Papers by Keyword: Physical Properties

Abstract: In the presented work the features of formation of metal-fullerene films of the systems Al-C₆₀, Au-C₆₀, Cu-C₆₀, Ti-C₆₀ from atomic-molecular flows in vacuum were investigated, the processes of surface resonance plasmon absorption and diffusion were studied. It is shown that electron microscopy, optical, Auger-electron and X-ray spectroscopy methods are effective for the study of metal-fullerene films. The combination of different methods of spectroscopy and electron microscopy allowed to establish the dependence of the grain size of the films, the shift of the position of the plasmon absorption maximum, diffusion parameters on the ratio of metal and fullerene components, to establish the fact of formation of the chemical compound Cu₆C₆₀.

Abstract: The research focused on investigating the physical and mechanical properties of stretch films containing recycled materials. The objective of the study was to examine how the use of recycled materials affects the structure and physical and mechanical properties of 5-layer stretch films. The results showed that incorporating up to 50% recycled materials in the stretch films can be a viable option for securing containers on pallets, provided that the film's composition is appropriately modelled using specific primary polymers in the film layers. The study employed extrusion methods to create the stretch films.

Abstract: Spent coffee ground (SCG) consists of impact compositions and functional ingredients that could be applied to food products. Drying techniques and conditions had an impact on the qualities of SCG. The aim of this research was to investigate the chemical compositions of roasted coffee ground (CG) and SCG from Arabica (A) and Robusta (R) coffee, as well as the physical and functional properties of SCG before and after different drying using hot air tray dryer and freeze dryer. It was found that SCG had moisture and carbohydrate content of 64.79–65.87% wb and 16.55–18.57%. Arabica spent coffee ground (ASCG) had more lipid and less protein, caffeine and phenolic content than that of Robusta spent coffee ground (RSCG). The dried SCG had moisture content lower than 5% for all drying conditions. Moreover, the dried SCG had Aw, solubility, and rehydration in a range of 0.25-0.55, 6.02-6.92%, and 140.67-180.37%, respectively. Freeze-dried SCG retained more functional ingredients than tray-dried SCG across all drying conditions.

Abstract: Making edible films from potato starch by adding glycerol from used cooking oil with various concentrations of 10, 20 and 30% (v/w starch). This study aims to determine the physical properties of edible films made using these materials and the effect of adding variations in glycerol concentration on the physical properties of the resulting edible films. The physical property tests carried out included thickness, tensile strength, elongation and WVTR (Water Vapor Transmission Rate) tests as well as to see the effect using the pearson correlation test on SPSS version 25. The physical properties of edible film made from potato starch raw materials with the addition of variations in glycerol concentration produced successive thicknesses respectively 0.0670; 0.0674 and 0.0818 mm. Tensile strength respectively 24.237; 14.929 and 3.417 N/m2. Consecutive elongation 2.4064; 5.6768 and 20.096 %. As well as WVTR 5.05556 respectively; 6.38426 and 8.36574. The addition of variations in glycerol concentration to the physical properties of the edible film showed that the addition of glycerol did not significantly affect the thickness, but greatly affected the tensile strength, elongation and WVTR of the resulting edible film.

Abstract: Irreversible hydrocolloid impression material is extensively used in dentistry to record and duplicate the details of tooth structure, surrounding tissue, and other intraoral structures. The materials allow dentists to work more easily and perform better diagnosis and treatment planning. When used, the material is exposed to oral microorganisms, some are pathogens, from the patient’s teeth, mucosa, blood, and saliva. These pathogens can be absorbed into the material and transmitted to dentists and other dental workers. Hydrocolloid impression material incorporated with vanillin has been shown to exhibit antimicrobial potential, however, its physical properties have not been performed. Therefore, this study aims to investigate the physical properties of a vanillin-incorporated irreversible hydrocolloid impression material on four different physical properties: working time, setting time, elastic recovery, and strain-in compression. The impression powder was mixed with varying concentrations of vanillin (0.1%, 0.5%, and 1.0% w/w) using the electric vacuum mixer. The impression material without vanillin was used as a control. All the tests were done following the ISO specification 21563: 2021 for dental materials with 15 specimens for each test. The result showed that at concentrations of 0%, 0.1%, and 0.5% w/w vanillin, no significant change in the four physical properties has been observed. However, the working time and setting time values of impression material with 1% vanillin were reduced significantly and did not meet the ISO standard. In conclusion, the incorporation of 0.1%, 0.5%, and 1% w/w vanillin into irreversible hydrocolloid impression material showed a significant reduction in setting time and working time. However, when considering the ISO standard specifications, the 0.1% and 0.5% w/w vanillin-added materials can still be used due to their acceptable values of all physical properties (setting time, working time, elastic recovery, and strain-in compression). These impression materials will be valuable for use in clinical settings to reduce the disinfection procedure and the risk of cross-contamination.

