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Modern automotive designs are needed to increase mechanical and thermal loads that have longer lifespans and are lighter. The power transmissions and motors often use low-friction hard coatings to prevent wear and reduce friction. The Cr-doped graphite-like carbon method is employed for evaluating coating friction and responses to chromium-doped graphite-like carbon (Cr-GLC) under lubrication. Cr-GLC coatings and chromium-doped diamond-like carbon (Cr-DLC) coatings are arranged using physical vapor deposition (PVD) and plasma-enhanced chemical vapor deposition (PECVD), respectively. The results have demonstrated in comparison to the dry friction coefficient, the friction coefficient under lubrication conditions has been reduced by 40%. Due to its excellent frictional physicochemical properties and compact microstructure, Cr-DLC has an optimum tribological resistance that is significantly higher than that of Cr-GLC. Viscosity, corrosivity, and coating microstructure are used to measure the impact of composite elements. The most ideal characteristics of the Cr-GLC coating are attributed to the non-reaction of additives in oil with friction surfaces.

The total mass attenuation coefficient of trichloride gadolinium has been investigated utilizing Geant4 compared with WinXCom simulation data at energies; 1–10 MeV. The simulated results are used to calculate the total cross section, atomic and electronic cross sections. The aim of this work is to characterize new materials and their interactions with radiation in order to be able for using in shielding or detection. The GdCl3 is applied for super–Kamiokande detector of neutrons. From our comparison study, it is found that the mass attenuation coefficient of GdCl3 with those of two detectors of X-ray (Si and CdTe) is very closed. Also, the total mass transfer attenuation coefficient increases as high energies increases at pairs effect production. From our comparison study, we can predict that GdCl3 can be a good detector of X-ray and concluded that this material has shown good interaction with electromagnetic radiations at high energies.

Abstract Piezoelectric microelectromechanical system (piezo-MEMS)-based mass sensors including the piezoelectric microcantilevers, surface acoustic waves (SAW), quartz crystal microbalance (QCM), piezoelectric micromachined ultrasonic transducer (PMUT), and film bulk acoustic wave resonators (FBAR) are highlighted as suitable candidates for highly sensitive gas detection application. This paper presents the piezo-MEMS gas sensors’ characteristics such as their miniaturized structure, the capability of integration with readout circuit, and fabrication feasibility using multiuser technologies. The development of the piezoelectric MEMS gas sensors is investigated for the application of low-level concentration gas molecules detection. In this work, the various types of gas sensors based on piezoelectricity are investigated extensively including their operating principle, besides their material parameters as well as the critical design parameters, the device structures, and their sensing materials including the polymers, carbon, metal–organic framework, and graphene.

The structural properties and characteristics of date palm fiber-based low-cost carbon nanotubes (CNTs) and nanostructured powder activated carbon (DP-NPAC) are investigated. The DP-NPAC and CNTs are prepared using an environmentally friendly method, and characterized and analyzed using field emission-scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results have showed that both DP-NPAC and CNTs possess crystallite structure, nano-scale, high capacity, cost-effective for multi-application that make them efficient for future fabrication and manufacturing. It is supposed that DP-NPAC biomass is to be used as potential and cost-effective precursor for synthesized CNTs.

Green technique or chemical co-precipitation technique has been employed to synthesize the MgZnFe2O3, CoZnFe2O3 and NiZnFe2O3 quaternary alloys nanoparticles. The structural properties are investigated by X-ray diffraction (XRD) to determine structural parameters and crystallite size. XRD peaks index numbers and intensities are varied with the atomic number. The study of morphology for the mentioned quaternary alloys nanoparticles is analyzed by scanning electron microscopy (SEM) to measure the grain size. The optical properties are investigated via ultraviolet–visible (UV–vis) and Fourier-transform infrared spectroscopy (FTIR) to reveal the changing of absorption, transmission, reflection and bandgap as the atomic number changes for verifying optical dielectric constant and refractive index models. The obtained results suggest that MgZnFe2O3, CoZnFe2O3 and NiZnFe2O3 quaternary alloys nanoparticles are very suitable for potential application in optoelectronics and antibacterial treatment.

Nanostructure such as quaternary alloy offers an unprecedented opportunity for alloy composition control in a wide range, unavailable with traditional epitaxial film materials. The technique of chemical co-precipitation has been employed to synthesize the NiZnFe2O3 quaternary alloy nanostructure, which is cost-effective and friendly environmentally. The study of morphology for the mentioned NiZnFe2O3 quaternary alloy nanostructure is elaborated by scanning electron microscopy (SEM) to measure the grain size. The optical properties are investigated via UV-visible spectrophotometry (UV-vis) and Fourier-transform infrared spectroscopy (FTIR) to research the absorption, transmission, reflection and bandgap for the mentioned NiZnFe2O3 quaternary alloy nanostructure, also, for verifying optical dielectric constant and refractive index models using specific empirical models. The grains size and energy gap are investigated to recommend the suitability results for NiZnFe2O3 quaternary alloy nanostructure. Finally, Ravindra et al. models are an appropriate for potential application in optoelectronics.

