In this research an experimental study has done for testing the thermal performance of selective surfaces used in solar collectors for substrate of iron, galvanized iron and aluminum which are commercially available. The coating process for the samples has done in two ways, the electroplating and the chemical spray pyrolysis. The results of the thermal performance test of these samples are comparing with the thermal performance of a sample without paint and other paint with black paint without shines commercially available. For the electroplated samples, the performance study has done for different immersion time in plating bath, the
distance between electrical poles, the current density, and area ratio of the sample plated area to the nickel pole face area. The chemical sprayed pyrolysis samples, study has done for different coating times, atomizing gas pressures, distance between the aperture of atomizer and the sample and the paint mass flow rate. The results showed that the best performance of the iron's
samples is the sample which is coated with two layers. The first layer is of zinc done by electroplating where the time of plating is (2 min.) and the second layer is of black nickel done by electroplating, where the time is (20 min.), the distance between the poles is (6 cm), the current density is (0.15 A/dm2 ) and area ratio of the sample plated area to the nickel pole face area is equal to (1). The percentage of the increasing in heat storage of electroplating sample to galvanized iron sample without paint at the beginning of testing the performance of samples and at the end were (58.23%& 44.97%) respectively. For aluminum samples, the best performance was regarded for two samples electroplating sample and chemical spray pyrolysis sample. The best electroplating sample was coated with a layer of black nickel where the time of plating is (20 min.), the distance between the poles is (6 cm), the current density is (0.15 A/dm2) and area ratio of the sample plated area to the nickel pole face area is equal to (1). While the best chemical spray pyrolysis sample has been coated with a layer of black nickel where the time of plating is (16 sec.) and the distance between the aperture of the reservoir and the surface of the sample is (27 cm), the amount of flow is (4.8 ml / min.), the atomizing gas pressure is (1 bar) and temperature of the sample surface is (290 0C).
Pultruded materials made of Fiber-Reinforced Polymer (FRP) come in a broad range of shapes, such as bars, I-sections, C-sections, etc. FRP materials are starting to compete with steel as structural materials owing to their great resistance, low self-weight, and cheap maintenance costs, especially in corrosive conditions. This study aims to evaluate the effectiveness of a novel concrete Composite Column (CC) using Encased I-Section (EIS) as a reinforcement in contrast to traditional steel bars by using Glass Fiber-Reinforced Polymer (GFRP) as I-section (CC-EIS) to evaluate the effectiveness of the hybrid columns which have been built by combining GFRP profiles with concrete columns. To achieve the aims of this study, nine circular co
... Show MoreDuring COVID-19, wearing a mask was globally mandated in various workplaces, departments, and offices. New deep learning convolutional neural network (CNN) based classifications were proposed to increase the validation accuracy of face mask detection. This work introduces a face mask model that is able to recognize whether a person is wearing mask or not. The proposed model has two stages to detect and recognize the face mask; at the first stage, the Haar cascade detector is used to detect the face, while at the second stage, the proposed CNN model is used as a classification model that is built from scratch. The experiment was applied on masked faces (MAFA) dataset with images of 160x160 pixels size and RGB color. The model achieve
... Show MoreThe present paper addresses cultivation of Chlorella vulgaris microalgae using airlift photobioreactor that sparged with 5% CO2/air. The experimental data were compared with that obtained from bioreactor aerated with air and unsparged bioreactor. The results showed that the concentration of biomass is 0.36 g l-1 in sparged bioreactor with CO2/air, while, the concentration of biomass reached to 0.069 g l-1 in the unsparged bioreactor. They showed also that aerated bioreactor with CO2/air gives more biomass production even the bioreactor was aerated with air. This study proved that application of sparging system for cultivation of Chlorella vulgaris microalgae using either CO2/air mixture or air has a significant growth rate, since the biorea
... Show MoreTime-domain spectral matching commonly used to define seismic inputs to dynamic analysis in terms of acceleration time history compatible with a specific target response spectrum is used in this study to investigate the second-order geometric effect of P-delta on the seismic response of base-isolated high-rise buildings. A synthetic time series is generated by adjusting reference time series that consist of available readings from a past earthquake of the 1940 El Centro earthquake adopted as an initial time series. The superstructure of a 20-story base isolated building is represented by a 3-D finite element model using ETABS software. The results of the base isolated building show that base isolation technique significantly reduces inter-s
... Show MoreThe approach of green synthesis of bio-sorbent has become simple alternatives to chemical synths as they use for example plant extracts, plus green synthesis outperforms chemical methods because it is environmentally friendly besides has wide applications in environmental remediation. This paper investigates the removal of ciprofloxacin (CIP) using green tea nano zero-valent iron (GT-NZVI) in an aqueous solution. The synthesized GT-NZVI was categorized using SEM, AFM, BET, FTIR, and Zeta potentials techniques. The spherical nanoparticles were found to be nano zero-valent, with an average size of 85 nm and a surface area of 2.19m2/g. The results showed that the removal efficiency of ciprofloxacin depends on the initial pH (2.5-10),
... Show MoreA new simple and sensitive spectrophotometric method for the determination of trace amount of Co(II) in the ethanol absolute solution have been developed. The method is based on the reaction of Co(II) with ethyl cyano(2-methyl carboxylate phenyl azo acetate) (ECA) in acid medium of hydrochloric acid (0.1 M) givining maximum absorbance at ((λmax = 656 nm). Beer's law is obeyed over the concentration range (5-60) (μg / ml) with molar absorptivity of (1.5263 × 103 L mol-1 cm-1) and correlation coefficient (0.9995). The precision (RSD% ˂ 1%). The stoichiometry of complex was confirmed by Job's method which indicated the ratio of metal to reagent is (2:1). The studied effect of interference elements Zn(II), Cu(II), Na(I), K(I), Ca(II) and Mg
... Show MoreIn this work a model of a source generating truly random quadrature phase shift keying (QPSK) signal constellation required for quantum key distribution (QKD) system based on BB84 protocol using phase coding is implemented by using the software package OPTISYSTEM9. The randomness of the sequence generated is achieved by building an optical setup based on a weak laser source, beam splitters and single-photon avalanche photodiodes operating in Geiger mode. The random string obtained from the optical setup is used to generate the quadrature phase shift keying signal constellation required for phase coding in quantum key distribution system based on BB84 protocol with a bit rate of 2GHz/s.