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

Digital Commons Network™

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

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 421 - 450 of 952

Full-Text Articles in Entire DC Network

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 Feb 2021

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

Go to article

Effectiveness Of Common Household Washing Of Tomatoes On The Removal Of Pesticide Residues, John Mahugija, Flaviana Ngabala, Faustin Ngassapa Feb 2021

Effectiveness Of Common Household Washing Of Tomatoes On The Removal Of Pesticide Residues, John Mahugija, Flaviana Ngabala, Faustin Ngassapa

Tanzania Journal of Science

The effectiveness of common household washing processes of tomatoes on the removal of pesticide residues was investigated in Iringa, Tanzania. Analyses of cleaned-up extracts were carried out using gas chromatography-mass spectrometry (GC-MS). Nine pesticide residues were detected in unwashed and washed samples. The compounds detected were chlorothalonil, pirimiphos-methyl, chlorpyrifos, profenofos, endosulfan sulphate, endosulfan ether, lambda cyhalothrin, cypermethrin and metalaxyl. The concentrations of chlorothalonil, pirimiphos-methyl, chlorpyrifos, profenofos, cypermethrin and lambda cyhalothrin in some unwashed and washed samples exceeded the maximum residue limits (MRLs). Washing reduced the concentrations of chlorothalonil and endosulfan sulphate in tomatoes by 22.2–98.0% (mean = 70%) and 33.3–55.6% …

Go to article

Mobile Pedestrian Navigation Framework For Multi-Factors Resources Allocation, Joseph Mushi, Baraka Jungwa Feb 2021

Mobile Pedestrian Navigation Framework For Multi-Factors Resources Allocation, Joseph Mushi, Baraka Jungwa

Tanzania Journal of Science

Although it is possible for pedestrian to walk to unfamiliar places, familiarizing and finding a way out of new environments is quite challenging unless a pedestrian navigation system (PNS) is used. Most existing PNS solutions are employing vehicle navigation framework, however, such systems are designed to work efficiently for vehicular systems and not suitable for finding shortest path in environment with poor geospatial mapping. This study designed pedestrian navigation framework for PNS that supports resource allocations in environment with poor geospatial mapping. Mixtures of qualitative and quantitative methods have been used to interview prospective users for requirement specifications and experimental …

Go to article

Monthly And Seasonal Rainfall Concentrations And Predictability In Tanzania, Pasvolo Mwinuka, Christian Uiso, Ladslaus Chang’A, Mwingereza Kumwenda Feb 2021

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.

Go to article

Climate, Vegetation, And Weathering Across Space And Time In Lake Tanganyika (Tropical Eastern Africa), Sarah J. Ivory, Michael M. Mcglue, Cara Peterman, Patrick Baldwin, Joseph Lucas, Andrew Cohen, James Russell, Justina Saroni, Emma Msaky, Ishmael Kimirei, Michael Soreghan Feb 2021

Climate, Vegetation, And Weathering Across Space And Time In Lake Tanganyika (Tropical Eastern Africa), Sarah J. Ivory, Michael M. Mcglue, Cara Peterman, Patrick Baldwin, Joseph Lucas, Andrew Cohen, James Russell, Justina Saroni, Emma Msaky, Ishmael Kimirei, Michael Soreghan

Earth and Environmental Sciences Faculty Publications

Climate and vegetation influence weathering rates and processes; however, evaluating the effects of each and feedbacks between systems, has yet to be accomplished for many types of landscapes. A detailed understanding of how these processes interact to shape landscapes is particularly crucial for reconciling future scenarios of changing climate, where profound alterations to both the biosphere and geosphere are anticipated. In the tropics, ecosystem services, such as soil and water quality, are linked to both vegetation and weathering processes that form a strong control on natural resources that are the foundation of many communities’ daily subsistence. This understanding is further …

