The Once and Future Great Lakes Country: An Ecological History

Review of: The Once and Future Great Lakes Country: An Ecological History, by John L. Riley. Rural, Wildland, and Resource Studies Series

The Once and Future Great Lakes Country: An Ecological History

Review of: "The Once and Future Great Lakes Country: An Ecological History," by John L. Riley. Rural, Wildland, and Resource Studies Series

Green investment strategies: a positive force in cities

Deterioration of urban neighborhoods is known to induce out migration, but how well do public investments to reverse decline actually work? To evaluate Philadelphia’s greening investment, researchers measured property buyers’ willingness to pay more—and found that greening works.Community development

Transformation of Char Carbon During Bubbling Fluidized Bed Gasification of Biomass

This study focuses on the fate of carbon in the char generated by devolatilization of biomass during fluidized bed gasification. A carbon balance model was developed to distinguish between char transformed to carbon-bearing gases and its comminution and elutriation as fine char during gasification. The model accurately predicts the transient accumulation of char carbon in the reactor. Experiments revealed steady state reactor char carbon loadings were achieved after multiple hours of gasification. The model formed the basis of an experimental methodology that assesses the transformation of char carbon based on collection of elutriated solids from the reactor and assessment of the steady state char carbon loading in the reactor. Experiments were performed to distinguish the relative contributions of chemical reaction and physical comminution toward conversion of char to gaseous and solid products. The effects of equivalence ratio, gasification temperature, superficial gas velocity, biomass particle size, and the addition of steam on the partitioning of char carbon between gaseous and solid products during gasification of ground seed corn in a bubbling fluidized bed were investigated. This study revealed that char conversion during gasification of biomass was limited by elutriation of fine char particles arising from fragmentation or attrition of primary char product. Additionally, increased chemical reaction of char to form gases was usually accompanied by increased elutriation of fine char, which suggests that chemical reaction increased the porosity of the char and its susceptibility to fragmentation and attrition. Finally, decreasing superficial gas velocity, increasing equivalence ratio, and decreasing particle size led to increased carbon conversion, while increasing temperature and steam concentration in the reactor had negligible effect

Thermal history of the early Miocene Waitemata Basin and adjacent Waipapa Group, North Island, New Zealand

Apatite fission track (AFT) and vitrinite reflectance (VR) data for early Miocene outcrops from the Waitemata Basin reveal that the basin sequence was subjected to shallow burial before denudation. AFT results suggest that the total sediment thickness within the basin was <=1 km and maximum paleotemperatures during burial never exceeded c. 60deg.C. Statistical analyses of the detrital AFT ages distinguish four dominant sources of sediment supply: contemporaneous volcanism; metagreywacke rocks of the Waipapa Group; the Northland Allochthon; and an unidentified source south of the basin. The apatite and zircon fission track results from the Waipapa Group rocks (Gondwana Terrane) adjacent to the basin suggest two discrete phases of accelerated cooling: the first during the early Cretaceous (c. 117 Ma) and the second during the mid Cretaceous (c. 84 Ma). These events probably reflect key stages in the tectonic development of the New Zealand microcontinent during the Cretaceous period, the earlier event being related to the climax of compressional deformation (Rangitata Orogeny) and the latter to extensional tectonism associated with the opening of the Tasman Sea. Waipapa Group rocks now exposed at the surface cooled from maximum paleotemperatures of c. 250deg.C at an estimated rate of c. 180-36deg.C/m.y., involving substantial denudation

Estimation of surface area and volume of a nematode from morphometric data

Nematode volume and surface area are usually based on the inappropriate assumption that the animal is cylindrical. While nematodes are approximately circular in cross section, the radius varies longitudinally. We use standard morphometric data to obtain improved estimates of volume and surface area based on (i) a geometrical approach and (ii) a Bezier representation of the nematode. These new estimators require only the morphometric data available from Cobb's ratios, but if fewer coordinates are available the geometric approach reduces to the standard estimates. Consequently, these new estimators are better than the standard alternatives

Longitudinal surveys of Australian youth : active citizenship and the secondary school experience : community participation rates of Australian youth

LSAY is a research program that follows young Australians as they move through secondary school, into further education or training, and into the labour market and adult life. This website provides access to the electronic full text versions of LSAY research reports, from 1996 to present. <br /

Extraction-free, direct determination of caffeine in microliter volumes of beverages by thermal desorption-gas chromatography mass spectrometry

An extraction-free method requiring microliter (μL) volumes has been developed for the determination of caffeine in beverages.Using a pyrolysis-gas chromatography mass spectrometry system, the conditions required for the direct thermal desorption-gaschromatography mass spectrometry (TD-GC/MS) determination of caffeine were optimised. A 5 μL aliquot was introduced to thethermal desorption unit, dried, and thermally desorbed to the GC/MS. *e response was linear over the range 10 to 500 μg/mL(R2 = 0.996). *e theoretical limit of detection (3 σ) was 0.456 μg/mL. No interferences were recorded from endogenous beveragecomponents or from commonly occurring drugs, such as nicotine, ibuprofen, and paracetamol. Replicate caffeine determinationson fortified latte style white coffee and Pepsi Max® gave mean recoveries of 93.4% (%CV = 4.1%) and 95.0% (%CV = 0.98%),respectively. Good agreement was also obtained with the stated values of caffeine for an energy drink and for Coca-Cola®. *esedata suggest that the method holds promise for the determination of caffeine in such samples