Large deviation for stationary processes

A quasi-local variational characterization of the entropy for stationary processes is given. This is used to establish upper and lower large deviation estimates for arbitrary stationary processes. The upper and lower rate functions are shown to coincide for all quasi-local stationary processes. The contents of the paper is the following: 1. Introduction; 2. Notations; 3. Relative entropy of conditional expectations; 4. Relative entropy of a stationary process with respect to a covariant family of conditional expectations; 5. The role of locality and quasi-locality properties; 6. Large deviation upper estimate; 7. The Lower estimate; 8. The variational principle.     

Voltammetric determination of N-nitrosamines in the hypoglycemic agent tolazamide

Summary Exposure to N-nitrosamines has been indicted as one cause of cancer and so their presence has to be controlled. Voltammetry has been used for the detection of N-nitrosamines and has the advantage that it can be applied to both volatile and non-volatile compounds.The proposed method consists in dissolving 50 mg of tolazamide drug in 1 M potassium hydroxide and, after deaeration, the solution is directly submitted to differential pulse polarography. The response at about —1.50 V (vs. Ag/AgCl reference electrode) is proportional to the N-nitrosamine content from 0.5 ppm to more than 1,000 ppm into the tolazamide sample, with a relative standard deviation of ± 3 – 4% at 1 ppm. The sensitivity of the proposed method is essentially limited by a sharp peak due to N-[(hexahydro-1H-azepin)carbonyl]-4-methylbenzensulphonamide (usually present as impurity in tolazamide), that occurs at about –1.23 V (vs. Ag/AgCl reference electrode).

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Voltammetrische Bestimmung von N-Nitrosaminen in dem hypoglykämischen Mittel Tolazamid

     

Stable cores of large games

We give general conditions, based on the largeness of the core, under which cores of exact TU games are their unique von Neumann-Morgenstern stable sets. We show that this condition is satisfied by convex games and by nonatomic exact market games. In this way, we extend and unify earlier results existing in literature. Under some additional conditions we also prove the equivalence between the core and the Mas-Colell bargaining set.We thank Jean-Francois Mertens, Enrico Minelli, William Thomson, and two anonymous referees for helpful comments. We also thank seminar audiences at CORE, Cornell, Pescara, and Rochester. We gratefully acknowledge the financial support of the Ministero dell’Istruzione, dell’Universitá e della Ricerca.     

Electronic structure of graphite: Single particle and collective excitations studied by EELS,SEE and K edge loss techniques

We present some EELS, SEE and K edge loss measurements on in situ cleaved graphite. Single particle excitations in the EELS measurements have been identified accordingly with some previous results on pure polycrystalline iron and are compared with available band structure calculations of graphite. The core edge loss spectroscopy performed in the reflection mode at low primary electron energy proved to be a powerful and rapid technique to study the partial density of empty states.     

Sulla formulazione intrinseca dei continui iperelastici

On the wake of a work carried out by Prof. G. Ferrarese, a differential system is fixed for the determination of the iperelastic continuum's motion, supposing the mass acting forces should explicitly depend on the lagrangean speed. This is taken as an indipendent variable, together with the actual metrics. The formulation has an intrinsic character, that means it is under actual variables, even if the compatibility conditions cannot leave apart from the euclidean character of any initial configuration.     

Round‐robin experiment in high‐temperature gel permeation chromatography

The results of an interlaboratory or round‐robin experiment in high‐temperature gel permeation chromatography (HT‐GPC) analysis are presented. The intention was to determine and raise awareness of interlaboratory reproducibility of HT‐GPC techniques. Fifteen laboratories performed analyses of five polyethylene samples and standards SRM 1475 and 1476. Reproducibility, as measured by the interlaboratory standard deviation (s_LAB), was greatly influenced by the breadth of the molecular weight distribution (MWD) and branching. The s_LAB values for the weight‐average molecular weight (M_w) of linear polyethylenes of narrow and broad MWDs were 4 and 14%, respectively. For branched polymers, GPC viscometry methods are shown to measure significantly higher molecular weights than the noncoupled GPC method, with higher variance. For branched polyethylenes measured with GPC viscometry, the reproducibility of M_w was characterized by s_LAB = 18%. Reproducibility of the SRM 1475 standard was better than for unknowns. The results for branched standard SRM 1476 emphasize the important role of the detection method in GPC but call into question the use of this material as a molecular weight standard. For single‐site polyethylene, only a handful of labs measured an MWD that closely matched the Flory distribution. Qualitatively, the responses indicate that many variations in instrument and analytical methods exist among laboratories; this is partly a reflection of the development and refinements that this technique must yet undergo before a truly standard method is widely accepted and practiced. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 905–921, 2002