Effects of Heavy-Duty Diesel Vehicle Idling Emissions on Ambient Air Quality at a Truck Travel Center and Air Quality Benefits Associated with Advanced Truck Stop Electrification Technology

United States Department of Transportation (DOT) requires truck drivers to rest for 10 hours after every 14 hours of driving. During this time and while waiting for loading and unloading of their trucks, truck drivers idle their engine to provide heat or air conditioning for the cab and sleeping compartment, keep the engine warm during cold climate, and provide electrical power for their onboard appliances. At large truck stops, 200 or more trucks may be idling at the same time. At these truck stops idling emissions can significantly contribute to the concentrations of NOx and PM2.5 pollutants in the ambient air in the vicinity of the truck stop. In this study monitoring of ambient air at the Petro truck travel center located at I40/I75 and Watt Road interchange was performed between mid December 2003 and August 2004. Concentrations of PM2.5 and NOx were measured continuously at two locations. Computer modeling was also performed using EPA’s ISCST3 model to predict ambient concentrations of PM2.5 and NOx at the truck stop. Ambient concentrations of NOx and PM2.5 were found to be higher at nighttime and early morning hours compared to daytime. The number of trucks idling at the truck travel center was also found to have similar trend as that of ambient concentrations of considered pollutants. Average ambient concentrations of 276 ppb and 213 ppb of NOx and 35 mg/m3 and 29 mg/m3 of PM2.5 were monitored at the two selected locations over the course of this research. The monitored concentrations of PM2.5, and NOx were then compared to the predicted values in an effort to verify and calibrate the model. The ISCST3 model was used to predict annual average and maximum 24-hour average NOx and PM2.5 and concentrations in the Watt Road area and three hot-spots corresponding to the three truck travel centers at the area were observed. If sufficient number of IdleAire electrification units were provided to accommodate all trucks (that would otherwise idle), the ambient concentrations (not considering background concentrations) would be lower by 70% and 48% at the two monitoring locations as predicted by ISCST3 model

Multi-Pluridisciplinary approach of the evolution of the agro-pastural activities in the surroundings of the " narse d'Espinasse " (French Massif Central, Puy de Dôme).

The ldquonarserdquo or peat marsh of Espinasse (Saulzet-le-Froid district) situated in the southern part of the Chaîne des Puys has been the subject of a new pollen analysis concentrating on the anthropogenic impact on vegetation evolution since the Sub-Boreal. Human occupation of the surroundings of the narse is dated as early as the Neolithic, which is usual for the region. There is nevertheless an isolated record of Fagopyrum related to the Neolithic. This is a unique occurrence in the Massif Central. For successive periods and up to the recent past, a dynamic of various anthropization phases has been reconstructed. The combination of palynological data with archaeological and historical sources has for certain periods, mainly from the 11th to 13th centuries, provided new insights on the social and technical management of the territory. Furthermore, geochemical and micromorphological characterisation of sedimentary organic matter has led to the identification of erosive crises and silting which would have followed massive tree cutting in the region. On the local scale, the highly degraded organic matter at the top of the peat profile is the consequence of the current drainage of the marsh

Un modèle numérique pour structures en béton fibré à ultra-hautes performances : prise en compte de l'orientation des fibres par une approche d'endommagement micromécanique

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2012-2013.Le comportement des bétons fibrés à ultra-hautes performances (BFUP) dépend fortement de l’orientation des fibres vis-à-vis de la direction des sollicitations. L’orientation des fibres étant principalement due à la mise en oeuvre de la structure, la ductilité d’un ouvrage s’en retrouve fortement dépendant. Dans ce mémoire de maîtrise, un modèle numérique est développé pour capturer l’effet de l’orientation des fibres via leurs mécanismes d’extraction. Il s’agit d’un modèle d’endommagement micromécanique, utilisé dans le cadre de la mécanique de la rupture linéaire élastique permettant de modéliser la propagation des fissures, la dissipation d’énergie et donc la ductilité de la structure. Cette approche permet également de rendre le modèle indépendant de la finesse du maillage et de modéliser l’effet d’échelle. Dans ce travail, les BFUP sont composés de fibres courtes en acier dont le pourcentage volumique est inférieur à 3%. La résistance en compression du BFUP est si grande que le matériau est admis être purement linéaire élastique en compression. Le modèle est implanté dans le logiciel Code_Aster pour calibration, validation et application sur des essais de traction et sur des essais de flexion quatre points : le modèle développé reproduit très bien ces résultats expérimentaux.The behavior of ultra-high performance fiber reinforced concrete (UHPFRC) strongly depends on fibers’ orientations relatively to the direction of stresses. Fibers’ orientations are mostly due to concrete casting of the structure and therefore the ductility of a structure is highly dependent of those orientations. In this MSc thesis, a numerical model is developed to capture the effect of fiber orientation considering the fiber pull-out mechanism. A micromechanical damage model based on linear elastic fracture mechanics to model crack propagation, energy dissipation and thus structure’s ductility. This approach also corrects spurious mesh sensitivity and captures size effect. In this work, UHPFRC are made of short steel fibers with fiber content inferior to 3%. The compressive strength of UHPFRC is so important that the material is assumed to be purely linear elastic in compression. The model is implemented in Code_Aster software for calibration, validation and application on tensile tests and four-point bending tests : the developed model can reproduce these experimental results

