Search

Melt-quenching bioglass-ceramics with the following chemical composition have been prepared 44SLS11Na2CO324ES6P2O56CaF29Al2O3(wt%). The bioglass-ceramics were sintered at 650 °C, 750 °C, 850 °C, and 950 °C. The aim was to identify the optimal sintering temperature before glass crystallization. The physical properties were characterized by density and linear shrinkage. To characterize the structure properties, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were utilized. The high composition of Si and Ca in soda lime silica (SLS) glass and eggshells (ES), respectively, encourage the utilization of waste materials in the production of bioglass-ceramics. The results showed that at a sintering temperature of 950 °C, the crystallization of fluorapatite was the main phase. Moreover, the high density and optimum linear shrinkage were obtained as the sintering temperature increased. Additionally, grain growth and densification took place at this temperature. The compressive strength of bioglass-ceramics is influenced by sintering temperature and the optimal compressive strength is 136.58 MPa.

17ß-Estradiol (E2) is an endocrine-disrupting chemical that has become a matter of concern across the globe for more than a decade due to potential health risks. This study reports facile methods to fabricate label-free aptasensor based on the non-Faradaic impedance mode using amine-functionalized graphene oxide polypyrrole (NH2-GO/PPy)-modified gold interdigitated electrode for direct capacitive detection of 17β-estradiol. The as-prepared NH2-GO/PPy nanocomposites have been successfully characterized by field-emission scanning electron microscopy ( FESEM), atomic force microscopy, Fourier transform infrared spectroscopy, and electrochemical impedance spectroscopy. The results show that NH2-GO/PPy/IDE was able to detect E2 binding through aptamer conformational change by simply observing the capacitance change before and after immobilization. In addition, the biosensor showed a dynamic range of detection from 100 nM to 1 pM with a low detection limit of about 0.13 pM. The recoveries result also presented in this paper was validated using HPLC exhibited high sensitivity for bisphenol-A (BPA) detection and was successfully applied to detect E2 in real water samples with good recoveries.

In this study, the impact of thulium oxide on the structural and elastic characteristics of magnesium borotellurite glass systems produced through the melt-quenching technique is examined. The findings reveal a direct relationship between the thulium concentration and several elastic parameters in the glass sample, such as ultrasonic velocity and elastic modulus. The sample’s density increased from 4.12 to 4.30 g/cm3, and its molar volume increased from 29.29 to 29.62 cm3/mol as Tm3+concentration progressed. The XRD study confirmed that the samples were amorphous. The incorporation of Tm2O3into the glass acts as a network modifier and leads to an increase in NBO content. Moreover, the shear and longitudinal velocities range within the respective ranges of 1966.02 to 2495.90 m/s and 3474.78 m/s to 4085.13 m/s. Young’s modulus, bulk, shear, and longitudinal elastic moduli fall between 40.28 and 64.45 GPa, 28.51 and 36.07 GPa, 15.92 and 26.81 GPa, and 49.75 and 71.81 GPa, respectively. Moreover, the sample’s Poisson ratio decreases from 0.26 to 0.20 with an increase in Tm3+concentration. The experimental results are compared to the theoretically calculated results. By comparing to experimental data, the Mackenzie Makishima and Rocherulle models demonstrate a high level of accuracy.