Go to article

Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu Jan 2021

Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu

Turkish Journal of Chemistry

Cadmium dithiocarbamate and cadmium ethyl xanthate complexes were synthesized and characterized by microanalysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses. The complexes were employed as molecular precursors for the fabrication of CdS nanoparticles in hexadecylamine (HDA) and oleylamine (OLA) at a temperature of 250 °C. Spherical and oval shaped particles with sizes ranging from 9.93 ± 1.89 to 16.74 ± 2.78 nm were obtained in OLA while spherical, oval and rod shaped particles with sizes ranging from 9.40 ± 1.65 to 29.90 ± 5.32 nm were obtained in HDA. Optical properties of the nanoparticles showed blue shifts as compared …

Go to article

Bivariate Probit Model For Testing Joint Effect Of Affordability And Desirability To Connect Electricity In Mtwara And Pwani, Tanzania, Amina S. Msengwa, Deogratias Matayo Bengesi Rugaimukamu Nov 2020

Bivariate Probit Model For Testing Joint Effect Of Affordability And Desirability To Connect Electricity In Mtwara And Pwani, Tanzania, Amina S. Msengwa, Deogratias Matayo Bengesi Rugaimukamu

Journal of Humanities and Social Sciences

The objective of this study is to determine perceptions of joint effect of affordability and desirability to connect electricity in a household to propose an appropriate advocacy strategy for the regions of Mtwara and Pwani in Tanzania. Bivariate probit model is used to analyse data involving 162 households. Constructed Likert Scales of delightful and wary perceptions on oil- and gas-based on three questions with Likert response formats are used as part of the explanatory set of variables in the model. Marginal mean effects of the bivariate probit model indicate that wary perceptions on the use of gas are statistically significant …

Go to article

Status Of Soil Transmitted Helminths Infection Among School-Going Children In Momba, Mbeya, Siame Zebius, Winifrida B. Kidima Nov 2020

Status Of Soil Transmitted Helminths Infection Among School-Going Children In Momba, Mbeya, Siame Zebius, Winifrida B. Kidima

Journal of Humanities and Social Sciences

This study conducted cross-sectional and retrospective studies to investigate the burden of intestinal helminths among school-going children in Momba. Direct wet mount and Kato-Katz thick smears techniques were used to determine the prevalence and intensity of intestinal parasites, respectively. Out of 359 stool samples analysed, 28% were positive for intestinal parasites. Hookworm infections attributed to 10% of total infection, Ascaris lumbricoides 6%, Giardia lamblia 7%, and Entamoeba histolytica 5%. The prevalence of intestinal infection decreased with increasing age (p < 0.5). Hookworm was the most prevalent STH infection among children (p = 0.048). There was an association between taking ant-helminthic drugs and the absence of helminth infection in children (OR = 1.9, p < 0.05). No relationship existed between parents’ education level and the presence of STH infection among children (p > 0.05). Overall, children in Momba harboured low intensity helminths infection. The mean intensity of hookworm and ascaris infection decreased with age, …

Go to article

Ethoxylation And Polymerization Of Cardanol Derived Bifunctional Monomers, James Mgaya Nov 2020

Ethoxylation And Polymerization Of Cardanol Derived Bifunctional Monomers, James Mgaya

Journal of Humanities and Social Sciences

Cardanol and its derivative; 3-(non-8-enyl)phenol (obtained by ethenolysis reaction of cardanol) were ethoxylated via one-pot reaction with urea and ethylene glycol using Na2CO3/ZnO as co-catalysts. The ethoxylates were later methoxycarbonylated using a 1,2-bis(ditertbutylphosphinomethyl)benzene (DTBPMB) modified palladium catalyst to produce ethoxylated bifunctional monomers. Polymerization of these monomers by heating in the presence of a standard polymerization catalyst, Ti(OBu)4, formed oligomers that were plastic-like. Analysis of these oligomers by MALDI-TOF MS indicated the condensation of up to nine monomer units.

