This work deals with a computational investigation emphasized on the calibration of a turbulence model regarding to the operational capability of a SS-HAWT (small-scale horizontal axis wind turbine). ...Experimental field tests were carried out to collect data to evaluate the performance (power) coefficient, Cp, as a function of the tip-speed ratio, lambda . The prototype examined was a three-bladed wind turbine (NACA (National Advisory Committee for Aeronautics) 0012 profile) designed for fixed tip-speed ratio (with lambda = 5), constructed and operated at the Federal University of Ceara. The maximum value experimentally achieved for Cp was about 14%. The k- omega SST (shear stress transport) turbulence model, solved by the open source CFD (computational fluid dynamics) toolbox OpenFOAM (Open Source Field Operation and Manipulation), assessed the wind turbine performance. The experimental data information obtained reporting the aerodynamic performance of the SS-HAWT prototype was required to calibrate the model. The turbulence intensity and the characteristic length were studied in terms of the beta lowast parameter. The power coefficient numerically predicted tends to agree with the experimental assessment. The variation of beta lowast mainly affects viscous friction over the blades.
High-entropy alloy (HEA) nanoparticles (NPs) hold great promise in electrocatalysis because of their nearly unlimited compositions, tailorable active sites, and high durability. However, the ...synthesis of these compositionally complex structures as monodisperse NPs remains a challenge by colloidal routes because the different rates of metal precursor reduction lead to phase separation. Here, we report the conversion of core@shell NPs into HEA NPs through annealing, with conservation of sample monodispersity. This potentially general route for high-quality HEA NPs was demonstrated by preparing PdCu@PtNiCo NPs
via
seed-mediated co-reduction, wherein Pt, Ni, and Co were co-deposited on PdCu seeds in solution. These multimetallic NPs were then converted to single-crystalline and single-phase PdCuPtNiCo NPs through annealing. On account of their small particle size, highly dispersed Pt/Pd content, and low elemental diffusivity, these HEA NPs were found to be a highly efficient and durable catalyst for the oxygen reduction reaction. They were also highly selective for the four-electron transfer pathway. We expect that this new synthetic strategy will facilitate the synthesis of new HEA NPs for catalysis and other applications.
Annealing core@shell nanoparticles (NPs) yields high-entropy alloy NPs. Owing to their dispersed Pt/Pd content and low elemental diffusivity, they exhibit enhanced electrocatalytic performance and durability for the oxygen reduction reaction.
Finding suitable low-cost materials to be used as oxygen carrier in Chemical Looping Combustion (CLC) of coal is a key issue to achieve the CO2 capture at low economic cost. Recently, a Mn-ore from ...Gabon has been identified as an alternative to the state of the art of oxygen carriers based on minerals or wastes with high iron content. This Mn-ore showed a high reactivity and a long particle lifetime during batch characterization to be considered as a suitable oxygen carrier. To evaluate the potential of this material in CLC, this work analyses the behaviour of the Mn-ore during continuous combustion of a bituminous coal in a 0.5 kWth CLC unit. The CLC process was evaluated and the effect of the main operating variables - such as fluidizing medium, oxygen carrier circulation rate, temperature, and solids inventory in the fuel reactor - on the combustion efficiency and CO2 capture was investigated. A direct relation between the char conversion rate and the CO2 capture is given, being mainly affected by the mean residence time of solids and temperature in the fuel reactor. The use of a carbon separation system with separation efficiency above 90% would be required to achieve CO2 capture rates higher than 95%. Total oxygen demand values as low as 4.5% were found when optimal operating conditions were selected, mainly being related to oxygen carrier to fuel ration higher than ϕ > 3. At these conditions, the Mn-ore material showed similar combustion efficiencies than other Fe-based low-cost materials previously tested, but with higher CO2 capture rates.
•100 h of iG-CLC has been carried out using coal and a new Mn-ore in a 0.5 kWth unit.•The performance of the ore was compared to other Fe-based low-cost materials.•The Mn-ore showed similar oxygen demands but with higher carbon captures.•This Mn-ore can be an alternative to Fe-based minerals for CLC scale-up process.
