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Articles 1921 - 1950 of 6161

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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 …

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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 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, …

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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, …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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, …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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Sign Language Recognition Using Kinect Sensor Based On Color Stream And Skeleton Points, Isack Bulugu May 2021

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 …

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Evaluation Of Scatter Suppression Algorithm For X-Ray Exposure Of Soft Tissue Equivalent Phantoms Over Nominal Energy Range Using Fluka Code, Samson O Omondi, Innocent J Lugendo, Ramadhan R Kazema, Robert Kinyua May 2021

Evaluation Of Scatter Suppression Algorithm For X-Ray Exposure Of Soft Tissue Equivalent Phantoms Over Nominal Energy Range Using Fluka Code, Samson O Omondi, Innocent J Lugendo, Ramadhan R Kazema, Robert Kinyua

Tanzania Journal of Science

Soft tissue imaging is heavily impaired by streaks and cupping effects associated with X-ray scatter. Quality of images from projection imaging may be improved by the use of enhanced anti-scatter grids’ designs with potency to reject significant scatter. However, optimization of grid characteristics requires investigation to improve diagnostic image quality. Transmitted scatter spatially distributed degrades images engendering need for effective scatter correction protocols. This study investigated the pre-scan scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range. Adipose tissue and polymethyl methacrylate phantoms of cross-sectional area (30 x 30) cm2 and of varying thickness …

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Biodiesel Production By Esterification Of Ricinoleic Acid Over A Series Of Synthesized Sulfated Zirconia Catalysts, Elianaso Elimbinzi, Stephen S Nyandoro May 2021

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 …

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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 May 2021

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 …

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Count Time Series Models For Road Traffic Accidents In Tanzania Mainland, Amina S Msengwa, Florence D Ngari May 2021

Count Time Series Models For Road Traffic Accidents In Tanzania Mainland, Amina S Msengwa, Florence D Ngari

Tanzania Journal of Science

A pairwise analysis was conducted to assess the trends and factors associated with road traffic accidents in Tanzania. The Poisson and Negative Binomial Autoregressive Models were used to extend log linear functions by accounting time-varying components. A total of 85,514 road traffic accidents in Tanzania mainland that occurred from 2012 to 2017 were extracted from Tanzania Police Office records. Eleven factors were grouped into a human, vehicle, physical/environmental and pedestrian-related factors. The Likelihood ratio test, Akaike Information Criterion, Bayesian Information Criterion and residual ACF plots were used to evaluate the performance of the models in Dar es Salaam and other …

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Hydrogeophysical Investigation For The Aquifers In Part Of Ilorin, Central Nigeria: Implication On Groundwater Prospect, Ayodele Kehinde Olawuyi May 2021

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 …

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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 May 2021

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 …

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Spatial Distribution Patterns Of The Populations Of Two Subterranean Termites (Blattodea: Termitidae) In Eucalyptus (Myrtales: Myrtaceae) Plantations, Olaniyi T Alamu, Francis K Ewete, Ayangbade E Ayandokun, John A Ete May 2021

Spatial Distribution Patterns Of The Populations Of Two Subterranean Termites (Blattodea: Termitidae) In Eucalyptus (Myrtales: Myrtaceae) Plantations, Olaniyi T Alamu, Francis K Ewete, Ayangbade E Ayandokun, John A Ete

Tanzania Journal of Science

The study was conducted in Afaka, Northern Guinea Savanna of Nigeria to determine the spatial distribution patterns of the populations of Ancistrotermes sp. and Microtermes sp. in Eucalyptus camaldulensis Dehnh, Eucalyptus citriodora Hook, Eucalyptus cloeziana F. and Eucalyptus tereticornis Muell plantations. Spatial distributions patterns of the two termite species populations were determined using indices such as ratios of population variance to mean, Lloyd’s index, Green coefficient, Taylor power and Iwao’s regression models. The values of variance to mean ratios, Lloyd’s index and Green coefficient showed that the populations of both termite species had aggregated distribution pattern in all the Eucalyptus …

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Synergistic Effects Of Halide Ions And Acacia Senegal Gum On The Corrosion Inhibition Of Mild Steel In Sulfuric Acid Solution, Jovine Emmanuel, Joseph Buchweishaija May 2021

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 …

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Influence Of Carbonitriding Conditions On Phase Composition And Residual Stresses For 20mncr5 Low Alloy Steel, Richard J Katemi, Jeremy Epp May 2021

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 …

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