Stand-off LIBS in space exploration. New facility for the simulation of different planetary conditions

The availability of facilities capable of simulating extraterrestrial environments represents a need in today's planetary research to design, simulate and optimize those experiments carried out outside of Earth1,2. A thermal vacuum chamber (TVC) must be capable of operating under representative conditions (temperature, pressure, gas composition, radiation flux …) of space exploration targets and have a helpful volume compatible with the performing experiments and the testing of equipment under mimicked scenarios. Stand-off spectroscopies and connected techniques have gained a proper niche within the modern tools in situ compositional analysis for space exploration using rovers. The latest missions sent for space geo-exploration, e.g. NASA's Mars 2020 mission, show that Laser-Induced Breakdown Spectrometry (LIBS) is currently one of the key tools in understanding mineralogy and geochemistry of planetary surface. LIBS can obtain real-time information at distances up to 12 meters, together with other techniques such as RAMAN or VIS-IR spectroscopy3. The convenience of a TVC capable of performing stand-off spectroscopies under different analysis ranges allows reproducing the results obtained in Perseverance rover and for future missions, gaining insights about data treatment and data modelling, and anticipating experiments on Earth before the launch. This work presents the TVC available in the UMALASER lab and the stand-off LIBS experiments carried out at different atmospheric conditions up to 12m. Furthermore, the versatility of this camera in the field of stand-off analysis will be demonstrated by combining LIBS analysis with Laser-Induced Acoustics detections or other spectroscopic techniques (i.e. Raman). This array of remote analysis techniques has been applied for the compositional analysis of geological samples under Martian atmospheric conditions of pressure (8 mbar), composition (CO2 rich atmosphere) and air temperature (250 K).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Estudio experimental del comportamiento del turbogrupo de sobrealimentación de un motor de encendido provocado de inyección directa de gasolina

[ES] El objetivo del trabajo es evaluar un conjunto de turbogrupos de sobrealimentación para determinar el más apropiado para el tipo de motor donde será aplicado, por lo que el trabajo consistirá en realizar ensayos experimentales de un motor térmico instalado en banco de ensayo dinámico, con el propósito de evaluar las diferentes combinaciones de turbomáquinas de sobrealimentación. Para realizar este estudio el alumno debe realizar las tareas que se indican a continuación: - Instrumentar el motor, el turbogrupo y resto de sistemas auxiliares, para poder obtener los parámetros que caracterizan su funcionamiento durante los experimentos. - Diseñar. sistema soporte del motor a la bancada y el sistema de acoplamiento del eje de transmisión mecánica entre motor y dinamómetro del banco de - Colaborar en la instalación del motor en el banco de ensayos y en la definición de la metodología experimental que se utilizará en el estudio. - Ejecutar los ensayos experimentales tanto en régimen estacionario como dinámico.[EN] The objective of the work is to evaluate a set of turbocharger to determine the most appropriate for the type of engine where it will be applied, so the work will be to perform experimental tests of a thermal engine installed in a dynamic test bench, for the purpose of evaluating the different combinations of turbine and compressor. To make this study the student carry out the following tasks: - To install transducers on the engine, the turbocharger and other engine auxiliary systems, in order to obtain the parameters that characterize its operation during the experiments. - To desing the support system from engine to the bench and the coupling system of the mechanical transmission shaft between the engine and the dynamometer - Collaborate in the installation of the engine in the test bench and in the definition of the experimental methodology to be used in the study. - Execute the experimental tests in both steady and dynamic cycles.Calabuig Llamas, C. (2018). Estudio experimental del comportamiento del turbogrupo de sobrealimentación de un motor de encendido provocado de inyección directa de gasolina. Universitat Politècnica de València. http://hdl.handle.net/10251/106411TFG

LIBS-Acoustic Mid-Level Fusion Scheme for Mineral Differentiation under Terrestrial and Martian Atmospheric Conditions

The shockwave produced alongside the plasma during a laser-induced breakdown spectroscopy event can be recorded as an acoustic pressure wave to obtain information related to the physical traits of the inspected sample. In the present work, a mid-level fusion approach is developed using simultaneously recorded laser-induced breakdown spectroscopy (LIBS) and acoustic data to enhance the discrimination capabilities of different iron-based and calcium-based mineral phases, which exhibit nearly identical spectral features. To do so, the mid-level data fusion approach is applied concatenating the principal components analysis (PCA)-LIBS score values with the acoustic wave peak-to-peak amplitude and with the intraposition signal change, represented as the slope of the acoustic signal amplitude with respect to the laser shot. The discrimination hit rate of the mineral phases is obtained using linear discriminant analysis. Owing to the increasing interest for in situ applications of LIBS + acoustics information, samples are inspected in a remote experimental configuration and under two different atmospheric traits, Earth and Mars-like conditions, to validate the approach. Particularities conditioning the response of both strategies under each atmosphere are discussed to provide insight to better exploit the complex phenomena resulting in the collected signals. Results reported herein demonstrate for the first time that the characteristic sample input in the laser-produced acoustic wave can be used for the creation of a statistical descriptor to synergistically improve the capabilities of LIBS of differentiation of rocksFundings for this work were provided by the projects UMA18-FEDERJA-272 from the Junta de Andalucía and PID2020-119185GB-I00 from Ministerio de Ciencia e Innovación, Spain. P.P. is grateful to the Junta de Andalucía for his contract under the program Garantía Juvenil. Universidad de Málaga / CBUA"

Simultaneous LIBS acoustic detection for mineral differentiation. Imaging and standoff studies under terrestrial and martian atmospheric conditions

