2,365 research outputs found
RANDOM ROAD ANALYSIS AND IMPROVED GEAR RATIO SELECTION OF A FRONT WHEEL DRIVE DRAG RACING CAR
Drag racing has been around since the 1950\u27s and has become a very popular and very competitive sport. The difference between winning and losing can be hundredths and even thousandths of a second. Drag racing teams need every advantage they can get in order to excel in their field. On-track testing is very expensive and can consume large amounts of time and resources that a race team may not be able to afford. One way to address this potential problem of high cost is by using computer simulation to show how your drag race car may perform at different tracks and how changes to your car may affect the performance at those tracks. A simulation could allow you to \u27run\u27 a test at different tracks without actually having to go to those tracks. While computer simulation can not completely replace real testing, it could save money and increase productivity at testing sessions. Additionally, the ability to generate vehicle dynamic responses specific to different tracks could be helpful in selecting vehicle parameters specifically for those tracks. This thesis describes the development of a tool to study the vehicle dynamics of a front wheel drive drag racing car. A 5 degrees-of-freedom (DOF) model of the dynamic response of the vehicle on different track surfaces is developed and simulated in MATLAB and Simulink. The input to the simulation is a user-specified power spectral density (PSD) of the vertical road profile, tire-to-road adhesion level, and specific vehicle parameters. Outputs of the model include drag times, normal forces, longitudinal accelerations, heave, pitch angle, wheel slip, traction force, vehicle and wheel speeds, and engine RPM. Simulations are run comparing the effects of different road surfaces on the vehicle dynamic response and drag performance. Also, a gear ratio improvement loop is used to evaluate different gear sets on drag performance in an effort to improve the quarter mile time and trap speed. The vehicle simulation shows that differing road surfaces have a large effect on vehicle dynamics and affect the overall performance of the vehicle on the drag run. The gear ratio improvement loop shows that quarter mile time improvements of 2% and trap speed improvements of over 4% could be achieved simply by using gear ratios that are chosen for a particular track surface. This simulation could produce beneficial and significant improvements in the drag racing world for teams looking for that extra edge on the competition. An overall improvement of 4% could be the difference between winning and losing
Contributions to the Study of Lithospheric Deformation and Seismicity in Stable Continental Regions
Recently, the field of geophysics has seen increasing recognition of the unique character of deformation and seismicity in stable continental regions (SCRs). However several important questions remain understudied. What controls the locations of earthquakes in SCRs? How well do observations, in SCRs, of elastic strain accumulation and release correlate with each other? How well do they correlate with stresses and geological proxies for rheological variation? The ultimate goal of this study was to better understand stable continental regions like southern Africa, where large earthquakes occur despite not being near plate boundaries, for example the 2017 Mw 6.5 earthquake in Moiyabana, Botswana. One way of studying the stress and strain in stable continental regions is by understanding the surface deformation of the region. This deformation is easily studied using global navigation satellite system (GNSS) velocity data. One of the biggest difficulties when it comes to GNSS data is that it isn't collected on a regular grid, but rather as irregular data points that need to be interpolated. This research investigated multiple interpolation methods and recommended two methods that best replicate the original velocity field (using a well populated dataset from Southeast Asia). These interpolated GNSS data can then be used to determine deviatoric strain in a region, which can in turn be fed into numerical stress models. However, limited GNSS data exist across southern Africa, and therefore topographic data was used to calculate the gravitational potential energy, and in turn the body stress and deviatoric stress for the region. This study also investigated how this deviatoric stress (or deviatoric strain) can be more accurately calculated on a spherical rather than a flat surface, which is particularly important over large study areas. Across southern Africa, data show that deviatoric stress lined up with stress data within mobile belts. This suggests that in these weaker mobile belt crust (such as the Namaqua-Natal and Damara-Chobe belts), gravitational collapse is the dominant driver of deformation, which is in line with conclusions that have been made in previous literature. In other regions, deviatoric stress vectors and stress data do not coincide and therefore there are other forces at play. These observations are obviously restricted by limited data coverage; it remains an open question if areas that have increased deviatoric stress due to gravitational collapse, which are also aligned with the orientation of weak zones, will have elevated strain in the long term
Patrol Comique / music by Thomas Hindley; words by Thomas Hindley
Cover: caricature of three African Americans dancing to a banjo tune; Publisher: New York Music Publishing Co. (New York)https://egrove.olemiss.edu/sharris_a/1018/thumbnail.jp
Nesting behaviour influences species-specific gas exchange across avian eggshells
Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between GH2O and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher GH2O than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher GH2O than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the GH2O are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher GH2O to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher GH2O to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours
Colorado River Basin Study Comments--New Mexico Interstate Stream Commission
Comments on the Colorado River Basin Study prepared by the the Western Water Policy Review Advisory Commission
My Pretty Yaller Gal / music by Thomas Vaughn; words by Thomas Vaughn
Cover: beautiful drawing of the Christys Minstrels performing, surrounded by drawings of African American men and women dancing and African American cherubs playing musical instruments; text reads: Christys Melodies as composed and sung by them at their concerts with distinguished success.; Publisher: Jaques and Brother (New York)https://egrove.olemiss.edu/sharris_a/1002/thumbnail.jp
Cost Analysis and Water Conservation Potential of Irrigation Technologies in the Texas Panhandle Water Planning Area
Six irrigation systems are analyzed considering cost and potential water savings. The investment cost of furrow and drip is 260,120, respectively. The cost of quarter mile pivot ranges from 64,000. Per ac-in variable pumping cost ranges 14.86 assuming natural gas price $7.00 per MCF.Irrigation Technology, Ground Water Planning, Texas Panhandle, Water Conservation, Ogallala, Agribusiness, Environmental Economics and Policy, Farm Management, Production Economics, Resource /Energy Economics and Policy,
Designing Urban Policy for a Thriving New Jersey • New Jersey Urban Mayors Association Addresses Policy Priorities
Cities are the Solution, Not the Problem:
While decades of suburban development might suggest otherwise, New Jersey is at its core an urban state. It is dense, covered by one of the largest transit networks in the country and incredibly diverse. Every region of the state has great livable cities, with small, midsized and large cities all represented — most states are lucky to have just a handful. But, for decades, new jersey cities have too often been portrayed as problems that need to be fixed. As the economic and lifestyle preferences of future generations shift back toward cities and away from suburbs, New Jersey must embrace this core strength and invest in it in order to ensure it maintains its enviable place in the national economy
Don\u27t You Remember or Ben Bolt / music by Nelson Kneass; words by Thomas Dunn English
Cover: Photos of Gecko, Svengali and Trilby, Mme. Vinard, Little Billee- Taffy- The Laird, Angele and Zou-Zou; Text reads: as sung by Miss Phyllis Neilson-Terry in the play of TRILBY; Publisher: Dana T. Bennett Co. (New York)https://egrove.olemiss.edu/sharris_f/1012/thumbnail.jp
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