Showing 671 results for Type of Study: Research Paper
Ghada Ben Salah,
Volume 21, Issue 3 (9-2024)
Abstract
This study reported the biological changes occurring after γ-irradiation of in vivo rat model and the osteochondral protective effect of Gelatine-Chitosan-Ginger (GEL-CH-GING). The results showed that Electron Paramagnetic Resonance (EPR) Spectroscopy of GEL-CH-GING showed two paramagnetic centres which correspond to g=2.19 and g= 2.002. The Fourier transform infrared spectroscopy (FTIR) analyses revealed an increase in peak intensity at C–H chains, as well as, C=O carbonyl groups. The X-ray diffraction (XRD) analysis showed no change of crystallinity. After gamma ray exposure, the rat groups have received an osteochondral defect and then were treated with GEL-CH-GING composite. Sixty days post-surgery, a significant reduction in thiobarbituric acid-reactive compounds (TBARs) was seen when compared to non-implanted rat group. Concerning oxidative stress status, GEL-CH-GIN significantly improved Superoxide Dismutase (SOD) 76 nmol/l, Catalase (CAT) 0.79 nmol/l, and Glutathione Peroxidase (GPx) 1.77 nmol/l activities in osteochondral tissue. Regarding the histomorphometric parameters of cartilaginous tissue (nCg.Th, µm), (cCg.Th, µm), (Cg.Th, µm), irradiated-GEL-CH-GIN group showed a significant increase as compared to irradiated group with 116, 74 and 188 µm, respectively (p<0.01). The microanalysis showed a high percentage of O and C in the regenertaed osteochondral tissue and indicated the deposition of novel collagen matrix. The biomechanical behaviour showed a significantly enhanced hardness measurement (1.73±0 .029 VH, p<0.05) when compared with that of irradiated group
Biochemical markers suggested an osteocartilage repair capacity. In fact, the levels of IL-1β, IL-6, TNF-α and VEGF in the implanted rat with GEL-CH-GING composite exhibited 51±3.48, 30.05±5.18, 65.12±4.33 and 40.42±3.32 ng/l, respectively. Our findings suggested that GEL-CH-GING composite might have promising potential applications for cartilage healing.
Hadi Sharifidarabad, Alireza Zakeri, Mandana Adeli,
Volume 21, Issue 3 (9-2024)
Abstract
The sensitivity of lead dioxide coating properties to the deposition conditions and electrolyte composition has allowed the preparation of coatings with different properties for different applications. In this study, the effects of electrolyte additives on the electrodeposition process were investigated using electrochemical measurements such as cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results showed that the presence of fluoride ions significantly reduce the possibility of TiO2 formation. The addition of copper ions not only prevents lead loss at the cathode, but also leads to the formation of copper oxide on the surface at initial stages, which hinders nucleation of PbO2. The presence of sodium dodecyl sulfate (SDS) also interferes with the nucleation process as it occupies active nucleation sites. The α-PbO2 interlayer prevents copper oxidation and solves the problem of lead dioxide nucleation. Finally, it was found that the simultaneous use of all additives together with the α-PbO2 interlayer has a positive effect on the coating process.
Dewi Qurrota A'yuni, Hadiantono Hadiantono, Velny Velny, Agus Subagio, Moh. Djaeni, Nandang Mufti,
Volume 21, Issue 3 (9-2024)
Abstract
Rice husk carbon by-product from the industrial combustion is a promising source to produce a vast amount of activated carbon adsorbent. This research prepared rice husk-activated carbon adsorbent by varying the concentration of potassium hydroxide solution (5, 10, 15, 20 % w/v) and activation time (2, 4, 6, 8 hours). Fourier-transform infrared spectral characterization (FTIR) indicated a significant effect before and after activation, especially the presence of hydroxyl groups. Based on the iodine adsorption, the specific surface area of the produced-activated carbon was approximately 615 m2/g. Experimental results showed that increasing potassium hydroxide concentration and activation time increases the water vapor adsorption capacity of the activated carbon. Compared with the rice husk carbon, the KOH-activated carbon enhanced the water vapor adsorption capacity to 931%. In the adsorption observation, changing the temperature from 15 to 27 ℃ caused a higher water vapor uptake onto the activated carbon. Two adsorption kinetics (pseudo-first- and pseudo-second-order models) were used to evaluate the adsorption mechanism. This research found that rice husk-activated carbon performed a higher water vapor adsorption capacity than other adsorbents (silica gel, zeolite, and commercially activated carbon).
