Pseudochaotic poloidal transport in the laminar regime of the resistive ballooning instabilities

In toroidal geometry, and prior to the establishment of a fully developed turbulent state, the so-called topological instability of the pressure-gradient-driven turbulence is observed. In this intermediate state, a narrow spectral band of modes dominates the dynamics, giving rise to the formation of iso-surfaces of electric potential with a complicated topology. Since E x B advection of tracer particles takes place along these iso-surfaces, their topological complexity affects the characteristic features of radial and poloidal transport dramatically. In particular, they both become strongly non-diffusive and non-Gaussian. Since radial transport determines the system confinement properties and poloidal transport controls the equilibration dynamics (on any magnetic surface), the development of non-diffusive models in both directions is thus of physical interest. In previous work, a fractional model to describe radial transport was constructed by the authors. In this contribution, recent results on periodic fractional models are exploited for the construction of an effective model of poloidal transport. Numerical computations using a three-dimensional reduced magnetohydrodynamic set of equations are compared with analytical solutions of the fractional periodic model. It is shown that the aforementioned analytical solutions accurately describe poloidal transport, which turns out to be superdiffusive with index $\alpha=1$.Comment: 17 pages, 6 figures. Accepted for publication in Phys. Plasma

Experimental evaluation of CO2/R-152a mixtures in a refrigeration plant with and without IHX

In recent years, CO2-based mixtures have been considered as a way to improve the performance of refrigerating plants using pure CO2 as refrigerant. Combining CO2 with a fluid with higher critical temperature generates a blend which allows to run a refrigeration plant in subcritical conditions at higher heat rejection temperature when compared to pure carbon dioxide, and consequently reach higher COP. This work evaluates from an experimental point of view two CO2/R-152a mixtures, ([90/10 %] and [95/5 %]), used as refrigerants in a single-stage refrigeration plant with and without internal heat exchanger, and compares the results to those obtained using pure CO2. The work analyses the main energy parameters of the plant for secondary fluid inlet temperature of 2.5 °C at the evaporator, and in the range from 20 °C to 40 °C with 5 °C step at the condenser/gas-cooler. The use of such mixtures, compared to the use of pure CO2, allowed to obtain a higher COP in the base cycle for heat rejection temperature above 25 °C, reaching the largest increment at the highest temperature while, when working with IHX cycle, no improvements in the COP were measured

Effect of Different Parameters (Treatment Administration Mode, Concentration and Phenological Weed Stage) on Thymbra capitata L. Essential Oil Herbicidal Activity

The essential oil (EO) of Thymbra capitata has been demonstrated to possess herbicidal activity and could be used as an alternative to synthetic herbicides with reduced persistence in soil and new mode of action. Nevertheless, it is necessary to determine the adequate doses for its use, the proper way for its application and the best phenological stage of weeds and crops in which the EO should be applied to obtain maximum efficacy against weeds without compromising crop production. In this work, T. capitata EO was tested at three different concentrations against weeds grown from a citrus orchard soil seedbank untreated with herbicides and against three important weed species grown in substrate to determine the efficacy of the concentrations on different weed species. All experiments were carried out under greenhouse conditions. To find out the best way for applying the EO, it was applied by irrigation and by spraying on the targeted weeds, and to verify the influence of timing, it was tested on Lolium rigidum at two different phenological stages and on wheat at a later phenological stage than weeds. The highest concentration tested (12 μL·mL−1) showed the best performance to control weeds. The more effective mode of application was by spraying on dicotyledons and by irrigation on monocotyledons at the earliest phenological stage. T. capitata EO was phytotoxic for wheat. More trials in different crops are needed to determine the best conditions for its use

Herbicidal Potential of the Natural Compounds Carvacrol, Thymol, Eugenol, p-Cymene, Citral and Pelargonic Acid in Field Conditions: Indications for Better Performance

In recent years, interest in natural products with herbicidal activity as new tools for integrated weed management has increased. The European Union is demanding a reduction in the number of herbicides used, forbidding use of the most toxic ones, despite the problem of weed resistance increasing. Pelargonic acid (PA) is the only natural herbicide available in Spain. In this work, two field assays were performed with the natural compounds carvacrol (CAR), citral (CIT), eugenol (EUG), thymol (THY), p-cymene (P-CYM), (PA), and the combination of PA with CIT-all except P-CYM formulated by Seipasa-to test their herbicidal efficacy in real conditions. They were compared with commercial PA, glyphosate (GLY) and oxyfluorfen (OXY). In both experiments, GLY achieved the best weed control. Considering the natural herbicides, PA formulated by Seipasa and PA plus CIT were the most effective. From both experiments, some conclusions can be extracted for better herbicidal performance of natural products: (1) use products on sensitive weed species, (2) treat weeds at earlier phenological stages, (3) find the active doses in field conditions, (4) cover weeds well when treating, (5) ensure adequate formulation of products, and (6) develop a strategy for correct application