Commercial TiO2 (P25, from Degussa) was modified with variable amounts of La, Ce, Y, Pr, Sm (generally rare earth (RE)), by thermal treatment of physical mixtures of TiO2 and the nitrates of the ...various RE. Doping of P25 with RE, combined with calcination at 600 or 800 °C, yields materials with surface areas ranging from ∼10 to 50 m2/g, and an anatase to rutile phase ratio ranging from ∼0.03 to 0.7, as determined by evaluation of XRD data. After calcination at 600 °C, unpromoted P25 yields the highest activity in methylene blue degradation, while RE addition decreases the activity. After pretreatment of P25 at 800 °C, RE modified catalysts perform better than unpromoted P-25, La being the preferred RE. By evaluation of the DRIFT spectra of the various catalysts, a correlation between the number of a specific anatase Ti–OH group, yielding an IR absorption at 3635 cm−1, and the methylene blue degradation rate was determined. This suggests that this OH-group is an important precursor for the reactive site in aqueous phase methylene blue degradation, and a dominant factor in controlling performance of P-25 in this reaction.
Urban heat islands (UHIs) have become an especially relevant phenomenon as a consequence of global warming and the growing proportion of people living in cities. The health impacts that are sometimes ...attributed to the rise in temperature generated in an UHI are not always adequately justified.
The objective is to analyse what effect UHIs have on maximum (Tmax) and minimum daily temperatures (Tmin) recorded in urban and non-urban observatories, and quantify the impact on morbidity and mortality during heat waves in Spain's five cities.
Data were collected on natural-cause daily mortality and unscheduled emergency hospital admissions (ICD-10: A00-R99) registered in these 5 cities across the period 2014–2018. We analysed daily Tmax and Tmin values at urban and non-urban observatories in these cities, and quantified the impact of Tmax and Tmin values during heat waves in each of these cities, using GLM models that included Tmax only, Tmin only, and both. We controlled for air pollution and other meteorological variables, as well as for seasonalities, trend and the autoregressive nature of the series.
The UHI effect was observed in Tmin but not in Tmax, and proved to be greater in coastal cities than in inland and more densely populated cities. The UHI value in relation to the mean Tmin in the summer months ranged from 1.2 °C in Murcia to 4.1 °C in Valencia (difference between urban/non-urban observatories). The modelling process showed that, while a statistically significant association (p < 0.05) was observed in inland cities with Tmax for mortality and hospital admissions in heat waves, in coastal cities the association was obtained with Tmin, and the only impact in this case was the UHI effect on morbidity and mortality.
No generalisations can be made about the impact of UHI on morbidity and mortality among the exposed population in cities. Studies on a local scale are called for, since it is local factors that determine whether the UHI effect will have a greater or lesser impact on health during heat-wave events.
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•The UHI effect was observed in Tmin but not in Tmax.•The UHI value ranged from 1.2 °C in Murcia to 4.1 °C in Valencia.•The association in inland cities on morbidity and mortality is with Tmax.•The association in coastal cities on morbidity and mortality is with Tmin.
Studies show a relationship between some mental illnesses and suicides and different environmental variables such as air pollution, characterized by stress at the neuropsychological level. Despite ...the fact that traffic noise is also a powerful neurological stressor, studies that relate traffic noise to these mental disorders are practically non-existent.
The objective is to analyze the short-term impact that chemical air pollution, traffic noise and thermal extremes have on emergency hospital admissions due to anxiety, dementia and suicides in the city of Madrid.
This ecological, longitudinal study uses generalized linear models with Poisson link to analyze the short-term impact of the average daily concentrations of chemical pollutants (NO2, PM10, PM2.5, O3), noise pollution indicators (Leqday, Leqnight and Leq24h) and temperatures during heat waves (Theat) and cold waves (Tcold) on daily admissions to emergency services in the city of Madrid from 2010 to 2013 due to anxiety (ICD-10: F32), depression (ICD-10: F40-F42) and suicide (ICD-10: X60-X84).
The results show no association between any of the chemical pollutants considered and the dependent variables studied. On the contrary, the values of Leqday are associated with the three variables analyzed in lag 0 for the cases of anxiety and depression and in lag 1 for suicides, with RR: 1.20 (IC95% 1.14 1.26), RR: 1.11 (IC95% 1.06 1.16) and RR: 1.17 (IC95% 1.05 1.30), respectively, for increases of 1 dB(A) in the values of Leqday. An association was also found between Tcold and admissions for anxiety in lag 9 with RR: 1.62 (IC95% 1.18 2.22) for increases of 1 °C in the values of Tcold.
