The beneficiation of lunar regolith for space resource utilisation: A review

Space Resource Utilisation (SRU) technology will enable further exploration and habitation of space by humankind. The production of oxygen on the Moon is one of the first objectives for SRU; this can be achieved through the thermo-chemical reduction of the lunar regolith. Several techniques, such as hydrogen reduction and molten salt electrolysis, have been proposed. All reduction techniques require a consistent feedstock from the regolith to reliably and consistently produce oxygen. The preparation of this feedstock, known as beneficiation, is a critical intermediate stage of the SRU flowsheet, however it has received little consideration relative to the preceding excavation, and the subsequent oxygen production stage. This review describes the physics of the main beneficiation methods suitable for SRU. Further, we collate and review all of the previous studies on the beneficiation of lunar regolith

Methods and tools for the formulation, evaluation and optimization of rover mission concepts

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2007.Page 256 blank.Includes bibliographical references (p. 245-255).Traditionally, Mars rover missions have been conceived with a single point design approach, exploring a limited architectural trade space. The design of future missions must resolve a conflict between increasingly ambitious scientific objectives and strict technical and programmatic constraints. Therefore, there is a need for advanced mission study engineers to consider a wider range of surface exploration concepts in order to identify those with superior performance and robustness with respect to evolving mission objectives. To this end, a three stage trade space exploration approach has been developed to supplement point design development in the early conceptual phase of Mars rover missions. The product is an integrated set of theoretical methods and analytical tools which enhances the understanding and enables the rapid exploration of the rover mission trade space. In the formulation stage, the first stage of the approach, a parallel decomposition of the functional and physical aspects of Mars exploration architectures is employed to explore trade space of surface mission concepts. At each step of the decomposition, architectural alternatives are assessed with respect to stakeholder figures of merit.(cont.) The resulting concept development trees allow for a rapid assessment of a given design's strength and robustness with respect to stakeholder priorities. In the evaluation stage, the Mars Surface Exploration (MSE) rover system design tool is used to support quantitative analysis of the superior designs identified in the formulation stage. This tool, for advanced mission studies, offers unique functionality: breadth of exploration, system-level modeling fidelity and rapidity. As a demonstration of its capabilities, the tool is used to model and evaluate a multi-rover mission concept in less than two hours. In the optimization stage, two systems engineering methods are developed to optimize, with MSE, the more complex technical and physical aspects of rover mission architectures. The first method assesses the value of autonomy technologies in future missions; it is based on the principle that the monetary worth of autonomy can be evaluated by benchmarking its performance against competing solutions with known cost. The method is applied to value autonomy development for site-to-site traverse and sample approach activities.(cont.) The second method optimizes platform strategies for space exploration systems; an innovative optimization technique is developed to enumerate of all platform options. In the six rover mission campaigns analyzed, the best platform strategies are shown to generate very limited savings compared to traditional strategies. The two case studies demonstrate that the analytical capabilities of MSE combined with a theoretical structure form a valuable decision making tool for early conceptual design trade-offs.by Julien-Alexandre Lamamy.Ph.D

Experimental investigation of an optimised tribocharger design for space resource utilisation

Triboelectric charging and free-fall separation are attractive technologies for lunar mineral beneficiation. Here, an optimised tribocharger design was built and evaluated under terrestrial conditions. The charging behaviour of pure silica and ilmenite were tested using the optimised design, as were mixtures of silica and ilmenite, and samples of lunar regolith simulant JSC-1. Pure silica and ilmenite acquired negative and positive charge, respectively, through contact with the tribocharger. The tribocharger affected significantly the movement of the pure minerals in the electrostatic field. Results from the binary mixtures indicate that ilmenite recovery is independent of initial ilmenite concentration, and can be predicted from the mass distribution of pure ilmenite samples. For JSC-1, the tribocharger was found to increase the density of the material in certain collectors, indicating an upgrading of denser constituents. The optimised tribocharger design has a significant effect on the charging and separation performance

A methodology for tribocharger design optimisation using the Discrete Element Method (DEM)

