Showing papers in "Chemical physics letters in 2022"
TL;DR: In this article , terbium complexes with 1-phenyl-1,3-butanedione and heteroaromatic bidentate neutral ligands were synthesized and spectroscopically investigated.
Abstract: • Ternary terbium complexes with 1-phenyl-1,3-butanedione and heteroaromatic bidentate neutral ligands were synthesized and spectroscopically investigated. • Most intense at 548 nm credited to 5 D 4 → 7 F 5 is responsible for the characteristic green emission of synthesized terbium complexes. • The band gap values have illustrated the conducting behavior of complexes as situated in the range of semiconductor materials. • Due to high color purity and better thermal stability, these complexes might be utilized as green emissive component in displays. Green luminescent complexes of terbium based on derivatives of 1,10-phenanthroline auxiliary ligand and 1-phenyl-1,3-butanedione (PBD) with general formula [Tb(PBD) 3 L] were synthesized. The complexes were characterized by spectroscopic and thermal methods. Photoluminescence spectra demonstrated that on excitation under UV radiations, four emission peaks were displayed in the emission spectra. These characteristic peaks appeared due to transition from the energized ( 5 D 4 ) to the ground state ( 7 F J ) positioned at 491, 547, 584, 622 nm, where J = 6–3 respectively. The hypersensitive peak located at 547 nm is responsible for the characteristic green emission of terbium ion. Absorption and electrochemical analytical results point out the application of synthesized complexes in lighting and displays. Optical and electronic band gap in 3–4 eV range were also found comparable to each other and revealed the use of ternary terbium complexes as semiconductor material.
36 citations
TL;DR: In this article , the authors deal with the heat transfer and entropy generation analysis of unsteady blood flow through a tapered multi-stenosed artery incorporating hybrid nanoparticles (gold and alumina) with Joule heating, viscous dissipation, radiation, and inclined magnetic field.
Abstract: • Entropy generation analysis on a tapered multi-stenosed artery is studied. • Effects of viscous dissipation, radiation, and magnetic field are also discussed. • The Crank-Nicolson scheme is applied to solve the mathematical modeling. • For the realistic behavior of blood, Reynold's viscosity model is considered. • The current findings may be helpful for biomedical scientists. This paper deals with the heat transfer and entropy generation analysis of unsteady blood flow through a tapered multi-stenosed artery incorporating hybrid nanoparticles (gold and alumina) with Joule heating, viscous dissipation, radiation, and inclined magnetic field. For the realistic behavior of blood, Reynold’s viscosity model is considered in this study. The Crank-Nicolson scheme is applied to solve the continuity, momentum, and energy equations with appropriate initial and boundary conditions. The important findings are represented graphically and have been analyzed for different values of the dimensionless parameters. The velocity contours for several emerging parameters are presented to study the overall behavior of blood flow patterns. It is observed that the axial flow accelerates with increasing wall slip velocity ( w s ) due to the presence of the hydrodynamic wall slip effect. The velocity profile increases as the concentration of Au nanoparticles increases, while the reverse effect is noted for the concentration of Al 2 O 3 nanoparticles. The current findings may be helpful for biomedical scientists who are interested in investigating the treatment of various cardiovascular diseases.
33 citations
TL;DR: In this paper , a semi-analytical solution of energy and momentum profile is described by utilizing the mathematical technique Laplace transform and different numerical algorithms are utilized for the inverse of Laplace i.e. Stehfest and Tzou's schemes via MATLAB computational software.
Abstract: • Comparative thermal aspect of nanofluid with kerosene oil and water base fluid subject to the inclined magnetic force is addressed. • The inclined surface induced the flow. • Newtonian heating with nonlinear relations are accounted. • Analytical solutions are obtained through Laplace transform. This investigation deals with comparative thermal aspect of nanofluid with kerosene oil and water base fluid subject to the inclined magnetic force. The inclined surface induced the flow. The Newtonian heating with nonlinear relations are also focused to modify the analysis. The fractional model of non-dimensional leading equations is formulated by utilizing a recent definition of fractional derivative technique namely Atangana-Baleanu (AB) time fractional derivative. The semi-analytical solution of energy and momentum profile is described by utilizing the mathematical technique Laplace transform and different numerical algorithms are utilized for the inverse of Laplace i.e. Stehfest and Tzou’s schemes via MATLAB computational software. The behavior of different parameters with changed values is analyzed and plotted graphically for energy and momentum profiles. The comparative thermal analysis for the kerosene oil and water base material is presented. It is observed the enhancement in heat transfer is comparatively higher for the water-based nanofluid as compared to kerosene oil-based nanofluid. The change is velocity is more progressive for the viscous case as compared to the Casson fluid. Moreover, the rate of velocity is larger for the ordinary derivative model as compared to fractional model derivative.
