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Considering the problems associated with COVID-19 in Brazil, our research aims to highlight the main emerging challenges to be overcome by society and environmental educators in order to minimize the impacts of the pandemic and promote a more just and balanced post-pandemic context. Through qualitative research, through bibliographic consultation on specialized platforms such as Scientific Electronic Library Online SciELO and Google Scholar, our article aimed to emphasize the importance of the conservation of biodiversity and natural resources to reduce the chances of the occurrence of new diseases of zoonotic origin and talk about the challenges of the environmental educator. We found that the articulation of educators in social media is essential to promote Environmental Education (EE) and overcome the challenges related to the marked social inequality in Brazil. Nevertheless, it is necessary to join efforts to promote social transformation and improve environmental quality, highlighting the need for changes in public administration and social habits. We conclude that it is urgent to develop a new culture and way of life, capable of giving a new meaning to the current paradigm which represents a strong obstacle to sustainable development. [ABSTRACT FROM AUTHOR]

Trustworthy information about the thermophysical properties of phase-change-materials (PCMs) is vital for designing low temperature thermal energy storage systems for buildings and for modelling their thermal behaviour. However, data provided by manufacturers are recurrently optimistic, insufficient and/or uncertain for developing reliable numerical approaches, which requires further investigation. This paper aims to assess the key thermophysical properties of ten paraffin-based PCMs: microencapsulated and bulk paraffins. The melting/solidification peak temperatures, the enthalpy of fusion/solidification and the specific heat capacity were measured by Modulated-Differential-Scanning-Calorimetry. The Transient-Plane-Source-method was used to estimate the variations of the thermal conductivity/diffusivity with temperature. The thermal stability was assessed by High-Resolution-Thermogravimetric-Analysis. The microstructures of the microencapsulated PCMs were examined via Scanning-Electron-Microscopy. It was concluded that some information provided in the datasheets is roughly corroborated by the experimental results. However, in some cases, it was too optimistic (particularly the enthalpy of fusion/solidification), incoherent (mainly the melting/solidification peak temperatures) or scarce (e.g. , the values of the thermal conductivity and the specific heat of the solid/liquid phases). The major contribution of this work is a reliable dataset for upcoming numerical modelling, saving time and resources in future studies. The results can also be used as a reference for future inter-laboratorial comparison studies. [Display omitted] • The key thermophysical properties of ten commercial paraffin-based PCMs are evaluated. • Two types of PCMs are assessed: microencapsulated and bulk PCMs. • Results show that the values of some properties provided in the datasheets are too optimistic, incoherent or nonexistent. • The results complete the scarce information provided by some manufacturers. • The reliable data provided can save time, resources and funds in future modelling tasks. [ABSTRACT FROM AUTHOR]

Aerogel-like silica based materials were obtained by microwave drying of the gels synthesized with methyltrimethoxysilane (MTMS) precursor. The microwave drying is an alternative ambient pressure drying technique for these nanostructured materials that allows a fast fine drying stage and avoids the high temperature cycles of conventional evaporative drying. The gels were synthesized by a two-step acid-base catalyzed sol-gel process following the procedures described in an earlier work. After 2 days of aging, they were placed in an oven at 60°C, during one day, and then washed with distilled water at 40°C. Finally, the gels were dried in a microwave oven, at 450 W, in three cycles of two minutes each with two minutes of interval. During drying, a reduction of the gel volume was observed, but the major part of this volume was recovered by spring-back effect in 2 days, giving aerogel-like materials with a density in the interval 60-80 kg/m3. The final materials are monolithic, flexible and have a thermal conductivity of ˜0.04 W/(m K), which make them suitable for insulation applications. Additionally, they exhibit high hydrophobicity (contact angle ˜150°) and surface area (414 m2/g), what can be beneficial for adsorption of some organic pollutants. [ABSTRACT FROM AUTHOR]

