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Krol J.B.,Warsaw University of Technology | Khan R.,University of Engineering & Technology, Peshawar | Collop A.C.,De Montfort University
Road Materials and Pavement Design | Year: 2017

X-ray computed tomography (CT) and laboratory permeability techniques were applied to study the internal properties of porous asphalt mixture. Specimens containing aggregate of different gradations and of different mineral compositions were prepared in the laboratory. The air voids of all the specimens were determined in the laboratory and the specimens were then scanned in X-ray CT. The same samples were then tested for laboratory permeability. The active air voids and contact points of aggregate with nearby aggregate particles were determined from X-ray CT images. The laboratory permeability test results were found in comparison with X-ray CT values of voids’ internal connectivity. A comparatively high permeability value was observed for porous asphalt with maximum aggregate size irrespective of its mineral composition. The size of air voids and volume of active (connected) air voids were also found high for mixtures made up of large aggregate size. The difference in mineral composition of aggregate was found to have considerably less effect on permeability of porous asphalt. © 2017 Informa UK Limited, trading as Taylor & Francis Group


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: INCO.2013-1.6 | Award Amount: 335.55K | Year: 2013

CASCADE aims to provide the foundation for a future INCONET programme targeting South Asian Countries, which will promote bi-regional coordination of Science &Technology (S&T) cooperation, including priority setting and definition of S&T cooperation policies. The objectives of CASCADE, as an 18-month supporting action, are to: compile a regional position paper that identifies global challenges and research priorities; map and develop an inventory of national and regional stakeholders related to global challenges; and, raise awareness on research & innovation priorities for fostering cooperation and towards building mutual understanding on how to address common global societal challenges. CASCADE targets & has the participation of all South Asian countries specified in the Call: Afghanistan, Bangladesh, Bhutan, Maldives, Nepal, Pakistan and Sri Lanka. The project comprises five work packages (WP). WP1 will, coordinate the delivery of project outputs, ensure achievement of anticipated outcomes, and develop and manage project infrastructure. WP2 will produce national (Afghanistan, Bangladesh,Bhutan, Maldives, Nepal, Pakistan and Sri Lanka) and regional (Southern Asia) position papers providing a consensus on the key societal challenges in the region linked to Horizon2020. These papers will be used as the basis for WP3: the identification and mapping of key national and regional stakeholders that can influence and address these societal challenges. WP4 will engage these key stakeholders, raise awareness of the potential for EU-Southern Asia cooperation, and stimulate their participation in Horizon 2020. WP5 will use the position papers from WP2 and stakeholder maps from WP3 to compile a policy brief with recommendations to the European Commission on how to promote bi-lateral cooperation with Southern Asia with a view to tackling key societal challenges of mutual interest. WP5 will also promote Southern Asian contacts among major European stakeholders.


PubMed | Beijing University of Chemical Technology, Mehran University of Engineering and Technology, Heriot - Watt University and University of Engineering & Technology, Peshawar
Type: | Journal: Bioresource technology | Year: 2014

The remediation kinetics of simulated sugar factory wastewater (SFW) using an algal-bacterial culture (ABC) of Chlorella vulgaris in association with Pseudomonas putida in a raceway reactor was found to be enhanced by 89% with the addition of 80ppm of copolymer Polyacrylate polyalcohol (PAPA). This was achieved by efficient suspension of the ABC throughout the water body maintaining optimum pH and dissolved oxygen that led to rapid COD removal and improved algal biomass production. The suspension of the ABC using the co-polymer PAPA maintained a DO of 8-10mgl(-1) compared to 2-3mgl(-1) when not suspended. As a result, the non-suspended ABC only achieved a 50% reduction in COD after 96h compared to a 89% COD removal using 80ppm PAPA suspension. In addition, the algae biomass increased from 0.4gl(-1)d(-1) for the non-suspended ABC to 1.1gl(-1)d(-1) when suspended using 80ppm PAPA.


El-Dessouky H.,Islamic University | Ahmad J.,University of Engineering & Technology, Peshawar | Alzarah A.,King Abdulaziz City for Science and Technology
Chemical Engineering Communications | Year: 2016

The main objective of this study is to experimentally evaluate the effect of the air precooler heat transfer area on the effectiveness of a two-stage evaporative air cooler. To the best of our knowledge, this effect has not been studied before. In the experimental unit used, there were three identical heat exchangers to precool the ambient air prior to its flow into the direct evaporative cooling unit. These heat exchangers can work individually or be combined to control the total heat transfer area of the air precooler. In addition, the effectiveness of the two-stage system was measured as a function of the ratio between the mass flow rate of water flowing over the packing and the mass flow rate of the dry air passing through the packing; the effectiveness also depends on the mass flow rate of water flowing into the precoolers. The data obtained showed that there is an optimum value for the air precooler heat transfer area at which the thermal performance of the two-stage evaporative cooler has the maximum value. Moreover, the system effectiveness improved with the rate of flow of water into the first and the second precoolers. Note that the optimum value of the precooler heat transfer area should be determined accurately for each set of design and operating conditions. © 2016, Copyright © Taylor & Francis Group, LLC.