32 citations
TL;DR: In this paper , the effects of Yb-Zn doping on structural, optical and electric properties of nanocrystalline M type hexaferrites were explored by using sol-gel autocombustion method.
Abstract: Nanocrystalline M type hexaferrites Ca0.5Pb0.5-xYbxZnyFe12-yO19 (x = 0.00–0.1, y = 0.00–1.00) were synthesized by sol-gel autocombustion method. The effects of Yb-Zn doping on structural, optical and electric nature of Ca-Pb M type hexaferrites were explored. The crystal structure of the hexaferrites revealed magnetoplumbite phase with Yb-Zn varying contents (x, y) from 0.00 to 0.1 and 0.00 to 1.00. While the SEM confirmed the presence of well-developed flake shaped particles with size of 16–17 nm. Increase in the dielectric parameters from12.3 to 344.65 k has been observed by dielectric spectroscopy. The results demonstrate that band gap (2.6–2.5 eV) of CaPbFe12O19 can be tuned by the intervention of Yb and Zn ions to enhance the photocatalytic performance. The photocatalytic degradation of methylene blue (MB) dye with undoped CaPbFe12O19 and doped Ca0.5Pb0.5-xYbxZnyFe12-yO19 M type hexaferrites was performed at pH 07 varying time intervals from 0 to 90 min. The Ca0.5Pb0.5-xYbxZnyFe12-yO19 (x = 0.1, y = 1.00) exhibited enhanced percentage degradation efficiency 96.1 % at visible light irradiation in 90 min at pH 07 following the first order kinetics. On the basis of obtained results, Yb-Zn doped CaPbFe12O19 M type hexaferrites can be proposed as excellent material for dielectric, microwave and photocatalyst for the removal of textile contamination.
29 citations
TL;DR: In this paper , five push-pull acceptor molecules with A-B, D-B-A arrangement were formulated in the quest to boost the organic solar cells (OSCs), with respect to their electrical, optical, and chemical characteristics.
Abstract: In this study, five novel push-pull acceptor molecules with A-B-D-B-A arrangement have been formulated in the quest to boost the organic solar cells (OSCs), with respect to their electrical, optical, and chemical characteristics. Substitution of end-capped acceptor moieties in non-fullerene materials is an effective approach of molecular modeling, which finely tunes the optoelectronic attributes of OSCs. The recently altered molecules (Y1-Y5) were flanked with different electron withdrawing units carrying indacenodithiophene (IDT) as the central electron donating core. The density functional theory (DFT) and time-dependent density functional theory (TD-DFT) analysis were executed at B3LYP functional with 6-31G (d,p) basis set to investigate the geometrical as well as optical parameters such as quantum mechanical descriptors, light harvesting efficiency, ionization potential energy, absorption properties, electron affinity, dipole moment, molecular electrostatic potential, transition density matrix, the density of states, and reorganization energies. All of these studied molecules revealed greater electronic transitions, superior optical properties, fast charge mobilities, and better solubility in the polar solvent when compared to the reference molecule. Amongst all these derived molecules, Y1 emerged as a distinctive candidate, exhibiting the highest maximum absorption wavelength (884 nm) in chloroform along with the smallest energy gap (1.72 eV) as well as the lowest optical gap (1.40 eV). Moreover, it has the highest electron affinity and ionization potential energy, least interaction coefficient, exciton binding energy, and reorganization energy (λe = 0.00340 eV), which can be ascribed to its potent electron withdrawing moieties, which intensifies the transfer of charge between the donor and acceptor units within a molecule. We expect these modifications in the terminal groups around the central core to provide strong theoretical strategies to construct and amplify the photovoltaic parameters of OSCs in the future.
28 citations
TL;DR: In this paper , a green synthesis of metal nanoparticles is expected to be a cost-effective and environmentally benign alternative to the conventional metal synthesis, where the fruit extracts from the Syzygium cumini extract was used as reducing agent to synthesize silver nanoparticles (AgNPs).
Abstract: The biosynthesis of silver nanoparticles have received great attention in the field of nanotechnology because of its antimicrobial and biomedical applications. In the current research scenario, the green synthesis of metal nanoparticles is expected to be cost-effective and environmentally benign alternative. In this effort, the fruit extracts from the Syzygium cumini was used as the reducing agent to synthesize silver nanoparticles (AgNPs) and the antioxidant, antibacterial, and anti-inflammatory properties of the synthesized nanoparticles have been evaluated. The synthesized Ag nanoparticles were characterized by UV–Visible spectroscopy (UV), Fourier-transform infrared spectroscopy (FTIR), Powder X-ray Diffraction (XRD) and scanning electron microscope (SEM).The formation of silver nanoparticles was confirmed by optical performance i.e change in color using UV–Visible spectroscopy showing a characteristic peak of silver nanoparticles at 443 nm. The presence of OH and C=O of plant secondary metabolites of Syzygium cumini were confirmed by FTIR spectroscopy, liable for capping and reduction of metal nanoparticles surface. Powder XRD analysis was used to analyze the crystal structure. This medicinal plant extract mediating green biosynthesized silver nanoparticles exhibited good in vitro- antioxidant, antibacterial and anti-inflammatory activities. Therefore, results of the present study highlights the synthesis of cost-effective, eco-friendly drugs with less side effects, which showed that there is the urge of in vivo studies at a molecular level to develop silver nanoparticles through greener approach using the medicinal plant (Syzygium cumini) extract as antibacterial, antioxidant, and anti-inflammatory agent for the treatment of bacterial infection, inflammation and many free radical oriented diseases.
