Thermodynamic Bethe Ansatz and Threefold Triangulations

In the Thermodynamic Bethe Ansatz approach to 2D integrable, ADE-related quantum field theories one derives a set of algebraic functional equations (a Y-system) which play a prominent role. This set of equations is mapped into the problem of finding finite triangulations of certain 3D manifolds. This mapping allows us to find a general explanation of the periodicity of the Y-system. For the $A_N$ related theories and more generally for the various restrictions of the fractionally-supersymmetric sine-Gordon models, we find an explicit, surprisingly simple solution of such functional equations in terms of a single unknown function of the rapidity. The recently-found dilogarithm functional equations associated to the Y-system simply express the invariance of the volume of a manifold for deformations of its triangulations.Comment: 17 pages, 2 eps figures, enlarged version to appear in IJMP

A topological invariant of RG flows in 2D integrable quantum field theories

We construct a topological invariant of the renormalization group trajectories of a large class of 2D quantum integrable models, described by the thermodynamic Bethe ansatz approach. A geometrical description of this invariant in terms of triangulations of three-dimensional manifolds is proposed and associated dilogarithm identities are proven.Comment: 12 pages, 6 figures. Presented at the Euroconference on New Symmetries in Statistical Mech. and Cond. Mat. Physics, Torino, July 20- August 1 1998. typos correcte

Dynkin TBA's

We prove a useful identity valid for all $ADE$ minimal S-matrices, that clarifies the transformation of the relative thermodynamic Bethe Ansatz (TBA) from its standard form into the universal one proposed by Al.B.Zamolodchikov. By considering the graph encoding of the system of functional equations for the exponentials of the pseudoenergies, we show that any such system having the same form as those for the $ADE$ TBA's, can be encoded on $A,D,E,A/Z_2$ only. This includes, besides the known $ADE$ diagonal scattering, the set of all $SU(2)$ related {\em magnonic} TBA's. We explore this class sistematically and find some interesting new massive and massless RG flows. The generalization to classes related to higher rank algebras is briefly presented and an intriguing relation with level-rank duality is signalled.Comment: 29 pages, Latex (no macros) DFUB-92-11, DFTT-31/9

On the Thermodynamic Bethe Ansatz Equation in Sinh-Gordon Model

Two implicit periodic structures in the solution of sinh-Gordon thermodynamic Bethe ansatz equation are considered. The analytic structure of the solution as a function of complex $\theta$ is studied to some extent both analytically and numerically. The results make a hint how the CFT integrable structures can be relevant in the sinh-Gordon and staircase models. More motivations are figured out for subsequent studies of the massless sinh-Gordon (i.e. Liouville) TBA equation.Comment: 32 pages, 18 figures, myart.st

Preliminary data on volatile composition of olive fruits of cv. "Simona" and possible relationship to resistance to fly oviposition

By characterizing the volatile compounds of the olive cultivar \u201cSimona\u201d from southern Italy (Apulia region), we identified a way to analyze characteristics possibly linked to this olive\u2019s well-known resistance to fly oviposition. The pool of volatile compounds in the unripe and ripe fruits was identified, and even if the relative amounts of these compounds tended to vary with ripening, the fly repellent action appeared to be related to the sesquiterpenes such as alpha-copaene, cycloisosativene, alpha-muurolene, beta-cubebene and hydrocarbons such as (E)-2-dodecene, undecane, tridecane, and 3-methyl undecane. In agreement with the concept that the collective pool of volatile substances can enhance olfactory pleasure/repulsion more than would the effects of a single compound, the pool of volatile compounds identified in this paper may be among the possible characteristic mixtures with repellent action against Bactrocera oleae. The selection of volatile compounds made by the cuticle and responsible of the headspace quality surrounding the whole olive fruit is also demonstrated to be markedly different from the headspace volatile compounds produced by the extracted oil

Determination of gamma-butyrolactone (GBL) in foods by SBSE-TD/GC/MS

4-hydroxybutyric acid lactone, or gamma-butyrolactone (GBL), is a molecule included in the FEMA (Flavor Extract Manufacturers Association) list of flavouring substances (No. 3291) and used as natural-identical substance in flavouring formulation. Recently, the use of GBL has been subjected to restrictions by FDA because, together with the conversion derivative GHB (gamma-hydroxybutyric acid), it has been recognized and classified as psychotropic. In 1999 the Italian law included GBL in the list of psychotropic substances and more recently in the Table of substances inducing psychic and physical addiction. However, GBL has been detected in several natural products. Under a toxicological point of view the difference between natural and natural-identical GBL in food is not relevant. In any case, the evaluation of the total content of GBL in many foods contributes to evaluate the consumption ratio and the aim of this paper is to evidence the possibility of detecting GBL with a high sensitivity method also in complex matrices with analytical procedure characterized by high recovery. This paper proposes a new, simplified, sensitive and selective method (SBSE-TD/GC/MS) useful to detect and quantify the GBL in foods. The work shows, as an application of this method, the detection of this molecule in the very complex matrix of a confectionery product on the international market. The reliability of the method was verified by recovery and repeatability tests. Recovery average values result between 85\u201392% (CV%=8.2\u20135.3) for the concentration range 1\u201310mg/l and between 92\u201395% (CV%=6.5\u20134.2) for the concentration range 10\u201325mg/l