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Articles 1 - 30 of 116
Full-Text Articles in Physics
Monte Carlo Analysis Of Dose Distribution In Tumour And Adjacent Healthy Tissues During 192Ir Hdr Brachytherapy In The Presence Of Gold Nanoparticles, Damian P. Tippe, Innocent J. Lugendo
Monte Carlo Analysis Of Dose Distribution In Tumour And Adjacent Healthy Tissues During 192Ir Hdr Brachytherapy In The Presence Of Gold Nanoparticles, Damian P. Tippe, Innocent J. Lugendo
Tanzania Journal of Science
High dose rate (HDR) brachytherapy using 192Ir is an effective modality for cancer treatment; however, its therapeutic efficiency is often constrained by unintended radiation exposure to healthy tissues surrounding the tumour. Fortunately, the incorporation of high atomic number (Z) nanoparticles as radiosensitizers has emerged as a promising strategy to enhance tumour dose while sparing adjacent normal tissues. In this study, the dose distribution in tumour and nearby healthy tissues during 192Ir HDR brachytherapy was investigated in the presence of gold (Au) nanoparticles using Monte Carlo simulations based on the Geant4 toolkit. Radial dose distributions and anisotropy characteristics were analysed …
The Role Of Zinc Precursor Concentration In Modulating The Structural, Optical, And Electrical Properties Of Sol-Gel Derived Czts Thin Films, Justine John Tibaijuka
The Role Of Zinc Precursor Concentration In Modulating The Structural, Optical, And Electrical Properties Of Sol-Gel Derived Czts Thin Films, Justine John Tibaijuka
Tanzania Journal of Science
This study reports on CZTS thin films fabricated by sol–gel spin coating using zinc acetate dihydrate, copper acetate dihydrate, tin chloride, and thiourea dissolved in methanol with monoethylamine as a stabilizer. The films were annealed rapidly at 540 °C by using an RTP furnace. Results show the significant influence of zinc concentration on films’ properties with band gap evolution between 1.46 and 1.7 eV, along with high absorption coefficients exceeding 10⁴ cm⁻¹ in the visible range. Structurally, the films evolved from poorly crystalline at low Zn content to well- crystallized, (112)-oriented kesterite near stoichiometry. However, excessive Zn caused slight degradation …
Natural Radioactivity And Radiological Hazards In Sediments From The Lindi Coast, Indian Ocean, Tanzania, Viator Mujuni, Innocent J. Lugendo
Natural Radioactivity And Radiological Hazards In Sediments From The Lindi Coast, Indian Ocean, Tanzania, Viator Mujuni, Innocent J. Lugendo
Tanzania Journal of Science
The Lindi coast of the Indian Ocean, located in southeastern Tanzania, supports rich biodiversity and has recently experienced rapid growth in socio-economic activities such as fishing, mining, and oil and gas exploration. These activities may enhance levels of natural radioactivity in coastal sediments, potentially increasing radiation exposure to local populations. Therefore, monitoring radioactivity levels and estimating associated radiation doses in this region is important. In this study, thirty-six sediment samples were collected from twelve locations along the Lindi coast and analysed for naturally occurring radionuclides using high-purity germanium (HPGe) gamma-ray spectrometry. The activity concentrations of 226Ra, 232Th, and …
Optimization Of Pediatric Multidetector Ct Imaging Parameters Using A Machine Learning–Based Monte Carlo Simulation Model, Ali O. Masoud, Adithya Rajnaryanan, Khamis O. Amour, Ahmed M. Jusabani, Justin E Ngaile, Manoj Kumar, Mwingereza John Kumwenda Dr
Optimization Of Pediatric Multidetector Ct Imaging Parameters Using A Machine Learning–Based Monte Carlo Simulation Model, Ali O. Masoud, Adithya Rajnaryanan, Khamis O. Amour, Ahmed M. Jusabani, Justin E Ngaile, Manoj Kumar, Mwingereza John Kumwenda Dr
Tanzania Journal of Science
This study utilized Monte Carlo (MC) simulations to optimize radiation doses in pediatric multidetector computed tomography (MDCT) head scans by analyzing key parameters like tube current (mA), tube voltage (kV), pitch, and slice thickness. The findings indicate that reducing tube current significantly lowers the Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP), effectively minimizing patient radiation exposure. Higher pitch values (0.7–0.9) further reduced radiation by decreasing beam overlap, while using a thinner slice thickness (0.6 mm) improved dose efficiency. A comparison highlighted the effectiveness of optimization: simulated parameters kVp 100, mAs 81, pitch 0.98 yielded a CTDIvol of …
