Effects of high pressure and temperature conditions on the chemical fate of flowback water related chemicals

Environmental risk assessment is generally based on atmospheric conditions for the modelling of chemical fate after entering the environment. However, during hydraulic fracturing, chemicals may be released deep underground. This study therefore focuses on the effects of high pressure and high temperature conditions on chemicals in flowback water to determine whether current environmental fate models need to be adapted in the context of downhole activities. Crushed shale and flowback water were mixed and exposed to different temperature (25-100 °C) and pressure (1-450 bar) conditions to investigate the effects they have on chemical fate. Samples were analysed using LC-HRMS based non-target screening. The results show that both high temperature and pressure conditions can impact the chemical fate of hydraulic fracturing related chemicals by increasing or decreasing concentrations via processes of transformation, sorption, degradation and/or dissolution. Furthermore, the degree and direction of change is chemical specific. The change is lower or equal to a factor of five, but for a few individual compounds the degree of change can exceed this factor of five. This suggests that environmental fate models based on surface conditions may be used for an approximation of chemical fate under downhole conditions by applying an additional factor of five to account for these uncertainties. More accurate insight into chemical fate under downhole conditions may be gained by studying a fluid of known chemical composition and an increased variability in temperature and pressure conditions including concentration, salinity and pH as variables

Interactions between Magnetic Nanowires and Living Cells : Uptake, Toxicity and Degradation

We report on the uptake, toxicity and degradation of magnetic nanowires by NIH/3T3 mouse fibroblasts. Magnetic nanowires of diameters 200 nm and lengths comprised between 1 {\mu}m and 40 {\mu}m are fabricated by controlled assembly of iron oxide ({\gamma}-Fe2O3) nanoparticles. Using optical and electron microscopy, we show that after 24 h incubation the wires are internalized by the cells and located either in membrane-bound compartments or dispersed in the cytosol. Using fluorescence microscopy, the membrane-bound compartments were identified as late endosomal/lysosomal endosomes labeled with lysosomal associated membrane protein (Lamp1). Toxicity assays evaluating the mitochondrial activity, cell proliferation and production of reactive oxygen species show that the wires do not display acute short-term (< 100 h) toxicity towards the cells. Interestingly, the cells are able to degrade the wires and to transform them into smaller aggregates, even in short time periods (days). This degradation is likely to occur as a consequence of the internal structure of the wires, which is that of a non-covalently bound aggregate. We anticipate that this degradation should prevent long-term asbestos-like toxicity effects related to high aspect ratio morphologies and that these wires represent a promising class of nanomaterials for cell manipulation and microrheology.Comment: 21 pages 12 figure

Neanderthal Use of Fish, Mammals, Birds, Starchy Plants and Wood 125-250,000 Years Ago

Neanderthals are most often portrayed as big game hunters who derived the vast majority of their diet from large terrestrial herbivores while birds, fish and plants are seen as relatively unimportant or beyond the capabilities of Neanderthals. Although evidence for exploitation of other resources (small mammals, birds, fish, shellfish, and plants) has been found at certain Neanderthal sites, these are typically dismissed as unusual exceptions. The general view suggests that Neanderthal diet may broaden with time, but that this only occurs sometime after 50,000 years ago. We present evidence, in the form of lithic residue and use-wear analyses, for an example of a broad-based subsistence for Neanderthals at the site of Payre, Ardèche, France (beginning of MIS 5/end of MIS 6 to beginning of MIS 7/end of MIS 8; approximately 125–250,000 years ago). In addition to large terrestrial herbivores, Neanderthals at Payre also exploited starchy plants, birds, and fish. These results demonstrate a varied subsistence already in place with early Neanderthals and suggest that our ideas of Neanderthal subsistence are biased by our dependence on the zooarchaeological record and a deep-seated intellectual emphasis on big game hunting

Conférence de Mme Hélène Brunner

Brunner Hélène. Conférence de Mme Hélène Brunner. In: École pratique des hautes études, Section des sciences religieuses. Annuaire. Tome 92, 1983-1984. 1983. pp. 157-164

Le rituel quotidien dans la tradition šivaïte de l'Inde du Sud, selon la Somašambupaddhati

Brunner Hélène. Le rituel quotidien dans la tradition šivaïte de l'Inde du Sud, selon la Somašambupaddhati. In: École pratique des hautes études. 4e section, Sciences historiques et philologiques. Annuaire 1962-1963. 1962. pp. 221-224

Un Tantra du Nord : le Netra Tantra

Brunner Hélène. Un Tantra du Nord : le Netra Tantra. In: Bulletin de l'Ecole française d'Extrême-Orient. Tome 61, 1974. pp. 125-197

Mṛgendrāgama. Section des rites et section du comportement : Avec la Vṛtti de Bhaṭṭanārāyaṇakanṭha.

Le Mṛgendrāgama est un traité Śivaïte sanskrit de l’école appelée Śaivasiddhānta. Ayant joui d’une grande renommée, il fut commenté au xe ou au début du xie siècle par Nārāyaṇakaṇṭha et fut souvent cité tant par les maîtres de l’école dualiste que par ceux de l’école non-dualiste. Il est l’un des rares āgama à posséder les quatre parties dont ces textes sont censés être composés: section de la doctrine (vidyā ou jñānapāda), des rites (kriyāpāda), du yoga (yogapāda) et de la discipline ou du comportement (caryāpāda). Il s’intéresse exclusivement au culte privé (et non au rituel « public » des temples). Ce volume est la traduction en français des kriyā et caryāpāda