The Experts below are selected from a list of 12555 Experts worldwide ranked by ideXlab platform
John Kaiser Calautit - One of the best experts on this subject based on the ideXlab platform.
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influence of urban form on the performance of Road Pavement solar collector system symmetrical and asymmetrical heights
Energy Conversion and Management, 2017Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Recent works have highlighted the importance of mitigating the urban heat island effect using innovative technologies. Several studies have emphasised the capabilities of the Road Pavement solar collector system to dissipate high temperature from the Pavement/Road surfaces not only to expand its lifecycle but also to reduce the Urban Heat Island effect. This study builds on previous research combining an urban configuration and a Road Pavement solar collector system in Computational Fluid Dynamics in order to understand the complicated connection of the urban environment and the Road Pavement. This study investigates the impact of the urban form on the performance of the Road Pavement solar collector focusing on comparing symmetrical and asymmetrical height of the urban street canyon. A tridimensional de-coupled simulation approach was used to simulate a macro domain (urban environment) and micro domain, which consists of Road Pavement solar collector pipes. ANSYS Fluent 15.0 was employed with the solar load model, Discrete Ordinate radiation model and Reynold Averaged Navier Stokes with standard k-epsilon equation. The simulation was carried out based on the summer month of June in Milan urban centre, Italy. Results showed a significant variation in the temperature results of Road surface in comparing the three configurations. It was also found that there was a significant reduction in the Road Pavement solar collector system performance when taller building row was behind the first approaching building row. The method presented in this research could be useful for studying the system integration in various urban forms.
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a cfd analysis of several design parameters of a Road Pavement solar collector rpsc for urban application
Applied Energy, 2017Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Previous investigations of the Urban Heat Island (UHI) effects have highlighted the long-term negative impacts of urban street canyons on surroundings temperatures that indirectly contribute to global warming. Studies on Road Pavement solar collector (RPSC) system have shown the potential of reducing the heat from the Pavement surface by absorbing the heat from the Pavement and harnessing the thermal energy. This study expands the investigation of optimising the RPSC system based on four tested parameters (pipe diameter, pipe depth, water velocity and water temperature) comparing the system performance in terms of Delta T of inlet-outlet, potential thermal collection (PTC) and surface temperature reduction (STR). Two types of external environmental conditions were considered: (i) urban domain resembling a street canyon (ii) flat surface resembling a low density or rural area. ‘De-coupled’ CFD method was employed based on previously author’s published work by simulating the effect of external environment (macro domain) onto RPSC system (micro domain) in two separate CFD modelling. Initially, both domains were validated with numerical and experimental data from previously published works. In comparing the RPSC application in urban domain and flat/rural domain; it was found that the system adjustment based on high and low conditions of water velocity provided the best performance improvement with average 28% higher in terms of PTC and STR as compared to other simulated parameters. Yet, insignificant Delta T (less than 5K) was obtained with values over 0.02m in the pipe diameter and in the 0.25m/s water velocity.
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a study of the impact of building geometry on the thermal performance of Road Pavement solar collectors
Energy, 2015Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Studies on RPSC (Road Pavement solar collectors) have shown the potential of reducing the UHI (urban heat island) effects by dissipating the heat from the Pavement for energy harness. Several works have shown that the generated heat could be utilised for sustainable urban energy system. However, none of the previous literatures have assessed the effect of building geometry on the performance of the RPSC. This study investigates the thermal performance of an urban-integrated RPSC system by using CFD (computational fluid dynamic) simulation of integrated RPSC system with a standard urban canyon domain and an empty domain. Based on 21st June at 13:00, it was found that the RPSC system in urban canyon domain was on average 36.08% more effective in thermal collection and provided on average 27.11% more surface temperature reduction as compared to the RSPC application in rural/flat domain. The RPSC performance based on the effect from daily solar intensity was initiated with results demonstrated the efficiency of the RPSC in an urban setting was 7.14%–63.26% more than the rural/flat setting. Simulations of various wind speeds in summer day(s) and the impact of seasonal changes to the RPSC system were also conducted to investigate the deficiency factors to the system.
