in this paper, an approximate axisymmetric method is developed which can reliably calculate fully viscous hypersonic flow over blunt-nosed bodies. in this method, a maslen’s second-order pressure expression is used instead of the normal momentum equation. the combination of maslen’s second-order pressure expression and viscous shock layer equations is developed to accurately and efficiently com...

When the stagnation temperature increases, the specific heat does not remain constant and start to vary with this temperature. The gas is perfect, it ’ s state equation remains always valid, except, it was called by gas calorically imperfect or gas at high temperatures. The purpose of this work is to develop a mathematical model for a normal shock wave normal at high temperature when the stagna...

Roussel and Rubio proved a lemma which is essential in the proof of the Strong Perfect Graph Theorem. We give a new short proof of the main case of this lemma. In this note, we also give a short proof of Hayward’s decomposition theorem for weakly chordal graphs, relying on a Roussel–Rubio-type lemma. We recall how Roussel–Rubio-type lemmas yield very short proofs of the existence of even pairs ...

We will extend Reed's Semi-Strong Perfect Graph Theorem by proving that unbreakable C 5-free graphs diierent from a C 6 and its complement have unique P 4-structure.

High-temperature gas effects are known as the physical processes which result in a deviation of the behavior of the calorically perfect gas in the hypersonicflow regime. These effects may have a significant impact on laminar-turbulent transition of the boundary layer, and thus affect the heat loads of hypersonic vehicles. In the present paper we deal with thermal effects, i.e. rotational and vi...

The system we consider here is a charged fermions gas in the effective mass approximation, and in grand-canonical conditions. We assume that the particles are confined in a three dimensional cubic box Λ with side L ≥ 1, and subjected to a constant magnetic field of intensity B ≥ 0. Define the grand canonical generalized susceptibilities χL , N ≥ 1, as successive partial derivatives with respect...

The Wonderful Lemma, that was first proved by Roussel and Rubio, is one of the most important tools in the proof of the Strong Perfect Graph Theorem. Here we give a short proof of this lemma.

iranian oil buy back contract is a kind of service contract that foreign party carries out all operations in development or reconstruction of oil or gas field with its costs. in return, national iranian oil company obliges to compensate contractor all capital or non-capital costs necesserly by produced oil or gas from the same field. the energy charter treaty as the most perfect international t...