Volume Fraction Of Silver Research Articles

Thermal and velocity slip conditions together with thermal radiative effects on Joule heating mixed convection MHD hybrid nanofluid flow induced by an exponentially shrinking or stretching sheet

ABSTRACT The present study analyzes the mixed convection with magnetohydrodynamic (MHD) flow, Joule heating, and heat transfer in hybrid nanofluids on exponentially stretching or shrinking sheets. The study aims to optimize heat transfer and fluid dynamics properties in engineering and industrial applications. The governing partial differential equations are converted into ordinary differential equations by employing appropriate similarity transformations and then solved using the BVP4C MATLAB tool. In this study, the effects of silver volume fraction, velocity slip, thermal slip, magnetic field, heat generation, Eckert number, and thermal radiation on the skin friction coefficient, Nusselt number, velocity profile, and temperature profile are examined and graphically discussed. The base fluid water contained 2% silver (Ag) and 0.1% titanium oxide (TiO2) nano-particles in this hybrid model. The dual solution was present for a shrinking sheet ( λ < 0 ) when λ ≥ λ c . The skin friction coefficient values decreased by approximately 37%, while the local Nusselt number increased by approximately 3.1% when the velocity slip increased in the first solution. The Nusselt number increased by approximately 0.28% and 12% when the Eckert number and radiative parameter increased, respectively, but decreased by approximately 7.5% and 0.20% when the thermal slip and heat generation increased, respectively.

Development of high superconductor fraction (Ba, K)Fe2As2 wires with improved uniformity by two-axial rolling

Iron-based superconductors are regarded as prospective candidates for high magnetic field applications since they have very high upper critical field and low anisotropy. For practical applications, it is important to develop superconducting wires with strong current carrying capability. In this work, Cu/Ag composite sheathed (Ba, K)Fe2As2 (Ba-122) iron-based superconducting wires were fabricated by a two-axial rolling deformation process and a subsequent hot isostatic pressing (HIP) heat treatment. Compared with the previously reported Cu/Ag/Ba-122 wires prepared by groove rolling, the two-axial rolling allowed to use much thinner Cu/Ag composite sheath for wire fabrication, thus greatly increasing the filling factor of superconducting materials by about 5 times to 24 %, and lowering the volume fraction of silver down to 16 % in wires. By a comparative study on the microstructure and superconducting properties between the wires made by two-axial rolling and groove rolling processes, it is found that besides the significantly increased engineering critical current density, the former also exhibits improved homogeneity of mass distribution and uniformity of Ba-122/Ag interfaces, resulting in significantly enhanced n-values over 40 in magnetic fields up to 14 T. Our work suggests that two-axial rolling, combined with HIP processes, presents a promising approach to prepare iron-based superconducting wires with high filling factor, high uniformity and low cost for practical applications.

Exploring the effects of TiO2${\rm TiO}_2$–Ag/water hybrid nanofluid on MHD flow over a permeable exponentially stretching–shrinking sheet with radiative heat transfer and slip conditions

AbstractThe objective of this article is to study the importance of velocity and thermal slip in the exponentially stretching or shrinking sheet with the megnetohydrodynamic (MHD) hybrid nanofluid flow along with magnetic field, radiative, heat generation effects. This study has practical importance in enhancing heat transfer efficiency, improving energy conversion and optimizing thermal management systems. The findings can also contribute to the development of sustainable energy systems and aid in assessing the stability and safety of nanofluid applications. The governing partial differential equations are transformed into nonlinear ordinary differential equations using similarity transformation. The ODEs are solved using bvp4c solver in MATLAB. The dual solutions are achieved for specific range of the stretching or shrinking parameter and mass suction parameter. The first solution is physically significant after considering stability analysis. The hybrid nanofluid has numerous real‐life and industrial applications, such as microelectronics, manufacturing, naval structures, nuclear system cooling, biomedical, and drug reduction. The skin‐friction increases but Nusselt number decreases over the stretching sheet whereas the opposite effect shows over shrinking sheet for the both solution with the increasing velocity slip parameter. On the other hand, The Nusselt number decreases over the shrinking or stretching sheet for both solutions with the increasing in the thermal slip parameter. The skin friction increases over shrinking sheet but decreases over stretching sheet for the first solution with increasing silver volume fraction parameter and porosity parameter (). Enhancing magnetic field parameter leads to the skin friction increases over the shrinking sheet but decreases over stretching sheet but Nusselt number shows opposite trend. The Nusselt number decreases over shrinking sheet but increases over stretching sheet for the first solution with increasing porosity parameter (). The Nusselt number decreases over shrinking or stretching sheet as the increases heat generation () and variable thermal conductivity parameter () but Nusselt number shows opposite trend as the increases radiative parameter ().

