3,800 research outputs found
New data of the genus Boccardia Carazzi, 1893 (Polychaeta: Spionidae) for the Iberian Peninsula and the Atlantic Ocean
The first record for the Iberian coast and the Atlantic Ocean of two species of polychaetous annelids belonging to the genus Boccardia Carazzi, 1893 (Spionidae) is presented. Boccardia semibranchiata Guérin, 1990 is a recently described species from the Mediteranean Sea, whereas Boccardia proboscidea Hartman, 1940 is a very common species from the Pacific coasts. Both species have been collected in two intertidal zones from San Sebastián (Iberian Peninsula - Bay of Biscay). In the present paper, the collected specimens of both species are described, illustrated and discussed, and notes on their ecology and distribution are included. A simple key for the genus Boccardia for the Atlantic coasts is also provided.Dos especies de anélidos poliquetos pertenecientes al género Boccardia Carazzi, 1893 (Spionidae) se citan por primera vez para la costa de la península Ibérica y aguas del océano Atlántico. Boccardia semibranchiata Guérin, 1990 es una especie descrita recientemente en el mar Mediterráneo, mientras que Boccardia proboscidea Hartman, 1940 es una especie común en las costas del Pacífico. Ambas especies de poliquetos han sido recolectadas en dos zonas intermareales de San Sebastián (península Ibérica - golfo de Vizcaya). En el presente trabajo se realiza una descripción de los ejemplares colectados de ambas especies, se ilustran y se discuten, aportándose, además, notas sobre su distribución y ecología. Complementariamente, se presenta una sencilla clave del género Boccardia para el Atlántico.Instituto Español de Oceanografí
Optimisation of energy supply at off-grid healthcare facilities using Monte Carlo simulation
In this paper, we present a methodology for the optimisation of off-grid hybrid systems (photovoltaic-diesel-battery systems). A stochastic approach is developed by means of Monte Carlo simulation to consider the uncertainties of irradiation and load. The optimisation is economic; that is, we look for a system with a lower net present cost including installation, replacement of the components, operation and maintenance, etc. The most important variable that must be estimated is the batteries lifespan, which depends on the operating conditions (charge/discharge cycles, corrosion, state of charge, etc.). Previous works used classical methods for the estimation of batteries lifespan, which can be too optimistic in many cases, obtaining a net present cost of the system much lower than in reality. In this work, we include an advanced weighted Ah-throughput model for the lead-acid batteries, which is much more realistic. The optimisation methodology presented in this paper is applied in the optimisation of the electrical supply for an off-grid hospital located in Kalonge (Democratic Republic of the Congo). At the moment, the power supply relies on a diesel generator; batteries are used in order to ensure the basic supply of energy when the generator is unavailable (night hours). The optimisation includes the possibility of adding solar photovoltaic (PV) panels to improve the supply of electrical energy. The results show that optimal design could achieve a 28% reduction in the levelised cost of energy and a 54% reduction in the diesel fuel used in the generator, thereby reducing pollution. Furthermore, we discuss possible improvements to the telecommunications of the hospital
Optical to ultraviolet spectra of sandwiches of benzene and transition metal atoms: Time dependent density functional theory and many-body calculations
Creación de un paquete de análisis de series temporales para RStudio
En este trabajo se presenta el paquete CBJTSA para el lenguaje de programación R, el
cual implementa distintas funciones para el análisis de series temporales mediante modelos
ARIMA, completando las salidas de otros paquetes de R. Este paquete está enfocado al ámbito
educativo, por lo que el objetivo del mismo será facilitar el acceso a herramientas de
análisis de series temporales, usando este paquete como sustituto de otras herramientas más
complejas y costosas.
A lo largo de esta memoria se describen las distintas funciones que contiene el paquete
con detalle, explicando su uso y las salidas que proporciona. Además, se incluye un ejemplo
práctico de análisis de una serie temporal utilizando el paquete CBJTSA, para ilustrar su
funcionamiento en un caso más específico.This paper presents the CBJTSA package for the R programming language, which implements
different functions for the analysis of time series using ARIMA models, complementing
the outputs of other R packages. This package is focused on the educational enviroment, so its
objective is to facilitate access to time series analysis tools, using this package as a substitute
for other more complex and expensive tools.
Throughout this report, the different functions contained in the package are described in
depth, explaining its use and the outputs it provides. In addition, a practical example of a
time series analysis using the CBJTSA package is included to illustrate its operation in a
more specific case.Departamento de Estadística e Investigación OperativaGrado en Estadístic
Prevalence and factors associated with problematic internet use in a population of spanish university students
(1) Background: To examine the prevalence, and associated factors of, problematic Internet use in a sample of Spanish university students. (2) Methods: Cross-sectional descriptive study of a convenience sample of 698 university students. Self-esteem, alcohol consumption, perceived social support, depression, anxiety, stress and problematic Internet use were evaluated using the Rosenberg, CAGE, DUKE-UNC-11, DASS-21 and Young’s Internet Addiction Test, respectively. (3) Results: Problematic internet use was reported by 21% of respondents. Risk of problematic Internet use was independently associated with the preferred use of the smartphone, time of exposure to the Internet, less perceived social support, problematic alcohol consumption and symptoms of stress and anxiety. We found significant association between problematic internet use and time of exposure to the Internet, residential status, alcohol consumption, self-esteem, perceived social support and psychological distress, after bivariate analysis. (4) Conclusions: A considerable prevalence of problematic Internet use was found; in our sample problematic Internet use was associated with stress, alcohol consumption, anxiety and perceived social support. Strategies aimed at the early identification of problematic Internet use may lead to an improvement in the psychosocial health of the university student population. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Tablon3: adaptación de una herramienta de gamificación al entorno de ejecución Python 3
En este trabajo se describe el proceso de adaptación del código de la herramienta de gamificación
Tablon al lenguaje de programación Python 3. Como paso anterior a este proceso se analiza
de manera exhaustiva el funcionamiento de la aplicación y se redacta una documentación que
detalla la estructura, funcionamiento e implementación de la aplicación. En la documentación de
esta herramienta se incluyen desde explicaciones detalladas del contenido de cada fichero hasta
diagramas de diseño que representan la estructura de Tablon. También se recoge en este documento
una explicación del proceso de conversión que se ha realizado para obtener la aplicación final
Tablon3.This manuscript describes the process of adapting the code of the gamification tool Tablon to
the Python 3 programming language. As a previous step to this process, the operation of the
application is thoroughly analyzed and a documentation detailing the structure, operation and
implementation of the application is written. This documentation includes detailed explanations of
the content of each file, design diagrams that represent the structure of Tablon, etc. This document
also includes an explanation of the conversion process that has been carried out to obtain the final
Tablon3 application.Grado en Ingeniería Informátic
The association between diet and sleep quality among Spanish university students
While it has long been recognized that diet is a leading behavioral risk factor for human health, recent scientific findings have also suggested that diet and sleep quality may be connected. The purpose of the present study is to evaluate the association between diet and sleep quality among a group of Spanish university students. To do so, a cross-sectional study of 868 students was carried out. Sleep quality was assessed using the Spanish version of the Pittsburgh Sleep Quality Index (PSQI), while diet was assessed using the Spanish Healthy Eating Index (SHEI). The study revealed a noteworthy rate of bad sleepers (51.6%) and students whose diet needed modifications (82.2%). Unhealthy eaters were more likely to have poor sleep quality (aOR = 4.20; CI 95%: 2.07-8.52). The unbalanced intake of vegetables (aOR = 1.63; CI 95%: 1.14-2.34), fruits (aOR = 4.08; CI 95%: 2.90-5.74), dairy products (aOR = 1.96; CI 95%: 1.41-2.72), lean meats (aOR = 1.82; CI 95%: 1.19-2.78), legumes (aOR = 1.43; CI 95%: 1.00-2.02), sweets (aOR = 1.60; CI 95%: 1.13-2.25) and sugary soft drinks (aOR = 1.46; CI 95%: 1.07-1.99) was associated with lower sleep quality
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