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Background: Electrochemical sensing has been widely used as a glucose sensor. Methods: In the present work, we have investigated the application of nickel ferrite (NiFe2O4) nanoparticles (NFNPs) for dextrose sensing applications. NFNPS were synthesized by using a simple and low-cost probe sonication method (PSM). The structural, optical and electrochemical properties of prepared nanoparticles were measured by using XRD, FTIR and DRS techniques. Results: The PXRD pattern confirmed the formation of inverse spinel structure for NFNPs with a face-cente red cubic (FCC) structure. The diffuse reflectance spectral studies revealed the energy band gap of NFNPs as deduced to be 2.50 eV by using Kubelka-Munk function. The efficiencies in the photocatalytic degradation of Acid Red 88 (AR-88) and Acid Blue 88 (AB-88) dyes were found to be better with 93.45% and 84.45%, respectively. The EIS parameters corroborated the significant reduction in the charge transfer resistance of NFNPs electrode. The sensing of dextrose in acidic solution by using NFNP through carbon paste electrode was successful. Conclusion: The obtained sensing and photocatalytic results revealed that the synthesized NFNPs could be a better electrode material for the detection of dextrose with high electrode reversibility, in addition to its excellent photocatalytic characteristics towards the dye degradation.
Waqas Alam Mir. Electrochemical sensing of dextrose and Photocatalytic activities by nickel ferrite nanoparticles synthesized by probe sonication method. Current Nanoscience 2021, 17, 1 -1.
AMA StyleWaqas Alam Mir. Electrochemical sensing of dextrose and Photocatalytic activities by nickel ferrite nanoparticles synthesized by probe sonication method. Current Nanoscience. 2021; 17 ():1-1.
Chicago/Turabian StyleWaqas Alam Mir. 2021. "Electrochemical sensing of dextrose and Photocatalytic activities by nickel ferrite nanoparticles synthesized by probe sonication method." Current Nanoscience 17, no. : 1-1.
Several materials, such as aluminum and copper, exhibit non-Newtonian rheological behaviors. Aluminum and copper nanoparticles are ideal for wiring power grids, including overhead power transmission lines and local power distribution lines, because they provide a better conductivity-to-weight ratio than bulk copper; they are also some of the most common materials used in electrical applications. Therefore, the current investigation inspected the flow characteristics of homogeneous–heterogeneous reactions in a hybrid nanofluid flowing over a rotating disc. The velocity slip condition was examined. The energy equation was developed by employing the first law of thermodynamics. Mixed convection thermal radiation and the convective condition effect were addressed. The dimensionless governing models were solved to give the best possible investigative solution using the fourth- and fifth-order Runge–Kutta–Felhberg numerical method. The effects of different influential variables on the velocity and temperature were scrutinized graphically. The effects of the variation of various sundry parameters on the friction factor and Nusselt numbers were also analyzed. The results revealed that the velocity gradient increased significantly for augmented values of the mixed convection parameter. Here, the velocity gradient increased more rapidly for a hybrid nanoliquid than for a nanofluid. The thermal distribution was enhanced due to a significantly increased radiation parameter.
Mir Alam; Syed Hussain; Basma Souayeh; Muhammad Khan; Mohd Farhan. Numerical Simulation of Homogeneous–Heterogeneous Reactions through a Hybrid Nanofluid Flowing over a Rotating Disc for Solar Heating Applications. Sustainability 2021, 13, 8289 .
AMA StyleMir Alam, Syed Hussain, Basma Souayeh, Muhammad Khan, Mohd Farhan. Numerical Simulation of Homogeneous–Heterogeneous Reactions through a Hybrid Nanofluid Flowing over a Rotating Disc for Solar Heating Applications. Sustainability. 2021; 13 (15):8289.
Chicago/Turabian StyleMir Alam; Syed Hussain; Basma Souayeh; Muhammad Khan; Mohd Farhan. 2021. "Numerical Simulation of Homogeneous–Heterogeneous Reactions through a Hybrid Nanofluid Flowing over a Rotating Disc for Solar Heating Applications." Sustainability 13, no. 15: 8289.
