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

Digital Commons Network™

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

2021

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 211 - 240 of 416

Full-Text Articles in Entire DC Network

Copper Slag As A Potential Waste Filler For Polyethylene-Based Composites Manufacturing, Aleksander Hejna, Paulina Kosmela, Mateusz Barczewski, Olga Mysiukiewicz, Adam Piasecki May 2021

Copper Slag As A Potential Waste Filler For Polyethylene-Based Composites Manufacturing, Aleksander Hejna, Paulina Kosmela, Mateusz Barczewski, Olga Mysiukiewicz, Adam Piasecki

Tanzania Journal of Science

The present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile tests) and dynamic (dynamical mechanical analysis (DMA)) mechanical properties of composites were investigated. Proper dispersion of filler implicated that the incorporation of up to 5 wt% of filler caused only slight, 5% drop of tensile strength, with the simultaneous 16% …

Go to article

Upgrading Biogas Using Eburru Zeolitic Rocks And Other Adsorbent Materials To Remove Carbon Dioxide And Hydrogen Sulphide, James K Mbugua, Joseph M Mwaniki, Damaris M Nduta, Francis B Mwaura May 2021

Upgrading Biogas Using Eburru Zeolitic Rocks And Other Adsorbent Materials To Remove Carbon Dioxide And Hydrogen Sulphide, James K Mbugua, Joseph M Mwaniki, Damaris M Nduta, Francis B Mwaura

Tanzania Journal of Science

The trace amounts of carbon dioxide and hydrogen sulfide in raw biogas lower its calorific value,cause corrosion and make it hard to compress biogas into the cylinder. Raw biogas was obtainedfrom anaerobic digestion of cow dung and market wastes. The gas was stored in tubes or urine bagbefore upgrading. Natural zeolite rocks, maize cobs, steel wire, desulphurizer, and worn-out tyreswere used as the upgrade materials. The composition of biogas was recorded before and afterupgrading using a GP180 portable biogas analyzer from Henan, China. The measured level of rawbiogas was 0.0227% H2S, >20% CO2 and 52-56% CH4. The most efficient upgrade …

Go to article

Thermodynamic Analysis Of A Variable Viscosity Reactive Hydromagnetic Couette Flow Within Parallel Plates, Anthony R Hassan, Olufemi W Lawal, Funmilayo F Amurawaye May 2021

Thermodynamic Analysis Of A Variable Viscosity Reactive Hydromagnetic Couette Flow Within Parallel Plates, Anthony R Hassan, Olufemi W Lawal, Funmilayo F Amurawaye

Tanzania Journal of Science

This investigation is to consider the impact of a temperature-dependent variable viscosity of a reactive hydromagnetic Couette fluid flowing within parallel plates. The variable property of the fluid viscosity is thought to be an exponential relation of temperature under the impact of magnetic strength. The differential equations controlling the smooth movement of fluid and energy transfer are modeled and solved by using the series solution of modified Adomian decomposition technique (mADM). The outcomes are shown in tables and graphs for different estimations of thermophysical properties present in the flow regime together with the rate of entropy generation and irreversibility distribution …

Go to article

Mapping Of Geological Structural Features In Lolgorien, Narok County, Kenya: Using Hillshade Analysis, Sammy O Ombiro, Akinade S Olatunji, Eliud M Mathu, Taiwo R Ajayi May 2021

Mapping Of Geological Structural Features In Lolgorien, Narok County, Kenya: Using Hillshade Analysis, Sammy O Ombiro, Akinade S Olatunji, Eliud M Mathu, Taiwo R Ajayi

Tanzania Journal of Science

Despite Lolgorien being one of the most active gold mining areas in Kenya, it is one of the most geologically understudied areas. To the best knowledge of the authors, Lolgorien geological map was last updated in the 1940s. Current technologies such as remote sensing allow new structural features such as faults to be easily identified. In this regard, this study employed remote sensed data to map structural features found in and around Lolgorien Subcounty, Narok, Kenya. This was done to identify any new structural features that might have been missed in the past. Shuttle Radar 152 Topography Mission Digital Elevation …

