Ultra High Resolution Transmission Electron Microscopy of Matrix Mineral Grains in CM Chondrites: Preaccretionary or Parent Body Aqueous Processing?

CM chondrites are highly hydrated meteorites associated with a parent asteroid that has experienced significant aqueous processing. The meteoritic evidence indicates that these non-differentiated asteroids are formed by fine-grained minerals embedded in a nanometric matrix that preserves chemical clues of the forming environment. So far there are two hypothesis to explain the presence of hydrated minerals in the content of CM chondrites: one is based on textural features in chondrule-rim boundaries [1-3], and the other ‘preaccretionary’ hypothesis proposes the incorporation of hydrated phases from the protoplanetary disk [4-6]. The highly porous structure of these chondrites is inherited from the diverse materials present in the protoplanetary disk environment. These bodies were presumably formed by low relative velocity encounters that led to the accretion of silicate-rich chondrules, refractory Ca- and Al-rich inclusions (CAIs), metal grains, and the fine-grained materials forming the matrix. Owing to the presence of significant terrestrial water in meteorite finds [7], here we have focused on two CM chondrite falls with minimal terrestrial processing: Murchison and Cold Bokkeveld. Anhydrous carbonaceous chondrite matrices are usually represented by highly chemically unequilibrated samples that contain distinguishable stellar grains. Other chondrites have experienced hydration and chemical homogeneization that reveal parent body processes. We have studied CM chondrites because these meteorites have experienced variable hydration levels [8-10]. It is important to study the textural effects of aqueous alteration in the main minerals to decipher which steps and environments promote bulk chemistry changes, and create the distinctive alteration products. It is thought that aqueous alteration has particularly played a key role in modifying primordial bulk chemistry, and homogenizing the isotopic content of fine-grained matrix materials [7, 11, 12]. Fortunately, the mineralogy produced by parent-body and terrestrial aqueous alteration processes is distinctive [5, 11]

Can we detect internal moisture content in hardened concrete with an infrared camera?

The main goal of this paper was to assess the ability of infrared thermography to detect non-superficial moisture content in concrete elements. For this purpose, a commercial camera (Flir i5) was used and firstly its capacities and technical limitations were analyzed by comparing it with other commonly commercialized. Secondly, the experiments were undertaken using a concrete specimen (water/cement=0.5) and water under a pressure of 500 kPa was injected over 72 hours into one side of the specimen. The specimen was then left at room temperature (20ºC) for 24 hours, so the surface moisture disappeared. Prior to the images acquisition, the specimen surface was heated by a lamp located at a distance of 0.68 m from the central point of the specimen. In this way, two areas (dry and injected) to be registered would receive the same energy, since they were equidistant from the heating source. The first record was acquired before heating the specimen and then, the heating process was interrupted every 10 minutes to perform the infrared images acquisitions. Finally, by means of the destructive test, the average water penetration depth was assessed to be 3 cm. The infrared images acquired before heating the specimen showed a small temperature variation as a result of the presence of water, 16,3 ºC in the dry area and 15,8 ºC in the injected area. However, after the heating, due to the greater specific heat of water, the injected part achieved a temperature 4º C lower than the symmetrical dry area. This result was very interesting because, in the initial moment (before heating) the surface specimen was dry, but there was a wet area inside of the specimen that was not visually identifiable. Nevertheless, by means of infrared imaging an indicator was obtained that allowed to detect the presence of this internal moisture content

Psychological elements explaining the consumer's adoption and use of a website recommendation system: A theoretical framework proposal

The purpose of this paper is to understand, with an emphasis on the psychological perspective of the research problem, the consumer's adoption and use of a certain web site recommendation system as well as the main psychological outcomes involved. The approach takes the form of theoretical modelling. Findings: A conceptual model is proposed and discussed. A total of 20 research propositions are theoretically analyzed and justified. Research limitations/implications: The theoretical discussion developed here is not empirically validated. This represents an opportunity for future research. Practical implications: The ideas extracted from the discussion of the conceptual model should be a help for recommendation systems designers and web site managers, so that they may be more aware, when working with such systems, of the psychological process consumers undergo when interacting with them. In this regard, numerous practical reflections and suggestions are presented

Ultra High Resolution Transmission Electron Microscopy of Matrix Mineral Grains in CM Chondrites: Preaccretionary or Parent Body Aqueous Processing?

