The present exploration discusses the influence of Newtonian heating on the magnetohydrodynamic (MHD) three dimensional couple stress nanofluid past a stretching surface. Viscous dissipation and ...Joule heating effects are also considered. Moreover, the nanofluid model includes the combined effects of thermophoresis and Brownian motion. Using an appropriate transformation, the governing non linear partial differential equations are converted into nonlinear ordinary differential equations. Series solutions using Homotopy Analysis method (HAM) are computed. Plots are presented to portrait the arising parameters in the problem. It is seen that an increase in conjugate heating parameter results in considerable increase in the temperature profile of the stretching wall. Skin friction coefficient, local Nusselt and local Sherwood numbers tabulated and analyzed. Higher values of conjugate parameter, Thermophoresis parameter and Brownian motion parameter result in enhancement of temperature distribution.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Perovskite solar cells have gained immense interest from researchers owing to their good photophysical properties, low‐cost production, and high power conversion efficiencies. Hole transport ...materials (HTMs) play a dominant role in enhancing the power conversion efficiencies (PCEs) and long diffusion length of holes and electrons in perovskite solar cells. In hole transport materials, modification of π‐linkers has proved to be an efficient approach for enhancing the overall PCE of perovskite solar cells. In this work, π‐linker modification of a recently synthesized H−Bi molecule (R) is achieved with novel π‐linkers. After structural modifications, ten novel HTMs (HB1–HB10) with a D−π−D backbone are obtained. The structure–property relationship, and optoelectronic and photovoltaic characteristics of these newly designed hole transport materials are examined comprehensively and compared with reference molecules. In addition, different geometric parameters are also examined with the assistance of density functional theory (DFT) and time‐dependent DFT. All the designed molecules exhibit narrow HOMO–LUMO energy gaps (Eg=2.82–2.99 eV) compared with the R molecule (Eg=3.05 eV). The designed molecules express redshifting in their absorption spectra with low values of excitation energy, which in return offer high power conversion efficiencies. Further, density of states and molecular electrostatic potential analysis is performed to locate the different charge sites in the molecules. The reorganizational energies of holes and electrons are found to have good values, suggesting that these novel designed molecules are efficient hole transport materials for perovskite solar cells. In addition, the low binding energy values of the designed molecules (compared with R) offer high current charge density. Finally, complex study of HB9:PC61BM is also undertaken to understand the charge transfer between the molecules of the complex. The results of all analyses advocate that these novel designed HTMs are promising candidates for the construction of future high‐performance perovskite solar cells.
Perovskite solar cells: Advanced quantum chemical techniques are employed to explore the photophysical, photovoltaic, and optoelectronic properties as well as the structure–property relationship of R and HB1–HB10 molecules. The studied systems may be targeted for the development of high‐performance perovskite solar cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The key objective of the present research is to examine the hybrid magnetohydrodynamics (MHD) nanofluid (Carbon-nanotubes and ferrous oxide-water) CNT-Fe
O
/H
flow into a horizontal parallel channel ...with thermal radiation through squeezing and dilating porous walls. The parting motion is triggered by the porous walls of the channel. The fluid flow is time-dependent and laminar. The channel is asymmetric and the upper and lower walls are distinct in temperature and are porous. With the combination of nanoparticles of Fe
O
and single and multi-wall carbon nanotubes, the hybrid nanofluid principle is exploited. By using the similarity transformation, the set of partial differential equations (PDEs) of this mathematical model, governed by momentum and energy equations, is reduced to corresponding ordinary differential equations (ODEs). A very simple numerical approach called the Runge-Kutta system of order four along with the shooting technique is used to achieve the solutions for regulating ODEs. MATLAB computing software is used to create temperature and velocity profile graphs for various emerging parameters. At the end of the manuscript, the main conclusions are summarized. Through different graphs, it is observed that hybrid-nanofluid has more prominent thermal enhancement than simple nanofluid. Further, the single-wall nanotubes have dominated impact on temperature than the multi-wall carbon nanotubes. From the calculations, it is also noted that Fe
O
-MWCNT-water has an average of 4.84% more rate of heat transfer than the Fe
O
-SWCNT-water. On the other hand, 8.27% more heat flow observed in Fe
O
-SWCNT-water than the simple nanofluid. Such study is very important in coolant circulation, inter-body fluid transportation, aerospace engineering, and industrial cleaning procedures, etc.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The study concerns with the mechanical characteristics of heat and mass transfer flow of a second grade nanofluid as well as gyrotatic microorganism motion past a thin needle with dipole effect, ...entropy generation, thermal radiation, Arrhenius activation energy and binar chemical reaction. The governing equations and boundary conditions are simplified by the use of suitable similarity transformations. Homotopy analysis method is implemented to obtain the series solution of non-linear ordinary differential equations. Physical behaviors of heat and mass transfer flow with gyrotatic microorganisms and entropy generation are investigated through the embedded parameters. The nanofluid velocity is enhanced for higher values of the ferromagnetic parameter, local Grashof number, bioconvection Rayleigh number and radiation parameter. The Reynolds number, radiation parameter and Eckert number decrease the nanofluid temperature. The entropy generation is increased with the enhancement of radiation parameter, Eckert number, Lewis number, temperature difference parameter, dimensionless constant parameter, Curie temperature, Prandtl number and concentration difference parameter.
