UAS pilot support for departure, approach and airfield operations

Unmanned Aerial Systems (UAS) have great potential to be used in a wide variety of civil applications such as environmental applications, emergency situations, surveillance tasks and more. The development of Flight Control Systems (FCS) coupled with the availability of other Commercial Off-The Shelf (COTS) components is enabling the introduction of UAS into the civil market. The sophistication of existing FCS is also making these systems accessible to end users with little aeronautics expertise. However, much work remains to be done to deliver systems that can be properly integrated in standard aeronautical procedures used by manned aviation

An assessment for UAS depart and approach operations

Unmanned Aerial Systems (UAS) have great potential to be used in a wide variety of civil applications such as environmental applications, emergency situations, surveillance tasks and more. The development of Flight Control Systems (FCS) coupled with the availability of other Commercial Off-The Shelf (COTS) components is enabling the introduction of UAS into the civil market. The sophistication of existing FCS is also making these systems accessible to end users with little aeronautics expertise. However, much work remains to be done to deliver systems that can be properly integrated in standard aeronautical procedures used by manned aviation. In previous research advances have been proposed in the flight plan capabilities by offering semantically much richer constructs than those present in most current UAS autopilots. The introduced flight plan is organized as a set of stages, each one corresponding to a different flight phase. Each stage contains a structured collection of legs inspired by current practices in Area Navigation (RNAV). However, the most critical parts of any flight, the depart and approach operations in an integrated airspace remain mostly unexplored. This paper introduces an assessment of both operations for UAS operating in VFR and IFR modes. Problems and potential solutions are proposed, as well as an automating strategy that should greatly reduce pilot workload. Although th

Germination differences between seeds from apical and basal fruits of "Camelina microcarpa" Andrz. ex DC. produced in two different climates

En el presente trabajo se han estudiado las diferencias de germinación entre semillas de una población de “Camelina microcarpa” Andrz. ex DC. producidas en los frutos apicales y basales de las mismas infrutescencias, y producidas en dos condiciones climáticas diferentes (Lleida y Minnesota). Las semillas apicales germinaron más y antes que las basales, principalmente cuando fueron producidas en Lleida, mientras que estas diferencias se difuminaron en las semillas procedentes de Minnesota; estas últimas semillas también germinaron en mayor medida que las de Lleida. A pesar de las diferencias, los ritmos de germinación fueron similares en casi todos los casos. Los resultados ponen de manifiesto la importancia del lugar de producción de las semillas de cara a su posible comercialización como cultivo oleaginoso.Germination characteristics of seeds collected from apical and basal fruits of the infrutescences, and produced in two different climatic conditions (Lleida and Minnesota) were studied. Apical seeds germinated more and earlier than basal seeds, mainly when they were produced in Lleida, while these differences blur between seeds produced in Minnesota, which germinated in a greater amount than those of Lleida. Despite these differences, germination rates were similar in all cases. The results show the importance of the seed production site if these species was considered as a potential commercial oilseed crop

Investigation of acceptor levels and hole scattering mechanisms in p-gallium selenide by means of transport measurements under pressure

The effect of pressure on acceptor levels and hole scattering mechanisms in p-GaSe is investigated through Hall effect and resistivity measurements under quasi-hydrostatic conditions up to 4 GPa. The pressure dependence of the hole concentration is interpreted through a carrier statistics equation with a single (nitrogen) or double (tin) acceptor whose ionization energies decrease under pressure due to the dielectric constant increase. The pressure effect on the hole mobility is also accounted for by considering the pressure dependencies of both the phonon frequencies and the hole-phonon coupling constants involved in the scattering rates.Comment: 13 pages, Latex, 4 ps figures. to appear in High Pressure Research 69 (1997

Depart and approach procedures for UAS in a VFR environment

This paper assesses the depart and approach operations of Unmanned Aircraft Systems (UAS) in one of the most challenging scenarios: when flying under Visual Flight Rules (VFR). Inspired by some existing procedures for (manned) general aviation, some automatic and predefined procedures for UAS are proposed. Hence, standardized paths to specific waypoints close to the airport are defined for depart operations, just before starting the navigation phase. Conversely, and for the approach maneuvers, it is foreseen a first integration into a holding pattern near the landing runway (ideally above it) followed by a standard VFR airfield traffic pattern. This paper discusses the advantages of these operations which aim at minimizing possible conflicts with other existing aircraft while reducing the Pilot-in-Command workload. Finally, some preliminary simulations are shown where these procedures have been successfully tested with simulated surrounding traffic

