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Full-Text Articles in Atmospheric Sciences
Projections Of The Characteristics Of Extreme Precipitation In East Africa Using Bias-Corrected Cmip6 Models, Exavery K. Makula
Projections Of The Characteristics Of Extreme Precipitation In East Africa Using Bias-Corrected Cmip6 Models, Exavery K. Makula
Tanzania Journal of Science
In the context of ongoing global climate change, the intensification of the hydrological cycle is expected to modify the frequency, magnitude, and spatial distribution of extreme precipitation events. Understanding how precipitation extremes will evolve under climate change is critical for East Africa (EA), a region highly vulnerable to hydroclimatic hazards and strongly dependent on rainfall-driven socioeconomic systems. The region experiences two main rainfall seasons, namely the long rains (March-May, MAM) and the short rains (October-December, OND). This study investigates future projections of the characteristics of extreme precipitation across the EA using an ensemble of biascorrected CMIP6 global climate models. Extreme …
Performance Comparison Of Kriging Models Used For Estimation Of Rainfall Variability In The Northern Coast Of Tanzania, Salma Suleiman, Clement Mromba
Performance Comparison Of Kriging Models Used For Estimation Of Rainfall Variability In The Northern Coast Of Tanzania, Salma Suleiman, Clement Mromba
Tanzania Journal of Science
Accurate rainfall estimation underpins effective disaster preparedness and sustainable socioeconomic planning. The performance of Ordinary Kriging (OK), Universal Kriging (UK), and Simple Kriging (SK) in estimation of rainfall variability were assessed across eight stations in the northern coast of Tanzania for the period from 1960 to 2020. Using ArcGIS 10.3, each method was evaluated and cross-validated using six performance metrics, namely; Mean Error (ME), Mean Square Error (MSE), Root Mean Square Error (RMSE), Root Mean Standardized Square Error (RMSSE), Average Standardized Error (ASE), and the Coefficient of Determination (R²). Performance comparison results indicate OK to have achieved the lowest bias, …
Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda
Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda
Tanzania Journal of Science
Measurement of angular distribution (AD) of the bremsstrahlung spectral temperature from a full dimension of the Electron Cyclotron Resonance Ion Source (ECRIS) along the beam axis is challenging. To overcome some challenges, this paper presents the AD of the bremsstrahlung spectral temperature measured in a full dimension of the ECRIS along the beam axis using data obtained from the Busan Center of Korea Basic Science Institute (KBSI). The bremsstrahlung spectral temperature from 28-GHz ECR Ion source at the KBSI was measured in six, three, and nine azimuthal angles at the injection, centre, and extraction sides of the ECRIS using three …
Application Of Remote Sensing And Spectroradiometry In Geological Mapping: A Case Study Of Handeni (Qds 148) Block, Eastern Mozambique Belt, Tanzania, Masota M. Magigita, Elisante Mshiu, Cassy Mtelela
Application Of Remote Sensing And Spectroradiometry In Geological Mapping: A Case Study Of Handeni (Qds 148) Block, Eastern Mozambique Belt, Tanzania, Masota M. Magigita, Elisante Mshiu, Cassy Mtelela
Tanzania Journal of Science
This study applies remote sensing (RS) as a geologic mapping aid tool , using Handeni Block of Tanzania as a case study. To achieve the objective of this study, we have utilized various RS processing and image enhancement techniques on multispectral data, including ASTER, Landsat 5, Landsat 8, and Sentinel 2A. The method proved successful whereby both Landsat-5-data with band combination (BC) 7:4:2 and 7:5:4 and band ratio (BR) 5/3:5/1:7/5 and Landsat-8 data with BCs 5:6:7 and 7:6:4 mapped out marble units. Sentinel 2A data (with BC 8:11:3, BRs 12/2:11/2:8/11; 12/4:11/3:11/2 and 12/4:12/2:11/3) together with image enhancement decorrelation stretch on …
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 …
Quantifying The Strength Of The El Niño Southern Oscillation And The Indian Ocean Dipole In Influencing The Ond Rainfall Season In Tanzania, Benjamin William Ongito, Paul T.S. Limbu
Quantifying The Strength Of The El Niño Southern Oscillation And The Indian Ocean Dipole In Influencing The Ond Rainfall Season In Tanzania, Benjamin William Ongito, Paul T.S. Limbu
Tanzania Journal of Science
