Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

University of Dar es Salaam

Discipline
Keyword
Publication Year
Publication
File Type

Articles 1951 - 1980 of 2227

Full-Text Articles in Entire DC Network

Absolute Migration And The Evolution Of The Rodriguez Triple Junction Since 75 Ma, D. C. P. Masalu Dec 2002

Absolute Migration And The Evolution Of The Rodriguez Triple Junction Since 75 Ma, D. C. P. Masalu

Tanzania Journal of Science

The Rodriguez Triple Junction (RTJ) is a junction connecting three mid-ocean ridges in the Indian Ocean: the Southwest Indian Ridge (SWIR), the Central Indian Ridge (CIR) and the Southeast Indian Ridge (SEIR). The evolution of the RTJ has been studied extensively for the past 10 Ma and the triple junction is believed to be largely a ridge-ridge-ridge (RRR) triple junction. However, due to the scarcity of data, its configuration prior to that period is poorly understood. The migration of the RTJ in the hotspot reference frame, for the past 75 million years has been mapped, by reconstructing its traces on …


Engineering Geological Mapping Of Dar Es Salaam City, Tanzania, K. A. Msindai Dec 2002

Engineering Geological Mapping Of Dar Es Salaam City, Tanzania, K. A. Msindai

Tanzania Journal of Science

Engineering geological mapping of Dar es Salaam city in Tanzania has been carried out using desk studies supplemented by field reconnaissance as well as limited laboratory tests. Desk studies involved interpretation of medium to large-scale topographical maps, Landsat imagery and sequential aerial photographs from 1953-1990. These studies also evaluated small to medium scale geological, pedological maps together with ground water data from 50 boreholes. Two basic maps were prepared, namely, geomorphological and geological map depicts the spatial extent of the Neogene geological formations. Three distinct sandstone terraces could be distinguished in Dar es Salaam region at 0-15 m and 30 …


A Simple Method For Indexing Powder Diffraction Patterns Of Cubic Materials:(1) Using The Θ-Values Of Reference, Me Kamwaya Nov 2002

A Simple Method For Indexing Powder Diffraction Patterns Of Cubic Materials:(1) Using The Θ-Values Of Reference, Me Kamwaya

Tanzania Journal of Science

From the values of sin2θ taken from powder photographs of the cubic crystal system, a variable constant, K, which is a multiple of (h2 + k2 + l2) can be determined. The smallest value of sin2θ1 gives rise to a multiple of one, two, or three which corresponds to the smallest value of Σhl2 for the primitive, bcc and fcc crystals, respectively. The old assumption that when indexing, the occurrence of numbers of the form (h2 + k2 + l2) = 8n + 7, where n = 0.1.2.3… should cause each of (h2 + k2 + l2) to be multiplied …


Optimization Of Edxrf For The Study Of Heavy Metal Pollution Of Lake Victoria, Nk Mahommed, In Makundi Nov 2002

Optimization Of Edxrf For The Study Of Heavy Metal Pollution Of Lake Victoria, Nk Mahommed, In Makundi

Tanzania Journal of Science

This study reports on the optimisation and calibration of the Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer installed in the Department of Physics, University of Dar es Salaam. The spectrometer was subsequently utilized to determine concentrations of heavy metals in water hyacinth (Eichhornia crassipes (Mart) Solms.) found growing along the shore of Lake Victoria. The optimal conditions and detection limits were determined experimentally by variation of the excitation parameters. The study found that the use of a collimator with two apertures of diameter 4 mm each placed 8 mm apart and made of materials that do not interfere with elements to …


Comparison Of Various Methods For Estimating Wave Incident Angles In The Nearshore Zone, As Ngusaru Nov 2002

Comparison Of Various Methods For Estimating Wave Incident Angles In The Nearshore Zone, As Ngusaru

