Masters theses : Science

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Start date: 2000End date: 2009

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    THE ROLE OF H YDROX YL TERMINA TED POLYBUTADIENE IN SPECIAL POLYURETHANE FORMULATIONS A THESIS
    (ALNEELAIN UNIVERSITY, 2007-08) ELSHRIEF ELMISKI KHAMIS
    ABSTRACT Hydroxyl-terminated polybutadiene (HTPB) resins occupy a unique position among the commercially available polyols. This class of materials may be used to prepare polyurethane elastomers that are characterized by low temperature flexibility, hydrophobicity and hydrolytic stability. Due to the hydrocarbon nature of the polymer backbone, these elastomers also possess extremely low dielectric constant, dissipation factor, and low MVTR (moisture vapor transmission rate) properties. Depending on the hydroxyl functionality and backbone microstmcture, namely, the l,2-vinyl, 1,4-cis, or 1,4-trans distribution of each repeating unit, the HTPB- derived polyurethane elastomers can have a wide range of physical properties including glass transition temperature and viscosity. This thesis is concemed with the role of (HTPB) as a soft segment in the preparation of special polyurethane which can be utilized in composite binding system, based on the following materials: I Hydroxyl terminated poly butadiene as a pre polymer. 0 2,4 toluene diisocyanate as a curing agent. 0 dioctyl sebacate as a plasticizer. 0 Tris methyl azidrinyl phosphinoxide(MAPO) as a cross linker. the dynamic mechanical behavior was studied followed by morphological studies using, (Electron Scan Micrograph), by tracing the different behavior of results regarding the relation between sofi segment and hard segment, and the means of controlling the disorder played by the long chain and entangled soft segment. MAPO was used as a cross linker in this manner. Different parameters has been gathered for tailoring a binding system, based on (HTPB) pre polymer, which can fit for use in solid composite propellants. ll
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    synthesis of some2 bromo-3ary laimion5 acetoxy1.4 naphtoquinones as antibacterial agent
    (Al-Neelain University, 2009) suhyla mohmoud ali elzeber
    ABSTRACT Two groups of - amino quinones ,2-bromo-3-aryl amino -5- acetoxy-1,4-naphthoquinones and compound 2-amino-1,4- naphthoquinones were synthesis in this work by coupling some amines through nucleophilic substitution of their free amnino groups at position-2 of quinone. The compound 2-bromo-5-acetoxy-1,4- naphthoquinones were refluxed with the different aromatic amines to produce compound 2-bromo-3-a1ylamino-5-acetoxy-1,4- naphthoquinones. Under the same condition compounds l,4- naphthoquinone was reacted with the some amines to give 2-ainino-l,4- naphthoquinones . Compounds 2-bromo-5-acetoxy-l,4-naphthoquinone and 1,4- napthtoquinone were prepared as the first step in this work. The structure of the target molecules were deducted on basis of their spectral data (UV,IR,NMR and MS). The targeted molecules were screened for their antibacterial potential and significant activity was observed for most of them .
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    Chemical and Physical Characteristics of oils of seeds of some Cmaferea Plants Growing in the Sudan . ( A comparative Study )
    (ALNEELAIN UNIVERSITY, 2004) Mahmoud Mohamed Ali Mahmoud
    Abstract Seeds of four species of the family Cructfirea were analyzed for seed Crude protein, Crude fiber, total ash ,and oil contents using Petroleum ether (40-60C°) as the solvent for extraction .The physical and chemical characteristics such as : Acid value, Saponification value unsaponiable matter , Peroxide and iodine value, Colour, refractive index, relative viscosity ,and relative density of oils were determined . Phytochemical screening of oil samples, and Thin layer chromatography were used to detect the expected compounds in Cructfirea oil seeds.Triterpenoids , flovanoid aglycones ,and phenolic acids were detected in all species. Fatty acids and other compounds in the oils were determined by Gas chromatography /mass spectrometric analysis. 13-Docosenoic acid(Erucic acid)generally highly considered in cruciferous plants was 21.15% in ‘Emca sativus and 36.05% in Rapfianus satillu_s.Oih8r acids found in the four species were hexadecanoic,9-Octadecen0iC,0ctadecanoic, 8,11,14-eicosatrienoic,9,12,15-octadecatrienoic,1 1-eicosanoic, eicosenoic,docosonoic ,15-tetracosenoic ,tetrac0sanoic and the di iso — octyl ester of 1,2-benzene dicarboxylic acid . Data from the literature based on previous studies in oils from other countries showed some differences in composition and yield .These differences may be due to the variations in the climate ,soil and geographic location .
