Papers by Keyword: Glass

Abstract: This study investigates the effects of fiber type and hybridization on the tensile properties of epoxy composites produced using the temperature-controlled vacuum-assisted resin transfer molding (VARTIM) method. Tensile strengths and fracture behaviors are examined by fabricating 6-layer glass fiber-reinforced composites [G6], 6-layers carbon fiber-reinforced composites [C6], and hybrid composites consisting of six layers of glass and carbon fibers [H1] and [H2]. The microstructures of the composites are analyzed using an optical microscope, and tensile tests are conducted in accordance with ASTM standards. Tensile tests are performed at a constant speed and room temperature, and the fracture surfaces after tensile testing are analyzed using a Stereo Microscope. The results showed that the highest tensile strength is achieved in the carbon fiber-reinforced composite (CFRP), with an increase of approximately 123% compare to the glass fiber-reinforced composite (GFRP). Hybrid composite exhibits the reduced tensile strength compare to CFRP, with decreases of 23% for H2 and 29% for H1, respectively, whereas, increased the fracture toughness of the tested samples. Additionally, fracture surface analysis reveals that GFRP exhibits incomplete separation of the fractured surfaces, while CFRP shows a brittle and clean fracture surface. This study highlights the significant impact of fiber type and hybridization on the tensile property and fracture behavior of epoxy composite, demonstrating the better tensile performance of CFRP, while improving the fracture toughness and manufacturing cost of both GFRP and Hybrid composite.

Abstract: Thin film semiconductors are broadly applied in optical and energy conversion devices. Some thin films comprise titanium dioxide, tin oxide, and zinc oxide. The characteristics of the thin films can be changed according to their application. Zinc oxide semiconductors thin films were combined with different concentrations of LiClO₄, varying between 5 and 15% weight percentage. This study aimed to qualify and quantify the morphological, structure, and optical changes in ZnO affected by the presence of lithium salt in the microstructure. The x-ray measurements demonstrated larger polycrystalline sizes, a maximum of 57.53 nm. The band gap energy values lowered to 3.16 eV, lower than the usual 3.37 eV, and reflectance values reached 80%.

Abstract: Different types of fabrics, such as aramid, carbon, basalt, glass, and flax, as well as powder fillers, were used to manufacture the epoxy-based hybrid composites by the vacuum bagging method. In this work, the resistance of hybrid composites was examined in terms of their resistance to acts of vandalism, such as resistance to cuts with sharp objects, impacts, and flames. These technics were applied to determine the impact of the type of fillers and fabrics on the performance of hybrid composites.

Abstract: The improvement of mixture quality has been the priority of the modern-day construction industry while reducing the financial implications of the final product. This investigation concentrated on the application of glass as fine aggregate in the production of concrete. The fine aggregates used were partially substituted with fine glass. The replacement was done at (0, 10, 20, 30, 40, and 50%) by weight of fine aggregates, with other materials constant. A concrete mixture was prepared and the slump flow test and density were examined. The concrete specimens were produced, cured, and compressive, flexural, and splitting tensile intensity tested at 7, 14, and 28 durations. The workability and density of concrete reduce as the percentage replacement increases and the maximum reduction are (25 and 6.5%) respectively for (50%) glass aggregate replacement. The highest development in concrete compressive strength, flexural and splitting tensile intensity is (16.4, 14.7, and 15.1%) for 28 days of the glass aggregate percentage (20%) and the highest decrease is (3.4, 3.1, and 3.6%) for the percentage (50%).

Abstract: The use of inorganic matrix in fiber reinforced composites has been studied in the last years for strengthening applications in masonry construction. At the moment different systems are available after a technical qualification that allows a safe and certified use in construction industry. In the field of historical masonry the benefits of such materials are well known respect to the most known Fiber Reinforced Polymers (FRPs), due to a very poor substrate. In this study the experimental results of a larger research program are presented and discussed. A Fiber Reinforced Cementitious Matrix (FRCM) system has been tested in order to measure the tensile mechanical properties and bond properties respect to different substrates: clay masonry and natural tuff masonry. Tensile properties of the FRCM composite were measured in presence of a cement mortar, and results are illustrated. In addition pull-off tests and bond shear lap tests of the FRCM are described and commented respect to the two substrates. Tensile tests on glass fiber mesh and glass FRP (GFRP) connectors were performed and results are presented in the paper.

