Composed Index for the Evaluation of Energy Security in Power Systems within the Frame of Energy Transitions—The Case of Latin America and the Caribbean

Energy transitions are transforming energy systems around the globe. Such a shift has caused the power system to become a critical piece of infrastructure for the economic development of every nation on the planet. Therefore, guaranteeing its security is crucial, not only for energy purposes but also as a part of a national security strategy. This paper presents a multidimensional index developed to assess energy security of electrical systems in the long term. This tool, named the Power System Security Index (PSIx), which has been previously used for the evaluation of a country in two different time frames, is applied to evaluate the member countries of the Latin American Energy Organization, located within the Latin America and the Caribbean region, to measure its performance on energy security. Mixed results were obtained from the analysis, with clear top performers in the region such as Argentina, while there are others with broad areas of opportunity, as is the case of Hait

Knickpoints in Martian channels indicate past ocean levels

On Mars, the presence of extensive networks of sinuous valleys and large channels provides evidence for a wetter and warmer environment where liquid water was more abundant than it is at present. We undertook an analysis of all major channel systems on Mars and detected sharp changes in elevation along the river long profiles associated with steep headwall theatre-like valleys and terraces left downstream by channel incision. These breaks in channel longitudinal slope, headwalls and terraces exhibit a striking resemblance with terrestrial fluvial features, commonly termed 'knickpoints'. On Earth, such knickpoints can be formed by more resistant bedrock or where changes in channel base-level have initiated erosion that migrates upstream (such as tectonic uplift or sea level change). We observed common elevations of Martian knickpoints in eleven separate channel systems draining into the Martian Northern lowlands. Numerical modeling showed that the common elevations of some of these knickpoints were not random. As the knickpoints are spread across the planet, we suggest that these Martian knickpoints were formed in response to a common base level or ocean level rather than local lithology. Thus, they potentially represent a record of past ocean levels and channel activity on Mars

L’escola rural. CRA El Trescaire

Dissetenes Jornades de Foment de la Investigació de la FCHS (Any 2012)Ens ha semblat oportú ampliar el concepte d'educació al món rural. En aquest sentit, hem recollit unes pautes que vénen en un llibre editat pel MRP el títol del qual és del tot significatiu: Treballar a l'escola rural ¿Treballar a l'escola rural? ¡Treballar a l'escola rural! Si pensem que possiblement aquest siga el nostre primer destí com a mestres el títol podria ser: Treballar a l'escola rural(m'ha tocat una escola rural) ¿Treballar a l'escola rural?(¡ufh no tinc ni idea que es fa aquí!) ¡Treballar a l'escola rural! (ja estic treballant en una escola rural, ¡és genial!) En aquest llibre figuren algunes de les funcions i objectius fonamentals de l’educació al mon rural, nosaltres mitjançant el nostre treball d’investigació en volgut fer una primera aproximació a aquest mon tan proper i necessari per la futura tasca com docents.We thought it appropriate to extend the concept of education in rural areas. In this regard, we have collected some guidelines that come in a book published by MRP whose title is quite significant: Working at the rural school ¿Work mean? ¡Working in the rural school! If you think this may be our first destination as Masters title could be: Working at the rural school (I have had a rural school) ¿Work mean? (¡Ufh I have no idea what is done here!) ¡Working in the rural school! (I'm working in a rural school, ¡is great!) In this book are some of the fundamental objectives and functions education in rural areas, we work with our research wanted to make a first approach to this world as next and necessary for future work as teachers

Effect of processing on microstructure and mechanical properties of pentaglycerine based solid-solid phase change materials

The present work addresses the lack of reported information about the mechanical properties of solid-solid PCMs, and how these are affected by their processing, considering that they usually incorporate fillers to increase their thermal conductivity. To this end, this work analyzes pentaglycerine (PG) based composites, which are of great interest in TES intended for 80 °C. These composites are also doped with various contents of expanded graphite (EG) with two different particle sizes. With these combinations, the effect of two typical processing methods, pressing and casting, on the microstructure of the composites is evaluated. Furthermore, the mechanical behavior of these composites in both crystal and plastic phases, as well as their thermal expansion during the transition process, is also reported in the current study. Besides demonstrating the important role that processing plays in these properties in PG/EG-based composites, it has been found that the use of EG is also beneficial for mitigating the permanent deformations experienced by these composites during thermal cycling. Finally, the exposed results give the first evidence of the interesting effect these processing methods have on the thermal properties of the composites.This research was funded by the FEDER/Ministerio de Ciencia e Innovaci ́on–Agencia Estatal de Investigacion, SWEET-TES project (RTI2018-099557-B-C21), as well as from The Basque Government (Elkartek CICe2020, KK-2020/00078). The authors also gratefully acknowledge Yagmur Polat and Cristina Luengo for their technical support

Failure of ProTaper rotary Ni-Ti instruments used by undergraduate students

Objective: To evaluate the effect of number of uses, angle and radius of curvature and type of instrument on the fracture of ProTaper rotary instruments when used by undergraduate students. Study design: Three hundred and seventy-six molars, with a total of 1114 root canals, extracted were instrumented by undergraduate students using ProTaper instruments according to the manufacturer´s recommendations. When fracture occurred, data were collected concerning the number of uses, type of instrument, level of fracture, angle and radius of curvature. ANOVA test were used to determine the influence of type of instrument in the incidence of instrument fracture. Logistic regression model was used to determine the influence of number of uses, angle and radius of curvature in the incidence of instrument fracture. Significance was set at p< 0.05. Results: A total of 37 Ni-Ti rotary instruments fractured during the treatment. Fracture occurred in 9.84% (37/376) of the teeth treated and 3.32% of the canals prepared with Ni-Ti rotary instruments (37/1114). A decrease in the radius of curvature of the canal significantly increased the likelihood of fracture (p=0.0001). Instrument fracture significantly increased as the number of uses increased (p=0.0037). No significant differences were found between the 6 types of ProTaper instruments (p=0.8). A reduction in the angle of curvature did not produce a significant decrease in the incidence of instrument separation (p=0.08). Conclusions: The results of this study imply that instrument fracture is linked to radius of curvature and number of uses