It has been studied that both two-dimensional (2D) MoS2and V2O5, which are classified as transition metal dichalcogenides and transition metal oxides, are good photocatalyst materials. For this purpose, the hydrothermal method was practiced to synthesize V2O5(1−x)MoS2(x)(X= 1–5% w/w) nanocomposites with different 1–5% w/w weight percent of MoS2as a prominent photocatalyst under laser irradiation for 2, 4, 6, 8, and 10 min to tune photocatalytic degradation of industrial wastage water. The surface of the 2D molybdenum nanolayered matrix was efficaciously decorated with V2O5nanoparticles. The crystal phase and layered structures of the V2O5(1−x)MoS2(x)(X= 1–5% w/w) nanocomposites samples were verified by X-ray diffraction and scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy respectively. In the range of the UV visible spectrum, the increment in light absorption from 3.6 to 14.5 Ω−1cm−1with an increase of active surface from 108 to 169 μm2{{\rm{\mu }}{\rm{m}}}^{2}with increased MoS2doping percentage. Furthermore, dielectric findings like the complex dielectric function, tangent loss, electrical conductivity, quality factors, and impedance of V2O5(1−x)MoS2(x)(X= 1–5% w/w) nanocomposites are studied. According to photoluminescence studies, the intensity of peaks decreases when laser irradiation time and doping percentages of MoS2are increased. As a result, a small peak indicates a decrement rate of electron–hole pair recombination, which increases the capacity for separation. Thermo-gravimetric analysis and differential thermal analysis results revealed that weight loss decreased from 0.69 to 0.35 mg and thermal stability increased with increased doping concentrations. Methylene blue was degraded in 150 min, proving that the prepared MoS2-doped V2O5material was a stable and economically low-cost nanocomposite for photocatalytic activity.

Hetrometal oxides of (1−x)Al2O3/xPbO2(NPs) nanoparticles with different PbO2content (x=0, 0.3, 0.4, 0.5, 0.6 and 0.7) have been prepared by irradiation method. The NPs powder has been checked by X-ray diffraction (XRD). XRD measurements affirmed the presence of both pure NPs and nanocomposites of (1−x)Al2O3/xPbO2NPs with different PbO2contents. The calculated structural parameters which using the experimental result of XRD charts to give a complete image of these measurements. Moreover, the results using FLUKA code showed that the values attenuation coefficient (μm), high effective atomic number (Zeff) and neutron shielding parameters increase as the lead dioxide increase in the Al2O3/PbO2samples. While the values of half-value layer (HVL) and mean free path (MFP) decrease with increasing PbO2content. The investigated shielding features of the chosen Al2O3/PbO2would be advantageous for exposure control.

Artificial neural networks (ANN) is known as one of the artificial intelligence tools which are inspired by the biological nerve system, have a capability to predict the physical and elastic parameter of glasses without melting the raw materials. The experimental of bismuth-tellurite glasses with the composition yBi2O3- (1-y)TeO2where y=0, 0.05, 0.07, 0.10, 0.13, 0.15 have been fabricated using melting and quenching methods. These works were discovered that the prediction value by artificial neural networks for density, ultrasonic velocity, and elastic moduli of bismuth-tellurite glass composition gives a very good agreement as compared with the experimental measurements. The goodness of fit from the graph used R2value to represent the relationship between the data presented from the experiment and prediction model. The great fit of coefficient R2value elucidates in all figures is around 0.99942–1.0000 which is considered to be very satisfactory.

This research attempts to propose the fabrication and characterization of highly amorphous zinc silicate glasses derived from zinc oxide (ZnO) and white rice husk ash (WRHA). Three zinc silicate glasses were produced based on empirical formula (ZnO)x(WRHA)1−xwhere x=0.50, 0.55 and 0.60wt.% by using melt-quenching methods. When ZnO increased, the transparency of the three glasses increased. Meanwhile, X-ray diffraction (XRD) analysis of the zinc silicate glasses revealed that the glassy state of the zinc silicate glasses increased along with the increment of ZnO, and at lowest ZnO (0.50wt.%), the presence of silicon dioxide (SiO2) peak were observed showing uncomplete melted of silica. Additional vibrational band due to the presence of tridymite was found in the Fourier transform infrared spectroscopy (FTIR) at lowest ZnO content supporting the XRD result while other glasses showed the formation of zinc silicate glasses with the presence of SiO4and ZiO4vibrational band. The zinc silicate absorption also increased as the ZnO increased as a result from the formation of non-bridging oxygen (NBO's). Hence, optical band gap of zinc silicate glasses was decreased from 4.35 to 4.23eV as the ZnO increased due to increment of NBO's. All zinc silicate glasses showed three different emission peaks which is at 535, 596 and 728nm correspond to green, yellow and red emission respectively. This luminescence properties of zinc silicate were attributed to the defect inside the ZnO particle.