Muddukrishnaiah Kotakonda, Sajisha V.s, Aiswarya G, Safeela Nasrin Pakkiyan, Najamol A Alungal, Mayoora Kiliyankandi K, Divya Thekke Kareth, Naheeda Ashraf Verali Parambil, Saranya Sasi Mohan, Renjini Anil Sheeba, Sarika Puthiya Veettil, Dhanish Joseph, Nishad Kakkattummal, Afsal Bin Haleem Mp, Safeera Mayyeri, Thasneem Chemban Koyilott, Nasiya Nalakath, Samuel Thavamani B, Famila Rani J, Aruna Periyasamy, Chellappa V Rajesh, Rameswari Shanmugam, Marimuthu Poornima, Tina Raju, Roshni E R, Sirajudheen Mukriyan Kallungal, Lekshmi Ms Panicker, Saranya K G, Shilpa V P,
Volume 21, Issue 3 (9-2024)
Abstract
Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H2O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections
Majid Tavoosi,
Volume 21, Issue 3 (9-2024)
Abstract
The present study focuses on the phase and structural features of MnAl intermetallic compound during solid-state synthesis. In this regard, the milling process was done in differentMn50+xAl50-x (0<x<7.5)powder mixtures and the prepared samples were evaluated using X-ray diffractometer, scanning and transmission electron microscopy, differential thermal analysis and vibrating sample magnetometer. The results showed that the τ-MnAl magnetic phase with L10 structure could not be formed during the milling and low temperature annealing. During milling process, Al atoms dissolve in Mn network and a single β-Mn supersaturated solid solution (SSSS) form. The β-Mn (SSSS) phase is unstable and transforms into the icosahedral quasi-crystal as well as γ2-Al8Mn5 and β-Mn stable phases during subsequent annealing.
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.
Bakhrom Abdulazizov,
Volume 21, Issue 4 (12-2024)
Abstract
In this work, the effect of variation of the non-ideality coefficient of the p-n-junction volt-ampere (I-V) characteristic located in the strong microwave field on the differential resistance, diffusion capacitance and differential conductance is studied. Here, it is shown that the p-n junction I-V characteristics increases with the value of the non-ideality coefficient, whether the differential resistance is in a strong microwave field or a weak microwave field. Diffusion capacitance and differential conductance are shown to decrease with increasing value of non-ideality coefficient.
Zahra Rezayi, Mostafa Mirjalili, Jalil Vahdati Khaki,
Volume 21, Issue 4 (12-2024)
Abstract
Celestite ore, the primary mineral for producing strontium compounds, particularly strontium carbonate, is processed using the black ash method, which involves carbothermic reduction, water leaching, and carbonation. This study aims to investigate the combined effect of mechanical activation and additional graphite on the recovery rate and purity of strontium carbonate. Celestite ore with a strontium sulfate content of 79% was obtained from the Dasht-e-Kavir mine. Acid washing with 10% hydrochloric acid significantly reduced carbonate impurities, resulting in a celestite purity of 96.9%. Mixtures of celestite and graphite with varying amounts of graphite were prepared with and without milling. The mixtures were roasted at 900 °C for 1 hour to form strontium sulfide, followed by hot water leaching. After filtration, sodium carbonate was added to the leachate containing SrS, resulting in the formation and precipitation of white strontium carbonate crystals. The results showed that the addition of graphite increased the recovery rate in unmilled specimens. However, the recovery rate decreased significantly when 1 and 10 hours of milling were applied in the presence of excess graphite. Conversely, in the absence of additional graphite, milling for 1 and 10 hours increased the strontium recovery rate to over 95%. Furthermore, the analysis of strontium carbonate obtained from the sample with the highest recovery rate showed a purity of over 99.9%.
