الزهراني ، جميلة محمد عيدان

The effect of reduced Graphene Oxide (Graphene) (RGO) on the Photovoitaic performance of TiO2-based dye-sensitized solar cells (DSSCs) has been investigated. The different amounts of RGO (in mg) was mixed to one gram (1 g) of TiO2solution. The RGO content was varied in the range from 0 mg (pure TiO2) to 12 mg to form TiO2/RGO composite pastes before deposition as films on FTO (F-doped tin oxide)-coated glass substrates. The morphological, structural, optical and photovoltaic properties of the TiO2/ RGO films and corresponding DSSCs were studied as functions of the RGO content. Two regions were identified: The region of RGOcontents below 5 mg: The SEM images show morphology with flat and homogeneous surface and the TiO2 particles bridged and more or less covered by the RGO. The XRD spectra show no trace of the RGO due to its small content. The optical band-gap Eg of the TiO2/RGO film in this region decreases linearly with increasing RGO and the efficiency of the corresponding DSSC increases linearly. In fact, the decrease of Eg is accompanied with the lowering of the minimum level of the conduvtive band of the TiO2/RGO semiconductor and this must enhance the rate of injection of the photo-excited electrons from the dye. As a result, the photocurrent and the efficiency ƞ is increase. An improvement of ƞ by about 70% (from 2.3% to 4%) was observed at the optimal RGO content 5 mg . The region of RGO contents above 5 mg to 12 mg: The SEM images show morphology dominated in structure by the RGO which appears to form an envelope for the TiO2 particles with a very structured and random surface containing large cavities. The XRD spectra show a clear peak at 44°for the RGr associated with the (100) planes. The optical band-gap Eg of the TiO2/ RGO film in this region varies randomly with increasing RG O content and the efficiency ƞ of the corresponding DSSC falls back to the value of the pure TiO2 or less.

الزهراني، مرام جمعان رده

The objective of this study objective is to promote and prepare biogreases from waste cooking oil and banana peel which are representing the biomass wastes. The utilization of such wastes as raw materials for biogrease lead to significant cost saving. On the other hand, the identification and utilization of renewable source, such as waste cooking oil and banana peel, as green alternatives in lubricating grease is the key to promote the biode-gradable lubricants as the ultimate goal of this study. In this respect, WCO and Bp were analyzed and identified using different analytical tech-niques such as gas chromatography, infrared spectroscopy (IR), thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques, X-Ray Fluorescence, scanning electron microscope (SEM) and rheology behavior aiming to understand of chemical com-positions and their applicability to use as a raw material for biogrease. Biogrease was prepared based on WCO and BP as fluid part and filling agent respectively. The physicochemical properties of the prepared biogrease were determined using standard methods of analysis. These include penetration, dropping point, apparent viscosity, oxida-tion stability, total acid number and oil separation. Abstract iii It was evaluate and classified according to National Lubricating Grease Institute (NLGI). The results show about 85% to 67.5% of purified waste cooking oil and 10% to 30% of the treated banana peel are required to prepare biogrease with consistency NLGI 2. Also,the dropping point and oxidation stability tests of prepared biogrease are increasing with in-crease the treated banana peel. In oil separation test, the prepared biogreases show oil sep-aration ranged from 1.5% to 0.3 which indicates acceptable limits of NLGI requirements. Corrosion test for all prepared biogreases shows the results of 1a indicating the good per-formance of the raw materials; this confirmed with results of total acid number.In conclu-sion, results reveal that the waste cooking oil and banana peel used successfully in prepar-ing biogrease cost-effective, easily biodegradable and less hazardous. On other hand, they proved to be a good fluid, thickening and filing agents for the production of suitable envi-ronmental friendly grease according to National Lubricating Grease Institute (NLGI). Keywords: Lubrication, vegetable oil, waste cooking oil, agriculture waste, banana peels, biogreases.

