Shape Factor Analysis Research Articles

Shape Factor and Sensitivity Analysis on Stagnation Point of Bioconvective Tetra-hybrid Nanofluid over Porous Stretched Vertical Cylinder

Shape Factor and Sensitivity Analysis on Stagnation Point of Bioconvective Tetra-hybrid Nanofluid over Porous Stretched Vertical Cylinder

Unsteady flow of a ternary hybrid nanofluid over an inclined flat plate when Ohmic heating and quadratic thermal radiation are significant: couple stress model with shape factor analysis

Unsteady flow of a ternary hybrid nanofluid over an inclined flat plate when Ohmic heating and quadratic thermal radiation are significant: couple stress model with shape factor analysis

Analysis of hybrid nanoparticles shape factor and thermal radiation effect on solidification in latent energy storage in a triplex chamber

Analysis of hybrid nanoparticles shape factor and thermal radiation effect on solidification in latent energy storage in a triplex chamber

A millimeter-wave atomic receiver

Rydberg quantum sensors are sensitive to radio-frequency fields across an ultra-wide frequency range spanning megahertz to terahertz electromagnetic waves resonant with Rydberg atom dipole transitions. Here, we demonstrate an atomic millimeter-wave heterodyne receiver employing continuous-wave lasers stabilized to an optical frequency comb. We characterize the atomic receiver in the W-band at a signal frequency of f = 95.992 512 GHz and demonstrate a sensitivity of 7.9 μV/m/Hz with a linear dynamic range in power greater than 70 dB. We develop frequency selectivity metrics for atomic receivers and demonstrate their use in our millimeter-wave receiver, including signal rejection levels at signal frequency offsets Δf/f = 10−4, 10−5, and 10−6; 3, 6, 9, and 12-dB bandwidths; filter roll-off; and shape factor analysis. Our work represents an important advance toward future studies and applications of atomic receiver science and technology in weak millimeter-wave and high-frequency signal detection.

A novel hybridity model for (Cu-Al2O3-H2O) hybrid nanofluid flow with melting heat transfer, shape factor, and irreversibility analysis: A development on Blasius and Sakiadis problems

The mass-based hybrid nanofluid model is applied for the flow over the flat plate with melting heat transfer phenomenon by considering Blasius and Sakiadis problems. Instead of the volumetric concentration of the first and second nanoparticles, the masses of the base fluid and nanoparticles are taken into account. This model is used for the first time to develop the Blasius and Sakiadis problem along with the irreversibility analysis. The nanoparticles of various shapes are also taken for investigation. Appropriate similarity transformations are applied to turn the partial differential equations into ordinary differential equations. To numerically solve the transformed boundary layer equations, the shooting technique with the Runge Kutta–Felhberg scheme was employed. Copper and alumina nanoparticles of two different sorts have been incorporated into the base fluid. The influence of controlling physical factors on the velocity profile, thermal profile, coefficient of skin friction, and Nusselt number for both the Sakiadis and Blasius flows are graphically investigated. In addition, the fluctuation in the entropy generation as well as Bejan number has been illustrated through graphs. In-depth discussion is given regarding the traits of physical and engineering interest.

Shape factor analysis of a magnetohydrodynamics mixed convective Nimonic 80A/water nanofluid flow over a moving wedge in the presence of thermal radiation

One of the most common problems faced in the industries is the lack of proper heat energy and temperature distribution management systems. The study of the effects of thermal radiation and magnetohydrodynamics on a water-based nanofluid flow with various shapes of the nanoparticle Nimonic 80A, over a moving wedge, is yet to be studied by any researcher. Being a superalloy of nickel–iron–chromium, Nimonic 80A is often used in exhaust systems and chemical plants as an anti-corrosive agent. The mathematical model presented in this article was transformed using similarity transformations and solved using MATLAB bvp4c code. All the results and graphs were formulated after a positive outcome of our results with that available in the existing literature. Increases in velocity and temperature were observed with the increase in empirical shape factors of the nanoparticle for various parameters. Local Nusselt number and skin-friction coefficients decreased under the influence of augmenting shape factors of the nanoparticles. The velocity profile decreased at a rate of 1.5% while the temperature profile augmented by 0.24% for an augmenting magnetic parameter from M = 0.6 to 0.8 while the velocity profile increased for an increase in radiation parameter. An increment in the nanoparticle concentration resulted in incrementing streamline values and skin friction coefficient by 0.38% and 6.83%, respectively.

