Designing Perovskite Oxides for Solid Oxide Fuel Cells

Perovskite-type oxides with the general formula ABO3 have been widely studied and are utilized in a large range of applications due to their tremendous versatility. In particular, the high stability of the perovskite structure compared to other crystal arrangements and its ability, given the correct selection of A and B cations, to maintain a large oxygen vacancy concentration makes it a good candidate as electrode in solid oxide fuel cell (SOFC) applications. Utilizing this novel structure allows the engineering of advanced, effective electrolytes for such devices. This review details the development of current state-of-the-art perovskite-type oxides for solid oxide fuel cell (SOFC) applications

Rate-Dependent Nucleation and Growth of NaO2 in Na-O2 Batteries

Understanding the oxygen reduction reaction kinetics in the presence of Na ions and the formation mechanism of discharge product(s) is key to enhancing Na–O2 battery performance. Here we show NaO2 as the only discharge product from Na–O2 cells with carbon nanotubes in 1,2-dimethoxyethane from X-ray diffraction and Raman spectroscopy. Sodium peroxide dihydrate was not detected in the discharged electrode with up to 6000 ppm of H2O added to the electrolyte, but it was detected with ambient air exposure. In addition, we show that the sizes and distributions of NaO2 can be highly dependent on the discharge rate, and we discuss the formation mechanisms responsible for this rate dependence. Micron-sized (∼500 nm) and nanometer-scale (∼50 nm) cubes were found on the top and bottom of a carbon nanotube (CNT) carpet electrode and along CNT sidewalls at 10 mA/g, while only micron-scale cubes (∼2 μm) were found on the top and bottom of the CNT carpet at 1000 mA/g, respectively.Seventh Framework Programme (European Commission) (Marie Curie International Outgoing Fellowship, 2007-2013))National Science Foundation (U.S.) (MRSEC Program, award number DMR-0819762)Robert Bosch GmbH (Bosch Energy Research Network (BERN) Grant)China Clean Energy Research Center-Clean Vehicles Consortium (CERC-CVC) (award number DE-PI0000012)Skolkovo Institute of Science and Technology (Skoltech-MIT Center for Electochemical Energy Storage

Statistically induced phase transitions and anyons in 1D optical lattices

Anyons-particles carrying fractional statistics that interpolate between bosons and fermions-have been conjectured to exist in low-dimensional systems. In the context of the fractional quantum Hall effect, quasi-particles made of electrons take the role of anyons whose statistical exchange phase is fixed by the filling factor. Here we propose an experimental setup to create anyons in one-dimensional lattices with fully tuneable exchange statistics. In our setup, anyons are created by bosons with occupation-dependent hopping amplitudes, which can be realized by assisted Raman tunnelling. The statistical angle can thus be controlled in situ by modifying the relative phase of external driving fields. This opens the fascinating possibility of smoothly transmuting bosons via anyons into fermions and of inducing a phase transition by the mere control of the particle statistics as a free parameter. In particular, we demonstrate how to induce a quantum phase transition from a superfluid into an exotic Mott-like state where the particle distribution exhibits plateaus at fractional densities

Genomic structure and insertion sites of Helicobacter pylori prophages from various geographical origins

We present the full genomic sequences, insertion sites and phylogenetic analysis of 28 prophages found in H. pylori isolates from patients of distinct disease types, ranging from gastritis to gastric cancer, and geographic origins, covering most continents. The gentic diversity of H pylori is known to be influenced by these genomic elements including prophages who’s geneomes range from 22.6 to 33.0 Kbp. There was a high conservation of integration site shared in over 50% of cases with greater than 40% or prophage genomes harbouring insertion sequences (IS). Furthermore prophage genomes present a robust phylogeographic pattern, revealing four distinct clusters: one African, one Asian and two European prophage populations. There was evidence of recombination within the genome of some prophages, which resulted in genome mosaics composed by different populations, which may yield additional H. pylori phenotypes

Fit between humanitarian professionals and project requirements: hybrid group decision procedure to reduce uncertainty in decision-making

