Purification of dairy wastewaters by advanced oxidation processes and membrane filtration

Membrane separation processes are space and cost-efficient, easy to scale-up operations, which have proved to treat food industrial wastewaters efficiently. Beside the advantages like high separation efficiency without any chemical changes and low energy-intensity, membrane filtration also has drawbacks, like decreased operational efficiency caused by flux decile resulting from fouling and concentration polarization. Combination of oxidation pre-treatment and membrane filtration is a promising method for decreasing fouling due to the physicochemical changes caused by pre-oxidation of the wastewater in structure of colloidal pollutants and in the interactions between the foulants and the membrane material. The aim of this work is to identify the parameters affecting the membrane fouling during treatment of dairy wastewaters, and present the current trends of research in this field

New observations of NGC 1624-2 reveal a complex magnetospheric structure and underlying surface magnetic geometry

NGC 1624-2 is the most strongly magnetized O-type star known. Previous spectroscopic observations of this object in the ultraviolet provided evidence that it hosts a large and dense circumstellar magnetosphere. Follow-up observations obtained with the \textit{Hubble Space Telescope} not only confirm that previous inference, but also suggest that NGC 1624-2's magnetosphere has a complex structure. Furthermore, an expanded spectropolarimetric time series shows a potential departure from a dipolar magnetic field geometry, which could mean that the strongest field detected at the surface of an O-type star is also topologically complex. This result raises important questions regarding the origin and evolution of magnetic fields in massive stars.Comment: 12 pages, 3 figures, accepted for publication by MNRAS (2020 December 1

Volcanism on Io: Insights from Global Geologic Mapping

We are preparing a new global geo-logic map of Jupiter s volcanic moon, Io. Here we report the type of data that are now available from our global mapping efforts, and how these data can be used to investigate questions regarding the volcano-tectonic evolution of Io. We are using the new map to investigate several specific questions about the geologic evolution of Io that previously could not be well addressed, including (for example) a comparison of the areas vs. the heights of Ionian mountains to assess their stability and evolution (Fig. 1). The area-height relationships of Io s visible mountains show the low abundance and low relief of volcanic mountains (tholi) relative to tectonic mountains, consistent with formation from low-viscosity lavas less likely to build steep edifices. Mottled mountains are generally less high than lineated mountains, consistent with a degradational formation

Volcanism on Io: Results from Global Geologic Mapping

We have completed a new 1:15,000,000 global geologic map of Jupiter's volcanic moon, Io, based on a set of 1 km/pixel combined Galileo- Voyager mosaics produced by the U.S. Geological Survey. The map was produced over the last three years using ArcGIS(TM) software, and has undergone peer-review. Here we report some of the key results from our global mapping efforts, and how these results relate to questions regarding the volcano-tectonic evolution of Io

Global Geologic Mapping of Io: Preliminary Results

A new global geologic map of Jupiter's volcanic moon, Io is being prepared, with the focus being on completion of a draft map by July 2008. Here initial results of the mapping are reported: a preliminary distribution of material units in terms of areas and a visual representation. Additionally, the mapping hopes to address some of the problems in Io geology. Thus far it has been discovered that Io's surface is dominated by plains material, thought to consist of Io's silicate crust covered by pyroclastic deposits and lava flows of silicate and sulfur-bearing composition. Many plains areas contain flow fields that cannot be mapped separately due to a lack of resolution or modification by alteration processes. Discrete lava flows and flow fields are the next most abundant unit, with bright (sulfur?) flows in greater abundance than dark (silicate?) flows. The source of most of Io's heat flow, the paterae, are the least abundant unit in terms of areal extent.Upon completion of the draft map for peer review, it will be used to investigate several specific questions about the geological evolution of Io that previously could not be well addressed, including: comparison of the areas versus the heights of Ionian mountains to assess their stability and evolution; correlation and comparison of Galileo Near-Infrared Mapping Spectrometer and Photopolarimeter-Radiometer hot spot locations with the mapped location of dark versus bright lava flows and patera floors to assess any variations in the types of sources for Io's active volcanism; and the creation of a global inventory of the areal coverage of dark and bright laval flows to assess the relative importance of sulfur versus silicate volcanism in resurfacing Io, and to assess whether there are regional concentrations of either style of volcanism that may have implications on interior processes

The effects of surface fossil magnetic fields on massive star evolution: II. Implementation of magnetic braking in MESA and implications for the evolution of surface rotation in OB stars

The time evolution of angular momentum and surface rotation of massive stars is strongly influenced by fossil magnetic fields via magnetic braking. We present a new module containing a simple, comprehensive implementation of such a field at the surface of a massive star within the Modules for Experiments in Stellar Astrophysics (MESA) software instrument. We test two limiting scenarios for magnetic braking: distributing the angular momentum loss throughout the star in the first case, and restricting the angular momentum loss to a surface reservoir in the second case. We perform a systematic investigation of the rotational evolution using a grid of OB star models with surface magnetic fields ($M_\star=5-60$ M$_\odot$, $\Omega/\Omega_{\rm crit} =0.2-1.0$, $B_{\rm p} =1-20$ kG). We then employ a representative grid of B-type star models ($M_\star=5, 10, 15$ M$_\odot$, $\Omega/\Omega_{\rm crit} =0.2 , 0.5, 0.8$, $B_{\rm p} = 1, 3 ,10, 30$ kG) to compare to the results of a recent self-consistent analysis of the sample of known magnetic B-type stars. We infer that magnetic massive stars arrive at the zero age main sequence with a range of rotation rates, rather than with one common value. In particular, some stars are required to have close-to-critical rotation at the ZAMS. However, magnetic braking yields surface rotation rates converging to a common low value, making it difficult to infer the initial rotation rates of evolved, slowly-rotating stars.Comment: accepted for publication in MNRAS, a zenodo record is available at: https://zenodo.org/record/325041