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Result: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.

The radiation shielding effects and elastic properties of adding lead (Pb) and bismuth (Bi) to glasses was analyzed. Six different glasses, coded as G1-G6, were simulated with varying compositions of bismuth oxide and lead oxide, with G1 having the lowest density and G6 having the greatest. MCNP-5 code was used to calculate the mass attenuation coefficient, half value layer, tenth value layer, and mean free path of the glasses, the latter of which was compared with other radiation shields. These parameters were investigated between 0.015MeV and 15MeV. The bond compression model was utilized to analyze various parameters that describe the elastic properties of the glass samples. From the ultrasonic wave measurement result, the substitution of PbO and Bi2O3which working as a network modifier towards SiO2glass systems would break up the Si–O–Si bonds along with all the formation of non-bridging oxygen's which give the impact in the elastic moduli analysis of the glasses.

New low-cost and high strength porous glass-ceramics have been successfully fabricated in the Na2O–CaO–SiO2glass system by powder sintering method, using pre-calcined clamshell (CS) and waste soda-lime-silica (SLS) glass as raw materials. The effect of pre-calcined CS content and sintering temperature on crystal growth, physical properties, compressive strength and pore structure of foamed glass-ceramic samples were systematically investigated by means of X-ray diffraction (XRD), physical properties test, Brunauer–Emmett–Teller (BET) and field emission scanning electron microscopy (FESEM) micrograph. Besides, the pore-forming mechanism of the glass-ceramic samples was also presented in detail. This study used 3wt.% of CS contents where the prepared powder was compacted into pellet form prior to sintered at 700–900°C for 1h. The minimum density (2.43g/cm3) with maximum expansion (83.98%) was obtained after sintered at 800°C. The XRD measurement shows the wollastonite (CaSiO3) crystalline phase has formed at 800°C and the highest value of mechanical strength (1.21MPa) with acceptable high total porosity value (58.27%) was obtained after sintered at 900°C. Besides, the FESEM micrograph has visualized the porous structure of foam glass-ceramics samples sintered at 800°C has the largest porous structure with closed pore characteristics.

The influence of boron oxide on glass-forming ability, phase transformation, and optical properties of new zinc-boro-soda-lime-silicate (ZBSLS) glass system with formulation 60–x(ZnO)x(B2O3)40(SLS) where x=0, 1, 5, 10 and 15wt.% using the conventional melt-quenching technique was comprehensively studied. The glass powder samples were subjected to true density measurement using Helium Pycnometer. Besides, the XRD and FTIR spectroscopy was used to examining the phase and structural rearrangement in the ZBSLS glass system. The XRD result emphasizes the glass samples (G3, G4, and G5) in amorphous nature when boron concentration is more than 5wt.% in the ZBSLS glass matrix. Also, the UV–Vis spectra were observed within 200–800nm. At that point, the data from optical absorbance was converted to justify the optical band gap energy using Mott and Davis theory. The optical band gap energy show increment behavior from 4.35 to 5.25eV for direct allowed transition and 3.25–4.30eV for indirect allowed transition with the progress of boron concentration, respectively.

This study was conducted to synthesize foam glass-ceramic using SLS glass as a precursor; eggshell (ES) as a foaming agent and investigated the effect of sintering temperature on the crystal growth, microstructure and mechanical properties of the final product. The samples undergo the sintering process at different temperatures such as 700, 800 and 900°C for 60min with the heating rate of 10°C/min. The structural properties were studied by XRD, FTIR and FESEM measurement. The cristobalite (SiO2) and wollastonite (CaSiO3) phases were identified after the sintering process and their microstructure was recorded by the FESEM micrograph. The physical properties of the samples were measured by average density measurement, linear expansion and compressive strength. The lowest density measurement using the Archimedes principle was achieved by 0.421g/cm3with the highest volumetric expansion at 92% after the sample sintered at 800°C. Good correlations between porosity, mechanical strength and crystal phase were observed. The invention of foam glass-ceramics from waste materials can be applied as a potential building insulation material that gives benefit to the environment and energy usage.

