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Levels Of Selected Toxic And Essential Elements In Fish And Oysters From Western Indian Ocean, Coast Of Tanzania, Daniel A Shilla, Shovi F Sawe
Levels Of Selected Toxic And Essential Elements In Fish And Oysters From Western Indian Ocean, Coast Of Tanzania, Daniel A Shilla, Shovi F Sawe
Tanzania Journal of Science
Concentrations of toxic and essential elements in selected finfish and shellfish collected from Dar es Salaam and Tanga, Indian Ocean coast of Tanzania are presented. The elemental concentrations were determined using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer coupled with X-lab ProTM software. The mean concentrations of metals observed in finfish and shellfish collected from Tanga ranged from 3.40–5.75, 1.8–37.17, 3.5–7.1, 0.6–1.3, 0.53–0.73 and 16.80–96.70 mg kg–1 for As, Cu, Mn, Ni, Pb and Zn, respectively. For Dar es Salaam, the mean concentrations of metals ranged from 3.34–9.46, 2.90–30.53, 3.4–6.9, 0.7–1.0, 0.57–0.80 and 14.2–100.90 mg kg–1 for As, Cu, Mn, Ni, …
Probabilistic Seismic Hazard Assessment And Site Analyses Of Arusha International Conference Centre (Aicc), Arusha, Tanzania, Richard W Ferdinand
Probabilistic Seismic Hazard Assessment And Site Analyses Of Arusha International Conference Centre (Aicc), Arusha, Tanzania, Richard W Ferdinand
Tanzania Journal of Science
This work presents the evaluation of earthquake resistance of the Arusha International Conference Centre (AICC) complex, in Tanzania. The evaluation included probabilistic seismic hazard analysis (PSHA) and site response analysis. Seismic sources considered to constitute a seismic hazard in this study were randomly occurring seismicity located within five tectonic provinces around the site. For each province the seismic hazard is based on a cursory analysis of earthquake data from compiled ESARSWG bulletins and temporary deployed networks within the North Tanzania Divergence (NTD). Bedrock response signal together with the information of material characteristics from boreholes around the AICC site were used …
Integration Of Geophysics And Remote Sensing Techniques In Mapping Zones Mineralised With Disseminated Gold And Sulphide Minerals In Lolgorien, Narok County, Kenya, Sammy O Ombiro, Akinade S Olatunji, Eliud M Mathu, Taiwo R Ajayi
Integration Of Geophysics And Remote Sensing Techniques In Mapping Zones Mineralised With Disseminated Gold And Sulphide Minerals In Lolgorien, Narok County, Kenya, Sammy O Ombiro, Akinade S Olatunji, Eliud M Mathu, Taiwo R Ajayi
Tanzania Journal of Science
Even though ground geophysical surveys (especially Induced polarization and resistivity) are applied in mineral exploration, their effectiveness in identification of mineralised zones is often enhanced by integrating other mineral exploration techniques such as remote sensing and geological investigations. Integrating different techniques helps in reducing uncertainty that is often associated with mineral exploration. The methods being integrated also depend on characteristics of mineralisation and those of host rock. In this study, geophysical survey methods (induced polarization and resistivity) were integrated with remote sensing and geological methods to delineate mineralised zones in Lolgorien beyond reasonable doubt. By integrating these methods, it was …
Probabilistic Seismic Hazard Analysis For Northern Tanzania Divergence Region And The Adjoining Areas, Michael M Msabi, Richard W Ferdinand
Probabilistic Seismic Hazard Analysis For Northern Tanzania Divergence Region And The Adjoining Areas, Michael M Msabi, Richard W Ferdinand
Tanzania Journal of Science
This paper presents the seismic hazard levels for the Northern Tanzania Divergence (NTD) and adjoining areas by using area seismic source zones. The 15 source zones were considered based on the major geological and tectonic features, faulting style, and seismicity trends. For each source, earthquake recurrence parameters were computed by using the earthquake catalogue with events compiled from 1956 to 2011. The peak ground accelerations (PGA) and spectral accelerations (SA) at 0.2 and 2.0 second, respectively, were computed for a 10% probability of exceedance in 50 years at sites defined by a 0.1° x 0.1° grid. The recurrence parameters of …
