Project-level instantaneous emission modeling from mobile sources for freeway lane closure using SHRP2 Naturalistic Driving Study data and microscopic traffic simulation

This dissertation is one of the first studies which used the Second Strategic Highway Research Program (SHRP2) Naturalistic Driving Study (NDS) data to perform modal emission modeling at the project-level. SHRP2 NDS was the largest naturalistic driving study to date conducted in the U.S. which included instrumented vehicles with over 3,000 drivers that were recruited from six states. There is great potential to apply this data in modeling emissions as it will capture differences in driver behavior, roadway geometry, traffic conditions and their impact on emissions. The dissertation had two primary objectives: (1) apply the SHRP2 NDS data to model instantaneous exhaust emissions from passenger vehicles at four-lane divided freeway segments with work zones, and (2) examine the accuracy of microscopic traffic simulation models to replicate real-world vehicle trajectories in order to estimate emissions at work zones. Research studies related to assessing the impact of lane closure on vehicular emissions are limited considering that collecting data from field observations is resource intensive and expensive. In addition, the application of microsimulation models instigates certain constraints because various driver behavior and lane changing parameters must calibrated to ensure that the output from traffic simulation models can represent accurate real-world driving activity. Therefore, the first study focused on utilizing the vehicle kinematics data collected as part of the SHRP2 NDS to model emissions from passenger cars for work zones employed on four-lane divided principal arterials. The emissions models in this study considered different work zone configurations and varying congestion levels. Furthermore, the second analysis examined the ability of Vissim microsimulation model to replicate field conditions. A generic guidance to calibrate the driver behavior parameters in Vissim for freeway lane closure was applied and findings were compared to field observations from the SHRP2 study. Three different construction scenarios were implemented, i.e. AM-peak hour, PM-peak hour and nighttime off-peak lane closure

Evaluation of systemic safety methodologies on low-volume rural paved roadways

Prioritizing locations in rural areas has been a major concern to various transportation agencies due to the wide-spread nature of crashes on rural roadways. A systemic (more proactive) approach is required to rank sites in this case since the traditional hot spot method only considers crash data. The thesis was based on a prioritization project funded by Mid-America Transportation Center (MATC). Several systemic safety methodologies were explored and summarized in the report. However, one technique was selected, i.e. Minnesota CRSP approach, on the basis of a decision-making matrix that included five factors. The selected technique was applied on secondary paved rural roadways in Buchanan and Dallas counties in Iowa. Data was collected along 197 miles in Buchanan County and 156 miles in Dallas County. Initial prioritized ranking lists were generated for the three transportation elements (horizontal curves, stop-controlled intersections and rural segments) that were identified in the Minnesota CRSP approach. The tool was then evaluated to determine if a change in the weight/coefficient of risk factors in each transportation element would have a statistical impact on the prioritized list. Three different sensitivity analysis approaches were designed and tested. Results showed no statistical significance in the shift of rankings for all cases. A top 20 analyses was then conducted to evaluate the number of sites that shifted from the prioritization lists compared to the initial ranking. A maximum of 50 percent shift was recorded for rural horizontal curves in Dallas County when the third sensitivity analysis approach was applied

Suivi de la qualité bactériologique des eaux de surface (rivière Nahr Ibrahim, Liban)