Tanzania Journal of Science

Five different methods were examined for their suitability in estimating the inshore wave incident angles on a nearshore zone with a complex topography. Visual observation provided preliminary estimates. Two frequency independent methods and one frequency dependent method based on current meter measurements were examined. Another frequency dependent method based on collocated bottom pressure and current meter measurements was also examined. The results from all the methods provided a reasonably consistent estimate of the inshore wave incident angles. The frequency independent methods gave exactly the same results while the frequency dependent methods had a 5% relative error among themselves. Between frequency …


The Polarising Effects In Sintered Kaolin, Fm D'Ujanga, Y Kaahwa, L Atteraas Nov 2002

The Polarising Effects In Sintered Kaolin, Fm D'Ujanga, Y Kaahwa, L Atteraas

Tanzania Journal of Science

The polarizing effects in sintered kaolin samples were analysed in terms of the sample density (or porosity) using direct current (dc) techniques. More porous samples exhibited higher polarizing effects than the less porous ones. The conduction carriers in kaolin samples at room temperature were found to be mainly electrons, with ionic conduction being enhanced by the moisture content with the pores. The influence of the uniaxial pressure and particle-size on the compacted and sintered density of the ceramic have been studied, and a density-pressure relationship before- and after-sintering conditions obtained


Studies On Benthic Denitrification In The Chwaka Bay Mangrove Sediments, Zanzibar, Sm Mahommed, Rw Johnstone Nov 2002

Studies On Benthic Denitrification In The Chwaka Bay Mangrove Sediments, Zanzibar, Sm Mahommed, Rw Johnstone

Tanzania Journal of Science

Denitrification was measured at three sites in a narrow tidal creek in the Chwaka mangrove ecosystem. Denitrification arising from water column nitrate (Dw) was low (< 0.1μM Nm-2h-1) and there was little spatial and seasonal variation in Dw rates in the creek. Coupled nitrification-denitrification (Dn) was found to be low, but within the range measured in other mangrove sediments. Average values ranged from 0.01 to 0.45 μM Nm-2h-1 and showed strong spatial variations. The low denitrifcation rates observed in the creek were possibly as a result of the low availability of NO3 and high C:N values of the organic matter in the sediment. Spatial variations in denitrification rates were due to variations in concentration levels of organic matter and possibly to disproportionate competition for inorganic nitrogen between denitrifiers and benthic autotrophs among sites. There were no seasonal differences in denitrification rates. Results from the present study suggest that sediment denitrification does not play a major role as a sink for N in this ecosystem


Interpretation Of Refelction Seismic Data From The Usangu Basin, East African Rift System, Ei Mbede Nov 2002

Interpretation Of Refelction Seismic Data From The Usangu Basin, East African Rift System, Ei Mbede

Tanzania Journal of Science

Reflection seismic data collected by AMOCO Tanzania Oil Company in the 80s, are herin used to correlate the main Usangu Basin parameters to those estimated from outcrop, gravity and aeromagnetic data. The seismic data are further used to constrain the geometry of crustal extension in this south-western sector of the East African Rift System (EARS) in Tanzania. Three distinct sedimentary packages on top of the basement reflector are interpreted and correlated to the Permo-Carboniferous Karoo rocks, the Jurassic/Cretaceous and Miocene Red Sandstone Group and Miocene to recent Lake Beds in the adjacent Rukwa basin, where the ages of the sedimentary …


Tectonic Setting Of Gabbroic Rocks In The Western Part Of The Lupa Gold Field, South-West Tanzania, Sr Mnali Nov 2002

Tectonic Setting Of Gabbroic Rocks In The Western Part Of The Lupa Gold Field, South-West Tanzania, Sr Mnali

Tanzania Journal of Science

There is a pronounced occurrence of gabbroic rocks in the western part of the Lupa gold field, SW Tanzania. These rocks occur in the peripheral part around the Saza-Chuya granodiorite with which it makes a gradiational, unchilled contact. The rocks have been altered or metamorphosed to low-grade greenschist facies as indicated by the presence of secondary epidote, penninite, chlorite, sericite and calcite. The majority of major-element oxides show scattered variation trends against immobile elements such as Zr, indicating some degree of element mobility during post-crystallization processes of alteration or metamorphism. Major-trace-element data show that the gabbroic rocks in the study …