Tony Parry - One of the best experts on this subject based on the ideXlab platform.
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Rolling resistance contribution to a Road Pavement life cycle carbon footprint analysis
The International Journal of Life Cycle Assessment, 2017Co-Authors: Laura Trupia, Tony Parry, Luís C. NevesAbstract:A bstractPurposeAlthough the impact of Road Pavement surface condition on rolling resistance has been included in the life cycle assessment (LCA) framework of several studies in the last years, there is still a high level of uncertainty concerning the methodological assumptions and the parameters that can affect the results. In order to adopt Pavement carbon footprint/LCA as a decision-making tool, it is necessary to explore the impact of the chosen methods and assumptions on the LCA results.MethodsThis paper provides a review of the main models describing the impact of the Pavement surface properties on vehicle fuel consumption and analyses the influence of the methodological assumptions related to the rolling resistance on the LCA results. It compares the CO_2 emissions, calculated with two different rolling resistance models existing in literature, and performs a sensitivity test on some specific input variables (Pavement deterioration rate, traffic growth, and emission factors/fuel efficiency improvement).Results and discussionThe model used to calculate the impact of the Pavement surface condition on fuel consumption significantly affects the LCA results. The Pavement deterioration rate influences the calculation in both models, while traffic growth and fuel efficiency improvement have a limited impact on the vehicle CO_2 emissions resulting from the Pavement condition contribution to rolling resistance.Conclusions and recommendationsExisting models linking Pavement condition to rolling resistance and hence vehicle emissions are not bRoadly applicable to the use phase of Road Pavement LCA and further research is necessary before a widely-used methodology can be defined. The methods of modelling and the methodological assumptions need to be transparent in the analysis of the impact of the Pavement surface condition on fuel consumption, in order to be interpreted by decision makers and implemented in an LCA framework. This will be necessary before product category rules (PCR) for Pavement LCA can be extended to include the use phase.
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traffic modelling in system boundary expansion of Road Pavement life cycle assessment
Transportation Research Part D-transport and Environment, 2015Co-Authors: F Galatioto, Tony Parry, Yue Huang, Roger Bird, M C BellAbstract:This paper uses a case study of a UK inter-urban Road, to explore the impact of extending the system boundary of Road Pavement life cycle assessment (LCA) to include increased traffic emissions due to delays during maintenance. Some previous studies have attempted this but have been limited to hypothetical scenarios or simplified traffic modelling, with no validation or sensitivity analysis. In this study, micro-simulation modelling of traffic was used to estimate emissions caused by delays at Road works, for several traffic management options. The emissions were compared to those created by the maintenance operation, estimated using an LCA model. In this case study, the extra traffic emissions caused by delays at Road works are relatively small, compared to those from the maintenance process, except for hydrocarbon emissions. However, they are generally close to, or above, the materiality threshold recommended in PAS2050 for estimating carbon footprints, and reach 5–10% when traffic flow levels are increased (hypothetically) or when traffic management is imposed outside times of lowest traffic flow. It is recommended, therefore, that emissions due to traffic disruption at Road works should be included within the system boundary of Road Pavement LCA and carbon footprint studies and should be considered in developing guidelines for environmental product declarations of Road Pavement maintenance products and services.
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sensitivity analysis of methodological choices in Road Pavement lca
International Journal of Life Cycle Assessment, 2013Co-Authors: Yue Huang, Alan Spray, Tony ParryAbstract:Purpose There are methodological questions concerning life cycle assessment (LCA) and carbon footprint evaluation of Road Pavements, including allocation among co-products or at end-of-life (EOL) recycling. While the development and adoption of a standard methodology for Road Pavement LCA would assist in transparency and decision making, the impact of the chosen method on the results has not yet been fully explored.
Paulo Lobato Correia - One of the best experts on this subject based on the ideXlab platform.