CM chondrites are highly hydrated meteorites associated with a parent asteroid that has experienced significant aqueous processing. The meteoritic evidence indicates that these non-differentiated asteroids are formed by fine-grained minerals embedded in a nanometric matrix that preserves chemical clues of the forming environment. So far there are two hypothesis to explain the presence of hydrated minerals in the content of CM chondrites: one is based on textural features in chondrule-rim boundaries [1-3], and the other ‘preaccretionary’ hypothesis proposes the incorporation of hydrated phases from the protoplanetary disk [4-6]. The highly porous structure of these chondrites is inherited from the diverse materials present in the protoplanetary disk environment. These bodies were presumably formed by low relative velocity encounters that led to the accretion of silicate-rich chondrules, refractory Ca- and Al-rich inclusions (CAIs), metal grains, and the fine-grained materials forming the matrix. Owing to the presence of significant terrestrial water in meteorite finds [7], here we have focused on two CM chondrite falls with minimal terrestrial processing: Murchison and Cold Bokkeveld. Anhydrous carbonaceous chondrite matrices are usually represented by highly chemically unequilibrated samples that contain distinguishable stellar grains. Other chondrites have experienced hydration and chemical homogeneization that reveal parent body processes. We have studied CM chondrites because these meteorites have experienced variable hydration levels [8-10]. It is important to study the textural effects of aqueous alteration in the main minerals to decipher which steps and environments promote bulk chemistry changes, and create the distinctive alteration products. It is thought that aqueous alteration has particularly played a key role in modifying primordial bulk chemistry, and homogenizing the isotopic content of fine-grained matrix materials [7, 11, 12]. Fortunately, the mineralogy produced by parent-body and terrestrial aqueous alteration processes is distinctive [5, 11]

Factors that influence the process of formation of the olympic judokas

Con el objetivo de analizar los factores que influyen en el proceso de formación deportiva de los judokas españoles olímpicos, se aplicó una entrevista semiestructurada de 52 preguntas agrupadas en 6 dimensiones (Contexto Deportivo, Contexto Social, Proceso de Formación, Psicológica, Técnico-táctica, Condición Física). Los resultados muestran que los judokas olímpicos se iniciaron en la práctica del Judo a los 6,90 ± 3,02 años, concretamente las mujeres a los 6,80 ± 2,88 años y los hombres algo más tarde, a los 7 ± 3,42 años, el 95% (n=19) influenciados, fundamentalmente, por un familiar. Además, destaca que ninguno de los entrevistados consiguió medalla en categorías inferiores. Para el 75% (n=15) de los judokas olímpicos es muy importante llevar una sincronización del entrenamiento técnico-táctico, de la condición física y de los aspectos psicológicos de forma integradaWith the aim of analizing the factors that have an influence on the sports training process of the olympic Spanish judokas, a semistructured interview of 52 questions grouped in 6 aspects was carried out: Sports Context, Social Context, Training Process, Psychological Condition, Technical-Tactical Condition and Physical Conditon). The results show that olympic judokas began practising judo at the age of 6.90 ± 3.02 years. Specifically, women started at the age of 6.80 ± 2.88, and men slightly later, at the age of 7 ± 3.42 years. 95% (n=19) of them were mainly influenced by a relative. Moreover, it is to be highlighted that none of the interviewees won a medal in low categories. For 75% (n=15) of the olympic judokas, it is very important that technical-tactical training, physical condition training and psychological aspects be synchronised in an integrated wa

A Systematic Review of Augmented Reality in Health Sciences: A Guide to Decision-Making in Higher Education

The objective of this study was to investigate the usability of the augmented reality (AR) in higher education in the area of health sciences to describe what type of interventions have been developed, their impact on various psychopedagogical aspects of the students as well as the main advantages, disadvantages and challenges in incorporating AR in the teaching-learning process. A systematic review was carried out in the CINAHL, PsycINFO, MEDLINE,Web of Science databases and the Google Scholar search engine. The search was limited to original research articles written in English, Spanish or Portuguese since 2014. The quality of the selected articles (n = 19) was assessed using the Mixed Methods Appraisal Tool (MMAT). The applications and electronic devices used and the measurement instruments used were described. The use of AR made it easier for students to acquire skills, especially in courses with a high component of three-dimensional visualization, and positively influenced various aspects of the learning process such as motivation, satisfaction or autonomous learning. As an educational technological tool applied to higher education in health sciences, AR improves the teaching-learning process by influencing it in a multidimensional wayS

Intra-varietal diversity for agronomic traits in 'Garnacha Blanca'

'Garnacha Blanca' is a somatic variant derived from 'Garnacha Tinta', an old variety with large genetic and phenotypic variability. In this work we have studied for two years the phenotypic variation existing in 'Garnacha Blanca' for yield and quality related traits in accessions from 14 sampling locations of ancient vineyards in the Ebro Valley, Spain. The results showed high variability among the accessions in many of the traits studied in 'Garnacha Blanca'. Different accessions could be distinguished both years using several traits, including two important traits in terms of quality and yield: bunch compactness and yield per plant. A large environment effect, intrinsic to the 'Garnacha' group, enhances phenotypic variation among years, what requires increasing the number of bunches and years for clonal characterization in this variety. The dimensions of the berry showed the least variability, while traits related to bunch architecture like bunch length were discriminant and also stable

