Influence of thermal treatment and aging time on the stability and swelling properties of nano/micron-sized polymeric spheres for improved oil recovery application

Understanding the knowledge of swelling and stability properties of polymeric spheres are essential for improved oil recovery; these properties will allow guaranteeing an efficient block of high permeability channels and large pore throats. These properties of nano/micron-sized polymeric spheres commercially available for improved oil recovery applications were investigated. The polymeric spheres emulsion was characterized by scanning electron microscopy (SEM). Data analysis reveals uniform and spherical structures with an average diameter of 47 ± 4.8 nm. After hydration, polymeric spheres can swell due to water absorption reaching an average particle diameter of 3.3 ± 0.2 μm. The effect of aging time, thermal treatment, the removal of the oil phase, and the dispersing stabilizer on the swelling and stability was studied. It has been found that polymeric spheres structure suffers deterioration with the progressive aging time, temperature increase, and with the removal of the oil phase and dispersing stabilizer. As a result, crosslinked polymer aggregates are formed which subsequently acquiring fibrillar morphologies. Further, this study provides an understanding of the stability and swelling behavior of polymeric microspheres using polydimethylsiloxane microdevices. The results evidenced that the behavior of the polymeric spheres can be beneficial to improve oil recovery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48030.     

Desulfurization and Denitrogenation Processes to Treat Diesel Using Mo(VI)-Bipyridine Catalysts

High efficiency was found for desulfurization and denitrogenation processes to treat diesel using either the hybrid material {[MoO₃(2,2′-bipy)][MoO₃(H₂O)]}_n or the octanuclear complex [Mo₈O₂₂(OH)₄(di-tBu-bipy)₄] (2,2′-bipy = 2,2′-bipyridine, di-tBu-bipy = 4,4′-di-tert-butyl-2,2′-bipyridine) as catalysts. These processes were employed in a single procedure to simultaneously remove sulfur (dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) and nitrogen (indole and quinoline) compounds from diesel. A reaction time of two hours was sufficient to achieve at least 99.9 % S removal and 97 % N removal. Furthermore, the catalytic systems presented a high capacity to be reused/recycled for consecutive desulfurization/denitrogenation cycles.     

Molecularly imprinted hydrogels from colloidal crystals for the detection of progesterone

The synthesis of new nanoporous materials based on molecularly imprinted polymers (MIPs) is investigated. The novel procedure combines the non‐covalent imprinting method with the colloidal crystal template technique to produce membranes with pre‐specified morphology capable of selectively recognizing progesterone. The colloidal crystals made of silica particles were obtained by Langmuir ? Blodgett and self‐assembly techniques, and exhibited a considerable control of the film thickness. Hydrogel films were prepared by copolymerization of acrylic acid and ethylene glycol dimethacrylate in the presence of 2,2′‐azobisisobutyronitrile as initiator. The polymerization took place in the interspaces of the colloidal crystal and after the reaction was finished the silica particles were etched with hydrofluoric acid to produce a 3D ordered structure. The nanocavities derived from progesterone were distributed within the walls of the internal structure of the films. The equilibrium swelling properties of the MIPs were studied as a function of crosslinking degree and pH. The pore morphology of the film was analyzed by SEM. The MIP characterizations were accomplished by several techniques, e.g. Fourier transform infrared spectroscopy, DSC and evaluation of their sensing and selective properties. © 2014 Society of Chemical Industry     

Photodegradation process of Eosin Y using ZnO/SnO2 nanocomposites as photocatalysts: experimental study and neural network modeling

A series of coupled ZnO/SnO₂ nanocomposites were prepared with different molar ratios (1:10, 1:2, 2:1, and 10:1), using a homogeneous co-precipitation method. The structural properties were evaluated by different techniques: XRD, UVDR, SEM, N₂ adsorption, and IR. The photocatalytic activity of the samples was tested with the main goal of Eosin Y degradation from wastewaters. The prepared nanocomposites/systems exhibit higher photocatalytic activity than a single semiconductor photocatalyst and ZnO can effectively improve the photocatalytic efficiency of SnO₂ under UV illumination. A direct neural network modeling methodology, based on feed-forward neural networks, was performed in order to evaluate the efficiency of the photodegradation process of Eosin Y, depending of the reaction conditions. The developed model considered the following parameters with significant influence on the approached process: crystallite size, surface area, absorbtion edge, TOC values, time of reaction, and catalyst concentration as inputs and the final dye concentration as output. Accurate results were obtained in the validation phase of the neural model: relative average error under 4 % and a correlation between experimental and simulation data of 0.999.     

