562 research outputs found
Durability and mode-I fracture of fiber-reinforced plastic (FRP)/wood interface bond
Fiber-reinforced plastic (FRP) composites are being used for reinforcement of wood, concrete, and steel. The objective of this study is to develop a qualification program to evaluate the service performance and fracture of composite/wood bonded interfaces. The proposed method is used for two types of FRP wood interface: FRP strips (plates) bonded to wood (used commercially for glulam timber beams) and wood cores wrapped with FRP by filament winding (being investigated for reinforced railroad wood crossties and utility wood poles). First, the service performance and durability of FRP-wood interface bond is evaluated using a modified ASTM delamination test. Second, the apparent shear strengths of interface bond under both dry and wet conditions are obtained from modified ASTM block shear tests. Finally, a simplified design of an innovative contoured double cantilever beam (CDCB) specimen is developed, and this specimen is used to evaluate Mode-I fracture of interface bonds; interface fracture toughness data are experimentally obtained for dry, wet and 3-cycle aging conditions. (Abstract shortened by UMI.)
The Effect of Use and Access on Citations
It has been shown (S. Lawrence, 2001, Nature, 411, 521) that journal articles
which have been posted without charge on the internet are more heavily cited
than those which have not been. Using data from the NASA Astrophysics Data
System (ads.harvard.edu) and from the ArXiv e-print archive at Cornell
University (arXiv.org) we examine the causes of this effect.Comment: Accepted for publication in Information Processing & Management,
special issue on scientometric
A Chandra Search for Coronal X Rays from the Cool White Dwarf GD 356
We report observations with the Chandra X-ray Observatory of the single,
cool, magnetic white dwarf GD 356. For consistent comparison with other X-ray
observations of single white dwarfs, we also re-analyzed archival ROSAT data
for GD 356 (GJ 1205), G 99-47 (GR 290 = V1201 Ori), GD 90, G 195-19 (EG250 = GJ
339.1), and WD 2316+123 and archival Chandra data for LHS 1038 (GJ 1004) and GD
358 (V777 Her). Our Chandra observation detected no X rays from GD 356, setting
the most restrictive upper limit to the X-ray luminosity from any cool white
dwarf -- L_{X} < 6.0 x 10^{25} ergs/s, at 99.7% confidence, for a 1-keV
thermal-bremsstrahlung spectrum. The corresponding limit to the electron
density is n_{0} < 4.4 x 10^{11} cm^{-3}. Our re-analysis of the archival data
confirmed the non-detections reported by the original investigators. We discuss
the implications of our and prior observations on models for coronal emission
from white dwarfs. For magnetic white dwarfs, we emphasize the more stringent
constraints imposed by cyclotron radiation. In addition, we describe (in an
appendix) a statistical methodology for detecting a source and for constraining
the strength of a source, which applies even when the number of source or
background events is small.Comment: 27 pages, 4 figures, submitted to the Astrophysical Journa
Pneumococcal colonisation is an asymptomatic event in healthy adults using an experimental human colonisation model
Introduction
Pneumococcal colonisation is regarded as a pre-requisite for developing pneumococcal disease. In children previous studies have reported pneumococcal colonisation to be a symptomatic event and described a relationship between symptom severity/frequency and colonisation density. The evidence for this in adults is lacking in the literature. This study uses the experimental human pneumococcal challenge (EHPC) model to explore whether pneumococcal colonisation is a symptomatic event in healthy adults.
Methods
Healthy participants aged 18â50 were recruited and inoculated intra-nasally with either Streptococcus pneumoniae (serotypes 6B, 23F) or saline as a control. Respiratory viral swabs were obtained prior to inoculation. Nasal and non-nasal symptoms were then assessed using a modified Likert score between 1 (no symptoms) to 7 (cannot function). The rate of symptoms reported between the two groups was compared and a correlation analysis performed.
