Microalgae contain an abundance of valuable bioactive compounds such as chlorophylls, carotenoids, and phenolics and, consequently, present great commercial interest. The aim of this work is the ...study and optimization of recovering the aforementioned components from the microalgae species
through conventional extraction in a laboratory-scale apparatus using a "green" mixture of ethanol/water 90/10
/
. The effect of three operational conditions-namely, temperature (30-60 °C), duration (6-24 h) and solvent-to-biomass ratio (20-90 mL
/g
), was examined regarding the extracts' yield (gravimetrically), antioxidant activity, phenolic, chlorophyll, and carotenoid contents (spectrophotometric assays), as well as concentration in key carotenoids, i.e., astaxanthin, lutein, and β-carotene (reversed-phase-high-performance liquid chromatography (RP-HPLC)). For this purpose, a face-centered central composite design (FC-CCD) was employed. Data analysis resulted in the optimal extraction conditions of 30 °C, for 24 h with 37 mL
/g
and validation of the predicted models led to 15.39%
/
yield, 52.58 mg
/mg
(IC50) antioxidant activity, total phenolic, chlorophyll, and carotenoid content of 18.23, 53.47 and 9.92 mg/g
, respectively, and the total sum of key carotenoids equal to 4.12 mg/g
. The experimental data and predicted results were considered comparable, and consequently, the corresponding regression models were sufficiently reliable for prediction.
The effect of mixing rules and the incorporation of an association term in a cubic equation of state (EoS), on the modelling of phase equilibria of natural gas mixtures in the presence of hydrogen ...bonding compounds, is investigated. To this purpose, the Peng-Robinson equation of state coupled with the van der Waals one-fluid mixing rules, the UMR-PRU group contribution EoS and the CPA-PR EoS, are evaluated in the prediction of phase equilibrium in ternary and multicomponent mixtures containing natural gas components, water and methanol or monoethylene glycol. It is concluded that UMR-PRU and CPA-PR give significantly improved results over the classical Peng-Robinson EoS, indicating that the use of advanced mixing rules and the explicit implementation of an association term in a cubic EoS is important for modelling the phase equilibrium of natural gas mixtures containing associating compounds.
•Hydropulping and selective dissolution/precipitation separate Tetrapak® constituents.•Effective separation of paper, AL and LDPE is achieved.•LDPE from inner layers exhibits properties comparable to ...virgin LDPE grades.
Tetra Pak cartons, i.e. multilayer packaging consisting of paper, low density polyethylene (LDPE) and aluminium, are widely used as aseptic packages in the food and beverage industry. Paper can be easily recovered from this type of post-consumer beverage cartons (PCBCs) by the pulp industry. The remaining LDPE/aluminium by-product, however, cannot be easily separated to its constituents so currently it is mostly downcycled or used for energy recovery. The aim of this work is to develop an effective process that separates and recovers LDPE and aluminium of high purity and good quality from Tetra Pak cartons. To this purpose, following paper recovery by hydropulping, LDPE and aluminium are separated using a selective dissolution-precipitation (SDP) process. The recovered LDPE is characterized by FTIR spectroscopy, thermogravimetric analysis (TGA), differential scanning (DSC) and melt flow rate (MFR) measurements. The findings reveal that the SDP separation process is an effective method to recover LDPE and aluminium from PCBCs.
► New thermodynamically consistent low-pressure VLE data for the ethanol/water mixture with emphasis near the azeotropic region. ► New temperature-dependent binary interaction parameters for the ...UNIQUAC, Wilson and NRTL models. ► Simultaneous fitting of VLE data, azeotropic points and excess enthalpies.
Recovery of bioethanol from the fermentation broth is classically achieved by distillation. The design and optimization of the distillation requires a reliable thermodynamic model that describes sufficiently the properties of the ethanol/water mixture, and, especially, the vapor–liquid equilibrium (VLE) near the azeotropic point. The purpose of this study is twofold: first, to provide new reliable low-pressure VLE data for the ethanol/water mixture with emphasis given near the azeotropic region, and second, to develop new temperature-dependent binary interaction parameters for three excess Gibbs energy models (UNIQUAC, Wilson and NRTL), by fitting simultaneously VLE data, azeotropic points and excess enthalpies for this mixture.
