Quenching of Meridional Circulation in Flux Transport Dynamo Models

Guided by the recent observational result that the meridional circulation of the Sun becomes weaker at the time of the sunspot maximum, we have included a parametric quenching of the meridional circulation in solar dynamo models such that the meridional circulation becomes weaker when the magnetic field at the base of the convection zone is stronger. We find that a flux transport solar dynamo tends to become unstable on including this quenching of meridional circulation if the diffusivity in the convection zone is less than about 2 * 10^{11} cm^2/s. The quenching of alpha, however, has a stabilizing effect and it is possible to stabilize a dynamo with low diffusivity with sufficiently strong alpha-quenching. For dynamo models with high diffusivity, the quenching of meridional circulation does not produce a large effect and the dynamo remains stable. We present a solar-like solution from a dynamo model with diffusivity 2.8 * 10^{12} cm^2/s in which the quenching of meridional circulation makes the meridional circulation vary periodically with solar cycle as observed and does not have any other significant effect on the dynamo.Comment: Consistent with the published version. Solar Physics, in pres

Microwave hydrodiffusion and gravity: an emergent technology for green extraction of non-volatile compounds

Microwave technologies are more and more present in food applications due to their performance in shortening the time of treatments such as drying, pasteurization, defrosting, or postharvesting. While solvent-free microwave extraction has been extensively used as a green procedure for essential oil and volatile compounds from aromatic herbs [1], its applications have been extended to enhance extraction of phytocompounds simultaneously with drying. In this work, microwave hydrodiffusion and gravity was performed in a laboratory microwave oven (NEOS-GR, Milestone, Italy), in order to evaluate its efficiency in the extraction of nonvolatile compounds such as: free sugars, f1bers, colour, and phenolic compounds. Five different matrices were tested: broccoli by-products (90% moisture), apple pomace (80% moisture), spent coffee grounds (65% moisture), Pterospartum tridentatum inflorescences, and brown algae, the latter two in dried state. The flow behaviour was very dependent on matrix (Figure 1): for broccoli, the time to obtain 50 ml aliquots increased along time while for apple pomace it was always the same after the initial and final heating periods, and for the spent coffee grounds it was always decreasing. Good recoveries were observed when using high water content matrices, such as apple pomace and broccoli. However, when using hydrated matrices, such as brown algae and Pterospartum tridentatum inflorescences, it was observed that the amount of material extracted is very low. In the case of spent coffee qrounds (a material where water is added to the ground coffee when preparing espresso coffee), the initial low recoveries can be overcome by the eo-addition of ethanol, allowing to obtain fractions rich in phenolic compounds, as well as brown compounds (with antioxidant activity) and caffeine. NEOS-GR, using microwave hydrodiffusion and gravity is a green extraction technology obtain hydrophilic compounds from wet matrices using its own water, allowing the extraction of valuable non-volatile compounds.info:eu-repo/semantics/publishedVersio

Microwave hydrodiffusion and gravity: an emergent technology for green extraction of non-volatile compounds

Microwave technologies are more and more present in food applications due to their performance in shortening the time of treatments such as drying, pasteurization, defrosting, or post-harvesting [1]. While solvent-free microwave extraction has been extensively used as a green procedure for essential oil and volatile compounds from aromatic herbs [2], its applications have been extended to enhance extraction of phytocompounds simultaneously with drying. In microwave drying, operational cost is lower because energy is not consumed in heating the walls of the apparatus or the environment [3].info:eu-repo/semantics/publishedVersio

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset