The loyalty of young residents in an island destination: An integrated model.

This paper investigates the factors that influence the loyalty of young residents as tourists in their home destination in the context of domestic tourism. The interest in studying the loyalty of this particular population segment stems from their consumption potential, their influence, and for the triple role they can play as tourists in the destination, as residents in the destination and as collaborators with local tourism companies. The setting for this study is one of growing domestic tourism in a destination made up of islands, the Canary Islands (Spain). The importance of this kind of research for island destinations arises from the negative impacts of tourism that island destinations suffer more than others, often with negative repercussions on loyalty. This paper studies the role of tourism companies, the product, the place and the young residents themselves in the formation of loyalty. A sample of 678 young residents from the Canary Islands responded to an ad hoc questionnaire of 22 items. The descriptive analysis highlights that young residents value to varying degrees all the variables included in the model (tourism companies, place, product and tourist variables). The discriminant analysis shows that there are no significant differences in the perceptions of young residents according to gender, island of residence or the number of trips made within the destination, which confirms the generational nature of the study and the possibility of extrapolating the results. Using the causal model proposed, the formation of loyalty among young residents is explained. In this model, the variables related to the company and the product hardly influence loyalty formation among young residents when these variables are integrated into the same model with place variables (identity, attachment and familiarity). These variables initiate the chain of cause and effect that culminates in the formation of satisfaction and loyalty among tourists, relegating company and product variables to the background

SORPTION OF LINEAR ALKYLBENZENE SULFONATES AND SULFOPHENYLCARBOXYLIC ACIDS ON MARINE SEDIMENTS

The sorption of linear alkylbenzene sulfonates (LAS) and of their main biodegradation intermediates, sulfophenylcarboxylic acids (SPC) has been characterized in marine sediments. The required equilibrium time for undecylbenzene sulfonate (C11LAS) sorption is 12 h, and 24 h for sulfophenyl undecanoic acid (C11SPC). C11LAS sorption decreases with temperature due to the exothermic character of this process. C11SPC sorption is less complete and less homogeneous than for C11LAS. The alkylic or carboxylic chain length (C10-C13) is correlated positively with the partition coefficient, and the effect of the carboxylic group is more significant than that of the additional methylene group. Sorption of LAS and SPC homologues (C10-C13) are reversible processes. Desorption of SPC homologues is almost complete, but the desorption percentage of LAS homologue decreases with alkylic chain length. Small fractions of sorbed LAS homologues could take longer to be desorbed than the times covered by this study.This research has been supported by the Environmental and Climate Program of the European Commission PRISTINE (Contract ENV4-CT97-494) from Waste Water Cluster and by the Spanish Inter-Ministerial Science and Technology Commission “BALAS” project (CICYT, REN2001-2980-C02-01/HID)

Stability of liquid bridges between twisted elliptical disks

The influence in the stability of long liquid bridges supported between two elliptical-shaped disks of their main axis relative orientation is investigated. A numerical continuation method capable of finding equilibrium shapes, both stable and unstable, is used to calculate a series of equilibrium shapes supported by disks of increasing eccentricity for different relative orientation of the disks axis. The stable or unstable character of each of the shapes is calculated to determine the position of the stability limit and its characte

Analysis of Modified Mechanical Properties in the Repair by SMAW Welding of Plow Discs in Andean Agricultural Areas

