| 11. |
- Asim, Muhammad, et al.
(författare)
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Techno-economic assessment of energy and environmental impact of waste-to-energy electricity generation
- 2023
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Ingår i: Energy Reports. - : Elsevier. - 2352-4847. ; 9:Suppl 1, s. 1087-1097
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Tidskriftsartikel (refereegranskat)abstract
- This study explored cumulative 127.5MW waste to energy (WtE) potential in five populous cities of Pakistan based on local waste characterization profiles and global standards. The 50MW WtE plant in Lahore using National electricity regulator codes and practices resulted in an attractive Levelized cost of electricity (LCOE) of US¢ 7.86/kWh over 25 years with a $151.5 million investment cost. The net savings to Lahore Waste Management Company can be $103.4 and $137.7 million respectively with and without tipping fees on account of waste disposal cost, bricks revenue using bottom ash, and waste fee. The project developers can get net savings of $16.9 and $51.5 million respectively with and without tipping fees other than LCOE. Furthermore, the greenhouse gas emissions of 216.6 million tons of CO2eq can be saved throughout plant life against 279 GWh/year energy generation, in terms of grid emission factor and current methane release into the atmosphere from the dumping site.
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| 12. |
- Javed, Muhammad Shahzad, et al.
(författare)
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Solar and wind power generation systems with pumped hydro storage : Review and future perspectives
- 2020
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Ingår i: Renewable energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0960-1481 .- 1879-0682. ; 148, s. 176-192
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Forskningsöversikt (refereegranskat)abstract
- It has been globally acknowledged that energy storage will be a key element in the future for renewable energy (RE) systems. Recent studies about using energy storages for achieving high RE penetration have gained increased attention. This paper presents a detailed review on pumped hydro storage (PHS) based hybrid solar-wind power supply systems. It also discusses the present role of PHS, its total installed capacity, future research and technical challenges associated with the use of this storage in the context of RE based systems. This review paper considers the economical, environmental and technical aspects of solar-wind-PHS systems which have been discussed in the papers published over last 10 years. Additionally, studies are categorized with respect to objective, approach employed, location and key findings. Reflected from the literature, PHS technology has again emerged as a technologically and economically viable option. The integration of reversible pump turbine machines has increased the flexibility, response time and performance of PHS, however, hybridization of PHS with other storages can increase the range of services and overall system reliability, especially when RE systems are off-grid. This review will be useful for researchers to explore RE-based PHS systems in the fields of modelling and techno-economic optimization. Hybrid storage, like the PHS-battery, is an emerging option to supplement the weakness of each other and will be a promising field for future research.
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| 13. |
- Majeed, Fiza, et al.
(författare)
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Recent Advances in Fire-Suppressing Agents for Mitigating Lithium-Ion Battery Fires
- 2024
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Ingår i: Journal of the Electrochemical Society. - : Institute of Physics (IOP). - 0013-4651 .- 1945-7111. ; 171:6
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Forskningsöversikt (refereegranskat)abstract
- The rising energy density and widespread use of lithium-ion batteries (LIBs) pose a growing safety challenge, marked by the potential for fires and explosions. Given the unique combustion characteristics of LIBs, the need for efficient and prompt fire suppression is paramount. Here we explore the mechanisms and characteristics of LIBs fires, emphasizing the critical design principles for effective fire-extinguishing agents and evaluating various agents, including gaseous, dry powders, water-based, aerosol-based, and composite-based fire-extinguishing agents, elucidating their mechanisms and effectiveness in suppressing LIBs fires. Noteworthy agents such as C6F12O and water-based solutions are highlighted for their superior extinguishing and cooling capabilities. Water-based fire-extinguishing agents show promise, exhibiting superior cooling capacity and anti-flash properties. Despite certain limitations, the review underscores the necessity of identifying an ideal fire-extinguishing agent that is thermally conductive, electrically insulating, cost-effective, non-toxic, residue-free, and capable of absorbing toxic gases. We conclude by discussing perspectives and outlooks, emphasizing the synergy between the ideal agent and innovative extinguishing strategies to ensure the high safety standards of current and future LIB-based technologies.The vulnerability of LIBs to fire and explosion in harsh environments presents