Le bassin versant du Narh Ibrahim est classé parmi les sites du patrimoine mondial. Les rejets sauvages solides et liquides ont un impact important sur le développement d’une contamination bactériologique tout au long de la rivière. Dans cette étude, des paramètres physico-chimiques et bactériologiques ont été suivis sur neuf sites de prélèvement qui couvrent la rivière Nahr Ibrahim de son amont jusqu’à son estuaire. L’ensemble des paramètres est étudié pendant des périodes de l’année caractérisées par un temps sec ou un temps de crue. Au cours de ces périodes, ces paramètres ont révélé une influence importante du type d’occupation des sols et des phénomènes de lessivage sur la composition bactériologique de la rivière. L’origine et le degré de la contamination bactérienne instantanée ont été également identifiés. Une approche statistique multivariée a montré que l’effet de la localisation du site masque l’effet date sur un même site et pendant la même période. Les sites en aval de la rivière sont caractérisés par une pollution en nitrate et une contamination bactériologique alors que les sites en amont sont marqués par une contamination bactériologique seulement.The Nahr Ibrahim catchment area is classified as an international heritage site. Along the Nahr Ibrahim River, solid and liquid effluents have an important impact on bacterial contamination. Physico-chemical and bacteriological parameters were studied at nine sampling sites located along the Nahr Ibrahim River from its source to its estuary. Total bacteria, total coliforms, fecal coliforms and fecal streptococci were studied during dry and wet weather periods. During these periods, the studied parameters revealed an important influence of the type of soil and leaching on the bacteriological composition of the river. Furthermore, the origin and the degree of temporary bacteriological contamination were identified. A multivariate statistical approach demonstrated that the effect of site location masked the effect of sampling date on the degree of bacteriological contamination. Downstream river sites were characterized by nitrate and bacterial pollution whereas upstream sites showed only by bacterial contamination

Political psychology in the Arab region: a commentary on navigating research in unstable contexts from Part IV - Diversifying Perspectives in Political Psychology

This chapter examines the history, challenges, and future of political psychology research in the Arab region, and argues that lack of attention to such regions is detrimental not only for these regions, but also for Western research and for the discipline as a whole

International support for the Arab uprisings: Understanding sympathetic collective action using theories of social dominance and social identity

Inspired by the popular Arab protests against oppressive regimes that began in 2010, people around the world protested in sympathy with the Arab peoples. The present research draws on two major theories of intergroup relations to develop an initial integrative model of sympathetic collective action. We incorporate social dominance theory’s (SDT) concept of (rejectionist) legitimizing myths with the solidarity and emotional mediation concept of the social identity model of collective action (SIMCA) to understand motivations for sympathetic collective action among bystanders. Using data from 12 nations (N = 1,480), we tested three models: (a) SIMCA (i.e., solidarity, anger, and efficacy), (b) a social dominance theory model of collective action (i.e., social dominance orientation and ideologies concerning Arab competence), and (c) an integrated model of sympathetic collective action combining both theories. Results find the greatest support for an integrated model of collective action. Discussion focuses on theoretical pluralism and suggestions for future research

Connexin26 and PPARᵧ signaling pathway in human airway epithelial cell repair

The airway epithelium forms a protective barrier between the lungs' clean milieu and the outside environment. Several mechanisms, that include proper ion transport, mucus secretion and the expression of junctional proteins, such as connexins (Cx), are involved in ensuring its function. Being the first line of contact with inhaled hostilities, this tissue is in constant threat of injury and has to repair and re-differentiate continuously. The repair process has been widely studied. However, the mechanisms regulating it, which might be deregulated in Cystic Fibrosis (CF), are poorly understood. Here, we investigated mechanisms involved in re-differentiation in injured non-CF and CF epithelia, and whether these intersect with the expression of Cxs at different times of wound repair. Our study shows defects in the differentiating signals in CF and that these signals intersect with Cx expression during repair. We suggest that these mechanisms are synchronized to ensure the re-differentiation of repairing cells

Eco-friendly bioconversion of triterpenoids by bacteria immobilized on Luffa cylindrica

