8,069 research outputs found
Strength in Shear of the Thin Curved Sheets of Alclad
This note is on an investigation made to obtain information on the strength of thin curved sheets of Alclad in shear. Designers may utilize this material as a strength member as well as for a covering for the wings and fuselages. A reduction may then be made in the size of the internal strength members. These experiments were undertaken with the object of securing the maximum value from the metal in this respect. The point at which buckling occurs is of primary importance. The buckling shear of a curved thin plate was determined mathematically and also experimentally. The following formula was obtained mathematically: s=K E t/r in which s is the unit shear, K is a constant, E is the modulus of elasticity, t is the thickness of the material, and r is the radius of curvature. The value of K as determined by the experiments was found to be .075. This formula applies only when s is within the elastic limit of the material. The breaking point of the material was obtained in most of the tests as a matter of information and the results are included in this report. The effect of the supporting ribs was determined by varying the number used
Big Bang Nucleosynthesis with Independent Neutrino Distribution Functions
We have performed new Big Bang Nucleosynthesis calculations which employ
arbitrarily-specified, time-dependent neutrino and antineutrino distribution
functions for each of up to four neutrino flavors. We self-consistently couple
these distributions to the thermodynamics, the expansion rate and scale
factor-time/temperature relationship, as well as to all relevant weak,
electromagnetic, and strong nuclear reaction processes in the early universe.
With this approach, we can treat any scenario in which neutrino or antineutrino
spectral distortion might arise. These scenarios might include, for example,
decaying particles, active-sterile neutrino oscillations, and active-active
neutrino oscillations in the presence of significant lepton numbers. Our
calculations allow lepton numbers and sterile neutrinos to be constrained with
observationally-determined primordial helium and deuterium abundances. We have
modified a standard BBN code to perform these calculations and have made it
available to the community.Comment: 9 pages, 5 figure
The Impact of Vein Mechanical Compliance on Arteriovenous Fistula Outcomes
© 2016 Elsevier Inc. Background Arteriovenous fistulae (AVFs) are the preferred access for hemodialysis but suffer a high early failure rate. The aim of this study was to determine how venous distensibility, as measured in vitro, relates to early outcomes of AVF formed with the sampled vein. Methods Ethical approval was obtained for all aspects of this study. During AVF formation a circumferential segment of the target vein was sampled. Mechanical stress testing of the venous segments was undertaken using a dynamic mechanical analyzer, with progressive stress loading at 2 N/min to a maximum of 10 N or until sample disruption. Stress-strain curves were obtained for vein samples and Young's modulus (YM) calculated. Duplex assessment of the fistulae was undertaken at 30 days. Results Thirty patients consented to participate with 29 samples obtained for analysis. Statistical comparison of YM demonstrated no relationship with common cardiovascular risk factors or dialysis status. Subject age greater than 65 was the only patient factor which showed a significant difference in YM (P = 0.05). Furthermore, a negative correlation was confirmed between age and YM (Pearson's r = -0.465, P < 0.05). Nine of the 29 subjects suffered an early AVF failure. Mann-Whitney U testing for differences in distribution reported that YM was significantly higher in those fistulas which failed (P < 0.005). Conclusions Reduced venous compliance appears to result in higher failure rates of AVFs. With the advancement of clinical tools such as speckle tracing ultrasound identification of vessel compliance in vivo may produce valuable additional information for clinicians planning AVF surgery
The Public Trust Doctrine and Natural Law: Emanations Within a Penumbra
In American jurisprudence, the public trust doctrine emerged as a means of protecting certain limited environmental interests, such as coastal waterways and fishing areas, which were preserved for the benefit of the public and distinguished from grants of private ownership. However, modern scholars have called for an expansive application of the public trust doctrine, citing the growing inventory of “changing public needs” in the environmental context, such as the need for improved air and water quality, and the conservation of natural landscape. This Article examines the history and scope of the public trust doctrine to determine how modern resource management fits within the doctrine’s development under the Constitution and common law. Such an examination is incomplete without reviewing the important principles of Natural Law underlying the original doctrine. In the end, the Article concludes that modern trust expansion should be limited within the ancient values of principled economic reasoning
