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Wireless structural health monitoring of bridges: present and future
Neil A. Hoult,Paul R.A. Fidler,Peter G. Hill,Campbell R. Middleton 국제구조공학회 2010 Smart Structures and Systems, An International Jou Vol.6 No.3
Internationally the load carrying capacity of bridges is decreasing due to material deterioration while at the same time increasing live loads mean that they are often exposed to stresses for which they were not designed. However there are limited resources available to ensure that these bridges are fit for purpose, meaning that new approaches to bridge maintenance are required that optimize both their service lives as well as maintenance costs. Wireless sensor networks (WSNs) provide a tool that could support such an optimized maintenance program. In many situations WSNs have advantages over conventional wired monitoring systems in terms of installation time and cost. In order to evaluate the potential of these systems two WSNs were installed starting in July 2007 on the Humber Bridge and on a nearby approach bridge. As part of a corrosion prevention strategy, a relative humidity and temperature monitoring system was installed in the north anchorage chambers of the main suspension bridge where the main cables of the bridge are anchored into the foundation. This system allows the Bridgemaster to check whether the maximum relative humidity threshold, above which corrosion of the steel wires might occur, is not crossed. A second WSN which monitors aspects of deterioration on a reinforced concrete bridge located on the approach to the main suspension bridge was also installed. Though both systems have provided useful data to the owners, there are still challenges that must be overcome in terms of monitoring corrosion of steel, measuring live loading and data management before WSNs can become an effective tool for bridge managers.
Wireless structural health monitoring of bridges: present and future
Hoult, Neil A.,Fidler, Paul R.A.,Hill, Peter G.,Middleton, Campbell R. Techno-Press 2010 Smart Structures and Systems, An International Jou Vol.6 No.3
Internationally the load carrying capacity of bridges is decreasing due to material deterioration while at the same time increasing live loads mean that they are often exposed to stresses for which they were not designed. However there are limited resources available to ensure that these bridges are fit for purpose, meaning that new approaches to bridge maintenance are required that optimize both their service lives as well as maintenance costs. Wireless sensor networks (WSNs) provide a tool that could support such an optimized maintenance program. In many situations WSNs have advantages over conventional wired monitoring systems in terms of installation time and cost. In order to evaluate the potential of these systems two WSNs were installed starting in July 2007 on the Humber Bridge and on a nearby approach bridge. As part of a corrosion prevention strategy, a relative humidity and temperature monitoring system was installed in the north anchorage chambers of the main suspension bridge where the main cables of the bridge are anchored into the foundation. This system allows the Bridgemaster to check whether the maximum relative humidity threshold, above which corrosion of the steel wires might occur, is not crossed. A second WSN which monitors aspects of deterioration on a reinforced concrete bridge located on the approach to the main suspension bridge was also installed. Though both systems have provided useful data to the owners, there are still challenges that must be overcome in terms of monitoring corrosion of steel, measuring live loading and data management before WSNs can become an effective tool for bridge managers.
THE 2014 ALMA LONG BASELINE CAMPAIGN: OBSERVATIONS OF ASTEROID 3 JUNO AT 60 KILOMETER RESOLUTION
Hunter, T. R.,Kneissl, R.,Moullet, A.,Brogan, C. L.,Fomalont, E. B.,Vlahakis, C.,Asaki, Y.,Barkats, D.,Dent, W. R. F.,Hills, R. E.,Hirota, A.,Hodge, J. A.,Impellizzeri, C. M. V.,Liuzzo, E.,Lucas, R.,M IOP Publishing 2015 ASTROPHYSICAL JOURNAL LETTERS - Vol.808 No.1
<P>We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum images of the asteroid 3 Juno obtained with an angular resolution of 0 ''.042 (60 km at 1.97 AU). The data were obtained over a single 4.4 hr interval, which covers 60% of the 7.2 hr rotation period, approximately centered on local transit. A sequence of 10 consecutive images reveals continuous changes in the asteroid's profile and apparent shape, in good agreement with the sky projection of the three-dimensional model of the Database of Asteroid Models from Inversion Techniques. We measure a geometric mean diameter of 259 +/- 4 km, in good agreement with past estimates from a variety of techniques and wavelengths. Due to the viewing angle and inclination of the rotational pole, the southern hemisphere dominates all of the images. The median peak brightness temperature is 215 +/- 13 K, while the median over the whole surface is 197 +/- 15 K. With the unprecedented resolution of ALMA, we find that the brightness temperature varies across the surface with higher values correlated to the subsolar point and afternoon areas and lower values beyond the evening terminator. The dominance of the subsolar point is accentuated in the final four images, suggesting a reduction in the thermal inertia of the regolith at the corresponding longitudes, which are possibly correlated to the location of the putative large impact crater. These results demonstrate ALMA's potential to resolve thermal emission from the surface of main belt asteroids and to measure accurately their position, geometric shape, rotational period, and soil characteristics.</P>
Lunavat, Taral R.,Cheng, Lesley,Einarsdottir, Berglind O.,Olofsson Bagge, Roger,Veppil Muralidharan, Somsundar,Sharples, Robyn A.,Lasser, Cecilia,Gho, Yong Song,Hill, Andrew F.,Nilsson, Jonas A.,Lotva National Academy of Sciences 2017 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.114 No.29
