Model of the Radio Frequency (RF) Excitation Response from Monopole and Dipole Antennas in a Large Scale Tank

Good antenna-mode coupling is needed for determining the amount of propellant in a tank through the method of radio frequency mass gauging (RFMG). The antenna configuration and position in a tank are important factors in coupling the antenna to the natural electromagnetic modes. In this study, different monopole and dipole antenna mounting configurations and positions were modeled and responses simulated in a full-scale tank model with the transient solver of CST Microwave Studio (CST Computer Simulation Technology of America, Inc.). The study was undertaken to qualitatively understand the effect of antenna design and placement within a tank on the resulting radio frequency (RF) tank spectrum

Equation of state of strongly coupled Hamiltonian lattice QCD at finite density

We calculate the equation of state of strongly coupled Hamiltonian lattice QCD at finite density by constructing a solution to the equation of motion corresponding to an effective Hamiltonian using Wilson fermions. We find that up to and beyond the chiral symmetry restoration density the pressure of the quark Fermi sea can be negative indicating its mechanical instability. This result is in qualitative agreement with continuum models and should be verifiable by future numerical simulations.Comment: 14 pages, 2 EPS figures. Revised version - added discussion on the equation of stat

Learning to Live With Wolves: Community-based Conservation in the Blackfoot Valley of Montana

We built on the existing capacity of a nongovernmental organization called the Blackfoot Challenge to proactively address wolf (Canis lupus)-livestock conflicts in the Blackfoot Valley of Montana. Beginning in 2007, wolves started rapidly recolonizing the valley, raising concerns among livestock producers. We built on an existing program to mitigate conflicts associated with an expanding grizzly bear population and worked within the community to build a similar program to reduce wolf conflicts using an integrative, multi-method approach. Efforts to engage the community included one-on-one meetings, workshops, field tours, and regular group meetings as well as opportunities to participate in data collection and projects. Initial projects included permanent electric fencing of calving areas and livestock carcass removal to address the threat of grizzly bears and, later, wolves. Subsequently we used intensive livestock and wolf monitoring through range riders in an attempt to reduce the frequency of encounter rates among wolves and livestock. Although we cannot claim causation from our efforts, results are encouraging. Confirmed livestock losses to wolves from 2006-2015 have been 2.2 confirmed depredations per year across nearly 50 ranches on about 3,240 km2 that are annually grazed by 16,000-18,000 head of livestock. Fewer than three wolves per year have been removed (2.4 wolves per year) due to these depredations for the same period as the population increased from one confirmed pack to approximately twelve. Our collaborative approach and prior experience with grizzly bears was key in building a proactive program to help reduce conflict with wolves in a community adjusting to an increasing large carnivore presence over a short period

Testing a Simplified Version of Einstein's Equations for Numerical Relativity

Solving dynamical problems in general relativity requires the full machinery of numerical relativity. Wilson has proposed a simpler but approximate scheme for systems near equilibrium, like binary neutron stars. We test the scheme on isolated, rapidly rotating, relativistic stars. Since these objects are in equilibrium, it is crucial that the approximation work well if we are to believe its predictions for more complicated systems like binaries. Our results are very encouraging.Comment: 9 pages (RevTeX 3.0 with 6 uuencoded figures), CRSR-107

Do ACE inhibitors or ARBs help prevent kidney disease in patients with diabetes and normal BP?

Q: Do ACE inhibitors or ARBs help prevent kidney disease in patients with diabetes and normal BP? Evidence-based answer: Yes for angiotensin-converting enzyme (ACE) inhibitors, no for angiotensin receptor blockers (ARBs). In normotensive patients with type 1 and type 2 diabetes, ACE inhibitor therapy reduces the risk of developing diabetic kidney disease, defined as new-onset microalbuminuria or macroalbuminuria, by 18% (strength of recommendation [SOR]: C, meta-analysis of randomized controlled trials [RCTs], disease-oriented evidence). ACE inhibitor treatment improves all-cause mortality by 16% in patients with diabetes, including patients with and without hypertension. Patients on ACE inhibitor therapy are at increased risk of cough (SOR: A, meta-analysis of RCTs). ARB therapy doesn't lower the risk of developing kidney disease in normotensive patients with type 2 diabetes (SOR: C, meta-analysis of RCTs, disease-oriented evidence); nor does it reduce all-cause mortality in patients with or without hypertension (SOR: A, meta-analysis of RCTs). ARBs aren't associated with significant adverse events (SOR: A, meta-analysis of RCTs)

