الثبيتي، أروى عوض

This study is aimed at investigating the impact of English language spread and use on the attitudes of Taif University students. It seeks to examine how English language affects the Saudi lifestyle and students’ language attitudes through its growth in Saudi. It also explores the difference in attitudes towards English language based on students’ demographic profiles of language proficiency, field of study and academic level. The study takes into consideration factors that affect the perceptions of Saudi learners towards the spread of English. Data was collected via questionnaire and the target participants were Saudi males and females at Taif University. The random sample of 358 students from all year groups provided personal information about subject, source and proficiency as well as their attitudes towards English as an International language in the Saudi society. The data collected was analysed through descriptive statistics with language aspects analysed using categorization and illustrated by means of SPSS. The findings provided valuable insights on students’ attitudes towards English associated with Western culture. Results presented students’ disagreement with the spread of English use and its culture in their society. However, they strongly agree with learning the language for intrinsic motivations and better future career opportunities. The overall positive attitudes towards the use of English in many life domains was offset by the indication that the subjects’ attitudes were not affected by the study’s variables but rather their fear of the extensive use of the language as a threat to their religious and national values. Results presented no statistically significant attitudinal difference concerning respondents’ field of study or degree of English proficiency. Variances in student attitude were more evidenced concerning their academic level more than any other demographic profile diversity. The study’s outcomes presented respondents’ favourable attitudes towards English not as a compulsory educational requirement, rather for the globally acknowledged position of English in the world today indicating their positive motivation. However, such perception implies their fear of the effect of the Western history the language might hold. Participants’ results towards the culture of English-speaking countries showed a variety of positive and negative attitudes. They were in favour of methods towards English acquisition intrinsically without risking their traditional and religious heritages.

العدواني ، مديحة عبود عبدالله

Dynamical systems in the real domain are currently One of the most popular areas of scientific study. There is a wide variety of the physical problems which , from mathematical point of views , can be studied more conveniently by using complex variables, in this thesis , we introduce and analyze a novel chaotic complex nonlinear system. The dynamics of this system is rich in the sense that our system exhibit chaotic attractors as well periodic , quasi periodic solutions and solutions that approach fixed points , the stability analysis of the trivial fixed point is stated. Numerically the range of parameters values of this system at which chaotic attractors exist is calculated . Lyapunov exponents are computed to classify the dynamics of this system . Symmetry invariance and dissipation are discussed. The principal target of this work is to introduce and examine a novel kind of complex synchronization . this sort may be called complex anti synchronization (CAS ) there are surprising properties of CAS that do not exist in the writing for example (i) this sort synchronizations can dissect just for complex nonlinear systems . (ii) the CAS contains two sorts of synchronizations (anti synchronization AS and synchronization CS) . (iii) In CAS the attractors of the master and slave systems are moving orthogonal to each other with a similar form (iv ) the state variable of the master system synchronizes with a different state variable of the slave system . An explanation of CAS is presented for two identical chaotic complex nonlinear models. In view of Lyapunov function, a plan is intended to accomplish CAS of disordered or chaotic attractors of these systems. Chapter one : in this chapter we show the preliminaries of nonlinear dynamical systems . we give a review of some basic concepts and definitions of nonlinear dynamical systems such as fixed points , Lyapunov , functions , attractors, Lyapunov exponents , chaotic systems , control and synchronization . Chapter two : this chapter introduces and analyzes a new chaotic complex . nonlinear system . this system is six dimensional systems of real first order autonomous differential equations . the dynamics of this system are very complicated. The Lyapunov dimension of the chaotic attractors of these systems is calculated . Bifurcation analysis is used to demonstrate chaotic behaviors of our new system . we convert the chaotic behavior of our system to its unstable trivial fixed point via the Lyapunov stability theorem . An approach proposed to analyze the system chaos synchronization . Analytical expressions are derived for control functions . the chaos synchronization results were employed to develop simple application in secure communication . Chapter three : the aim of this chapter is to present and investigate a novel type of complex synchronization. We may call this type " complex anti synchronization (CAS). A definition of CAS is introduced for two identical chaotic complex nonlinear models . Based on Lyapunoy function a scheme is designed to achieve CAS of chaotic attractors of these systems . the effectiveness of the obtained results is illustrated by a simulation example . Chapter four : in this chapter , we conclude our main results and suggest some future works I , Madeha A. Al – Adwani , declare that this thesis , submitted in partial fulfillment of the requirements for the award of Master degree , in the department of Mathematics and Statistics , Taif University , is Wholly my own work unless otherwise referenced or acknowledged . the document has not been submitted for qualifications at any other academic institution .