Khan S.,University of Engineering & Technology, Peshawar | Ahmad N.,University of Engineering & Technology, Peshawar | Wahid M.,University of Engineering & Technology, Peshawar
Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an | Year: 2015

Variable least significant bits (VLSB) steganography is a pretty powerful and secure technique for data hiding in cover images, having variable data hiding capacity, signal-to-noise ratio, peak signal-to-noise ratio, and mean square error (MSE). This study presents a new algorithm for the implementation of VLSB steganography named varying index varying bits substitution (VIVBS). The VIVBS algorithm is a very secure, high capacity, flexible, and statistically unpredictable mechanism to conceal information in cover images. The method uses a secret stego-key comprising a reference point, and variation of the number of bits to be hidden with varying indices of pixels in the cover image. The secret key adds an extra feature of security to steganography, making it much immune to steganalysis. The VIVBS algorithm is capable of providing variable data hiding capacity and variable key size which can be changed by changing the range of least significant bits used. A data hiding capacity of 43.75% with a negligible MSE 14.67 dB has been achieved using the VIVBS algorithm. For larger data hiding capacity, the MSE and distortion increases significantly which make the existence of information predictable but the key size also increases significantly, making the retrieval of hidden information difficult for the unauthorized person. © 2015 The Chinese Institute of Engineers


Waqas M.,Quaid-i-Azam University | Farooq M.,Riphah International University | Khan M.I.,Quaid-i-Azam University | Alsaedi A.,King Abdulaziz University | And 4 more authors.
International Journal of Heat and Mass Transfer | Year: 2016

The present paper addresses magnetohydrodynamics (MHD) flow of micropolar liquid towards nonlinear stretched surface. Analysis is presented with viscous dissipation, Joule heating and convective boundary condition. Characteristics of heat transfer are analyzed with mixed convection phenomenon. Dimensional nonlinear equations are converted into dimensionless expressions by employing suitable transformations. Homotopic procedure is implemented to solve the governing dimensionless problems. Behaviors of several sundry variables on the flow and heat transfer is scrutinized. Skin friction coefficient and local Nusselt number are presented and evaluated. Obtained results are also compared with the available data in the limiting case and good agreement is noted. © 2016 Elsevier Ltd


Arshad M.A.,University of Engineering & Technology, Peshawar
Earthquake Science | Year: 2016

An inversion method was applied to crustal earthquakes dataset to find S-wave attenuation characteristics beneath the Eastern Tohoku region of Japan. Accelerograms from 85 shallow crustal earthquakes up to 25 km depth and magnitude range between 3.5 and 5.5 were analyzed to estimate the seismic quality factor Qs. A homogeneous attenuation model Qs for the wave propagation path was evaluated from spectral amplitudes, at 24 different frequencies between 0.5 and 20 Hz by using generalized inversion technique. To do this, non-parametric attenuation functions were calculated to observe spectral amplitude decay with hypocentral distance. Then, these functions were parameterized to estimate Qs. It was found that in Eastern Tohoku region, the Qs frequency dependence can be approximated with the function 33 f1.22 within a frequency range between 0.5 and 20 Hz. However, the frequency dependence of Qs in the frequency range between 0.5 and 6 Hz is best approximated by Qs (f) = 36 f0.94 showing relatively weaker frequency dependence as compared to the relation Qs (f) = 6 f2.09 for the frequency range between 6 and 15 Hz. These results could be used to estimate source and site parameters for seismic hazard assessment in the region. © 2016, The Author(s).


Khan M.I.,Heriot - Watt University | Yasmeen T.,Imperial College London | Yasmeen T.,University of Engineering & Technology, Peshawar | Khan M.I.,Quaid-i-Azam University | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2016

Among all alternative fuels, compressed natural gas (CNG) has been considered as one the best solutions for fossil fuel substitution because of its availability throughout the world, inherent clean burning, economical as a fuel and adaptability to the gasoline and diesel engines. This bibliography reviews the potential of CNG as a transportation fuel. The added bibliography at the end of this article contains 1102 references to papers, conference proceedings and theses/dissertations on the subject that were published between 1991 and 2016. These references have been retrieved from 137 scientific journals. The references are classified in the following categories: Regional Experience with CNG Vehicles; Economic Aspect of CNG Vehicles; CNG Engine's Design, Control and Performance; Combustion and Fuel Injection Characteristics of CNG Engines; CNG/ Diesel Dual Fuel Operations; Hydrogen Enriched CNG Vehicles; Environmental Aspect of CNG Vehicles; Safety Aspect of CNG Vehicles. © 2016 Elsevier Ltd


Kang C.W.,Hanyang University | Ullah M.,Hanyang University | Sarkar B.,Hanyang University | Hussain I.,University of Engineering & Technology, Peshawar | Akhtar R.,University of Engineering & Technology, Peshawar
International Journal of Production Research | Year: 2016

Literature has focused inventory models with intensive emphasis on imperfect production processes in recent past. However, the work-in-process-based inventory models have been ignored, relatively, in general and the impact of random defects in the form of reworkable and non-reworkable defect rate on lot size and total cost function in particular. This paper develops mathematical models for work-in-process-based inventory by incorporating the effect of random defects rate on lot size and expected total cost function. Our proposed models assume that defective products produced during the production process follow random distributions. Defective products, either in the form of reworkable or rejected production units, follow four types of distribution density functions: uniform, triangular, double triangular and beta distribution. Mathematical models are derived for optimum lot size based on minimization of expected total cost function through the analytical optimization approach. Numerical examples and detailed sensitivity analysis are carried to illustrate and compare the proposed models at different levels of distribution functions’ parameters. © 2016 Informa UK Limited, trading as Taylor & Francis Group


PubMed | University of Engineering & Technology, Peshawar
Type: | Journal: TheScientificWorldJournal | Year: 2016

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908mV at the current level of 155A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1F, 5.5V) and rechargeable battery (Nickel-Cadmium, 3.8V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented.

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