27 citations
TL;DR: In this paper , the authors analyzed the heat and mass transfer characteristics of ternary nanofluid formed by suspending three different nanoparticles in order to achieve proper bioconvection caused by microorganisms, the nanoparticle concentration was assumed to be dilute and the fluid with these characteristics is assumed to flow as a jet past a stretching sheet.
Abstract: The analysis of enhancing the heat transfer of a traditional fluid by adding nanoparticles was effectively studied by many researchers across the globe. In later stages, these nanofluids were made chemically stable by suspending an additional inert nanoparticle thus forming a hybrid nanofluid. The heat transfer characteristics of hybrid nanofluids are discussed in various aspects. Considering these studies, the heat and mass transfer characteristics of ternary nanofluid formed by suspending three different nanoparticles is analysed in this article. The self-propelled microorganisms move within the nanofluid due to the density gradient and it ensures proper mixing of nanoparticles. In order to achieve proper bioconvection caused by microorganisms, the nanoparticle concentration is assumed to be dilute and the fluid with these characteristics is assumed to flow as a jet past a stretching sheet. The mathematical model to analyse such a characteristic flow is framed using the modified Buongiorno’s model that describes the impact of volume fraction, thermophoresis and Brownian motion. The mathematical model obtained will be further converted into non-linear differential equations that are solved through the RKF-45 method. The results obtained through this method are interpreted graphically and the impact of fluid flow parameters on the heat and mass transfer rates are tabulated. It is perceived that the mixed convection parameter enhances the velocity profile. Similarly, the increase in the Brownian motion and thermophoresis enhances the thermal profile. Meanwhile, the increase in the nanoparticle volume fraction helps in enhancing the thermal conductivity and thus the temperature is found to be increasing.
26 citations
TL;DR: In this article , the authors investigated the thermal applications of radiative Casson nanoparticles in presence of the radiative phenomenon and activation energy and reported the impact of different involved parameters on skin fraction, heat transfer rate and mass transfer rate.
Abstract: The flow of nanoparticles presents many dynamic applications in thermal sciences, solar systems, cooling and heating phenomenon, energy resources and much other multidisciplinary significance. Following to such valuable applications and motivations in mind, this research pronounced the thermal applications of radiative Casson nanoparticles in presence of radiative phenomenon and activation energy. The oblique stagnation point flow has been considered due to the stretching cylinder. To analyze the flow problem, the problem is formulated in the cylindrical coordinates. The numerical solution is computed via bvp4c built solver by using the MATLAB software. The impact of different involved parameters on skin fraction, heat transfer rate and mass transfer rate is reported and discussed in tables.
25 citations
TL;DR: In this article , a review of the various synthetic pathways, applications, and future prospects of rare earth metal oxides is presented, including the use of REMOSs in trace gas sensors, batteries, magnetic storage devices, photovoltaic cells, catalysts, energy conversion, engineering, medicines, food, agriculture, cosmetics, textiles and antennas.
Abstract: Rare earth elements have seen a rise in demand in recent years due to their distinctive properties and diverse applications. Rare earth-based nanomaterials can be synthesized using techniques such as hydrothermal, solvothermal, electrode position, and atomic layer deposition methods. REMOSs nanoparticles have found use in trace gas sensors, batteries, magnetic storage devices, photovoltaic cells, catalysts, energy conversion, engineering, medicines, food, agriculture, cosmetics, textiles, and antennas. This review elaborates the various synthetic pathways, applications and future prospects of rare earth metal oxides.
21 citations
TL;DR: In this paper , the density functional theory concepts were used to identify redox reactive sites on ALGR and analytical Fukui functions were applied to locate electron transfer (ET) sites at ALGR.
Abstract: • Alanine graphene (ALGR) complex is modeled for electroanalysis applications. • The first report uses the Fukui function to locate electron transfer (ET) sites at ALGR. • Density functional theory concepts were used to identify redox reactive sites on ALGR. • Our results are in agreement with previous experimental interpretations. Alanine (AL) has been used as a electrode modifier to alter the carbon paste interface for sensing applications. Unfortunately, still, electron transfer (ET) properties of AL modified graphene (GR) interface are not known. Density Functional Theory (DFT) based GR interface will help to know the molecular view of interface. In the current article AL modified GR interface modeled using DFT-based frontier molecular orbital (FMO) theory and analytical Fukui functions. At the AL modified GR interface, the N atom of AL acts like an additional electron donor site, and a carboxylic acid, methyl, and amine group act like a reduction center.
