All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration < 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc^3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range 5 10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see also the public announcement at http://www.ligo.org/science/Publication-S6BurstAllSky

Improvement in carbohydrate and phlorotannin extraction from Macrocystis pyrifera using carbohydrate active enzyme from marine Alternaria sp as pretreatment

The commercial importance of brown seaweed has been increasing over the past decade, especially due to industries interested in the extraction of phycocolloids and, more recently, of polyphenol compounds such as phlorotannins. The objective of this work was to optimize the extraction conditions of carbohydrates and phlorotannins from Macrocystis pyrifera, evaluated enzymatic pretreatment and different parameters of extraction using design of experiment. The optimal conditions upon extraction of the carbohydrates and phlorotannins were determined by means of a pretreatment protocol taking advantage on a carbohydrate active enzyme, followed by an alkaline hydrolysis with 0.5 N NaOH at 100 degrees C, 180 min, and S/L ratio of 1/20. In order to extract the carbohydrates, the best conditions found for the pretreatment procedure were 37 degrees C, pH 7.0 for 24 h, and a S/L ratio of 1/10, giving an extraction yield (EY) of 89.67 +/- 12.3 wt.%. In turn, for the extraction of phlorotannins, the best conditions identified in terms of the pretreatment were 25 degrees C, pH 7.0 for 36 h, and a S/L ratio of 1/20, thus giving a yield (EY) of 2.14 +/- 0.25 wt.%. Statistical analysis of both processes revealed a maximum EY of 91.24 wt.% for carbohydrates and 3.31 wt.% EY for phlorotannins.CONICYT, AKA-ERNC 009 / Centre for Biotechnology and Bioengineering (CeBiB), FB-0001 / Academy of Finland, 268937 / Knut and Alice Wallenberg Foundation / Abo Akademi Universit

Identification and efficient extraction method of phlorotannins from the brown seaweed Macrocystis pyrifera using an orthogonal experimental design

The brown seaweed contains a type polyphenol compound characteristic of its species, the phlorotannins,which are produced from the polymerization of phloroglucinol units. They have been extensively studied due to their pharmacological and nutraceutical properties, but there is still a need for an optimized extraction protocol. In this study, the brown seaweedMacrocystis pyriferawas employed to determine the best conditions for extraction of phlorotannins. A set of different variableswere evaluated such as the use of pre-treatment, type of solvent, drying temperature, particle size, temperature and extraction time as well as the solid/liquid ratio upon extraction. The optimal conditions for the extraction of phlorotanninswere: pre-treatmentwith hexane, extraction with water, drying temperature 40 °C, particle size below 1.4 mm, at 55 °C for 4 h and a solid-to-liquid ratio of 1:15. Under these conditions, the concentration of phlorotannins achieved in the extractwas 200.5±5.6 mg gallic acid equivalent (GAE)/100 g dry seaweed (DS) and total antioxidant activity of the extract of 38.4±2.9 mg trolox equivalent (TE)/100 g DS. Further, it was possible to identify two phlorotannins through HPLC-ESI-MS analyses: phloroeckol and a tetrameric phloroglucinol. These phlorotannins have been reported in the literature to have an antidiabetic effect and prevention of Alzheimer's disease for phloroeckol, and free radical scavenging ability and antiallergic effect for tetrameric phloroglucinol. Therefore, the extract of phlorotannins has potential as medicinal foods or therapeutics for human health applications.CONICYT AKA-ERNC 0009 Centre for Biotechnology and Bioengineering (CeBiB) FB-0001 Academy of Finland 268937 Bio4energy program Kempe Foundations (Kempe Stiftelserna) Wallenberg Wood Science Center under Knut and Alice Wallenberg Foundatio

Deconstruction of the green alga Ulva rigida in ionic liquids: Closing the mass balance

Artículo de publicación ISIAlgae are known to grow at high rates compared to terrestrial plants that contain comparable amounts of carbohydrates by weight. Therefore, this renders them attractive in terms of any biorefinery concept. In this work the green alga Ulva rigida, containing 40 wt.% of carbohydrates was pretreated with a switchable ionic liquid (SIL), distillable ionic liquid (DIL) and low-viscosity ionic liquid (LVIL). The SIL DBU-MEA-SO2 was prepared from a mixture of mono-ethanolamine (MEA) and 1,8-diazabicyclo-[5,4,0]-undec-7-ene (DBU) that was coupled with sulfur dioxide (SO2), whereas the DIL [TMGH(+)][EtCO2-] (1,1,3,3-tetramethylguanidine propionate) was synthesized by a simple acid-base neutralization reaction. Consequently, the LVIL [HDBU+][5OF(-)] protonated 1,8-diazabicyclo-[5,4,0]-undec-7-ene-2,2,3,3,4,4,5,5-octafluoro-1-pentoxide was used as received. The treatments were carried out in the temperature range of 100-160 degrees C for 6 h. The products obtained after the treatments were analyzed using different techniques like ICP, OES, SEM, TEM, TGA, FTIR and carbohydrate determination by GC. Upon treatment with DIL up to 67 wt.% of carbohydrates could be dissolved. For the first time, processing of U. rigida was carried out in ionic liquids so that the mass balance of the process was obtained. It can be concluded that 1,1,3,3-tetramethylguanidine propionate shows significant potential when aiming at releasing carbohydrates from algal biomass that, consequently, can be applied in the production of platform chemicals and/or biofuels such as bioethanol.Academy of Finland - AKA 268937 National Commission for Scientific and Technologic Research of the Government of Chile - CONICYT AKA-ERNC 000

Aqueous Extraction of the Sulfated Polysaccharide Ulvan from the Green Alga Ulva rigida—Kinetics and Modeling

The incentives for utilizing a versatile range of renewable feedstocks in novel ways are continuously increasing. Sulfated polysaccharides from green algae, such as ulvan, are interesting due to the rare sugar constituents which can be utilized for new materials and chemicals in industry. However, before valorization fractionation needs to be performed in a controlled way. In the current work, the kinetics of the aqueous extraction of ulvan was studied in the temperature range 60–130 °C. The highest yield of 97.6 wt.% was attained after 2 h of extraction at 130 °C, and the extraction efficiency was observed to be heavily temperature dependent. Interestingly, two regimes of extraction kinetics were observed, presumably due to the different ulvan fractions contained within the cell wall of green algae. The experimental data was modeled with first-order kinetics, and an apparent activation energy of 53.8 kJ mol−1 was obtained for the process. The algal residue was processed using simultaneous saccharification and fermentation, and 0.48 g ethanol g−1 of sugars was obtained.</p

Integrated Biorefineries for Algal Biomolecules

Algae are a renewable source of biomolecules for multiple applications ranging from fuels to specialties. However, their implementation as feedstock in industrial processes has only been achieved for few high-value products. This is due to the elevated costs in cultivation and downstream processing. In order to decrease the biorefinery costs and to enhance the overall process profitability, new separation processes need to be developed. Such processes must start from the understanding of the cell architecture, as a basis to develop an optimal fractionation strategy, and must include selective and mild disentanglement processes, in order to preserve the functionality of the target molecules. In this regard, we propose novel integration concepts such as self-disintegration, simultaneous disintegration and disentanglement, and self-separating systems within the framework of process intensification, in such a way that auxiliary chemicals, solvents and numerous unit operations become redundant