562 research outputs found

    A Survey on Big Data, Hadoop and it’s Ecosystem

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    Now days, The 21st century is emphasized by a rapid and enormous change in the field of information technology. It is a non-separable part of our daily life and of multiple other industries like education, genetics, entertainment, science & technology, business etc. In this information age, a vast amount of data generation takes place. This vast amount of data is referred as Big Data. There is a number of challenges present in the Big Data such as capturing data, data analysis, searching of data, sharing of data, filtering of data etc. Today Big Data is applied in various fields like shopping websites such as Amazon, Flipkart, Social networking sites such as Twitter, Facebook, and so on. It is reviewed from some literature that, the Big data tends to use different analysis methods, like predictive analysis, user analysis etc. This paper represents the fact that, Big Data required an open source technology for operating and storing huge amount of data. This paper greatly emphasizes on Apache Hadoop, which has become dominant due to its applicability for processing of big data.Hadoop supports thousands of terabytes of data. Hadoop framework facilitates the analysis of big data and its processing methodologies as well as the structure of an ecosystem

    Metabolite and enzyme profiles of glycogen metabolism in Methanococcoides methylutens

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    When a buffered anaerobic cell suspension of Methanococcoides methylutens was maintained under methanol-limited conditions, intracellular glycogen and hexose phosphates were consumed rapidly and a very small amount of methane formed at 4 h of a starvation period. When methanol was supplemented after a total of 20 h of starvation, a reverse pattern was observed: the glycogen level and the hexose phosphate pool increased, and formation of methane took place after a lag period of 90 min. A considerable amount of methane was formed in 120 min after its detection with a rate of 0.18 µmol mg-1 protein min-1. When methane formation decreased after 270 min of incubation and finally came to a halt, probably due to complete assimilation of supplemented methanol, the levels of glycogen and hexose monophosphates decreased once again. However fructose 1,6-diphosphate levels showed a continuous increase even after exhaustion of methane formation. In contrast to the hexose phosphate pool, levels of other metabolites showed a small increase after addition of methanol. The enzyme profile of glycogen metabolism showed relatively high levels of triose phosphate isomerase. Glyceraldehyde 3-phosphate dehydrogenase reacted with NADPH with a three-fold higher activity as compared to that with NADH

    Kinetic and Mechanistic Study of Glucose Isomerization Using Homogeneous Organic Brønsted Base Catalysts in Water

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    The isomerization of glucose to fructose represents a key intermediate step in the conversion of cellulosic biomass to fuels and renewable platform chemicals, namely, 5-hydroxymethyl furfural (HMF), 2,5-furandicarboxylic acid (FDCA), and levulinic acid (LA). Although both Lewis acids and Brønsted bases catalyze this reaction, the base-catalyzed pathway received significantly less attention due to its lower selectivity to fructose and the poor yields achieved (\u3c10%). However, we recently demonstrated that homogeneous organic Brønsted bases present a similar performance (∼31% yield) as Sn-containing beta zeolite, a reference catalyst for this reaction. Herein, we report on the first extensive kinetic and mechanistic study on the organic Brønsted base-catalyzed isomerization of glucose to fructose. Specifically, we combine kinetic experiments performed over a broad range of conditions (temperature: 80–120 °C; pH 9.5–11.5; reactant: glucose, fructose) with isotopic studies and in situ 1H NMR spectroscopy. Pathways leading to isomerization and degradation of the monosaccharides have been identified through careful experimentation and comparison with previously published data. Kinetic isotope effect experiments were carried out with labeled glucose to validate the rate-limiting step. The ex situ characterization of the reaction products was confirmed using in situ 1H NMR studies. It is shown that unimolecular (thermal) and bimolecular (alkaline) degradation of fructose can be minimized independently by carefully controlling the reaction conditions. Fructose was produced with 32% yield and 64% selectivity within 7 min

    Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water

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    The isomerization of glucose into fructose is a large-scale reaction for the production of high-fructose corn syrup (HFCS; reaction performed by enzyme catalysts) and recently is being considered as an intermediate step in the possible route of biomass to fuels and chemicals. Here, it is shown that a large-pore zeolite that contains tin (Sn-Beta) is able to isomerize glucose to fructose in aqueous media with high activity and selectivity. Specifically, a 10% (wt/wt) glucose solution containing a catalytic amount of Sn-Beta (1∶50 Sn:glucose molar ratio) gives product yields of approximately 46% (wt/wt) glucose, 31% (wt/wt) fructose, and 9% (wt/wt) mannose after 30 min and 12 min of reaction at 383 K and 413 K, respectively. This reactivity is achieved also when a 45 wt% glucose solution is used. The properties of the large-pore zeolite greatly influence the reaction behavior because the reaction does not proceed with a medium-pore zeolite, and the isomerization activity is considerably lower when the metal centers are incorporated in ordered mesoporous silica (MCM-41). The Sn-Beta catalyst can be used for multiple cycles, and the reaction stops when the solid is removed, clearly indicating that the catalysis is occurring heterogeneously. Most importantly, the Sn-Beta catalyst is able to perform the isomerization reaction in highly acidic, aqueous environments with equivalent activity and product distribution as in media without added acid. This enables Sn-Beta to couple isomerizations with other acid-catalyzed reactions, including hydrolysis/isomerization or isomerization/dehydration reaction sequences [starch to fructose and glucose to 5-hydroxymethylfurfural (HMF) demonstrated here]

    Mechanical sequential counting with liquid marbles

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    © 2018, Springer International Publishing AG, part of Springer Nature. Here we demonstrate the first working example of a liquid marble-operated sequential binary counting device. We have designed a lightweight gate that can be actuated by the low mass and momentum of a liquid marble. By linking a number of these gates in series, we are able to digitally count up to binary 1111 (upper limit only by our requirements). Using liquid marbles in such a system opens up new avenues of research and design, by way of modifying the coating and/or core of the liquid marbles, and thereby giving extra dimensions for calculation (e.g. a calculation that takes into consideration the progress of a chemical reaction inside a liquid marble). In addition, the new gate design has multiple uses in liquid marble rerouting

    High temperature optical absorption investigation into the electronic transitions in sol–gel derived C12A7 thin films

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    Optical absorption into 6 mm thick sol–gel derived films, annealed at 1300 °C of 12CaO·7Al2O3 calcium aluminate binary compound on MgO〈100〉 single crystal substrates was studied at temperatures ranging from room temperature to 300 °C. Experimental data were analysed in both Tauc and Urbach regions. The optical band gap decreased from 4.088 eV at 25 °C to 4.051 eV at 300 °C, while Urbach energy increased from 0.191 eV at 25 °C to 0.257 eV at 300 °C. The relationship between the optical band gap and the Urbach energy at different temperatures showed an almost linear relationship from which the theoretical values of 4.156 and 0.065 eV were evaluated for the band gap energy and Urbach energy of a 12CaO·7Al2O3 crystal with zero structural disorder at 0 K

    Lutein Protects RGC-5 Cells Against Hypoxia and Oxidative Stress

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    Retinal ischemia and oxidative stress lead to neuronal death in many ocular pathologies. Recently, we found that lutein, an oxy-carotenoid, protected the inner retina from ischemia/reperfusion injury. However, it is uncertain whether lutein directly protects retinal ganglion cells (RGCs). Here, an in vitro model of hypoxia and oxidative stress was used to further investigate the neuroprotective role of lutein in RGCs. Cobalt chloride (CoCl2) and hydrogen peroxide (H2O2) were added to a transformed RGC cell line, RGC-5, to induce chemical hypoxia and oxidative stress, respectively. Either lutein or vehicle was added to cultured cells. A higher cell count was observed in the lutein-treated cells compared with the vehicle-treated cells. Our data from this in vitro model revealed that lutein might protect RGC-5 cells from damage when exposed to either CoCl2-induced chemical hypoxia or H2O2-induced oxidative stress. These results suggest that lutein may play a role as a neuroprotectant
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