Analysis And Comparison Of Optical Performance And Collectible Solar Energy Between Multi-Sectioned Compound Parabolic Concentrator (Cpc) And Restricted Exit Angle Cpc, Damasen Ikwaba Paul
Analysis And Comparison Of Optical Performance And Collectible Solar Energy Between Multi-Sectioned Compound Parabolic Concentrator (Cpc) And Restricted Exit Angle Cpc, Damasen Ikwaba Paul
Tanzania Journal of Science
This study was conducted to analyse and compare the optical performance and collectible solar radiation energy of two different Compound Parabolic Concentrators (CPCs): multi-sectioned CPC (hereafter called M-CPC) and restricted exit angle CPC (hereafter called R-CPC) so as to ascertain the best CPC for photovoltaics applications. For easy comparison between M-CPC and R-CPC, a standard CPC (hereafter called S-CPC) was also designed. A detailed ray trace simulation analysis was undertaken to compare ray trace diagrams, angular acceptance, optical efficiency and energy flux distribution of the three CPCs. Results indicated that the angular acceptance and optical efficiency of the three CPCs …
Mineralogical And Geochemical Characteristics Of Graphite-Bearing Rocks At Chenjere Area, South-Eastern Tanzania: Implications For The Nature And Quality Of Graphite Mineralization, Charles D Moye, Michael M Msabi
Mineralogical And Geochemical Characteristics Of Graphite-Bearing Rocks At Chenjere Area, South-Eastern Tanzania: Implications For The Nature And Quality Of Graphite Mineralization, Charles D Moye, Michael M Msabi
Tanzania Journal of Science
This study focused on the mineralogical and geochemical characteristics of graphite-bearing rocks at Chenjere area by conducting surface geological mapping, geochemical and petrographical analyses with the intention of characterizing the nature of graphite occurrence in these lithological units. This paper presents results of the flake size, grade and mineralization extension of graphite in the graphitic gneiss. Field observations, petrographic investigation and comparison with other studies indicate that graphite occurrence at the Chenjere area is of sedimentary origin which fall under syngenetic type. The petrographic study revealed that nature of metamorphism of rocks in the Chenjere area is of high grade …
Geological Controls On Brine Discharge In Itumbula Salt Dam Within The Rukwa Rift In Momba District, Tanzania, Mwita S Maswi, Octavian Minja, Chakutema Batwenge
Geological Controls On Brine Discharge In Itumbula Salt Dam Within The Rukwa Rift In Momba District, Tanzania, Mwita S Maswi, Octavian Minja, Chakutema Batwenge
Tanzania Journal of Science
The Itumbula salt dam of the Rukwa Rift Basin is a depression formed through extraction of spring-derived salt crystals. Brine yield by springs which is the primary cause of significant amounts of salt in the dam required further geological investigations to understand yield controls. In this study, detailed field geological investigations in the salt dam and its surroundings were conducted to ascertain brine discharge controls. These included documentation of lithology and surface manifestations of brine deposition. Geophysical methods (i.e. magnetic and electric surveys) for studying geologic structures associated with brine deposits, and laboratory analysis of cations and anions (e.g. chlorides, …
Effects Of Xanthan Gum On Rheological Properties Of Aloe Vera-Moringa Leaf Juice Blends, Victor V Matabura, Leonard Mp Rweyemamu
Effects Of Xanthan Gum On Rheological Properties Of Aloe Vera-Moringa Leaf Juice Blends, Victor V Matabura, Leonard Mp Rweyemamu
Tanzania Journal of Science