Modelling and performances assessment of a nanofluids-based PV/T hybrid collector

ABSTRACT An efficient option to transform solar radiation into electrical and heat energies simultaneously is the utilization of hybrid photovoltaic thermal solar collectors (PV/T). A temperature decrease in the photovoltaic cells in the PV/T manifold can be achieved using nanofluids. In the present work, a finite difference numerical model of nanofluid-based PV/T collectors, which fits the literature’s experimental results, is developed to evaluate the electrical and thermal outputs. Two different analyses have been performed: in the first group. silver, copper, and iron nanoparticles are dispersed in water, while in the second group, ethylene glycol (EG) and thermal oil (THO) are used as base fluids, where nanoparticles of silver are dispersed. To evaluate how the nanofluid’s volume fraction and the mass flow rate affect the PV/T thermal and electrical outputs, further analyses have been carried out. The results deduced that dispersing a 2% volume fraction of silver, copper, and iron nanoparticles in water allows for achieving an increase in thermal power and electrical power in comparison with pure water. The thermal and electrical outputs of a PV/T collector using a mixture of ethylene glycol (EG), or thermal oil (THO), as base fluid with silver nanoparticles, 87.93 and 60.02 W for silver/EG, and 55.05 and 59.02 W for silver/THO, which are lesser than 206.5 and 63.63 W achieved with the couple silver/water. Finally, silver/water with a 2.0% of volume fraction and mass flow rate of 3.0 × 10–3 kg/s resulted in the most effective mixture of nanofluid.

Estimation of entropy generation and heat transfer of magnetohydrodynamic quadratic radiative Darcy–Forchheimer cross hybrid nanofluid (GO + Ag/kerosene oil) over a stretching sheet

The steady two-dimensional magnetohydrodynamic flow and heat transfer behavior of Darcy–Forchheimer non-Newtonian (Cross) hybrid nanofluid consisting of Go/Kerosene oil and Go + Ag/Kerosene oil through the porous medium past astretched sheet are analyzed here. The heat energy is augmented with quadratic thermal radiation, Ohmic heating, and convective boundary conditions. There is a huge market for nanotechnology, and the development of these materials can be predicted to be very light. Non-Newtonian hybrid nanofluids have several uses in the biomedical, culinary, industrial, and polymer industries. The governing set of nonlinear partial differential equations is converted to ordinary differential equations before being solved numerically. Numerical simulation is completed through MATLAB solver bvp4c by setting the default tolerance. The solver is applied recursively to achieve the desired accuracy in picking the best blend of the assorted parameters we entrenched in the system. The influence of different fluid flow parameters on the velocity, temperature, skin friction, and local Nusselt number are analyzed tabularly and graphically. It is observed that velocity and temperature profile upsurges for the higher values of Weissenberg number. It is also found that quadratic thermal radiation has a significant impact on fluid temperature and heat transfer rate. Forchheimer number and magnetic field resistance make the flow slower and cause enhancement in liquid temperature. Further, adding a volume fraction of silver with Graphene oxide becomes responsible for stabilizing the flow and enhancing heat transportation. The entropy generation becomes more significant with quadratic thermal radiation and Eckert number.

