Transport efficiency and dynamics of hydraulic fracture networks

Acknowledgments This study is carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 “Mineral Vein Dynamics Modeling,” which is funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, RWE Dea AG and Wintershall Holding GmbH, within the basic research programme of the WEG Wirtschaftsverband Erdöl- und Erdgasgewinnung e.V. We thank the companies for their financial support and their permission to publish our results. We further acknowledge support by Deutsche Forschungsgemeinschaft and Open Access Publishing Fund of University of Tübingen.Peer reviewedPublisher PD

Action Flow in Obsessive-Compulsive Disorder Rituals: a model based on Extended Synergetics and a Comment on the 4th Law

The flow of actions in rituals of obsessive individuals is discussed from a nonlinear physics perspective. An amplitude equation model based on extended synergetics is studied. The amplitude dynamics describes both the behavioral actions and the experienced emotions during obsessive-compulsive disorder rituals. The model suggests that in addition to the behavioral and emotional levels that are accessible to external observation and self-reports there are hidden levels captured by parameter dynamics that determine the action flow in obsessive-compulsive disorder rituals. The model can also be used to discuss on the mechanistic and behavioral levels differences between purposeful and purposeless rituals. While purposeful rituals involve a continuous control of the emotional level over the behavioral level, purposeless rituals do not exhibit such a continuous control mechanism. Finally, it is argued that the selection principle determining the action flow in obsessive-compulsive disorder rituals is consistent with the so-called 4th law of non-equilibrium phase transitions in animate and inanimate system

Structural analysis of the GH43 enzyme Xsa43E from Butyrivibrio proteoclasticus

The rumen of dairy cattle can be thought of as a large, stable fermentation vat and as such it houses a large and diverse community of microorganisms. The bacterium Butyrivibrio proteoclasticus is a representative of a significant component of this microbial community. It is a xylan-degrading organism whose genome encodes a large number of open reading frames annotated as fibre-degrading enzymes. This suite of enzymes is essential for the organism to utilize the plant material within the rumen as a fuel source, facilitating its survival in this competitive environment. Xsa43E, a GH43 enzyme from B. proteoclasticus, has been structurally and functionally characterized. Here, the structure of selenomethionine-derived Xsa43E determined to 1.3 Å resolution using single-wavelength anomalous diffraction is reported. Xsa43E possesses the characteristic five-bladed β-propeller domain seen in all GH43 enzymes. GH43 enzymes can have a range of functions, and the functional characterization of Xsa43E shows it to be an arabinofuranosidase capable of cleaving arabinose side chains from short segments of xylan. Full functional and structural characterization of xylan-degrading enzymes will aid in creating an enzyme cocktail that can be used to completely degrade plant material into simple sugars. These molecules have a range of applications as starting materials for many industrial processes, including renewable alternatives to fossil fuels

Ab initio calculations of edge-functionalized armchair graphene nanoribbons: Structural, electronic, and vibrational effects

We present a theoretical study on narrow armchair graphene nanoribbons (AGNRs) with hydroxyl functionalized edges. Although this kind of passivation strongly affects the structure of the ribbon, a high degree of edge functionalization proves to be particularly stable. An important consequence of the geometric deviations is a severe reduction of the band-gap of the investigated 7-AGNR. This shift follows a linear dependence on the number of added hydroxyl groups per unit cell and thus offers the prospect of a tunable band-gap by edge functionalization. We furthermore cover the behavior of characteristic phonons for the ribbon itself as well as fingerprint modes of the hydroxyl groups. A large down-shift of prominent Raman active modes allows the experimental determination of the degree of edge functionalization.Comment: 6 pages, 9 figure

A study for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft

The results of a feasibility study and preliminary design for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft are documented. Active control functions which can be demonstrated on the TIFS aircraft and the cost of preparing, equipping, and operating the TIFS aircraft for active control technology development are determined. It is shown that the TIFS aircraft is as a suitable test bed for inflight research and validation of many ACT concepts

An Investigation into the Use of a Movement Assessment Protocol for Under-14 Rugby League Players in a Talent Development Environment