a significant obstacle to their widespread use. LIB fires are challenging to put out because of their combustion properties, which include high temperature increasing rates, jet flames, TR propagation, and the creation of poisonous and explosive gasses. Numerous fire-extinguishing chemicals have been investigated; each has its own set of restrictions. These include gaseous, dry powders, aerosols, and water-based agents. A comprehensive comparison of various fire-extinguishing agents highlights their distinct characteristics and effectiveness in addressing LIB fires. This study emphasizes the critical factors of insulation, toxicity, fire suppression speed, reactivity with fire sources, degradation capacity, and corrosion in selecting appropriate extinguishing agents. While offering certain advantages, current fire-extinguishing agents exhibit significant drawbacks such as poor cooling effects, electrical conductivity, toxicity, and the potential for re-ignition. Composite-based fire suppressants are a better option for mitigating LIB fires as they present benefits such as environmental friendliness, high heat dissipation rate, electric insulation, and prevention from re-ignition. Present and future research should be based on the design of highly efficient composite-based fire extinguishers that are cost-effective and practical for use in the real world. Alongside this, scientists should also work on the case and removal of the factors which result in fire generation. Moreover, developing a proper sensing system for LIB fires should be designed to take timely preventive measurements.
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| 14. |
- Nizami, Abdul-Sattar, et al.
(författare)
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Energy, economic and environmental savings by waste recycling : A case study of Madinah City
- 2017
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Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY. - : Elsevier. ; 142, s. 910-915
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Konferensbidrag (refereegranskat)abstract
- In the Kingdom of Saudi Arabia (KSA), millions of worshippers come from across the globe to perform religious rituals of Pilgrimage (Hajj) and Umrah. Madinah-tul-Munawara is one of the holiest city, where pilgrims come after performing rituals in Makkah. In this city, most of the collected municipal solid waste (MSW) is disposed of in the landfills after a partial recycling of paper, cardboard, and metals (similar to 10-20% of total MSW). The Saudi's government has recently launched a new policy of Vision 2030, which outlined the safeguard of local environment through increased efficiency of waste recycling and management, pollution prevention strategies and generating renewable energy from indigenous sources, including the waste. Currently, the recycling practices in KSA are mainly regulated by an informal sector through waste pickers or waste scavengers. This has led to the need of recycling schemes, especially in the holiest cities of Makkah and Madinah through a public-private partnership (PPP). Huge amounts of energy can be conserved, that would otherwise be spent on raw material extraction, transportation, and manufacturing of materials, through recycling into the same materials. Around 10,009 TJ of energy can be saved through recycling of 24.21% of MSW in Madinah city, including glass, metals, aluminum, cardboard, and paper. It is estimated that around 10,200 tons of methane (CH4) emissions and 254,600 Mt center dot CO2 eq. of global warming potential (GWP) can also be saved. In addition, carbon credit revenue of US $5.92 million, and landfill diversion worth of US $32.78 million can be achieved with a net revenue of US $49.01 million every year only by recycling 24.21% of MSW in Madinah city. The waste recycling doesn't require high technical skills and labor, and complicated technologies for large-scale implementation, and therefore, can be implemented easily in the holiest cities of Makkah and Madinah to achieve multiple economic and environmental benefits. (C) 2017 The Authors. Published by Elsevier Ltd.
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| 15. |
- Nizami, Abdul-Sattar, et al.
(författare)
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Waste biorefineries : enabling circular economies in developing countries
- 2017
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 241, s. 1101-1117
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing countries represents a significant source of biomass, recycled materials, chemicals, energy, and revenue if wisely managed and used as a potential feedstock in various biorefinery technologies such as fermentation, anaerobic digestion (AD), pyrolysis, incineration, and gasification. However, the selection or integration of biorefinery technologies in any developing country should be based on its waste characterization. Waste biorefineries if developed in developing countries could provide energy generation, land savings, new businesses and consequent job creation, savings of landfills costs, GHG emissions reduction, and savings of natural resources of land, soil, and groundwater. The challenges in route to successful implementation of biorefinery concept in the developing countries are also presented using life cycle assessment (LCA) studies. (C) 2017 Elsevier Ltd. All rights reserved.
