57 research outputs found
HYDROCRACKING OF FISCHER-TROPSCH PRODUCTS
The hydrocracking behavior the product of a Fischer-Tropsch synthesis consisting of a C4–C30 mixture of paraffins and olefins on a platinum/amorphous silica–alumina catalyst has been analyzed and optimized. The influence of temperature on the selectiveness of the hydrocracking has been investigated. Time and temperature optimization was performed in order to obtain the best operating conditions for the enhancement of gasoline and diesel cuts
Optimization of osmotic dehydration of papaya followed by air-drying
FERNANDES, Fabiano A. N. et al. Optimization of Osmotic Dehydration of Papaya of followed by air-drying. Food Research Internation, v. 39, p. 492-498, 2006.ABSTRACT: Papayas are a fragile fruit; characteristic that limits large-scale exportation from the producing centers to countries in temperate
regions. Loss of fruit ranges from 10% to 40% and could be reduced if papayas were dried. The process of osmotic dehydration followed
by air-drying was studied and modeled for papaya preservation, so it could be optimized. The developed model has been validated with
experimental data and simulations have shown how the operating conditions affect the process. An optimization was done using the
model in order to search for the best operation condition that would reduce the total processing time
Dual-stage sugar substitution in strawberries with a \u3ci\u3eStevia\u3c/i\u3e-based sweetener
The present study introduces and analyzes a new process denominated dual-stage sugar substitution (D3S). This process aims to induce sugar substitution in strawberries. In a first stage, high-calorie sugars (sucrose, fructose and glucose) are partially removed from the fruit samples and in a second stage, low-calorie sugar (stevioside and rebaudioside) is incorporated to the fruit to maintain its sweetness. The process was evaluated by studying the use of ultrasound application in one or both stages of the D3S process. Best performance of the process was obtained by subjecting the fruit samples to ultrasound in the sugar removal stage followed by immersion of the samples in Stevia-based solution without application of ultrasound in the sweetener incorporation stage. These operating conditions result in the highest sugar removal during the first stage, highest water loss during the process and highest sweetener incorporation during the second stage of the D3S process. The work described in this research is relevant to the production of dried fruits. A process to produce low-calorie dried fruit is presented. The process removes high-calorie sugars from the fruit and replaces it with a natural low-calorie sugar restoring the sweetness of the fruit
Produção de biossurfactante por Aureobasidium thailandense utilizando resÃduos agroindustriais
info:eu-repo/semantics/publishedVersio
Esterase production by Aureobasidium pullulans URM 7059 in stirred tank and airlift bioreactors using residual biodiesel glycerol as substrate
Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.bej.2021.107954.Aureobasidium pullulans URM 7059 produced esterase using residual glycerol from biodiesel as the sole carbon source. The culture medium containing residual glycerol (0.1% v/v), (NH4)2SO4 (4g/L), and yeast extract (8g/L) resulted in the highest esterase production using shake-flasks. The enzyme exhibited a molar mass of 50kDa and was stable at neutral pH and temperatures below 30°C. The cations Cu2+ and Al3+ did not affect the esterase activity, while Ca2+ promoted the highest activity loss. The enzyme kinetic parameters were determined using different substrates (p-nitrophenylcaprylate and p-nitrophenylbutyrate). Km and Vmax were 1.4mM and 218µmolmin-1 for p-NPC, and 1.55mM and 76.7µmolmin-1 for p-NPB. The esterase production was further evaluated using stirred tank and 2-L airlift bioreactors. The airlift reactor operating at the highest air flow rate (8L/min) increased the enzyme productivity 3-fold compared to the shake-flasks experiments. However, the crude enzymatic extract showed 3 active protein bands by zymography with molecular masses of 172kDa, 66kDa, and 40kDa approximately, suggesting that the pattern of enzyme production changed due to aeration. The crude enzyme degraded the MACO-Sty biopolymer in 14 days, being stable in a wide range of pH (7.0 9.0) and temperatures (40°C 80°C). The results suggest that this enzyme is a promising catalyst in remediation processes.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004), projects MultiBiorefinery (POCI-01-0145-FEDER016403) and Lignozymes (POCI-01-0145-FEDER-029773), all funded by the European Regional Development Fund under the scope of Norte2020
– Programa Operacional Regional do Norte. In Brazil, this study was financed in part by the Coordenaçao Ëœ de Aperfeiçoamento de Pessoal de NÃvel Superior - Brasil (CAPES) - Finance Code 001. The authors also
thank the CNPq and FUNCAP for financial support.info:eu-repo/semantics/publishedVersio
Ultrasound-Assisted Osmotic Dehydration of Strawberries: Effect of Pretreatment Time and Ultrasonic Frequency
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
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Evidence confirms an anthropic origin of Amazonian Dark Earths.
Arising from: Silva et al. Nature Communications https://doi.org/10.1038/s41467-020-20184-2 (2021
Cold Plasma Processing on Fruits and Fruit Juices: A Review on the Effects of Plasma on Nutritional Quality
This review aims to present the effects of cold plasma technology on the nutritional quality of fruits and fruit juices. This review focuses on the chemical changes induced by plasma on several bioactive compounds, such as sugars, starch, lipids, vitamins, phenolic compounds, carotenoids, and anthocyanins. The main plasma-reacting species that reacts with fruit compounds are presented and discussed. The review presents the mechanisms that lead to the improvement and degradation of the main compounds, showing both the advantages and disadvantages of cold plasma technology
Development of Polymer Resins using Neural Networks
The development of polymer resins can benefit from the application of neural networks, using its great ability to correlate inputs and outputs. In this work we have developed a procedure that uses neural networks to correlate the end-user properties of a polymer with the polymerization reactor's operational condition that will produce that desired polymer. This procedure is aimed at speeding up the development of new resins and help finding the appropriate operational conditions to produce a given polymer resin; reducing experimentation, pilot plant tests and therefore time and money spent on development. The procedure shown in this paper can predict the reactor's operational condition with an error lower than 5%
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