4,633 research outputs found
The effect of heat treatment and test parameters on the aqueous stress corrosion cracking of D6AC steel
The crack growth behavior of D6AC steel as a function of stress intensity, stress and corrosion history and test technique, under sustained load in natural seawater, 3.3 percent NaCl solution, distilled water, and high humidity air was investigated. Reported investigations of D6AC were considered with emphasis on thermal treatment, specimen configuration, fracture toughness, crack-growth rates, initiation period, threshold, and the extension of corrosion fatigue data to sustained load conditions. Stress history effects were found to be most important in that they controlled incubation period, initial crack growth rates, and apparent threshold
Electrical conductivity cell and method for fabricating the same
A flask having a threaded neck and a cap adapted for threaded engagement on the neck are used. A laminated disc between the cap and the neck forms a gas tight seal and the cap has a central opening that exposes a medial region of the disc. Piercing the disc through the opening are two electrodes, the inner ends of which contact the sample within the flask and the outer ends of which can be connected to test equipment. Cylindric glass tubes are fitted over the external portion of the electrodes to provide physical support and silicone rubber or a similar material serves to retain the glass cylinders in place and form a gas tight seal between the cylinders and the electrodes. Shrinkable tubing is shrunk over the glass tubes to afford further mechanical support and sealing. A final relatively large diameter shrinkable tube is shrunk over both electrodes and their associated glass cylinders. The support and sealing means for the electrodes is confined to a limited portion of the medial region of the disc so that the remainder of such region can be punctured by a hollow needle to introduce a test sample within the flask
International Trade Effects And The Decline In The Union Sector
Since the 1960s, U.S. manufacturing has undergone tremendous changes due to international trade and technological convergence. Not all industry sectors have fared equally. High-tech sectors (e.g., aircraft and computers) have maintained a high degree of international competitiveness as evidenced by an increasing export share. Common technology sectors (e.g., autos and steel), conversely, have not as they have experienced a declining export share and increasing import competition. High-tech industries typically employ highly skilled, human capital intensive workers while common technology industries are characterized by unskilled labor with lower levels of human capital. International trade theory suggests that the more skilled high-tech labor force should receive relatively higher wages than the relatively less skilled common-tech sector under international competition. Secondly, the level of unionization in a given industry may or may not have adverse impacts on international competitiveness. Also, unions tend to oppose adoption of new technologies, drive highly educated workers into the nonunion sector, and may adopt end game strategies to maximize current wages at the expense of future economic viability. Consequently, international trade and high-tech industries may have a negative effect on union participation rates. The issues addressed include the effect of international trade and technological comparative advantage on union and nonunion wage levels, and the indirect effect of trade and technology on union participation. This study uses the National Longitudinal Survey (NLS) panel data set. The empirical results suggest that international trade effects wage levels, and high-tech industries appear to have a higher wage distribution after controlling for labor market, product market, and individual characteristics. Furthermore, trade and technology appear to be negatively related to the degree of union density. The secondary effect tends to lower union and nonunion wages, primarily for less-skilled workers. It also may partially explain the trend of increasing income inequality for less-skilled workers and the opposition of unions to free-trade policies.(JEL J3, J5
Restorative Practices: Graduate Students\u27 Perspectives Seen through a Transformative Learning Lens: A Dissertation
This dissertation explores students’ learning experiences in a newly accredited graduate school focused on Restorative Practices Theory, which enables people to restore and build community collectively. This exploration was conducted using a Transformative Adult Learning Theory lens in order to understand graduate students’ perspectives regarding their learning experiences. Data were gathered using a qualitative and quantitative mixed method concurrent nested strategy design (Creswell, 2003). Fifteen total participants at multiple phases of graduate study made up the sample, including both current students and alumni. Participants were involved in a semi-structured interview, submitted a previously completed course reflection paper and gave permission to access previously completed Course Improvement Surveys. Through the triangulation of collected data this dissertation describes students’ perceptions of their formal learning experiences and found that: restorative processes cultivated emotional and relational learning, participants learned and implemented restorative concepts, classroom environment mattered to participants, and evidence of transformative learning was present in the students reported experiences
NOON states from cavity-enhanced down-conversion: High quality and super-resolution
Indistinguishable photons play a key role in quantum optical information
technologies. We characterize the output of an ultra-bright photon-pair source
using multi-particle tomography [R. B. A. Adamson et al., Phys. Rev. Lett. 98,
043601 (2007)] and separately identify coherent errors, decoherence, and
distinguishability. We demonstrate generation of high-quality indistinguishable
pairs and polarization NOON states with 99% fidelity to an ideal NOON state.
Using a NOON state we perform a super-resolving angular measurement with 90%
visibility.Comment: 4 Pages, 5 figure
Controlled nanochannel lattice formation utilizing prepatterned substrates
Solid substrates can be endued with self-organized regular stripe patterns of
nanoscopic lengthscale by Langmuir-Blodgett transfer of organic monolayers.
Here we consider the effect of periodically prepatterned substrates on this
process of pattern formation. It leads to a time periodic forcing of the
oscillatory behavior at the meniscus. Utilizing higher order synchronization
with this forcing, complex periodic patterns of predefined wavelength can be
created. The dependence of the synchronization on the amplitude and the
wavelength of the wetting contrast is investigated in one and two spatial
dimensions and the resulting patterns are discussed. Furthermore, the effect of
prepatterned substrates on the pattern selection process is investigated
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