In the present decade, research regarding solar thermal air heaters (SAHs) has noticed a continuous progression in thermo-hydraulic performance augmentation approaches. There now exists a wide variety of thermo-hydraulic performance augmentation approaches and researchers have designated various structures. Nevertheless, there seems to be no generalization to any of the approaches employed. The present numerical investigation reports on the thermo-hydraulic characteristics and thermal performance for flow through a varied length (full, medium, half, and short length) dimple solar air heater (SAH) tube. The study highlights recent developments on enhanced tubes to augment heat transfer in SAH. The influence of different length ratio, dimple height ratio (H), and pitch ratio (s) on thermo-hydraulic characteristics have been investigated in the Reynolds number (Re) range from 5000 to 25,000. Air is used as the working fluid. The commercial software ANSYS Fluent is used for simulation. The shear stress transport (SST) model is used as the turbulence model. Thermal energy transport coefficient is increased in the full-length dimple tube (FLDT), compared to the medium-length dimple tube (MLDT), half-length dimple tube (HLDT) and short-length dimple tube (SLDT). Similarly, the pitch ratio (s) has more influence on Nusselt number (Nu) compared to the dimple height ratio (H). The friction factor decreases with an increase in pitch ratio. Nu increases and f decreases with increasing Re for all combinations of H and s. Low s and higher H yields high enhancement of HT and PD. Integration of artificial roughness on the tube increases the values of Nu and f by 5.12 times and 77.23 times for H = 0.07, s = 1.0 at Re value of 5000 and 25,000, respectively, in regard to the plain tube. For all the tested cases, the thermo-hydraulic performances (η) are greater than unity.
Mir Alam; Basma Souayeh. Parametric CFD Thermal Performance Analysis of Full, Medium, Half and Short Length Dimple Solar Air Tube. Sustainability 2021, 13, 6462 .
AMA StyleMir Alam, Basma Souayeh. Parametric CFD Thermal Performance Analysis of Full, Medium, Half and Short Length Dimple Solar Air Tube. Sustainability. 2021; 13 (11):6462.
Chicago/Turabian StyleMir Alam; Basma Souayeh. 2021. "Parametric CFD Thermal Performance Analysis of Full, Medium, Half and Short Length Dimple Solar Air Tube." Sustainability 13, no. 11: 6462.
A circular tube fitted with novel corrugated spring tape inserts has been investigated. Air was used as the working fluid. A thorough literature review has been done and this geometry has not been studied previously, neither experimentally nor theoretically. A novel experimental investigation of this enhanced geometry can, therefore, be treated as a new substantial contribution in the open literature. Three different spring ratio and depth ratio has been used in this study. Increase in thermal energy transport coefficient is noticed with increase in depth ratio. Corrugated spring tape shows promising results towards heat transfer enhancement. This geometry performs significantly better (60% to 75% increase in heat duty at constant pumping power and 20% to 31% reduction in pumping power at constant heat duty) than simple spring tape. This paper also presented a statistical analysis of the heat transfer and fluid flow by developing an artificial neural network (ANN)-based machine learning (ML) model. The model is evaluated to have an accuracy of 98.00% on unknown test data. These models will help the researchers working in heat transfer enhancement-based experiments to understand and predict the output. As a result, the time and cost of the experiments will reduce. The results of this investigation can be used in designing heat exchangers.
Basma Souayeh; Suvanjan Bhattacharyya; Najib Hdhiri; Mir Waqas Alam. Heat and Fluid Flow Analysis and ANN-Based Prediction of A Novel Spring Corrugated Tape. Sustainability 2021, 13, 3023 .
AMA StyleBasma Souayeh, Suvanjan Bhattacharyya, Najib Hdhiri, Mir Waqas Alam. Heat and Fluid Flow Analysis and ANN-Based Prediction of A Novel Spring Corrugated Tape. Sustainability. 2021; 13 (6):3023.
Chicago/Turabian StyleBasma Souayeh; Suvanjan Bhattacharyya; Najib Hdhiri; Mir Waqas Alam. 2021. "Heat and Fluid Flow Analysis and ANN-Based Prediction of A Novel Spring Corrugated Tape." Sustainability 13, no. 6: 3023.
Synthesis based on biomaterial technology has high potential in structural applications. Blending metal oxides with plant extract is an attractive alternative for preparing materials with superior material properties. Here, we report for the first time, the synthesis of NiO bio-composite materials by employing Aloe vera leaf extract. The work mainly highlights the synergistic influence of biomolecules of Aloe vera plant on the electrochemical and photocatalytic properties of NiO. The structure, morphology, band gap and bonding features of NiO bio-composites were characterized by XRD, Electron Microscopy, UV-DRS and FT-IR techniques, respectively. The average crystallite size of the composites was within 60 nm. FT-IR spectra confirmed the strong bonding interactions between biomolecules and NiO. A maximum band gap of 3.88 eV with a good thermal stability for the synthesized composites was observed. The addition of biomolecules to NiO resulted in the improvement of the reversibility of the electrode by reducing the anodic (Epa) and cathodic (Epc) peak potential difference in KOH electrolyte. Also, the composite exhibited greater stability due to recyclability and less resistance even after 1000 charge-discharge cycles, revealing a stable electrode material for supercapacitors applications. The photocatalytic experiments confirmed a maximum of 95% dye degradation efficiency by the composite for AR88 dye. It was also found that 50 % of dye degradation occurred within 74.61 min. The encouraging results project out the potential of the synthesized NiO-biocomposites to be a better supercapacitor and photocatalyst.
