Automated topology optimisation of hybrid electric vehicle powertrains

Ing, A. H., & McPhee, J. (2015). Automated topology optimisation of hybrid electric vehicle powertrains. International Journal of Electric and Hybrid Vehicles, 7(4), 342. Final version published by Inderscience Publishers, and available at: https://doi.org/10.1504/IJEHV.2015.074671Gasoline and electric powertrain components can be connected in numerous configurations to create hybrid powertrains. Owing to the exponential increase of permutations as the number of components increases, a framework to determine the best possible powertrain configuration that minimises fuel consumption was developed. This framework uses enumeration to discover all powertrains, the Graph-Theoretic Method to generate system equations, dynamic programming to evaluate fuel consumption and generate an objective score, and Pattern Search to optimise the sizing of each component. A multi-stage screening process was used to reduce computation time. Parallel and powersplit-like topologies with additional discrete gearboxes were found to be the most efficient. The best performing topology is a powersplit hybrid type: a discrete gearbox connected to the final drive, with the output gear of the planetary carrier and electric motor in parallel.The project is funded by Toyota, Maplesoft, and NSERC

Anomalous sea-ice reduction in the Eurasian Basin of the Arctic Ocean during summer 2010

Special Issue: The Second International Symposium on the Arctic Research (ISAR - 2

The Formation of the Double Pulsar PSR J0737-3039A/B

Recent timing observations of the double pulsar J0737-3039A/B have shown that its transverse velocity is extremely low, only 10 km/s, and nearly in the Plane of the Galaxy. With this new information, we rigorously re-examine the history and formation of this system, determining estimates of the pre-supernova companion mass, supernova kick and misalignment angle between the pre- and post-supernova orbital planes. We find that the progenitor to the recently formed `B' pulsar was probably less than 2 MSun, lending credence to suggestions that this object may not have formed in a normal supernova involving the collapse of an iron core. At the same time, the supernova kick was likely non-zero. A comparison to the history of the double-neutron-star binary B1534+12 suggests a range of possible parameters for the progenitors of these systems, which should be taken into account in future binary population syntheses and in predictions of the rate and spatial distribution of short gamma-ray burst events.Comment: To appear in MNRAS Letters. Title typo fix only; no change to pape

EFFECTS OF REARING ENVIRONMENT ON BEHAVIOR OF CAPTIVE-REARED WHOOPING CRANES

Whooping cranes (Grus americana) are 1 of the most endangered bird species in North America. In 1999 the Whooping Crane Eastern Partnership was formed to establish a migratory population of whooping cranes in eastern North America. These efforts have been extremely successful in terms of adult survival but reproductive success post-release has been low. One hypothesis developed to explain such low reproductive success is that captive-rearing techniques fail to prepare the birds to be effective parents. Captive-reared whooping cranes at the U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, Maryland, are either reared by humans in crane costumes or by surrogate conspecific adults. We hypothesized that the 2 captive-rearing techniques differentially shaped chick behavior. To test this, we measured chick behavior daily as well as when chicks were placed in novel environments. Twice per day, every day, 5-minute focal observations were conducted on each chick. When they were introduced to a novel environment, 10-minute focal observations were conducted within 1 hour of introduction. The 2 groups differed significantly: costume-reared chicks were, on average, more stationary than parent-reared birds. These data suggest that future research should be done to determine whether or not rearing technique could have longterm effects on post-release behavior and reproductive success

An optimal gear-shifting strategy for heavy trucks with trade-off study between trip time and fuel economy

© Inderscience Enterprises Ltd. The original source of publication is available at InderScience. Zhao, X. x., Ing, A. h., Azad, N. l., & McPhee, J. (2015). An optimal gear-shifting strategy for heavy trucks with trade-off study between trip time and fuel economy. International Journal of Heavy Vehicle Systems, 22(4), 356–374. https://doi.org/10.1504/IJHVS.2015.073205We show how the fuel efficiency of heavy mining trucks can be improved by optimising the gear-shifting strategy. Using characteristic tests of the diesel engine, a high-fidelity model of a mining truck was built in MapleSim and a consistent low-order model was developed in Matlab. Dynamic programming was used to optimise the low-order model of the specialised off-road 30-tonne truck over a fixed route in a mining area. There were two competing objectives: fuel use and trip time, which were combined in a single objective function using weighting coefficients. A Pareto curve was created to analyse the effect of the weights on the fuel use and trip time. Applying the control strategy obtained from dynamic programming to the high-fidelity model, it is estimated that 40,000 L of fuel can be saved annually for a mine that produces 110 kilotonnes of coal per day

Comparison of MRI and DXA to measure muscle size and age-related atrophy in thigh muscles.

