Comparative Life Cycle Assessment Study of Green Extraction Processes to Obtain Antioxidants from Rosemary Leaves

Trabajo presentado al 10th International Symposium on Supercritical Fluids celebrado en San Francisco (US) del 13 al 16 de mayo de 2012.Rosemary is one of the most appreciated natural sources for bioactive compounds with different activities such as antioxidant, antimicrobial or anticarcinogenic. Antioxidant activity has been associated to some of its components, among them, phenolic diterpenes such as carnosic acid, carnosol and rosmarinic acid. A careful selection of the extraction process together with the optimization of the extraction conditions, are of high importance to obtain rosemary extracts with high bioactivity. Among the different extraction processes, supercritical fluid extraction (SFE) and pressurized hot water extraction (PHWE) have demonstrated to be the most selective and environmental friendly techniques. However, extracts obtained by these processes usually require a drying step (freeze or hot drying step) which is both energy and time consuming. In this work, a new process combining PHWE and powder formation on-line (water extraction and particle formation on-line process, WEPO®) has been developed to obtain dry antioxidant powder from rosemary leaves in one step. In this process, parameters related to the extraction efficiency and selectivity (water flow rate and temperature) as well as parameters involving spray stability and powder formation have been considered at the same time. The obtained extracts have been evaluated in terms of their antioxidant activity using the DPPH method. Finally, in order to assess the viability and environmental impact of the new process, a comparison with other green processes used for antioxidant extraction from rosemary leaves such as SFE and PHWE (both followed by a freeze drying step) has been performed in terms of Life Cycle Assessment (LCA). Moreover, a sensitivity analysis of the LCA has been carried out to study the different environmental impact between the processes whether they are employed in different countries.This work was supported by AGL2008-05108-C03-01 (Ministerio de Educación y Ciencia), CSD2007-00063 FUN-CFOOD (Programa CONSOLIDER-INGENIO 2010), and S-0505/AGR/000153 (Comunidad Autónoma de Madrid) projects. C.T. acknowledges the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS, 2006-1346); the Swedish Research Council (VR, 2006-4084); and the Swedish Foundation for Strategic Research (SSF, 2005:0073/13, RMA08-0044). M.C-P. thanks MICINN for her “Juan de la Cierva” contract.Peer Reviewe

Antiviral compounds obtained from microalgae commonly used as carotenoid sources

Pressurized liquid extraction (PLE), an environmentally friendly technique, has been used to obtain antiviral compounds from microalgae commonly used as carotenoid sources: Haematococcus pluvialis and Dunaliella salina. The antiviral properties of PLE extracts (hexane, ethanol and water) were evaluated against herpes simplex virus type 1 (HSV-1) at different stages during viral infection. Pretreatment of Vero cells with 75 μg mL -1 of H. pluvialis ethanol extract inhibited virus infection by approximately 85%, whereas the same concentration of water and hexane extracts reduced the virus infectivity 75% and 50%, respectively. D. salina extracts were less effective than H. pluvialis extracts and presented a different behaviour since water and ethanol extracts produced a similar virus inhibition (65%). Moreover, H. pluvialis ethanol extract was also the most effective against HSV-1 intracellular replication. The antiviral activity of water PLE extracts was found to correlate with polysaccharides since the polysaccharide-rich fraction isolated from these extracts showed higher antiviral activity than the original water extracts. A gas chromatography-mass spectrometry (GC-MS) characterization of the H. pluvialis ethanol extract showed the antiviral activity of this extract could be partially related with the presence of short-chain fatty acids, although other compounds could be involved in this activity; meanwhile, in the case of D. salina ethanol extract other compounds seemed to be implied, such as: β-ionone, neophytadiene, phytol, palmitic acid and α-linolenic acid. The results demonstrate the use of PLE allows obtaining antiviral compounds from microalgae used as carotenoids sources, which gives the microalgae biomass an added value. © 2011 Springer Science+Business Media B.V.This work has been financed by the Spanish Ministry of Education and Science (AGL2005-06726-C04), the programme CONSOLIDER-INGENIO 2010 (CDS2007-00063) and the regional programme ALIBIRD-CM S-0505/AGR-0153 from the Comunidad de Madrid, Spain.S0505/AGR-0153/ALIBIRDPeer Reviewe

Experimental characterization of post-installed anchors of high capacity in seismic situations