Abstract: The production of MgAl2O4 spinel is evaluated using a thermochemical program, THOR, which calculates the equilibrium products resulting from the adiabatic combustion (isobaric and isochoric) or detonation of energetic materials. A classic metalized emulsion was used (ammonium nitrate, fuel oil, aluminium, water and glass microballoons), to which MgO was added. The Al/MgO proportion and the reaction regime were varied, the maximum spinel yield being achieved for the detonation of a fuel-rich emulsion with 5Al:3MgO (mol). In parallel, MgAl2O4 was experimentally synthesized by solution combustion of Al and Mg nitrates with various urea contents. The same reactions were simulated with THOR and the results obtained for products type and amounts were found to be in good agreement. Additionally, THOR simulations provided clear explanations for the experimental observations, which can be of invaluable help in the selection of fuel type and content in solution combustion synthesis of any given mixed oxide. [Copyright &y& Elsevier]

The traditional method to determine the nutritional requirements of animals is based on individual dose–response experiments that are time consuming and costly. One alternative to establish the dietary protein profile is the use of the ideal ratio between essential amino acids and digestible lysine to estimate essential amino acid requirements. The objective of this study was to determine the digestible lysine requirement of bullfrogs and to estimate essential amino acid requirements based on the ideal ratio. The experimental design was completely randomized and consisted of five treatments and three replicates. Six hundred froglets with an initial mean weight of 51.53 ± 1.91 g, identified through an implanted transponder, were used. The experimental diet (30.42% digestible protein) was supplemented with five levels of lysine HCl (0, 0.7, 1.4, 2.1, and 2.8%), so that the diets contained 1.38, 2.11, 2.85, 3.65 and 4.39% digestible lysine. The performance variables were feed intake, weight gain, feed conversion, specific growth rate, protein efficiency ratio, protein retention efficiency, and body protein and lysine deposition. The optimum level of digestible lysine was obtained at the intersection of the ascending line with the response plateau. Weight gain increased until reaching 222.7 g at 2.23% digestible lysine in the diet. The best feed conversion (1.4 g/g) and body protein (48.28 g) and lysine (4.07 g) deposition were observed at 2.29%, 2.33% and 2.39% digestible lysine, respectively. The digestible lysine requirement of bullfrogs is 2.71% of dry weight or 8.91% of dietary digestible protein, a level that provides the highest protein retention efficiency. The requirements of the other digestible amino acids estimated based on the concept of the ideal ratio of essential amino acids are (of dry weight): 2.16% arginine; 0.94% histidine; 1.34% isoleucine, 2.39% leucine; 0.79% methionine; 1.31% phenylalanine; 1.34% threonine; 0.23% tryptophan; 1.58% valine; 0.36% cystine, and 1.07% tyrosine. Statement of Relevance The estimate requirement of digestible essential amino acid using the concept of the ideal ratio permits the elaboration of diets with an appropriate amino acid, maximizing growth, protein utilization efficiency and carcass quality for bullfrogs. [ABSTRACT FROM AUTHOR]

Adjusting aquafeed to obtain sustainable growth and maximum profit margin of harvest is a worthy stride toward achieving the Sustainable Development Goals (SDGs) outlined by the United Nations. Therefore, this research aimed at modeling of nutritional behavior and harvest profit margin in fattening pacu (Piaractus mesopotamicus) fed on balanced digestible protein (BDP) contents and raised in an intensive recirculating aquaculture system (RAS). The feeding trial consisted of six treatments with three randomly arranged replicates (tanks) per treatment. A total of ten fattening pacus (490.60 ± 14.39 g, initial weight) were stocked per tank. Six experimental feeds containing the increasing contents (163, 201, 238, 272, 315, and 348 g kg-1 diet, dry matter) of BDP were manually fed to the fish for seven weeks three times a day until apparent satiation. The data obtained over the test diets were assessed through appropriate statistical procedures and mathematical models. Optimal levels of BDP were calculated for different nutritional and economic scenarios. Feed cost showed an ascending linear relationship with the BDP intake. Feed intake, feed efficiency, final body weight, weight gain, and specific growth rate (%) showed an inverted U-shaped quadratic behavior (P < 0.05). Feed conversion ratio showed a U-shaped quadratic behavior (P < 0.05). Protein efficiency ratio significantly (P < 0.05) decreased linearly in response to the increasing BDP contents. Final weights of the eviscerated and sliced fish showed an ascending linear behavior, but the overall effect was insignificant (P > 0.05) between the treatments. Whole body moisture and crude protein content increased (P < 0.05) linearly, while the whole body lipid content decreased (P < 0.05) linearly over the increasing BDP intake. Whole body ash content showed a U-shaped quadratic behavior (P < 0.05). The nutritionally optimal BDP content corresponding to the maximum gain in body weight of fattening pacu was calculated as 292 g kg-1 diet (dry matter). To obtain sustainable growth and maximum profit margin of harvest when it will be sold in the form of whole-body, eviscerated, and sliced fish the economically functional BDP intakes were calculated as 249, 256, and 260 g kg-1 diet (dry matter), respectively. This research revealed that the optimal BDP intake greatly improve the nutritional performance of fattening pacu. Moreover, harvest profit margin and eventually the economically sustainable BDP intakes were found dependent on the way the fish harvest is marketed and the changes in total feed cost. • Growth and economic performance was greatly influenced by dietary balanced protein. • Production characteristics of fattening pacu were mathematically modeled. • Harvest profit margin was subjected to marketing strategy and feed cost. • Sliced fish produced more profit margin than the eviscerated or whole fish. • Sustainable protein intakes were greatly affected by harvest profit margin. [ABSTRACT FROM AUTHOR]