Influence of silver addition on wear characteristics of Cu-Al-Mn shape memory alloys

The aim of the present work is to study wear resistance and hardness of Cu-Al-Mn shape memory alloys prepared by the addition of Silver(Ag) as alloying element. Cu-Al-Mn-Ag shape memory alloys are prepared by varying the Ag concentration of 2%, 4% & 6% (wt.%). Wear behavior of alloys are investigated by using a Pin on disc tribometer at room temperature under dry sliding conditions by considering three parameters i.e. applied load, sliding speed and sliding distance. Hardness measurement is recorded by Rockwell hardness testing equipment. From the experimental findings it is observed that the amount of silver added in the alloys has shown significant effect in the improvement of wear resistance and hardness of prepared alloys. As the pin on disc speed increased, wear was reduced by 55%. A reduction in wear of 42% was observed with an increase in the volume fraction of silver.

Investigation of a two-dimensional photovoltaic thermal system using hybrid nanofluids and a rotating cylinder.

This article focuses on a numerical investigation aimed at enhancing the electrical performance of a two-dimensional photovoltaic thermal system (PV/T) through the application of cooling using hybrid nanofluids. The hybrid nanofluids consist of titanium oxide and silver nanoparticles suspended in water, while the PV/T system is based on polycrystalline silicon, copper, and a flow channel with a rotating cylinder. PV/T devices generate electricity from sunlight, but their performance degrades over time due to the heat generated by solar radiation. Therefore, nanofluids can be circulated through the bottom flow channel to cool the device. This study utilizes 2D incompressible Navier-Stokes equations to control fluid flow and energy equations to manage energy distribution. The COMSOL 6.0 finite element software is employed for comprehensive modeling and simulation. To enhance the performance of the PV/T system, a parametric study is conducted by varying the Reynolds number (ranging from 100 to 1000), cylinder rotational speed (varying from 0.01 to 0.2 m s-1), and silver volume fraction (ranging from 0.01 to 0.2). The results show that increasing the Reynolds number and the volume fraction of silver leads to a reduction in the maximum temperature of the cell. The maximum temperature of the cell also decreases with the rotational speed of the cylinder but only for high Reynolds numbers. By applying the present model, the cell's efficiency is improved by 5.93%.

Structure and Mechanical Properties of Porous TiNi Alloys with Ag Nanoparticles

The work studies the influence of the silver dopant (&lt;0.5 at.%) on the structure and mechanical properties of porous TiNi alloys obtained by self-propagating high-temperature synthesis. These alloys are of high scientific and practical interest in medicine. The presence of silver in the TiNi alloy will ensure improved cytocompatibility and antibacterial properties. The TiNi porous alloys with 0.2 and 0.5 at.% Ag nanoparticles have multiphase composition. Quantitative X-ray diffraction analysis of the obtained alloys showed that an increase in the silver content is accompanied by a quantitative decrease in the austenite phase TiNi(B2) and an increase in the martensite phase TiNi(B19’), as well as in secondary phases Ti2Ni, Ti4Ni2O. Evenly distributed silver nanoparticles up to 10 nm were found in the surface layer by transmission electron microscopy. The results of the scanning electron microscopy showed that inclusions containing silver are located mainly in the zones of Ti2Ni peritectic crystallization. The mechanical characteristics were studied by means of compression tests and it was found that with an increase in the silver dopant, the elastic modulus and elastic limit decrease, but the maximum deformation to fracture increases significantly. It was found that with an increase in the volume fraction of silver, the plastic properties of the alloy increase. No dependency of the tensile strength on the amount of silver was found.