19 citations
TL;DR: In this article , gene expression programming (GEP) has been used to establish empirical models for estimation of mechanical properties of concrete made with NaOH treated crumb rubber (CR), which can boost the reusage of CR for expansion of green concrete leading to environmental safety and economic advantages.
Abstract: To encourage the consumption of crumb rubber (CR), gene expression programming (GEP) has been exercised in this paper to establish empirical models for estimation of mechanical properties of concrete made with NaOH treated CR. An extensive and reliable database of compressive strength of concrete made with NaOH treated CR is established through a comprehensive literature review. Literature review showed that compressive strength of NaOH treated CR concrete is affected by percentage of CR used as a replacement of sand (RS%), concentration of NaOH solution (NC in %), period of NaOH pre-treatment (PTP in hours), water to cement ratio (W/C), quantity of sand (S in kg/m3) and quantity of superplasticizer (SP in kg/m3). The performance of the established model is evaluated by doing parametric analysis, applying statistical checks and comparing with regression models. The R-values in the testing phase of GEP, linear and non-linear regression (LR and NLR) equations are 0.90 and 0.77 each respectively. Furthermore, objective function (OF) of GEP model is 25%, and 33% better than LR and NLR model. Thus, results reflected that the proposed GEP model is more accurate and possess a high generalization and prediction capability than LR and NLR equations with resolved overfitting issue. The results of this research can boost the re-usage of CR for expansion of green concrete leading to environmental safety and economic advantages.
TL;DR: In this article , polyaniline with chitosan was used for removal of Acetaminophen (AAP) in the presence of poly(1)-poly(1) poly(2)-polysilicon.
Abstract: New adsorbent based on polyaniline with chitosan were utilized for removal of Acetaminophen (AAP). The structure of these materials was studied by surface area, XPS, TPD, XRD, FTIR, TGA and SEM analysis. The higher adsorption rate of 385.25 mg.g−1 for [email protected] was obtained at contact time of 360 min and pH 7.0. Obtained results showed that removal of AAP was best fit by the pseudo-second-order and Langmuir adsorption models. Thermodynamic parameters of adsorption process of AAP showed the endothermic and spontaneous processes. Moreover, when reused, the hybrid adsorbent remains at around 69% of their original capacities after five adsorption cycles.
TL;DR: In this article , a series of samarium β-diketonates comprising nitrogen-heterocyclic auxiliary moiety were synthesized and characterized spectroscopically, which suggests the octacoordinated environment about samarium ion and similar structural behavior of complexes.
Abstract: A series of samarium β-diketonates comprising nitrogen-heterocyclic auxiliary moiety were synthesized and characterized spectroscopically. A comprehensive analysis of complexes suggests the octacoordinated environment about samarium ion and similar structural behavior of complexes. The samarium ion is coordinated via carbonyl oxygen of diketone unit and nitrogen of neutral ligand. Energy band gap values of complexes lie in range of semiconducting materials. The photophysical properties of complexes were evaluated from photoluminescence spectra of complexes. By examining the energy transfer pathway and emission spectra, the sensitizing nature of chromophoric ligands is revealed. These synthesized complexes have shown peak around 649 nm (4G5/2→6H9/2) due to electric dipole transition. Results of luminescence spectra and colorimetric analysis have demonstrated the emission of synthesized samarium complexes in reddish orange region. The optical and photophysical properties of complexes claim the usefulness of prepared samarium complexes in designing display devices.
TL;DR: Using tartaric acid and triammonium citrate as environmentally friendly precursor reactants, multicolor fluorescent carbon dots with adjustable emission wavelength and high quantum yield were successfully synthesized via one-step solvothermal method by only changing the reaction solvent as mentioned in this paper .
Abstract: • We successfully synthesized full-color carbon dots (CDs) using one-step solvothermal method by only changing the reaction solvent. • Using tartaric acid and triammonium citrate as environmentally friendly precursor reactants. • The as-synthesized blue, green and red CDs have high quantum yield (all over 40%). • A high-quality white LED was successfully fabricated, which indicate that the prepared multicolor CDs have a potential and broad application prospect in the field of white LED. Using tartaric acid and triammonium citrate as environmentally friendly precursor reactants, multicolor fluorescent carbon dots with adjustable emission wavelength and high quantum yield were successfully synthesized via one-step solvothermal method by only changing the reaction solvent. The morphology, structure and optical properties of the carbon dots were investigated in detail. Characterization results showed that the as-synthesized carbon dots have good dispersibility, rich surface functional groups and high quantum yield (all over 40%). A high-quality white LED with CIE color coordinate (0.34, 0.35) was successfully fabricated using the prepared multicolor carbon dots as the light conversion material. The correlated color temperature was 5336 K, and the color rendering index was up to 83.1. The prepared LED emitted warm white light and was suitable for indoor lighting. It is of great significance to prepare multicolor carbon dots with high quantum yield by single-factor control, and the prepared multicolor carbon dots have potential and broad application prospects in the field of white LED.