Biosensor devices hold great potential for various applications in detecting disease and monitoring disease progression. Electrochemical biosensors represent an important subclass of chemical sensors, they are extremely inexpensive, rapid and sensitive. Aluminium nanoparticle doped zinc oxide nanostructure based integrated electrochemical biosensor has been designed and developed for the dengue virus’s diagnosis. By utilizing a hard mask and thermal evaporator systems (PVD), interdigitated electrode (IDE) is designed with Ag (silver) and integrated on Si-AZO. The platform of fabricated (IDE(Ag)/AZO/Si) is functionalized involving DNA immobilization, hybridization and surface modification to set up electrical detection for DNA probe specific to dengue in concentrations, 100 fM, 100 pM, 10 nM and DNA probe. The sensitivity of wide ranged detected achieved is 55.54 μA nM−1 cm−2, as well as for limit detection, 15.46 μA nM−1 and limit quantification, 51.53 μA nM−1. Also, it is extracted, 0.0604 μA nM−1, the linear regression 0.8563 and the standard deviation of current is 0.34 μA. Our biosensors device is fast and highly effective; thus, it may potentially assist future advances in the diagnosis of dengue viruses.

The benefits of the electrical-based biosensor include cheap production and fast response time of detecting diseases. An interdigitated electrode (IDE) is fabricated using silver (Ag) as a metal contact that is deposited on aliminium (Al) nanoparticles doped with both zinc oxide (ZnO) and Silicon (Si) forming AZO/Si nanostructures by vacuum coater in a thermal evaporator. The electrical properties are studied as a function of frequency and voltage using I–V characteristics. Sol–gel method under annealing temperature, 500 °C is utilized to generate Al nanoparticles doped ZnO nanostructures. UV–vis spectrophotometer, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD) are used for analyzing optical, topographical, morphological and structural studies of AZO nanostructure, respectively. Specific empirical models of optical dielectric constant, bulk modulus and refractive index are also verified. PACS: 75.75.Fk, 77.55.hf, 87.85.fk, 88.10.gp, Keywords: AZO, Sol–gel method, Characterization, Optical

Chemicals and pesticides contamination in the food, drinking water, and environment ecosystem have become one of the most serious problems for human public health in the world due to their large amount used and wide application in the agriculture industry. Therefore, the detection and analysis of contamination in the food and drinking water by using techniques that are simple and suitable for fast screening are important. This review gives an overview of the last trends and recent advances biosensors for chemicals and pesticides detection based on electrochemical, optical and mechanical transducers strategies. Furthermore, the biosensors are classified according to their immobilized biorecognition elements including aptamer, antibodies, enzymes, and molecularly imprinted polymers. The implementation of nanomaterials such as graphene, carbon nanotubes, and metals nanoparticles are also emphasized and discussed in this review, these nanomaterials provides remarkable features to the biosensors such highly sensitive and accurate which allowing efficient pesticides detection. In addition to highlighting and summarizing various novel sensors, this review also provided some drawbacks, challenging, prospects as well as the current efforts to enhanced optical sensors.

Saudi Arabia is enriched by geothermal resources and related to the tectonic activity of Red Sea, volcanic rocks and ridges. The geothermal energy reserve, potential and their reserve for possible energy production are investigated. Nowadays, production process of crude oil accompanied with flaring of gases result in excessive CO2 emissions. If the growth rate of national oil consumption continues, local demand will be doubled within a decade. The study of geothermal energy is covered. A selection of possible applications of geothermal futures is discussed. Furthermore, the study has focused on necessity of maintaining green and clean environment as well as climate of lowest dust content. Keywords: Geothermal, Energy, Potential, Saudi Arabia

Abstract The impact of ionic liquid (IL) solution on the recycling process of polyethylene terephthalate (PET) waste containers used to store drinking water, with a focus on optimizing the added percentage and processing conditions of IL was studied. Characterization using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), Fourier transform infrared spectroscopy (FTIR) and nano-indentation tests were performed. Generally, an increase in the degradation temperatures was observed with increasing IL%. Since they were quite comparable, their good thermal stability could be considered. An increase in the hardness was noticed from 0.41 at 0% to 0.45 at a 2% IL solution. A rise in the modulus of elasticity was also observed from 5.5 GPa at 0% to 8 GPa at 2% IL solution. Although there has been some improvement in the properties of the IL blends, limitations such as IL cost and their effective recycling remains a challenge and needs more efforts to fully explore their potential.