الزهراني ، مرام جمعان

The objective of this study objective is to promote and prepare biogreases from waste cooking oil and banana peel which are representing the biomass wastes. The utilization of such wastes as raw materials for biogrease lead to significant cost saving. On the other hand, the identification and utilization of renewable source, such as waste cooking oil and banana peel, as green alternatives in lubricating grease is the key to promote the biode- gradable lubricants as the ultimate goal of this study. In this respect, WCO and Bp were analyzed and identified using different analytical tech- niques such as gas chromatography, infrared spectroscopy (IR), thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques, X-Ray Fluorescence, scanning electron microscope (SEM) and rheology behavior aiming to understand of chemical com- positions and their applicability to use as a raw material for biogrease. Biogrease was prepared based on WCO and BP as fluid part and filling agent respectively. The physicochemical properties of the prepared biogrease were determined using standard methods of analysis. These include penetration, dropping point, apparent viscosity, oxida- tion stability, total acid number and oil separation. Abstract iii It was evaluate and classified according to National Lubricating Grease Institute (NLGI). The results show about 85% to 67.5% of purified waste cooking oil and 10% to 30% of the treated banana peel are required to prepare biogrease with consistency NLGI 2. Also,the dropping point and oxidation stability tests of prepared biogrease are increasing with in- crease the treated banana peel. In oil separation test, the prepared biogreases show oil sep- aration ranged from 1.5% to 0.3 which indicates acceptable limits of NLGI requirements. Corrosion test for all prepared biogreases shows the results of 1a indicating the good per- formance of the raw materials; this confirmed with results of total acid number.In conclu- sion, results reveal that the waste cooking oil and banana peel used successfully in prepar- ing biogrease cost-effective, easily biodegradable and less hazardous. On other hand, they proved to be a good fluid, thickening and filing agents for the production of suitable envi- ronmental friendly grease according to National Lubricating Grease Institute (NLGI)

الشهري، أحلام عبدالله علي

Vibration, occurring in most machines, vehicles, structures, building and dynamic systems is undesirable, the reduction in performance which accompany vibrations and the dynamic stresses which may lead to fatigue and failure of the structure or machine. Vibration analysis of machines and structures is often a necessary prerequisite for controlling vibration. The vibrations of any dynamical system are needed to be controlled to minimize or eliminate the risk of damage or destruction. So many passive and active control techniques are used to eliminate or suppress the vibrations to minimum level. One of the important subjects expressed here is the dynamical systems, which are governed by different types of non-linear differential equations. The main object of this thesis is a mathematical and numerical study for the vibration behaviors in two different systems which are described by non-linear differential equations. The first system describe the active vibration control of a nonlinear two-degree-of-freedom system due to electromechanical system under external and parametric excitation. The second system study the nonlinear integral positive position feedback control of a cantilever beam system carrying an intermediate lumped mass by a three -degree-of-freedom with external excitation force. For each system, the investigation includes the analytical solutions applying the multiple scales perturbation technique (MSPT), determination of the resonance cases, which are classified into different categories. Some of resonance cases are confirmed numerically. The stability of each vibrating system and its steady state solutions are investigated by using both the frequency response equation and phase-plane technique. The numerical solutions are focused on both the effects of the different parameters and the behavior of the system at the selected resonance cases. Comparison between analytical and numerical solutions is obtained. Also all the numerical results are obtained using MAPLE and MATLAB algorisms. Some recommendations are given regarding the design of such system.

العتيبي ، ريم سطام منير

This work has been studied fabrication of film composite membrane using macro-hydrogel method in presence of nanoparticles that was titanium dioxide (TiO2). The preparation of the film composite membranes was optimized by investigating different parameters such as the amount of the added chitosan, the amount of the added nanoparticles 0.03 g,0.05 g and 0.07g of (TiO2) the type of nanoparticles, and the thickness of the film membranes. The fabricated materials were characterized using different techniques such as scanning electron microscopy (SEM), ultraviolet spectroscopy (UV), energy dispersive X-ray spectroscopy (EDX) and swelling ratio. The prepared film composite membranes were used for degradation of harmful dyes (single dye and binary dyes). Different parameters such as pH (3,6,12) and amounts of oxidizing agent (250, 150, 25, 20 mg) of Potassium persulfate (K2S2O8) was optimized. In addition, the optimised conditions and film (chitosan (CS) + TiO2 (high concentration) membrane) were utilised for photodigradation of binary dyes methyl orange (MO), methyl blue (MB) from ground water and sewage water.

الطويرقي، عبدالله عابد

The main role of mathematics is to construct models for obtaining best solutions of real life problems. Set theories are models for general representations of collections under study. Rough set theory is an extension of conventional set theory that have great importance in applications. Rough set theory was proposed in 1982 by Z. Pawlak [19], is in a state of constant development. Its methodology is concerned with the classification and analysis of impreciseuncertain or incomplete information and knowledge is considered one of the first which did not depend on statistics in data analysis. This thesis consists of three chapters: Chapter One,is devoted to give an account on basic rough set concepts with examples. Section 1.1 Is given an introduction these concepts, the purpose of section 1.2 is to give an account on basic concepts of rough sets, section 1.3 is devoted to give for attribute redaction. Chapter Two, is to purpose of this chapter two is to explore some connections between Boolean algebra and rough set in general and with special interest to knowledge reduction of information systems , Section2.1is devoted to give a basic concept of Boolean algebra, the main goal ofSection 2.2 is to explain adetail the concept of attribute reduction and decision rule extraction by the aim using Boolean algebra . Chapter Three, The aim of chapter three is to study rough equality in Boolean algebra by using lower and upper approximation. Also, we construct the equality and the inclusion relations on the power set byusing topology and rough approximations section 3.1is contained on basic notions and examples of topological Boolean algebra. In section 3.2 some properties of rough equality in topological Boolean algebra is introduced.Section 3.3 is devoted to give rough ordering on power sets. Finally, section 3.4 is reserved for topological equality and inclusion relations.

الطويرقي، عبدالله عابد

The main role of mathematics is to construct models for obtaining best solutions of real life problems. Set theories are models for general representations of collections under study. Rough set theory is an extension of conventional set theory that have great importance in applications. Rough set theory was proposed in 1982 by Z. Pawlak [19], is in a state of constant development. Its methodology is concerned with the classification and analysis of impreciseuncertain or incomplete information and knowledge is considered one of the first which did not depend on statistics in data analysis. This thesis consists of three chapters: Chapter One,is devoted to give an account on basic rough set concepts with examples. Section 1.1 Is given an introduction these concepts, the purpose of section 1.2 is to give an account on basic concepts of rough sets, section 1.3 is devoted to give for attribute redaction. Chapter Two, is to purpose of this chapter two is to explore some connections between Boolean algebra and rough set in general and with special interest to knowledge reduction of information systems , Section2.1is devoted to give a basic concept of Boolean algebra, the main goal ofSection 2.2 is to explain adetail the concept of attribute reduction and decision rule extraction by the aim using Boolean algebra . Chapter Three, The aim of chapter three is to study rough equality in Boolean algebra by using lower and upper approximation. Also, we construct the equality and the inclusion relations on the power set byusing topology and rough approximations section 3.1is contained on basic notions and examples of topological Boolean algebra. In section 3.2 some properties of rough equality in topological Boolean algebra is introduced.Section 3.3 is devoted to give rough ordering on power sets. Finally, section 3.4 is reserved for topological equality and inclusion relations.

