10 results on '"Tariq, Muhammad Atiq Ur Rehman"'
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2. Analysis of upper and lower nappe profiles of large orifice for the design of bottom and roof profiles of high head orifice spillway
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Bhatti, Shafqat Hussain, Ur Rehman, Habib, Sarwar, Muhammad Kaleem, Zaffar, Muhammad Waqas, Zafar, Muhammad Awais, and Tariq, Muhammad Atiq Ur Rehman
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- 2024
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3. Performance Evaluation of Subsidiary Weir for Energy Dissipation in the Stilling Basin Using CFD Modelling
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Arshad, Muhammad Jawad, Sarwar, Muhammad Kaleem, Haq, Faraz Ul, Tariq, Muhammad Atiq Ur Rehman, and Zaffar, Muhammad Waqas
- Abstract
This study was aimed at assessing the utility of the subsidiary weir in the post-rehabilitation scenario of Taunsa Barrage Pakistan wherein a 7 ft. high subsidiary weir was constructed at a distance of 920 ft. downstream of the main weir. In addition to the construction of the Subsidiary weir, auxiliary devices were also provided in the stilling basin downstream of the main weir. These devices include chute blocks and dented end sill. CFD (Computation Fluid Dynamics) based software Flow-3D was employed in the current study to numerically model the Taunsa Barrage, Pakistan and simulate the flow scenario. Based on the simulations of these flow scenarios, flow parameters were recorded for each scenario and comparative analysis was carried out to assess the effectiveness of the subsidiary weir. The study concluded that the addition of a subsidiary weir affected the flow parameters (Flow depth, depth-averaged velocity, and Froude number) and the location of the hydraulic jump. Furthermore, the study concluded that the addition of a subsidiary weir resulted in lesser energy dissipation as compared to the energy dissipation observed in the absence of a subsidiary weir.
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- 2024
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4. Effects of hooked-collar on the local scour around a lenticular bridge pier.
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Farooq, Rashid, Azimi, Amir Hossein, Tariq, Muhammad Atiq Ur Rehman, and Ahmed, Afzal
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This paper presents the results of comprehensive laboratory experiments to investigate the effects of hooked-collar on the scour development around a vertical pier with a lenticular cross section. The flow around the pier was uniform, steady, and under the clear-water condition. The axial scour profiles for cases without and with a lenticular hooked-collar were measured and the effects of hooked-collar dimensions and elevation from the bed were examined. To compute the efficiency of hooked-collar for scour prevention, the results of local scour for a bridge pier without a collar and a bridge pier with a plain collar, without a hooked wall, were used as benchmark data sets. A wide range of hooked-collar geometries such as the ratio of collar width to the pier width, W c / W p , ranging from 1.5 to 3.5, the ratio of hooked-collar wall height to the pier width, H c / W p , ranging from 0.15 to 0.6, and the ratio of collar elevation to the pier width, E c / W p , of −0.5, 0, and 0.5 were tested. The experimental results indicated that the equilibrium scour depth decreased with the ratio of hooked-collar to the pier width when W c is twice the pier width, W p. For W c / W p > 2, the scour depth was similar to the tests with an infinitely large pier width. In addition, the scour depth consistently reduced as the hooked-collar wall height, H c , to the pier width, W p , approached 0.3. The highest scour reduction efficiency was achieved when the hooked-collar being placed on the bed surface. Empirical models were developed for prediction of maximum scour depth near the lenticular bridge pier with a modified collar. The results showed that the volume of scour hole around a lenticular pier increased non-linearly with the maximum scour depth and it was independent of the hooked-collar geometry. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Investigation of Hydraulic Performance of Standard and Modified USBR Type III Stilling Basin Using Scale Modeling: A Case Study of Mohmand Dam Spillway, Pakistan
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Raza, Hassan, Sarwar, Muhammad Kaleem, Haq, Faraz ul, Tariq, Muhammad Atiq Ur Rehman, Altaf, Tariq, and Abduljaleel, Yasir
- Abstract
The stilling basins are used for dissipating the flow energy in spillways. The hydraulic performance of the stilling basin is dependent on the shape and dimension of the basin. The literature review indicates that the convergence of the side walls of the stilling basin enhances the efficiency of the stilling basin and stabilizes the jump within the basin. The research aimed to investigate the hydraulic performance of USBR type III stilling basin by modifying its standard geometry. The stilling basin of the Mohmand Dam spillway located on the Swat River; Pakistan was selected as a study area. The model was operated with parallel walls of stilling basin and by converging the walls of stilling basin from 1° to 5°. The results indicated that the efficiency of the hydraulic jump with converged wall stilling basin has improved as compared to parallel walls and loss of energy increased due to convergence. The efficiency of stilling basin increased up to 4% with the increment in wall convergence, but the optimum efficiency of the hydraulic jump was obtained at 3° wall convergence. The results also indicated that an increase in convergence angle leads to an increase in bottom pressures. Furthermore, the modified baffle blocks increased the energy dissipation efficiency to 1% as compared to standard baffle blocks. The study concludes that wall convergence not only improves the hydraulic performance of the stilling basin but also reduces the construction cost of the stilling basin.
