30 research outputs found
Enhancement in Optical Properties of Lanthanum-Doped Manganese Barium Hexaferrites under Different Substitutions
No full textThe permeability and electrical resistivity of barium hexaferrite magnetic materials can be used in various products such as magnetic recording media, computers, electronic devices, materials for permanent magnets, and communication devices. This work focuses on the synthesis of rare earth lanthanum (La3+)-doped manganese in barium hexaferrite (Ba1−xLaxMnyFe12−yO19) (x = 0.02–0.10 and y = 0.02–0.10) prepared by using the coprecipitation method. The intensity peak is increased with increasing the concentration of lanthanum, which shows the enhancement in the degree of crystallinity and increase in the size of crystallite. The band gap energy decreased gradually with the increase of concentration of lanthanum. The micrographs observed that the material is basically made up of some rings or rods such as particles in pure La-Ma in barium hexaferrite. The agglomeration was observed because of heat behavior at 600°C or may be concentration effect. The structural studies are done using X-ray diffraction, UV, FT-IR, and SEM techniques
Flexible Nanocomposite Thin Films for Electronic Devices
No full textElectronic technology is moving towards flexible, durable, and smaller devices with multifunctional capability. To accelerate this movement, creating materials with outstanding properties is critical. Nanocomposites based on single wall carbon nanotubes (SWCNTs) have received considerable attention because of their unique mechanical and electrical properties. When SWCNTs are formed as a sheet, they provide large contact area and ease of control, especially when incorporated into a flexible format. However, when SWCNT films are adhered to an elastic substrate, there are challenges with their use in flexible electronics, such as a reduction Young?s modulus under deformation. SWCNT films can undergo plastic behavior at even a small strain because individual SWCNTs slide past each other in response to deformation. To address these challenges, a strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) method was used to query SWCNT film mechanics. The buckling wavelength and the film thickness are two main factors that influence the mechanics of nanocomposite thin films adhered to elastomeric substrates. SWCNT films coated with a second nanomaterial, such as a polymer thin film or nanocrystals (NCs), have shown a significant enhancement in elasticity. The studies described in this dissertation demonstrate that polymer thin film can reduce the strain softening of SWCNT films, where both yield strain and Young?s modulus increase with the introduction of SWCNT-polymer layers. Specifically, the films started to exhibit a strong synergy between SWCNT and polymer at a film thickness of around 20 nm, which is attributed to the thickness approaching the characteristic interfacial width between the two materials. Both a ?passive? polymer thin film (for example, polystyrene-PS) and an ?active? polymer thin film, the conducting polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS), were investigated, spanning a bilayer to the bulk limit of SWCNT-polymer multilayers. In addition, ultrathin SWCNT films coated with colloidal NCs have also been investigated. We have utilized two approaches to coat SWCNT films with NCs: Langmuir-Blodgett (LB) and spray coating. Both Si and CdSe nanocrystals showed a roughly two-fold enhancement in film elasticity, which was attributed to an excluded volume effect that prevents the SWCNT rearrangement under an applied strain
Sulfonylureas in the Treatment of Type 2 Diabetes Mellitus: A Fresh Look and New Insights
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Characterization and Modeling Quality Analysis of Edible Oils Using Electrochemical Impedance Spectroscopy
No full textThe dielectric characteristics of six culinary oils were measured over the frequency range of 0.01 Hz–100 kHz. The results showed that the dielectric constants of oils had the same frequency relationship (i.e., they decreased with increasing frequency). The dielectric constants at lower frequencies for olive oil A, olive oil B, sesame oil, Nigella sativa, sunflower oil, and corn oil are approximately 2.75, 2.5, 2.0, 1.75, 1.5, and 0.9. An FT-IR analysis showed that the spectral differences were very small, because most vegetable oils contain the same type of fatty acids. The model built using COMSOL Multiphysics for the potential and electric field distributions for different oils and used to calculate the dielectric constant was simulated under various conditions in the AC/DC module. The model results were compared with the experimental results, which showed satisfactory convergence between them. The experimental and model results obtained in this study could be useful for evaluating the edible oil quality
Interaction of a Phospholipid and a Coagulating Protein: Potential Candidate for Bioelectronic Applications
No full textIn the present communication,
we have investigated the interaction
between a biomembrane component 1,2-dioleoyl-sn-glycero-3-phosphocholine
(DOPC) and a coagulating protein protamine sulfate (PS) using the
Langmuir–Blodgett (LB) technique. The π–A isotherm, π–t characteristics,
and analysis of isotherm curves suggested that PS strongly interacted
with DOPC, affecting the fluidity of the DOPC layer. Electrical characterization
indicates that PS as well as the PS–DOPC film showed resistive
switching behavior suitable for Write Once Read Many (WORM) memory
application. Trap-controlled space charge-limited conduction (SCLC)
was the key mechanism behind such observed switching. The presence
of DOPC affected the SCLC process, leading to lowering of threshold
voltage (VTh), which is advantageous in
terms of lower power consumption
Effect of Asymmetric Fins on Thermal Performance of Phase Change Material-Based Thermal Energy Storage Unit
No full textPhase change material (PCM)-based thermal energy storage units (TESU) have very low thermal conductivity that compromise their charging and discharging rate. The present study focuses on an enhancement in charging rate as well as an increase in the uniformity of the melting rate. A rectangular cavity consisting of two horizontal partial fins is studied. The horizontal partial fins are placed symmetrically in a PCM-based TESU. In the current work, the melting rate of PCM was enhanced using asymmetric arrangement while keeping all other parameters the same, thus showing the positive effect of asymmetric configuration in such storage systems. The position and the pitch of each fin is optimized to improve heat transfer characteristics of the TESU. The numerical investigation of the problem is performed. TESU with asymmetrically placed fins show better performance in terms of higher charging rate as well as uniformity of the charging rate. The asymmetric placement of the fins suggested by present study increased the charging rate by 74.3% on average as compared to the symmetrically placed fins in the storage system. The charging rate uniformity is improved by 43.7%. The asymmetric fin’s placement conserved the convection strength for a longer melting duration and so increased the Nusselt number by 80.2% as compared to the symmetrically placed fins. Thus, it can be concluded that the performance of asymmetric fins is better in the charging of PCMs than the symmetrically placed fins in a PCM-based TESU
Copper doped cobalt-manganese phosphate ternary composites for high-performance supercapattery devices
No full textDrive towards Sonochemically Synthesized Ternary Metal Sulfide for High‐Energy Supercapattery
No full textCellulose Triacetate/Zinc Oxide Membrane for Bioethanol Recovery via Pervaporation
No full textIn this study, cellulose triacetate (CTA) hybrid membrane is successfully prepared via the phase-inversion method for bioethanol recovery through pervaporation. Nano zinc oxide (ZnO) particles are mixed into the polymer matrices of CTA to enhance the pervaporation membrane’s performance. The fabricated hybrid membrane is characterized using environmental scanning electron microscopy (ESEM) and thermogravimetric analysis (TGA) to reveal the surface morphology and thermal resistance, respectively. The pervaporation performance of the hybrid membrane is assessed for recovering bioethanol from its dilute solution. Pervaporation results show that the hybrid membrane prepared with 3 wt.% ZnO achieved a permeation flux of 1065.71 g/m2h, while the separation factor was around 1038 at 50 °C operating temperature
