Using the principle of energy conservation has been considered for gravity field determination from satellite observations since the early satellite era. CHAMP is the first satellite to which the energy balance approach can be usefully applied, now that near-continuous orbit tracking by GPS is available, aided by accelerometry. The feasibility of this approach has recently been demonstrated. Th...

geophysical fluids such as atmosphere and ocean often have stable density stratification; hence internal gravity waves are generated and propagated through them which are important in momentum and energy transfer in these media. these waves are also believed to generate layered structures in such media. recently there have been numerous theoretical, experimental and numerical studies on the way...

This paper assesses the determinants of trade in services using a gravity model, with particular attention given to the role of barriers to services trade. Initially, the application of the gravity equation to services trade is examined. A variety of econometric estimators are tested and the Hausman-Taylor model is found to be the best estimator. The gravity model fits services trade flows in a...

In most of gravity balancing approaches devoted to robot manipulators, the gravity compensation is carried out for cancelling of the static efforts due to robot element masses, as well as a fixed payload. When the payload is variable, i.e. if for each cycle of the robot operation it is different, the known compensation techniques are not efficient. Some solutions permitting to compensate the gr...

This paper uses a gravity model to assess ex-post regional trade agreements. The model includes 130 countries and is estimated with panel data over the period 1962–1996. The introduction of the correct number of dummy variables allows for identification of Vinerian trade creation and trade diversion effects, while the estimation method takes into account the unobservable characteristics of each...

Liquid distributions in unsaturated porous media under different gravitational accelerations and corresponding macroscopic gaseous diffusion coefficients were investigated to enhance understanding of plant growth conditions in microgravity. We used a single-component, multiphase lattice Boltzmann code to simulate liquid configurations in two-dimensional porous media at varying water contents fo...