Multi-scale CFD study of multiphase flow in structured sinusoidal corrugated sheets packings

Structured packing is an important equipment and has wide applications in chemical separation process. In this study, the complex hydrodynamics characteristics of structured sinusoidal corrugated sheets packings were investigated by 2D liquid film model and 3D Representative Element Unit model. Volume of Fluid method was employed to investigate the effect of eleven different structures of sinusoidal corrugated sheets packings (i.e. wavelength, amplitude, and corrugated angle) on liquid holdup, wet pressure drop, and interfacial area. In addition, a shape factor was proposed to characterize the effect of flow regime on packing hydrodynamics characteristics and wetting performance. The packing shape factor analysis method proposed in this study could provide a reference for the structural optimization and evaluation of structured packing in the future.

Shape factor analysis in stagnation point flow of Casson nanofluid over a stretching/shrinking sheet using Cattaneo–Christov model

In this article, the stagnation point flow of an incompressible Au–blood fluid over a stretching sheet in porous medium is examined with suction/injection and Cattaneo–Christov effects. The transformed ODEs are solved numerically by the shooting-based bvp4c method with MATLAB software. The flow phenomenon is influenced by thermal relaxation with slip boundary conditions. The shape of gold (Au) nanoparticle is considered as: cylindrical, platelet, and blade, and the Hamilton–Crosser model of thermal conductivity is taken. The Casson parameter increases the nanofluid velocity and decreases the fluid temperature. The increment in the thermal relaxation parameter increases the fluid temperature profiles. The particle shape can also enhance the temperature. The nanoparticles of blade shape have huge influences on temperature rise due to greater thermal properties. A comparative analysis is made in accordance with previous works and is in good agreement.

Theoretical analysis of shape factor of gas hydrate sediments under stress dependence

The Kozeny-Carman (KC) equation is used extensively to characterize the effective permeability of gas hydrate sediments. However, most existing modeling approaches ignore the changes in the effective stress, hydrate saturation, and pore structures of porous media, which significantly affect the extraction and exploration of gas hydrates. In addition, theoretical models that can accurately describe shape factors during the imbibition process and predict the effective permeability of gas hydrate sediments are rarely reported. This paper proposes a theoretical stress-dependent shape factor model to study the physical relations between the shape factor and relevant parameters (e.g., effective stress, hydrate saturation, effective porosity, and pore fractal dimension). Then, the derived model is extended to study the shape factor during the imbibition process. The two main novel features of the proposed model are: (1) it takes the effective stress, hydrate saturation, and pore structures into account; and (2) it can be used to study the evolution of shape factors during the imbibition process in gas hydrate sediments. The predictions from the developed model provide a good agreement with experimental results, which validates the model. In addition, based on the derived model, the effects of relevant parameters on shape factors are studied theoretically. From a practical standpoint, the model can not only estimate the effective permeability of gas hydrate sediments under stress dependence but also provide insight into the evolution of shape factor, pore structures (e.g., capillary total number, pore fractal dimension, tortuosity fractal dimension, and effective porosity) and hydrate pore habits during the extraction of hydrates.

Synthesis of highly efficient novel two-step spatial 2D photocatalyst material WS2/ZnIn2S4 for degradation/reduction of various toxic pollutants

In this article, we report the synthesis, characterization of novel biofriendly 2D/2D heterostructure WS2/ZnIn2S4 material in which 2D WS2 nanosheets are uniformly distributed spatially onto the spherically arranged 2D leaves of ZnIn2S4. We then studied the in-depth photocatalytic degradation activity of this novel nanocomposite and its pristine component materials on cationic dye: malachite green, anionic dye: congo red and reduction of heavy metal: chromium(VI) and the degradation efficiency of composite material was also tested on rhodamine-B, methylene blue, methyl orange dyes and acetaminophen/paracetamol drug. Form factor, structure factor and shape factor analysis has been carried out using X-ray diffractometry (XRD). Bond vibrations, functional groups and phonon vibration mode analysis has been done based on Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Morphological and compositional analysis has been done using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDAX) and X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM). Surface area and pore size/distribution was characterized using Brunauer–Emmett–Teller (BET) method and Barrett-Joyner-Halenda Model. Degradation pathways and intermediate products are proposed using the high-performance liquid chromatography (HPLC). Photocatalytic activity of the nanocomposite WS2/ZnIn2S4 is compared with pristine ZnIn2S4 and pristine WS2, which shows more than 50% enhancement in both efficiency and rate of degradation/reduction for all the pollutants. A scavenger study was carried out to get insight of primary and secondary reactive oxygen species (ROS) taking part in degradation. Exciton lifetime, surface charge and stability, and flat band positions were studied based on time-correlated single photon counting (TCSPC) also known as time-resolved photoluminescence (TRPL), zeta potential, and Mott-Schottky respectively. Rate kinetics study was performed to analyze the physical and chemical behaviour of the nanocomposite with pollutants in consideration. Results show ∼100%, ∼90%, and ∼95% degradation efficiency by the heterostructure for malachite green (MG), congo red (CR), and reduction of heavy metal chromium (Cr(VI)) respectively within 5 min, which is a huge improvement as compared to pristine WS2 and pristine ZnIn2S4, both of which show the efficiencies of only ∼25% to∼75% in all the cases.

