Overview of Sources and Characteristics of Nanoparticles in Urban Traffic-Influenced Areas

2021 ◽  
Author(s):  
Topi Rönkkö ◽  
Hilkka Timonen
Keyword(s):  
Urban Areas ◽  
Current Knowledge ◽  
Combustion Process ◽  
Complex Mixture ◽  
Urban Traffic ◽  
Gaseous Emissions ◽  
Atmospheric Processing ◽  
Primary Particles ◽  
Brake Wear Particles ◽  
Different Sources

Atmospheric nanoparticles can be formed either via nucleation in atmosphere or be directly emitted to the atmosphere. In urban areas, several combustion sources (engines, biomass burning, power generation plants) are directly emitting nanoparticles to the atmosphere and, in addition, the gaseous emissions from the same sources can participate to atmospheric nanoparticle formation. This article focuses on the sources and formation of nanoparticles in traffic-influenced environments and reviews current knowledge on composition and characteristics of these nanoparticles. In general, elevated number concentrations of nanoparticles are very typically observed in traffic-influenced environments. Traffic related nanoparticles can originate from combustion process or from non-exhaust related sources such as brake wear. Particles originating from combustion process can be divided to three different sources; 1) primary nanoparticles formed in high temperature, 2) delayed primary particles formed as gaseous compounds nucleate during the cooling and dilution process and 3) secondary nanoparticles formed from gaseous precursors via the atmospheric photochemistry. The nanoparticles observed in roadside environment are a complex mixture of particles from several sources affected by atmospheric processing, local co-pollutants and meteorology.

scholarly journals Recognition of combustion process irregularities in small volume displacement diesel engines with the use of non-dimensional characteristics of the vibration signal

2017 ◽  
Vol 169 (2) ◽  
pp. 18-23
Author(s):  
Jerzy MERKISZ ◽  
Marek WALIGÓRSKI
Keyword(s):  
Urban Areas ◽  
Small Volume ◽  
Fuel Injection ◽  
Combustion Process ◽  
Diagnostic Algorithm ◽  
Vibration Signal ◽  
Technical Object ◽  
Operation Process ◽  
Short Time ◽  
Direct Fuel Injection

The subject of the considerations described in the paper is the problem of early detection of abnormalities and damages during operation process of the turbo diesel engine with small volume displacement and direct fuel injection, which is used in modern LDV vehicles dedicated especially for urban areas, in the context of present and future requirements for a technical object diagnostics, taking into account the criteria of optimizing overall efficiency, toxic compound emission and safety of the object in real conditions of its operation. The paper presents the results of empirical research of vibroacoustic signal application to the diagnostic evaluation of correctness of short-time engine main processes. The evaluation of the combustion process variability from structural and operational abnormalities by using dimensionless estimates of a vibration process was conducted, and functional characteristics necessary to built the diagnostic algorithm in accordance with the requirements of on-board diagnostics were obtained.

scholarly journals Spectral Analysis of Traffic Functions in Urban Areas

2015 ◽  
Vol 27 (6) ◽  
pp. 477-484 ◽  
Author(s):  
Florin Nemtanu ◽  
Ilona Madalina Costea ◽  
Catalin Dumitrescu
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Fourier Analysis ◽  
Traffic Flow ◽  
Traffic Control ◽  
Urban Areas ◽  
Urban Traffic ◽  
The Fourier Transform ◽  
The City ◽  
Different Time Scales

The paper is focused on the Fourier transform application in urban traffic analysis and the use of said transform in traffic decomposition. The traffic function is defined as traffic flow generated by different categories of traffic participants. A Fourier analysis was elaborated in terms of identifying the main traffic function components, called traffic sub-functions. This paper presents the results of the method being applied in a real case situation, that is, an intersection in the city of Bucharest where the effect of a bus line was analysed. The analysis was done using different time scales, while three different traffic functions were defined to demonstrate the theoretical effect of the proposed method of analysis. An extension of the method is proposed to be applied in urban areas, especially in the areas covered by predictive traffic control.

