1,056 research outputs found
A Comparative Analysis Of Green Roof Designs Including Depth Of Media, Drainage Layer Materials, And Pollution Control Media
Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different green roof designs including depth of media, an additional pollution control layer beneath the growth media, and different drainage layer materials. Furthermore, a comparison study is performed on the cistern water quality, direct filtrate water quality, and control roof filtrate water quality. Results show that phosphorus concentrations are lower when using a pollution control layer beneath the growing media, and that evapotransporation and filtrate factor values from the 4-inch media and the 8-inch media are approximately equal for one year. However, hydrograph results show that the 8-inch media design has a lower peak flow and longer attenuation when compared to the 4-inch media design for a single storm event. Furthermore, the drainage layer material has no significant effect on the water quality or hydrology of the green roof discharge. The data also emphasizes the importance and effectiveness of the incorporation of a cistern into a green roof system
Examining The Continuity Of The Long-Lived (Triassic-Recent) Freshwater Mussel Genus Diplodon (family Hyriidae)
This paper addresses the question of how strong the record of contiguity is for the 250 million-year-old Diplodon lineage by examining the geographic and temporal distribution of fossil specimens identified as Diplodon.
Diplodon (Mollusca, Bivalvia, Unionoida, Hyriidae) has a fossil record extending back to the Middle Triassic (Anisian Stage). The known distribution of fossil specimens identified as this genus occurs on four continents (North America, South America, Australasia, and Antarctica). The place of origin and pathways of range expansion through time are far from well explained. Both fossil and extant freshwater mussel taxa are subject to evolutionary and phenotypic morphological convergence, which has resulted in problems of identification and classification.
Because of the tendency of freshwater mussels to converge toward similar morphologies, project methods focused on metadata rather than the specimens themselves. The biostratigraphic ranges of specimens identified as Diplodon were determined in order to target temporal and geographic gaps in the fossil record. Without a comprehensive taxonomic review, only Diplodon taxa in current use from documented specimen locations are used in this report. This project has produced paleolandscape maps of the regions that have recorded Diplodon specimens. These first-generation maps were used to qualitatively analyze possible avenues of taxon dispersion through time. Production of paleolandscape maps was based on a new methodology that can be expanded for with other taxa on a global scale.
The evolutionary lineage represented by use of the name Diplodon is not well supported. Geographic and temporal data suggest that hard-part morphology has been an incorrect basis for classification. Five distinct temporal gaps of at least a single geologic stage in duration were identified in the Diplodon fossil record between 245 Ma (beginning of the Anisian Stage) and 5 Ma (end of the Messinian Stage). These gaps occurred during the 1) Middle Triassic (Ladinian); 2) Late TriassicâMiddle Jurassic (NorianâBathonian); 3) Early Cretaceous (BerriasianâBarremian), 4) late Early CretaceousâLate Cretaceous (AlbianâCenomanian); and 5) early-middle Eocene (YpresianâBartonian) intervals.
Gaps in the record are supported by 1) the pattern of additional specimens that lack as much temporal resolution; 2) geographic distances and paleolandscape features between known fossil localities; and 3) the species names applied to these specimens. Continued study of genus-group morphological characters of fossil specimens and molecular analyses of living specimens is necessary to create a Diplodon diagnosis that takes into account morphologic variation (including convergence with other taxa) and the geologic age and geographic relationships among specimens
Making and doing: critical and cross-disciplinary engagement within interdisciplinary iSchools
Introduction:
Like many iSchools, the Faculty of Information at the University of Toronto integrates a variety of
disciplinary fields (LIS, Records Management, Information Systems and Design, Critical and Cultural
theory, Policy, Technology Studies, etc.) and a diversity of institutional foci (libraries, archives, museums,
universities, government, corporate contexts, etc.) Such diversity is both an asset and a challenge for the
Faculty as we seek to provide professional and academic training for our masters and PhD students and
look to engage in collaborative work among faculty members. Importantly, the types of skills and
experiences that we collectively bring to bear and the kinds of issues and questions addressed by faculty
and graduate students transgress more than just standard disciplinary barriers. In order to address the
important social, cultural, and political questions posed by the continuing transformation of information
practices, the boundary between material and technical work and reflexive, critical, social scholarship must
be bridged. This is a crucial challenge for iSchools ??? how do we bring various perspectives, interests, and
backgrounds to bear while staying connected through an emphasis on common theoretical concerns
Climatic and eustatic controls on the development of a Late Triassic source rock in the Jameson Land Basin, East Greenland
This work was undertaken as part of the continuing work of CASP in East Greenland. The sponsoring companies are thanked for their continued support of this work. Help in the field by T. Kinnaird and useful discussions with A. Whitham are gratefully acknowledged. The reviews of L. Clemmensen and an anonymous reviewer, and the input from S. Jones led to improvements to the original paper.Peer reviewedPostprin
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A Comprehensive Analysis on the Healthcare Systems in Latin America
This comprehensive report summarizes and analyzes the current state of healthcare in Latin America, specifically in the countries of Mexico, Brazil, the Northern Triangle (El Salvador, Guatemala, and Honduras), the Andean Region (Ecuador, Peru, and Bolivia) and the Rioplatense Region (Uruguay, and Argentina). Each country's healthcare system is examined in depth, in terms of health infrastructure, the healthcare providing industry, and the effects of healthcare on the countries' respective populations.Mosser, Michael W.International Relations and Global Studie
Discovery of a ~5 day characteristic timescale in the Kepler power spectrum of Zw 229-15
We present time series analyses of the full Kepler dataset of Zw 229-15. This
Kepler light curve --- with a baseline greater than three years, composed of
virtually continuous, evenly sampled 30-minute measurements --- is
unprecedented in its quality and precision. We utilize two methods of power
spectral analysis to investigate the optical variability and search for
evidence of a bend frequency associated with a characteristic optical
variability timescale. Each method yields similar results. The first
interpolates across data gaps to use the standard Fourier periodogram. The
second, using the CARMA-based time-domain modeling technique of Kelly et al.
(2014), does not need evenly-sampled data. Both methods find excess power at
high frequencies that may be due to Kepler instrumental effects. More
importantly both also show strong bends ({\Delta}{\alpha} ~ 2) at timescales of
~5 days, a feature similar to those seen in the X-ray PSDs of AGN but never
before in the optical. This observed ~5 day timescale may be associated with
one of several physical processes potentially responsible for the variability.
A plausible association could be made with light-crossing, dynamical or thermal
timescales, depending on the assumed value of the accretion disk size and on
unobserved disk parameters such as {\alpha} and H/R. This timescale is not
consistent with the viscous timescale, which would be years in a ~10^7 Solar
mass AGN such as Zw 229-15. However there must be a second bend on long (>~1
year) timescales, and that feature could be associated with the viscous
timescale.Comment: 10 pages, 5 figures, 1 table. To appear in the Astrophysical Journal,
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