Search results for "Serie"
showing 10 items of 1270 documents
Die kristallstruktur von cycloalkanen
1982
An X-ray structure analysis was performed on single crystals of the cycloalkane (CH2)36. The lattice belongs to the space group Aa and is arranged in layers. The unit cell has the dimensions α = 1,033 nm, b = 0,824 nm, c = 4,22 nm, β = 107, 1° and contains four molecules. The molecules consist of two stretched stems which are linked by sharp folds at each end. The folds have the conformation …t(g g t g g) t… lying parallel to the b-axis. Raman measurements suggest that the stems are slightly twisted. A comparison of the homologous series (CH2)n, n = 36, 48, 60, and 72 using X-ray powder methods showed that the (CH2)36-structure, including the fold conformation, is also representative for th…
Spektroskopische analyse mehrfacher methacrylsäureester von oligo[(2-hydroxy-1,3-phenylen)methylen]en mittels UV-, IR-, 1H NMR- und massenspektren
1977
The structures of two homologous series of oligo[(2-hydroxy-1,3-phenylene)methylene]s completely esterified with methacrylic acid, were spectroscopically analysed. The molar decadal absorption coefficients of ultraviolet absorption maxima of the two homologous series confirm Hunter's relation. The vinylidene, ester, and substitution bands of the infrared spectra as well as the mass spectra agree with the accepted structures. The 1H NMR spectra permit to differentiate between exterior and interior groups of the molecules.
¿SE PUEDE MEDIR LA NEGOCIACIÓN INFORMADA?: UNA REVISIÓN DE LA METODOLOGÍA BASADA EN LAS COVARIANZAS DE LAS SERIES DE PRECIOS / CAN WE MEASURE THE INS…
2009
El desarrollo en los modelos teóricos de microestructura ha motivado la aparición de un grupo de trabajos encaminado al estudio empírico de los costes de transacción y sus componentes dada la importancia que han tenido los mismos en el estudio del funcionamiento de los mercados y la comparación entre éstos así como sus numerosas aplicaciones en campos afines (finanzas corporativas, eficiencia de los mercados, etc.). Por otra parte, la contrastación empírica de los distintos modelos establecidos muestra resultados claramente dispares. Por ello, el objetivo de nuestro trabajo es analizar con detalle y en conjunto dichos modelos centrándonos en un grupo con características muy similares. Concr…
Arsenic Pollution in the Southwest of Tuscany: Monitoring of Cornia Catchment Basin
2006
The territory of Colline Metallifere, in SW Tuscany, is characterized by the presence of strong arsenic anomalies. Some hypotheses, formulated in the last 20 years, based on geological and mineralogical factors have failed to explain the peculiar distribution of this toxic element in soil, fluvial sediments and ground water. Our research group has been studying for four years the problem of arsenic pollution in this district to investigate the origin and the mechanism of As diffusion in the environment. In particular we started a comparative study based on the extensive sampling of the stream sediments of the main waterways of Colline Metallifere (Pecora, Bruna and Cornia and their tributar…
Spatial distribution and temporal changes in river water temperature in the Baltic States
2017
Abstract The thermal regime of rivers in the Baltic States (Estonia, Latvia and Lithuania) is not sufficiently studied. The presented research describes the spatial distribution and temporal variation of river water temperature (WT) in the Baltic States using a unified methodology. The object of the research is the WT of rivers during the warm season (May–October) and the warmest month of the year (July). The contour maps of WT were compiled for the rivers of the Baltic States using data series for the period 1961–1990 from 17 water measuring stations in Estonia (EST), 36 stations in Latvia (LV) and 40 stations in Lithuania (LT). These maps allow the evaluation of WT for the unmonitored riv…
Assessing soil moisture regimes with traditional and new methods
2002
Soil moisture regime classes are required by U.S. soil taxonomy and other classification systems. Soil moisture regimes are based on long-term daily data of soil water content, which are as a rule estimated by means of models. International Commitee on Soil Moisture and Temperature Regimes (ICOMMOTR) has proposed classifying pedoclimate on the basis of biweekly water potential. This study was conducted to validate the use of the Erosion-Productivity Impact Calculator (EPIC) model in assessing soil water content of experimental fields placed in different European pedoclimatic conditions, to compare the pedoclimatic classification obtained with EPIC with those produced by the traditional Bill…
Darstellung einer homologen Reihe von oligoallylalkoholen mit 1-cyano-1-methylethyl-endgruppen. Beispiel einer mehrfachen matrizenreaktion und einer …
1984
Reduction and hydrolysis of the ladder oligomers 1, 2, 3, 4, and 5 prepared from the acrylates of oligo (hydroxyphenylene-methylene)s was found to lead to a homologous series of oligo (allylalcohol)s (6a, 7a, 8a, 9a and10a) with good yields. These alcohols were characterized by analytical and spectroscopic methods. The reaction sequences, starting with the esterification of the oligo[(hydroxyphenylene) methylene]s 11a – 11e with acryloyl chloride followed by the formation of the ladder oligomers and ending with their reduction and hydrolysis into the oligo(allyl alcohol)s and the starting compounds 11a – 11e, represent a simple matrix reaction. A mixture of multiple acrylates was also subje…
Dominating Clasp of the Financial Sector Revealed by Partial Correlation Analysis of the Stock Market
2010
What are the dominant stocks which drive the correlations present among stocks traded in a stock market? Can a correlation analysis provide an answer to this question? In the past, correlation based networks have been proposed as a tool to uncover the underlying backbone of the market. Correlation based networks represent the stocks and their relationships, which are then investigated using different network theory methodologies. Here we introduce a new concept to tackle the above question--the partial correlation network. Partial correlation is a measure of how the correlation between two variables, e.g., stock returns, is affected by a third variable. By using it we define a proxy of stoc…
A filtration model applied to submerged anaerobic MBRs (SAnMBRs)
2013
The aim of this study was to develop a model able to correctly reproduce the filtration process of submerged anaerobic MBRs (SAnMBRs). The proposed model was calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. Three suspended components were contemplated in the model: total solids concentration; dry mass of cake on the membrane surface; and dry mass of irreversible fouling on the membrane surface. The model addressed the following physical processes: the build-up and compression of the cake layer during filtration; cake layer removal using biogas sparging to scour the membrane; cake layer removal during back-flushing; and the consoli…
A complex network analysis of inbound tourism in Sicily
2019
In this article, the complex dynamics of inbound tourism in Sicily is analyzed for the period 1998–2017. The horizontal visibility graph algorithm is used to transform the overnight stays' time series into a network whose topology is investigated by standard network analysis. Discontinuities in the domestic and international tourism demand were identified in order to detect signals of change and the timing of the directional change in tourism growth. The network degree distribution confirms the complex structure of the destination and reveals the random and thus more unpredictable nature of the international tourism demand in Sicily, compared with a more stable domestic segment. Some policy…