The problem of slow drilling in deep shale formations occurs worldwide causing significant expenses to the oil industry. Bit balling which is widely considered as the main cause of poor bit performance in shales, especially deep shales, is being drilled with water-based mud. Therefore, efforts have been made to develop a model to diagnose drilling effectivity. Hence, we arrived at graphical cor...

In order to assess the accuracy of commonly used approximate exchange-correlation density functionals, we present a comparison of accurate exchange and correlation potentials, exchange energy densities and energy components with the corresponding approximate quantities. Four systems are used as illustrative examples: the model system of two electrons in a harmonic potential and the He, Be and N...

Energy transfer process is examined numerically for the binary collision of intrinsic localized modes (ILMs) in the Fermi-Pasta-Ulam beta lattice. Unlike "solitons" in the integrable systems, ILMs exchange their energy in collision due to the discreteness effect. The mechanism of this energy exchange is examined in detail, and it is shown that the phase difference is the most dominant factor in...

STATCOMs are widely used to enhance power system stability. They can exchange reactive power with the power system, but they have limited ability to exchange real power because they don’t include energy storage devices. STATCOMs coupled with energy storage devices such as batteries have been introduced to improve their ability to exchange real power. However, batteries have a limitation in thei...

We are interested in the problem of coherent energy exchange in the spin-boson model augmented with loss, in the limit of infinite loss. This model is interesting because it predicts rapid coherent energy exchange under conditions when the transition energy of the two-level systems is much greater than the characteristic energy of the oscillator. Here we introduce the local approximation, in wh...

in this study, polystyrene ethylene butylene polystyrene (psebs) was functionalized to prepare mono and bipolar ion exchange membranes. in the case of the bipolar membrane, platinum was used as the intermediate layer. nacl solution of concentration ranging from 5 g/l to 25 g/l was used as the feed solution. a commercially procured ion exchange membrane made of polystyrene divinyl benzene was al...

The multiphonon energy exchange between a neutral He atom and a stepped Ni~977! surface has been measured in order to examine how the presence of a regular array of atomic-scale steps on a surface modifies energy exchange in the classical multiphonon scattering regime. At elevated substrate temperatures, we compare the multiphonon scattering with the predictions of a classical theory that has p...

Using the standard Hartree-Fock approximation on the basis of the random-phase approximation, we calculate the self-energy induced by exchange scattering due to electron-electron interaction in a spin-polarized two-dimensional electron gas 2DEG system. Applying the exchange self-energy to a Green’s function approach, we examine how the exchange interaction affects the spin-splitting in a 2DEG w...

Survey respondents often use simple strategies to answer retrospective questions about their level of consumption expenditure, resulting in the heaping of data at certain round numbers. In the panel context, wave-to-wave ‘leaping’ from one ‘heap’ to another can distort the sample pattern of consumption movements over time. Using BHPS energy expenditure data, we show that respondents use a varie...