2,196 research outputs found
Tuning cathode porosity for electrochemical reduction of CO2 at high pressure [Resumo]
ABSTRACT: The development of active and stable catalytic cathodes is critical for advancing electrochemical carbon dioxide reduction into fuels and chemicals from Lab to market. This is a technology with a high potential to contribute to combat climate changes by using captured CO2, water and renewable energy [1]. The use of
pressures higher than atmospheric pressure to carry out the co-electrolysis of CO2 and water has been
recognized as an important process intensification parameter to increase productivities and energy efficiency
[2]. Ongoing work addresses the preparation of aerogels by the sol gel method and impregnation with zinc
and copper metallic particles to be used as cathodes for the co-electrolysis of CO2 and water to produce
syngas at temperatures near room temperature and high-pressure. Ionic liquid-based electrolytes are used to
increase CO2 concentration at the surface of the electrode and consequently productivities, as some ionic
liquid families are known to solubilize high amounts of CO2. Aerogels have been investigated for many different applications including as catalyst supports, due to their high surface area, stability in gaseous or
liquid phases, and efficient transport through large meso and macropores. The present work reports a strategy
to tune the pore sizes of the catalytic electrodes by the use of reticulating agents and supercritical CO2 drying.
Productivities and faradaic efficiencies of the porous materials with the different reticulating agents are
compared and interpreted in respect to their surface characterization e.g. BET surface areas and
morphologies determined by SEM. The potential of new aerogel-based catalytic cathodes on the efficiency
of the electrochemical CO2 reduction will be discussed and its impact in fostering supercritical fluids
technology through its use in processes for the mitigation of climate changes.N/
Loxosceles gaucho Venom-Induced Acute Kidney Injury – In Vivo and In Vitro Studies
Loxosceles (recluse or brown spider) is the most important spider genus causing human envenomation. In Brazil Loxosceles spiders were responsible for approximately 7,000 cases of spider envenomation per year. The brown spider accidents may cause late cutaneous necrosis at the bite site, intravascular hemolysis, rhabdomyolysis, coagulation system changes and acute kidney injury (AKI). Even patients with mild cutaneous lesion may develop severe hemolysis and AKI, which is the main cause of death after these accidents. The mechanisms causing kidney injury are poorly understood. In this manuscript we described a consistent rodent model of Loxosceles gaucho venom-induced AKI and studied some of the possible mechanisms of the renal lesion. The results of this research showed that kidney injury may occur independently of the cutaneous lesion and without changes in the systemic blood pressure. Kidney dysfunction occurred likely due to intra-renal vasoconstriction and rhabdomyolysis, although a direct toxic effect of the venom on the proximal tubules cannot be ruled out
OBSERVATORIO TERRITORIAL Y AMBIENTAL ALENTEJO, EXTREMADURA, CENTRO (OTALEX C): DE GIS A IDE.
In the scope of the Spain-Portugal INTERREG projects and FEDER funded POCTEP program, OTALEX C (Territorial and Environmental Monitoring Alentejo Extremadura Center) project aims at studying of various territorial, socioeconomic and environmental indicators. It is the fundamental objective of this project, to develop a geo-portal accessible via internet, for anyone, so that the information will be useful in making decisions related to land use and therefore sustainable development of the environment.