Resolving Sample Traces in Complex Mixtures with Microarray Analyses

2011 ◽  
pp. 108-155
Author(s):  
George I. Lambrou ◽  
Eleftheria Koultouki ◽  
Maria Adamaki ◽  
Maria Moschovi
Keyword(s):  
Nucleic Acids ◽  
Statistical Methods ◽  
Current Knowledge ◽  
Complex Mixture ◽  
Theoretical Framework ◽  
Complex Mixtures ◽  
Complex Signal ◽  
Microarray Technology ◽  
Detailed Review ◽  
Microarray Analyses

This chapter reviews the microarray technology and deal with the majority of aspects regarding microarrays. It focuses on today’s knowledge of separation techniques and methodologies of complex signal, i.e. samples. Overall, the chapter reviews the current knowledge on the topic of microarrays and presents the analyses and techniques used, which facilitate such approaches. It starts with the theoretical framework on microarray technology; second, the chapter gives a brief review on statistical methods used for microarray analyses, and finally, it contains a detailed review of the methods used for discriminating traces of nucleic acids within a complex mixture of samples.

scholarly journals An Examination of the Safety Impacts of Bus Priority Routes in Major Israeli Cities

2020 ◽  
Vol 12 (20) ◽  
pp. 8617
Author(s):  
Victoria Gitelman ◽  
Anna Korchatov ◽  
Wafa Elias
Keyword(s):  
Traffic Safety ◽  
Public Transport ◽  
Urban Areas ◽  
Urban Traffic ◽  
Bus Priority ◽  
Safety Level ◽  
Comparison Groups ◽  
Pedestrian Crashes ◽  
Crash Types ◽  
Increasing Trends

Bus priority routes (BPRs) promote public transport use in urban areas; however, their safety impacts are not sufficiently understood. Along with proven positive mobility effects, such systems may lead to crash increases. This study examines the safety impacts of BPRs, which have been introduced on busy urban roads in three major Israeli cities—Tel Aviv, Jerusalem and Haifa. Crash changes associated with BPR implementation are estimated using after–before or cross-section evaluations, with comparison-groups. The findings show that BPR implementation is generally associated with increasing trends in various crash types and, particularly, in pedestrian crashes at junctions. Yet, the results differ depending on BPR configurations. Center lane BPRs are found to be safer than curbside BPRs. The best safety level is observed when a center lane BPR is adjacent to a single lane for all-purpose traffic. Local public transport planners should be aware of possible negative implications of BPRs for urban traffic safety. Negative safety impacts can be moderated by a wider use of safety-related measures, as demonstrated in BPRs’ operation in Haifa. Further research is needed to delve into the reasons for the negative safety impacts of BPRs under Israeli conditions relative to the positive impacts reported in other countries.

scholarly journals City Maker: Reconstruction of Cities from OpenStreetMap Data for Environmental Visualization and Simulations

2019 ◽  
Vol 8 (7) ◽  
pp. 298 ◽  
Author(s):  
I. Alihan Hadimlioglu ◽  
Scott A. King
Keyword(s):  
Emergency Management ◽  
Urban Areas ◽  
Smart Cities ◽  
Data Availability ◽  
Data Formats ◽  
3D Processing ◽  
Environmental Simulations ◽  
Simulation Parameters ◽  
The City ◽  
Different Sources

Recent innovations in 3D processing and availability of geospatial data have contributed largely to more comprehensive solutions to data visualization. As various data formats are utilized to describe the data, a combination of layers from different sources allow us to represent 3D urban areas, contributing to ideas of emergency management and smart cities. This work focuses on 3D urban environment reconstruction using crowdsourced OpenStreetMap data. Once the data are extracted, the visualization pipeline draws features using coloring for added context. Moreover, by structuring the layers and entities through the addition of simulation parameters, the generated environment is made simulation ready for further use. Results show that urban areas can be properly visualized in 3D using OpenStreetMap data given data availability. The simulation-ready environment was tested using hypothetical flooding scenarios, which demonstrated that the added parameters can be utilized in environmental simulations. Furthermore, an efficient restructuring of data was implemented for viewing the city information once the data are parsed.

scholarly journals Long-Term Assessment of Air Quality and Identification of Aerosol Sources at Setúbal, Portugal

2020 ◽  
Vol 17 (15) ◽  
pp. 5447 ◽  
Author(s):  
Alexandra Viana Silva ◽  
Cristina M. Oliveira ◽  
Nuno Canha ◽  
Ana Isabel Miranda ◽  
Susana Marta Almeida
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Air Pollutants ◽  
Air Pollutant ◽  
Urban Traffic ◽  
Anthropogenic Sources ◽  
World Health ◽  
Mitigation Measures ◽  
Guideline Values ◽  
Health Organization

