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Glass series of quaternary lead-zinc-borosilicate glass was fabricated using melt-quenching method. It was successfully prepared using silicon dioxide (SiO2 99.37 %) as the network former, which was obtains from rice husk ash (RHA). The thickness of the prepared glass samples used during the measurement was 0.3, 0.4 and 0.5 cm. As the percentage of PbO increased from 5% to 40%, the density and molar volume of glass sample increased from 3.719 g/cm3 to 5.010 g/cm3 and 21.44 cm3 to 25.82 cm3, respectively. The significant modification was due to augmentation in bond length and increment in inter-atomic spacing between atoms with the presence of Pb, Zn and B atoms. Nevertheless, the oxygen packing density decreased from 79.29 g-atom/l to 65.84 g-atom/l. The mass attenuation coefficient was found to be increased for 0.3 cm, 0.4 cm and 0.5 cm. The escalating mass attenuation coefficient was due to the increment of PbO percentage mole, which related to the emergent photoelectric absorption of the glass sample. Thus, it also affects the decreasing trend of Half Value Layer (HVL) and the increasing of Effective atomic number (Zeff).

A glass series of erbium doped zinc borosilicate glass system was prepared by using the melt-quenching method. The absorption spectra revealed several bands at visible range which correspond to the following transitions (from the ground state); ⁴F5/2 + ⁴F7/2 + ²H11/2 + ⁴S3/2 + ⁴F9/2 + ⁴I9/2. The density and molar volume obtained increased and decreased respectively as the concentration of erbium oxide varied from 0 mol % to 1.0 mol %. Meanwhile, oxygen packing density (OPD) increased as the concentration of erbium oxide increased up to 3.0 mol % due to the build-up of bridging oxygen. The indirect band gap energy was achieved from 2.56 eV to 2.80 eV and the Urbach energy values lies between 0.15 eV and 0.61 eV.

The glass samples of zinc borotellurite glass doped with dysprosium nanoparticles with chemical formula TeO20.7B2O30.30.7ZnO0.31-xDy2O3x (where x= 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction) have been fabricated by using melt quenching technique. In this study, the structural and optical properties of the zinc borotellurite glass doped with dysprosium nanoparticles were characterized by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis spectroscopy. From the XRD, the amorphous nature of the glass samples has been confirmed. The infrared spectra revealed four obvious bands which are assigned for BO3, BO4 and TeO4 vibrational groups. The direct and indirect optical band gap, as well as Urbach energy, was calculated through absorption spectra obtained from UV-Vis spectroscopy. From the spectra, it is observed that both direct and indirect optical band gap decreases as the concentration of dysprosium nanoparticles increase. Other than that, the Urbach energy is observed to have an inverse trend with the optical band gap. The Urbach energy is increases as the concentration of dysprosium nanoparticles increases.

This paper aims to compare the structural and optical properties of ternary Boro-tellurite glass with the addition of two different chemical modifier. Six glass samples from composition [(TeO2)0.7 (B2O3)0.3]1-x (BaO)x (x = 0.10, 0.20 and 0.30 mol%) and [(TeO2)0.7 (B2O3)0.3]1-x (Bi2O3)x (x = 0.10, 0.20 and 0.30 mol%) were prepared by melt quenching method with suitable melting and quenching temperature. The X-ray diffraction (XRD) pattern confirms the amorphous nature of all glasses and the Fourier transform infrared spectroscopy (FTIR) spectra explore the fundamental groups and the local structural units in two different boro-tellurite glasses. The density for both glass series increased as barium oxide and bismuth oxide content increased. The optical band gap, Eopt values for bismuthboro-tellurite glasses are between 2.15–2.4 eV, while barium-boro-tellurite glasses are between 2.25–2.44 eV. The highest concentration of Bi2O3 in glass system shows the smallest Eopt. In conclusion, the obtained results shows that the addition of bismuth oxide in boro-tellurite glass improves its structural and optical properties.

A simple rectangular microstrip sensor for determination of moisture content in Hevea Rubber Latex is presented in this paper. The microstrip patch sensor was designed to operate at microwave frequency range from 1 to 5 GHz on a RT/Duroid substrate with 6.15 ±0.015 permittivity and 1.27 mm thickness. The width and length of the rectangular patch antenna was 18 mm and 38 mm, respectively. The reflection coefficient of the sensor loaded with Hevea latex at various percentages of moisture content from approximately 36.1% to 88.6 %. Calibration equations have been established between moisture content and phase of reflection coefficient at several selected frequencies. These equations were used to predict the amount of moisture content on Hevea latex based on the measured reflection coefficient values. The actual values of moisture content were obtained using standard oven drying method. The lowest mean relative error between actual and predicted moisture contents was 0.04 at 1 GHz.

Rice husk ash (RHA) is a product from the burning of the rice husk and it become a significant material for glass preparation due to high amount of amorphous silica that can be produced. From the recent studies, the highest amount of silica is observed at 550°C at 6 hours which is 99.36% by XRF detection. Nevertheless, the amount of silica decreasing proportionally if the temperature profile is higher than 550°C and the time taken is more than 6 hours. Quaternary glasses are prepared using melt-quenching method using the highest amount of silica from RHA combined with Bismuth Oxide (Bi2O3), Boron Oxide (B2O3), and Zinc Oxide (ZnO). The ratio of quaternary glass that used are 30%SiO2: 20%B2O3: xZnO : (50-x)%Bi2O3 (% mole) ; where x= 10,20,30,40. The physical properties and glass transition temperature (Tg) profiles are determined using standard measurement instrument. Moreover, the density measured will enhance the verification of Oxygen Packing Density for prepared quaternary glasses.

