906 research outputs found

    3d crs analysis: a new data-driven optimization strategy for the simultaneous estimate of the eight stacking parameters

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    We devised a data-driven strategy for the simultaneous estimate of the eight CRS traveltime attributes, solving a global non-linear minimization problem without the need of computing gradients. The essential elements in this Eni research and development activity are the following: a conjugate-direction method supported by well known convergence properties and an iterative line-search implementing the strong Wolfe-Powell rule for the control of the steplength. The resulting algorithm can reach very good solutions in presence of many local minima.3284-329

    Butanol production in a first-generation Brazilian sugarcane biorefinery: Technical aspects and economics of greenfield projects

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    AbstractThe techno-economics of greenfield projects of a first-generation sugarcane biorefinery aimed to produce ethanol, sugar, power, and n-butanol was conducted taking into account different butanol fermentation technologies (regular microorganism and mutant strain with improved butanol yield) and market scenarios (chemicals and automotive fuel). The complete sugarcane biorefinery with the batch acetone–butanol–ethanol (ABE) fermentation process was simulated using Aspen Plus®. The biorefinery was designed to process 2million tonne sugarcane per year and utilize 25%, 50%, and 25% of the available sugarcane juice to produce sugar, ethanol, and butanol, respectively. The investment on a biorefinery with butanol production showed to be more attractive [14.8% IRR, P(IRR>12%)=0.99] than the conventional 50:50 (ethanol:sugar) annexed plant [13.3% IRR, P(IRR>12%)=0.80] only in the case butanol is produced by an improved microorganism and traded as a chemical

    The effects of integrated food and bioenergy cropping systems on crop yields, soil health, and biomass quality: The EU and Brazilian experience

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    Integrated food and bioenergy production is a promising way to ensure regional/national food and energy security, efficient use of soil resources, and enhanced biodiversity, while contributing to the abatement of CO2 emissions. The objective of this study was to assess alternative crop rotation schemes as the basis for integrating and enhancing the sustainable biomass production within the food-energy agricultural context. Sunn hemp (Crotalaria spp.) in rotation with wheat (Triticum spp.) in the EU and with sugarcane (Saccharum spp.) in Brazil were evaluated. Sunn hemp did not negatively affect crop's productivity and soil fertility; wheat grain yields were maintained around the mean regional production levels (6, 7, 3 and Mg ha(-1) in Greece, Italy, and Spain, respectively), and the cumulative biomass in the extended rotation (wheat straw+sunn hemp) was between 1.5 and 2.0 times higher than in the conventional rotation. In Brazil, sugarcane stalks yield in clay soils increased by around 15 Mg ha(-1) year(-1) under sunn hemp rotation in comparison with bare fallow. Moreover, sunn hemp in the EU rotations did not have negative effects on soil available macronutrients, organic matter, pH, and cation exchange capacity, neither on C and N stocks in Brazil. The qualitative characteristics (mineral, ash, and hemicelluloses contents) of the cumulated biomass were somehow higher (in average +26%, +35%, and +3.4%, respectively) than in the conventional system. In summary, in temperate and tropical climates the integration of dedicated biomass legume crops within conventional systems could lead to enhanced biomass availability, crop diversification, and efficient use (in space and time) of the land resources

    A 45-Second Self-Test for Cardiorespiratory Fitness:Heart Rate-Based Estimation in Healthy Individuals

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    Cardio-respiratory fitness (CRF) is a widespread essential indicator in Sports Science as well as in Sports Medicine. This study aimed to develop and validate a prediction model for CRF based on a 45 second self-test, which can be conducted anywhere. Criterion validity, test re-test study was set up to accomplish our objectives. Data from 81 healthy volunteers (age: 29 ± 8 years, BMI: 24.0 ± 2.9), 18 of whom females, were used to validate this test against gold standard. Nineteen volunteers repeated this test twice in order to evaluate its repeatability. CRF estimation models were developed using heart rate (HR) features extracted from the resting, exercise, and the recovery phase. The most predictive HR feature was the intercept of the linear equation fitting the HR values during the recovery phase normalized for the height2 (r2 = 0.30). The Ruffier-Dickson Index (RDI), which was originally developed for this squat test, showed a negative significant correlation with CRF (r = -0.40), but explained only 15% of the variability in CRF. A multivariate model based on RDI and sex, age and height increased the explained variability up to 53% with a cross validation (CV) error of 0.532 L ∙ min-1 and substantial repeatability (ICC = 0.91). The best predictive multivariate model made use of the linear intercept of HR at the beginning of the recovery normalized for height2 and age2; this had an adjusted r2 = 0. 59, a CV error of 0.495 L·min-1 and substantial repeatability (ICC = 0.93). It also had a higher agreement in classifying CRF levels (κ = 0.42) than RDI-based model (κ = 0.29). In conclusion, this simple 45 s self-test can be used to estimate and classify CRF in healthy individuals with moderate accuracy and large repeatability when HR recovery features are included

    Decellularized silk fibroin scaffold primed with adipose mesenchymal stromal cells improves wound healing in diabetic mice

