Showing 667 results for Type of Study: Research Paper
Mahnaz Dashti, Saeid Baghshahi, Arman Sedghi, Hoda Nourmohammadi,
Volume 21, Issue 3 (9-2024)
Abstract
Abstract
The power line insulators are permanently exposed to various environmental pollutants such as dust and fine particles. This may lead to flashovers and therefore widespread power blackouts and heavy economic damage. One way to overcome this problem is to make the insulator surface superhydrophobic. In this research, the superhydrophobic properties of the insulators were improved by applying room-temperature cured composite coatings consisting of epoxy and hydrophobic nano-silica particles. Either octadecyl trichlorosilane (ODTS) or hexamethyldisilazane (HMDS) was used to coat the silica nanoparticles and make them hydrophobic. Then, the hydrophobic silica was added to a mixture of epoxy resin and hardener. The suspension was applied on the surfaces of a commercial porcelain insulator and cold cured at ambient temperature. The coating increased the water contact angle from 50° to 149°. Even after 244 h exposure to the UV light, the samples preserved their hydrophobic properties. The adhesion of the coating was rated as 4B according to the ASTM D3359 standard. The coating decreased the leakage current by 40% and increased the breakdown voltage by 86% compared to the uncoated sample and showed promise for making power line insulators self-cleaning.
Tumelo Moloi, Thywill Cephas Dzogbewu, Maina Maringa, Amos Muiruri,
Volume 21, Issue 3 (9-2024)
Abstract
The stability of microstructure at high temperatures is necessary for many applications. This paper presents investigations on the effect of changes in temperature on the microstructures of additively manufactured Ti6Al4V(ELI) alloy, as a prelude to high temperature fatigue testing of the material. In the present study, a Direct Metal Laser Sintering (DMLS) EOSINT M290 was used to additively manufacture test samples. Produced samples were stress relieved and half of these were then annealed at high temperatures. The samples were then heated from room temperature to various temperatures, held there for three hours and thereafter, cooled slowly in the air to room temperature. During tensile testing, the specimens was heated up to the intended test temperature and held there for 30 minutes, and then tensile loads applied to the specimens till fracture. Metallographic samples were then prepared for examination of their microstructures both at the fracture surfaces and away from them. The obtained results showed that changes in temperature do have effects on the microstructure and mechanical properties of Ti6Al4V(ELI) alloy. It is concluded in the paper that changes in temperature will affect the fatigue properties of the alloy.
Hossein Momeni, Sasan Ranjbar Motlagh,
Volume 21, Issue 3 (9-2024)
Abstract
The present work deals with the hot deformation behavior of commercial Nb alloy C-103 and its microstructure evolution during uniaxial compression tests in the temperature range of 700-1100 °C and the strain rate range of 0.001-0.4 s-1. Strain rate sensitivity, calculated from the compression tests data, was almost constant and showed a negative value in the temperature range of 700-900 °C but increased significantly beyond 900 °C. Dynamic strain aging was found to have a predominant effect up to 900 °C, beyond which dynamic recovery and oxidation influenced the compressive properties. The microstructure of the deformed samples showed indications of dynamic recrystallization within the high strain rate sensitivity domain and features of flow instability in the regime of low strain rate sensitivity. The 950–1000 °C temperature range and strain rate range of 0.001-0.1 s-1 were suggested as suitable hot deformation conditions. The constitutive equation was established to describe the alloy's flow behavior, and the average activation energy for plastic flow was calculated to be 267 kJ/mol.
Tushar Wagh, Sagar Mane, Gotan Jain, Madhavrao Deore,
Volume 21, Issue 3 (9-2024)
Abstract
Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe2 nanoparticles by hydrothermal method. The ZrSe2 nanoparticles were synthesis using precursors such as ZrOCl2.8H2O and Na2SeO3.5H2O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe2 nanopowder thick films were developed on a glass substrate
using the screen printing method. The structural properties of ZrSe2 powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe2 were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe2 nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe2 thick films were studied. The developed ZrSe2 thick films show maximum sensitivity and selectivity towards the ammonia NH3 gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe2 nanoparticles by hydrothermal method. The ZrSe2 nanoparticles were synthesis using precursors such as ZrOCl2.8H2O and Na2SeO3.5H2O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe2 nanopowder thick films were developed on a glass substrate
using the screen printing method. The structural properties of ZrSe2 powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe2 were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe2 nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe2 thick films were studied. The developed ZrSe2 thick films show maximum sensitivity and selectivity towards the ammonia NH3 gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.