Go to article

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 Oct 2020

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 …

Go to article

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 Oct 2020

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 …

Go to article

Geological And Geochemical Characterisation Of Pegmatites Around Olode, Southwestern Nigeria, Razak O. Jimoh, Akinade S. Olatunji Oct 2020

Geological And Geochemical Characterisation Of Pegmatites Around Olode, Southwestern Nigeria, Razak O. Jimoh, Akinade S. Olatunji

Tanzania Journal of Science

Olode is prolific in terms of pegmatites, occurring in different ways as large intrusive bodies, as veins and dykes, discordantly intruding the host rocks of mica schist, gneiss and granite. This study is aimed at the geological and geochemical characterisation of pegmatites around Olode. Field investigation was undertaken to determine the occurrences and relationships of the pegmatites with the host rocks. Fresh pegmatite samples were studied petrographically and geochemically. Two main lithologically and chronologically different groups of pegmatites were distinguishable in the study area. These were the tourmaline pegmatites associated with the Older Granite rocks and the NE-SW trending beryl-bearing …

Go to article

Levels And Exposure Risks Of Lead, Arsenic And Mercury From Selected Lipstick And Nail Polish Cosmetics Marketed In Dar Es Salaam, Tanzania, Gerald S. Kulwa, Matobola J Mihale Oct 2020

Levels And Exposure Risks Of Lead, Arsenic And Mercury From Selected Lipstick And Nail Polish Cosmetics Marketed In Dar Es Salaam, Tanzania, Gerald S. Kulwa, Matobola J Mihale

Tanzania Journal of Science

Presence of Pb, As and Hg in selected lipstick and nail polish cosmetics sold at different shopping malls and retail outlets in Dar es Salaam was determined by microwave plasma  atomic emission spectrometry due to their public health effects. Pb was detected in 100% (n = 25) of lipsticks and 53.3% (n = 15) of nail polishes. Arsenic was detected in 36% of lipsticks and 86.7% of nail polishes, and Hg was detected in 44% of lipsticks and 80% of nail polishes. All metal levels in both cosmetics were below the World Health Organisation (WHO) and Tanzania Bureau of Standards …

Go to article

Corn Stover As Substrate For Biogas Generation And Precursor For Biosilica Production Via Anaerobic Digestion, Akinola D. Olugbemide, Lajide Labunmi, Ikhazuagbe H Ifijen, Damilare I. Ogungbemide Oct 2020

Corn Stover As Substrate For Biogas Generation And Precursor For Biosilica Production Via Anaerobic Digestion, Akinola D. Olugbemide, Lajide Labunmi, Ikhazuagbe H Ifijen, Damilare I. Ogungbemide

Tanzania Journal of Science

Production of fuels and chemicals from renewable biomass is crucial to sustainability of bio-based economy. In this study, anaerobic digestion of corn stover (CS) was carried out to produce biogas under mesophilic conditions. The study also investigated the potential of corn stover digestate ash as a potential source for biosilica production. A cumulative volume of 930 mL of biogas was produced with methane content of 85.87%. Higher and lower calorific values of biogas were calculated to be 36.30 MJ/m3 and 32.70 MJ/m3, respectively. Calcination of raw CS (RCS) and the digestate (CSD) was carried out at 600 °C for 3 …

Go to article

Total And Available Fluoride Content In Toothpastes Sold In Dar Es Salaam, Tanzania, Monica Mbaraka Ndoile Oct 2020

Total And Available Fluoride Content In Toothpastes Sold In Dar Es Salaam, Tanzania, Monica Mbaraka Ndoile

Tanzania Journal of Science

A total of eleven (11) different toothpaste brands (imported and manufactured in Tanzania) sold in Dar es Salaam were evaluated for Total Fluoride (TF) and Total Soluble Fluoride (TSF) concentrations. To protect the subject’s identity, the samples were coded. Four selected toothpastes were analyzed for potentially bioavailable fluoride by examining the relationship between TSF in tooth brushing residues and in that of the toothpaste. The results indicated that measured TF of the toothpaste samples coded as TPSA, TPSC and TPSH were consistent to the one declared by the manufacturers. On the other hand, samples coded as TPSB, TPSD, TPSE, TPSF, …

Go to article

Coal Exploration Using Electrical Resistivity Method In Some Parts Of Benue Trough, Nigeria, Saminu Olatunji, Abdulgafar T. Jimoh Oct 2020

