Search results for " head"
showing 10 items of 503 documents
Low-cost underwater navigation systems by multi-pressure measurements and AHRS data
2017
This paper deals with accurate navigation for underwater remotely operated vehicles. A feasibility study for a multi-pressure device to be mounted on an ROV is presented. The device can provide accurate estimates of a ROV orientation and angular speed. It is based on the well-known total pressure principle, also used in a Pitot tube, and allows reconstruction of static and dynamic pressures, which in turn provide good estimates of the ROV's orientation and rotational speed, respectively. An appealing feature of the proposed device is its ability to provide accurate estimates even for low-speed movements.
Skull and Encephalic Injuries Caused by Beach Umbrellas: Case Reports and Review of Literature
2016
This study reports two unusual cases of skull-encephalic injuries in bathers that were caused by violent impacts with beach umbrellas. The first case concerned a 36-year-old man who, while lying on a sun bed, was struck on his left temple by a beach umbrella, which had been blown away by a gust of wind. The second case concerned a six-year-old child who was struck on the right temporal region while he was playing on the sand. Both subjects died. A review of the literature was carried out. Various skull and brain injuries caused by several objects were found, but no injuries caused by beach umbrellas were detected. There were only cases of injuries caused by normal umbrellas. These cases sho…
An FPGA-Based Software Defined Radio Platform for the 2.4GHz ISM Band
2006
A prototype of a Software Defined Radio (SDR) platform has been successfully designed and tested implementing a reconfigurable IEEE 802.11 and ZigBee receiver. The system exploits the reconfiguration capability of an FPGA for implementing a number of receiver configurations that share the same RF front-end. Configurations can be switched at run time, or can share the available logic and radio resource.
Contribution to the platoon distribution analysis in steady-state traffic conditions
2014
The traffic flow analysis and the relevant vehicle distribution (“free-moving” or “platooned” vehicles) on highway facilities at uninterrupted flow has always had fundamental importance in Highway Engineering, with special reference to topics like traffic operations, car accidents, road safety and air pollution emissions. In light of this, the study suggests a calculation algorithm as a random test generator to simulate a steady state traffic flow and to provide time headways. Thanks to the outcome produced by numerical simulations, we analysed platoon distributions within traffic flows in a steady-state regime and showed the results of numerical analyses carried out by traffic random proce…
Finite Element Simulation of Multilayer Metal Cylinder Head Gaskets
2006
ABAQUS gasket elements are an efficient and flexible tool to study gasket applications. Nevertheless the usage of the ABAQUS gasket elements is not limited to gasket analysis, but it provides an effective improvement in structural analysis. The results point out that both the predicted contact pressure and the predicted stress distribution depend on the mesh topology. Several combinations of mesh dimension and topology are investigated. The purpose is the definition of a calculation methodology and the demonstration of the application potentiality. Complex models analysis highlights that the set methodology constitutes a very effective tool for the design and optimization of gasket, cylinde…
Dynamic railroad inspection using the laser-air hybrid ultrasonic technique
2006
Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave laser-generation apparatus can be metres away from the interrogated surface while air-coupled detection standoff can be on the order of several centimetres. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detection te…
Multimodal user interface for a semi-robotic visual assistance system for image guided neurosurgery
2005
Abstract We developed a visual assistance system for image guided neurosurgery, consisting of a stereoscopic digital camera (exoscope) mounted on a semi-robotic manipulator. In order to minimize the operation time, the application-specific multimodal user interface enables hands-free manipulation of the exoscope. The surgeon wears thereby a head-mounted unit with a binocular display, a head tracker, a microphone and earphones. Different modes of view positioning and adjustment can be selected by voice and controlled by head rotation while pressing a miniature confirmation button mounted on a finger ring or suction device. Apart from the development of the mechatronic and software modules of…
Cross-Flow Turbine Design For Energy Production And Discharge Regulation
2015
Cross-flow turbines are very efficient and cheap turbines that allow a very good cost/benefit ratio for energy production located at the end of conduits carrying water from a water source to a tank. In this paper a new design procedure for a cross-flow turbine working with a variable flow rate is proposed. The regulation of the head immediately upstream the turbine is faced by adopting a shaped semicircular segment moving around the impeller. The maximum efficiency of the turbine is attained by setting the velocity of the particles entering the impeller at about twice the velocity of the rotating system at the impeller inlet. If energy losses along the pipe are negligible, the semicircular …
How to derive the analytical capacity model for not-conventional urban roundabouts
2008
The inapplicability of current methods for analyzing operations of urban not-conventional roundabouts (i.e. not referable to standard schemes) hampers seriously the assessment of their operational performances. Moreover, local constraints and the road network structure have produced lots of geometric layouts that make hard to propose an only framework to explain performances of not-conventional roundabouts. Also for these intersections it is hoped to have scientifically based methods to analyze operations with a proper reliability. Starting from these considerations, the paper shows the conceptual path followed to analyze operations at not-conventional roundabouts along an arterial of Paler…
Sewage sludge acidogenic fermentation for organic resource recovery towards carbon neutrality: an experimental survey testing the headspace influence
2022
Volatile fatty acids (VFAs) produced by acidogenic digestion of sewage sludge are very interesting bio-products which can contribute to carbon neutrality of wastewater treatment plants. Studies on the production of VFAs from sewage sludge from fermenters with membrane are limited. In view of above, VFAs from a fermenter pilot plant equipped with a membrane bioreactor and fed with real sewage sludge has been monitored. The effect of headspace volume (HdV) on VFA production was studied for the first time to elucidate the optimal operation conditions. Specifically, three fermenter HdV values (namely, 20, 40 and 60% of the total volume) have been investigated. Results revealed that the HdV of 2…