Traffic noise can be considered an important risk factor related to the illnesses and anxiety and depression and for suicides in the city of Madrid, although new studies are needed to support the findings shown here.
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•The results show no association between chemical pollutants and the dependent variables.•Leqday are associated in lag 0 for the cases of anxiety and depression.•Leqday are associated in lag 1 for suicides.•An association was also found between Tcold and admissions for anxiety in lag 9.
Introduction
Patients who receive primary medical care at the Health Center “La Barca” and its corresponding services receive mental health assistance at the Jerez Community Mental Health Unit ...(CMHU), which belongs to the Clinical Area of Jerez within the structure of the Andalusia Health Service. A psychiatrist from Jerez CMHU is in charge of the consulting and coordination program with Health Center “La Barca”. Any case that may require mental health assistance is brought for discussion at weekly meetings between primary care physicians and the psychiatrist at the health center, with one of the following case resolutions:
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Maintain mental health assistance with primary care physician.
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Refer to the Jerez CMHU for specialized care.
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Single-appointment evaluation and assistance by the psychiatrist within primary care.
Objectives
The aim of this descriptive study was to analyze socio-demographic and clinical characteristics of the population assisted through the consulting and coordination program.
Methods
Socio-demographic and clinical data belonging to the cases brought to the program was collected between 01/06/2018 and 28/02/2020. An
ad-hoc
data collection survey was used for this purpose.
Results
Female/Male 53/23. Mean age: 47.13. Only 20% of the cases discussed were referred for specialized care to Jerez CMHU. 65% of the patients attended the appointments given with the psychiatrist within primary care. The most frequent diagnosis were anxiety disorders, adjustment disorders, and dysthymia.
Conclusions
A significant fraction of the cases discussed at the coordination program are resolved within this framework or through a single appointment with the psychiatrist, implying that the program achieves an important optimization of resources, all the while maintaining high quality healthcare. The data suggests that the consulting and coordination program is an improvement in terms of referral protocols within mental health care. A more detailed study would be necessary to confirm and enhance current data.
Disclosure of Interest
None Declared
We evaluated the side-effects of insecticides, herbicides and fungicides on adults of the egg parasitoid Telenomus remus (Nixon) under laboratory conditions. The protocol was adapted from that ...proposed by the Pesticides and Beneficial Organisms Working Group of the International Organization for Biological Control (IOBC) for Trichogramma cacoeciae (Marchal). Chlorpyrifos, acephate, beta-cyfluthrin + imidacloprid, spinosad, and pyrethroids were harmful to the parasitoid, whereas methoxyfenozide, diflubenzuron, and flufenoxuron had no effect. Of the herbicides examined, only glyphosate + imazethapyr and 2,4-D amine were classified as harmless on the first and second days of parasitism; paraquat was the most harmful. Other herbicides were harmless on the first day of parasitism, but caused various levels of reduction of T. remus parasitism on the second day. The fungicides were harmless or only slightly harmful.
The infrared properties of blazars can be studied from the statistical point of view with the help of sky surveys, like that provided by the Wide-field Infrared Survey Explorer and the Two Micron All ...Sky Survey. However, these sources are known for their strong and unpredictable variability, which can be monitored for a handful of objects only. In this paper, we consider the 28 blazars (14 BL Lac objects and 14 flat-spectrum radio quasars, FSRQs) that are regularly monitored by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope since 2007. They show a variety of infrared colours, redshifts, and infrared–optical spectral energy distributions (SEDs), and thus represent an interesting mini-sample of bright blazars that can be investigated in more detail. We present near-IR light curves and colours obtained by the GASP from 2007 to 2013, and discuss the infrared–optical SEDs. These are analysed with the aim of understanding the interplay among different emission components. BL Lac SEDs are accounted for by synchrotron emission plus an important contribution from the host galaxy in the closest objects, and dust signatures in 3C 66A and Mrk 421. FSRQ SEDs require synchrotron emission with the addition of a quasar-like contribution, which includes radiation from a generally bright accretion disc (νL
ν up to ∼4 × 1046 erg s−1), broad-line region, and a relatively weak dust torus.
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