TL;DR: In this paper , the structural, electronic, optical, and thermoelectric properties of lead-based double perovskite Pb2ScBiO6 have been investigated using FP-LAPW technique as implemented in the Wien2k code.
Abstract: In this paper, using the FP-LAPW technique as implemented in the Wien2k code, we have studied the structural, electronic, optical, and thermoelectric properties of lead-based double perovskite Pb2ScBiO6. The exchange–correlation potentials PBE-GGA, WC-GGA, PBE-sol GGA, and TB-mBJ were used to estimate the results, and a comparative analysis is presented. This Pb-based double perovskite possesses an energy gap of 2.171 eV according to the computed electronic band structure using the TB-mBJ potential, which is consistent with the experimental results. The estimated optical properties of this compound, such as dielectric function, absorption coefficient, and reflectivity, indicate that it could be used in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The thermoelectric properties of this compound, such as Seebeck coefficient, electrical conductivity, thermal conductivity, and power factor, have been analyzed at temperatures ranging from 100 to 1200 K. In this temperature range, the compound has a positive Seebeck coefficient indicates that holes are the majority charge carriers and that the material is p-type. The variation of thermoelectric properties has also been investigated with chemical potential. Our calculated SLME analysis shows that Pb2ScBiO6 has an SLME of 29.5% at 293.15 K, suggesting that it could be used in solar cells.
TL;DR: In this article , the dielectric properties of polyimides were analyzed by different theoretical methods, including the density functional theory (DFT) calculation for polyimide prediction and the molecular dynamic simulation for polymeric performance explanation, and the best functional/basis set combinations were optimized to be CAM-B3LYP and 6-311++g(d,p) in DFT study.
Abstract: The dielectric properties of polyimides were analyzed by different theoretical methods, including the density functional theory (DFT) calculation for dielectric constant prediction and the molecular dynamic simulation for dielectric performance explanation. The best functional/basis set combinations are optimized to be CAM-B3LYP and 6–311++g(d,p) in DFT study. On the other hand, the molecular parameters of band gap, chain mobility, solubility parameter and fractional free volume were simulated and the latter two show high correlation with the dielectric constant. This work is the starting point for developing a reliable and efficient database to accelerate the overall process toward low dielectric-constant polymer discovery.
TL;DR: In this article , an environmentally friendly green approach for the synthesis of NiO nanoparticles was developed using orange leaf extract using FTIR spectroscopy revealed the vibrational stretching mode of Ni-O bond, which demonstrated significant antibacterial activity against both positive-gram (staphylococcus aureus) and negativegram (Escherichia coli) bacteria.
Abstract: An environmentally friendly green approach for the synthesis of NiO nanoparticles was developed using orange leaf extract. The XRD exhibits formation of cubic crystalline structure. FTIR spectroscopy revealed the vibrational stretching mode of Ni-O bond. The FE-SEM image show some agglomerations of spherical and like oval nanoparticles. The presence of Ni and O peaks in the EDX spectrum indicated the presence of NiO phase with other impurities such as C, Cl, N, and Fe. Furthermore, the NiO nanopartcles obtained demonstrated significant antibacterial activity against both positive-gram (staphylococcus aureus) and negative-gram (Escherichia coli) bacteria.
TL;DR: In this paper , a magnetically separable nanocomposite of γ-Fe 2 O 3 /montmorillonite has been synthesized by a hydrothermal method.
Abstract: • γ-Fe 2 O 3 /montmorillonite with single phase dispersed γ-Fe 2 O 3 nanoparticles was synthesized using hydrothermal method. • γ-Fe 2 O 3 /montmorillonite exhibits high adsorptivity and photocatalytic activity for rhodamine B removal. • Magnetic properties of γ-Fe 2 O 3 /montmorillonite gives easy separation characteristics. • γ-Fe 2 O 3 /montmorillonite is reusable with high stability. The magnetically separable nanocomposite of γ-Fe 2 O 3 /montmorillonite (γ-Fe 2 O 3 /Mt) has been synthesized by a hydrothermal method. The as-obtained nanocomposite is composed of a single phase of γ-Fe 2 O 3 nanoparticles homogeneously dispersed in a montmorillonite structure with high photocatalytic activity for rhodamine B photodegradation. Physicochemical characterization revealed particle sizes ranging from 10 to 30 nm with a band-gap energy of 2.3 eV. This study reveals a significant contribution of the adsorption mechanism to the degradation mechanism. The nanocomposite could be easily separated and reused by magnetic separation owing to its magnetism of 22 emu/g. The nanocomposite is also reusable without any chemical change until five cycles.