The current paper examines the strength of variability between the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) in influencing October to December (OND) rainfall over the bimodal rainfall regime of Tanzania. The empirical orthogonal function (EOF), correlation analysis, and composite analysis were used during the data analysis. The results show more rainfall distribution over the western part of the Lake Victoria basin and to the peripheral of the northern coast of the country, thus suggesting that, during the OND rainfall season, the onset starts in the western part of the Lake Victoria basin, then spreads to the …
Design Of A Cooling System Integrated With Ultraviolet Light For Preservation Of Fruits And Vegetables At Variable Tropical Weather Conditions: A Case Study Of Arusha, Tanzania, John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge
Design Of A Cooling System Integrated With Ultraviolet Light For Preservation Of Fruits And Vegetables At Variable Tropical Weather Conditions: A Case Study Of Arusha, Tanzania, John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge
Tanzania Journal of Science
Post-harvest losses of fruits and vegetables pose significant challenges, especially in tropical climates. This study introduces the development and performance evaluation of a solar-powered evaporative cooling storage system integrated with ultraviolet light (UV) designed for preservation of perishable fruits and vegetables. The cooling chamber supplied with ultraviolet lamp was developed using locally available materials such as sisal, sponge, and bricks. The performance of the system was evaluated in terms of air temperature decrease, relative humidity increase, and evaporative cooling power capacity both for sunny and cloudy tropical weather conditions. The study reveals that activating the UV light considerably extends the …
Influence Of Urban Land Use Land Cover Changes On Land Surface Temperature In Dar Es Salaam Metropolitan City, Tanzania: The Use Of Geospatial Approach, Olipa Simon, Nestory Yamungu, James Lyimo
Influence Of Urban Land Use Land Cover Changes On Land Surface Temperature In Dar Es Salaam Metropolitan City, Tanzania: The Use Of Geospatial Approach, Olipa Simon, Nestory Yamungu, James Lyimo
Tanzania Journal of Science
Land use land cover (LULC) changes affect the planet's energy balance and region's climate. Land Surface Temperature (LST) is a vital indicator of this change. Studies in Dar es Salaam Metropolitan City have investigated LST and its relationships with building heights and densities, urban heat islands, spectral indices, and urban morphological determinants. The present study used cross-sectional profiles, chord diagrams, and simple linear regression models to examine the influence of LULC changes on the LST in Dar es Salaam Metropolitan City (DMC). LST was extracted from Landsat 5 TM and 8 OLI/TIRS images for 1995, 2009, and 2017. LULC was …
Geo-Statistical Analysis Of Meteorological Drought And Recurrence Intervals In The Context Of Climate Change Over Extreme Northeastern Region Of Nigeria, Iliya B. Abaje
Tanzania Journal of Science
This study examined the occurrence of meteorological drought in the context of climate change over the extreme northeastern region of Nigeria using rainfall and temperature data spanning a period of 60 years (1961-2020) and 40 years (1981-2020), respectively. Linear regression, 5-year moving average and Cramer’s test were used to examine the changes in the rainfall and temperature. Rainfall Anomaly Index was used in depicting periods of different drought intensities in the region. The trend analysis of the climate data revealed that the region has been experiencing increasing rainfall and temperature in recent years. Findings also revealed that the droughts of …
Spatiotemporal Variability Of Drought And Its Relationships To Enso And Iod Indices In Somaliland, Mohamed S Bile, Paul Ts Limbu
Spatiotemporal Variability Of Drought And Its Relationships To Enso And Iod Indices In Somaliland, Mohamed S Bile, Paul Ts Limbu
Tanzania Journal of Science
Drought is one of Somaliland’s most prevalent natural hazards, causing serious socioeconomic and environmental harm. This study investigated the spatial and temporal variability of drought and its relationships with El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) indices using the Standardized Evapotranspiration Index (SPEI) from 1981 to 2020. The Mann-Kendall trend test and Sen's slope estimator were used to assess the trends of annual and seasonal SPEI time series. The Empirical Orthogonal Function (EOF) was employed to examine the dominant modes of the SPEI series, and Pearson and partial correlation analyses were performed to investigate the associations between …
