609 research outputs found
Deposition of ZnO-Al (AZO) thin films for optical properties
Zinc Oxide (ZnO) is an inorganic compound and it is doped with aluminum to increase its capabilities.
Aluminum Zinc Oxide (AZO) thin films are semiconductor materials that have band gap energy of 3.3eV. Various method
of deposition have been study to growth AZO thin films. It has been extensively use in solar cell application, display
application, gas sensing purposes, and thin film transistors (TFTs). In this work, sol gel method and spin coating was used
to deposited AZO thin films. The ZnO sol-gel were synthesized using zinc acetate dihydrate as precursor, isopropanol as
solvent, diethanolamine as sol stabilizer, and distilled water as oxidation agent. Then, synthesized ZnO were doped with
different mole ratio of aluminum nitrate nanohydrate to produced AZO. The glass substrate was used as substrate and AZO
thin films were then calcinated at 300°C and 500°C. The characterization of AZO thin film were done using X-ray
Diffraction (XRD), Atomic Force Microscopy (AFM), Ultraviolet-visible spectroscopy (UV-Vis), Field Emission
Scanning Electron Microscope (FESEM), and Energy Dispersive X-ray spectroscopy (EDX). The XRD results show that
the ZnO with hexagonal wurtzite-type structure and temperature does have effect on the film intensity which related to
crystallinity of thin films. Through AFM analysis, the value of RMS decreases from 3.018 nm to 2.240 nm as the
temperature increases. Meanwhile, from UV-Vis result, it can be seen that AZO thin film have a high transmittance
percentage above 90% after wavelength 400 nm with band gap value of 3.3 eV. FESEM image show that the grain boundary
of AZO decrease with both parameter (mole ratio and calcinations temperature). Both parameters do have effect on AZO
thin film. EDX analysis shows that there are existence of zinc, oxide, and aluminum
Structural characterization of sulfoborate glasses containing magnesium oxide
Magnesium sulfoborate glasses of different compositions were prepared using melt quenching method with the purpose of using it for optical properties. The Fourier Transform Infra-red (FTIR) Spectroscopy, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have been carried out. Density and molar volume have been evaluated and analysed. From the results of XRD, the absent of discrete and continuous sharp peaks confirmed the amorphous nature of the glass compositions while the results from both FTIR and NMR revealed the existence of BO3, BO4 units. Addition of MgO to sulfoborate influenced the conversion of the dominant BO3 groups to BO4 groups. The BO4 groups are known for creating complex defects that transform into that stable trap good for optical phenomena. It was observed that the density of glass increases while the molar volume is decreases with respect to increase in concentration of alkaline earth oxide in the glass compositions
Structural and physical properties of Sm3+ doped magnesium zinc sulfophosphate glass
Samarium (Sm3+ ) doped magnesium zinc sulfophosphate glass system of composition (60-x)P2O5-20MgO-20ZnSO4-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol%) were synthesized using melt-quenching technique. The structure and physical properties of prepared glass samples were characterized. The X-ray diffraction pattern verified their amorphous nature. The physical properties such as density, refractive index, molar volume, rare earth ion concentration, etc. were calculated. The decrease in the optical bandgap energy with increasing Sm2O3 contents was attributed to the alteration in the glass network structures. Fourier transformed infrared spectra and Raman analyses manifested the depolymerization of ZnSO4 in the phosphate host matrix. The present findings may be beneficial for the advancement of functional glasses
Comparison of the frying performance of refined, bleached and deodorized palm olein and coconut oil
The frying performance of refined, bleached and deodorized palm olein (RBDPO) and refined, bleached and deodorized coconut oil (RBDCO) was compared in this study. The oils were studied during intermittent frying of potato chips at 180C for 5 h/day for 5 consecutive days. The indices used for assessment of frying performance of the oils were fatty acid composition (FAC), peroxide value (PV), anisidine value (AnV), % free fatty acid (FFA), iodine value (IV), % polar component, polymer content, color, viscosity, smoke point and foaming tendency. The results showed that RBDPO was superior to RBDCO in frying performance in terms of % FFA, iodine value, foaming tendency and smoke point. However, RBDCO performed better than RBDPO with respect to % polar component, polymer content, resistance to oxidation, color and viscosity. Flavor evaluation showed that potato chips fried in RBDPO were preferred by the panelists