Numerical simulations of the flow in the HYPULSE expansion tube

Axisymmetric numerical simulations with finite-rate chemistry are presented for two operating conditions in the HYPULSE expansion tube. The operating gas for these two cases is nitrogen and the computations are compared to experimental data. One test condition is at a total enthalpy of 15.2 MJ/Kg and a relatively low static pressure of 2 kPa. This case is characterized by a laminar boundary layer and significant chemical nonequilibrium in the acceleration gas. The second test condition is at a total enthalpy of 10.2 MJ/Kg and a static pressure of 38 kPa and is characterized by a turbulent boundary layer. For both cases, the time-varying test gas pressure predicted by the simulations is in good agreement with experimental data. The computations are also found to be in good agreement with Mirels' correlations for shock tube flow. It is shown that the nonuniformity of the test gas observed in the HYPULSE expansion tube is strongly linked to the boundary layer thickness. The turbulent flow investigated has a larger boundary layer and greater test gas nonuniformity. In order to investigate possibilities of improving expansion tube flow quality by reducing the boundary layer thickness, parametric studies showing the effect of density and turbulent transition point on the test conditions are also presented. Although an increase in the expansion tube operating pressure level would reduce the boundary layer thickness, the simulations indicate that the reduction would be less than what is predicted by flat plate boundary layer correlations

GRAIL-identified gravity anomalies in Oceanus Procellarum:Insight into subsurface impact and magmatic structures on the Moon

Four, quasi-circular, positive Bouguer gravity anomalies (PBGAs) that are similar in diameter (~90–190 km) and gravitational amplitude (>140 mGal contrast) are identified within the central Oceanus Procellarum region of the Moon. These spatially associated PBGAs are located south of Aristarchus Plateau, north of Flamsteed crater, and two are within the Marius Hills volcanic complex (north and south). Each is characterized by distinct surface geologic features suggestive of ancient impact craters and/or volcanic/plutonic activity. Here, we combine geologic analyses with forward modeling of high-resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL) mission in order to constrain the subsurface structures that contribute to these four PBGAs. The GRAIL data presented here, at spherical harmonic degrees 6–660, permit higher resolution analyses of these anomalies than previously reported, and reveal new information about subsurface structures. Specifically, we find that the amplitudes of the four PBGAs cannot be explained solely by mare-flooded craters, as suggested in previous work; an additional density contrast is required to explain the high-amplitude of the PBGAs. For Northern Flamsteed (190 km diameter), the additional density contrast may be provided by impact-related mantle uplift. If the local crust has a density ~2800 kg/m3, then ~7 km of uplift is required for this anomaly, although less uplift is required if the local crust has a lower mean density of ~2500 kg/m3. For the Northern and Southern Marius Hills anomalies, the additional density contrast is consistent with the presence of a crustal complex of vertical dikes that occupies up to ~50% of the regionally thin crust. The structure of Southern Aristarchus Plateau (90 km diameter), an anomaly with crater-related topographic structures, remains ambiguous. Based on the relatively small size of the anomaly, we do not favor mantle uplift; however, understanding mantle response in a region of especially thin crust needs to be better resolved. It is more likely that this anomaly is due to subsurface magmatic material given the abundance of volcanic material in the surrounding region. Overall, the four PBGAs analyzed here are important in understanding the impact and volcanic/plutonic history of the Moon, specifically in a region of thin crust and elevated temperatures characteristic of the Procellarum KREEP Terrane

An enigmatic group of arctic island caribou and the potential implications for conservation of biodiversity