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| 16. |
- Sarfraz, Yasir, et al.
(författare)
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Application of statistical and machine learning techniques for landslide susceptibility mapping in the Himalayan road corridors
- 2022
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Ingår i: Open Geosciences. - : De Gruyter Open Ltd. - 2391-5447. ; 14:1, s. 1606-1635
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Tidskriftsartikel (refereegranskat)abstract
- Landslides are frequent geological hazards, mainly in the rainy season along road corridors worldwide. In the present study, we have comparatively analyzed landslide susceptibility by employing integrated geospatial approaches, i.e., data-driven, knowledge-driven, andmachine learning (ML), along themain road corridors of the Muzaffarabad district. The landslide inventory of three road corridors is developed to evaluate landslide susceptibility, and eleven landslide causative factors (LCFs) were analyzed. After statistical significance analysis, these eleven LCFs generated susceptibility models using WoE, AHP, LR, and RF. Distance from roads, landcover, lithological units, and slopes are considered more influential LCFs. The performancematrix of different LSMs is evaluated through the area under the curve (AUC-ROC), overall accuracy, Kappa index, F1 score, Mean Absolute Error, and Root Mean Square Error. The AUC-ROC for WoE, AHP, LR, and RF techniques along Neelumroad is 0.86, 0.82, 0.91, and 0.97, respectively, along Jhelum Valley road is 0.83, 0.81, 0.93, and 0.95, respectively, while along Kohala road is 0.89, 0.88, 0.89, and 0.92, respectively. The produced LSMs through ML (i.e., RF and LR) showed better prediction accuracies than WoE and AHP along these three road corridors. The LSMs are categorized into very high, high, moderate, and low susceptible zones along these roads. The LSM generated through hybrid models can facilitate the concerned local agencies to implement landslide mitigation policies for the landslideprone zones along road corridors.
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| 17. |
- Shahid, Muhammad, et al.
(författare)
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Selection of a Graduate Thesis Topic in a Multicultural Educational Environment
- 2013
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Konferensbidrag (refereegranskat)abstract
- This article presents a case study, performed at Blekinge Institute of Technology (BTH), Sweden, about the topic selection routines for a graduate thesis. The study focuses on the international graduate students who are having different academic cultures of their respective countries. Given that BTH has succeeded in the provision of an academic environment that has been efficient in absorbing different academic cultures in a productive manner at a reasonably good scale. However, in a multi-cultural educational environment, it is a challenge for most international students to adapt to the new academic culture and select the graduate thesis topic according to their real potential. Our findings gathered through an online survey, questionnaire, and focus group discussion is presented. The conclusions indicate, albeit, BTH has well defined routines for the thesis selection, the international graduate students face problems at the stage of thesis selection. The article concludes with suggestions to refine the thesis selection process at the micro level to help both students and staff.
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| 18. |
- Shahzad, Muhammad, et al.
(författare)
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Evaluation of Storage Conditions and the Effect on DNA from Forensic Evidence Objects Retrieved from Lake Water
- 2024
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Ingår i: Genes. - : MDPI. - 2073-4425. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- DNA analysis of traces from commonly found objects like knives, smartphones, tapes and garbage bags related to crime in aquatic environments is challenging for forensic DNA laboratories. The amount of recovered DNA may be affected by the water environment, time in the water, method for recovery, transport and storage routines of the objects before the objects arrive in the laboratory. The present study evaluated the effect of four storage conditions on the DNA retrieved from bloodstains, touch DNA, fingerprints and hairs, initially deposited on knives, smartphones, packing tapes, duct tapes and garbage bags, and submerged in lake water for three time periods. After retrieval, the objects were stored either through air-drying at room temperature, freezing at -30 degrees C, in nitrogen gas or in lake water. The results showed that the submersion time strongly influenced the amount and degradation of DNA, especially after the longest submersion time (21 days). A significant variation was observed in success for STR profiling, while mtDNA profiling was less affected by the submersion time interval and storage conditions. This study illustrates that retrieval from water as soon as possible and immediate storage through air-drying or freezing before DNA analysis is beneficial for the outcome of DNA profiling in crime scene investigations.