Conceptual Paper: Sentience of Big Data towards User Privacy Concerns and Online Self-Disclosure Activities
Big data allows widespread use and exchange of user data, and this will lead to the possibility of privacy breaches. Governments and corporations will incorporate personal data from different sources and learn a great deal about people and in turn, raise concerns about privacy. This paper will provide a conceptual understanding on the antecedents towards user privacy concerns and online self-disclosure activities, which are the knowledge and perceived risks of big data. In this paper, big data knowledge is hypothesized to decrease privacy concerns, meanwhile perceived risks is suggested to increase the outcome. Based on the framework, propositions are formulated as a basis for the study that will follow
Hydrophobic silica thin films by sol-gel processing and spin coating technique at low temperature
Hydrophobic silica thin films were prepared by sol-gel processing and self-assembly by chemical vapor reaction with Trimethylchlorosilane (TMCS) at low temperature. The sols were divided into Sol A with ethanol, Polyethylene glycol (PEG) and water (H2O) while Sol B were contain precursor of silica Tetraethylorthosilicate (TEOS) hydrolyze with ethanol which was stirred for 15 minutes. HCl was added into the mixture and stirred for another 10 minutes. After deposition on 1 x 1 cm corning glass using spin coating technique (two-step timer), the films were heated at 60˚C for 10 minutes and finally annealed at 150°C for 1 hour. The films were characterized by using Rudolph/Auto EL Ellipsometer, Shimadzu Spectrophotometer, Perkin Elmer Fourier Transform Infrared (FTIR) and Atomic Force Microscope (AFM). The results showed that the films thickness and refractive index were in the range of 105.2 to 112.4 nm and 1.35 to 1.38, respectively. The films were transmitted 70-80% of light (in visible range) with various bondings of C-H, Si-O-Si, Si-C and Si-OH. Surface roughness of the films was increased from 30.6 nm (silica thin film) to 140.5 nm (hydrophobic silica thin films) after modification have been done on the films by using TMCS (heated at 40˚C). It was found that the water contact angles increased when time of reaction increased from 109° to 124
Silver influence of physical and thermo luminescence properties on lithium-Strontium-borate LSBO: Ag exposed to cobalt-60 gamma ray
This work investigates the properties of glow curve of lithium Strontium borate doped sliver glass (LSBO: Ag), subjected to Co-60 gamma irradiation. The glass samples were prepared in different compositions based on 15%Li2CO3+2%SrCO3 (83-x) H3BO3 +xAgNO3, where x = 0.001, 0.003, 0.005, 0.007, 0.009 and 0.01 mol% by traditional melting quenching method at temperature 1300 °C for 1 hour. The structural pattern of glass samples has been identified by X-ray diffraction. The XRD pattern shows that the samples are glasses since there is broader peak appearing in the spectral pattern. FESEM images verify the homogeneous and transmitting surface morphology of all samples. Stable glasses with Hurby parameter ~ 0.5 are achieved. EDX spectra determine the accurate elemental compositions in the samples. Physical properties are determined in terms of glass density, molar volume, polar on radius, inter-nuclear distance, and ion concentration. Glass density is found to increase from 2.45 to 2.46 g cm-1 after addition of AgNO3 concentration. The TL intensity at different compositions of lithium borate doped sliver glass after exposed to 50 Gy Co-60 gamma-rays is presented. The results clearly show that the highest TL intensity is found in glass composition of 0.09 mol% of AgNO3
Influence of Eu3+ dopant on physical and optical properties of lithium-borosulfophosphate glasses