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    Introduction: Silk fibroin (SF) scaffolds have been shown to be a suitable substrate for tissue engineering and to improve tissue regeneration when cellularized with mesenchymal stromal cells (MSCs). We here demonstrate, for the first time, that electrospun nanofibrous SF patches, cellularized with human adipose-derived MSCs (Ad-MSCs-SF) or decellularized (D-Ad- MSCs-SF) are effective in the treatment of skin wounds, improving skin regeneration in db/db diabetic mice. Methods: The conformational and structural analyses of SF and D-Ad-MSCs-SF patches were performed by scanning electron microscopy, confocal microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Wounds were performed by a 5mm punch biopsy tool on the mouse\u2019s back. Ad-MSCs-SF and D-Ad-MSCs-SF patches were transplanted and the efficacy of treatments was assessed by measuring the wound closure area, by histological examination and by gene expression profile. We further investigated the in vitro angiogenic properties of Ad-MSCs-SF and D-Ad-MSCs-SF patches by affecting migration of human umbilical vein endothelial cells (HUVECs), keratinocytes (KCs) and dermal fibroblasts (DFs), through the aortic ring assay and, finally, by evaluating the release of angiogenic factors. Results: We found that Ad-MSCs adhere and grow on SF, maintaining their phenotypic mesenchymal profile and differentiation capacity. Conformational and structural analyses on SF and D-Ad- MSCs-SF samples, showed that sterilization, decellularization, freezing and storing did not affect the SF structure. When grafted in wounds of diabetic mice, both Ad-MSCs-SF and DAd- MSCs-SF significantly improved tissue regeneration, reducing the wound area respectively by 40% and 35%, within three days, completing the process in around 10 days compared to 15-17 days of controls. RT2 gene profile analysis of the wounds treated with Ad- MSCs-SF and D-Ad-MSCs-SF showed an increment of genes involved in angiogenesis and matrix remodelling. Finally, Ad-MSCs-SF and D-Ad-MSCs-SF co-cultured with HUVECs, DFs and KCs, preferentially enhanced the HUVECs\u2019 migration and the release of angiogenic factors stimulating microvessel outgrowth in the aortic ring assay. Conclusions: Our results highlight for the first time that D-Ad-MSCs-SF patches are almost as effective as Ad-MSCs-SF patches in the treatment of diabetic wounds, acting through a complex mechanism that involves stimulation of angiogenesis. Our data suggest a potential use of DAd- MSCs-SF patches in chronic diabetic ulcers in humans

    Evaluación económica y ambiental de la quema conjunta de carbón y bagazo en la industria colombiana de la caña de azúcar

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    Energy generation is key to any country’s development, and the threats to energy supply have led the Colombian government to establish national policies that stimulate energy generation projects. In response, this manuscript reports the economic impact and the GHG emission that have been simulated in this study to evaluate the co-firing of the coal-bagasse mixture in the cogeneration systems of the ethanol industry in the Cauca River Valley in Colombia as an opportunity to increase the economic benefits due to the increase of electricity sell to the national grid in the strong dry seasons. This study was carried out using the Virtual Sugarcane Biorefinery (VSB) modeling software employed for the simulation of agricultural and industrial parameters in integrated alternatives for the sugarcane industry, which was adjusted to the Colombian conditions to allow simulating the current electricity production in the sugarcane mills in the assessed region. The economic assessment of the co-firing process in the cogeneration system demonstrates that this industrial process represents an opportunity to increase the economic benefits by about 26%. However, the coal combustion in the boiler generates about 54% of the total GHG emissions for the consumption of coal, whereas the burning of bagasse corresponds to only 5%.La generación de energía es clave para el desarrollo de cualquier país, y las amenazas para el suministro de energía han llevado al gobierno colombiano a establecer políticas nacionales que estimulen los proyectos de generación de energía. En respuesta, este manuscrito informa sobre el impacto económico y la emisión de GEI que se han simulado en este estudio, para evaluar la quema conjunta de carbón y bagazo en los sistemas de cogeneración de la industria del etanol en el Valle del río Cauca, en Colombia, como una oportunidad para aumentar los beneficios económicos, debido al aumento en la venta de electricidad a la red nacional en las fuertes temporadas secas. Este estudio se realizó utilizando el software de modelado Biorrefinería Virtual de Caña de Azúcar (BVC), utilizado para la simulación de parámetros agrícolas e industriales en alternativas integradas para la industria de la caña de azúcar. La BVC, que se ajustó a las condiciones colombianas para permitir simular la producción actual de electricidad en los ingenios de caña de azúcar de la región estudiada. La evaluación económica del proceso de quema conjunta en el sistema de cogeneración demuestra que este proceso industrial representa una oportunidad para aumentar los beneficios económicos de alrededor del 26 %. Sin embargo, la combustión del carbón en la caldera genera aproximadamente el 54 % de las emisiones totales de GEI para el consumo de carbón, mientras que la quema de bagazo corresponde a solo el 5 %
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