The exploration of novel biomarkers to assess poultry health is of paramount importance, not only to enhance our understanding of the pathogenicity of zoonotic agents but also to evaluate the ...efficacy of novel treatments as alternatives to antibiotics. The present study aimed to investigate potential gut health biomarkers in broiler chicks challenged by
and subjected to a continuous water disinfection program. A total of 144 one-day-old hatched broiler chicks were randomly allocated to four treatment groups with four replicates each, according to the following experimental design: Group A received untreated drinking water; Group B received drinking water treated with 0.01-0.05%
/
Cid 2000™ (hydrogen peroxide, acetic acid and paracetic acid); Group C was challenged by
and received untreated drinking water; and Group D was challenged by
and received drinking water treated with 0.01-0.05%
/
Cid 2000™. The use of Cid 2000™ started on day 1 and was applied in intervals until the end of the experiment at 36 days, while the
challenge was applied on day 18. Potential biomarkers were investigated in serum, feces, intestinal tissue, intestinal content, and liver samples of broilers. Statistical analysis revealed significant increases (
< 0.001) in serum cortisol levels in
-challenged broilers. Serum fluorescein isothiocyanate dextran (FITC-d) increased significantly (
= 0.004) in broilers challenged by
and treated with drinking water disinfectant, while fecal ovotransferrin concentration also increased significantly (
< 0.001) in broilers that received the drinking water disinfectant alone. The gene expression levels of
(
= 0.003) and
(
0.001) were significantly upregulated in broilers challenged by
, while mucin-2 significantly increased in birds that were challenged and received the drinking water disinfectant (
< 0.001).
expression levels were significantly (
0.013) decreased in both groups that received the drinking water disinfectant, compared to the negative control group. Finally, the
challenge significantly increased (
0.032) the crypt depth and decreased (
= 0.021) the villus height-to-crypt-depth ratio in the ileum of birds, while the tested disinfectant product increased (
= 0.033) the villus height in the jejunum of birds. Furthermore, the counts of
in the ceca of birds (
= 0.01), as well as its translocation rate to the liver of broilers (
= 0.001), were significantly reduced by the addition of the water disinfectant. This research contributes to novel insights into the intricate interplay of water disinfection and/or
challenge with potential intestinal biomarkers. In addition, it emphasizes the need for continued research to unveil the underlying mechanisms, expands our understanding of broiler responses to these challenges and identifies breakpoints for further investigations.
The UNIFAC model is extended to mixtures of ionic liquids consisting of the imidazolium cation and the hexafluorophosphate anion with alkanes, cycloalkanes, alcohols and water. Two new main groups, ...the imidazolium and the hexafluorophosphate groups, are introduced in UNIFAC. The required group interaction parameters between these groups and the existing UNIFAC main groups, CH
2, OH and H
2O, are determined by fitting binary liquid–liquid equilibrium and infinite dilution activity coefficient experimental data. The predictive capability of the extended UNIFAC model is examined against experimental data for vapour–liquid equilibrium, liquid–liquid equilibrium and activity coefficients at infinite dilution of binary and ternary systems containing 1-alkyl-3-alkyl′-imidazolium hexafluorophosphate ionic liquids, alkanes, cycloalkanes, alcohols and water. The results indicate that UNIFAC is a reliable model for phase equilibrium predictions in mixtures containing this type of ionic liquids.
Two types of Equations of State (EoS), which are characterized here as “simple” and “complex” EoS, are evaluated in this study. The “simple” type involves two versions of the Peng–Robinson (PR) EoS: ...the traditional one that utilizes the experimental critical properties and the acentric factor and the other, referred to as PR-fitted (PR-f), where these parameters are determined by fitting pure compound vapor pressure and saturated liquid volume data. As “complex” EoS in this study are characterized the EoS derived from statistical mechanics considerations and involve the Sanchez–Lacombe (SL) EoS and two versions of the Statistical Associating Fluid Theory (SAFT) EoS, the original and the Perturbed-Chain SAFT (PC-SAFT).
The evaluation of these two types of EoS is carried out with respect to their performance in the prediction and correlation of vapor liquid equilibria in binary and multicomponent mixtures of methane or ethane with alkanes of various degree of asymmetry. It is concluded that for this kind of systems complexity offers no significant advantages over simplicity. Furthermore, the results obtained with the PR-f EoS, especially those for multicomponent systems that are encountered in practice, even with the use of zero binary interaction parameters, indicate that this EoS may become a powerful tool for reservoir fluid phase equilibria modeling.
Methods for the estimation of the differential molar heat capacity, the difference between the heat capacity of the solid and the liquid form of organic compounds at their melting point Δc p(T m), ...are presented. Three schemes are considered: the first involves use of group contribution methods for the prediction of solid heat capacity (c p S) and liquid heat capacity (c p L); the other two, empirical correlations through the entropy of fusion at the melting point ΔS f(T m). Recommendations for the different categories of organic compounds are made that provide substantial improvement over the commonly used assumption of Δc p = 0, in the prediction of ideal solid solubility and solid vapor pressure.
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