Go to article

Assessment Of Fluoride Bioaccumulation Potential In African Catfish (Clarias Gariepinus) Reared In Fluoride Rich Water, Jophillene Bejumula, Revocatus L Machunda, Liliane J Pasape, Kelvin M Mtei May 2021

Assessment Of Fluoride Bioaccumulation Potential In African Catfish (Clarias Gariepinus) Reared In Fluoride Rich Water, Jophillene Bejumula, Revocatus L Machunda, Liliane J Pasape, Kelvin M Mtei

Tanzania Journal of Science

Fluoride bioaccumulation in fish poses a significant impact on their growth, survival and consequently to upper trophic levels. Few studies have reported the impacts of high fluoride concentrations and their accumulation potential to catfish in African settings. A 60-day catfish cultivation was conducted at Ngarenanyuki ward and the Nelson Mandela African Institution of Science and Technology (NM-AIST) in Arusha, Tanzania to determine fluoride bioaccumulation and its impacts to catfish growth and survival. Juvenile catfish were exposed to 36 mg F–/L pond water and synthetic water containing fluoride (NaF) concentrations of 5, 15, 36 and 45 mg/L in aquaria set at …

Go to article

A Gate-Based Monte Carlo Simulation Of A Dual-Layer Pixelized Gadolinium Oxyorthosilicate (Gso) Detector Performance And Response For Micro Pet Scanner, Leonid L Nkuba, Innocent J Lugendo, Idrissa S Amour May 2021

A Gate-Based Monte Carlo Simulation Of A Dual-Layer Pixelized Gadolinium Oxyorthosilicate (Gso) Detector Performance And Response For Micro Pet Scanner, Leonid L Nkuba, Innocent J Lugendo, Idrissa S Amour

Tanzania Journal of Science

The purpose of this study was to simulate the GSO detector of a micro PET using GATE simulation platform. The performance and responses of the simulated GSO detector assembly were evaluated by comparing the simulated data to the experimental and XCOM data to validate the simulation platform and procedure. Based on NEMA NU-4 2008 protocols, the performance of GSO detector in terms of sensitivity was simulated and compared to the experimental data. Similarly, the GSO detector response to photons interaction was simulated and compared against the XCOM data for absorbed intensity ratio in the GSO detector and survived intensity ratio …

Go to article

Coupled Effects Of Hydrophilic Nano Silica Oxide And Anatase Nano Titanium Oxide On Strengths Of Oilwell Cement, Petro E Mabeyo, Jun Gu May 2021

Coupled Effects Of Hydrophilic Nano Silica Oxide And Anatase Nano Titanium Oxide On Strengths Of Oilwell Cement, Petro E Mabeyo, Jun Gu

Tanzania Journal of Science

The life of oilwells depends on the stability of cement sheath and bond strength with the formation and casing. Extreme subsurface conditions cause substantial stresses on the cement sheath resulting in a serious impact on well integrity. The recommended API cement for oilwell fails to provide the required durability of the cemented well due to such conditions. Supplementary cementitious materials such as nanoparticles are added to improve the cement for long-lasting zonal isolation. In this study, the compressive and shear bond strengths of oilwell cement containing nano-SiO2 and nano-TiO2 were studied at 80 °C for 3, 7, 14, and 28 …

Go to article

Effects Of Rapid Thermal Annealing On The Properties Of Room-Temperature Oxygenated Dc Sputtered Zinc Thin Films For Czts Solar Cells Application, Emmanuel R Ollotu, Nuru R Mlyuka, Margaret E Samiji May 2021

Effects Of Rapid Thermal Annealing On The Properties Of Room-Temperature Oxygenated Dc Sputtered Zinc Thin Films For Czts Solar Cells Application, Emmanuel R Ollotu, Nuru R Mlyuka, Margaret E Samiji