Coal Exploration Using Electrical Resistivity Method In Some Parts Of Benue Trough, Nigeria, Saminu Olatunji, Abdulgafar T. Jimoh

Tanzania Journal of Science

Geoelectrical resistivity sounding technique was used to delineate the occurrence and extents of coal seam. Fifteen points were sounded with Schlumberger configuration in the suspected coal deposit site bounded by longitudes 7.344° E and 7.366° E, and latitudes 7.318° N and 7.33° N. The vertical electrical sounding (VES) data were analyzed and the corresponding geo-electric parameters at various depths were modeled. The earth model within the study area was correlated with available lithology of a nearby mine site. The sounding signatures are KQHK and KHK curve types which revealed five to six distinct geo-electrical equivalent layers. The wet to dry …

Go to article

Contour Mapping For Rain Rate And Rain Attenuation In Microwave And Millimetre Wave Earth-Satellite Link Design In Tropical Tanzania, Promota Haule Linga, Hashim Uledi Iddi, Mussa Kissaka Oct 2020

Contour Mapping For Rain Rate And Rain Attenuation In Microwave And Millimetre Wave Earth-Satellite Link Design In Tropical Tanzania, Promota Haule Linga, Hashim Uledi Iddi, Mussa Kissaka

Tanzania Journal of Science

Rain rate and rain attenuation predictions are vital in the analysis of the performance of earth-satellite link at higher frequencies beyond 10 GHz for satellite system planning. This study intended to address lack of rain attenuation profile based on local rainfall data collected from various parts of the country. A one-minute integration time rainfall rate used to estimate the rain-induced attenuation was obtained by converting the annual rainfall data collected for 40 years from 22 locations in Tanzania using a combination of Chebil and refined Moupfouma-Martin methods. The International Telecommunication Union (ITU) standard was used to predict attenuation caused by …

Go to article

Verification Of Depth Dose Curves Derived On Beeswax, Paraffin And Water Phantoms Using Fluka Monte Carlo Code, Khamis O. Amour, Peane P. Maleka, Khamza Maunda, Mohammed S. Mazunga, Peter K. Msaki Oct 2020

Verification Of Depth Dose Curves Derived On Beeswax, Paraffin And Water Phantoms Using Fluka Monte Carlo Code, Khamis O. Amour, Peane P. Maleka, Khamza Maunda, Mohammed S. Mazunga, Peter K. Msaki

Tanzania Journal of Science

This study aimed on the investigation of depth dose curves from beeswax, water and paraffin phantoms using FLUKA Monte Carlo code. In order to test the validity of FLUKA code, computational values of depth doses in water, beeswax and paraffin have been obtained using this code. The relative average coefficient of variation of percentage depth dose was observed to be less than 0.38% between beeswax and water, below 0.2% between water and paraffin and 0.98% between beeswax and British Journal of Radiology supplement 25 data. The deviations of percentage depth doses within the beeswax phantom material were also calculated and …

Go to article

Sensitivity Analysis And Uncertainty Parameter Quantification In A Regression Model: The Case Of Deforestation In Tanzania, Thadei Sagamiko, Nyimvua Shaban, Isambi S. Mbalawata Oct 2020

Sensitivity Analysis And Uncertainty Parameter Quantification In A Regression Model: The Case Of Deforestation In Tanzania, Thadei Sagamiko, Nyimvua Shaban, Isambi S. Mbalawata

Tanzania Journal of Science

In this paper a multiple regression model for the economic factors and policy that influence the rate of deforestation in Tanzania is formulated. Sensitivity analysis for parameters of explanatory variables using one-at-a time and direct methods is carried out and the model is fitted by classical least square (LSQ) and Markov Chain Monte Carlo (MCMC) methods. Uncertainty quantification of parameters by adaptive Markov Chain Monte Carlo methods is performed. The coefficient of determination indicates that 87% of deforestation rate is explained by explanatory variables captured in the model. Household poverty rate is found to be the most sensitive factor to …

Go to article

Security Model For Tracking Creation Of Mobile Money Using Transport Layer Security Protocol, Sigsbert Rwiza, Mussa Kissaka, Kosmas Kapis Oct 2020