Weathering The Storm: Community Socio-Economic And Physical Vulnerability Assessment Of Informal Settlements To Disasters In Arusha City, Tanzania, Herbert Hambati
Weathering The Storm: Community Socio-Economic And Physical Vulnerability Assessment Of Informal Settlements To Disasters In Arusha City, Tanzania, Herbert Hambati
Tanzania Journal of Science
Urban population growth has demonstrated a synergetic relationship with the growth of informal settlements and vulnerability to disasters in urban areas. This study employed Community Participatory Vulnerability Assessment (CPVA) to analyse vulnerability in informal settlements in Arusha City, Tanzania. The results show that a plethora of factors, including socio-economic and physical realities interact in complex non-linear ways to shape vulnerability to disasters in informal settlements in the city. The study shows that coping strategies of some individuals in informal settlements reinforce their risks to disasters. This is particularly demonstrated by the stones that are positioned on weak roof structures for …
Effects Of Temperature And Salinity On Incubation Time, Hatching Success, And Larvae Survival Of The Giant Tiger Prawn Penaeus Monodon Under Experimental Conditions, Sawadi Ndunguru, Marcelian Njau, Blandina Robert Lugendo
Effects Of Temperature And Salinity On Incubation Time, Hatching Success, And Larvae Survival Of The Giant Tiger Prawn Penaeus Monodon Under Experimental Conditions, Sawadi Ndunguru, Marcelian Njau, Blandina Robert Lugendo
Tanzania Journal of Science
Prawns are commercially one of the most important marine resources. However, in their early developmental stages, they face challenges related to physico-chemical and environmental changes. This study aimed at investigating the effects of temperature and salinity on egg incubation time, hatching success, larval and postlarval survival of the giant tiger prawn, Penaeus monodon (Fabricius 1798) obtained from the coastal waters of Tanzania. The adult females P. monodon collected off Rufiji delta were left to acclimatize and spawn at 28.5 ± 0.5 °C and 32 ppt in the hatchery. Spawned eggs were incubated at experimental temperatures of 27 °C, 31 °C …
Effects Of Feed Moisture Content, Soybean Ratio And Barrel Temperature On Physical And Functional Properties Of Extruded Maize-Soybean Flour Blends, Robert Mugabi, Stellah Byakika, Ivan Muzira Mukisa
Effects Of Feed Moisture Content, Soybean Ratio And Barrel Temperature On Physical And Functional Properties Of Extruded Maize-Soybean Flour Blends, Robert Mugabi, Stellah Byakika, Ivan Muzira Mukisa
Tanzania Journal of Science
The effects moisture content, temperature and soybean ratio on expanded product characteristics of extruded maize-soybean blends were studied. Response surface methodology was used to study the effects of extrusion conditions on extrudate properties taking barrel temperature (BT), feed moisture content (FM) and soybean flour ratio (SR) as factors. Expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), hardness and colour (b* - (+) yellowness) of the extrudates were determined. BT and FM had significant effects on ER (p < 0.05). At low FM levels, ER increased with BT. It was observed that both FM and BT significantly affected WAI and WSI. WAI increased as FM increased. Increasing FM to 20% resulted in a decrease in WSI, beyond which an increase was observed. Hardness increased significantly as feed moisture content increased. High SR content significantly increased the extrudate hardness. FM had no significant effect on colour. Colour increased as the SR and BT increased. Significant regression models explained the effects of SR, FM, and BT on all response variables. All of the response variables' R2, were higher than 0.89. Keywords: Maize, Soybean, moisture content, extrusion
Suitability Of Flood Hazard Assessment Methods For Tanzania: A Case Of Little Ruaha And Upper Ngerengere Catchment, Kashimbi J. Kihara, Patrick Valimba, Joel Nobert
Suitability Of Flood Hazard Assessment Methods For Tanzania: A Case Of Little Ruaha And Upper Ngerengere Catchment, Kashimbi J. Kihara, Patrick Valimba, Joel Nobert
Tanzania Journal of Science