The objective of this contribution is to analyze the results of the technical studies of mechanical properties in standard plow discs, after their repair by manual arc welding with a SMAW coated electrode, commonly used in tillage tasks in Andean agricultural areas. For the repair process, the available, convenient, and easily acquired resources are implemented, such as consumables, equipment, and accessories necessary for the procedure. The nature of the base material was initially determined, by means of a spark spectrometry study for the case of worn plow discs, in such a way that the characteristic alloying elements of AISI-SAE 1340 steel are evident. The base of the original material allows defining and implementing essential and non-essential variables of the SMAW welding process according to AWS D1.1 and D14.3; therefore, the lap joint is designed, comprising of a worn disc plus similar sacrificial metals of identical conditions. As a conventional part of the welding processes, the quality control of the welds is carried out by means of penetrating inks under the ASTM E-165 standard, the respective measurements of the mechanical properties achieved, maintain analog factory hardness values of 37 HRC and increases the hardenability of the lap-type weld bead. Finally, it is concluded that the repair process contributes to a sustainable and efficient alternative that preserves the average hardness and improves hardenability, which are necessary to withstand the operational context that induces the typical premature wear of clayey and humid soils. Keywords: Hardness, hardenability, plow disc, welding, agricultural soil. Resumen El presente aporte tiene el objetivo de analizar los resultados de los estudios técnicos de propiedades mecánicas en discos de arado estándar, posterior a su reparación por soldadura de arco manual con electrodo revestido SMAW, de uso común en labores de labranza de zonas agrícolas andinas. Para el proceso de la reparación, se implementan los recursos disponibles, convenientes y de fácil adquisición, como consumibles, equipos y accesorios necesarios para el procedimiento. Se determina inicialmente la naturaleza del material base, mediante un estudio de espectrometría de chispa para el caso de discos de arado desgastados, de tal manera se evidencia los elementos aleantes característicos del acero AISI-SAE 1340. La base del material original permite definir e implementar variables esenciales y no esenciales del proceso de soldadura SMAW según AWS D1.1 y D14.3, por lo tanto, se diseña la junta de traslape, que comprende de un disco desgastado más metales similares de sacrificio de condiciones idénticas. Como parte convencional de los procesos de soldadura se realiza el control de calidad de las soldaduras mediante tintas penetrantes bajo la normativa ASTM E-165, las respectivas mediciones de las propiedades mecánicas conseguidas, mantienen valores de dureza de fábrica 37 HRC análogos y la templabilidad aumenta en el cordón de soldadura de tipo traslape. Finalmente, se concluye que el proceso de reparación contribuye con una alternativa sustentable y eficiente que conserva la dureza promedio y mejora la templabilidad, necesaria para soportar el contexto operacional que induce el desgaste prematuro típico de terrenos arcillosos y húmedos. Palabras Clave: Dureza, templabilidad, disco de arado, soldadura, suelo agrícola

Magnetic effect in viscosity of magnetorheological fluids

ABSTRACT: In this work the study of viscosity is presented for a magnetorheological fluid made from iron oxides micrometre, under an external magnetic field. The material was characterized by magnetic loops in a vibrating sample magnetometer and its crystal structure by X-ray diffraction. The results show that saturation magnetization and coercive field have dependence with the powder size. The material has different crystal structure which lattice parameters were determined by Rietveld refinement. The viscosity of the magnetorheological fluid was measured by a viscometer with rotational symmetry with and without external field. This result evidence a dependency on the size, percentage iron oxide and the applied magnetic field, it is due to the hydrodynamic volume of iron oxide interacts with the external magnetic field, increasing the flow resistance

La computadora en la educación en el siglo XXI. Un mapeo científico de la literatura en Web of Science

Computers have evolved over the course of history through successive generations. The impact of this technology on society has revolutionised the way we communicate, participate in the political life of a country or access education. The potential of the computer in the field of education has been highlighted by last year's global event. The objective of the study is to analyze the literature on the term computer in the field of education (CoMPU-EdU) in the Web of Science database. for this, a bibliometric methodology based on a scientific mapping of the publications on the state of the question has been used. It has worked with an analysis unit of 10939 documents. The results indicate that research related to "computer" in education is mainly presented in English and in research articles. In addition, the journal with the most manuscripts on this line of research is Computer & Education. The analysis of the scientific evolution of this line of research shows that studies are mainly focused on teaching and learning processes, as well as on students' attitudes towards computer use. It can be concluded that the CoMPU-EdU investigations are currently at an inflection point, given that there is a downward trend, as far as production volume is concerned. The scientific community is beginning to focus its research on other more specific branches of computer, such as augmented reality or robotics. In addition, the scientific production of CoMPU-EdU in the 21th century focuses mainly on the attitudes of the members involved in the pedagogical act, on gender differences, on the elements of the teaching and learning processes - pedagogical methods and evaluation - and in the attention of students with special educational needs. Probably in the future the lines of research will begin to focus on self-regulation of learning, computational-thinking and gamificationLas computadoras han evolucionado a lo largo de la historia a través de generaciones sucesivas. El impacto de esta tecnología en la sociedad ha revolucionado la forma en que nos comunicamos, participamos en la vida política de un país o accedemos a la educación. El potencial de la computadora en el campo de la educación ha sido destacado por el evento global del año pasado. El objetivo del estudio es analizar la literatura sobre el término informática en el campo de la educación (CoMPU-EdU) en la base de datos de Web of Science. Para ello se ha utilizado una metodología bibliométrica basada en un mapeo científico de las publicaciones sobre el estado de la cuestión. ha trabajado con una unidad de análisis de 10939 documentos. Los resultados indican que la investigación relacionada con la "computadora" en la educación se presenta principalmente en inglés y en artículos de investigación. Además, la revista con más manuscritos en esta línea de investigación es Computer & Education. El análisis de la evolución científica de esta línea de investigación muestra que los estudios se centran principalmente en los procesos de enseñanza y aprendizaje, así como en las actitudes de los estudiantes hacia el uso de la computadora. Se puede concluir que las investigaciones CoMPU-EdU se encuentran actualmente en un punto de inflexión, dado que existe una tendencia a la baja, en lo que se refiere al volumen de producción. La comunidad científica empieza a centrar su investigación en otras ramas más específicas de la informática, como la realidad aumentada o la robótica. Además, la producción científica de CoMPU-EdU en el siglo XXI se centra principalmente en las actitudes de los integrantes involucrados en el acto pedagógico, en las diferencias de género, en los elementos de los procesos de enseñanza y aprendizaje - métodos pedagógicos y de evaluación - y en la atención de alumnos con necesidades educativas especiales. Probablemente en el futuro las líneas de investigación comiencen a centrarse en la autorregulación del aprendizaje, el pensamiento computacional y la gamificació

