Applied Science Private University

About: Applied Science Private University is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Catalysis & Population. The organization has 4124 authors who have published 5299 publications receiving 116167 citations.

Error-Correction Coded Orbital-Angular-Momentum Modulation for FSO Channels Affected by Turbulence

Abstract: The performance of LDPC-precoded, orbital-angular-momentum (OAM) modulation is studied over a 1-km free-space laser communication link subject to OAM modal crosstalk induced by atmospheric turbulence. The multidimensional signal constellation is designed as the Cartesian product of a one-dimensional non-negative pulse-amplitude modulation and a set of orthogonal OAM modes. We evaluate the performance of this modulation scheme by first determining conditional probability density functions (PDFs) of the modal crosstalk for each symbol, resulting from the propagation in weak turbulence using a numerical propagation model. It is observed that OAM modulation is more sensitive to atmospheric turbulence as the number of dimensions increases. However, this can be efficiently mitigated by an error-correction code. The coded OAM modulation scheme provides an energy-efficient alternative to single-mode transmission, since a larger rate can be obtained per given bandwidth.

Characterization and Properties

Abstract: This chapter concentrates on the characterization of Langmuir—Blodgett (LB) monolayer and multilayer films on solid surfaces. Experimental techniques to study the properties of monolayers floating on the surface of a subphase have been discussed by Gaines(1) and are, to some extent, covered in the earlier chapters of this book. A review of the properties of LB films could be arranged in a number of ways: subdivisions according to the type of material or to the nature of the experimental technique are probably the most straightforward approaches. In this chapter the latter plan is adopted. It is hoped that this will not only aid the researcher wishing to investigate monolayer and multilayer systems, but also keep the work relevant as more novel LB materials are synthesized. Examples used have generally been chosen from published data on the simpler types of LB assemblies (e.g., longchain fatty acids).

Determination of Multiphase Boundaries and Swelling Factors of Solvent(s)–CO2–Heavy Oil Systems at High Pressures and Elevated Temperatures

Abstract: A generalized methodology has been proposed and successfully applied to determine multiphase boundaries as well as swelling factors of solvent(s)–CO2–heavy oil systems at high pressures and elevated temperatures. Experimentally, two- and three-phase boundaries and swelling factors have been respectively measured by conducting PVT tests in the temperature range of 280.45 to 396.15 K. Theoretically, the Peng–Robinson equation of state (PR EOS) combined with the modified alpha function has been applied to describe phase behavior of the solvent(s)–CO2–heavy oil systems. More specifically, an exponential distribution function is used to split a heavy oil sample, whereas the logarithm-type lumping method is employed to group single carbon numbers (SCNs) into multiple carbon numbers (MCNs). The exponents associated with two binary interaction parameter (BIP) correlations are respectively tuned for the alkane solvent-pseudocomponent pair and CO2-pseudocomponent pair to match the measured saturation pressures. It ...