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Articles 31 - 60 of 116
Full-Text Articles in Physics
Effects Of Multilayer Structure On The Microstructure And Optical Properties Of The Dc Sputtered Chromium Thin Films For Selective Solar Absorber Applications, Justine J. Tibaijuka, Margaret E. Samiji, Mmantsae Diale, Nuru R. Mlyuka
Effects Of Multilayer Structure On The Microstructure And Optical Properties Of The Dc Sputtered Chromium Thin Films For Selective Solar Absorber Applications, Justine J. Tibaijuka, Margaret E. Samiji, Mmantsae Diale, Nuru R. Mlyuka
Tanzania Journal of Science
Chromium thin films exhibit several properties that make them potential for solar thermal applications. In this work the effect of film thickness and sputtering power based multilayer structure on the optical properties of DC sputtered chromium thin films is reported. The structural, topological, and optical properties of these films were determined by X-ray diffractometer, Atomic Force Microscopy, and Ultraviolet-Visible-Near Infrared spectrophotometer, respectively. XRD spectra revealed a single peak with preferential orientation of (200) and (210) for single layer and multilayer chromium films, respectively. The grain size and roughness were relatively higher for the multilayer compared to single layer Chromium films. …
Solar Cells: Types, Modules, And Applications–A Review, Amira Abd-Elfattah Darwish, Rana S. Abdelmohsen, Mohamed Ahmed, M. Megeed
Solar Cells: Types, Modules, And Applications–A Review, Amira Abd-Elfattah Darwish, Rana S. Abdelmohsen, Mohamed Ahmed, M. Megeed
Tanzania Journal of Science
The basic operating principle of photovoltaic (PV) devices is the conversion of solar irradiation into electricity. There are various applications of this principle in many countries such as Egypt, Nigeria and Denmark. Most of the solar PV projects are designed for street lighting, water pumping and water desalination. However, we hope about wide range of using the appropriate components and best technical procedures, standard PV projects with maximum performance output. The present systems now provide 20% to 40% only of the community's heat or lightness on annual basic needs. These include innovative and alternative ways to reduce material uses and …
Effects Of Annealing Ambient On The Structural, Optical And Electrical Properties Of Tio2:Ge Thin Films, Lilian A. Owino, Sebastian Waita, Robinson J. Musembi, Francis W Nyongesa
Effects Of Annealing Ambient On The Structural, Optical And Electrical Properties Of Tio2:Ge Thin Films, Lilian A. Owino, Sebastian Waita, Robinson J. Musembi, Francis W Nyongesa
Tanzania Journal of Science
TiO2, a semiconducting material with a wide energy band gap, has been researched intensively due to its interesting properties and many potential applications. The films properties can as well be modified by preparing the films under diverse ambient to suit diverse applications. In this work, the effects of the annealing atmosphere on the structural, optical and electrical properties of pure TiO2 and TiO2:Ge composite thin films deposited by sputtering from commercially available pure TiO2 and TiO2:Ge (85:15) targets respectively were studied. The films were deposited on fluorine doped tin oxide glass substrates by radio frequency magnetron sputtering technique at room …
Reproductive Potential Of The Mackerel Scad, Decapterus Macarellus (Cuvier, 1833) In The Coastal Waters Of Tanzania, Joseph S Sululu, Blandina R Lugendo, Benaiah L Benno
Reproductive Potential Of The Mackerel Scad, Decapterus Macarellus (Cuvier, 1833) In The Coastal Waters Of Tanzania, Joseph S Sululu, Blandina R Lugendo, Benaiah L Benno
Tanzania Journal of Science
This study investigated the reproductive biology of Decapterus macarellus locally known as ''Msumari", one of the most economically important scad fish along the coastline of Tanzania. Fish samples were collected from ring net artisanal fishers operating in Tanga and Bagamoyo coastal waters, monthly between April 2019 and September 2020. Findings indicated that D. macarellus spawns throughout the year with peaks in August at Tanga and September at Bagamoyo. Overall sex ratios (M: F) were 1:1.03 (Tanga) and 1:1.2 (Bagamoyo) in favour of females. The males and females of D. macarellus at Tanga attained the first maturity at 145.5 mm and …
Investigation Of The Vertical Profile Radio Refractivity Gradient And Effective Earth Radius Factor (K-Factor) In Transmission Link Over Oyo, Oyo State, South Western Nigeria, Akeem L. Sheu, Kamaldeen O Suleman, Qasim A Adeniji