Parental genomic imprinting

In placentalmammals, certain genes are expressed dependent on whether they arematernally or paternally inherited. This functional asymmetry, leading to monoallelic expression, is not due to a change in the primary structure of the encoding DNA but, on the contrary, is caused by reversible epigenetic changes in chromatin structure influencing the transcription. Genomic imprinting concerns only a small proportion of genes but it plays a major role during embryonic development and its dysregulation can lead to serious diseases. Its purpose is not yet fully established and is still the subject of speculation.Chez les mammifères placentaires, certains gènes font l'objet d'une empreinte parentale qui se caractérise par une différence d'expression selon qu'ils proviennent du père ou de la mère. Cette asymétrie fonctionnelle, qui se traduit par l'expression d'un seul allèle sur les deux, n'est pas la conséquence d'une modification de la structure primaire des séquences d'ADN, mais résulte au contraire de modifications épigénétiques réversibles de la structure de la chromatine, qui ont une influence sur la transcription. L'empreinte génomique parentale ne concerne qu'une faible proportion des gènes, mais elle a une grande importance pendant le développement embryonnaire et son dérèglement peut conduire à des maladies graves. Sa finalité n'est pas totalement élucidée et fait encore l'objet de spéculations

One century of genetics with mice

Laboratory mice stem from specimens belonging to different species of the Mus genus, bred since time immemorial both in Europe and Asia. They played a key role in the development of mammalian genetics since the early twentieth century, particularly helped by the existence of various inbred strains. Numerous mutations, whether spontaneous or induced by mutagenic agents, have also produced valuable models to study human diseases. With technical progress achieved over the past twenty years, scientists are now able to modify the mouse genome almost at will, either by adding in vitro one or several exogenous genes, or by knocking out a previously-targeted gene known only by its sequence. The mouse genome, like the human one, is entirely sequenced, and the inventory of messenger RNAs and their resulting proteins (transcriptome and proteome) is under way. It is now evident that only a small fraction of these genes is currently known, and that a long process of gene annotation has to be undertaken in which mice are bound to play a central role. Extensive knowledge of both human and mouse genome sequences will provide a reference for other species, especially those with zootechnical interest. Comparisons will also generate interesting data to help us understand the regulation of gene expression as well as the mechanisms at work during evolution.Les souris de laboratoire dérivent de spécimens appartenant à plusieurs espèces du genre Mus, élevés depuis les temps les plus reculés en Europe et en Asie. Elles ont joué un rôle primordial dans le développement de la génétique des mammifères depuis le début du vingtième siècle, grâce notamment à l'existence d'une grande variété de lignées consanguines. De nombreuses mutations, survenues spontanément ou induites par des agents mutagènes, ont également fourni de précieux modèles pour l'étude de la pathologie humaine. Au cours des vingt dernières années et grâce aux progrès de la technique, l'homme s'est donné les moyens de modifier, presque à volonté, le génome de la souris soit en ajoutant in vitro un ou plusieurs gènes d'origine exogène, soit en invalidant un gène préalablement ciblé et connu uniquement par sa séquence. Enfin, le génome de la souris, comme celui de l'homme, est aujourd'hui entièrement séquencé et l'inventaire des ARNs messagers et des protéines qui sont codés (le transcriptome et le protéome) est en train d'être réalisé. On s'aperçoit alors que seule une très petite partie de ces gènes est connue et un long travail d'annotation va commencer, dans lequel la souris jouera, à n'en pas douter, un rôle primordial. La connaissance de la séquence complète des génomes de l'homme et de la souris constitue une référence pour d'autres espèces, en particulier pour celles qui ont un intérêt zootechnique. Elle permettra aussi, au travers de comparaisons, de faire d'intéressantes observations aussi bien pour comprendre la régulation de l'expression des gènes que pour comprendre certains mécanismes mis en place par l'évolution

Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first-order kinetics. We then compared the PRIM model and the standard first-order decay model incorporated into the global land biosphere model ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems). A test of both models was performed at ecosystem scale using litter manipulation experiments from five sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE-PRIM could simulate the observed priming (R² = 0.54)in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter

Defining Quantitative Targets for Topsoil Organic Carbon Stock Increase in European Croplands: Case Studies With Exogenous Organic Matter Inputs

The EU Mission Board for Soil Health and Food proposed a series of quantitative targets for European soils to become healthier. Among them, current soil organic carbon (SOC) concentration losses in croplands (0.5% yr(-1) on average at 20 cm depth) should be reversed to an increase of 0.1-0.4% yr(-1) by 2030. Quantitative targets are used by policy makers to incentivize the implementation of agricultural practices that increase SOC stocks. However, there are different approaches to calculate them. In this paper, we analyzed the effect of exogenous organic matter (EOM) inputs on the evolution of SOC stocks, with a particular focus on the new European targets and the different approaches to calculate them. First, we illustrated through two case-study experiments the different targets set when the SOC stock increase is calculated considering as reference: 1) the SOC stock level at the onset of the experiment and 2) the SOC stock trend in a baseline, i.e., a control treatment without EOM addition. Then, we used 11 long-term experiments (LTEs) with EOM addition in European croplands to estimate the amount of carbon (C) input needed to reach the 0.1 and 0.4% SOC stock increase targets proposed by the Mission Board for Soil Health and Food, calculated with two different approaches. We found that, to reach a 0.1 and 0.4% increase target relative to the onset of the experiment, 2.51 and 2.61 Mg C ha(-1) yr(-1) of additional C input were necessary, respectively. Reaching a 0.1 and 0.4% increase target relative to the baseline required 1.38 and 1.77 Mg C ha(-1) yr(-1) of additional input, respectively. Depending on the calculation method used, the estimated amounts of additional C input required to reach each quantitative target were significantly different from each other. Furthermore, the quality of C input as represented by the C retention rate of the additional organic material (EOM and crop residue), had a significant effect on the variation of SOC stocks. Our work highlights the necessity to take into consideration the additional C input required to increase SOC stocks, especially for soils with decreasing SOC stocks, when targets are set independently of the baseline