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| 19. |
- Yameen, Muhammad Zubair, et al.
(författare)
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Biodiesel production from marine macroalgae Ulva lactuca lipids using novel Cu-BTC@AC catalyst : Parametric analysis and optimization
- 2024
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Ingår i: Energy Conversion and Management. - : Elsevier. - 2590-1745. ; 23
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Tidskriftsartikel (refereegranskat)abstract
- The pursuit of renewable fuels for the transportation sector, particularly for combustion engines like diesel, is crucial in reducing greenhouse gas emissions. This study introduces an innovative strategy for biodiesel production utilizing marine macroalgae Ulva lactuca as the primary feedstock, emphasizing sustainability and resource efficiency. Lipids were extracted from the macroalgae via a Soxhlet process and characterized using GC–MS and FTIR to ascertain fatty acid composition and functional groups. The Cu–BTC@AC catalyst, synthesized from the lipid-extracted algae residue via pyrolysis and hydrothermal treatment, underwent characterization using SEM–EDS, XRD, and FTIR techniques. Subsequently, the Cu–BTC@AC catalyst was employed in the transesterification process to efficiently convert the extracted algal lipids into biodiesel, achieving a high yield of 92.56 % under RSM-optimized conditions: 65 °C temperature, 3.96 wt% catalyst amount, 15:1 methanol-to-lipid ratio, and 140 min reaction time. Kinetic and thermodynamic parameters for biodiesel production were calculated as follows: Ea = 33.20 kJ mol−1, ΔH# = 30.39 kJ mol−1, ΔS# = –165.86 J mol−1 K−1, and ΔG# = 86.48 kJ mol−1. GC–MS analysis identified a significant FAME content in the biodiesel, comprising 98.12 % of its composition. Notably, the Cu–BTC@AC catalyst exhibited excellent reusability, maintaining 80.21 % biodiesel yield after the third cycle. Moreover, physicochemical analysis of the biodiesel confirmed its compliance with ASTM D6751 specifications, underscoring its potential as a viable alternative fuel for the transportation sector.
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| 20. |
- Abbas, Haider, et al.
(författare)
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DUDE: Decryption, Unpacking, Deobfuscation, and Endian Conversion Framework for Embedded Devices Firmware
- 2023
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Ingår i: IEEE Transactions on Dependable and Secure Computing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1545-5971 .- 1941-0018.
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Tidskriftsartikel (refereegranskat)abstract
- Commercial-Off-The-Shelf (COTS) embedded devices rely on vendor-specific firmware to perform essential tasks. These firmware have been under active analysis by researchers to check security features and identify possible vendor backdoors. However, consistently unpacking newly created filesystem formats has been exceptionally challenging. To thwart attempts at unpacking, vendors frequently use encryption and obfuscation methods. On the other hand, when handling encrypted, obfuscated, big endian cramfs, or custom filesystem formats found in firmware under test, the available literature and tools are insufficient. This study introduces DUDE, an automated framework that provides novel functionalities, outperforming cutting-edge tools in the decryption, unpacking, deobfuscation, and endian conversion of firmware. For big endian compressed romfs filesystem formats, DUDE supports endian conversion. It also supports deobfuscating obfuscated signatures for successful unpacking. Moreover, decryption support for encrypted binaries from the D-Link and MOXA series has also been added, allowing for easier analysis and access to the contents of these firmware files. Additionally, the framework offers unpacking assistance by supporting the extraction of special filesystem formats commonly found in firmware samples from various vendors. A remarkable 78% (1424 out of 1814) firmware binaries from different vendors were successfully unpacked using the suggested framework. This performance surpasses the capabilities of commercially available tools combined on a single platform.
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