Laboratory study on the effects of hydro kinetic turbines on hydrodynamics and sediment dynamics

© 2018 The Authors The need for hydrokinetic turbine wake characterisation and their environmental impact has led to a number of studies. However, a small number of them have taken into account mobile sediment bed effects. The aim of the present work is to study the impact of the presence of a horizontal-axis three-bladed turbine with the flow and a mobile sediment bed. We use a series of laboratory experiments with a scaled modelled turbine installed in a flume with a mobile sandy bed at the bottom. Acoustic instruments were used to monitor flow, suspended sediment and bed behaviour. Results show a velocity decrease of about 50% throughout the water column and no flow recovery after a distance of 15 rotor diameters. Clearly visible ripples in the absence of the model turbine were replaced by horseshoe-shaped scour pit in the near wake region, and a depositional heap in the far wake. Suspended sediment differences were recorded in the streamwise direction with a possible effect of the wake as far as 15 rotor diameters. These results imply potentially important effects on the efficiency of turbine arrays, if the flow were to be lower than expected, on turbine foundations and modify coastal sediment transport

Unconventional Charge Ordering in Na0.70CoO2 below 300 K

We present the results of measurements of the dc-magnetic susceptibility chi(T) and the 23Na-NMR response of Na_{0.70}CoO_{2} at temperatures between 50 and 340 K. The chi(T) data suggest that for T > 75 K, the Co ions adopt an effective configuration of Co^{3.4+}. The 23Na-NMR response reveals pronounced anomalies near 250 and 295 K, but no evidence for magnetic phase transitions is found in chi(T). Our data suggest the onset of a dramatic change in the Co 3d-electron spin dynamics at 295 K. This process is completed at 230 K. Our results maybe interpreted as evidence for either a tendency to electron localization or an unconventional charge-density wave phenomenon within the cobalt oxide layer, CoO_2, 3d electron system near room temperature.Comment: 4 pages, 4 figures, re-submitted to Physical Review Letters. The manuscript has been revised following the recommendations of the referees. The discussion section contains substantial change

High Magnetic Field Microwave Conductivity of 2D Electrons in an Array of Antidots

We measure the high magnetic field ($B$) microwave conductivity, Re$\sigma_{xx}$, of a high mobility 2D electron system containing an antidot array. Re$\sigma_{xx}$ vs frequency ($f$) increases strongly in the regime of the fractional quantum Hall effect series, with Landau filling $1/3<\nu<2/3$. At microwave $f$, Re$\sigma_{xx}$ vs $B$ exhibits a broad peak centered around $\nu=1/2$. On the peak, the 10 GHz Re$\sigma_{xx}$ can exceed its dc-limit value by a factor of 5. This enhanced microwave conductivity is unobservable for temperature $T \gtrsim 0.5$ K, and grows more pronounced as $T$ is decreased. The effect may be due to excitations supported by the antidot edges, but different from the well-known edge magnetoplasmons.Comment: 4 pages, 3 figures, revtex

Association studies of polybrominated biphenyls in aquatic systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47983/1/128_2005_Article_BF01606089.pd

Interatomic potentials for atomistic simulations of the Ti-Al system

Semi-empirical interatomic potentials have been developed for Al, alpha-Ti, and gamma-TiAl within the embedded atomic method (EAM) by fitting to a large database of experimental as well as ab-initio data. The ab-initio calculations were performed by the linear augmented plane wave (LAPW) method within the density functional theory to obtain the equations of state for a number of crystal structures of the Ti-Al system. Some of the calculated LAPW energies were used for fitting the potentials while others for examining their quality. The potentials correctly predict the equilibrium crystal structures of the phases and accurately reproduce their basic lattice properties. The potentials are applied to calculate the energies of point defects, surfaces, planar faults in the equilibrium structures. Unlike earlier EAM potentials for the Ti-Al system, the proposed potentials provide reasonable description of the lattice thermal expansion, demonstrating their usefulness in the molecular dynamics or Monte Carlo studies at high temperatures. The energy along the tetragonal deformation path (Bain transformation) in gamma-TiAl calculated with the EAM potential is in a fairly good agreement with LAPW calculations. Equilibrium point defect concentrations in gamma-TiAl are studied using the EAM potential. It is found that antisite defects strongly dominate over vacancies at all compositions around stoichiometry, indicating that gamm-TiAl is an antisite disorder compound in agreement with experimental data.Comment: 46 pages, 6 figures (Physical Review B, in press