Tanzania Journal of Science

This work investigated the potential to achieve zinc oxide (ZnO) films for Cu2ZnSnS4 (CZTS) solar cells window layer at controlled annealing conditions as a potential approach to address elemental inter-diffusion in CZTS solar cells. This involved rapid thermal annealing (RTA) of room-temperature oxygenated DC sputtered zinc thin films in an ambient of nitrogen gas at different temperatures. Structural, morphological, optical, and electrical properties of these films were determined by X-ray diffractometer, Scanning Electron Microscopy, Ultraviolet-visible-near infrared spectrophotometer, and Hall Effect measurement, respectively. ZnO phases were observed after annealing the films over 150 °C. The films’ grains sizes improved with increasing …

Go to article

Larvicidal Potency Of Dioscorea Sansibarensis Leaf Extract Against Vector Mosquitoes: Anopheles Gambiae S.S. And Culex Quinquefasciatus, Anitha Philbert May 2021

Larvicidal Potency Of Dioscorea Sansibarensis Leaf Extract Against Vector Mosquitoes: Anopheles Gambiae S.S. And Culex Quinquefasciatus, Anitha Philbert

Tanzania Journal of Science

Mosquitoes are responsible for transmission of illnesses of public health importance including malaria, lymphatic filariasis, dengue, chikungunya, and many other diseases caused by viruses. Vector control using synthetic insecticides has been the cornerstone for management of vector-borne diseases. However, the chemical based interventions have not been sustainable due to emergency of resistance against insecticides among disease vectors. Plant based mosquitocidal products can be potential alternative tools in vector control. Therefore, the present study aimed at exploring the larvicidal properties of Dioscorea sansibarensis leaf extract against malaria and lymphatic filariasis vectors; Anopheles gambiae s.s. and Culex quinquefasciatus. The larvicidal activities of …

Go to article

Solving The University Course Timetabling Problem Using Bat Inspired Algorithm, Ushindi Limota, Egbert Mujuni, Allen Mushi May 2021

Solving The University Course Timetabling Problem Using Bat Inspired Algorithm, Ushindi Limota, Egbert Mujuni, Allen Mushi

Tanzania Journal of Science

Many mathematical optimization problems from real-life applications are NP-hard, and hence no algorithm that solves them to optimality within a reasonable time is known. For this reason, metaheuristic methods are mostly preferred when their size is big. Many meta-heuristic methods have been proposed to solve various combinatorial optimization problems. One of the newly introduced metaheuristic methods is a bat-inspired algorithm, which is based on the echolocation behaviour of microbats. Bat algorithm (BA) and its variants have been used successfully to solve several optimization problems. However, from the No-free Lunch Theorem, it is known that there is no universal metaheuristic method …

Go to article

Application Of Linguistic/Non-Numeric Fuzzy Aggregation To The Ranking Of Processed Crops, David Koloseni May 2021

Application Of Linguistic/Non-Numeric Fuzzy Aggregation To The Ranking Of Processed Crops, David Koloseni

Tanzania Journal of Science

A non-numeric fuzzy aggregation approach is applied for the fusion of information obtained from farmers and experts for evaluation and selection of alternatives under multiple criteria. The technique has the ability to assign linguistic variable to fused information and find consensus of gathered opinions from a number of experts on crop processing for each processed crop. The technique is illustrated with a crop processing problem by adding value to the crop and increase income to entrepreneurs. The proposed technique has been successfully applied to the ranking of the processed crops based on the expert’s opinions, thus obtaining best preferences based …

Go to article

Levels Of Selected Toxic And Essential Elements In Fish And Oysters From Western Indian Ocean, Coast Of Tanzania, Daniel A Shilla, Shovi F Sawe May 2021

