Jouf University
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/396
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Item Restricted A Study The Behavior of Solutions of Some Nonlinear Difference Equations(Saudi Digital Library) لمى شجاع عواد الجوفيIn this study, we obtained the solutions of nonlinear difference equations of fifteenth-order with conditions imposed on the initial values. Moreover, we investigated boundedness, stability, oscillation and the periodic character of these solutions. Finally, we confirmed these results with some numerical examples and graphs by using Matlab program. Also, we investigated the behavior of solutions of a third-order nonlinear difference equation. More precisely, we studied the boundedness, stability and oscillation of these solutions of this equation.This thesis contains four chapters: The first chapter, contains introduction and some basic definitions to the difference equations, equilibrium points, stability, periodicity and oscillations of solutions of difference equations and some results which are used throughout thesis The second chapter, contains a survey to some recent papers in this field In the third chapter, we obtain the solutions of the following nonlinear difference equations????????+????=????????−????????±????±????????−????????????−????????????−????????????−????????????????−????????, ????=????,????,????,…, with conditions imposed on ????−????????,????−????????,????−????????,…,???????? Moreover, we investigate boundedness, stability, oscillation and the periodic character of these solutions. Finally, we confirm the results with some numerical examples and graphs by using Matlab program. The results of this chapter have been published in the Journal of Mathematics and Computer Science In the fourth chapter, we investigate the behavior of solutions of the following difference equationμ????+????=????(μ????−????+μ????−????)+(????−????)μ????−????μ????−????μ????−????μ????−????+????, ????=????,????,????,…, where μ−????,μ−????,μ????∈[????,∞) and the parameter ????∈[????,∞). More precisely, we study the oscillation, boundedness, stability of the solutions of this equation. The results of this chapter have been accepted for publication in the Journal of Mathematics and Computer Science.1 0Item Restricted BIOMASS DERIVED ELECTRODE MATERIAL FOR RENEWABLE ENERGY STORAGE APPLICATIONS(Saudi Digital Library) في مثقال محمد الصالحThe supercapacitors with prestigious electrochemical performance have achieved exceptional worth however, a facile environmentally friendly approach is still desired for electrode material with high charge storage capability. In this study, we have demonstrated and analyzed the charge storage mechanism of tea waste derived activated carbon (AC) for supercapacitor applications. The tea waste is collected, washed, and dried. Chemical activation is performed with different concentrations of potassium hydroxide (KOH) which is followed by carbonization at 800ºC in an argon environment. The surface morphology and crystal structure of the synthesized AC are investigated via performing X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Electrochemical performance of synthesized AC is carried out in three electrode assembly. The AC activated by 50 % KOH delivers the high specific capacitance of 349.45 F/g at 3 mV/s and 319.41 Fg-1 at 1 Ag-1. Further, the electrolytic environment was optimized by testing the best performer in different concentrations of electrolytes. The maximum specific capacitance of 550.37 F/g at a scan rate of 3 mV/s and 496.1 Fg-1 at the current density value of 0.5 Ag-1 is achieved for AC in 3M KOH electrolyte concentration. This optimized material and the electrolytic environment was further employed in a symmetric architecture for real device application. The fabricated device delivers excellent specific energy of 16.2 Wkg-1 along with specific power of 498.4 Wkg-1. An outstanding power of 3499.1 Wkg-1was also achieved via this supercapacitor along with specific energy of 4.8 Whkg-1.8 0Item Restricted CALCIUM TITANATE NANOPARTICLES: PREPARATION, STRUCTURE, PROPERTIES PREPARED FROM GYPSUM(Saudi Digital Library) مرام مزهر محمد الشهريThe goal is to use the sol-gel process to make perovskite CaTiO3 nanopowder. Different highly developed