In the present work, a modified equation of state has been presented for the calculation of volumetric properties of supercritical fluids. The equation of state is van der Waals basis with temperature and density-dependent parameters. This equation of state has been applied for predicting the volumetric properties of fluids. The densities of fluids were calculated from the new equation of state...

We propose a general estimation principle based on the assumption that instrumental variables (IV) do not explain the error term in a structural equation. The estimators based on this principle is independent of the normalization constraint, unlike the standard IV estimators such as the two-stage least squares estimator. Using the new principle, we propose the L1 IV estimator, which is an IV es...

In this paper, we provide an explicit upper bound on the absolute value of solutions n < m 0 to Diophantine equation F(k)n = ±F(k)m, assuming k is even. Here {F(k)n}n ∈ Z denotes k-generalized Fibonacci sequence. The depends only k.

An analysis of the kinetics of H2 formation on interstellar dust grains is presented using rate equations. It is shown that semi-empirical expressions that appeared in the literature represent two different physical regimes. In particular, it is shown that the expression given by Hollenbach, Werner & Salpeter [ApJ, 163, 165 (1971)] applies when high flux, or high mobility, of H atoms on the sur...

Bidimensional spiking models are garnering a lot of attention for their simplicity and their ability to reproduce various spiking patterns of cortical neurons and are used particularly for large network simulations. These models describe the dynamics of the membrane potential by a nonlinear differential equation that blows up in finite time, coupled to a second equation for adaptation. Spikes a...

We will extend Ostrowki’s theorem from Q to the quadratic field Q(i). On Q, every nonarchimedean absolute value is equivalent to the p-adic absolute value for a unique prime number p, and the archimedean absolute values are all equivalent to the usual absolute value on Q. We will see a similar thing happens in Q(i): any non-archimedean absolute value is associated to a prime in Z[i] (unique up ...

Gas-condensate reservoirs contain hydrocarbon fluids with characteristics between oil and gas reservoirs and a high gas-liquid ratio. Due to the large gas-liquid ratio, wellhead choke calculations using the empirical equations such as Gilbert may contain considerable error. In this study, using drill stem test (DST) data of a gas-condensate reservoir, coefficients of Gilbert equation was modifi...

The proposed method for calculation of potential evapotranspiration is Penman-Monteith FAO method, but there are other methods that require less meteorological data but estimates close to the FAO Penman-Monteith method in different climatic conditions.  Performance evaluation of these methods on the same basis is prerequisite for selecting an alternative approach in accordance with available da...