Nanocrystalline TiO 2 and CuO doped TiO 2 thin films were successfully deposited on suitably cleaned glass substrate at constant room temperature and different concentrations of CuO (0.05,0.1,0.15,0.2) wt% using pulse laser deposition(PLD) technique at a constant deposition parameter such as : (pulse Nd:YAG laser with λ=1064 nm, constant energy 800 mJ, with repetition rate 6 Hz and No. of pulse (500). The films were annealed at different annealing temperatures 423K and 523 K. The effect of annealing on the morphological and electrical properties was studied. Surface morphology of the thin films has been studied by using atomic force microscopes which showed that the films have good crystalline and homogeneous surface. The Root Mean Square value of thin films surface roughness is increased with the increase of annealing temperature. Also, the grain size increases with the increasing of CuO concentration and annealing. The temperatures dependence of the electrical conductivity and the activation energy at temperature ranging from (293-473) K of the as-deposited and films annealed at different annealing temperatures have been studied. The results show that as the film concentration of and conductivity increases, while the activation energy (Ea 1 , E a2 ) decreases. Both, the annealing and composition effects on Hall constant, charge carrier concentration, Hall mobility were investigated. Hall Effect measurements show that all films have n- type charge carriers, and the concentration and annealing increase carriers concentration while the mobility decreases.
Several azo dyes were synthesized through coupling reaetion of some substituted phenols and B.naphthol with diazonium salt of 2- amino-1,3-4- thiadiazol -5- thiol. All the synthesized compounds during this work were characterized using some speetral data (F.TIRand UV)andM.P . 2-[4 --Hydroxy napthyl-azo ] -1,3,4-Thiadiazol -5-Thiol • 2- [2-- hydroxy –4- NO2 – phenyl- azo]- 1,3,4 - Thiadiazol –5-Thiol. • 2- [3--Amino-4-Hydroxy phenyl –azo]-1,3,4 - Thiadiazol –5-Thiol. . • 2-[2--Amino-4-Hydroxy phenyl -azo]-1,3,4 - Thiadiazol –5-Thiol . • 2- [3--Amino-6- Hydroxy phenyl -azo]-1,3,4 - Thiadiazol –5-Thiol. • 2-[2-- Hydroxy- 5 – chloro – Pheny - azo]- 1,3,4 - Thiadiazol –5-Thiol . • 2- [4-- Hydroxy phenyl -azo] -1,
... Show MoreThe interplay of species in a polluted environment is one of the most critical aspects of the ecosystem. This paper explores the dynamics of the two-species Lokta–Volterra competition model. According to the type I functional response, one species is affected by environmental pollution. Whilst the other degrades the toxin according to the type II functional response. All equilibrium points of the system are located, with their local and global stability being assessed. A numerical simulation examination is carried out to confirm the theoretical results. These results illustrate that competition and pollution can significantly change the coexistence and extinction of each species.
The Sliding Mode Control (SMC) has been among powerful control techniques increasingly. Much attention is paid to both theoretical and practical aspects of disciplines due to their distinctive characteristics such as insensitivity to bounded matched uncertainties, reduction of the order of sliding equations of motion, decoupling mechanical systems design. In the current study, two-link robot performance in the Classical SMC is enhanced via Adaptive Sliding Mode Controller (ASMC) despite uncertainty, external disturbance, and coulomb friction. The key idea is abstracted as follows: switching gains are depressed to the low allowable values, resulting in decreased chattering motion and control's efforts of the two-link robo
... Show MoreCatalytic wet air oxidation of aqueous phenol solution was studied in a pilot plant trickle bed reactor using copperoxide catalyst supported on alumina and silica. Catalysts were prepared by impregnating method. Effect of feed solutionpH (5.9, 7.3, and 9.2), gas flow rate (20%, 50%, 80%, and 100%), WHSV (1, 2, and 3 h-1), temperature (120°C, 140°C,and 160°C), oxygen partial pressure (6, 9, 12 bar), and initial phenol concentration (1, 2, and 4 g/l).Generally, theperformance of the catalysts was better when the pH of feed solution was increased. The catalysts deactivation is relatedto the dissolution of the metal oxides from the catalyst surface due to the acidic conditions. Phenol oxidation reactionwas strongly affected by WHSV,
... Show MoreFemtosecond laser pulse propagation in monomode optical fibers is demonstrated and investigated numerically (by simulations) and experimentally in this paper. A passively mode locked Nd:glass laser giving a pulse duration of about 200 fsec at 1053 nm wavelength and 120 mW average optical power with 100 MHz repetition rate is used in the experimental work. Numerical simulations are done by solving the nonlinear Schrödinger equation with the aid of Matlab program. The results show that self phase modulation (SPM) leads to compression of the spectral width from 5 nm to 2.1 nm after propagation of different optical powers (34, 43, 86 and 120 mW) in fibers of different length (5, 15, 35 m). The varying optical powers produced a varying
... Show MoreThis work included synthesis of several new polymers of polyacryloyl chloride in two steps . The first step the included the reaction of N-( sub. or un sub. benzoyl and sub. or un sub. acetyl ) amidyl sub. 2,6- diamino -4-methyl-1,3,5-triazine (1-5) by condensation of many substituted acid chlorides with 2,6- diamino -4-methyl-1,3,5-triazine . While the second step included the reaction of polyacryloyl chloride with the produced compounds (1-5) in step (1) in the presence amount triethyl amine (Et3N) to obtain new polyimides (6-10). The prepared compounds were characterized by UV. , FT-IR, and some of them by 1H-NMR and 13C- NMR spectroscopy.
Arrested precipitation methode used to synthesize CuInSe2 (CIS) nanocrystals were added to a hot solvent with organic capping ligands to control nanocrystal formation and growth. CIS thin films deposited onto Soda-Lima Glass (SLG) substrate by spray-coat, then selenized in Ar-atmosphere to form CIS thin films. PVs were made with power conversion efficiencies of 0.631% as-deposited and 0.846% after selenization, for Mo coated, under AM 1.5 illuminations. (XRD) and (EDX) it is evident that CIS have chalcopyrite structure as the major phase with a preferred orientation along (112) direction and Cu:In:Se nanocrystals is nearly 1:1:2 atomic ratio.