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•A new micromixer with triangular baffles and circular obstructions was proposed.•High mixing index was observed for the oil/ethanol and water/ethanol mixing.•The micromixer was ...employed as the millireactor, providing conversion of 92.67%.•Millidevices can be more efficient than microdevices.
A new micromixer design (MTB – micromixer with triangular baffles and circular obstructions) was proposed aiming the combination of three mass transfer enhancements mechanisms: reduction of molecular diffusion path, split and recombination of streams and vortex generation. The geometric variables were also optimized considering the mixing performance and the required pressure drop. The optimal design was used for the mixing of different binary mixtures (vegetable oil/ethanol and water/ethanol) under the Reynolds number range from 0.01 to 200 and the chemical reaction process of vegetable oil transesterification with ethanolic solution of sodium hydroxide (biodiesel synthesis). High mixing index (M = 0.99) was observed for the oil/ethanol mixing for several channel heights (200 μm – 2000 μm) and widths (1500 μm – 3000 μm). The geometry W3000H400 (i.e., MTB with channel width of 3000 μm and height of 400 μm) was employed as the millireactor, providing a maximum oil conversion of 92.67% for a residence time of 30 s. For the water/ethanol mixing, the geometry W1500H200 was used. High mixing index (M = 0.99) was observed at very low Reynolds number (Re = 0.1) and also in higher Reynolds numbers of 50 and 100. Moreover, at Re = 0.1, high mixing index (M ≌ 0.90) was obtained already at 3.5 mm of channel length. However, for higher Reynolds number the fluids required longer distances to achieve superior mixing, about 10.5 mm at Re = 100. The MTB, unlike the ones found in the literature, can be used in microdevices (e.g., sensors) with low flow rates and in microdevices with large dimensions (eg, millidevices and milireactors) with high flow rates, allowing an easier application in chemical process aiming the commercial production.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Study of biodiesel synthesis in micromixer with static elements are evaluated.•The presence of static elements optimized the fluid mixing and reaction.•The highest mixing was noticed ...for a Reynolds number of 100.•Experimentally the higher ethyl esters percentage was 99.53%.•Microreactors are a viable option to produce biodiesel.
The biodiesel synthesis intensification can be performed using microdevices. The present research investigated numerical and experimentally the transesterification of sunflower oil with ethanol and sodium hydroxide catalyst in microchannel reactors with static elements. In the numerical study, two micromixer designs (Length=35mm; Width=1500μm, Height=200μm) were evaluated: T-micromixer (micromixer without static elements) and MSE (micromixer with static elements). The mixing of fluids was analyzed for a range of Reynolds number of 0.1–100. The oil conversion was investigated for a range of operating conditions: temperature (25–75°C), ethanol/oil molar ratio (6–12) and catalyst concentration (0.75–1.25%). Similar conditions were experimentally tested in microchannels with static elements (Length=411mm) made of polydimethylsiloxane (PDMS). The MSE showed superior performance of mixing index and oil conversion. The highest mixing was noticed for a Reynolds number of 100. The optimum oil conversion (91.53%) was observed numerically at conditions of 75°C, ethanol/oil molar ratio of 9 and catalyst concentration of 1%. The MSE showed experimentally the highest ethyl esters percentage (99.53%) at 50°C, ethanol/oil molar ratio of 9 and catalyst concentration of 1%, for a residence time of approximately 12s. The use of static elements in micromixer enhanced the biodiesel synthesis.