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•New NFAs have been designed by employing advanced quantum chemical techniques.•All the designed molecules have shown narrow band gaps.•SGS-1 to SGS-4 expressed high mobility of the ...hole and electron.•Low excitation and binding energy values have been observed.•All the designed systems are efficient for high-performance organic solar cells.
Simultaneous enhancement in the fill factor (FF) and power conversion efficiency (PCE) is a crucial task for the development of photovoltaic (PV) devices. In addition, symmetrical acceptor molecules lack photo and thermal stability due to low extinction coefficient and dipole moment. Breaking of symmetry in typical fullerene-free acceptors brings high values of dipole moments along with crystalline features. In this regard, a series of new acceptor molecules have been designed by deep end-capped remodeling of the IPC-BEH-IC2F. Newly remodeled systems disclosed high values of electronic charge shifting and perfect molecular packing. The impact of symmetry breaking is examined through density functional theory (DFT) and time-dependent density functional theory (TDDFT) at CAM-B3LYP/6-311G(d,p) level. Photovoltaic and geometric aspects like frontier molecular orbitals (FMOs), excitation energy, open circuit voltage (Voc), FF%, and PCE have been computed theoretically. Reshaped systems expressed high mobilities of the electrons and holes towards the metal electrodes together with easy excitation of the exciton. High Voc enhances the FF% and PCE in the SGS-1 to SGS-4. Results of all analyses showed that SGS-1 to SGS-4 are well-designed systems for the development of the highly efficient active layer for OSCs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The aim of present paper is to study the series solution of time dependent MHD second grade incompressible nanofluid towards a stretching sheet. The effects of mixed convection and thermal radiation ...are also taken into account. Because of nanofluid model, effects Brownian motion and thermophoresis are encountered. The resulting nonlinear momentum, heat and concentration equations are simplified using appropriate transformations. Series solutions have been obtained for velocity, temperature and nanoparticle fraction profiles using Homotopy Analysis Method (HAM). Convergence of the acquired solution is discussed critically. Behavior of velocity, temperature and concentration profiles on the prominent parameters is depicted and argued graphically. It is observed that temperature and concentration profiles show similar behavior for thermophoresis parameter Νt but opposite tendency is noted in case of Brownian motion parameter Νb. It is further analyzed that suction parameter S and Hartman number Μ depict decreasing behavior on velocity profile.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A superlative combination of the Board of Directors (BOD) with diverse members is considered a sign of a good governance structure. Meanwhile, the key decision taken by BOD to make organizations ...profitable is the capital structure with the optimal mix of debt and equity. Unfortunately, previous literature has reported this relationship with a mixed trend, which may be due to research gaps in the statistical analysis. Moreover, it also shows that the relationship between them has not yet been fully predicted and can still be completely understood. This study contains time-variant and time-invariant variables, and these variables usually have an outlier's problem. As we know that the OLS estimators are more sensitive to react adversely to this problem, yet we have not received enough evidence from similar researches that cares about it. Consistent with these arguments, this study focuses primarily on exploring the influence of corporate governance structure and the capital structure on firms' market-oriented and accounting-based performance, especially with the contemplation of outliers. Hypotheses have been evaluated using M-estimators and S-estimators of robust regression for 45 listed firms for the period from 2013 to 2017. The findings reveal that the governance structure of firms with BOD, independent director, institutional investors, audit committee and female directors accelerates its performance. Further, we find that the leverage ratio improves accounting performance, but it has a downward impact on the share prices of listed firms. Our study contributes to the prevailing literature by proving that the kind of governance structure that based on diverse expert members and a capital structure with a high volume of debt is of utmost importance to the performance of firms as a whole.