Design Of Virtual Impedance Controller For Parallel-Connected Converters In A Microgrid, Manyanda Makoye, Francis Mwasilu, Peter M. Makolo, Jackson Justo
Design Of Virtual Impedance Controller For Parallel-Connected Converters In A Microgrid, Manyanda Makoye, Francis Mwasilu, Peter M. Makolo, Jackson Justo
Tanzania Journal of Science
This paper addresses the significant challenge of inaccurate power sharing among Distributed Generators (DGs) in islanded microgrids, which is primarily caused by mismatched feeder and line impedances. Conventional decentralized control solutions often fail to ensure accurate power sharing, especially when line impedances are resistive. To overcome this, the paper proposes a robust, coordinated Virtual Impedance Control (VIC) strategy for DGs. This method implements fixed virtual resistance and virtual inductance to standardize the output impedance characteristics of parallel-connected inverters, thereby minimizing impedance discrepancies and enhancing system stability through increased damping. The theoretical analysis and design of the VIC were validated through …
Analysis Of The Effects Of Magnetic Field, Heat Transfer, And Thermal Radiation On Blood Flow Through Bifurcated Artery To Enhance Tumor Treatments, Abdullahi Isah, Dauda Gulibur Yakubu, Ali Musa
Analysis Of The Effects Of Magnetic Field, Heat Transfer, And Thermal Radiation On Blood Flow Through Bifurcated Artery To Enhance Tumor Treatments, Abdullahi Isah, Dauda Gulibur Yakubu, Ali Musa
Tanzania Journal of Science
The work presents the effects of some pertinent parameters on blood flow through bifurcated artery to enhance tumor treatments. Combining appropriately the basic equations, together with the fractionalized Maxwell fluid model allow us to determine the velocity, temperature and concentration of blood flow through bifurcated artery. The study adopted the Atangana-Baleanu fractional time derivative on fluid model to describe the non-Newtonian behavior of blood flow. The numerical simulations were performed using the combined Laplace transform and the method of undetermined coefficients and the results obtained with the aid of Mathcad software were simulated and presented graphically. From the graphical results, …
Extension Of The Local Vibrational Mode Theory To Periodic Systems, Filippo Bodo
Extension Of The Local Vibrational Mode Theory To Periodic Systems, Filippo Bodo
Chemistry Theses and Dissertations
Over the years, vibrational spectroscopy was used to gain a deeper understanding of the electronic structure and the chemical bond in both molecular and periodic systems. In this framework, the Local Vibrational Mode Theory (LVMT), as first introduced by Konkoli and Cremer in 1998, provides a unique tool to quantify the strength of a chemical bond, and better interpret the molecular vibrational spectra, thanks to the adiabatic force constants ($k^a$) and the composition of normal modes (CNM). While LVMT was originally developed for molecular systems, its application to periodic solids has remained limited. This thesis presents a complete and systematic …
Optimization Of Image Quality Of Simulated Multiple Detectors Computed Tomography Acquisition Parameters Using Machine Learning And Catphan Phantom, Ali O. Masoud, Najat K. Mohammed, Khamis O. Amour, Ahmed M. Jusabani, Denise Mwalongo, Mwingereza John Kumwenda
Optimization Of Image Quality Of Simulated Multiple Detectors Computed Tomography Acquisition Parameters Using Machine Learning And Catphan Phantom, Ali O. Masoud, Najat K. Mohammed, Khamis O. Amour, Ahmed M. Jusabani, Denise Mwalongo, Mwingereza John Kumwenda
Tanzania Journal of Science
The study successfully employed Monte Carlo (MC) simulation and a Machine Learning (ML) approach using a Random Forest Regression (RFR) model to develop optimized Multi-Detector CT (MDCT) protocols that significantly reduce radiation dose while maintaining diagnostic image quality. The MC engine accurately modeled X-ray spectra, and the RFR model demonstrated high predictive power for key metrics, achieving R2 scores of 0.97 for CTDIvol and over 0.92 for image quality metrics (Noise, CNR). Through multi-objective optimization guided by the RFR, the final protocol (Optimization-3) was found on the Pareto front, achieving a notable 35% dose reduction (from 15.5 mGy to 9.9 …
Thermal Performance And Specific Energy Consumption Of Traditional Tobacco Curing Barns In Tanzania, Seuri S. Kilakoi, Baraka Kichonge, Thomas Kivevele, Mtaki T. Maagi, Jacob B. Lisuma
