A series of binary tellurite based glasses (Bi(2)O(3))(x) (TeO(2))(100-) (x) was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi(3+) increase, this is due to the increased polarization of the ions Bi(3+) and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, E(opt) decreases while the refractive index increases when the ion Bi(3+) content increases.
Bone regeneration is a rapidly growing field that seeks to develop new biomaterials to regenerate bone defects. Conventional bone graft materials have limitations, such as limited availability, complication, and rejection. Glass ionomer cement (GIC) is a biomaterial with the potential for bone regeneration due to its bone-contact biocompatibility, ease of use, and cost-effectiveness. GIC is a two-component material that adheres to the bone and releases ions that promote bone growth and mineralization. A systematic literature search was conducted using PubMed-MEDLINE, Scopus, and Web of Science databases and registered in the PROSPERO database to determine the evidence regarding the efficacy and bone-contact biocompatibility of GIC as bone cement. Out of 3715 initial results, thirteen studies were included in the qualitative synthesis. Two tools were employed in evaluating the Risk of Bias (RoB): the QUIN tool for assessing in vitro studies and SYRCLE for in vivo. The results indicate that GIC has demonstrated the ability to adhere to bone and promote bone growth. Establishing a chemical bond occurs at the interface between the GIC and the mineral phase of bone. This interaction allows the GIC to exhibit osteoconductive properties and promote the growth of bone tissue. GIC's bone-contact biocompatibility, ease of preparation, and cost-effectiveness make it a promising alternative to conventional bone grafts. However, further research is required to fully evaluate the potential application of GIC in bone regeneration. The findings hold implications for advancing material development in identifying the optimal composition and fabrication of GIC as a bone repair material.
Biodegradable elastomers have clinical applicability due to their biocompatibility, tunable degradation and elasticity. The addition of bioactive glasses to these elastomers can impart mechanical properties sufficient for hard tissue replacement. Hence, a composite with a biodegradable polymer matrix and a bioglass filler can offer a method of augmenting existing tissue. This article reviews the applications of such composites for skeletal augmentation.
We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.
This work discusses the preparation and characterizations of glass hollow fiber membranes prepared using zeolite-5A as a starting material. Zeolite was formed into a hollow fiber configuration using the phase inversion technique. It was later sintered at high temperatures to burn off organic materials and change the zeolite into glass membrane. A preliminary study, that used thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), confirmed that zeolite used in this study changed to glass at temperatures above 1000 °C. The glass hollow fiber membranes prepared using the phase inversion technique has three different microstructures, namely (i) sandwich-like structure that originates from inner layer, (ii) sandwich-like that originates from outer layer, and (iii) symmetric sponge like. These variations were influenced by zeolite weight loading and the flow rate of water used to form the lumen. The separation performances of the glass hollow fiber membrane were studied using the pure water permeability and the rejection test of bovine serum albumin (BSA). The glass hollow fiber membrane prepared from using 48 wt% zeolite loading and bore fluid with 9 mL min(-1) flow rate has the highest BSA rejection of 85% with the water permeability of 0.7 L m(-2) h(-1) bar(-1). The results showed that the separation performance of glass hollow fiber membranes was in the ultrafiltration range, enabled the retention of solutes with molecular sizes larger than 67 kDa such as milk proteins, endotoxin pyrogen, virus, and colloidal silica.
A new contactless technique for latent fingerprint visualization on nonporous curved surfaces of circular cross section was introduced by Low et al. (1). The technique utilizes a plane mirror to convey the light rays toward the inspected surfaces for latent fingerprint visualization. This research activity came up as an extension of the previous study which utilized an aluminum plate as the plane mirror to illuminate the inspected surfaces. Dulling spray was used to increase the diffuse component of the reflective aluminum plate. However, the amount of dulling spray will affect the uniformity of the illumination on the inspected curved surfaces. In this study, a study on the new materials for the plane mirror was carried out. Coated aluminum, opal, and ground glass diffusers were selected as the new materials. The performance of the new materials was compared to the aluminum based on the quality of the captured images on various nonporous cylindrical surfaces. A statistical approach known as randomized complete block design was used to design the experiment. The quality of the captured images was obtained using Spectral Image Validation and Verification. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the quality of the images. From the results of the statistical analysis, coated aluminum has the best performance compared to aluminum, opal, and ground glass diffusers.