B. Avinash; C.R. Ravikumar; M.R. Anil Kumar; M.S. Santosh; C. Pratapkumar; H.P. Nagaswarupa; H.C. Ananda Murthy; V.V. Deshmukh; Aarti S. Bhatt; A.A. Jahagirdar; Mir Waqas Alam. NiO bio-composite materials: Photocatalytic, electrochemical and supercapacitor applications. Applied Surface Science Advances 2020, 3, 100049 .
AMA StyleB. Avinash, C.R. Ravikumar, M.R. Anil Kumar, M.S. Santosh, C. Pratapkumar, H.P. Nagaswarupa, H.C. Ananda Murthy, V.V. Deshmukh, Aarti S. Bhatt, A.A. Jahagirdar, Mir Waqas Alam. NiO bio-composite materials: Photocatalytic, electrochemical and supercapacitor applications. Applied Surface Science Advances. 2020; 3 ():100049.
Chicago/Turabian StyleB. Avinash; C.R. Ravikumar; M.R. Anil Kumar; M.S. Santosh; C. Pratapkumar; H.P. Nagaswarupa; H.C. Ananda Murthy; V.V. Deshmukh; Aarti S. Bhatt; A.A. Jahagirdar; Mir Waqas Alam. 2020. "NiO bio-composite materials: Photocatalytic, electrochemical and supercapacitor applications." Applied Surface Science Advances 3, no. : 100049.
Several parts of the Moringa oleifera plant have revealed incredible potential for water quality improvement. However, the purification potential of a combined leaf and seed extract of Moringa oleifera plants remains unexplored. To the best of our knowledge, this research would be the first to work towards exploiting the combined potential of a leaf and seed extract of the Moringa oleifera plant in the process of water purification. In this study, we investigated the combined effectiveness of the leaf and seed extract in the purification of groundwater. The jar test method was used to analyze the effectiveness of Moringa plant extract (in combination) on different quality parameters of groundwater. Treatment with the combined plant extract (seed and leaf) resulted in significant improvement of various physicochemical (hardness, pH, turbidity, Total Dissolved Solid (TDS), and metallic impurities) and biological parameters (E.coli count) over individual seed and leaf extracts in groundwater samples. Experimental findings have strongly shown the enhanced purification efficacy of the hexane extract of combined plant materials in comparison to the individual extracts, thereby providing us with a potent natural coagulant that could combat the side effects of chemical coagulants.
Mir Waqas Alam; Pratibha Pandey; Fahad Khan; Basma Souayeh; Mohd Farhan. Study to Investigate the Potential of Combined Extract of Leaves and Seeds of Moringa oleifera in Groundwater Purification. International Journal of Environmental Research and Public Health 2020, 17, 7468 .
AMA StyleMir Waqas Alam, Pratibha Pandey, Fahad Khan, Basma Souayeh, Mohd Farhan. Study to Investigate the Potential of Combined Extract of Leaves and Seeds of Moringa oleifera in Groundwater Purification. International Journal of Environmental Research and Public Health. 2020; 17 (20):7468.
Chicago/Turabian StyleMir Waqas Alam; Pratibha Pandey; Fahad Khan; Basma Souayeh; Mohd Farhan. 2020. "Study to Investigate the Potential of Combined Extract of Leaves and Seeds of Moringa oleifera in Groundwater Purification." International Journal of Environmental Research and Public Health 17, no. 20: 7468.
Background: Herbicides are very beneficial in the crop yield with the aid of controlling weeds within the agriculture, but several herbicides are chronic in soil. Objective: In this study, nanoparticles and the packages of synthesized novel silica nanoparticles were studied for the preconcentration of herbicides. Methods: These nanoparticles prepared by the Stöber mechanism were purified and functionalized. Nanoparticles thus prepared successfully were used as supporting material for the preconcentration of residues of herbicides in the water. Results: Preconcentration was achieved by preparing the silica-based solid-phase-extraction cartridges. Nanoparticles used for this purpose were within the range of 50-250 nm. An SPE cartridge was prepared by packing 200 mg of silica nanoparticle in the empty cartridge of diameter 5.5 cm and length 0.6 cm in between PTFE frits. Aqueous solutions of 0.1 μg/ml of herbicides were prepared separately, and 10 ml of the solution was passed through the cartridge at the rate of 0.2 ml/min. After passing 10 ml volume of the aqueous solution, residues adsorbed on the cartridge were eluted using 2 ml of acetonitrile. The eluate was injected to determine the herbicide residue adsorbed on the SPE cartridge. Conclusion: In the study, it was found that greater than 90% of the herbicide residues were trapped on silica nanoparticle-based SPE cartridge. An analytical method was developed for the simultaneous determination of these herbicides. The residues were quantified by LC-MS/MS with ESI mode.
