HAL Portal usj Université Saint-Joseph de Beyrouth-Liban
Not a member yet
1220 research outputs found
Sort by
Comprehensive chemical characterization of PM2.5 in the large East Mediterranean-Middle East city of Beirut, Lebanon
No full textInternational audienceThe chemical composition of PM2.5 at two sites in Lebanon, a country in the East Mediterranean - Middle East region, is investigated in the spring and summer seasons. The average PM2.5 concentrations were of (29 ± 16) µg/m3 for Beirut urban site and (32 ± 14) µg/m3 for Beirut suburban site. This study showed that the geographic location of the East Mediterranean region, such as its proximity to the Mediterranean Sea and the dust storm intrusion are a significant contributor to the high PM levels from natural sources, which cannot be mitigated, rendering the PM2.5 WHO annual Air Quality guideline unattainable due to high natural background, which also applies to the entire Middle East region. Turkey and Eastern Europe are the dominant origin of air masses throughout our sampling days, suggesting the long-range transport as an important potential contributor to the high observed concentrations of V, Ni, and sulfate in this region most probably in other East Mediterranean countries than Lebanon too. Main local sources determined through the chemical speciation including organics are road transport, resuspension of dust and diesel private generators. A health risk assessment of airborne metals was performed and the carcinogenic risk for all the metals exceeded by 42 (adults) and 14 (children) times the acceptable risk level (10−6) at both sites. Vanadium was the predominant carcinogenic metal, emphasizing the need to replace energy production with cleaner energy on a regional level and highlighting the severe impact of air pollution on the health of inhabitants in this region's main cities
Comparison of mean diffusivity, R2* relaxation rate and morphometric biomarkers for the clinical differentiation of parkinsonism
No full textInternational audienceIntroduction: Quantitative biomarkers for clinical differentiation of parkinsonian syndromes are still lacking. Our aim was to evaluate the value of combining clinically feasible manual measurements of R2* relaxation rates and mean diffusivity (MD) in subcortical regions and brainstem morphometric measurements to improve the discrimination of parkinsonian syndromes.Methods: Twenty-two healthy controls (HC), 25 patients with Parkinson's disease (PD), 19 with progressive supranuclear palsy (PSP) and 27 with multiple system atrophy (MSA, 21 with the parkinsonian variant -MSAp, 6 with the cerebellar variant -MSAc) were recruited. R2*, MD measurements and morphometric biomarkers including the midbrain to pons area ratio and the Magnetic Resonance Parkinsonism Index (MRPI) were compared between groups and their diagnostic performances were assessed.Results: Morphometric biomarkers discriminated better patients with PSP (ratio: AUC 0.89, MRPI: AUC 0.89) and MSAc (ratio: AUC 0.82, MRPI: AUC 0.75) from other groups. R2* and MD measurements in the posterior putamen performed better in separating patients with MSAp from PD (R2*: AUC 0.89; MD: AUC 0.89). For the three-class classification "MSA vs PD vs PSP", the combination of MD and R2* measurements in the posterior putamen with morphometric biomarkers (AUC: 0.841) outperformed each marker separately. At the individual-level, there were seven discordances between imaging-based prediction and clinical diagnosis involving MSA. Using the new Movement Disorder Society criteria for the diagnosis of MSA, three of these seven patients were clinically reclassified as predicted by quantitative imaging.Conclusion: Combining R2* and MD measurements in the posterior putamen with morphometric biomarkers improves the discrimination of parkinsonism
Physico-chemical characteristics and phenolic compounds content of OMWW resulting from three different processes in Lebanon
No full textInternational audienc
Some like it complex: Building a common interdisciplanry background from local experiences within the south-mediterranean environmental research community
No full textInternational audienceThis article addresses the difficulty to introduce and settle multidisciplinarity in environmental researches within and among the South-Mediterranean environmental research national communities. Moreover, this work attends to assess the internal and external structural factors treating such complex issues in rural, urban and periurban contexts and finally the connections and dependences over these components. Throughout a series of programs, projects and actions having involved scientists and scholars from Algeria, France, Lebanon, Morocco and Tunisia, some common patterns can be observed despite notable differences in environmental and political contexts. Thus, the main common issues involve funding matters (budget reductions and less versatility), administrative and social hierarchy, relatively small connection with public services and community representatives and finally the reluctance shown by many researchers to make data available for the community. Nevertheless, the fact that national and international (Arabic and French speaking sphere) researcher's communities have progressively built mutual knowledge thanks to different collaborations, is a major achievement sustaining the multidisciplinarity in the environmental research. Indeed, this allowed the elaboration of sustainability metrics, demarches and procedures for assessing environmentally and socioeconomically complex issues
Évaluation de l’aphasie bilingue au Liban : défis rencontrés lors de l’adaptation de la version courte du Bilingual Aphasia Test français au contexte libanais plurilingue
No full textInternational audienc
Operating Areas Overview of Electrically Excited Synchronous Motors
No full textInternational audienceIncreasing environmental concerns are driving the development of electric vehicles. Permanent Magnet Synchronous Motors (PMSMs) and Electrically Excited Synchronous Motors (EESMs) have been widely sought after for their potential use in these vehicles. This paper presents a comprehensive overview of salient poles rotor EESMs operating areas defined by: Minimum Current Per Torque (minCPT), Field-weakening maximum voltage limit area, Field-weakening maximum current and maximum voltage limit area and Maximum Torque per Voltage (MTPV). The latter are analyzed and showcased in both d-q and torque-speed domains. The minCLPT (Minimum Copper Losses per Torque) novel optimization method, which uses the EESM excitation current as third degree of freedom, is then explored while investigating the impact of applying negative d-axis current results of the latter algorithm. Findings emphasize on the potential benefits of using the EESM excitation current to extend the machine speed range while providing opportunities of experimenting how the optimal reference field current calculated by minCLPT algorithm can affect the forementioned operating areas. The paper provides valuable insight for researchers and engineers working in the field of electric vehicle propulsion systems
Optimal Sizing Assessment of an Islanded Microgrid Based on Different EMS Strategies
No full textInternational audienc
Storytelling for Non-profits: How Do Socio-economic Interventions Recount the Organization?
No full textInternational audienc
Edge Learning as a Hedonic Game in LoRaWAN
No full textInternational audienceFederated learning provides access to more data which is paramount for constrained LoRaWAN devices with limited memory storage. Learning on a larger data set will reduce the variance of the learned model, hence reducing its error. However, federating the learning process incurs a communication cost among learning devices that must be taken into account. In this paper, we formulate a Cooperative Hedonic game and introduce a new cost function that captures both the learning error and communication cost. LoRaWAN devices engage in the devised game by identifying if they should keep their learning local or federate with other devices in order to reduce both their learning error and communication cost. We compute the optimal size of formed coalitions and assess their stability. Then, we show through extensive simulations that devices have incentive to form learning coalitions depending on the data characteristics at hand and the communication cost in LoRaWAN