ORCID Profile
0000-0002-2771-0251
Current Organisations
Chongqing University
,
COMSATS University Islamabad, Lahore Campus, Pakistan
,
COMSATS University Islamabad - Lahore Campus
,
Lanzhou University
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Publisher: MDPI AG
Date: 29-06-2021
DOI: 10.3390/NANO11071710
Abstract: Cu- and Sm-doped ZnO nanorod arrays were grown with 1 wt% of Sm and different weight percents (0.0, 0.5, 1.0 and 1.5 wt%) of Cu by two-step hydrothermal method. The influence of Cu concentration and precursor of Sm on the structural, optical and photovoltaic properties of ZnO nanorod arrays was investigated. An X-ray diffraction study showed that the nanorod arrays grown along the (002) plane, i.e., c-axis, had hexagonal wurtzite crystal structure. The lattice strain is present in all s les and shows an increasing trend with Cu/Sm concentration. Field emission scanning electron microscopy was used to investigate the morphology and the nanorod arrays grown vertically on the FTO substrates. The diameter of nanorod arrays ranged from 68 nm to 137 nm and was found highly dependent on Cu concentration and Sm precursor while the density of nanorod arrays almost remains the same. The grown nanorod arrays served as photoelectrodes for fabricating dye-sensitized solar cells (DSSCs). The overall light to electricity conversion efficiency ranged from 1.74% (s le S1, doped with 1 wt% of Sm and 0.0 wt% of Cu) to more than 4.14% (s le S4, doped with 1 wt% of Sm and 1.5 wt% of Cu), which is 60% higher than former s le S1. The increment in DSSCs efficiency is attributed either because of the doping of Sm3+ ions which increase the absorption region of light spectrum by up/down conversion or the doping of Cu ions which decrease the recombination and backward transfer of photo-generated electrons and increase the electron transport mobility. This work indicates that the coupled use of Cu and Sm in ZnO nanorod array films have the potential to enhance the performance of dye-sensitized solar cells.
Publisher: MDPI AG
Date: 12-09-2022
DOI: 10.3390/SU141811422
Abstract: With the development of intelligent transportation systems, research into intelligent traffic signal control has received considerable attention. To date, many traffic signal control models have been studied, where most of the models concentrate on how to minimize travel time, vehicle delay, and the number of stops or how to maximize capacity. This study introduces the Garra Rufa–inspired (GRI) algorithm, which is used to optimize traffic signal control modelling considering the number of vehicles in a queue. GRI has the characteristics of using the decision variables of the code as the operation object, directly using the objective function value for the search information, using multiple search points at the same time, and using probability search technology. Theoretical analysis of intelligent optimization and research into application methods were carried out to resolve the problem of traffic signal optimization control. The output of the GRI algorithm was compared, calibrated, and validated with SIDRA. Furthermore, to obtain more comprehensive results, the genetic algorithm (GA) and particle swarm optimization (PSO) were also compared. The results of the analysis show that the GRI decreases by 10.1% (intersection A) and 16.5% (intersection B) in the number of vehicles in the queue.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 02-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TA04855D
Abstract: We proposed an effective strategy to address the structural limitations of metal organic frameworks for energy storage devices. An oriented n-type Ni–Co-MOF was grown on solution-free p-type CuO nanowires.
Publisher: American Chemical Society (ACS)
Date: 23-03-2023
Publisher: Elsevier BV
Date: 11-2020
Publisher: MDPI AG
Date: 15-08-2022
DOI: 10.3390/NANO12162796
Abstract: Nanocomposites of polyvinylidene fluoride (PVDF) with dimensional (1D) cobalt oxide (Co3O4) and f-MWCNTs were prepared successfully by the solution casting method. The impact of 1D Co3O4 filler and 1D Co3O4/f-MWCNTs co-fillers on the structural, thermal, and electrical behavior of PVDF were studied. The crystal structural properties of pure PVDF and its nanocomposite films were studied by XRD, which revealed a significant enhancement of β-phase PVDF in the resulting nanocomposite films. The increase in β-phase was further revealed by the FTIR spectroscopic analysis of the s les. TG, DTA, and DSC analyses confirmed an increase in thermal stability of PVDF with the addition of nano-fillers as well as their increasing wt.%. From impedance spectroscopic studies, it was found that the DC conductivity of PVDF increases insignificantly initially (up to 0.1 wt.% of nano-fillers addition), but a significant improvement in DC conductivity was found at higher concentrations of the nano-fillers. Furthermore, it was observed that the DC conductivity decreases with frequency. The increase in DC conductivity corresponded to the strong interactions of nano-fillers with PVDF polymer chains.
Publisher: Elsevier BV
Date: 02-2016
Publisher: MDPI AG
Date: 27-09-2020
Abstract: The application of wide band-gap power electronic devices brings more challenges to insulating packaging technology. Knowing the influence of applied voltage parameters on insulation performance is helpful to evaluate the insulation condition of electric power equipment. In this paper, the effect of repetitive square wave voltage duty cycle on the growth characteristics of electrical trees in epoxy resin was studied. The experimental results show that the square wave voltage duty cycle has a significant influence on treeing features. The electrical tree proportion initiation has shown a decreasing trend, and the shape of the electrical tree changes from pine-like to branch-like by increasing the duty cycles. The length and damaged area of electrical tree increased with the increase in the duty cycle up to 10% and then decrease by increasing the duty cycle higher than 30%. It indicates that a low duty cycle will enhance the electron injection and accumulate space charges and thus accelerate electrical tree development. Under short duty cycles, the electric field due to the shielding effect near the needle tip suppresses the electrical tree growth, which results in treeing growth stagnation. The obtained results are helpful to keep these parameters in mind during the design of epoxy-based insulation such high-voltage rotating machines and power electronic device packaging.
Publisher: Elsevier BV
Date: 11-2015
Publisher: American Chemical Society (ACS)
Date: 02-2022
Abstract: Not only are new and novel materials sought for electrode material development, but safe and nontoxic materials are also highly being intensively investigated. Herein, we prepare ZnNiBO
Publisher: Elsevier BV
Date: 08-2016
Location: Pakistan
No related grants have been discovered for Muhammad Sufyan Javed.