Coupling road vehicle aerodynamics and dynamics in simulation

A fully coupled system in which a vehicle s aerodynamic and handling responses can be simulated has been designed and evaluated using a severe crosswind test. Simulations of this type provide vehicle manufacturers with a useful alternative to on road tests, which are usually performed at a late stage in the development process with a proto- type vehicle. The proposed simulations could be performed much earlier and help to identify and resolve any aerodynamic sensitivities and safety concerns before significant resources are place in the design. It was shown that for the simulation of an artificial, on-track crosswind event, the use of the fully coupled system was unnecessary. A simplified, one-way coupled system, in which there is no feedback from the vehicle s dynamics to the aerodynamic simulation was sufficient in order to capture the vehicle s path deviation. The realistic properties of the vehicle and accurately calibrated driver model prevented any large attitude changes whilst immersed in the gust, from which variations to the aerodynamics could arise. It was suggested that this system may be more suited to other vehicle geometries more sensitive to yaw motions or applications where a high positional accuracy of the vehicle is required

Saving Money: The Massachusetts Tobacco Cessation Medicaid Benefit: A Policy Paper

In the United States, about 70% of smokers want to quit and 50% make a quit attempt each year. Unfortunately, only a small percent are successful, due in part to the lack of easy access to tobacco dependence treatments that have been proven effective. In light of the societal costs of tobacco-related illness, government must do everything it can to encourage and enable smokers to quit. The tobacco use landscape in this country has changed in recent years -- people with lower income and education levels have a much higher probability of smoking. For instance, the smoking rate for those with a college degree is under 10%, but for those insured by Medicaid it is over 35%. Unfortunately, Medicaid coverage for tobacco cessation treatment depends on the state in which you live. While federal health reform guarantees nationwide coverage for pregnant women, it does not for all other Medicaid beneficiaries. Some states have made this a public health priority, but others have not

Cultivating Water Literacy in STEM Education: Undergraduates’ Socio-Scientific Reasoning about Socio-Hydrologic Issues

Water-literate individuals effectively reason about the hydrologic concepts that underlie socio-hydrological issues (SHI), but functional water literacy also requires concomitant reasoning about the societal, non-hydrological aspects of SHI. Therefore, this study explored the potential for the socio-scientific reasoning construct (SSR), which includes consideration of the complexity of issues, the perspectives of stakeholders involved, the need for ongoing inquiry, skepticism about information sources, and the affordances of science toward the resolution of the issue, to aid undergraduates in acquiring such reasoning skills. In this fixed, embedded mixed methods study (N = 91), we found SHI to hold great potential as meaningful contexts for the development of water literacy, and that SSR is a viable and useful construct for better understanding undergraduates’ reasoning about the hydrological and non-hydrological aspects of SHI. The breadth of reasoning sources to which participants referred and the depth of the SSR they exhibited in justifying those sources varied within and between the dimensions of SSR. A number of participants’ SSR was highly limited. Implications for operationalizing, measuring, and describing undergraduate students’ SSR, as well as for supporting its development for use in research and the classroom, are discussed

The Neon Gap: Probing Ionization with Dwarf Galaxies at z~1

We present measurements of [NeIII]{\lambda}3869 emission in z~1 low-mass galaxies taken from the Keck/DEIMOS spectroscopic surveys HALO7D and DEEPWinds. We identify 167 individual galaxies with significant [NeIII] emission lines, including 112 "dwarf" galaxies with log(M_{\star}/M_{\odot}) < 9.5, with 0.3 < z < 1.4. We also measure [NeIII] emission from composite spectra derived from all [OII]{\lambda}{\lambda}3727,3729 line emitters in this range. This provides a unique sample of [NeIII]-emitters in the gap between well-studied emitters at z = 0 and 2 < z < 3. To study evolution in ionization conditions in the ISM over this time, we analyze the log([NeIII]{\lambda}3869/[OII]{\lambda}{\lambda}3727,3729) ratio (Ne3O2) as a function of the stellar mass and of the log([OIII]{\lambda}{\lambda}4959,5007/[OII]{\lambda}{\lambda}3727,3729) ratio (O32). We find that the typical star-forming dwarf galaxy at this redshift, as measured from the composite spectra, shares the Ne3O2-M_{\star} relation with local galaxies, but have higher O32 at given Ne3O2. This finding implies that the ionization and metallicity characteristics of the z~1 dwarf population do not evolve substantially from z~1 to z=0, suggesting that the known evolution in those parameter from z~2 has largely taken place by z~1. Individual [NeIII]-detected galaxies have emission characteristics situated between local and z~2 galaxies, with elevated Ne3O2 and O32 emission potentially explained by variations in stellar and nebular metallicity. We also compare our dwarf sample to similarly low-mass z > 7 galaxies identified in JWST Early Release Observations, finding four HALO7D dwarfs with similar size, metallicity, and star formation properties.Comment: Accepted to ApJL, 16.01.202