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- 2023
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6. Improving Irrigation Performance of Raised Bed Furrow Using WinSRFR Model
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Shah, Muhammad Ayub, Waseem, Muhammad, Iqbal, Mudassar, Nabi, Ghulam, Tariq, Muhammad Atiq Ur Rehman, Arshed, Abu Bakar, Sultan, Umar, Laraib, Muhammad, and Abbas, Khawar
- Abstract
Agricultural productivity is intricately tied to efficient water management strategies, with raised bed furrow systems being a prevalent method for irrigation. However, the optimization of these systems remains a critical area of exploration. The border irrigation method is commonly employed in developing countries for irrigation and leads to significant water loss, reduced irrigation efficiency, and increased irrigation durations. In contrast, raised bed furrow irrigation represents an improved surface irrigation technique that optimizes water usage in irrigated systems. This study seeks to assess the irrigation performance of raised bed furrows, encompassing deep percolation loss, distribution uniformity, adequacy, and application efficiency. The evaluation will be conducted for both existing conditions and an optimized scenario achieved through the application of the WinSRFR model. Field data facilitated the numerical simulation and the model was calibrated to reflect the existing irrigation system dynamics accurately. The performance of the model was assessed by utilizing the statistical indicator of root mean square error (RMSE) and revealed good agreement between advance and recession time. Results revealed that existing raised bed furrow irrigation exhibited up to 40% deep percolation loss, 80% distribution uniformity, and 60% application efficiency. Increasing furrow length had adverse effects; decreased application efficiency and distribution uniformity; and increased deep percolation losses. In contrast, reducing the furrow length and cutoff time by up to 33% and 40%, respectively, and increasing the width and inflow rate by up to 55% and 100%, respectively, enhanced the application efficiency and distribution uniformity, and minimized deep percolation loss. Overall, improved raised bed furrow irrigation provides a more efficient option and is encouraged to adopt for irrigation.
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- 2024
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7. Investigating the flood risk perception of residents in informal settlements around the floodplains of river ravi in Lahore, Pakistan.
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Khawaja, Shaiza Zaib, Gul, Ahmad Ali, Tariq, Muhammad Atiq Ur Rehman, Vink, Karina, Jafri, Syed Hassan Amir, and Gujree, Ishfaq
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With a rapid rate of urbanization in Lahore, Pakistan, many vulnerable residents of the city are forced to settle in katchi abadis or informal settlements at the outskirts along River Ravi. These people living within Ravi's embankments, are often slow to respond or heed flood disaster warnings and evacuation messages. This article studies the flood risk perception of River Ravi's residents to better understand their choices and evacuation behaviour during floods. Surveys were conducted with the sample population utilizing dominant worldviews of Douglas and Wildavsky's Cultural Theory and qualitative risk variables from Slovic, Fischhoff, and Lichtenstein's Psychometric Paradigm to form major questionnaire items. This was further combined with Lindell and Perry's Protective Action Decision Model (PADM) for the analysis. An egalitarian worldview was found to dominate within the population where most residents were socially well bonded but had a weak authority subjection. Results further described the PADM outcome as mostly delayed or no evacuation based on the residents' worldview and result of their pre-decisional processes. Effect of threat, hazard adjustment, and stakeholders' perceptions on PADM's outcome was not definitive. For better flood risk management in Pakistan, policies need to shift towards improving stakeholders' perception as key to changing flood risk perception. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Calibration, validation and uncertainty analysis of a SWAT water quality model
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Das, Sushil K., Ahsan, Amimul, Khan, Md. Habibur Rahman Bejoy, Yilmaz, Abdullah Gokhan, Ahmed, Shakil, Imteaz, Monzur, Tariq, Muhammad Atiq Ur Rehman, Shafiquzzaman, Md., Ng, Anne W. M., and Al-Ansari, Nadhir
- Abstract
Sediment and nutrient pollution in water bodies is threatening human health and the ecosystem, due to rapid land use changes and improper agricultural practices. The impact of the nonpoint source pollution needs to be evaluated for the sustainable use of water resources. An ideal tool like the soil and water assessment tool (SWAT) can assess the impact of pollutant loads on the drainage area, which could be beneficial for developing a water quality management model. This study aims to evaluate the SWAT model’s multi-objective and multivariable calibration, validation, and uncertainty analysis at three different sites of the Yarra River drainage area in Victoria, Australia. The drainage area is split into 51 subdrainage areas in the SWAT model. The model is calibrated and validated for streamflow from 1990 to 2008 and sediment and nutrients from 1998 to 2008. The results show that most of the monthly and annual calibration and validation for streamflow, nutrients, and sediment at the three selected sites are found with Nash–Sutcliffe efficiency values greater than 0.50. Furthermore, the uncertainty analysis of the model shows satisfactory results where the p-factor value is reliable by considering 95% prediction uncertainty and the d-factor value is close to zero. The model's results indicate that the model performs well in the river's watershed, which helps construct a water quality management model. Finally, the model application in the cost-effective management of water quality might reduce pollution in water bodies due to land use and agricultural activities, which would be beneficial to water management managers.
