663,756 research outputs found
Superconducting switch permits measurement of small voltages at cryogenic temperatures
Dual-coil, superconducting, on-off switch measures small, thermoelectrically generated voltages produced by thermocouples in a liquid helium bath. Placed in a shunt configuration between the thermocouple and the measuring device, the measuring device sees the sum of the voltage to be measured and the spurious thermoelectric voltages
A MEMS viscometer for unadulterated human blood
The design and theoretical modelling of an oscillating micro-mechanical-viscometer designed for the measurement of whole unadulterated human blood, is described. The proposed device utilises the dependence of the squeeze-film damping ratio on properties of the surrounding fluid to measure fluid viscosity using an oscillating plate structure. The optimum geometrical configuration for the device structure has been investigated and a methodology for defining the optimum configuration of the micro-mechanical sensor identified. This is then applied to calculate the predicted noise equivalent viscosity change . It was found that the device performance is limited by electronic noise within the detection circuitry rather than thermal mechanical noise. An electronic noise limited measurement resolution of , is predicted for measurement over a shear range of , at a measurement bandwidth of . The linearity of response of the micro-mechanical-viscometer is considered and the device is predicted to provide a linear measurement response
Performance Analysis of Unsupervised LTE Device-to-Device (D2D) Communication
Cellular network technology based device-to-device communication attracts
increasing attention for use cases such as the control of autonomous vehicles
on the ground and in the air. LTE provides device-to-device communication
options, however, the configuration options are manifold (leading to 150+
possible combinations) and therefore the ideal combination of parameters is
hard to find. Depending on the use case, either throughput, reliability or
latency constraints may be the primary concern of the service provider. In this
work we analyze the impact of different configuration settings of unsupervised
LTE device-to-device (sidelink) communication on the system performance. Using
a simulative approach we vary the length of the PSCCH period and the number of
PSCCH subframes and determine the impact of different combinations of those
parameters on the resulting latency, reliability and the interarrival times of
the received packets. Furthermore we examine the system limitations by a
scalability analysis. In this context, we propose a modified HARQ process to
mitigate scalability constraints. Our results show that the proposed reduced
HARQ retransmission probability can increase the system performance regarding
latency and interarrival times as well as the packet transmission reliability
for higher channel utilization
Heat transfer device
An improved heat transfer device particularly suited for use as an evaporator plate in a diffusion cloud chamber. The device is characterized by a pair of mutually spaced heat transfer plates, each being of a planar configuration, having a pair of opposed surfaces defining therebetween a heat pipe chamber. Within the heat pipe chamber, in contiguous relation with the pair of opposed surfaces, there is disposed a pair of heat pipe wicks supported in a mutually spaced relationship by a foraminous spacer of a planar configuration. A wick including a foraminous layer is contiguously related to the external surfaces of the heat transfer plates for uniformly wetting these surfaces
SECY APP: self configuration and easy management for software defined smart homes
In this paper we address configuration and management issues of smart homes. Current platforms requires the user to deal with several management inconvenience problems, such as increasing devices, operating between devices, and using new devices. From a user perspective, system configuration and management are major issues: ordinary consumers want to use systems performing minimal configuration. To address this issue, we propose a platform, composed of a web application and Software Defined Network (SDN). While the user interacts with an easy-to-use interface on a smart device, the app automatically generates and installs SDN rules. Our platform, besides facilitating configuration and management, results more efficient --- up to 4 times faster --- and reliable --- able to operate even in case of no connection with the cloud --- than current solutions
Large magnetoresistance using hybrid spin filter devices
A magnetic "spin filter" tunnel barrier, sandwiched between a non-magnetic
metal and a magnetic metal, is used to create a new magnetoresistive tunnel
device, somewhat analogous to an optical polarizer-analyzer configuration. The
resistance of these trilayer structures depends on the relative magnetization
orientation of the spin filter and the ferromagnetic electrode. The spin
filtering in this configuration yields a previously unobserved
magnetoresistance effect, exceeding 100%.Comment: 3.5 pages, 3 figures, submitted to Appl. Phys. Let
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