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In membrane bioreactors (MBRs), aeration is widely used for fouling mitigation. To characterize the bubbly flow in MBRs, employing a solution that properly mimics the sludge behavior is essential. Therefore, this work investigates (i) the influence of the aerator pore size on the bubbly flow in xanthan gum solution, and (ii) the effect on the bubbly flow of using water as the continuous fluid and of the absence of the membrane module, conditions sometimes employed as model systems for MBRs. A MBR with a hollow fiber membrane module and a sintered glass plate for the aeration system was studied. Image analysis of the flow was made to assess key bubble parameters: area, circularity, Feret diameter, quantity, and velocity. The bubbly flow formed in the xanthan gum solution presented a lower turbulence level, differing greatly from the one formed in water. Nevertheless, for both fluids, the aerator with smaller pores generated a higher quantity of small bubbles, indicating a larger area of contact with the membrane surface. Such bubbles presented a higher level of size reduction with the presence of the membrane module and higher stability (higher circularity under similar velocities). This suggests that smaller bubbles should present higher antifouling activity.

The present work aimed to evaluate ohmic heating (OH) as an alternative technology to produce starch gels, and compare it with conventional heating (CH) process. Thermal properties of starches were characterized through differential scanning calorimetry. Native maize (MS) and cassava (CS) starches showed onset gelatinization temperatures of 70 °C and 57 °C, respectively. Suspensions of MS and CS were submitted to CH and OH at 90 °C and the resulting gels were evaluated regarding their physical stability (water holding capacity (WHC), sedimentation index (SI), and stability to freeze-thaw cycles) and rheological properties. Concerning the physical stability, CS gels showed better values of WHC and SI. However, when freeze-thaw cycles stability was analyzed, MS gels showed lower values of syneresis than CS gels, 20%, and 54%, respectively. Regarding rheological tests, MS gel data (tan δ∼0.1) showed a true gel-type structure, differently from CS gel (tan δ∼1) that shows a soft gel-type behavior. MS presented higher values of quality factor (Q) than CS, indicating the formation of a more stable gel. OH can replace CH in the food industry since it did not interfere in the structure of the starch gels analyzed, meanwhile there was no difference between all properties analyzed.

Digital, Housing construction consumes more materials than any other economic activity, with a total of 40.6 Gt/year. Boards are placed between construction materials to serve as non-load-bearing partitions. Studies have been performed to find alternatives to conventional materials using recycled fibers, agro-industrial waste, and protein binders as raw materials. Here, fire-resistant cellulose boards with low density and adequate flexural strength were produced for use as non-load-bearing partitions using waste newspapers, soy protein, boric acid, and borax. A central composite design was employed to study the influence of the board component percentage on flame retardancy (UL 94 horizontal burning test), density (ASTM D1037–12), and flexural strength (ISO 178–2010). The cellulose boards were characterized by thermal analysis (ASTM E1131–14) and scanning electron microscopy. Fire-resistant cellulose boards were successfully made with low densities (120–170 kg/m3) and flexural strength (0.06–0.64 MPa). The mechanical performance and fire resistance of cellulose boards suggest their suitability for use as building materials. A useful and sustainable construction material with great potential is produced with the valorization of waste materials., Ingeniería Ambiental

With the aim of predicting mixture behavior based on information of pure components only, COSMO-based models have emerged as a promising alternative. Several works in the literature are available attesting the good performance of COSMO-RS variants in several different applications. However, the extension of COSMO calculations for polymers and other macromolecules was not extensively explored. In this work, a new procedure to evaluate the parameters of the polymers repeating unit for COSMO-based models is proposed. The idea of a large polymer molecule consisting of many repeating units is employed, however, a more comprehensive analysis using oligomers of different sizes is suggested. The COSMO-SAC model with parameters from the literature was used to test the new methodology. Infinite dilution activity coefficient (IDAC) and vapor-liquid equilibrium (VLE) calculations with homopolymer and copolymer systems were performed to verify the predictive capability of the approach. The good results obtained showed the adequacy of the proposed methodology to represent IDAC and VLE data of solvent-polymer and -copylymer systems.

