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Synthesis Of 1-(2,4-Dinitrophenyl)-3,5-Diphenyl-1h-Pyrazol-4-Ol Via Trans-1,3-Diphenyl-2,3-Epoxy-1-Propanone, Oluwaseyi B Ovonramwen Aug 2021

Synthesis Of 1-(2,4-Dinitrophenyl)-3,5-Diphenyl-1h-Pyrazol-4-Ol Via Trans-1,3-Diphenyl-2,3-Epoxy-1-Propanone, Oluwaseyi B Ovonramwen

Tanzania Journal of Science

The trans-1,3-diphenyl-2,3-epoxy-1-propanone was synthesized from benzaldehyde and 2-bromoacetophenone in 20 min which is more economical. The presence of ethanol and Br in 2-bromoacetophenone facilitated the reaction. The vicinal diaxial coupling constant of trans-1,3-diphenyl-2,3-epoxy-1-propanone was zero, an indication of trans configuration for a rigid 3-membered ring at ~90o dihedral angle. 1-(2,4-Dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol was synthesized from trans-1,3-diphenyl-2,3-epoxy-1-propanone and 2,4-dinitro phenylhydrazine in glacial CH3COOH to give 85.5% yield and characterized using FTIR, 1H, 13C NMR, DEPT 135 and MS spectra. The 1-(2,4-dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol can be exploited for unique biological activities and in the synthesis of synthetic fibers. Keywords:    1-(2,4-dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol, trans-1,3-diphenyl-2,3-epoxy-1-propanone, synthesis, 2,4-dinitro phenylhydrazine.

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Effects Of Climate Changes On Water Resources: A Case Of Mindu Dam In Morogoro Municipality, Tanzania, Simon R Melchioly Aug 2021

Effects Of Climate Changes On Water Resources: A Case Of Mindu Dam In Morogoro Municipality, Tanzania, Simon R Melchioly

Tanzania Journal of Science

This paper presents the findings of the research conducted in Morogoro Municipality, central Tanzania. The main objective of the research was to assess the climate change impacts on water resources, taking the Mindu Dam as the case study. The study methodology involved collection, processing and analysis of both primary and secondary data. Data collection involved acquisition of Dam water level data, climate data, and Landsat 8 satellite imagery. Research findings showed that the maximum air temperature increased at a rate of 0.045% on a span of 30 years, while rainfall has been decreasing with time. Also there has been a …

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Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi Aug 2021

Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi

Tanzania Journal of Science

Spatial modelling was conducted to examine community factors associated with cholera incidence rates in Morogoro Municipality. The study employed both secondary (cholera cases) and primary (geographic coordinates of community risk factors) data. Spatial lag model was applied in examining association between the variables. All wards of Morogoro Municipality were considered in the study to capture their variations because cholera cases have a tendency to be clustered. Results indicated that market density, distance to the market and distance to the dumpster are significant factors associated with cholera incidence rates in the wards (p < 0.05). Geographically weighted Poisson model was used to show the variations of those factors between the wards in Municipality. A statistically significant positive association of cholera incidence rates; and market density was only found in Mazimbu ward (p < 0.05) and distance from the community to the dumpster was found in Kihonda, Kingolwira, Bigwa, Kichangani, Kilakala and Boma wards (p < 0.001) and some wards at the centre of the municipality which are Mji Mkuu and Kingo (p < 0.05). A statistically significant negative association of cholera incidence rates and distance from the centre of the community to the market was found in Kihonda, Kingolwira and Kichangani (p < 0.001) and Bigwa wards (p < 0.05). Therefore, measures taken to control and prevent cholera disease should base on the variations of the risk factors found in the Municipal wards.  Keywords:    Cholera incidence rate, Spatial lag regression model, Community risk factor, Geographically weighted Poisson model

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Physicochemical And Bacteriological Water Quality Parameters In Relation To Land-Use Practices At A Rural Catchment, Mbinga District, Tanzania, Harieth Hellar-Kihampa, Patrick Isdory Ndunguru Aug 2021