Alpha-B-Crystallin overexpression is sufficient to promote tumorigenesis and metastasis in mice

Background: αB-Crystallin is a heat shock chaperone protein which binds to misfolded proteins to prevent their aggregation. It is overexpressed in a wide-variety of cancers. Previous studies using human cancer cell lines and human xenograft models have suggested potential tumor promoter (oncogene) roles for αB-Crystallin in a widespectrum of cancers. Methods: To determine the causal relationship between CRYAB overexpression and cancer, we generated a Cryab overexpression knock-in mouse model and monitor them for development of spontaneous and carcinogen (DMBA)- induced tumorigenesis. In order to investigate the mechanism of malignancies observed in this model multiple techniques were used such as immunohistochemical characterizations of tumors, bioinformatics analysis of publically available human tumor datasets, and generation of mouse embryonic fbroblasts (MEFs) for in vitro assays (clonogenic survival and migration assays and proteome analysis by mass-spectrometry). Results: This model revealed that constitutive overexpression of Cryab results in the formation of a variety of lethal spontaneous primary and metastatic tumors in mice. In vivo, the overexpression of Cryab correlated with the upregulation of epithelial-to-mesenchymal (EMT) markers, angiogenesis and some oncogenic proteins including Basigin. In vitro, using E1A/Ras transformed MEFs, we observed that the overexpression of Cryab led to the promotion of cell survival via upregulation of Akt signaling and downregulation of pro-apoptotic pathway mediator JNK, with subsequent attenuation of apoptosis as assessed by cleaved caspase-3 and Annexin V staining. Conclusions: Overall, through the generation and characterization of Cryab overexpression model, we provide evidence supporting the role of αB-Crystallin as an oncogene, where its upregulation is suffcient to induce tumors, promote cell survival and inhibit apoptosis.Behnam Rashidieh, Amanda Louise Bain, Simon Manuel Tria, Sowmya Sharma, Cameron Allan Stewart, Jacinta Ley Simmons, Pirjo M. Apaja, Pascal H. G. Duijf, John Finnie, and Kum Kum Khann

Global warming and the cosmopolitan political conception of justice

Within the literature in green political theory on global environmental threats one can often find dissatisfaction with liberal theories of justice. This is true even though liberal cosmopolitans regularly point to global environmental problems as one reason for expanding the scope of justice beyond the territorial limits of the state. One of the causes for scepticism towards liberal approaches is that many of the most notable anti-cosmopolitan theories are also advanced by liberals. In this paper, I first explain why one of the strongest expressions of liberal anti-cosmopolitanism cannot simply be dismissed because it may fail to support desired environmental ends. The political conception of justice represents one of the most important challenges to cosmopolitanism generally and is thus a serious challenge to viewing global environmental problems in terms of cosmopolitan justice. Second, I will show through the case of anthropogenic global warming that the political conception of justice under current conditions does have clear cosmopolitan implications despite its proponents' claims

Geriatric oncology health services research: Cancer and Aging Research Group infrastructure core

Founded by the late Dr. Arti Hurria, the Cancer and Aging Research Group (CARG) is a collaborative, interdisciplinary team of investigators dedicated to improving the care of older adults with cancer through research, advocacy, and other scholarly initiatives.1 As part of the CARG National Institute on Aging R21/R33 infrastructure grant to harness the available expertise and prioritize the development of high-impact research, the Health Services Research (HSR) Core was developed to foster and advance HSR in geriatric oncology. The mission of the HSR Core is to support clinical investigators to design and conduct highquality HSR focused on older adults with cancer and their caregivers including patterns of care, comparative effectiveness, and care delivery. At the first R21/R33 conference held at City of Hope in October 2018, Dr. Harvey Jay Cohen (Chair, CARG Oversight Board and HSR Core) led the development of this Core. In this perspective paper, we present a review of HSR in geriatric oncology to build a foundation for the Core rationale; proposed Core function, workflow, policies, and procedures; anticipated interactions with other CARG Cores; and proposed plans for sustainabilit

New polarimetric constraints on axion-like particles

We show that the parameter space of axion-like particles can be severly constrained using high-precision measurements of quasar polarisations. Robust limits are derived from the measured bounds on optical circular polarisation and from the distribution of linear polarisations of quasars. As an outlook, this technique can be improved by the observation of objects located behind clusters of galaxies, using upcoming space-borne X-ray polarimeters.Comment: Submitted to JCA