procedures were used to characterize the generated samples. The X-ray Diffraction Method was used to evaluate the structural properties of nanopowder (XRD). Scanning Electron Microscopy (SEM) was used to examine the surface morphology, while transmission electron spectroscopy was used to investigate the microstructure (TEM). In comparison to other nanopowder production methods, this method is convenient, low-cost, easy, simple, and effective. Using the Scherrer equation and the Williamson–Hall method, a Matlab algorithm was created to easily compute crystal size.0 0Item Restricted Chemical Characterization and Biological Activities of Some Aromatic Plants in Aljouf, Saudi Arabia(Saudi Digital Library) بشاير سلامه عبدالله الدغمانيImportance: Natural food additives, especially antioxidants, are the future of food preservation industry as synthetic ones could have a long-term potential harm to human health, including toxicity and carcinogenicity. Results: The volatile constituents of fresh and dried Mentha suaveolens L in Saudi Arabia (Aljouf area) for the whole plant, leaves, and stems were extracted via maceration and analyzed using Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC/MS). According to our knowledge, this study was unique for including all parts of the M. suaveolens L. The volatile constituents of fresh and dried M. suaveolens L for each part contained 125 compounds. Carvone was the main volatile constituent for fresh and dried M. suaveolens L for the whole plant (43.65% and 39%, respectively), leaves (64.31% and 53.45%, respectively), and stems (58.8% and 49%, respectively). The volatile constituents of M. suaveolens L belonged to the carvone chemotype because the volatile extracts were rich in carvone. Also, the analysis of non-volatile constituents of fresh and dried M. suaveolens L whole plant, leaves, and stems was performed by High-Performance Liquid Chromatography (HPLC). Rosmarinic acid was the main phenolic compound of fresh and dried M. suaveolens L for the whole plant (2223.3µg/g and 21191.9µg/g, respectively), leaves (28002.5µg/g and 15165.1µg/g, respectively), and stems (6558µg/g and 8378.4µg/g, respectively). All Mentha extracts showed strong antioxidant activity because it was rich in phenolic compounds. For the first time, a fungus (Penicillium glabrum) isolated from white cheese was inhibited by Mentha extracts. Leaves of fresh M. suaveolens L presented a higher antifungal activity compared with the other hexane extracts. In comparison, fresh M. suaveolens L stems showed higher antifungal activity than the other ethanolic extracts. Application aspects: This study indicates that M. suaveolens L could be used to manufacture unique natural antioxidants and a flavoring component. Although the observed biological activities of M. suaveolens L extracts were less than those recorded for synthetic antioxidants, they have the advantage of being safe and available as natural food additives in large and cost-effective quantities.7 0Item Restricted Cu DOPED ZnO NANOMATERIALS: PREPARATION, STRUCTURE, PROPERTIES AND APPLICATION(Saudi Digital Library) مأثر جدعان الجديعThis work has concentrated on the synthesis of undoped and copper (Cu) doped zinc oxide (ZnO) nanowires (NWs) via vapor phase transport method as well as on their physical and chemical characterizations. All X-ray diffraction patterns were indexed to ZnO single phase of hexagonal structure, and no Cu or Cu compounds characteristic peaks were observed. The evaluated Cu at.% was proportional with Cu ratios used in the source alloys. NWs morphology with quite long and smooth surfaces was observed for undoped sample, whereas NWs with agglomerations of particles were observed for higher Cu doped samples. The overall transmittance decreased with increasing Cu doping ratio with a blue shift for the onset of absorption. The optical energy gap was decreased from 3.33 to 3.10 eV upon increasing the Cu ratio from 0 to 5 at.