Millimetre continuum observations of comet C/2009 P1 (Garradd)

Little is known about the physical properties of the nuclei of Oort cloud comets. Measuring the thermal emission of a nucleus is one of the few means for deriving its size and constraining some of its thermal properties. We attempted to measure the nucleus size of the Oort cloud comet C/2009 P1 (Garradd). We used the Plateau de Bure Interferometer to measure the millimetric thermal emission of this comet at 157 GHz (1.9 mm) and 266 GHz (1.1 mm). Whereas the observations at 266 GHz were not usable due to bad atmospheric conditions, we derived a 3-sigma upper limit on the comet continuum emission of 0.41 mJy at 157 GHz. Using a thermal model for a spherical nucleus with standard thermal parameters, we found an upper limit of 5.6 km for the radius. The dust contribution to our signal is estimated to be negligible. Given the water production rates measured for this comet and our upper limit, we estimated that Garradd was very active, with an active fraction of its nucleus larger than 50%.Comment: Accepted for publication in Astronomy & Astrophysics. 5 pages, 2 figure

Project-Based Learning in Financials Advice

[EN] The efficient use of the economic resources of companies, both large enterprises and SMEs, as well as the different means to obtain these resources, are critical aspects. For this reason, the new generation of students of degrees such as Business Administration and Management should know in depth the different types of banking entities, the main asset and liability operations of banking entities and the existing risk, as well as the main challenges of the banking sector for the following years. In the same way, a profound comprehension about the stock market and the simulation models to analyse different financial situations are aspects highly valued by companies. Based on this, learning requirements arise to seek active methodologies that allow students to acquire the knowledge and key competencies that companies currently require. Among these methodologies, we would like to highlight the Project-based Learning (PBL) through which the teaching-learning process is carried out through the development of a project that tries to give an answer to a real problem. Through PBL, students develop a high degree of autonomy and responsibility, since they are responsible for planning, structuring the work and preparing the project to solve a specific problem or situation. The lecturers¿ work in this methodology is to guide and support students throughout all the process of project development. Therefore, this article defines a PBL model to satisfy the current needs of the market in terms of financials advice. The PBL model involves two subjects: (i) Banking and Stock Market and (ii) Advanced financial simulation techniques taught in the Degree of Business Administration and Management in the Campus of Alcoy of Universitat Politècnica de València (Spain). The PBL model has been defined collaboratively to be performed on both subjects during one academic year. This PBL model provides students with the necessary skills and abilities to perform financial advisory tasks in the today's business context.This article has been supported by Universitat Politècnica de València, particularly by the Vice-rectorate for Digital Resources and Documentation (Vicerrectorado de Recursos Digitales y Documentación) and Vice-Rectorate for Studies, Quality and Accreditation (Vicerrectorado de Estudios, Calidad y Acreditación) under the Call for Learning + Teaching (Convocatoria A+D2019: Aprendizaje + Docencia. Proyectos de Innovación y Mejora Educativa) and Project Code: A157. The authors would like to acknowledge the support of the Institute of Educational Sciences (Instituto de Ciencias de la Educación), the Evaluation and Monitoring Commission for Educational Innovation and Improvement Projects (Comisión de Evaluación y Seguimiento de Proyectos de Innovación y Mejora Educativa (CESPIME) and Escuela Politécnica Superior de Alcoy.Capó I Vicedo, J.; Benito, A.; Montava-Jorda, S.; Sanchis, R. (2021). Project-Based Learning in Financials Advice. EDULEARN Proceedings (Internet). 7522-7528. https://doi.org/10.21125/edulearn.2021.1526S7522752

Energy in the home: Everyday life and the effect on time of use

The application of building simulation and modelling is becoming more widespread, particularly in the analysis of residential buildings. The energy consumption and control of systems in residential buildings are tightly linked to the behaviour of people, arguably more so than in commercial buildings which have traditionally been the preserve of building simulation analysis. The input profiles used in simulation pay little attention to the link between numerical characterisations of observed ‘behaviour’ and the way people actually live in the home. Understanding this is important if we are to improve the modelling of buildings, gain greater insight into energy consumption and make better decisions about future energy production and generation. This paper explores this link by combining conventional numerical analysis of appliance data with insights from the ethnographic study of families in 20 UK homes. Ethnographic insights provide a context to the analysis and understanding of monitoring data that would not otherwise be possible. Importantly, this paper highlights the need to rethink previously static notions of simulation input, such as occupancy and individual appliance use

P/2010 A2 LINEAR II: dynamical dust modelling

P/2010 A2 is an object on an asteroidal orbit that was observed to have an extended tail or debris trail in January 2010. In this work, we fit the outburst of P/2010 A2 with a conical burst model, and verify previous suspicions that this was a one--time collisional event rather than an sustained cometary outburst, implying that P/2010 A2 is not a new Main Belt Comet driven by ice sublimation. We find that the best--fit cone opening angle is about 40 to 50 degrees, in agreement with numerical and laboratory simulations of cratering events. Mapping debris orbits to sky positions suggests that the distinctive arc features in the debris correspond to the same debris cone inferred from the extended dust. From the velocity of the debris, and from the presence of a velocity maximum at around 15 cm/s, we infer that the surface of A2 probably has a very low strength (<1 kPa), comparable to lunar regolith.Comment: 14 pages, 25 figures; accepted by Astronomy and Astrophysic