A potential alternative for tissue transplants is tissue engineering, in which the interaction of cells and biomaterials can be optimized. Tissue development in vitro depends on the complex interaction of several biological processes such as extracellular matrix synthesis, vascularization and cell proliferation, adhesion, migration, death, and differentiation. The complexity of an individual phenomenon or of the combination of these processes can be studied with phenomenological modeling techniques. This work reviews the main biological phenomena in tissue development and their mathematical modeling, focusing on mesenchymal stem cell growth in three-dimensional scaffolds.

Tissue engineering is a multidisciplinary field of research in which the cells, biomaterials, and processes can be optimized to develop a tissue substitute. Three-dimensional (3D) architectural features from electrospun scaffolds, such as porosity, tortuosity, fiber diameter, pore size, and interconnectivity have a great impact on cell behavior. Regarding tissue development in vitro, culture conditions such as pH, osmolality, temperature, nutrient, and metabolite concentrations dictate cell viability inside the constructs. The effect of different electrospun scaffold properties, bioreactor designs, mesenchymal stem cell culture parameters, and seeding techniques on cell behavior can be studied individually or combined with phenomenological modeling techniques. This work reviews the main culture and scaffold factors that affect tissue development in vitro regarding the culture of cells inside 3D matrices. The mathematical modeling of the relationship between these factors and cell behavior inside 3D constructs has also been critically reviewed, focusing on mesenchymal stem cell culture in electrospun scaffolds.

Andiroba oil is a popular Amazonian product that stands out for its numerous medicinal properties, such as anti-inflammatory, antimicrobial, and repellent action. This work reports the synthesis of andiroba oil polyol (AOP) by enzymatic glycerolysis and its use as raw material for the production of polyurethane foams (PUF). The AOP synthesis was carried out in a tubular fixed bed reactor containing commercial lipase Novozym 435®, using a reaction mixture composed of andiroba oil, glycerol and t-butanol. Three percent solvent contents (50, 100, and 150% volume of solvent per weight of substrate) and temperatures (40, 50, and 60 °C) were evaluated. The AOP synthesized at 50 °C with 150% of solvent showed the highest yield of monoacylglycerol – MAG (66.47 %), being the most suitable for PUF production. PUFs were prepared using AOP or AOP/glycerol blends, hexamethylene diisocyanate biuret, dibutyl-tin dilaurate as catalyst and water as blowing agent. Polyurethane formation was confirmed by FTIR. Due to the low average functionality of AOP ( F ¯ ( OH ) = 1.23), the production of dimensionally stable foams, was possible only through its combination with glycerol.

One of the most widely used techniques for evaluating the wettability of powdered foods is the capillary rise method, in which the contact angle is usually estimated using the classical Washburn model. However, this model does not take into account the effect of the dissolution of the particle bed in the rising process, which is an important limitation for its application to many powdered foods. This work presents a new mathematical model for the analysis of capillary rise data considering the partial dissolution of the particle bed. As in the case of the classical Washburn model, the proposed model, designated Dissolution-Modified Washburn Model (DM-Washburn), was obtained by the integration of the Navier-Stokes equation, but introducing a dependency of the capillary diameter as a function of meniscus position and time as a strategy to quantify the dissolution effects. The comparison between the DM-Washburn and the classical Washburn models in terms of quality of fit was performed using experimental data of capillary rise in d -(+)-glucose and lactose using as wetting liquids pure water and aqueous solutions of these two materials with concentrations up to saturation. The DM-Washburn model provided better fit to the height versus time data, with mean relative deviation (MRD) values lower than 5% for all tested conditions. Further, the estimates of contact angle obtained with the DM-Washburn model showed to be independent of the carbohydrate concentration in the wetting liquid, differently from what was observed using the classical Washburn model. Additionally, tests with microcrystalline cellulose (MCC), a water insoluble material, showed the consistency of the DM-Washburn model in conventional capillary experiments, i.e., without significant dissolution of the particle bed. The obtained results indicate that the model has great potential for evaluating the wettability of soluble materials.