Identification Of Mushroom Mycelia Using Dna Techniques, Mhs Muruke, Ak Kivaisi, Fss Magingo, E Danell Nov 2002

Identification Of Mushroom Mycelia Using Dna Techniques, Mhs Muruke, Ak Kivaisi, Fss Magingo, E Danell

Tanzania Journal of Science

The suitability of using DNA techniques in the determination of relatedness of mushroom fruiting bodies to isolated mycelia was examined. Nine isolates of edible mushroom mycelia of general Oudemansiella, Coprinus and Pleurotus were identified using fruiting bodies as references. Polymerase Chain Reaction (PCR) in conbination with Restriction Fragment Length Polymorphism (RLFP) analyses were carried out on fruiting bodies and mycelia of the isolates. The internally transcribed spacer region (ITS) and ribosomal RNA gene (rDNA) was amplified using ITS1 and ITS4 primers. The RLFP analysis was carried out on the regions amplified by PCR from fruiting bodies and the mycelia was …


Mobility And Immobility Of Mid-Ocean Ridges And Their Implications To Mantle Dynamics, Me Kamwaya Nov 2002

Mobility And Immobility Of Mid-Ocean Ridges And Their Implications To Mantle Dynamics, Me Kamwaya

Tanzania Journal of Science

In the past two decades, the mobility of mid-ocean ridges relative to the mantle (absolute migration) have been correlated with major observable features, such as, spreading asymmetry and asymmetry in the abundance of seamounts. The mobility of mid-ocean ridges is also thought to be an important factor that influences the diversity of ridge-crest basalts. However, the mobility of mid-ocean ridges have not yet been defined and mapped. The absolute migration of global mid-ocean ridges since 85 Ma has been computed and mapped. Global mid-ocean ridges have migrated extensively at varying velocities during that period. Presently, the fast-migrating ridges are the …


Analysis On Possible Solution To Decreasing The Effect Of Non-Uniform Air-Gaps Due To Rotor Eccentricity In Asynchronous Machines, Dominic Chambega Jun 2002

Analysis On Possible Solution To Decreasing The Effect Of Non-Uniform Air-Gaps Due To Rotor Eccentricity In Asynchronous Machines, Dominic Chambega

Tanzania Journal of Engineering and Technology (TJET)

Rotor eccentricity introduces non-uniformity of the airgap which in turn causes additional frictional torques and losses in addition to establishing a uni-directional pulling magnetic force which is disastrous to the machine. This paper analyses the extent of the damage to the machine due to non-uniformity of the air-gap and proposes increasing the number of poles as a possible solution to arrest the effect. It is found through the analysis that as the number of poles increases the effect of eccentricity decreases.


Comparison Of Repair Costs Of Two Wheel Drive Tractors Under Tanzania Conditions, S. M. Mpanduji Jun 2002

Comparison Of Repair Costs Of Two Wheel Drive Tractors Under Tanzania Conditions, S. M. Mpanduji

Tanzania Journal of Engineering and Technology (TJET)

The repair costs of 2WD tractors were investigated in order to provide important information, which lacks in the scope of agricultural mechanization in Tanzania. Previously repair cost functions established for tractors in developed countries were used for both theoretical and practical purposes. The findings of this study have revealed that repair costs of tractors vary substantially from one make to another. The prediction functions developed in this study indicated that the magnitudes of repair costs in Tanzania are higher than the repair costs established in Europe and North America. The reason for this could be either due to high cost …


Evaluation Of Water Levevaluation Of Water Levels In Relation To The Design Of Coastal Structures In Tanzaniaels In Relation To The Design Of Coastal Structures In Tanzania, Alfonse Dubi Jun 2002

