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Evaluation of user’s perceptions regarding performance indicators of intercity bus terminals in Lahore, Pakistan

Ikhlaq S., Javid M. A., Qayyum T. I.

Transport Problems

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2017

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T. 12, z. 2

123--136

EN

This study aims to evaluate the intercity bus terminals in metropolitan Lahore, Pakistan. In this regard eleven intercity bus terminals of Lahore (three government-owned & eight privately owned) were selected. Evaluation of performance indicators (PIs) for a sustainable design of intercity bus terminals was conducted with the help of different surveys. Six PIs on user perception were evaluated, i.e., safety and security, access, information, connection and reliability, environment and allied facilities. The bus terminals and PIs were also ranked according to user satisfaction. The results showed that the privately owned intercity bus terminals perform better and are more likely to be sustainable as compared with government-owned terminals. Likewise, the users indicated more satisfaction with the privately owned terminals. In addition, the users rated ‘safety and security’ as the most important among the six PIs. It is recommended to establish standards for sustainable design of intercity bus terminals using the six PIs as measures of performance.

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First principle calculations of electronic and magnetic properties of Mn-doped CdS (zinc blende): a theoretical study

Ahmed N., Nabi A., Nisar J., Tariq M., Javid M. A., Nasim M. H.

Materials Science Poland

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2017

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Vol. 35, No. 3

479--485

EN

The electronic structure and magnetic properties of Mn doped zinc blende cadmium sulfide Cd1-xMnxS (x = 6.25 %) have been studied using spin-polarized density functional theory within the framework of Generalized Gradient Approximation (GGA), its further corrections including Hubbard U interactions (GGA + U) and a model for exchange and correlation potential Tran Blaha modified Becke-Johnson (TB-mBJ). Ferromagnetic interactions have been observed between Mn atoms via S atom due to strong p-d hybridization. The magnetic moments on Mn and its neighboring atoms have also been studied in detail using different charge analysis techniques. It has been observed that p-d hybridization reduced the value of local magnetic moment of Mn in comparison to its free space charge value and produced small local magnetic moments on the nonmagnetic S and Cd host sites. The magnetocrystalline anisotropy in [1 0 0] and [1 1 1] directions as well as exchange splitting parameters Noα and Noβ have been analyzed to confirm that ferromagnetism exists. We conclude that the ferromagnetic phase in Mn-doped CdS is not stable in “near” configuration but it is stable for “far” configuration. Mn doped CdS is a p-type semiconductor and the d-states at the top of the valence band edge give a very useful material for photoluminescence and magneto-optical devices.

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Synthesis and study of structural properties of Sn doped ZnO nanoparticles

Javid M. A., Rafi M., Ali I., Hussain F., Imran M., Nasir A.

Materials Science Poland

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2016

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Vol. 34, No. 4

741--746

EN

Pure and Sn-doped ZnO nanostructures were synthesized by simple chemical solution method. In this method we used zinc nitrate and NaOH as precursors. Sn doping content in ZnO was taken with the ratio 0, 5, 10, 15 and 20 percent by weight. Physical properties of Sn-doped ZnO powder were studied by XRD analysis which revealed that Sn doping had a significant effect on crystalline quality, grain size, intensity, dislocation density and strain. The calculated average grain size of pure ZnO was 21 nm. The best crystalline structure was found for 0 wt.%, 5 wt.% and 10 wt.% Sn doping as observed by FESEM and XRD. However, higher Sn-doping (> 10 wt.%) degraded the crystallinity and the grain size of 27.67 nm to 17.76 nm. The structures observed in FESEM images of the samples surfaces were irregular and non-homogeneous. EDX depicted no extra peak of impurity and confirmed good quality of the samples.