Understanding air pollution in urban areas is crucial to identify mitigation actions that may improve air quality and, consequently, minimize human exposure to air pollutants and their impact. This study aimed to assess the temporal evolution of the air quality in the city of Setúbal (Portugal) during a time period of 10 years (2003–2012), by evaluating seasonal trends of air pollutants (PM10, PM2.5, O3, NO, NO2 and NOx) measured in nine monitoring stations. In order to identify emission sources of particulate matter, PM2.5 and PM2.5–10 were characterized in two different areas (urban traffic and industrial) in winter and summer and, afterwards, source apportionment was performed by means of Positive Matrix Factorization. Overall, the air quality has been improving over the years with a decreasing trend of air pollutant concentration, with the exception of O3. Despite this improvement, levels of PM10, O3 and nitrogen oxides still do not fully comply with the requirements of European legislation, as well as with the guideline values of the World Health Organization (WHO). The main anthropogenic sources contributing to local PM levels were traffic, industry and wood burning, which should be addressed by specific mitigation measures in order to minimize their impact on the local air quality.

Measuring Economic Costs of Urban Traffic Congestion to Business

2003 ◽  
Vol 1839 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Glen Weisbrod ◽  
Don Vary ◽  
George Treyz
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Economic Benefits ◽  
Urban Traffic ◽  
Production Costs ◽  
Market Area ◽  
Economic Costs ◽  
Local Data ◽  
Economic Implications ◽  
Reduction Strategies

Key findings are provided from NCHRP Study 2-21, which examined how urban traffic congestion imposes economic costs within metropolitan areas. Specifically, the study applied data from Chicago and Philadelphia to examine how various producers of economic goods and services are sensitive to congestion, through its impact on business costs, productivity, and output levels. The data analysis showed that sensitivity to traffic congestion varies by industry sector and is attributable to differences in each industry sector's mix of required inputs and hence its reliance on access to skilled labor, access to specialized inputs, and access to a large, transportation-based market area. Statistical analysis models were applied with the local data to demonstrate how congestion effectively shrinks business market areas and reduces the "agglomeration economies" of businesses operating in large urban areas, thus raising production costs. Overall, this research illustrates how it is possible to estimate the economic implications of congestion, an approach that may be applied in the future for benefit-cost analysis of urban congestion-reduction strategies or for development of congestion pricing strategies. The analysis also shows how congestion-reduction strategies can induce additional traffic as a result of economic benefits.

Analysis of Trends in Data on Transit Bus Dwell Times

2017 ◽  
Vol 2619 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Isaac K. Isukapati ◽  
Hana Rudová ◽  
Gregory J. Barlow ◽  
Stephen F. Smith
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Traffic Signal ◽  
Urban Traffic ◽  
Distribution Model ◽  
Signal Control ◽  
Traffic Signal Control ◽  
Real Time Control ◽  
Arrival Times ◽  
On The Road

Transit vehicles create special challenges for urban traffic signal control. Signal timing plans are typically designed for the flow of passenger vehicles, but transit vehicles—with frequent stops and uncertain dwell times—may have different flow patterns that fail to match those plans. Transit vehicles stopping on urban streets can also restrict or block other traffic on the road. This situation results in increased overall wait times and delays throughout the system for transit vehicles and other traffic. Transit signal priority (TSP) systems are often used to mitigate some of these issues, primarily by addressing delay to the transit vehicles. However, existing TSP strategies give unconditional priority to transit vehicles, exacerbating quality of service for other modes. In networks for which transit vehicles have significant effects on traffic congestion, particularly urban areas, the use of more-realistic models of transit behavior in adaptive traffic signal control could reduce delay for all modes. Estimating the arrival time of a transit vehicle at an intersection requires an accurate model of dwell times at transit stops. As a first step toward developing a model for predicting bus arrival times, this paper analyzes trends in automatic vehicle location data collected over 2 years and allows several inferences to be drawn about the statistical nature of dwell times, particularly for use in real-time control and TSP. On the basis of this trend analysis, the authors argue that an effective predictive dwell time distribution model must treat independent variables as random or stochastic regressors.

The Truer Picture of the Continuing Education Preferences of NL Pharmacists: Can We Apply What We Learned to Managing Diseases Such as HIV?

