Francisco Garcia de Quiros

EMXYS · Engineering

Electrodynamic tethers are proposed as propulsion and energy harvesters for space probes orbiting planets with a magnetic field and ionosphere, however there are no descriptions in the technical literature of the design of an electrical power system for such an application at subsystem and circuit detail. This paper presents a proposal for such a p...

When considering the deployment of a radio communications network, the study of multipath interference and its impact on the quality of signal reception is of the outmost importance in order to meet the necessary performance requirements. This work considers specifically the case of the lunar surface as the mission scenario for a community of auton...

A simple multiplier for the estimation of the power yield of a solar panel may be realized with a pulse-width-modulator working as analog multiplier circuit. Though the output of the pulse width modulator multiplication is not proportional to the output power of the solar panel, it will be shown that its maximum follows the maximum of the power cur...

A simple analog multiplier for the estimation of the power yield of a solar panel may be realized with a pulse width modulator working as analog multiplier circuit of the current yield and the duty cycle of the converter used to condition the panel. Though the output of the pulse width modulator multiplication is not exactly proportional to the out...

A 3-year Project financed by the European Commission is aimed at developing a universal system to de-orbit satellites at their end of life, as a fundamental contribution to limit the increase of debris in the Space environment. The operational system involves a conductive tapetether left bare to establish anodic contact with the ambient plasma as a...

A spaceflight validation of bare electrodynamic tape tether technology was conducted. A S520-25 sounding rocket was launched successfully at 05:00am on 31 August 2010 and successfully deployed 132.6m of tape tether over 120 seconds in a ballistic flight. The electrodynamic performance of the bare tape tether employed as an atmospheric probe was mea...

A 3-year Project started on November 1 2010, financed by the European Commision within the FP-7 Space Program, and aimed at developing an efficient de-orbit system that could be carried on board by future spacecraft launched into LEO, will be presented. The operational system will deploy a thin uninsulated tape-tether to collect electrons as a gian...

We have constructed a small animal PET with four identical detector modules, each consisting of a continuous LYSO crystal attached to a Position Sensitive Photomultiplier Tube (PSPMT). The dimensions of the continuous crystal are 50×50 mm2 and 10 mm thickness. The modules are separated 11 cm between each other in the scanner. In this paper we discu...

We report on the design of a small animal PET scanner based on continuous LYSO crystals and position sensitive photomultiplier tubes (PSPMTs), together with the first results from the calibration. The scanner consists of eight compact modules forming an octagon and leaving a port of 110 mm aperture. Each module is made out of a continuous LYSO crys...

We have developed two prototypes of portable gamma cameras for medical applications based on a previous prototype designed and tested by our group. These cameras use a CsI(Na) continuous scintillation crystal coupled to the new flat-panel-type multianode position-sensitive photomultiplier tube, H8500 from Hamamatsu Photonics. One of the prototypes,...

Purpose: Our objective is to demonstrate the feasibility of a neuroprosthesis, interfaced with the visual cortex, as a means through which a limited but useful visual sense may be restored to peripherally blind people. This requires the development of bioinspired reconfigurable software/hardware devices able a) to transform and map the visual infor...

A study of the electrical parameters of a microelectrode array designed for chronic current stimulation through cortical tissue was carried out. The microelectrode array was inmersed in ringer solution for measurements. Resistive and capacitive components, as well as total equivalent impedances were analyzed at different current levels using Electr...

Information Theory is used for analyzing the neural code of retinal ganglion cells. This approximation may quantify the amount of information transmitted by the whole population, versus single cells. The redundancy inherent in the code may be determined by obtaining the information bits of increasing cells datasets and by analyzing the relation bet...

Our main objective is to demonstrate the feasibility of a cortical neuroprosthesis, interfaced with the visual cortex, as a means through which a limited but useful visual sense may be restored to profoundly blind people. Although there are still a number of important unanswered questions and many problems have to be solved before a Cortical Visual...

In this paper information theory is used to analyze the coding capabilities of populations of retinal ganglions cells for transmitting information. The study of a single code versus a distributed code has been contrasted using this methodology. The redundancy inherent in the code has been quantified by computing the bits of information transmitted...