Understanding the impacts of hydrocolloid agents on the rheological properties of nutraceutical beverages like Aloe vera-moringa juice blend is very useful for functional properties and product stability. To this end, the effects of xanthan gum on rheological properties in Aloe vera-moringa leaf juice blends were investigated using a Brookfield rheometer. Aloe vera-moringa leaf juice blends were prepared and then incorporated with xanthan gum at different ratios (w/w) of 0.2%, 0.4%, 0.6%, 0.8%, and 1%. The results revealed that the viscosity of Aloe vera-moringa juice blend was strongly affected by the xanthan gum addition. The viscosity profiles depicted a decreasing trend …
Assessment Of Natural Radioactivity And Radiation Hazards Of Building Materials In Kinondoni District, Dar Es Salaam, Tanzania, Huruma P Mammba, Vitus A Balobegwa, Alex P Muhulo, Peter A Pantaleo, Remigius A Kawala
Assessment Of Natural Radioactivity And Radiation Hazards Of Building Materials In Kinondoni District, Dar Es Salaam, Tanzania, Huruma P Mammba, Vitus A Balobegwa, Alex P Muhulo, Peter A Pantaleo, Remigius A Kawala
Tanzania Journal of Science
Natural radionuclides from building materials are one of the potential sources of external as well as internal radiation exposure to the human body. Currently, this exposure has been increasing since people spend more than of their time indoors (ICRP 1991). Commonly used building materials from Kinondoni District were investigated using γ-spectrometry; their activity concentrations of 226Ra, 232Th and 40K in Bq/kg were measured. The results showed that average values of activity concentrations of 226Ra, 232Th and 40K were 15.62, 21.51 and 237.99 Bq/kg, respectively. All the activity concentrations in the studied samples were lower than the world average values of …
Sign Language Recognition Using Kinect Sensor Based On Color Stream And Skeleton Points, Isack Bulugu
Sign Language Recognition Using Kinect Sensor Based On Color Stream And Skeleton Points, Isack Bulugu
Tanzania Journal of Science
This paper presents a sign language recognition system based on color stream and skeleton points. Several approaches have been established to address sign language recognition problems. However, most of the previous approaches still have poor recognition accuracy. The proposed approach uses Kinect sensor based on color stream and skeleton points from the depth stream to improved recognition accuracy. Techniques within this approach use hand trajectories and hand shapes in combating sign recognition challenges. Therefore, for a particular sign a representative feature vector is extracted, which consists of hand trajectories and hand shapes. A sparse dictionary learning algorithm, Label Consistent K-SVD …
Biodiesel Production By Esterification Of Ricinoleic Acid Over A Series Of Synthesized Sulfated Zirconia Catalysts, Elianaso Elimbinzi, Stephen S Nyandoro
Biodiesel Production By Esterification Of Ricinoleic Acid Over A Series Of Synthesized Sulfated Zirconia Catalysts, Elianaso Elimbinzi, Stephen S Nyandoro
Tanzania Journal of Science
A series of sulfated zirconia (SZ) were synthesized and evaluated for catalytic esterification of ricinoleic acid obtained from the castor oil with butanol at 110 °C. The effect of alcohols’ chain length was studied using butanol (C4), propanol (C3), ethanol (C2) and methanol (C1) at 65 °C, and reflux of corresponding alcohol boiling points. The synthesized catalysts were characterized using nitrogen porosimetry, X-ray powder diffraction, thermogravimetric analysis and Diffuse Reflectance Infrared Fourier Transform Spectroscopy. Analysis of ricinoleic conversion was performed using gas chromatography. Sulfuric acid loading improved the surface area of zirconia at a lower dose. The surface areas of …
Variations In The Effects Caused By Magnetic Field On Chlorophyll, Nitrogen, Calcium, And Iron Contents In Species Of Vegetable Plants, Olusegun O. Alabi, Samuel O. Sedara, Kafayat Adeyemi, Felix Oladejo, Funmilayo Ayedun
Variations In The Effects Caused By Magnetic Field On Chlorophyll, Nitrogen, Calcium, And Iron Contents In Species Of Vegetable Plants, Olusegun O. Alabi, Samuel O. Sedara, Kafayat Adeyemi, Felix Oladejo, Funmilayo Ayedun
Tanzania Journal of Science