Mir Waqas Alam; Tentu Nageswara Rao; Yarasani Prashanthi; Vourse Sridhar; Adil Alshoaibi; Basma Souayeh; Hatem Abuhimd; Faheem Ahmed. Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy. Current Nanoscience 2020, 16, 748 -756.
AMA StyleMir Waqas Alam, Tentu Nageswara Rao, Yarasani Prashanthi, Vourse Sridhar, Adil Alshoaibi, Basma Souayeh, Hatem Abuhimd, Faheem Ahmed. Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy. Current Nanoscience. 2020; 16 (5):748-756.
Chicago/Turabian StyleMir Waqas Alam; Tentu Nageswara Rao; Yarasani Prashanthi; Vourse Sridhar; Adil Alshoaibi; Basma Souayeh; Hatem Abuhimd; Faheem Ahmed. 2020. "Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy." Current Nanoscience 16, no. 5: 748-756.
Mir Waqas Alam; Alaaedeen Abuzir; Basma Souayeh; Essam Yasin; Najib Hdhiri; Fayçal Hammami. Theoretical analysis of carbon nanotubes (SWCNT/MWCNT) over a Wang’s stretching sheet under C-C heat flux. Physica Scripta 2020, 95, 105207 .
AMA StyleMir Waqas Alam, Alaaedeen Abuzir, Basma Souayeh, Essam Yasin, Najib Hdhiri, Fayçal Hammami. Theoretical analysis of carbon nanotubes (SWCNT/MWCNT) over a Wang’s stretching sheet under C-C heat flux. Physica Scripta. 2020; 95 (10):105207.
Chicago/Turabian StyleMir Waqas Alam; Alaaedeen Abuzir; Basma Souayeh; Essam Yasin; Najib Hdhiri; Fayçal Hammami. 2020. "Theoretical analysis of carbon nanotubes (SWCNT/MWCNT) over a Wang’s stretching sheet under C-C heat flux." Physica Scripta 95, no. 10: 105207.
The intricate three-dimensional natural convection and entropy generation of a flow between cuboidal enclosure and a spherical surface is numerically examined in this study. The sphere is maintained hot and centrally located in cubical enclosure with four cooled walls, whereas top and bottom walls are perfectly insulated. The effects of inner shape, Rayleigh numbers, and inclination angles on fluid flow and heat transfer characteristics are analyzed in detail for Rayleigh numbers ranging from 103 to 107 and a tilted angle of the enclosure varying from 0 to 90°. The working fluid is air so that the Prandtl number equates to 0.71. The developed mathematical model is governed by the coupled equations of continuity, momentum, and energy and is solved by a finite volume method. Based on numerical results, two correlation expressions for predicting average Nusselt number of lateral walls of the cubical enclosure and the inner sphere are proposed as a function of Rayleigh number and inclination angle under different wake parameters. By comparing inner spherical shape results with that of cylindrical shape, it can be inferred that using a spherical shape provides the highest thermal performance for heat transfer. Moreover, this comparison reveals that the inner spherical shape decelerates the unsteadiness for the considered inclinations. Results indicate also that the optimal average heat transfer rate is obtained for extreme Rayleigh number, 107, and an inclination of 90° for both cases of the inner sphere and lateral walls of the cuboidal enclosure. The Bejan number and total entropy generation are found to be increased by increasing the inclination angle for the considered Rayleigh numbers. Maximum local entropy generation due to heat transfer and that due to fluid friction decrease gradually by increasing the inclination angle. The results of this investigation find extensive array of applications in several engineering devices, which will be mentioned in the paper content.
Basma Souayeh; Najib Hdhiri; Mir Waqas Alam; Fayçal Hammami; Huda Alfannakh. Convective Heat Transfer and Entropy Generation Around a Sphere Within Cuboidal Enclosure. Journal of Thermophysics and Heat Transfer 2020, 34, 605 -625.
AMA StyleBasma Souayeh, Najib Hdhiri, Mir Waqas Alam, Fayçal Hammami, Huda Alfannakh. Convective Heat Transfer and Entropy Generation Around a Sphere Within Cuboidal Enclosure. Journal of Thermophysics and Heat Transfer. 2020; 34 (3):605-625.
