permeability is a key parameter in reservoir characterization. in fact, without accurate information about reservoir permeability, there is no good solution for reservoir engineering problems. up to now, permeability values of a reservoir have been calculated through laboratory measurements or well testing methods. these methods are useful but they cannot describe a reservoir reliably and preci...

A new broadband in-phase power divider based on multilayer technology is presented. A simple design procedure is developed for the proposed multilayer power divider. An S-band four-way multilayer power divider was designed and measured. The simulated results are compared with the measured data, and good agreement is reported. The measured 15 dB return loss bandwidth is demonstrated to be about ...

Reservoir operation involves many critical decisions due to unpredicted circumstances, such as drought or flood. The reservoir water release decision is one of the challenging tasks for the reservoir operator since the decision to deal with many complicated decision variables and multipurpose operation. Typically, the water that flow into the reservoir comes from the upstream river network. The...

the chemical surfactant flooding can mobilize the trapped oil by lowering the interfacial tension between oil and brine and in some cases altering the reservoir rock wettability. in this work, the effect of surfactants on oil/brine interfacial tension was experimentally investigated. first, the effect of surfactants concentration was surveyed. afterwards, the effect of salinity on surfactant be...

In most natural and engineered systems, a set of entities interact with each other in complicated patterns that can encompass multiple types of relationships, change in time and include other types of complications. Such systems include multiple subsystems and layers of connectivity, and it is important to take such ‘multilayer’ features into account to try to improve our understanding of compl...

Metal–dielectric multilayer metamaterials with extreme loss-anisotropy, in which the longitudinal component of the permittivity tensor has an ultra-large imaginary part, are proposed and designed. Diffraction-free deep subwavelength beam propagation and manipulation, due to the nearly flat iso-frequency contour, is demonstrated in such loss-anisotropic metamaterials. It is also shown that deep ...

Limitations on water resources and the high costs of new hydraulic structure construction intensify the need for an optimum operation of Iranian reservoir systems. For appropriate water distribution and management in a 9-reservoir system on the Kalamarz river, Mianeh basin optimizing mathematical models are applied. Considering the stochastic nature of river discharges and the constant amount o...

Limitations on water resources and the high costs of new hydraulic structure construction intensify the need for an optimum operation of Iranian reservoir systems. For appropriate water distribution and management in a 9-reservoir system on the Kalamarz river, Mianeh basin optimizing mathematical models are applied. Considering the stochastic nature of river discharges and the constant amount o...

background: several reservoir systems have been constructed for hydropower generation around the world. hydropower offers an economical source of electricity with reduce carbon emissions. therefore, it is such a clean and renewable source of energy. reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. yet, reservoir systems are inefficiently ope...

Eutrophication is considered as a serious problem in water reservoirs. Awareness about the eutrophic status of each reservoir could help in providing a better understanding of the problem in a global scale. The present study was conducted to assess temporal and spatial eutrophication index in a water reservoir (Sahand dam) in the northwest of Iran. Physico-chemical parametres that are effective...