Physicochemical And Bacteriological Water Quality Parameters In Relation To Land-Use Practices At A Rural Catchment, Mbinga District, Tanzania, Harieth Hellar-Kihampa, Patrick Isdory Ndunguru

Tanzania Journal of Science

Data on physicochemical water quality parameters and contamination levels is crucial for protection and sustainable utilization of water resources. This study assessed the physicochemical water quality parameters, faecal coliform bacteria and nutrient loads in water at a catchment used for municipal supply in Mbinga District, Tanzania. Samples were seasonally collected from three areas characterized by distinct geographical features, settlement patterns and land-use practices, and analyzed using standard analytical protocols. Data were subjected to paired-sampled t-test and cluster analysis. The parameters varied as follows: pH (4.75–6.83); temperature (16.4–26.2 ºC); electrical conductivity (14.6–121.1 µS/cm); total dissolved solids (7.0–23.2 mg/L); total suspended solids …

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Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain Aug 2021

Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain

Tanzania Journal of Science

Water is one of the renewable resources essential for sustaining all forms of life and quality of drinking water is very fundamental for human health. Human activities such as mining act as sources of water contamination which consequently lead to ecological, environmental and health problems. To the best of our knowledge, no study has been conducted around the Thundulu Phosphate Mine to establish the quality of drinking water. In this regard, this study was carried out to evaluate the physico-chemical water quality parameters of areas surrounding the Thundulu Phosphate Mine in Phalombe District. Groundwater samples from the villages surrounding the …

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Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti Aug 2021

Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti

Tanzania Journal of Science

Post-harvest losses of stored Phaseolus vulgaris to the bean weevil Callosobruchus chinensis have reached levels of significant concern. Governments and health organisations propose the discovery of reliable,  healthy and biodegradable pesticides with higher selectivity and a broad spectrum. This study presents investigations on the activities of Dioscorea sansibarensis leaf extracts on the mortality of C. chinensis and reduction of their egg-laying ability. Laboratory experiments under Completely Randomized Design (CRD) were carried out to determine the mortality and anti-oviposition activity of the vacuum liquid chromatography (VLC) eluates of n-hexane (HE), chloroform (CE), ethyl acetate (EE), n-butanol (BE) and methanol (BE) at …

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Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku Aug 2021

Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku

Tanzania Journal of Science

Bayesian estimations have the advantages of taking into account the uncertainty of all parameter estimates which allows virtually the use of vague priors. This study focused on determining the quantile range at which optimal hyperparameter of normally distributed data with vague information could be obtained in Bayesian estimation of linear regression models. A Monte Carlo simulation approach was used to generate a sample size of 200 data-set. Observation precisions and posterior precisions were estimated from the regression output to determine the posterior means estimate for each model to derive the new dependent variables. The variances were divided into 10 equal …

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Assessment Of Farm Households’ Vulnerability To Desertification In Rural Dry Lands Of Katsina State, Nigeria, Olanrewaju Yusuf Yahaya Aug 2021

Assessment Of Farm Households’ Vulnerability To Desertification In Rural Dry Lands Of Katsina State, Nigeria, Olanrewaju Yusuf Yahaya

Tanzania Journal of Science

The purpose of this study was to use a Vulnerability Index (VI) to assess farm households' vulnerability to desertification in Northern Katsina's dry land ecosystem. The specific objectives were to identify socio-economic characteristics of farm households; and determine the degree of their vulnerability to desertification. A systematic random sampling technique was used to select 633 respondents from 18 rural communities across six Local Government Areas (LGAs). Data from 21 indicators for the three components of vulnerability (exposure, sensitivity and adaptive capacity) were used to measure the degree of vulnerability and thus, classify households into less, moderate and highly vulnerable. The …

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Robust Trilateration Based Algorithm For Indoor Positioning Systems, Simeon Pande, Kwame S Ibwe Aug 2021

Robust Trilateration Based Algorithm For Indoor Positioning Systems, Simeon Pande, Kwame S Ibwe

Tanzania Journal of Science

Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used in self-navigating robots and helping hands. To obtain position information, positioning algorithms employing Received Signal Strength Indicator (RSSI) are of great benefits since they reuse the existing radio wireless infrastructures for indoor positioning. However, the changes in the indoor environment decrease the overall accuracy of the developed indoor positioning algorithms. To cope with the challenge of environmental dependency in indoor positioning, a robust algorithm using radio signal identification was developed. The algorithm uses circle expansion and reduction mechanism to achieve better RSSI-Distance relationship. The distances from RSSI-Distance …

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Effect Of Lowering Tube Potential And Increase Iodine Concentration Of Contrast Medium On Radiation Dose And Image Quality In Computed Tomography Pulmonary Angiography Procedure: A Phantom Study, Justin E Ngaile, Peter K Msaki, Evarist M Kahuluda, Furaha M Chuma, Jerome M Mwimanzi, Ahmed M Jusabani Aug 2021

Effect Of Lowering Tube Potential And Increase Iodine Concentration Of Contrast Medium On Radiation Dose And Image Quality In Computed Tomography Pulmonary Angiography Procedure: A Phantom Study, Justin E Ngaile, Peter K Msaki, Evarist M Kahuluda, Furaha M Chuma, Jerome M Mwimanzi, Ahmed M Jusabani

Tanzania Journal of Science

The aim of the study was to examine the effect of lowering tube potential and increase iodine concentration on image quality and radiation dose in computed tomography pulmonary angiography procedure. The pulmonary arteries were simulated by three syringes. The syringes were filled with 1:10 diluted solutions of 300 mg, 350 mg and 370 mg of iodine per millilitre concentration in three water-filled phantoms simulating thin, intermediate and thick patients. The phantoms were scanned at 80 kVp, 110 kVp and 130 kVp and 0.6 second rotation time using a 16 slice computed tomography (CT) scanner. The tube current was either fixed …

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Mineral Liberation: A Case Study For Buzwagi Gold Mine, Alphonce Wikedzi, Thomas Leißner Aug 2021

Mineral Liberation: A Case Study For Buzwagi Gold Mine, Alphonce Wikedzi, Thomas Leißner

Tanzania Journal of Science

Buzwagi Gold Mine (BGM) process plant was designed such that, after secondary grinding, gold and copper are recovered by flotation. However, the flotation circuit had been inefficient, and as a result, cyanidation of flotation tailings is currently conducted to improve gold recovery. The inefficient flotation is suspected to be due to mineralogical variations of ores treated. Hence, mineral liberation characteristics of three ore blends treated by BGM were investigated by automated Scanning Electron Microscope (SEM) whereby five fractions (i.e.  -1 +0.5 mm, -0.5 +0.25 mm, -0.25 +0.125 mm, -0.125 +0.063 mm and -0.063 mm) were used. It was found that …

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Utilization Of Iron Filings As Partial Replacements For Sand In Self-Compacting Concrete, Simon O. Olawale, Mutiu A. Kareem, Habeeb T. Muritala, Abiola U. Adebanjo, Olusegun O. Alabi, Oluwole A. Olawuyi, Olusola O. Fadipe Aug 2021

Utilization Of Iron Filings As Partial Replacements For Sand In Self-Compacting Concrete, Simon O. Olawale, Mutiu A. Kareem, Habeeb T. Muritala, Abiola U. Adebanjo, Olusegun O. Alabi, Oluwole A. Olawuyi, Olusola O. Fadipe

Tanzania Journal of Science

The use of industrial by-products in concrete production is part of concerted efforts on the reduction of environmental hazards attributed to the mining of conventional aggregates. Consideration of iron filings (IF), a by-product from steel production process, is an environmentally friendly way of its disposal which is expected to yield economic concrete production. Six self-compacting concrete (SCC) mixes were made by partially substituting river sand with IF at 5%, 10%, 15%, and 20% and the mix without IF (0% IF) served as the control. The water-binder (w/b) ratio of 0.45 was adopted for all mixes. The fresh state properties of …

