علوم - دكتوراة
Permanent URI for this collectionhttps://repository.neelain.edu.sd/handle/123456789/511
Browse
6 results
Search Results
Item Evaluation of sudanese crude oil of the production of lubridcants base stoks(Al Neelain University, 2009) AbdElmahmod Saad Ahmed ElaminAbstract Due to fast growing of the petroleum industry in the Sudan and the very huge need for lubricating oils, they are considered to be the back bone of the modern industry. This study is carried out to determine the suitability of saponin as a natural detergent to be used in engine lubricating oil and also to determine the visibility of producing base oil stocks to supply the local demand of the Sudanese market. Three different blends of crude oils are produced in the Sudan namely: Nile blend, Dar blend block 5B blend. These were preliminary evaluated to choose the most suitable crude oil to produce base oil stocks by comparing of their percentage yields, pour point and wax content. It was found that block 5B blend is the most suitable one for the producing of base oil stocks due to many technical and economical reasons. The studied crude oil samples were collected from the fields and distillated atmospherically using the minitop-combi apparatus which is very advanced automatic equipment complying with the ASTM D2892 (15theoretical plate column) to separate the light component from the crude oil. Then appropriate lube cuts were collected by vacuum distillation according to ASTM D 5236 using the same equipment. The cuts collected at predetermined temperature ranges 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 other properties. XV The vacuum residues were subjected to deasphalting process to remove all the asphalts from the cut after that all cuts were dewaxed including the deasphalted oil (DAO) using solvent system "methyl ethyl keton (MEK) and toluene" to enhance the cooling properties of the collected cuts i.e. pour point. A solvent extraction process was then carried out to all cuts to improve the viscosity index and quality of the produced base oil cuts. The produced cuts were tested to determine their characteristics and the production yield was calculated. This study came to conclude that block 5B blend is quite suitable for the manufacturing of lube base oils and it gave different grades of lube base stocks with reasonable yields. The extraction of saponin was carried out from three different plants (Ziziphus abyssinica, Citrullus colocynthis, Balanistes aegyptiaca). The quantity of saponin in these species is 0.3823, 0.1779 and 3.5626 respectively. Then the thin layer chromatography was done for the three saponin to determine the best one. The saponin from Balanistes aegyptiac is the best one and the quantity is greater than the other two saponin. Then the blend of sea w30 was done between cut 480-520°C and cut 520+ and its clearly was done and it found 432mg in 240 hour and classify that it is very clean.Item IODINE DEFICIENCY DISORDERS IN SHENDI CITY - NORTH OF SUDAN(Al Neelain University, 2009) FAROUG BAKHEIT MOHAMED AHMED ELSONNIItem Determination and Characterization of Tannin Material Extract From Three Common Acacia Species in Sudan(Al Neelain University, 2009) AYMAN AHMED AL-KHDIR ALI JACKNOONThis research is dealing with the analysis and comparative studies of tannins of three common Acacia species of Sudan. Since vegetab1e tannins are important for leather industry, A. nilotica and A. seyal samples were collected from Sunut forest in Khartoum State while A. tomentosa, samples were collected from the shmbata Forest. Bark samples From collections of the three acacia species ,were extracted with distilled water, 80% methanol and 70% acetone ;two sets of extraction were made, one by boiling, and the other by shaking the samples in the respective solvent for eight hours at room temperature. Although the amount of material extracted by these two procedures did not differ greatly , 70% acetone was a more efficient solvent than either water or 80% methanol. Qualitative analysis showed that the fruits (garad) contain tannins materials, flavinoid coumarins, and quantitative analysis showed that the fruits (pods) contain a higher percentage of tanning materials, that can be used commercially, barks contain XIII low tannin content compared with fruits. Also it was found that the unripe fruits give the highest percentage of the tannins content. Rotary system (with extraction changing in size of powder, rate of solvent to the fruits weight, and solvent temperatures), enabled access to extracts with high concentration when using crushed fruits, water at 70°C and ratio of (3:1) of water to fruits weight. Sodium fluoride and a mixture of oxalic acid and sodium sulphite showed high efficiency as antifungal reagents. With the mixture of acid - sulphite was found to be the best bleaching agent compared with sodium fluoride The amount of tannins present in the bulk samples was determined by