Waqas Muhammad Khan

Dr. Waqas Muhammad Khan


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 September 2020
Verified
Book Chapter
Open access
PDF file
WSWiqar H Shah
Wiqar H Shah
WKWaqas Muhammad Khan
Waqas Muhammad Khan
We will discuss the development of a new ternary and quaternary tellurium telluride chalcogenide nanoparticles used for efficient thermo-electric waste heat energy convertor called thermo-electric generator. Nanoparticles-based tellurium telluride chalcogenide nanoparticles, which will be used for thermoelectric generator, will eventually solve an important issue of the energy crises, that is, conversion of waste heat into useful electrical energy. By injecting charge carriers in the host matrix of Tl10-x-yAxByTe6 nanomaterials system, different types of dopants (A = Pb, Sn, Ca and B = Pb, Sb Sr, etc.), with x = 0–2.5 and y = 0–2.5 on tellurium telluride has been introduced to synthesize new materials by Co-precipitation techniques and also by solid state reaction techniques followed by Ball-Milling for the fabrication of nanomaterials. We will study the effect of reduction of charge carriers in thermal and transport properties using different dopants contents by replacing host atoms. The charge carrier’s concentration will affect the ratio of electron-hole concentration which in turns increases the electron scattering in these chalcogenide nanoparticles, which will affect the electrical conductivity and thermo-power. The prime purpose of doping with different ionic radii and different concentration is to enhance the power factor for the tellurium telluride nanosystem. At the end one will be able to control different physical parameters such as, thermally assisted electrical conductivity, and thermopower. Different characterization technique will be applied, for example, X-Ray diffraction techniques will be used for structural analysis, SEM will shows the morphological structure of the particles at 100 nm and energy dispersive x-rays spectroscopy will be used for elemental analysis. The electrical conductivity will be measured by four-probe resistivity measurement techniques, and Seebeck coefficient will be measured by standard temperature gradient techniques.

3 September 2025
Verified
Book Chapter
Open access
PDF file
RKRaj Bano Khan
Raj Bano Khan
SKSajjad Muhammad Khan
Sajjad Muhammad Khan
WKWaqas Muhammad Khan
Waqas Muhammad Khan
This study explores the evolution of sentiment expressed in a fictional dataset by characters and inspect the correlation between specific events and important change in sentiment. We employ completely sentiment analysis framework to examine carefully selected set of text in order to capture the emotional journeys that the characters take throughout the story. Using VADER and TextBlob, among other techniques, we measure changes in sentiment at different story points and pinpoint the critical areas that elicit strong emotion reaction. Our results shows that significant character interactions, including disputes and reconciliations, and large plot twists, like unexpected disclosures, are highly correlated with the significant changes in sentiment. Tjis study sheds the light on the complex interplay between character emotions and story structure, offering insightful observations about the dynamics.

17 November 2021
Verified
Book Chapter
Open access
PDF file
WKWaqas Muhammad Khan
Waqas Muhammad Khan
WSWiqar Hussain Shah
Wiqar Hussain Shah
In future, the most common batteries will be the thallium. As there is many types of batteries but the thallium batteries are better from them. In here, we have made the compound which is more positive work than the other batteries. The different elements are doping in the tellurium telluride to determine the different properties like electrical and thermal properties of nanoparticles. The chalcogenide nanoparticles can be characteristics by the doping of the different metals which are like the holes. We present the effects of Pb and Sn doping on the electrical and thermoelectric properties of Tellurium Telluride Tl10-xPbxTe6 and Tl10-xSnxTe6 (x = 1.00, 1.25, 1.50, 1.75, 2.00) respectively, which were prepared by solid state reactions in an evacuated sealed silica tubes. Structurally, all these compounds were found to be phase pure as confirmed by the x-rays diffractometery (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis. The thermo-power or Seebeck co-efficient (S) was measured for all these compounds which show that S increases with increasing temperature from 295 to 550 K. The Seebeck coefficient is positive for the whole temperature range, showing p-type semiconductor characteristics. Similarly the electrical conductivity (σ) and the power factors have also complex behavior with Pb and Sn concentrations. The power factor (PF = S2σ) observed for Tl10-xPbxTe6 and Tl10-xSnxTe6 compounds are increases with increase in the whole temperature range (290 K–550 K) studied here. Telluride’s are narrow band-gap semiconductors, with all elements in common oxidation states, according to (Tl+)9(Pb3+)(Te2−)6 and (Tl+)9(Sn3+)(Te2−)6. Phases range were investigated and determined with different concentration of Pb and Sn with consequents effects on electrical and thermal properties.

6 July 2022
Verified
Book Chapter
Open access
WKWaqas Muhammad Khan
Waqas Muhammad Khan
WSWiqar Hussain Shah
Wiqar Hussain Shah
The different elements are doping in the tellurium telluride to determine the different properties like electrical and thermal properties of nanoparticles. The chalcogenide nanoparticles can be characteristics by the doping of the different metals which are like the holes. We present the effects of Pb doping on the electrical and thermoelectric properties of Tellurium Telluride Tl10-xPbxTe6 (x = 1.000, 1.250, 1.500, 1.750, 2.000) respectively, which were prepared by solid state reactions in an evacuated sealed silica tubes. Structurally, all these compounds were found to be phase pure as confirmed by the x-rays diffractometery (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis. The thermo-power or Seebeck co-efficient (S) was measured for all these compounds which show that S increases with increasing temperature from 295 to 550 K. The Seebeck coefficient is positive for the whole temperature range, showing p-type semiconductor characteristics. Similarly, the electrical conductivity (σ) and the power factors have also complex behavior with Pb and Sn concentrations. The power factor (PF=S2σ) observed for Tl10-xPbxTe6 compounds are increases with increase in the whole temperature range (290 K-550 K) studied here. Telluride’s are narrow band-gap semiconductors, with all elements in common oxidation states, according to (Tl+) 9 (Pb3+)(Te2−)6. Phases range were investigated and determined with different concentration of Pb and Sn with consequents effects on electrical and thermal properties.