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, …

Go to article

Mathematical Analysis Of Harvested Predator-Prey System With Prey Refuge And Intraspecific Competition, Alanus Mapunda, Thadei Sagamiko May 2021

Mathematical Analysis Of Harvested Predator-Prey System With Prey Refuge And Intraspecific Competition, Alanus Mapunda, Thadei Sagamiko

Tanzania Journal of Science

In this paper, a predator-prey relationship in the presence of prey refuge was studied. The analysis of the dependence of locally stable equilibrium points on the parameters of the problem was carried out. Bifurcation and limit cycles for the model were analyzed to show the dynamical behaviour of the system. The results showed that the system is stable at a constant prey refuge m = 0.3 and prey harvesting rate H = 0.3. However, increasing m and decreasing H or vice versa, the predator-prey system remains stable. It was further observed that for a constant prey refuge m ≥ 0.78, …

Go to article

Determination Of 40k, 226ra And 228ra Concentrations With Dose Rates In Crayfish From Ode Omi River And Radiological Implications To The Consumers, Olusegun Sowole, Qasim Abolanle Adeniji, Muyideen O Olagunju May 2021

Determination Of 40k, 226ra And 228ra Concentrations With Dose Rates In Crayfish From Ode Omi River And Radiological Implications To The Consumers, Olusegun Sowole, Qasim Abolanle Adeniji, Muyideen O Olagunju

Tanzania Journal of Science

Natural radionuclides such as 40K, 226Ra and 228Ra are found naturally in water and sediments of rivers, likewise in soils. They are transferred to aquatic animals through ingestion. Radioactivity concentrations and dose rates of 40K, 226Ra and 228Ra in crayfish species from Ode Omi River in coastal region, Ogun State Southwest of Nigeria were determined by gamma spectrometry using NaI (TI) detector coupled with a pre-amplifier base to a multiple channel analyzer (MCA). 15 samples of crayfish were collected. Cherax tenuimanus had the highest mean concentration and dose rate of values 106.87 ± 9.11 Bq kg–1 and 0.00960 mGy hr–1 …

Go to article

Synthesis And Antimicrobial Activities Of Some New Sulfonyl Phenoxides, Oluwaseyi B Ovonramwen, Bodunde J Owolabi, Abiodun Falodun May 2021

Synthesis And Antimicrobial Activities Of Some New Sulfonyl Phenoxides, Oluwaseyi B Ovonramwen, Bodunde J Owolabi, Abiodun Falodun

Tanzania Journal of Science

Four new sulfonyl phenoxides were synthesized through O-sulfonylation reaction of phenolic compounds with 5-chloro-1-ethyl-2-methylimidazole-4-sulfonyl chloride in good yield. FT-IR, 1H-NMR, 13C-NMR, and DEPT 135 NMR were carried out to characterize and the thin layer chromatography (TLC) confirm the purity. Antimicrobial activities of the sulfonyl phenoxides against Gram-positive (methicillin-susceptible Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Bacillus subtilis), Gram-negative (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae), and Candida albicans were carried out using the standard microbiological method. The antimicrobial activities were referenced to ciprofloxacin and itraconazole, antibacterial and antifungal drug respectively. The in vitro antimicrobial studies of 5-chloro-1-ethyl-2-methyl-1H-imidazole-4-sulfonyl(4-chloro-3-methyl)phenoxide and 5-chloro-1-ethyl-2-methyl-1H-imidazole-4-sulfonyl-2-methylphenoxide showed moderate activity …

Go to article

Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla May 2021

Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla

Tanzania Journal of Science

This study was carried out to investigate spatial changes in the quality and quantity of sedimentary organic matter in the Rufiji mangrove system, Tanzania. Sediment samples were collected from three sampling sites. Total organic matter in mangrove sediments ranged from 7.28 ± 2.02% to 10.58 ± 1.34%. Protein concentrations varied from 1,145.33 ± 20.33 μg/g to 2,747.50 ± 25.14 μg/g in the mangrove sediments. Total carbohydrates, lipids and biopolymeric carbon in mangrove sediments ranged between 1,110.50 ± 16.31 μg/g and 1,914.17 ± 27.79 μg/g, 1,436.50 ± 24.13 μg/g and 6,373.50 ± 25.79 μg/g, and 4,496 μg C/g and 10,231.50 μg …

