scholarly journals Carcinogenic Content of PM10-Bound PAHs in University Classrooms and Outdoors at an Urban Location in Rome, Italy, during Winter Working and Not-Working Days

2021 ◽  
Vol 13 (19) ◽  
pp. 10790
Author(s):  
Monica Gherardi ◽  
Andrea Gordiani ◽  
Nunziata L’Episcopo ◽  
Armando Pelliccioni
Keyword(s):  
Ambient Air ◽  
External Source ◽  
Additional Contribution ◽  
Indoor Environments ◽  
Infiltration Capacity ◽  
Carcinogenic Potency ◽  
Eu Directive ◽  
Carcinogenic Pahs ◽  
Toxicity Equivalent ◽  
Traffic Source

To assess the contribution of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) in ambient air, EU Directive 2004/107/EC indicates to monitor relevant carcinogenic PAHs in PM10 fraction other than benzo(a)pyrene at a limited number of measurement sites. This indication refers to outdoor environments, and the environmental air quality being taken as a reference also for indoors, it can be extended to indoor environments. In this work, the contribution of carcinogenic PAHs bound to PM10 has been evaluated in winter in two classrooms of a University campus in Rome with the aim of studying the relationship with the outdoors and with working activity. PM10-boundPAHs were monitored over five different periods selected to distinguish Weekend from daytime and nighttime Weekdays, separated into two parts of the week. Data aggregated over Weekend and Weekdays allowed calculating of the concentration of carcinogenic PAHs, the mass contribution to PM10, the Infiltration Factor, the indoor to outdoor Ratio, and the Total Carcinogenic Potency by Toxicity Equivalent Factors, for “not-working” and “working” days. In addition, some indications on contributions to the source have been obtained from the chemical profile normalized to the maximum value of concentration, which also provides the source fingerprint compound. Indoor PAH concentrations were lower than outdoor, and both accumulated as the week progressed. Although the two indoor environments were on the same floor and had a similar volume, they presented different contribution to PM10 and infiltration capacity, both higher during Weekend than on Weekdays. The analysis of indoor and outdoor chemical profiles normalized to the maximum concentration indicated an external source infiltrating the indoors environment. During Weekdays, the indoor fingerprint compound changed compared to that observed during Weekend, probably due to an additional contribution of local “fresh-traffic” source. The calculation of Total Carcinogenic Potency gave indoor values always lower than outdoor, confirming in the two classrooms different dynamics for carcinogenic PAHs. Moreover, the Total Carcinogenic Potency on Weekdays was twice that of Weekend, meaning a higher toxicological impact when urban “fresh-traffic” source is added. The present study shows that the dynamics of PM10-related carcinogenic PAHs can be different within adjacent classrooms of a building and during working and not-working days. This evidence suggests the possibility of a potential different impact on occupant exposure to be taken into account in planning monitoring programs of indoor pollution.

scholarly journals IMPROVED REFERENCE KEY FRAME ALGORITHM

2019 ◽  
Vol IV-2/W5 ◽  
pp. 133-139 ◽  
Author(s):  
H. A. Mohamed ◽  
A. Moussa ◽  
M. M. Elhabiby ◽  
N. El-Sheimy
Keyword(s):  
Autonomous Vehicles ◽  
Previous History ◽  
External Source ◽  
Indoor Environments ◽  
Scan Matching ◽  
Detection Range ◽  
Key Frame ◽  
Matching Process ◽  
Map Construction ◽  
Localization And Mapping

