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排序方式: 共有231条查询结果,搜索用时 15 毫秒
1.
Fernanda R C Damasceno Denise M G Freire Magali C Cammarota 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(5):730-738
BACKGROUND: The application of lipase‐rich enzyme pools (such as the crude solid enzymatic preparation (SEP) obtained from Penicillium restrictum solid‐state fermentation of agro‐industrial wastes) to activated sludge systems may be an effective strategy for preventing various operational problems. The continuous addition of SEP to the treatment system can become cost‐prohibitive when in situ production and/or storage are factored in. The application of SEP to high‐fat wastewater treatment would only be justified as an emergency measure, such as a sudden increase in the fat content of the bioreactor influent. Therefore, the primary objective of this work was to investigate the efficiency of a crude SEP during fat shock loads, simulated through the periodic addition of dairy industry waste containing high fat concentrations to the feed stock of an activated sludge system, operated in continuous mode. RESULTS: The test bioreactor exhibited a higher average chemical oxygen demand (COD) removal efficiency than the control bioreactor (83% for control and 90% for test) and the fat accumulation in the biological flocs of the test bioreactor was 3.2 times lower than that in the control bioreactor. Turbidity was also lower in the effluent of the test bioreactor (123 and 66 FTU in control and test, respectively) and it had a shorter recovery time between shock loads, especially when the interval between loads was shorter than one month (biweekly and weekly shock loads). CONCLUSION: The addition of SEP during fat overloads in the reactor feed maintained efficient COD removal in the test bioreactor for 270 days without any operational problems. Copyright © 2008 Society of Chemical Industry 相似文献
2.
Maritza F. Díaz José A. Gavín Magali Gómez Vicente Curtielles Frank Hernández 《臭氧:科学与工程》2006,28(1):59-63
Prior studies have proven that ozonated vegetable oils present a high germicidal power. Ozonation of sunflower oil at different applied ozone dosage was carried out and peroxide and aldehydes indices along with antimicrobial activity were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR). The principal signals intensity values were used for following the reaction course between ozone and sunflower oil. The reaction was following up to peroxide index values of 1202 mmol-equi/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration but without disappearing completely. The Criegee ozonides obtained at 107.1 mg/g of ozone doses were approximately 3.9-fold higher than that at beginning of the reaction. The aldehyde protons were observed as a weak intensity signal in all the spectra. The signals belonging to olefinic protons from hydroperoxides appeared weak and increased with the increase in ozone doses. Signals from other oxygenated groups were assigned. The highest action spectrum of antimicrobial activity was obtained with the higher peroxide index. It was concluded that at higher applied ozone doses, the higher the antimicrobial activity potential of ozonized sunflower oil 相似文献
3.
We revisit in this paper the concept of decoding binary cyclic codes with Gröbner bases. These ideas were first introduced by Cooper, then Chen, Reed, Helleseth and Truong, and eventually by Orsini and Sala. We discuss here another way of putting the decoding problem into equations: the Newton identities. Although these identities have been extensively used for decoding, the work was done manually, to provide formulas for the coefficients of the locator polynomial. This was achieved by Reed, Chen, Truong and others in a long series of papers, for decoding quadratic residue codes, on a case-by-case basis. It is tempting to automate these computations, using elimination theory and Gröbner bases.Thus, we study in this paper the properties of the system defined by the Newton identities, for decoding binary cyclic codes. This is done in two steps, first we prove some facts about the variety associated with this system, then we prove that the ideal itself contains relevant equations for decoding, which lead to formulas.Then we consider the so-called online Gröbner basis decoding, where the work of computing a Gröbner basis is done for each received word. It is much more efficient for practical purposes than preprocessing and substituting into the formulas. Finally, we conclude with some computational results, for codes of interesting length (about one hundred). 相似文献
4.
Hugo Durou David Pech David Colin Patrice Simon Pierre-Louis Taberna Magali Brunet 《Microsystem Technologies》2012,18(4):467-473
In this paper a wafer-level process is proposed to fully integrate carbon-based micro-supercapacitor onto silicon substrate.