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GEOZS, IJS, IMTLJ, KISLJ, NUK, OILJ, SAZU, SBCE, UL, UM, UPCLJ, UPUK
Proposal techniques that reduce financial costs in the diagnosis and treatment of animal diseases are welcome. This work uses some machine learning techniques to classify whether or not cases of ...canine visceral leishmaniasis are present by physical examinations. For validation of the method, four machine learning models were chosen: K-nearest neighbor, Naïve Bayes, support vector machine and logistic regression models. The tests were performed on three hundred and forty dogs, using eighteen characteristics of the animal and the ELISA (enzyme-linked immunosorbent assay) serological test as validation. Logistic regression achieved the best metrics: Accuracy of 75%, sensitivity of 84%, specificity of 67%, a positive likelihood ratio of 2.53 and a negative likelihood ratio of 0.23, showing a positive relationship in the evaluation between the true positives and rejecting the cases of false negatives.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The objective of this research was to study the physical properties, water sorption, thermal and structure of films made from citrus pectin (CP), babassu coconut mesocarp (BCM) and glycerol (G). ...Seventeen formulations were prepared according to a central compound rotational design combining different proportions of the materials and evaluating the films produced according to their moisture contents, solubility, thicknesses and water vapor permeability. The results showed a direct relationship between the composition of the film and each physical property, providing films with unique mechanical characteristics and barrier properties. In the second phase, the films were reformulated, maintaining the proportions of CP and BCM constant and altering the G content. The results showed films with permeable structures, thus favoring the use of high drying temperatures (up to 70 °C) for the confection of films, without altering their physical and structural properties.
•Films based on pectin, babassu mesocarp and glycerol were elaborated by the casting method.•Physical and barrier properties were studied for seventeen filmogenic solutions.•The components of the filmogenic solutions had a direct relationship with the quality of the final film.•Studies with two reformulated solutions showed films with high mechanical resistance and barrier properties.•The films showed a uniform structure with the potential for industrial applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Experimental and numerical study of biodiesel synthesis in microdevices.•The influence of temperature, ethanol/oil ratio and catalyst concentration.•Microreactors are a viable option ...to produce biodiesel.•Yield parameters and selectivity better capture the experimental process.
The transesterification of vegetable oils with alcohols is the most widely used method in biodiesel synthesis, generally taking place in batch processes. However, this production is currently being explored in microdevices, due to its short residence times and high conversions. This paper presents an experimental and numerical study of biodiesel synthesis in a microdevice from sunflower oil and ethanol using sodium hydroxide as catalyst. The influence of three operating variables were studied (temperature, ethanol/oil ratio and catalyst concentration). This paper also compares the reaction performance of a batch reactor with a microdevice reactor. The highest percentages of biodiesel found for the batch process and for the microdevice were 94.1% and 95.8%, respectively. These results proved the efficiency of microdevice in the biodiesel synthesis over conventional reactors. The superior results predicted for oil conversion, production yield and esters selectivity in numerical simulations were 99.90%, 2.10 and 0.42, respectively. The transesterification process simulation and intensification can be performed numerically evaluating reaction yield and selectivity parameters.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Several studies have investigated the antinociceptive, immunomodulatory and anti-inflammatory properties of compounds found in the lavender essential oil (LEO), however to date, there is still lack ...of substantial data. The objective of this study was to assess the antioxidant, anti-inflammatory and antinociceptive effects of lavender essential oil. The 1,1-diphenyl-2-picrylhydrazyl radical decolorization assay was used for antioxidant activity evaluation. The anti-inflammatory activity was tested using two models of acute inflammation: carrageenan-induced pleurisy and croton oil-induced ear edema. The antinociceptive activity was tested using the pain model induced by formalin. LEO has antioxidant activity, which is dose-dependent response. The inflammatory response evoked by carrageenan and by croton oil was reduced through the pre-treatment of animals with LEO. In the pleurisy model, the drug used as positive control, dexamethasone, was more efficacious. However, in the ear swelling, the antiedematogenic effect of the oil was similar to that observed for dexamethasone. In the formalin test, LEO consistently inhibited spontaneous nociception and presented a similar effect to that of tramadol. The results of this study reveal (in vivo) the analgesic and anti-inflammatory activities of LEO and demonstrates its important therapeutic potential.
Aims
Staphylococcus aureus is one of the most common pathogens in hospital environment and community. Panton‐Valentine leukocidin (PVL) production is clinically associated with skin abscesses, soft ...tissues infections, bacteraemia and sepsis. This study aimed to investigate the effects of the presence of genes lukF/S‐PV coding for PVL, in histological and haematological features during systemic infection, using a Swiss mice experimental model.