2005 ◽  
Vol 138 (7) ◽  
pp. 41-41
Author(s):  
Gerry Mugford
Keyword(s):  
Disease Management ◽  
Continuing Education ◽  
Urban Areas ◽  
Clinical Skills ◽  
Current Knowledge ◽  
Educational Needs ◽  
Standards Of Care ◽  
Post Exposure Prophylaxis ◽  
Hiv Disease ◽  
Delivery Times

Background: The treatment of HIV disease is made more complex by rapid changes in disease management. Two primary objectives of this study were to evaluate the continuing education (CE) needs and preferences of pharmacists and to utilize this information to develop CE HIV disease management strategies. Our hypothesis was that current knowledge of HIV disease management is outdated and that CE related to HIV should be delivered in ways that meet the preferences of pharmacists. Methods: A 14-page needs assessment (NA) was developed to assess the CE needs and preferences of Newfoundland and Labrador (NL) pharmacists and their knowledge of HIV disease management. The NA was validated by pharmacists, physicians, nurses, and social workers from Memorial University of Newfoundland and the Health Care Corporation of St. John's. Respondents' answers were scored using a six-point Likert scale. Space was available for respondents to provide open answers and opinions related to the questionnaire, CE, and HIV. Piloting and feedback suggested the NA could be completed in 20–30 minutes. The NA was mailed to 470 pharmacists. Results: Thirty percent of the pharmacists returned a completed questionnaire. Mean scores (MS) were calculated for specific CE topics. The top three CE topics were: update professional skills (MS = 4.46); current standards of care (MS = 3.9); and professional practice standards (MS = 3.85). CE topics for clinical skills were also highlighted and included pharmacology and therapeutics, infectious disease, and patient education. CE topics specific to HIV included drug interactions, resistance, management of adverse events, opportunistic infections, alternative therapies, HAART therapy, post-exposure prophylaxis, and pregnancy in HIV/AIDS. Most pharmacists (81%) had access to Internet and e-mail (76%). Few respondents had access to teleconference (19%) and videoconference (11%). Pharmacists' preferences for CE delivery times were workday evenings (2–3 hours), weekend half-day, and workday half-day. Conferences, correspondences courses, structured courses, and seminars were the preferred delivery modes. Conclusions/Implications: Pharmacists in NL appear to have specific educational needs. Although the study achieved a lower-than-expected response rate, perhaps partly due to its length, most respondents indicated that computer-based technology could enhance the delivery of CE. Continuous, discipline-specific, real-time assessment of educational needs may be essential for optimum management of patients with HIV. It is likely the findings reflect the needs of pharmacists across the country, especially those outside urban areas. The preferences identified in this study could apply to delivering CE for a variety of diseases.

scholarly journals An ego-centred approach for the evaluation of health inequalities in urban areas

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
O Sauzet ◽  
K A Zolitschka ◽  
J Spallek ◽  
J Breckenkamp ◽  
O Razum
Keyword(s):  
Health Outcomes ◽  
Spatial Correlation ◽  
Health Inequalities ◽  
Urban Areas ◽  
Complex Mixture ◽  
Urban Setting ◽  
Neighbourhood Effects ◽  
Spatially Correlated ◽  
Using Data ◽  
Definition Of

Abstract Background Neighbourhood possesses attributes, structural, physical and social, for which pathways to health inequalities could be hypothesized. Hence, neighbourhood is a complex mixture of factors which cannot be simply defined by a delineation on a map, making common definitions of neighbourhood (e.g. administrative borders) problematic. We present a new concept for the evaluation of contextual health inequalities in an urban setting. Methods An ego-centred approach to neighbourhood effects on health allows to establish to what degree the health outcomes of a person are on average correlated to the health outcomes of his/her neighbours. This approach does not necessitate the definition of what a neighbourhood is, or of its boundaries. Using data from the BaBi birth cohort following up 958 mother-child pairs in Bielefeld/Germany we illustrate how the method provides information about the spatial structure of a possible association between unmeasured neighbourhood factors and birthweight. Spatially correlated birthweight indicates a neighbourhood effect on maternal health. Results A parametric model of the correlation structure gives two indicators: a distance after which health outcomes are no longer correlated (practical range), and the strength of correlation (RSV). We modelled birthweight directly and residuals after controlling for (spatially correlated) covariates. After adjusting for the mother’s demographics and neighbourhood characteristics, birthweights remained spatially correlated with RSV of 11% and a practical range of 128 m. Conclusions Modelling the spatial correlation of a health outcome provides a measure of the degree of health correlation, thus offering new evidence on the production of health inequalities while incorporating current modelling approaches. Moreover, it measures heterogeneity in a city. This could be used as an indicator for policy makers or town planners to identify areas in need of socioeconomic investment. Key messages Modelling the spatial correlation of health outcomes is an approach which enable to assess unmeasured neighbourhood effects. The health correlation neighbourhood approach helps to investigate the production of health inequalities and to identify urban areas in need of socioeconomic investment.

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