1,354,969 research outputs found
Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity
No full text Pages R837–R847: K. A. Engelke, D. F. Doerr, and V. A. Convertino. “Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity.” On p. 837, the author line of the article and abstract and the affiliation line should read as follows: KEITH A. ENGELKE, DONALD F. DOERR, CRAIG G. CRANDALL, AND VICTOR A. CONVERTINO Department of Physiology, University of Florida, Gainesville, Florida 32610; National Aeronautics and Space Administration-Kennedy Space Center, Cape Canaveral, Florida 32899; Department of Physiology, University of North Texas Health Science Center, Ft. Worth, Texas 76107; and Physiology Research Branch, Clinical Science Division, Brooks Air Force Base, Texas 78235 </jats:p
Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity
No full text Pages R837–R847: K. A. Engelke, D. F. Doerr, and V. A. Convertino. “Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity.” On p. 837, the author line of the article and abstract and the affiliation line should read as follows: KEITH A. ENGELKE, DONALD F. DOERR,CRAIG G. CRANDALL, AND VICTOR A. CONVERTINO Department of Physiology, University of Florida, Gainesville, Florida 32610; National Aeronautics and Space Administration-Kennedy Space Center, Cape Canaveral, Florida 32899;Department of Physiology, University of North Texas Health Science Center, Ft. Worth, Texas 76107; and Physiology Research Branch, Clinical Science Division, Brooks Air Force Base, Texas 78235 </jats:p
Gold doping effects on swelling of teflon-like thin films
No full textWe report on the swelling process in gold-doped teflon-like films as a function of metal concentrations. The film thickness variation, measured in low-pressure acetone vapour using an ellipsometric technique, shows, with a range of 0.001-9 mbar, a linear increase in gold content. This trend disappears for metal percentages near to the percolation threshold, an effect which is also evident from the time evolution of the swelling process at constant pressure. PACS: 07.07Df; 81.15Cd; 83.85Gk
A wearable, wireless, long-term recording electrocardiograph, improving the non-invasive diagnosis of cardiac deseases
No full textWe have designed a microcontroller-based medical device for long term recording electrocardiograph (Holter applications) allowing data from up to 12 channels to be stored, thus providing the diagnostic capabilities of the static electrocardiograph (ECG) together with the wearability and the long term registration of the cardiac activity. Thanks to its specific sensors, embedded in a kind elastic band, it is possible to place on the thorax many electrodes without reducing the movement potentials. Moreover, the elastic band is provided with a wireless module (Bluetooth) to send the data to the recorder unit. The storage support is a flash card. Therefore, the new system is miniaturised and results more comfortable than the commonly used taperecorder type portable electrocardiographs. The microcontroller permits to implement a diagnostics algorithm and/or to download real time the data by UDP channel
Detecting fingerprints of landslide drivers: A MaxEnt model
No full textLandslides are important geomorphic events that sculpt river basins by eroding hillslopes and providing sediments to coastal areas. However, landslides are also hazardous events for socio-ecological systems in river basins causing enormous biodiversity, economic, and social impacts. We propose a probabilistic spatially explicit model for the prediction of landslide patterns based on a maximum entropy principle model (MAXENT). The model inputs are the centers of mass of historical landslides and environmental variables at the basin scale. The model has only three parameters requiring calibration: the threshold for the network extraction, the trade-off factor between model complexity and accuracy, and the threshold of landslide susceptibility. The calibration on a subset of observations detects the environmental drivers and their relative importance for landslides. We employ the model in the Arno basin, Italy, selected because of its widespread landslide dynamics and the large availability of landslide observations. The model reproduces the size distribution and location of over 27,500 historical landslides for the Arno basin with an accuracy of 86% obtained from the variable-landslide inference on about 37% of observed landslides. Future landslide patterns are predicted for 17 A1B and A2 rainfall scenarios and for a multimodel ensemble from 2000 to 2100. We show that potential landslide hazard is strongly correlated with variation in the 12 and 48 h rainfall with a return time of 10 years. As the climate gets wetter, the average probability of landslides gets higher which is shown by the landslide size distribution. Hence, the landslide size distribution is a fingerprint of the geomorphic effectiveness of rainfall as a function of climate change. MAXENT is proposed as a parsimonious model for the prediction of landslide patterns with respect to more complex models. The need for very accurately sampled and delineated landslides is lower than for other prediction models. Moreover, the model informs about the drivers of landslides and their relative importance without assumptions on the main triggering factors. This is important to inform monitoring of environmental variables. Our modeling approach can enhance the planning of socio-ecological systems in river basins by improving the accuracy of landslide prediction in space and time. ©2013. American Geophysical Union. All Rights Reserved
A new model of microwave quasi 3D PBG-based devices
No full textWe present a very accurate and fast model of Photonic Band-Gap (PBG) structure characterized by a two-dimensional (2D) periodic change of the refractive index and finite height, therefore named quasi 3D PBG. The model is based on the Floquet-Bloch formalism, we have demonstrated to be particularly suitable to design PBG devices. The model allows both a significantly faster convergence than other more complex numerical models, and a greater accuracy than other approximate models. Simulations run very quickly providing the geometrical dimensions, the forbidden frequency range, the propagation constants, the total field distribution and the modal losses
High reflectivity Bragg reflectors based on a gold nanoparticle/Teflon-like composite material as a new approach to the organic solvent detection
No full textWe report on the properties of a new optical sensing element for organic solvents based on polymeric distributed Bragg reflector (DBR), which can be easily interfaced with optical fibers. The DBR is a periodic stack of alternating Teflon-like and gold nanoparticle/Teflon-like composite layers showing high reflectivity in the optical telecommunication spectral range and sensing proper-ties due to the peculiar absorbing properties of the composite layers. The swelling of the composite layers in presence of organic vapors causes a DBR periodicity change and this results in the shift of the high reflectivity window
Swelling of CFx and CFx(Au) films
No full textThe article reports on the swelling phenomenon, observed in the presence of acetone vapors in undoped and Au doped Teflon-like films. The Au presence enhances the degree of the swelling of the Teflon. Moreover, the metal grains embedded in the insulating matrix are used to detect swelling with an electrical method. A conductance model of metal embedded dielectric materials is used to describe the conductance variations with the polymer volume change. (C) 2000 American Institute of Physics. [S0021-8979(00)05504-3]
A New Approach to Organic Solvent Detection: High reflectivity Bragg reflectors based on a gold nanoparticle/Teflon-like composite materia
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