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Bayesian Hetero-Elasticnet (A Gibbs Sampler Approach), Isiaka Oloyede Aug 2021

Bayesian Hetero-Elasticnet (A Gibbs Sampler Approach), Isiaka Oloyede

Tanzania Journal of Science

Combined heteroscedasticity and multicollinearity as dual non-spherical disturbances were experimented asymptotically. A Gibbs Sampler technique was used to investigate the asymptotic properties of hetero-elasticnet estimator with mean squares error (MSE) and bias as performance metrics. The seed was set to 12345;  is set at ; Xs variables were generated as follow: the design matrix was generated from the multivariate normal distribution with mean > 0 and variance .  and  are truncated with Harvey (1976) heteroscedastic error structure;  are collinear covariate with pairwise correlation between 0.6 and 0.9, the sample sizes were 25, 100 and 1000. The number of replications of the …

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Multi-Vehicle Speed Estimation Algorithm Based On Real-Time Inter-Frame Tracking Technique, Ernest Kisingo, Ndyetabura Hamisi, Hashim U. Iddi, Baraka J. Maiseli Aug 2021

Multi-Vehicle Speed Estimation Algorithm Based On Real-Time Inter-Frame Tracking Technique, Ernest Kisingo, Ndyetabura Hamisi, Hashim U. Iddi, Baraka J. Maiseli

Tanzania Journal of Science

Inappropriate vehicle speeding remains a central factor that causes road accidents claiming millions of lives every year. This challenge has raised concerns for vehicle speed estimation as an attempt to promote speed enforcement methods. Traditionally, radar and lidar systems have widely been used for this purpose, despite their several shortfalls: cosine error effects, need for direct line-of-sight, and inability to simultaneously and accurately measure speed from multiple vehicles. The current work proposes an algorithm and a multi-vehicle speed estimation system in a multi-lane road environment to address multi-vehicle speed estimation shortfalls. The proposed solution exploits image processing and computer vision …

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Weighted Statistical A-Optimal Designs For Two-Variable Poisson Regression Model With Application To Fertility Studies, Emmanuel Idowu Olamide, Femi Barnabas Adebola, Olusoga Akin Fasoranbaku Aug 2021

Weighted Statistical A-Optimal Designs For Two-Variable Poisson Regression Model With Application To Fertility Studies, Emmanuel Idowu Olamide, Femi Barnabas Adebola, Olusoga Akin Fasoranbaku

Tanzania Journal of Science

This research extends design optimization to model involving count data. A two-variable Poisson regression model was investigated for A-optimality on a constrained design space and the weights of the optimal design points were obtained. The constructed designs were verified to be A-optimal at 4-point design through the general equivalence theorem. The efficiency of the constructed optimal design was found to be 100% A-efficient. The concept of weighted optimal designs for Poisson regression model was applied to fertility studies. Approximate A-optimal design weights of educational level of women were obtained for each marriage duration period with respect to their places of …

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Efficient Load Balancing Algorithm In Long Term Evolution (Lte) Heterogeneous Network Based On Dynamic Cell Range Expansion Bias, Emmanuel Bakuza, Hashimu U. Iddi, Abdi T. Abdalla Aug 2021

Efficient Load Balancing Algorithm In Long Term Evolution (Lte) Heterogeneous Network Based On Dynamic Cell Range Expansion Bias, Emmanuel Bakuza, Hashimu U. Iddi, Abdi T. Abdalla

Tanzania Journal of Science

The traditional scheme for load balancing in a homogeneous Long Term Evolution (LTE) Network where User Equipment (UEs) associate to a node with the strongest received signal strength is not practical for LTE Heterogeneous Network (LTE HetNet) due to power disparity between the nodes. Therefore, dynamic Cell Range Expansion (CRE) based load-balancing schemes were employed by several scholars to address the challenges in the LTE HetNet. However, the fairness index in achieving the desired average user throughput and UE offloading effect is relatively low. In this work, an efficient load-balancing algorithm for LTE HetNet based on dynamic Cell Range Expansion …

