633,499 research outputs found
Rock Identification
This hands-on activity covers the basics of rock identification. After a brief discussion of the terms 'rock' and 'mineral', students will study the characteristics and classifications of the three major rock groups (igneous, metamorphic, and sedimentary). Using an online tutorial to test their knowledge and to learn more about rocks, they will identify 10 different specimens, record their observations, and provide a name for each. Educational levels: Undergraduate lower division, High school
Development and test of a Microwave Ice Accretion Measurement Instrument (MIAMI)
The development of an ice accretion measurement instrument that is a highly sensitive, accurate, rugged and reliable microprocessor controlled device using low level microwave energy for non-instrusive real time measurement and recording of ice growth history, including ice thickness and accretion rate is discussed. Data is displayed and recorded digitally. New experimental data is presented, obtained with the instrument, which demonstrates its ability to measure ice growth on a two-dimensional airfoil. The device is suitable for aircraft icing protection. It may be mounted flush, non-intrusively, on any part of an aircraft skin including rotor blades and engine inlets
Revealing structure-function relationships in functional flow networks via persistent homology
Complex networks encountered in biology are often characterized by
significant structural diversity. Whether it be differences in the
three-dimensional structure of allosteric proteins, or the variation among the
micro-scale structures of organisms' cerebral vasculature systems, identifying
relationships between structure and function often poses a difficult challenge.
Here we showcase an approach to characterizing structure-function relationships
in complex networks applied in the context of flow networks tuned to perform
specific functions. Using persistent homology, we analyze flow networks tuned
to perform complex multifunctional tasks, answering the question of how local
changes in the network structure coordinate to create functionality at at the
scale of the entire network. We find that the response of such networks encodes
hidden topological features - sectors of uniform pressure - that are not
apparent in the underlying network architectures, Regardless of differences in
local connectivity, these features provide a universal topological description
for all networks that perform these types of functions. We show that these
features correlate strongly with the tuned response, providing a clear
topological relationship between structure and function and structural insight
into the limits of multifunctionality.Comment: 22 pages (double column), 12 figure
Whoops - The Imminent Reconciliation of U.S. Securities Laws with International Comity after Morrison v. National Australia Bank and the Drafting Error in the Dodd-Frank Act
The article contends that the Dodd-Frank Act and the case, Morrison v. National Australia Bank, restrict the extraterritorial reach of U.S. fraud laws to private rights of action involving domestic transactions of U.S. securities. The author notes that the U.S. legal jurisdiction is governed by the policy of minimal interference and respect for sovereignties and by the principle of comity. He states that this position will help establish a cooperative regulatory effort across global markets
The Impact of Social Support on Diet Quality in Stroke Survivors
Stroke is a leading cause of death and disability in the United States, and nearly 25% of strokes are repeat events. Secondary prevention strategies are needed to reduce the disabling sequelae of recurrences. Dietary modification to include more fruits, vegetables, and polyunsaturated fats is a promising tactic. If stroke leads to disability, patients may not be able to cook or grocery shop for themselves. Thus, one factor that may influence diet quality is social support, but its effect on post-stroke diet has not been assessed. In this cross-sectional study, we will examine the association between social support and diet quality among stroke survivors. We will measure participants’ perceived social support and diet quality, while analyzing contributory behaviors, like cooking and shopping. We anticipate that patients with greater social support will have a higher quality diet. By establishing this relationship, interventions that increase social support may be utilized in secondary prevention
New Advances in Forming Functional Ceramics for Micro Devices
Micro electromechanical systems (MEMS) are finding uses in an increasing number of diverse applications. Currently the fabrication techniques used to produce such MEMS devices are primarily based on 2-D processing of thin films. The challenges faced by producing more complex structures (e.g. high aspect ratio, spans, and multi-material structures) require the development of new processing techniques. Potential solutions to these challenges based on low temperature processing of functional ceramics, selective chemical patterning, and micro-moulding are presented to show that it is possible to create complex functional ceramic structures which incorporate non-ceramic conducting and support structures. The capabilities of both techniques are compared and the relative advantages of each explored
X-ray and UV spectroscopy of Galactic diffuse hot gas along the LMC X--3 sight line
We present Suzaku spectra of X-ray emission in the fields just off the LMC
X-3 sight line. OVII, OVIII, and NeIX emission lines are clearly detected,
suggesting the presence of an optically thin thermal plasma with an average
temperature of 2.4E6. This temperature is significantly higher than that
inferred from existing X-ray absorption line data obtained with Chandra grating
observations of LMC X-3, strongly suggesting that the gas is not isothermal. We
then jointly analyze these data to characterize the spatial and temperature
distributions of the gas. Assuming a vertical exponential Galactic disk model,
we estimate the gas temperature and density at the Galactic plane and their
scale heights as 3.6(2.9, 4.7)E6 K and 1.4(0.3, 3.4)E-3 cm^{-3} and 1.4(0.2,
5.2) kpc and kpc, respectively. This characterization can
account for all the \ovi line absorption, as observed in a FUSE spectrum of LMC
X-3, but only predicts less than one tenth of the OVI line emission intensity
typically detected at high Galactic latitudes. The bulk of the OVI emission
most likely arises at interfaces between cool and hot gases.Comment: 10 pages, 7 figures, 3 tables, accepted for publication in ApJ, 200
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