%. Two emission bands were observed in the photoluminescent spectra at 385 and 545 nm, and they were strongly tailored via Cu-doping. The electrical conductivity of all the samples was of semiconducting behavior with two activation energies. The sensitivity to the NO2 gas was increased with Cu doping ratio. The magnetization measurements revealed ferromagnetic behavior for all the NWs samples at room temperature.5 0Item Restricted DEPOSITION OF A THIN LAYER OF OXIDE ON THE SILICON SUBSTRATE AND STUDYING THE PHYSICAL AND ELECTRICAL PROPERTIES OF THE STRUCTURE(Saudi Digital Library) ساره سعد عبدالله العتيبيThe Dysprosium oxide film Dy2O3 was deposited on p-type Silicon substrate by electron beam deposition under ultra-vacuum. The morphological characterizations are investigated by a scanning electron microscopy (SEM) and atomic force microscopy (AFM). Then the electric properties of the MOS structure Al/Dy2O3/p-Si are studied through current- voltage I (V), capacitance– voltage C (V), conductance- frequency dependencies G (f). The total conductance curves for the sample are found to obey Jonscher power law (σ(ω) = σdC +Aωn ) with an increase of frequency exponent (n) as temperature increases. The impedance studies reveal the presence of temperature dependent dielectric relaxation. Likewise, the analysis of the temperature variation of the imaginary part of modulus (M″) spectra confirms the existence of relaxation phenomena. The electrical modulus studies show that the relaxation is associated with grain boundaries effects. Nyquist representation (Z″ vs. Zʹ) was plotted and their characteristic behavior was analyzed in terms of electrical equivalent circuit. It can be concluded that the Dy2O3 shows promising dielectric and insulating behavior for the application in future microelectronics technology.0 0Item Restricted EFFECT OF CHROMIUM CONCENTRATION ON STRUCTURAL, MAGNETIC AND MAGNETOCALORIC PROPERTIES IN La0.8Sr0.15Na0.05Mn (1-x)CrxO3 (x=0.00 and 0.10) MANGANITES(Saudi Digital Library) ريم فاهد سالم السرحانيThe physics properties of manganite oxides La0.8Sr0.15Na0.05Mn1-xAlxO3 synthesized by solid-solid method were studied in details. X-ray diffraction analyses showed a single rhombohedral phase with R3-c space group. The inhomogeneous magnetic comportment coupled was used to explain the magnetic properties and the evolution of the paramagnetic-ferromagnetic transition of the materials. The maximum values of magnetic entropy change (ΔSMax) decreased from 5.15 Jkg-1K for La0.8Sr0.15Na0.05MnO3 to 4.46 Jkg-1K for La0.8Sr0.15Na0.05Mn0.9Al0.1O3 upon an applied magnetic field of μ0H=5 T, indicating an excellent quality of our samples as compared to many manganite oxides. The high quality of our samples was also checked by the large relative cooling power (RCP) which provides a good performance for industrial technologies in refrigeration device.1 0Item Restricted INVESTIGATION OF THE PHYSICAL PROPERTIES OF DOPED SPINEL FERRITE NANO SYSTEMS(Saudi Digital Library) بشاير ناعم خيرالله البخيتIn this study, pure cobalt ferrite (CoFe2O4) nanoparticles and Co1-xCuxFe2O4 nano spinel ferrite samples with different Cu+2 doping contents were successfully synthesized via the precipitation method. The impact of replacing divalent cobalt (Co2+) ions by divalent copper (Cu2+) ions on the microstructure, optical and magnetic properties of the produced Co1-xCuxFe2O4 nano spinel ferrite samples was studied. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra exposed the consistency of a single cubic phase with the evidence of CuO phases for x ≥ 0.2. XRD and energy dispersive X-ray spectroscopy studies affirmed the integration of Cu2+ions within CoFe2O4 host lattice. Transmission electron microscopy (TEM) analysis showed the crucial role played by Cu2+added to CoFe2O4 in controlling the particle size distribution of Co1-xCuxFe2O4 nano spinel ferrite samples in agreement with XRD analysis. Optical energy gap investigated by UV-Vis spectroscopy were found to range from 1.77 eV to 2.2 eV. Magnetic properties investigated by the vibrating sample magnetometer technique illustrated that the doping with copper can be an effective way to control the magnetic properties of Co1-xCuxFe2O4 nano spinel ferrite samples.1 0Item Restricted Knoevenagel Condensation Reaction over Acid-Base Bifunctional Non-Precious Metal Oxide/Metal Organic-Framework Catalysts(Saudi Digital Library) هدى إبراهيم الجدوعMetal organic frameworks (MOFs) are a unique type of hybrid porous materials in which metal ions or clusters are interconnected through polyfunctional organic ligands. Compared to conventional