Evaluation Of Water Levevaluation Of Water Levels In Relation To The Design Of Coastal Structures In Tanzaniaels In Relation To The Design Of Coastal Structures In Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Water levels on the coastline of Tanzania vary under the influence of meteorological conditions (winds and barometric pressure) and the East African Coastal Current, whose strength varies with the monsoon winds. Available tidal information is not enough to warrant statistical analysis for evaluating extreme water levels. The highest mean water springs occur at Bagamoyo and Pangani (3.93 m) and the lowest are found at Lindi (2.96 m). The highest astronomical tide is 3.7 m for Dar es Salaam and 4.6 m for Zanzibar, both of which occur during March/April and November. Measured highest water levels approach 4.80 m for Dar …


Evaluation Of Corrosion Inhibitor On Pre-Corroded Carbon Steel In Co2 Medium By Impedance Spectroscopy, Joseph Buchweishaija Jun 2002

Evaluation Of Corrosion Inhibitor On Pre-Corroded Carbon Steel In Co2 Medium By Impedance Spectroscopy, Joseph Buchweishaija

Tanzania Journal of Engineering and Technology (TJET)

The effect of pre-corrosion of carbon steel on the performance of a commercial amine based fatty acid corrosion inhibitor, KI384, was investigated in formation water solutions saturated with CO₂ using electrochemical impedance spectroscopy (EIS) measurements. The investigation was performed at constant partial pressure of CO₂ using an autoclave system with Rotating Cylinder Electrodes (RCE). Carbon steel was pre-corroded for periods up to 7 days at 35 and 80 °C in the test solution prior to inhibitor injection. The results showed that when KI384 was applied on non-corroded carbon steel specimen, high inhibitor performance (99.8 %) was achieved independent of temperature. …


Investigation Of Forces Acting On Plain Discs, S. M. Mpanduji Jun 2002

Investigation Of Forces Acting On Plain Discs, S. M. Mpanduji

Tanzania Journal of Engineering and Technology (TJET)

An investigation was carried out to study the mutually perpendicular forces generated by rotating and non-rotating plain discs similar to those used in disc ploughs. Experiments were conducted in a soil bin containing sand loam soil (Ryton sand) where forces were measured while changing disc rake and sweep angles. The results showed that draught forces were higher for non-rotating discs, while vertical and lateral forces were lower compared to rotating discs. Rotating discs were found to be suitable for counteracting high side forces because of less draught and higher lateral forces. The recommended optimum angles are between 8°–12° for disc …


Comparative Analysis Of H₂S Removal Ability Of Different Calcium-Based Absorbents Under Coal Gasification Conditions, Hassan Katalambula Jun 2002

Comparative Analysis Of H₂S Removal Ability Of Different Calcium-Based Absorbents Under Coal Gasification Conditions, Hassan Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Calcium-based sorbents, such as limestone and dolomite are viable candidates for capturing pollutants in an in-situ coal gasification/desulphurisation process. Recently, scallop shell is also used as a Ca-based sorbent. However, the ability in capturing pollutants varies from one type to another and it also depends on the process involved. In this study, two types of limestone, scallop shell and dolomite were characterized and studied for H₂S absorption ability under the coal gasification conditions. The characterizations were done using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Thermal analysis and Surface Area analysis. All of the samples showed a porous structure, and …


A Comparative Application Of Telecommunication Traffic Forecasting Methods To A Backbone Link In Tanzania, M. L. Luhanga Jun 2002

A Comparative Application Of Telecommunication Traffic Forecasting Methods To A Backbone Link In Tanzania, M. L. Luhanga

Tanzania Journal of Engineering and Technology (TJET)