The combination of data simultaneously generated by laser-induced breakdown spectroscopy (LIBS) and laser-induced acoustics (LIAc) is a topic of many potential applications as both phenomena cover different sample traits. LIAc could add information concerning some physico-chemical parameters elusive to LIBS. Results indicated a strong dependence of the generated acoustic wave with physical properties such as the hardness of the material, and therefore the ablation rate, the density, and the thermal conductivityUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Ciencia e Innovació

Measuring the coefficient of restitution and more: a simple experiment to promote students’ critical thinking and autonomous work

Innovación EducativaAbstract A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by the students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to think of physics as a whole subject instead of a set of, more or less, isolated parts. The experiment can be done either in teaching laboratories or as an autonomous work by students at home. Students’ smartphones and cheap balls of different materials are the only experimental materials required to do the experiment. The proposed work also permits the students to analyse the limitations of a physical model used in the experiment by analysing the approximations considered in it, and then enhancing their critical thinking

Is Open Science the Same as Open Source Science?

How open source hardware and software can help to level up open science into open research when used for both methods and tools in the research activities

Open source hardware based sensor platform suitable for human gait identification

Most initiatives about embedded sensing capabilities in computational systems lead to de- vise an ad hoc sensor platform, usually poorly reusable, as a first stage to prepare a data corpus or production prototype. In this paper, an open source hardware platform for sensing is described. This platform was intended to be used in data acquisition for gait identification, and is designed in a way general enough so many other projects could reuse the design to accelerate prototyping. The platform is based on popular open source hardware and software like Arduino and Raspberry Pi using well known languages and libraries. Some experimental results about the throughput of the overall system are reported showing the feasibility of acquiring data from up to 6 sensors with a sampling frequency no less than 118 Hz

A systematic evaluation on the impact of sample-related and environmental factors in the analytical performance of acoustic emission from laser-induced plasmas

Acoustics recordings from laser-induced plasmas are becoming increasingly regarded as a complementary source of information from the inspected sample. The propagation of these waves is susceptible to be modified by the physicochemical traits of the sample, thus yielding specific details that can be used for sorting and identification of targets. Still, the relative fragility of the acoustic wave poses major challenges to the applicability of laser-induced acoustics. Echoes and reflections sourcing from intrasample parameters as well as from interactions of the acoustic wave with the surroundings of the inspected target can dilute the analytical information directly related to the object contained within the recordings. The present work aims to experimentally scrutinize the impact of different parameters internal and external to the sample into the final acoustic signal from laser-induced plasmas in order to accurately use this information source for characterization purposes. Variables inherent to the sample such as dimensions, porosity and absorption coefficient, which guides the laser-matter coupling process, have been, for the first time, systematically studied using ad-hoc solids to thoroughly isolate their influence on the signal. Moreover, modulation of soundwave induced by the surroundings of the probed target and the anisotropy of the acoustic signal because of the angle at which the plasma is formed, have been evaluated.The present research has been supported with funding provided by the projects UMA18-FEDERJA-272 from the Junta de Andalucía and PID2020-119185GB-I00 from Ministerio de Ciencia e Innovación, Spain. M.B. is grateful to the Specific Research Project, Masaryk University MUNI/A/1412/2021. P.P. is grateful to the European Union's Next Generation EU (NGEU) plan and the Spanish Ministerio de Universidades for his Margarita Salas fellowship under the program ʺAyudas para la Recualificación del Sistema Universitario Españolʺ. Funding for open access charge: Universidad de Málaga / CBU

Identifying users from the interaction with a door handle

Ambient intelligence pursues the integration of intelligent approaches on an IoT infrastructure, mainly using everyday objects of the environment. The main hypothesis of the work is that the way in which a user interacts with a door handle is suitable to be used in the identification task. Our proposal contributes with a new method to identify persons in a seamless and un-obstrusive way, suitable to be used in a smart building scenery without the need to bring any additional device. In this case, we embed accelerometers and gyroscopes in a door handle in order to obtain a data set comprising samples of 47 individuals. A parametric approximation is adopted to reduce each sample to a feature vector by using a dynamic time warping technique. A study has been made of the outcomes of different classification techniques over six different feature sets in order to assess the feasibility of this identification challenge. The AUC values observed with the selected feature set show promising results above 0.90 using neural networks and SVM classifiers

Thermal Vision for Soil Assessment in a Multipurpose Environmental Chamber under Martian Conditions towards Robot Navigation

Soil assessment is important for mobile robot planning and navigation on natural and planetary environments. Terramechanic characteristics can be inferred from the thermal behaviour of soils under the influence of sunlight using remote sensors such as Long-Wave Infrared cameras. However, this behaviour is greatly affected by the low atmospheric pressures of planets such as Mars, so practical models are needed to relate robot remote sensing data on Earth to target planetary exploration conditions. This article proposes a general framework based on multipurpose environmental chambers to generate representative diurnal cycle dataset pairs that can be useful to relate the thermal behaviour of a soil on Earth to the corresponding behaviour under planetary pressure conditions using remote sensing. Furthermore, we present an application of the proposed framework to generate datasets using the UMA-Laserlab chamber, which can replicate the atmospheric \ch{CO2} composition of Mars. In particular, we analyze the thermal behaviour of four soil samples of different granularity by comparing replicated Martian surface conditions and their Earth's diurnal cycle equivalent. Results indicate a correlation between granularity and thermal inertia that is consistent with available Mars surface measurements recorded by rovers. The resulting dataset pairs, consisting of representative diurnal cycle thermal images with heater, air, and subsurface temperatures, have been made available for the scientific community.Comment: 10 pages, 13 figure