<p><strong>Abstract.</strong> The autonomous vehicles, such as wheeled robots and drones, efficiently contribute in the search and rescue operations. Specially for indoor environments, these autonomous vehicles rely on simultaneous localization and mapping approach (SLAM) to construct a map for the unknown environment and simultaneously to estimate the vehicle’s position inside this map. The result of the scan matching process, which is a key step in many of SLAM approaches, has a fundamental role of the accuracy of the map construction. Typically, local and global scan matching approaches, that utilize laser scan rangefinder, suffer from accumulated errors as both approaches are sensitive to previous history. The reference key frame (RKF) algorithm reduces errors accumulation as it decreases the dependency on the accuracy of the previous history. However, the RKF algorithm still suffers; as most of the SLAM approaches, from scale shrinking problem during scanning corridors that exceed the maximum detection range of the laser scan rangefinder. The shrinking in long corridors comes from the unsuccessful estimation of the longitudinal movement from the implemented RKF algorithm and the unavailability of this information from external source as well. This paper proposes an improvement for the RKF algorithm. This is achieved by integrating the outcomes of the optical flow with the RKF algorithm using extended Kalman filter (EKF) to overcome the shrinking problem. The performance of the proposed algorithm is compared with the RKF, iterative closest point (ICP), and Hector SLAM in corridors that exceed the maximum detection range of the laser scan rangefinder.</p>

Experience with Mechanical Seal of Prototype Fast Breeder Reactor’s Secondary Sodium Pump during Testing

2014 ◽  
Vol 592-594 ◽  
pp. 1544-1548
Author(s):  
Bhagwana Ram Manda ◽  
K.V. Sreedharan ◽  
S. Athmalingam ◽  
V. Balasubramaniyan ◽  
P. Chellapandi
Keyword(s):  
Sodium Pump ◽  
Ambient Air ◽  
External Source ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Rotating Shaft ◽  
Gas Leakage ◽  
Oil Leakage ◽  
Successful Resolution

Prototype fast breeder reactor’s (PFBR) secondary pumps have sealing between the rotating shaft and the stationary parts to prevent cover gas leakage into ambient air. This is achieved by means of triple mechanical seals with oil as buffer fluid. The oil for cooling the mechanical seals and bearing is supplied from an external source and is re-circulated after cooling and cleaning. During testing of secondary pumps several issues related to mechanical seal arrangement, material, oil temperature and oil leakage into process side were confronted. This paper discusses the successful resolution of such issues.

scholarly journals LIFE Monza: comparison between ante and post-operam noise and air quality monitoring activities in a Noise Low Emission Zone

Noise Mapping ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 171-191
Author(s):  
Rosalba Silvaggio ◽  
Salvatore Curcuruto ◽  
Enrico Mazzocchi ◽  
Francesco Borchi ◽  
Chiara Bartalucci ◽  
...  
Keyword(s):  
Air Quality ◽  
Measurement Techniques ◽  
Ambient Air ◽  
Environmental Noise ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Limit Values ◽  
Eu Directive ◽  
Low Emission ◽  
Monitoring Activities

AbstractLIFE MONZA project (Methodologies fOr Noise low emission Zones introduction And management) aims at defining an easy-replicable method for the identification and management of the Noise Low Emission Zones (Noise LEZ), urban areas subject to traffic restrictions, usually introduced in order to ensure compliance with the air pollutants limit values, prescribed by the European Directive on ambient air quality 2008/50/EC, whose impacts and potential benefits regarding noise issues have been taken into account, tested and analysed in a pilot area of the city of Monza, located in North Italy. Noise LEZ has been established in Libertà district, introducing infrastructural interventions carried out by the municipality (top-down actions) and encouraging an active involvement of the citizens, in the definition of a more sustainable lifestyle (bottom-up actions). The analysis of potential effects on noise reduction due to the Noise LEZ can contribute to the implementation of the EU Directive 2002/49/EC, related to the assessment and management of environmental noise (Environmental Noise Directive – END), which introduces noise action plans, designed to manage noise issues and their effects, suggesting the adoption of urban and mobility planning. Noise and air quality monitoring activities have been carried out in pilot area in ante and post-operam conditions. The monitoring methods, the measurement techniques, the analysis procedures, able to describe the effects due to Noise LEZ establishment, for both the main environmental issues are reported in this paper, as proposals to be applied in other different contexts. Results of monitoring activities highlight a reduction of noise, in term of sound pressure levels, between ante and post-operam, during the day and particularly during the night period, and it is essentially due to the interventions realised. The effect of the Noise LEZ on air pollution seems to be negligible for combustion related pollutant and carbon fractions of PM, due both to the moderate spatial effects of the measures undertaken and confounding factors due to concomitant emission sources and meteorology.