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Accelerated unsupervised filtering for the smoothing of Road Pavement surface imagery
2014 22nd European Signal Processing Conference (EUSIPCO), 2014Co-Authors: Henrique Oliveira, José Caeiro, Paulo Lobato CorreiaAbstract:An accelerated formulation of the Unsupervised Information-theoretic Adaptive Image Filtering (UINTA) method is presented. It is based on a parallel implementation of the algorithm, using the Open Computing Language (OpenCL), while maintaining the precision and efficiency of the original method, which are briefly discussed focusing on the respective computational complexities. The experimental computational efficiency is compared with the one obtained using the standard implementation, highlighting the significant improvement of computational times achieved with the proposed one. This new implementation is tested for the smoothing of Road Pavement surface images, for which the original method had been previously applied, showing the clear advantage of its use.
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Identifying and retrieving distress images from Road Pavement surveys
2008 15th IEEE International Conference on Image Processing, 2008Co-Authors: Henrique Oliveira, Paulo Lobato CorreiaAbstract:This paper proposes a system capable of identifying and retrieving distress images from a Road Pavement survey image database. A database of images acquired during Road Pavement surface surveys along Portuguese Roads is considered. Regions corresponding to cracks are detected over the acquired images, based on a subdivision of the images into a set of non-overlapping windows, which may be classified as containing cracks, or not. Crack detection results, represented by binary images where windows containing crack pixels are set to one, undergo a second classification stage to distinguish several crack types. This classification follows the structure proposed by the Portuguese Distresses Catalog, produced by the national entity in charge of Road maintenance. Three crack types are identified at this stage: longitudinal cracks, transversal cracks and miscellaneous cracks. The experimental results, obtained by processing real survey imagery over Portuguese Roads, present encouraging results for automating the process of identifying Road distresses from images.
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Supervised strategies for cracks detection in images of Road Pavement flexible surfaces
2008 16th European Signal Processing Conference, 2008Co-Authors: Henrique Oliveira, Paulo Lobato CorreiaAbstract:The detection of cracks and other degradations in Road Pavement surfaces is traditionally done by experts using visual inspection, while driving along the surveyed Road. An automatic cracks detection system based on Road Pavement images, as proposed here, can speed up the process and reduce results' subjectivity. The paper confronts six supervised classification strategies, three parametric and three non-parametric. The analysis is done on data resulting from dividing the image into a set of non-overlapping windows. Dealing with supervised classification strategies, a technique for automatic selection of training images from an image database is proposed as the initial step, after which a human expert should select the image windows containing cracks. The selected classification strategies work with a 2D feature space. Classifiers are evaluated using a set of well-know metrics, indicating that a better performance can be achieved using parametric classification strategies.
Diana S N M Nasir - One of the best experts on this subject based on the ideXlab platform.
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influence of urban form on the performance of Road Pavement solar collector system symmetrical and asymmetrical heights
Energy Conversion and Management, 2017Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Recent works have highlighted the importance of mitigating the urban heat island effect using innovative technologies. Several studies have emphasised the capabilities of the Road Pavement solar collector system to dissipate high temperature from the Pavement/Road surfaces not only to expand its lifecycle but also to reduce the Urban Heat Island effect. This study builds on previous research combining an urban configuration and a Road Pavement solar collector system in Computational Fluid Dynamics in order to understand the complicated connection of the urban environment and the Road Pavement. This study investigates the impact of the urban form on the performance of the Road Pavement solar collector focusing on comparing symmetrical and asymmetrical height of the urban street canyon. A tridimensional de-coupled simulation approach was used to simulate a macro domain (urban environment) and micro domain, which consists of Road Pavement solar collector pipes. ANSYS Fluent 15.0 was employed with the solar load model, Discrete Ordinate radiation model and Reynold Averaged Navier Stokes with standard k-epsilon equation. The simulation was carried out based on the summer month of June in Milan urban centre, Italy. Results showed a significant variation in the temperature results of Road surface in comparing the three configurations. It was also found that there was a significant reduction in the Road Pavement solar collector system performance when taller building row was behind the first approaching building row. The method presented in this research could be useful for studying the system integration in various urban forms.