microporous and mesoporous inorganic materials, these metal–organic structures display advantages such as unprecedented internal surface areas (up to 10000 m2g-1), tunable and extra large pore sizes, an intrinsically high metal content, structural diversity, crystalline open structures and the ease of processability, flexibility and geometrical control. These outstanding properties render MOFs nascent candidates for being used as heterogeneous catalysts, catalyst supports and adsorbents. Hybrid catalysts currently offer an appropriate route for boosting the catalytic performance. More than thousands of MOFs of various compositions have been reported to date. The number of studies on MOFs and MOF composite materials has risen year after year over the last decade. The main objective of this thesis was to fabricate a series of CaO-immobilized metal-organic-framework (MOF) nanoparticles, using an in-situ growth and scalable approach, combining excellent thermal and chemical stability, and recyclability. Using different characterization techniques, comprising FTIR, XRD, UV-Vis, TGA, 1H NMR, N2-isotherms, FESEM-EDS, and TEM, the fabricated catalyst was investigated. The CaO-immobilized MOF nanoparticles comprising of stable NH2-MIL-101 (Cr) provide both Lewis acidic and basic sites and CaO offers Lewis basic sites. Hence, the MOF composite showed outstanding catalytic properties for Knoevenagel condensation reaction with facile reusability. The CaO/NH2-MIL-101 (Cr) catalyst used in Knoevenagel reaction is applicable to benzaldehyde derivatives comprising both withdrawing and donating electron moieties with exceptional conversions.7 0Item Restricted Microporous Magnetic Carbon Spheres Functionalized with Metallic Nanoparticles and Their Applications in Heterogeneous Catalysis.(Saudi Digital Library) محمد عبدالله المرعضيInexpensive catalyst support with large surface areas are extremely common in the chemical manufacturing sector. Here, we describe how we used a hydrothermal polymerization method to move glucose carbon spheres in a simple and environmentally friendly way (CSPs). Besides, a hydrothermal method integrated with microwave irradiation technique for the synthesizing of Fe3O4-CSPs core-shell decorated with Pd nanoparticles has been employed. High resolution transmission electron microscope (HRTEM), Field Emission Scanning Electron Microscopy (FESEM), nitrogen isotherms, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy have investigated the prepared composites. The composite is largely spherical, with a core-shell structure, according to the findings. Moreover, the resulting Pd/Fe3O4-CSPs catalyst shows the strong tolerance Suzuki–Miyaura cross-coupling reactions in 30 min at 80oC to various substrate scope of aryl halide with phenylboronic acid. Furthermore, without substantial decrease of performance we were able to reuse the catalyst up to four catalytic cycles. Only this work doesn't demonstrates a simple method for fabricating Pd/Fe3O4-CSPs composites, but also encourages the use of Pd/Fe3O4-CSPs catalysts in organic transformation processes.7 0Item Restricted Optimal control of semi linear infinite dimensional systems: Theory & Simulations(Saudi Digital Library) عهد خالد ناجي الشمريThe aim of this thesis is to study the notion of the controllability of a class of the semi linear systems on a boundary sub region of the evolution domain Ω. We give an extension of previous work on optimal control theory of distributed systems to the case of nonlinear systems a type semi linear. We introduce the notion of gradient optimal control of distributed semi linear systems. The idea focus on the characterization of the control achieving a regional boundary target with minimum energy. Using optimization techniques. The results which are performed through numerical examples and simulations. This studies leads to many open problems as the optimal control of semi linear systems.1 0Item Restricted PHYSICAL INVESTIGATIONS ON NIMOO4 THIN FILM PREPARED BY CHEMICAL SPRAY TECHNIQUE(Saudi Digital Library) سلمى محمد عيدروس المباركيThis study concerns the preparation of sprayed binary molybdenum oxide, MoO3, thin films and ternary and quaternary derivatives by alloying. The characterization of their physical properties was carried