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- 2024
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9. Classification of Pharynx from MRI Using a Visual Analysis Tool to Study Obstructive Sleep Apnea
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Shahid, Muhammad Laiq Ur Rahman, Mir, Junaid, Shaukat, Furqan, Saleem, Muhammad K., Tariq, Muhammad Atiq Ur Rehman, and Nouman, Ahmed
- Abstract
Background: Obstructive sleep apnea (OSA) is a chronic sleeping disorder. The analysis of the pharynx and its surrounding tissues can play a vital role in understanding the pathogenesis of OSA. Classification of the pharynx is a crucial step in the analysis of OSA. Methods: A visual analysis-based classifier is developed to classify the pharynx from MRI datasets. The classification pipeline consists of different stages, including pre-processing to select the initial candidates, extraction of categorical and numerical features to form a multidimensional features space, and a supervised classifier trained by using visual analytics and silhouette coefficient to classify the pharynx. Results: The pharynx is classified automatically and gives an approximately 86% Jaccard coefficient by evaluating the classifier on different MRI datasets. The expert’s knowledge can be utilized to select the optimal features and their corresponding weights during the training phase of the classifier. Conclusion: The proposed classifier is accurate and more efficient in terms of computational cost. It provides additional insight to better understand the influence of different features individually and collectively. It finds its applications in epidemiological studies where large datasets need to be analyzed.
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- 2021
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10. Urban Heat Island vulnerability mapping using advanced GIS data and tools
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Sidiqui, Paras, Roös, Phillip B, Herron, Murray, Jones, David S, Duncan, Emma, Jalali, Ali, Allam, Zaheer, Roberts, Bryan J, Schmidt, Alexander, Tariq, Muhammad Atiq Ur Rehman, Shah, Ashfaq Ahmed, Khan, Nasir Abbas, and Irshad, Muhammad
- Abstract
Urban Heat Island (UHI) is a phenomenon that can cause hotspots in city areas due to dense, impervious infrastructure and minimal vegetation cover. UHI hotspots may become worse in extreme heat events that are already affecting many regions across the globe due to increased frequent hot extremes, human-induced warming in cities, and rapidly growing urbanization, as documented by the latest IPCC report 2021. In seeking to support designers, planners, and decision-makers in developing and implementing adaptation strategies and measures to make our cities sustainable and resilient, reliable projections and modelling are required. In this study, we modelled UHI vulnerability using high-resolution spatial data, advanced geospatial tools, and socio-demographic data. This modified vulnerability approach drew upon UHI index maps and 20 select customized indicators of heat exposure, population sensitivity, and mobility/adaptive capacity. The indicators were Delphi evaluated and weighted, and the methodology was applied against the City of Greater Geelong municipality in Australia. The resulting UHI index maps indicated significant hotspots in areas of high building density, commercial/industrial zones, newly constructed sites, and zones with low urban green infrastructure. These UHI maps, in combination with selected indicators, highlighted the areal concentration of heat risk areas and vulnerable locations for the sensitive human population. The highlighted areas were primarily concentrated in high building density and high population density areas, which was seen through correlation curves. However, the building density showed a weak correlation, and population per meshblock indicated a strong correlation with UHI measurements. This study provides a comprehensive analysis of risk mapping and vulnerability assessment using GIS geospatial data for the advancement of a major local government area and concludes that this methodology has replicability incomparable geographical regions.
- Published
- 2022
- Full Text
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