Flow-induced birefringence is a technique with numerous potential applications in polymers, because the bright and dark fringe patterns of the birefringence images can be related to principal stress difference (PSD) profile along the flow centerline. In this work, we developed an easy-to-use methodology for birefringence image processing using the GIMP open-source software. In order to illustrate its application, images obtained in previous work during the flow of two grades of general purpose polystyrene through the slit-die geometry in the multipass rheometer MPR4, located at the University of Cambridge, UK, were reprocessed. The results showed that the PSD module profile along the flow centerline obtained with the proposed methodology is more accurate than the manual technique and is obtained with shorter processing time.

In order to reduce fouling, membranes are modified by several techniques, among them, blending with hydrophilic additives are the most practical. N-phthaloyl-chitosan (NPhthCs) was obtained by the reaction of chitosan with phthalic anhydride in dimethylformamide and used as additive in the casting solution. Polyethersulfone (PES) membranes without and with NPhthCs were prepared by phase inversion via immersion precipitation. Modified membranes showed higher hydraulic permeance (27 ± 4 L m −2 h −1 bar −1 ) and hydrophilicity by contact angle (CA) measurement (CA = 56 ± 5°) than pure PES membranes. In bovine serum albumin (BSA) membrane filtration experiments, PES/NPhthCs membranes showed higher permeate fluxes, but the relative flux loss and recovery and also the BSA retention (90 ± 2% PES and 86 ± 10% PES/NPhthCs membranes) were not significantly different. Resistance-in-series analysis showed that both concentration polarization and fouling resistances were significantly lower for PES/NPhthCs membranes, indicating that the chemical modification improved the antifouling property of these membranes.

The separation of low molecular weight organic compounds such as the ethanol from aqueous solutions represents an important area to be investigated and increment the range of applications of forward osmosis. This investigation assesses the effects of using different draw solutes for ethanol separation from dilute aqueous solutions. The influence of glucose, sucrose, sodium chloride, and magnesium chloride was evaluated in terms of total permeate, reverse solute and ethanol fluxes. Inorganic solutes promoted higher total permeate and ethanol fluxes than the organic solutes (2.5 and 1.5 times higher in average, respectively) for the same molar concentration, while presenting only 1.1 times higher reverse solute fluxes. Despite the lower ethanol flux promoted by the organic draw solutes, these osmotic agents promoted higher concentration of ethanol in the total permeate flux, suggesting that they can also be alternatives for specific processes. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4499–4507, 2017

Computational modeling has been proven to be very useful in tissue engineering over the past years. Because the model is a simplification of the experimental system, the processes accounted for in the model should be analyzed carefully. However, new and complex models are usually proposed without a clear comparison with the basic ones. In this study, the contribution of oxygen to Contois growth kinetics and porosity variation with time due to polymer degradation was evaluated through a sensitivity analysis. The effect of initial glucose concentration, porosity and thickness of the scaffold on the cell volume fraction and substrate concentration was analyzed for three models. Even with the inclusion of oxygen concentration in the model, the output variables are more affected by the initial cell number, while the model with variable porosity is quite robust to variations in the input variables.

Accurate spatial discretization error estimates are essential for some CFD applications. Notwithstanding, this subject has been systematically disregarded in the literature on bubbly flow simulation. This work evaluated the suitability of three error estimators (EEMs) in simulations of a benchmark bubble column. The employed EEMs were: Direct Taylor series (DTS), Richardson Extrapolation (RExt), and Eca-Hoekstra Least-Squares (EH-LS). The modeling approaches for the bubbly flow were: standard two-fluid model (TFM), hyperbolic TFM (hTFM), and mixture model (MixtM). Geometric means of the estimated error and of the difference between the solution obtained with the considered mesh and a nearly mesh-independent solution were used as comparison metrics. DTS resulted in inaccurate estimates for coarse meshes. Both EH-LS and RExt generated accurate results for MixtM, the latter presenting lower computational cost. RExt could not deal adequately with the oscillatory convergence pattern of hTFM. EH-LS was the only method suitable for both MixtM and hTFM.