Tribocharger design optimisations presented in the literature are based typically on experimental investigations. While this approach is useful and necessary to evaluate the performance of a design, experimental investigations are limited to studying a finite matrix of parameters. Computational approaches, such as the discrete element method (DEM), offer greater flexibility, however they have not been used previously for tribocharger design optimisation. This work presents a novel approach using the DEM to study the effect of different tribocharger designs on the charging process using particle–wall and particle–particle contact areas as proxies for charge transfer. The bulk sample charge output from the model are compared with bulk charges measured experimentally, showing good agreement. Furthermore, a method to predict approximately the charging behaviour of complex mixtures from linear combinations of the simulation outputs of single species, single size particle samples is presented, demonstrating good agreement

Global distribution and diversity of ovine-associated Staphylococcus aureus

Staphylococcus aureus is an important pathogen of many species, including sheep, and impacts on both human and animal health, animal welfare, and farm productivity. Here we present the widest global diversity study of ovine-associated S. aureus to date. We analysed 97 S. aureus isolates from sheep and sheep products from the UK, Turkey, France, Norway, Australia, Canada and the USA using multilocus sequence typing (MLST) and spa typing. These were compared with 196 sheep isolates from Europe (n = 153), Africa (n = 28), South America (n = 14) and Australia (n = 1); 172 bovine, 68 caprine and 433 human S. aureus profiles. Overall there were 59 STs and 87 spa types in the 293 ovine isolates; in the 97 new ovine isolates there were 22 STs and 37 spa types, including three novel MLST alleles, four novel STs and eight novel spa types. Three main CCs (CC133, CC522 and CC700) were detected in sheep and these contained 61% of all isolates. Four spa types (t002, t1534, t2678 and t3576) contained 31% of all isolates and were associated with CC5, CC522, CC133 and CC522 respectively. spa types were consistent with MLST CCs, only one spa type (t1403) was present in multiple CCs. The three main ovine CCs have different but overlapping patterns of geographical dissemination that appear to match the location and timing of sheep domestication and selection for meat and wool production. CC133, CC522 and CC700 remained ovine-associated following the inclusion of additional host species. Ovine isolates clustered separately from human and bovine isolates and those from sheep cheeses, but closely with caprine isolates. As with cattle isolates, patterns of clonal diversification of sheep isolates differ from humans, indicative of their relatively recent host-jump

Análisis genético preliminar para el estudio de las interacciones intraespecíficas de oso pardo de la Cordillera Cantábrica

XIV Congreso de la Sociedad Española para la Conservación y Estudio de los Mamíferos (SECEM), Jaca, 5-8 diciembre de 2019.El rascado en los árboles juega un papel fundamental en la comunicación intraespecífica de los osos pardos (Ursus arctos), cuyas áreas de campeo a menudo se encuentran solapadas. A través de estos mensajes, los osos son capaces de reconocer a todos los individuos de su zona sin necesidad de interacciones directas. Se ha demostrado que los osos pardos invierten una parte de su tiempo en la búsqueda activa de las señales químicas dejadas por los conspecíficos como parte esencial de su red de comunicación. El presente trabajo busca descubrir: (a) la red social existente en torno a los árboles de rascado (o árboles de marcaje) del occidente de la Cordillera Cantábrica (n= 18 árboles de rascado); (b) los patrones de marcaje a lo largo de todo el año (n= 32 árboles de rascado); así como(c) entender dinámicas de envejecimiento en la población sujeta a estudio, mediante la toma de muestras de pelo depositado en trampas no lesivas, situadas en Asturias y León, tras el rascado. La recogida de los pelos se ha realizado mensualmente durante un período de un año, por lo que disponemos de un volumen total de 216 muestras, cada una de ellas con material de distintos ejemplares de oso. Se ha realizado la extracción genética de cada pelo con un total de ocho folículos pilosos por muestra, de forma que la posibilidad de error disminuya al 5% y se obtenga una concentración de ADN nuclear suficiente para su identificación. Para la determinación del individuo, sexo y rango de edad se han escogido siete marcadores microsatélites, descritos como los más informativos para este fin. La población occidental es la que cuenta con el mayor número de individuos de la población pero, en base a los resultados preliminares y debido a la limitada variabilidad genética es necesario determinar si es suficiente para realizar una correcta identificación individual. Datos preliminares muestran que los patrones anuales en el rascado se han estudiado como una variable en torno a la época del año, siendo los meses de abril a septiembre de los que mayor cantidad de pelo se obtiene, así como en los meses en torno a la hibernación cuando se denota una reducción en el comportamiento de rascado coincidente con su disminución de actividad