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a cfd analysis of several design parameters of a Road Pavement solar collector rpsc for urban application
Applied Energy, 2017Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Previous investigations of the Urban Heat Island (UHI) effects have highlighted the long-term negative impacts of urban street canyons on surroundings temperatures that indirectly contribute to global warming. Studies on Road Pavement solar collector (RPSC) system have shown the potential of reducing the heat from the Pavement surface by absorbing the heat from the Pavement and harnessing the thermal energy. This study expands the investigation of optimising the RPSC system based on four tested parameters (pipe diameter, pipe depth, water velocity and water temperature) comparing the system performance in terms of Delta T of inlet-outlet, potential thermal collection (PTC) and surface temperature reduction (STR). Two types of external environmental conditions were considered: (i) urban domain resembling a street canyon (ii) flat surface resembling a low density or rural area. ‘De-coupled’ CFD method was employed based on previously author’s published work by simulating the effect of external environment (macro domain) onto RPSC system (micro domain) in two separate CFD modelling. Initially, both domains were validated with numerical and experimental data from previously published works. In comparing the RPSC application in urban domain and flat/rural domain; it was found that the system adjustment based on high and low conditions of water velocity provided the best performance improvement with average 28% higher in terms of PTC and STR as compared to other simulated parameters. Yet, insignificant Delta T (less than 5K) was obtained with values over 0.02m in the pipe diameter and in the 0.25m/s water velocity.
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a study of the impact of building geometry on the thermal performance of Road Pavement solar collectors
Energy, 2015Co-Authors: Diana S N M Nasir, Ben Richard Hughes, John Kaiser CalautitAbstract:Studies on RPSC (Road Pavement solar collectors) have shown the potential of reducing the UHI (urban heat island) effects by dissipating the heat from the Pavement for energy harness. Several works have shown that the generated heat could be utilised for sustainable urban energy system. However, none of the previous literatures have assessed the effect of building geometry on the performance of the RPSC. This study investigates the thermal performance of an urban-integrated RPSC system by using CFD (computational fluid dynamic) simulation of integrated RPSC system with a standard urban canyon domain and an empty domain. Based on 21st June at 13:00, it was found that the RPSC system in urban canyon domain was on average 36.08% more effective in thermal collection and provided on average 27.11% more surface temperature reduction as compared to the RSPC application in rural/flat domain. The RPSC performance based on the effect from daily solar intensity was initiated with results demonstrated the efficiency of the RPSC in an urban setting was 7.14%–63.26% more than the rural/flat setting. Simulations of various wind speeds in summer day(s) and the impact of seasonal changes to the RPSC system were also conducted to investigate the deficiency factors to the system.
Helmi Zulhaidi Mohd Shafri - One of the best experts on this subject based on the ideXlab platform.
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Road Pavement density analysis using a new non-destructive ground penetrating radar system
Progress in Electromagnetics Research-pier, 2020Co-Authors: Mardeni Roslee, R.s.a. Raja Abdullah, Helmi Zulhaidi Mohd ShafriAbstract:Density is an important parameter to determine the strength of Road, and it will ensure the safety of the use as well as maintaining the quality of Road Pavement. In this paper, the validation of GPR mixture model based on the microwave nondestructive free space method to determine the density of Road Pavement typed Hot Mix Asphalt (HMA) will be presented. The frequency range of operation used is 1.7{2.6GHz. The attenuation is a major factor for gathering the density of Road Pavement predictably. The existing mixture model has been used to produce simulation data for determining the predicted complex permittivity and attenuation due to various densities of Road Pavement. The GPR laboratory measurement is performed where the measured attenuation due to various densities was obtained. The comparison results between measurement and simulation were investigated, and the relative errors
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Evaluation of Road Pavement density using Ground Penetrating Radar.
