1,085 research outputs found

    Screening reservoir candidates for enhanced oil recovery (EOR) in Angolan offshore projects.

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    The neuro-fuzzy (NF) approach presented in this work is based on five (5) layered feedforward backpropagation algorithm applied for technical screening of enhanced oil recovery (EOR) methods. Associated reservoir rock-fluid oilfield data from successful EOR projects were used as input and predicted output in the training and validation processes, respectively. The developed model was then tested by using data set from Block B of an Angolan oilfield. The results of the sensitivity analysis between the Mamdani and the Takagi-Sugeno-Kang (TSK) approach incorporated in the algorithm has shown the robustness of the TSK ANFIS (Adaptive Neuro-Fuzzy Inference System) approach in comparison to the other approach for the prediction of a suitable EOR technique. The simulation test results showed that the model presented in this study can be used for technical selection of suitable EOR techniques. Within the area investigated (Block B, Angola) polymer, hydrocarbon gas, and combustion were identified as the suitable techniques for EOR

    Al2o3 Coated With 3-n-propyl-1-azonia-4-azabicyclo[2. 2.2]octane Silsesquioxane Chloride And Its Use For Immobilization Of Cobalt(ii) Tetrasulfonated Phthalocyanine In Oxalic Acid Electrooxidation

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    A water-soluble polymer prepared by sol-gel process, 3-n-propyl-1-azonia-4- azabicyclo[2.2.2]octane silsesquioxane chloride, was adsorbed on alumina surface. This polymer-coated alumina was able to effectively immobilize cobalt(II) tetrasulfonated phthalocyanine complexes as counter ions. Cobalt phthalocyanine immobilized in this way is well and tightly adsorbed on Al 2O3/3-n-propyl-1-azonia-4-azabicyclo[2.2.2]octane silsesquioxane chloride surface. Furthermore, when incorporated to a carbon paste electrode showed a good electrocatalytic response toward the acid oxalic oxidation, making it a suitable electrode material. A linear relationship (r = 0.998) between the current responses obtained by chronoamperometric measurements and the oxalic acid concentration in the range of 7.4 × 10-5 - 9.1 × 10-4 mol L-1 was observed. A detection limit of 18 μmol L-1 was also determined. ©2008 Sociedade Brasileira de Química.194755761Templin, M., Franck, A., Du Chesne, A., Leist, H., Zhang, Y., Ulrich, R., Schädler, V., Wiesner, U., (1997) Science, 278, p. 1795Lee, K., Itharaju, R.R., Puleo, D.A., (2007) Acta Biomaterialia, 3, p. 515Yuan, J., Zhou, S., You, B., Wu, L., (2005) Chem. Mater, 17, p. 3587Fujiwara, M., Nishiyama, M., Yamamura, I., Ohtsuki, S., Nomura, R., (2004) Anal. Chem, 76, p. 2374Sayari, A., Hamoudi, S., (2001) Chem. Mater, 13, p. 3151Tien, P., Chau, L.K., Shieh, Y.Y., Lin, W.C., Wei, G.T., (2001) Chem. Mater, 13, p. 1124Gushikem, Y., Alfaya, R.V.S., Alfaya, A.A.S., (1998) Br PI, , 9.803.053-AArenas, L.T., Langaro, A., Gushikem, Y., (2003) J. Sol-Gel Sc. Tech, 28, p. 51Tundo, P., Venturello, P., Angeletti, E., (1982) J. Am. Chem. Soc, 104, p. 6547Wotring, V.J., Johnson, D.M., Bachas, L.G., (1990) Anal. Chem, 62, p. 1506Scindia, Y.M., Pandey, A.K., Reddy, A.V.R., (2005) J. Membr. Sci, 249, p. 143Arenas, L.T., Vaghetti, J.C.P., Moro, C.C., Lima, E.C., Benvenutti, E.V., Costa, T.M.H., (2004) Mater. Lett, 58, p. 895Kobayasbit, J., Anson, F.C., (1991) J. Phys. Chem, 95, p. 2595Ribeiro, E.S., Gushikem, Y., (1999) Electroanalysis, 11, p. 1280Lucho, A.M.S., Pissetti, F.L., Gushikem, Y., (2004) J. Sol-Gel Sc. Tech, 275, p. 251Arenas, L.T., Aguirre, T.A.S., Langaro, A., Gushikem, Y., Benvenutti, E.V., Costa, T.M.H., (2003) Polymer, 44, p. 5521Castellani, A.M., Gonçalves, J.E., Gushikem, Y., (2002) J. New Mat. Electrochem. Syst, 5, p. 169Arenas, L.T., Dias, S.L.P., Moro, C.C., Costa, T.M.H., Benvenutti, E.V., Lucho, A.M.S., Gushikem, Y., (2006) J. Colloid Interface Sci, 297, p. 244Min Jin, Z., Jiang Pan, Y., Feng Li, X., Lin Hu, M., Shen, L., (2003) J. Mol. Struct, 660, p. 67Marzocchi, M.P., Sbrana, G., Zerbi, G., (1965) J. Am. Chem. Soc, 87, p. 1429Fidalgo, A., Ilharco, L.M., (2004) Chem. Eur. J, 10, p. 392Ray, S., Vasudevan, S., (2003) Inorg. Chem, 42, p. 1711Tackley, D.R., Dent, G., Smith, W.E., (2001) Phys. Chem. Chem. Phys, 3, p. 1419Anson, F.C., (1966) Anal. Chem, 38, p. 54Xuan, G.S., Jang, S., Kwag, G., Kim, S., (2005) Bull. Korean Chem. Soc, 26, p. 671Lucho, A.M.S., Oliveira, E.C., Pastore, H.O., Gushikem, Y., (2004) J. Electroanal. Chem, 73, p. 55Bard, A.J., Faulkner, L.R., (2001) Electrochemical Methods. Fundamentals and Applications, , 2nd ed, Wiley: New York, ch. 9Yamazaki, S., Yamada, Y., Fujiwara, N., Ioroi, T., Siroma, Z., Senoh, H., Yasuda, K., (2007) J. Electroanal. Chem, 602, p. 96Casella, I.G., (1999) Electrochim. Acta, 44, p. 3353Mandanas, M.M., Shaffer, W., Adair, J.H., (2002) J. Am. Ceram. Soc, 85, p. 2156Shaidarova, L.G., Chelnokova, I.A., Gedmina, A.V., Budnikov, G.K., Ziganshina, S.A., Mozhanova, A.A., Bukharaev, A.A., (2006) J. Anal. Chem, 61, p. 37

