The homogeneous hydroformylation of pent-4-enal, the preferred aldehyde intermediate from 1,3-butadiene hydroformylation, was systematically investigated with Rh catalyst complexes in neat and ...CO2-expanded toluene media at 40–80 °C, syngas partial pressures ranging from 5–50 bar, and different ligand/Rh ratios. At similar operating conditions, the TOFs are generally greater with Rh/DIOP relative to a Rh/TPP catalyst. On both catalyst complexes, the chemoselectivity toward the dialdehydes ranges from 75%–100%, with the maximum adipaldehyde selectivity reaching approximately 75% (n/i ∼ 3) at 60 °C, 10 bar syngas, and molar DIOP/Rh ratio of 2.5. By using CO2-expanded toluene, the regioselectivity toward the adipaldehyde (desired product), and therefore its yield, is significantly enhanced. Interestingly, even with the simple Rh/TPP catalyst complex, adipaldehyde selectivity of up to 85% (n/i ∼ 5.6) is achieved at 60 °C, 10 bar syngas, and 50 bar CO2. The beneficial effects of CO2-expanded media are attributed to the facile tunability of the H2/CO ratio in such a phase with a fixed syngas feed composition. This approach to accelerate pent-4-enal hydroformylation to form adipaldehyde could also help in overcoming equilibrium limitations typically associated with the catalytic isomerization of pent-3-enal (the dominant product from 1,3-butadiene hydroformylation) to pent-4-enal (the preferred isomer).
•NMR analysis allows determining the composition of the samples with 0.3% accuracy•Oil and NMP mixtures present LLE in NMP/oil ratio ranging 0.4 to 4 mol/mol•Selectivity range 1-15 for aromatics and ...even higher for polyaromatics•Mod. UNIFAC (Dortmund) obtained the best predictions for compositions and selectivities
Optimization of the extraction process for reducing aromatic and/or polyaromatic compounds is of primary interest in crude oil refining. Several solvents are described for carrying out such operations (furfural, N-methyl-pyrrolidone -NMP-, dimethyl-sulfoxide -DMSO-, …) and experimental data and model description are required for the correct design of the separation operations and the optimization of the conditions.
In this work, liquid-liquid equilibria (LLE) data were determined for oil multicomponent mixtures formed by n-dodecane + mono-aromatic + poly-aromatic with NMP at ambient temperature (298.15 K) and pressure and covering a wide range of the solvent/oil ratios.
A new analytical method based on NMR was developed, calibrated, and tested to fully determine the composition of equilibrium phases despite the high number of compounds.
Obtained values for distribution constants and selectivities are higher than one and ranging 1-15, respectively, for aromatic compounds and even higher for polyaromatic components. Thus NMP appears as a suitable solvent for carrying both separations.
The experimental data were predicted by several versions of the UNIFAC model, including the UNIFAC, modified UNIFAC (Dortmund), modified UNIFAC (NIST), and UNIFAC, including fitting parameters. Overall, modified UNIFAC (Dortmund) yields the best results, even when deviations obtained for some of the compositions are around 40% of the value, and simulations carried out with such models should be considered cautiously
Smoothies are an excellent way to intake nutrients and bioactive compounds from both the fruits and the milk or soymilk with which they are made. High pressure processing (HPP) is an efficient ...alternative to traditional thermal pasteurization (TP), obtaining microbiologically-safe smoothies with minimum impact on nutritional and sensorial properties. Untreated, pasteurized (80 °C/3 min) and HPP (450–650 MPa for 3 min at 20 °C) milk- and soy-smoothies were compared. Milk- and soy-smoothies showed a total reduction in microorganisms after pasteurization and HPP at the pressure conditions applied. HPP maintained microbial stability until the end of the storage period (45 days at 4 °C). Soluble sugars (glucose and fructose), organic acids (citric, malic, tartaric, oxalic and quinic) and minerals (sodium, potassium, calcium, magnesium, iron, copper, zinc and manganese) showed no significant changes after the treatments and storage. No significant differences were found in sensorial attributes between untreated and HPP samples, although the aroma and acceptability scores decreased significantly for pasteurized smoothies. Based on the data obtained, 450 MPa are sufficient to obtain safe smoothies whose organoleptic properties are equally acceptable to consumers as freshly-made smoothies.
•Microorganisms are reduced after HPP, and shelf life can be extended to 45 days at 4 °C.•HPP and storage show a limited effect on sugar, organic acid and mineral composition.•High pressure barely changes the organoleptic characteristics of the fresh product.
•The Hansen theory was used to choose the best cosolvent for sc-CO2 extraction.•The best cosolvents for fatty acids solubilization were short-chain alcohols.•The predictions were validated with ...bubble pressures.•The experimental results agreed with the predictions.