TL;DR: In this paper , a series of heteroleptic luminescent europium moieties based on 1,10-phenanthroline and its derivatives (L) namely Eu(BAP)3L; BAP = 2-benzoylacetophenone.
Abstract: We have synthesized a series of heteroleptic luminescent europium moieties based on 1,10-phenanthroline and its derivatives (L) namely Eu(BAP)3L; BAP = 2-benzoylacetophenone. The structural inspection of complexes was done by several spectroscopic techniques. Energy band gap values of complexes lie in region of semiconductors. Metal-ligand interaction results a notable effect on the η (quantum efficiency) and Ω2 (JO parameters) of the prepared complexes. A detailed explanation about photophysical characteristics of the complexes was studied via theoretical and experimental methods. With the help of LUMPAC, theoretical photophysical properties were calculated and discovered to be in good concurrence with experimental values. The hypersensitive electric dipole peak positioned at 612 nm (5D0→7F2) is reasonable for the red emission. The color coordinates are also situated in the red region of CIE triangle. Therefore, these efficient materials could be utilized as red emanating material in designing various display devices.
TL;DR: In this article , a mathematical model describing the thermo-bioconvection of Sutterby nanofluid flow including motile gyrotactic microorganisms near a perforated Riga plate under the physical impacts of heat radiation, and Arrhenius kinetics associated with binary chemical reaction is formulated and simulated.
Abstract: In modern era, thermo-migration of microorganisms is an appealing research topic in bio-nanotechnology, bio engineering, and biomedical. In this context, a mathematical model describing thermo-bioconvection of Sutterby nanofluid flow including motile gyrotactic microorganisms near a perforated Riga plate under the physical impacts of heat radiation, and Arrhenius kinetics associated with binary chemical reaction is formulated and simulated here. The Darcy-Forchheimer (DF) law is applied to determine the porosity of porous media. The Grinberg term is taken for the Lorentz force owing to the parallel Riga plate wall. Appropriate translations are discharged to turn the constitutive partial differential equations (PDEs) into ordinary differential equations (ODEs), that are numerically computed by opting the Runge–Kutta-Fehlberg method (RKF-45) along with shooting strategy. The physical insights of various controlling variables on the transport profiles, Sherwood number, Nusselt number, and microorganisms density number are exemplified through requisite graphs and tables. It must be admitted that with enlarging Darcy number, the nanofluid velocity declines, while Forchheimer number has opposite consequence on it. The motile microorganisms density sharply decreases for improving values of activation parameter. The present modeling would provide preliminary guidances in a variety of biotechnological and industrial applications.
TL;DR: In this paper , the effects of hybrid nanoparticles (Au-Al2O3/blood) on hemodynamical characteristics of unsteady blood flow through a curved artery with stenosis and aneurysm have been analyzed.
Abstract: In the present study, effects of hybrid nanoparticles (Au-Al2O3/blood) on hemodynamical characteristics of unsteady blood flow through a curved artery with stenosis and aneurysm have been analysed. Blood viscosity is assumed as hematocrit-dependent viscosity. The Crank-Nicolson method is applied to solve governing equations with 10-6 tolerance in each iteration. The acquired results for both stenotic and aneurysm segments are presented graphically and have been examined for various physical parameters. It is noted that with an increment in volume fraction of gold (Au) nanoparticles, the velocity profile rises, while, reverse effect is noticed for the volume fraction of Aluminium Oxide (Al2O3) nanoparticles. It is also observed that hybrid nanoparticles may help to control the blood velocity and temperature, which allow the surgeons to readjust it as and when required. The current findings are in good agreement with recent outcomes in previous research studies. The motive of this research is to provide a mathematical analysis of some diseases conditions, which can be helpful in the process of diagnosis and treatment related to the problems of plaque deposition and aneurysm in cardiovascular disorders without surgery, reduction in medical expenses, and minimizing post-surgical effects. Present study also has various applications in the treatment of a variety of pathological conditions such as tumors, removal of blood clots, brain aneurysms, infections. It can be utilized for controlling the blood flow rate, resistance to flow, wall shear stress, and heating effect during surgical processes by varying the strength of the applied magnetic field, the volume fraction of nanoparticles, radiation effect, etc.
TL;DR: In this paper , the structural firmness including electronic properties and adsorption behavior of insulating gas, sulfur hexafluoride (SF6), and its decomposed form thionyl fluoride (SOF2) on Tricycle Red Phosphorene (TRP) using density functional theory method.