scholarly journals Evaluation of the Directive 2008/50/EC on Ambient Air Quality

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Marina Langkamp ◽  
◽  
Vinicius Valente Bayma
Keyword(s):  
Air Quality ◽  
Evaluation Criteria ◽  
Ambient Air ◽  
Added Value ◽  
Ambient Air Quality ◽  
Eu Member States ◽  
Eu Directive ◽  
Better Regulation ◽  
Efficiency And Effectiveness ◽  
The Eu

The EU Directive 2008/50/EC on Ambient Air Quality and Cleaner Air for Europe is one of the actions taken at the European Levelto reach sustainable air quality levels that do not threaten the Environment and EU citizens across EU Member States. After over 10 years, it was considered appropriate to evaluate the EU intervention with the aim to comment, on its shortcomings and to provide policy recommendations. According to the EU “better regulation guidelines”, every assessment should use the evaluation criteria framework and investigate five main aspects of the intervention, namely effectiveness, efficiency, coherence, relevance and EU added value. Although this framework must guide every evaluation, the level of investigation implemented for each of the five criteria stills depends on the initiative being assessed, as well as the timing and data reliability. The analysis of the five criteria demonstrated a solid difficulty in implementing EU-wide measures to improve air quality. Although there’s no doubt about the relevance, cohesion and EU-added value aspects of the Directive, its efficiency and effectiveness can be debated.

scholarly journals Influence of Microenvironments and Personal Activities on Personal PM2.5 Exposures among Children and Adults

2020 ◽  
Author(s):  
Mahima Habil ◽  
David D. Massey ◽  
Ajay Taneja
Keyword(s):  
Fine Particles ◽  
Activity Patterns ◽  
Age Groups ◽  
Personal Exposure ◽  
Ambient Air ◽  
Effective Control ◽  
Indoor Environments ◽  
Outdoor Environments ◽  
Indoor Particulate Matter ◽  
Pm2.5 Concentration

Environmental issues are a major worldwide problem of significant concern. Due to the growing human population and advancement in every sector, the environmental related issues are multiplying in recent years. Scalable exposures assessments approach that captures personal exposure to particles for purposes of epidemiology are currently limited, but very valuable especially for a country like India. The high levels of indoor particulate matter and the apparent scale of its impact on the global burden of disease underline the importance of particulate as an environmental health risk and the need for monitoring them. Human exposure especially to fine particles can have significant harmful effects on the respiratory and cardiovascular system. To investigate daily exposure characteristics to PM2.5 with ambient concentrations in an urban environment, personal exposure measurements were conducted for different age groups of people residing in different indoor environments. To account for PM2.5 exposure and measurements personal environment monitors (PEM) and medium volume sampler APM 550 was used to measure PM2.5 concentration. On comparing the annual average PM2.5 concentration with National Ambient Air Quality and WHO standards the concentrations were found to be many folds higher for personal and ambient monitoring at homes, schools, and offices. Moreover, the questionnaire data study explains the fact that the health hazards experienced by occupants linked to various activity patterns pose a greater risk in different indoor environments as compared to outdoor environments. The presented research method and analysis can help develop environmental awareness in identifying these pollutants and can also help in elucidating these contaminants. A real understanding of these possible causes of airborne contaminant is crucial for selecting and developing suitable and effective control methods.