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    HYDROGEOLOGY OF THE SOUTH KOSTI PROVINCE
    (AlNEElAN UNVERSLTY, 2002-12) Abdel Rhman Hassan Shiekh Ldris
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    Evaluation of Rigle EL-fools Crude oils by studying Physical and chemical, specification extraction of paraffin Wax and the capability of manufacturing the base oils
    (Al-Neelain University, 2009) Haitham Kamal Awad Ali
    jitfistract The studied crude oil sample was collected from the field and distillated atmospherically using the (minitop-combi) apparatus which. is a very advanced automatic equipment complying with the ASTMD 2892 (l5 theoretical plat column) to separate the light component from the crude oil. Then appropriates lube cuts was collected by vacuum distillation according to ASTMD523o using the same equipment. The predetermined temperature ranges of the collected cuts were analyzed and tested to determine their characteristics. As in the industry, all cuts were subjected to several processes either to eliminate some of the undesired components or to enhance some properties. The vacuum residue were subjected to deasphaltin process to remove all the asphalts from the cut. after that all cuts were dewaxed including the deasphalted oil using (methyl ethyl ketone) to enhance the cooled properties. Then carried out to all of the aromatics to improve the viscosity index and the quality of the produced base oil cuts (using Phenol). The study conclude that Rile EL- foola crude oil is quite suitable for the manufacturing of base oils and it has gave different types and grades oflube base oils. Ill
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    Analysis of Topological Structure of Artificially Porous Gum Arabic by Scanning Electron Microscope(SEM)
    (ALNEELAIN UNIVERSITY, 2007-10) Amna Adam Hamid
    Abstract Artificial porosity in Gum Arabic has been formed after being blended with Potassium bromate by using chemical method. Structural characterization is carried out by scaning electron microscope (SEM) micrographs exhibited equal K Br distribution and poly dispersed porosity by the combination of SEM and image analysis techniques we are enabled to trace the features and topology of the produced porosity. From the results obtained we have found that, the porosity had show random growth and increases in size and density after thermal treatment. This increment can be attributed to the connectivity of pores.
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    EFFECT OF ANNEALING ON BIPOLAR PnP TRANSISTOR JUNCTION - TYPE ( AC-128 )
    (ALNEELAIN UNIVERSITY, 2004-09) AMIN AHMED CMAR YOUSIF
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    Wax content and treatment of wax in the sudanese crude oil
    (ALNEELAIN UNIVERSITY, 2005-06) Osman Mustafa Ahmed ldriss
    Abstract In this study, Wax was isolated from several different fields (Heglig, Unity. El-Nar, El-Toor, Toma South, Bamboo and Munga) located in Heglig region. These fields composed the Nile blend. These fields under care of the Greater Nile Petroleum Operating Co. Ltd. The isolated wax was in a comparement with that wax isolated from the different fields (Fal, Pal and Anbar) located in Malut basin. These fields under care of Petro-Dar Petroleum Operating Co. Ltd. Wax content was measured by using three different methods. - It was found that the wax content depends on the method used. - Pour point and viscosity of crude oil samples were measured. - Gas chromatography tests have been conducted by using high temperature column in order to characterize the wax in crude oil samples. - The wax isolated from crude oil sample was quantitatively subdivided into pentane soluble fractions containing macro- crystalline wax (< C40 — C45) and pentane insoluble fractions containing micro-crystalline wax (> C40). The results showed significant correlation between the weight (wt%) of the wax fractions, viscosity and pour point ofthe crude oil samples. - The pour point and viscosity of the crude oil increased when the concentration of micro-crystalline wax was high, also the pour point was affected by the carbon chain present in the crude oil, i. e., the longer carbon chain the higher pour point and viscosity of the crude oil. The results showed no correlation between the total of wax content, viscosity and pour point. (m) - The effects of two types of chemical additives used to decrease the pour point of the crude oil were analyzed by using the viscosity and pour point tests. - The efficiency of chemical additives used was decreased by increasing of the weight (w%) of micro-crystalline wax fractions and carbon chain length.
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    Determination of Serum Chromium (Cr), lron (Fe), Copper (Cu), and Cobalt (Co) Levels and Hematological Parameters of People from Blue Nile State, (Engassana Mountains) and Khartoum State
    (ِِAl-neelain University, 2008) Ali Abd Al Ghaffar Abd Al Raheem Mohammed
    In the present study, determination of serum trace elements using Atomic Absorption Spectrophotometry and evaluation of hematological parameters using an Automated Hematology Analyzer in human blood samples of people from Blue Nile State (Bao and Jam areas) and Khartoum State were investigated. Serum elements, Chromium (Cr), Iron (Fe), Copper (Cu) and Cobalt (Co) concentrations and hematological values, hemoglobin (Hb), hematocrit (I-lct), red blood cell counts (RBC), white blood cell counts (WBCs), mean corpuscular volume (MCV), mean cell hemoglobin concentration (MCHC) and mean corpuscular hemoglobin (MCH), concentrations were evaluated regarding sex and location. Chromium and Iron showed significant differences (P< 0.05) in the three different areas however, Iron values were found to be within the 1'10l'lTl8l ranges. Serum levels ofChromium in Jam area showed significant increase (P< 0.05). Copper and Cobalt revealed no significant variations (P>0.05) and the values were found to be in the nonnal reference ranges. Sex had no influence on Chromium, Copper and Cobalt but Iron values were higher in male than female however, the difference was not significant (P>0.05). The hematological values, WBC, RBC, Hb, PCV red cell indices and differential WBC counts showed significant differences (P>0.05) among the three different populations but all of them remained within the normal reference ranges. At the same time all of these values were found to be similar in Bao and Jam areas. The values among sex groups did not show significant differences except for hemoglobin, which was found to be higher in male groups.