Rubbing behavior of European brown bears: factors affecting rub tree selectivity and density

Scent-mediated communication is considered the principal communication channel in many mammal species. Compared with visual and vocal communication, odors persist for a longer time, enabling individuals to interact without being in the same place at the same time. The brown bear (Ursus arctos), like other mammals, carries out chemical communication, for example, by means of scents deposited on marking (or rub) trees. In this study, we assessed rub tree selectivity of the brown bear in the predominantly deciduous forests of the Cantabrian Mountains (NW Spain). We first compared the characteristics of 101 brown bear rub trees with 263 control trees. We then analyzed the potential factors affecting the density of rub trees along 35 survey routes along footpaths. We hypothesized that: (1) bears would select particular trees, or tree species, with characteristics that make them more conspicuous; and (2) that bears would select trees located in areas with the highest presence of conspecifics, depending on the population density or the position of the trees within the species’ range. We used linear models and generalized additive models to test these hypotheses. Our results showed that brown bears generally selected more conspicuous trees with a preference for birches (Betula spp.). This choice may facilitate the marking and/ or detection of chemical signals and, therefore, the effectiveness of intraspecific communication. Conversely, the abundance of rub trees along footpaths did not seem to depend on the density of bear observations or their relative position within the population center or its border. Our results suggest that Cantabrian brown bears select trees based on their individual characteristics and their location, with no influence of characteristics of the bear population itself. Our findings can be used to locate target trees that could help in population monitoring

Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing.

Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity. A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay. Fifteen laboratories returned results, obtained using a wide range of wet-lab and informatics methods. Six of 25 target viruses were detected by all laboratories, with the remaining viruses detected by 4-14 laboratories. Six non-target viruses were detected by three or more laboratories. The study demonstrated that a wide range of methods are currently used for adventitious virus detection screening in biological products by deep sequencing and that they can yield significantly different results. This underscores the need for common reference materials to ensure satisfactory assay performance and enable comparisons between laboratories

CC9 Livestock-Associated Staphylococcus aureus Emerges in Bloodstream Infections in French Patients Unconnected With Animal Farming

We report 4 bloodstream infections associated with CC9 agr type II Staphylococcus aureus in individuals without animal exposure. We demonstrate, by microarray analysis, the presence of egc cluster, fnbA, cap operon, lukS, set2, set12, splE, splD, sak, epiD, and can, genomic features associated with a high virulence potential in human

Enhancing the science return of Mars missions via sample preparation, robotic surface exploration and in orbit fuel production

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.Includes bibliographical references (p. 225-230).The future of Mars exploration is challenging from multiple points of view. To enhance their science return, future surface probes will most likely be equipped with complex Sample Preparation And Transfer (SPAT) facilities. Future rovers will need to be able to perform longer traverses and delicate sample acquisition operations. Mars return missions would benefit from a new propulsion system, with better fuel and travel time efficiencies than chemical and electric propulsions, respectively. A model was developed that optimizes SPAT facilities in terms of productivity and system mass. The SPAT model especially investigates two trade-offs: shared versus specific preparation, and warm versus cold redundancy for SPAT elements. A Mars Surface Exploration (MSE) framework was created to help designers perform preliminary studies on rover missions. MSE applies multidisciplinary design optimization techniques for the analysis of design trade-offs relevant to the rover design community. The Propellant Production In Mars Orbit (PPIMO) is presented as a promising solution for performing return travels to Mars. PPIMO uses the concept of regenerative aerobraking to produce fuel in-situ. The SPAT model shows that warm redundancy improves productivity by both reducing risk and removing sample throughput bottlenecks. A method is presented for determining the economy of scale the shared preparation architecture must exhibit for it to be competitive in comparison to the distributed architecture. MSE is used to budget the future development costs of rover autonomy, in addition to assessing: the benefits of oversized suspensions, the practicality of solar versus nuclear power for future missions, and the advantages of multi-rover missions. When compared(cont.) to chemical and electric propulsions, PPIMO propulsion shows a better performance in terms of transportation ratio for payloads larger than 1000 kilograms.by Julien-Alexandre Lamamy.S.M