Investigation Of The Vertical Profile Radio Refractivity Gradient And Effective Earth Radius Factor (K-Factor) In Transmission Link Over Oyo, Oyo State, South Western Nigeria, Akeem L. Sheu, Kamaldeen O Suleman, Qasim A Adeniji
Tanzania Journal of Science
Surface radio refractive gradient and k-factor are very imperative in observing propagation conditions, designing and planning of microwave communication links in the lower part of the atmospheric boundary layer. The measurement of weather variables (air temperature, atmospheric pressure, relative humidity and wind speed) were conducted in this study at the School of Science, Emmanuel Alayande College of Education, Oyo (7.83°N, 3.95°E), Oyo State, Nigeria. The research was carried out for a period of one year (January to December, 2020) using self-designed cost effective portable weather monitoring systems. The systems were sited from the ground to a height of 200 m …
Design And Implementation Of Distributed Identity And Access Management Framework For Internet Of Things (Iot) Enabled Distribution Automation, Ally T Bitebo, Hellen Maziku, Ndyetabura Hamisi, Charles N Tarimo, Kwame S Ibwe, Abdi T. Abdalla
Design And Implementation Of Distributed Identity And Access Management Framework For Internet Of Things (Iot) Enabled Distribution Automation, Ally T Bitebo, Hellen Maziku, Ndyetabura Hamisi, Charles N Tarimo, Kwame S Ibwe, Abdi T. Abdalla
Tanzania Journal of Science
The smart grid and Internet of Things (IoT) technologies play vital roles in improving the quality of services offered in traditional electrical grid. They open a room for the introduction of new services like distribution automation (DA) that has a significant advantage to both utility companies and final consumers. DA integrates sensors, actuators, intelligent electrical devices (IED) and information and communication technologies to monitor and control electrical grid. However, the integration of these technologies poses security threats to the electrical grid like Denial of Service (DoS) attacks, false data injection attacks, and masquerading attacks like system node impersonation that can …
Boron Doped Zno Films Deposited By Dc Reactive Sputtering Using Zn:B Target: Influence Of The Deposition Temperature On The Structural, Electrical And Optical Properties, Lwitiko P. Mwakyusa, Nuru R. Mlyuka, Margaret E. Samiji
Boron Doped Zno Films Deposited By Dc Reactive Sputtering Using Zn:B Target: Influence Of The Deposition Temperature On The Structural, Electrical And Optical Properties, Lwitiko P. Mwakyusa, Nuru R. Mlyuka, Margaret E. Samiji
Tanzania Journal of Science
ZnO-based transparent and conducting oxides (TCOs) are commonly used as a window layer in thin-film solar cells. However, TCOs with high transparency in the visible and near-infrared parts of the electromagnetic spectrum, plus excellent electrical properties are required in this application. In this study, TCOs based on ZnO:B films deposited by DC reactive sputtering using Zn:B alloy target were investigated. The impact of deposition temperature on the growth and physical properties of the films was examined. Structural, optical and electrical properties of these films were investigated by means of x-ray diffraction (XRD), Ultraviolet-Visible-Near Infrared (UV-VIS-NIR) spectroscopy, and Hall effect measurement, …
Adaptive Sliding Mode Contouring Control Design Based On Reference Adjustment And Uncertainty Compensation For Feed Drive Systems, Mathew Renny Msukwa, Santos Kihwele
Adaptive Sliding Mode Contouring Control Design Based On Reference Adjustment And Uncertainty Compensation For Feed Drive Systems, Mathew Renny Msukwa, Santos Kihwele
Tanzania Journal of Science
Industrial feed drive systems, particularly, ball-screw and lead-screw feed drives are among the dominating motion components in production and manufacturing industries. They operate around the clock at high speeds for coping with the rising production demands. Adversely, high-speed motions cause mechanical vibrations, high-energy consumption, and insufficient accuracy. Although there are many control strategies in the literature, such as sliding mode and model predictive controls, further research is necessary for precision enhancement and energy saving. This study focused on design of an adaptive sliding mode contouring control based on reference adjustment and uncertainty compensation for feed drive systems. A combined reference …
Rural Electrification Using Iliceto Shield Wire Scheme In Developing Countries: Tanzania Case Study, Heavenlight M Munisi, Santos Kihwele
Rural Electrification Using Iliceto Shield Wire Scheme In Developing Countries: Tanzania Case Study, Heavenlight M Munisi, Santos Kihwele