The rates of reduction in chlorophyll and nutrients such as nitrogen, calcium and iron with the distance or range of source of Magnetic Field (MF) had not been considered. In this work, patterns of damage or reduction caused by a magnetic field on two different species of vegetables were studied. The first group was planted in an environment without the influence of MF, while the second group was subjected to high MF under the 330 kV electric lines. The magnetometer was used to measure the MF intensities. The chlorophyll content of each vegetable sample was determined on the field with …
Hydrogeophysical Investigation For The Aquifers In Part Of Ilorin, Central Nigeria: Implication On Groundwater Prospect, Ayodele Kehinde Olawuyi
Hydrogeophysical Investigation For The Aquifers In Part Of Ilorin, Central Nigeria: Implication On Groundwater Prospect, Ayodele Kehinde Olawuyi
Tanzania Journal of Science
Hydrogeophysical study involving the use of Vertical Electrical Sounding (VES) was carried out in part of the basement complex rocks of Ilorin, central Nigeria, with the aim of determining its geoelectric parameters and groundwater potential. A total of thirty (30) VES were carried out using Schlumberger electrode configuration, with half electrode separation (AB/2) varying from 1m to 100m. Information on the subsurface lithologies, overburden thickness and aquiferous layers were obtained from the different VES locations in the study area. From the quantitative interpretations of the data collected, using the method of curve matching with the Orellana-Mooney master curves and 1-D …
Evaluation Of Petroleum Hydrocarbons Contamination In Soils And Groundwater Using Electrical Resistivity And Hydrochemical Methods-Case Study: Ayetoro, Osogbo Southwestern Nigeria, Mutiu A Fakunle, Muhydeen A Ibraheem, Wasiu B Agbaje, Luqman A Abidoye
Evaluation Of Petroleum Hydrocarbons Contamination In Soils And Groundwater Using Electrical Resistivity And Hydrochemical Methods-Case Study: Ayetoro, Osogbo Southwestern Nigeria, Mutiu A Fakunle, Muhydeen A Ibraheem, Wasiu B Agbaje, Luqman A Abidoye
Tanzania Journal of Science
The presence of Petroleum Hydrocarbons (PHCs) in hand-dug wells has become a concern to the residents of Ayetoro area, Osogbo. Consequently, the detection of PHCs was evaluated using, nine Vertical Electrical Soundings (VES) and 2D electrical resistivity tomography surveys. Soil samples collected were analyzed for porosity and permeability. Hand-dug well water samples were screened for PHCs. VES revealed that second layer had high apparent resistivity of 14415.0 Ωm, indicating presence of PHCs that had penetrated to maximum depth of 19.1 m. The highest resistivity of the control points was 48.0 Ωm, indicating absence of PHCs. The 2D resistivity revealed highest …
Synergistic Effects Of Halide Ions And Acacia Senegal Gum On The Corrosion Inhibition Of Mild Steel In Sulfuric Acid Solution, Jovine Emmanuel, Joseph Buchweishaija
Synergistic Effects Of Halide Ions And Acacia Senegal Gum On The Corrosion Inhibition Of Mild Steel In Sulfuric Acid Solution, Jovine Emmanuel, Joseph Buchweishaija
Tanzania Journal of Science
The synergistic effects of halide ions, Br– and I– and Acacia senegal gum exudates on the corrosion inhibition of mild steel in 0.5 M sulfuric acid solution has been investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy techniques. Results showed that Acacia senegal gum exudate moderately reduces the corrosion rate of mild steel. The inhibition efficiencies on mild steel electrodes increased with increase in gum exudate concentrations up to 300 ppm, corresponding to the inhibition efficiency of about 43% and its inhibition efficiency increased up to 81.6% with addition of halide ions due to synergistic effects. The enhancement effect …
Influence Of Carbonitriding Conditions On Phase Composition And Residual Stresses For 20mncr5 Low Alloy Steel, Richard J Katemi, Jeremy Epp
Influence Of Carbonitriding Conditions On Phase Composition And Residual Stresses For 20mncr5 Low Alloy Steel, Richard J Katemi, Jeremy Epp
Tanzania Journal of Science
