33,623 research outputs found
Roadmap on semiconductor-cell biointerfaces.
This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world
Is There Light at the Ends of the Tunnel? Wireless Sensor Networks for Adaptive Lighting in Road Tunnels
Existing deployments of wireless sensor networks (WSNs) are often conceived as stand-alone monitoring tools. In this paper, we report instead on a deployment where the WSN is a key component of a closed-loop control system for adaptive lighting in operational road tunnels. WSN nodes along the tunnel walls report light readings to a control station, which closes the loop by setting the intensity of lamps to match a legislated curve. The ability to match dynamically the lighting levels to the actual environmental conditions improves the tunnel safety and reduces its power consumption. The use of WSNs in a closed-loop system, combined with the real-world, harsh setting of operational road tunnels, induces tighter requirements on the quality and timeliness of sensed data, as well as on the reliability and lifetime of the network. In this work, we test to what extent mainstream WSN technology meets these challenges, using a dedicated design that however relies on wellestablished techniques. The paper describes the hw/sw architecture we devised by focusing on the WSN component, and analyzes its performance through experiments in a real, operational tunnel
Instrumentation for sensing moisture content of material using a transient thermal pulse
Instrumentation is developed for sensing moisture content of material using a transient thermal pulse and is comprised of a sensing probe having a sensing element in the form of a ribbon excited by a constant current pulse to increase the temperature, and therefore the resistance, of the ribbon linearly. Moisture in web material limits the increase of temperature during the pulse in proportion to the moisture content. This increase in temperature produces a proportional increase in resistivity which is measured with a Wheatsone bridge as a change in voltage displayed by a measurement display unit. The probe is glued in a shallow groove of a lucite bar and connected to copper pins embedded in the bar
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Measuring Electric Charge and Molecular Coverage on Electrode Surface from Transient Induced Molecular Electronic Signal (TIMES).
Charge density and molecular coverage on the surface of electrode play major roles in the science and technology of surface chemistry and biochemical sensing. However, there has been no easy and direct method to characterize these quantities. By extending the method of Transient Induced Molecular Electronic Signal (TIMES) which we have used to measure molecular interactions, we are able to quantify the amount of charge in the double layers at the solution/electrode interface for different buffer strengths, buffer types, and pH values. Most uniquely, such capabilities can be applied to study surface coverage of immobilized molecules. As an example, we have measured the surface coverage for thiol-modified single-strand deoxyribonucleic acid (ssDNA) as anchored probe and 6-Mercapto-1-hexanol (MCH) as blocking agent on the platinum surface. Through these experiments, we demonstrate that TIMES offers a simple and accurate method to quantify surface charge and coverage of molecules on a metal surface, as an enabling tool for studies of surface properties and surface functionalization for biochemical sensing and reactions
Future of smart cardiovascular implants
Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition
The High Energy Telescope on EXIST
The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed next
generation multi-wavelength survey mission. The primary instrument is a High
Energy telescope (HET) that conducts the deepest survey for Gamma-ray Bursts
(GRBs), obscured-accreting and dormant Supermassive Black Holes and Transients
of all varieties for immediate followup studies by the two secondary
instruments: a Soft X-ray Imager (SXI) and an Optical/Infrared Telescope (IRT).
EXIST will explore the early Universe using high redshift GRBs as cosmic probes
and survey black holes on all scales. The HET is a coded aperture telescope
employing a large array of imaging CZT detectors (4.5 m^2, 0.6 mm pixel) and a
hybrid Tungsten mask. We review the current HET concept which follows an
intensive design revision by the HET imaging working group and the recent
engineering studies in the Instrument and Mission Design Lab at the Goddard
Space Flight Center. The HET will locate GRBs and transients quickly (<10-30
sec) and accurately (< 20") for rapid (< 1-3 min) onboard followup soft X-ray
and optical/IR (0.3-2.2 micron) imaging and spectroscopy. The broad energy band
(5-600 keV) and the wide field of view (~90 deg x 70 deg at 10% coding
fraction) are optimal for capturing GRBs, obscured AGNs and rare transients.
The continuous scan of the entire sky every 3 hours will establish a
finely-sampled long-term history of many X-ray sources, opening up new
possibilities for variability studies.Comment: 10 pages, 6 figures, 3 tables, SPIE conference proceedings (UV,
X-ray, and Gamma-Ray Space Instrumentation for Astronomy XVI, 7435-9
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