Understanding the applicability of flood quantile estimation methods in flood hazard assessment is fundamental for planning, prevention, and management of flood risks. Therefore, this study evaluates and compares three hydrological methods, namely Hydrologiska Byråns Vattenbalansavdelning (HBV), Soil Conservation Service-Curve Number (SCS-CN), and regional regression equation (RRE), to estimate flood quantiles embedded in the existing flood damage assessment framework by applying them to two different river catchments, Little Ruaha (LR) and Upper Ngerengere (UN), Tanzania. The evaluation of method performance was carried out using three standard statistical measures for data from 1954 to 2010 and the 1971–1988 period in LR and …
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, …
Atmospheric Instability Conditions During Rainy Seasons Over Tanzania, Pasvolo J Mwinuka, Christian Bs Uiso, Ladslaus B Chang’A, Mwingereza J Kumwenda
Atmospheric Instability Conditions During Rainy Seasons Over Tanzania, Pasvolo J Mwinuka, Christian Bs Uiso, Ladslaus B Chang’A, Mwingereza J Kumwenda
Tanzania Journal of Science
The amount of rainfall and its distribution in time and space is dependent on the atmospheric instability conditions, and on its moisture content. The aim of this study was to determine the atmospheric instability conditions during January to March (JFM), February to April (FMA), March to May (MAM), and October to December (OND) rainy seasons over local climate zones in Tanzania. Zone area average seasonal Convective Available Potential Energy (CAPE), Convective Inhibition (CIN), Precipitable Water (PW) and Lifted index (Li) were calculated and analyzed. Results showed Li < 0 in JFM and FMA over whole Tanzania. During MAM and OND, Li < 0 over the Lake Zone, Western Highlands Zone and Central Zone only. CAPE ranged from 793 J/kg to 1183 J/kg during JFM, and 700 J/kg to 1080 J/kg during FMA. During MAM, CAPE ranged from 170 J/kg to 921 J/kg and from 173 J/kg to 833 J/kg during OND. Results also showed CAPE > 1000 J/kg over the Lake Zone, Western Highlands Zone, Island Zone, and Central …
Analysis Of The Current And Future Land Use/Land Cover Changes In Peri-Urban Areas Of Dar Es Salaam City, Tanzania Using Remote Sensing And Gis Techniques, Erick T Mnyali, Silvia F Materu
Analysis Of The Current And Future Land Use/Land Cover Changes In Peri-Urban Areas Of Dar Es Salaam City, Tanzania Using Remote Sensing And Gis Techniques, Erick T Mnyali, Silvia F Materu
Tanzania Journal of Science
A rapid increase in population and urban development has direct impacts on the natural environment of peri-urban areas of big cities, especially in the developing countries. This study examined land use and land cover changes (LULCC) of peri-urban areas of Kinondoni Municipality in Dar es Salaam city for the period between 1999 and 2019 and predicted future changes by 2039. The specific objectives were to; (i) map the spatial-temporal land use and cover changes (ii) analyze settlements (built-up areas) patterns and factors influencing their changes (iii) predict changes that might happen for the next two decades. LULCC for 1999 to …
Temperature Effects On The Corrosion Inhibition Of Mild Steel In Sulfuric Acid Solution By Acacia Senegal Gum With Halide Ions, Jovine Emmanuel, Joseph Buchweishaija
Temperature Effects On The Corrosion Inhibition Of Mild Steel In Sulfuric Acid Solution By Acacia Senegal Gum With Halide Ions, Jovine Emmanuel, Joseph Buchweishaija
Tanzania Journal of Science
The effects of temperature on the inhibitive effect of naturally occurring Acacia senegal gum exudate on the corrosion of mild steel in sulfuric acid was studied between 35 and 70 °C using electrochemical impedance spectroscopy and potentiodynamic polarization methods. Findings showed that Acacia senegal gum exudate decreases the corrosion rate of mild steel. The inhibition efficiency declined with raising temperature above 35 °C. The increase in the corrosion rate with increasing temperature was observed for both uninhibited and inhibited systems. Addition of halide ions to the Acacia senegal gum exudate solution enhanced the corrosion inhibition efficiency because of synergistic effects, …
Design And Performance Analysis Of Composite Airfoil Wind Turbine Blade, Hegespo H Mwanyika, Yusufu Ac Jande, Thomas Kivevele
Design And Performance Analysis Of Composite Airfoil Wind Turbine Blade, Hegespo H Mwanyika, Yusufu Ac Jande, Thomas Kivevele
Tanzania Journal of Science