Thermal Performance And Specific Energy Consumption Of Traditional Tobacco Curing Barns In Tanzania, Seuri S. Kilakoi, Baraka Kichonge, Thomas Kivevele, Mtaki T. Maagi, Jacob B. Lisuma
Tanzania Journal of Science
Traditional tobacco curing barns remain the dominant technology in Tanzania due to their low construction cost and accessibility, particularly in major producing regions such as Tabora. However, their thermal inefficiency results in excessive firewood use and environmental degradation. This study presents a field-based performance evaluation of a traditional flue-curing barn at the Tobacco Research Institute of Tanzania. Environmental parameters and fuel consumption were monitored at 15- minute intervals throughout the yellowing, leaf drying, and stem drying stages. The curing process handled 429 kg of fresh tobacco using 1,016 kg of firewood, equivalent to 16,256 MJ of energy input. The specific …
Geochemical Fingerprinting Of Tanzanian Uranium Deposits: The Insights Of Ree Ratios (La/Ce, Nd/Ce, And Sm/Nd) As A Provenance Tool, Lazaro H. Meza, John W. Kondoro, Iyabo T. Usman, Najat K. Mohammed, Titus A. Msagati, Mwingereza John Kumwenda, Mohamed S. Mazunga
Geochemical Fingerprinting Of Tanzanian Uranium Deposits: The Insights Of Ree Ratios (La/Ce, Nd/Ce, And Sm/Nd) As A Provenance Tool, Lazaro H. Meza, John W. Kondoro, Iyabo T. Usman, Najat K. Mohammed, Titus A. Msagati, Mwingereza John Kumwenda, Mohamed S. Mazunga
Tanzania Journal of Science
Accurate uranium provenance determination is crucial for nuclear non-proliferation and environmental protection, yet a forensic-level geochemical framework for Tanzanian uranium deposits has been lacking. This study establishes a robust analytical method using forty-five samples from three major deposits (Mkuju, Manyoni, and Bahi), analyzing elemental compositions, particularly Rare Earth Elements (REEs), via ICP-MS, and validating results using Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). Despite their proximity, the deposits exhibit distinct geochemical signatures as revealed by key REE ratios and anomalies. Mkuju (mean La/Ce 1.17, Nd/Ce 0.62, Sm/Nd 0.56) is characterized by a positive Europium (Eu) anomaly and heavy …
Assessment Of Tumour Control Probability And Equivalent Uniform Dose In Conventional 3d-Crt Vs. Hypo-Fractionated Imrt, Jumaa D. Kisukari, Mwingereza J. Kumwenda, Khamis O. Amour, Ehab M. Attalla, Emmanuel Lugina
Assessment Of Tumour Control Probability And Equivalent Uniform Dose In Conventional 3d-Crt Vs. Hypo-Fractionated Imrt, Jumaa D. Kisukari, Mwingereza J. Kumwenda, Khamis O. Amour, Ehab M. Attalla, Emmanuel Lugina
Tanzania Journal of Science
Hypo-fractionated (HF) radiotherapy offers a promising solution to improve access to cancer treatment in resource-limited settings, such as developing countries, by reducing the number of treatment sessions compared to conventional fractionation (CF). For effective implementation, evaluating Equivalent Uniform Dose (EUD) and Tumour Control Probability (TCP) is essential to ensure treatment efficacy across different radiotherapy techniques. This study compares treatment plans generated using Three-Dimensional Conformal Radiation Therapy with Conventional Fractionation (3D-CRT CF) and Intensity Modulated Radiation Therapy with Hypo-fractionation (IMRT HF) in patients with localized prostate cancer. A total of 50 patients were CT-simulated, and their images were imported into a …
Design Of High-Performance Synchronous Reluctance Motor For Hybrid Electric Vehicle Application, Fred Loita, Jackson Justo
Design Of High-Performance Synchronous Reluctance Motor For Hybrid Electric Vehicle Application, Fred Loita, Jackson Justo
Tanzania Journal of Science
This paper presents the simulation-based design of a synchronous reluctance motor (SynRM) coupled electromechanical system suitable for the hybrid electric vehicle. The study considers SynRM with a 75kW power rating with the capability to produce up to 125kW maximum power for the electric vehicle. The focus is mainly on rotor and stator design; the angles of the flux-barrier ends are considered to reduce the torque ripple due to the slot harmonics. Reluctance machines are indeed competitive for applications requiring high efficiency at low cost. However, it is a challenging task to find design solutions that ensure structural integrity of the …