الزهراني، مصلحة واقت صالح

In this thesis, Bayesian optimal design for mixture experiments is discussed in term of finding the best designs to get precise estimates of model parameters. We found Bayesian D-optimal designs for mixture experiments using the second-degree Scheffé polynomial models. To find optimal designs, we used Point-Exchange algorithm for discrete designs and Multiplicative Algorithm and first order algorithm for continuous designs. In each algorithm, Simplex-Lattice design points are used to find Bayesian optimal designs. The difference between D-optimal design in both classical and Bayesian design for mixture experiments is showed by an example. We found that D-optimal classical design distributes the trails equality on the design points, while Bayesian D-optimal design gives the point of factor corresponding to the parameter with the largest value of prior variance the most number of trails.

الزير ، داليا هشام

Richard Wright’s relationship with language, as manifested in his autobiography Black Boy, is best described as elusive. Since he was a young kid, he used language over which he had no control—a fact which led to his being either punished, rejected, pitied, or scorned. As he grows up and his hardships multiply, he becomes speechless, especially when he is nervous, afraid, angry, or frustrated. Thus, his frustration with his own speechlessness turns into a lifelong quest to master language by becoming a writer. Exploring how language has a powerful impact on Richard Wright’s identity, this thesis seeks to: 1) find out how Richard Wright was betrayed by words; and 2) explore his elusive relationship with language. The first stage is in his childhood, when language, over which he had no control, was something of a mystery to him. However, he realizes the power of language without understanding his words. This realization leads him to isolation. To understand language, Richard, in the second stage, starts reading and observing his surroundings. The third stage is when he moves to the North and starts a new relationship with language that differs from that in the South. Drawing upon race theory, African-American literary studies, and psychoanalytic critical studies, this thesis aims to track, in Richard Wright’s Black Boy, the writer’s struggle to control words in order to gain power over the most elusive means of communication with the outside world: language. With an exceptional autobiography like Black Boy, many scholars and researchers discuss and analyse Wright’s work from different perspectives on the use of language. The importance of the issues which will be considered in this thesis stems from the developing interest in examining and analysing one seminal sample of African American literature, in an attempt to understand the circumstances that shaped African-American literary discourse

الحارثي، هيف سلطان

This project is to study nonlinear dynamics of a 1550 nm Vertical Cavity Surface Emitting Lasers (VCSELs).The aim of this thesis is to explore and explain various nonlinear dynamical effects in solitary and optically injected VCSELs using simple experimental approaches and compare the obtained results with theory.The phenomenon of polarization switching and locking with respect to current are investigated. Also the crucial parameters of a solitary VCSEL as a function of temperature are presented; we studied the parameters of solitary VCSELs at different temperature (15, 25, and 30) oC for many devisce. The nonlinear dynamics of optically injected VCSELs are investigated with respect to bias current of 3 mA and temperature 20 oC . The stability maps showing the presence of nonlinear dynamics. Effect of linewidth enhancement factor (LEF) on nonlinear dynamics of the injected laser for VCSELs and edge emitting is simulated and determined theoretically.

دوارى، عفاف أحمد عبدالله

Fluoride is considered as one of the important elements that the human is exposed to it continuously where it is found in a lot of human daily needs and the most important is drinking water and thus human will be exposed to a lot of dangerous side effects. The previous studies have confirmed that fluoride causes health side effects to human when present in large percents in drinking water due to oxidative damage to cellular components by free radicals and other reactive oxygen species also is believed to be associated with oxidative stress. The present study was an attempt to elucidate the toxic effect of sodium fluoride alone and it’s combinations with either selenium or Curcumin extract. The present study aimed to elucidate the possible ameliorative effect of selenium and curcumin in alleviating the toxicity of both sodium fluorides when given to normal mice. This was done through studying the effects of sodium fluoride on some liver and kidney function parameters, lipogram, some male sex hormones as well as, reproductive performance and testosterone level, antioxidant enzyme activities, immunological parameters (IgG, IgM and TNF-α), as well as histopathological changes in vital organs (liver and testis). The use of supportive natural compounds like curcumin extract and vital element like selenium and their combinations with sodium fluoride was also evaluated in male mice in order to get the best and safer treatment for hazardous side effects of sodium fluoride

