9,026 research outputs found
Toward a constitutive model for cure dependent modulus of a high temperature epoxy during the cure
A constitutive model, based on Kohlrausch-Williams-Watts (KWW) equations, was
developed to simulate the evolution of the dynamic relaxation modulus during the
cure of a "high temperature' epoxy. The basic assumption of the modelling
methodology proposed is the equivalence of the mechanisms underlying the
evolution of the glass transition temperature and the relaxation time shift
during the cure, leading to the use of a common potential function. This
assumption is verified by the comparison of normalized glass transition data and
principal relaxation times, which have been found to follow a single master
curve. Results show satisfactory agreement between experimental data and model
prediction over the range of chemical conversion considered
The Winner's Choice: Sustainable Economic Strategies for Successful 21st Century Regions
Throughout the second half of the 20th Century, urbanization, new technologies, rapid labor-saving productivity growth in primary industries, and improved highways combined to create large-scale rural-urban functionally integrated regions. These forces have raised the stakes for regions in their pursuit of economic development and growth, making successful regional policy even more important. Changes to the governance structures consistent with the increased interdependence within broad rural-urban regions will improve the region's competitiveness; adopting fad-based approaches and policies aimed at “picking winners” will be less fruitful. Going forward, continuing globalization and environmental sustainability have the potential to fundamentally reshape relative regional attractiveness.Regional Policy, Rural Development
An ontological approach for recovering legacy business content
Legacy Information Systems (LIS) pose a challenge for many organizations. On one hand, LIS are viewed as aging systems needing replacement; on the other hand, years of accumulated business knowledge have made these systems mission-critical. Current approaches however are often criticized for being overtly dependent on technology and ignoring the business knowledge which resides within LIS. In this light, this paper proposes a means of capturing the business knowledge in a technology agnostic manner and transforming it in a way that reaps the benefits of clear semantic expression - this transformation is achieved via the careful use of ontology. The approach called Content Sophistication (CS) aims to provide a model of the business that more closely adheres to the semantics and relationships of objects existing in the real world. The approach is illustrated via an example taken from a case study concerning the renovation of a large financial system and the outcome of the approach results in technology agnostic models that show improvements along several dimensions
Changes in Behavior, Movement, and Home Ranges of Largemouth Bass Following Large-scale Hydrilla Removal in Lake Seminole, Georgia
About 1,200 ha of hydrilla (
Hydrilla verticillata
L.f. Royle)
was eliminated in the Spring Creek embayment of Lake Seminole,
Georgia, using a drip-delivery application of fluridone
(1- methyl-3-phenyl-5-[3-(trifluoromethl) phenyl]-4(1H)-pyridinone)
in 2000 and 2001.
Two groups of 15 and 20 largemouth
bass (Micropterus salmoides Lacepede) were implanted
with 400-day radio tags in February 2000 and 2001 to determine
changes in movement and behavior before and after
hydrilla reduction.(PDF contains 8 pages.
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The effect of elevated hydrostatic pressure on the spectral absorption of deep-sea fish visual pigments
The effect of hydrostatic pressure (0.1-54 MPa, equivalent to pressures experienced by fish from the ocean's surface to depths of ca. 5400 m) on visual pigment absorption spectra was investigated for rod visual pigments extracted from the retinae of 12 species of deep-sea fish of diverse phylogeny and habitat. The wavelength of peak absorption (λmax) was shifted to longer wavelengths by an average of 1.35 nm at 40 MPa (a pressure approximately equivalent to average ocean depth) relative to measurements made at one atmosphere (ca. 0.1 MPa), but with little evidence of a change in absorbance at the λmax. We conclude that previousλ max measurements of deep-sea fish visual pigments, made at a pressure close to 0.1 MPa, provide a good indication ofλ max values at higher pressures when considering the ecology of vision in the deep-sea. Although not affecting the spectral sensitivity of the animal to any important degree, the observed shift inλ max may be of interest in the context of understanding opsin-chromophore interaction and spectral tuning of visual pigments
Georgia Women and Their Struggle for the Vote
Women in the United States gained the right through the 19th Amendment in 1920. Even though women constitutionally had this right, Georgia and Mississippi did not allow women to cast a ballot in the 1920 election. By looking into the most prominent religion in these states, the Southern Baptist church, I explore connections between the beliefs and culture of the South, specifically Georgia, and how these played an important role in the obstacles women faced
Fabrication and optimisation of a fused filament 3D-printed microfluidic platform
A 3D-printed microfluidic device was designed and manufactured using a low cost
($2000)
consumer grade fusion deposition modelling (FDM) 3D printer. FDM printers are not typically
used, or are capable, of producing the fine detailed structures required for microfluidic
fabrication. However, in this work, the optical transparency of the device was improved
through manufacture optimisation to such a point that optical colorimetric assays can be
performed in a 50 µl device. A colorimetric enzymatic cascade assay was optimised using
glucose oxidase and horseradish peroxidase for the oxidative coupling of aminoantipyrine
and chromotropic acid to produce a blue quinoneimine dye with a broad absorbance peaking
at 590 nm for the quantification of glucose in solution. For comparison the assay was run in
standard 96 well plates with a commercial plate reader. The results show the accurate and
reproducible quantification of
0–10 mM glucose solution using a 3D-printed microfluidic
optical device with performance comparable to that of a plate reader assay
Quantitying the Effects of Traffic Calming on Emissions Using on-road Measurement
The objective of this work was to determine the effect of
one form of traffic calming on emissions. Traffic calming
is aimed at reducing average vehicle speeds, especially
in residential neighborhoods, often using physical road
obstructions such as speed bumps, but it also results in
a higher number of acceleration/deceleration events
which in turn yield higher emissions. Testing was
undertaken by driving a warmed-up Euro-1 spark ignition
passenger car over a set of speed bumps on a level
road, and then comparing the emissions output to a noncalmed
level road negotiated smoothly at a similar
average speed. For the emissions measurements, a
novel method was utilized, whereby the vehicle was
fitted with a portable Fourier Transform Infrared (FTIR)
spectrometer, capable of measuring up to 51 different
components in real-time on the road. The results
showed that increases in emissions were much greater
than was previously reported by other researchers using
different techniques. When traffic-calmed results were
compared to a smooth non-calmed road, there were
substantial increases in CO2 (90%), CO (117%), NOx
(195%) and THC (148%). These results form the basis
for a good argument against traffic calming using speed
bumps, especially for aggressive drivers. Slowing traffic
down with speed restrictions enforced by speed
cameras is a more environmentally friendly option
Fatigue delamination behaviour of unidirectional carbon fibre/epoxy laminates reinforced by Z-Fiber® pinnin
-Pin reinforced carbon-fibre epoxy laminates were tested under Mode I and Mode
II conditions, both quasi-statically and in fatigue. Test procedures were
adapted from existing standard or pre-standard tests. Samples containing 2% and
4% areal densities of carbon-fibre Z-pins (0.28mm diameter) were compared with
unpinned laminates. Quasi-static tests under displacement control yielded a
dramatic increase of the apparent delamination resistance. Specimens with 2% pin
density failed in Mode I at loads 170N, equivalent to an apparent GIC of 2kJ/m2.
Fatigue testing under load control showed that the presence of the through-
thickness reinforcement slowed down fatigue delamination propagation
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