La regulación del referendo en el derecho comparado: aportaciones para el debate en España

Desde la propia teoría de la democracia representativa, resulta coherente la defensa del referendo como un instrumento de contrapeso y control al poder del Parlamento. Si la voluntad del pueblo se expresa a través de sus representantes y este es el fundamento último de las democracias representativas, la lógica consecuencia es que los depositarios últimos de esa voluntad general puedan manifestar un sentimiento contrario a aquel que, sobre una cuestión concreta, han manifestado en su nombre esos representantes. El referendo constituye, pues, el complemento necesario que refuerza el fundamento último de la representación. No obstante, los beneficios que pueden surgir del referendo como un complemento de la democracia representativa se materializan solo si los procedimientos están bien diseñados y garantizan la información y la transparencia a los ciudadanos. La regulación del referendo y la iniciativa popular que en el derecho comparado se ha realizado y las consecuencias prácticas que ha tenido dicha regulación pueden constituir un buen marco de referencia para una adecuada regulación del referendo en España. The defense of referendum as a counterbalancing and monitoring instrument over Parliament's power is consistent from the very theory of representative democracy. If the will of the people is expressed through their representatives and this is the ultimate foundation of representative democracies, the logical consequence is that people will be able to show sentiment against the will, on a specific issue, expressed by representatives on behalf of the people. Then the referendum is the corollary that reinforces the ultimate basis of representation. However, the advantages that can arise from the referendum as a complement of representative democracy materialize only if the procedures are well designed and ensure information and transparency for citizens. The regulation of the referendum and the popular initiative in comparative law and the practical consequences that has had such regulation may provide a framework for a proper regulation of the referendum in Spain

¿Democracia de abajo arriba vs. democracia de arriba abajo? El papel de los partidos en los instrumentos de democracia directa

En esta costumbre tan humana de establecer dicotomías irreconciliables, se enmarca la disociación —hoy de enorme actualidad— entre la democracia de arriba- abajo y la democracia de abajo-arriba. Como si la voluntad del pueblo pudiera ser aislada, cuan en una bella burbuja, de las influencias del exterior y, muy especialmente, de los partidos políticos. O como si el pronunciamiento popular directo supusiera una deslegitimación del sistema representativo y un debilitamiento de los partidos políticos de difícil solución. Solo desde la inteligencia y la reflexión se puede conciliar lo que parece irreconciliable e, incluso, descubrir que no son democracias tan diferentes. Y es desde una intuición inteligente y reflexiva desde donde surge este libro que coordina la profesora Biglino y que lleva por título Partidos políticos y mediaciones de la democracia directa..

Isospin phases of vertically coupled double quantum rings under the influence of perpendicular magnetic fields

Vertically coupled double quantum rings submitted to a perpendicular magnetic field $B$ are addressed within the local spin-density functional theory. We describe the structure of quantum ring molecules containing up to 40 electrons considering different inter-ring distances and intensities of the applied magnetic field. When the rings are quantum mechanically strongly coupled, only bonding states are occupied and the addition spectrum of the artificial molecules resembles that of a single quantum ring, with some small differences appearing as an effect of the magnetic field. Despite the latter has the tendency to flatten the spectra, in the strong coupling limit some clear peaks are still found even when $B\neq 0$ that can be interpretated from the single-particle energy levels analogously as at zero applied field, namely in terms of closed-shell and Hund's-rule configurations. Increasing the inter-ring distance, the occupation of the first antibonding orbitals washes out such structures and the addition spectra become flatter and irregular. In the weak coupling regime, numerous isospin oscillations are found as a function of $B$.Comment: 27 pages, 11 figures. To be published in Phys. Rev.

High pressure oxidation of dimethoxymethane

The oxidation of dimethoxymethane (DMM) has been studied under a wide range of temperatures (373-1073 K), pressures (20-60 bar) and air excess ratios (¿ = 0.7, 1 and 20), from both experimental and modeling points of view. Experimental results have been interpreted and analyzed in terms of a detailed gas-phase chemical kinetic mechanism for describing the DMM oxidation. The results show that the DMM oxidation regime for 20, 40 and 60 bar is very similar for both reducing and stoichiometric conditions. For oxidizing conditions, a plateau in the DMM, CO and CO2 concentration profiles as a function of the temperature can be observed. This zone seems to be associated with the peroxy intermediate, CH3OCH2O2, whose formation and consumption reactions appear to be important for the description of DMM conversion under high pressure and high oxygen concentration conditions