A photon calorimeter using lead tungstate crystals for the CEBAF Hall A Compton polarimeter

The performances of the calorimeter of the Jlab Hall A Compton Polarimeter have been measured using the Mainz tagged photon beam.Comment: 13 page

Activity distribution of comet 67P/Churyumov-Gerasimenko from combined measurements of non-gravitational forces and torques

Aims. Understanding the activity is vital for deciphering the structure, formation, and evolution of comets. We investigate models of cometary activity by comparing them to the dynamics of 67P/Churyumov-Gerasimenko. Methods. We matched simple thermal models of water activity to the combined Rosetta datasets by fitting to the total outgassing rate and four components of the outgassing induced non-gravitational force and torque, with a final manual adjustment of the model parameters to additionally match the other two torque components. We parametrised the thermal model in terms of a distribution of relative activity over the surface of the comet, and attempted to link this to different terrain types. We also tested a more advanced thermal model based on a pebble structure. Results. We confirm a hemispherical dichotomy and non-linear water outgassing response to insolation. The southern hemisphere of the comet and consolidated terrain show enhanced activity relative to the northern hemisphere and dust-covered, unconsolidated terrain types, especially at perihelion. We further find that the non-gravitational torque is especially sensitive to the activity distribution, and to fit the pole-axis orientation in particular, activity must be concentrated (in excess of the already high activity in the southern hemisphere and consolidated terrain) around the south pole and on the body and neck of the comet over its head. This is the case for both the simple thermal model and the pebble-based model. Overall, our results show that water activity cannot be matched by a simple model of sublimating surface ice driven by the insolation alone, regardless of the surface distribution, and that both local spatial and temporal variations are needed to fit the data. Conclusions. Fully reconciling the Rosetta outgassing, torque, and acceleration data requires a thermal model that includes both diurnal and seasonal effects and also structure with depth (dust layers or ice within pebbles). This shows that cometary activity is complex. Nonetheless, non-gravitational dynamics provides a useful tool for distinguishing between different thermophysical models and aids our understanding

Fatigue in celiac disease: A review of the literature

Fatigue is increasingly recognized as a significant problem in patients with chronic inflammatory and autoimmune diseases. In celiac disease, a chronic immune‐mediated disease triggered by dietary gluten, conflicting opinions exist regarding both the size of the problem and the effect of a gluten‐free diet (GFD) on fatigue. We reviewed the existing literature regarding fatigue in celiac disease. We conducted a systematic search in the Embase, Ovid Medline, and Cochrane databases using subject terms from controlled vocabularies. Articles were reviewed based on language, type of article, title, and abstract or full text. Eighteen articles were finally selected for review. Fatigue was significantly greater in patients with celiac disease compared to healthy control subjects. Fatigue prevalence ranged from 8 to 100%. Fatigue severity was assessed in six studies. The fatigue visual analogue scale was the most frequently used fatigue instrument with scores from 57 to 79 prior to starting a GFD and from 39 to 59 in patients on a GFD. Seven studies investigated the effect of a GFD on fatigue, including five studies that reported less fatigue while on the diet and two studies that showed no significant difference. This review concludes that fatigue is a substantial complaint in patients with celiac disease. A GFD seems to reduce fatigue, but existing data are limited.publishedVersio

Angular Correlations in Internal Pair Conversion of Aligned Heavy Nuclei

We calculate the spatial correlation of electrons and positrons emitted by internal pair conversion of Coulomb excited nuclei in heavy ion collisions. The alignment or polarization of the nucleus results in an anisotropic emission of the electron-positron pairs which is closely related to the anisotropic emission of $\gamma$-rays. However, the angular correlation in the case of internal pair conversion exhibits diverse patterns. This might be relevant when investigating atomic processes in heavy-ion collisions performed at the Coulomb barrier.Comment: 27 pages + 6 eps figures, uses revtex.sty and epsf.sty, tar-compressed and uuencoded with uufile

Flights in my hands : coherence concerns in designing Strip'TIC, a tangible space for air traffic controllers

Best Paper Honorable Mention awardInternational audienceWe reflect upon the design of a paper-based tangible interactive space to support air traffic control. We have observed, studied, prototyped and discussed with controllers a new mixed interaction system based on Anoto, video projection, and tracking. Starting from the understanding of the benefits of tangible paper strips, our goal is to study how mixed physical and virtual augmented data can support the controllers' mental work. The context of the activity led us to depart from models that are proposed in tangible interfaces research where coherence is based on how physical objects are representative of virtual objects. We propose a new account of coherence in a mixed interaction system that integrates externalization mechanisms. We found that physical objects play two roles: they act both as representation of mental objects and as tangible artifacts for interacting with augmented features. We observed that virtual objects represent physical ones, and not the reverse, and, being virtual representations of physical objects, should seamlessly converge with the cognitive role of the physical object. Finally, we show how coherence is achieved by providing a seamless interactive space