In this paper various mathematical models to characterize and forecast telecommunication traffic time series traffic have been applied, and the ranges of validity of the models are determined by comparing them with measured traffic data using the measurement errors criteria method which resulted into the superior model. Based on this model the ARIMA (0,2,1) model for smoothed data, the traffic forecast findings show that by the year 2006, the traffic demand will exceed the current installed capacity of 140 Mbps in the Tanzania Telecommunications Company Limited (TTCL) network along the major link between the Dar es Salaam and Dodoma backbone …


Requirements Of A Sustainable Pavement Management System For Tanzania, N. K.M. Mushule Jun 2002

Requirements Of A Sustainable Pavement Management System For Tanzania, N. K.M. Mushule

Tanzania Journal of Engineering and Technology (TJET)

Since the introduction of pavement management concepts in mid-1960s, more than three decades ago, a considerable number of Pavement Management Systems (PMS) have been developed and implemented widely in many parts of the world. These systems differ in scope and sophistication. However, in some cases, pavement management systems have fallen into marginal use, if not into complete disuse, because of a number of reasons. One of the major reasons leading to the marginalisation or abandonment of pavement management systems, is the failure of system developers to recognise specific and unique needs of the agency or authority responsible for road management. …


Assessment Of Heavy Metal Pollution In The Lupa Gold Field, Sw Tanzania, S. R. Mnali Dec 2001

Assessment Of Heavy Metal Pollution In The Lupa Gold Field, Sw Tanzania, S. R. Mnali

Tanzania Journal of Science

The concentrations of AS, Cd, Cr, Cu, Hg and Pb were determined in water, stream sediments, soil, and mine tailings from Lupa Gold Field (LGF), SW Tanzania, in order to assess their pollution levels. As, Cd and Cr were determined by automated Graphite Furnace Absorption Spectrophotometry. Cu and Pb were analysed by Air-Acetylene Flame, while Hg was analysed by Cold Vapour Atomic Absorption Spectrophotometry. The mean concentrations obtained were: As: 0.44 ppb (water), 1.2 ppm (sediments), 0.44 ppm (soil) and 5.2 ppm (tailings); Cd: 0.03 ppb (water), 0.03 ppm (sediments), 0.03 ppm (soil) and 0.50 ppm (tailings); Cr: 1.4 ppb …


Tectonic Setting And Uplift Analysis Of The Pangani Rift Basin In Northern Tanzania Using Apatite Fission Track Thermochronology, E. I. Mbede Dec 2001

Tectonic Setting And Uplift Analysis Of The Pangani Rift Basin In Northern Tanzania Using Apatite Fission Track Thermochronology, E. I. Mbede

Tanzania Journal of Science

Thirty four new Apatite Fission Track (AFT) ages and 32 track length distributions from samples of basement rocks flanking the Pangani rift, East African Rift System (EARS) are presented, in an attempt to elucidate the uplift and erosion of the rift flanks. The ages fall in the range of 207±15 to 48±4 Ma, spanning from Early Jurassic to Early Tertiary. These ages are much younger than the last termal event in the Mozambique belt that form the basement complex and are interpreted to represent the most recent tectonic events. Track length (TL) distributions suggest that uplift and erosion of the …


Sources And Diagenetic Alteration Of Organic Matter In Coastal Waters At The Vicinity Of Dar Es Salaam, Tanzania, Ann Muzuka Dec 2001

Sources And Diagenetic Alteration Of Organic Matter In Coastal Waters At The Vicinity Of Dar Es Salaam, Tanzania, Ann Muzuka

Tanzania Journal of Science

The stable isotope compositions of organic carbon (OC) and nitrogen, contents of OC and nitrogen, and C/N ratios for four short cores, which were recovered from Msansani Bay (WO 57), off Msimbazi River (WO 76) and Dar es Salaam harbour (WO 62 and WO 74), are used to document temporal variation in the sources and diagenetic alteration of organic matter (OM). The δ15N and δ13C values at sites WO 57, WO 62 and WO 74 show a trend of down-core decrease to the base of the core, and such a down-core trend could be related to diagenetic loss of compounds …