Factor analysis of linear alkylbenzene sulphonate (LAS) vertical distribution in coastal sediments of Cadiz Bay (southwest Spain)

El comportamiento del alquilbenceno lineal sulfonato (LAS) en los sistemas costeros no se conoce con precisión, y este conocimiento es aun menor si nos restringimos al compartimento sedimentario. En este trabajo se aplica un análisis factorial a los resultados obtenidos para distintas variables determinadas en tres estaciones, tanto en sedimento como en agua intersticial, con el objetivo de evaluar sus interrelaciones con el LAS. Las variables analizadas presentan dos modos principales de distribución con la profundidad en el compartimento sedimentario: lineal y/o exponencial. En casi todos los casos, el LAS se asocia a ambos modos de distribución, lo que indica que su concentración sufre una disminución con la profundidad, pero se produce de forma especialmente acusada en la capa superficial.Very little is known concerning the behaviour of linear alkylbenzene sulphonate (LAS) in coastal systems, and even less when we consider the sedimentary field only. In the present study, a factor analysis is applied to the results obtained for different variables at three stations, both in the sediment and in interstitial water, with the aim of evaluating their relationship with LAS. The variables analysed have two main types of distribution in the sedimentary area in relation to depth: linear and/or exponential. LAS is, in most cases, associated with both types of distribution, indicating that its concentration decreases with depth, especially in the surface layer.Instituto Español de Oceanografí

An overview of geometrid moths (Lepidoptera: Geometridae) in the Andean Region s.l.: A systematic review

The Andean Region, spanning from 23° S to 55° S, including the South American Transition Zone, harbours many unique species but faces significant human-induced pressures. It encompasses two biodiversity hotspots, underscoring the importance of understanding its biota for effective conservation. Notably, the Andean Region boasts one of the world’s largest concentrations of endemic geometrid moths, vital for ecosystem services and potential as bioindicators. However, limited expertise and comprehensive knowledge hinder their applications. No synthesis of this region’s Geometridae exists, unlike well-documented Palearctic and Nearctic regions. Geometridae information in the Andean Region is fragmented, mostly from small-scale studies. Consequently, we conducted a systematic review following the PRISMA protocol, analyzing 151 scientific articles. We assessed topics in five categories: studied taxa, methodologies, evolution, biogeography, and ecology. While evolution and ecology were well-studied, there was a bias towards taxonomic and immature state studies, neglecting other ecological and evolutionary questions. Biogeographic studies were infrequent, often local. Catching methods, morphological analysis, and museological studies were predominant, being cost-effective. Emerging methodologies include genetics, population studies, phylogenetic comparisons, and geometric morphometrics. Keyword analysis revealed common concepts such as taxonomy, Geometridae, immature stages, Chile, Lepidoptera, herbivory, Ecuador, Neotropical Region, Systematics, and Ennominae. In conclusion, we urge prioritizing ecological research on geometrid moths’ interactions with other taxa, especially mutualistic and predation interactions. Enhanced efforts are needed for biogeographic patterns, phylogenetic studies, and systematic assessments of incertae sedis taxa and those assigned to Palearctic genera