Thermal characteristics of kerosene oil-based hybrid nanofluids (Ag-MnZnFe2O4): A comprehensive study

Hybrid nanofluids are new and most fascinating types of fluids that involve superior thermal characteristics. These fluids exhibit better heat-transfer performance as equated to conventional fluids. Our concern, in this paper, is to numerically interpret the kerosene oil-based hybrid nanofluids comprising dissimilar nanoparticles like silver (Ag) and manganese zinc ferrite (MnZnFe2O4). A numerical algorithm, which is mainly based on finite difference discretization, is developed to find the numerical solution of the problem. A numerical comparison appraises the efficiency of this algorithm. The effects of physical parameters are examined via the graphical representations in either case of nanofluids (pure or hybrid). The results designate that the porosity of the medium causes a resistance in the fluid flow. The enlarging values of nanoparticle volume fraction of silver sufficiently increase the temperature as well as velocity. It is examined here that mixture of hybrid nanoparticles (Ag-MnZnFe2O4) together with kerosene oil can provide assistance in heating up the thermal systems.

Thermal transport in silver-coated polymer sphere composites by the bidirectional 3ω method

The bidirectional 3ω method is an electrothermal technique that is commonly used to obtain the thermal conductivity of materials such as liquids, biological samples, and pastes. In this work, an epoxy-based adhesive was filled with monodisperse 10 μm polymethyl methacrylate spheres coated with silver thin films (AgPS), such that a metallic network that dominated the thermal transport was formed through the composite. The bidirectional 3ω method was used to obtain the thermal conductivity of the conductive adhesive at different volume fractions of AgPS. For 50 vol.% AgPS, corresponding to 3.4 vol.% silver, the thermal conductivity was 2.03±0.21 W m−1 K−1. The results show that the thermal conductivity is strongly correlated with the AgPS volume fraction, while maintaining a volume fraction of silver far below the commercial silver paste, which has typical filler fractions of 40 vol.% silver. The results of this work were compared to thermal measurements of the same material by other techniques, and advantages and disadvantages of the methods were finally discussed.

Tunable Plasmonic Resonance Sensor Using a Metamaterial Film in a D-Shaped Photonic Crystal Fiber for Refractive Index Measurements

Subwavelength cells of metallic nanorods arrayed in a dielectric background, termed “metamaterials”, present bulk properties that are useful to control and manipulate surface plasmon resonances. Such feature finds tremendous potential in providing a broad manifold of applications for plasmonic optical sensors. In this paper, we propose a surface-plasmon-resonance-based sensor with spectral response tunable by the volume fraction of silver present in a metamaterial layer deposited on a D-shaped photonic crystal fiber. Using computational simulations, we show that sensitivity and resolution can be hugely altered by changing the amount of constituents in the metamaterial, with no further modifications in the structure of the sensor. Moreover, the designed sensor can also be applied to label the average volume fraction of silver in the metamaterial layer and then to estimate its effective constitutive parameters.

Гибридный металлополимер как потенциальная активная среда оптоакустического генератора

A hybrid material was studied, consisting of polydimethylsiloxane and silver nanoparticles distributed throughout its volume, its optical and thermodynamic characteristics were calculated for different volume fractions of silver content. It is theoretically shown that this material with a volume fraction of silver of about 30% can be used as an active medium for an optoacoustic transducer with an operating frequency range of about 10 MHz.

Hybrid metal polymer as a potential active medium of an optoacoustic generator

A hybrid material was studied, consisting of polydimethylsiloxane and silver nanoparticles distributed throughout its volume, its optical and thermodynamic characteristics were calculated for different volume fractions of silver content. It is theoretically shown that this material with a volume fraction of silver of about 30% can be used as an active medium for an optoacoustic transducer with an operating frequency range of about 10 MHz. Keywords: ultrasonic generator, polydimethylsiloxane, hybrid material

ENTROPY GENERATION ANALYSIS OF MAGNETOHYDRODYNAMIC DARCY-FORCHHEIMER WILLIAMSON HYBRID NANOFLUID FLOW THROUGH POROUS MEDIUM WITH NONLINEAR THERMAL RADIATION