Yofentina Iriani, Novia Puspita, Dianisa Sandi, Fahru Nurosyid, Risa Suryana, Didier Fasquelle,
Volume 21, Issue 4 (12-2024)
Abstract
In this research, Lanthanum (La)-doped Strontium Titanate (STO) with the formula of Sr1-xLaxTiO3 (LSTO; x=0, 0.03, 0.05, and 0.07) powders have been successfully fabricated by co-precipitation route. The impacts of La3+ on the structural, microstructure, band-gap, and photocatalytic activity for the degradation of organic pollutants, in this case, methylene blue, under UV exposure, were reported in detail. The formation of undoped and La-doped STO samples with cubic perovskite structures was confirmed by X-ray Diffraction (XRD) results. The presence of La doping affected the microstructure morphology by producing LSTO powders with a larger specific surface area. Besides, the UV absorption of the LSTO powders was enhanced due to the narrowed band gap caused by La3+ dopants. Accordingly, an improvement in photocatalytic activity applied for the photodegradation of methylene blue solution was exhibited by the LSTO samples.
Seyed Mohammad Mirghasemi, Ehsan Mohammad Sahrifi, Gholam Hossein Borhani, Mirtaher Seyed Beigi,
Volume 21, Issue 4 (12-2024)
Abstract
In this study, the hot deformation and dynamic recrystallization behavior of low carbon steel containing 21 ppm boron was investigated. After homogenizing the samples at 1250 ℃ for 1-hour, hot compression tests were conducted at temperatures ranging from 850 ℃ to 1150 ℃ and strain rates from 0.01 to 10 s⁻¹, resulting in strain-stress flow curves. Following corrections, calculations and modeling were performed based on Arrhenius equations. Among them, the hyperbolic sine relationship provided the most accurate estimate and was selected as the valid model for the applied strain range. According to this model, the deformation activation energy (Q), was determined to be 293.37 KJ/mol. Additionally, critical and peak stress and strain values were obtained for each temperature and strain rate, and power relationships were established to describe their variation with respect to the Zener-Hollomon parameter (Z). Recrystallization fractions were derived by comparing the hypothetical recovery curves with the material flow curves, and the results were successfully modeled using the Kolmogorov-Johnson-Mehl-Avrami (KJMA) equation. The Avrami exponent was measured at approximately 2, indicating that nucleation predominantly occurred at grain boundaries. Microstructural analysis revealed that at higher Z values, recrystallization occurred along with a fraction of elongated grains, while lower Z values resulted in a greater fraction of equiaxed dynamic recrystallization (DRX) grains. The average grain sizes after compression tests at 950 ℃, 1050 ℃, and 1150 ℃ were measured as 21.9 µm, 30.4 µm, and 33.6 µm respectively at a strain rate of 0.1 s⁻¹, and 17.7 µm, 28.7 µm, and 31.3 µm at 1 s⁻¹. The overall microstructure displayed a more uniform grain size distribution with increasing deformation temperature.
Hella Houda, Guettaf Temam Elhachmi, Hachemi Ben Temam, Saâd Rahmane, Mohammed Althamthami,
Volume 21, Issue 4 (12-2024)
Abstract
In this study, we thoroughly examine β-Bi2O3 thin films as potential photocatalysts. We produced these films using an environmentally friendly Sol Gel method that is also cost-effective. Our research focuses on how different precursor concentrations, ranging from 0.1 M to 0.4 M, affect the photocatalytic performance of these films. We conducted a comprehensive set of tests to analyze various aspects of the films, including their structure, morphology, topography, optical properties, wettability, and photocatalytic capabilities. These tests provided us with a well-rounded understanding of the films' characteristics. To assess their photocatalytic efficiency, we used Methylene Blue (MB) as a contaminant and found that the films, particularly those with a 0.1 M concentration, achieved an impressive 99.9% degradation of MB within four hours. The 0.1 M film had a crystalline size of 39.7 nm, an indirect band gap of 2.99 eV, and a contact angle of 51.37°. Our findings suggest that β-Bi2O3 films, especially the 0.1 M variant, have promising potential for treating effluents from complex industrial dye processes. This research marks a significant step in utilizing sustainable materials to address pollution and environmental remediation challenges.
