Thermal modeling of industrial-scale vanadium redox flow batteries in high-current operations

A cell-resolved model that simulates the dynamic thermal behavior of a Vanadium Redox Flow Battery during charge and discharge is presented. It takes into account, at a cell level, the reversible entropic heat of the electrochemical reactions, irreversible heat due to overpotentials, self-discharge reactions due to ion crossover, and shunt current losses. The model accounts for the heat transfer between cells and toward the environment, the pump hydraulic losses and the heat transfer of piping and tanks. It provides the electrolyte temperature in each cell, at the stack inlet and outlet, along the piping and in the tanks. Validation has been carried out against the charge/discharge measurements from a 9kW/27kWh VRFB test facility. The model has been applied to study a VRFB with the same stack but a much larger capacity, operating at \uf0b1400 A for 8 h, in order to identify critical thermal conditions which may occur in next-generation industrial VRFB stacks capable to operating at high current density. The most critical condition has been found at the end a long discharge, when temperatures above 50\ub0C appeared, possibly resulting in \u3016VO\u3017_2^+ precipitation and battery faults. These results call for heat exchangers tailored to assist high-power VRFB systems

Formal Global Perturbative Quantization of the Rozansky-Witten Model in the BV-BFV Formalism

We describe a globalization construction for the Rozansky-Witten model in the BV-BFV formalism for a source manifold with and without boundary in the classical and quantum case. After having introduced the necessary background, we define an AKSZ sigma model, which, upon globalization through notions of formal geometry extended appropriately to our case, is shown to reduce to the Rozansky-Witten model. The relations with other relevant constructions in the literature are discussed. Moreover, we split the model as a $BF$-like theory and we construct a perturbative quantization of the model in the quantum BV-BFV framework. In this context, we are able to prove the modified differential Quantum Master Equation and the flatness of the quantum Grothendieck BFV operator. Additionally, we provide a construction of the BFV boundary operator in some cases.Comment: 85 pages, 20 figures, comments are welcom

Sylloge Fungorum Omnium Hucusque Cognitorum : Vol. XVII. Supplementum universale. Pars VI. Hymenomycem - Laboulbeniomycetae

Sylloge Fungorum Omnium Hucusque Cognitorum es una importante obra micológica que consta de 26 volúmenes compilada por Pier Andrea Saccardo (1845-1920), quien fuera un micólogo y botánico italiano. Esta importante obra de taxonomía de hongos (escrita entre 1882 y 1890) es una lista con todos los nombres científicos utilizados y una breve descripción de los hongos. Estas descripciones siguen siendo referencias para los taxónomos actuales. Esta importante colección se encuentra depositada en el Instituto Spegazzini gracias a la generosa donación que hiciera el principal discípulo de Saccardo, el Dr. Carlos Spegazzini, y constituye la única colección de su tipo disponible en América del Sur.Material digitalizado en SEDICI gracias a la colaboración del Instituto de Botánica "Dr. Carlos Spegazzini" (Facultad de Ciencias Naturales y Museo, UNLP).Instituto de Botánica "Dr. Carlos Spegazzini

Sylloge Fungorum Omnium Hucusque Cognitorum : Vol. XVIII. Supplementum universale. Pars VII. Discomycetae - Deuteromycetae

Sylloge Fungorum Omnium Hucusque Cognitorum es una importante obra micológica que consta de 26 volúmenes compilada por Pier Andrea Saccardo (1845-1920), quien fuera un micólogo y botánico italiano. Esta importante obra de taxonomía de hongos (escrita entre 1882 y 1890) es una lista con todos los nombres científicos utilizados y una breve descripción de los hongos. Estas descripciones siguen siendo referencias para los taxónomos actuales. Esta importante colección se encuentra depositada en el Instituto Spegazzini gracias a la generosa donación que hiciera el principal discípulo de Saccardo, el Dr. Carlos Spegazzini, y constituye la única colección de su tipo disponible en América del Sur.Material digitalizado en SEDICI gracias a la colaboración del Instituto de Botánica "Dr. Carlos Spegazzini" (Facultad de Ciencias Naturales y Museo, UNLP).Instituto de Botánica "Dr. Carlos Spegazzini

A thermo-responsive, self-assembling biointerface for on demand release of surface-immobilised proteins

