Papers by Keyword: Morphological

Abstract: Aluminum-doped NiO thin films were generated on glass substrates by dip coating at different temperatures (400 to 500 °C) using 0.05 M of the precursor nickel acetate. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structural and morphological aspects of the films. UV-visible spectroscopy was utilized to assess the optical properties of the films, and the energy band gap was confirmed to be 3.42,3.6, and 3.8 eV for as-prepared and thin films, respectively. Photoluminescence (PL) measurements were used to investigate electronic faults. The XRD lines of the transferred Al-doped NiO were strengthened due to the fact the film's temperature content increased due to the improved crystalline structure. This research article focuses on the optical properties and morphologies of thin films which have been deposited. Crystalline proportions of the thin films that were deposited were determined using the Debye-Scherer formula. The outcomes were computed after taking measurements of absorbance (A), transmittance and Band Gap.

Abstract: The purpose of this research is to study the mechanical and morphology of sugarcane bagasse (SGB) reinforced unsaturated polyester resin (UPR) composites by utilizing a different percentage of fibre contents and different chemical treatments on fibres. Sugarcane bagasse reinforced unsaturated polyester resin composites have been prepared using the compression molding technique. To enhance better adhesion between fibre and matrix, the SGB was chemically treated with alkaline (NaOH) solution and silane solution for 2 hours. The characterization of mechanical properties such as tensile and flexural strength, and tensile and flexural modulus of SGB-UPR composites were studied and compared. The incorporation of the alkaline + silane treatment of SGB resulted in better tensile and flexural properties of composites than untreated or alkaline-only treated SGB composites. Overall, it can be seen that the 5 % of fibre treated with NaOH + silane treatment showed the best results for tensile and flexural properties. Surfaces of cracked composites were observed using SEM and treated SGB showed better interfacial adhesion with matrix rather than the untreated SGB. Chemical treatment plays an important in enhancing the interfacial adhesion of fibre and matrix in composites.

Abstract: Automated retinal vascular network detection and analysis using digital retinal images continue to play a major role in the field of biomedicine for the diagnosis and management of various forms of human ailments like hypertension, diabetic retinopathy, retinopathy of prematurity, glaucoma and cardiovascular diseases. Although several literature have implemented different automatic approaches of detecting blood vessels in the retinal and also determining their tortuous states, the results obtained show that there are needs for further investigation on more efficient ways to detect and characterize the blood vessel network tortuosity states. This paper implements the use of an adaptive thresholding method based on local spatial relational variance (LSRV) for the detection of the retinal vascular networks. The suitability of a multi-layer perceptron artificial neural network (MLP-ANN) technique for the tortuosity characterization of retinal blood vascular networks is also presented in this paper. Some vessel geometric features of detected vessels are fed into ANN classifier for the automatic classification of the retinal vascular networks as being tortuous vessels or normal vessels. Experimental studies conducted on DRIVE and STARE databases show that the vascular network detection results obtained from the method implemented in this paper detects large and thin vascular networks in the retina. In comparison to preious methods in the literature, the proposed method for vascular network segmentation achieved better performance than several methods in the literature with a mean accuracy value of 95.04% and mean sensitivity value of 75.16% on DRIVE and mean accuracy value of 94.02% and average sensitivity value of 76.55% on STARE with computational processing time of 4.5 seconds and 9.4 seconds on DRIVE and STARE respectively. The MLP-ANN method proposed for the vascular network tortuosity characterization achieves promising accuracy rates of 77.5%, 80%, 83.33%, 85%, 86.67% and 100% for varying training sample sizes.

Abstract: Ultrastructural characteristic and morphological changes of untreated and treated breast cancer MCF-7 cells were observed by energy-filtered transmission electron microscope (EFTEM). Morphological observation of MCF-7 after being treated with 13 nm, 50 nm, and 70 nm AuNPs, were looking unhealthy and dying out of the populace, the observed cells were more reduced and dying as treatment with 50 nm and 70 nm AuNPs. Cells detachment, clumping, shrunken, and dispersed cells in the culture medium and floating cells were also observed. The observed morphological changes increase in 50 nm and 70 nm AuNPs than in 13 nm AuNPs, which is less toxic to MCF-7 cells. The presented morphological analysis has established that 13 nm AuNPs showed less toxic to MCF-7 breast cancer cells. Whereas, control cells of MCF-7 were treated with only complete culture media, despite the duration of treatment, whereby the cells maintained most of their morphological features and observed to have a typical morphology of healthy cells that are well attached to the surface. These results indicate that AuNPs were clustered in the cells and there was no significant difference between images of different sizes of AuNPs observed in the cells, because the AuNPs always clustered together inside the cells.

