GaN thin films were deposited by thermal evaporation onto
glass substrates at substrate temperature of 403 K and a thickness of
385 nm . GaN films have amorphous structure as shown in X-ray
diffraction pattern . From absorbance data within the range ( 200-
900 ) nm direct optical energy gap was calculated . Also the others
optical parameters like transmittance T, reflectance R , refractive
index n , extinction coefficient k , real dielectric constant 1 Î , and
imaginary dielectric constant 2 Î were determined . GaN films
have good absorbance and minimum transmittance in the region of
the visible light .
The local asphalt concrete fracture properties represented by the fracture energy, J-integral, and stress intensity factor are calculated from the results of the three point bending beam test made for pre notches beams specimens with deformation rate of 1.27 mm/min. The results revealed that the stress intensity factor has increased by more than 40% when decreasing the testing temperature 10˚C and increasing the notch depth from 5 to 30mm. The change of asphalt type and content have a limited effect of less than 6%.
Cadmium Oxide thin films were deposited on glass substrate by spray pyrolysis technique at different temperatures (300,350,400, 500)oC. The optical properties of the films were studied in this work. The optical band-gap was determined from absorption spectra, it was found that the optical band-gap was within the range of (2.5-2.56)eV also width of localized states and another optical properties.
In the present work, lead silicate glasses have been prepared with
different amount of lead oxide content. Structure properties such as
X-ray diffraction, AFM, and FTIR analyses have been done. The
exceeding of PbO content more than 25wt% revealed a decreasing in
density. The X- ray revealed that the strongest peak related to
Hexagonal silica dioxide and the other crystal phases formed were
related to silica oxide (SiO2) and lead oxide (PbO). Growth and
decayed phases in X-ray have been observed with changing lead
oxide content. Homogeneous surface was obtained using AFM
analyzer with an average diameter around 100 nm. Infrared spectrum
is characterized by the presence of large absorption band between
120
The cost‐effective dual functions zeolite‐carbon composite (DFZCC) was prepared using an eco‐friendly substrate prepared from bio‐waste and an organic adhesive at intermediate conditions. The green synthesis method used in this study ensures that chemically harmless compounds are used to obtain a homogeneous distribution of zeolite over porous carbon. The greenly prepared dual‐function composite was extensively characterized using Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, N2 adsorption/desorption isotherms, field emission scanning electron microscope, dispersive analysis by X‐ray, and point of zero charges. DFZCC had a surface area o
In this study, zinc oxide was prepared by pulsed laser ablation method (PLAL), which is an easy-to-use and inexpensive physical method. The optical properties were studied using UV-Vis spectrometers, structure properties by (XRD) to calculate the crystalline size, and particle size determination by Field emission scanning electron microscopy (FE-SEM) and (EDS), transmission electron microscopy (TEM) assays and it was proved that they are within the ideal nanoscale for biological application. These ZnO NPs were employed on the inhibitory activity of different types of Gram-positive and Gram-negative bacteria, as well as on fungi, and it was noted their ability to penetrate the bacterial cell wall and inhibit its action.
Photocatalytic materials are being investigated as effective bactericides due to their superior ability to inactivate a broad range of dangerous microbes. In this study, the following two types of bacteria were employed for bactericidal purposes: Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). The shape, crystal structure, element percentage, and optical properties of Ag9(SiO4)2NO3 were examined after it was successfully synthesized by a standard mixing and grinding processing route. Bactericidal efficiency was recorded at 100% by the following two types of light sources: solar and simulated light, with initial photocatalyst concentration of 2 µg/mL, and 97% and 95% of bactericidal acti
... Show MoreSolar hydrogen line emission has been observed at the frequency of 1.42 GHz (21 cm wavelength) with 3m radio telescope installed inside the University of Baghdad campus. Several measurements related to the sun have been conducted and computed from the radio telescope spectrometer. These measurements cover the solar brightness temperature, antenna temperature, solar radio flux, and the antenna gain of the radio telescope. The results demonstrate that the maximum antenna temperature, solar brightness temperature, and solar flux density are found to be 970 K, 49600K, and 70 SFU respectively. These results show perfect correlation with recent published studies.
In this paper, a national grid-connected photovoltaic (PV) system is proposed. It extracts the maximum power point (MPP) using three-incremental-steps perturb and observe (TISP&O) maximum power point tracking (MPPT) method. It improves the classic P&O by using three incremental duty ratio (ΔD) instead of a single one in the conventional P and O MPPT method. Therefore, the system's performance is improved to a higher speed and less power fluctuation around the MPP. The Boost converter controls the MPPT and then is connected to a three-phase voltage source inverter (VSI). This type of inverter needs a high and constant input voltage. A second-order low pass (LC) filter is connected to the output of VSI to reduce t
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