This process relies on the deposition of a paste containing carbon, PVDF and acetone into cavities etched in silicon. After
electrolyte deposition in a controlled atmosphere, a wafer-level encapsulation is realized. Cyclic voltammetry performed on
non-encapsulated micro-components showed specific energy of 257 mJ cm−2 for 336 μm deep cavities. The specific encapsulation process developed was tested separately and proved to be efficient in
terms of resistance to organic electrolytes and mechanical strength. 相似文献
5.
Marek Vančo Bernd Hamann Oliver Kreylos Magali I. Billen Margarete A. Jadamec 《Computing and Visualization in Science》2011,14(4):143-156
The three-dimensional shapes of tectonic plates that sink into the Earth’s mantle (slabs) are the starting point for a range
of geoscience studies, from determining the forces driving the motion of tectonic plates, to potential seismic and tsunami
hazards, to the sources of magmas beneath active volcanos. For many of these applications finite element methods are used
to model the deformation or fluid flow, and therefore the input model parameters, such as feature geometries, temperature
or viscosity, must be defined with respect to a smooth, continuous distance field around the slab. In this paper we present
a framework for processing sparse and noisy seismic data (earthquake locations), defining the shape of the slab and computing
a continuous distance function on a mesh with variable node spacing. Due to the inhomogeneous volumetric distribution of earthquakes
within the slab and significant inaccuracies in the locations of earthquakes occurring hundreds of kilometers below the Earth’s
surface, the seismicity data set is extremely noisy and incomplete. Therefore, the preprocessing is the major part of the
framework consisting of several steps including a point based smoothing procedure, a powerful method to use other observational
constraints on slab location (e.g., seismic tomography or geologic history) to extend of the slab shape beyond earthquake
data set and continuous resampling using moving least squares method. For the preprocessed point data we introduce approaches
for finding the three-dimensional boundary of the slab and a subdivision of the slab into quadric implicit polynomials. The
resulting distance field is then compiled from distances to the piecewise continuous approximation of the slab and distances
to slab boundary. 相似文献
6.
Development and validation of a near-infrared method for the quantitation of caffeine in intact single tablets 总被引:2,自引:0,他引:2
A near-infrared spectroscopic method was developed and validated for determining the caffeine concentration of single and intact tablets in a Finnish pharmaceutical product containing 58.82% (m/m) caffeine.The spectral region of interest contained a total of 474 data points. The second derivative of Savitsky-Golay, a standard normal variate, and mean centering were used as spectral preprocessing options. The feasibility study showed nonuniformity of caffeine repartition within each tablet. Thus, spectra were recorded from both faces of the tablets, and the analysis result for a single tablet was reported as the average of both face determinations. Precision of the method was validated because the relative standard deviations from repeatability and intermediate precision tests were below 0.75% (m/m). Accuracy validation proved that the NIR results were not significantly different (P = 0.09, n = 12) from the results obtained with the reference HPLC method. The limit of quantification for caffeine was 13.7% (m/m) in the tablets. The method was found to be unaffected by NIR source replacement, but the repeatability of the results was affected if the sample holder was not placed in the correct position in the light beam. Routine NIR analysis of caffeine in tablet form was found to be more flexible and much faster than that performed with the HPLC method. 相似文献
7.