Tanzania Journal of Science
Rural electrification rate in Tanzania is still very low despite the efforts made by the Rural Energy Agency (REA) in Tanzania. Rural electrification using medium voltage (MV) method has two major obstacles. First obstacle is high cost associated with the cost of extending the grid electricity to rural areas. Second obstacle is remoteness of the villages, which leads to high power loss during transmission. In lieu of economic extension of rural electrification areas, this paper proposes a low cost solution of Iliceto Shield Wire Scheme (ISWS). This technique involves insulating shield wires (SW) from high voltage (132-400 kV) transmission line …
Smart Electric Meter Deployment In Tanzania: A Survey, Theresia B Maziku, Kwame S Ibwe, Abdi Abdalla, Ellen A Kalinga
Smart Electric Meter Deployment In Tanzania: A Survey, Theresia B Maziku, Kwame S Ibwe, Abdi Abdalla, Ellen A Kalinga
Tanzania Journal of Science
Using information and communication technologies (ICT) to make the electrical power network intelligent and smarter (smart grid) has been the focal point in transforming electrical power industry. The idea behind smart grid is to transform the Tanzanian power sector into a secure, adaptive, sustainable, and digitally enabled ecosystem that provides reliable and quality energy for all with active participation of stakeholders. Smart metering is a central segment in realizing smart grid. However, a big question is whether Tanzanian power stakeholders are ready for smart metering technology investments for household applications. Operation and maintenance of a smart metering solution is a …
Automated Detection Of Bilingual Obfuscated Abusive Words On Social Media Forums: A Case Of Swahili And English Texts, Geofrey Njovangwa, Godfrey Justo
Automated Detection Of Bilingual Obfuscated Abusive Words On Social Media Forums: A Case Of Swahili And English Texts, Geofrey Njovangwa, Godfrey Justo
Tanzania Journal of Science
The usage of social media has exponentially grown in recent years leaving the users with no limitations on misusing the platforms through abusive contents as deemed fit to them. This exacerbates abusive words exposure to innocent users, especially in social media forums, including children. In an attempt to alleviate the problem of abusive words proliferation on social media, researchers have proposed different methods to help deal with variants of the abusive words; however, obfuscated abusive words detection still poses challenges. A method that utilizes a combination of rule based approach and character percentage matching techniques is proposed to improve the …
Stocking Density, Growth And Survival Rate Of Post-Settled Juveniles Of Holothuria Scabra (Jaeger 1833) Reared In An Ocean-Based Floating Hapa, Yussuf S Yussuf, Saleh As Yahya
Stocking Density, Growth And Survival Rate Of Post-Settled Juveniles Of Holothuria Scabra (Jaeger 1833) Reared In An Ocean-Based Floating Hapa, Yussuf S Yussuf, Saleh As Yahya
Tanzania Journal of Science
Ocean-based nursery system using floating hapa have proved to be the best option for raising early sandfish juveniles. However, the nursery system can be further improved by providing key information that will support their application. The present study provides information on the effect of stocking density on growth and survival of sandfish juveniles reared in floating hapa (1 x 0.5 x 1 m). Three densities were tested, 100, 200 and 400 early juveniles (5 mm; 0.093 g) per hapa net in a randomized set-up. Initial density of 100 and 200 showed significant higher growth rate and final size (0.082–0.074 g/day; …
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
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 …
Assessment Of Farm Households’ Vulnerability To Desertification In Rural Dry Lands Of Katsina State, Nigeria, Olanrewaju Yusuf Yahaya
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 …
Josephson Effect In Mgb2/Pd/Nb Trilayer Josephson Junctions, Anayesu B Malisa
Josephson Effect In Mgb2/Pd/Nb Trilayer Josephson Junctions, Anayesu B Malisa
Tanzania Journal of Science
This paper reports fabrication techniques and results of MgB2/Pd/Nb trilayer Josephson junctions. The MgB2 bottom electrode was co-evaporated by molecular beam epitaxy (MBE) technique from both magnesium and boron sources at a low substrate temperature ~ 300 °C, while the interlayer and the top niobium electrode (Pd/Nb bilayer) were deposited ex-situ using RF sputtering. The junctions exhibited and Josephson effect as well as a modulation of the critical current in a magnetic field applied in a direction normal to the junction plane. Fractional and integer Shapiro steps were observed at voltages corresponding to the frequency of the applied microwave radiation …