Distinguishing nanoparticle drug release mechanisms by asymmetric flow field-flow fractionation.

This research demonstrates the development, application, and mechanistic value of a multi-detector asymmetric flow field-flow fractionation (AF4) approach to acquire size-resolved drug loading and release profiles from polymeric nanoparticles (NPs). AF4 was hyphenated with multiple online detectors, including dynamic and multi-angle light scattering for NP size and shape factor analysis, fluorescence for drug detection, and total organic carbon (TOC) to quantify the NPs and dissolved polymer in nanoformulations. The method was demonstrated on poly(lactic-co-glycolic acid) (PLGA) NPs loaded with coumarin 6 (C6) as a lipophilic drug surrogate. The bulk C6 release profile using AF4 was validated against conventional analysis of drug extracted from the NPs and complemented with high performance liquid chromatography - quadrupole time-of-flight (HPLC-QTOF) mass spectrometry analysis of oligomeric PLGA species. Interpretation of the bulk drug release profile was ambiguous, with several release models yielding reasonable fits. In contrast, the size-resolved release profiles from AF4 provided critical information to confidently establish the release mechanism. Specifically, the C6-loaded NPs exhibited size-independent release rate constants and no significant NP size or shape transformations, suggesting surface desorption rather than diffusion through the PLGA matrix or erosion. This conclusion was supported through comparative experimental evaluation of PLGA NPs carrying a fully entrapped drug, enrofloxacin, which showed size-dependent diffusive release, along with density functional theory (DFT) calculations indicating a higher adsorption affinity of C6 onto PLGA. In summary, the development of the size-resolved AF4 method and data analysis framework fulfills salient analytical gaps to determine drug localization and release mechanisms from nanomedicines.

Fuzzy C-Means Clustering Applied to Load Profiling of Industrial Customers

Nowadays, knowing load profiles of different customers in electricity market-oriented operation of power system is very important. Smart metering system provides more than enough information about it. However, even if there is a load measurement on each customer in the system, it is economically unjustified and it is time consuming to conduct a detailed analysis each of them. In this study, unlike literature approaches, the different industrial load profiles are observed. The fuzzy c-means clustering is applied to get typical load curves representing different type of industry. For that purpose, the detailed statistical analysis and calculations of load shape factors of the industrial customers for different period of the year have been carried out. Customer’s 15-min load was collected by developing Advanced Metering Infrastructure in the power system of Bosnia and Herzegovina. According to available data, statistical analysis and applied fuzzy c-means clustering, three typical load profiles for different industrial customers are proposed.

Study of physicochemical characteristics of calcium hydroxyapatite «Kalident Powder 100» in the development of dental medicine