Chicago/Turabian StyleBasma Souayeh; Najib Hdhiri; Mir Waqas Alam; Fayçal Hammami; Huda Alfannakh. 2020. "Convective Heat Transfer and Entropy Generation Around a Sphere Within Cuboidal Enclosure." Journal of Thermophysics and Heat Transfer 34, no. 3: 605-625.
This investigation addresses a systematic numerical method based on the finite volume method and a full multigrid technique to study two-dimensional and three-dimensional flow of an incompressible fluid inside a cavity driven by the motion of the upper lid. Quantitative aspects of two and three dimensional flows in lid-driven cavities are analyzed by encompassing descriptive Reynolds numbers Re bounded by 1000 and 8000 for 2D case, 100 and 1000 for 3D case. Furthermore, the effects of inner spherical shape on fluid flow characteristics have been also investigated. An analysis of the flow evolution demonstrates that, by further increasing Reynolds beyond a certain critical value, the steady flow becomes unstable and bifurcates to the unsteady flow. Results show that the transition to the unsteady regime follows the classical scheme of a Hopf bifurcation, giving rise to a perfectly periodic state. Flow periodicity has been verified through time history plots for the velocity component and phase-space trajectories as a function of Reynolds number for both cases 2D and 3D. It is also concluded that for 2D and 3D configurations, whether the cavity is obstructed or non-obstructed, the refinement of the grid accelerates the appearance of the unsteady regime and delays it in the opposite case. A one-to-one comparison results between a cavity induced by a centrally located inner shape (a sphere for the 3D case and a circle for the 2D case) and a cavity without an inner shape confirms that by using a grid size 642 for the 2D case or 803 for the 3D case, critical Reynolds number for a cavity with an inner shape are less than that without an inner shape.
Basma Souayeh; Mir Waqas Alam; Fayçal Hammami; Najib Hdhiri; Essam Yasin; B. Suaye. Predicting the unsteady states of 2D and 3D lid-driven cavities induced by a centrally located circle and sphere. Fluid Dynamics Research 2020, 52, 025507 .
AMA StyleBasma Souayeh, Mir Waqas Alam, Fayçal Hammami, Najib Hdhiri, Essam Yasin, B. Suaye. Predicting the unsteady states of 2D and 3D lid-driven cavities induced by a centrally located circle and sphere. Fluid Dynamics Research. 2020; 52 (2):025507.
Chicago/Turabian StyleBasma Souayeh; Mir Waqas Alam; Fayçal Hammami; Najib Hdhiri; Essam Yasin; B. Suaye. 2020. "Predicting the unsteady states of 2D and 3D lid-driven cavities induced by a centrally located circle and sphere." Fluid Dynamics Research 52, no. 2: 025507.
The cooling capability of heat sinks is important for a central processing unit (CPU). In this work, simulation has been done to study heat transfer (HT) in a heat sink (HS) mounted on the triangular cylinder chip of a CPU is studied, to explore the thermofluid behaviour of the designed micro-pin-fin heat sink. Air cooling methods are used for heat extraction. This numerical work considers the effects of inlet turbulence intensity (TI) and fin diameter (D) of the micro-pin-fin on the performance of the heat sink. Turbulent SST model is applied to capture turbulence regime in the system. The heat transfer and pressure coefficient were obtained at different Reynolds number (Re) (i.e. different inlet velocities). As shown in this study, the Nusselt number (Nu) increases with increase in air flow velocity which enhance the heat extraction from CPU.
Mir Waqas Alam; Suvanjan Bhattacharyya; Basma Souayeh; Kunal Dey; Faicel Hammami; Mohammad Rahimi-Gorji; Ranjib Biswas. CPU heat sink cooling by triangular shape micro-pin-fin: Numerical study. International Communications in Heat and Mass Transfer 2020, 112, 104455 .
AMA StyleMir Waqas Alam, Suvanjan Bhattacharyya, Basma Souayeh, Kunal Dey, Faicel Hammami, Mohammad Rahimi-Gorji, Ranjib Biswas. CPU heat sink cooling by triangular shape micro-pin-fin: Numerical study. International Communications in Heat and Mass Transfer. 2020; 112 ():104455.
Chicago/Turabian StyleMir Waqas Alam; Suvanjan Bhattacharyya; Basma Souayeh; Kunal Dey; Faicel Hammami; Mohammad Rahimi-Gorji; Ranjib Biswas. 2020. "CPU heat sink cooling by triangular shape micro-pin-fin: Numerical study." International Communications in Heat and Mass Transfer 112, no. : 104455.