[Resumen:] A medida que mejoran la tecnología y disponibilidad de las resinas, el campo de aplicación del anclaje post instalado se va extendiendo a situaciones de mayor demanda mecánica. En el caso planteado en este estudio, se analiza la adecuación de anclajes post instalados de gran capacidad en un muro pantalla y una losa de hormigón armado de gran tamaño situados en zona sísmica. El anclaje tipo objeto de estudio se conforma con barras de acero equivalente al B500S de 32 mm de diámetro instalado con resina en un taladro de 40 mm de diámetro y 800 mm de profundidad. El procedimiento de validación más común para estos casos es el recogido en la norma ACI 355.4-11 (Qualification of Post-Installed Adhesive Anchors in Concrete). En esta norma se prescribe un diseño de probeta de la norma dirigido a anclajes de pequeño tamaño que, extrapolado al caso de estudio, haría inviable el ensayo. En este trabajo se propone un nuevo diseño de probeta compatible con los condicionantes mecánicos conceptuales de la ACI 355.4. Sobre el nuevo diseño se aplican procedimientos de ensayo análogos a los marcados por la norma para obtener las características mecánicas de la unión hormigón-resina-barra en caso de sismo: (1) tracción hasta rotura tras cargas cíclicas, con apertura de fisura de forma controlada de 0.5 mm durante todo el ensayo; (2) carga transversal hasta rotura tras cargas cíclicas, con apertura de fisura de forma controlada 0.5 mm durante todo el ensayo. Como resultado de las baterías de ensayos se obtienen los valores garantizados (percentil del 95 %) para hormigones de resistencia reducida (hipótesis conservadora prescrita por la normativa) y se compara su comportamiento con hormigones de resistencia convencional.[Abstract:] This research focuses on the development of a characterization system for large (32 mm), resin-bonded post-installed anchors in concrete in case of an earthquake. It is based on the tests required by ACI 355.4- 11 and its conditions, proposing a new test and test design that meets these since the design proposed in the standard makes the test unfeasible. Tensile characterization tests are carried out on cracked concrete (0.3 mm crack opening), seismic tension (0.5 mm crack opening plus loading cycles) and seismic shear (0.5 mm crack opening plus loading cycles) obtaining guaranteed values (95% percentile) for reduced resistance concretes

Bio-inspired model of ground temperature behavior on the horizontal geothermal exchanger of an installation based on a heat pump

[Abstract] Nowadays the Heat Pump is one of the best systems to warm a building with a good performance. Usually, with the aim to increase the efficiency, a geothermal heat exchanger is added to the installation. This component shows a disturbing effect on the ground where it is placed. On this research a bio-inspired system was developed to test the ground temperature behavior where there is a heat exchanger. The novel approach has been implemented and tested under a real dataset. One year temperature measurements were recorded. The final approach is based on clustering and regression techniques. Then, the model was validated and tested with a dataset from a real installation with a good performance

Missing data imputation of solar radiation data under different atmospheric conditions

[Abstract] Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE). This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW) and Multiple Linear Regression (MLR). The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW.Ministerio de Economía y Competitividad; AYA2010-1851

Electromyogram prediction during anesthesia by using a hybrid intelligent model

[Abstract] In the search for new and more efficient ways to administer drugs, clinicians are turning to engineering tools. The availability of these models to predict physiological variables are a significant factor. A model is set out in this research to predict the EMG (electromyogram) signal during surgery, in patients under general anaesthesia. This prediction hinges on the Bispectral Index™ (BIS) and the infusion rate of the drug propofol. The results of the research are very satisfactory, with error values of less than 0.67 (for a Normalized Mean Squared Error). A hybrid intelligent model is used which combines both clustering and regression algorithms. The resulting model is validated and trained using real data.Ministerio de Innovación y Ciencia; DPI2010-1827

Simplified method based on an intelligent model to obtain the extinction angle of the current for a single-phase half wave controlled rectifier with resistive and inductive load

With the aim of calculating the extinction angle of the current of a single-phase half wave controlled rectifier with resistive and inductive load, present work shows a method to obtain a regression model based on intelligent methods. This type of circuit is a typical non-linear case of study that requires a hard work to solve it by hand. To create the intelligent model, a dataset has been obtained with a computational method for the working range of the circuit. Then, with the dataset, to achieve the final solution, several methods of regression were tested from traditional to intelligent types. The model was verified empirically with electronic circuit software simulation, analytical methods and with a practical implementation. The advantage of the proposed method is its low computational cost. Then, the final solution is very appropriate for applications where high computational requirements are not possible, like low-performance microcontrollers or web applications

Intrusion Detection With Unsupervised Techniques for Network Management Protocols Over Smart Grids

[Abstract] The present research work focuses on overcoming cybersecurity problems in the Smart Grid. Smart Grids must have feasible data capture and communications infrastructure to be able to manage the huge amounts of data coming from sensors. To ensure the proper operation of next-generation electricity grids, the captured data must be reliable and protected against vulnerabilities and possible attacks. The contribution of this paper to the state of the art lies in the identification of cyberattacks that produce anomalous behaviour in network management protocols. A novel neural projectionist technique (Beta Hebbian Learning, BHL) has been employed to get a general visual representation of the traffic of a network, making it possible to identify any abnormal behaviours and patterns, indicative of a cyberattack. This novel approach has been validated on 3 different datasets, demonstrating the ability of BHL to detect different types of attacks, more effectively than other state-of-the-art methods

An intelligent fault detection system for a heat pump installation based on a geothermal heat exchanger

The heat pump with geothermal exchanger is one of the best methods to heat up a building. The heat exchanger is an element with high probability of failure due to the fact that it is an outside construction and also due to its size. In the present study, a novel intelligent system was designed to detect faults on this type of heating equipment. The novel approach has been successfully empirically tested under a real dataset obtained during measurements of one year. It was based on classification techniques with the aim of detecting failures in real time. Then, the model was validated and verified over the building; it obtained good results in all the operating conditions ranges

Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur

Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life