Results
Data from 54 participants were analysed. 46 were inoculated with S. pneumoniae (29 with serotype 6B, 17 with serotype 23F) and 8 received saline (control). In total, 14 became experimentally colonised (30.4%), all of which were inoculated with serotype 6B. There was no statistically significant difference in nasal (p = 0.45) or non-nasal symptoms (p = 0.28) between the inoculation group and the control group. In those who were colonised there was no direct correlation between colonisation density and symptom severity. In the 22% (12/52) who were co-colonised, with pneumococcus and respiratory viruses, there was no statistical difference in either nasal or non-nasal symptoms (virus positive p = 0.74 and virus negative p = 1.0).
Conclusion
Pneumococcal colonisation using the EHPC model is asymptomatic in healthy adults, regardless of pneumococcal density or viral co-colonisation
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Preservation of Our Astronomical Heritage: State of the Profession White Paper for Astro2020
We argue that it is essential that the Astro2020 survey of the present state of American astronomy and the recommendations for the next decade address the issue of ensuring preservation of, and making more discoverable and accessible, the fieldâs rich legacy materials. These include both archived observations of scientific value and items of historical importance. Much of this heritage likely will be lost if action is not taken in the next decade. It is proposed that the decadal plan include recommendations on (1) compiling a list of historic sites and development of models for their preservation, (2) carrying out a comprehensive inventory of astronomyâs archival material, and (3) digitizing, with web-based publication, those photographs and papers judged to have the most value for scientific and historical investigations. The estimated cost for an example project on plate preservation is a one-time investment of less than $10 million over ten years plus the typical on-going costs to maintain and manage a medium-sized database
Robust Egocentric Photo-realistic Facial Expression Transfer for Virtual Reality
Social presence, the feeling of being there with a real person, will fuel the
next generation of communication systems driven by digital humans in virtual
reality (VR). The best 3D video-realistic VR avatars that minimize the uncanny
effect rely on person-specific (PS) models. However, these PS models are
time-consuming to build and are typically trained with limited data
variability, which results in poor generalization and robustness. Major sources
of variability that affects the accuracy of facial expression transfer
algorithms include using different VR headsets (e.g., camera configuration,
slop of the headset), facial appearance changes over time (e.g., beard,
make-up), and environmental factors (e.g., lighting, backgrounds). This is a
major drawback for the scalability of these models in VR. This paper makes
progress in overcoming these limitations by proposing an end-to-end
multi-identity architecture (MIA) trained with specialized augmentation
strategies. MIA drives the shape component of the avatar from three cameras in
the VR headset (two eyes, one mouth), in untrained subjects, using minimal
personalized information (i.e., neutral 3D mesh shape). Similarly, if the PS
texture decoder is available, MIA is able to drive the full avatar
(shape+texture) robustly outperforming PS models in challenging scenarios. Our
key contribution to improve robustness and generalization, is that our method
implicitly decouples, in an unsupervised manner, the facial expression from
nuisance factors (e.g., headset, environment, facial appearance). We
demonstrate the superior performance and robustness of the proposed method
versus state-of-the-art PS approaches in a variety of experiments
Defining the genetic susceptibility to cervical neoplasia - a genome-wide association study
Funding: MAB was funded by a National Health and Medical Research Council (Australia) Senior Principal Research Fellowship. Support was also received from the Australian Cancer Research Foundation. JL holds a Tier 1 Canada Research Chair in Human Genome Epidemiology. The Seattle study was supported by the following grants: NIH, National Cancer Institute grants P01CA042792 and R01CA112512. Cervical Health Study (from which the NSW component was obtained) was funded by NHMRC Grant 387701, and CCNSW core grant. The Montreal study was funded by the Canadian Institutes of Health Research (grant MOP-42532) and sample processing was funded by the Reseau FRQS SIDA-MI. The Swedish Research Council, the Swedish Foundation for Strategic Research, the ALF/LUA research grant in Gothenburg and UmeĂ„, the Lundberg Foundation, the Torsten and Ragnar Soderbergâs Foundation, the Novo Nordisk Foundation, and the European Commission grant HEALTH-F2-2008-201865-GEFOS, BBMRI.se, the Swedish Society of Medicine, the KempeFoundation (JCK-1021), the Medical Faculty of UmeĂ„ University, the County Council of Vasterbotten (Spjutspetsanslag VLL:159:33-2007). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewedPublisher PDFPublisher PD
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