Abstract: Formic acid, commonly used in bioprocesses of cellulosic polymeric materials, has been considered for the treatment of cellulose-based textile. Therefore, different concentrations of formic acid (10, 20, 30, 40, and 50 g L^-1) were used to treat cotton (CO) and viscose (CV) fabrics to improve their properties. Weight variation, tensile strength, stiffness, drape coefficient, crease recovery angle, and vertical wicking of the treated substrates were assessed. Fourier transform infrared spectroscopy attenuated total reflection (FTIR-ATR) analysis confirmed the acid hydrolysis process of the cellulosic substrates treated with formic acid solutions. Formic acid solutions with concentrations equal to 30 g L^-1 and 40 g L^-1 are the most adequate to treat the CV and CO fabrics, respectively. In addition, the fabrics treated under optimal conditions were dyed with the reactive dye Levafix Blue CA. The dyeing properties were assessed through colour absorption coefficient and scattering coefficient (K/S) values. A clear improvement in the fastness and dyeing performance of the treated substrates was observed. Finally, the antibacterial properties of the treated substrates were evaluated, for the bacteria Escherichia coli and Staphylococcus aureus. It was found that only cotton substrates treated with a 40 g L^-1 formic acid solution could be classified as weak decontaminants against S. aureus bacteria.

Abstract: The rapid construction activity in Malaysia has increased the demand of concrete. One of the key ingredients in concrete is cement. The production of cement emits carbon dioxide (CO₂) which is harmful to the environment. To overcome this issue, waste materials such as eggshell powder (ESP) and silica fume (SF) are incorporated in concrete as partial replacement to cement. In this research, the characterization and strength activity index (SAI) of ESP and SF as partial cement replacement were performed. The results showed that only SF was classified as pozzolanic materials of Class F, as specified in ASTM C618. Meanwhile, ESP had higher loss on ignition (LOI) than SF, hence contained higher amount of unburnt carbon. SF mortar had the highest SAI and compressive strength due to the small size of SF particles. Although ESP mortar fulfilled the minimum requirement of SAI as specified in ASTM C618, its compressive strength was lower than the Ordinary Portland Cement (OPC) mortar because the LOI content of ESP was more than 20%.

Abstract: This work investigates the influence of date palm and sisal fibers on the mechanical and physical behavior of lightweight concrete based on expanded clay aggregates. The choice of these fibers types is aimed at the recovery of agricultural waste in Tunisia. Their exploitation serves to improve the mechanical and physical properties of a new material dedicated to filling and insulation in buildings. In this context, series of tests were carried out using untreated short fibers in lightweight concrete. The evaluation of the mechanical and physical behavior of the material was obtained by determining the compressive strength, bending strength and thermal conductivity. The results obtained showed the influence of the fibers volume fraction. For mechanical behavior, the optimum of fibers volume fraction was estimated at 1% for lightweight concrete with date palm and sisal fibers. The thermal conductivity is inversely proportional to the fibers volume fraction, which justifies the use of this composite as a filling and insulation material.

Abstract: This work describes a study that utilizes the Nd³⁺ ions (1.0 mol%) doped in glass material with the chemical formula 59P₂O₅ - 20Li₂O - 10AlF₃ - 10NaF. To obtain a glass medium with good homogeneity, all samples in the form of powder were mixed thoroughly and melted at 1100 °C for 3 hours. This sample preparation method is widely known as the melt-quenching method. The cutt and polish process is carried out to obtain a proportional and highly transparent of glass sample. Several parameters of physical properties were measured and then calculated to obtain the values of other parameters. The optical properties and stimulated emission cross sections (ECS) of a glass medium were obtained by observing the absorption and emission spectra. Based on the analysis of ECS, it was found that the radiative lifetime (τR) for Nd3+ ions experimentally and calculated were 132μs and 248μs respectively. Meanwhile, the quantum efficiency is achieved up to 53%

Abstract: In this study, PMS gasoline gotten from randomly selected commercial fuel stations was blended with ethanol gotten from agricultural waste and developed nanoparticles Additives (D-NA). The blended samples were analyzed for their physical properties using methods recommended by the American Society for Testing and Materials (ASTM). The tests were carried out on the fuel's density, oxygenates, benzene content, research octane number (RON) and sulphur content. The results shown in the physical property tests done on these blended fuels when compared with the neat gasoline gotten from the Nigerian National Petroleum Corporation (NNPC), industry standards (DPR/SON) and global markets (United States US & United Kingdom UK) shows that the blended fuels meet all required standards and specifications. The additives had little effect on the fuel’s density but showed a sharp drop in its benzene content levels which makes it a healthier choice of fuel. Ethanol blended fuel had a higher oxygenate level than neat gasoline and the D-NA blended fuel. The research octane number for the three fuel samples showed favorably high numbers that fit the standards of the global market. The most interesting result is the Sulphur content which showed an increase in its values for the blended fuels although the values are within industrial and global limits. Keywords: PMS Fuel; physical properties; density; oxygenates; nanoadditives; ethanol