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The multi-walled carbon nanotubes (MWCNTs) were initially functionalized with polyaniline (PANI) through an in-situ polymerization approach. The ternary transition metal phosphate of ...Ni0.50Co0.25Zn0.25(PO4)2 was then chemically grafted onto different masses of PANI/CNTs (20, 40, 60, 100, and 130 mg) aided with probe sonication. The structural morphology and elemental analysis of the nanocomposites were evaluated by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM), whereas chemical grafting and compositional analysis were evaluated by EDX, XRD, Raman spectroscopy and FTIR analysis. The hierarchical structure of ternary metal phosphates nanocomposites with 100 mg PANI/CNTs provided excellent specific capacity of 1438 Cg−1 (2400 Fg−1, at 1.5 Ag−1). An asymmetric supercapacitor device (ASC) of Ni0.50Co0.25Zn0.25 (PO4)2-100 mg PANI/CNT//AC demonstrated excellent electrochemical performance with an energy density of 104 Whkg−1 (@540 Wkg−1 and very good cyclic stability and columbic efficiency (100 %)). According to a capacitive-diffusive investigation, the ASC device has 63.5 % diffusive and 33.5 % capacitive behavior at low scan rates. The reason for the excellent electrochemical performance of nanocomposite is the combined contribution of PANI/CNTs and uniform chemical grafting of tri-metallic phosphate structures onto the PANI/CNTs. As a result, the Ni0.50Co0.25Zn0.25 (PO4)2-100mg PANI/CNTs composite exhibited good potential to be used in energy storage devices.
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•Sonochemical synthesis of Ni-Co-Zn ternary metal phosphate/PANI-CNTs composites•NCZP100 showed excellent CS 1438Cg−1 (2400Fg−1) @1.5 Ag−1 with lowest Rs and RCT.•Representative ASC device gave outstanding energy density of 104WhKg−1@0.6 Ag−1 with ~100 % cyclic stability.•The device showed 63.5 % diffusive and 33.5 % capacitive behavior at low scan rates.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The present study deliberates the nanofluid flow containing multi and single-walled carbon nanotubes submerged into Ethylene glycol in a Darcy-Forchheimer permeable media over a stretching cylinder ...with multiple slips. The innovation of the envisaged mathematical model is enriched by considering the impacts of non-uniform source/sink and modified Fourier law in the energy equation and autocatalytic chemical reaction in the concentration equation. Entropy optimization analysis of the mathematical model is also performed in the present problem. Pertinent transformations procedure is implemented for the conversion of the non-linear system to the ordinary differential equations. The succor of the Shooting technique combined with the bvp4c MATLAB software is utilized for the solution of a highly nonlinear system of equations. The impacts of the leading parameters versus engaged fields are inspected through graphical sketches. The outcomes show that a strong magnetic field strengthens the temperature profile and decays the velocity profile. Also, the fluid velocity is lessened for growing estimates of the parameter of slip. Additionally, it is detected that entropy number augmented for higher thermal relaxation parameter and Reynolds number. To substantiate the existing mathematical model, a comparison table is also added. An excellent correlation is achieved here.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Green growth is a novel theme, gaining prominence in the current era. Therefore, this study investigates the impact of green innovation and financial globalisation on green growth in the BRICS ...(Brazil, Russia, India, China and South Africa) economies. The study employs the CS-ARDL model for the analysis. The findings confirm that the long-run estimates of environmental innovations and patents are positively significant, ensuring that environment-related technologies are helpful in attaining green growth in the BRICS economies. Moreover, the estimates of financial globalisation are significantly positive, suggesting that a rise in financial globalisation leads to an increase in green growth in the BRICS economies. Our findings imply that, to promote green growth in the BRICS economies, policymakers should focus on R&D activities that can encourage the development of green innovations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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