Glass Ionomer Cement (GIC) is produced from an acid-base reaction between various type of alkaline glass powder and polymeric acid. In this research, calcium fluoro-alumino-silicate (CFAS) glass was derived from waste materials such as soda-lime-silica (SLS) glass and clam shell (CS) which are sources of silica and calcium oxide respectively. The polyacrylic acid (PAA) is used to produced mobile carboxyl group and then, react with metal ions on the surface of CFAS glass. To study the influence of ageing time on physical, structural and mechanical properties of GIC, deionized water was used as a soaking medium. The density results increase throughout the ageing time from 7–28 days. The density of GIC at 7 days shows 1.622 g/cm3and increasing to 1.789 g/cm3at 28 days. However, the molar volume shows the opposite action comparing with the density of GIC. The molar volume shows continue decreasing from 357.63–324.25 cm3 mol−1. From the XRD result, GIC was indicating amorphous structure during ageing range between 7–28 days. FTIR analysis shows this phenomenon occurs due to the deformation of Si−OH bonding and formation of Si-O-Si simultaneously in the presence of water which is influence the mechanical strength of GIC. The mechanical properties of GIC increase by ageing time through the compressive test from 42.23–50.28 MPa. Thus, the observed results in this study promise the GIC derived from waste materials have a high potential in dental application due to excellence structural and mechanical properties against ageing.

An investigation was conducted to explore the optimum composition to fabricate a zinc silicate glass substrate for optoelectronic device applications. The composition was determined based on the empirical formula (ZnO)x-(SiO2)1-x, where x  = 0.40, 0.50, 0.60 and 0.70 wt%, which was prepared by the conventional melt quenching technique. The focus is on characterizing the physical and structural aspects as well as the optical properties of the glass substrate. The physical properties of zinc silicate samples were assessed using the densitometer and their physical appearance. In addition, the materials' amorphous and glassy characteristics were verified using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. Finally, ultraviolet–visible (UV–Vis) spectroscopy and photoluminescence spectrometer were used to study the optical properties of samples. The density of the samples was observed to increase from 2805 to 3878 kg/m3as the percentage of ZnO in the glass composition increased. X-ray diffraction analysis indicated the absence of sharp peaks in the samples containing up to 0.60 wt% of ZnO, suggesting the presence of an amorphous phase. Furthermore, the results of this study indicate that ZnO-SiO2glass substrate samples favor direct forbidden transitions, with an increase in ZnO leading to higher absorption and consequently a lower band gap. The photoluminescence spectrum showed blue light emissions at 422 nm, associating with the variation of band gaps in the ZnO phase. Overall, from the interesting results achieved, this zinc silicate-based composite material at 0.60 wt% ZnO can be a potent candidate in optoelectronic applications, among other concentrations used in this study.

This paper presents a small angle neutron scattering (SANS) study of a novel porous gehlenite-based ceramic, synthesised from a homogeneous powder mixture of soda-lime-silicate (SLS) glass, α-alumina, calcite and calcium fluoride via solid-state sintering at 1200 °C. The products of sintering at single temperatures from 600 to 1200 °C are examined by X-ray diffraction (XRD). Sintering of the mixture below 1200 °C forms two intermediate phases (Na2CaSi3O8 and Ca4Si2O7F2). Nepheline and α-alumina are minor phases in the gehlenite-based ceramic fabricated through sintering at 1200 °C. The microstructure of the gehlenite-based ceramic is investigated using field-emission scanning electron microscopy (FESEM) and SANS at the Australian Centre for Neutron Scattering. This study also evaluated the specific surface area of the gehlenite-based ceramic (~3.0 m2 cm–3) from quantitative analysis of SANS data.