Organic thin-film transistors (OTFTs) in device physics is currently considered as a standout amongst the most progressive concepts of device applications. Currently, due to humongous technological progress, OTFT with high mobilities can be produced that are comparable to silicon technology. This remarkable mobility is considered as a benchmark for more demanding applications which is accomplished by novel, tenable organic semiconductor materials such as pentacene and the tailoring of their geometries and characteristics. In addition, pentacene demonstrates charge carrier mobilities up to 5.5 cm2/Vs. However very low mobility was achieved in OTFTs due to fabrication defects, material processing etc. The most important defect that arise during the fabrication process is contact interfaces in OTFTs, which highly effect the device performance. Thus, in this article, we will review the current progress of contact engineering of OTFTs with special emphasis on electrode/pentacene interfaces of pentacene-based organic thin film transistors. Further, this review aims to provide an in-depth understanding of bottlenecks to improve the OTFTs performance. After a short introduction, the historical background of pentacene-based OTFTs is discussed that focuses on different methods and materials employed so far to improve the contact between pentacene layer. Also, the review presents the key challenges in the geometry of pentacene based OTFT that is the direct deposition of metal electrodes onto the pentacene channel layer in top contact interface due to which poor carrier injection, high barrier height, chemical diffusion between both layers, high contact resistance and surface roughness has been observed which highly affects the device performance especially the field effect mobility. Also, the state-of-the-art devices and related models that widely employ pentacene are presented. This detailed review will assist the future researchers in understanding and improving field-effect properties of OTFTs.
Mir Waqas Alam. Current progress in electrode/pentacene interfaces of pentacene-based organic thin films transistors: A review. Materials Express 2019, 9, 691 -703.
AMA StyleMir Waqas Alam. Current progress in electrode/pentacene interfaces of pentacene-based organic thin films transistors: A review. Materials Express. 2019; 9 (7):691-703.
Chicago/Turabian StyleMir Waqas Alam. 2019. "Current progress in electrode/pentacene interfaces of pentacene-based organic thin films transistors: A review." Materials Express 9, no. 7: 691-703.
The finite size effect of CuO nanoparticles and their effect on the magnetic behavior of a CuO–Al2O3 nanocomposite synthesized via a solution combustion method are discussed here. It is observed that the introduction of CuO nanoparticles of ∼20 nm in size on the surfaces of Al2O3 nanosheets strongly influences the magnetic moment of the nanocomposite. The X-ray diffraction pattern reveals the presence of a CuO phase in the CuO–Al2O3 nanocomposite. Electron microscopy imaging shows the presence of CuO nanoparticles distributed over the surfaces of Al2O3 nanosheets. Magnetic measurements performed at 5 and 300 K revealed a strong enhancement in the saturation magnetization of the CuO–Al2O3 nanocomposite at both temperatures. This increase is due to the formation of CuO nanoparticles on the surfaces of the Al2O3 nanosheets. These CuO nanoparticles show a ferromagnetic nature due to the uncompensated surface Cu2+ spins of the copper ions. The presence of the Cu2+ state in the CuO nanoparticles in the CuO–Al2O3 nanocomposite was confirmed by X-ray photoelectron spectroscopy (XPS) measurements.
Mir Waqas Alam; Farooq Ahmad Dar; Fida Mohmed; Abdullah Aljaafari; Osama Saber Mohamed. Augmentation of ferromagnetism in CuO–Al2O3 nanocomposite synthesized via solution combustion method. Materials Express 2019, 9, 653 -659.
AMA StyleMir Waqas Alam, Farooq Ahmad Dar, Fida Mohmed, Abdullah Aljaafari, Osama Saber Mohamed. Augmentation of ferromagnetism in CuO–Al2O3 nanocomposite synthesized via solution combustion method. Materials Express. 2019; 9 (6):653-659.
Chicago/Turabian StyleMir Waqas Alam; Farooq Ahmad Dar; Fida Mohmed; Abdullah Aljaafari; Osama Saber Mohamed. 2019. "Augmentation of ferromagnetism in CuO–Al2O3 nanocomposite synthesized via solution combustion method." Materials Express 9, no. 6: 653-659.
We present electronic and transport properties of a zigzag nanoribbon made of $\alpha-\mathcal{T}_3$ lattice. Our particular focus is on the effects of the continuous evolution of the edge modes ( from flat to dispersive) on the thermoelectric transport properties. Unlike the case of graphene nanoribbon, the zigzag nanoribbon of $\alpha-\mathcal{T}_3$ lattice can host a pair of dispersive (chiral) edge modes at the two valleys for specific width of the ribbon. Moreover, gap opening can also occur at the two valleys depending on the width. The slope of the chiral edge modes and the energy gap strongly depend on the relative strength of two kinds of hoping parameters present in the system. We compute corresponding transport coefficients such as conductance, thermopower, thermal conductance and the thermoelectric figure of merits by using the tight-binding Green function formalism, in order to explore the roles of the dispersive edge modes. It is found that the thermopower and thermoelectric figure of merits can be enhanced significantly by suitably controlling the edge modes. The figure of merits can be enhanced by thirty times under suitable parameter regime in comparison to the case of graphene. Finally, we reveal that the presence of line defect, close to the edge, can cause a significant impact on the edge modes as well as on electrical conductance and thermopower.
