Knowledge of the refractivity index in the lower atmosphere is very important in the design, transmission and performance analysis of line-of-sight (LOS) terrestrial links. In oceanic environments, radio wave propagation is affected by the high variability with space and time of the meteorological parameters. Radiosonde data have been used in the analysis of the effect of climatic conditions in...

QSAR models of 22 benzamidine derivatives reported as inhibitors of thrombin have been developed using the descriptors heat of formation, valence connectivity index, shape index, solvent accessibility surface area, molar refractivity, log P and molecular weight. QSAR models, in which either heat of formation or shape index or molar refractivity is present, have good predictive powers as correla...

[1] Non‐standard radio wave propagation in the atmosphere is caused by anomalous changes of the atmospheric refractivity index. In recent years, refractivity from clutter (RFC) has been an active field of research to complement traditional ways of measuring the refractivity profile in maritime environments which rely on direct sensing of the environmental parameters. Higher temporal and spatial...

a robust linear quantitative structure-property relationship (qspr) model has been constructed to model and predict the refractivity indices of 101 organic compounds as common halo-derivatives of normal paraffin by application of the structural descriptors combined with multiple linear regression (mlr) method. in the main part of this study, theoretical molecular descriptors were adopted from t...

Purpose. In this work, a novel descriptor of atoms in molecules is introduced. The Refractotopological State Index for atoms (R-state,R ), rectifies the atomic refractivity values reported by Crippen et al with the atomic refractivity values of the topological environment of each skeletal atom in the molecule. Method. The R-state (R i), for atom i is an hybrid index that is defined as the intri...

[1] Estimation of the rangeand height-dependent index of refraction over the sea surface facilitates prediction of ducted microwave propagation loss. In this paper, refractivity estimation from radar clutter returns is performed using a Markov state space model for microwave propagation. Specifically, the parabolic approximation for numerical solution of the wave equation is used to formulate t...

Influence of atmospheric refraction on the propagation of electromagnetic waves has been studied from the beginnings of radio wave technology (Kerr, 1987). It has been proved that the path bending of electromagnetic waves due to inhomogeneous spatial distribution of the refractive index of air causes adverse effects such as multipath fading and interference, attenuation due to diffraction on th...

Time laps microscopy (microphotography) is one of the important measurements in many biological experiments. To describing life cycle of observed culture, cell division, fusion or comunication, both automaticaly or semiautomaticaly evaulation, is crucial to guarantee optimal camera settings, in case of observing long time experiment run by digital capture device. Monolayer of human cells – ofte...

Molar refractivity of diverse functional acyclic compounds (n = 166) has been correlated with first order TAU indices to unravel the diagnostic feature of the TAU scheme. It has been found that TAU relations could satisfactorily explain the variances of the molar refractivity values of diverse functional compounds (up to 98.6% predicted variance and explained variance for the composite set of 1...