المالكي ، وجدان مسفر محمد

BACKGROUND: cadmium is among the toxic and hazardous metals widely dispersed in the environment at high levels; it is known to be toxic for the kidney. Tribulus terrestris L. (TT) plants in Saudi Arabia. It has been used as a protective herb for kidney disorders. The present research aims to study the possible ameliorative potential of T. terrestris extract on Cd- induced effects in human embryonic kidney (HEK 293) cell line. METHODS: we have studied the cell viability and IC₅₀ by using SRB. Then, cells were divided into six groups of triplicates treated for 12 h and 24 h as follows: group 1, normal (untreated) control; group 2, cadmium chloride (CdCl₂) treated for 12 h; group 3, T. terrestris extract-treated for 12 h; group 4, (amelioration) CdCl₂ for 12 h proceeded by T. terrestris extract for 12 h ; group 5 (mix), CdCl₂ plus T. terrestris extract-treated for 12 h; group 6, cadmium chloride (CdCl₂) treated for 24 h. We investigated the ameliorative potential at the cellular and molecular levels; apoptosis by using acridine orange/ethidium bromide staining, Annexin V/PI staining, cell kinetics, and induction response of some detox (SOD1, CYP1A1, and UGT) and anti-apoptotic (Bcl-2) genes. RESULTS: Cd decreased HEK 293 viability in a dose-dependent manner with with an IC₅₀ value of 15.06 g/ml Nuclear morphological analysis revealed that Cd-induced cell necrosis. It also positively induced detox genes and reduced Bcl-2. The inoculation of T. terrestris extract after CdCl₂ treatment reduced most of the Cd-induced toxicity. However, mixing or contaminating the extract with Cadmium rendered the ameliorative potential of the extract. CONCLUSION: the ameliorative action of the plant could be due to the presence of antioxidants and tribulin, which is the major ingredient in the plant. Our study recommends the use T. terrestris as a Cd-toxicity recovery herb. However, the current study needs to be confirmed at further research levels such as microarray, and the application on experimental animals (in vivo

الغامدي، رقية سعيد علي

This thesis explores the ways in which some American poets justify the confiscation of Native American lands. Drawing upon postcolonial theory, selected poems are analyzed to uncover the mythical representations of the New World and Native Americans. American Poets raise up the American land as the New Canaan given by God to his Chosen People—the Christians, not the pagan Indians. The land is sometimes depicted as uninhabited to legitimize America’s claim to it. Furthermore, American poets create images of an exotic, fruitful, paradisiacal landscape to encourage European colonization and investment in the New World. In some texts, the land is a virgin female seeking protection and the fulfillment of her desires from the perfect masculinity represented by the American colonizer. American poets also emphasize the superiority of the white civilization which has improved the land and put its resources to higher purposes. The land is a wasteland under the control of the natives, demonstrating their deficiencies. Early American epic poets manipulate religion to stereotype and other the colonized and to devalue their culture. Some poets also manipulate science, applying the Darwinian theory of the inevitable conflict between races and civilizations to naturalize the displacement and extinction of the natives. Some poets promote the myth of Manifest Destiny, emphasizing the whites’ destined expansion and mission to redeem the Old World while portraying Native Americans as savages. Even poets who depart from the stereotypes of savagism and portray the natives as noble and wise still believe in the inevitability of their death. The thesis concludes by showing that the American poets studied adhere to the discourse justifying the national colonial enterprise in the New World.

الخضري، فاطمة تميم عمر

The present study aimed at filling a gap in the field of using cultural linguistic strategies in D-P communication in Saudi Arabia. This thesis has explored how Ob/Gyn physicians use language to communicate sexual topics with patients, and the effect of certain cultural variables on vocabulary, or style choices in such contexts. A comprehensive questionnaire was distributed among the main seven hospitals in Jeddah and some minor clinics. The thesis employs euphemism theory to examine the data which comprise 165 responses to the questionnaire. A descriptive quantitative analysis was conducted, which examined the frequencies and percentages of the use of the linguistic strategies and the effect of the social variables. The findings revealed the existence of social norms that lead to restrictions on language along with difficulties in choosing the best linguistic style for the medical sexual issue which might lead to misunderstandings or bad treatment. The results also showed high applicability of euphemism in the form of, formal Standard Arabic and Pun words. In addition, patients’ level of education was found to be the main factor that can have either a positive or negative influence. Consequently, this asserts the importance of having the right scientific knowledge about sexual health issues. Cultural distinctions between doctors and patients along with misunderstanding of Islamic values of modesty were the main reasons for miscommunication with patients on sexual problems. The study also showed that sexual relation with the husband with all its complexities was mostly linguistically restricted. Finally, there might be a need for true education of Islamic values on sexual health, high knowledge of both Arabic and English linguistic styles, and good communication skills which would lead to successful doctor-patient communications.