This 45‐day work aimed to determine the response of juvenile pacu (Piaractus mesopotamicus) to balanced digestible protein (BDP) and to use these responses to determine whether the optimum economic levels of BDP would differ depending on the form in which the fish is sold. Six isoenergetic diets containing 163, 201, 238, 272, 315 and 348 g/kg BDP (dry‐matter basis) were prepared through the serial dilutions of a high‐protein diet with the low‐protein diet. Fish (initial average body weight, 10.82 ± 0.14 g) were fed with respective experimental diets three times a day until apparent satiation. The optimum biological level of BDP was calculated as 326 g/kg (dry‐matter basis) by the quadratic regression model for maximum body weight gain of juvenile pacu. To maximize economic returns (US$/kg) for different end products, the optimum economic levels of BDP were calculated as 311, 317 and 319 g/kg (dry‐matter basis) by an economic model for whole‐body, eviscerated and sliced juvenile pacu respectively. This finding revealed that obtaining maximum biological performance of fish in the case of high feed costs or low prices of the end product in consumer market would substantially reduce the economic returns. [ABSTRACT FROM AUTHOR]

Summary: Hepatitis C virus (HCV) genotype 4 (GT4) is genetically diverse with 17 confirmed and 4 provisional subtypes. In this report, HCV GT4‐infected patient samples from Phase 2/3 clinical studies were analysed to characterize global demographics and genetic diversity of GT4 infection among patients treated with ombitasvir (OBV, NS5A inhibitor) plus paritaprevir/r (NS3/4A inhibitor codosed with ritonavir). Among 17 subtypes isolated from GT4‐infected patients in the PEARL‐I and AGATE‐I studies, subtype prevalence by country of enrolment and country of origin suggested that subtypes 4a and 4d were likely circulating in Europe, while heterogeneous GT4 subtypes and a portion of GT4a detected in European and North American countries were likely due to immigration of HCV‐infected patients from Africa. The distributions of birth cohort and race were also significantly different across GT4 subtypes 4a, 4d, and non‐4a/4d. In addition, phylogenetic analyses of NS5A sequences revealed clustering within subtype 4a which segregated by the patient‐reported country of origin and the presence of the L30R/S polymorphism. HCV NS5A sequences derived from GT4a‐infected patients who originated from Europe and the United States clustered separately from sequences derived from patients who originated from Egypt, suggesting that genetically distinct strains of subtype 4a may be circulating globally. Finally, NS5A baseline polymorphisms were frequently detected at amino acid positions of interest for the inhibitor‐class and OBV retained activity against 37 of 39 NS5A GT4 clinical isolates, with no impact on treatment outcome in the PEARL‐I and AGATE‐I studies. [ABSTRACT FROM AUTHOR]