This paper reports an investigation of the influence of carbonitriding conditions for 20MnCr5 low alloy steel. Three gaseous carbonitriding conditions were investigated based on different carbon and nitrogen potentials to attain varying levels of carbon between 0.62 and 0.93% mass, whereas for nitrogen between 0.19 and 0.26% mass at the surface. Analysis of retained austenite and residual stress distributions was conducted using X-ray diffraction technique. The effective case depth varied between 900 and 1200 µm. The case microstructures were characterized by varying proportions of retained austenite and martensite, while the core contained essentially bainitic microstructures. The maximum amount of retained …
Perceived Risk Factors Of Dysmenorrhea Among Female Undergraduates In University Of Ilorin, Ilorin, Nigeria, Ibrahim Ologele, Precious Daniel Oyiza, Ogunsola Tijani
Perceived Risk Factors Of Dysmenorrhea Among Female Undergraduates In University Of Ilorin, Ilorin, Nigeria, Ibrahim Ologele, Precious Daniel Oyiza, Ogunsola Tijani
Tanzania Journal of Science
Dysmenorrrhea is one of the leading causes of school absenteeism among female undergraduates in University of Ilorin, Nigeria. Therefore, the study investigated the perceived risk factors of dysmenorrhea among female undergraduates in the University of Ilorin, Nigeria. Descriptive research design of survey type was used for the study. Population for this study comprised of female undergraduates in the University of Ilorin for 2018/2019 academic session. Multi-stage sampling technique of simple, proportionate, purposive and convenience sampling techniques were used to select 263 respondents that participated in the study. The researcher developed a questionnaire which was validated by 3 experts from the …
Determination Of Aquifer Parameters From Resistivity Data: A Case Of University Of Ilorin Campus, Northcentral Nigeria, Babatunde Onawola, Saminu Olatunji, Oluwatoyin Ologe, Razak Jimoh
Determination Of Aquifer Parameters From Resistivity Data: A Case Of University Of Ilorin Campus, Northcentral Nigeria, Babatunde Onawola, Saminu Olatunji, Oluwatoyin Ologe, Razak Jimoh
Tanzania Journal of Science
A total of twenty-one (21) vertical electrical sounding (VES) data were acquired using Pz-02 resistivity meter within the Precambrian basement area of part of Ilorin Metropolis north central Nigeria to evaluate the hydraulic characteristics of aquifers. The Schlumberger configuration with half-current electrode separation (AB/2) varying from 1 m to 60 m was used. The aquifer hydraulic characteristics such as hydraulic conductivity K and transmissivity T (Ωm2) were calculated from the interpreted VES data using the concept of Dar-Zarrouk parameters. The data, processed with computer software IPI2WIN, indicated three to four geo-electric layers, namely; topsoil, clayey (wet to dry), weathered or …
Seismic Attributes Analysis As A Precursor To Hydrocarbon Indicators: A Case Study Of “Ok” Field, Niger Delta, Oluwatoyin Ologe, Mary Olowokere
Seismic Attributes Analysis As A Precursor To Hydrocarbon Indicators: A Case Study Of “Ok” Field, Niger Delta, Oluwatoyin Ologe, Mary Olowokere
Tanzania Journal of Science
Seismic data volume was employed to gain more insights into the complexities of the hydrocarbon hosting units within and outside the vicinity of well control in the OK-field Niger Delta to overcome wrong deductions from complexly faulted subsurface configuration for the oilfield exploration programme. The methodology involved integration of well log with seismic data, seismic structural analysis and seismic attributes analysis. Horizons and fault interpretations were carried out to produce subsurface attribute maps. Lithologic panels derived from well log data showed that the study area is characterized by sand-shale interbedding. Two hydrocarbon bearing reservoirs were delineated within the study interval, …
Analyzing The Electricity Consumption And Costs Of Electrical-Powered Machines When There Is Orepass Failure In Underground Mine, Bartłomiej Skawina, Abubakary Salama
Analyzing The Electricity Consumption And Costs Of Electrical-Powered Machines When There Is Orepass Failure In Underground Mine, Bartłomiej Skawina, Abubakary Salama