Recent Developments on Synthetic Jets (Review Paper)

2016 ◽  
Vol 66 (5) ◽  
pp. 489 ◽  
Author(s):  
T. Murugan ◽  
Monami Deyashi ◽  
Santanu Dey ◽  
Subhas Chandra Rana ◽  
P.K. Chatterjee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Review Paper ◽  
Ambient Air ◽  
External Source ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Transfer Enhancement ◽  
Aerospace Applications ◽  
Recent Developments

<p>Synthetic jet is a form of pulsatile jet where the flow is synthesised from the ambient air and it does not need any external source as the flow is induced from the fluid existing around orifice/nozzle. This property makes synthetic jet unique compared to pulsatile and continuous jets. Recently, the synthetic jet is being widely used for flow control, mixing and heat transfer enhancement in aerospace applications. Focused on reviewing the recent developments on synthetic jet characterization and their applications resulting from the development of advanced diagnosing tools.</p>

PAH characteristics in the ambient air of traffic-source

1995 ◽  
Vol 159 (2-3) ◽  
pp. 185-200 ◽  
Author(s):  
Wen-Jhy Lee ◽  
Ya-Fen Wang ◽  
Ta-Chang Lin ◽  
Ying-Yuan Chen ◽  
Weng-Chang Lin ◽  
...  
Keyword(s):  
Ambient Air ◽  
Traffic Source

scholarly journals Modelling and 3D simulations of the dispersion of droplets and drops carrying the SARS-CoV-2 virus inside semi-confined ventilated spaces – Application to a public railway transport coach

2021 ◽  
Author(s):  
Patrick ARMAND ◽  
Jérémie TACHE
Keyword(s):  
Numerical Study ◽  
Air Flow ◽  
Ambient Air ◽  
Face Mask ◽  
Lagrangian Model ◽  
Specific Situation ◽  
Indoor Environments ◽  
Cfd Modelling ◽  
3D Simulations ◽  
Modes Of Transmission

Abstract Computational Fluid Dynamics (CFD) modelling and 3D simulations of the air flow and dispersion of droplets or drops in semi-confined ventilated spaces have found topical applications with the unfortunate development of the Covid-19 pandemic. As an illustration of this scenario, we have considered the specific situation of a railroad coach containing a seated passenger infected with the SARS-CoV-2 virus (and not wearing a face mask) who, by breathing and coughing, releases droplets and drops that contain the virus and that present aerodynamic diameters between 1 and 1,000 µm. The air flow is generated by the ventilation in the rail coach. While essentially 3D, the flow is directed from the bottom to the top of the carriage and comprises large to small eddies visualised by means of streamlines. The space and time distribution of the droplets and drops is computed using both an Eulerian model and a Lagrangian model. The results of the two modelling approaches are fully consistent and clearly illustrate the different behaviours of the drops, which fall down close to the infected passenger, and the droplets, which are carried along with the air flow and invade a large portion of the rail coach. This outcome is physically sound and demonstrates the relevance of CFD for simulating the transport and dispersion of droplets and drops with any diameter in enclosed ventilated spaces. As coughing produces drops and breathing produces droplets, both modes of transmission of the SARS-CoV-2 virus in human secretions have been accounted for in our 3D numerical study. Following these initial results, physical and biological modelling will be extended to the mass transfer between the droplets and the ambient air and to the fate of the virus throughout its transport and dispersion in droplets or drops. Furthermore, a model will be developed to take into account the influence of a face mask on the production of droplets and drops. Beyond the specific, practical application of the rail coach, this study offers a much broader scope by demonstrating the feasibility and usefulness of 3D numerical simulations based on CFD. As a matter of fact, the same computational approach that has been implemented in our study can be applied to a huge variety of ventilated indoor environments such as restaurants, performance halls, classrooms and open-plan offices in order to evaluate if their occupation could be critical with respect to the transmission of the SARS-CoV-2 virus or to other airborne respiratory infectious agents, thereby enabling relevant recommendations to be made.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

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