous annuli saturated by a nanoliquid whose inner and outer vertical radial walls are respectively subjected to uniform heat and mass influxes and out fluxes is studied analytically using the modified Buongiorno-Darcy model (MBDM) and the Oseen-linearization technique. Nanoliquid-saturated porous medium made up of water as base liquid, copper nanoparticles of five different shapes, viz., spheres, bricks, cylinders, platelets and blades, and glass balls porous material is considered as working medium for investigation. The thermophysical properties of nanoliquid -saturated porous medium is modeled using phenomenological laws and mixture theory. The effect of various parameters and individual effects of five different shapes of copper nanoparticles on velocity, temperature and heat transport are found. From the study, it is clear that the addition of a dilute concentration of nanoparticles increases the effective thermal conductivity of the system and thereby increases the velocity and the heat transport, and decreases the temperature. In other words, the heat transport is more in the case of heat and mass driven convection compared to purely heat-driven convection. Among the five different shapes of nanoparticles, blade-shaped nanoparticles facilitate the transport of maximum temperature compared to all other shapes. Maximum heat transport is achieved in a shallow cylindrical annulus compared to square and tall circular annuli. The increase of the inner solid cylinder’s radius is to decrease heat transport. The results of the KVL single-phase model are obtained from the present study by setting to zero the value of the nanoparticles’ concentration Rayleigh number. Also, neglecting the curvature effect in the present problem, we obtain the results of the rectangular enclosure problem.

Synergy between surface mechanochemistry and subsurface dissolution on wear of soda lime silica glass in basic solution

AbstractThe polishing of oxide glass in aqueous solution is sensitive to not only the mechanical conditions applied by abrasives but also the chemistry of solution. This study elucidates the synergistic interactions of mechanical and chemical effects—especially, the synergetic effects of surface mechanochemical wear and subsurface dissolution are studied by measuring the material removal rate of soda lime silica (SLS) glass upon rubbing with a Pyrex glass ball in noncorrosive (neutral pH) in corrosive solutions (pH 10 and 13 NaOH) as a function of sliding speed. Based on the synergetic model of surface wear and subsurface dissolution, it is found that the mechanochemical surface reaction dominates the wear behavior of SLS glass in neutral and pH 10 solution conditions; the wear of SLS glass in pH 10 is enhanced, compared to the neutral pH case, due to the presence of OH‐ ions at the sliding interface. In the case of pH 13, the dissolution of the densified subsurface region, which is formed due to interfacial friction during the surface wear, becomes significant, further enhancing the material removal yield. The finding provides an insight for designing an efficient polishing process in manufacturing of oxide glass materials with a good surface finish.