    CERTIFICATION REPORT The certification of the mass fraction of pesticides in cucumber: ERM-BC403

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    This report describes the production of ERM®-BC403, which is a cucumber material certified for the mass fraction of selected pesticides. This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. Cucumbers from a biodynamic farm were used as base material. The cucumbers were transformed into slurry, freeze-dried and cryogenically milled. The obtained product was partially reconstituted with water and a separate portion was spiked with a pesticide mixture. The contaminated portion was then mixed with the rest of the material, homogenised and accurately dispensed into 100-ml vials. A second freeze-drying cycle was applied with the vials placed directly in the freeze-dryer. Prior to analysis the resulting sponge of dry cucumber must be reconstituted with a specific volume of water. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. The material was characterised by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outliers were eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for the quality control / assessment of method performance. As with any reference material, it can be used for establishing control charts or used for validation of analytical methods. The CRM is available in sets of two glass vials containing each approximately 3.2 g of dried material. The vials were sealed under an atmosphere of argon. The minimum amount of sample to be used is 2.5 g of the reconstituted material.JRC.F.6-Reference Material

    An approximation algorithm for the solution of the nonlinear Lane-Emden type equations arising in astrophysics using Hermite functions collocation method

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    In this paper we propose a collocation method for solving some well-known classes of Lane-Emden type equations which are nonlinear ordinary differential equations on the semi-infinite domain. They are categorized as singular initial value problems. The proposed approach is based on a Hermite function collocation (HFC) method. To illustrate the reliability of the method, some special cases of the equations are solved as test examples. The new method reduces the solution of a problem to the solution of a system of algebraic equations. Hermite functions have prefect properties that make them useful to achieve this goal. We compare the present work with some well-known results and show that the new method is efficient and applicable.Comment: 34 pages, 13 figures, Published in "Computer Physics Communications

    Genome-wide inhibition of pro-atherogenic gene expression by multi-STAT targeting compounds as a novel treatment strategy of CVDs