The effect of different sintering temperatures on structural and optical properties of ZnO-Zn2SiO4composite was investigated. In this study, a ZnO-Zn2SiO4composite was prepared by encapsulated zinc nitrate hexahydrate with amorphous silica nanoparticles in deionized water. The amorphous silica nanoparticles were prepared by reacting sodium silicate with ethanol. Zinc nitrate was mixed with the obtained amorphous silica nanoparticles with the ratio of 2:1 and 1.25:1 for Zn:Si and subjected to the different sintering temperatures from 600 to 1000 °C. Field emission scanning electron microscope (FESEM) microstructure showed that samples exhibit spherical morphology up to 700 °C and dumbbell morphology above 800 °C sintering temperature. The formation of Zn2SiO4crystal phase appears from 700 °C and onwards together with ZnO crystal phase. The gaining of sintering temperature has also raised the amount of Zn2SiO4phase and band gap values of the ZnO-Zn2SiO4composite.

A series of MnO-doped zinc soda lime silica glass systems was prepared by a conventional melt and quenching technique. In this study, the x-ray diffraction analysis was applied to confirm the amorphous nature of the glasses. Fourier transform infrared spectroscopy shows the glass network consists of MnO_4, SiO_4, and ZnO_4 units as basic structural units. The glass samples under field emission scanning electron microscopy observation demonstrated irregularity in shape and size with glassy phase-like structure. The optical absorption studies revealed that the optical bandgap (E_opt) values decrease with an increase of MnO content. Through the results of various measurements, the doping of MnO in the glass matrix had effects on the performance of the glasses and significantly improved the properties of the glass sample as a potential host for phosphor material.

Currently, many researchers interested studying waste materials to recycle them or reuse them in new products. From the sustainable perspective development, it is necessary to implement new technologies to help reduce waste and thus minimize the environmental problems associated with disposal. In this study, the preparation of SiO2-Na2O-CaO-P2O5 (SNCP) glass-ceramic is composed of Soda Lime Silicate (SLS), Clam Shell (CS), Na2CO3 and P2O5 in the ratio of 50: 25: 20: 5 respectively. The waste materials that were used for fabricate glass-ceramic are SLS and CS. All the compounds were mixed to fabricate the SNCP glass-ceramic through solid state reaction. The samples were investigated through X-ray diffraction (XRD), field emission microscope (FESEM) and density measurement. The samples were sintered at temperature 550°C, 650°C, 750°C, 850°C until 950°C. The main phase obtained from XRD analysis is Sodium Calcium Silicate, Na2CaSiO4 with cubic crystal system at 550°C. The highest intensity phase of the diffraction peak is (220) and at the angle 33.7°. There was new peak presence at right side of the main phase Na2CaSiO4, which belong to Silicon Phosphate, SiP2O7 at 650°C and 750°C. When heat treatment increased at 850°C - 950°C, the main phase is Combeite, Na4Ca4(Si6O18) at diffraction peak (220) with rhombohedral crystal system which is assigned to high crystallization temperature (Tc). The density of samples increases at 550°C - 750°C and decreases when heat treatment 850°C - 950°C. Sample density decreases at heat treatment 850°C - 950°C due to increases of sample lattice parameter. FESEM analysis showed that the grain size and porosity increased when the heat treatment increased.

In this work, the designed bioactive glass utilized waste is expected to improve mechanical properties while maintaining the bioactivity performance during the in-vitro assessment. Herein, the novel bioactive glasses were prepared using the melt-quenching approach. Phosphate buffer saline was used as an immersion medium during the in-vitro bioactivity and biodegradability evaluation to ascertain the glass’s bioactivity characteristics. The XRD results indicated the carbonate apatite phase for sample 0F and the fluorapatite and calcite phase for sample 3F, supported by the FTIR spectra. Further, the pH increased from (7.437±0.004) to (9.699 ± 0.058) for 0F and (9.635±0.014) for 3F, indicating the samples’ bioactivity in response to the immersion medium. In addition, 3F exhibited a higher hardness (3.29±0.07 GPa) and toughness (2.4 ±0.08 MPa·m1/2), supported by the weight gained in the biodegradability analysis. This work offers a promising technique to fabricate the bioactive glass incorporating waste, adding fluoride content into the glass for potential dental application.