We had successfully synthesised Mg-doped zinc oxide (MZO) and Cudoped zinc oxide (CZO) nanorod arrays (NRAs) on Al-doped ZnO (ZAO)-coated glass substrates using immersion method and investigated their structural properties. With the incorporation of the Mg dopant, the length and crystallinity of MZO NRAs is higher compared to that of the CZO NRAs. The average optical transmittance of MZO NRAs was slightly lower than that of the CZO NRAs over the visible wavelength region. With the incorporation of the Cu dopant, the morphology of the CZO sample was slightly different from that of the MZO NRAs. The CZO NRAs present granular with small sphere shape. On the other hand, the MZO NRAs exhibit a hexagonal shape structure with a flat-top facet. Rods with a diameter of 58.9-96.7 nm were uniformly grown on the ZAO-coated glass substrate. This paper presents the growth behaviors of the MZO and CZO NRAs.
The development of Transparent Solar Cells (TSC) has become the main focus of solar energy research in recent years. The TSC has a number of applications and make use of unexploited space such as skyscraper windows. In this paper, TSC is fabricated using commercially available titanium dioxide (TiO2) P25 to make a paste, which is deposited on FTO glass using screen printing and spin coating methods. The effects of the thickness of the TiO2 film on transparency are examined. The paste is synthesised in the Cleanroom and used in both methods of deposition. The final cell fabrication is a Dye sensitised solar cell (DSSC). The obtained transparency of the FTO glass is 83%, and after the deposition of TiO2 it is reduced to less than 80%. The overall transparency of the DSSC, which was made using the spin coating method, is 70% with an Isc of 9.5 mA and Voc 853mV.
The effects of hole size on open hole tensile properties of Kevlar-glass fibre hybrid composite laminates were thoroughly investigated in this work. Woven Kevlar/glass fibre epoxy composite laminates were fabricated using hand lay-up and vacuum bagging technique. Specimens of five different hole size (1 mm, 4 mm, 6 mm, 8 mm and 12 mm) were carefully prepared before the tensile test was performed according to ASTM D5766. Results indicated that hybridizing Kevlar to glass fibres improved tensile strength and failure strain of hybrid composite specimen. In addition, increasing the hole size reduced strength retention of the hybrid specimen from 96% for 1 mm hole size to 62% and 44% for 6 mm and 12 mm, respectively. Fractography analysis showed that several types of failure mechanisms were observed such as brittle failure, ductile failure, fibre breakage, delamination and fibre-matrix splitting. It is concluded that as hole size increased, failure behaviour changed from a matrix dominated failure mode to a fibre-dominated failure mode.
Efforts to reduce manufacturing cost and negative environmental impacts have seen the mixture of natural fibre with synthetic fibre in composite structures. However, there are limited studies on the notch effect and fibre orientation on mechanical properties of hybrid fibre metal laminate (FML). In this study, tensile properties of FML with notch and different fibre orientation were investigated. The hybrid FML incorporated with kenaf fibre at the middle layer was compared with FML with three layers of E-glass fibre. Kenaf fibre and E-glass fibre used were in plain woven form. The FML in 2/1 configuration was manufactured through hot press manufacturing method to bond layers of annealed aluminium 5052 to the composite. Tensile test was conducted in a quasi-static manner according to ASTM E8. The results showed FML with three layers of glass fibre exhibited higher tensile strength compared with hybrid FML. However, the introduction of kenaf fibre in hybrid FML reduces the notch and fibre orientation sensitivity compared with glass fibre reinforced FML.
This aim of this study is to study the effects of various contents of Automotive Windscreen Glass Waste Powder (WGWP) as a cement replacement. Mortar incorporating several compositions of WGWP (0%, 5%, 10%, 15% and 20%) by weight of cement was prepared. Three batching systems of cement to sand (C:S) ratios of 1:2.5 superplasticizers (SP), 1:3.0 SP and 1:3.5 SP was also employed. Fixed water to cement (w/c) ratio of 0.5 was used. The samples were water cured and the assessment of the strength performance of mortar cubes carried out at 7 and 28 days. Studies conducted have shown that WGWP has good pozzolanic properties. In term of compressive strength, it was observed that employing C:S ratio of 1:3.5 SP is better than 1:2.5 SP and 1:3.0 SP.
