in this paper, the ultraspherical operational matrices of derivatives are constructed. based on these operational matrices, two numerical algorithms are presented and analyzed for obtaining new approximate spectral solutions of a class of linear and nonlinear lane-emden type singular initial value problems. the basic idea behind the suggested algorithms is basically built on transforming the eq...

Nowadays, centrifugal compressors are commonly used in the oil and gas industry, particularly in the energy transmission facilities just like a gas pipeline stations. Therefore, these machines with different operational circumstances and thermodynamic characteristics are to be exploited according to the operational necessities. Generally, the most important operational parameters of a gas pipel...

heat exchangers are the critical components of refrigeration and liquefaction processes. selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in joule-thomson cooling system results in improving the performance and efficiency. in the current study, a straightforward procedure is introduced to design an efficient joule-thomson co...