A new method for the evaluation of radiotherapy 3D polymer gel dosimeters has been developed using ultrasound to assess the significant structural changes that occur following irradiation of the dosimeters. Polymer gel dosimeters were being fabricated using a monomer named 2-Hydroxyl-Ethyl-Meta-Acrylate (HEMA) with the presence of gelatine as a gelling agent. The readymade gel which is the concentration for HEMA fixed at 2, 4 and 5% would then undergo an ultrasonic evaluation to test for the propagation of sound speed through it. In the observation of relationship between the ultrasound propagation speeds as the doses increase (focusing at the cross region from overlapped beams) and concentration of monomer, the propagation speed for all the three polymer gel dosimeter phantoms still varies between 1460 to 1570 m/s which is still in the range of speed of sound for human tissue [3]. The ultrasonic absorption attenuation coefficient dose sensitivity for polymer gel dosimeters for 2, 4 and 5% of monomer are in the range of 0.02 to 0.6 dB which is equivalent to human tissue. As a comparison, it can be seen that gel phantoms with high concentration of monomer (5%) is more sensitive to the radiation compared to the lower (2% and 4%) concentrations. Regarding the absolute results of mechanical and acoustic properties; the copolymer-in-oil phantom is equivalent with soft tissue.

The effects of the X-ray irradiation and chemical etching on the physical and optical properties of CR-39 plastic detectors were investigated for different doses of X-ray. CR-39 detectors were etched in the solution of the 3 M of NaOH after irradiation for revelations of the track. The tracks formed on CR-39 either by irradiated X-ray or due to the effect of environment. The changes in the thickness after exposed have significant decrease in 60 kVp and started to increase in range of 70 kVp up to 100 kVp due to the formation of oxidation layer on surface by free radicals. The optical band gaps before etching and after etching were determined by using Ultraviolet-visible (UV-Vis) spectroscopy. The optical band gap is attributed to the indirect transition due to its amorphous nature which is significantly decline trend energy in increase of the energy fluence of radiation. The Urbach’s energy, is defined as the width of the tail localized states in the forbidden band gap which change increment trend as increase in dose delivered due to the distortion structure of the CR-39 in terms of the electron charges in valences electron hence attributes to the induced modification of angle bond between the neighboring atoms.

A series of (Li2O)x(B2O3)1-x has been synthesized with mole fraction x=0.10, 0.15,0.20,0.25 and 0.30 mol% using melt quenching method. The structure of the glass system was determined by FTIR and X-ray diffraction. The density and molar volume were determined and the density increases with Li2O content whereas molar volume decreases with Li2O. Refractive index of glass samples were measured by ellipsometer. Refractive index increases with increase of Li2O. The absorption spectra of the studied glass showed that position of fundamental absorption edge shifts to longer wavelength with Li2O. Optical band gap varies from 0.10 to 2.22 eV and Urbach energy varies from 2.91 to 1.55 eV. The variation in optical band gap and Urbach energy were due to the variation in the glass structure.

The objective of the work is to study the effect of photon on the optical properties of dyed polyvinyl alcohol-trichloroacetic acid (PVA-TCA) blends prepared through solvent casting technique at radiotherapy dose. The films were cut into 2 × 2 cm2 and kept away from direct sunlight at room temperature until irradiation process. The films were simultaneously irradiated with a 6 MV photon beam produced by linear accelerator Siemens MXE-2. The dose exposure given was set from 50 to 400 cGy. The optical properties were measured using the UV-visible spectrophotometer Shimadzu-1800, set at a wavelength range between 200 nm and 800 nm. The absorbance spectra were obtained with the existence of three absorbance band peaks at 273 nm, 444 nm and 582 nm. Initially, all absorbance increased with increasing dose applied. The results gained indicate that the optical energy band gap, Eg is equivalent to 5.20 eV while the absorption edge is 4.96 eV. These two parameters decreased with increasing dose. It is due to the increase of structural order between the conduction band and the valence band getting narrower. This also indicates that the film is undergoing a red shift. Hence, the value of Urbach energy, ΔE obtained is 0.089 eV, which increased with increasing dose since the lattice vibration depended on the applied dose. In conclusion, the PVA/TCA blends have a good optical characteristic in terms of dose response and optical transition.

Spectrophotometric studies of lead borotellurite glasses were carried out before and after gamma irradiation exposure. The increasing peak on the TeO4 bi-pyramidal arrangement and TeO3+1 (or distorted TeO4) is due to augmentation of irradiation dose which is attributed to an increase in degree of disorder of the amorphous phase. The structures of lead tellurate contain Pb3TeO6 consisting of TeO3 trigonal pyramid connected by PbO4 tetragonal forming a three-dimensional network. The decrease of glass rigidity is due to irradiation process which is supported by the XRD diffractograms results. The decreasing values of absorption edge indicate that red shift effect occur after irradiation processes. A shift in the optical absorption edge attributed to an increase of the conjugation length. The values of optical band gap, Eopt were calculated and found to be dependent on the glass composition and radiation exposure. Generally, an increase and decrease in Urbach’s energy can be considered as being due to an increase in defects within glass network.