Inclusion of chemical effect in a fully coupled THM finite element code

Bentonite-rich clays can be used as a buffer / backfill material in deep geological repositories for nuclear waste. The prediction of the long-term performance of a buffer / backfill in such a complex environment, where the temperature, humidity and chemistry of water change, requires a fully thermo-hydro-mechanical-chemical (THMC) coupled numerical code. This paper presents a simple extension of a THM coupled finite element code to include chemical effects. After deriving the governing salt mass balance equation and discussing its implementation into the code, the paper verifies the extended framework against an analytical solution for 1D salt transport. In addition, the article presents a validation example in which the code replicates experimental data. The numerical results obtained from the extended THMC coupled finite element code encourage further investigation of the chemical effects on the mechanical and thermal behaviour of the material, which would serve the ultimate goal of achieving a safer design of the nuclear waste storage facility.Postprint (published version

Microstructure and Crystallographic Characteristics of Stenolaemate Bryozoans (Phylum Bryozoa and Class Stenolaemata)

The bryozoan class Stenolaemata is currently represented by the order Cyclostomata. They produce skeletons made exclusively of calcite crystals assembled into different microstructures. Despite extensive previous research, no appropriate crystallographic techniques have been applied to decipher their crystallographic organization. We present an in-depth crystallographic study of the microstructures of three extant species (Fasciculipora ramosa, Hornera robusta, and Cinctipora elegans) using scanning electron microscopy and associated techniques (energy dispersive spectroscopy and electron backscatter diffraction), together with atomic force microscopy and micro-computed tomography. We differentiate two microstructures: foliated and tabular calcite, and establish consistent models of their crystallography. Foliated calcite of Fasciculipora ramosa and Cinctipora elegans consists of co-oriented laths arranged with their c-axes parallel to their elongation axis and to their main surfaces, and one a*-axis perpendicular to the latter (sheet texture). Tabular calcite of Hornera robusta consists of polygonal tablets with the c-axis as fiber axis (axial texture), perpendicular to the tablet surface. The foliated calcite of bryozoans is homeomorph to that of bivalves but has a significantly different crystallography. The tabular calcite of bryozoans lacks the spiral morphology of the tablet-shaped calcite of craniiform brachiopods, and has a different orientation of the c-axis with respect to the constituent tablets.Proyectos CGL2017-85118-P y PID2020116660GB-I00 (Ministerio de Ciencia e Innovación)Proyecto B-RNM-265UGR18 (Junta de Andalucía)Grupo de Investigación RNM363 (Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía)Open Access financiado por la Universidad de Granada y por el Consorcio de Bibliotecas Universitarias de Andalucía (CBUA

The argonaut constructs its shell via physical self-organization and coordinated cell sensorial activity.

We acknowledge TESCAN and Carl Zeiss Microscopy GmbH for the acquisition and early processing of the images by FIB-SEM. This research was funded by projects CGL2017-85118-P (A.G.C., C.G.), PID2020- 116660GB-I00 (A.G.C., C.G., A.B.R.-N.) (Spanish Ministerio de Ciencia e Innovación), and B-RNM-265- UGR18 (A.G.C., C.G., A.B.R.-N.) (Junta de Andalucía), the Unidad Científica de Excelencia UCE-PP2016-05 (A.G.C., C.G., A.B.R.-N.) (University of Granada), and the Research Group RNM363 (A.G.C., C.G.) (Junta de Andalucía).Conceptualization: A.G.C.; methodology: A.G.C., F.L., A.B.R.-N., and E.G.; investigation and formal analysis: all authors; visualization: A.G.C., F.L.; writing – original draft: A.G.C.; writing – review & editing: F.L., C.G., E.G., A.B.R.-N., W.W.S.The shell of the cephalopod Argonauta consists of two layers of fibers that elongate perpendicular to the shell surfaces. Fibers have a high-Mg calcitic core sheathed by thin organic membranes (>100 nm) and configurate a polygonal network in cross section. Their evolution has been studied by serial sectioning with electron microscopy-associated techniques. During growth, fibers with small cross-sectional areas shrink, whereas those with large sections widen. It is proposed that fibers evolve as an emulsion between the fluid precursors of both the mineral and organic phases. When polygons reach big cross-sectional areas, they become subdivided by new membranes. To explain both the continuation of the pattern and the subdivision process, the living cells from the mineralizing tissue must perform contact recognition of the previously formed pattern and subsequent secretion at sub-micron scale. Accordingly, the fabrication of the argonaut shell proceeds by physical self-organization together with direct cellular activity.Unidad Científica de Excelencia UCE-PP2016-05Ministerio de Ciencia e Innovación B-RNM-265-UGR18Universidad de Granada RNM363Junta de Andalucí

Enhanced Pulse Propagation in Non-Linear Arrays of Oscillators

The propagation of a pulse in a nonlinear array of oscillators is influenced by the nature of the array and by its coupling to a thermal environment. For example, in some arrays a pulse can be speeded up while in others a pulse can be slowed down by raising the temperature. We begin by showing that an energy pulse (1D) or energy front (2D) travels more rapidly and remains more localized over greater distances in an isolated array (microcanonical) of hard springs than in a harmonic array or in a soft-springed array. Increasing the pulse amplitude causes it to speed up in a hard chain, leaves the pulse speed unchanged in a harmonic system, and slows down the pulse in a soft chain. Connection of each site to a thermal environment (canonical) affects these results very differently in each type of array. In a hard chain the dissipative forces slow down the pulse while raising the temperature speeds it up. In a soft chain the opposite occurs: the dissipative forces actually speed up the pulse while raising the temperature slows it down. In a harmonic chain neither dissipation nor temperature changes affect the pulse speed. These and other results are explained on the basis of the frequency vs energy relations in the various arrays