Heavy Metal Contamination And Health Risks In Katoro's Artisanal Gold Mining Soils, Tanzania, Innocent J. Lugendo, Venance Mwesiga
Heavy Metal Contamination And Health Risks In Katoro's Artisanal Gold Mining Soils, Tanzania, Innocent J. Lugendo, Venance Mwesiga
Tanzania Journal of Science
This study assessed heavy metal contamination in surface soils from artisanal gold mining areas in Katoro, Tanzania, evaluating ecological and human health risks. Thirty-six soil samples were systematically collected from three mining villages (Bingwa, Isenye, and CCM) at varying distances ranging from 30 to 90 m from active mining pits alongside twelve control samples from a non-mining area for comparison purposes. Concentrations of Cr, Cu, Ni, Zn, Pb, and As in soil samples were analyzed using energy-dispersive X-ray fluorescence spectrometry (EDXRF). Results revealed severe contamination, with Cr (117–1255 mg/kg), Cu (81–104 mg/kg), and Ni (89–271 mg/kg) exceeding permissible limits. The …
Rainwater Harvesting For Domestic Use In Suburb Areas Of Dar Es Salaam, Tanzania: A Case Study Of Wazo Hill, Scholastica S. Ishengoma, Mahir Mohammed Said, Neema O. Msuya
Rainwater Harvesting For Domestic Use In Suburb Areas Of Dar Es Salaam, Tanzania: A Case Study Of Wazo Hill, Scholastica S. Ishengoma, Mahir Mohammed Said, Neema O. Msuya
Tanzania Journal of Science
Despite the increasing reliance of rainwater harvesting in semi-urban areas, there is a lack of comprehensive localized data on the safety of harvested rainwater, particularly in areas such as Wazo Hill where communities predominantly depend on it. This study evaluates the quality of harvested rooftop rainwater intended for human consumption and assesses its compliance with the World health Organization (WHO) and Draft East Africa Standards (DEAS) for drinking water. Rainwater samples were collected from various catchment surfaces and storage systems located in Wazo Hill, Tanzania. A stratified random sampling technique was employed to select the households equipped with rainwater harvesting …
Dynamic Lqr Control For Improved Dc Link Voltage Stability In Grid-Integrated Solar Pv System, Peter Makolo, Mwanajuma Gora, Francis Mwasilu, Jackson Justo
Dynamic Lqr Control For Improved Dc Link Voltage Stability In Grid-Integrated Solar Pv System, Peter Makolo, Mwanajuma Gora, Francis Mwasilu, Jackson Justo
Tanzania Journal of Science
The integration of photovoltaic (PV) systems into power grids poses a significant challenge to voltage stability, especially at the DC link. Fluctuations in solar irradiance directly cause power variations and instability in this critical interface. If not properly controlled, this variability can lead to inefficiencies, equipment damage, and widespread grid disturbances. To address the abovementioned challenge, this paper proposes a dynamic converter control strategy designed to enhance DC link voltage stability in grid-integrated solar PV system. The core of the proposed control system is based on a Linear Quadratic Regulator (LQR) mechanism, implemented within a two-stage, PV grid connected system …
Maximizing Legged Accelerations: A Matter Of Force, Time, And Gravity, Lance Brooks
Maximizing Legged Accelerations: A Matter Of Force, Time, And Gravity, Lance Brooks
Applied Physiology and Wellness Theses and Dissertations
Sprint running accelerations require runners to apply surface forces that: support body weight by pushing downward, accelerate the body horizontally by pushing backward, and align the direction of the push with the body’s mass center to maintain balance and posture, which imposes an upper limit on the average forward acceleration force equal to the average gravitational force (1.0 G) acting on the runner. This expectation arises from the mechanical constraints imposed by the need to generate sufficient vertical force to support body weight against gravity while simultaneously producing horizontal force to accelerate forward and aligning the push through the center …
Geological Structure And Possible Mineralized Zones In Ikungi – Manyoni Area, Tanzania: Delineated From High-Resolution Aeromagnetic Data, Raymond K. Pius, Michael M. Msabi
Geological Structure And Possible Mineralized Zones In Ikungi – Manyoni Area, Tanzania: Delineated From High-Resolution Aeromagnetic Data, Raymond K. Pius, Michael M. Msabi
Tanzania Journal of Science
