204 research outputs found
Thermodynamic Comparison of alternative Biomass Gasification Techniques for producing Syngas for Gas Turbine Application
In this paper, Aspen PlusÂź models of biomass gasification process combined with plasma reactor for tar removal and plasma gasification process were developed respectively, validated and analyzed thermodynamically. The analysis shows that plasma technology is capable of producing syngas with acceptable tar content for gas turbine application. However, this comes with a huge energy penalty. For example, within the context of the analysis carried out in this paper, the thermodynamic efficiency of the biomass gasification process combined with plasma tar cleaning was found to be 43.6% while that of the plasma gasification process was 37.3% despite its higher bio-syngas calorific value. The lower efficiency recorded for the plasma gasification process occurs as a result of the higher electrical energy required to attain the high temperature needed for the gasification of the biomass material. As a result of the low efficiency, plasma tar cleaning of raw bio-syngas or plasma gasification, although technologically feasible, may not be a viable route for producing bio-syngas for gas turbine application. However, it may be a viable option for energy storage if the plasma reactor will be powered with electricity from wind and other renewable energy resources during off peak period
Plasma-photocatalytic conversion of CO2 at low temperatures: Understanding the synergistic effect of plasma-catalysis
A coaxial dielectric barrier discharge (DBD) reactor has been developed for plasma-catalytic conversion of pure CO2 into CO and O2 at low temperatures (<150°C) and atmospheric pressure. The effect of specific energy density (SED) on the performance of the plasma process has been investigated. In the absence of a catalyst in the plasma, the maximum conversion of CO2 reaches 21.7% at a SED of 80kJ/L. The combination of plasma with BaTiO3 and TiO2 photocatalysts in the CO2 DBD slightly increases the gas temperature of the plasma by 6-11°C compared to the CO2 discharge in the absence of a catalyst at a SED of 28kJ/L. The synergistic effect from the combination of plasma with photocatalysts (BaTiO3 and TiO2) at low temperatures contributes to a significant enhancement of both CO2 conversion and energy efficiency by up to 250%. The UV intensity generated by the CO2 discharge is significantly lower than that emitted from UV lamps that are used to activate photocatalysts in conventional photocatalytic reactions, which suggests that the UV emissions generated by the CO2 DBD only play a very minor role in the activation of the BaTiO3 and TiO2 catalysts in the plasma-photocatalytic conversion of CO2. The synergy of plasma-catalysis for CO2 conversion can be mainly attributed to the physical effect induced by the presence of catalyst pellets in the discharge and the dominant photocatalytic surface reaction driven by the plasma
Amyloid ÎČ-protein oligomers upregulate the ÎČ-secretase, BACE1, through a post-translational mechanism involving its altered subcellular distribution in neurons
Surfactants-based remediation as an effective approach for removal of environmental pollutantsâA review
Deterioration of environmental quality and equilibrium by rampant industrial expansion, accelerated urbanization and unchecked population growth has become a high-priority concern. The release of an alarming number of toxic polluting agents such as volatile organic compounds, dyes, heavy metals, pharmaceuticals, pesticides, industrial wastes, and personal care products due to natural or anthropogenic activities pose direct adverse effects on human health and living entities. This issue is inescapably increased because of the lack of efficient technologies for the proper disposal, management, and recycling of waste. It is of paramount importance to track alternative solutions to address these pollution problems for an eco-sustainable environment. Conventional remediation techniques are either inefficient, cumbersome or restricted due to certain techno-economic limitations. Environmental compatibility and high pollutant-removal efficacy make surfactants valuable for removal of organic pollutants and toxic heavy metal ions from different mediums. In this review, we present recent and up-to-date information on micelles/surfactants-assisted abatement of a vast number of toxic agents of emerging concern from water/wastewater including volatile organic compounds, personal care products, pharmaceutically active residues, toxic metals, dye pollutants, pesticides, and petroleum hydrocarbons. Based on the literature survey, it can be concluded that micelles-assisted water and soil treatment technology can have a better future on large-scale decontamination of wastewater. Though bio-surfactants are environmentally friendlier matrices and have successfully been employed for environmental decontamination; their large-scale applicability is challenging owing to high costs. Additional research efforts on the development and employment of novel bio-surfactants might render wastewater treatment technology greener, smarter and economical
A global agenda for advancing freshwater biodiversity research
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation
A global agenda for advancing freshwater biodiversity research
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.Peer reviewe
Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora
The Pandora Software Development Kit and algorithm libraries provide
pattern-recognition logic essential to the reconstruction of particle
interactions in liquid argon time projection chamber detectors. Pandora is the
primary event reconstruction software used at ProtoDUNE-SP, a prototype for the
Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at
CERN, is exposed to a charged-particle test beam. This paper gives an overview
of the Pandora reconstruction algorithms and how they have been tailored for
use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam
background particles, the simulated reconstruction and identification
efficiency for triggered test-beam particles is above 80% for the majority of
particle type and beam momentum combinations. Specifically, simulated 1 GeV/
charged pions and protons are correctly reconstructed and identified with
efficiencies of 86.1% and 84.1%, respectively. The efficiencies
measured for test-beam data are shown to be within 5% of those predicted by the
simulation.Comment: 39 pages, 19 figure
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
Impact of cross-section uncertainties on supernova neutrino spectral parameter fitting in the Deep Underground Neutrino Experiment
A primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is
to measure the MeV neutrinos produced by a Galactic
core-collapse supernova if one should occur during the lifetime of the
experiment. The liquid-argon-based detectors planned for DUNE are expected to
be uniquely sensitive to the component of the supernova flux, enabling
a wide variety of physics and astrophysics measurements. A key requirement for
a correct interpretation of these measurements is a good understanding of the
energy-dependent total cross section for charged-current
absorption on argon. In the context of a simulated extraction of
supernova spectral parameters from a toy analysis, we investigate the
impact of modeling uncertainties on DUNE's supernova neutrino
physics sensitivity for the first time. We find that the currently large
theoretical uncertainties on must be substantially reduced
before the flux parameters can be extracted reliably: in the absence of
external constraints, a measurement of the integrated neutrino luminosity with
less than 10\% bias with DUNE requires to be known to about 5%.
The neutrino spectral shape parameters can be known to better than 10% for a
20% uncertainty on the cross-section scale, although they will be sensitive to
uncertainties on the shape of . A direct measurement of
low-energy -argon scattering would be invaluable for improving the
theoretical precision to the needed level.Comment: 25 pages, 21 figure
Lipid nanocarriers loaded with natural compounds: Potential new therapies for age related neurodegenerative diseases?
Article in pressAge related neurodegenerative disorders (ARND) are presented as the most debilitating and challenging diseases
associated with the central nervous system. Despite the advent of active molecules with a positive role on
neurodegenerative mechanisms, many of the current therapeutic strategies remain ineffective in treating or
preventing ARND. Lipid nanocarriers have emerged as efficient delivery systems with the capability to cross
biological barriers, especially the blood brain barrier (BBB). Also, when associated to natural compounds, lipid
nanocarriers have demonstrated to be an interesting alternative to ARND therapies with multiple beneficial
effects. This comprehensive review focus on state-of-the-art lipid based nanocarriers for the delivery of natural
compounds targeting neurodegeneration. A critical analysis of published reports will be also provided giving
indications to researchers about the most promising ARND nanotherapy strategies.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. Marlene LĂșcio acknowledges the exploratory project funded by FCT with the reference IF/00498/2012. Telma Soares acknowledges COMPETE 2020 âPrograma Operacional Competitividade e internacionalizaçãoâinfo:eu-repo/semantics/publishedVersio
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