Cosolvents are employed to improve the extraction efficiency and modify the selectivity of the main solvent. However, choosing a proper cosolvent in supercritical extraction is an arduous task. This study aimed to predict the best cosolvents for the supercritical CO2 extraction of oleic and linoleic acids using the Hansen solubility theory. Calculations were performed for eight organic cosolvents used in food and pharmaceutical production. The best cosolvents for the solubilization of both fatty acids were short-chain alcohols, ethanol and methanol. The predictions were validated with bubble pressures of the mixtures with a 0.003 fatty acid molar fraction at temperatures of 313.2 K and 323.2 K. The experimental results agreed with the predictions. The effect of pressure was well predicted via the direct relationship between pressure and the solvent density. However, the impact of temperature was not properly foreseen because the variation of solute vapour pressure was not considered. The Hansen theory predicted that the miscibility enhancement of the solute in the supercritical mixture is maximum at low pressures and low cosolvent concentrations, as was experimentally confirmed.
The COVID-19 pandemic and its related restrictions forced the reorganization of learning methodology and gave a central role to remote learning. Laboratory experiments are the most affected activity, ...and several alternatives were described. This work proposes to create calculation tools by simply programming in Visual Basic of Excel to emulate the data acquisition of specific laboratory experiments. The approach appears useful in experiments with a simple setup followed by data analysis. The experiment of gas volumetric properties allows fixing pressure and temperature conditions and measuring the occupied volume. The developed program emulates such operations and reports a computed volume. Further data reduction is the same in both procedures. Such a virtual experience was successfully used with groups of over 100 students. The results obtained were satisfactory compared with those obtained in the laboratory. Detailed analysis of the grades shows that acquired skills are comparable in both methodologies. Consequently, the virtual approach is a flexible option for remote laboratory teaching to complement traditional experimentation.
This work presents new experimental viscosity and density data for aromatic and polyaromatic compounds in binary and ternary pyrene, 1-methylnaphthalene, and dodecane mixtures. The lack of ...experimental viscosity data for these mixtures requires the development of a new database, which is vital for understanding the behavior of mixtures in more complex systems, such as asphaltenes and fuels. The mixtures proposed in this work have been measured over a temperature range of (293.15 to 343.15) K at atmospheric pressure. Several mixture compositions have been studied at these conditions: 1.0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0% pyrene mass fraction. The concentration of pyrene correlates with an increase in the viscosity and density values. At the lowest temperature in binary mixtures, the corresponding values reach 4.4217 mPa·s for viscosity and 1.0447 × 103 kg·m–3 for density, respectively. In ternary mixtures, the introduction of dodecane leads to the lowest maximum values of 3.5555 mPa·s for viscosity and 1.0112 × 103 kg·m–3 for density at the same temperature. The experimental data have been employed for the specific modification of viscosity models. These modifications could facilitate the prediction of the viscosity of mixtures that are more complex than those presented in this work. Various viscosity models have been employed, such as Linear, Ratcliff and Khan, modified UNIFAC-Visco, and Krieger–Dougherty. The settings in the models used reliably reproduce the experiment reliably. However, the Ratcliff model agrees excellently with the experiment, having a low standard deviation (2.0%) compared to other models. Furthermore, a model based on the equation of state of Guo is proposed to predict the viscosity values by modifying the specific parameters and adjusting them to the mixtures proposed in this work. The results from this study are compared to previous work, where pyrene, toluene, and heptane mixtures were analyzed. In this case, we find that the decrease of aggregation grade in the present systems is predicted by the model fixed in this work.
This study aims to describe changes in gender and wealth inequalities in leisure-time physical activity (PA) of Brazilians during a 6-year interval. It also aims to evaluate inequalities regarding PA ...public programs awareness, participation, and access to public spaces for PA.
Data from 2 population-based surveys conducted in 2013 and 2019 were used. Leisure-time PA prevalence was assessed considering those reporting ≥150 minutes per week. The authors evaluated gender inequalities calculating differences and ratios, and wealth inequalities using the slope index of inequality and the concentration index- assessing changes over time.
National levels of leisure-time PA increased from 2013 to 2019, and an increase in inequalities was observed; women and the poorest groups still presented lower prevalence. A decline in socioeconomic inequalities was observed from 2013 to 2019 regarding the availability of public spaces and awareness about public programs. However, outcomes remained more common among the richest group. Inequalities did not vary for participation in public programs.
Although leisure-time PA increased from 2013 to 2019 at a national level, there were no improvements in gender inequalities, and wealth inequalities worsened over time. Indicators of public strategies for PA increased for the population, but inequalities remain.
•Up to 50% of TAN reduction is achieved by extraction with non-basic ionic liquids.•TAN reduction improves by increasing ionic liquid/oil ratio and temperature.•Washing with water is enough to ...recover ionic liquid but acid content slightly increase.•COSMO model allow qualitative description of extraction process and the effect of higher acid contents.