Mir Waqas Alam; Basma Souayeh; S K Firoz Islam. Enhancement of thermoelectric performance of a nanoribbon made of $\alpha-\mathcal{T}_3$ lattice. Journal of Physics: Condensed Matter 2019, 31, 485303 .
AMA StyleMir Waqas Alam, Basma Souayeh, S K Firoz Islam. Enhancement of thermoelectric performance of a nanoribbon made of $\alpha-\mathcal{T}_3$ lattice. Journal of Physics: Condensed Matter. 2019; 31 (48):485303.
Chicago/Turabian StyleMir Waqas Alam; Basma Souayeh; S K Firoz Islam. 2019. "Enhancement of thermoelectric performance of a nanoribbon made of $\alpha-\mathcal{T}_3$ lattice." Journal of Physics: Condensed Matter 31, no. 48: 485303.
Interest in pseudocapacitive materials, especially cuprous oxide, has grown owing to its various advantageous properties and application as electrode materials in the energy storage devices. The work presented here, a cubic Cu2O framework was synthesized using a simple and one-step modified polyol-assisted (metal-organic framework) solvothermal method. The structural configuration was rationalized by systematically studying the effect of the reaction time on the morphology and growth of the Cu2O. In addition, a range of microscopic and spectroscopic techniques was employed to further characterize the obtained cubic Cu2O. The morphological effect on the electrochemical supercapacitive performance of the obtained cubic Cu2O was also examined by cyclic-voltammetry (CV) and galvanostatic-charge-discharge (G-C-D) method. The obtained outcome shows that the cubic Cu2O synthesized using a reaction time of 12 h (Cu2O-12h; Csp ~365 Fg−1) exhibited superior capacitive performance as compared to the cubic Cu2O synthesized at 8 h (Cu2O-8h; Csp ~151 Fg−1) and 10 h (Cu2O-10h; Csp ~195 Fg−1) at the current density of 0.75 Ag−1. Furthermore, the Cu2O-12h electrode exhibits energy density of 16.95 Wh/Kg at a power density of 235.4 W/Kg and higher power density of 2678.5 W/Kg at low current density. In particular, the cube-like Cu2O-12h exhibited excellent capacitive performance and rate capability as compared to Cu2O-8h and Cu2O-10h, owing to its unique three-dimensional morphology, which facilitates the formation of various active sites for intercalation of the electrolyte during the electrochemical process. These results show the as-obtained Cu2O could be a promising supercapacaitive electrode material for various applications.
Abdullah Aljaafari; Nazish Parveen; Faheem Ahmad; Mir Waqas Alam; Sajid Ali Ansari. Self-assembled Cube-like Copper Oxide Derived from a Metal-Organic Framework as a High-Performance Electrochemical Supercapacitive Electrode Material. Scientific Reports 2019, 9, 1 -10.
AMA StyleAbdullah Aljaafari, Nazish Parveen, Faheem Ahmad, Mir Waqas Alam, Sajid Ali Ansari. Self-assembled Cube-like Copper Oxide Derived from a Metal-Organic Framework as a High-Performance Electrochemical Supercapacitive Electrode Material. Scientific Reports. 2019; 9 (1):1-10.
Chicago/Turabian StyleAbdullah Aljaafari; Nazish Parveen; Faheem Ahmad; Mir Waqas Alam; Sajid Ali Ansari. 2019. "Self-assembled Cube-like Copper Oxide Derived from a Metal-Organic Framework as a High-Performance Electrochemical Supercapacitive Electrode Material." Scientific Reports 9, no. 1: 1-10.
Mir Waqas Alam; Ahsanulhaq Qurashi. Metal Chalcogenide Quantum Dots for Hybrid Solar Cell Applications. Metal Chalcogenide Nanostructures for Renewable Energy Applications 2014, 233 -246.
AMA StyleMir Waqas Alam, Ahsanulhaq Qurashi. Metal Chalcogenide Quantum Dots for Hybrid Solar Cell Applications. Metal Chalcogenide Nanostructures for Renewable Energy Applications. 2014; ():233-246.
Chicago/Turabian StyleMir Waqas Alam; Ahsanulhaq Qurashi. 2014. "Metal Chalcogenide Quantum Dots for Hybrid Solar Cell Applications." Metal Chalcogenide Nanostructures for Renewable Energy Applications , no. : 233-246.
