Promoting Bicycle Commuter Safety, Research Report 11-08

We present an overview of the risks associated with cycling to emphasize the need for safety. We focus on the application of frameworks from social psychology to education, one of the 5 Es—engineering, education, enforcement, encouragement, and evaluation. We use the structure of the 5 Es to organize information with particular attention to engineering and education in the literature review. Engineering is essential because the infrastructure is vital to protecting cyclists. Education is emphasized since the central focus of the report is safety

Influence of Landscape Structure and Human Modifications on Insect Biomass and Bat Foraging Activity in an Urban Landscape

Urban landscapes are often located in biologically diverse, productive regions. As such, urbanization may have dramatic consequences for this diversity, largely due to changes in the structure and function of urban communities. We examined the influence of landscape productivity (indexed by geology), housing density and vegetation clearing on the spatial distribution of nocturnal insect biomass and the foraging activity of insectivorous bats in the urban landscape of Sydney, Australia. Nocturnal insect biomass (g) and bat foraging activity were sampled from 113 sites representing backyard, open space, bushland and riparian landscape elements, across urban, suburban and vegetated landscapes within 60 km of Sydney's Central Business District. We found that insect biomass was at least an order of magnitude greater within suburban landscapes in bushland and backyard elements located on the most fertile shale influenced geologies (both p<0.001) compared to nutrient poor sandstone landscapes. Similarly, the feeding activity of bats was greatest in bushland, and riparian elements within suburbs on fertile geologies (p = 0.039). Regression tree analysis indicated that the same three variables explained the major proportion of the variation in insect biomass and bat foraging activity. These were ambient temperature (positive), housing density (negative) and the percent of fertile shale geologies (positive) in the landscape; however variation in insect biomass did not directly explain bat foraging activity. We suggest that prey may be unavailable to bats in highly urbanized areas if these areas are avoided by many species, suggesting that reduced feeding activity may reflect under-use of urban habitats by bats. Restoration activities to improve ecological function and maintain the activity of a diversity of bat species should focus on maintaining and restoring bushland and riparian habitat, particularly in areas with fertile geology as these were key bat foraging habitats

A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines are considered for their potential to yield a new, more active injection scheme for a rocket engine. Inkjets are found to be unable to pump at sufficient pressures, and have possibly dangerous failure modes. Active injection is found to be feasible if high pressure drop along the injector plate is used. A conceptual design is presented and its basic behavior assessed

Fast Hydrothermal Liquefaction of Nannochloropsis sp. To Produce Biocrude

We investigated the fast hydrothermal liquefaction of green marine alga Nannochloropsis sp. at batch reaction times of 1, 3, and 5 min and set-point temperatures of 300–600 °C. We also performed conventional liquefaction for 60 min at the same temperatures. These experiments cover the broadest range of reaction conditions yet reported for algae liquefaction. The biocrude yield obtained for 1 min reaction times, which was only long enough to heat the reactor from room temperature to about half of the set-point temperature (in °C), increased with an increasing set-point temperature to 66 ± 11 wt % (dry and ash-free basis) at a set-point temperature of 600 °C. The biocrude obtained at this condition contains 84% of the carbon and 91 ± 14% of the heating value present in the dry algae feedstock. This biocrude yield and corresponding energy recovery are the highest reported for liquefaction of this alga. For a reaction time of 1 min, as the set-point temperature increases, light biocrude (e.g., hexane solubles) makes up less of the total biocrude. The biocrudes produced by fast liquefaction have carbon contents and higher heating values similar to biocrudes from the traditional isothermal liquefaction process, which involves treatment for tens of minutes. These results indicate that biocrudes of similar quality may be produced in higher yields and in a fraction of the time previously thought necessary. Such a decrease in the reaction time would greatly reduce the reactor volume required for continuous biocrude production, subsequently reducing the capital costs of such a process. We also show that the reaction ordinate is a useful parameter for interpreting results from algae liquefaction performed at different temperatures and reaction times

Hydrothermal Liquefaction of Bacteria and Yeast Monocultures

We hydrothermally treated monocultures of Escherichia coli, Pseudomonas putida, Bacillus subtilis, and Saccharomyces cerevisiae at isothermal (350 °C for 60 min) and fast (rapid heating for 1 min) liquefaction conditions. Fast hydrothermal liquefaction (HTL) of P. putida and S. cerevisiae produced the highest biocrude yields of 47 ± 13 and 48 ± 9 wt %, respectively. Biocrudes generated via fast HTL were always richer in O and N and had a higher yield of hexane-insoluble products. Isothermal HTL of all microorganisms always produced an aqueous phase richer in NH₃ than the aqueous phase from fast HTL. Up to 62 ± 9% of the chemical energy in the biomass could be recovered in the biocrude product fraction. These results demonstrate the feasibility of applying HTL to produce high yields of biocrude from bacteria and yeast that are high in protein [>80 wt %, dry and ash-free basis (daf)] and low in lipids (<3 wt %, daf). Such microorganisms could serve as a renewable feedstock for biofuels

Novel way of measuring the fracture toughness of leaves and other thin films using a single inclined razor blade

10.1111/j.1469-8137.2007.02302.xNew Phytologist1773830-837NEPH