الغامدي ، لجين ساعد يعن الله

In this work, several phenol degrading fungi were isolated. Three fungal isolates were selected on the basis of the highest growth rate using spectrophotometer. Also, after exposure fungal isolates to UV and ethidium bromide, the fungal isolates appeared highly degradation rate for the phenol, these isolates were identified on microbiological basis and molecular basis using sequencing, and they were found (Aspergillus niger, Penicillium griseofulvum and Aspergillus terreus) growth optimizations for these three isolates were carried out. Also, phenol degradation increased with increase the size of fungal disk of the tested cultures, phenol degradation increased as the incubation period increase, and the degradation rate of phenol decreased as the concentration of phenol increase. Immobilization technique by encapsulation of fungal strains into calcium alginate beads was performed for enhancement of degradation rate of phenol

الغامدي ، لجين ساعد يعن الله

In this work, several phenol degrading fungi were isolated. Three fungal isolates were selected on the basis of the highest growth rate using spectrophotometer. Also, after exposure fungal isolates to UV and ethidium bromide, the fungal isolates appeared highly degradation rate for the phenol, these isolates were identified on microbiological basis and molecular basis using sequencing, and they were found (Aspergillus niger, Penicillium griseofulvum and Aspergillus terreus) growth optimizations for these three isolates were carried out. Also, phenol degradation increased with increase the size of fungal disk of the tested cultures, phenol degradation increased as the incubation period increase, and the degradation rate of phenol decreased as the concentration of phenol increase. Immobilization technique by encapsulation of fungal strains into calcium alginate beads was performed for enhancement of degradation rate of phenol

المالكي، ريم حسين

Biological synthesis of gold, silver and its alloy nanoparticles using plants extracts have received profound interest because it is a simple, costeffective, stable for long time and their potential to synthesize nanoparticles of various size, shape and morphology. In the current study, biosynthesis of AuNPs, AgNPs and Au/Ag alloy NPs by Zingiber officinale (Ginger) and Citrus sinensis (Orange peels) extract was carried out. The nanoparticles obtained are characterized by UV–vis spectrum that showed the surface plasmon resonance (SPR) peak at 564, 554, 552, 541, 457 and 540.5, 535, 539, 493.5, 411 nm respectively. Transmission electron microscopy (TEM) analysis revealed that they are generally found to be spherical in shape with size range of ∼ 20 to 50, 10 to 45, 2 to 14, 1 to 40, 5 to 50 nm and 15 to 50, 10 to 80, 5 to 20, 2 to 10, 5 to 45 nm respectively. Fourier Transform Infrared [FTIR] Spectroscopy confirmed the presence of proteins as the stabilizing agent surrounding the AuNPs, Au/Ag alloy NPs & AgNPs. Furthermore, study the optimizing conditions employed during the synthesis which included pH, temperature and extract concentrations. In the present study, the antibacterial efficacy of the biogenic AuNPs, Au/Ag alloy NPs & AgNPs against Gram negative bacteria, Escherichia coli, Proteus mirabilis, Enterobacter sp. and Pseudomonas aeruginosa and the Gram positive bacteria, Bacillus cereus, Staphylococcus aureus, MRSA and MRSA 442, and study the low concentrations of Au0.75- Ag 0.25 alloy NPs have great antibacterial better than low concentrations of Ag NPs alone. However, this study chooses seven of antibiotics: Norfloxacin, Amoxicillin-Clavulanic acid, Ampicillin, Amikacin, Gentamicin, Vancomycin, Ciprofloxacin to explore their synergistic mechanism when combined with AuNPs, Au/Ag alloy NPs & AgNPs against the multidrug resistant pathogenic bacteria. Tested antibiotics showed synergistic inhibition against growth of the multidrug resistant pathogenic bacteria. In addition, combination of Fluconazole against Candida albicans, Trichoderma sp. and two toxigenic isolate of Aspergillus niger. The effect of NPs on morphology and structure of bacteria and C.albicans by Scanning electron microscopy(SEM) was studies. A damage and randomly distribution in the cell wall of the tested microbes were observed which resulting the death of cells treated by different prepared NPs. AuNPs, AgNPs and its alloy NPs exhibit very good potential as free radical scavengers.