Security Model For Tracking Creation Of Mobile Money Using Transport Layer Security Protocol, Sigsbert Rwiza, Mussa Kissaka, Kosmas Kapis

Tanzania Journal of Science

Mobile Network Operator (MNO) financial service model has security vulnerabilities in addressing verification of cash and mobile money. For instance, monthly returns are transferred in plain text from banks and MNOs to financial regulators. This may result to failure of financial regulators in detecting creation of fake mobile money. This study was conducted to develop a security model for tracking creation of mobile money using Transport Layer security protocol as a way of protecting returns in transit from banks and MNOs to financial regulators. The proposed model was developed using insights from literature, function decomposition and composition techniques and was …

Go to article

Solar Irradiance And Enso Affect Food Security In Lake Tanganyika, A Major African Inland Fishery, Michael M. Mcglue, S. J. Ivory, J. R. Stone, A. S. Cohen, T. M. Kamulali, J. C. Latimer, M. A. Brannon, I. A. Kimirei, M. J. Soreghan Oct 2020

Solar Irradiance And Enso Affect Food Security In Lake Tanganyika, A Major African Inland Fishery, Michael M. Mcglue, S. J. Ivory, J. R. Stone, A. S. Cohen, T. M. Kamulali, J. C. Latimer, M. A. Brannon, I. A. Kimirei, M. J. Soreghan

Earth and Environmental Sciences Faculty Publications

Food security in a warming world is a grave concern for rapidly growing impoverished populations. Low-latitude inland fisheries provide protein for millions of rural poor, yet the impacts of high-frequency climate oscillations on these aquatic ecosystems are unknown. Here, we present a sub-annual-to-annual resolution paleolimnological reconstruction of upwelling, productivity, and algal composition at Lake Tanganyika, one of Africa's largest landlocked fisheries. The data reveal increases in diatom production at centennial-scale solar irradiance maxima, and interannual variability in upwelling linked to La Niña. Our study shows that interactions between global climatic controls and El Niño-Southern Oscillation teleconnections exert profound influences on …

Go to article

The Geochemical Compositions And Origin Of Sand Dunes In The Olduvai Gorge–Eastern Serengeti Plains, Northern Tanzania, Dalaly Kafumu Jun 2020

The Geochemical Compositions And Origin Of Sand Dunes In The Olduvai Gorge–Eastern Serengeti Plains, Northern Tanzania, Dalaly Kafumu

Tanzania Journal of Science

This paper reports the composition and origin of black sand dunes that occur in the eastern Serengeti plains near the Olduvai Gorge hominid site in Tanzania.  Grain size analysis reflected light microscopic examination, and scanning electron microscopy (SEM) analysis identified very fine to coarse sand fraction mineral grains of between 0.065 mm and 1 mm, composed of augite, fassaite and omphacite pyroxenes; garnet and sillimanite silicate mineral grains.  The pyroxene minerals (augite, omphacite and fassaite) constitute 95.4% by volume of the sand dunes. The other mineral grains are silicate minerals that include garnet and sillimanite, together form the remaining 4.6% …

Go to article

Monitoring Impervious Surface Area Dynamics To Assess Urbanisation Of A Catchment: Msimbazi River Valley Dar Es Salaam, 1989 - 2015, Befrina Igulu, Elisante Mshiu Jun 2020

Monitoring Impervious Surface Area Dynamics To Assess Urbanisation Of A Catchment: Msimbazi River Valley Dar Es Salaam, 1989 - 2015, Befrina Igulu, Elisante Mshiu

Tanzania Journal of Science

This work examined the effects of land use and cover change on the impervious surface as a measure of urbanisation together with its driving factors such as population growth and economic development. The spatial and temporal variations of the impervious surface area were extracted from the Landsat images of the years 1989, 1995, 2005, and 2015. Data analyses involved the selection of the endmember through Minimum Noise Fraction (MNF) and Linear Spectral Mixed Analysis (LSMA) on the images. Four dominant land cover types were mapped as results, which are forest, non-forest vegetation, bare-land, and built-up area. The non-forest vegetation and …