Tanzania Journal of Science
In underground mining environment where the loss of orepasses is a dominant factor, the mine may face a challenge of improving the loading and hauling operations. Some of the options will be to rehabilitate the lost orepasses, or developing the new ones. When the rehabilitation cost is high, alternative strategies should be applied to compensate for the orepasses failure. One of the possible options is to use diesel or electric Load-Haul-Dumps (LHDs). The use of diesel-powered LHDs will increase heat and gas emissions which increase environmental concerns and ventilation costs, while adoption of electric-powered vehicles needs to be analysed. Therefore, …
Physicochemical And Sensory Evaluation Of Mixed Juices From Banana, Pineapple And Passion Fruits During Storage, Victor Matabura, Oscar Kibazohi
Physicochemical And Sensory Evaluation Of Mixed Juices From Banana, Pineapple And Passion Fruits During Storage, Victor Matabura, Oscar Kibazohi
Tanzania Journal of Science
Juices from fresh fruits offer various health benefits, including strengthening the immune system and preventing diseases. Mixed fruit juices tend to have good nutritional contents and organoleptic properties like colour, flavour, taste, and overall appeal of different fruits. This work investigated the physicochemical and sensory attributes of fruit juice of low viscosity banana juice blended with pineapple and passion juices. The prepared juices were pasteurised at 92 °C for 15 s, bottled in air-tight glass bottles, and subsequently stored in two different conditions: an ambient temperature of approximately 28 ± 2 °C and a fridge at 4 ºC for one …
Corrosion Inhibition Of Mild Steel In Seawater By 2,4,6-Triamino-3-Pentadecylphenyl Acetate Derived From Cashew Nut Shell Liquid, Emanuel Ricky, Esther Lugwisha, Joseph Philip
Corrosion Inhibition Of Mild Steel In Seawater By 2,4,6-Triamino-3-Pentadecylphenyl Acetate Derived From Cashew Nut Shell Liquid, Emanuel Ricky, Esther Lugwisha, Joseph Philip
Tanzania Journal of Science
The corrosion inhibition performance of 2,4,6-triamino-3-pentadecylphenyl acetate on mild steel in seawater at stationary condition, 30 °C and pH 8 was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. The maximum inhibition efficiency of 93% was found in the presence of 300 ppm of 2,4,6-triamino-3-pentadecylphenyl acetate for both potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The potentiodynamic polarization curves show that 2,4,6-triamino-3-pentadecylphenyl acetate acts as a mixed type inhibitor which influences more the anodic processes. The Nyquist plots revealed that the polarization resistance (Rp) increases whereas the double-layer capacitance (Cdl) and corrosion current density (icorr) decrease as the concentrations of …
Characterization, Antimicrobial And Toxicity Studies Of Silver Nanoparticles Using Opuntia Ficus Indica Leaves Extracts From Effurun, Delta State, Christiana Ogwuche, Harrison Moses
Characterization, Antimicrobial And Toxicity Studies Of Silver Nanoparticles Using Opuntia Ficus Indica Leaves Extracts From Effurun, Delta State, Christiana Ogwuche, Harrison Moses
Tanzania Journal of Science
The silver nanoparticles were synthesized by reacting silver nitrate, a metal precursor with the extract obtained from the leaves of Opuntia ficus indica, which acts as a reducing and stabilizing agent. Formation of silver nanoparticles was indicated by colour change from light yellow to dark brown which was confirmed by ultraviolet-visible (UV-Vis) spectroscopy showing surface plasmon band at 369 nm resulting from relatively small amount of reductive biomolecules for the silver ion reduction. Scanning electron microscope (SEM) analysis gave the morphology of the nanoparticles and showed that the silver particles were of spherical shape. Fourier transform infrared (FTIR) spectrometer presented …
Application Of Guided Local Search (Gls) In Portfolio Optimization, Collether John
Application Of Guided Local Search (Gls) In Portfolio Optimization, Collether John
Tanzania Journal of Science