out by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, spectrophotometry and impedancemetry. It appears from the elec- trical study that the great value of resistance R corresponds to the NiMoO4, thin films. The equivalent ac circuit of these films is composed by a parallel resistor R and capacitor C connected together. This work also focused on the photo- catalysis process applied to the studied samples. Under solar irradiation, the photocatalytic application was tested in terms of the degradation reaction of wastewater containing methylene blue. Under similar experimental conditions, the NiMoO4 thin film shows a higher rate of degradation than the other thin layers .5 0Item Restricted Regional optimal control of distributed bilinear systems(Saudi Digital Library) بدريه شويش بيوض العنزيThis thesis concerns the regional optimal control of distributed bilinear systems. We begin by studying the existence and uniqueness of solutions for bilinear evolution equations, which model a large class of real problems. Next, we consider the regional minimum energy control problems governed by a parabolic bilinear distributed system. We give methods of solution using quadratic problems and optimality systems. Furthermore, we propose a solution of the regional minimum energy control problem governed by a hyperbolic bilinear distributed system. This problem consists in minimizing the norm of the command under constraint. The problem is solved using optimality systems and by considering a set of quadratic problems. The results are successfully tested by examples and simulations, and the thesis ends by open problem and conclusion. The scientific contributions of this thesis are the following: 1- Participating in the scientific conference "The third international conference on research in applied mathematics and computer science ICRAMCS’2021,"and presenting a scientific paper entitled "Flux Control Problem for a Class of Bilinear Distributed Systems". 2- Submit a paper entitled "Flux problems using a regular bilinear optimal control" for publication in an international journal.3 0Item Restricted ROLE OF Cu DILUTE ON MICROSTRUCTURE, OPTICAL, MAGNETIC, PHOTOLUMINESCENCE AND ELECTRICAL PROPERTIES OF CdS FILMS(Saudi Digital Library) مهره عبدالرحمن الوشيحThin films of CdS1-xCux (with 0 ≤ x ≤ 0.10) were deposited using electron beam evaporation. Using XRD, EDX, SEM and UV-Vis-NIR spectroscopy, the impact of [Cu]/[S] on the film properties was examined. The influences of various concentrations of Cu are also elucidated on the optical parameters of the films. The XRD analysis shows that the thin films of CdS1-xCux have been improved and have hexagonal polycrystalline structure with the increase of Cu doping ratio. Additionally, the crystallite size is reduced while the micro-strain ε increases with enhancement of the incorporation of Cu in CdS lattice. The envelope method was used to extract the optical parameters of the undoped and Cu-doped CdS films. With the increase of Cu concentration, the energy optical bandgap decreased, and the variation values of band gap could play an important role in solar cell applications. Another optical parameter such as dissipation factor and real / imaginary dielectric constant parts were evaluated and demonstrated a strong Cu doping dependence. The shift observed in the photoluminescence spectra emission band confirmed Cu's substitution to CdS lattice. The measurements of magnetization using vibrating sample magnetometer illustrated a hysteresis loop in Cu-doped CdS films and confirmed the room temperature ferromagnetism. Finally, the Hall effect results show that the pure CdS film corresponds to an n-type semiconductor with a resistivity of 8.11×10-2 Ωcm and a carrier concentration of 29.6×1019 cm-3, and the CdS:Cu film is a p-type semiconductor and the resistivity is reduced from 6.8×10-2 to 3.7×10-2 Ωcm, and the carrier concentration is reduced from 26.4×1019 to 4.1×1019 cm-3, which has potential application prospects in solar cells.4 0Item Restricted Semi E-convex Multi-Objective Programming Problems(Saudi Digital Library) خالد سليمان محمد السلميIn this thesis, we interested in optimizing multi-objective programming problems which are involving generalized semi E-convex functions. The study goes through