OBJECTIVES Magnetic resonance imaging (MRI) and dual-energy x-ray absorptiometry (DXA) were used to examine the thigh lean mass in young and old men and women. METHODS A whole-body DXA scan was used to estimate thigh lean mass in young (20 men; 22.4±3.1y; 18 women; 22.1±2.0y) and older adults (25 men; 72.3±4.9y; 28 women; 72.0±4.5y). Thigh lean mass determined with a thigh scan on the DXA or full thigh MRI scans were compared. RESULTS Although the thigh lean mass quantified by DXA and MRI in young and older participants were correlated (R(2)=0.88; p<0.001) the magnitude of the differences in thigh lean mass between young and old was smaller with DXA than MRI (old vs. young men 79.5±13.1% and 73.4±11.2%; old vs. young women 88.6±11.8% and 79.4±12.3%, respectively). Detailed analysis of MRI revealed 30% smaller quadriceps muscles in the older than young individuals, while the other thigh muscles were only 18% smaller. CONCLUSIONS DXA underestimates the age-related loss of thigh muscle mass in comparison to MRI. The quadriceps muscles were more susceptible to age-related atrophy compared with other thigh muscles

The Costs of an Outreach Intervention for Low-Income Women With Abnormal Pap Smears

INTRODUCTION: Follow-up among women who have had an abnormal Papanicolaou (Pap) smear is often poor in public hospitals that serve women at increased risk for cervical cancer. This randomized controlled trial evaluated and compared the total cost and cost per follow-up of a tailored outreach intervention plus usual care with the total cost and cost per follow-up of usual care alone. METHODS: Women with an abnormal Pap smear (n = 348) receiving care at Alameda County Medical Center (Alameda County, California) were randomized to intervention or usual care. The intervention used trained community health advisors to complement the clinic's protocol for usual care. We assessed the costs of the intervention and the cost per follow-up within 6 months of the abnormal Pap smear test result. RESULTS: The intervention increased the rate of 6-month follow-up by 29 percentage points, and the incremental cost per follow-up was $959 (2005 dollars). The cost per follow-up varied by the severity of the abnormality. The cost per follow-up for the most severe abnormality (high-grade squamous intraepithelial lesion) was$681, while the cost per follow-up for less severe abnormalities was higher. CONCLUSION: In a health care system in which many women fail to get follow-up care for an abnormal Pap smear, outreach workers were more effective than usual care (mail or telephone reminders) at increasing follow-up rates. The results suggest that outreach workers should manage their effort based on the degree of abnormality; most effort should be placed on women with the most severe abnormality (high-grade squamous intraepithelial lesion)

Rapid change in freshwater content of the Arctic Ocean

Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 36 (2009): L10602, doi:10.1029/2009GL037525.The dramatic reduction in minimum Arctic sea ice extent in recent years has been accompanied by surprising changes in the thermohaline structure of the Arctic Ocean, with potentially important impact on convection in the North Atlantic and the meridional overturning circulation of the world ocean. Extensive aerial hydrographic surveys carried out in March–April, 2008, indicate major shifts in the amount and distribution of fresh-water content (FWC) when compared with winter climatological values, including substantial freshening on the Pacific side of the Lomonosov Ridge. Measurements in the Canada and Makarov Basins suggest that total FWC there has increased by as much as 8,500 cubic kilometers in the area surveyed, effecting significant changes in the sea-surface dynamic topography, with an increase of about 75% in steric level difference from the Canada to Eurasian Basins, and a major shift in both surface geostrophic currents and freshwater transport in the Beaufort Gyre.Support for this work was provided by the National Science Foundation Office of Polar Programs under grants 0352687, 0634097 (MGM); 0633979, 0806115 (AP); 0633885, 0352754, 0634226 (MAS, JHM); and 06341222 (MBA)

Cardiovascular Risk Factors and Knowledge of Symptoms Among Vietnamese Americans

BACKGROUND: There are few population-based studies of cardiovascular risk factors, knowledge, and related behaviors among Vietnamese Americans. OBJECTIVE: To describe cardiovascular risk factors, knowledge, and related behaviors among Vietnamese Americans and compare the results to non-Hispanic whites. DESIGN: Comparison of data from two populationbased, cross-sectional telephone surveys

Upper -extremity musculoskeletal symptoms and physical health related quality of life among women employed in poultry processing and other low -wage jobs in Northeastern North Carolina

The purpose of this study was to evaluate the association between upper-extremity musculoskeletal symptoms (MS) and diminished physical health related quality of life (PHRQoL) in a population of women, mostly African-American working in poultry processing and other low-wage jobs in rural northeastern North Carolina