The goal of this work was to examine the effect of water activity (aw) of a material—in this case microcrystalline cellulose (MCC)—on the contact angle obtained by the Washburn technique. The effect of the difference between the relative humidity of the gaseous phase in equilibrium with a sample of a given water activity and the actual relative humidity (RH) of the ambient in which the measurements are being performed was also evaluated. The choice of MCC as case study was based on its importance as component for particulate foods, on the lack of information in the literature regarding its wettability characteristics, and on its low dissolution rate and swelling in water. Eight MCC samples of different aw were prepared and analysed. Additionally, the moisture sorption isotherm of MCC was determined experimentally and fitted to the GAB model. The MCC-water contact angle decreases linearly with aw and nonlinearly with the moisture content, showing more pronounced changes below the monolayer moisture content. Although it was observed that RH does not affect the results obtained during the capillary rise measurement, this parameter is relevant in the determination of the contact angle by the Washburn technique because it affects the moisture content of the sample prepared for analysis. The results here presented show that the Washburn technique has sufficient accuracy to quantify the effects of the considered variables on the wettability of MCC particles.

Power ultrasound has vast potential in the food industry; however, there are no works on its effects on desserts. Thus, the objectives of this study were to investigate the effect of ultrasound as a mixing or homogenization step or as a tool to modify the texture of the soy-based desserts without reformulating the product. Different properties of soybased desserts were evaluated and the behaviour of the samples during storage under refrigeration (60 days) was monitored. The samples were treated with an ultrasound probe for 1, 3, and 5 min. The treated samples showed lower mean particle size, lower consistency index, higher flow index, and clear difference in their microstructure. However, water holding capacity and particle size dispersion index values did not differ among untreated and treated soy based desserts for 1 and 3 minutes, and none of the treatments caused visible colour differences among the samples. Periodically, rheological properties, pH, soluble solids content, colour, particle size, and water holding capacity were determined. After 60 days, all evaluated properties differed significantly, except for the pH.

In this work the parameters of a PC-SAFT model combined with the group contribution of Tamouza et al. [Fluid Phase Equilib. 228–229 (2005) 409–419. http://dx.doi.org/10.1016/j.fluid.2004.10.003] were estimated using not only pure component experimental data, but also mixture vapor–liquid equilibrium (VLE) and infinite–dilution activity coefficient (IDAC) data. With the resulting parameters, the percent average absolute deviation values for vapor pressure and molar liquid volume were under 2.6% for n-alkanes and were under 7.4% for vapor pressure and 2% for molar liquid volume for 1-alkanols. For the studied mixtures, the average absolute relative deviation for bubble pressures was under 5.2%, considering 1239 experimental VLE data points in the temperature range from 273 to 422 K. For IDAC, the predictions were very similar to those obtained by other similar models. These results reveal that the proposed group contribution PC-SAFT model can be used to predict vapor–liquid equilibrium with a satisfactory accuracy for 1-alkanols and n-alkanes binary systems with no binary interaction parameter.

The high cost and long duration of the existing standard tests, such as ASTM D5338 and ISO 14855, represents an important drawback in evaluating the biodegradability of polymers. This works presents a new accelerated method for this purpose, based on the use of a Bartha respirometer and biostimulation with yeast extract. The new method was applied to microcrystalline cellulose (MCC), low density polyethylene (LDPE), poly(3-hidroxybutyrate) (PHB), poly(lactic acid) (PLA), poly(vinyl alcohol) (PVOH), polypropylene (PP) and poly(ethylene terephthalate) (PET). The results obtained with these polymers were consistent with those of the standard methods in terms of differentiating biodegradable and non-biodegradable polymers and relative order of biodegradation extent. Besides, a significant reduction of test duration was achieved (from 45 to 110 days with ASTM D5338 or ISO 14855 to 28 days). These results corroborate the potential of the proposed method as a fast test for assessment of biodegradation of polymeric materials.

