Recent advances in wireless communication systems have made use of OFDM technique to achieve high data rate transmission. The sensitivity to frequency offset between the carrier frequencies of the transmitter and the receiver is one of the major problems in OFDM systems. This frequency offset introduces inter-carrier interference in the OFDM symbol and then the BER performance reduced. In this paper a Multi-Orthogonal-Band MOB-OFDM system based on the Discrete Hartley Transform (DHT) is proposed to improve the BER performance. The OFDM spectrum is divided into equal sub-bands and the data is divided between these bands to form a local OFDM symbol in each sub-band using DHT. The global OFDM symbol is formed from all sub-bands together using
... Show MoreAs a result of the increase in wireless applications, this led to a spectrum problem, which was often a significant restriction. However, a wide bandwidth (more than two-thirds of the available) remains wasted due to inappropriate usage. As a consequence, the quality of the service of the system was impacted. This problem was resolved by using cognitive radio that provides opportunistic sharing or utilization of the spectrum. This paper analyzes the performance of the cognitive radio spectrum sensing algorithm for the energy detector, which implemented by using a MATLAB Mfile version (2018b). The signal to noise ratio SNR vs. Pd probability of detection for OFDM and SNR vs. BER with CP cyclic prefix with energy dete
... Show MoreBackground: Bilastine (BLA) is a second-generation H1 antihistamine used to treat allergic rhinoconjunctivitis. Because of its limited solubility, it falls under class II of the Biopharmaceutics Classification System (BSC). The solid dispersion (SD) approach significantly improves the solubility and dissolution rate of insoluble medicines. Objective: To improve BLA solubility and dissolution rate by formulating a solid dispersion in the form of effervescent granules. Methods: To create BLA SDs, polyvinylpyrrolidone (PVP K30) and poloxamer 188 (PLX188) were mixed in various ratios (1:5, 1:10, and 1:15) using the kneading technique. All formulations were evaluated based on percent yield, drug content, and saturation solubility. The fo
... Show MoreAn improved Metal Solar Wall (MSW) with integrated thermal energy storage is presented in this research. The proposed MSW makes use of two, combined, enhanced heat transfer methods. One of the methods is characterized by filling the tested ducts with a commercially available copper Wired Inserts (WI), while the other one uses dimpled or sinusoidal shaped duct walls instead of plane walls. Ducts having square or semi-circular cross sectional areas are tested in this work.
A developed numerical model for simulating the transported thermal energy in MSW is solved by finite difference method. The model is described by system of three governing energy equations. An experimental test rig has been built and six new duct configurations have b
The complexes of para-chloranil as electron acceptor and the anions of amide, azide and cyanide as electron donors in aqueous ethanol as a solvent, were studied spectrophotometrically . The reactions lead to the formation of charge transfer complexes. The CT complexes were stable in excess acceptor concentration, while they were underwent another transformations in excess donors concentrations. Stoichiometries were determined, the molecular ratio was determined by continuous variation method (Job method) and is was 1:1 (donor: acceptor). The maximum wavelength (λ max.), the energy (hυCT), ionization potential (Ip) and activation energy (w ) of excited state f
... Show MoreAzo derivative ligand[H3L] have been synthesized by the reaction of diazonium salt of p-amino benzoic acid with orcinol in(1:1)mole ratio. The bidente ligand was reacted with the metal ions MnII,FeIIandCrIIIin(2:1)mole ratio via reflux in ethanol using Et3N as a base to give complexes of the general formula: [ M(H2L)2(H2O)x]Cly The synthesized compounds were characterized by spectroscopic methods[ I.R , UV-Vis, A.A and H1 NMR]along with melting point, chloride content and conductivity measurements. The complexes were screend for their in vitro antibacterial activity against one strain of staphylococcus as Gram(+) positive and one strain of pseudomonas as Gram(-) Negative, using the agar diffusion technique.
The purpose of this study is to determine the useful of Schiff bases derivatives containing (oxazepine, tetrazole) rings with biological activity which can be used as drug and antimicrobial, the present work is started from [Binary (2,5(4,'4-diaminophenyl) – 1,3,4 – oxadiazole]. A variety of Schiff bases and heterocyclic (oxazepine, tetrazole) have been synthesis, and confirm that structures by physical properties , FTIR , 1H-NMR, 13C-NMR, elemental analysis, [Microbial study against three type of bacteria (staphylococcus aurea and klebsiella pneumonia) and (Canadida albncans) fungi].All analyzation performed in center of consulatation University of Jordan.
Charge-transfer (CT) complexes of adenine (Ade.), guanine (Gua.), xanthine (Xan.), and inosine (Ino.) as electron donors with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,3,5,6-tetrabromo-1,4-benzoquinone (Bromanil)(BA) as π – electron acceptors and iodine (Iod.) as σ – electron acceptor were studied and their electronic spectra recorded .In each case one (CT) band was observed and recorded. These spectroscopic investigations made in ethanol solvent at (20°C) temperature. The values of equilibrium constant (KCT), change in standard free energy (ΔG°), molar extinction coefficient (εCT(, absorption band energy (hνCT) of CT complexes and the association energy of the CT complexes-excited state (W) were calculated and studie
... Show MoreIn this study a new ligand ,(potassium 2-carbomethoxy amino-5-trithiocarbonate 1,3,4-thiadiazole) (L) has been prepared from 2-carbomethoxy amino-5-mercapto 1,3,4-thiadiazole with CS2 in alkali media . The product has been isolated and characterized by appropriate physical measurements, vibrational and electronic spectroscopy. The ligand was used to prepare a number of complexes with some metal ions Co(II), Ni(II) and Cu(II). These complexes have been characterized by FT-IR, UV-Vis spectra, molar conductivity, magnetic susceptibility, melting points and atomic absorption measurements. The nickel and copper complexes have an octahedral geometry while cobalt complex has a tetrahedral geometry. The nature of bonding between the metal ion
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