folindenis method for total phenolic materials, followed by precipitation with hide-powder. The difference between the amount of phenolic materials present before and after addition of hide-powder represent the amount of tannins present. The extracts of the bark of A. nilotica A. seyal and A. tomentosa, contain (80.45% ,59.9% and 33.5%) tannins respectively. The amount of iron content of the extracts and samples of Acacia species was determined since the Iron hinders the process of retanning leather of Iron content was determined by atomic absorption spectrophotometry. The iron content of bark extracts of A nilotica, A tomentosa and A seyal is 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (0.00475%), which is imported from Kenya. The tannins of a mixture of powder of Acacia nilotica and bark of the acacia seyal were identified by using thin layer chromatography (TLC), ultraviolet and infrared spectroscopy. Comparisons of the absorption spectra and TLC of the reference tannins and some phenolics with that of a mixture extracts revealed the presence of both condensed and hydrolysable tannins, since it consists of catechin, tannin and gallic acids. The leaching materials were powdered using spray drier. They exhabited excellent properties, when used for tannage of leather. Better physical and chemical properties of leather were achieved compared with leather tanned using mimosa powder.Item Optical Properties of Zinc Oxide Thin Films(Al Neelain University, 2008) Hashim Mohammed Mosleh Alsana .The aim of this study to investigate the influence of annealing of temperatures and the effect of laser radiation on the optical transmittance and absorbance of ZnO thin films. In this study evaporation, casting and coating methods were used for preparation and deposition of ZnO on glass substrate . The materials ZnCL 2 , NaOH and NH 3 as completing agents were used for preparation of ZnO thin films at room temperature. The weighting and micro office picture manager methods are used for thickness measured. The UV spectrophotometer in range 190 nm are to 1100 nm to investigate samples ZnO thin film before and after treatment. The transmittance of ZnO thin films samples is found before annealing to approximately between zero and 2.34 % at 296 nm≤ λ≤ 302 nm at throughout UV – VIS regions . Also the film show that the optical absorbance high in UV region then decay exponentially with increasing the wavelength . After annealing temperature, it was noticed that the optical transmittance increased linearly with increasing temperature . The film high transmittance value 69% in wavelength 400 nm at 550 ̊C with lower thickness (0.009 μm) . And the film is lower transmittance value approximately 0% in wavelength 301 nm at lower temperature 450 ̊C. Also the film show increase of the optical absorbance with decrease of temperature where the beak value in UV region at wavelength 301nm at 450 ̊C with higher thickness , then decreasing with increasing wavelength to reach lower value approximately at wavelength 316nm at higher temperature 550 ̊C . Other samples at constant temperatures in 500 ̊C show the film high transmittance approximately (1.97%) in UV region at wavelength 292 nm at 500 ̊C, and the film show peak absorbance in UV region at wavelength 301 nm then decreasing with 2 increasing wavelength throughout UV-VIS-NIR regions at 500 ̊C . Finally some samples annealed with laser radiation at 20 minutes . These samples show the increasing of transmittance and decreasing of absorbance after annealing with laser radiation throughout UV-VIS- NIR regions . Also we notice increasing of transmittance and decreasing of absorbance with laser radiation at 20 minutes exposuredItem دراسات جيولوجية اقتصادية لخامات ولاية النيل الأبيض(جامعة النيلين, 2007) أمل صالح أحمد الزينItem Molecular Genotyping of Methicillin Resistant Staphylococcus aureus in Khartoum Teaching Hospital(Al Neelain University, 2009) Eidha Ali Awadh Bin HameedAbstract Introduction Methicillin-resistant Staphylococcus aureus (MRSA) is a major problem in hospitals around the world. There is a growing concern about the rapid rise in resistance of nosocomial infections to antimicrobial agents. The aims of present study were to determine the frequency rate of infection of MRSA strains in Khartoum Teaching Hospital and to define the molecular genotyping of Staphylococcus aureus strains using polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Materials and methods This is a cross-sectional study performed to detect the methicillin resistant S. aureus (MRSA) isolates collected from Khartoum Teaching Hospital during September 2005 and August 2007 by various molecular genotyping methods. The samples were collected from clinical wound specimens in the wards of surgery, orthopaedic and burns, then processed, cultured and subsequently susceptibility test was performed using disc diffusion method. Polymerase chain reaction (PCR) was used to