In the ZnO based varistor, the improvement of nonlinear coefficient (α) and prevention of evaporation of Bi2O3 during heat treatments can be achieved by the addition of MnO2 or Co3O4. In this conjunction, it is proper to see the effect of these additives at different low mol percentage and sintering conditions to nonlinear coefficient improvement of the varistor ceramics. In this paper, the investigation regarding to the α variation of Co3O4 doping on ZnO-Bi2O3-TiO2 system is discussed. Here, the crystalline phases were identified by an XRD (PANalytical (Philips) XPert Pro PW3040/60) with CuKα radiation and the data were analyzed by using XPert High Score software. The density of varistor ceramics was measured by the geometrical method. The current-voltage characteristics of the varistor ceramics were evaluated. The average grain size (d) was determined by lineal intercept method. The α of ZnO doped with 0.5 mol% of Bi2O3, 0.5 mol% of TiO2 and x mol% of Co3O4 was calculated from data analysis of current-voltage characteristics obtained through a Source Measure Unit (Keithley 236). The calculation of α is done by using Origin Pro8.0 software. The value of α at low concentration at 1170 °C has the value 5.36 and 3 at 45 and 90 min sintering time, respectively, and then decreases to 4.99 and 2.98 at 0.8 mol% Co3O4 concentrations. When the amount of dopant is increased then the value of α increase up to 0.4 mol% and then the value are slightly dropped after further addition. The addition of Co3O4 dopant in Zn-Bi-Ti oxide ceramics sintered at 45 minutes cause the value of α to increase up to 0.4 mol% and decrease after further addition.

Surface preparation is a process of treating a surface to increase its attraction to coatings and imperative to ensure satisfactory coating can be attained. Conventional techniques of surface preparation usually involve blasting of abrasive material on the surface which usually associated with airborne debris and hazardous contaminant from the process. A relatively new technology in surface preparation is the usage of sponge media as an alternative to the conventional abrasive material. Being soft and elastic, sponge media can reduce airborne emission from surface preparation significantly while being able to be recycled. Unfortunately, the recovery of used sponge media becomes difficult during rainy conditions in which the sponge absorbs water and quickly becomes saturated. Therefore, this paper presents the drying characteristics of sponge media using a swirling fluidized bed dryer (SFBD) for rapid drying to overcome the long, inefficient sun drying as per current practice. Several laboratory scale experiments were carried out to dry water laden of the sponge media in the SFBD. Three bed loadings of 1.7, 2.0 and 2.3 kg were used at drying temperatures of 80°C, 90°C and 100°C. The experimental works revealed the excellent potential of the SFBD in drying the sponge media rapidly. The behaviour of moisture ratio and drying rate against time were discussed. Keywords: Sponge media drying, Swirling Fluidized Bed Dryer (SFBD), Moisture ratio, Drying rate

Metallic materials have propelled human advancements for centuries. Nevertheless, the rapid degradation of metallic structures in corrosive environments is inevitable. To date, the demand for metal alloys in multiple sectors, including construction and transportation, continues to escalate, with the trend it is predicted to reach beyond 250% by 2050. Thus, the need for corrosion inhibitors (CI) with qualities of high efficiency, excellent solubility, low toxicity, and inexpensiveness drive researchers to examine various possibilities. Here, we review the novelty, methods, and outputs from the latest studies on organic CI with the primary purpose of protecting mild steel and stainless steel in salt and acidic solutions. We reviewed the effectiveness, synergism impacts, and technological availability of each inhibitor and also comprehensively discussed related mechanisms of metallic corrosion and inhibition of CI.