Abstract: Nowadays, the two-dimensional semiconductor-based sensor has been widely used to sense different toxic gas and vapour molecules due to their high sensitivity, selectivity, and stability. In the present work, we explored the structural firmness including electronic properties and adsorption behaviour of insulating gas, sulfur hexafluoride (SF6), and its decomposed form thionyl fluoride (SOF2) on Tricycle Red Phosphorene (TRP) using density functional theory method. Noticeably, the TRP nanosheet shows semiconducting nature with an indirect band gap of 1.139 eV. Chiefly, three dissimilar prominent interaction sites comprising bridge, top, and valley-sites of SF6 and SOF2 gases on TRP nanosheet were explored. In addition, the computed adsorption energy of these interaction sites is observed between −0.089 eV to −0.407 eV supporting van der Waals's interaction with regard to insulating gas and TRP substrate. The overall outcomes support that the TRP nanosheet can be cogently used as a sensor to monitor the leakage of insulating gases present in gas-insulated switch gears.
TL;DR: In this article , the electronic, optical, and mechanical properties of quasi-hexagonal and quasi-tetragonal crystalline phase of C$60$ molecules (named qHPC$_{60}$) were investigated.
Abstract: Closely packed quasi-hexagonal and quasi-tetragonal crystalline phase of C$_{60}$ molecules (named qHPC$_{60}$) was recently synthesized. Here, we used DFT simulations to investigate the electronic, optical, and mechanical properties of qHPC$_{60}$ monolayers. qHPC$_{60}$ has a moderate direct electronic bandgap, with anisotropic mechanical properties. Their elastic modulus ranges between 50 and 62 GPa. The results for optical properties suggest that qHPC$_{60}$ can act as UV collectors for photon energies until 5.5 eV since they present low reflectivity and refractive index greater than one. The estimated optical bandgap (1.5-1.6 eV) is in very good agreement with the experimental one (1.6 eV).
TL;DR: In this article , two crystalline schiff bases: (E)-2,4-dibromo-6-(((3, 4-dichlorophenyl)imino)methyl)phenol (DCBA) and TCCA) were prepared by treating halosubstituted benzaldehydes with chloro-substitized aniline through condensation reaction.
Abstract: Herein, two crystalline schiff bases: (E)-2,4-dibromo-6-(((3,4-dichlorophenyl)imino)methyl)phenol (DCBA) and (E)-2,4-dichloro-6-(((2,4,5-trichlorophenyl)imino)methyl)phenol(TCCA) were prepared by treating halo-substituted benzaldehydes with chloro-substituted aniline through condensation reaction. The crystal structures of DCBA and TCCA were confirmed by SC-XRD analysis, which unambiguously revealed that C-H···Br, C-Cl···π, and off-set π···π stacking interactions were the key aspects of crystal packing of DCBA, whereas π···π off-set stacking interactions were the main aspect of crystal packing of TCCA. Hirshfeld surface analysis had been implemented for the further probe of intermolecular interactions. Accompanying with experimental, DFT investigation had also been performed at M06/6-311G(d,p) level to analyze these crystalline architectures. By comparative analysis of geometrical parameters, an efficient agreement was observed between DFT and SC-XRD data. Additionally, natural bond orbital (NBO) findings revealed that most dominant hyper-conjugative transitions with higher stability (31.06 and 30.70 kcal/mol) had been examined for DCBA and TCCA, respectively, which may cause the stability of these molecules. Further, global reactivity parameters disclosed that both compounds showed larger value of hardness (η = 2.181–2.205 eV) with least value of softness (σ = 0.226–0.229 eV) which indicated them kinetically enormous stable and show excellent concurrence with NBO and SC-XRD. The band gaps of DCBA and TCCA had been rationalized to be 4.40 and 4.36 eV, respectively. Interestingly, significant values of dipole moment [µtotal = 1.03 and 4.16 a.u.], linear polarizability [<α>=309 and 1167.51 a.u.] and second order hyperpolarizability [<γ> =3.90–4.18 × 105a.u.] were investigated in the entitled compounds. Remarkable NLO response of aforesaid compounds designated them as outstanding NLO materials for the hi-tech optoelectronic applications.
TL;DR: In this article , the Gibbs free energy and entropy of S2 were derived from the experimental values of four molecular constants of S 2 and the average absolute deviations between these values and the NIST data were 0.23236 % and 0.62573 %, respectively.
Abstract: We present new explicit representations with temperature and pressure as independent variables for the Gibbs free energy and entropy of S2. The developed representations only involve experimental values of four molecular constants of S2, and this feature is different from that the conventional NIST polynomial expressions contain eight coefficients achieved from fitting a plenty of experimental spectroscopic data. In the temperature range of 298 to 6000 K, the average absolute deviations between the predicted Gibbs free energy and entropy values and the NIST data are 0.23236 % and 0.62573 %, respectively.