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E-Optimal Experimental Designs For Poisson Regression Models In Two And Three Variables, Emmanuel Idowu Olamide, Olusoga Akin Fasoranbaku, Femi Barnabas Adebola Aug 2021

E-Optimal Experimental Designs For Poisson Regression Models In Two And Three Variables, Emmanuel Idowu Olamide, Olusoga Akin Fasoranbaku, Femi Barnabas Adebola

Tanzania Journal of Science

In the context of generalized linear models, most of the recent studies were on logistic regression models and many of them focussed on optimal experimental designs with concentration on D-optimality. In this research, two- and three-variable Poisson regression models were considered for E-optimization on restricted design space [0, 1]. The two-variable Poisson regression model was not optimal at 3-design points, but was found to be E-optimal at 4-design points (1, 1), (0, 0), (0, 1) and (1, 0) with equal design weights of 0.25. The three-variable Poisson regression model was E-optimal at 4-design points (0, 0, 1), (0, 1, 0), …

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Elegant Iterative Methods For Solving A Nonlinear Matrix Equation X-A^* E^X A=I, Chacha S Chacha Aug 2021

Elegant Iterative Methods For Solving A Nonlinear Matrix Equation X-A^* E^X A=I, Chacha S Chacha

Tanzania Journal of Science

The nonlinear matrix equation   was solved by Gao (2016) via standard fixed point method. In this paper, three more elegant iterative methods are proposed to find the approximate solution of the nonlinear matrix equation  namely: Newton’s method; modified fixed point method and a combination of Newton’s method and fixed point method. The convergence of Newton’s method and modified fixed point method are derived. Comparative numerical experimental results indicate that the new developed algorithms have both less computational time and good convergence properties when compared to their respective standard algorithms. Keywords: Hermitian positive definite solution, nonlinear matrix equation, modified fixed point …

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Current State Of Seagrasses In Zanzibar: Impacts Of Coastal Economic Activities And Marine Protected Areas On Seagrass Cover, Danielle Purvis, Narriman Jiddawi Aug 2021

Current State Of Seagrasses In Zanzibar: Impacts Of Coastal Economic Activities And Marine Protected Areas On Seagrass Cover, Danielle Purvis, Narriman Jiddawi

Capstone Collection

Seagrass meadows are located abundantly in Zanzibar, Tanzania and provide essential ecosystem services, such as sediment nutrient enrichment and blue carbon sequestration. However, seagrasses have been less researched or protected than other marine ecosystems. Although environmental variables affect seagrass health, evidence suggests that anthropogenic impacts are their greatest threats. The rapid expansion of seaweed farming and tourism and widespread use of harmful small-scale fishing practices in Zanzibar have contributed to the degradation and removal of seagrass meadows, disrupted coastal marine food chains, and reduced local biodiversity that seagrasses support. Public or private marine protected areas (MPAs) protect most of Zanzibar’s …

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Socio-Technical Perspective For Electronic Tax Information System In Tanzania, Lucas Ngowi, Ellen Kalinga Jul 2021

Socio-Technical Perspective For Electronic Tax Information System In Tanzania, Lucas Ngowi, Ellen Kalinga

Tanzania Journal of Engineering and Technology (TJET)

Socio-technical systems theory has rarely been used by system architects in setting up computing systems. However, the role of socio-technical concepts in computing, which is becoming social in nature, has made the concepts more relevant and commercial. Tax information systems are examples of such systems because they are influenced by external variables such as the political environment, technological trends, and social environment, introducing complexity in their deployment and determining the type of e-services and their delivery to a diverse group of people. It was observed that in Tanzania there is resistance, reluctance and minimal use of electronic tax system because …

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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% …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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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