Journal of X-Ray Science and Technology - Volume 26, issue 3

Authors: Nwadike, Uchechukwu I. | Agwu, Kenneth K. | Eze, Charles U. | Kani, Duke | Agu, Gregory | Enwereuzo, Emmanuel | Obika, Mike | Umoh, Effiong | Ufomba, Emmanuel

Article Type: Research Article

Abstract: BACKGROUND: There is abundant quartz deposit in Nigeria which has been used for export and building purposes. However, its electrical and piezoelectric properties have not been studied. Thus, whether it can be used as raw material for the indigenous electric industries is unknown to date. OBJECTIVE: This study aims to characterize the piezoelectric properties of smoky quartz for ultrasonic transducer and determine its sonic properties. METHOD: In the research approach, the raw quartz was cut into six crystals of rectangular shape using a universal cutter. The crystals were purified with a 100 ml hydrofluoric and hydrochloric acid …solution under a temperature of 250°C in a furnace. The sizes, weights, and capacitance of crystals were determined using the standard measuring instruments. The resonance method was used for the determination of the frequency of minimum and maximum impedance of the crystals. The piezoelectric constants of the crystals were derived using the standard formula for determination of piezoelectric constants. RESULTS: The results show that the sonic properties represented by the piezoelectric charge constant (d31 ) and the piezoelectric voltage constant (g31) values are 2.52 (±1.075) ×10-8 c /m 2 and 1030.6114 ± 250.89v /m 2 respectively. CONCLUSION: The present study has characterized Nigerian quartz for its piezoelectric properties and found that it was suitable for use in the construction of ultrasonic transducers. Show more

Keywords: Nigerian quartz, piezoelectricity, transducer, sonic properties, characterization

DOI: 10.3233/XST-17340

Citation: Journal of X-Ray Science and Technology, vol. 26, no. 3, pp. 499-508, 2018

Authors: Goudarzi, M. | Saviz, Sh. | Ghoranneviss, M. | Salar Elahi, A.

Article Type: Research Article

Abstract: The objective of this study is to investigate antibacterial characteristics of a thermal plasma spray system. For this purpose, copper powder was coated on a handmade atmospheric plasma spraying system made by the stainless steel 316 substrate, which is preheated at different temperatures before spraying. A number of deposition characteristics such as antibacterial characteristics, adhesion strength and hardness of coating, was investigated. All of the spray parameters are fixed except the substrate temperature. The chemical composition was analyzed by X-ray diffraction (XRD). A scanning electron microscopy (SEM) and back scattering electron microscopy (BSE) were used to show the coating microstructure, …its thickness and also the powder micrograph. The energy dispersive X-ray spectroscopy (EDX) was used to analyze the coating particles. Hardness of the deposition was examined by Vickers tester (HV0.1). Its adhesion strength was declared by cross cut tester (TQC). In addition, the percentage of bactericidal coating was evidenced with Staphylococcus aurous and Escherichia coli bacteria. Study results show that as the substrates temperature increases, the number of splats in the shape of pancake increases, the greatness and percentage of the deposition porosity both decrease. The increment of the substrate temperature leads to more oxidation and makes thicker dendrites on the splat. The enhancement of the substrate temperature also enlarges thickness and efficiency of coating. The interesting results are that antibacterial properties of coatings against the Escherichia coli are more than Staphylococcus aurous bacteria. However the bactericidal percentage of the coatings against Staphylococcus aurous and Escherichia coli bacteria roughly does not change with increasing the substrate temperature. Furthermore, by increment of the substrate temperature, coatings with both high adhesion and hardness are obtained. Accordingly, the temperature of substrate can be an important parameter for progressing mechanical properties of the antiseptic deposition. Show more

Keywords: Atmospheric plasma spray, antiseptic

DOI: 10.3233/XST-17318

Citation: Journal of X-Ray Science and Technology, vol. 26, no. 3, pp. 509-521, 2018