Over the past few years, there has been an increase in the production of biopolymers, including poly(3-hydroxybutyrate) P(3HB). However, finding compatible solvents for these new materials can be a challenging task. The infinite dilution activity coefficient (IDAC) is a thermodynamic property that indicates the level of interactions between two substances and can be determined from experiments of inverse gas chromatography (IGC). In this work, IGC was used to determine IDAC of 12 solvents in P(3HB). The substances studied were 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), 1,2-dichloroethane, 2,2,2-trifluoroethanol, 2-butanone, 2-heptanone, benzene, chloroform, cyclohexane, dimethyl carbonate, ethyl acetate, isooctane and toluene. HFIP was found to be the most compatible solvent with P(3HB) with IDAC values smaller than 1. Isooctane presented the highest IDAC value, in agreement with the well known incompatibility between hydrocarbons and P(3HB). In addition, P(3HB) crystallinity was determined through IGC technique, enabling the calculation of the IDAC of amorphous phase only, where vapor-liquid equilibrium can be assumed. The degree of crystallinity obtained with HFIP analysis in P(3HB) was 68%, a value close to that previously reported in the literature.

Membrane separation processes used for beer dealcoholization have as main advantage the operation at mild temperatures when compared to traditional thermal technologies. Such alternatives to thermal treatment preserve the organoleptic quality of the foods that are being processed. This work assesses the use of forward osmosis to dealcoholize a commercial beer containing 5 vol% of alcohol. In this process, water and ethanol are removed from the beer simultaneously, and diafiltration is used to rehydrate the beer, reducing its alcohol content. We assess this study by characterizing the chemical profile of the beer before and after the FO diafiltration process. It was possible to obtain a low alcohol beer containing 0.5 vol%, but physical-chemical properties were impaired. The turbidity and salinity increased by 44% and 70%, respectively, while color decreased 7%. We also noticed the loss of flavor compounds. Results indicate that forward osmosis can be an alternative to reduce the ethanol content of aqueous solutions such as beverages and fermentation broths.

This work reports a new method to obtain polypropylene/titanium dioxide (PP/TiO2) films with antibacterial activity through the in situ synthesis of nanostructured TiO2 directly in the polymer solution. In order to compare the performance of the different types of particles, TiO2 particles were also prepared utilizing the sol-gel method and subsequently incorporated into the polymer to form PP/TiO2 films. The obtained TiO2 and PP/TiO2 films were characterized by X-ray diffraction (XRD), dispersive scanning electron microscopy with dispersive energy (SEM/EDS), Brunauer-Emmett-Teller (BET) method, and contact angle. The properties of the particles and the PP/TiO2 films were correlated to the antibacterial activity against Gram-positive (Listeria monocytogenes and Staphylococcus aureus) and Gram-negative (Salmonella typhimurium and Escherichia coli) bacteria. The TiO2 nanostructured obtained in situ presented small particle size (7.7 nm), high surface area (159.8 m2.g-1) and high crystallinity (even without heat treatment), presenting a mixture of anatase and rutile phases, which together exert a beneficial synergistic effect on the antibacterial properties of the TiO2 particles. Experimental results showed a reduction of around 90% of the bacterial population. In situ method showed to be the simplest way to obtain PP/TiO2 films in a single step, which can be used in manufacturing active packaging with antibacterial action for both Gram-positive and Gram-negative bacteria.

A sulfated polysaccharide fraction from the red alga Gracilaria intermedia (PLS) was obtained by papain digestion (60 °C, 30 min). The extract was subjected to colorimetry and turbidimetry analysis, Fourier transform infrared (FTIR) spectroscopy, 1H, 13 C and 2D 1H COSY nuclear magnetic resonance (NMR) and gas chromatography/mass spectrometry analysis. Antioxidant activity tests were performed (chelation of ferrous ion, total antioxidant capacity, and scavenging of DPPH radicals); significant activity of the extract indicated that these polysaccharides may be used as non-synthetic antioxidants. The rheological behavior of aqueous polysaccharide solutions was studied at 25 ± 1 °C using steady-shear and dynamic oscillatory measurements. All the solutions analyzed showed pseudoplastic behavior and potential to act as a thickening agent, as proved through a preliminary comparison with a commercial product used for this application.