Abstract: Fiber reinforced composite material is used widely in oil fields for its high specific strength and resistance to corrosion. Glass reinforced plastics (GRP) and Glass reinforced epoxy (GRE) pipe samples were investigated under oil field conditions. The samples were subjected to ultraviolet radiation, moisture and elevated temperature using accelerating weathering machine and then aged in different environments encountered in oil well streams and characterized by using Scanning Electron Microscopy (SEM). The surface morphology was analyzed and the images produced from wet crude and effluent water has shown different degree of deformation of the glass fiber and debonding with the polymer matrix. The tensile and modulus properties were also evaluated and effect of ageing found to be more pronounced in the case of wet crude especially for the GRE. The study revealed some tendency of GRP samples to reform the polymer matrix interface with the glass fiber after weathering. The assessment of physical properties provided information about the structural stability of composite pipes under harsh environments, which in turn can impact their overall performance and service life.

Abstract: Mg doped Zinc oxide nanorods films were successfully deposited on glass substrate prepared by aqueous solution-immersion method. The influence of annealing temperature on the nanorod films were studied at different annealing temperatures 0°C, 250°C and 500°C respectively. FESEM showed the morphology of the films with hexagonal nanorods growth. XRD results indicated the crystalline structure of ZnO doped Mg nanorods films where the peak intensity of ZnO was decreased as annealing temperature increases. Photoluminescence (PL) measurement at room temperature showed the increasing of intensity peak for visible spectra with increasing of annealing temperature.

Abstract: Sol gel immersion method has been used to synthesize magnesium doped zinc oxide (Mg:ZnO) thin film on glass substrate. The morphological of annealed thin film was study using atomic force microscopy (AFM) while UV-Visible spectroscopy was used to examine the optical transmittance properties. The optical band gap was estimated by using Tauc’s method. From the results, the surface roughness was change as annealing temperature increases. The increasing of annealing temperature also affects the transmittance spectra which are shifted to lower wavelength. The optical band gaps of the thin film were varied due to different annealed temperature.

Abstract: The purpose of this paper is to study the morphological characterization of aluminum interdigitated electrodes (IDE) of different gap sizes on silicon substrate. The electrodes were fabricated using standard photolithography process and were done so with sizes of 12 μm, 10 μm and 7 μm. The electrodes were morphologically characterized using scanning electron microscope (SEM) and high-powered microscope (HPM).Keywords: morphological, interdigitated electrodes, aluminum

Abstract: In the current research we have studied the structural, morphological, optical and ultraviolet (UV) light sensing properties of ZnO thin film. The film was prepared by sol-gel technique and deposited on glass substrate by spin coating method. The structural analysis was performed by X-ray diffractometer (XRD) while the surface morphology and optical properties of the deposited thin film were monitored using field emission scanning electron microscope and UV-VIS spectrophotometer. The FESEM image displayed the homogenous coverage of ZnO nanoparticles over the surface of glass substrate. The deposited thin film shows an average transmittance value of more than 90%, in the visible light spectrum. The calculated value for optical band-gap was 3.26 eV. Refractive indices and dielectric constants were calculated by utilizing the bandgap value by considering different relations. Current to voltage characterization was conducted by using Kiethley sourcemeter connected with ultraviolet (UV) light illuminated LED’s. The excellent photo to dark current (Iph/Id) ratio (5.49) and rapid rise and decay time (15 s and 6 s) and the measured responsivity (1 A/W) suggest that the deposited ZnO thin film can be used for ultraviolet (UV) light sensing application.

Abstract: Iron (Fe) doped ZnO nanorods were synthesized on glass substrate using a sol-gel hydrothermal growth method by adopting various concentration ratios of 0.8 at% Fe, 1 at% Fe and 3 at% Fe respectively. The X-ray diffraction (XRD) analysis show that all the grown ZnO nanorods have a hexagonal wurtzite structure and are preferentially oriented along the c-axis perpendicular to the substrate surface. At 3 at% Fe-doping, the crystalline quality and the preferential orientation of ZnO nanorods are improved and below 3 at% Fe-doping concentration crystalline quality and the preferential orientation of ZnO nanorods is weakened in turn. The surface morphology analysis of the samples show that the ZnO nanorods are grown vertically to the substrate surface and highly interconnected. Such interconnected network will facilitates the electron transport along the nanorods axis. Current-voltage and current-time characterization under the exposure of UV light ON/OFF sates with exhibited excellent current gain of 1.12 and good response/recovery time of 30 and 10 s showed that the fabricated device can be used for UV sensing applications.