Choosing the right professional that has to meet indeterminate requirements is a critical aspect in humanitarian development and implementation projects. This paper proposes a hybrid evaluation methodology for some non-governmental organizations enabling them to select the most competent expert who can properly and adequately develop and implement humanitarian projects. This methodology accommodates various stakeholders’ perspectives in satisfying the unique requirements of humanitarian projects that are capable of handling a range of uncertain issues from both stakeholders and project requirements. The criteria weights are calculated using a two-step multi-criteria decision-making method: (1) Fuzzy Analytical Hierarchy Process for the evaluation of the decision maker weights coupled with (2) Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to rank the alternatives which provide the ability to take into account both quantitative and qualitative evaluations. Sensitivity analysis have been developed and discussed by means of a real case of expert selection problem for a non-profit organisation. The results show that the approach allows a decrease in the uncertainty associated with decision-making, which proves that the approach provides robust solutions in terms of sensitivity analysis

P2-Na<inf>2/3</inf>Mn<inf>0.8</inf>M<inf>0.1</inf>M′<inf>0.1</inf>O<inf>2</inf>(M = Zn, Fe and M′ = Cu, Al, Ti): A Detailed Crystal Structure Evolution Investigation

Incorporation of various transition metals has been shown to improve the electrochemical performance of Mn-rich Na-ion cathode materials. A greater comprehension of the role of dopant ions, particularly with regard to Mn-rich layered oxides as materials for the positive electrode of Na-ion batteries, is required for their continual development. Here two similar series of Mn-rich P2 cathode materials P2-Na2/3Mn0.8M0.1M′0.1O2 (M = Fe, Zn and M′ = Cu, Al, Ti) are explored, focusing on structural analysis using high-resolution operando synchrotron X-ray diffraction. Notably, under the cycling conditions employed, no P2 to O2 phase transitions toward the charged state were identified for any of the materials investigated. Particularly stable solid solution evolution was observed for P2-Na2/3Mn0.8Zn0.1Cu0.1O2 and P2-Na2/3Mn0.8Zn0.1Al0.1O2 when cycled at 40 mA.g-1 which reflects the electrochemical properties of the materials investigated herein and illustrates that Zn is an excellent choice of dopant for Mn-rich cathode materials. Moreover, the better cyclability of P2-Na2/3Mn0.8Zn0.1Al0.1O2 compared with P2-Na2/3Mn0.8Zn0.1Cu0.1O2 is in keeping with the minimal structural changes observed. This demonstrates that although oxidation state predictions to optimize the initial Mn oxidation state are a good way of initially selecting materials, to truly exploit Mn-rich P2-type materials it is necessary to build up an in-depth understanding of both oxidation states and the associated Jahn-Teller distortion as well as the subtle interplay of synergistic and antagonistic interactions between dopants. Overall, this study illustrates the value of structural investigations to assist in the rational design and validation of novel high-performance materials; the results highlight that the interplay between dopants in addition to the average Mn oxidation state are both crucial considerations when designing high-performance Mn-rich layered oxide materials

Demandas da cadeia econômica de hortaliça no planejamento da pesquisa.

A pesquisa parte da premissa de que o planejamento das ações da pesquisa agropecuária pública deve ser orientado pelas demandas das cadeias produtivas, visando aumentar a competitividade dos agricultores. Para isso, foram aplicados questionários a empresas atacadistas da Ceagesp, importantes stakeholders, com o objetivo de identificar as principais características exigidas pelos compradores de alface, cenoura e batata-doce. Essas informações são cruciais para direcionar os programas de melhoramento genético dessas três hortaliças e maximizar o retorno social do investimento em pesquisa.SOBER

Ulcerogenic Helicobacter pylori Strains Isolated from Children: A Contribution to Get Insight into the Virulence of the Bacteria

Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD). In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by mass-spectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA “on” status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence factors

A lexicographical dynamic flow model for relief operations

Emergency management is a highly relevant area of interest in operations research. Currently the area is undergoing widespread development. Furthermore, recent disasters have highlighted the importance of disaster management, in order to alleviate the suffering of vulnerable people and save lives. In this context, the problem of designing plans for the distribution of humanitarian aid according to the preferences of the decision maker is crucial. In this paper, a lexicographical dynamic flow model to solve this problem is presented, extending a previously introduced static flow model. The new model is validated in a realistic case study and a computational study is performed to compare both models, showing how they can be coordinated to improve their overall performance