Portfolio optimization is a major activity in any operating business. Conventional portfolio optimization research makes simplifying assumptions; for example, they assume no constraint in how many assets one holds (cardinality constraint). They also assume no minimum and maximum holding sizes (holding size constraint). Once these assumptions are relaxed, conventional methods become inapplicable, and hence new methods are needed to tackle this challenge. Threshold Accepting is an established algorithm in the extended portfolio optimization problem. In this paper, an algorithm called Guided Local Search (GLS) is applied using an accurate and efficient designed hill climbing algorithm, named HC-C-R. GLS sitting on …
Multi-Bands Circular Ring Monopole Antenna With Double L-Shape For Wlan/Wimax Applications, Hassan Mkindu, Hashim Iddi
Multi-Bands Circular Ring Monopole Antenna With Double L-Shape For Wlan/Wimax Applications, Hassan Mkindu, Hashim Iddi
Tanzania Journal of Science
The rapid growth of technology increases the demands of low profile and compact antennas, supporting different wireless systems standards in mobile devices. Recently, several multi-band antenna designs have been proposed for mobile devices due to the current advancement of antenna technology. In this paper, a multi-band circular ring with a double L-shaped monopole antenna for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications is presented. The proposed antenna consists of a circular-shaped and rectangular strip connected with two inverted L-shaped trips. The H-shaped-strips are attached within the rectangular-strips. The antenna is fed by a 50 …
Analysis Of A Reform Option For The Tanzanian Pension System, Andongwisye Mwakisisile, Torbjörn Larsson
Analysis Of A Reform Option For The Tanzanian Pension System, Andongwisye Mwakisisile, Torbjörn Larsson
Tanzania Journal of Science
In this study, an analysis of a reform option for the Tanzanian pension system was done. The current system is dominated by mandatory defined benefit operating under pay-as-you-go principles. The retirement benefits are based on the average of the three best final salaries in the ten years preceding retirement. Several studies and international experts have shown that such systems face unsustainability. We propose a reform to a notional defined contribution system in which the benefits depend on accumulated contributions indexed by internal rates of returns. Simulation of results for a time horizon of fifty years shows that the notional defined …
Mineralogy And Geochemistry Of Shale-Hosted Copper Of The Middle Buanji Group, Chimala Area, South-Western Tanzania, Almachius Mutasingwa, Michael Msabi, Neema Jackson, Seetharamaiah Jagarlamudi
Mineralogy And Geochemistry Of Shale-Hosted Copper Of The Middle Buanji Group, Chimala Area, South-Western Tanzania, Almachius Mutasingwa, Michael Msabi, Neema Jackson, Seetharamaiah Jagarlamudi
Tanzania Journal of Science
The mineralogical and geochemical assessments are presented in this paper to constrain the mineralogy and copper concentrations of the shale-hosted copper in the Middle Buanji Group of the Upper Paleoproterozoic (1.67 Ga). The XRD analysis revealed that illite and chamosite are the major clay minerals present in the shales together with pseudomalachite, quartz, and muscovite that constitute over 95% by proportion of the sample. The minerals biotite, birnessite, ferroselite, bearsite, chloritoid, and anatase are present in association with shale-hosted copper in low amounts (i.e., <5% by proportion of the sample). The pseudomalachite [Cu5(PO4)2(OH)4] is considered as ore mineral of copper in the shales of the Middle Buanji Group. Field observations revealed the presence of different shale layers within the Middle Buanji Group such as red, grey and green/blue in which copper mineral is distributed. On average, the copper concentrations in the shale layers were unevenly distributed throughout the red-grey-green shales layers with values of 0.31 wt%, 5.2 wt% and 13.19 wt%, respectively. A noticeable amount of copper mineralization up to 25.7 wt% was restricted within the green shale layer as compared to red (0.31 wt%) and grey (10.9 wt%) layers. Keywords: Pseudomalachite; Supergene enrichment; Shale-hosted copper; Green shale layer