الفريم، امل سعد سعيد

The present study is intended to determine the rationale behind English language course's revision units, investigate to what extent do intermediate stage English language course's revision units meet the alternative assessment principles, and propose guidelines to reconstruct the activities in those units in the light of the alternative assessment principles. The study adopted the content analysis technique based on the descriptive methodology. The researcher designed the checklist of alternative assessment principles , in order to ask jury to get their opinion upon the most appropriate principles for intermediate stage English language learners. After modifying the checklist, the researcher designed the content analysis card to collect the needed data. The research sample was the first revision unit from each term in each grade consist of pupil's books, work books, and teacher's books at KSA intermediate stage. The results showed that the average score of the revision units' activities in intermediate English language course books was very weak in meeting the alternative assessment principles. The pupil's books scored 1.11, workbooks scored 1.17 and finally teacher's books scored 1.1 out of 3.00 . The difference of quantity and quality of revision units' activities caused the miss logical connection between the revision units' activities of pupil's books, work books, and teacher's books in dealing with alternative assessment principles. Based on the study findings, guidelines to reconstruct intermediate stage English language course's revision units in the light of the alternative assessment principles were propose.

الثبيتي، فاطمة سفران خلف

The present study aimed at identifying the extent of the inclusion of cultural content in the English textbook "Flying High " in the light of globalization challenges. Thus, this analytical study intended to answer the following question: to what extent does the English textbook "Flying High" include the cultural content in the light of globalization challenges? The researcher conducted the descriptive analytical approach to answer the research question. The material of the study consisted of the English textbook of 1st Secondary Stage "Flying High" , level (1) which is taught in some schools in Saudi Arabia. A content analysis tool was prepared by the researcher for collecting data depending on theoretical framework. The results of the study can be summarized as follows:1)Local cultural content" received the lion's share of total cultural contents in (56.8%) for big "C" culture and (63.5 %) for small "c" culture. 2)Target cultural content received (16,2%) for big "C" culture and (25,4%) for small "c" culture. 3)International cultural content received(27%) for big "C" culture and (11,1%) for small "c" culture. Therefore, the results revealed that there is an extensive use of local cultural references while there is an obvious absence of many other target and international cultural contents. It is also clear that cultural elements are presented in many positions, but in a superficial and narrow way as the frequencies show a high concentration on certain elements and ignoring the others without taking into consideration the cultural issues which form an important base for the development of intercultural communicative competence ICC, cultural identity and cultural awareness that prepare students in the era of globalization. Based on the findings of the study, several suggestions for enhancing the cultural content of English textbooks have been offered.