Mir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. Temperature Dependence of Barrier Height and Performance Enhancement of Pentacene Based Organic Thin Film Transistor with Bi-Layer MoO3/Au Electrodes. Current Nanoscience 2013, 9, 407 -410.
AMA StyleMir Waqas Alam, Zhaokui Wang, Shigeki Naka, Hiroyuki Okada. Temperature Dependence of Barrier Height and Performance Enhancement of Pentacene Based Organic Thin Film Transistor with Bi-Layer MoO3/Au Electrodes. Current Nanoscience. 2013; 9 (3):407-410.
Chicago/Turabian StyleMir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. 2013. "Temperature Dependence of Barrier Height and Performance Enhancement of Pentacene Based Organic Thin Film Transistor with Bi-Layer MoO3/Au Electrodes." Current Nanoscience 9, no. 3: 407-410.
We fabricated top-contact pentacene-based organic thin-film transistors (OTFTs) with bilayer WO3/Au electrodes. Compared with those of a device without a WO3 layer, the performance characteristics including field-effect mobility, threshold voltage, and On/Off ratio were highly improved in a device with a 5 nm WO3 hole injection layer inserted. The field-effect mobility was increased from 0.47 to 0.69 cm2 V-1 s-1 and the On/Off ratio was also increased from 1.8×104 to 4.1×104. From the results of evaluating the temperature dependence of ID–VD characteristics and the surface morphology of pentacene, the improved device performance was attributed to reductions in barrier height and surface roughness after inserting a suitable WO3 layer between the pentacene and gold electrodes.
Mir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. Performance Enhancement of Top-Contact Pentacene-Based Organic Thin-Film Transistors with Bilayer WO3/Au Electrodes. Japanese Journal of Applied Physics 2013, 52, 03BB08 .
AMA StyleMir Waqas Alam, Zhaokui Wang, Shigeki Naka, Hiroyuki Okada. Performance Enhancement of Top-Contact Pentacene-Based Organic Thin-Film Transistors with Bilayer WO3/Au Electrodes. Japanese Journal of Applied Physics. 2013; 52 (3):03BB08.
Chicago/Turabian StyleMir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. 2013. "Performance Enhancement of Top-Contact Pentacene-Based Organic Thin-Film Transistors with Bilayer WO3/Au Electrodes." Japanese Journal of Applied Physics 52, no. 3: 03BB08.
The enhancement of the charge injection and field effect mobility by inserting a thin (5 nm) germanium oxide (GeO) interlayer between the Auelectrode and pentacene layer in a top contact pentacene based organic thin-film transistor (OTFTs) was reported. In comparison with the pentacene-based OTFT with only-Au electrode, the device performance has been considerably improved, which exhibits the highest field effect mobility of 0.96 cm2/Vs. The improvement was attributed to significant reduction of barrier height at Au/pentacene interfaces and smoothed surface of pentacene layer after inserting a thin GeO layer.
Mir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. Mobility enhancement of top contact pentacene based organic thin film transistor with bi-layer GeO/Au electrodes. Applied Physics Letters 2013, 102, 061105 .
AMA StyleMir Waqas Alam, Zhaokui Wang, Shigeki Naka, Hiroyuki Okada. Mobility enhancement of top contact pentacene based organic thin film transistor with bi-layer GeO/Au electrodes. Applied Physics Letters. 2013; 102 (6):061105.
Chicago/Turabian StyleMir Waqas Alam; Zhaokui Wang; Shigeki Naka; Hiroyuki Okada. 2013. "Mobility enhancement of top contact pentacene based organic thin film transistor with bi-layer GeO/Au electrodes." Applied Physics Letters 102, no. 6: 061105.
Mir Waqas Alam; Usmah Khatoon; Ahsanulhaq Qurashi. Synthesis and Characterization of Cu-SnO2 Nanoparticles Deposited on Glass Using Ultrasonic Spray Pyrolysis and their H2S Sensing Properties. Current Nanoscience 2012, 8, 919 -924.
AMA StyleMir Waqas Alam, Usmah Khatoon, Ahsanulhaq Qurashi. Synthesis and Characterization of Cu-SnO2 Nanoparticles Deposited on Glass Using Ultrasonic Spray Pyrolysis and their H2S Sensing Properties. Current Nanoscience. 2012; 8 (6):919-924.
Chicago/Turabian StyleMir Waqas Alam; Usmah Khatoon; Ahsanulhaq Qurashi. 2012. "Synthesis and Characterization of Cu-SnO2 Nanoparticles Deposited on Glass Using Ultrasonic Spray Pyrolysis and their H2S Sensing Properties." Current Nanoscience 8, no. 6: 919-924.