Technological study of kaolinitic clays from Fms. Escucha and Utrillas to be used in dermo-pharmaceutical products

The present study aims to evaluate five clay samples from different pits in the Teruel province, Spain. While these clays are primarily utilized as raw materials in ceramics, their potential applications in pharmaceutical and cosmetic domains, notably in sun protection and thermal mud products, are under investigation. Characterization of these clays entailed X-ray diffraction, X-ray fluorescence, scanning electron microscopy, pH measurement, analysis of technological properties, rheological assessment, and thermal property evaluation. Furthermore, given the predominant composition of kaolin in most of the samples, their Sun Protection Factor (SPF) in suspensions and physical stability were assessed. The studied samples exhibited varied mineralogical compositions, primarily consisting of kaolinite (70% to 15%), quartz (75% to 5%), and illite (26% to 7%). The pH values of these dispersions closely matched the skin's pH, exhibiting anti-thixotropic behavior at 50% w/w and demonstrating suitable viscosity for skin application. Based on their composition and rheological properties, the samples exhibited potential for use as therapeutic thermal muds. Analyses of cooling kinetics were performed to validate this potential. Results showed that the dispersions systems attained temperatures between 33.89 ◦C and 34.62 ◦C within 20 min (the common application time for thermal muds) and reached 32 ◦C (skin temperature) in 24.3 to 26.22 min, confirming their appropriateness as therapeutic muds. The SPF values of the dispersions varied from 7.46 to 16.65, with the majority of samples showing significant stability during 45 h. Consequently, it can be inferred that most of the studied samples show advantageous characteristics for inclusion in topical formulations, especially in sun protection and thermal mud products

On Roth’s “human fossil” from Baradero, Buenos Aires Province, Argentina: morphological and genetic analysis

The "human fossil" from Baradero, Buenos Aires Province, Argentina, is a collection of skeleton parts first recovered by the paleontologist Santiago Roth and further studied by the anthropologist Rudolf Martin. By the end of the nineteenth century and beginning of the twentieth century it was considered one of the oldest human skeletons from South America's southern cone. Here, we present the results of an interdisciplinary approach to study and contextualize the ancient individual remains. We discuss the context of the finding by first compiling the available evidence associated with the historical information and any previous scientific publications on this individual. Then, we conducted an osteobiographical assessment, by which we evaluated the sex, age, and overall preservation of the skeleton based on morphological features. To obtain a 3D virtual reconstruction of the skull, we performed high resolution CT-scans on selected skull fragments and the mandible. This was followed by the extraction of bone tissue and tooth samples for radiocarbon and genetic analyses, which brought only limited results due to poor preservation and possible contamination. We estimate that the individual from Baradero is a middle-aged adult male. We conclude that the revision of foundational collections with current methodological tools brings new insights and clarifies long held assumptions on the significance of samples that were recovered when archaeology was not yet professionalized

Shallow whole-genome sequencing of Aedes japonicus and Aedes koreicus from Italy and an updated picture of their evolution based on mitogenomics and barcoding

Aedes japonicus and Aedes koreicus are two invasive mosquitoes native to East Asia that are quickly establishing in temperate regions of Europe. Both species are vectors of arboviruses, but we currently lack a clear understanding of their evolution. Here, we present new short-read, shallow genome sequencing of A. japonicus and A. koreicus individuals from northern Italy, which we used for downstream phylogenetic and barcode analyses. We explored associated microbial DNA and found high occurrences of Delftia bacteria in both samples, but neither Asaia nor Wolbachia. We then assembled complete mitogenomes and used these data to infer divergence times estimating the split of A. japonicus from A. koreicus in the Oligocene, which was more recent than that previously reported using mitochondrial markers. We recover a younger age for most other nodes within Aedini and other Culicidae. COI barcoding and phylogenetic analyses indicate that A. japonicus yaeyamensis, A. japonicus amamiensis, and the two A. koreicus sampled from Europe should be considered as separate species within a monophyletic species complex. Our studies further clarify the evolution of A. japonicus and A. koreicus, and indicate the need to obtain whole-genome data from putative species in order to disentangle their complex patterns of evolution

Soft-state optical spectroscopy of the black hole MAXI J1305-704

The X-ray dipper MAXI J1305-704 is a dynamically confirmed black hole (BH) X-ray binary discovered a decade ago. While its only outburst has been studied in detail in X-rays, follow-up at other wavelengths has been scarce. We report here the results from an optical spectroscopy campaign across the outburst of MAXI J1305-704. We analysed two epochs of data obtained by the Magellan Clay Telescope during two consecutive nights, when the source was in a soft X-ray spectral state. We identified typical emission lines from outbursting low-mass X-ray binaries, such as the hydrogen Balmer series, He II 4686 angstrom and the Bowen blend. We focused our analysis on the prominent H alpha line, which exhibits asymmetric emission and variable absorption components. We applied both traditional analytical methods and machine-learning techniques in order to explore the association of the absorption features with outflowing phenomena, and we conclude that they are best explained by broad absorption. This result is consistent with reports from other outbursting BHs, where optical outflows have predominantly been observed in the hard state. Further observations at different X-ray states are key to properly test whether this behaviour is universal and to determine the implications for the disc wind physics