Summary: The efficacy and safety of an investigational combination of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) plus sofosbuvir (SOF) ± ribavirin (RBV) in patients with HCV genotype 2 or 3 infection with or without cirrhosis was evaluated. Patients with HCV genotype 3 infection without cirrhosis were randomized to receive OBV/PTV/r + SOF ± RBV for 12 weeks; OBV/PTV/r + SOF + RBV was administered to genotype 3‐infected patients with cirrhosis for 12 weeks and to genotype 2‐infected patients without cirrhosis for either 6 or 8 weeks. Efficacy was assessed by sustained virologic response [HCV RNA <25 IU/mL] 12 weeks post‐treatment (SVR12). Safety was assessed in all treated patients. In patients with genotype 3 infection with or without cirrhosis treated with 12 weeks of OBV/PTV/r + SOF ± RBV, the overall SVR12 rate was 98% (50/51), with no virologic failures. Patients with genotype 2 infection treated with OBV/PTV/r + SOF + RBV had SVR12 rates of 90% (9/10) and 44% (4/9) following 8‐ and 6‐week treatment durations, respectively; failure to achieve SVR12 for these patients was due to relapse without baseline or treatment‐emergent resistance‐associated substitutions. Thus, the investigational combination of OBV/PTV/r with SOF ± RBV was well tolerated and achieved high SVR rates with no virologic failures in patients with genotype 3 infection. Combining direct‐acting antivirals with complementary mechanisms of action and different viral targets may be an effective treatment strategy that may allow for shorter durations of therapy. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) nanoparticles are extremely attractive materials for numerous applications, especially in the anatase form. We have made these shaped, ＜10 nm anatase nanoparticles (NPs) via the supercritical (SC) drying of a titania sol, made by a “green” aqueous sol–gel nanosynthesis route. The SC drying was carried out in alcohol at 255–260 °C, and no further heating or processing of the NPs was required. The true phase composition (crystalline and amorphous phases) and the microstructure of the NPs was thoroughly characterised by the advanced X-ray methods, such as Rietveld-reference intensity ratio (RIR) and the whole powder pattern modelling (WPPM) technique, and HR-TEM analysis. Furthermore, the NPs were also characterised by Raman, FT-IR and optical spectroscopy. These anatase NPs showed themselves to exhibit a truncated tetragonal bipyramidal shape, exposing the {101} (side) and {001} (top) faces. They had a euhedral crystal habit, with sharply defined and easily recognised faces, and were very homogeneous and monodisperse in both shape and size. The photocatalytic activity (PCA) of the samples was assessed in gas–solid phase by monitoring the degradation of nitrogen oxides (NOx), a major atmospheric pollutant. Results showed that the particular shape of these anatase NPs played a key role in their photocatalytic behaviour. In fact, these truncated tetragonal bipyramidal nanocrystals exhibited an enhanced photocatalytic activity, double that of spherical anatase NPs of a similar size reported previously by the authors. This was attributed to the exposure of mainly the {101} and, to a lesser extent, {001} crystal faces, which are more reactive under photocatalysis for redox reactions. [ABSTRACT FROM AUTHOR]

This paper assesses the thermal performance of four microencapsulated-PCM-based samples that can be used in the design of new thermal energy storage systems for buildings: a PCM-enhanced plasterboard; three different fin-enhanced aluminium containers filled with the PCM. The methodology covers: the thermophysical characterization of the PCM-based products; the development of charging and discharging experiments to provide data for numerical validation purposes; the numerical modelling considering five different methods dispersed in literature, and a new-improved method. The main goals are to validate the numerical predictions against reliable experimental results and to find out which method is preferable for future simulations. The 3D numerical simulations were based on the effective heat capacity (EHC), additional heat source (AHS) and enthalpy (H-P) approaches. The first two methods were implemented in ANSYS CFX®; the other in ANSYS FLUENT®. For the EHC method, four different ways to specify the variation of the effective specific heat with temperature were assessed. While the H-P commercial code already implemented in ANSYS FLUENT® was used, the other two methods implemented in ANSYS CFX® were developed and validated for the purpose of this study. Good agreement between numerical and experimental results was achieved for all numerical approaches. In fact, it was concluded that the six numerical methods can be used to simulate heat diffusion with solid-liquid phase-changes. However, it was verified that the EHC method with the triangular or the self-adjusted triangular profiles is preferable for both charging and discharging simulations, since it can be drawn based on few information about the PCM-based products; it ensures good predictions of both charging/discharging kinetics and stored/released energy; it can be used without compromising computation time in comparison to other methods. The EHC method with the rectangular profile, recurrently used in literature, exhibits some convergence issues whose resolution has required longer computation times. • Good match between numerical and experimental results for six numerical approaches. • The EHC method with the triangular or self-adjusted triangular profiles is preferable. • It can be drawn based on few information about the PCM's thermophysical properties. • It ensure good predictions of both phase-change kinetics and stored/released energy. • It can be used without compromising computation time in comparison to other methods. [ABSTRACT FROM AUTHOR]