Crude oil acidity, usually quantified through total acid number (TAN) and mainly due to carboxylic compounds, is a main problem because causes high corrosion rates and fouling during refining process. Reduction of crude oil TAN by means of ionic liquids (ILs) can be due to neutralization (basic ILs) or to extraction (ILs acting as solvent).
In this work, a synthetic crude oil (SC, 150 g/mol, TAN equal to 3.8) was treated with EMImEtSO4, EMImSCN, and EMImCl in the temperature range 30–120 °C and IL/crude ratio in the range 0.03–1 g/g. TAN reductions were up to 50% at high temperature and IL/SC ratio.
Water washing and reuse of EMImSCN were studied. No structural changes were detected but IL TAN increased and reduced the extraction efficiency, probably due to the strong interaction between IL and acid that makes washing with water not completely efficient. However, the reduction in extraction efficiency was much faster for IL without any treatment and such reuse is not possible.
The COSMO-RS model was used for the ILs characterization through the σ-profile and was successfully included in the simultaneous correlation of all the experimental data. COSMO-Therm was used to study the liquid-liquid equilibria and the predictions of the TAN of the organic phase were in fair agreement with the experimental results. However, COSMO-RS was unable to predict the effect of temperature and described a decrease in TAN reduction as temperature increases.
Reuse of IL was also modelled with COSMO-RS and the decrease in extraction efficiency was correctly described related to the IL acid content.
BACKGROUND: Physical education (PE) plays a critical role in the healthy development of youth; however, the influence of PE classes in helping to provide students with health‐related behavior ...patterns is not clear. This study aims to analyze whether participation in PE classes is associated with health‐related behavior among high school students.
METHODS: A total of 4210 students attending public high schools in Pernambuco (northeast of Brazil) were selected using random 2‐stage cluster sampling. Data were collected by using the Global School‐based Student Health Survey. The independent variable was the frequency of participation in PE classes, whereas physical activity, television viewing, smoking, and alcohol, fruit, vegetables and soda consumption were dependent variables. Logistic regressions were carried out to perform crude and adjusted analysis of the association between enrollment in PE classes and health‐related behaviors.
RESULTS: Sixty‐five percent of students do not take part in PE classes, with a significantly higher proportion among females (67.8%). It was observed that enrollment in PE classes was positively associated with physical activity, TV viewing, and fruit consumption, but was negatively associated with soda drinking. The likelihood of reporting being active and eating fruit on a daily basis was 27% and 45% higher, respectively, among those who participate in at least 2 classes per week in comparison with those who do not. Students who participate in PE classes had 28–30% higher likelihood of reporting lower TV viewing during week days.
CONCLUSIONS: Findings suggest that higher levels of enrollment in PE classes could play a role in the promotion of health‐related behaviors among high school students.
The Structured Days Hypothesis (SDH) posits that children's behaviors associated with obesity - such as physical activity - are more favorable on days that contain more 'structure' (i.e., a ...pre-planned, segmented, and adult-supervised environment) such as school weekdays, compared to days with less structure, such as weekend days. The purpose of this study was to compare children's moderate-to-vigorous physical activity (MVPA) levels on weekdays versus weekend days using a large, multi-country, accelerometer-measured physical activity dataset.
Data were received from the International Children's Accelerometer Database (ICAD) July 2019. The ICAD inclusion criteria for a valid day of wear, only non-intervention data (e.g., baseline intervention data), children with at least 1 weekday and 1 weekend day, and ICAD studies with data collected exclusively during school months, were included for analyses. Mixed effects models accounting for the nested nature of the data (i.e., days within children) assessed MVPA minutes per day (min/day MVPA) differences between weekdays and weekend days by region/country, adjusted for age, sex, and total wear time. Separate meta-analytical models explored differences by age and country/region for sex and child weight-status.
Valid data from 15 studies representing 5794 children (61% female, 10.7 ± 2.1 yrs., 24% with overweight/obesity) and 35,263 days of valid accelerometer data from 5 distinct countries/regions were used. Boys and girls accumulated 12.6 min/day (95% CI: 9.0, 16.2) and 9.4 min/day (95% CI: 7.2, 11.6) more MVPA on weekdays versus weekend days, respectively. Children from mainland Europe had the largest differences (17.1 min/day more MVPA on weekdays versus weekend days, 95% CI: 15.3, 19.0) compared to the other countries/regions. Children who were classified as overweight/obese or normal weight/underweight accumulated 9.5 min/day (95% CI: 6.9, 12.2) and 10.9 min/day (95% CI: 8.3, 13.5) of additional MVPA on weekdays versus weekend days, respectively.
Children from multiple countries/regions accumulated significantly more MVPA on weekdays versus weekend days during school months. This finding aligns with the SDH and warrants future intervention studies to prioritize less-structured days, such as weekend days, and to consider providing opportunities for all children to access additional opportunities to be active.
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