A New SiF–Dipropargyl Glycerol Scaffold as a Versatile Prosthetic Group to Design Dimeric Radioligands: Synthesis of the [18F]BMPPSiF Tracer to Image Serotonin Receptors 下载免费PDF全文
Dr. Puja Panwar Hazari Dr. Jurgen Schulz Delphine Vimont Nidhi Chadha Prof. Michele Allard Dr. Magali Szlosek‐Pinaud Prof. Eric Fouquet Dr. Anil Kumar Mishra 《ChemMedChem》2014,9(2):337-349
A novel SiX–dipropargyl glycerol scaffold (X: H, F, or 18F) was developed as a versatile prosthetic group that provides technical advantages for the preparation of dimeric radioligands based on silicon fluoride acceptor pre‐ or post‐labeling with fluorine‐18. Rapid conjugation with the prosthetic group takes place in microwave‐assisted click conjugation under mild conditions. Thus, a bivalent homodimeric SiX–dipropargyl glycerol derivatized radioligand, [18F]BMPPSiF, with enhanced affinity was developed by using click conjugation. High uptake of the radioligand was demonstrated in 5‐HT1A receptor‐rich regions in the brain with positron emission tomography. Molecular docking studies (rigid protein–flexible ligand) of BMPPSiF and known antagonists (WAY‐100635, MPPF, and MefWAY) with monomeric, dimeric, and multimeric 5‐HT1A receptor models were performed, with the highest G score obtained for docked BMPPSiF: ?6.766 as compared with all three antagonists on the monomeric model. Multimeric induced‐fit docking was also performed to visualize the comparable mode of binding under in vivo conditions, and a notably improved G score of ?8.455 was observed for BMPPSiF. These data directly correlate the high binding potential of BMPPSiF with the bivalent binding mode obtained in the biological studies. The present study warrants wide application of the SiX–dipropargyl glycerol prosthetic group in the development of ligands for imaging with enhanced affinity markers for specific targeting based on peptides, nucleosides, and lipids. 相似文献
8.
9.
Patricia A. Fair Jeff Adams Thomas C. Hulsey Magali Houde Ed Wirth Eric Zolman Gregory D. Bossart 《The Science of the total environment》2010,408(7):1577-1597
Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanes (CHLs), dieldrin, hexachlorobenzene (HCB), and mirex), polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), and polyaromatic hydrocarbons (PAHs) were measured in blubber biopsy samples collected from 139 wild bottlenose dolphins (Tursiops truncatus) during 2003-2005 in Charleston (CHS), SC and the Indian River Lagoon (IRL), FL. Dolphins accumulated a similar suite of contaminants with ∑ PCB dominating (CHS 64%, IRL 72%), followed by ∑ DDT (CHS 20%, IRL 17%), ∑ CHLs (CHS 7%; IRL 7%), ∑ PBDE (CHS 4%, IRL 2%), PAH at 2%, and dieldrin, PFCs and mirex each 1% or less. Together ∑ PCB and ∑ DDT concentrations contributed ∼ 87% of the total POCs measured in blubber of adult males. ∑ PCBs in adult male dolphins exceed the established PCB threshold of 17 mg/kg by a 5-fold order of magnitude with a 15-fold increase for many animals; 88% of the dolphins exceed this threshold. For male dolphins, CHS (93,980 ng/g lipid) had a higher ∑ PCBs geomean compared to the IRL (79,752 ng/g lipid) although not statistically different. In adult males, the PBDE geometric mean concentration was significantly higher in CHS (5920 ng/g lipid) than the IRL (1487 ng/g). Blubber ∑ PFCs concentrations were significantly higher in CHS dolphins. In addition to differences in concentration of PCB congeners, ∑ PBDE, TEQ, ∑ CHLs, mirex, dieldrin, and the ratios ∑ DDE/∑DDT and trans-nonachlor/cis-nonachlor were the most informative for discriminating contaminant loads in these two dolphin populations. Collectively, the current ∑ PCB, ∑ DDT, and ∑ PBDEs blubber concentrations found in CHS dolphins are among the highest reported values in marine mammals. Both dolphin populations, particularly those in CHS, carry a suite of organic chemicals at or above the level where adverse effects have been reported in wildlife, humans, and laboratory animals warranting further examination of the potential adverse effects of these exposures. 相似文献
10.
Michael Knorr Fabrice Guyon Abderrahim Khatyr Magali Allain Shawkat M. Aly Antony Lapprand Daniel Fortin Pierre D. Harvey 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(3):534-543