Cell adhesion in three-dimensional scaffolds plays a key role in tissue development. However, stem cell behavior in electrospun scaffolds under perfusion is not fully understood. Thus, an investigation was made on the effect of flow rate and shear stress, adhesion time, and seeding density under direct perfusion in polycaprolactone electrospun scaffolds on human dental pulp stem cell detachment. Polycaprolactone scaffolds were electrospun using a solvent mixture of chloroform and methanol. The viable cell number was determined at each tested condition. Cell morphology was analyzed by confocal microscopy after various incubation times for static cell adhesion with a high seeding density. Scanning electron microscopy images were obtained before and after perfusion for the highest flow rate tested. The wall pore shear stress was calculated for all tested flow rates (0.005–3 mL/min). An inversely proportional relationship between adhesion time with cell detachment under perfusion was observed. Lower flow rates and lower seeding densities reduced the drag of cells by shear stress. However, there was an operational limit for the lowest flow rate that can be used without compromising cell viability, indicating that a flow rate of 0.05 mL/min might be more suitable for the tested cell culture in electrospun scaffolds under direct perfusion.

The objective of this study was to use pinhão derivatives, starch and coat extract, as new natural ingredients to develop cosmetic formulations. Two types of formulation, gel and emulgel, and their controls were developed. The formulations were characterized by stability studies using thermal stress. The parameters analyzed were resistance to centrifugation, pH, spreadability, rheology, content of phenolic compounds and antioxidant activity. Sensory analysis was also performed to verify the acceptability of the ingredients to potential consumers. The pH was kept the same after heating/freezing cycles for all formulations, and the formulations showed stability by resistance to centrifugation. The formulations did not induce any skin irritation or cutaneous pH alteration. The pinhão starch addition improved spreadability stability and increased viscosity when compared with control formulations. The pinhão coat extract used in these formulations is a good source of phenolic compounds and antioxidant activity. Moreover, sensory analysis indicates that the emulgel formulation is the best vehicle for adding pinhão starch and pinhão coat extract.

A model for studying the catalyst fragmentation in the early stages of olefin polymerization is presented. The model is based on measurable and observable parameters of the catalyst and on the energy balance for the fragmentation phenomenon. The model allows the fragmentation behaviors to be discriminated regarding the influence of particle size, polymerization rate, and active site distribution. The results are supported by experimental studies available in the literature indicating the deterministic nature of the model and its capabilities of prediction. The performance of the model allows the optimization of the catalyst synthesis in terms of the nature of the support as well as particle and pore morphology.

In the literature there are several studies comparing the accuracy of various models in describing the PvT behavior of polymers. However, most of these studies do not provide information about the quality of the estimated parameters or the sensitivity of the prediction of thermodynamic properties to the parameters of the equations. Furthermore, there are few studies exploring the prediction of thermal expansion and compression coefficients. Based on these observations, the objective of this study is to deepen the analysis of Tait, HH (Hartmann-Haque), MCM (modified cell model) and SHT (simplified hole theory) equations of state in predicting the PvT behavior of polymers, for both molten and solid states. The results showed that all equations of state provide an adequate description of the PvT behavior in the molten state, with low standard deviations in the estimation of parameters, adequate sensitivity of their parameters and plausible prediction of specific volume, thermal expansion and isothermal compression coefficients. In the solid state the Tait equation exhibited similar performance to the molten state, while HH showed satisfactory results for amorphous polymers and difficulty in adjusting the PvT curve for semicrystalline polymers.

In this study, buffalo milk powder was produced with and without added soy lecithin. The fresh buffalo milk was partially skimmed, pasteurized, concentrated to 40% (mass percentage) of total solids and dried by spray drying. For the samples prepared with lecithin, its addition was made prior to the drying process in concentrations of 0.3, 0.5 and 1.0 g of lecithin/100 g of total solids in the concentrated milk. The effect of lecithin concentration on the moisture content, morphology, color, surface area, particle size distribution and wettability of the powdered milk produced was evaluated. The wettability was assessed by the static wetting test and the Washburn technique, the latter giving the water contact angle ( θ ) of the powder material. The addition of lecithin decreased the wetting time (ranging from 5 min to 63.9 s) and θ (ranging from 89° to 81°, approximately) of the buffalo milk powder, but it did not show much influence on the moisture, morphology, color, surface area and size distribution of the powder particles.