Abstract: The impact resistance improvement is important for window glass to protect people from injury. Although it has been proved that the impact resistance of a glass plate can be improved easily by fitting a thin polymeric film, its mechanism has not been clarified yet. The purpose of this study is to clarify the reinforcing mechanism of the impact resistance of a glass plate by fitting a polymeric film. To clarify it, a numerical simulation model was built using ANSYS Autodyn to simulate the dynamic fracture of a glass plate fitted with a polymeric film. The simulation model and results were examined by comparing them to the experimental result in the previous study. The Johnson-Holmquist (JH2) damage model was used for the constitutive law of the glass plate. A polymeric film with 0.2 mm thickness (3% with the glass plate) was modeled at the non-impact surface of the glass plate. The nodes of the glass plate at the interface with the film connected the nodes of the film by perfect bonding. By comparing the simulation results to the experiment, it was indicated the importance of modeling the remaining fragments of the glass plate and the adhesive layer of the film in simulating the dynamic fracture of the glass plate fitted with polymeric film.

Abstract: Present-day materials science requires development of compositions and technologies for production of composites with enhanced physical and technical properties. One of requirements towards such materials is an elevated heat strength. Materials, earlier used in electrothermy (ceramics, porcelain, asbestos and items made of them), have operating temperature of 400-500°С, high cost, low mechanical strength and a number of other drawbacks. Therefore, development of heat-resistant, mechanically strong and inexpensive insulation materials is an immediate problem. Mica’s characteristics to the maximum extent meet the requirements to a filler for the composite materials. Its use would enhance electric and physical properties of composites, contribute to development of waste-free technology, thus favoring the environment. Objectives of the paper: development of technology for production of heat-resistant materials on the base of heat-proof mica and special glass with elevated softening point; study of the interaction between composite components and high-temperature medium; giving recommendations on technology for fabricating heat-resistant composites with enhanced physical and technical properties. Objects of study: specimens of heat-proof mica (phlogopite), wastes of abrasive production, modifiers, glasses with high softening point. Methods of investigation: methods of thermodynamic and quantum-chemical studies were used with involvement of a complex of state-of-art physical and chemical methods. Results of study: development of theoretical grounds for forming the heat-resistant composite materials on the base of experimental studies and scientific generalizations. The technology for production of new heat-resistant materials on the base of rational use of mineral raw material and production wastes is proposed.

Abstract: Through this research we have prepared samples of glass, which includes 60 mol%B₂O₃ – x mol %barite – (40-x) mol %Li₂O, where x= 5, 7.5, 10, and 15 mol%. The samples fabricated by the melt quenching technique. The samples are melted in alumina crucible at 1473 K for 1.5 h in an electric muffle furnace (LENTON). The glasses were casted into stainless molds, and then immediately transferred to an annealing furnance at about 400°C. The aim of this work is to determine the extent of the effect of raw barite on the physical and optical properties of this glass. The optical transmittance and reflectance spectrum of the glasses in this work were determined in the wavelength range 300–2500 nm at room temperature. The physical and optical properties of the following prepared glass samples have been determined and calculated (density, volume molar, refraction index, Optical dielectric constant, molar refractivity and electronic polarizability) for glasses prepared.

Abstract: Surface finishing of glass and ceramics flats is difficult to perform using already existing traditional processes because of the brittle nature of these materials. In order to make traditional processes be able to accommodate these materials, relatively expensive aiding devices and approaches are required. The newly developed magnetorheological (MR) fluid finishing offers a solution to this problem at a relatively low cost. Magnetorheological fluids have been used in mechanical engineering applications because of the rheological behavior they possess under a magnetic field which enables the manipulation and pressure of loose abrasives on the machined surfaces and perform cutting action. This paper describes the design and development of an MR fluid machine-tool for flat surface finishing. The design presented herewith includes the design of the mechanical aspects of the ball-end tool machine and its support structure for a three-axis motion system. The objective of this study is realized based on utilizing a magnetic field, magnetorheological fluid and CNC router design to perform flat surface finishing.

Abstract: Poor transmission of sunlight through the top glass cover is one of the major hindrances in realizing better performance from a PV module. Adoption of appropriate cleaning technique might enhance glass transmissivity to a good extent. In the present study, the effect of manual cleaning with nylon sponge, microfiber cloth and nylon brush on optical and mechanical properties of PV glass have been investigated for several samples of borosilicate and soda lime glasses. Examination of transmittance of the samples using UV-VIS NIR scanning spectrophotometer confirmed enhanced transmissivity. Borosilicate glass exhibited better performance in terms of transmissivity as compared to soda lime glass. Cleaning with nylon sponge shows the highest transmittance of 91.98% for borosilicate glass at 630 nm wavelength and that of 91.094% with soda lime at 525 nm wavelength.