Low temperature behaviour and glass line of the symmetrical colloidal electrolyte

We report on the low temperature behaviour of the colloidal electrolyte by means of Molecular Dynamics simulations, where the electrostatic interactions were modeled using effective screened interactions. As in previous works, we have found a region of gas-liquid coexistence located in the low $T$- low $\rho$ region. At temperatures much lower than the critical one, the system cannot reach equilibrium, that is, the gas-liquid transition is arrested. Two different mechanisms have been identified to cause arrest: gelation in the lowest $T$ and crowding at intermediate $T$ values, the latter associated with the crossing point between the binodal and the glass line. To test the latter, the dynamics of the colloidal electrolyte near this crossing point has been computed and compared to the universal predictions of the ideal MCT. As in other glass-forming liquids, we found good agreement between this mean field theory and the dynamics of this complex system, although it fails just at the transition. Interestingly, in this region we found that the dynamics of this system is driven mainly by the steric interactions, showing all the typical properties of a repulsive colloidal glass. Finally, the isodiffusivity lines show that in this system with short range attractions, there is no re-entrant glass phenomenon, as opposed to monocomponent systems

The Development of the Bengamides as New Antibiotics against Drug-Resistant Bacteria

The bengamides comprise an interesting family of natural products isolated from sponges belonging to the prolific Jaspidae family. Their outstanding antitumor properties, coupled with their unique mechanism of action and unprecedented molecular structures, have prompted an intense research activity directed towards their total syntheses, analogue design, and biological evaluations for their development as new anticancer agents. Together with these biological studies in cancer research, in recent years, the bengamides have been identified as potential antibiotics by their impressive biological activities against various drug-resistant bacteria such as Mycobacterium tuberculosis and Staphylococcus aureus. This review reports on the new advances in the chemistry and biology of the bengamides during the last years, paying special attention to their development as promising new antibiotics. Thus, the evolution of the bengamides from their initial exploration as antitumor agents up to their current status as antibiotics is described in detail, highlighting the manifold value of these marine natural products as valid hits in medicinal chemistry.Supported by grants RTI2018-098296-BI00 (Ministerio de Ciencia e Innovación), PI19/01478 from Instituto de Salud Carlos III (ISCIII) (FEDER), P20_00540 (Andalusian Government and FEDER), K99GM138758 and R35GM136286 (National Institute of General Medical Sciences of the National Institutes of Health), A-CTS-666-UGR20 (University of Granada) (FEDER), CTS-107 (Andalusian Government) and 2021-GRIN-30998 (University of Castilla-La Mancha). Partial funding for open access charge: Universidad de Málag

Mitochondrial Na+ controls oxidative phosphorylation and hypoxic redox signalling

All metazoans depend on O2 delivery and consumption by the mitochondrial oxidative phosphorylation (OXPHOS) system to produce energy. A decrease in O2 availability (hypoxia) leads to profound metabolic rewiring. In addition, OXPHOS uses O2 to produce reactive oxygen species (ROS) that can drive cell adaptations through redox signalling, but also trigger cell damage1–4, and both phenomena occur in hypoxia4–8. However, the precise mechanism by which acute hypoxia triggers mitochondrial ROS production is still unknown. Ca2+ is one of the best known examples of an ion acting as a second messenger9, yet the role ascribed to Na+ is to serve as a mere mediator of membrane potential and collaborating in ion transport10. Here we show that Na+ acts as a second messenger regulating OXPHOS function and ROS production by modulating fluidity of the inner mitochondrial membrane (IMM). We found that a conformational shift in mitochondrial complex I during acute hypoxia11 drives the acidification of the matrix and solubilization of calcium phosphate precipitates. The concomitant increase in matrix free-Ca2+ activates the mitochondrial Na+/Ca2+ exchanger (NCLX), which imports Na+ into the matrix. Na+ interacts with phospholipids reducing IMM fluidity and mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III, generating a redox signal. Inhibition of mitochondrial Na+ import through NCLX is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na+ import into the mitochondrial matrix controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences in cellular metabolism

A tool for predicting the thermal performance of a diesel engine

This paper presents a thermal network model for the simulation of the transient response of diesel engines. The model was adjusted by using experimental data from a completely instrumented engine run under steady-state and transient conditions. Comparisons between measured and predicted material temperatures over a wide range of engine running conditions show a mean error of 7◦C. The model was then used to predict the thermal behavior of a different engine. Model results were checked against oil and coolant temperatures measured during engine warm-up at constant speed and load, and on a New European Driving Cycle. Results show that the model predicts these temperatures with a maximum error of 3◦C.Torregrosa, AJ.; Olmeda González, PC.; Martín Díaz, J.; Romero Piedrahita, CA. (2011). A tool for predicting the thermal performance of a diesel engine. Heat Transfer Engineering. 32(10):891-904. doi:10.1080/01457632.2011.548639S891904321

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson