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233 results on '"Qamar, Adnan"'

28. Validating global horizontal irradiance estimated by McClear model under clear-sky and all-sky conditions in Pakistan.

Author

Tahir, Zia ul Rehman, Amjad, Ghulam Murtaza, Hamza, Muhammad, Shad, Muhammad Rizwan, Qamar, Adnan, Blanc, Philippe, Abbas, Sabtain, Azhar, Muhammad, Safyan, Muhammad, Abdullah, Muhammad, Atif, Muhammad, and Haider, Syed Tauqeer

Subjects
STANDARD deviations, SOLAR radiation, SOLAR energy, STATISTICAL correlation, CLOUD storage
Abstract

The availability of accurate and reliable solar radiation data is very important to explore solar energy potential for commercial power plants. This study presents the validation of global horizontal irradiance (GHI) from McClear model under clear-sky and all-sky conditions against measured data for complex topography of Pakistan. The McClear GHI shows good agreement with measured GHI under clear-sky conditions for nine stations and good correlation was achieved with correlation coefficient ranging from 0.972 to 0.992. The relative mean bias error (rMBE) and relative root mean square error (rRMSE) using GHI data having temporal resolution of 10 minutes was ranging from −2.3 to 6.4% and 3.6 to 7.8% respectively. A seasonal statistical analysis shows variation of errors during seasons, significant variation of errors was observed for monthly statistical analysis, the overall errors for all stations were maximum in January and minimum in June. Cloud fraction (CF) from three state-of-the-art datasets (ERA-5, MERRA-2 and MODIS) was incorporated into McClear clear-sky GHI (GHIMC,clear-sky) to derive commercially resourceful all-sky GHI data (GHIMC,all-sky) using a noval approach. The rMBE of GHIMC,all-sky using CF from ERA-5, MERRA-2 and MODIS ranges from 0.1 to 8.4%, 0.1 to 14.1% and 0.2 to 16.8% respectively. The application of ERA-5 cloud fraction shows good correlation with correlation coefficient ranging from 0.871 to 0.966 and gave best results as rMBE for all stations is less than 4% except one station, the long-term GHIMC,all-sky data can be used for the solar resource assessment of Pakistan in the absence of measured data. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Effect of surfactants on the convective heat transfer and pressure drop characteristics of ZnO/DIW nanofluids: An experimental study

Author

Qamar, Adnan, primary, Shaukat, Rabia, additional, Imran, Shahid, additional, Farooq, Muhammad, additional, Amjad, Muhammad, additional, Anwar, Zahid, additional, Ali, Hassan, additional, Farhan, Muhammad, additional, Mujtaba, M.A., additional, Korakianitis, Theodosios, additional, Kalam, M.A., additional, and Almomani, Fares, additional

Published
2023
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34. Heat transfer and pressure drop characteristics of ZnO/DIW based nanofluids in small diameter compact channels: An experimental study

Author

Siddiqi, Habib-ur-Rehman, primary, Qamar, Adnan, additional, Shaukat, Rabia, additional, Anwar, Zahid, additional, Amjad, Muhammad, additional, Farooq, Muhammad, additional, Abbas, Muhammad Mujtaba, additional, Imran, Shahid, additional, Ali, Hassan, additional, Khan, T.M.Yunus, additional, Noor, Fahad, additional, Ali, Hafiz Muhammad, additional, Kalam, M.A., additional, and Soudagar, Manzoore Elahi M., additional

Published
2022
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35. Fracture energy of fiber-reinforced and rubberized cement-based composites: A sustainable approach towards recycling of waste scrap tires.

Author

Gillani, S. Asad Ali, Riaz, Muhammad Rizwan, Hameed, Rashid, Qamar, Adnan, Toumi, Ahmed, and Turatsinze, Anaclet

Subjects
MORTAR, TIRE recycling, CRUMB rubber, WASTE tires, ELASTIC modulus, FRACTURE strength, ENERGY dissipation, TENSILE strength
Abstract

Using crumb rubber particles obtained from end-of-life tires as aggregate in concrete can reduce the environmental overburden caused by the huge accumulation of these scrap tires. However, reduction in the mechanical properties of concrete is observed with the incorporation of rubber aggregates. To counter this detrimental effect of crumb rubber in concrete, amorphous metallic fibers are added to balance the loss in strength and durability issues. Mechanical characteristics along with the fracture energy of rubberized fiber-reinforced mortar are presented here. Four mortar mix compositions were investigated; the first one is reference mortar (control mortar), the second mix containing 30 kg/m3 of metallic fibers, the third mix containing 30% of rubber aggregates as replacement of sand by equivalent volume and fourth containing both rubber aggregates and metallic fibers with the dosage 30% and 30 kg/m3, respectively. Compression tests, modulus of elasticity and direct tension tests were conducted for mechanical characterization. Deformation capacity, residual post-cracking strength and fracture energy of these composite mortar mixes were evaluated through uniaxial direct tension tests. The fracture energy was determined from the obtained complete softening curves. Test results show a reduction in mechanical properties with the incorporation of crumb rubber as aggregates in mortar. However, a significant increase in fracture energy was observed in rubberized fiber-reinforced mortar mixes. Moreover, the mortar mixes containing both rubber aggregates and metallic fibers show positive synergetic effect resulting in enhanced post-cracking residual tensile strength, strain capacity and energy dissipation capacity. [ABSTRACT FROM AUTHOR]