Despite the development of the dental industry, the prevalence of dental hypersensitivity does not decrease but increases at a progressive rate. Given the above, the subject of our research was the development of dental medicinal films with micronized calcium hydroxyapatite under the trade name «Kalident Powder 100» (Kalichem, Italy) for the treatment of dental hyperesthesia and caries prevention. To establish the optimal method of calcium hydroxyapatite introduction into the dental film, it was necessary to study the influence of different dispersion mediums on the physicochemical characteristics of the substance under study.
 Purified water, ethyl alcohol 96%, polysorbate 80, glycerol, polyethylene oxide-400, propylene glycol, sunflower oil, vaseline oil were used as dispersion medium in the studies. Research of physico-chemical characteristics was performed both for the substance «Kalident Powder 100» separately and for its mixtures with the studied liquids and their combinations (in a ratio of 1:1). The following physico-chemical characteristics have been determined: disperse and diffraction analysis of particle size distribution, morphological description, linear dimensions, shape factor, volume coefficient, Martin and Ferret diameters, wettability.
 The results of crystallographic and disperse analysis have revealed the polydispersity of the substance «Kalident Powder 100» and its high ability to agglomerate, which may adversely affect the homogeneity of its distribution in the dental medicinal product. A study of the effect of different dispersion medium on the physicochemical characteristics of calcium hydroxyapatite has shown a positive effect of hydrophilic liquids on the wettability of powder particles, changes in their shape, size, and distribution in the studied samples. It has been established that the combination of the substance «Kalident Powder 100» with combined solvent systems containing purified water, polysorbate 80, glycerol, and PEO-400, allows achieving optimal shape and particle size of calcium hydroxyapatite with their uniform distribution throughout the liquid, which is also confirmed by the results of laser diffraction. The obtained results will be used in further research on the development of dental medicinal film.

Theoretical analysis of shape factor on performance of annular thermoelectric generators under different thermal boundary conditions

The annular thermoelectric generator (ATEG) has received growing research interest due to its improved energy conversion efficiency compared to conventional flat-plate thermoelectric generators (FTEG). In this study, considering the influence of ceramic substrate and copper contact layer, a numerical model of the annular thermoelectric module (ATEM) was established for the studies of the influence of geometrical parameters on output performance under three typical application scenarios with different boundary conditions. It is found that when the heat flow on hot side is constant, the shape factors of the optimal performance are slightly different either if the convection coefficient or the temperature is considered constant on cold side. In both cases, the output power and the conversion efficiency decrease with the increase of the thickness of the thermocouple, and increase with the increase of the angle, length, and number of the thermocouples. When the temperatures are considered constant on both sides of the thermocouples, a conflicting relationship between the optimal output power and the efficiency exists. In this case, to obtain the best ATEG performance, multi-optimization problem is formulated and solved by the non-dominant sorting genetic algorithm with elite strategy method (NSGA-II).

Effects of first-order chemical reaction and melting heat on hybrid nanoliquid flow over a nonlinear stretched curved surface with shape factors

The aim of the current study is to disclose the results of shape factor analysis of the flow of a hybrid nanofluid over a curved sheet. The flow is caused by a stretchable curved sheet. Mathematical modeling and analyses have been performed in the presence of curvature, melting heat and heterogeneous-homogeneous reactions. Autocatalysis and the coefficients of the reactant are dealt with in a similar manner. The physical properties of the fluid, including the fluid velocity, the heat and mass transfer properties, the skin friction and the Nusselt number have been acquired and analyzed under the influences of the dimensionless curvature, melting and heterogeneous–homogeneous reaction variables. Boundary layer approximations are used in the mathematical formulation. Suitable transformations have been used to transform differential equations into nonlinear ordinary differential equations. The resulting nonlinear system of equations has been analyzed via the matlab bvp4c solver. Comparisons of nanoliquids with the hybrid nanoliquid are presented through graphs and tables. The results of this analysis show that the skin friction and the heat transfer rate in the hybrid nanofluid are seen more prominently than those of the nanofluid for larger values of the curvature parameter [Formula: see text].

Influence of flow limiter and grain shape factor of sand particles on erosion activity in pipeline

Erosion has been evaluated as the main cause of failure in pipework. The focus of this work is the effect of erosion activity on two-phase flow (solid-liquid) condition. Pressure distribution of liquid flow, velocity profile of liquid flow and trajectories of sand particles are scrutinized. Based on the experimental data, different limiter pipeline was simulated to validate the data and an overall grain shape factor of 0.265 was obtained. From the qualitative and quantitative analysis of grain shape factor (GSF), it was identified that the 75 % of sand are composed of high sphericity particles (GSF=0.2), 25 % of sand composed of slightly lower sphericity particles (GSF=0.45). For the simulation work, the fluid flow rate, grain shape factor and sand concentration is altered ranging between 25 litres/s to 50 litres/s, 0.2 to 1.0 and 0.5 % to 1.0 % respectively. Through ANOVA analysis and it demonstrated the significant influence on erosion activity in descending order (fluid flow rate > shape factor > sand concentration). After numerical optimization, the minimum erosion activity on limiter was obtained by obeying the settings of fluid flow rate, shape factor and sand concentration as 50 litres/s, 0.2 and 1.0 % respectively.