<P>The BRAF inhibitors vemurafenib and dabrafenib can be used to treat patients with metastatic melanomas harboring BRAF(V600) mutations. Initial antitumoral responses are often seen, but drug-resistant clones with reactivation of the MEK-ERK pathway soon appear. Recently, the secretome of tumor-derived extracellular vesicles (EVs) has been ascribed important functions in cancers. To elucidate the possible functions of EVs in BRAF-mutant melanoma, we determined the RNA content of the EVs, including apoptotic bodies, microvesicles, and exosomes, released from such cancer cells after vemurafenib treatment. We found that vemurafenib significantly increased the total RNA and protein content of the released EVs and caused significant changes in the RNA profiles. RNA sequencing and quantitative PCR show that cells and EVs from vemurafenib-treated cell cultures and tumor tissues harvested from cell-derived and patient-derived xenografts harbor unique miRNAs, especially increased expression of miR-211-5p. Mechanistically, the expression of miR-211-5p as a result of BRAF inhibition was induced by increased expression of MITF that regulates the TRPM1 gene resulting in activation of the survival pathway. In addition, transfection of miR-211 in melanoma cells reduced the sensitivity to vemurafenib treatment, whereas miR-211-5p inhibition in a vemurafenib resistant cell line affected the proliferation negatively. Taken together, our results show that vemurafenib treatment induces miR-211-5p up-regulation in melanoma cells both in vitro and in vivo, as well as in subsets of EVs, suggesting that EVs may provide a tool to understand malignant melanoma progression.</P>
The State-of-Play of Anomalous Microwave Emission (AME) research
Dickinson, Clive,Ali-Haï,moud, Y.,Barr, A.,Battistelli, E.S.,Bell, A.,Bernstein, L.,Casassus, S.,Cleary, K.,Draine, B.T.,Gé,nova-Santos, R.,Harper, S.E.,Hensley, B.,Hill-Valler, J.,Hoang, Th Elsevier 2018 New astronomy reviews Vol.80 No.-
<P><B>Abstract</B></P> <P>Anomalous Microwave Emission (AME) is a component of diffuse Galactic radiation observed at frequencies in the range ≈ 10–60 GHz. AME was first detected in 1996 and recognised as an additional component of emission in 1997. Since then, AME has been observed by a range of experiments and in a variety of environments. AME is spatially correlated with far-IR thermal dust emission but cannot be explained by synchrotron or free–free emission mechanisms, and is far in excess of the emission contributed by thermal dust emission with the power-law opacity consistent with the observed emission at sub-mm wavelengths. Polarization observations have shown that AME is very weakly polarized ( ≲ 1 %). The most natural explanation for AME is rotational emission from ultra-small dust grains (“spinning dust”), first postulated in 1957. Magnetic dipole radiation from thermal fluctuations in the magnetization of magnetic grain materials may also be contributing to the AME, particularly at higher frequencies ( ≳ 50 GHz). AME is also an important foreground for Cosmic Microwave Background analyses. This paper presents a review and the current state-of-play in AME research, which was discussed in an AME workshop held at ESTEC, The Netherlands, June 2016.</P>
THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW
Partnership, ALMA,Fomalont, E. B.,Vlahakis, C.,Corder, S.,Remijan, A.,Barkats, D.,Lucas, R.,Hunter, T. R.,Brogan, C. L.,Asaki, Y.,Matsushita, S.,Dent, W. R. F.,Hills, R. E.,Phillips, N.,Richards, A. M IOP Publishing 2015 ASTROPHYSICAL JOURNAL LETTERS - Vol.808 No.1
Materials Genome in Action: Identifying the Performance Limits of Physical Hydrogen Storage
Thornton, Aaron W.,Simon, Cory M.,Kim, Jihan,Kwon, Ohmin,Deeg, Kathryn S.,Konstas, Kristina,Pas, Steven J.,Hill, Matthew R.,Winkler, David A.,Haranczyk, Maciej,Smit, Berend American Chemical Society 2017 Chemistry of materials Vol.29 No.7
<P/><P>The Materials Genome is in action: the molecular codes for millions of materials have been sequenced, predictive models have been developed, and now the challenge of hydrogen storage is targeted. Renewably generated hydrogen is an attractive transportation fuel with zero carbon emissions, but its storage remains a significant challenge. Nanoporous adsorbents have shown promising physical adsorption of hydrogen approaching targeted capacities, but the scope of studies has remained limited. Here the Nanoporous Materials Genome, containing over 850 000 materials, is analyzed with a variety of computational tools to explore the limits of hydrogen storage. Optimal features that maximize net capacity at room temperature include pore sizes of around 6 Å and void fractions of 0.1, while at cryogenic temperatures pore sizes of 10 Å and void fractions of 0.5 are optimal. Our top candidates are found to be commercially attractive as “cryo-adsorbents”, with promising storage capacities at 77 K and 100 bar with 30% enhancement to 40 g/L, a promising alternative to liquefaction at 20 K and compression at 700 bar.</P>
Woo, W.,An, G.B.,Kingston, E.J.,DeWald, A.T.,Smith, D.J.,Hill, M.R. Elsevier Science 2013 ACTA MATERIALIA Vol.61 No.10
Spatial variations of residual stresses were determined through the thickness of 70mm thick ferritic steel welds created using low (1.7kJmm<SUP>-1</SUP>) and high (56kJmm<SUP>-1</SUP>) heat inputs. Two-dimensional maps of the longitudinal residual stress were obtained by using the contour method. The results were compared to neutron diffraction measurements through the thickness at different locations from the weld centerline. The deep hole drilling technique was utilized to confirm the maximum stress locations and magnitudes. The results show that significant tensile stresses (~90% of yield strength) occur along the weld centerline near the top surface (within 10% of the depth) in the low heat-input specimen. Meanwhile, in the high heat-input weld, the peak stress moved towards the heat-affected zone at a depth of ~40% of the thickness. Finally, the influence of residual stresses on potential fracture behavior of the welded joints is discussed.