Search results for "PAIRS"
showing 10 items of 82 documents
Leitfahigkeitsmessungen an Polystyrylnatrium in Dimethoxiäthan (DME) und Tetrahydrofuran (THF)
1971
An Polystyrylnatrium werden in zwei polaren organischen Losungsmitteln Leitfahigkeitsmessungen uber einen groseren Temperaturbereich ausgefuhrt. Aus der Temperaturabhangigkeit der Dissoziationskonstante ergibt sich, das die undissoziierte Verbindung in zwei Formen, dem Kontaktionenpaar (I) und dem solvatgetrennten Ionenpaar (II), vorkommt. Enthalpie- und Entropiedifferenz beim ubergang von I nach II, sowie die entsprechenden thermodynamischen Parameter der Dissoziation von II werden ermittelt. Der effektive Ladungsabstand im solvatgetrennten Ionenpaar betragt etwa 7 A. Conductivity measurements were carried out with polystyryl sodium in two polar solvents within a large temperature range. T…
An Ecology and Economy Coupling Model. A global stationary state model for a sustainable economy in the Hamiltonian formalism
2020
Abstract The severity of the two deeply correlated crises, the environmental and the economic ones, needs to be faced also in theoretical terms; thus, the authors propose a model yielding a global “stationary state”, following the idea of a “steady-state economics” by Georgescu-Rogen and Herman Daly, by constructing only one dynamical system of ecological and economic coupled variables. This is possible resorting to the generalized Volterra model, that, translated in the Hamiltonian formalism and its Hamilton equations, makes possible to “conjugate” every pair of variables, one economic, the other one ecological, in describing the behavior in time of a unique dynamical system. Applying the …
Design and optimization of bonded patch repairs of laminated composite structures
2015
International audience; The present study proposes a method for design optimization of external patched repairs. The tensile behavior of notched specimens with patched repair was studied using finite element analysis and compared with experimental results. It was found that high stress concentrations along the transverse edges of circular patches and/or at the longitudinal edges of the hole leads to early damage initiation in the parent plate. The damage initiation site and its propagation depend on the patch in-plane stiffness. The optimal patch design can be characterized by a strength ratio R*. The overall design of the patch repair can be considered using a dimensionless design paramete…
Improving Pairs Trading Using Neural Network Techniques and Fundamental Ratios
2020
Pairs trading is a quantitative trading strategy consisting on identifying two stocks that historically move together and, using the assumption that their prices difference has mean- reverting properties, exploit the deviation from the mean by taking long – short position in the chosen pair to profit. Throughout the years, different approaches have been developed in order to exploit this strategy. However, there is little literature who looks whether the divergences in the prices are generated by poor company results, i.e. whether the deviation from the mean are product of bad (or good) fundamentals and are justified, or if they generate a new equilibrium point for the pair. In addition, si…
A Comprehensive Look at the Real-Life Performance of Moving Average Trading Strategies
2015
Despite the enormous current interest in market timing and a series of publications in academic journals, there is still lack of comprehensive research on the evaluation of the profitability of trading rules using methods that are free from the data-snooping bias. In this paper we utilize the longest historical dataset that spans 155 years and extend previous studies on the performance of moving average trading rules in a number of important ways. Among other things, we investigate whether overweighting the recent prices improves the performance of timing rules; whether there is a single optimal lookback period in each trading rule; and how accurately the trading rules identify the bullish …
Soft-dielectron excess in proton-proton collisions at $\sqrt{s}$ = 13 TeV
2021
Physical review letters 127(4), 042302 (2021). doi:10.1103/PhysRevLett.127.042302
Development of an efficient system for the separation of indole alkaloids by high performance liquid chromatography and its applications
2001
An efficient system for the analysis of indole alkaloids by HPLC on a reversed-phase column using an ion pair technique is described. The optimised chromatographic conditions allowed the successful separation of 22 standard monoterpenoid indole alkaloids (including some isomers) and tryptamine. The described HPLC system was applied to the analysis of alkaloids in intergeneric somatic hybrid cell cultures of Rauvolfia serpentina x Rhazya stricta.
N-Heterocyclic Phosphenium, Arsenium, and Stibenium Ions as Ligands in Transition Metal Complexes: A Comparative Experimental and Computational Study
2005
Reaction of 2-chloro-1,3,2-diazaarsolenes and -diazaphospholenes with Tl[Co(CO)4] gives instable complexes of type [Co(ER2)(CO)4] which decarbonylated to yield [Co(ER2)(CO)3]. Spectroscopic and X-ray diffraction studies revealed that the tetracarbonyl complexes can be formulated as ion pair for E = P and as covalent metalla-arsine for E = As, and the tricarbonyl complexes as carbene-like species with a formal E=Co double bond. A similar reactivity towards Tl[Co(CO)4] was also inferred for 1,3,2-diazastibolenes although the products were not isolable and their constitution remained uncertain. Evaluation of structural and computational data suggests that the weak and polarized Co–As bond in […
On the Ion-Pair Recognition and Indication Features of a Fluorescent Heteroditopic Host Based on a BODIPY Core
2014
A fluorescent heteroditopic host for ion pairs and zwitterionic species has been synthesized. Its affinity towards a series of anions, cations and ion pairs in acetonitrile has been assessed, and the spectroscopic response has been evaluated. Solid–liquid extraction experiments of inorganic salts, α-amino acids and γ-aminobutyric acid (GABA) into acetonitrile solutions were performed, and the resulting complexes were analyzed by UV/Vis absorption, fluorescence and 1H NMR spectroscopy. The discrimination patterns observed have been rationalized in terms of the molecular topologies of the host and guests.