An experimental low Reynolds number comparison of a Wortmann FX67-K170 airfoil, a NACA 0012 airfoil and a NACA 64-210 airfoil in simulated heavy rain

Wind tunnel experiments were conducted on Wortmann FX67-K170, NACA 0012, and NACA 64-210 airfoils at rain rates of 1000 mm/hr and Reynolds numbers of 310,000 to compare the aerodynamic performance degradation of the airfoils and to attempt to identify the various mechanisms which affect performance in heavy rain conditions. Lift and drag were measured in dry and wet conditions, a variety of flow visualization techniques were employed, and a computational code which predicted airfoil boundary layer behavior was used. At low angles of attack, the lift degradation in wet conditions varied significantly between the airfoils. The Wortmann section had the greatest overall lift degradation and the NACA 64-210 airfoil had the smallest. At high angles of attack, the NACA 64-210 and 0012 airfoils had improved aerodynamic performance in rain conditions due to an apparent reduction of the boundry layer separation. Performance degradation in heavy rain for all three airfoils at low angles of attack could be emulated by forced boundary layer transition near the leading edge. The secondary effect occurs at time scales consistent with top surface water runback times. The runback layer is thought to effectively alter the airfoil geometry. The severity of the performance degradation for the airfoils varied. The relative differences appeared to be related to the susceptibility of each airfoil to premature boundary layer transition

Partner choice, relationship satisfaction, and oral contraception: the congruency hypothesis

Hormonal fluctuation across the menstrual cycle explains temporal variation in women’s judgment of the attractiveness of members of the opposite sex. Use of hormonal contraceptives could therefore influence both initial partner choice and, if contraceptive use subsequently changes, intrapair dynamics. Associations between hormonal contraceptive use and relationship satisfaction may thus be best understood by considering whether current use is congruent with use when relationships formed, rather than by considering current use alone. In the study reported here, we tested this congruency hypothesis in a survey of 365 couples. Controlling for potential confounds (including relationship duration, age, parenthood, and income), we found that congruency in current and previous hormonal contraceptive use, but not current use alone, predicted women’s sexual satisfaction with their partners. Congruency was not associated with women’s nonsexual satisfaction or with the satisfaction of their male partners. Our results provide empirical support for the congruency hypothesis and suggest that women’s sexual satisfaction is influenced by changes in partner preference associated with change in hormonal contraceptive use

Vailulu’u Seamount

Author Posting. © Oceanography Society, 2010. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 23, 1 (2010): 164-165.Vailulu’u seamount is an active underwater volcano that marks the end of the Samoan hotspot trail

The ACPI Project, Element 1: Initializing a Coupled Climate Model from Observed Conditions

A problem for climate change studies with coupled ocean-atmosphere models has been how to incorporate observed initial conditions into the ocean, which holds most of the ‘memory’ of anthropogenic forcing effects. The first difficulty is the lack of comprehensive three-dimensional observations of the current ocean temperature (T) and salinity (S) fields to initialize to. The second problem is that directly imposing observed T and S fields into the model results in rapid drift back to the model climatology, with the corresponding loss of the observed information. Anthropogenic forcing scenarios therefore typically initialize future runs by starting with pre-industrial conditions. However, if the future climate depends on the details of the present climate, then initializing the model to observations may provide more accurate forecasts. Also, this ∼130 yr spin up imposes substantial overhead if only a few decades of predictions are desired. A new technique to address these problems is presented. In lieu of observed T and S, assimilated ocean data were used. To reduce model drift, an anomaly coupling scheme was devised. This consists of letting the model’s climatological (pre-industrial) oceanic and atmospheric heat contents and transports balance each other, while adding on the (much smaller) changes in heat content since the pre-industrial era as anomalies. The result is model drift of no more than 0.2 K over 50 years, significantly smaller than the forced response of 1.0 K. An ensemble of runs with these assimilated initial conditions is then compared to a set spun up from pre-industrial conditions. No systematic differences were found, i.e., the model simulation of the ocean temperature structure in the late 1990s is statistically indistinguishable from the assimilated observations. However, a model with a worse representation of the late 20th century climate might show significant differences if initialized in this way.This work was supported by the Department of Energy under grant DE-FG03– 98ER62505

The Beta Problem: A Study of Abell 262

We present an investigation of the dynamical state of the cluster A262. Existing optical line of sight velocities for select cluster galaxies have been augmented by new data obtained with the Automated Multi-Object Spectrograph at Lick Observatory. We find evidence for a virialized early-type population distinct from a late-type population infalling from the Pisces-Perseus supercluster ridge. We also report on a tertiary population of low luminosity galaxies whose velocity dispersion distinguishes them from both the early and late-type galaxies. We supplement our investigation with an analysis of archival X-ray data. A temperature is determined using ASCA GIS data and a gas profile is derived from ROSAT HRI data. The increased statistics of our sample results in a picture of A262 with significant differences from earlier work. A previously proposed solution to the "beta-problem" in A262 in which the gas temperature is significantly higher than the galaxy temperature is shown to result from using too low a velocity dispersion for the early-type galaxies. Our data present a consistent picture of A262 in which there is no "beta-problem", and the gas and galaxy temperature are roughly comparable. There is no longer any requirement for extensive galaxy-gas feedback to drastically overheat the gas with respect to the galaxies. We also demonstrate that entropy-floor models can explain the recent discovery that the beta values determined by cluster gas and the cluster core radii are correlated.Comment: 31 pages, 14 figures, AAS LaTeX v5.0, Encapsulated Postscript figures, to be published in The Astrophysical Journa

Repeat treatment with rifaximin is safe and effective in patients with diarrhea-predominant irritable bowel syndrome