La influencia del autoconcepto en el rendimiento académico en estudiantes universitarios

ABSTRACTThere are some researches that confirm the positive relationship between self-concept and academic achievement, usually of the academic self‐concept dimension and almost always in non‐university students. In this work we were looking for confirming the influence of self-concept in the academic achievement of the university students. In order to do it we worked with a sample of 1298 students from the three universities located in the city of Valencia (Spain): the University of Valencia, the Polytechnic University of Valencia and the Catholic University of Valencia. The first two were public universities and the third one was private. We assessed the self‐concept by means of the AF5 questionnaire, which gives scores of five types of self-concept: academic/labour, emotional, family self‐concept, physical and social. We also took data from the academic achievement of university students by using the mean score of grades of five compulsory subjects of the academic year in which the research was conducted. From these scores we carried out correlations between self‐concept scores and grades, and also linear multiple regression analysis that showed a moderate relationship between three of the five types of self-concept that assesses the questionnaire (academic, physical and family self‐concept) and academic achievement. We also conducted hierarchical cluster analysis (k-means) with self-concept scores, finding three groups of students, one of them with a good profile of self-concept and the other two with a weaker profile. The first one had better grades, although di‐ fferences between the three groups were not significant in ANOVA. These results help us to realize the importance of supporting, as teachers, the development of a good self‐concept in our university students. Additionally, they complement the results of other studies that have examined other constructs and its impact on the academic achievement of university students.RESUMEN Existen algunas investigaciones que confirman la relación positiva existente entre autoconcepto y rendimiento académico, generalmente de la dimensión autoconcepto académico y casi siempre en estudiantes no universitarios. En este trabajo se busca confirmar la influencia del autoconcepto en el rendimiento académico de los estudiantes universitarios. Para ello trabajamos con una muestra de 1298 estudiantes de las tres universidades de la ciudad de Valencia (España): Universidad de Valencia, Universidad Politécnica de Valencia y Universidad Católica de Valencia. Las dos primeras eran universidades públicas y la tercera lo era privada. Evaluamos el autoconcepto mediante el cuestionario AF5, que permite obtener puntuaciones de cinco tipos de autoconcepto: académico/laboral, emocional, familiar, físico y social. También tomamos datos del rendimiento obteniendo la media de cinco asignaturas troncales y obligatorias del curso en que se realizó la investigación. A partir de estas puntuaciones llevamos a cabo correlaciones entre puntuaciones de autoconcepto y calificaciones, y también análisis de regresión lineal que reflejaron una relación moderada entre tres de los cinco tipos de autoconcepto que evalúa el cuestionario (académico, familiar y físico) y el rendimiento. También realizamos análisis jerárquico de conglomerados (k‐medias) con las puntuaciones de autoconcepto, encontrando tres grupos de estudiantes, uno con buen perfil de autoconcepto y dos con peor perfil. El grupo con buen perfil tenía mejores calificaciones, aunque las diferencias existentes entre los tres grupos no llegaron a ser significativas en el ANOVA realizado. Estos resultados ayudan a tomar conciencia de la importancia de apoyar, como profesores, el desarrollo de un buen autoconcepto en nuestros estudiantes universitarios. Además complementan los resultados de otras investigaciones que han analizado otros constructos y su incidencia en el rendimiento de estos estudiantesABSTRACT There are some researches that confirm the positive relationship between self-concept and academic achievement, usually of the academic self‐concept dimension and almost always in non‐university students. In this work we were looking for confirming the influence of self-concept in the academic achievement of the university students. In order to do it we worked with a sample of 1298 students from the three universities located in the city of Valencia (Spain): the University of Valencia, the Polytechnic University of Valencia and the Catholic University of Valencia. The first two were public universities and the third one was private. We assessed the self‐concept by means of the AF5 questionnaire, which gives scores of five types of self-concept: academic/labour, emotional, family self‐concept, physical and social. We also took data from the academic achievement of university students by using the mean score of grades of five compulsory subjects of the academic year in which the research was conducted. From these scores we carried out correlations between self‐concept scores and grades, and also linear multiple regression analysis that showed a moderate relationship between three of the five types of self-concept that assesses the questionnaire (academic, physical and family self‐concept) and academic achievement. We also conducted hierarchical cluster analysis (k-means) with self-concept scores, finding three groups of students, one of them with a good profile of self-concept and the other two with a weaker profile. The first one had better grades, although di‐ fferences between the three groups were not significant in ANOVA. These results help us to realize the importance of supporting, as teachers, the development of a good self‐concept in our university students. Additionally, they complement the results of other studies that have examined other constructs and its impact on the academic achievement of university students