Zinc oxide has been synthesized using sol-gel method with different Al nanoparticles (40, 70 and 100 nm). It has been analysed and characterized by UV–vis, X-ray diffraction (XRD), atomic force microscopy (AFM) and Scanning Electron Microscopy (SEM), respectively. It has been revealed that Al nanoparticles (Al NPs) affect ZnO’s particle size, thickness, roughness, bulk modulus, energy gap, absorbance and transmittance. The optical band gap is varied with Al nanoparticles. The bulk modulus has been calculated to investigate the stiffness of AZOs. Our measured values are in good agreement with other data available in the literature. Keywords: ZnO, Nanoparticles, Analysis, Characterization

Eddy current testing plays an important role in numerous industries, particularly in material coating, nuclear and oil and gas. However, the eddy current testing technique still needs to focus on the details of probe structure and its application. This paper presents an overview of eddy current testing technique and the probe structure design factors that affect the accuracy of crack detection. The first part focuses on the development of different types of eddy current testing probes and their advantages and disadvantages. A review of previous studies that examined testing samples, eddy current testing probe structures and a review of factors contributing to eddy current signals is also presented. The second part mainly comprised an in-depth discussion of the lift-off effect with particular consideration of ensuring that defects are correctly measured, and the eddy current testing probes are optimized. Finally, a comprehensive review of previous studies on the application of intelligent eddy current testing crack detection in non destructive eddy current testing is presented.

Lubricated pin-on-disk sliding wear tests were performed on applied to Al-0.1Mg-0.35Ni-Si Alloy by using the spray coating method has been investigated. Different loads were 5, 10, and 15 N at a sliding velocity, 1.32 m/s at room temperature and 60% relative humidity. The surfaces were analyzed by using X-ray diffraction the residual (XRD), energy dispersive (EDS), scanning of (SEM) and (AFM), respectively. The results have showed that the thickness of Cr2O3 coating was significantly related under the identical cold spray condition. These methods have contributed much of the understanding of quality and properties of surfaces. The (Cr2O3) coating has great potential as a wear-resistant. The hardness increased from 102 ± 5 HV to 116.4 ± 2.5 HV at coating thickness 45 µm and friction coefficient reduced from 0.29 to 0.24; and the wear rate was about 2.11X10-13 m3N-1m-1 while hardness was increased from 102 ± 5 HV to 108 ± 3.5 HV at coating thickness 15 µm. The friction reduced from 0.31 to 0.29 at same coating thickness alloys, and the wear rate was about 2.73X10-13 m3N-1m-1. The tribological properties of Cr2O3 coating have exhibited low friction and beneficial to improve the adhesion which was clear on worn surfaces of Cr2O3 coating. Crack, powder flocculation and powder formation are caused by the wear mode of the surface. Brittle fracture was found; while, adhesion and oxidation are the main mechanism of wear during the test.

The fabrication of an optical waveguide by designing the device and using a positive photoresist via photo lithography (ultraviolet light) to transfer the pattern of the sample has been studied. A direct coupler method was used to investigate a different wavelength pointer laser beam coupled with a fiber-fiber test coupling coupler employing different wavelength lasers ≈5 mW to measure propagation loss and lattice mismatch. The speed of light and numerical aperture were correlated with refractive index. The result showed a good efficiency of laser transfer to fabricate the optical waveguide.

This research deals with the effect of the temperature on the physical, thermal, electrochemical, and adsorption properties of the carbon micro-spheres using hydrothermal carbonization (HTC). Until recently, limited research has been conducted regarding the effects of delignification during the HTC process of biomass residues especially Dimocarpus longan. In this regard, lignin was first extracted from the lingo-cellulosic waste of Longan fruit peel (Dimocarpus longan). The holocellulose (HC) separated from lignin and raw biomass substrates (Longan fruit exocarp/peel powder, LFP) were carbonized at different temperatures using water as the green catalyst. Hydrothermal carbonization (HTC) was performed for both of the samples (LFP and HC) at 200 °C, 250 °C, and 300 °C for 24 h each. The surface morphological structures, the porosity, and the Brunauer-Emmett-Teller (BET) surface area of the prepared micro-spherical carbon were determined. The BET surface areas obtained for HC-based carbon samples were lower than that of the raw LFP based carbon samples. The carbon obtained was characterized using ultimate and proximate analyses. The surface morphological features and phase transformation of the synthesized micro-spherical carbon was characterized by a field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. The results demonstrated that the extraction of lignin could significantly alter the end properties of the synthesized carbon sample. The carbon spheres derived from LFP showed a higher carbon content than the HC-based carbon. The absence of lignin in the holo-cellulose (HC) made it easy to disintegrate in comparison to the raw, LFP-based carbon samples during the HTC process. The carbonaceous samples (LFP-300 and HC-300) prepared at 300 °C were selected and their adsorption performance for Pb (II) cations was observed using Langmuir, Freundlich, and Temkin linear isotherm models. At 30 °C, the equilibrium data followed the Langmuir isotherm model more than the Freundlich and Temkin model for both the LFP-300 sample and the HC-300 sample. The potential of the synthesized carbon microspheres were further analyzed by thermodynamic characterizations of the adsorption equilibrium system.