Go to article

Geochronology Of Massif-Type Anorthosites From The Ubendian Belt, Tanzania, Nelson Boniface Jun 2020

Geochronology Of Massif-Type Anorthosites From The Ubendian Belt, Tanzania, Nelson Boniface

Tanzania Journal of Science

Massif-type anorthosites occur in East Africa at the margins of the Tanzania Craton in the Ubendian Belt. The massif assemblage constitutes of mafic-composition plutons (meta-anorthosite and meta-gabbro), ultramafic plutons, and titaniferous iron-ore. Silicic ortho-gneisses (tonalitic, dioritic, and granodioritic intrusives) also occur in the vicinity of the said massif-type anorthosites. This article presents ages of meta-anorthosites and meta-gabbros. The new U-Pb zircon age indicates that meta-gabbros and meta-anorthosites crystallized between 1915 ± 24 and 1905 ± 24 Ma concomitantly with the silicic magmatic bodies. Geochronological databases indicate that the period between 1920 and 1850 Ma HP-LT metamorphic interface was formed at …

Go to article

Stabilizing Capability Of Gum Arabic On The Synthesis Of Poly(Styrene-Methylmethacrylate-Acrylic Acid) Latex For The Generation Of Colloidal Crystal Films, Ikhazuagbe Ifijen, Stanley Omorogbe, Muniratu Maliki, Ifeanyi Odiachi, Aireguamen Aigbodion, Esther Ikhuoria Jun 2020

Stabilizing Capability Of Gum Arabic On The Synthesis Of Poly(Styrene-Methylmethacrylate-Acrylic Acid) Latex For The Generation Of Colloidal Crystal Films, Ikhazuagbe Ifijen, Stanley Omorogbe, Muniratu Maliki, Ifeanyi Odiachi, Aireguamen Aigbodion, Esther Ikhuoria

Tanzania Journal of Science

This article describes the generation and characterization of colloidal crystals from particles of gum arabic (GA) and sodium dodecylbenzene sulfate (SDBS) emulsified poly(styrene methylmethacrylate-acrylic acid) (P(St-MMA-AA) latex. The colloidal latex was synthesized using GA and SDBS as the emulsifying agents and then used to generate colloidal crystal films via the vertical deposition technique. Dynamic light scattering analysis placed the average particle diameter, polydispersity and Zeta potential at about 122 nm, 0.014 and –36.20 mV for the as-synthesized GA emulsified terpolymer latex and 213 nm, 0.006, –35.60 mV for the SDBS emulsified terpolymer latex, respectively. Thermo-gravimetric analysis and differential scanning calorimetry …

Go to article

Short Wavelength Infrared Spectral Characterization Of The Mineralogy Of Gokona And Nyabigena Andesite-Hosted Gold Deposits In North Mara, Tanzania, Emmanuel Kazimoto Jun 2020

Short Wavelength Infrared Spectral Characterization Of The Mineralogy Of Gokona And Nyabigena Andesite-Hosted Gold Deposits In North Mara, Tanzania, Emmanuel Kazimoto

Tanzania Journal of Science

The mineralogy of Gokona and Nyabigena gold deposits in Tanzania have been studied using Short Wavelength Infrared (SWIR) Spectrometry technique with an aim to fingerprint hydrothermal system responsible for the formation of the deposits and establish pertinent mineralogical signatures for gold deposition. Gokona and Nyabigena deposits are hosted in porphyritic andesite to basaltic andesite that contains plagioclase phenocrysts, pyroxene, hornblende and Fe-Ti oxides as primary minerals. Other minerals are actinolite, chlorite, epidote, albite and hematite, which indicate metamorphism of the rock under greenschist facies conditions. Hydrothermal alteration of the rock produced chlorite, sericite, carbonates (ankerite, siderite and calcite), pyrite and …

Go to article

1-D Transport Behaviour Of Emerging Contaminants In The Unidirectional Flowing Surface Waters Of The Msimbazi River, Hossein Miraji, Eunice Mureithi, Othman Othman, Faustin Ngassapa Jun 2020