Monthly And Seasonal Rainfall Concentrations And Predictability In Tanzania, Pasvolo Mwinuka, Christian Uiso, Ladslaus Chang’A, Mwingereza Kumwenda
Monthly And Seasonal Rainfall Concentrations And Predictability In Tanzania, Pasvolo Mwinuka, Christian Uiso, Ladslaus Chang’A, Mwingereza Kumwenda
Tanzania Journal of Science
This study aimed at determining the monthly and seasonal rainfall concentration, predictability and the changes in rainfall seasons in Tanzania. Rainfall predictability was determined using Colwell’s indices, Rainfall Concentration Index (RCI) and Coefficient of Variation (CV). Results showed that rainfall in December–February (DJF), January–March (JFM) and February–April (FMA) has predictability due to constancy of 60%, RCI ≤ 9 and CV < 0.4 in Lake zone, Central zone, Southern Coast zone, Western and Southern Highlands zone. Rainfall in October to December (OND) was reliable in the Island zone, North-Eastern highlands zone and Northern coast zone with an average predictability due to constancy of 65%. In the Lake zone, all seasons (DJF, JFM, FMA, MAM, OND and DJFMAM) had uniform rainfall distribution (RCI = 8.7, CV = 0.35) and predictability due to constancy of 80% which leads to the conclusion that Lake Zone has unimodal rainfall distribution. Rainfall predictability in Tanzania has a West-East gradient. The western zones had an average predictability due to constancy of 68%. In general, rainfall in Tanzania is observed to be highly variable; only 20% of the predictability is concerned with reliability in the rainfall occurrence within the seasons and 80% is due to seasonality. Keywords: Rainfall concentration index; predictability; coefficient of variation; seasonality; constancy.
Comparison Of Centrifugation And Solid Phase Extraction (Spe) Methods Of Sample Preparations In Determination Of Residues Of Drugs Of Abuse In Urine, John Mahugija, Anastazia Wandwi, Kessy Kilulya
Comparison Of Centrifugation And Solid Phase Extraction (Spe) Methods Of Sample Preparations In Determination Of Residues Of Drugs Of Abuse In Urine, John Mahugija, Anastazia Wandwi, Kessy Kilulya
Tanzania Journal of Science
Detection of drugs of abuse in urine samples depends on their composition, absorption, distribution, physical and chemical properties, concentrations, elimination properties, and the techniques employed. This study compared the performance of centrifugation and solid phase extraction (SPE) methods in the determination of levels of drugs of abuse and their metabolites in urine samples collected from drug abusers. Analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Calibration was done using both internal and external standards. The recovery values were generally greater in centrifugation method than in SPE method, but the recoveries in both methods were within an acceptable range. Linearity …
Synthesis And Ftir Characterization Of Mg-Hydroxylapatite Derived From Dolostone With High Dolomite Mineral Content, Wilson L. Mahene, Charles Gervas, Askwar H. Hilonga, Revocatus L. Machunda
Synthesis And Ftir Characterization Of Mg-Hydroxylapatite Derived From Dolostone With High Dolomite Mineral Content, Wilson L. Mahene, Charles Gervas, Askwar H. Hilonga, Revocatus L. Machunda
Tanzania Journal of Science
We present the synthesis of magnesium-substituted hydroxylapatite starting from locally available dolostone. The apatite was prepared by a reaction between heat pre-treated dolostone powder with phosphoric acid, maintained at the pH of 12.5 using sodium hydroxide. The resultant material was then calcined at 500 °C, 600 °C, 700 °C, 800 °C and 900 °C. The precursor dolostone was characterized by organic elemental analyser (CHNS-O analyser), X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FTIR), while the synthesized material was characterized by using FTIR. Results indicated that the dominant mineral in the carbonate rock materials was near-stoichiometric dolomite, while the synthesized …