La cocina de la empresa turística Aventura Mayas en la Rivera Maya, México. Una propuesta de reducción de desperdicio de alimentos

El presente artículo es resultado de la experienciade estancia profesional realizada en la empresaAventuras Mayas, en la Riviera Maya, México.Participando en el área de Alimentos y Bebidas,se identificó la problemática del desperdicio dealimentos, propiciados por procesos, movimientosy acciones realizadas por los colaboradores yclientes. Considerando la situación mundial sobreel uso y pérdida de los alimentos y la situaciónde hambre de población vulnerable, se desarrollóuna propuesta de proyecto para mitigar el desperdicioy contribuir a la mejora de las prácticasmediante la utilización de la filosofía Lean,generando resultados prósperos y aplicables a laproblemática señalada.AbstractThis article is the result of the experience of a professional stay at Aventuras Mayas, in the Riviera Maya, Mexico. Identifying in the Food and Beverages area, the problem of food waste, caused by processes, movements and actions by employees and customers. Considering the world situation on the use and loss of food and the hunger situation of vulnerable population, a project proposal was developed to mitigate waste and contribute to the improvement of practices using the Lean philosophy, generating prosperous and applicable results to the mentioned problem

Size-dependent behaviour of hard rock under triaxial loading

Understanding size effects is important to rigorously analyse the behaviour of rocks and rock masses at different scales and for different applications. A number of empirical and numerical studies have included size effects on the uniaxial compressive strength of different rocks, but only few have focussed on the triaxial compressive strength. In this study, several triaxial tests were conducted on granite samples at different confinements (from 0.2 to 15 MPa) and sizes (from 30 to 84 mm in diameter). The most relevant strength parameters were recovered including peak and residual strengths, orientation and frictional response of shear bands. Size effects were observed to be less dominant at high confining pressures for both peak and residual strengths. The resulting data were analysed in the context of size-dependent rock strength theories. For peak strength analyses, the unified size effect law (USEL) and the improved unified size law (IUSEL) were used, in which the double trends, ascending descending behaviours were observed. Size-dependent Hoek–Brown modified failure criteria based on USEL and IUSEL were fit to peak strengths exhibiting a good agreement between the models and the laboratory data. The brittle-ductile transition and the frictional behaviour of shear band under triaxial loading were also analysed. A clear brittle behaviour was particularly observed in samples with large-diameters tested at low confinements. Finally, in regards to frictional behaviour, the shear band angle found to be affected by both confinement and sample size.Ministerio de Ciencia e Innovación | Ref. PRE2019-087397Ministerio de Ciencia e Innovación | Ref. RTI2018-093563-B-I00Universidade de Vigo/CISU

Prácticas turísticas en áreas naturales protegidas: Su estudio desde enfoques críticos

artículoLas áreas naturales protegidas son los espacios preferidos para realizar actividades turísticas. Con conceptos de sustentabilidad, tratan de mejorar las condiciones de vida de las comunidades rurales e indígenas, promoviendo el desarrollo y protegiendo la naturaleza. Sin embargo, la realidad demuestra que su objetivo no se ha cumplido de la forma esperada, manteniendo e incrementando la degradación social y ambiental. El presente artículo tiene el objetivo de mostrar las perspectivas críticas del estudio del turismo en dichos espacios, analizando artículos y capítulos de libros publicados en el periodo 2015-2021. Los principales resultados muestran que las crisis actuales son el resultado de mantener el sistema capitalista, pues las áreas protegidas y las actividades turísticas se promueven en términos mercantilistas bajo la idea de conservación neoliberal. Todo facilitado por la configuración de las políticas que permiten la llegada y formación de capital en el ámbito rural-natural. Protected natural areas seem to be the preferred space for tourist’s activities. With concepts of sustainability, they try to improve the living conditions of rural and indigenous communities, promoting development and protecting nature. However, in reality it proves that the objective has not been fulfilled in the expected way, maintaining and increasing social and environmental degradation. This article's objective is to show the critical perspectives regarding the study of tourism in said spaces, analyzing articles and book chapters published during 2015-2021. The main results shows that the current crises are the result of maintaining the capitalist system, seeing as protected areas and tourist activities are promoted in mercantilist terms under the idea of neoliberal conservation. All facilitated by policies configuration that allows arrival and formation of capital in the rural-natural environment