Sawdust is considered a waste material and a number of innovative ways are being taken to mitigate its effects on the environment. The use of sawdust as additional admixture in cement-sand brick production is an alternative option to mitigate the problem. In this study, three different types of cement-sand brick mixture in proportion of 1%, 2% and 3% of sawdust added to the normal mixture are prepared. Compression test was conducted on the brick mixture and results indicated 1% sawdust satisfy the Class 1 loadbearing brick whilst the 2% sawdust is slightly above the minimum required strength of 5.2 MN/ m2 for an ordinary quality brick set by the Standards MS 76:1972. Thus, the use of sawdust as admixture in cement-sand brick should not exceed 3%.
Ahmad Fuad Ab Ghani, Mohamad Kamarul Anwar Sahar, Muhammad Ridzuan Husyairi Azmi, Nurul Izzati Medon, Muhammad Syazwan Samsuri, Muhammad Syurabil Abdani
There are several types of grating, such as platform, bridge decks and filters. In design process, there
are several important terms that have to be prioritised; engineering design, strength to weight ratio, cost,
maintainability, reparability etcetera. Advanced materials, such as composite materials offer great
strength to weight ratio and high mechanical properties for grating fabrication. Furthermore the
reparability and maintenance problems could be solved as it is anti corrosion and the long service life
attribute of composite makes it a great design material for replacement of conventional steel or
aluminium. Bio composites, such as bamboo and coir fiber yield advantage in terms of less cost and
abundance availability compared to commercial unidirectional composite materials, such as glass fiber
reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) which is considerably
expensive yet possess higher mechanical properties. This papers presents a conceptual design of
grating design utilizing bamboo composite as material. Pugh method has been chosen as design criteria
selection matrix in finalizing the design of industrial grating for scaffolding (Pugh, 1991).
Introduction: The purpose of this study was to decide on the relation between types of mixing and the porosity of diameter (1-100) µm and compressive strength of RMGIC. Methods: Fifteen specimens 6mm height and 4mm in diameter were prepared for each type of luting cement and were stored in distilled water at 37° C for 24 hours. The compressive strength was determined. The fractured surfaces of 10 randomly selected specimens of each cement type were analyzed using SEM at 250 times magnification, and five photomicrographs were taken at five random places. All the photomicrographs were analyzed using image analyzer software to determine the amount and size of porosity present. Results: There was no significant difference in compressive strength between different mixing methods, but it had a significant impact by increasing the percentage of porosity of diameter (1-100) µm in diameter of RMGIC. There was no linear relationship between compressive strength and porosity (1-100) µm in diameter for both types of luting cements (P>0.05). Conclusion: No significant differences in compressive strength were found using different mixing methods. The size and number of porosity in the specimens of encapsulated cements were greater than those of hand-mixed cements. The porosity (1-100) µm in diameter and the compressive strength bore no linear relationship to each other.
Reinforced concrete (RC) structures require strengthening for numerous factors, such as increased load, modification of the structural systems, structural upgrade or errors in the design and construction stages. The side near-surface mounted (SNSM) strengthening technique with glass fiber-reinforced polymer (GFRP) bars is a relatively new emerging technique for enhancing the flexural capacities of existing RC elements. Nine RC rectangular beams were flexurally strengthened with this technique and tested under four-point bending loads until failure. The main goal of this study is to optimize the structural capacity of the RC beams by varying the amount of strengthening reinforcement and bond length. The experimental test results showed that strengthening with SNSM GFRP bars significantly enhanced the flexural responses of the specimens compared with the control specimen. The first cracking and ultimate loads, energy absorption capacities, ductility and stiffness were remarkably enhanced by the SNSM technique. It was also confirmed that the bond length of the strengthened reinforcement greatly influences the energy absorption capacities, ductility and stiffness. The effect of the bond length on these properties is more significant compared to the amount of strengthening reinforcement.
