Path planning for reconfigurable rovers in planetary exploration

This paper introduces a path planning algorithm that takes into consideration different locomotion modes in a wheeled reconfigurable rover. Such algorithm, based on Fast Marching, calculates the optimal path in terms of power consumption between two positions, providing the most appropriate locomotion mode to be used at each position. Finally, the path planning algorithm is validated on a virtual Martian scene created within the V-REP simulation platform, where a virtual model of a planetary rover prototype is controlled by the same software that is used on the real one. Results of this contribution also demonstrate how the use of two locomotion modes, wheel-walking and normal-driving, can reduce the power consumption for a particular area.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Multi-scale path planning for a planetary exploration vehicle with multiple locomotion modes

Planetary exploration vehicles (rovers) can encounter with a great variety of situations. Most of them are related to the terrain, which can cause the end of the mission if these vehicles are not able to traverse it. It was the case of Spirit rover, which got stuck in loose sand, making it impossible to continue advancing. A solution to this is to make rovers capable of modifying their locomotion to traverse terrains with particular terramechanic parameters.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Nanometer-scale InGaAs Field-Effect Transistors for THz and CMOS technologies

Integrated circuits based on InGaAs Field Effect Transistors are currently in wide use in the RF front-ends of smart phones and other mobile platforms, wireless LANs, high data rate fiber-optic links and many defense and space communication systems. InGaAs ICs are also under intense research for new millimeter-wave applications such as collision avoidance radar and gigabit WLANs. InGaAs FET scaling has nearly reached the end of the road and further progress to propel this technology to the THz regime will require significant device innovations. Separately, as Si CMOS faces mounting difficulties to maintain its historical density scaling path, InGaAs-channel MOSFETs have recently emerged as a credible alternative for mainstream logic technology capable of scaling to the 10 nm node and below. To get to this point, fundamental technical problems had to be solved though there are still many challenges to be addressed before the first non-Si CMOS technology becomes a reality. The intense research that this exciting prospect is generating is also reinvigorating the prospects of InGaAs FETs to become the first true THz electronics technology. This paper reviews progress and challenges of InGaAs-based FET technology for THz and CMOS.Focus Center Research Program. Center for Materials, Structures and DevicesIntel CorporationUnited States. Army Research LaboratorySemiconductor Research Corporatio

The High-Electron Mobility Transistor at 30: Impressive Accomplishments and Exciting Prospects

2010 marked the 30th anniversary of the High-Electron Mobility Transistor (HEMT). The HEMT represented a triumph for the, at the time, relatively new concept of bandgap engineering and nascent molecular beam epitaxy technology. The HEMT showcased the outstanding electron transport characteristics of two-dimensional electron gas (2DEG) systems in III-V compound semiconductors. In the last 30 years, HEMTs have been demonstrated in several material systems, most notably AlGaAs/GaAs and AlGaN/GaN. Their uniqueness in terms of noise, power and high frequency operation has propelled HEMTs to gain insertion in a variety of systems where they provide critical performance value. 2DEG systems have also been a boon in solid-state physics where new and often bizarre phenomena have been discovered. As we look forward, HEMTs are uniquely positioned to expand the reach of electronics in communications, signal processing, electrical power management and imaging. Some of the most exciting prospects in the near future for HEMT-like devices are those of GaN for high voltage power management and III-V CMOS to give a new lease on life to Moore’s Law. This paper briefly reviews some highlights of HEMT development in the last 30 years in engineering and science. It also speculates about potential future applications

Tendencias internacionales en la investigación en la Organización del Deporte

Son presentados los resultados de una investigación original sobre las tendencias internacionales de investigación en todo el mundo en el campo de la Organización del Deporte. La investigación presentada en esta ponencia, ha sido efectuada con la dirección de Jesús Martínez del Castillo y con la colaboración de los siguientes profesores e investigadores del Master Interuniversitario Oficial en Dirección de Organizaciones e Instalaciones Deportivas de las Universidades de Alcalá, Politécnica de Madrid y León: Victor Jiménez Díaz-Benito; José Emilio Jiménez-Beatty; Cristina López de Subijana; Antonio Rivero Herráiz y José Antonio Santacru

Absorption and Scattering 2D Volcano Images from Numerically Calculated Space-weighting functions

Acknowledgments Yosuke Aoki and an anonymous reviewer greatly improved the quality of the paper. All calculations were made with Mathematica-10TM. Discussions with Marie Calvet, Danilo Galluzzo, Mario La Rocca, Salvatore De Lorenzo, Jessie Mayor and Ludovic Margerin are gratefully acknowledged. The authors are supported by MEDSUV European project and by Spanish Project Ephestos, CGL2011-29499-C02-01 and NOWAVES, TEC2015-68752. The TIDES EU travel Cost action provided travel money to support cooperation between Luca De Siena and the other authors.Peer reviewedPostprin