Journal of Environmental Science and Technology, 2009Co-Authors: R.s.a. Raja Abdullah, Helmi Zulhaidi Mohd Shafri, R. Mardeni, Sabira Khatun, R. MuniandyAbstract:This study describes an analysis of Ground Penetrating Radar (GPR) measurements at frequency range of 1.7-2.6 GHz to get a relationship between attenuation and density for nine Road Pavements slabs with different densities. There are about four different frequencies had been tested. The method is simple, fast, non-destructive and accurate way to determine the density of Road Pavement. Density is a one of the important parameter in order to determine the compressive strength of Road Pavement for Road user safety. In laboratory, the measurement system consists of a signal generator (250 kHz-3 GHz) as a source, spectrum analyzer (100 Hz-8 GHz), directional coupler with adapter and horn antenna. The first part of the measurement system setup is to determine the amplitude of transmitted wave (received signal strength). A few of received signal strength and attenuation for nine Road Pavement slab samples were taken at four different frequencies. An instantaneous method for measuring the density of Road Pavement was developed by using microwave reflection technique and free space method. The MATLAB software is used to analyze the measurement data and also for the graphs comparisons. At the end of this study, it is found that density plays an important factor in causing a major in the recorded signal strength as well as the differences of attenuation of the GPR signal.
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Optimization of Ground Penetrating Radar (GPR) Mixture Model in Road Pavement Density Data Analysis
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: Helmi Zulhaidi Mohd Shafri, Mardeni Roslee, Rsa Raja Abdullah, R. MuniandyAbstract:This paper presents an optimization of GPR mixture model based on the measurements and simulation results at frequency range of 1.7-2.6 GHz. The purpose is to get a most accurate relationship between attenuation and density for various Road Pavements densities. The proposed method is simple, fast, nondestructive and accurate way to determine the density of Road Pavement. Density is a one of the important parameter in order to determine the compressive strength of Road Pavement. In laboratory, a few of received signal strength and measured attenuation for nine Road Pavement slab samples were taken at four different frequencies. The GPR mixture model has been used to produce the predicted attenuation due to the Pavement density. The calculation and selection of mixture model has been discussed thoroughly and only the best performance of GPR mixture model was selected for optimization.
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Data analysis of Road Pavement density measurements using Ground Penetrating Radar (GPR)
2008 International Conference on Computer and Communication Engineering, 2008Co-Authors: Rsa Raja Abdullah, Helmi Zulhaidi Mohd Shafri, Mardeni RosleeAbstract:This work describes an analysis of ground penetrating radar (GPR) measurements at frequency range of 1.7-2.6 GHz to get a relationship between attenuation and density for nine Road Pavements slabs with different densities. There are about two different frequencies had been tried. The method is simple, fast, contact less and accurate way to determine the density of Road Pavement. The most important parameter that used in this project is density where it can be used to determine the compressive strength of Road Pavement. In laboratory, the measurement system consists of a signal generator (250 kHz-3 GHz) as a source, spectrum analyzer (100 Hz-8 GHz), directional coupler with adapter and horn antenna. The first part of the measurement system setup is to determine the amplitude of transmitted wave (received signal strength). A few of received signal strength and attenuation for nine Pavement slab samples were taken at two different frequencies. The GPR mixture model has been used to produce the simulation data and has been compared with measurement data. An instantaneous method for measuring the density of Road Pavement in wave propagation was developed by using microwave transmission/ reflection technique and free space method at two frequencies. The MATLAB software is used to analyze the measurement and simulation data and also for the graphs comparisons. The relative error between measurement and simulation were calculated. The results from the GPR measurement were used and were elaborated in data statistical analysis.
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Field test validation of optimized ground enetrating Radar (GPR) mixture model at frequency range 1.7 GHz to 2.6 GHz
2008 IEEE International RF and Microwave Conference, 2008Co-Authors: R. Mardeni, Rsa Raja Abdullah, Helmi Zulhaidi Mohd ShafriAbstract:This paper presents the validation of optimized GPR mixture model based on the microwave nondestructive free space method in order to determine the density of Road Pavement. Density is an important parameter to determine the compressive strength of Road Pavement for Road user safety. The attenuation is a major factor for gathering the density of Road Pavement predictly. A few of measured attenuation were taken at nine Road Pavement slab samples in laboratory. The GPR mixture model has been used to produce the simulation data to predict the attenuation. The comparison results between measurement and simulation were investigated. The best performance of GPR mixture model was selected in the optimization technique due to the smallest mean error. An improved attenuation formula or optimized GPR model was obtained from the optimization technique. The validation at field test had been conducted in order to see the performance of optimized GPR model.