Small horizontal axis wind turbine rotors with composite airfoil rotor blades were designed and investigated in the present study in order to improve its performance in low wind speed and low Reynolds number (Re) conditions for standalone system. The geometrical and aerodynamic nature of a single airfoil small horizontal axis wind turbine blade curtails efficient energy harnessing of the rotor blade. The use of composite airfoil rotor blade improves energy production but imposes uncertainty in determining an optimal design angle of attack and the off design aerodynamic behaviour of the rotor. This research investigated the effects of two airfoils used …
Vulnerability And Responses Of Smallholder Farmers To Climate Change Effects In Semiarid Areas Of Bahi And Kongwa Districts, Tanzania, Helena Elias Myeya
Vulnerability And Responses Of Smallholder Farmers To Climate Change Effects In Semiarid Areas Of Bahi And Kongwa Districts, Tanzania, Helena Elias Myeya
Tanzania Journal of Science
This study examined the vulnerability and responses of smallholder farmers to climate change effects in Semiarid Areas of Bahi and Kongwa Districts. A total of 366 household heads were involved in this study. The study employed questionnaire, interviews and documentary review as data collection techniques. Archival data for temperature, rainfall and crop yields were collected for trend analysis. Descriptive and inferential statistics were used to analyse quantitative data, content analysis was employed to analyse qualitative data. Simple linear trend analysis and Mann Kendall were used to establish trends. The findings indicate that smallholder farmers in the study area have noted …
Analysing Climate Change Mitigation Policy Options In The Renewable Energy Sub-Sector In Tanzania, Ladislaus Kyaruzi, Patrick M Ndaki, Richard Ym Kangalawe
Analysing Climate Change Mitigation Policy Options In The Renewable Energy Sub-Sector In Tanzania, Ladislaus Kyaruzi, Patrick M Ndaki, Richard Ym Kangalawe
Tanzania Journal of Science
Public policies influence reduction of greenhouse gas emissions. Also the extent to which policies are developed and implemented can influence the achievement of the national, regional and international climate change mitigation policy framework in the renewable energy sub-sector. This paper provides a critical overview of key policy options influencing the development of renewable energy sub-sector through climate change mitigation policy options in Tanzania. Questionnaire surveys were used to collect primary data from 100 relevant experts who represented 64 organizations in Tanzania. Secondary data were collected by literature review. The state of climate change mitigation policy options in the renewable energy …
Effects Of Climate Changes On Water Resources: A Case Of Mindu Dam In Morogoro Municipality, Tanzania, Simon R Melchioly
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 …
Monthly And Seasonal Rainfall Concentrations And Predictability In Tanzania, Pasvolo Mwinuka, Christian Uiso, Ladslaus Chang’A, Mwingereza Kumwenda
Monthly And Seasonal Rainfall Concentrations And Predictability In Tanzania, Pasvolo Mwinuka, Christian Uiso, Ladslaus Chang’A, Mwingereza Kumwenda
Tanzania Journal of Science
This study aimed at determining the monthly and seasonal rainfall concentration, predictability and the changes in rainfall seasons in Tanzania. Rainfall predictability was determined using Colwell’s indices, Rainfall Concentration Index (RCI) and Coefficient of Variation (CV). Results showed that rainfall in December–February (DJF), January–March (JFM) and February–April (FMA) has predictability due to constancy of 60%, RCI ≤ 9 and CV < 0.4 in Lake zone, Central zone, Southern Coast zone, Western and Southern Highlands zone. Rainfall in October to December (OND) was reliable in the Island zone, North-Eastern highlands zone and Northern coast zone with an average predictability due to constancy of 65%. In the Lake zone, all seasons (DJF, JFM, FMA, MAM, OND and DJFMAM) had uniform rainfall distribution (RCI = 8.7, CV = 0.35) and predictability due to constancy of 80% which leads to the conclusion that Lake Zone has unimodal rainfall distribution. Rainfall predictability in Tanzania has a West-East gradient. The western zones had an average predictability due to constancy of 68%. In general, rainfall in Tanzania is observed to be highly variable; only 20% of the predictability is concerned with reliability in the rainfall occurrence within the seasons and 80% is due to seasonality. Keywords: Rainfall concentration index; predictability; coefficient of variation; seasonality; constancy.