Understanding geological structures is important in mineral exploration. Delineating subsurface geological structures, structural intersections, and complexities of potential geological settings for the formation of hydrothermal mineral deposits, such as gold requires using magnetic data, particularly, high-resolution aeromagnetic data. To define possible targets for mineral exploration, this study used linear detection and the Centre for Exploration Targeting (CET) techniques on high-resolution aeromagnetic data for structural delineation and interpretation. The study's conclusions indicate that the majority of geological features, such as faults, shears, fault intersections, and fracture systems, trend NE-SW, N-S, and occasionally NW-SE. These structures create potentially large areas that have …
Influence Of Stacking Order On The Structural And Optical Properties Of Cu2znsns4 Absorber Layer Prepared From Dc-Sputtered Oxygenated Precursors, January S Gwaydi, Hezekiah B Sawa, Egidius R Rwenyagila, Nathanael R Komba, Talam E Kibona, Nuru R Mlyuka, Margaret E Samiji, Lwitiko P Mwakyusa
Influence Of Stacking Order On The Structural And Optical Properties Of Cu2znsns4 Absorber Layer Prepared From Dc-Sputtered Oxygenated Precursors, January S Gwaydi, Hezekiah B Sawa, Egidius R Rwenyagila, Nathanael R Komba, Talam E Kibona, Nuru R Mlyuka, Margaret E Samiji, Lwitiko P Mwakyusa
Tanzania Journal of Science
Several studies have attempted to overcome the sudden volume expansion of the precursor during sulfurization by the use of oxygen-containing precursors when growing the CZTS absorber. This work demonstrates the influence of precursor stacking orders on the properties of the CZTS thin film absorber layer from DC-sputtered oxygenated precursors for solar cell applications. CZTS absorber layers were prepared from three types of DC-sputtered stacks, namely, Zn-O/Sn/Cu, Sn/Zn-O/Cu, and Sn/Cu/Zn-O. The precursors were sequentially deposited on a soda lime glass (SLG) using DC-magnetron sputtering and annealed in a sulfur and nitrogen ambient. X-ray diffractometry (XRD) and Raman spectroscopy analyses reveal the …
Effect Of Substrate Temperature And Deposition Power On The Surface Morphology And Optical Properties Of Zno:Mg Thin Films Deposited By Dc Magnetron Sputtering, Saidi Saidi, Margaret E. Samiji, Nuru R. Mlyuka
Effect Of Substrate Temperature And Deposition Power On The Surface Morphology And Optical Properties Of Zno:Mg Thin Films Deposited By Dc Magnetron Sputtering, Saidi Saidi, Margaret E. Samiji, Nuru R. Mlyuka
Tanzania Journal of Science
Magnesium doped zinc oxide (ZnO:Mg) thin films were deposited on soda lime glass slides by DC magnetron sputtering method. Atomic force microscope (AFM), and UV/VIS spectrophotometer were used to investigate the effect of sputtering power and substrate temperature on the surface morphology and optical properties of ZnO:Mg thin films. AFM images revealed that sputtering power and deposition temperature have significant influence on surface morphology of the ZnO:Mg thin films. For all sputtering powers and substrate temperatures investigated, ZnO:Mg films had peak transmittance above 85%. Samples deposited at 110 W sputtering power and 450 °C substrate temperature showed the best peak …
Preparation Of 2d Tungsten Diselenide (Wse2) Thin Films By Selenization Of Dc-Sputtered W Precursors, Lwitiko P. Mwakyusa
Preparation Of 2d Tungsten Diselenide (Wse2) Thin Films By Selenization Of Dc-Sputtered W Precursors, Lwitiko P. Mwakyusa
Tanzania Journal of Science
Two-dimensional layered transition metal dichalcogenides based on WSe2 films demonstrated promising properties for nano-electronics and photovoltaic applications. In this work, WSe2 films were prepared by selenization of DC-sputtered W precursors. The influence of the selenization temperature on the structural, morphology, and optical properties of the WSe2 films was investigated. The selenization temperature was varied from 350 °C to 450 °C at the interval of 50 °C. Structural, morphology and optical properties of the WSe2 were investigated using X-ray diffractometry (XRD), Atomic Force Microscope (AFM), and UV-VIS-NIR spectrophotometer, respectively. XRD analysis revealed that all WSe2 were polycrystalline and exhibited the co-existence …
Micro Machining Of A Si3n4/Sio2/Ti/Pt Hotplate And Its Ir Emissivity Properties, Egidius R. Rwenyagila
Micro Machining Of A Si3n4/Sio2/Ti/Pt Hotplate And Its Ir Emissivity Properties, Egidius R. Rwenyagila
Tanzania Journal of Science