1-D Transport Behaviour Of Emerging Contaminants In The Unidirectional Flowing Surface Waters Of The Msimbazi River, Hossein Miraji, Eunice Mureithi, Othman Othman, Faustin Ngassapa

Tanzania Journal of Science

The primary objectives of this investigation of environmental pollution were to assess spatio-temporal concentrations and predictions of transport behaviour of pollutants in aqueous media. In order to attain these goals for the Msimbazi river, the analytical and numerical solutions to the 1-D advection-dispersion equation (ADE) implemented the first-type inlet condition. The MATLAB software was used to solve the analytical equation resulting from the ADE equation. The solution to the ADE model enabled effective prediction of contaminants’spatial distribution within a distance of 200 m from a point source in the direction of flowing water. Among the first and third-types inlet conditions, …

Go to article

Device–To-Device Association Algorithm For Optimal Neighbour Selection And Channel Sharing In 5g Cellular Networks, Chiza Christophe, Omar Hamad, Libe Massawe, Abdi Abdalla Jun 2020

Device–To-Device Association Algorithm For Optimal Neighbour Selection And Channel Sharing In 5g Cellular Networks, Chiza Christophe, Omar Hamad, Libe Massawe, Abdi Abdalla

Tanzania Journal of Science

The integration of device-to-device (D2D) communication in 5G cellular networks has generated the possibility of multiple transmission modes in a single cell. This has motivated scholars to investigate different mode selection and D2D association algorithms that guarantee the selection of proper transmission mode. However, the complexity of algorithms and tractability of devices in the cell are still remarkably challenging. This paper, therefore, presents a utility based D2D association algorithm that ensures optimal neighbour selection by using numerical linear algebra to minimize computational complexity. Simulation results show that the minimum utility based D2D association increases the expected values of attached devices …

Go to article

Comparison Of Experimental And Monte Carlo Simulation Of Angular Distributions Of Bremsstrahlung Photons From 28-Ghz Electron Cyclotron Resonance (Ecr) Ion Source, Mwingereza Kumwenda Jun 2020

Comparison Of Experimental And Monte Carlo Simulation Of Angular Distributions Of Bremsstrahlung Photons From 28-Ghz Electron Cyclotron Resonance (Ecr) Ion Source, Mwingereza Kumwenda

Tanzania Journal of Science

Angular distributions of deceleration radiation or bremsstrahlung in German, both experimental and simulated from Electron Cyclotron Resonance Ion Source (ECRIS) are not well understood so far. The bremsstrahlung photons of the angular distributions from 28-GHz ECR ion source at Busan Centre of Korea Basic Science Institute (KBSI) were measured in nine azimuthal angles for the first time. Three round type NaI(Tl) detectors were used to measure the angular distributions of the bremsstrahlung photons emitted at the extraction side of the ECRIS at the same time. Another NaI(Tl) detector was placed downstream from the ECR ion source for monitoring photon intensity. …

Go to article

Evidence For A Record Of Possible Paleo-Tsunami Or Storm Deposits In The Fluviatile Neoproterozoic Malagarasi Supergroup Of North-Western Tanzania, Charles Kasanzu, Shukrani Manya Jun 2020

Evidence For A Record Of Possible Paleo-Tsunami Or Storm Deposits In The Fluviatile Neoproterozoic Malagarasi Supergroup Of North-Western Tanzania, Charles Kasanzu, Shukrani Manya

Tanzania Journal of Science

Two different localities within the fluviatile Neoproterozoic Malagarasi Supergroup of north-western Tanzania show striking evidence for tsunami related clastic sedimentary deposits. In each locality, the outcrops are characterised by the association of fine grained, thinly laminated shales at the bottom that are overlain by thick deposits of sandstones and conglomerates whose clasts and pebbles vary in size and angularity/roundness. In each case, the two rock units are separated by an erosional surface. The basal shale layers are consistent with deposition in deep shelf environments which are in stark contrast to the immediately overlying conglomerates/sandstones that suggest reworking under high energy …

Go to article

First Prev Next Last