Browsing by Author "Omari, Athumani"

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    Analysis and derivatization of castor oils extracted from castor seeds collected from six regions in Tanzania
    (University of Dar es Salaam, 2014) Omari, Athumani
    The oil yields, physico-chemical parameters and the fatty acid profiles of castor oils extracted from seeds collected from different regions in Tanzania were determined. The oil was extracted from castor seeds by Soxhlet method using n-hexane solvent and its physico-chemical analysis was done using standard methods with some minor modifications. The physico-chemical properties were, oil yields (43.69% -52.78 %), refractive index (1.468-1.473), pH(5.7- 6.3), viscosity (0.943 - 0.954), specific gravity (165.50 – 187.46 mg KOH/g Oil), saponification value (76.68- 80.12 g I2/100 g Oil), iodine value(0.44- 1.97 mg NaOH/g Oil), acid value, free fatty acid (0.22- 0.99) and peroxide value (10.79 – 13.73). Castor seeds collected from Dodoma had the highest oil yield of 52.78% while those from Dar es Salaam had the lowest yield of 43.69%. The fatty acid profile of the castor oil was determined from prepared FAME of each sample using GC-MS and ricinoleic acid which was found to range between 83.5% and 92.3 %. A series of oxidation reactions on castor oil was done using Pyridinium chlorochromate (PCC) converting it to ketone (2,3-Bis[[(Z)-12-oxooctadec-9-enoyl]oxy]propyl(E)-12-oxooctadec-9-enoate) and then the ketone to ester (2,3-Bis[[(Z)-11-heptanoyloxyundec-9-enoyl]oxy]propyl(E)-11-heptanoylundec-9-enoate) by m-CPBA (Baeyer Villiger oxidation). The chemical structures of these compounds were elucidated using ATR-FTIR, 1H-NMR and 13C-NMR techniques. This study has produced the first report on the oil yield, fatty acid profile and physicochemical properties of castor oil extracted from castor beans harvested from six regions of Tanzania.
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    An sms-based systems for remote verification of motor vehicle registration status
    (University of Dar es Salaam, 2011) Omari, Athumani
    The absence of a possibility for timely retrieval of motor vehicle registration details when needed on site impedes the normal operations of day to day activities of the Tanzanian Traffic Police Department that deals with, among other things, verification of motor vehicles registration status during road patrol. The verification procedures in place are somehow difficult to be implemented since they consume money and time, however, they do not motivates the traffic polices to perform their duties effectively and efficiently. Along this dissertation. I have proposed and developed the two-way interactive text messaging prototype system that will help the traffic police department in having a capacity to timely and flexibly retrieve motor vehicle registration details from a remote Motor Vehicle Registration (MVR) database while on site using a mobile handset. The proposed system makes use of Short Message Service (SMS) technology platform found in mobile telecommunication operators. In attaining the system development, the findings of the study was specifically based on five steps of software development in which one is required to go through. These are; system requirements elicitation, system analysis, system design, system implementation, and system testing. A prototype system called Remote Vehicle Registration Verifier (RVRV) has been developed and tested. According to the tested results, the prototype system meets the defined objective. System users were allowed to send requests towards the system using SMS and the system was able to responds back the requested information of a registered motor vehicle from MVR database through their mobile handsets. Nothing is perfect like an angel; a prototype system developed like other systems has some limitations caused by the technology used. These are: The SMS technology does not guarantee set transmission times or guaranteed delivery of the message; therefore some messages may be delayed, blocked or lost.