three broad lines. The first concerns with thegeneralized semi E-convex functions which are quasi semi E-convex functions and pseudo semi E-convex functions. Optimality criteria for nonlinear programming problem involving those functions are investigated. Along the second line, the characterization of efficientsolutions for multi-objective programming problems involving semi E-convex functions are considered. We are interested in characterizing those problems by weighting and ε-constraint approaches. The necessary and sufficient conditions for a feasible solution to be an efficient or properly efficient solution are derived. An approximation algorithm for finding efficient solutions for semi E-convex multi-objective programming problems is investigated along the Third line.0 0Item Restricted Sn INDUCED CHANGES IN THE STRUCTURE AND OPTICAL PROPERTIES OF AMORPHOUS As–Se–Sn THIN FILMS FOR OPTICAL DEVICES(Saudi Digital Library) تهاني عائض لافي العنزيThe demand for clean and renewable energy has been constantly increased all over the world. Therefore, harnessing solar energy from the sun to generate electricity using solar cells was the main focus which has been achieved by exerting more effort into research. Solar energy is converted directly into electricity by solar cells. In this research, the thin films of As40Se60-xSnx were prepared by thermal evaporation technique. XRD has been estimated the amorphous nature of As40Se60-xSnx (x = 0, 5, 10, 15 and 20 at. %) thin films. XRD pattern shows that the investigated films have two broad peaks which are ascribed to the two amorphous phases existence. The optical characterization of these films has been performed throughout the estimation of the refractive index, optical band gap, dielectric constants, and energy loss functions. It was found that the refractive index and the dielectric constants increase while the energy gap decreases with the increment of Sn content for the studied thin films. The increase of the refractive index may be attributed to the increasing polarizability of the Tin when it is comparing with selenium. It has become apparent that the optical bandgap of the studied films decreased from 1.751 to 1.511 eV as the Sn content increases from 0 to 20 at.%. This behavior is illustrated in terms of the Urbach energy which is found to increase with the increase of Tin (Sn) content and, therefore, leads to shrinking of the bandgap. The values of two energy loss functions SELF and VELF are increased in the high photon energy region for the investigated films. SELF and VELF values have been found to shift toward the high photon energy with increasing tin content. Other physical parameters such as average coordination number, average heat of atomization, numbers of lone pairs electrons, and cohesive energy have been determined all of these parameters have increased with increasing of the Sn content, which may refer to increasing the glass stability of these compositions. Finally, the optical dispersion, phase, and group velocity are discussed based on the refractive index dispersion of the studied thin films. There is limited information onAs40Se60-xSnx thin films for solar cell applications. This study was aimed at investigating both the optical and electrical properties of As40Se60-xSnx thin films using by thermal evaporation technique method. In addition to investigation of the opto-electric properties, this study was aimed at improving these properties as well as to provide additional information on the As40Se60-xSnx solar cell.1 0Item Restricted Stability analysis of some dynamical systems(Saudi Digital Library) فيصل فائز مشعل الحربيThe present study has tackled the stability of the solutions of differential equations in the Lyapunov’s concept. All this as preamble to uncover the stability of some dynamical systems given by differential equations using Lyapunov functions, to recognize the importance of the nonlinear systems in physics, engineering, mechanics, weather reading, and many natural phenomena. In the case of ordinary differential equations, main theorems and definitions of Lyapunov’s methods have been treated. In the case of fractional differential equations, the fundamentals of fractional calculus and the stability analysis have been describe1 0Item