College of Science
https://repository.sustech.edu/handle/123456789/1174
2024-03-28T22:36:59ZEffective Estimate with Self-Similarity for Lebesgue Measure of Some Cantorval
https://repository.sustech.edu/handle/123456789/28360
Effective Estimate with Self-Similarity for Lebesgue Measure of Some Cantorval
Abd Alfadel, Alzakey Abd Alfadel Mohammed; Supervisor, -Shawgy Hussein AbdAlla
We obtain the spectrum and an effective estimate for the Lebesgue measure of the preimages of iterates of Farey and Gauss maps. The intervals and dichotomy between Farey fractions and sequence in the limit of infinite level and uniform distribution of the Stern-Brocot are determined. The structure, topology, separation and measure properties of the self-similar sets and Fractals and interated function systems of bounded distortion are characterize. We examine the asymptotic behavior of the Lebesgue measure of sum-level sets of continued function, self-similarity and nonempty interior. The family of self-affin and self-conformal sets with uniqueness, simultaneous and positive Hausdorff measure are studied. The nultigemetric. Subsum sets of sequences with recovering a purely atomic finite measure and Cantorvals with Lebesgue measure of M-Contorvals of Farey type are established.
Thesis
2022-07-25T00:00:00ZNew Direction in Derivative Free Optimization
https://repository.sustech.edu/handle/123456789/28359
New Direction in Derivative Free Optimization
Ahmed, Ahmed Mohamed Nageeb Alwasela; Supervisor, -Mohsin Hassan Abdalla Hashim
In this thesis, we study a derivative-free trust-region algorithm for large-scale unconstrained optimization, using symmetric-rank1 (SR1) to update the Hessian at every iteration. The centeral finite-difference iterations are used to approximate the gradient of the function. The iterative solution method and truncated Newton method were used to solve the trust-region sub-problem. Its performance is tested on some problems and compared the solutions found by truncated Newton method and iterative solution method.
Thesis
2023-01-19T00:00:00ZExtraction and Analysis of Baobab seeds Oil (Ophelussitularius)
https://repository.sustech.edu/handle/123456789/28358
Extraction and Analysis of Baobab seeds Oil (Ophelussitularius)
Mustafa, Esraa Abdelmonem Fudol; Supervisor, -Mutasim Maknoon Hassan
This study aimed to extract and analyses Baobab seeds oil. for some physical properties, chemical properties, anti-biological effect, antioxidant and GC-MS for some essential oils. 98 mL of the oil were extracted from 450 grams of seeds powder with soxhlet apparatus using hexane as a solvent. The solvent was separated by a rotary evaporator and the oil content was found to be 19.94%. The physical analysis carried out are; the density, specific gravity, viscosity, color, flash point and moisture content gave the results; (0.9158g/cm3, 0.9168, 40.58cSt, 1.5 Yellow , 280.90 Co, 0.18% ) respectively. The chemical properties analysed are; Acidity value, saponification value, iodine number and peroxide number gave the results; (0.49g KoH, 190. 70 mg/ KoH/g , 102.45 and 2.98mg Eq.O2/g oil), respectively. The results of the biological analysis showed that the oil does not contain antibacterial activity. The baobab seeds oil was found to exhibited an antioxidant and its oxidation value equals ± 46.00 %. The baobab seeds oil was also analysed by GC-MS. The results were interpreted using the data of the NIST library for mass spectrometry, and the compositions were confirmed by studying the disintegration pattern. A match was found up to 5-9% between the spectra of the components and the library data attached to the device. While the results of the gas chromatography analysis showed that the oil contains seven components, the most important of which are:
9,12-Octadecadienoic acid (Z,Z)-, methyl ester (23.71%).
9-Octadecenoic acid, methyl ester, (E) (38.50%) .
Methyl stearate (4.43%)
Hexadecanoic acid, methyl ester(30.16%)
Thesis
2022-03-19T00:00:00ZChange of the Electrical Magnetic and Optical Properties of Nano Sodium Chloride Due to the Change of its Nano Structure
https://repository.sustech.edu/handle/123456789/28349
Change of the Electrical Magnetic and Optical Properties of Nano Sodium Chloride Due to the Change of its Nano Structure
Fadl, Mahmoud Hassan Osman; Supervisor, -Mubarak Dirar Abd-Alla Yagoub
Nano science represents one of the most popular powerful tools for controlling and changing the physical properties of matter. It is now widely used in many applications. One of the most popular known one is the field of electronics, where the optical and electrical properties of matter are important. This encourages to do this work.
In this work 8 Na Cl samples were prepared and crushed for different micro sizes and nano sizes using crushing machine. Before that the samples where purified by being dissolved in water that flows through sever and dried using drying machine. Their optical, electrical and magnetic properties were investigated by UV, FTIR and XRD. The ultraviolet - visible (UV) determines absorption coefficient, energy gap and conductivity. Fourier transform infra-red spectrometer (FTIR) determines the chemical energy bonds. The X-ray diffraction (XRD) technique determines the crystal structure as well as the nana structure.
The crushing of Nacl into small particles having different micro sizes shows that this causes their physical properties to change. It was found that their nano size increases upon increasing their micro size, where each micro particle consists of aggregates of nano crystals. The absorption coefficient, crystal spacing increases upon increasing the nano and micro size. The energy gap decreases upon increasing the nano and micro size. The optical conductivity also increases for a wide range of wavelengths. The electric conductivity, permittivity, refractive index and magnetic permeability decreases for short wavelengths and increases for long wave lengths upon increasing the nano and micro size
Thesis
2022-06-28T00:00:00Z