الزهراني ، سهام سعيد

الحارثي، جميل حميدي

This study was aimed to isolate some genes belonging to some hepatitis viruses, i.e., HBV, and/or HCV from some blood samples collected from different regions of KSA representing south, north, east, middle and west KSA. This will be followed by determining the nucleotide sequences of these genes, and carrying out some bioinformatics analysis on such genes, in a trail to detect how much mutations could done in such genes that effect on their functions.

الحارثي، منيرة سعد محمد

This study was performed to isolation and identify the most important genes that up regulate in Rhizoctonia solani during pathogenesis in order to find a new approach to control Rhizoctonia disease on legume plants. Twenty one isolates of Rhizoctonia spp. were isolated of legume plants infected with root-rot and stem canker collected from different plant ages from different locations in Taif governorate. On the basis of morphological features of Rhizoctonia isolates, isolates were divided into six groups. All isolates from the different groups were chosen for pathogenicity test procedure. The five isolate of different pathogenicity and belonging to polynucleate Rhizoctonia were identified as Rhizoctonia solani by using specific primers of ITS regions of rDNA. Anastomosis test was executed between five isolates belong to polynucleate groups. All aforementioned isolates were perfectly fused with each other. This result indicated that the five chosen isolates are belonging to the same anastomosis group. The infection of R.solani was more severe on the cowpea seeds followed by the lupine seeds in the host range examination in vitro . Starvation of R.solani leads to significantly increase of its aggressiveness in vitro test.. Keywords: Rhizoctonia solani ,Legumes, Root rot, , Molecular identifications, Pathogenicity, Host rang , Anastomosis test and Starvation.

الحارثي ، منيره سعد محمد

This study was performed to isolation and identify the most important genes that up regulate in Rhizoctonia solani during pathogenesis in order to find a new approach to control Rhizoctonia disease on legume plants. Twenty one isolates of Rhizoctonia spp. were isolated of legume plants infected with root-rot and stem canker collected from different plant ages from different locations in Taif governorate. On the basis of morphological features of Rhizoctonia isolates, isolates were divided into six groups. All isolates from the different groups were chosen for pathogenicity test procedure. The five isolate of different pathogenicity and belonging to polynucleate Rhizoctonia were identified as Rhizoctonia solani by using specific primers of ITS regions of rDNA. Anastomosis test was executed between five isolates belong to polynucleate groups. All aforementioned isolates were perfectly fused with each other. This result indicated that the five chosen isolates are belonging to the same anastomosis group. The infection of R.solani was more severe on the cowpea seeds followed by the lupine seeds in the host range examination in vitro . Starvation of R.solani leads to significantly increase of its aggressiveness in vitro test.