TL;DR: In this paper , the fundamental laws of fluid mechanics are utilized to model the problem and the implementation of order ensued in PDEs of governed physical problem and appropriate transformations are introduced to transfigure these PDES into ordinary differential expressions.
Abstract: This study focusses on two-dimensional rate type Maxwell material flow configured by a vertical moving surface. Heat source/sink and variable conductivity attributes are included in energy expression. Mass transport analysis is scrutinized through variable diffusivity and chemical reaction. Thermo-solutal buoyancy forces are introduced to capture mixed convection effects. The fundamental laws of fluid mechanics are utilized to model the problem. The implementation of order ensued in PDEs of governed physical problem. Apposite transformations are introduced to transfigure these PDEs into ordinary differential expressions. Computations of significant physical quantities are achieved through homotopy scheme. The convergence is ensured through tabular and graphical outcomes. The description of sundry variables is elucidated via pictorial forms.
TL;DR: In this article , the structural, electronic, magnetic, thermoelectric, optical, elastic and thermal properties of Co2Mn1-xTixGe were investigated using the first-principles full-potential linearized augmented plane wave method with the GGA and mBJ approximations.
Abstract: We have investigated the structural, electronic, magnetic, thermoelectric, optical, elastic and thermal properties of Co2Mn1-xTixGe using the first-principles full-potential linearized augmented plane wave method with the GGA and mBJ approximations. The ferromagnetic state was more stable than nonmagnetic state. These compounds have been found to be perfectly half-metallic ferromagnetic. The magnetic moments of all compounds are calculated. Co2Mn1-xTixGe with x = 0, 0.50 and 1 are mechanically anisotropic stable, while for x = 0.25 and 0.75 are not mechanically stable. These properties play an important role to understand the nature of material whether it can be used as optoelectronic devices.
TL;DR: In this article , the heat transfer impact on magneto-hydrodynamic peristalsis of Boron Nitride-Ethylene Glycol nanofluid past a curved channel is investigated.
Abstract: • MHD peristalsis of nanofluid past a curved channel is investigated. • Hall current, Joule dissipation, viscous heating, velocity, and thermal slip effects are accounted. • Governing equations are derived using the curvilinear coordinate system. • The temperature and velocity profiles exhibit a decreasing behavior with an augmentation in nanoparticles volume-fraction. The present investigation explores the heat transfer impact on magneto-hydrodynamic peristalsis of Boron Nitride-Ethylene Glycol nanofluid past a curved channel . Experimental study revealed that the nanofluid formed by suspending Boron Nitride particles in Ethylene Glycol mixture exhibits the non-Newtonian behavior. Further, Carreau-Yasuda model is utilized to characterize the shear thinning features of nanofluid. The obtained non-linear differential expressions are solved numerically using built in solver NDSolve. The temperature and the velocity of nanofluid drop as the volume fraction of Boron Nitride nanomaterial increases. Further, it is discovered that temperature decreases, and fluid momentum/velocity is assisted with increasing curvature parameter.
TL;DR: In this article , a dye-sensitized solar cell (DSSC) fabrication and performance analysis was performed to evaluate the photosensitization with CVL, DRF and mixed dyes.
Abstract: Codiaeum Variegatum Leaf (CVL) and Delonix Regia Flower (DRF) extracts were utilized as a photosensitizer, coated on the TiO2 nanorods (NRs) photo anodes in the dye sensitized solar cell (DSSC) fabrication and performance analysis. Current density-Voltage (J-V) analysis were performed to evaluate the photosensitization with CVL, DRF and mixed dyes, interestingly mixed dyes have shown improved performance owing to plausible mechanism of synergistic effect. The optimum power conversion efficiency (PCE) of the DSSCs having CVL and DRF dyes are 0.12 and 0.17%. Whereas enhanced PCE of 0.24% is achieved with mixed (1:1, v:v) CVL and DRF dyes based DSSC.
TL;DR: In this paper , a longitudinal fin with linear and nonlinear temperature-dependent thermal conductivities and heat transfer coefficient, subject to radiative heat flux and convective heat transport, is explained.
Abstract: Temperature variation through a longitudinal fin with linear and nonlinear temperature-dependent thermal conductivities and heat transfer coefficient, subject to radiative heat flux and convective heat transport is explained in the present examination. For the radiative heat flux, the Rosseland approximation is incorporated and convection mode of energy transmission is accounted on the fin's surface. The associated physical problem is developed in such a manner that the steady-state heat transmission problem is governed with the help of dimensionless variables signified by a second order differential equation (ODE). To solve this equation, an analytical approach, DTM-Pade, and the LSM are implemented. Moreover, the consequence of a few non-dimensional factors on the temperature field are depicted graphically. The investigation's main findings illustrate that a significant decline in the thermal field is caused by an increment in the convection and the radiation mechanism. The internal development of heat affects the thermal distribution in the fin.