Dedicated chemistries for on-demand capture and release of biomolecules at the solid-liquid interface are required for applications in drug delivery, for the synthesis of switchable surfaces used in analytical devices and for the assembly of next-generation biomaterials with complex architectures and functions. Here we report the engineering of a binary self-assembling polypeptide system for reversible protein capture, immobilisation and controlled thermo-responsive release from a solid surface. The first element of the binary system is a universal protein substrate immobilised on a solid surface. This protein is bio-inspired by the neuronal SNAP25, which is the protein involved in the docking and fusion of synaptic vesicles to the synaptic membrane. The second element is an artificial chimeric protein engineered to include distinct domains from three different proteins: Syntaxin, VAMP and SNAP25. These native proteins constitute the machinery dedicated to vesicle trafficking in eukaryotes. We removed approximately 70% of native protein sequence from these proteins and constructed a protein chimera capable of high affinity interaction and self-assembly with immobilised substrate. The interaction of the two parts of the engineered protein complex is strong but fully-reversible and therefore the chimera can be recombinantly fused as a tag to a protein of interest, to allow spontaneous assembly and stimuli-sensitive release from the surface upon heating at a predetermined temperature. Two thermo-responsive tags are reported: the first presents remarkable thermal stability with melting temperature of the order of 80°C; the second disassembles at a substantially lower temperature of about 45°C. The latter is a promising candidate for remote-controlled localised delivery of therapeutic proteins, as physiologically tolerable local increase of temperatures in the 40-45°C range can be achieved using magnetic fields, infra-red light or focused ultrasound. Importantly, these two novel polypeptides provide a broader blueprint for the engineering of future functional proteins with predictable folding and response to external stimuli

Bribery: Greed versus reciprocity

It is estimated that a trillion dollars are annually exchanged in bribes, distorting justice and economic efficiency. In a novel experiment, we investigate the drivers of bribery. Two participants compete for a prize; a referee picks the winner. Participants can bribe the referee. When the referee can keep only the winner's bribe, bribes distort her judgment. When the referee keeps the bribes regardless of the winner, bribes no longer influence her judgment. An extra-laboratory experiment in an Indian market confirms these results. Hence, our participants are influenced by bribes out of greed, and not because of a desire to reciprocate

Adult and Egg Mortality of Rhynchophorus Ferrugineus Oliver (Coleoptera: Curculionidae) Induced by Thiamethoxam and Clothianidin.

The red palm weevil (RPW) is the major pest of palms in the Mediterranean region. One of the most interesting control solutions for this pest is endotherapy, comprising injections of biologically active substances directly into the stem of the palm. The objective of the present work was to study the ovicidal and adulticidal properties of two neonicotinoid insecticides (clothianidin and thiamethoxam) under laboratory conditions, to obtain evidence for application of endotherapy in the control of RPW infestations. Our results show that both commercial compounds display a dose-dependent action and exhibit different modes of action: clothianidin is more rapid in its action, but in general is less effective for control of the adult stages, while thiamethoxam is more effective, but its action requires longer to show efficacy. The eggs are much less sensitive to treatments, especially for clothianidin

Sylloge Fungorum Omnium Hucusque Cognitorum : Vol. XIV. Supplementum universale. Pars IV

Sylloge Fungorum Omnium Hucusque Cognitorum es una importante obra micológica que consta de 26 volúmenes compilada por Pier Andrea Saccardo (1845-1920), quien fuera un micólogo y botánico italiano. Esta importante obra de taxonomía de hongos (escrita entre 1882 y 1890) es una lista con todos los nombres científicos utilizados y una breve descripción de los hongos. Estas descripciones siguen siendo referencias para los taxónomos actuales. Esta importante colección se encuentra depositada en el Instituto Spegazzini gracias a la generosa donación que hiciera el principal discípulo de Saccardo, el Dr. Carlos Spegazzini, y constituye la única colección de su tipo disponible en América del Sur.Material digitalizado en SEDICI gracias a la colaboración del Instituto de Botánica "Dr. Carlos Spegazzini" (Facultad de Ciencias Naturales y Museo, UNLP).Instituto de Botánica "Dr. Carlos Spegazzini

Thermoresponsive Molecular Interface For In-Demand Release of Surface-Immobilised Proteins