أبو عاصي، روان سامي صبحي

Biological synthesis of selenium nanoparticles (SeNPs) and cadmium selenide quantum dots (CdSe QDs) using microorganisms has received profound interest because of their potential to synthesize nanoparticles of various size, shape and morphology. In the current study, 206 selenium resistant bacterial isolates were isolated from 18 samples from different environmental sources of Saudi Arabia. Among These isolates, bacterial strain BGRW was selected on the basis of its ability to produce extra/intracellular selenium nanoparticles and extra/intracellular cadmium selenide quantum dots. Molecular and biochemical characterization of this isolate indicated that BGRW strain is belonged to the genus Providencia and identified as Providencia vermicola BGRW. Our strain has discriminatory ability to resist many metals such as Selenium, Cadmium, Silver, Zinc, Copper, Lead, Nickel, Cobalt and Bismuth metals. When 8mM of SeO2 was added to tryptic soy broth inoculated with Providencia vermicola BGRW, it was found to have the ability to form stable extra/intracellular selenium nanoparticles at 37°C, pH 7 within 24 h, these conditions were the optimized conditions for selenium nanoparticles production. The best conditions for extra/intracellular cadmium selenide quantum dots were 0.1mM SeO2: 0.9mM CdCl2, 37°C, pH 9 within 24 h. The biosynthesis of SeNPs and CdSe QDs was monitored by UV–Visible spectrum that showed surface plasmon resonance (SPR) peaks at 295 nm and 388 nm respectively, as an important characteristic of nanoparticles. Depending on fluorescence property of quantum dots, photoluminescence characteristics of the biogenic CdSe QDs were at 385 nm. Providencia vermicola BGRW was found to be highly resistant to selenium dioxide up to 20 mM and was able to grow in the presence of 6 mM of CdCl2. Further characterization of synthesized SeNPs and CdSe QDs were carried out using the X-ray Diffraction (XRD), Transmission Electron Microscope (TEM) and Fourier Transform Infrared (FTIR) spectroscopy. TEM and XRD analysis revealed that the SeNPs synthesized by Providencia vermicola BGRW was hexagonal in shape with a size range of ∼3 to 50 nm with average 28nm, while CdSe QDs was cubic in shape with a size range of ∼2 to 4 nm. The XRD analysis confirmed the successful biosynthesis and the crystalline nature of SeNPs and EDS analysis confirmed the composition of QDs from cadmium and selenium ions. FTIR spectroscopy confirmed the presence of proteins as the stabilizing agent surrounding the nanoparticles. In the present study six antibiotics were investigated to explore their synergistic effect when combined with SeNPs and CdSe QDs against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, MRSA, Streptococcus agalactiae and Bacillus cereus, these antibiotics were norfloxacin, gentamicin, ampicillin, sulfamethoxazole, penicillin G and penicillin V. All tested antibiotics showed synergistic inhibition against growth of the pathogenic bacteria. The biocide action of SeNPs and CdSe QDs on pathogens such as Gram-positive strains (B. cereus and S. aureus) and Gram-negative (E. coli) was studied using Scanning Electron Microscopy (SEM). The results showed damage, blebs, clumps and randomly distribution in the cell wall of the tested microbes resulting the death of cells. The MIC 90 of SeNPs was 10μg/mL, 15μg/mL and 20μg/mL for S. aureus, B. cereus and E. coli respectively, while the MIC 90 of CdSe QDs was at 10μg/mL, 5μg/mL and 25μg/mL for S. aureus, B. cereus and E. coli respectively. The antimicrobial effect of SeNPs and CdSe QDs under different pH was also studied, whereas the optimum pH of SeNPs was 7 while the optimum pH of CdSe QDs was 9. The antimicrobial effects of SeNPs and CdSe QDs without capping agent were also studied, whereas the uncapped SeNPs lost their antimicrobial effect completely, while the uncapped CdSe QDs had antimicrobial effect less than capped CdSe QDs. The effect of SeNPs and CdSe QDs on the prevention and removing of biofilm against Salmonella enteritidis, B. cereus, S. aureus, E. coli, Proteus sp. and Pseudomonas aeruginosa were also studied, whereas the antibiofilm concentration of SeNPs was 12μg/mL against Sal. enteritidis and B. cereus, 16μg/mL against S. aureus and E. coli while the antibiofilm concentration was 18μg/mL against Proteus sp. and P. aeruginosa. The antibiofilm concentration of CdSe QDs was 8μg/mL against S. aureus, 16μg/mL against B. cereus, Sal. enteritidis and E. coli whiles the antibiofilm concentration was 18μg/mL against Proteus sp. and P. aeruginosa. Although the biogenic SeNPs and CdSe QDs had antimicrobial and antibiofilm effects, they did not show significant ability to remove the established biofilm up to 32μg/mL. The concentration of 24μg/mL showed a slight effect on removing the established biofilm. The antibiofilm effect of the combination of SeNPs and CdSe QDs with amoxicillin were investigated against six bacterial biofilms and result show a synergistic effect at a lower than the antibiotic, SeNPs or CdSe QDs minimum antibiofilm concentrations.

العتيبي، حصة متعب ناصر

In our study, the FTIR spectroscopy has been used to study the molecular structures of these new materials. In addition, different physical tools such as electron microscopy, XRD, SEM and thermal analysis have been conducted to investigate the other structural and physical properties of these new materials.