Under this general framework over the past fifteen years, we have developed different projects that have set the standardization of data between Portugal and Spain, also was designed GIS systems, and developed regional models and indicator systems, culminating in the current Spatial Data Infrastructure SDI-OTALEX C
Search for W' bosons decaying to an electron and a neutrino with the D0 detector
This Letter describes the search for a new heavy charged gauge boson W'
decaying into an electron and a neutrino. The data were collected with the D0
detector at the Fermilab Tevatron proton-antiproton Collider at a
center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity
of about 1 inverse femtobarn. Lacking any significant excess in the data in
comparison with known processes, an upper limit is set on the production cross
section times branching fraction, and a W' boson with mass below 1.00 TeV can
be excluded at the 95% C.L., assuming standard-model-like couplings to
fermions. This result significantly improves upon previous limits, and is the
most stringent to date.Comment: submitted to Phys. Rev. Let
Spreading Patterns of the Influenza A (H1N1) Pandemic
We investigate the dynamics of the 2009 influenza A (H1N1/S-OIV) pandemic by
analyzing data obtained from World Health Organization containing the total
number of laboratory-confirmed cases of infections - by country - in a period of
69 days, from 26 April to 3 July, 2009. Specifically, we find evidence of
exponential growth in the total number of confirmed cases and linear growth in
the number of countries with confirmed cases. We also find that, i) at early
stages, the cumulative distribution of cases among countries exhibits linear
behavior on log-log scale, being well approximated by a power law decay; ii) for
larger times, the cumulative distribution presents a systematic curvature on
log-log scale, indicating a gradual change to lognormal behavior. Finally, we
compare these empirical findings with the predictions of a simple stochastic
model. Our results could help to select more realistic models of the dynamics of
influenza-type pandemics
Ionization and Fragmentation of a Global Warming Gas by EUV and X-Ray Photons
An experimental investigation of the processes leading tothe fragmentation of the singly ionized 1,1,1,2-tetrafluoroethane (HFC-134a, CH2FCF3) by EUV and soft X-rays is presented. HFC-134ais taken into consideration as the most convenient replacement for CFC-12 in refrigeration applications due to the fact that it has null ozone depletion factor. Dissociation of the singly ionized HFC-134amolecule was induced by valence, direct and indirect C 1s core photoionization or photoexcitation and the ionic fragments were detected in coincidence (PEPICO mode) with the ejected electrons without energy analysis. The singly ionized parent ion CF4CH2+can be detected even at photon energies above the C 1s threshold
Building a Portuguese Coalition for Biodiversity Genomics
The diverse physiography of the Portuguese land and marine territory, spanning from continental Europe to the Atlantic archipelagos, has made it an important repository of biodiversity throughout the Pleistocene glacial cycles, leading to a remarkable diversity of species and ecosystems. This rich biodiversity is under threat from anthropogenic drivers, such as climate change, invasive species, land use changes, overexploitation or pathogen (re)emergence. The inventory, characterization and study of biodiversity at inter- and intra-specific levels using genomics is crucial to promote its preservation and recovery by informing biodiversity conservation policies, management measures and research. The participation of researchers from Portuguese institutions in the European Reference Genome Atlas (ERGA) initiative, and its pilot effort to generate reference genomes for European biodiversity, has reinforced the establishment of Biogenome Portugal. This nascent institutional network will connect the national community of researchers in genomics. Here, we describe the Portuguese contribution to ERGA’s pilot effort, which will generate high-quality reference genomes of six species from Portugal that are endemic, iconic and/or endangered, and include plants, insects and vertebrates (fish, birds and mammals) from mainland Portugal or the Azores islands. In addition, we outline the objectives of Biogenome Portugal, which aims to (i) promote scientific collaboration, (ii) contribute to advanced training, (iii) stimulate the participation of institutions and researchers based in Portugal in international biodiversity genomics initiatives, and (iv) contribute to the transfer of knowledge to stakeholders and engaging the public to preserve biodiversity. This initiative will strengthen biodiversity genomics research in Portugal and fuel the genomic inventory of Portuguese eukaryotic species. Such efforts will be critical to the conservation of the country’s rich biodiversity and will contribute to ERGA’s goal of generating reference genomes for European species.info:eu-repo/semantics/publishedVersio
EpIG‐DB: A database of vascular epiphyte assemblages in the Neotropics
Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil‐rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large‐scale distribution patterns. EpIG‐DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG‐DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and ‘understory’ plots). EpIG‐DB reports the occurrence of ‘true’ epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up‐to‐date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG‐DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG‐DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes
Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium
Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio
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