n-3 Ingestion may modulate the severity of periodontal disease? Systematic review

The aim of this study was to determine the effects of n-3 ingestion on periodontal disease. Besides, we also investigated the relationship between plasma concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and/or aracdonic acid (AA), and periodontal disease. An electronic search was performed in several databases with the following keywords: “n-3,” DHA, EPA and polynsaturated fatty acids (PUFA) in combination with the term “periodontal disease” (PD). Only studies conducted with humans, involving clinical parameters of PD assessment and use of n-3 were selected, without restriction to the date of publication. The search has returned 1368 articles, 11 of which were selected. The results were separated according to the type of n-3 ingestion: supplementation or n-3 content in normal diet. In the studies where n-3 has been supplemented, there was no significant difference in the clinical severity of PD compared to the control subjects. However, in patients where levels of n-3 were evaluated in a usual diet, a lower disease severity was reported. We have detected a preventive effect related to plasma levels of EPA and DHA against PD progression. Thus, n-3 ingestion may beneficially interfere in PD progression, depending on the duration and dosage of consumption.     

Delactosed permeate as a dairy processing co-product with major potential value: a review

Delactosed permeate (DLP) is the co-product generated during the separation of pre-crystallised lactose from milk and whey permeates. DLP production has grown with the increased production of high protein content ingredients such as whey protein concentrates and isolates. Although DLP is nutritionally rich, with approximately 0.5–1.5, 68–70, 9–10 and 8–9 g/100 g dry matter of protein, total sugars, total mineral and organic acids, respectively, it is still currently underutilised, mostly for animal feed or energy production. There are a number of novel, promising and sustainable DLP-derived food and non-food applications which are the subject of current research. Therefore, there exists the opportunity to exploit this dairy co-product in the development of new value-added ingredients. In this comprehensive review, DLP production, processing challenges and potential applications are discussed, along with identification and assessment of selected strategies for the valorisation of DLP.     

Solvent-Cast 3D Printing of Biodegradable Polymer Scaffolds

3D printing is a popular fabrication technique because of its ability to produce complex architectures. Melt-based 3D printing is widely used for thermoplastic polymers like poly(caprolactone) (PCL), poly(lactic acid) (PLA), and poly(lactic-co-glycolic acid) (PLGA) because of their low processing temperatures. However, traditional melt-based techniques require processing temperatures and pressures high enough to achieve continuous flow, limiting the type of polymer that can be printed. Solvent-cast printing (SCP) offers an alternative approach to print a wider range of polymers. Polymers are dissolved in a volatile solvent that evaporates during deposition to produce a solid polymer filament. SCP, therefore, requires optimizing polymer concentration in the ink, print pressure, and print speed to achieve desired print fidelity. Here, capillary flow analysis shows how print pressure affects the process-apparent viscosity of PCL, PLA, and PLGA inks. Ink viscosity is also measured using rheology, which is used to link a specific ink viscosity to a predicted set of print pressure and print speed for all three polymers. These results demonstrate how this approach can be used to accelerate optimization by significantly reducing the number of parameter combinations. This strategy can be applied to other polymers to expand the library of polymers printable with SCP.     

A Parametrizable High-Level Synthesis Library for Accelerating Neural Networks on FPGAs

Journal of Signal Processing Systems - In recent years, Convolutional Neural Network CNN have been incorporated in a large number of applications, including multimedia retrieval and image...     

Integrating Microwave-Assisted Extraction of Essential Oils and Polyphenols from Rosemary and Thyme Leaves

The extraction of essential oils (EOs) and polyphenols from rosemary and thyme has been done using an integrated process: microwave hydro-diffusion and gravity (MHG) for EOs and microwave-assisted extraction (MAE) for polyphenols. The innovative installation based on the MHG principle allows uniform microwave irradiation field due to a mechanical stirring and experiments done at low pressure. The results of quantitative analysis of the EOs extracted by MHG after 10?min were similar with those obtained by traditional methods (conventional hydro-distillation (CHD) and microwave-assisted hydro-distillation (MHD)) after 150 and 105?min, respectively. The specific energy for MHG was 5–15 times lower compared with these classical methods. The MHG extraction of EOs is also an effective method for plant material pretreatment before polyphenol extraction. Total phenolic content increased from 35 to 55?mg GAE/g DM for rosemary and from 23 to 38?mg GAE/g DM for thyme.