The objective of this research was to evaluate the relationship between the multimedia usage in the understanding level and students’ interest. While the emphasis on the effectiveness of using multimedia teaching system as an aid in the exploration of ideas in learning instruments need to be addressed. A rapidly growing technology, comprehensive and interest in education in Malaysia has provided space and opportunities for educators to contribute their ideas and experience. Application of method helps in understanding concepts, processes and terms in multimedia, simultaneously provide conducive teaching and learning environment which dynamically visualize information in an interesting and effective manner. To realize the main objective, the literature research and a detailed monitoring are performed. Comparison of student progress obtained after examining the traditional learning methods and education system using multimedia technology as a means of support. In addition, educational technology has posed challenges, impact and responsibilities to educators and requires more than just the involvement of the students. Assimilation in the expertise is required in implementing teaching using available technology, thus improving the quality and creates a capable generation to face challenges.

A stability loss of varistor is subjected to any of variety extreme conditions such different stresses AC or DC, temperature, pulse, pressure, humidity, etc. This causes degradation phenomenon and leads to thermal runaway or failure of varistor. The investigation of degradation phenomena is an important subject for prolonging their lives. In this study, we investigate the degradation process of ZnO1-x-CoO2.0-SLSx varistor ceramics where x= 0.5, 1.0, 1.5, and 2.0 mol % by using conventional solid state method at sintering temperature of 1100 °C for 2 hour. The stability of their nonlinear properties was investigated under prolonged application of DC electric field at different SLS glass concentration. The degradation process was speeded up by applying direct current (DC) 85 % of electric field for 12 hours at temperature of 85 °C. A concentration of 2 mol % SLS glass doped ZnO varistor shows the best degradation properties as its nonlinear coefficient has increased by 3.56 %, the breakdown field has increased by 3.85 %, and the leakage current density (JL ) increased by 2.40 % in comparison to its initial value.

Eu3+-doped Zn2SiO4/ZnO phosphor-based composites were prepared using a simple thermal treatment method. The effect of Eu3+content on the morphological and photoluminescence performance was examined using XRD, FTIR, FESEM, UV–Vis, and PL measurement. The existence of two crystal phases by the XRD measurement confirmed the development of zincite (ZnO) and zinc silicate (Zn2SiO4) crystal phases. Besides, the FTIR spectra and FESEM micrograph support the XRD result by verifying ZnO and Zn2SiO4phase formation through the existence of their characteristic Zn–O–Si and Zn–O vibration modes with the decrement of SiO4broad absorption band as the Eu3+concentration increased. Also, UV–Vis absorption spectra presented by the composite samples displayed a broad absorbance that confirmed the addition of Eu3+ions in the ZnO/Zn2SiO4has caused the absorption edge of the curve having red shift. The photoluminescence spectrum showed red shift light emissions at 485 and 615 nm, associating with the Zn2SiO4crystal phase, in addition to the ZnO crystal phase. From the interesting results achieved, this ZnO/Zn2SiO4phosphor-based composite material can be a potent candidate in optoelectronic applications.

The optical properties and radioactive attenuation parameters of doped tungsten oxide soda-lime-silica (SLS) waste glass were investigated in the current work. A novel series of lead-free transparent glass samples were manufactured with the possibility of developing radiation-absorbing glass shielding materials. The glass composition is WO3-Bi2O3-ZnO-B2O3-SLS. A new approach was employed in the utilization of soda-lime-silica (SLS) glass as an alternative for pure silicon dioxide having 74.1 % of SiO2and other elements in it. The optical properties were investigated with the help of a UV-Visible Spectrophotometer. The results for the optical properties showed that when WO3content is increased in the glass structure, the Urbach energy ΔE and refractive index n, increase from 0.337 to 0.431 and 2.84 to 2.94 respectively, the optical basicity Λ also increase with the increase in WO3while the energy optical band gap Eoptregistered a decrease. The metallization criterion (M) confirmed that the current glass samples are nonmetallic (insulator) because Rm/Vm< 1 which is confirmed in the condensed matter theory in the Lorentz-Lorenz equations. Moreover, the theoretical radiation shielding parameter results indicate that the linear attenuation coefficient μand effective atomic number Zeffwere increased with an increase in WO3. It can be seen also that the relationship between the μand HVL is an inverse one; larger values of μresult in lesser thickness of the HVL. Whereas, as the WO3concentration increases, the half-value layer HVL decreases. The results of this study demonstrate that the glass samples are harmless, transparent to visible light, and effective radiation shielding materials.