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
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 …
Thermodynamic Analysis Of A Variable Viscosity Reactive Hydromagnetic Couette Flow Within Parallel Plates, Anthony R Hassan, Olufemi W Lawal, Funmilayo F Amurawaye
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 …
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
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 …
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
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 …
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
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 …
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
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 …
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
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 …
Perceived Risk Factors Of Dysmenorrhea Among Female Undergraduates In University Of Ilorin, Ilorin, Nigeria, Ibrahim Ologele, Precious Daniel Oyiza, Ogunsola Tijani
Perceived Risk Factors Of Dysmenorrhea Among Female Undergraduates In University Of Ilorin, Ilorin, Nigeria, Ibrahim Ologele, Precious Daniel Oyiza, Ogunsola Tijani
Tanzania Journal of Science
Dysmenorrrhea is one of the leading causes of school absenteeism among female undergraduates in University of Ilorin, Nigeria. Therefore, the study investigated the perceived risk factors of dysmenorrhea among female undergraduates in the University of Ilorin, Nigeria. Descriptive research design of survey type was used for the study. Population for this study comprised of female undergraduates in the University of Ilorin for 2018/2019 academic session. Multi-stage sampling technique of simple, proportionate, purposive and convenience sampling techniques were used to select 263 respondents that participated in the study. The researcher developed a questionnaire which was validated by 3 experts from the …
Analysis Of A Reform Option For The Tanzanian Pension System, Andongwisye Mwakisisile, Torbjörn Larsson
Analysis Of A Reform Option For The Tanzanian Pension System, Andongwisye Mwakisisile, Torbjörn Larsson
Tanzania Journal of Science
In this study, an analysis of a reform option for the Tanzanian pension system was done. The current system is dominated by mandatory defined benefit operating under pay-as-you-go principles. The retirement benefits are based on the average of the three best final salaries in the ten years preceding retirement. Several studies and international experts have shown that such systems face unsustainability. We propose a reform to a notional defined contribution system in which the benefits depend on accumulated contributions indexed by internal rates of returns. Simulation of results for a time horizon of fifty years shows that the notional defined …
Levels And Exposure Risks Of Lead, Arsenic And Mercury From Selected Lipstick And Nail Polish Cosmetics Marketed In Dar Es Salaam, Tanzania, Gerald S. Kulwa, Matobola J Mihale
Levels And Exposure Risks Of Lead, Arsenic And Mercury From Selected Lipstick And Nail Polish Cosmetics Marketed In Dar Es Salaam, Tanzania, Gerald S. Kulwa, Matobola J Mihale
Tanzania Journal of Science
Presence of Pb, As and Hg in selected lipstick and nail polish cosmetics sold at different shopping malls and retail outlets in Dar es Salaam was determined by microwave plasma atomic emission spectrometry due to their public health effects. Pb was detected in 100% (n = 25) of lipsticks and 53.3% (n = 15) of nail polishes. Arsenic was detected in 36% of lipsticks and 86.7% of nail polishes, and Hg was detected in 44% of lipsticks and 80% of nail polishes. All metal levels in both cosmetics were below the World Health Organisation (WHO) and Tanzania Bureau of Standards …
Contour Mapping For Rain Rate And Rain Attenuation In Microwave And Millimetre Wave Earth-Satellite Link Design In Tropical Tanzania, Promota Haule Linga, Hashim Uledi Iddi, Mussa Kissaka
Contour Mapping For Rain Rate And Rain Attenuation In Microwave And Millimetre Wave Earth-Satellite Link Design In Tropical Tanzania, Promota Haule Linga, Hashim Uledi Iddi, Mussa Kissaka
Tanzania Journal of Science