This study investigated the use of a movement assessment protocol for under-14 rugby league players by evaluating the relationships between chronological age, maturation, and anthropometry, and fitness and qualitative movement assessments (QMA) of 84 rugby league players within a talent development environment. A one-way ANOVA showed Quartile 1 players were more mature, taller (173.0±7.4 vs 165.0±8.0 cm) and heavier (72.5 vs 58.7 kg) than Quartile 4 players, with no difference evident for fitness or QMA measures. Earlier maturing players had significantly greater upper body power (5.39±0.46 vs 4.42±0.68 m), 20m speed (3.48±0.14 vs 3.65±0.19s) and power pass QMA (13.88±2.18 vs 12.00±1.98) than later maturing players. Body mass was positively related to power pass fitness (r=0.50) and QMA (r=0.22) scores, with negative relationships found for vertical jump performance (r=-0.24), sprint QMA (r=-.29) and turn off either foot QMA (r=-0.26). There is a need to educate coaches about the use of both fitness testing and qualitative movement assessments to identify talented U14 rugby league players, which potentially reduces relative age and maturational biases

A comparison of rugby union match demands between age group categories in UK representative adolescent players

The physical match demands for professional rugby union are well established (Cahill et al., 2013, Journal of Sports Science, 31, 299–237). However, there is a lack of evidence for adolescent players, especially in the UK. Therefore, the purpose of this study was to quantify and compare the demands placed upon adolescent players representing county teams across three age groups (U16, U18 and U20) and two playing positions (forwards and backs). Two county representative games for each age group were assessed, with a total of 112 independent observations collected. Players were classified into age group categories and by position (forwards; U16 [n = 20], U18 [n = 21], U20 [n = 18] and backs; U16 [n = 15], U18 [n = 19], U20 [n = 19]). Match demands were analyzed via a microtechnology unit (OptimEye S5, Catapult Innovations, Melbourne, Australia) that contained a GPS system and triaxial accelerometer sampling at 10 and 100 Hz, respectively. The magnitudes of difference between age groups within positions for locomotive and accelerometer-based variables were investigated using Cohen’s d effect sizes (±90% CL). Institutional ethical approval was granted. For forwards, unclear differences between age groups were observed for total distance (TD), but relative distance (RD) showed very large (U16 vs. U20; d = −2.87 ± 0.53) and large (U18 vs. U20; d = −1.81 ± 0.52) differences between groups. Moderate effect sizes were found for both maximum sprint velocity (Vmax; d = −1.03 ±0.53) and total sprinting distance (d = −0.78 ± 0.53) between U16 and U20. When normalised for time, PlayerLoadSlowTM (PLslow · min-1) increased with age, showing moderate effects for U16 versus U18 (d = 0.68 ± 0.52) and U16 versus U20 (d = 0.80 ± 0.54). For backs, unclear differences between age groups were observed for TD, but RD showed moderate differences U16 versus U20 (d = −0.88 ± 0.58) and U18 versus U20 (d = −1.01 ± 0.54). Small effect sizes were observed for Vmax (d = −0.52 ± 0.54) and total sprinting distance (d = −0.46 ± 0.54) between U18 and U20, whereas U16 versus U20 showed a small difference for Vmax only (d = −0.46 ± 56). PLslow.min-1 increased with age, demonstrating a moderate difference between U16 and U18 (d = 0.86 ± 0.57) and a small difference between U16 and U20 (d = 0.56 ± 0.57). This study shows that the absolute locomotive demands are similar between age groups, although when expressed relative to time, differences were found. This is likely due to difference in playing time between age groups and the consequent fatigue and/or pacing strategies adopted by players. The increase in PLslowmin-1 with age suggests an increase in static exertions. Future research should look to explore the interaction between physical and technical performances at different ages of adolescent rugby

Experiment-based Comparison of Prediction Methods for Pump Head Degradation with Viscous and Power-law Fluids

Although several methods are known to calculate pump performance with highly viscous and non-Newtonian fluids, research has not yet determined all the key parameters of these predictions. It is unclear how these parameters depend on the pump geometry and the delivered fluid rheology, which can vary widely in the chemical industry. In our study, the performance curves of a radial centrifugal pump with a viscous Newtonian glycerol solution and a non-Newtonian power-law fluid were experimentally compared. The head degradation of the pump was also presumed with the ANSI/HI and the Ofuchi methods, which are evident and commonly used for viscous Newtonian fluids, but not for non-Newtonians. The required constants were estimated based on experimental data for both models, and the Ofuchi method was adapted to power-law fluid. Based on our results, the Ofuchi method proved to apply for head degradation prediction with the examined power-law fluid. This work is licensed under a Creative Commons Attribution 4.0 International License