Marketing strategies and feeding costs are key factors affecting the sustainability of intensive aquaculture systems. The present 44-day feeding trial aimed to model the optimum levels of balanced digestible protein (BDP) for adult pacu (Piaractus mesopotamicus) and develop an economic optimization procedure for the final yield. The experiment was conducted in a freshwater recirculation aquaculture system (RAS). A randomized block design with six treatments and three replicates was used. A total of 180 pacu adults with initial body weight of 1158.50 ± 21.59 g (± standard deviation) were distributed (10 fish per tank) among 18 concrete-tanks of 2000 L. Six consecutive isoenergetic experimental diets containing 163, 201, 238, 272, 315 and 348 g BDP kg−1 (dry matter basis – DM basis) were prepared through the diet dilution procedure. The triplicate groups of fish were hand-fed three times a day at 09:00, 12:00 and 17:00 h until apparent satiation. At the end of the trial, the productive and economic responses were evaluated through appropriate mathematical models and statistical analyses. The optimum levels of BDP were modeled as 232 and 245 g kg−1 (DM basis) by the quadratic model based on maximum final body weight (FBW) and body weight gain (BWG) of adult pacu, respectively. Using an individual based economic model, the economically optimized levels of BDP were modeled as 215, 217 and 222 g kg−1 (DM basis) for obtaining maximum profitability from the fish that are marketed in the form of whole-body, eviscerated and sliced adult pacu, respectively. The optimum levels of BDP modeled for maximum profitability were found considerably lower than those modeled for maximum FBW and BWG. The hypothesized scenarios confirmed that profitability and economically optimized levels of dietary protein were greatly affected by the fluctuations in feed costs and marketing strategy of the final yield. • The biological levels of balanced digestible protein resulted in maximum productive performance of adult pacu • The economic levels of balanced digestible protein yielded maximum profitability with better productive performance • The economic returns of the final yield were greatly subjected to the changes in marketing strategies • The development of economically optimized aquafeeds may play a substantial role in sustainable aquaculture [ABSTRACT FROM AUTHOR]

• Overview on how PCMs can be used for the thermal regulation of PV devices. • Experimental assessment of the performance of new PV/PCM systems. • Movable TES units filled with the PCM RT 22 HC were placed on the PV panels' back. • The TES units have a negative impact on the performance of the PV/PCM systems. • A PCM with a higher phase-change temperature must be chosen for Mediterranean climate. This paper provides an overview on how phase change materials (PCMs) can be used for the thermal regulation of photovoltaic (PV) devices, and describes an experimental apparatus to assess whether the performance of 250 W STC-rated commercial polycrystalline silicon PV panels can be improved by placing movable thermal energy storage (TES) units filled with the free-form PCM RT 22 HC on the panels' back. The outdoor apparatus is located at Coimbra, Portugal. Three identical PV panels were separately installed and individually monitored: one panel was taken as reference; the other two were considered together with a TES unit each with horizontally and vertically oriented cavities, PV/PCM 1 and PV/PCM 2 systems, respectively. The time evolutions of the temperature of the PV panels were compared with each other to analyse the possible thermal regulation potential of the TES units. The time evolution of the power output was also assessed to compare the efficiency of the different systems. Finally, the energy produced per day by each system was evaluated. The results showed that the PV operating temperature has increased ca. 16–21 °C and 14–18 °C in the PV/PCM 1 and PV/PCM 2 systems, respectively, in comparison with the reference PV panel (at peak time). Moreover, the daily energy produced by the PV panel of the PV/PCM 1 and PV/PCM 2 systems was, respectively, 3.3–6.5% and 3.3–6.0% lower than that produced by the reference PV panel during the measured short-term summer operation period. Therefore, it was concluded that the movable TES units have a negative impact on the performance of the PV/PCM systems, and that a PCM with a higher phase change temperature must be chosen for Mediterranean climate. [ABSTRACT FROM AUTHOR]