68 research outputs found
The high-temperature phase of calcium sulfate in relation to SO2 removal by the dry-limestone injection method
FLEXBLE ROBOTIC ACTUATORS
Some embodiments of the disclosed subject matter includes a laminated robotic actuator. The laminated robotic actuator includes a strain-limiting layer comprising a flexible, non extensible material in the form of a sheet or thin film, a flexible inflatable layer in the form of a thin film or sheet in facing relationship with the Strain-limiting layer, wherein the inflatable layer is selectively adhered to the strain-limiting layer, and wherein a portion of an un-adhered region between the strain-limiting layer and the inflatable layer defines a pressurizable channel, and at least one fluid inlet in fluid communication with the pressurizable channel. The first flexible non-extensible material has a stiffness that is greater than the stiffness of the second flexible elastomeric material and the flexible elastomer is non-extensible under actuation conditions
Racismo: Uma dura realidade brasileira
O racismo é o preconceito associado as raças, as etnias ou caracterÃsticasfÃsicas, sendo que, esse tipo de discriminação caracteriza-se principalmentepelo fato de haver superioriedade em relação ao outro, seja por cor de pele,ou, até mesmo motivados por circunstâncias culturais. O objetivo deste artigoé apontar fatos, entendimentos e acontecimentos ao longo da história, quede certa forma desencadearam o racismo. Diante disso, como esse processoafeta e influencia diretamente a vida dos negros na sociedade brasileiraatual? Para tanto, tomou-se como fonte de pesquisa livros de autores, os quaispreocuparam-se com a situação dos negros no Brasil bem como sua imagemperante a sociedade, além de sites, pesquisas e legislações inerentes aoassunto. Os resultados agregarão o conhecimento necessário para queentenda-se todo o processo ocorrido, desde os anos de escravidão até os diasatuais, e, demonstrar que, o negro continua inserido marginalmente nocenário social
Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout
The enormous stiffness and low density of graphene make it an ideal material
for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and
electrical readout of monolayer graphene resonators, and test their response to
changes in mass and temperature. The devices show resonances in the MHz range.
The strong dependence of the resonant frequency on applied gate voltage can be
fit to a membrane model, which yields the mass density and built-in strain.
Upon removal and addition of mass, we observe changes in both the density and
the strain, indicating that adsorbates impart tension to the graphene. Upon
cooling, the frequency increases; the shift rate can be used to measure the
unusual negative thermal expansion coefficient of graphene. The quality factor
increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing
many of the basic attributes of monolayer graphene resonators, these studies
lay the groundwork for applications, including high-sensitivity mass detectors
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Paper-Based, Capacitive Touch Pads
Metallized paper is patterned to create touch pads of arrayed buttons that are sensitive to contact with both bare and gloved fingers. The paper-based keypad detects the change in capacitance associated with the touch of a finger to one of its buttons. Mounted on an alarmed cardboard box, the keypad requires the appropriate sequence of touches to disarm the system.Chemistry and Chemical Biolog
Palynological evidence for environmental and climatic change in the lower Guadiana valley, Portugal, during the last 13 000 years
Pollen analysis of a 48 m AMS radiocarbon-dated sediment sequence from the Guadiana estuary provides the first record of Lateglacial and Holocene vegetation history in the Algarve province of Portugal. This paper focuses on the record of terrestrial pollen taxa, which document a series of forest expansions and declines during the period 13 000 cal. BP to 1600 cal. BP and provide insights into climate evolution in southwestern Iberia. The main vegetation phases identified in the Guadiana valley are (1) Lateglacial interstadial (Allerød) forest with Quercus and Pinus under a temperate, moist, continental climate;
(2) a Younger Dryas forest decline (Quercus) and expansion of pinewoods, xeric scrub and open ground habitats (with Juniperus, Artemisia, Ephedra distachya type, Centaurea scabiosa type) under arid and cold conditions; (3) an early Holocene forest/scrub/open-ground vegetation mosaic developing under a warm, dry and continental climate; (4) a maximum of Quercus forest and thermomediterranean evergreen taxa (Olea, Phillyrea, Pistacia) reflecting a warm, moist oceanic climate between c. 9000 cal. BP and c. 5000 cal. BP; and (5) the expansion of shrublands with Cistaceae and Ericaceae under a drier climatic regime and increasing anthropogenic activity since c. 5000 cal. BP. Holocene episodes of maximum climatic aridity are identified in the record of xerophytic taxa (Juniperus, Artemisia, Ephedra distachya type) centred around 10 200 cal. BP, 7800 cal. BP, 4800 cal. BP, 3100 cal. BP and 1700 cal. BP. Regional comparisons suggest a correlation of arid phases across southern Iberia and northwest Africa, which can be related to abrupt North Atlantic coolings (Bond events).Research Council studentship for WJF (NERC/S/A/2001/06109), with the support of Trinity College and the Department of Geography, University of Cambridg
A multicenter assessment of interreader reliability of LI-RADS version 2018 for MRI and CT
Background: Various limitations have impacted research evaluating reader agreement
for Liver Imaging-Reporting and Data System (LI-RADS).
Purpose: To assess reader agreement of LI-RADS in an international multi-center, multireader setting using scrollable images.
Materials and Methods: This retrospective study used de-identified clinical multiphase
CT and MRI examinations and reports with at least one untreated observation from six
institutions and three countries; only qualifying examinations were submitted.
Examination dates were October 2017 – August 2018 at the coordinating center. One
untreated observation per examination was randomly selected using observation
identifiers, and its clinically assigned features were extracted from the report. The
corresponding LI-RADS v2018 category was computed as a re-scored clinical read. Each
examination was randomly assigned to two of 43 research readers who independently
scored the observation. Agreement for an ordinal modified four-category LI-RADS scale
(LR-1/2, LR-3, LR-4, LR-5/M/tumor in vein) was computed using intra-class correlation
coefficients (ICC). Agreement was also computed for dichotomized malignancy (LR-4/LR5/LR-M/LR-tumor in vein), LR-5, and LR-M. Agreement was compared between researchversus-research reads and research-versus-clinical reads.
Results: 484 patients (mean age, 62 years ±10 [SD]; 156 women; 93 CT, 391 MRI) were
included. ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68
(95% CI: 0.62, 0.74), 0.63 (95% CI: 0.56, 0.71), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95%
CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher
than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68
vs. 0.62, P = .03) and for dichotomized malignancy (ICC, 0.63 vs. 0.53, P = .005), but not
for LR-5 (P = .14) or LR-M (P = .94).
Conclusion: There was moderate agreement for Liver Imaging-Reporting and Data
System v2018 overall. For some comparisons, research-versus-research reader
agreement was higher than research-versus-clinical reader agreement, indicating
differences between the clinical and research environments that warrant further study
Determination of Surface Area by Surfactant Adsorption in Aqueous Suspension—I. Dodecylamine Hydrochloride*
FLEXBLE ROBOTIC ACTUATORS
Some embodiments of the disclosed subject matter includes a laminated robotic actuator. The laminated robotic actuator includes a strain-limiting layer comprising a flexible, non extensible material in the form of a sheet or thin film, a flexible inflatable layer in the form of a thin film or sheet in facing relationship with the Strain-limiting layer, wherein the inflatable layer is selectively adhered to the strain-limiting layer, and wherein a portion of an un-adhered region between the strain-limiting layer and the inflatable layer defines a pressurizable channel, and at least one fluid inlet in fluid communication with the pressurizable channel. The first flexible non-extensible material has a stiffness that is greater than the stiffness of the second flexible elastomeric material and the flexible elastomer is non-extensible under actuation conditions
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