Background & AimsFew treatments have demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). A phase 3, randomized, double-blind, placebo-controlled trial was performed to evaluate the safety and efficacy of repeat treatment with the nonsystemic antibiotic rifaximin.MethodsThe trial included adults with IBS-D, mean abdominal pain and bloating scores of 3 or more, and loose stool, located at 270 centers in the United States and Europe from February 2012 through June 2014. Those responding to a 2-week course of open-label rifaximin 550 mg 3 times daily, who then relapsed during an observation phase (up to 18 weeks), were randomly assigned to groups given repeat treatments of rifaximin 550 mg or placebo 3 times daily for 2 weeks. The primary end point was percentage of responders after first repeat treatment, defined as a decrease in abdominal pain of ≥30% from baseline and a decrease in frequency of loose stools of ≥50% from baseline, for 2 or more weeks during a 4-week post-treatment period.ResultsOf 1074 patients (44.1%) who responded to open-label rifaximin, 382 (35.6%) did not relapse and 692 (64.4%) did; of these, 636 were randomly assigned to receive repeat treatment with rifaximin (n = 328) or placebo (n = 308). The percentage of responders was significantly greater with rifaximin than placebo (38.1% vs 31.5%; P = .03). The percentage of responders for abdominal pain (50.6% vs 42.2%; P = .018) was significantly greater with rifaximin than placebo, but not stool consistency (51.8% vs 50.0%; P = .42). Significant improvements were also noted for prevention of recurrence, durable response, and bowel movement urgency. Adverse event rates were low and similar between groups.ConclusionsIn a phase 3 study of patients with relapsing symptoms of IBS-D, repeat rifaximin treatment was efficacious and well tolerated. ClinicalTrials.gov ID: NCT01543178

Artistic Expression as a Source of Resilience for Transgender and Gender Diverse Young People

There is a paucity of research exploring sources of resilience among transgender and gender diverse (TGD) young people with multiple marginalized identities. Information and communication technologies (ICT) offer unique opportunities for authentic self-expression, which is not always possible offline. The primary aims of this study were to understand unique sources of resilience among TGD youth in their online and offline lives. Using photo elicitation and grounded theory methods, we conducted online in-depth interviews with TGD young people (N = 29) between the ages of 14-25 across the United States identifying with at least one of the following social statuses: (a) person of color, (b) immigrant, or (c) living in a rural area. Four themes were identified from the data, with both online and offline artistic expression being viewed as a: 1) form of authentic self-expression; 2) coping mechanism; 3) way to connect to others; and 4) pathway toward agency. Findings advance understanding about the use of artistic expression as an underexamined source of resilience among TGD youth with multiple marginalized identities. Within clinical settings, options for TGD youth to participate in various forms of expressive art may improve engagement and enhance youths’ abilities to authentically express their thoughts, feelings, and experiences to promote healing and growth

Mid-infrared InAs/InAsSb superlattice nBn photodetector monolithically integrated onto silicon

Mid-infrared (MIR) silicon photonics holds the potential for realizing next generation ultracompact spectroscopic systems for applications in gas sensing, defense, and medical diagnostics. The direct epitaxial growth of antimonide-based compound semiconductors on silicon provides a promising approach for extending the wavelength of silicon photonics to the longer infrared range. This paper reports on the fabrication of a high performance MIR photodetector directly grown onto silicon by molecular beam epitaxy. The device exhibited an extended cutoff wavelength at ∼5.5 μm and a dark current density of 1.4 × 10–2 A/cm2 under 100 mV reverse bias at 200 K. A responsivity of 0.88 A/W and a specific detectivity in the order of 1.5 × 1010 Jones was measured at 200 K under 100 mV reverse bias operation. These results were achieved through the development of an innovative structure which incorporates a type-II InAs/InAsSb superlattice-based barrier nBn photodetector grown on a GaSb-on-silicon buffer layer. The difficulties in growing GaSb directly on silicon were overcome using a novel growth procedure consisting of an efficient AlSb interfacial misfit array, a two-step growth temperature procedure and dislocation filters resulting in a low defect density, antiphase domain free GaSb epitaxial layer on silicon. This work demonstrates that complex superlattice-based MIR photodetectors can be directly integrated onto a Si platform, which provides a pathway toward the realization of new, high performance, large area focal plane arrays and mid-infrared integrated photonic circuits

Land Surface Climate in the Regional Arctic System Model

The article of record as published may be found at http://dx.doi.org/10.1175/JCLI-D-15-0415.1The Regional Arctic System Model (RASM) is a fully coupled, regional Earth system model applied over the pan-Arctic domain. This paper discusses the implementation of the Variable Infiltration Capacity land surface model (VIC) in RASM and evaluates the ability of RASM, version 1.0, to capture key features of the land surface climate and hydrologic cycle for the period 1979-2014 in comparison with uncoupled VIC simulations, reanalysis datasets, satellite measurements, and in situ observations. RASM reproduces the dominant features of the land surface climatology in the Arctic, such as the amount and regional distribution of precipitation, the partitioning of precipitation between runoff and evapotranspiration, the effects of snow on the water and energy balance, and the differences in turbulent fluxes between the tundra and taiga biomes. Surface air temperature biases in RASM, compared to reanalysis datasets ERA-Interim and MERRA, are generally less than 2 degrees C; however, in the cold seasons there are local biases that exceed 6 degrees C. Compared to satellite observations, RASM captures the annual cycle of snow-covered area well, although melt progresses about two weeks faster than observations in the late spring at high latitudes. With respect to derived fluxes, such as latent heat or runoff, RASM is shown to have similar performance statistics as ERA-Interim while differing substantially from MERRA, which consistently overestimates the evaporative flux across the Arctic region.U.S. Department of Energy (DOE) [DE-FG02-07ER64460, DE-SC0006856, DE-SC0006178]; DO