Midcourse navigation using statistical filter theory, a manual theodolite, and symbolic computer control

Midcourse navigation using statistical filter theory, manual theodolite, and symbolic computer control applied to manned spacecraf

The Hunt for Exomoons with Kepler (HEK): I. Description of a New Observational Project

Two decades ago, empirical evidence concerning the existence and frequency of planets around stars, other than our own, was absent. Since this time, the detection of extrasolar planets from Jupiter-sized to most recently Earth-sized worlds has blossomed and we are finally able to shed light on the plurality of Earth-like, habitable planets in the cosmos. Extrasolar moons may also be frequent habitable worlds but their detection or even systematic pursuit remains lacking in the current literature. Here, we present a description of the first systematic search for extrasolar moons as part of a new observational project called "The Hunt for Exomoons with Kepler" (HEK). The HEK project distills the entire list of known transiting planet candidates found by Kepler (2326 at the time of writing) down to the most promising candidates for hosting a moon. Selected targets are fitted using a multimodal nested sampling algorithm coupled with a planet-with-moon light curve modelling routine. By comparing the Bayesian evidence of a planet-only model to that of a planet-with-moon, the detection process is handled in a Bayesian framework. In the case of null detections, upper limits derived from posteriors marginalised over the entire prior volume will be provided to inform the frequency of large moons around viable planetary hosts, eta-moon. After discussing our methodologies for target selection, modelling, fitting and vetting, we provide two example analyses.Comment: 21 pages, 8 figures, 4 tables, accepted in Ap

On stellar limb darkening and exoplanetary transits

This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different characterizations of a given model atmosphere can give quite different numerical results (even for a given limb-darkening `law'), while light-curve analyses yield limb-darkening coefficients that are dependent on system geometry, and that are not directly comparable to any model-atmosphere representation. These issues are examined in the context of exoplanetary transits, which offer significant advantages over traditional binary-star eclipsing systems in the study of stellar limb darkening. `Like for like' comparisons between light-curve analyses and new model-atmosphere results, mediated by synthetic photometry, are conducted for a small sample of stars. Agreement between the resulting synthetic-photometry/atmosphere-model (SPAM) limb-darkening coefficients and empirical values ranges from very good to quite poor, even though the targets investigated show only a small dispersion in fundamental stellar parameters.Comment: Accepted, MNRAS, 4/8/201

Prevalence and associated harm of engagement in self-Asphyxial behaviours ('choking game') in young people:A systematic review

OBJECTIVE: To assess the prevalence of engagement in self-asphyxial (risk-taking) behaviour (SAB) (‘choking game’) and associated morbidity and mortality in children and young people up to age 20. DESIGN: Systematic literature review. SEARCH STRATEGY: Electronic database search of MEDLINE, Embase, PsycINFO, CINAHL, PubMed, Web of Science Core Collection, BIOSIS citation index and the Cochrane register with no language or date limits applied. References of key papers were reviewed, and experts were contacted to identify additional relevant papers. ELIGIBILITY CRITERIA: Systematic reviews, cross-sectional, cohort and case–control studies, and case reports examining SAB with regard to individuals aged 0–20 years, without explicitly stated autoerotic, suicidal or self-harm intentions were included. RESULTS: Thirty-six relevant studies were identified, and SAB was reported in 10 countries. In North America, France and Colombia, awareness of SAB ranged from 36% to 91% across studies/settings, and the median lifetime prevalence of engagement in SAB was 7.4%. Six studies identified the potential for SAB to be associated with engagement in other risk behaviours. Ninety-nine fatal cases were reported. Of the 24 cases described in detail, most occurred when individuals engaged in SAB alone and used a ligature. CONCLUSIONS: The current evidence on SAB among young people is limited, and stems predominantly from North America and France. Awareness of SAB among young people is high, and engagement varies by setting. Further research is needed to understand the level of risk and harm associated with SAB, and to determine the appropriate public health response