Toppling susceptibility of a single rock block resting on a regularly rough base

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGToppling of individual rock blocks resting on an inclined surface has often been observed in nature. This instability mechanism has typically been analysed for simple block geometries, considering the contact between the block and the base where it lies is a planar surface. In this study, the authors analyse the case where this contact is a regularly rough surface. To do that, the authors resort to analytical limit equilibrium formulations, laboratory physical models and discrete element methods. All these approaches show a consistent trend of behaviour, where roughness does affect the toppling response. Regularly rough surfaces are studied in detail and a general analytical formulation able to show the potential influence of roughness on the block toppling response is derived. Additionally, some considerations are provided regarding the combined effects of rough bases and rounded corners on toppling stability. The authors show how under particular circumstances, roughness can control the potential failure mechanism of a block to produce toppling instead of sliding, and they eventually discuss the impact of rough bases on the toppling response of natural rock blocks.Agencia Estatal de Investigación | Ref. RTI2018-093563-B-I0

Inertial domain wall characterization in layered multisublattice antiferromagnets

The motion of a Neel-like 180 degrees domain wall induced by a time-dependent staggered spin-orbit field in the layered collinear antiferromagnet Mn2Au is explored. Through an effective version of the two sublattice nonlinear a-model which does not take into account the antiferromagnetic exchange interaction directed along the tetragonal c-axis, it is possible to replicate accurately the relativistic and inertial traces intrinsic to the magnetic texture dynamics obtained through atomistic spin dynamics simulations for quasistatic processes. In the case in which the steady-state magnetic soliton motion is extinguished due to the abrupt shutdown of the external stimulus, its stored relativistic exchange energy is transformed into a complex translational mobility, being the rigid domain wall profile approximation no longer suitable. Although it is not feasible to carry out a detailed follow-up of its temporal evolution in this case, it is possible to predict the inertial-based distance travelled by the domain wall in relation to its steady-state relativistic mass. This exhaustive dynamical characterization for different time-dependent regimes of the driving force is of potential interest in antiferromagnetic domain wall-based device applications.R.R.-E., K.Y.G., and R.M.O. thanks O. Chubykalo-Fesenko, S. Khmelevskyi, A. A. Sapozhnik, M. Jourdan, A. K. Zvezdin, and B. A. Ivanov for the fruitful discussions that have helped us to improve this manuscript. The work of R.M.O. and K.Y.G. was partially supported by the STSM Grants from the COST Action CA17123 "Ultrafast opto-magneto-electronics for non-dissipative information technology''. K.Y.G. acknowledges support by IKERBASQUE (the Basque Foundation for Science) and the Spanish Ministry of Science and Innovation under grant PID2019-108075RB-C33/AEI/10.13039/501100011033

Study of size effects on the peak and residual strength of intact and artificially fissured granite samples

There are not many studies on jointed rock specimens, which can be considered small scale rock mass analogs. On the other hand, the scale effects in the mechanical properties of such samples have seldom been studied. With the aim of continuing previous research on intact granite rocks, the authors have carried out sets of 25 stress-strain triaxial compressive tests on 1 sub-vertical and 2 sub-horizontal 38 mm, 54 mm and 84 mm diameter jointed granite specimens at various confinements. Peak and residual strength values were obtained and compared to those recovered form intact rock samples. Results suggest that peak strength follows similar trends with scale to those observed on intact rock, even if lower strength values are logically recorded. Regarding residual strength, the obtained results are in line with those observed trends for standard size samples, showing a similar trend for all cases independently of scale, even if we observe larger variability for jointed samples. The authors have also compared the values fitting the generalized Hoek-Brown criterion for rock masses to better understand the behavior in relation to sample size. So scale effects clearly appear on jointed rock peak strength of jointed sample; even if residual strength seems hardly affected by scale.Agencia Estatal de Investigación | Ref. RTI2018-093563-B-I0