The analysis for heat and mass transfer with entropy generation influence on Darcy- Forchheimer non-Newtonian Williamson hybrid nanofluid flow consisting of $Go$/Kerosene oil and $Go$+$Ag$/Kerosene oil through the porous medium due to a permeable stretching surface in the presence of an external magnetic field is made. The heat energy is augmented with nonlinear thermal dissipation, heat source/sink, viscous dissipation, and convective boundary conditions. The mass transpiration with chemical reaction at the wall surface is taken into account. The model nonlinear partial differential equations are transmuted to ordinary differential form before being solved numerically by hiring the Runge-Kutta-Fehlberg method (RKF45) in the shooting technique. The growing strengths of the magnetic field and Forchheimer number resistance make the flow slower and cause to rise in temperature. Further, the addition of a volume fraction of silver with Graphene oxide becomes responsible for decelerating the flow and enhancing heat transportation. The skin friction factor declines in magnitude against exceeding inputs of the Weissenberg number. The entropy generation becomes larger with solid volume fraction and Weissenberg number.

Correlations for Total Entropy Generation and Bejan Number for Free Convective Heat Transfer of an Eco-Friendly Nanofluid in a Rectangular Enclosure under Uniform Magnetic Field

In this paper, focusing on the study of entropy generation (EGN), the convection flow of an eco-friendly nanofluid (N-F) in a rectangular enclosure is studied numerically. The nanoparticles (N-Ps) used are silver N-P, which are obtained in an eco-friendly manner from natural materials. By suspending these N-Ps in an equal mixture of water and ethylene glycol (E-G), the N-F has been prepared. There are two constant-temperature triangular obstacles with height w and base H that are placed on the hot wall. There is a magnetic field (M-F) in the x-direction. To simulate the N-F flow, eco-friendly N-P relations are used, and the equations are solved using the volume control method and the SIMPLE algorithm. The variables include Rayleigh number (Ra), Hartmann number (Ha), H, W, and the volume fraction of silver N-Ps. The effect of these parameters is evaluated on the EGN and Bejan number (Be). Finally, a correlation is expressed for the EGN for a range of variables. The most important results of this paper demonstrate that the addition of silver eco-friendly N-Ps intensifies the EGN so that the addition of 3% of N-Ps enhances the EGN by 3.8%. An increment in the obstacle length reduces the Be barrier while increasing the Ha, which enhances the Be when the convection is strong. Increasing the height of the obstacle intensifies entropy generation.

The improved thermal efficiency of Maxwell hybrid nanofluid comprising of graphene oxide plus silver / kerosene oil over stretching sheet

An analysis for heat transfer enhancement of Graphene oxide (Go)/Kerosene oil and Go + silver (Ag)/Kerosene oil hybrid nanofluid is made theoretically when the fluids flow through a porous medium over a stretching sheet in the presence of an applied magnetic field. The heat energy is augmented with thermal dissipation, heat source, and convective boundary conditions. The mass transpiration at the wall of the sheet is taken into account. The model equations are transmuted to ordinary differential form. The roles of controlling parameters are observed numerically by hiring Runge-Kutta method in Matlab coding. The flow speed becomes faster with Maxwell fluid parameter. The growing strengths of magnetic field and porosity resistance make the flow slower but cause to raise in temperature. Further, the additive volume fraction of silver with Graphene oxide becomes responsible to decelerate the flow and enhance heat transportation. The skin friction factor declines in magnitude against exceeding inputs of magnetic characteristic parameter M and porosity parameter Kp.

Plasmonic Nanocomposites Based on Silver Nanocube-Polymer Blends Displaying Nearly Perfect Absorption in the UV Region.