amplify a sequence of the S. aureus specific gene, methicillin resistant (mecA) gene and coagulase (coa) gene. PCR-restriction fragment length polymorphism (RFLP) based on coagulase gene polymorphism was also evaluated by Alu1 restriction enzyme. Results Forty eight S. aureus isolates were collected and the number of MRSA identified was 9(18.75%). All strains of MRSA and MSSA were sensitive to vancomycin, while multi-drug resistance was observed to be common among MRSA strains. The isolates were classified into 3 groups; group І: S. aureus isolated from the surgical ward (No. =28; 58.3%), group ІІ: S. aureus isolated from the orthopaedic ward (No. =14; 29.2%), and group ІІІ: S. aureus isolated from the burns unit (No. =6; 12.5%). PCR amplification of the S. aureus specific gene produced at 107 bp of all isolates. mecA gene yielded the amplicon size at 1319 bp (9/48), and coa gene produced amplification products approximately at 500 bp (26/48), and 580 bp (22/48). Two distinct PCR-restriction fragment length polymorphism (RFLP) patterns of coagulase gene exhibited among isolates of S. aureus; coaA and coaB. With AluΙ restriction enzyme digested, the product fragments were approximately at 190, 310 bp and 190, 390 bp with percentages of 54.2% (26/48) and 45.8% (22/48) respectively. Conclusion Wound infections showed common multiple antibiotic resistant of MRSA. The PCR assay appears to be more reliable and accurate test for both the genus and the species of S. aureus, as well as for detection of MRSAPBP. PCR-RFLP represents a powerful, rapid, and reliable molecular genotyping system for detection of S. aureus in hospitals. The PCR assay appears to be more reliable and accurate test for both the genus and the species of S. aureus, as well as for detection of MRSA-PBP. PCR-RFLP represents a powerful, rapid, and reliable molecular genotyping system for detection of S. aureus in hospitals. الخلاصــــة مقدمــة تمثل جراثيم المكورات العنقودية الذهبية المقاومة للميثيسيللين (MRSA) مشكلة صحية كبيرة في جميع مستشفيات العالم. ووجد أن معدل انتشار مقاومة جراثيم المكورات العنقودية الذهبية للمضادات الحيوية في زيادة متسارعة وخصوصا في العدوى المكتسبة في المستشفيات، لذا هدفت هذه الدراسة لتحديد معدل تكرار الإصابة بجراثيم المكورات العنقودية الذهبية المقاومة للمثيسيللين وتحديد أنماط انتشار حساسية المضادات الحيوية لهذه الجراثيم في مستشفى الخرطوم التعليمي في السودان، وتحليل النمط الجزيئي لهذه الجراثيم بواسطة اختبار تفاعل البلمرة التسلسلي (PCR) وتحديد الطول الجزيئي المحدد التبايني (PCR-RFLP). منهجيـة الدراســة هذه دراسة مقطعية لتشخيص جراثيم المكورات العنقودية الذهبية المقاومة للميثيسيلين (MRSA) المعزولة من مستشفى الخرطوم التعليمي في الفترة من سبتمبر 2005 إلى أغسطس 2007 م بطرق التنميط الجيني لمعرفة مصدر وانتشار العدوى المكتسبة بهذه الجراثيم. جمعت عينات جراثيم المكورات العنقودية الذهبية من أنواع مختلفة للجروح السريرية في أقسام الجراحة والعظام ووحدة الحروق بمستشفى الخرطوم التعليمي. جميع هذه العزلات تم تزريعها ودراسة حساسيتها للمضادات الحيوية بطريقة الانتشار من الأقراص. بالنسبة للخصائص الجزيئية للجينات فقد تحديدها بواسطة اختبار تفاعل البلمرة التسلسلي (PCR) للجين النوعي للمكورات العنقودية الذهبية (S. aureus specific gene) والجين المسئول عن وجود المقاومة للميثيسيلين (mecA gene) وجين إنزيم التلزن (coagulase gene)، أما الطول الجزيئي لإنزيم التلزن فتم تحديده بواسطة اختبار تفاعل البلمرة التسلسلي وتحديد الطول الجزيئي المحدد التبايني (PCR-RFLP) بواسطة الإنزيم القاطع Alu1. النتـــــائج تم عزل 48 من جراثيم المكورات العنقودية الذهبية بنجاح وتم التعرف على 9 منها كانت مقاومة للميثيسيلين وهي تمثل نسبة 18,75%. أظهرت النتائج أن جميع عزلات المكورات العنقودية الذهبية المقاومة والحساسة للميثيسيللين كانت حساسة للفانكومايسين، وأن المقاومات المركبة للمضادات الحيوية كانت شائعة في جراثيم الـ MRSA. قسمت جراثيم المكورات العنقودية الذهبية إلى 3 مجموعات: المجموعة الأولى من قسم الجراحة وعددها 28 (58.3%)، المجموعة الثانية من قسم العظام وعددها 14 (29.2%)، المجموعة الثالثة من وحدة الحروق وعددها 6 (12.5%). تفاعل البلمرة التسلسلي (PCR) للجين النوعي للمكورات العنقودية الذهبية (S. aureus specific gene) وجد عند 107 bp لجميع العزلات، والجين المسئول عن وجود المقاومة للميثيسيلين (mecA gene) وجد عند 1319 bp لعدد 9 عزلات، وجين إنزيم التلزن (coagulase gene) وجد تقريبًا عند 500 bp (26/48) و 580 bp (22/48). أما تفاعل البلمرة التسلسلي وتحديد الطول الجزيئي المحدد التبايني (PCR-RFLP) لإنزيم التلزن لجراثيم المكورات العنقودية الذهبية بواسطة الإنزيم القاطع AluI فقد وجد أن هناك نمطين coaA وcoaB عند 190, 310 bp و 190, 390 bp تقريبًا وبهذه النسب 54.2% (26/48) و 45.8% (22/48) على التوالي. الخلاصــة يستخلص من هذه الدراسة أن تكرار المقاومة والمقاومة المركبة للمضادات الحيوية لجراثيم الـ MRSA شائعة في الجروح الملتهبة. إن اختبار تفاعل البلمرة التسلسلي كان أكثر ثقة ودقة لتحديد الجينات المسؤلة عن الجنس والنوع لجراثيم المكورات العنقودية الذهبية بالإضافة إلى تحديد الجين المسئول عن المقاومة للميثيسيللين. يمثل فحص تفاعل البلمرة التسلسلي وتحديد الطول الجزيئي المحدد التبايني نظاماً أكثر ثقة ودقة للتنميط الجزيئي لجراثيم المكورات العنقودية الذهبية وانتشارها في المستشفيات