A drag coefficient for application to the WLTP driving cycle

The aerodynamic drag characteristics of a passenger car have, typically, been defined by a single parameter: the drag coefficient at a yaw angle of 0°. Although this has been acceptable in the past, it does not provide an accurate measure of the effect of aerodynamic drag on fuel consumption because the important influence of the wind has been excluded. The result of using drag coefficients at a yaw angle of 0° produces an underprediction of the aerodynamic component of fuel consumption that does not reflect the on-road conditions. An alternative measure of the aerodynamic drag should take into account the effect of non-zero yaw angles, and a variant of wind-averaged drag is suggested as the best option. A wind-averaged drag coefficient is usually derived for a particular vehicle speed using a representative wind speed distribution. In the particular case where the road speed distribution is specified, such as for a driving cycle to determine fuel economy, a relevant drag coefficient can be derived by using a weighted road speed. An effective drag coefficient is determined with this approach for a range of cars using the proposed test cycle for the Worldwide Harmonised Light Vehicle Test Procedure, WLTP. The wind input acting on the car has been updated for this paper using recent meteorological data and an understanding of the effect of a shear flow on the drag loading obtained from a computational fluid dynamics study. In order to determine the different mean wind velocities acting on the car, a terrain-related wind profile has also been applied to the various phases of the driving cycle. An overall drag coefficient is derived from the work done over the full cycle. This cycle-averaged drag coefficient is shown to be significantly higher than the nominal drag coefficient at a yaw angle of 0°

Keck Spectroscopy and HST Imaging of Field Galaxies at Moderate Redshift

We present 18 spectra, obtained with the Keck 10m telescope, of faint field galaxies (19 $<$ I $<$ 22, 0.2 $<$ z $<$ 0.84) previously imaged by {\it HST's} WFPC2. Though small, our sample appears to be representative of field spirals with a magnitude--limit of I $\le$ 22. Combining the results from the spectral and imaging data, we have derived various quantitative parameters for the galaxies, including colors, inclinations, emission line equivalent widths, redshifts, luminosities, internal velocity information and physical scale lengths. In particular, disk scale lengths (with sizes ranging from $\sim$1--5 kpc) have been measured from fits to the surface brightness profiles. We have also measured internal velocities with a rest frame resolution of $\sigma$ = 55 to 80 km s$^{-1}$ by fitting to the emission lines. The luminosity--disk size and luminosity--internal velocity (Tully--Fisher) relations for our moderate redshift galaxies are similar to the scaling relations seen for local galaxies, albeit with a modest brightening of $\sim$1 magnitude. The one bulge--dominated galaxy in our sample (at z = 0.324) has a relatively blue color, reveals weak emission lines and is $\sim$0.5 magnitude brighter in the rest frame than expected for a passive local elliptical. Our data suggest that galaxies at about half the age of the Universe have undergone mild luminosity evolution to the present epoch, but are otherwise quantitatively similar to galaxies seen locally.Comment: replaced short version of paper. 31 pages, figures and tables available at http://www.ucolick.org/~forbes/home.htm

In Silico Modeling of Shear-Stress-Induced Nitric Oxide Production in Endothelial Cells through Systems Biology

Nitric oxide (NO) produced by vascular endothelial cells is a potent vasodilator and an antiinflammatory mediator. Regulating production of endothelial-derived NO is a complex undertaking, involving multiple signaling and genetic pathways that are activated by diverse humoral and biomechanical stimuli. To gain a thorough understanding of the rich diversity of responses observed experimentally, it is necessary to account for an ensemble of these pathways acting simultaneously. In this article, we have assembled four quantitative molecular pathways previously proposed for shear-stress-induced NO production. In these pathways, endothelial NO synthase is activated 1), via calcium release, 2), via phosphorylation reactions, and 3), via enhanced protein expression. To these activation pathways, we have added a fourth, a pathway describing actual NO production from endothelial NO synthase and its various protein partners. These pathways were combined and simulated using CytoSolve, a computational environment for combining independent pathway calculations. The integrated model is able to describe the experimentally observed change in NO production with time after the application of fluid shear stress. This model can also be used to predict the specific effects on the system after interventional pharmacological or genetic changes. Importantly, this model reflects the up-to-date understanding of the NO system, providing a platform upon which information can be aggregated in an additive way.National Institutes of Health (U.S.) (Grant R01HL090856)Singapore-MIT Alliance Computational and Systems Biology Progra

Capacity-building barriers to S3 implementation: an empirical framework for catch-up regions

In this paper, we investigate the implementation challenge of Smart Specialisation Strategies (S3) in catch-up regional environments, through the lens of capacity building. We analyse capacity building at two levels: micro-level (individual organisations) and meso-level (regional inter-organisational networks). We use empirical evidence from 50 interviews conducted in the period 2015–2017 from two Greek regions dramatically hit by the economic crisis (Crete and Central Macedonia). We argue that in the Cretan and Central Macedonian context, the difficulty of implementing S3 is directly linked with firms’ lack of adsorptive capability to exploit university-generated knowledge, university knowledge that is too abstract for firm’s to easily acquire, as well as to the capability of regional actors to build inter-organisational networking that fits their strategic needs

A study of computational methods for wake structure and base pressure prediction of a generic SUV model with fixed and rotating wheels

This study is an evaluation of computational methods in reproducing experimental data for a generic SUV geometry and an assessment on the influence of fixed and rotating wheels for this geometry. Initially, comparisons are made in wake structure and base pressures between several CFD codes and experimental data. It was shown that steady-state RANS methods are unsuitable for this geometry due to a large scale unsteadiness in the wake caused by separation at the sharp trailing edge and rear wheel wake interactions. URANS offered no improvements in wake prediction despite a significant increase in computational cost. DES and Lattice Boltzmann methods showed the best agreement with experimental results in both wake structure and base pressure, with LBM running in approximately a fifth of the time for DES