In the last decades, biomedicine opened its doors to stimuli-responsive biomaterials, with applications ranging from tissue engineering to drug delivery systems. Among them, polymers are by far the most investigated, thanks to their biocompatibility and their vast range of properties, tunable to match their end-use. Protein-based thermoresponsive materials are increasingly being studied, especially for drug delivery applications, where dedicated chemistries for on-demand capture and release of biomolecules at the solid-liquid interface are essential. This is an important requirement for the synthesis of switchable surfaces used in analytical devices and for the assembly of novel smart materials with complex architectures and functions. Here the design, synthesis and characterisation of novel peptide tags for reversible protein capture and thermoresponsive release from a solid surface are reported. The peptide sequences were inspired by the selfassembling protein machinery dedicated to vesicle fusion in eukaryotes, known as the SNARE proteins. The three proteins involved, named SNAP25, syntaxin and VAMP, all present a highly preserved strand (SNARE motif) that allows them to assemble in a tight coiled-coil structure upon interaction, called SNARE complex. This four α-helix bundle has remarkable chemical and thermal stability, withstanding temperatures up to 80°C and changes of pH. The structural features of the native ternary protein complex were engineered to yield a binary self-assembling polypeptide system. The first element of the binary system is a universal protein substrate immobilised on a solid surface. This protein mimics the neuronal SNAP25, which is involved in the docking and fusion of synaptic vesicles to the synaptic membrane. The second element is a protein fusion of syntaxin and VAMP, acting as a polypeptide tag; it includes SNARE motifs from both syntaxin and VAMP, capable of self-assembly in a coiled-coil structure when coupled with SNAP25, even when immobilised on a surface. This interaction is strong but fully-reversible; therefore, this polypeptide tag can be recombinantly fused to a protein of interest to allow spontaneous assembly and stimuli-sensitive release from the surface upon heating at a predetermined temperature. Two VAMP-syntaxin protein fusions were produced, with different VAMP lengths: in the first, VAMP’s SNARE motif spans for 54 amino acids, matching syntaxin’s length. In the second, VAMP has been reduced to 25 amino acids, truncated before the residue involved in the ionic layer, which helps stabilise the coiled-coil structure of the SNARE complex. The protein fusion with the shortened VAMP has been designed to weaken the SNARE complex thermal stability and test its disassembly temperature. The recombinant proteins described above were characterised with pulldown assays and circular dichroism spectroscopy, testing their ability to form a stable SNARE complex. Two VAMP-syntaxin thermoresponsive tags are described: results show that the first one, with the 54-amino acid VAMP, presents remarkable thermal stability with Tm of the order of 80°C. The second tag, with the truncated VAMP, disassembles at a substantially lower temperature of about 45°C. The latter is a promising candidate for remote-controlled localised delivery of therapeutic proteins: the physiologically tolerable local increase of temperature in the 40-45°C range, also known as hyperthermia, can be achieved using magnetic fields, infra-red light or focused ultrasound. Notably, these two novel polypeptides provide an example for the engineering of future functional proteins with predictable folding and response to external stimuli

The effect of mycorrhizal symbiosis on the development of micropropagated artichokes

In this work, microrosettes of Cynara cardunculus L. var. scolymus Fiori of the "catanese" type were subcultured in a medium supplemented with 6-benzylaminopurine (BAP) (0.05 mg l-1). For root induction, indoleacetic acid (IAA), α-naphthalene acetic acid (NAA) and indole-3-butyrric acid (IBA) were used at three concentrations: 2, 5 and 10 mg l-1. The highest percentage of rooted shoots was aided by the presence of 10 mg l-1IAA. Once transplanted in pots, the plantlets were inoculated with 10 g Glomus viscosum strain A6 (AM fungus). Acclimatisation was clearly facilitated by the addition of the AM fungus. Indeed, the mycorrhizal plantlets registered a survival of between 90 and 95% for the rooting shoots and 60% for the non-rooting shoots. The botanical characterization of the material produced was carried out in field and was based on several morphological and productive parameters. Data collected confirm the characteristics of the original cultivar, the efficiency of the in vitro propagation material and the possibility of using this technique in early types of artichoke. © 2005 Elsevier B.V. All rights reserved