Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (578)
- Life Sciences (498)
- Biology (249)
- Earth Sciences (183)
- Plant Sciences (179)
-
- Plant Biology (178)
- Geology (139)
- Physics (128)
- Chemistry (118)
- Ecology and Evolutionary Biology (85)
- Environmental Sciences (79)
- Mathematics (75)
- Engineering (74)
- Hydrology (51)
- Microbiology (48)
- Oceanography and Atmospheric Sciences and Meteorology (48)
- Medicine and Health Sciences (46)
- Public Health (42)
- Atmospheric Sciences (41)
- Electrical and Computer Engineering (33)
- Environmental Health (33)
- Food Science (33)
- Pharmacology, Toxicology and Environmental Health (33)
- Computer Sciences (32)
- Pharmacology (32)
- Toxicology (32)
- Materials Science and Engineering (31)
- Agriculture (24)
- Biochemistry (19)
- Biochemistry, Biophysics, and Structural Biology (19)
- Keyword
-
- Physical Sciences (484)
- Biological Sciences (341)
- Mathematics and Computational Sciences (127)
- Tanzania (119)
- Heavy metals (26)
-
- Sediments (24)
- Lake Victoria (15)
- Pollution (15)
- Conservation (14)
- Dar es Salaam (13)
- Contamination (12)
- Adsorption (11)
- Diversity (9)
- Biogas (8)
- Fish (8)
- Forest (8)
- Maize (8)
- Tectonics (8)
- Antibacterial activity (7)
- Antimicrobial activity (7)
- Cytotoxicity (7)
- Malaria (7)
- Phytochemicals (7)
- Species diversity (7)
- Antimicrobial (6)
- Antioxidant (6)
- Climate change (6)
- Ecosystem (6)
- Fisheries (6)
- Pesticide residues (6)
- Publication Year
- File Type
Articles 631 - 660 of 1029
Full-Text Articles in Entire DC Network
Mixed Mode Device-To-Device Communication Scheme For Congestion Reduction And Channel Usage Optimization In 5g Cellular Networks, Chiza M. Christophe, Omar F. Hamad, Libe V. Massawe, Abdi T. Abdalla
Mixed Mode Device-To-Device Communication Scheme For Congestion Reduction And Channel Usage Optimization In 5g Cellular Networks, Chiza M. Christophe, Omar F. Hamad, Libe V. Massawe, Abdi T. Abdalla
Tanzania Journal of Science
Device-to-Device (D2D) communication schemes have gained more attention in cellular networks particularly in normalization process of the upcoming 5G networks. They have been investigated in core network offloading, congestion reduction and channel usage optimization. The two last cases are among the major constraints in current cellular networks and are the main concerns of this paper. The paper presents a mixed mode D2D communication scheme to decentralize data collection between devices and the base station in order to reduce the number of direct connections at the base station of ultra-dense cells characterized by different levels of channel utilizations or target data …
Assessment Of Tree Species Richness, Diversity, Population Structure And Natural Regeneration In Nongeni Forest Reserve In Morogoro Region, Tanzania, David Sylvester Kacholi
Assessment Of Tree Species Richness, Diversity, Population Structure And Natural Regeneration In Nongeni Forest Reserve In Morogoro Region, Tanzania, David Sylvester Kacholi
Tanzania Journal of Science
This study examined tree species richness, diversity, population structure and regeneration in Nongeni forest reserve, Morogoro, Tanzania. The study deployed plot sampling technique whereby a total of 20 plots of 0.05 ha each were randomly established in the forest. All species and individuals encountered in each plot were counted, identified and DBH measured. A total of 751 individuals/ha representing 24 species belonging to 11 families were recorded. Family Fabaceae was dominant with 9 species. The Shannon-Wiener, Margalef, Simpson’s and Pielou J index were calculated as 2.667, 3.474, 10.58 and 0.839, respectively. The Diplorhynchus condylocarpon (52.18) was the dominant species in …
Preliminary Palynology Of The Karoo Equivalent Tanga Beds, Coastal Tanzania: Insights On Preservation, Age And Depositional Environments, Stephen Peter Magohe
Preliminary Palynology Of The Karoo Equivalent Tanga Beds, Coastal Tanzania: Insights On Preservation, Age And Depositional Environments, Stephen Peter Magohe
Tanzania Journal of Science
The major challenge to the current understanding of the stratigraphy of the Tanga Basin is scarcity of biostratigraphy age-control data. A number of palynomorphs retrieved from core samples of the Tanga Beds and analysed for palynology are here presented. These include bisaccate pollen grains belonging to the Alisporites-Falcisporites complex, making about 55% average of the total assemblage. The rest of the assemblage comprises other palynomorphs (pollen and spores) and phytoclasts. The miospores documented from the studied samples have poor to fairly good preservation; the organic residues (non-pollen palynomorphs) are excellently preserved. Based on palynologic evidences, and the presence of fossil …
Quantitative Assessment Of Resistivity Anisotropy In Evaluation Of Laminated Shaly Sand Hydrocarbon Reservoirs–A Case Study In The Barents Sea, Norway, Ernest S. Mulaya
Quantitative Assessment Of Resistivity Anisotropy In Evaluation Of Laminated Shaly Sand Hydrocarbon Reservoirs–A Case Study In The Barents Sea, Norway, Ernest S. Mulaya
Tanzania Journal of Science
Resistivity anisotropy in shaly sand lamination sequences affects the hydrocarbon evaluation in multiple dimensions of petrophysical logs. Currently, vertical resistivity (Rv) and horizontal resistivity (Rh) from 3D triaxial induction measurements can be applied simultaneously to resolve these petrophysical impacts. In this paper, an extensive analysis is offered with a focus on the hydrocarbon evaluation based on advanced petrophysical logs from a well. A critical analysis is done on the three comparable cases including clean formation as a base case, shaly sand case and laminated shaly sand case towards resolving resistivity anisotropy in a typical shaly sand laminated reservoir. The analysis …
Total Electron Content Prediction Model Using The Artificial Neural Networks Over The Eastern Africa Region, Emmanuel D. Sulungu, Christian B.S. Uiso
Total Electron Content Prediction Model Using The Artificial Neural Networks Over The Eastern Africa Region, Emmanuel D. Sulungu, Christian B.S. Uiso
Tanzania Journal of Science
In this paper, development of a model using NN technique for prediction of GPS TEC over the Eastern Africa region is presented. TEC data was obtained from the Africa array and IGS network of ground based dual-frequency GPS receivers from 18 stations within the East African region. It covers approximately the area from ~2.6°N to ~26.9°S in magnetic latitudes and from ~95°E to ~112oE in magnetic longitudes. The input layer of the developed model consisted of seven neurons which were selected by considering the parameters that are known to affect the TECv data. The results showed that when the number …
An Investigation Of The Potentials Of 2-[(2-Hydroxyphenyl) Methylidene] Hydrazine-1-Carbothioamide And Its Mn(Ii) And Zn(Ii) Complexes As Antimicrobial Agents, Umar Sani, Musbahu Yahaya, Dailami S. Adam
An Investigation Of The Potentials Of 2-[(2-Hydroxyphenyl) Methylidene] Hydrazine-1-Carbothioamide And Its Mn(Ii) And Zn(Ii) Complexes As Antimicrobial Agents, Umar Sani, Musbahu Yahaya, Dailami S. Adam
Tanzania Journal of Science
Antibiotic resistance as a result of misuse, overuse or abuse of drugs is an issue of serious concern world over. The quest for more active and robust antimicrobial agents remains a scientific challenge and requires multimillion-dollar investment in the area of drug design and development. Here in, we report the synthesis and characterisation of a tridentate thiosemicarbazone (2-[(2-hydroxyphenyl)methylidene]hydrazine-1-carbothioamide) (HL) from salicylaldehyde and thiosemicarbazide. Its complexes with Mn(II) and Zn(II) were prepared following similar technique and characterised by melting point, FT-IR, UV –visible spectrophotometry, and elemental analysis. The Mn(II) complex showed paramagnetism with a magnetic moment value of 5.80 BM while …
Synthesis Of Semiochemicals And Related Fine Chemicals From Cashew Nut Shell Liquid, Godfrey Pius, Quintino A Mgani
Synthesis Of Semiochemicals And Related Fine Chemicals From Cashew Nut Shell Liquid, Godfrey Pius, Quintino A Mgani
Tanzania Journal of Science
This paper reports on syntheses of 3-hydroxybenzaldehyde (1) and tetradecanal (2) from the same renewable starting material (cashew nut shell liquid or CNSL), thus demonstrating the potential of the agro-waste cashew nut shells (CNS) as a source of valuable fine and industrial chemicals. The strategy employed in accomplishing the synthesis started with extraction of CNSL followed by isolation of anacardic acid (4) and decarboxylation to give cardanol (5). Compound 5 was hydrogenated followed by protection of phenolic group to give 3-pentadecylphenyl acetate (7). Benzylic oxidation of compound 7 followed by reduction and dehydration resulted into formation of 3-(pentadec-1-en-1-yl)phenol (9). Ozonolysis …
Generation Of Highly Ordered 3d Vivid Monochromatic Coloured Photonic Crystal Films Using Evaporative Induced Technique, Ikhazuagbe H. Ifijen, Esther U. Ikhuoria
Generation Of Highly Ordered 3d Vivid Monochromatic Coloured Photonic Crystal Films Using Evaporative Induced Technique, Ikhazuagbe H. Ifijen, Esther U. Ikhuoria
Tanzania Journal of Science
Structural coloured crystal films have attracted immense attention because of numerous applications like optical sensing, anti-counterfeiting and photonic fabrics. Herein, we successfully generated highly periodic three-dimensional (3D) monochromatic structural crystal films with brown, turquoise, blue and yellow colourations from as-synthesized poly(styrene-methyl methacrylate-acrylic acid) or P(St-MMA-AA) colloidal latex via the evaporative induced self-assembly technique. The colours were controlled through the modulation of their crystal lattice by varying their microspheres diameter from 180 nm, 120 nm, and 260 nm to 150 nm. Scanning electron microscope and atomic force microscope (SEM/AFM) analyses showed that the photonic crystal particles readily assembled into an impeccable …
Kleptoparasitism Of Shoebills Balaeniceps Rex By African Fish Eagles Haliaeetus Vocifer In Western Tanzania, Jasson John, Woo Lee
Kleptoparasitism Of Shoebills Balaeniceps Rex By African Fish Eagles Haliaeetus Vocifer In Western Tanzania, Jasson John, Woo Lee
Tanzania Journal of Science
Kleptoparasitism is a specialised form of foraging interference occurring throughout the animal kingdom and especially is well documented among birds including African fish eagle Haliaeetus vocifer. However, only one record is reported between fish eagle and shoebill Balaeniceps rex despite their habitat overlap and it remains undescribed. This paper documents kleptoparasitism of shoebills by fish eagles in Malagarasi wetlands, western Tanzania. Kleptoparasitism was highly seasonal occurring in the dry season, especially at low floods. Both adults and non-adult eagles stole prey from shoebills, with non-adults initiating attacks at shorter distances than adults perhaps because of the lack of experience. The …
Improved Hybrid Blind Papr Reduction Algorithm For Ofdm Systems, Kwame Ibwe
Improved Hybrid Blind Papr Reduction Algorithm For Ofdm Systems, Kwame Ibwe
Tanzania Journal of Science
The ever growing demand for high data rate communication services has resulted into the development of long-term evolution (LTE) technology. LTE uses orthogonal frequency division multiplexing (OFDM) as a transmission technology in its PHY layer for down-link (DL) communications. OFDM is spectrally efficient multicarrier modulation technique ideal for high data transmissions over highly time and frequency varying channels. However, the transmitted signal in OFDM can have high peak values in the time domain due to inverse fast Fourier transform (IFFT) operation. This creates high peak-to-average power ratio (PAPR) when compared to single carrier systems. PAPR drives the power amplifiers to …
Microstructure And Materials Characterization Of Sol-Gel Synthesized Zro2 Systems, Sungsoo Park, Godlisten Shao
Microstructure And Materials Characterization Of Sol-Gel Synthesized Zro2 Systems, Sungsoo Park, Godlisten Shao
Tanzania Journal of Science
The roles of pH and thermal treatment on the microstructures of sol-gel synthesized mesoporous ZrO2 systems have been investigated. In order to control the crystal structures and particle sizes of the final products, the pH values of the reaction mixtures were controlled between 5 and 12 followed by calcination at temperatures ranging from 450 to 1000 °C. The microstructures of the zirconia systems were then examined by XRD, TEM, TGA, UV-visible DRS and nitrogen physisorption study analyses. It was found that pH values and calcination temperatures have significant influence on the crystallization temperature, phase transformation and particle size of the …
Species Composition, Diversity And Distribution Of Vascular Epiphytes In The Kihansi Gorge Forest, Tanzania, Hashim Mangosongo, Martin Griffiths
Species Composition, Diversity And Distribution Of Vascular Epiphytes In The Kihansi Gorge Forest, Tanzania, Hashim Mangosongo, Martin Griffiths
Tanzania Journal of Science
This study aimed at assessing the species composition, diversity and distribution of vascular epiphytes in the Kihansi Gorge Forest. Epiphytes sampling was conducted in twenty sampling plots established in the strip of riverine forest within the Kihansi Gorge. All vascular epiphytes growing on trees (phorophytes) rooted in the plots were sampled using ground-based technique as the method of access to the tree canopies. A total of 476 epiphyte individuals belonging to 20 species and 10 families were recorded in the study area. Among the twenty species recorded, Drynaria laurentii was the most abundant and most widely distributed in the study …
Decision Rules For Supplier Selection Using Intuitionistic Fuzzy Topsis, Dickson Omorogbe, Sunday Omosigho
Decision Rules For Supplier Selection Using Intuitionistic Fuzzy Topsis, Dickson Omorogbe, Sunday Omosigho
Tanzania Journal of Science
This paper provides a methodology for addressing contradictions in the ranking of suppliers when more than one metric functions are adopted in intuitionistic fuzzy TOPSIS (Technique for Order Preference by Similarity to the Ideal Solution) for supplier selection. Our literature search revealed contradictions when more than one metric functions are adopted in the method. Two types of contradictions were addressed: (i) contradiction of the best supplier, and (ii) contradiction at the middle of the park. Decision rules algorithms were developed to address the problems.Worked examples were given to illustrate the rules for resolving the contradiction. A major thrust of this …
Geological Modeling Of Hydrocarbon Reservoir Rocks In The Mafia Basin, Offshore Tanzania, Bahati Mohamed, Elisante Mshiu, Ernest Mulaya
Geological Modeling Of Hydrocarbon Reservoir Rocks In The Mafia Basin, Offshore Tanzania, Bahati Mohamed, Elisante Mshiu, Ernest Mulaya
Tanzania Journal of Science
This study presents a 3D geological model of reservoir rocks in the Mafia Basin based on interpretation of 2D seismic and well data towards understanding the hydrocarbon prospectivity. 2D seismic data were used to generate surface maps and therefore the subsurface configuration of the reservoir complemented with petrophysical analysis to determine lithology and reservoir properties. Structural and petrophysical properties modeling were distributed stochastically within the constructed 3D grid using Sequential Indicator Simulation (SIS) and Gaussian Random Function Simulation (GRFS) algorithms. Results from well log analysis and petrophysical models classify the reservoir under a moderate reservoir quality with 19% to 20% …
Morphological And Molecular Identification Of Pratylenchus Goodeyi Associated With Banana In Tanzania, Doreen Mgonja, Gladness Temu, Magreth Mziray, Beatrice Kashando, Ambilikile Mwenisongole, Minza Masunga, Sylvester Lyantagaye4, Nessie Luambano
Morphological And Molecular Identification Of Pratylenchus Goodeyi Associated With Banana In Tanzania, Doreen Mgonja, Gladness Temu, Magreth Mziray, Beatrice Kashando, Ambilikile Mwenisongole, Minza Masunga, Sylvester Lyantagaye4, Nessie Luambano
Tanzania Journal of Science
Banana (Musa sp. [L]) is an important staple food and cash crop for about 30 percent of the total population in Tanzania. Root lesion nematodes, particularly Pratylenchus goodeyi, are among the major pests affecting banana production in Tanzania. Morphological, morphometric and molecular approaches are required for accurate identification of nematodes. In this study, 80 P. goodeyi isolates from major banana growing areas in Tanzania were identified. Sequence analysis of part of the small subunit (SSU), large subunit (LSU) and internal transcribed spacers (ITS) regions of ribosomal DNA (rDNA) confirmed the identity of P. goodeyi. DNA sequences were analysed using Geneious …
Assessment Of The Effect Of Acid Activation Of Kaolin From Malangali On Water Defluoridation, Hosea Shuma, Lupituko Mkayula, Yahya Makame
Assessment Of The Effect Of Acid Activation Of Kaolin From Malangali On Water Defluoridation, Hosea Shuma, Lupituko Mkayula, Yahya Makame
Tanzania Journal of Science
Malangali kaolin clay was activated by means of an acid for defluoridation studies. The Acid Activated Malangali Kaolin (AAMK) clay and the Untreated Malangali Kaolin (UMK) were both characterized using spectroscopic and adsorption techniques. BET analysis of AAMK and UMK showed that both clays have mesoporosity characteristics with surface areas ranging from 55 to 58 m2/g. Spectroscopic studies showed that in both clays the major mineral forms are kaolinites and albites with high amounts of SiO2 and Al2O3. AAMK and UMK are endowed with surface functional groups such as OH, Si–O–Si, and Al–O–Al all of which being suitable for adsorption …
Densification Behaviour And Structural Properties Of Niobium And Lanthanum-Doped Lead Zirconate Titanate And Lead Barium Zirconate Ferroelectrics For Low-Donor Dopants Concentrations, David Bahati, Ismael Makundi
Densification Behaviour And Structural Properties Of Niobium And Lanthanum-Doped Lead Zirconate Titanate And Lead Barium Zirconate Ferroelectrics For Low-Donor Dopants Concentrations, David Bahati, Ismael Makundi
Tanzania Journal of Science
In this paper we report the densification behaviour and structural properties of niobium and lanthanum-doped lead zirconate titanate (PZT) and lead barium zirconate (PBZ) ferroelectrics for low additive concentrations (0–2%). The PZT materials were calcined at 800 °C and sintered at 1200 °C while the PBZ materials were calcined at 850 °C and sintered at 1250 °C. Densification behaviour revealed that materials with lanthanum or niobium additives of greater than 0.5% for PZT and 0.2% for PBZ achieved complete densification. A strong distortion was observed in lattice parameters for lower dopants in which PBZ doped materials showed higher lattice distortions …
Multivariate Assessment Of Metal Contamination In Mtoni Sedimentary Environment, Tanzania, Matobola Mihale
Multivariate Assessment Of Metal Contamination In Mtoni Sedimentary Environment, Tanzania, Matobola Mihale
Tanzania Journal of Science
Enrichment factor, geo-accumulation factor, contamination factor, degree of contamination, modified degree of contamination and potential contamination index were applied to assess the contamination of metals (Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd and Pb ) in the Mtoni estuary sediments in Dar es Salaam, Tanzania. The sediment samples were sampled as appropriate, treated using established methods and analysed using inductively coupled plasma-high resonance mass spectrometry. The calculated enrichment factor values indicated contamination varying from minor (EF > 1) to severe contamination (EF > 50). The determined geo-accumulation index, contamination factor, degree of contamination, modified degree of contamination and potential contamination …
Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa
Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa
Tanzania Journal of Science
Wind speed data used in this study were from Makambako and were recorded at a height of 10 m. In the analysis, the data were extrapolated to 80 m above ground level and wind speed from July to November were found to have an average value of 17.58 m/s. November was found to be the windiest month for the whole duration while the calm month was found to be March. The wind power density was found to be highest in the month of November for the whole study duration. The months of July to November have higher wind power density …
Evaluation Of The Influence Of Additional Beam Filtration On Image Quality And Patient Dose In X-Ray Fluoroscopy Procedures, Justin Ngaile, Peter Msaki, Ramadhani Kazema, Jerome Mwimanzi, Mechris Mango
Evaluation Of The Influence Of Additional Beam Filtration On Image Quality And Patient Dose In X-Ray Fluoroscopy Procedures, Justin Ngaile, Peter Msaki, Ramadhani Kazema, Jerome Mwimanzi, Mechris Mango
Tanzania Journal of Science
The aim of the study was to evaluate the influence of additional filtration on radiation dose and image quality for patients during hysterosalpingography (HSG) and retrograde urethrography (RUG) procedures. The influence of filtering on image quality for each phantom thickness was made using a combination of different filter thicknesses. Entrance surface air kerma (ESAK) rates to Perspex phantom were measured using a solid state detector for various added combination of filter materials. Fluoroscopic image contrast was assessed using a Leeds TOR-18FG test object with a range of filter materials and phantom thicknesses. Phantom studies demonstrated that the use of additional …
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
Tanzania Journal of Science
The univariate kernel density estimator requires one smoothing parameter while the bivariate and other higher dimensional kernel density estimatorsdemand more than one smoothing parameter depending on the form of smoothing parameterizations used. The smoothing parameters of the higher dimensional kernels are presented in a matrix form called the smoothing matrix. The two forms of parameterizations frequently used in higher dimensional kernel estimators are diagonal or constrained parameterization and full or unconstrained parameterization. While thefull parameterization has no restrictions, the diagonal hassome form of restrictions.Thestudyinvestigates the performance of smoothing parameterizations of bivariate kernel estimator using asymptotic mean integrated squared error aserror …
Agro-Morphological Characterization Of The Wild Rice (Oryza Longistaminata) Populations From Selected Areas Of Tanzania, Hashim M. Mangosongo, Herbert V. Lyaruu, Emmarold E. Mneney
Agro-Morphological Characterization Of The Wild Rice (Oryza Longistaminata) Populations From Selected Areas Of Tanzania, Hashim M. Mangosongo, Herbert V. Lyaruu, Emmarold E. Mneney
Tanzania Journal of Science
The study assessed the variations in ten agro-morphological characters among and within the wild rice (O. longistaminata) populations from four selected areas, namely Bagamoyo, Kibaha, Kilombero and Mbarali in Tanzania. The study was carried out through measurement of ten quantitative agro-morphological characters, based on morphological descriptors for wild and cultivated rice species developed by Bioversity International and International Rice Research Institute (IRRI). Measurement of morphological characters of O. longistaminata plants was done soon after heading. One-way Analysis of Variance (ANOVA) was used to compare the variations in quantitative characters between O. longistaminata populations from the four study areas. The results …
Determination Of Radiation Doses To Patients Undergoing Fluoroscopically Guided Orthopaedic Procedures At Muhimbili Orthopaedic Institute In Tanzania, Jacob Busumabu, Ismael N. Makundi, Justin E. Ngaile
Determination Of Radiation Doses To Patients Undergoing Fluoroscopically Guided Orthopaedic Procedures At Muhimbili Orthopaedic Institute In Tanzania, Jacob Busumabu, Ismael N. Makundi, Justin E. Ngaile
Tanzania Journal of Science
The aim of the present study was to determine the magnitude of radiation doses delivered to patients undergoing Fluoroscopically Guided Orthopaedic Procedures (FGOP’s) in Tanzania. The air Kerma Area Product (KAP), fluoroscopy time, organ dose and effective dose to patients undergoing FGOP’s were obtained from Muhimbili Orthopaedic Institute. A total of 72 adult patients from selected three FGOPs namely Lumbar Spine (LS), Dynamic Hip Screw (DHS) and Thoracic Spine (TS) procedures were investigated using C-arm fluoroscopy machine. The knowledge of patient demographic data, radiographic data, KAP and Monte Carlo-based PCXMC software were used to obtain the magnitude of organ doses …
Plant Diet Selectivity And Some Environmental Parameters At Foraging Sites Of Wattled Crane (Bugeranuscarunculatus) In Malagarasi Wetlands, Tanzania, Jasson R.M. John
Plant Diet Selectivity And Some Environmental Parameters At Foraging Sites Of Wattled Crane (Bugeranuscarunculatus) In Malagarasi Wetlands, Tanzania, Jasson R.M. John
Tanzania Journal of Science
Wattled Crane Bugeranuscarunculatusis a threatened wetland-dependent bird species of sub-Saharan Africa with a declining population throughout its range due to habitat degradation. Ecological studies on this species have come from large populations in Botswana and Zambia. Little is known of the isolated small populations, especially those in Tanzania where about 200individuals survive. This study reports observations made on vegetation height, water depth and consumption of plant tubers at foraging locations of the Wattled Crane in Malagarasi-MuyovoziRamsar Site. Foraging birds preferred wet habitats with short vegetation. Birds fed mainly on Pycreusnitidus and Cyperusarticulatusplant tubersbut not those of Eleocharis, a chief food …
Cytotoxic And Antimicrobial Activities Of The Constituents Of Ten Plant Species From Tanzania, Joan J. E. Munissi
Cytotoxic And Antimicrobial Activities Of The Constituents Of Ten Plant Species From Tanzania, Joan J. E. Munissi
Tanzania Journal of Science
This paper reports on the antimicrobial and cytotoxicity activities of crude extracts from the plant species Clemaptosis scabiosifolia (Ranunculaceae), Diospyros mafiensis (Ebenaceae), Dolichos kilimandscharicus (Leguminosae), Gnidia kraussiana (Thymelaeaceae), Hugonia castaneifolia (Linaceae), Neorautanenia mitis (Pappilionaceae), Tagetes minuta (Asteraceae), Uvaria acuminata (Annonaceae), Vernonia amygdalina (Asteraceae) and Zanha africana (Sapindaceae). All crude extracts were screened for their cytotoxicities in the brine shrimp lethality test (BST). Fractions and pure compounds from Hugonia castaneifolia, Diospyros mafiensis and Uvaria acuminata were tested for their cytotoxicity and antimicrobial activities against ten microorganisms, namely Candida albicans, Bacillus anthracis, Escherichia coli, Klebsiela pneumoniae, Proteus sp., Pseudomonas aeruginosa, Salmonella typhimurium, …
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 …
Anempirical Performance Comparison Of Meta-Heuristic Algorithms For School Bus Routing Problem, Sherehe Semba, Egbert Mujuni
Anempirical Performance Comparison Of Meta-Heuristic Algorithms For School Bus Routing Problem, Sherehe Semba, Egbert Mujuni
Tanzania Journal of Science
School Bus Routing Problem is an NP-hard Combinatorial Optimization problem. Thus, mega-heuristic algorithms are widely used to solve instances of the School Bus Routing Problem with large data. In this work we present a model of the School Bus Routing Problem and empirical performances comparison between three meta-heuristic algorithms named Simulated Annealing (SA), Tabu Search (TS) and Ant-Colony Optimization (ACO) on the problem. We have analyzed their performances in terms of solution quality. The results show that all three algorithms have the ability to solve the School Bus Routing Problem. In addition, computational results show that TS performed best when …
Status Updates On Plastics Pollution In Aquatic Environment Of Tanzania: Data Availability, Current Challenges And Future Research Needs, Dativa J. Shilla
Status Updates On Plastics Pollution In Aquatic Environment Of Tanzania: Data Availability, Current Challenges And Future Research Needs, Dativa J. Shilla
Tanzania Journal of Science
Plastics are the most useful materials invented by man, and have brought great convenience to our daily lives but not without problems. Inappropriate disposal of wasted plastics has caused serious environmental problems. Over the past decade, microplastic debris in both marine and freshwater systems have become an emerging issue. A literature review was conducted to summarize the current state of knowledge of plastic pollution in Tanzanian aquatic systems. Although, Tanzania has vast coastlines and world’s largest freshwater lakes, the extent of microplastics presence in the aquatic environment remains largely unreported. Data from volunteer beach cleanups in Dar es Salaam areas …
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
Tanzania Journal of Science
The univariate kernel density estimator requires one smoothing parameter while the bivariate and other higher dimensional kernel density estimatorsdemand more than one smoothing parameter depending on the form of smoothing parameterizations used. The smoothing parameters of the higher dimensional kernels are presented in a matrix form called the smoothing matrix. The two forms of parameterizations frequently used in higher dimensional kernel estimators are diagonal or constrained parameterization and full or unconstrained parameterization. While thefull parameterization has no restrictions, the diagonal hassome form of restrictions.Thestudyinvestigates the performance of smoothing parameterizations of bivariate kernel estimator using asymptotic mean integrated squared error aserror …