PROCESO DE CARBONIZACIÓN HIDROTÉRMICA PARA INCREMENTAR LA TRANSPORTABILIDAD DE LA BIOMASA VEGETAL

Objective: Integration of the hydrothermal carbonization process in the treatment of biological wastes in order to increase biomass transportability by obtaining new products with added value. Design/methodology/approach: Fresh biomass is poured into a hermetic and pressurized reactor. Process progress is determined first from data coming of lignocellulose composition in the biomass and from processing conditions; temperature, pressure and processing time. Samples must be extracted which should be synchronized with technical pauses during the process advancement, to be analytically assessed. Slurry from HTC can be extracted in liquid state through valves placed on the reactor. Results: A stable quality of carbon obtained from biomass from various sources can be attained, when measurements are made at relatively short intervals along the process. This offers the opportunity to control and optimize the process performance, supported by results obtained in real time. Study limitations/implications: There are fluctuations in the quality of different types of biocarbon produced. Biomass composition must be analyzed, particularly the dry matter. At present, there are no suitable methods to monitor the carbonization process. Findings/conclusions: Hydrothermal carbonization is a faster process and it is possible to interfere with it, in order to balance the different types of biocarbon in terms of quality, by performing adequate adjustments in function of data obtained in real time.Objetivo: Integración del proceso de carbonización hidrotérmica en residuos biológicos para incrementar la transportabilidad de la biomasa mediante la obtención de productos con valor agregado. Diseño/metodología/aproximación: Se suministra biomasa fresca a un reactor de presión hermético. El progreso del proceso está determinado por los datos de la composición de la lignocelulosa en la biomasa y por las condiciones del proceso; la temperatura, la presión y el tiempo de residencia. Deben extraerse muestras de manera sincronizada con las pausas técnicas durante el avance del proceso y deben ser evaluadas analíticamente. El lodo del HTC puede extraerse en estado líquido a través de válvulas en el reactor. Resultados: Una calidad estable del carbón obtenido de biomasa proveniente de diferentes fuentes puede ser conseguida, al realizar mediciones a intervalos relativamente cortos durante el proceso, lo que abre la oportunidad para controlar y optimizar la conducción de estos procesos, sustentados en resultados obtenidos en tiempo real. Limitaciones del estudio/implicaciones: Hay fluctuaciones en la calidad de los diferentes tipos de biocarbón producidos. La composición de la biomasa debe ser analizada, en particular la materia seca. No se dispone de métodos apropiados para monitorear el proceso de carbonización. Hallazgos/conclusiones: La carbonización hidrotérmica es un proceso más rápido y es posible interferir en él para equilibrar los diferentes tipos de biocarbón en términos de calidad al realizar los ajustes adecuados en función de los datos obtenidos en tiempo real

GENERACIÓN DE BIOCARBÓN A PARTIR DEL MATERIAL SÓLIDO EN LA HIDRÓLISIS AERÓBICO-MICROBIOLÓGICA

Objective: Exploring the effectiveness of two processing methods in sequential operation in order to increase the profitability of individual processes during biomass transformation and its wastes for obtaining other products. Design/methodology/approach: Processes of hydrolysis and acidification are activated by the general process to obtain biogas, resulting in a highly acidic liquid biomass. The organic acids are removed through technical procedures to be utilized on other chemical processes. Leftover wastes contain few constituents able to be decomposed, and their appropriate disposal consumes resources, so they are processed through hydrothermal carbonization in order to obtain biocarbon. Results: When vegetation biomass with high moisture content is exposed to high temperatures for hydrothermal carbonization, water evaporation takes place as well as a selective amount of some particles contained in the biomass. Leftover waste is a solid and hard material, with a high carbon concentration. Study limitations/limitations: The technical process used to extract organic acids is slow, so the removal is partial and effectiveness is reduced. Findings/conclusions: Integration of processes with sequential operation, where useful compounds are obtained and wastes produced from the first processing become raw material for the following process, originating hydrothermal carbonization, improve efficiency and attain financial profitability.Objetivo: Explorar la efectividad de dos procesamientos en operación secuencial para incrementar la rentabilidad de los procesos individuales en la transformación de la biomasa y sus residuos para la obtención de productos. Diseño/metodología/aproximación: Se activan los procedimientos de hidrólisis y acido génesis del proceso general para producir biogas, en la que se obtiene una biomasa líquida muy ácida. Se rescatan los ácidos orgánicos mediante procedimientos técnicos para su utilización en otros procesos químicos. Los residuos resultantes contienen escasos elementos factibles de degradar y su apropiada disposición consume recursos, por lo que son sometidos al proceso de carbonización hidrotérmica, para obtener biocarbón. Resultados: La biomasa vegetal con alto contenido de humedad al ser expuesta a altas temperaturas para el proceso de carbonización hidrotérmica, genera evaporación de agua y una porción selectiva de algunas partículas contenidas en esa biomasa. El residuo final es un material sólido y duro, con alto concentración de carbón. Limitaciones del estudio/implicaciones: El proceso técnico de extraer los ácidos orgánicos es lento por lo que la separación es parcial y se reduce la efectividad. Hallazgos/conclusiones: La integración de los procesamientos con el funcionamiento de manera secuencial, donde se obtiene compuestos útiles y se generan residuos del primer procesamiento se convierten en la materia prima del siguiente, derivando en la carbonización hidrotérmica, mejoran la eficiencia y alcanzan rentabilidad financiera

Exomoon simulations

We introduce and describe our newly developed code that simulates light curves and radial velocity curves for arbitrary transiting exoplanets with a satellite. The most important feature of the program is the calculation of radial velocity curves and the Rossiter-McLaughlin effect in such systems. We discuss the possibilities for detecting the exomoons taking the abilities of Extremely Large Telescopes into account. We show that satellites may be detected also by their RM effect in the future, probably using less accurate measurements than promised by the current instrumental developments. Thus, RM effect will be an important observational tool in the exploration of exomoons.Comment: 5 pages, 2 figures with 9 figure panels, accepted by EM&