Ahmad Ostovari Moghaddam, Olga Zaitseva, Sergey Uporov, Rahele Fereidonnejad, Dmitry Mikhailov, Nataliya Shaburova, Evgeny Trofimov,
Volume 21, Issue 3 (9-2024)
Abstract
High entropy intermetallic compounds (HEICs) are an interesting class of materials combining the properties of multicomponent solid solutions and the ordered superlattices in a single material. In this work, microstructural and magnetic properties of (CoCuFeMnNi)Al, (CoCuFeMnNi)Zn3, (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs fabricated by induction melting are studied. The magnetic properties of the HEICs was determined mainly by the nature of the magnetic momentum of the constituent elements. (CoCuFeMnNi)Al and (CoCuFeMnNi)Zn3 displayed ferromagnetic behavior at 5 K, while indicated linear dependency of magnetization vs. magnetic (i.e. paramagnetic or antiferromagnetic state) at 300 K. The magnetization of (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs at 300 K exhibited a nearly linear dependency to magnetic field. Among all the investigated samples, (CoCuFeMnNi)Al exhibited the best magnetic properties with a saturation magnetization of about Ms = 6.5 emu/g and a coercivity of about Hc = 100 Oe.
Faraz Hussain, Muhammad Umar Manzoor, Muhammad Kamran, Tahir Ahmad, Fahad Riaz, Sehrish Mukhtar, Hafiz Muhammad Rehan Tariq, Muhammad Ishtiaq,
Volume 21, Issue 3 (9-2024)
Abstract
Magnesium alloys are increasingly valued for biomedical applications due to their biocompatibility. This study investigates Mg-AZ31B alloy samples treated with quartz and alumina grits (<200 μm) at varied pressures, followed by anodization in an eco-friendly alkaline electrolyte. The results show that increased blasting pressure produces a rougher surface. Anodization time significantly affects the thickness of the anodic film, leading to a transition in surface morphology from fine to coarse structures with complete film coverage. Characterization by XRD reveals that the anodic film mainly comprises magnesium oxide and hydroxide phases. Open Circuit Potential (OCP) measurements demonstrate enhanced corrosion resistance post-anodization, particularly notable at 40 minutes on alumina-blasted samples. ANOVA confirms that both blasting pressure and anodization time significantly influence coating thickness and OCP, indicating the formation of a dense anodized layer.
Umadevi Prasanna, Vijaya Kumar Kambila, Krishna Jyothi Nadella,
Volume 21, Issue 4 (12-2024)
Abstract
The composite solid polymer electrolyte films were prepared by doping nano-sized Fe2O3 particles on PVB (Polyvinyl Butyral) complexed with NaNO3 salt by solution casting technique. FTIR, XRD, and SEM methods characterized these electrolyte films. The Fourier Transform Infrared Spectroscopy and X-ray diffraction methods reveal the structural and complexation changes occurring in the electrolytes. The surface morphology of the electrolyte film was examined using the SEM (Scanning Electron Microscope) technique. The PVB+NaNO3+Fe2O3(70:30:3%) electrolyte shows a moderate ionic conductivity of 2.51×10−5 S cm−1 at ambient temperature (303 K). AC impedance spectroscopic analysis evaluates the ionic conductivity of the produced polymer electrolyte. Wagner's polarisation technique was applied to study the charge transport characteristics in the electrolyte films. The investigation revealed that ions constituted the majority of the transport carriers. An Open Circuit Voltage (OCV) of 2.0V and a Short Circuit Current (SCC) of 0.8 mA were found in the discharge characteristics data for the cell constructed with the polymer electrolyte sample.
