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131.
The aim of this note is to clarify a minor mistake in the article: Some Applications of the Hodge-de Rham Decomposition to Ricci solitons. 相似文献
132.
Sonia de Almeida Evaneide N. Lima Marisa S. Crespi Clóvis A. Ribeiro Valdir Schalch 《Journal of Thermal Analysis and Calorimetry》2009,97(2):529-533
Urban solid residues are constituted of food remaining, grass leaves, fruit peelings, paper, cardboard, rubber, plastic, etc.
The organic fraction formed represents about 50% during the decomposition yields biogas and leachate, which are sources of
pollution. Residue samples were collected from the landfill in different and cells from several ages and the corresponding
leachate, both after treatments, were submitted to thermal analysis. Kinetic parameters were determined using Flynn–Wall–Ozawa
method. The linear relation between the two kinetic parameters (ln A and E) was verified for organic residue urban’s samples, but not for leachate’s sample. The occurred difference can be attributed
to the constituents present in leachate. 相似文献
133.
M. Manso S. Pessanha F. Figueira S. Valadas A. Guilherme M. Afonso A. C. Rocha M. J. Oliveira I. Ribeiro M. L. Carvalho 《Analytical and bioanalytical chemistry》2009,395(7):2029-2036
The reddish-brown, brown or yellowish stains of circular or irregular shape known as foxing spots have been fully described
in conservation literature but still, this phenomenon does not find any scientific agreement since many hypotheses have been
raised concerning their origin. In this work a contribution to foxing definition not only focussed on its appearance but also
reported on its chemical information. For this purpose foxing stains present in drawings from two Portuguese artists dated
from the eighteenth to nineteenth centuries were observed under ultra-violet light and optical microscope and analysed by
three non-invasive spectroscopy techniques. The observations carried out on the stains provided information on their surface
morphology. The use of energy-dispersive X-ray fluorescence revealed a variation on the elemental content between foxing and
paper region. Although the results from X-ray diffraction analysis showed no signs of cellulose degradation in foxing stains,
Fourier-transformed infrared analysis revealed the presence of oxide groups. Both the information on the chemical nature and
surface morphology of the stains achieved in this study will contribute to increase foxing formation information and develop
future protocols for conservation purposes. 相似文献
134.
Joaquim J. Júdice Hanif D. Sherali Isabel M. Ribeiro 《Computational Optimization and Applications》2007,37(2):139-156
In this paper an eigenvalue complementarity problem (EiCP) is studied, which finds its origins in the solution of a contact
problem in mechanics. The EiCP is shown to be equivalent to a Nonlinear Complementarity Problem, a Mathematical Programming
Problem with Complementarity Constraints and a Global Optimization Problem. A finite Reformulation–Linearization Technique
(Rlt)-based tree search algorithm is introduced for processing the EiCP via the lattermost of these formulations. Computational
experience is included to highlight the efficacy of the above formulations and corresponding techniques for the solution of
the EiCP. 相似文献
135.
J. J. Júdice H. D. Sherali I. M. Ribeiro A. M. Faustino 《Journal of Optimization Theory and Applications》2007,134(3):467-481
In this paper, an algorithm for solving a mathematical programming problem with complementarity (or equilibrium) constraints
(MPEC) is introduced, which uses the active-set methodology while maintaining the complementarity restrictions throughout
the procedure. Finite convergence of the algorithm to a strongly stationary point of the MPEC is established under reasonable
hypotheses. The algorithm can be easily implemented by adopting any active-set code for nonlinear programming. Computational
experience is included to highlight the efficacy of the proposed method in practice. 相似文献
136.
S. Sofia M. Rodrigues Dr. David S. M. Ribeiro Dr. Christian Frigerio Susana P. F. Costa Prof. Dr. João A. V. Prior Dr. Paula C. A. G. Pinto Prof. Dr. João L. M. Santos Prof. Dr. M. Lúcia M. F. S. Saraiva Dr. Marieta L. C. Passos 《Chemphyschem》2015,16(9):1880-1888
Immobilization of quantum dots (QDs) onto solid supports could improve their applicability in the development of sensing platforms and solid‐phase reactors by allowing the implementation of reusable surfaces and the execution of repetitive procedures. As the reactivity of QDs relies mostly on their surface chemistry, immobilization could also limit the disruption of solution stability that could prevent stable measurements. Herein, distinct strategies to immobilize QDs onto porous aminated supports, such as physical adsorption and the establishment of chemical linking, were evaluated. This work explores the influence of QD capping and size, concentration, pH, and contact time between the support and the QDs. Maximum QD retention was obtained for physical adsorption assays. Freundlich and Langmuir isotherms were used to analyze the equilibrium data. Gibbs free energy, enthalpy, and entropy were calculated and the stability of immobilized QDs was confirmed. 相似文献
137.
138.
Inside Cover: Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid Ceramidase (Angew. Chem. Int. Ed. 2/2015)
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139.
Ultrasound‐assisted extraction method for the simultaneous determination of emerging contaminants in freshwater sediments
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Diana Nara Ribeiro de Sousa Guilherme Martins Grosseli Antonio Aparecido Mozeto Renato Lajarim Carneiro Pedro Sergio Fadini 《Journal of separation science》2015,38(19):3454-3460
Sediments are the fate of several emerging organic contaminants, such as pharmaceuticals, personal care products and hormones, and therefore an important subject in environmental monitoring studies. In the present work, a simple and sensitive method was developed, validated and applied for the simultaneous extraction of atenolol, caffeine, carbamazepine, diclofenac, ibuprofen, naproxen, propranolol, triclosan, estrone, 17‐β‐estradiol and 17‐α‐ethinylestradiol using ultrasound‐assisted extraction from freshwater sediment samples followed by solid‐phase extraction clean‐up and liquid chromatography with tandem mass spectrometry detection. The solvent type and extraction pH were evaluated to obtain the highest recoveries of the compounds. The best method shows absolute recoveries between 54.0 and 94.4% at 50 ng/g concentration. The method exhibits good precision with relative standard deviation ranging from 1.0–16%. The detection and quantification limits ranged from 0.006–0.067 and 0.016–0.336 ng/g, respectively. The developed method was successfully applied to freshwater sediment samples collected from different sites in Jundiaí River basin of São Paulo State, Brazil. The compounds atenolol, caffeine, propranolol and triclosan were detected in all the sampling sites with concentrations of 13.8, 41.0, 28.5 and 176 ng/g, respectively. 相似文献