Membrane-based technologies have been considered for separation of ethanol/water mixtures as an alternative to thermal based separations. In this work, we consider forward osmosis (FO) for ethanol separation from aqueous solutions using commercial cellulose triacetate (CTA) and thin film composite (TFC) forward osmosis membranes. Aqueous solutions containing ethanol were used as feed solution and sodium chloride was used as osmotic agent for the tests. The total permeate flux and the reverse salt flux are increased with the increase of the osmotic pressure difference, while the ethanol-water separation factor is decreased. CTA and TFC membranes presented similar total permeate fluxes (from 4 to 8 kg m-2 h-1), but CTA presented lower reverse salt flux (below 5 g m-2 h-1) and higher separation factor (αethanol-water between 1 and 2). Additional tests using reverse osmosis (RO) were conducted to compare with the FO results.

Tissue engineering and the manufacturing of regenerative medicine products demand strict control over the production process and product quality monitoring. In this chapter, the application of process systems engineering (PSE) approaches in the production of cell-based products has been discussed. Mechanistic, empirical, continuum and discrete models are compared and their use in describing cellular phenomena is reviewed. In addition, model-based optimization strategies employed in the field of tissue engineering and regenerative medicine are discussed. An introduction to process control theory is given and the main applications of classical and advanced methods in cellular production processes are described. Finally, new nondestructive and noninvasive monitoring techniques have been reviewed, focusing on large-scale manufacturing systems for cell-based constructs and therapeutic products. The application of the PSE methodologies presented here offers a promising alternative to overcome the main challenges in manufacturing engineered tissue and regeneration products.

The aim of this work was to assess to what extent rheological properties can explain the sensory texture in soy based desserts containing different amounts of water soluble soy extract, modified starch and guava pulp, as well as to correlate the sensory and instrumental color. Seventeen creamy soy based desserts were studied. Sensory ranking tests were performed by Quantitative Descriptive Analysis (QDA) and affective sensory tests. Correlations between sensory and instrumental data were determined using Pearson’s correlation coefficient. Results showed a moderate positive correlation between sensory color and a* , and significant negative correlations with L* and h ab . Loss modulus at 1 and 10 rad s -1 and the parameters n ” were the rheological parameters better correlated with the sensory attributes related to consistency and creaminess. Moreover, the results found in the affective tests can be explained by those verified in QDA

This study focuses on the correlation investigation between rheological and physical parameters and how it can contribute to optimize the topical formulations development. A gel and an emulgel containing pinhão derivatives, and their respective controls, were analyzed along six months of storage. A flowchart of analyses was proposed to use in topical formulation development when a benchmark is the goal or when it is necessary to change some raw material. All formulations were stable over the storage time and the formulations containing pinhão starch and coat extract presented similar properties to those of the control formulations. Correlations between rheological and physical data, as moisture content and particle size, were determined using Pearson's correlation coefficient. A moderate positive correlation was verified between particle size distribution and flow index, and a strong positive correlation between particle size and flow index. It was also found that the higher the moisture content, the higher the consistency index, quality factor, and apparent viscosity. The correlation analyses applied in this study contributed to build up an analytical route for topical formulation development, saving time and costs.

We developed a new approach to the phase-field model to predict morphologies of polymer membranes, with the following distinctions: (i) it satisfies the Gibbs-Duhem relation and the volume fraction constraint in calculation of the driving force for diffusion; and (ii) it employs a diffusive flux equation which includes the dependence of the flux on the volume fraction of the components. The model consistency was checked by mass conservation and thermodynamic behavior. The predictions of the model were compared to Doi-Onuki (DO) and classic Cahn-Hilliard (CH) models. Differently of the DO model, the application of the proposed model was not restricted to values of initial polymer concentration inside the spinodal region. In comparison to the CH model, the main difference observed was the prediction of lower phase separation rates and minor microdomains, which may be more realistic because it considers a more appropriate approach of the driving force for diffusion and of the diffusive flux equation.

Sweetened condensed milk is a widely studied product, including problems related to crystallization of the sugars during its process of industrial production and/or its shelf life. However, no studies on the standardization of techniques for measuring crystal size in sweetened condensed milk are found in the literature. In this work, a methodology for measuring crystal size in sweetened condensed milk samples, based on the use of the ImageJ software for digital processing/analysis of images obtained by optical microscopy, is proposed and tested. In its final format, the proposed methodology essentially requires only the product samples, the preparation of two microscope slides containing around 0.003 g of sample covered by a lightly pressed glass coverslip, and the recording of 12 images for each slide, followed by the automated processing and analysis of these images. It provides representative values for the mean crystal size but underestimated values for the total number of crystals present in the sample.

