Bioindication of Urban Air Polycyclic Aromatic Hydrocarbons Using Petunia Hybrida

Different ways can be used to determinate the effects of hydrocarbons on plants: the bioindication with plants is one of these methods. It consists of using sensitive plants like Petunia hybrida to evaluate the urban levels of hydrocarbon pollution. The sensitivity shows physiological and morphological modifications. In this context, this research aims to characterize the level of exposure to air pollutants resulting from anthropogenic activities in urban area of Bejaia (Algeria) by measuring the morphological impacts induced on Petunia hybrida using 11 parameters detailing the morphological development of this plant. During 7 weeks (March 23- May 11, 2017), ten monitoring stations were chosen in this city. The results showed that the most important morphological changes are directly associated with the stations closest to the main atmospheric emission zones. It is by moving away from these sources of exposure that the morphological changes observed in this bioindicating plant become less important. These results coincide with those found for particle matter concentrations including PM10 and PM2.5 which indicate that Daouadji and Aamriw stations are the most polluted sites in Bejaia. Analyzes carried out on research station located in rural area (more than 30 km from the studied city) revealed a greater general development compared to other stations

Assessment of Air Pollution Impacts on Population Health in Bejaia City, Northern Algeria.

To assess the health impact of air pollution on Bejaia population in the north of Algeria, we carried out a descriptive epidemiologic inquiry near the medical establishments of three areas.From hospital admissions registers, we collected data on the hospital mortality and admissions relating to the various cardiorespiratory pathologies generated by this type of pollution. In parallel, data on the automobile fleet of Bejaia and other measurements were exploited to show that the pollutants concentrations are strongly correlated with the urban traffic concentration.This study revealed that the whole of the population is touched, but the sensitivity to pollution can show variations according to the age, the sex and the residence place. Population of Bejaia town marked the most raised death and morbidity rates, followed by that of Kherrata. Weak rates are recorded for the rural population of Feraoun. Stronger correlation (>0.9) is evident amongst CO and deaths due to asthma and COPD in Béjaia city.This approach enables us to conclude that the population of Béjaia could not escape the urban pollution generated by her old automobile fleet. Installation of a monitoring and measuring site of air pollution in this city could provide a beneficial tool to protect its inhabitants by informing on air quality they breathe and the measures to following order to minimize the impacts on their health and by alerting the authorities during the critical situations

Complexity based on synchrosqueezing analysis in gear diagnosis

The Synchrosqueezing is a special case of the reassignment method and concentrates the time-frequency representation (TFR) in a scale dimension. Compared to other TFR enhancement methods, the synchrosqueezing offers better adaptability, less deformation for IF profile and an exact reconstruction formula for constituent components. This paper deals with the investigation of descriptors based on the combination of the synchrosqueezing transform (SST) and Lempel-Ziv complexity methods. This last one transforms the analyzed signal into a data sequence. In the first part, the vibration signal components are extracted by using the synchrosqueezing transform and the reconstruction method. Afterward, the Lempel-Ziv complexity values are calculated. Since the complexity values are not dependent on the magnitude of the measured signal, the proposed method is less sensitive to the data sets measured under different data acquisition conditions. This approach is applied for monitoring and diagnosing the defects during a fatigue test on a first gear reducer and also when varying the load on a second gear reducer by using the recorded vibration signals. It can also provide a new way for feature extraction and recognition of gear system faults

Bearing fault detection using motor current signal analysis based on wavelet packet decomposition and Hilbert envelope

To detect rolling element bearing defects, many researches have been focused on Motor Current Signal Analysis (MCSA) using spectral analysis and wavelet transform. This paper presents a new approach for rolling element bearings diagnosis without slip estimation, based on the wavelet packet decomposition (WPD) and the Hilbert transform. Specifically, the Hilbert transform first extracts the envelope of the motor current signal, which contains bearings fault-related frequency information. Subsequently, the envelope signal is adaptively decomposed into a number of frequency bands by the WPD algorithm. Two criteria based on the energy and correlation analyses have been investigated to automate the frequency band selection. Experimental studies have confirmed that the proposed approach is effective in diagnosing rolling element bearing faults for improved induction motor condition monitoring and damage assessment

Bearing fault detection using motor current signal analysis based on wavelet packet decomposition and Hilbert envelope

To detect rolling element bearing defects, many researches have been focused on Motor Current Signal Analysis (MCSA) using spectral analysis and wavelet transform. This paper presents a new approach for rolling element bearings diagnosis without slip estimation, based on the wavelet packet decomposition (WPD) and the Hilbert transform. Specifically, the Hilbert transform first extracts the envelope of the motor current signal, which contains bearings fault-related frequency information. Subsequently, the envelope signal is adaptively decomposed into a number of frequency bands by the WPD algorithm. Two criteria based on the energy and correlation analyses have been investigated to automate the frequency band selection. Experimental studies have confirmed that the proposed approach is effective in diagnosing rolling element bearing faults for improved induction motor condition monitoring and damage assessment