L'un des avantages majeurs des réactions de bioconversion résulte du fait que le milieu réactionnel des biocatalyseurs est l'eau. Ce dit avantage constitue l'une des principales limitations de ces réactions de bioconversion lorsqu'il s'agit de substances lipophiles non solubles dans l'eau connue les stérols. L'efficacité d'un procédé de bioconversion de substances lipophiles solides dépend essentiellement du contact et de 1'interaction entre le biocatalyseur et ce substrat lipophile. Les solutions proposées dans la littérature font appel à des solvants et des produits chimiques de natures souvent toxiques, inflammables et explosives. Ces solutions décrites font perdre à la bioconversion son caractère de biotechnologie blanche. Dans ce travail, nous avons montré qu'en plus de ses avantages connus, l'immobilisation passive de biocatalyseurs au sein d'un support poreux peut favoriser l'interaction cellule-substrat lipophile et augmenter le taux de bioconversion sans utiliser de solvants et de produits chimiques. La réaction modèle étudiée est le clivage de la chaine latérale des stérols par des mycobactéries en vue de l'obtention des androsténones précurseurs naturels des stéroïdes, molécules à forte valeur biologique ajoutée. Le support d'immobilisation le plus performant a été le fruit sec de Luffa cylindrica. Par rapport aux supports organiques classiques tels que les gels de polyacrylamide, les mousses de polyuréthane, la silicone et les plastiques, le fruit sec de Luffa cylindrica présente les avantages suivants : (i) c'est un produit naturel, (ii) biodégradable, (iii) peu onéreux, (iv) non toxique pour les microorganismes, (v) stable du point de vue mécanique et thermique, (vi) et réutilisable.One of the major advantages of using biocatalysts in organic synthesis is that water constitutes the reaction medium. However, water becomes a serious problem when bioconversion deals with lipophilic compounds, in particular those poorly soluble in water such as sterols. Bioconversion of lipophilic compounds depends on the close contact between the hydrophobic substrate and the biocatalyst. Increasing this contact requires usually the use of huge amounts of chemical which are often toxic, flammable and explosive. In this work, we showed that passive cell immobilization in porous materials can increase the contact between microorganisms and lipophilic substrates without using chemicals. The side chain cleavage of sterols was studied as a model multistep microbial bioconversion of lipophilic compounds. This reaction allows the production of androstenones which are the natural precursors of steroids. Among the studied immobilization carriers, the dried fruit of Luffa cylindrica was the most efficient Compared to other organic support carrier such as alginate beads, polyurethane foams, silicones and plastics, the dried fruit of Luffa cylindrica is advantageous since it is natural, renewable, biodegradable, cheap, mechanically strong, free of toxicity and it doesn't need a chemical pretreatment

Project-level instantaneous emission modeling from mobile sources for freeway lane closure using SHRP2 Naturalistic Driving Study data and microscopic traffic simulation

This dissertation is one of the first studies which used the Second Strategic Highway Research Program (SHRP2) Naturalistic Driving Study (NDS) data to perform modal emission modeling at the project-level. SHRP2 NDS was the largest naturalistic driving study to date conducted in the U.S. which included instrumented vehicles with over 3,000 drivers that were recruited from six states. There is great potential to apply this data in modeling emissions as it will capture differences in driver behavior, roadway geometry, traffic conditions and their impact on emissions. The dissertation had two primary objectives: (1) apply the SHRP2 NDS data to model instantaneous exhaust emissions from passenger vehicles at four-lane divided freeway segments with work zones, and (2) examine the accuracy of microscopic traffic simulation models to replicate real-world vehicle trajectories in order to estimate emissions at work zones. Research studies related to assessing the impact of lane closure on vehicular emissions are limited considering that collecting data from field observations is resource intensive and expensive. In addition, the application of microsimulation models instigates certain constraints because various driver behavior and lane changing parameters must calibrated to ensure that the output from traffic simulation models can represent accurate real-world driving activity. Therefore, the first study focused on utilizing the vehicle kinematics data collected as part of the SHRP2 NDS to model emissions from passenger cars for work zones employed on four-lane divided principal arterials. The emissions models in this study considered different work zone configurations and varying congestion levels. Furthermore, the second analysis examined the ability of Vissim microsimulation model to replicate field conditions. A generic guidance to calibrate the driver behavior parameters in Vissim for freeway lane closure was applied and findings were compared to field observations from the SHRP2 study. Three different construction scenarios were implemented, i.e. AM-peak hour, PM-peak hour and nighttime off-peak lane closure.</p