Behaviour of ewes (Ovis gmelini musimon x Ovis sp.) during the rut

It was tested whether male courtship induces changes in activities in female mouflon (Ovis gmelini musimon x Ovis sp.) due to the promiscuous mating system. For females in the presence of males, we expected a higher involvement in social interactions, reduced time spent feeding, increased time standinglscanning and moving, and a higher rate and level of act transition and diversity. We tested these hypotheses by comparing mouflon ewe activities in mixed-sex, mating (one estrous female with at least one adult male) and female groups during the pre-rut (16-31/0ct.), the rut (01-30/Nov.) and the post-rut (01-15/Dec.). Females devoted more time to feeding and less to standing/scanning from the pre- to the post-rut, in mixed and female groups. At the same time, act transition and diversity decreased in female groups. Females could experience reduced appetite during the oestrus period but ecological factors (better quality and higher abundance of food) may explain these results. Differences between mixed-sex and female groups were found only during the full-rut. Females devoted more time to standing/scanning and Jess to feeding in mixed-sex groups. Although significant, the percent of time dedicated to feeding and standing/scanning was weakly related to the interaction frequency. So the presence of males seems to have a low incidence on female activities, as seen through the low level of social interactions involving females, and their low behavioural responsiveness. Mating groups were observed only during the pre- and the full-rut. Because of small sample size (N = 8), data from the two periods were mixed in order to compare group types. Data on mating groups suggest that oestrous ewes feed much Jess, move more, change activity more often and are involved in social interactions more frequently than in mixed-sex and female groups. However, as oestrus lasts only 1 -3 days, the energy costs of the rut are thought to be low for femalesL'hypothèse que la cour des mâles induit une modification des activités des femelles en raison du système reproducteur de type promiscuité a été testée chez le Mouflon (Ovis gmelini musimon x Ovis sp.). On s'attendait à ce qu'en présence des mâles, les femelles soient plus fréquemment impliquées dans des interactions sociales et consacrent moins de temps à l'alimentation, plus de temps au « debout/observe » et au déplacement, changent plus souvent et diversifient davantage leurs actes. Nous avons donc comparé l'activité des femelles dans des groupes mixtes, reproducteurs (une femelle en oestrus avec au moins un mâle ≥ 1,5 ans) et dans des groupes de femelles, au cours du pré-rut (16-31/oct.), du rut (01-30/nov.) et du post-rut (01-15/déc.). Du pré-rut au post-rut, tant dans les groupes mixtes que de femelles, le temps consacré à l'alimentation s'accroît au détriment du « debout/observe », alors qu'aucune variation significative n'est détectée dans la part allouée au déplacement. Durant cette même période, la fréquence de transition des actes et la diversité comportementale diminue dans les groupes de femelles. Ces résultats peuvent s'expliquer par une diminution de l'appétit des femelles pendant la période des oestrus mais aussi par des facteurs écologiques (amélioration de la qualité et abondance des ressources alimentaires). Des différences entre groupes mixtes et de femelles n'ont été détectées que durant le plein rut. Les femelles passent moins de temps à se nourrir et plus de temps à observer dans les groupes mixtes. Bien que statistiquement significative, la relation entre fréquence de cour et pourcentage de temps consacré à l'alimentation et au « debout/observe » est faible. La relation disparaît si les données relatives aux groupes reproducteurs sont omises. L'impact de la présence des mâles sur l'activité des femelles semble donc minime, ce qui peut être relié aux faibles taux d'interactions impliquant les femelles, ou à la faible réactivité comportementale des femelles. Les groupes reproducteurs n'ont été observés que durant le pré- et le plein rut. En raison du petit échantillon (N = 8), les 2 périodes ont été rassemblées pour permettre une comparaison entre types de groupes. Dans les groupes reproducteurs, les femelles en oestrus broutent nettement moins, se déplacent plus, changent plus d'activité et sont plus souvent impliquées dans des interactions sociales que les brebis dans les groupes mixtes ou de femelles. Les résultats suggèrent que le comportement des femelles n'est sensiblement modifié que dans les groupes reproducteurs, pendant l'oestrus. Ce demier ne durant que de 1 à 3 jours, les coûts énergétiques du rut sont vraisemblablement faibles pour les femelles