21 research outputs found
Data for "Hydro-mechanical behaviour of high-density bentonite pellet on partial hydration"
No full textCompression test results: pellet modulus, pellet strength and maximal displacement for axial and radial directions (Fig. 8 and Fig 9. in article)
Selection at a single locus leads to widespread expansion of toxoplasma gondii lineages that are virulent in mice
No full textThe determinants of virulence are rarely defined for eukaryotic parasites such as T. gondii, a widespread parasite of mammals that also infects humans, sometimes with serious consequences. Recent laboratory studies have established that variation in a single secreted protein, a serine/threonine kinase known as ROPO18, controls whether or not mice survive infection. Here, we establish the extent and nature of variation in ROP18among a collection of parasite strains from geographically diverse regions. Compared to other genes, ROP18 showed extremely high levels of diversification and changes in expression level, which correlated with severity of infection in mice. Comparison with an out-group demonstrated that changes in the upstream region that regulates expression of ROP18 led to an historical increase in the expression and exposed the protein to diversifying selective pressure. Surprisingly, only three atypically distinct protein variants exist despite marked genetic divergence elsewhere in the genome. These three forms of ROP18 are likely adaptations for different niches in nature, and they confer markedly different virulence to mice. The widespread distribution of a single mouse-virulent allele among geographically and genetically disparate parasites may have consequences for transmission and disease in other hosts, including humans
Retrait-gonflement des argiles : un risque de plus en plus important
No full textInternational audienc
Retrait-gonflement des argiles : un risque de plus en plus important
No full textInternational audienc
Comparison of models for calculation of the thermodynamic properties of NH<sub>3</sub>-CO<sub>2</sub>-H<sub>2</sub>O mixture
No full textCouple of models have been developed to calculate thermodynamic properties of NH3-CO2-H2O systems. These models are typically an equation of state for the vapor phase and an activity coefficient model for the liquid phase (Que & Chen, 2011). The activity coefficient models can be divided into three groups based on previous studies, Pitzer model, electrolyte Non Random Two Liquid (e-NRTL) model and extended UNIQUAC model. Que & Chen (2011) deem the e-NRTL model the model the most suitable for process modelling and simulations since it requires only binary interaction parameters and makes use of mole fraction concentration scale consistently for both the short range local compositions interactions and the long range Debey-Huckel expression. Darde (2011) compared the built in e-NRTL model from Aspen Plus to an upgraded version of the extended UNIQUAC model developed by Thomsen et al. (1996). His findings were that the extended UNIQUAC model is significantly more accurate than the e-NRTL model from Aspen. He does mention that if the binary interaction parameters were better fitted to experimental data for NH3-CO2-H2O mixture, the e-NRTL model might become more competitive with the extended UNIQUAC model. Since then the e-NRTL model has been modified in this way by couple of authors, included Que & Chen (2011) and Niu et al. (2013). Both of their adjusted models have then been used by other authors for process modelling, for example Zhang & Guo (2014) used the model with adjusted parameters from Niu et al. (2013) and Liu et al. (2015) used the modified model from Que & Chen (2011). In this paper the extended UNIQUAC model is compared with the e-NRTL thermodynamic model that is built into the most recent version of Aspen Plus, and two modified e-NRTL models; the one developed by Que and Chen (2011) and a new fit. This is done to confirm if the modified models can reach similar accuracy as the extended UNIQUAC model and how much more accurate they are compared to the built in model in Aspen Plus.Paper no. 1614 http://docs.lib.purdue.edu/iracc/1641Engineering Thermodynamic
Victimology: rights, changes, and the need for continued change
No full textEach year millions of people are victimized in this country. Victimization occurs in many ways. The most serious type of victimization is violent victimization. Violent crimes against victims can take place as murder, manslaughter, assault, sexual assault, sexual abuse, domestic violence, rape, kidnapping, robbery, and even slavery, terrorism, and/or genocide. Throughout American history many changes have been made to laws, constitutions, statutes, rules and regulations, and orders to help and protect victims and to hold victimizers responsible for their crimes. Victims’ rights have come a long way, and have provided victims of violent crimes a voice and opportunity to receive help, closure, and justice. The study of victims is a fairly new field, and victimology, helps give a better understanding of victims and how the definition of a victim has changed throughout history to include more people and crimes against them. Programs and organizations have even been instituted to study victims, victimization, and victimology, report changes and statistics in incident and prevalence of crimes against victims, aid to raise funds for victims, to help victims recover, to help stop violent crimes, to help victims move forward from whatever violent crime they have experienced, and advocate for changes to assist victims more and to penalize victimizers to a higher extent of the law. The modern understanding of victim has drastically changed from 300 years ago and has even changed from 30 years ago. Even in modern society we still question if a victim is in fact a victim at all due to his/her own involvement in the victimization that took place against them. One pivotal and critical question remains, how much of a victim the victim actually is. In the case of victimology it is also predicted which kind of people are more likely to be victimized; it is predicted what kind of people are most vulnerable to violent crimes. The changes in victimology and victims’ rights throughout history, and how those changes affect us today, as well as changes that are still needed in regards to victimology and victims’ rights will be further discussed throughout this paper.M.A.L.S.Includes bibliographical referencesby Shantal Darde