We investigated the status of caribou classified as Rangifer tarandus pearyi by DNA analyses, with an emphasis on those large-bodied caribou identified as ultra pearyi that were collected in summer 1958 on Prince of Wales Island, south-central Canadian Arctic Archipelago. Our comparative assessment reveals that the ultra pearyi from Prince of Wales Island belong to a group of pearyi and are not hybrids of pearyi x groenlandicus, as we found for the caribou occurring on nearby Banks Island and northwest Victoria Island. The ultra pearyi from Prince of Wales Island cluster with high arctic pearyi and are separated genetically from the caribou populations that we sampled on the low Canadian Arctic Islands and the Canadian mainland. Our findings reveal biodiversity below the level of subspecies or regional designations. These results support the position that to retain the biodiversity present among caribou populations on the Canadian Arctic Islands, conservation efforts should be targeted at the smaller scale level of the geographic population, rather than on a wider regional or subspecific range-wide basis

A Jurassic (Bathonian-Callovian) Daghanirhynchia Brachiopod Fauna from Jordan

A Jurassic (Bathonian-Callovian) brachiopod fauna from Jordan consists of seven rhynchonellid species all belonging to the genus Daghanirhynchia of which two are new: Daghanirhynchia rawyaensis and D. jordanica. Emended diagnoses are given for Daghanirhynchia daghaniensis and D. macfadyeni. Additional taxa described include Daghanirhynchia angulocostata, D. susanae and D. triangulata. Threedimensional reconstructions illustrate the internal morphology of the articulated shells for the first time in this genus. The material studied herein was collected from Wadi Zarqa in northwestern Jordan, almost due north of the Dead Sea, and to the east of the Rift Valley. Most species seem to be geographically restricted within the Jurassic Ethiopian Province, however specimens from Somalia and Ethiopia are larger in size than in other parts of the Province and shell size increases in stratigraphically younger specimens. The occurrence of Daghanirhynchia in India is the only appearance of the genus outside the Ethiopian Province

Calibration of chron C29r: New high-precision geochronologic and paleomagnetic constraints from the Hell Creek region, Montana

The mass extinction at the Cretaceous- Paleogene boundary marks one of the most important biotic turnover events in Earth history. Yet, despite decades of study, the causes of the Cretaceous-Paleogene boundary crises remain under debate. An important tool that has the capacity to greatly improve our understanding of the events around the Cretaceous-Paleogene boundary is the geomagnetic polarity time scale (GPTS). The GPTS is used for age control in numerous Cretaceous-Paleogene boundary studies, including the timing of Deccan Traps volcanism, a majority of studies in marine sections, and studies on climate and ecological change across the Cretaceous-Paleogene boundary. The current calibration of the GPTS for circum- Cretaceous-Paleogene boundary polarity chrons (C30n-C28n) from the Geologic Time Scale draws heavily on astronomical tuning and uses a 40Ar/39Ar age for the Cretaceous- Paleogene boundary as a tie point that has since been shown to be 200 ka too old. Furthermore, complex sedimentation has been recorded in marine sections immediately following the Cretaceous-Paleogene boundary, which can possibly obscure orbital signals and complicate cyclostratigraphic interpretation. An independent test of the cyclostratigraphy for this time period is imperative for confidence in the astronomical time scale. Further, polarity reversal ages given in the GPTS do not include uncertainty estimates, making them unsuitable for quantitative chronometry. Recent calibrations have been attempted using U/Pb geochronology on zircons; however, U/Pb zircon dates may be biased by pre-eruptive zircon residence times of tens to hundreds of thousands of years. In this study, we provide constraints on the timing and duration of the most important circum-Cretaceous-Paleogene boundary chron, chron C29r, using high-precision 40Ar/39Ar geochronology and magnetostratigraphy on fluvial sediments from the Hell Creek region, Montana. Here, we show results for 14 new magnetostratigraphic sections, and 18 new high-precision 40Ar/39Ar dates, which together provide six independent constraints on the age of the C29r/C29n reversal and two constraints on the C30n/ C29r reversal. Together, these results show that the duration of C29r was 587 ± 53 ka, consistent with the most recent Geologic Time Scale calibration and previous U-Pb age models. We further present new geochronologic data for the Cretaceous-Paleogene boundary that provide the most precise date yet, of 66.052 ± 0.008/0.043 Ma. Integration of our results into the extensive paleontological framework for this region further provides important constraints on rates of terrestrial faunal change across the Cretaceous-Paleogene boundary