Restricted STRUCTURAL AND MAGNETIC PROPERTIES OF MIXED-VALENCE MANGANITES(Saudi Digital Library) شريفه عبدالله مجيليب الحلافيThe purpose of this work is to present the findings of an experimental analysis of structural, magnetic, and magnetocaloric properties of the nanocrystalline manganites, La0.8Sr0.15Na0.05MnO3 (LSNMO), with size about 50 nm elaborated via solgel route. X-ray diffraction presents that LSNMO crystallize in a rhombohedral structure with the 3Rc space group. Magnetic characterizations demonstrate that LSMNO exhibits a coexistence of interacting superparamagnetic (ISPM) phase with blocking temperature TB = 194 K and a ferromagnetic phase with Curie temperature TC = 255.5 K. At low temperatures, the SPM state undergoes a collective freezing state at Tf = 46 K. The maximum magnetic entropy change ( M pk S ) is about 1.41 Jkg-1K-1 and the refrigeration capacity (RC) is 288 JKg-1 for a field change of 5 T at T = 215 K. The magnetocaloric response is reasonably high compared to the bulk materials, and this makes nanoparticles of LSMNO a potential candidate material for active magnetic refrigerators.3 0Item Restricted Synthesis and Applications of Decorated Nanocomposite Chitosan for the Separation of Some Elements of Economic and Environmental Interest(Saudi Digital Library) أسماء سليمان موحش السالمIn this study, the modification of graphene oxide with magnetite and chitosan to form nanocomposite (MCh/GO) was investigated. The synthesized nanocomposite (MCh/GO) was tested for adsorption of Cd(II) and Nd(III) from aqueous medium.The nanocomposite (MCh/GO) was characterized using FTIR, XRD, SEM and TGA before and after the adsorption process. XRD analysis shows the interaction between magnetic chitosan and graphene oxide which can be considered as physical interaction (intermolecular and intramolecular H bonding, peptide bonding, and reveals the presence of distinct peaks for magnetite and graphene oxide. TGA data agreed that the prepared MCh/GO nanocomposite shows thermal stability Much higher than graphene oxide and chitosan samples.The adsorption kinetics of Cd(II) and Nd(III) obey pseudo-first order.Thermodynamic studies show that the adsorption processes of both Cd(II) and Nd(III) by MCh/GO nanocomposite under the conditions Optimal are endothermic processes and have a spontaneous character for Nd(III) and a non-spontaneous behavior of Cd(II).Langmuir isothermal, the absorption of Nd(III) (58.14 mg g-1) is preferably absorbed by the MCh/GO nanocomposite instead of Cd(II) (29.3 mg g-1).Therefore, the MCh/GO nanocomposite can be used at large scale for purification, processing and many industrial processes because of its promising properties.1 0Item Restricted Synthesis of high-performance antifouling hybrid ultrafiltration membranes combining sulfonated polyethersulfone and titania nanotube for water purification(Saudi Digital Library) صالح فهد الرويليTitania nanotubes (TNTs) were grafted by a facile surface covalent functionalization with 3-sulfopropyl methacrylate potassium salt (PSA). A new sulfonated polyethersulfone (SPES) ultrafiltration membrane (UF) was then fabricated by loading various concentration of TNTs-g-PSPA using a non-solvent induced phase separation (NIPS) approach. Thermogravimetric analysis (TGA), and Fourier-transform infrared (FT-IR) findings showed that the TNTs were successfully functionalized. By dint of the hydrophilic composition and homogeneous distribution of the tubular nanofiller in the membrane frameworks, the TNTs-g-PSPA membrane had a greater water flux and a narrower contact angle than a bare membrane Besides, with increased the loading concentration of the TNTs-g-PSPA, the pure water flux of the hybrid membranes boosted dramatically. The hybrid membrane’s pure water flux containing 5 wt% TNTs-−1, around 2-fold that of the pristine membrane. The −2 hg-PSPA hybrid was 402 L mfouling resistance of the fabricated membranes was explored using various foulants, comprising humic acid (HA), sodium alginate (SA), bovine serum albumin (BSA), and natural organic matter (NOM) authentic solution. The hybrid membrane with 4 wt% TNTs-g- PSPA hybrid achieved a significant increase over the pristine membrane and was able to remove greater than 96% of NOM, without a rejection rate losing.3 0