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991.
Angela Espinosa Ezequiel Reficco Andrea Martínez David Guzmán 《European Journal of Operational Research》2015
Soft OR tools have increasingly been used to support the strategic development of companies at operational and managerial levels. However, we still lack OR applications that can be useful in dealing with the “implementation gap”, understood as the scarcity of resources available to organizations seeking to align their existing processes and structures with a new strategy. In this paper we contribute to filling that gap, describing an action research case study where we supported strategy implementation in a Latin American multinational corporation through a soft OR methodology. We enhanced the ‘Methodology to support organizational self-transformation’, inspired by the Viable System Model, with substantive improvements in data collection and analyses. Those adjustments became necessary to facilitate second order learning and agreements on required structural changes among a large number of participants. This case study contributes to the soft OR and strategy literature with insights about the promise and constraints of this soft OR methodology to collectively structure complex decisions that support organizational redesign and strategy implementation. 相似文献
992.
993.
Good diastereocontrol of three stereocentres is obtained in the synthesis of cyclopropane pheny1 sulfoxides. 相似文献
994.
995.
Ivan Notardonato Pasquale Avino Angela Centola Giuseppe Cinelli Mario Vincenzo Russo 《Analytical and bioanalytical chemistry》2013,405(18):6137-6141
This paper proposes a new method for quantitative analysis of acrylamide in cereal-based foods and potato chips. The method uses reaction with trifluoroacetic anhydride, and analyses the resulting derivative by use of gas chromatography with electron-capture detection (GC–ECD). The effects of derivatization conditions, including temperature, reaction time, and catalyst, on the acylation reaction were evaluated. Chromatographic analysis was performed on an SE-54 capillary column. Under the optimum conditions, good retention and peak response were achieved for the acrylamide derivative. The analytical method was fully validated by assessment of LODs and LOQs (1 ng g?1 and 25 ng g?1, with relative standard deviations (RSD) 2.1 and 3.6, respectively), linearity (R?=?0.9935 over the range 0.03–10 μg g?1), and extraction recovery (>96 %, with RSD below 2.0, for acrylamide spiked at 1, 20, 50, and 100 ng g?1; 99.8 % for acrylamide content >1000 ng g?1). The method requires no clean-up of the acrylamide derivative before injection. The method has been successfully used to determine acrylamide levels in different commercial cereal-based foods, French fries, and potato chips. Figure
Novel derivatization method and GC-ECD analysis of acrylamide in cooked foods 相似文献
996.
Angela R. Piergiovanni 《Analytical and bioanalytical chemistry》2013,405(2-3):481-491
Capillary electrophoresis (CE) is a powerful analytical tool that is widely applied to the analysis of biological samples. Proteins, peptides, nonprotein amino acids, phenolic compounds, and ions can be analysed using this electrophoretic methodology. This review summarises some applications of CE to the evaluation and characterisation of plant genetic resources of both Triticum and legume species, as carried out at the Istituto di Genetica Vegetale, National Research Council (IGV-CNR) in Bari (Italy). Different protein fractions as well as nonprotein amino acids were investigated by capillary zone electrophoresis (CZE), the most user-friendly mode of CE application. The described case studies show that CZE can be applied to some institutional activities of gene banks such as the evaluation of genetic diversity within stored collections, the acquisition of new samples, the differentiation of species belonging to the same genus, the identification of misclassified accessions, and the measurement of compounds relevant to nutrition or health. 相似文献
997.
Angela Cuzzola Antonella Petri Francesco Mazzini Piero Salvadori 《Rapid communications in mass spectrometry : RCM》2009,23(18):2975-2982
Alteration of levels of glucocorticoids in plasma and urine can be related to several diseases. In particular, the determination of endogenous glucocorticoids in urine has been reported to provide information on cortisol and cortisone status, on the activities of steroid hormone enzymes and on glucocorticoid metabolism. In this study, the application of hyphenated mass spectrometry techniques (GC/MS without derivatization and LC/MS) for the simultaneous analysis of free urinary cortisol (F), cortisone (E), tetrahydrocortisol (THF), allo‐tetrahydrocortisol (A‐THF) and tetrahydrocortisone (THE) was evaluated. A sample preparation protocol by solid‐phase extraction, mass spectrometry parameters and chromatographic conditions for both techniques were carefully optimized in terms of extracting phase and solvents, matrix effects, recovery, sensitivity and compound resolution. Baseline separation was achieved for the five underivatized analytes both in GC and LC. The LC/MS/MS technique was more suitable for the analysis of urine samples, being less influenced by matrix effects and showing excellent sensitivity and selectivity. A preliminary application of the reported method for the diagnosis of metabolic diseases was also described. The determination of each analyte in its free form, described for the first time in the paper, offers new perspectives in the application of glucocorticoid analysis for diagnostic purposes. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
998.
We consider the boundary value problem Δu+⋎x⋎2α
u
p
=0, α>0, in the unit ballB with homogeneous Dirichlet boundary condition andp a large exponent. We find a condition which ensures the existence of a positive solutionu
p
concentrating outside the origin atk symmetric points asp goes to +∞. The same techniques lead also to a more general result on general domains. In particular, we find that concentration
at the origin is always possible, provided α⊄IN.
The first author is supported by M.U.R.S.T., project “Variational methods and nonlinear differential equations” and a PIMS
Postdoctoral Fellowship.
The second author is supported by M.U.R.S.T., project “Metodi variazionali e topologici nello studio di fenomeni non lineari.”
The third author is supported by an Earmarked Grant from RGC of HK. 相似文献
999.
We consider the boundary value problem Δu+up=0 in a bounded, smooth domain Ω in R2 with homogeneous Dirichlet boundary condition and p a large exponent. We find topological conditions on Ω which ensure the existence of a positive solution up concentrating at exactly m points as p→∞. In particular, for a nonsimply connected domain such a solution exists for any given m?1. 相似文献
1000.
Jon Links Angela Foerster Arlei Prestes Tonel Gilberto Santos 《Annales Henri Poincare》2006,7(7-8):1591-1600
The two-site Bose–Hubbard model is a simple model used to study Josephson tunneling between two Bose–Einstein condensates.
In this work we give an overview of some mathematical aspects of this model. Using a classical analysis, we study the equations
of motion and the level curves of the Hamiltonian. Then, the quantum dynamics of the model is investigated using direct diagonalization
of the Hamiltonian. In both of these analyses, the existence of a threshold coupling between a delocalized and a self-trapped
phase is evident, in qualitative agreement with experiments.
Communicated by Vincent Rivasseau
This work is dedicated to the memory of Daniel Arnaudon
Submitted: January 30, 2006; Accepted: June 6, 2006 相似文献