Short-Term Health Impact Assessment of Urban PM10 in Bejaia City (Algeria)

We used Health Impact Assessment (HIA) to analyze the impact on a given population’s health outcomes in terms of all-causes mortality and respiratory and cardiovascular hospitalizations attributable to short-term exposure to particulate matter less than 10 μm diameter (PM10) in Bejaia city, for which health effects of air pollution have never been investigated. Two scenarios of PM10 reduction were considered: first, a scenario where the PM10 annual mean is decreased by 5 µg/m3, and then a scenario where this PM10 mean is decreased to 20 µg/m3 (World Health Organization annual air quality guideline (WHO-AQG)). Annual mean level of PM10 (81.7 µg/m3) was calculated from objective measurements assessed in situ. Each year, about 4 and 55 deaths could be postponed with the first and the second scenarios successfully. Furthermore, decreasing PM10 annual mean by 5 µg/m3 would avoid 5 and 3 respiratory and cardiac hospitalizations, respectively, and not exceeding the PM10 WHO-AQG (20 µg/m3) would result in a potential gain of 36 and 23 per 100000 respiratory and cardiac hospitalizations, respectively. Lowering in current levels of PM10 has a nonnegligible impact in terms of public health that it is expected to be higher in the case of long-term effects

Etude et caracterisation des processus de recombinaisons non-radiatives dans Ga In As P

SIGLECNRS AR 10431 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Chapter 4. Air quality and climate in the Mediterranean region

Ambient air ranks number one among the natural resources vital to human beings, with an average individual daily need of 12 kg. Due to the specificities of the Mediterranean region (sunny, hot and dry climate; long-range transport converging over the basin), air pollution in reactive compounds over the Mediterranean is often higher than in most European inland regions. Climate change (increase in temperature and drought) and anthropogenic pressure (growing population) should significantly impact the regional air quality. As a result, Mediterranean inhabitants who are already regularly exposed to pollutant loads well above WHO air quality recommendations will be further exposed, resulting in an excess of premature deaths. Exposure monitoring and win-win strategies should be developed in the future both to improve air quality and develop a low carbon economy. The evolution of emissions under climate change is not always clear and much uncertainty remains around present emissions from large urban-industrial centers, although recent progress has been made on emissions of the different regional sources of pollutants. It has been established that the regional climate and water cycle are affected by atmospheric chemistry. By reducing solar radiation at the surface, aerosols reduce the yearly average precipitation in the Mediterranean by 10%, which is a major issue since water is already scarce. Aerosols could further reduce precipitations by reducing the size of cloud droplets or through the formation of cloud droplets and ice crystals. Moreover, recent in situ and model experiments indicate that anthropogenic nitrogen and desert dust phosphorus deposition in nutrient-depleted surface seawater favors phytoplankton development, which stimulates the sink of atmospheric CO2 into marine sediments. But Saharan dust deposition by rain also stimulates bacterial growth, which reemits CO2. The net effect of desert dust deposition at large scales needs to be established.L’air est sans aucun doute la ressource naturelle la plus essentielle à l’homme: chaque jour 12 kg d’air sont nécessaires à sa survie. Du fait des spécificités de la région méditerranéenne (climat ensoleillé, chaud et sec; convergence de masses d’air d’horizons lointains), la pollution de l’air en espèces réactives y est souvent plus forte que dans la plupart de l’Europe continentale. Les changements climatiques (augmentation des sécheresses et de la température) et la pression démographique devraient dégrader encore la qualité de l’air. En conséquence, les habitants de la Méditerranée qui sont déjà régulièrement soumis à des niveaux de pollution bien au-dessus des recommandations de l’OMS devraient se trouver plus exposés encore, ce qui engendrera une surmortalité. Un meilleur suivi de l’exposition des habitants et des solutions « gagnant-gagnant » devraient être mises en place dans le but d’améliorer la qualité de l’air et de s’engager dans une économie décarbonée. Les conséquences des changements climatiques sur les émissions de polluants par les principales sources régionales ne sont pas toujours très claires. Il a été établi que le climat régional et le cycle de l’eau sont altérés par la chimie de l’atmosphère. En réduisant le flux solaire en surface, les aérosols réduisent les précipitations moyennes annuelles de 10 % en moyenne sur le bassin méditerranéen, réduisant un peu plus une ressource déjà rare. Les aérosols pourraient réduire plus encore les précipitations en réduisant la taille des gouttes d’eau dans les nuages ou en agissant sur la formation de cristaux de glaces. Par ailleurs, de récentes expériences indiquent que le dépôt atmosphérique d’azote et le phosphore issu des poussières désertiques à la surface des eaux pauvres en nutriments de la Méditerranée favorise le développement du phytoplancton activant par la même occasion l’absorption de CO2 par l’océan. Cependant, il a aussi été observé que le dépôt de poussières favorise le développement de bactéries qui elles-mêmes rejettent du CO2 du fait de la respiration. L’effet net du dépôt de ces poussières à grande échelle reste à établir

The Mediterranean region under climate change

This book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines