We investigate the phase structure of three-dimensional quantum gravity coupled to an Ising spin system by means of numerical simulations. The quantum gravity part is modelled by the summation over random simplicial manifolds, and the Ising spins are located in the center of the tetrahedra, which constitute the building blocks of the piecewise linear manifold. We find that the coupling between ...

Gas hydrates are a costly problem when they plug oil and gas pipelines. The best way to determine the HFT and pressure is to measure these conditions experimentally for every gas system. Since this is not practical in terms of time and money, correlations are the other alternative tools. There are a small number of correlations for specific gravity method to predict the hydrate formation. As th...

T his paper is an attempt investigating the relationship between sanctions implications and geographical shift in trading partners. To this end, we analyze separately foreign trade patterns of two countries namely Iran and Russia - which are under imposed sanctions experience - with two United Nations Regional Groups (The Asia-Pacific and the Western European groups)  using a gravity...

Accurate knowledge of Antarctica’s topography, bedrock, and ice sheet thickness is pivotal for climate change and geoscience research. Building on recent significant progress made in satellite gravity mapping with European Space Agency’s Gravity field and Ocean Circulation Explorer (GOCE) mission, we here reverse the widely used approach of validating satellite gravity with topography and inste...

the relationship between technology and international competitiveness dates back to the neo-technological trade theories of the 1960s. this approach considers difference in technology as the primary motive for difference among nations in terms of trade performance. the technology gap approach emphasizes inter-country differences in innovativeness as the basis for international trade flows. the ...

Background: Laparoscopic Surgery (LS) may be associated with many port site complications such as hernia, bleeding, infection, subcutaneous emphysema and ugly scars. Some of these complications are serious such as obstructed port site hernia . Rate of these complications is low depending  on size and site of the port incision, type of the trocar that it is used, the condition of  the patient a...

In this paper, controlling the location of the tip of an L-shape beam under gravity field is investigated. The beam is covered with piezoelectric patches. The gravity filed moves the tip of beam downward and the actuators with induced voltage move the tip to the previous location. to optimize the best location and voltages for actuators, the particle swarm optimization algorithm code is develop...