LANGUAGE CHANGE AND MODES OF THINKING THE LOSS OF INFLEXIONS IN OLD ENGLISH

Language is the creation of meanings. A language is a technique for any kind of speech, functioning in a particular speech community. As a technique of speaking it is constituted by a set of forms, contents, rules, procedures, attitudes and a system of beliefs ruling in the so-called a state of the language, that is, the analogous language ruling in a period of time. Since human subjects, that is, speakers, have the peculiar condition of beingtogether- with-others, the manifestation of this condition of humans, a language, is nothing but a historical object. Because of this, languages, as the manifestation of human intelligence and freedom in a speech community, will change in history, because all speakers participate in the construction and reconstruction of it. The way every language changes is something to be explained internally in the speech community. My thesis is that the changes known as the loss of inflexions were prompted with the introduction of a new way of thinking. The way of thinking, for the Anglo-Saxons in Old English, was a dynamic way of conceiving of things. Things were considered events happening. With the contacts of Anglo-Saxons with Celtic-Roman people, first, the introduction of Christianity, second, and finally with the Norman invasion, their dynamic way of thinking was confronted with the static conception of things coming from the Mediterranean. The history of English up to the 15th century meant the confrontation of two mental conceptions, static vs. dynamic

Photocatalytic Degradation of Phenolic Compounds in Water: Irradiation and Kinetic Modeling

Scaling up a photoreactor requires both knowledge of optical properties of the slurry medium and an established kinetic model. Measuring the scattering and absorption coefficients of particles suspended in water involves the use of specialized optical equipment, as well as the partial solution of the radiative transfer equation (RTE). In addition, modeling of the radiation field in photoreactors with complicated geometries offers special challenges. On the other hand, most of the kinetic models (KM) for phenol photodegradation reported in the literature were obtained for a single organic chemical species only. In fact, neglecting all the intermediate species generated during the photoreaction, is a common oversimplification that limits the KM application. As a result, once the radiation and kinetic models fully established, energy efficiencies can be obtained. In this PhD dissertation, the photocatalytic degradation of phenol over four different TiO2 catalysts is studied. It is proven that phenol yields hydroquinone, catechol, benzoquinone, and acetic and formic acids as main intermediate species. The radiation field inside photocatalytic reactors is predicted by solving the RTE. From the solution of the RTE, the local volumetric rate of energy absorption (LVREA) is also calculated. The radiation field inside an annular photoreactor is simulated using the Monte Carlo (MC) method for different TiO2 suspensions in water. All simulations are performed by using both the spectral distribution, and the wavelength-averaged scattering and absorption coefficients. The Henyey-Greenstein phase function is adopted to represent forward, isotropic and backward scattering modes. It is assumed that the UV lamp reflects the back-scattered photons by the slurried medium. It is proven, photo-absorption rates, using MC simulations and spectral distribution of the optical coefficients, agree closely with experimental observations from a macroscopic balance (MB). It is also found that the scattering mode of the probability density function, is not a critical factor for a consistent representation of the radiation field. When solving the RTE, two optical parameters are needed: (1) the absorption and scattering coefficients, and (2) the phase function. In this research work, the MC method, along with an optimization technique, is shown to be effective in predicting the wavelength-averaged absorption and scattering coefficients for different TiO2 powders. To accomplish this, the LVREA and the transmitted radiation (Pt) in the photoreactor are determined by using a MB. The optimized coefficients are calculated ensuring that they comply with a number of physical constrains, falling in between bounds established via independent criteria. The optimization technique is demonstrated by finding the absorption and scattering coefficients for different semiconductors that best fit the experimental values from the MB. The objective function in this optimization is given by the least-squared error for the LVREA. A photocatalyst is synthesized and its optical properties determined by the proposed method. This approach is a general and promising one; not being restricted to reactors of concentric geometry, specific semiconductors and/or particular photocatalytic reactor unit scale. Based on the proposed intermediate reactions, a phenomenological based unified kinetic model is proposed for describing the obtained experimental observations in phenol photodegradation. This Langmuir-Hinshelwood (L-H) kinetic model is based on a “Series-Parallel” reaction network. This reaction model is found to be applicable to the various TiO2 photocatalyst in the present study. This unified kinetic network is based on the identified and quantified chemical species in the photoconversion of phenol and its intermediates. In order to minimize the number of optimized parameters, the adsorption constants of the different intermediate species on the different catalysts configuration, are obtained experimentally. It is shown that the unified kinetic model requires a number of significant assumptions to be effective; avoiding overparametization. As a result, the unified kinetic model is adapted for each specific TiO2 photocatalyst under study.These different models adequately describe the experimental results. It is shown that this approach results in good and objective parameter estimates in the L-H kinetic model, which is typically applied to photocatalytic reactors. Finally, two efficiency factors, the quantum yield and the photochemical and thermodynamic efficiency factor, are obtained, in this PhD dissertation. These factors are based on the kinetic model proposed and the radiation being absorbed by the photocatalyst particles. The efficiency calculations consider stoichiometric relationships involving observable chemical species and OH· groups. The obtained efficiency factors point toward a high degree of photon utilization and, as a result, the value of photocatalysis and Photo-CREC-Water reactors for the conversion of organic pollutants in water is confirmed