The Prototype and Plant Development Center (PDC) of Malaysian Nuclear Agency is developing a hot cell facility which is meant for research activities such as spent fuel inspection, fuel fabrication and post irradiation material examination/inspection. The hot cell is of alpha-gamma shielding hot cell type. The size of the hot cell is 4.4 x 3.9 x 3.825 meter. The 1-meter thickness hot cell wall consists of 89 pieces of interlocking curve design concrete. The 1-meter hot cell roof consists of 41 pieces of square shape concrete. The density of all concrete blocks is 2350kg/m3. The hot cell is designed to handle up to 227.5 Ci 60Co activity. This paper will discuss the detailed design of the shielding wall, as well as the shielding evaluation/analysis against gamma and fission products of 50% burnup RTP 20wt% fuel type using MCNP.

Willemite glass-ceramics were successfully derived from conventional melt-quench ZnO-SLS precursor glass by an isothermal heat treatment process. The effect of heat treatment temperatures on the physical properties was investigated by Archimedes principle and linear shrinkage. The generation of willemite crystal phase and morphology with increase in heat treatment temperature was examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and field emission scanning electron microscopy (FESEM) techniques. X-ray diffraction revealed that the metastable β-Zn2SiO4 and thermodynamically stable zinc orthosilicate α-Zn2SiO4 phases can be observed at temperatures above 700°C. The experimental results indicated that the density and shrinkage of the glass-ceramic vary with increasing the sintering temperature. FTIR studies showed that the structure of glass-ceramic consists of SiO2 and ZnO4 units and exhibits the structural evolution of willemite glass-ceramics. The characteristic of strong vibrational bands can be related to the SiO44- tetrahedron corresponding to reference spectra of willemite.

Mn-doped willemite (Zn2SiO4:Mn2+) glass-ceramics derived from ZnO-SLS glass system were prepared by a conventional melt-quenching technique followed by a controlled crystallization step employing the heat treatment process. Soda lime silica (SLS) glass waste, ZnO, and MnO were used as sources of silicon, zinc, and manganese, respectively. The obtained glass-ceramic samples were characterized using the X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR), UV-Visible (UV-Vis), and photoluminescence (PL) spectroscopy. The results of XRD revealed that ZnO crystal and willemite (β-Zn2SiO4) were presented as major embedded crystalline phases. This observation was consistent with the result of FESEM which showed the presence of irregularity in shape and size of willemite crystallites. FTIR spectroscopy exhibits the structural evolution of willemite based glass-ceramics. The optical band gap shows a decreasing trend as the Mn-doping content increased. Photoluminescent technique was applied to characterize the role of Mn2+ ions when entering the willemite glass-ceramic structure. By measuring the excitation and emission spectra, the main emission peak of the glass-ceramic samples located at a wavelength of 585 nm after subjecting to 260 nm excitations. The following results indicate that the obtained glass-ceramics can be applied as phosphor materials.

Willemite- (Zn2SiO4-) based glass ceramics doped with various amounts of europium oxide (Eu2O3) were prepared by solid state melting and quenching method. Effect of sintering temperature (600–1000°C) on structural and morphological properties of the doped samples was investigated. Phase composition, phase evolution, functional groups, and microstructure analysis were, respectively, characterized using X-ray diffractometer (XRD), fourier transform infrared spectroscopy, field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray. XRD analysis detected the presence of rhombohedral crystalline phase in the doped samples sintered at different temperatures. FE-SEM and bulk density results confirmed that doping of the willemite with Eu2O3 effectively enhanced densification. The microstructural analysis of the doped samples showed that the average grain size increased with the increase of sintering temperature.