Published
2023
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39. Validating global horizontal irradiance estimated by McClear model under clear-sky and all-sky conditions in Pakistan

Author

Tahir, Zia ul Rehman, primary, Amjad, Ghulam Murtaza, additional, Hamza, Muhammad, additional, Shad, Muhammad Rizwan, additional, Qamar, Adnan, additional, Blanc, Philippe, additional, Abbas, Sabtain, additional, Azhar, Muhammad, additional, Safyan, Muhammad, additional, Abdullah, Muhammad, additional, Atif, Muhammad, additional, and Haider, Syed Tauqeer, additional

Published
2022
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40. Blockchain adoption for sustainable supply chain management : economic, environmental, and social perspectives

Author

Munir, M. Adeel, Habib, M. Salman, Hussain, Amjad, Shahbaz, Muhammad Ali, Qamar, Adnan, Masood, Tariq, Sultan, M., Mujtaba, M. A., Imran, Shahid, Hasan, Mudassir, Akhtar, Muhammad Saeed, Uzair Ayub, Hafiz Muhammad, and Salman, Chaudhary Awais

Subjects
QA75, TJ
Abstract

Due to the rapid increase in environmental degradation and depletion of natural resources, the focus of researchers is shifted from economic to socio-environmental problems. Blockchain is a disruptive technology that has the potential to restructure the entire supply chain for sustainable practices. Blockchain is a distributed ledger that provides a digital database for recording all the transactions of the supply chain. The main purpose of this research is to explore the literature relevant to blockchain for sustainable supply chain management. The focus of this review is on the sustainability of the blockchain-based supply chain concerning environmental conservation, social equality, and governance effectiveness. Using a systematic literature review, a total of 136 articles were evaluated and categorized according to the triple bottom-line aspects of sustainability. Challenges and barriers during blockchain adoption in different industrial sectors such as aviation, shipping, agriculture and food, manufacturing, automotive, pharmaceutical, and textile industries were critically examined. This study has not only explored the economic, environmental, and social impacts of blockchain but also highlighted the emerging trends in a circular supply chain with current developments of advanced technologies along with their critical success factors. Furthermore, research areas and gaps in the existing research are discussed, and future research directions are suggested. The findings of this study show that blockchain has the potential to revolutionize the entire supply chain from a sustainability perspective. Blockchain will not only improve the economic sustainability of the supply chain through effective traceability, enhanced visibility through information sharing, transparency in processes, and decentralization of the entire structure but also will help in achieving environmental and social sustainability through resource efficiency, accountability, smart contracts, trust development, and fraud prevention. The study will be helpful for managers and practitioners to understand the procedure of blockchain adoption and to increase the probability of its successful implementation to develop a sustainable supply chain network.

Published
2022

41. Thermal Performance Analysis of Various Heat Sinks Based on Alumina NePCM for Passive Cooling of Electronic Components: An Experimental Study

Author

Zahid, Imran, Farooq, Muhammad, Farhan, Muhammad, Usman, Muhammad, Qamar, Adnan, Imran, Muhammad, Alqahtani, Mejdal A., Anwar, Saqib, Sultan, Muhammad, Javaid, Muhammad Yasar, Zahid, Imran, Farooq, Muhammad, Farhan, Muhammad, Usman, Muhammad, Qamar, Adnan, Imran, Muhammad, Alqahtani, Mejdal A., Anwar, Saqib, Sultan, Muhammad, and Javaid, Muhammad Yasar

Abstract

In the modern digital world, electronic devices are being widely employed for various applications where thermal performance represents a significant technical challenge due to continued miniaturization, high heat generated in the system, and non-uniform high-temperature causing failure. Phase change materials (PCMs) owing to the immense heat of fusion are primarily considered for thermal management, but their insulating properties hedge their applications in electronics cooling. Nano-enhanced phase change materials (NePCMs) have the ability to improve the thermal conductivity of PCM, decrease system temperature and escalate the operating time of devices. Accordingly, the current study focused on the experimental investigations for the thermal performance of three heat sinks (HS) with different configurations such as a simple heat sink (SHS), a square pin-fins heat sink (S pfHS), and Cu foam integrated heat sink (Cu fmHS) with various alumina nanoparticles mass concentrations (0.15, 0.20 and 0.25 wt%) incorporated in PCM (RT-54HC) and at heat flux (0.98–2.94 kW/m 2). All HSs reduced the base temperature with the insertion of NePCM compared to the empty SHS. The experimental results identified that the thermal performance of Cu fmHS was found to be superior in reducing base temperature and enhancing working time at two different setpoint temperatures (SPTs). The maximum drop in base temperature was 36.95%, and a 288% maximum working time enhancement was observed for Cu fmHS. Therefore, NePCMs are highly recommended for the thermal management of the electronic cooling system.

Published
2022

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