Validating Large Language Models with ReLM
Although large language models (LLMs) have been touted for their ability to
generate natural-sounding text, there are growing concerns around possible
negative effects of LLMs such as data memorization, bias, and inappropriate
language. Unfortunately, the complexity and generation capacities of LLMs make
validating (and correcting) such concerns difficult. In this work, we introduce
ReLM, a system for validating and querying LLMs using standard regular
expressions. ReLM formalizes and enables a broad range of language model
evaluations, reducing complex evaluation rules to simple regular expression
queries. Our results exploring queries surrounding memorization, gender bias,
toxicity, and language understanding show that ReLM achieves up to 15x higher
system efficiency, 2.5x data efficiency, and increased statistical and
prompt-tuning coverage compared to state-of-the-art ad-hoc queries. ReLM offers
a competitive and general baseline for the increasingly important problem of
LLM validation
Polygenic risk for schizophrenia and season of birth within the UK Biobank cohort
Background:
There is strong evidence that people born in winter and in spring have a small increased risk of schizophrenia. As this ‘season of birth’ effect underpins some of the most influential hypotheses concerning potentially modifiable risk exposures, it is important to exclude other possible explanations for the phenomenon.
Methods:
Here we sought to determine whether the season of birth effect reflects gene-environment confounding rather than a pathogenic process indexing environmental exposure. We directly measured, in 136 538 participants from the UK Biobank (UKBB), the burdens of common schizophrenia risk alleles and of copy number variants known to increase the risk for the disorder, and tested whether these were correlated with a season of birth.
Results:
Neither genetic measure was associated with season or month of birth within the UKBB sample.
Conclusions:
As our study was highly powered to detect small effects, we conclude that the season of birth effect in schizophrenia reflects a true pathogenic effect of environmental exposure
The Public Trust Doctrine and Natural Law: Emanations with a Penumbra
In American jurisprudence, the public trust doctrine emerged as a means of protecting certain limited environmental interests, such as coastal waterways and fishing areas, which were preserved for the benefit of the public and distinguished from grants of private ownership. Modern scholars have, however, called for an expansive application of the public trust doctrine - citing, as such, the growing inventory of changing public needs in the environmental context, such as the need for improved air and water quality, and the conservation of natural landscape. This Article examines the history and scope of the public trust doctrine in order to determine how modern resource management fits within the doctrine\u27s development under the Constitution and the Common Law. Such an examination is incomplete without reviewing the foundational Principles of Natural Law underlying the original doctrine. In the end, the Article concludes that modern trust expansion should be limited within the ancient values of principled economic reasoning
The Public Trust Doctrine and Natural Law: Emanations with a Penumbra
In American jurisprudence, the public trust doctrine emerged as a means of protecting certain limited environmental interests, such as coastal waterways and fishing areas, which were preserved for the benefit of the public and distinguished from grants of private ownership. Modern scholars have, however, called for an expansive application of the public trust doctrine - citing, as such, the growing inventory of changing public needs in the environmental context, such as the need for improved air and water quality, and the conservation of natural landscape. This Article examines the history and scope of the public trust doctrine in order to determine how modern resource management fits within the doctrine\u27s development under the Constitution and the Common Law. Such an examination is incomplete without reviewing the foundational Principles of Natural Law underlying the original doctrine. In the end, the Article concludes that modern trust expansion should be limited within the ancient values of principled economic reasoning
Engaging Diverse International Students: Promising Online Teaching Practices
With COVID-19 forcing post-secondary educational institutions to shift to open and online learning, understanding the needs of international students is more important than ever before. This paper will explore the connection between the promising practices for teaching online linguistically and culturally diverse international students with international student satisfaction and perceptions of learning. The study collected data through 15 individual interviews. Data analysis identified the teaching practices and individual characteristics that resonate with international student satisfaction and perceptions of learning. Recommendations for professional practice are discussed, along with potential areas for further research
- …