Modelling the hydromechanical behaviour of expansive granular mixtures upon hydration
No full textBentonite pellet-powder mixtures are candidate sealing materials in radioactive waste disposal concepts. The mixture is installed in galleries in dry state as a granular material. The material is progressively hydrated by the pore water of the host rock and becomes homogeneous. Before homogenisation, the granular structure controls the material behaviour. In the present work, a modelling approach able to address particular features of pellet-powder mixtures is introduced. Two domains are considered: i) granular, and ii) homogeneous. The material behaviour before homogenisation is studied through Discrete Element Method (DEM) simulations. Constitutive laws for the granular state are proposed from DEM results. The behaviour of the homogenised material is described by a modified Barcelona Basic Model (BBM). Transition from granular to homogeneous states depends on suction and relative volume fractions of pellets and powder. Swelling pressure tests performed in the laboratory are satisfactorily simulated using this approach
Modelling the behaviour of bentonite pellet-powder mixtures upon hydration from dry granular state to saturated homogeneous state
No full textInternational audienceBentonite pellet-powder mixtures are candidate materials for sealing the galleries in deep geological repositories for radioactive waste. In the present work, swelling pressure tests are performed on pellet-powder mixtures with different powder contents. Results highlight the influence of the initial granular structure on the mechanical behaviour of pellet-powder mixtures. In mixtures with a low density powder in the inter-pellet porosity, the macroscopic response of pellet-powder mixtures is identical to that of a pellet assembly with no powder. A model is proposed to describe the hydromechanical behaviour of pellet-powder mixtures. The formulation considers two distinct states of the material, Granular and Continuous. In the Granular state, the pellets control the mechanical behaviour of the mixture. In the Continuous state, both pellets and powder contribute to the mechanical behaviour of the mixture. In the Granular domain, the material behaviour is described by constitutive laws proposed after a numerical study using Discrete Element Method. In the Continuous domain, the material behaviour is described by a modified Barcelona Basic Model. Transition between the two domains depends on the density of the powder phase and suction. The model is implemented in a Finite Element Method code, and the swelling pressure tests performed in the laboratory are simulated with a single set of parameters. These results improve the knowledge on the behaviour of bentonite pellet-powder mixtures during hydration in repository conditions
Investigating the hydromechanical behaviour of bentonite pellets by swelling pressure tests and discrete element modelling
No full textInternational audienceBentonite pellet mixtures are candidate material for the sealing of galleries in radioactive waste disposals. The hydromechanical behaviour of assemblies of bentonite pellets is investigated upon partial hydration through (1) suction-controlled swelling pressure tests in the laboratory and (2) discrete element method simulations. The combination of these experimental and numerical approaches highlights that, before the mixture homogenization, the swelling pressure develops in two phases. The first phase is characterized by an increase in contact forces between pellets. The second phase is characterized by plasticity at contacts between pellets and is controlled by the progressive decrease in pellet strength and stiffness upon hydration. In addition, numerical results highlight that the swelling pressure measured in the laboratory can be influenced by the sample preparation, the cell size, and the diameter of the pressure sensor
Experiences of bodily disorder in French books 1573-1592
No full textMary Douglas, in Purity and Danger and Elizabeth Grosz, in Volatile Bodies concur that the human body whose boundaries are traversed or transgressed is troubling, threatening and risky. The threats to which Douglas and Grosz separately refer are largely ideological and cultural threats, but their identification of the problematic nature of ruptured or unusual bodily boundaries is nevertheless relevant to the analysis of the actual bodily disorder with which this thesis is concerned. Disease, cannibalism and monstrosity are forms of bodily behaviour or conditions in which boundaries are inherently, or are rendered, unclear, and in the sixteenth-century books of Ambroise Paré, Jean de Léry and Michel de Montaigne, the question of the disorderly nature of these three physical phenomena is addressed. A fundamental feature of the books produced by these three writers is the emphasis on the experience of the form of bodily disorder in question on which the written account is based. Paré, a surgeon, treated plague patients and dissected monstrous specimens before writing about his experiences in his Œuvres completes', Léry observed the practice of cannibalism in Brazil before returning to Europe and witnessing the consumption of human flesh during the siege of Sancerre; and Montaigne, whose final essay is significantly entitled 'De ľexperience', develops a method of writing, or essaying, which involves the writer attempting to evaluate critically all received experiences and information before arriving at his own conclusion. The depiction of cannibalism, monstrosity and disease in the books of these three writers will be examined using a methodology developed around the principles of Mikhail Bakhtin's theory of dialogism. The particular relevance of this literary theory to the theme of the disordered body in French sixteenth-century books is the emphasis that Bakhtm also places on the writer's experience of his subject matter. In addition, Bakhtm argues that writers experience an impulse to consummate, in other words to define, explain and contextualise, and present as complete the world they observe. This thesis argues that the question of bodily boundaries raised by Douglas and Grosz can be addressed by Bakhtinian theory, and seeks to illustrate the ways in which Paré, Léry and Montaigne exhibit an awareness of the problem of the disordered body, and develop narrative strategies to overcome it which correspond to the functions of a Bakhtinian Author