This paper presents the fabrication processes for a Si3N4/SiO2/Ti/Pt membrane based micro hotplate (MHP) using photolithography (PL) micro-machining techniques. The properties of the MHP filament are investigated and overall performance characteristics with regard to infrared (IR) radiation emissivity, resistance, breakdown voltage, and temperature of the fabricated Si3N4/SiO2/Ti/Pt micro heater. During characterization, the results show the device breakdown voltage of 24.24 V corresponding to the optimum operation temperature of ~ 1730.30 K. The device also showed an emissivity value of 5.2% with ~ 7% efficiency of transforming electrical power to IR thermal radiation power. The relationship between temperature and resistance, behaviour …
Impact Of Zn And W Doping Levels On Properties Of Thermochromic Vo2-Based Thin Films, Haji F. Haji, Margaret E. Samiji, Nuru R. Mlyuka
Impact Of Zn And W Doping Levels On Properties Of Thermochromic Vo2-Based Thin Films, Haji F. Haji, Margaret E. Samiji, Nuru R. Mlyuka
Tanzania Journal of Science
DC magnetron sputtering at a substrate temperature of 425 °C was used to successfully deposit W/Zn-doped VO2 thin films on soda lime glass (SLG) substrates. The aim was to investigate the influence of Zn doping levels on the transition temperature ( ), luminous transmittance (Tlum) and solar transmittance modulation (ΔTsol) of VO2-based thin films. UV/VIS/NIR spectrometer, X-ray Diffraction (XRD), Atomic Force Microscope (AFM), and Rutherford Backscattering Spectroscopy (RBS) were used to characterise the thin films. It was revealed that W/Zn co-doped VO2 thin films with ~ 10.8 at.% Zn showed a luminous transmittance of ~ 40.4%, with excellent solar transmittance …
Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam
Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam
Tanzania Journal of Science
Organic pollutants in water have been a challenge and pose significant risks to human health. As a result, research efforts to eliminate these pollutants have been on the rise. Photocatalysis has shown incredible potential in water treatment containing organic pollutants since it is affordable and utilizes solar energy. Tin oxide ( ) has ardently been investigated as a photocatalyst for water treatment due to its remarkable properties such as; non-toxicity, and stability. However, its wide band gap and the tendency for some electrons and holes to recombine during its use have been cited to be among limiting factors affecting its …
Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai
Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai
Tanzania Journal of Science
Lake Natron Basin (LNB) forms part of the eastern branch of the East African Rift System (EARS) in Tanzania. The basin is endowed with thermal springs flowing towards the lake from the western, northwestern, southwestern and eastern parts. The western, northwestern and south-western thermal springs emanate from fractures in the basaltic rocks while in the east, they originate from the western flank of the Gelai volcano. There are limited studies on these springs, thus their geochemical differences and distributions of physicochemical parameters are not well understood. A hydrogeochemical study was conducted to interpret available geochemical data from the LNB springs, …
Experimental Measurements Of Ignition Delay Times Of Iso-Octane/N-Butanol Blend Mixtures In Rapid Compression Machine (Rcm), Myeji Materego, Derek Bradley
Experimental Measurements Of Ignition Delay Times Of Iso-Octane/N-Butanol Blend Mixtures In Rapid Compression Machine (Rcm), Myeji Materego, Derek Bradley
Tanzania Journal of Science
Among oxygenated alternative fuels, n-butanol is considered as a promising alternative biofuel which can partially (or fully) replace conventional transportation fuels currently in use. However, before n-butanol can be commercially utilised, its fundamental combustion characteristics need to be fully understood. In this work, the effect of adding n-butanol on autoignition property of iso-octane was studied. Measurements of ignition delay times for the two blends of n-butanol proportions of 30% and 50% by mole weight were made in a Rapid Compression Machine for stoichiometric mixtures at 2.0 MPa and temperature range 651-918 K. n-butanol increased ignition delay times of iso-octane at …
Thermal Performance Of A Mechanical Thermostat For Charging An Energy Storage System, Swaleh Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal
Thermal Performance Of A Mechanical Thermostat For Charging An Energy Storage System, Swaleh Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal
Tanzania Journal of Science
Thermal energy storage (TES) systems enhance the use of solar energy for cooking by matching the energy demand to its supply. Useful energy is extracted from TES systems that are thermally stratified and this is enhanced when charged at an averagely constant-temperature. This paper presents an experimental analysis of a mechanical-thermostat used to control the charging of an oil based TES system. The thermostat consisted of a slider-valve, an expansion-system acting both as a thermal-sensor and actuator, and an adjusting-knob for setting the charging temperature. Oil from a cold-oil reservoir flows by gravity into a heating-chamber when a manual valve …
Measurement Of Solar Irradiance For Determining The Optimal Tilt Angle For Photovoltaic Panels, Gbadebo I. Olatona, Tolulope J. Fadairo
Measurement Of Solar Irradiance For Determining The Optimal Tilt Angle For Photovoltaic Panels, Gbadebo I. Olatona, Tolulope J. Fadairo
Tanzania Journal of Science
The challenge of solar panel installers in determining the tilt angle needed to obtain optimal performance from the photovoltaic panels was the focus of this paper. The performances of two 150 W panels under varied conditions of temperature and solar irradiance on a plane at two different heights (1 m and 11.5 m) from the ground surface were determined to find the effects of tilt angle and altitude on their performances. Measurements of solar irradiance, temperature, open-circuit voltage, and short circuit current were made at various tilt angles and compared to one another based on the measured irradiance. The optimal …
Constraining The Origin And Age Of The Thermal And Cold Water In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai, Mike J. Butler
Constraining The Origin And Age Of The Thermal And Cold Water In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai, Mike J. Butler
Tanzania Journal of Science
Springs on the eastern and western shores of Lake Natron Basin (LNB), located within the eastern branch of the East Africa Rift System (EARS) in Northern Tanzania had a discharge temperature that ranged between 34.0 °C and 51.2 °C, while the pH varied from 8.0 to 10.7. The electrical conductivity (EC) ranged between 5,007 µS/cm and 49,200 µS/cm. Cold waters had a temperature of 31.9 °C to 32.5 °C, while the pH ranged between 8.0 and 8.3, and the EC ranged between 1,401 µS/cm and 3,806 µS/cm. The stable isotope composition varied between -2.4 ‰ and -5.3 ‰ for δ18O, …
Performance Investigations Of The Charging And Discharging Processes In A 3-Tank Thermal Energy Storage System, Swalehe Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal
Performance Investigations Of The Charging And Discharging Processes In A 3-Tank Thermal Energy Storage System, Swalehe Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal
Tanzania Journal of Science
The paper presents a 3 tank thermal energy storage system. The system consists of cold oil reservoir, heat storage tank, and a residual drainage tank. Cold oil flows by gravity into a heating chamber and after being heated to the required temperature, a mechanical thermostat opens allowing the hot oil to flow into a heat storage tank. The storage tank was discharged through the cooking unit by boiling 0.5 litres of water. The used oil flowed by gravity to the drainage tank. The discharge flow rates of 0.5, 2.1, 2.8 and 6.5 g/s were considered. A charging efficiency of 51.3% …
Pulsed Lased Deposition Of Single-Crystalline (001) Oriented Pb(Zr0.5t0.5)O3 Thin Film On Prsco3 Substrate, Mahamudu H. Mtebwa, Nava Setter
Pulsed Lased Deposition Of Single-Crystalline (001) Oriented Pb(Zr0.5t0.5)O3 Thin Film On Prsco3 Substrate, Mahamudu H. Mtebwa, Nava Setter
Tanzania Journal of Science
High quality thin films are important for domain engineering applications such as on-volatile memory applications. Single crystalline (001) oriented Pb (Zr0.5T0.5)O3 thin films have been grown by pulsed laser deposition on PrScO3 with strontium ruthenate (SRO) electrodes. Thin films were prepared from PZT ceramic targets with 15% excess PbO to compensate for lead loss at high deposition temperature. Layer by layer/step flow growth mode observed on AFM images has been realised by using a single terminated PrScO3 substrate as well as optimized deposition parameters. XRD measurements have confirmed the highly (001) oriented tetragonal symmetry. Furthermore, analysis conducted using piezoresponse force …