Questionnaire to measure Educational Technologies Acceptance in Moroccan Public Universities

[EN]The project “Support to the Higher Education system in Morocco within the framework of a rapprochement with the European Higher Education Area” (Appui au Système de l'Enseignement supérieur au Maroc dans le cadre d'un rapprochement avec l'Espace européen de l'Enseignem), is an European Project whose general objective is accompanying, assisting and promoting the reform of the Moroccan higher education system within the framework of its strategic vision 2015-2030 and its approach to the European Higher Education Area in order to improve the employability of graduates and the governance of the university system. The project is organized into 6 components that involve different Spanish institutions. In the development of Component 3 (Mission 3.1), Diversification des modalités d’enseignement (stratégie e-learning), it is important to know the perception and opinion of teachers from Moroccan public universities related to the state, use and prospection of educational technologies (García-Peñalvo, 2018; García-Peñalvo & Seoane-Pardo, 2015; Gros & García-Peñalvo, 2016) in their teaching activity. To achieve this objective, a questionnaire based on the extended (Huang, Teo, Sánchez-Prieto, García-Peñalvo, & Olmos-Migueláñez, 2019; Sánchez-Prieto, 2018; Sánchez-Prieto, Hernández-García, García-Peñalvo, Chaparro- Peláez, & Olmos-Migueláñez, 2019; Sánchez-Prieto, Olmos-Migueláñez, & García-Peñalvo, 2016a, 2016b, 2017; Venkatesh & Bala, 2008) TAM model has been designed (Technology Acceptance Model). Thus, an evaluation model is proposed in which, in addition to evaluating the 3 usual dimensions of the TAM models (perceived utility, perceived facility, behavioural intention), 7 external dimensions are included related to social influence (Subjective norm; Social image), the professional context (Voluntariness, relevance, results of use, external control of the tool) and the personal context (Anxiety)

Questionnaire on Indicators of Incorporation and Use of Educational Technologies in Moroccan Public Universities

[EN]The project “Support to the Higher Education system in Morocco within the framework of a rapprochement with the European Higher Education Area” (Appui au Système de l'Enseignement supérieur au Maroc dans le cadre d'un rapprochement avec l'Espace européen de l'Enseignem), is an European Project whose general objective is accompanying, assisting and promoting the reform of the Moroccan higher education system within the framework of its strategic vision 2015-2030 and its approach to the European Higher Education Area in order to improve the employability of graduates and the governance of the university system. The project is organized into 6 components that involve different Spanish institutions. In the development of component 3 (Mission 3.1), Diversification des modalités d’enseignement (stratégie eLearning), it is important to have a basic knowledge of some indicators on the incorporation and use of educational technologies In Moroccan Public Universities. To this end, we present in the framework of this project a simple questionnaire, which each public university must answer separately. In this sense, it is important that the answers reflect the reality of each institution in the most reliable way possible. The data collected aimed to facilitate, on the one hand, the making of recommendations by the panel of experts of this Component 3. On the other hand, the information collected aims to guide the decision making in the use of educational technologies and in the definition of an eLearning strategy (García- Peñalvo & Seoane-Pardo, 2015; Gros & García-Peñalvo, 2016) in the Moroccan Public University System, both at the ministerial level and individually by the heads of the Moroccan Public Universities. The UNIVERSITIC reports (CRUE TIC, 2014; Gómez, 2016, 2018; Píriz, 2015), made by CRUE Universidades Españolas, have been taken as reference for the realization of this questionnaire http://www.crue.org/SitePages/Universitic.aspx

Growth monitoring with sub-monolayer sensitivity via real time thermal conductance measurements

Growth monitoring during the early stages of film formation is of prime importance to understand the growth process, the microstructure and thus the overall layer properties. In this work, we demonstrate that phonons can be used as sensitive probes to monitor real time evolution of film microstructure during growth, from incipient clustering to continuous film formation. For that purpose, a silicon nitride membrane-based sensor has been fabricated to measure in-plane thermal conductivity of thin film samples. Operating with the 3{\omega}-V\"olklein method at low frequencies, the sensor shows an exceptional resolution down to {\Delta}({\kappa}*t)=0.065 nm*W/(m*K), enabling accurate measurements. Validation of the sensor performance is done with organic and metallic thin films. In both cases, at early stages of growth, we observe an initial reduction of the effective thermal conductance of the supporting amorphous membrane, K, related with the surface phonon scattering enhanced by the incipient nanoclusters formation. As clusters develop, K reaches a minimum at the percolation threshold. Subsequent island percolation produces a sharp increase of the conductance and once the surface coverage is completed K increases linearly with thickness The thermal conductivity of the deposited films is obtained from the variation of K with thickness