Evaluation of stability of three different mini-implants, based on thread shape factor and numerical analysis of stress around mini-implants with different insertion angle, with relation to en-masse retraction force.

ABSTRACTObjectives: Assess the stability of three different mini-implants, based on thread shape factor (TSF), and evaluate stresses at the mini-implant site and surrounding cortical bone on application of retraction force, at two different insertion angles. Methods: Mini-implants of three different diameters (M1 - Orthoimplant, 1.8mm), (M2 - Tomas, 1.6mm) and (M3 - Vector TAS, 1.4mm) and length of 8mm were used. Using scanning electronic microscopy, the mean thread depth, pitch and relationship between the two (TSF) were calculated. The mini-implants were loaded into a synthetic bone block and the pull-out strength was tested. One way ANOVA and Tukey post-hoc tests were used to compare the pull-out strength of mini-implants. P values < 0.05 were considered statistically significant. Finite element models (FEM) were constructed with insertion angulation at 90° and 60°, with retraction force of 150 g. The results were analyzed using ANSYS software.Results: Statistically significant difference was found among all the three mini-implants for thread depth and pitch (< 0.001). Statistically significant higher pull-out force value was seen for Orthoimplant. The stress distribution level in mini-implant and surrounding bone was observed to be smaller for Orthoimplant. Conclusion: Orthoimplant mini-implants have more favorable geometric characteristics among the three types, and less stress with 90°angulation.

Fractal analysis of shape factor for matrix-fracture transfer function in fractured reservoirs

As the core function of dual-porosity model in fluids flow simulation of fractured reservoirs, matrix-fracture transfer function is affected by several key parameters, such as shape factor. However, modeling the shape factor based on Euclidean geometry theory is hard to characterize the complexity of pore structures. Microscopic pore structures could be well characterized by fractal geometry theory. In this study, the separation variable method and Bessel function are applied to solve the single-phase fractal pressure diffusion equation, and then the obtained analytical solution is used to deduce one-dimensional, two-dimensional and three-dimensional fractal shape factors. The proposed fractal shape factor can be used to explain the influence of microstructure of matrix on the fluid exchange rate between matrix and fracture, and is verified by numerical simulation. Results of sensitivity analysis indicate that shape factor decreases with tortuosity fractal dimension and characteristic length of matrix, increases with maximum pore diameter of matrix. Furthermore, the proposed fractal shape factor is effective in the condition that tortuosity fractal dimension of matrix is roughly between 1 and 1.25. This study shows that microscopic pore structures have an important effect on fluid transfer between matrix and fracture, which further improves the study on flow characteristics in fractured systems.

Mechanistic investigation for shape factor analysis of SiO2/MoS2 – ethylene glycol inside a vertical channel influenced by oscillatory temperature gradient

The present article aims to examine shape factor effects of SiO2/MoS2 hybrid nanoparticles suspended in ethylene glycol (EG) confined in a vertical rotating channel under the combined influence of ...

Particle analysis of shape factors according to American Society for Testing and Materials.

Polyethylene wear is one of the major factors influencing the survivorship of joint replacements. Depending on the number, size and morphology of the polyethylene particles, biological responses of the periprosthetic soft tissue in terms of inflammatory processes can occur, leading to loosening of the implant. Various parameters are used to analyze wear particles, which are usually determined by examining scanning electron microscopy (SEM) images with a particle analysis program. In this study, three different software solutions for particle analysis (self-developed Particleanalyzer_HD, Leica QWin and ImageJ) were compared regarding particle number, size and morphology. These solutions were also compared to the American Society for Testing and Materials (ASTM) F1877-16 specifications regarding particle morphology. SEM image analysis revealed no differences for the equivalent circle diameter (p = 0.969). However, a significant difference was found for the aspect ratio between the Particleanalyzer_HD and the other two software solutions (p < 0.001) and between Leica QWin and the other two software solutions regarding the roundness (p < 0.001). Only the Particleanalyzer_HD showed an excellent agreement with the ASTM standard for both morphology parameters (intraclass correlation = 1.000). Only the Particleanalyzer_HD calculated the two morphology parameters according to the ASTM standard. A comparison of the particle morphology between different studies is barely possible, as different algorithms for particle analysis are used. It is strongly recommended that the calculation according to the ASTM standard is used to improve future comparability of findings from wear analysis studies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:225-233, 2020.