Go to article

Probabilistic Seismic Hazard Assessment And Site Analyses Of Arusha International Conference Centre (Aicc), Arusha, Tanzania, Richard W Ferdinand May 2021

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 …

Go to article

Investigation Of Some Factors Associated With Utilization Of Maternal Health Care Services By Adolescent Mothers In Tanzania, Elia Magwaja, Jacqueline Minja, Majige Selemani Budeba, Rocky R.J. Akarro May 2021

Investigation Of Some Factors Associated With Utilization Of Maternal Health Care Services By Adolescent Mothers In Tanzania, Elia Magwaja, Jacqueline Minja, Majige Selemani Budeba, Rocky R.J. Akarro

Tanzania Journal of Science

This study examined some factors associated with the utilization of maternal health care servicesby adolescent mothers (15-19 years) in Tanzania in order to provide advice accordingly. The studyused cross-sectional study of adolescent mothers aged 15-19 years using Demographic HealthSurvey and Malaria indicator Survey 2015/16 data. The dependent variables were number ofantenatal care visits, the place where an adolescent mother delivered and post-natal checkup(adolescent mother’s health checking after being discharged or after a home delivery). Theindependent variables were birth order, education level of a mother, marital status of a mother,media exposure, wealth index, distance to health facility. Multiple binary logistic regression …

Go to article

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 May 2021

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 …

Go to article

Amending Traditional Substrate Rice Straw With Agroforestry Tree Foliage Increases Production Cycle And Nutritional Value Of Pleurotus Floridanus, Samora M Andrew, John R Mbwambo May 2021

Amending Traditional Substrate Rice Straw With Agroforestry Tree Foliage Increases Production Cycle And Nutritional Value Of Pleurotus Floridanus, Samora M Andrew, John R Mbwambo

Tanzania Journal of Science

The recent heightened attention on mushrooms has not considered shortening the production time and increasing nutritional value using substrates from agroforestry trees in addition to traditionally used agro-industrial residues. This study therefore, examined harvesting time, protein and essential minerals of Pleurotus floridanus grown on rice straw amended with Gliricidia sepium foliage in Morogoro, Tanzania. Mushrooms were cultivated in 30 x 40 cm 4 kg dry weight polythene bags in randomized complete block design (RCBD) experiment. Results showed that the addition of 5% G. sepium into rice straw reduced total time between spawning and first harvest of P. floridanus. Gliricidia sepium …

Go to article

Probabilistic Seismic Hazard Analysis For Northern Tanzania Divergence Region And The Adjoining Areas, Michael M Msabi, Richard W Ferdinand May 2021

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 …

Go to article

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 May 2021

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 …

Go to article

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 May 2021

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 …

Go to article

Geological Controls On Brine Discharge In Itumbula Salt Dam Within The Rukwa Rift In Momba District, Tanzania, Mwita S Maswi, Octavian Minja, Chakutema Batwenge May 2021

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, …

Go to article

Effects Of Xanthan Gum On Rheological Properties Of Aloe Vera-Moringa Leaf Juice Blends, Victor V Matabura, Leonard Mp Rweyemamu May 2021

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 …

Go to article

Screening Of Aflatoxin-Producing Fungi In Maize And Groundnuts From Three Regions In Tanzania, Kusiluka Agape, Valence Mk Ndesendo, Sartaz Begum May 2021

Screening Of Aflatoxin-Producing Fungi In Maize And Groundnuts From Three Regions In Tanzania, Kusiluka Agape, Valence Mk Ndesendo, Sartaz Begum

