Margaret Bell

Bio: Margaret Bell is an academic researcher from Newcastle University. The author has contributed to research in topics: Air quality index & Traffic congestion. The author has an hindex of 34, co-authored 209 publications receiving 3864 citations. Previous affiliations of Margaret Bell include University of Nottingham & University of Leeds.

Application of ADMS and AERMOD models to study the dispersion of vehicular pollutants in urban areas of India and the United Kingdom

Abstract: Urban air pollution poses a significant threat to human health, the environment and the quality of life of people throughout the world. In the United Kingdom 103 areas have been declared as local air quality management areas (LAQMA). While in India, 72 cities have been identified as cities having poor air quality/non-attainment area, i.e., the air quality in these cities are exceeding prescribed National Ambient Air Quality Standards (NAAQS). The transport sector is the principal source of local air pollution in urban areas, because of the increased vehicular population, vehicle kilometres travelled (VKT) and lack of infrastructure development. Many mathematical models have been widely used as tools in local air quality management in developed countries. Among them, ADMS [1] and AERMOD [2] models have been widely used for urban air quality management in Europe and the US, respectively. However, their applications are limited in developing countries like India due to the lack of readily available input data, time and the cost involved in collecting the required model input data. In this paper the performance evaluation of ADMS and AERMOD in predicting particulate matter (PM) concentrations at road sides in Chennai, India and Newcastle, UK is discussed. Air Pollution XX 3 doi:10.2495/AIR120011 www.witpress.com, ISSN 1743-3541 (on-line) WIT Transactions on Ecology and The Environment, Vol 1 , © 2012 WIT Press 57 The statistical parameters such as Index of Agreement (IA), Fractional Bias (FB), Normalized Mean Square Error (NMSE), Geometric Mean Bias (MG) and Geometric Mean Variance (VG) have been used to evaluate the ADMS and AERMOD model performance. Results indicated that both the models are able to predict the pollutant concentrations with reasonable accuracy. The IA values for ADMS and AERMOD are found to be 0.39 and 0.37 and 0.48 and 0.44, respectively, for the Chennai and Newcastle study sites.

Network programming to derive turning movements from link flows

Abstract: It is generally accepted that there is a need to develop traffic models to manage and control congestion in real time. This control needs to be integrated with route guidance systems in order to achieve rerouting. A basic requirement of such models is to automatically establish turning movements from link flows. Conventional models such as entropy maximizing and information minimizing have been developed for use off line for transportation planning and are not suitable for application on line. A novel approach is proposed that uses linear programming to forecast traffic congestion in an urban network and define junction turning flows. The algorithms, originally developed for optimizing flows of water and electricity, use detector flow measurements, weighted links, and constrained upper and lower flow bounds. The principles underlying this approach are explained. The development, calibration, validation, and implementation of the model in a real network in the city of Leicester, England, are described. The results show that turning movements can be predicted with sufficient accuracy to justify further work, in particular to carry out a demonstration of the application of the algorithm on street.

Analysis of Driving Parameters and Emissions for Real World Urban Driving Cycles using an on-board Measurement Method for a EURO 2 SI car

Abstract: A FTIR in-vehicle on-road emission measurement system was installed in a EURO 2 emissions compliant SI car to investigate exhaust emissions under different urban traffic conditions. The real time fuel consumption and vehicle traveling speed was measured and logged. The temperatures were measured along the exhaust pipe so as to monitor the thermal characteristics and efficiency of the catalyst. Two real world driving cycles were developed with different traffic conditions. One (WP cycle) was located in a quiet area with few trafficinterference and the other one (HPL cycle) was in a busy area with more traffic variations. The test car was pre-warmed before each test to eliminate cold start effect. The driving parameters were analyzed for two real world cycles. The WP cycle had higher acceleration rate, longer acceleration mode and shorter steady speed driving mode and thus harsher than the HPL cycle. The CO, THC, NOx CO2, benzene and other hydrocarbon emissions were higher for the WP cycle. The comparison with EU legislation shows that the CO and THC emissions from both real world cycles could meet the legislated limit but the NOx emissions from both cycle exceeded the legislated emissions when the engine was hot. The research analyzed the elements that affect urban traffic emissions and will be useful for a better traffic management to reduce emissions. The data of this research can be used for the prediction of emissions in cities.

openair - An R package for air quality data analysis

Abstract: openair is an R package primarily developed for the analysis of air pollution measurement data but which is also of more general use in the atmospheric sciences. The package consists of many tools for importing and manipulating data, and undertaking a wide range of analyses to enhance understanding of air pollution data. In this paper we consider the development of the package with the purpose of showing how air pollution data can be analysed in more insightful ways. Examples are provided of importing data from UK air pollution networks, source identification and characterisation using bivariate polar plots, quantitative trend estimates and the use of functions for model evaluation purposes. We demonstrate how air pollution data can be analysed quickly and efficiently and in an interactive way, freeing time to consider the problem at hand. One of the central themes of openair is the use of conditioning plots and analyses, which greatly enhance inference possibilities. Finally, some consideration is given to future developments.

A review and evaluation of intraurban air pollution exposure models

Abstract: The development of models to assess air pollution exposures within cities for assignment to subjects in health studies has been identified as a priority area for future research. This paper reviews models for assessing intraurban exposure under six classes, including: (i) proximity-based assessments, (ii) statistical interpolation, (iii) land use regression models, (iv) line dispersion models, (v) integrated emission-meteorological models, and (vi) hybrid models combining personal or household exposure monitoring with one of the preceding methods. We enrich this review of the modelling procedures and results with applied examples from Hamilton, Canada. In addition, we qualitatively evaluate the models based on key criteria important to health effects assessment research. Hybrid models appear well suited to overcoming the problem of achieving population representative samples while understanding the role of exposure variation at the individual level. Remote sensing and activity-space analysis will complement refinements in pre-existing methods, and with expected advances, the field of exposure assessment may help to reduce scientific uncertainties that now impede policy intervention aimed at protecting public health.

An updated roadmap for the integration of metal–organic frameworks with electronic devices and chemical sensors

Abstract: Metal-organic frameworks (MOFs) are typically highlighted for their potential application in gas storage, separations and catalysis. In contrast, the unique prospects these porous and crystalline materials offer for application in electronic devices, although actively developed, are often underexposed. This review highlights the research aimed at the implementation of MOFs as an integral part of solid-state microelectronics. Manufacturing these devices will critically depend on the compatibility of MOFs with existing fabrication protocols and predominant standards. Therefore, it is important to focus in parallel on a fundamental understanding of the distinguishing properties of MOFs and eliminating fabrication-related obstacles for integration. The latter implies a shift from the microcrystalline powder synthesis in chemistry labs, towards film deposition and processing in a cleanroom environment. Both the fundamental and applied aspects of this two-pronged approach are discussed. Critical directions for future research are proposed in an updated high-level roadmap to stimulate the next steps towards MOF-based microelectronics within the community.