Plasmonic nanocomposites based on well-dispersed silver nanocubes in poly(vinylpyrrolidone) are presented that are solution-processed into layers of varying volume fractions of nanocubes. We show that the high-energy modes of the nanocubes are almost insensitive to plasmonic coupling within the nanocube assemblies, leading to a linear increase in light absorption in the UV region with the nanocube densities. Concerning the main dipolar resonance mode at 450 nm, it is strongly affected by the formation of these assemblies, leading to an increased absorption in the UV region as well as a large absorption band in the visible region. Simulations of the optical response of the nanocube assemblies as a function of nanocube spacing and electric field polarization reveal that optical features in the visible region are due to intercube couplings at short intercube distances and parallel electric field orientation. In contrast, the additional plasmonic band in the UV region has its origin in residual dipolar oscillations of the nanocubes in combination with weak dipolar coupling for both parallel and transversal field polarizations. The combination of these effects leads to an enlarged absorption band in the UV region with nearly perfect light absorption of 98.8% at a high silver volume fraction of 8% that is accompanied by a very weak specular reflection of only 0.28%. Although such perfect absorption is usually observed only when nanocubes are assembled on a gold surface, nearly perfect absorption herein is achieved on a large palette of substrates including glass, plastic, and cheap metals such as aluminum, making it a promising approach for solution-processed robust and cheap quasi-perfect absorption coatings.

Study of surface plasmon resonance sensors based on silver–gold nanostructure alloy film coated tapered optical fibers

Surface plasmon resonance (SPR) based tapered fiber optic sensor having nanostructure film with different particle sizes and volume fractions are analyzed and compared. Using ray-tracing model change in resonance wavelength, propagation length and penetration depth in metal of coupled light are obtained for proposed sensor configuration. The sensitivity of the sensor has been estimated with volume fraction and particle size of nanostructure materials. The sensitivity of the sensor increases with raise in volume fraction along with decline in taper ratio. In addition, the particle size of nanostructure film only affects the detection accuracy. Among all proposed configurations the nanostructures allow film of 2 nm particle size over tapered fiber, shows better detection accuracy and better sensitivity for larger volume fraction of silver.

Nanofluid flow due to rotating disk with variable thickness and homogeneous-heterogeneous reactions

An analysis has been carried out to examine the water based nanofluid flow with silver nanoparticles. Flow due to a rotating disk with variable thickness is considered. Heat and mass transfer subject to volume fraction of nanoparticles and homogeneous-heterogeneous reactions are examined. Homotopy concept is utilized for the development of solutions. Special emphasis is given to the non-dimensional velocity, temperature, concentration, skin friction coefficient and Nusselt numbers. It is observed that with an increase in disk thickness the radial, axial and azimuthal velocities are enhanced. Here surface shear stress rates decays for larger thickness coefficient of disk while increases for volume fraction of silver based nanoparticles. Magnitude of heat transfer rate decreases for Reynold number.

Bending reliability of printed conductors deposited on plastic foil with various silver pastes

The cyclic bending reliability of printed conductors fabricated with different polymer thick film pastes is studied in this article. Three silver pastes with different properties, Asahi SW1400, Asahi LS411AW, and DuPont 5064H, were utilized to deposit test specimens on a 125-μm thick polyethylene terephthalate foil, Melinex ST506, and to investigate the paste characteristics affecting the mechanical durability of the test specimens. The main fabrication method for the traces was roll-to-roll printing with a rotary screen, but also a sheet-based screen printing process was used to compare the results between the two manufacturing techniques. The electrical behavior of the test components was monitored by measuring the DC resistance of the test samples in situ under cyclic bending in both compression and tension with about a 6 mm bending radius. The reliability of the studied test populations was assessed with the statistical Weibull analysis as the failure criterion was a 20 % increase in resistance. It was found that the conductors fabricated with the paste with the smallest silver particle size, Asahi SW1400, had the highest lifetimes. This was due to the more flexible micro-scale structure with a lower volume fraction of silver in the paste. In addition, heat-treatment during the printing process was observed to be a crucial factor from the both electrical and mechanical perspectives of the printed conductors.