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    Cardiovascular diseases (CVDs), including atherosclerosis, are globally the leading cause of death. Key factors contributing to onset and progression of atherosclerosis include the pro-inflammatory cytokines Interferon (IFN)a and IFN? and the Pattern Recognition Receptor (PRR) Toll-like receptor 4 (TLR4). Together, they trigger activation of Signal Transducer and Activator of Transcription (STAT)s. Searches for compounds targeting the pTyr-SH2 interaction area of STAT3, yielded many small molecules, including STATTIC and STX-0119. However, many of these inhibitors do not seem STAT3-specific. We hypothesized that multi-STAT-inhibitors that simultaneously block STAT1, STAT2, and STAT3 activity and pro-inflammatory target gene expression may be a promising strategy to treat CVDs. Using comparative in silico docking of multiple STAT-SH2 models on multi-million compound libraries, we identified the novel multi-STAT inhibitor, C01L-F03. This compound targets the SH2 domain of STAT1, STAT2, and STAT3 with the same affinity and simultaneously blocks their activity and expression of multiple STAT-target genes in HMECs in response to IFNa. The same in silico and in vitro multi-STAT inhibiting capacity was shown for STATTIC and STX-0119. Moreover, C01L-F03, STATTIC and STX-0119 were also able to affect genome-wide interactions between IFN? and TLR4 by commonly inhibiting pro-inflammatory and pro-atherogenic gene expression directed by cooperative involvement of STATs with IRFs and/or NF-κB. Moreover, we observed that multi-STAT inhibitors could be used to inhibit IFN?+LPS-induced HMECs migration, leukocyte adhesion to ECs as well as impairment of mesenteric artery contractility. Together, this implicates that application of a multi-STAT inhibitory strategy could provide great promise for the treatment of CVDsThis publication was supported by grants UMO-2015/17/B/NZ2/00967 (HB) and UMO-2015/16/T/NZ2/00055 (MS) from National Science Centre Poland. This work was supported by the KNOW RNA Research Centre in Poznan (No. 01/KNOW2/2014) and in part by PL-Grid Infrastructure (MS

    Cercosporin production by Cercospora coffeicola isolates: spectrophotometry and HPLC quantification and image analysis

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    Cercosporin has excellent properties of photosensitization that have been widely used in organophotocatalyst and photodynamic therapy as well as an antimicrobial agent. Therefore, there is a need to quantify it accurately with accessible methods. A comparative analysis of cercosporin quantification obtained by spectrophotometry (SPEC) and high-performance liquid chromatography (HPLC) was performed for nineteen Cercospora coffeicola isolates from different coffee-producing municipalities in Brazil. Image analysis of cercosporin crystals was performed in isolates with either high or low production of the toxin. Our results show that SPEC and HPLC are equally valid for the cercosporin evaluation of C. coffeicola cultures grown in vitro. The isolates with high cercosporin production had a higher crystal number and size when compared to the one with low cercosporin productioninfo:eu-repo/semantics/publishedVersio

    Dye-free retinal angiography using blood-oxygenation modulation

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    Fluorescence angiography (FA) is widely used for studying and diagnosing abnormalities in the retinal blood circulation, but has associated risks of nausea, skin irritation, and even death. We describe a new non-invasive angiography technique: Blood Oxygenation Modulation Angiography, in which multispectral imaging of a transient perturbation in blood-oxygen saturation, yields angiography sequences similar to FA, including key features such as sequential filling of choroidal and retinal-vessels, which underpin assessment of circulation health. This is the first non-invasive angiography technique capable of visualizing these circulation features

    CERTIFICATION REPORT: The certification of the mass fraction of pesticides in soya: ERM®-BC700

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    This report describes the production of ERM-BC700, which is a soya material certified for the mass fraction of selected pesticides. This material was produced following ISO Guide 34:2009 [ ] and is certified in accordance with ISO Guide 35:2006. Soya beans (Glycine max) originating from Uruguay were sprayed with 11 pesticides in solution. The beans were air dried, cryo-milled and homogenised. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The material was characterised by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for the quality control / assessment of method performance. As with any reference material, it can be used for establishing control charts or validation studies. The CRM is available in glass vials containing 32 g of cryo-milled soya powder which were sealed under an atmosphere of nitrogen. The minimum amount of sample to be used is 2 gJRC.F.6-Reference Material
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