Ahabboud Malika, Gouitaa Najwa, Ahjyaje Fatimazahra, Lamcharfi Taj-Dine, Abdi Farid, Haddad Mustapha,
Volume 21, Issue 4 (12-2024)
Abstract
This paper reports the preparation and characterization of (1-x) PbZr0.52Ti0.48O3 -xBiFeO3 (1-x)PZTxBFO) (x= 0.00, 0.15, 0.30, 0.45, 0.60 and 1.00) multiferroic ceramics which were prepared by a sol-gel method for PZT and hydrothermal reaction process for BFO. The perovskite structure of the composite system was confirmed by X-ray diffraction and Raman spectroscopy, while the composite microstructure w:as char:acterized by scanning electron microscopy. XRD results and Rietveld analysis for the (1-x)PZT-xBFO composites confirm the coexistence of these three phases; rhombohedral (R3m) and tetragonal phases (P4mm) for pure PZT and only the rhombohedral phase (R3c) for pure BFO. Raman spectroscopy of the (1-x)PZT-xBFO composites shows two clear bands around 150 and 180 cm-1. When the BFO content increases, the intensities of Raman modes are decreased. The SEM results suggested a formation of agglomerate and form into large complex clusters as BFO increased and a higher grain size was obtained for the BFO sample compared with the other composites. The EDS spectra of our pellets show that all the characteristic lines of the chemical elements Pb, Zr, Ti, and O and Bi, Fe, and O are present for the PZT and BFO materials respectively. The temperature-dependent dielectric constant shows different behavior dependent on BFO content. Indeed, the dielectric properties are found to be improved with an increase in dopant concentration of BFO in PZT, and novel dielectric behavior, resonance, and antiresonance, were obtained.
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.
Ferda Mindivan,
Volume 21, Issue 4 (12-2024)
Abstract
Natural-reinforced hybrid composites, called "eco-materials," are becoming increasingly important for protecting the environment and eliminating waste problems. In this study, hybrid biocomposites were produced by the colloidal mixing method using seashell (SS) as natural waste, two graphene derivatives (graphene oxide (GO) and reduced graphene oxide (RGO)) as filler material, and polyvinyl chloride (PVC) as the polymer matrix. The crystallization and mechanical properties of hybrid biocomposites were examined based on their thermal properties using TGA and DSC analysis. In comparison to PVC/GO and PVC/RGO composites with identical weight percentages of GO and RGO, the PVC/GO composite exhibited superior thermal stability and crystallinity, resulting in elevated hardness values for the same composite. These results were attributed to the better interaction of GO with PVC due to the higher number of oxygen-containing functional groups in GO than in RGO. However, the PVC/RGO/SS hybrid biocomposites exhibited superior properties than PVC/GO/SS hybrid biocomposites. The greatest crystallinity values were 39.40% for PVC/RGO/SS-20 compared to PVC/RGO at 20 wt% SS content and 29.21% for PVC/GO/SS-20 compared to PVC/GO. The PVC/RGO/SS-20 hybrid biocomposite showed the greatest gain in hardness value, up 18.47% compared to the PVC/RGO composite. No significant change was observed in the melting and weight loss temperatures as the SS content increased; however, the crystallinity and glass transition temperatures in hybrid biocomposites increased as the SS content increased. All analysis results demonstrated the achievement of SS-graphene-PVC interactions, suggesting that SS waste could enhance the thermal and mechanical properties of composite production.
Mehdi Mehranian, Hajar Ahmadimoghadam,
Volume 21, Issue 4 (12-2024)
Abstract
In this research study, a composite coating of Ni-Co/SiC-CeO2 was prepared on a copper substrate using the pulse electrodeposition technique. The effects of electrodeposition parameters, including current density, duty cycle, and frequency, on the properties of the prepared coating were investigated. The selected current density values were 0.1, 0.2, and 0.3 A/cm2, the duty cycle options were 10, 20, and 30%, and the frequency values were 10, 100, and 1000 Hz. Increasing the current density enhanced the microhardness of the coating but reduced its corrosion resistance. This behavior can be attributed to the grain refinement occurring within the coating as the current density increases. On the other hand, an increase in duty cycle resulted in a decrease in microhardness, which can be attributed to a decrease in the concentration of nanoparticles within the coating. The lower corrosion resistance observed at higher duty cycles could be attributed to the decrease in off-time, causing the pulse electrodeposition conditions to approach a DC (direct current) state. Furthermore, higher frequencies were found to be associated with increased microhardness and improved corrosion resistance of the coatings. The coatings with the highest corrosion resistance exhibited a corrosion current density of 0.29 µA/cm2 and a polarization resistance of 1063 Ω.cm2 in a 3.5% NaCl solution. These coatings were prepared using a current density of 0.2 A/cm2, a duty cycle of 10%, and a frequency of 1000 Hz.