The Occurrence Of Digenean Larvae In Freshwater Snails At Mbezi-Temboni Pond, Dar Es Salaam, Esp Esp Kigadye, G. Nkwengulila Dec 2001

The Occurrence Of Digenean Larvae In Freshwater Snails At Mbezi-Temboni Pond, Dar Es Salaam, Esp Esp Kigadye, G. Nkwengulila

Tanzania Journal of Science

The abundance of digenean larvae in snails at a pond in Mbezi-Temboni, Dar es Salaam, was investigated from July 1996 to June 1997. A total of 2,112 snails belonging to three species, Bulinus globosus Morelet 1866, Bulinus forskalii Ehrenberg 1869, and Melanoides tuberculata Müller 1774 were examined, and 28 (1.3%) were found infected by four species of digenean trematodes. Trematodes were recovered only from Bulinus species; none of the examined M. tuberculata was infected. B. globosus was infected by Schistosoma haematobium Bilharz 1852 (1.14%), unidentified furcocercous cercariae (0.4%), and echinostome cercariae (0.76%). B. forskalii was infected by echinostome cercariae (0.25%) …


Experimental Spat Collecting Of The Edible Oyster, Saccostrea Cucullata Born (Bivalvia) In The Kundichi Creek, Dar Es Salaam, Y. D. Mgaya Dec 2001

Experimental Spat Collecting Of The Edible Oyster, Saccostrea Cucullata Born (Bivalvia) In The Kundichi Creek, Dar Es Salaam, Y. D. Mgaya

Tanzania Journal of Science

A one year study was carried out at Kunduchi Creek, Dar es Salaam, to determine spat settlement using the three different substrates (clutches): coconut shells, asbestos and cockle shells, set at three different depths, 0.5 m, 1 m, and 1.5 m. The experiment was set up at three different sites within the creek. There were no significant differences among treatments (sites, depths, clutches). However, spat settlement exhibited seasonal differences, with peak spatfall recorded during the long rains (April to May). There were significant differences in the number of spat between the upper and lower surfaces of the substrates, with more …


The Emplacement Age Of Gabbroic Rocks And Associated Granitoids Of The Liganga-Msanyo Complex, South Eastern Tanzania, M. A. H. Maboko Dec 2001

The Emplacement Age Of Gabbroic Rocks And Associated Granitoids Of The Liganga-Msanyo Complex, South Eastern Tanzania, M. A. H. Maboko

Tanzania Journal of Science

The Msanyo Gabbro and the associated Mdando granitoids, which intrude Paleoproterozoic high-grade metamorphic rocks of the Ubendian Belt in southern Tanzania, yield imprecise Sm-Nd whole rock isochron ages of 1608±134 Ma (ε (Nd) = 2.1) and 1642±100 Ma (ε (Nd) = 1.6), respectively. These ages are indistinguishable at the 95% confidence level, indicating that the two rock suites were intruded at the same time. A more precise estimate of the time of emplacement is provided by a 5-point mineral isochron age of 1505±42 obtained from one of the gabbro samples. Calculated initial ε (Nd) values and mean crustal residence ages …


The Geochemistry Of Banded Iron Formations In The Sukumaland Greenstone Belt Of Geita, Northern Tanzania: Evidence For Mixing Of Hydrothermal And Clastic Sources Of The Chemical Elements, M A H Maboko Jul 2001

The Geochemistry Of Banded Iron Formations In The Sukumaland Greenstone Belt Of Geita, Northern Tanzania: Evidence For Mixing Of Hydrothermal And Clastic Sources Of The Chemical Elements, M A H Maboko