Multicomposition of Er3+ -Y11-3+ codoped tellurite oxide, Te02-ZnO-PbO-Ti02-Na20 glass has been investigated. A detailed spectroscopic study of the Judd-Ofelt analysis has been performed from the measured absorption spectrum in order to obtain the intensity parameters S2, (t=2, 4, 6). The calculated S2, values were then utilized in the determination of transition probabilities, radiative lifetimes and branching ratios of the Er3+ transitions between the J(upper)-J'(lower) manifolds. Both visible upconversion and near-infrared spectra were characterized under the 980 nm laser diode excitation at room temperature.
Synthetic materials that are capable of healing upon damage are being developed at a rapid pace because of their
many potential applications. Here, new healing chemically cross-linked hydrogel of poly(2-hydroxyethyl methacrylate)
(pHEMA) was prepared. The healing hydrogel was achieved by heating above its glass transition (Tg
). The intermolecular
diffusion of dangling chain and the chain slippage led to healing of the gel. The peaks in attenuated total reflectance
(ATR) confirmed that hydrogel was formed while rheological studies had determined the minimum for healing temperature
is 48.5o
C. The results showed that ratio stress of the healable hydrogel can reach until 92 and 91% of first and second
healing cycle, respectively. The morphology of the sample was carried out to evaluate the self-property of hydrogel.
This study was carried out to investigate the effect of adding 1 vol% of multi-walled carbon nanotubes (MWCNT) into
woven kenaf/epoxy laminated composites on their flexural properties and to compare between two techniques used to
incorporate MWCNT into the composite which are spraying and solution techniques. Furthermore, the effect of MWCNT
addition in woven glass/woven kenaf/epoxy hybrid composites at the same filler concentration on the flexural properties
were also investigated. All the laminated composites with and without MWCNT were fabricated using vacuum bagging
method. The flexural properties of the composite samples with and without MWCNT were evaluated by applying threepoint
bending test. The results were supported by morphological observation. It was found that the addition of MWCNT
using both spraying and solution techniques reduced the flexural strength and flexural modulus of MWCNT/woven kenaf/
epoxy composites, with obvious reduction trend was shown by former technique. The morphological observation of the
composites fracture surface showed that delamination failure occurred in MWCNT/woven kenaf/epoxy laminated composite
prepared by spraying technique. Further investigation on hybrid composites showed that MWCNT/woven glass/woven
kenaf/epoxy laminated hybrid composites exhibited significant improvement in the flexural properties.
A 50Hz glow discharge He/CH4
plasma was generated and applied for the glass surface modification to reduce the powder
adhesion on wall of spray dryer. The hydrophobicity of the samples determined by the water droplet contact angle and
adhesion weight on glass, dependent on the CH4 flow rate and plasma exposure time. The presence of CH3
groups and
higher surface roughness of the plasma treated glass were the factors for its hydrophobicity development. Response
surface methodology (RSM) results using central composite rotatable design (CCRD) showed that optimal responses
were obtained by the combination of parameters, CH4
gas flow rate = 3 sccm and exposure time = 10 min. In optimum
conditions, the contact angle increased by 47% and the weight of the adhesion reduced by 38% (w/w). The plasma
treatment could enhance the value of the contact angle and thus reduced the adhesion on the spray dryer glass surface.
The aim of this article is to provide a brief insight regarding the recent studies and their recommendations related to the modifications to glass ionomer cement (GIC) powder in order to improve their properties. An electronic search of publications was made from the year 2000 to 2018. The databases included in the current study were EBSCOhost, PubMed, and ScienceDirect. The inclusion criteria for the current study include publication with abstract or full-text articles, original research, reviews or systematic reviews, in vitro, and in vivo studies that were written in English language. Among these only articles published in peer-reviewed journals were included. Articles published in other languages, with no available abstract and related to other nondentistry fields, were excluded. A detailed review of the recent materials used as a filler phase in GIC powder has revealed that not all modifications produce beneficial results. Recent work has demonstrated that modification of GIC powder with nano-particles has many beneficial effects on the properties of the material. This is due to the increase in surface area and surface energy, along with better particle distribution of the nano-particle. Therefore, more focus should be given on nano-particle having greater chemical affinity for GIC matrix as well as the tooth structure that will enhance the physicochemical properties of GIC.