Influence Of Deposition Temperature On Properties Of Multilayered Gallium Doped Zinc Oxide Films Prepared By Dc Magnetron Sputtering Technique, Elisante Maloda, Anayesu Malisa
Influence Of Deposition Temperature On Properties Of Multilayered Gallium Doped Zinc Oxide Films Prepared By Dc Magnetron Sputtering Technique, Elisante Maloda, Anayesu Malisa
Tanzania Journal of Science
Multilayered transparent conducting films based on ZnO: Ga were deposited onto glass substrate by DC magnetron sputtering technique. The films were prepared from alloy (Zn: Ga) and ceramic (ZnO: Ga) targets with gallium composition of 3 at% and 4 at%, respectively. Crystal structure and phase analysis were measured using X-ray diffractometer (XRD). The XRD structural analysis results indicated that all multilayered films were polycrystalline with (002) orientation slightly shifted of diffracting angles due to gallium dopant concentrations as increase in the deposition temperatures. The films were hexagonal wurtzite structure, having preferred growth orientation in c-axis perpendicular to the substrate surface. …
Land Cover Change Detection In The Urban Catchments Of Dar Es Salaam, Tanzania Using Remote Sensing And Gis Techniques, Philip Mzava, Joel Nobert, Patrick Valimba
Land Cover Change Detection In The Urban Catchments Of Dar Es Salaam, Tanzania Using Remote Sensing And Gis Techniques, Philip Mzava, Joel Nobert, Patrick Valimba
Tanzania Journal of Science
In this study, the Maximum Likelihood (ML) classification, Normalized Difference Vegetation Index (NDVI) and Artificial Neural Network (ANN) methods were applied to three (3) Landsat images collected over time (1979, 1998 and 2014), that contained historical land cover features for the urban catchments of Dar es Salaam. Five major land cover classes were identified, mapped, and the land cover changes investigated. The major land cover changes observed from post-classification comparisons of the classified images are: the forest land losing 17.09% of its area in the period 1979-1998 to other land covers, mainly turning to grassland, and from 1998 to 2014, …
Performance Of A Customized Cryo-Cooling System Designed For The Measurement Of The Lifetime Of Nuclear Excited States At Cryogenic Temperatures, Innocent J. Lugendo
Performance Of A Customized Cryo-Cooling System Designed For The Measurement Of The Lifetime Of Nuclear Excited States At Cryogenic Temperatures, Innocent J. Lugendo
Tanzania Journal of Science
Theoretical predictions that the lifetime of nuclear excited states can be varied if the nucleus is subjected to a condition that allows multiple coherent emission and re-absorption of gamma photons by the nucleus is of much interest to the nuclear physicists. Therefore, an experiment has been designed to study the possibility of lifetime variation. Based on the theory requirements, lifetime variations can be observed when the nucleus is cooled to cryogenic temperatures. Both the cryo-cooling system and the fast timing system have been developed. In the current work, the design, operation and performance of the developed cryo-cooling system is discussed. …
Statistical Analysis Of Ambient Conditions And Water Temperature On Standard Achievement Of Volume Calibration Of Small Laboratory Glassware, Lazaro Revocatus, Nyimvua Shaban, Isambi S. Mbalawata
Statistical Analysis Of Ambient Conditions And Water Temperature On Standard Achievement Of Volume Calibration Of Small Laboratory Glassware, Lazaro Revocatus, Nyimvua Shaban, Isambi S. Mbalawata
Tanzania Journal of Science