Tanzania Journal of Science

Major and trace element compositions of samples of Banded Iron Formations (BIF) from the Neoarchaean Sukumaland Greenstone Belt of Geita in northern Tanzania reveal that the BIF precipitated from hydrothermal solutions. Fe-Ti-Al-Mn systematics suggest that the hydrothermal deposits have been contaminated, by up to 20% by weight, with detrital material having a composition similar to modern deep-sea pelagic clays. SiO2 and Fe2O3 contents are 48.2 to 88.5% and 8.9 to 49.1% respectively. Al2O3 contents lie between 0.33 and 2.1% and show no correlation with either Fe2O3 or SiO2. Al2O3 is, however, positively correlated with Ti, Ga, Hf, Rb,Th, Zr and …


Production Of Cell Wall Enzymes In Pepper Seedlings, Inoculated With Arbuscular Mycorrhiza Glomus Etunicatum, A C Odebode, A O Salami, O Osunubi Jul 2001

Production Of Cell Wall Enzymes In Pepper Seedlings, Inoculated With Arbuscular Mycorrhiza Glomus Etunicatum, A C Odebode, A O Salami, O Osunubi

Tanzania Journal of Science

Pepper seedlings inoculated with arbuscular mycorrhizal AM fungus, Glomus etunicatum, produced cellulase, polygal-acturonase and pectin methylestrase enzymes. The activities of the enzymes increased as the pepper seedlings matured in age, showing that the activity of the enzymes in the seedlings was age mediated. The pectinases showed higher activity than the cellulase enzyme which may indicate establishment of the mycorrhizal in the host. The significance of this finding is that there is an initial infectivity factor in (AM) fungi interactions with plant just like in other host-parasite interaction.


Physicochemical Characteristics Of Some Locally Manufactured Edible Vegetable Oils Marketed In Dar Es Salaam, F N Ngassapa, O C Othman Jul 2001

Physicochemical Characteristics Of Some Locally Manufactured Edible Vegetable Oils Marketed In Dar Es Salaam, F N Ngassapa, O C Othman

Tanzania Journal of Science

The physicochemical properties (refractive index, saponification value, Free Fatty Acid (FFA) value, iodine value, acid value, peroxide value and tocopherol content) of seven edible vegetable oils manufactured in Tanzania, were assessed using standard procedures of the Association of Official Analytical Chemists (AOAC). Also determined were the levels of these properties with respect to shelf storage of the products. When compared with standard values recommended by the Codex Alimentarius Commission of FAO/WHO and with other published results, the locally produced vegetable oils were found to be of fair quality but of poor storage stability.


Comparison Of Direct Return And Birth-Death Return Receivers, H N Kundaeli Jul 2001

Comparison Of Direct Return And Birth-Death Return Receivers, H N Kundaeli

Tanzania Journal of Science

The performance of frame synchronized communication systems is governed largely by the design chosen for the receiver. Some systems employ a structure in which the receiver returns directly to the sync phase when a valid marker is encountered while in the loss verify state. These have been greatly studied. In some systems, the return path in the loss verify phase is implemented as a birth-death process. These systems have not received much attention. In this report, a receiver which employs a birth-death like structure in the loss path is investigated. Expressions for the performance parameters are derived and compared with …


Occurrence And Activity Budget Of The Leopard Tortoise, Geochelone Pardalis, In Northern Tanzania, J Kabigumila Jul 2001

Occurrence And Activity Budget Of The Leopard Tortoise, Geochelone Pardalis, In Northern Tanzania, J Kabigumila

Tanzania Journal of Science

Occurrence and activity budget of the leopard tortoise, Geochelone pardalis were studied in northern Tanzania between October 1993 and June 1996. Tortoises occurred most frequently in short grass (51.5%) and along roads and track verges (33.9%), but only occasionally in the bush undergrowth (6.7%) and shambas (3.6%). Walking (46.3%) and feeding (37.2%) were the most frequent activities. Resting was observed only occasionally (13.6%) while courtship (1.9%) and drinking (0.9%) were rarely recorded. Activity budget differed significantly between the age classes and habitats, but not between the sexes. Juveniles walked more frequently (59.3%) than other age classes. Walking was most frequent …