The Dynamic Formation of Prominence Condensations

We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

On the structure of just infinite profinite groups

A profinite group $G$ is just infinite if every closed normal subgroup of $G$ is of finite index. We prove that an infinite profinite group is just infinite if and only if, for every open subgroup $H$ of $G$, there are only finitely many open normal subgroups of $G$ not contained in $H$. This extends a result recently established by Barnea, Gavioli, Jaikin-Zapirain, Monti and Scoppola, who proved the same characterisation in the case of pro-$p$ groups. We also use this result to establish a number of features of the general structure of profinite groups with regard to the just infinite property.Comment: 16 page

Age-dependent changes in insulin-like immunoreactivity in rat submandibular salivary glands.

In recent years, a growing interest had arisen in hormonal factors in salivary glands. We have investigated the changes in the content of an insulin-like immunoreactive (ILI) compound in the submandibular salivary glands of Sprague Dawley rats during physiological aging, in the range 15 days-27 months. The amount of ILI in the submandibular glands of young adult rats was found to be doubled in the post-natal period until the age of puberty and was maintained in senescence. No significant correlation was found between age-dependent variations in ILI levels of submandibular salivary glands and circulating insulin concentrations, further supporting previous indications that ILI is being synthesized in situ. It is possible that ILI could exert paracrine effects within the glands, as regards the development of other glandular structures during the first months of life, as well as the preservation of glandular function in senescent animals as well

Genetic analyses of celiac disease in a Spanish population confirm association with CELIAC3 but not with CELIAC4

[EN] Genetic predisposition to celiac disease (CD) is determined primarily by the human leukocyte antigen (HLA) genes (CELIAC1 region; 6p21), although many loci are involved in disease susceptibility. First, we have analysed a large series of CD patients from the Spanish Mediterranean region who had previously been characterised for the HLA complex. We have investigated how relevant regions contribute to CD susceptibility: CELIAC3 (CD28/CTLA4/ICOS region on 2q33) and CELIAC4 (19p13) as well as the tumour necrosis factor alpha (TNF-alpha) and the linfotoxin loci by case-control and association analyses. We highlight the association with the +49*A allele of cytotoxic T-lymphocyte-associated antigen 4 locus (P = 0.01), and the -308*A of TNF-alpha locus (P = 0.0008) in DQ2 individuals, although an independent role for TNF-alpha as risk factor has not been proven. Moreover, we do not confirm the association with the CELIAC4 region polymorphisms described in other populations.We are grateful for the kind collaboration of patients and families and Asociación de Celíacos de la Comunidad Valenciana (ACECOVA). This work was supported by the Fondo de Investigacio¿n Sanitaria (grant PI02573) and by the CSIC Intramural Frontiers Project (PROFICEL). ED holds a fellowship from the Fundacio¿n La Fe. English text revised by F. BarracloughCapilla, A.; Donat, E.; Planelles, D.; Espinós-Armero, CÁ.; Ribes-Koninckx, C.; Palau, F. (2007). Genetic analyses of celiac disease in a Spanish population confirm association with CELIAC3 but not with CELIAC4. Tissue Antigens. 70(4):324-329. https://doi.org/10.1111/j.1399-0039.2007.00899.x32432970

Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes

[EN] Crosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under simulated service conditions. The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion. These membranes are alternative polyelectrolytes, which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon.The authors would like to thank the support of the European Union through the European Regional Development Funds (ERDF). The Spanish Ministry of Economy, Industry and Competitiveness, is thanked for the research project POLYDECARBOCELL (ENE2017-86711-C3-1-R). The Spanish Ministry of Education, Culture and Sports is thanked for the FPU grant for O. Gil-Castell (FPU13/01916).Gil Castell, Ó.; Cerveró, R.; Teruel Juanes, R.; Badia, JD.; Ribes Greus, MD. (2019). Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes. Journal of Renewable Materials. 7(7):655-665. https://doi.org/10.32604/jrm.2019.04401S6556657

Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells

"This is the peer reviewed version of the following article: [Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells], which has been published in final form at [10.1002/ente.202000124]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The use nanotechnology along with the consideration of a functionalization and stabilization approach to the poly(vinyl alcohol) (PVA) was considered useful for the preparation of cost-effective polyelectrolyte membranes. A set of nanocomposite and crosslinked membranes based in PVA/SSA/GO were prepared and analyzed as polyelectrolytes in direct methanol fuel cells (DMFCs). The crosslinking and sulfonation by the use of sulfosuccinic acid (SSA) enhanced the stability and increased the proton conducting sites in the PVA structure. The presence of graphene oxide (GO) augmented the stability, remarkably decreased the methanol crossover and enhanced power density curves. An optimum value for proton conductivity was found for the 0.50%wt of GO proportion, which decreased to higher concentrations of GO. Given the power density curve dependency on both the proton conductivity and the crossover reduction, the performance of these membranes as polyelectrolytes in DMFCs is strictly related to the balance between both factors. Therefore, a proportion of GO of 0.75%wt may assure suitable proton conductivity 3 mS·cm-1 and high resistance to methanol permeability, reaching promising power density of 16 mW·cm-2 with lower hydration levels.The Spanish Ministry of Economy, Industry, and Competitiveness is acknowledged for the projects ENE2017-86711-C3-1-R, ENE2017-86711-C3-2-R, ENE2017-90932-REDT, and UPOV13-3E-1947. The Spanish Ministry of Education, Culture, and Sports is thanked for the predoctoral FPU grant for O. Gil-Castell (grant no. FPU13/01916).Gil-Castell, Ó.; Santiago, Ó.; Pascual-Jose, B.; Navarro, E.; Leo, TJ.; Ribes-Greus, MD. (2020). Performance of sulfonated poly(vinyl alcohol)/graphene oxide polyelectrolytes for direct methanol fuel cells. Energy Technology (Online). 8(7):1-10. https://doi.org/10.1002/ente.2020001241108

Ionically conducting and photoresponsive liquid crystalline terpolymers: Towards multifunctional polymer electrolytes

[EN] We have prepared a series of new ionically conducting polymer electrolytes consisting of side-chain liquid crystal terpolymers with mesogenic azobenzenes, sulfonic acid groups and methyl methacrylate. The poly[10-(4-methoxyazobenzene -4'-oxy)decyl methacrylate] -co-poly[2-acrylamido-2-methyl-1-propanesulfonic acid]-copoly [methyl methacrylate]s, 10-MeOAzB/AMPS/MMA terpolymers, were synthesised by a one-pot conventional radical polymerisation. All samples were characterised by NMR, GPC/SEC, FT-IR, POM, XRD, DSC, UV-visible spectrophotometry and EIS. The terpolymers have light responsive properties, and exhibit liquid crystallinity over a wide range of compositions. Above a certain threshold of AMPS content, the 10-MeOAzB/AMPS/MMA terpolymers exhibit ionic conductivities in the 10(-8)-10(-4)S.cm(-1) range, with signs of decoupling of ionic mobility from segmental motions of the polymer.ARG and AMF thank the financial support of the Generalitat Valenciana, through the Grisolia and Forteza programs, and the Spanish Ministry of Science and Innovation, through the Research Projects ENE2007-67584-C03 and UPOVCE-3E-013 and the awarding of two FPI and FPU pre-doctoral grants. AMF and NFKA would like to thank the Royal Academy of Engineering for the award of the Newton Research Collaboration Programme grant NRCP1516/4/61. AMF acknowledges the School of Engineering of the University of Aberdeen for financial support.Vanti, L.; Alauddin, SM.; Zaton, D.; Aripin, N.; Giaccinti-Baschetti, M.; Imrie, C.; Ribes-Greus, A.... (2018). Ionically conducting and photoresponsive liquid crystalline terpolymers: Towards multifunctional polymer electrolytes. European Polymer Journal. 109:124-132. https://doi.org/10.1016/j.eurpolymj.2018.08.033S12413210