Rain rate and rain attenuation predictions are vital in the analysis of the performance of earth-satellite link at higher frequencies beyond 10 GHz for satellite system planning. This study intended to address lack of rain attenuation profile based on local rainfall data collected from various parts of the country. A one-minute integration time rainfall rate used to estimate the rain-induced attenuation was obtained by converting the annual rainfall data collected for 40 years from 22 locations in Tanzania using a combination of Chebil and refined Moupfouma-Martin methods. The International Telecommunication Union (ITU) standard was used to predict attenuation caused by …
Variations Of Concentrations Of Lead, Zinc, Iron, Copper And Cadmium In Urine Of Primary School Pupils In Relation To Age, Sex And Academic Performance, John Mahugija, Zainab Kasenya, Kessy Kilulya
Variations Of Concentrations Of Lead, Zinc, Iron, Copper And Cadmium In Urine Of Primary School Pupils In Relation To Age, Sex And Academic Performance, John Mahugija, Zainab Kasenya, Kessy Kilulya
Tanzania Journal of Science
This study was conducted in order to assess the variations and correlations in the concentrations of lead, zinc, iron, copper and cadmium metals in the urine samples of selected primary school pupils with respect to their sex, age and academic performance. Urine samples were collected from 240 pupils in Dar es Salaam, Tanzania and then digested in concentrated acids and analysed using atomic absorption spectrometry (AAS). Lead, zinc, iron and copper were detected in most of the urine samples. Cadmium was not detected in any of the samples. The mean concentrations of lead, zinc, iron and copper in the samples …
Comparison Of Experimental And Monte Carlo Simulation Of Angular Distributions Of Bremsstrahlung Photons From 28-Ghz Electron Cyclotron Resonance (Ecr) Ion Source, Mwingereza Kumwenda
Comparison Of Experimental And Monte Carlo Simulation Of Angular Distributions Of Bremsstrahlung Photons From 28-Ghz Electron Cyclotron Resonance (Ecr) Ion Source, Mwingereza Kumwenda
Tanzania Journal of Science
Angular distributions of deceleration radiation or bremsstrahlung in German, both experimental and simulated from Electron Cyclotron Resonance Ion Source (ECRIS) are not well understood so far. The bremsstrahlung photons of the angular distributions from 28-GHz ECR ion source at Busan Centre of Korea Basic Science Institute (KBSI) were measured in nine azimuthal angles for the first time. Three round type NaI(Tl) detectors were used to measure the angular distributions of the bremsstrahlung photons emitted at the extraction side of the ECRIS at the same time. Another NaI(Tl) detector was placed downstream from the ECR ion source for monitoring photon intensity. …
Geochronology Of Massif-Type Anorthosites From The Ubendian Belt, Tanzania, Nelson Boniface
Geochronology Of Massif-Type Anorthosites From The Ubendian Belt, Tanzania, Nelson Boniface
Tanzania Journal of Science
Massif-type anorthosites occur in East Africa at the margins of the Tanzania Craton in the Ubendian Belt. The massif assemblage constitutes of mafic-composition plutons (meta-anorthosite and meta-gabbro), ultramafic plutons, and titaniferous iron-ore. Silicic ortho-gneisses (tonalitic, dioritic, and granodioritic intrusives) also occur in the vicinity of the said massif-type anorthosites. This article presents ages of meta-anorthosites and meta-gabbros. The new U-Pb zircon age indicates that meta-gabbros and meta-anorthosites crystallized between 1915 ± 24 and 1905 ± 24 Ma concomitantly with the silicic magmatic bodies. Geochronological databases indicate that the period between 1920 and 1850 Ma HP-LT metamorphic interface was formed at …
Evidence For A Record Of Possible Paleo-Tsunami Or Storm Deposits In The Fluviatile Neoproterozoic Malagarasi Supergroup Of North-Western Tanzania, Charles Kasanzu, Shukrani Manya
Evidence For A Record Of Possible Paleo-Tsunami Or Storm Deposits In The Fluviatile Neoproterozoic Malagarasi Supergroup Of North-Western Tanzania, Charles Kasanzu, Shukrani Manya
Tanzania Journal of Science
Two different localities within the fluviatile Neoproterozoic Malagarasi Supergroup of north-western Tanzania show striking evidence for tsunami related clastic sedimentary deposits. In each locality, the outcrops are characterised by the association of fine grained, thinly laminated shales at the bottom that are overlain by thick deposits of sandstones and conglomerates whose clasts and pebbles vary in size and angularity/roundness. In each case, the two rock units are separated by an erosional surface. The basal shale layers are consistent with deposition in deep shelf environments which are in stark contrast to the immediately overlying conglomerates/sandstones that suggest reworking under high energy …