5,136 research outputs found
Novel, simple, and environmentally safe method for wastewater pollutant removal
In this work, a new methodology has been developed for the elimination of cobalt, nickel and a mixture of both metals from synthetic wastewater in a continuous way. This methodology consists of the electrochemical formation of ferrites of these metals through the oxidation of iron sheets and the reduction of water. Two critical process parameters, current densities and initial pollutant concentration, were analysed. An initial batch prototype resulted in efficiencies on the order of 98% under conditions of applied densities of 50 mA/cm2 and concentrations of both metals of until 100 ppm of the ions. The obtained particles have been characterized by X-ray diffraction to determine the formation of ferrites without the appearance of secondary phases. The formed particle sizes are approximately 30 nm, with hemispherical or flower-like shapes. A flow system prototype was designed for the recirculation of the solution with 100 ppm of both contaminating metals, obtaining approximately 90% recovery with an easy magnetic harvesting. © 2021 The Author
Carrageenan from Chondracanthus Chamissoi Algae: Extraction process and experimental evaluation as green corrosion inhibitor for P22 steel in HCl
In this study, the extraction yield of carrageenan from the algae Chondracanthus Chamissoi and its efficiency as an ecological corrosion inhibitor for P22 steel in 1 M HCl at 65°C were evaluated. The extraction of carrageenan from the algae Chondracanthus chamissoi was carried out in cold water at 25°C (CC) and hot water at 80°C (HC), with different degreasing stages prior to the extraction (0, 1 and 2 stages). The codes of the six samples of carrageenan obtained were selected in terms of the production temperature and degreasing stages as: CC-0, CC-1, CC-2, HC-0, HC-1 and HC-2. All the carrageenan samples were characterized using: Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectrum. The CC shows crystallinity and is mainly composed of κ-carrageenan in the presence of KCl, NaCl and K3Na(SO4)2; while the degreasing stages reduce the content of KCl and NaCl. The HC presents an amorphous structure composed of κ/ι carrageenans. The highest carrageenan extraction yielded in cold water was 21.43%, without the degreasing stage (CC-0); while, the highest carrageenan extraction yielded in hot water was 28.96% with 2 degreasing stages (HC-2). The inhibition performance was investigated using gravimetric analysis, potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectroscopy and electrochemical frequency modulation. The experimental results demonstrated that all six carrageenan inhibitors act as good corrosion inhibitors for P22 steel in 1 M HCl at 65°C. However, the CC-0 presented the maximum corrosion inhibition efficiency (IEc) of 85.53% (EIS technique). In the HC, the degrease does not significantly affect IEc, allows to obtain 82.56% without degrease (EIS technique). Based on the results obtained, the extraction CC-0 and HC-0 in the same extraction process, allows to obtain a semi-refined, economical carrageenan, with a total carrageenan yield of 45.91%, and with a high IEc.Fil: Zavaleta Gutiérrez, N.. Universidad Nacional de Trujillo.; PerúFil: Alvarado Loyola, L.. Universidad Nacional de Trujillo.; PerúFil: Angelats Silva, L.. Universidad Privada Atenor Orrego; PerúFil: Ñique Gutierrez, N.. Universidad Nacional de Trujillo.; PerúFil: Duffó, Gustavo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín; Argentin
Global estimates for solutions to the linearized Monge--Amp\`ere equations
In this paper, we establish global estimates for solutions to the
linearized Monge-Amp\`ere equations under natural assumptions on the domain,
Monge-Amp\`ere measures and boundary data. Our estimates are affine invariant
analogues of the global estimates of Winter for fully nonlinear,
uniformly elliptic equations, and also linearized counterparts of Savin's
global estimates for the Monge-Amp\`ere equations.Comment: v2: presentation improve
Developments in the “Northern and Southern Hake” Case Study of FishPi
The overarching objective of the FishPi project is to strengthen regional cooperation in the area of fisheries data collection. The role of every case study within the project is to bring together the countries with the most involvement in the fisheries selected to coordinate and cooperate in the search of a probabilistic regional sampling design. To this aim, case study 4 (CS4) is focused in the Northern and Southern Hake stocks.
The work done in the case study include the description of the fishery at a regional level, the compilation of the present national sampling activity, the compilation of the logbooks and/or sales notes from 2013 and 2014 –to have a single regional data set of all trips of interest in the region– and different runs of simulations to test the selected sampling scenarios and stratifications. Finally, an objective evaluation of the performance of these regional designs is expected to understand the changes needed compared to the present situation.
This document presents the progress done in this case study, from the data compilation to the simulations, documenting the different steps taken and allowing an understanding of the pending tasks
The critical factor: The role of quality in the performance of supported accommodation services for complex mental illness in England
Rehabilitation services have a key role in ensuring integrated and comprehensive mental health (MH) care in the community for people suffering from long-term and severe mental disorders. MH-supported accommodation services aim to promote service users’ autonomy and independence. Given the complexity associated with MH-supported accommodation services in England, a comparative evaluation of critical performance indicators, including service provision and quality of care, seems to be necessary in designing evidence-informed policies. This study aims to explore the influence of service quality indicators on the performance of MH-supported accommodation services in England. The analysed sample includes supported accommodation services from 14 nationally representative local authorities in England from the QuEST study grouped by three main types of care: residential care homes (divided into two subgroups: move-on and non-move-on oriented), supported housing and floating outreach. EDeS-MH (efficient decision support-mental health) was used to assess the performance indicators for the selected services by combining a Monte Carlo simulation engine, data envelopment analysis and a fuzzy inference engine for integrating expert knowledge. Depending on the type of care, six/seven quality domains were sequentially included after a baseline scenario (only technical) was analysed. Relative technical efficiency scores for the baseline scenarios revealed high performance in all the selected supported accommodation services, but the statistical variability was high. Quality domains significantly improved performance in every type of care. The inclusion of quality indicators has a positive impact on the global performance of each type of care. Remaining at the corresponding services more than expected for two years has a negative impact on performance. These findings can be considered from a planning perspective to facilitate the design of pathways of care with more realistic expectations about gaining autonomy in two years
The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC
We analyzed the triple Higgs boson self-coupling at future
colliders energies, with the reactions . We evaluate the total cross-sections for both and ,
and calculate the total number of events considering the complete set of
Feynman diagrams at tree-level. We vary the triple coupling
within the range and +2. The numerical
computation is done for the energies expected to be available at a possible
Future Linear Collider with a center-of-mass energy and a luminosity 1000 . Our analysis is also extended to a
center-of-mass energy 3 and luminosities of 1000 and 5000
. We found that for the process , the
complete calculation differs only by 3% from the approximate calculation
, while for the process , the expected number of events, considering the decay products of both
and , is not enough to obtain an accurate determination of the triple Higgs
boson self-coupling.Comment: 19 pages, 12 figure
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