Volumetric apparatus calibration is a very sensitive matter in metrological institutions. Identification and evaluation of the uncertainty factors affecting volume calibration of volumetric apparatus such as small laboratory glassware is a critical issue to investigate in order to increase accuracy in calibration.This studyinvestigates the contributions of ambient conditions and water temperature in volume calibration of small laboratory glassware. The study used existing empirical data from the Tanzania Bureau of Standards.The multiple linear regression modelwas used to establish better relationship between explanatory variables and response variable. The model analyzedthree predictor variables namely ambient temperature, pressure and relative humidity. Water temperature was …
Construction Of A High Temperature (~ 200 °C) Oil Pump For Solar Thermal Energy Storage System For Cooking Applications, Jimmy Chaciga, Nyeinga Karidewa, Denis Okello, Benard Tabu
Construction Of A High Temperature (~ 200 °C) Oil Pump For Solar Thermal Energy Storage System For Cooking Applications, Jimmy Chaciga, Nyeinga Karidewa, Denis Okello, Benard Tabu
Tanzania Journal of Science
In this study, a positive displacement (PD) oil pump capable of operating at temperatures about 200 °C was constructed using locally available materials. The oil pump was tested to circulate pre-heated refined sunflower oil in Thermal Energy Storage (TES) tank comprising of an oil only and rock pebble-oil system and cooking application. The oil pump was constructed of harden steel and mild steel materials driven by AC/DC electric motor rated 8000 rpm. Standard gear teeth cutting tool was employed to produce the spurs and the pumps’ speed was varied using variable AC transformer connected to 220V AC main source. The …
Effect Of Storage Time And Temperature On Germination Ability Of Escoecaria Bussei, F Genes, Agnes Ms Nyomora
Effect Of Storage Time And Temperature On Germination Ability Of Escoecaria Bussei, F Genes, Agnes Ms Nyomora
Tanzania Journal of Science
This study was conducted in Botany Department Nursery to evaluate the effect of storage time and temperature on germinability of Excoecaria bussei. The orthodox seeds, collected from Dodoma and Singida regions were germinated monthly from September 2013 through June 2014. Each time, seeds were soaked in water for 6 hours to soften then sown in sterile potting media. A Split-Split plot was used to compare temperature [(15°C) and (30°C)] as main plots, populations (Maktupa, Kisalu and Ilola) as Sub plots and storage time (September 2013 through June 2014) as Sub-Sub-plots on percentage seed germination. ANOVA revealed average germination percentages of …
Effects Of Magnetic Fields On An Unsteady Mixed Convective Boundary Layer Flow Of An Electrically Conducting Fluid With Temperature Dependent Properties, Raymond Kitengeso, Eunice Mureithi, Makungu James, John Mango
Effects Of Magnetic Fields On An Unsteady Mixed Convective Boundary Layer Flow Of An Electrically Conducting Fluid With Temperature Dependent Properties, Raymond Kitengeso, Eunice Mureithi, Makungu James, John Mango
Tanzania Journal of Science
A mixed convective boundary layer flow of an electrically conducting fluid with temperature dependent properties over an inclined plate is investigated. The magnetohydrodynamic boundary layer governing equations are derived by using Boussinesq and boundary layer approximations. The equations are transformed to similarity form using a similarity transformation variable and the resulting boundary value problem is solved numerically. The effects of magnetic fields, unsteadiness, mixed convection and variable fluid properties on velocity and temperature in the boundary layer are analysed. The effects of pertinent parameters on skin friction and heat transfer are also analysed