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.</p

Risk factors for behavior problems in cats presented to an Australian companion animal behavior clinic

Behavior problems in companion animals are common reasons for relinquishment or euthanasia. Insight into the risk factors for problem behaviors will facilitate the construction of strategies for solutions. We identified risk factors for behavior problems in domestic cats whose owners contacted a companion animal behavior clinic in Brisbane, Australia. Owners of 1,556 cats reported on their cats' behavior problem, breed, sex and age, and owner's postcodes and work routine were also recorded. Risk factors were determined from proportional morbidities for the behavior problem that each cat was reported as having. Breed effects were also assessed by comparing the numbers of cats in each breed group with the breeds of registered cats in a part of the catchment area. Behavior problems in domestic cats where the owners sought professional advice were mostly (71% of all cats) related to house soiling, usually urination, and aggression, especially to familiar people. Persian and similar breeds were at reduced risk of aggression to familiar cats but increased risk of house soiling, compared to other breed groups. Overall, Persian, Siamese, Burmese, and similar breeds had more behavior problems than companion cat breeds. Older cats showed increasing tolerance of familiar people but reduced tolerance of other cats. Males were more likely to present with excessive vocalization and house soiling with urine and less likely to present with aggression between familiar cats. We conclude that cat breed, age and sex, and social advantage of the area in which the cat lives are risk factors for specific behavior problems

Modelling children's Gear task strategy use with the Dynamic Overlapping Waves Model

The Dynamic Overlapping Waves Model (DOWM) can model strategy use in problem-solving tasks for strategies that can be construed as developmentally and hierarchically ordered (Boom, 2015). We observed children's (M age = 11 years, SD = 6 months) strategy use during a task in which they had to find the rotation direction of the last gear in a series of connected gear chains, given the rotation direction of the first gear. Using DOWM, we found that strategy use was ordered as expected, from unskilled sensorimotor strategies to abstract strategies, and from less to more efficient in terms of speed and accuracy. This order aligns with the idea that perceptual learning is central to the emergence of abstract conceptual knowledge. Moreover, the current study shows that the DOWM does not preclude forward and backward transitions and even occasional transitions that skip certain strategies in the ordering. The DOWM seems a promising tool to developmentally capture the breadth of behavioral repertoire children display when they adopt new strategies for various problem-solving tasks

Natural isotopes support groundwater origin as a driver of mire type and biodiversity in Slitere National Park, Latvia

Contains fulltext : 219073.pdf (publisher's version ) (Open Access

KKF-Model Platform Coupling : summary report KKF01b

Nederland bereidt zich voor op een sneller stijgende zeespiegel en een veranderend klimaat. Hiervoor is het Deltaprogramma gestart. Dit deltaprogramma voorziet een serie beslissingen die grote gevolgen zullen hebben voor het beheer van het water in Nederland. Om deze beslissingen zorgvuldig te nemen is informatie nodig over hoe het klimaat en de stijgende zeespiegel dit waterbeheer zullen beïnvloeden. De modellen die de gevolgen van klimaatverandering berekenen zullen daarom met dezelfde klimaat forcering en gekoppeld aan elkaar moeten worden gebruikt. In dit onderzoek is gekeken naar het linken van hydrologische en hydrodynamische modellen – en daaraan gekoppelde modellen die de ontwikkelingen in natuur en landgebruik modelleren -- die het gebied van de Alpen tot en met de Noordzee inclusief Nederland beschrijven

User-made immobilities: a transitions perspective

In this paper we aim to conceptualize the role of users in creating, expanding and stabilizing the automobility system. Drawing on transition studies we offer a typology of user roles including user-producers, user-legitimators, user-intermediaries, user-citizens and user-consumers, and explore it on the historical transition to the automobile regime in the USA. We find that users play an important role during the entire transition process, but some roles are more salient than others in particular phases. Another finding is that the success of the transition depends on the stabilization of the emerging regime that will trigger upscaling in terms of the numbers of adopters. The findings are used to reflect on potential crossovers between transitions and mobilities research

Imaging single cells in a beam of live cyanobacteria with an X-ray laser

Citation: van der Schot, G., Svenda, M., Maia, F., Hantke, M., DePonte, D. P., Seibert, M. M., . . . Ekeberg, T. (2015). Imaging single cells in a beam of live cyanobacteria with an X-ray laser. Nature Communications, 6, 9. doi:10.1038/ncomms6704There exists a conspicuous gap of knowledge about the organization of life at mesoscopic levels. Ultra-fast coherent diffractive imaging with X-ray free-electron lasers can probe structures at the relevant length scales and may reach sub-nanometer resolution on micron-sized living cells. Here we show that we can introduce a beam of aerosolised cyanobacteria into the focus of the Linac Coherent Light Source and record diffraction patterns from individual living cells at very low noise levels and at high hit ratios. We obtain two-dimensional projection images directly from the diffraction patterns, and present the results as synthetic X-ray Nomarski images calculated from the complex-valued reconstructions. We further demonstrate that it is possible to record diffraction data to nanometer resolution on live cells with X-ray lasers. Extension to sub-nanometer resolution is within reach, although improvements in pulse parameters and X-ray area detectors will be necessary to unlock this potential.Additional Authors: Almeida, N. F.;Odic, D.;Hasse, D.;Carlsson, G. H.;Larsson, D. S. D.;Barty, A.;Martin, A. V.;Schorb, S.;Bostedt, C.;Bozek, J. D.;Rolles, D.;Rudenko, A.;Epp, S.;Foucar, L.;Rudek, B.;Hartmann, R.;Kimmel, N.;Holl, P.;Englert, L.;Loh, N. T. D.;Chapman, H. N.;Andersson, I.;Hajdu, J.;Ekeberg, T