Multi-components glass host with enhanced physical and optical features are greatly demanding for various photonics and optoelectronics devices. Selection of suitable glass former, modifier, and dopant ions with optimized composition is a key concern in the fabrication of novel optical glass materials for the aforementioned purpose. Thus, this work reports the convectional melt quench synthesis of europium (Eu3+) doped lithiumborosufophosphate glasses with composition 15Li2O-30B2O3-15SO3-(40-)P2O5-Eu2O3 (where = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%). The effect of P2O5 substitution by Eu2O3 on their physical (density, molar volume, ion concentration, polaron radius, inter-nuclear distance and field strength) and optical properties was examined. The amorphous nature of the samples was confirmed by XRD diffraction pattern. The density of glass samples was slightly increased with increasing concentration of Eu2O3. Such trend is attributed to the higher molecular weight of Eu2O3 (351.926 g/mol) than P2O5 (141.9445 g/mol). The room temperature absorption spectra revealed four weak bands in the UV-Vis range and two strong bands in the NIR range with 1.0 mol% glass sample possessing the highest intensity at 7F0→7F6 (2095 nm). Incorporation of Eu3+ ion significantly enhanced the glass absorbance and the physical properties. The results on high refractive index (~2.3), polarizability and non-linear physical features suggest that these glasses are potential for photonics and solid-state laser applications.Keywords: Borosulfophosphate glasses, Europium ions, physical properties, optical properties and photoluminescenc
Structural and luminescence characterization of lithium-borosulfophosphate glasses containing dysprosium ions
Rare earth doped glasses have been a great deal of research interest due to their prominent applications in laser lighting technology. However, achieving highly efficient yellow light emission from these materials require the collective efforts of many researchers across the world. Hence, a series of high optical quality dysprosium doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O-30B2O3-15SO3-(40-x)P2O5-xDy2O3 (where x = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%) were prepared by convectional melt quenching technique and characterized by X-Ray diffraction (XRD), Fourier Transform Infrared (FTIR) and Photoluminescence (PL) measurements. XRD pattern of the host glass confirms its amorphous nature while the results from FTIR spectra analysis indicates the presence of BO3, BO4, PO4 and SO42- groups in the host network structure. The photoluminescence spectral analysis revealed three emission bands at 494 nm, 585 nm and 673 nm attributed to the electronic transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H15/2,respectively, under the excitation of 386 nm. Among all the prepared glass samples, 1.0 mol% Dy3+ contained glass sample exhibits an intense yellow emission at 585 nm which specifies its prospective suitability for yellow laser applications.Keywords: Borosulfophosphate glasses, Dysprosium ions, Fourier transform infrared spectroscopy, Photoluminescence analysi
Experimental investigation on the effect of natural tropical weather on interfacial bonding performance of CFRP-concrete bonding system
The existing reinforced concrete structures may require rehabilitation and strengthening to overcome deficiencies due to defect and environmental deterioration. Fibre Reinforced Polymer (FRP)-concrete bonding systems can provide solution for the deficiencies, but the durability of the bonded joint needs to be investigated for reliable structural performance. In this research the interfacial bonding behaviour of CFRP-concrete system under tropical climate exposure is main interest. A 300 mm concrete prism was bonded with CFRP plate on its two sides and exposed for 3, 6, and 9 months to laboratory environment, continuous natural weather, and wet-dry exposure in 3.5% saltwater solution at room and 40 °C temperature. The prisms were subjected to tension and compression load under bonding test to measure the strain and determine stress distribution and shear stress transfer behaviour. The results of the bonding test showed that load transfer was fairly linear and uniform at lower load level and changed to non-linear and non- uniform at higher load level. The force transfers causes the shear stress distribution being shifted along the bonded length. The combination of climate effects may have provided better curing of the bonded joints, but longer duration of exposure may be required to weaken the bond strength. Nevertheless, CFRP-concrete bonding system was only minimally affected under the tropical climate and salt solution
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