العصيمي، منيرة ناصر ضيف الله

Pipelines are major part of any oil and petrochemical industry. In this study, the corrosion of oil and gas pipelines made from carbon steel is controlled by Protective coatings. An attempt has been made to develop Nano- Emulsion coatings based on olive oil , paraffin oil and silicon oil (oil phase) as a replacement of organic solvent based coatings system in surface finishing industry for environmental protection, public health and safety. In this research, oil-in-water (O/W) Nano-emulsions were prepared by means of a low-energy method .The O/W Nano-emulsion was prepared using three oils (olive oil , paraffin oil and silicon oil) ,tween 20 and tween 80 as surfactant and liquids phase( green tea extract ,fenugreek extract and Garlic extract) . It was formulated for various concentrations of oils and surfactants. The stable Nano-emulsion ratio was taken for the study. Eco-friendly coatings (Nano-emulsion +ZnO + poly(ethylene glycol) on the carbon steel surface were done using electrophoretic deposition method (EPD). ZnO plays an important role in the chemical industry because of its stable physical and chemical properties and high oxidation activity . The electrophoretic deposition (EPD) of eco-friendly Nano-Coatings on carbon steel substrates was investigated by FTIR, scanning electron microscopy, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy (EIS). Eco-friendly coatings showed very good inhibition efficiency (IE) in sulphuric acid solution, hydrocloric acid and formation water. The method enabled the formation of adherent, protective and uniform coatings. Comparing 24 Coating with one another based on the impedance and potentiodynamic polarization value to determine the best Coating in various test solutions. In HCl solution : the coating that contain paraffin oil with Garlic and tween 80 shows higher values of corrosion resistance and In H2SO4 and in formation water: , The coating containing olive oil with garlic and tween 80 shows higher values of corrosion resistance.

الربيعي ، أماني عبدالله

Most of the previous published studies in the field of language and news discourse investigated how the reporters express their ideologies and bias when reporting events. Moreover, most of these studies focused on the language used by the reporters as a construction of culture. However little attention has been paid to how language reveals the reporters' attitude towards different types of hard news, namely, political, economic, nature disaster, and crime reports. This present study addresses the question of how the reporters evaluated hard news, and highlighted the type of news which was appraised mostly by the reporters. Particularly, it analyses the attitudes of the reporters of Saudi English newspaper. This research seeks to examine the hard news in particular. It adapts the critical analysis and the appraisal theory by (Martin & White, 2005) to investigate the data, which comprises 40 reports chosen randomly, posted during 2015-2016 as the most recent reports. The most important findings of this study show that a reporter employed different evaluating strategies while reporting hard news. These strategies could be illustrated by the following. Firstly, the occurrences of judgmental instances were the most frequent among other subsystems of attitude and formed 42.5%. While the Affect instances were formed 32.5% of the total. Moreover, appreciative instances were detected apparently in the data but formed only 25%. Secondly, the instances of positive attitude were a bit more frequent than the negative attitude. On the other hand, regarding the directness of expressing reporters' attitudes were inscribed. Finally, which is the most interesting finding is that the reporters revealed their attitude extensively toward political report more than other types of hard news. This study strongly recommends that more writing courses for both academic and professional purposes are integrated into the training program of future news reporters

المالكي ، وعد عبد الله حسن

The purpose of this study was to investigate the challenges faced by visually impaired female students when studying English in Taif University and investigate attitudes towards learning English, the challenges the visually impaired students faced in classroom, from the teacher, curriculum design and lack of resources and equipment, students’ strategies in learning English and their recommendations to making learning English better for visually impaired female students. Narrative inquiry was used in this study. The participants of the study were four visually impaired female students studying in Foreign Languages Department, Taif University. They were randomly selected and all had average understanding of English. The range of their age was between 19-25 years. Additionally, 15 FLD instructors answered online questionnaires relating to the study to help in identifying the challenges encountered when teaching English to female students who were visually impaired. Inquiry approach was used for data collection. Data was collected by administering structured interviews to the four visually impaired female students. Online questionnaires were used to collect data from foreign language instructors. Comprehensive literature was reviewed to understand the meaning of visual impairment, learn more about English as foreign language in universities. The challenges faced by the female students were discussed. A common finding on the learners attitudes towards learning English was the three participants found learning English to be easy. On the other hand, one participant finds learning to be difficult. According to the questionnaires given to the teachers, most teachers of those who answered the questionnaires reported to have not attended any course to enable them to teach the visually impaired. They also reported that teachers as well as students required to be trained to enable them understand and handle the VI students with more attention, since there is no direct provision in the department .