Tanzania Journal of Science

This study screened aflatoxin-producing fungi in maize and groundnuts from Dodoma, Singida and Iringa regions in Tanzania, and assessed the level of peoples’ awareness on aflatoxins health effects. One hundred and twenty samples (20 each crop) were collected and inoculated on Sabouraud dextrose agar and one hundred and eleven samples were observed to have fungal growths that were identified to belong to four genera, namely Aspergillus, Rhizopus, Mucor and Dermatophyte with occurrence frequencies of 75, 2.5, 5 and 10%, respectively. Among the four screened genera of fungi, Aspergillus was observed to be the major aflatoxin-producing fungi. Five species of genus …

Go to article

Pathological Scanning Of Ochratoxigenic Moulds Impaired Feed In Vivo, Towards Conceptualizing Their Reverberations On Different Organs, Benjamin T Thomas, Omolara D Popoola, Moses O Efuntoye, Mercy O Coker, Ahmed O Tajudeen May 2021

Pathological Scanning Of Ochratoxigenic Moulds Impaired Feed In Vivo, Towards Conceptualizing Their Reverberations On Different Organs, Benjamin T Thomas, Omolara D Popoola, Moses O Efuntoye, Mercy O Coker, Ahmed O Tajudeen

Tanzania Journal of Science

The role of ochratoxigenic moulds in causing several invasive diseases has been documented but little is known about the effects of these ochratoxigenic moulds contaminated feeds in a laboratory control experiment. This study therefore, examined the pathological effects of ochratoxigenic moulds contaminated feed in order to understand their reverberations on different organs. Thirty two albino rats were randomly assigned to four experimental treatments (T) with eight rats per treatment (T1, T2, T3 and T4). T1 and T2 were female and male control rats, respectively that were fed normal feed, while T3 and T4 were male and female experimental rats that …

Go to article

Bacterial Growth Inhibitory Effects Of Calotropis Procera’S Latex, Leaves And Roots Extracts, Marco Baluhya, Charles O Joseph May 2021

Bacterial Growth Inhibitory Effects Of Calotropis Procera’S Latex, Leaves And Roots Extracts, Marco Baluhya, Charles O Joseph

Tanzania Journal of Science

This study was conducted to evaluate in vitro antibacterial potential of water and ethanolic extracts from Calotropis procera roots, leaves and latex. The growth inhibitory effects of the extracts were tested against Escherichia coli using disc diffusion method. Amoxicillin was used as positive control, whereas ethanol and distilled water were used as negative controls. Results showed that water extracts from root, latex and leaves had 3.27 ± 0.14, 3.1 ± 0.21 and 2.38 ± 0.24 cm of maximum inhibition zones, while the ethanolic extracts showed 2.91 ± 0.19, 3.02 ± 0.16 and 0.84 ± 0.31 cm, respectively of maximum inhibition …

Go to article

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 May 2021

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 …

Go to article

Application Of Optimal Control To Tuberculosis Model With Parameter Estimations: Bayesian Approach, Goodluck M Mlay, Alfred K Hugo May 2021

Application Of Optimal Control To Tuberculosis Model With Parameter Estimations: Bayesian Approach, Goodluck M Mlay, Alfred K Hugo

Tanzania Journal of Science

In this paper, one-strain tuberculosis (TB) model with two control mechanisms, education campaigns and chemoprophylaxis of TB-infected patients, was studied to determine their effects on the reduction of latent and active TB cases. In the case of analysis, boundedness and positivity of the model solutions were carried out to determine the biological feasibility of the study. Besides, the calibration of the parameters by utilizing the identifiability technique through the Markov chain Monte Carlo (MCMC) was thoroughly analysed. The optimum conditions for controlling TB were derived from the Pontryagin Maximum Principle. The numerical simulations were carried out using the forward-back sweep …

Go to article

First Prev Next Last