Search for food products containing functional ingredients such as soy derivatives and pulp fruits has stimulated the development of new formulations of desserts. The aim of this study was to evaluate the influence of the addition of water-soluble soy extract, modified starch and guava pulp on the rheological parameters, microstructure, water-holding capacity (WHC), creaming index, pH and soluble solid content of creamy soy-based desserts. Rheologically, the samples were characterized as no time-dependent, shear-thinning weak gel-like systems. The physicochemical and rheological parameters evaluated varied in a wide range as a function of the soy, starch and guava pulp contents, with the soy extract content being the variable that most affected these properties. There was a link between the microscopic analysis and the WHC, and a strong correlation between WHC and the rheological parameter Q was observed.

In membrane bioreactors (MBRs), aeration mitigates fouling by creating turbulence and increasing shear stress on the membrane surface. To study the hydrodynamics of MBRs, several researchers have been using computational fluid dynamics (CFD). However, the literature lacks papers on the sensitivity of the CFD predictions for MBRs to the modeling choices related to the different phenomena involved in MBRs, including turbulence. This work evaluates the bubbly flow in an immersed MBR with the most common turbulence models (k-e with two different wall functions and SST k-ω) at two aeration rates (5 and 15 m3 h−1). Predictions of velocities near the membranes and of local and spatially averaged shear stresses on the membrane modules were compared between the models and to literature data. The predictions were highly sensitive to the turbulence modeling approach, and their sensitivity was position dependent. The differences between the models reached 21.6% and 86.1% considering spatially averaged and local values of shear stress, respectively. The SST k-ω model exhibited the best prediction at the low aeration rate, indicating the relevance of the wall region for this condition. These findings show that more attention must be given to the choice of turbulence model in MBR simulations.

Beer is one of the most consumed beverages in the world, placing the brewing sector in a strategic economic position in the food industry. Beer production has a series of physical and chemical steps that are technically intensive when the production scale is increased. Although the production techniques have been improving for hundreds of years, many breweries still employ traditional techniques. The increasing consumption of beer and the competitive market have led the industry to search for alternative technologies to produce a better beer with reduced prices. Membrane separation processes are interesting alternatives that may be utilised in several steps of beer production and may replace some traditional and time-consuming techniques. The objective of this study is to summarise and present a literature survey of the membrane separation processes that are currently applied in the beer industry and those processes that have potential for future applications. The potential of microfiltration, ultrafiltration, reverse osmosis, pervaporation, and gas separation to accomplish almost all solid–liquid–gas separations in a brewery is discussed, providing a clear outline for researchers on the main aspects and developments of the beer-membrane field.

In this work, the new methodology for parameter estimation using less experimental data proposed in Staudt et al. (2013) is extended to be used with the GAB model. In addition, a modification in the Arrhenius form for temperature dependency of the energetic constant C is proposed in order to avoid numerical instabilities during parameter estimation. When compared to the original work, one additional parameter, k needs to be estimated but still only one isotherm and one value of net isosteric heat of sorption is required to build the whole set of sorption isotherms. Different food materials were successfully tested providing good fitting and prediction results attesting that the advantages of the methodology originally developed for the BET model are kept with the GAB model.

A new methodology for estimation of the kinetic parameters of epoxy resin systems using only global conversion data obtained by differential scanning calorimetry (DSC) in isothermal reactions is presented. For this, a modified version of the mathematical model proposed by Finzel et al. is presented to describe the curing reaction of a system composed by a diglycidyl ether of bisphenol A epoxy resin (DGEBA) and 4,4′-diaminodiphenylsulfone (4,4′-DDS). The model and parameter estimation methodology were implemented in the EMSO process simulator. Experimental data of curing reactions at 140 and 180 °C were used for parameters estimation, while data obtained at 200 °C were used for validation. The proposed model was shown to describe adequately the experimental data for the system studied, both in fitting and prediction. The methodology for parameter estimation allowed accurate values of all the parameters involved to be obtained.