Methods and Results
Experiments were performed using 25 mice distributed into five experimental groups, intravenously inoculated with 50 µl suspensions at density 1·0 × 107 CFU per ml of strains: methicillin‐susceptible (MSSA) and pvl‐negative strains isolated from nasal colonization; MSSA pvl‐positive strains isolated from nasal colonization; methicillin‐resistant (MRSA) and pvl‐positive strains isolated from peripheral blood of a patient with severe pulmonary infection; and a MRSA pvl‐positive strains isolated from a peripheral blood culture of a patient with bacteraemia. Haematological analysis was performed at 24, 48, 72 and 96 h post‐infection. Morphoanatomy and histopathological analyses were performed at 96 h post‐infection. For all S. aureus strains tested, the capability of intravenous dissemination and survival into mice tissues was demonstrated. Inflammatory processes at different levels were related to the presence of pvl genes, and included alterations in the format, size and colour of the organs. Staphylococcus aureus pvl‐positive strains were detected in greater numbers in the organs of the infected animals.
Conclusions
The pvl‐positive strains isolated from blood cultures were capable to induce the greatest modifications in both haematological and histopathological profiles, and seemed to aggravate the systemic infections.
Significance and Impact of the Study
These findings are valuable in characterizing infections caused by S. aureus in humans and murine.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Great advances have been recently made in the area of miniaturization of systems. One of the most important aspects of these microdevices is the mixing of the reacting species, which will determine ...its conversion to the desired product. These microdevices have been successfully applied in the synthesis of biodiesel, mainly due to increased conversion of reactants in a short residence time. Oils derived from non-edible oil seeds are promising feedstock sources for biodiesel, especially Jatropha species. As a result, this paper numerically studied the mixing and reaction of Jatropha curcas oil and ethanol in micromixers for the production of biodiesel. Three types of micromixers were studied: T-micromixer, Cross-micromixer and Double-T-micromixer. The efficiency of each type was analyzed using a mixing index, which is calculated using the variation of mass fraction, and the conversion of oil. The mixing of the fluid was analyzed with different Reynolds numbers and the conversion of oil was analyzed for different Reynolds numbers and residence times. All showed excellent degree of mixture for low Reynolds numbers, with the Cross-micromixer showing the highest degree of mixing. By increasing the Reynolds number the mixing in the T-micromixer was increased, reduced in the Double-T-micromixer and did not affect the mixture in the Cross-micromixer. It was observed that the conversion obtained in all micromixers is practically constant and is not affected by the variation of Reynolds number studied (10–100). The Cross-micromixer presented the best reaction yield. An increment in residence time increased the conversion of oil. This work numerically demonstrated the possibility of using J. curcas as a feedstock for synthesis of biodiesel in microchannels.
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•The J. curcas-ethanol mixing and reaction in micromixer are simulated.•Three types of micromixers were studied: T-, Cross- and Double-T-micromixer.•The Cross-micromixer showed the highest mixing index, with average values of 0.99.•The reaction are controlled by mixing and reaction kinetics processes.•The residence time played an important role in the conversion of the oil.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
ABSTRACT
The morphological diversity of galaxies is a relevant probe of galaxy evolution and cosmological structure formation. However, in large sky surveys, even the morphological classification of ...galaxies into two classes, like late-type (LT) and early-type (ET), still represents a significant challenge. In this work, we present a Deep Learning (DL) based morphological catalogue built from images obtained by the Southern Photometric Local Universe Survey (S-PLUS) Data Release 3 (DR3). Our DL method achieves a purity rate of 98.5 per cent in accurately distinguishing between spiral, as part of the larger category of LT galaxies, and elliptical, belonging to ET galaxies. Additionally, we have implemented a secondary classifier that evaluates the quality of each galaxy stamp, which allows to select only high-quality images when studying properties of galaxies on the basis of their DL morphology. From our LT/ET catalogue of galaxies, we recover the expected colour–magnitude diagram in which LT galaxies display bluer colours than ET ones. Furthermore, we also investigate the clustering of galaxies based on their morphology, along with their relationship to the surrounding environment. As a result, we deliver a full morphological catalogue with 164 314 objects complete up to rpetro < 18, covering ∼1800 deg2, from which ∼55 000 are classified as high reliability, including a significant area of the Southern hemisphere that was not covered by previous morphology catalogues.
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