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Uvarisesquiterpene D: A New Benzopyranyl Sesquiterpene Isolated From Uvaria Lucida Ssp. Lucida, Qa Mgani Dec 2012

Uvarisesquiterpene D: A New Benzopyranyl Sesquiterpene Isolated From Uvaria Lucida Ssp. Lucida, Qa Mgani

Tanzania Journal of Science

Hitherto unreported benzopyranyl sesquiterpene, uvarisesquiterpene D, has been isolated from the stem bark of Uvaria lucida ssp lucida. Its structure had been elucidated by spectroscopic analysis (IR, MS and NMR) and comparison of its spectral data with the known related compounds uvarisesquiterpene B and selin-11(12)-4α-ol. The latter compound was co-isolated with the new natural product as well as caryophyline oxide and lucidine.


Computational Chemistry Capacity Building In An Underprivileged Context: Challenges, Outcomes And Perspectives, L Mammino Dec 2012

Computational Chemistry Capacity Building In An Underprivileged Context: Challenges, Outcomes And Perspectives, L Mammino

Tanzania Journal of Science

Computational chemistry is a fast developing branch of modern chemistry, focusing on the study of molecules to enable better understanding of the properties of substances. Its applications comprise a variety of fields, from drug design to the design of compounds with desired properties (e.g., catalysts with specific actions) and to ample overlaps with nanotechnology. However, despite its relevance, the presence of computational chemistry research in Sub-Saharan Africa is still scarce, practically absent in many institutions. Bridging the gap with the other continents requires the identification of capacity building options that may enable a rapid growth. The recent experience at the …


Electrochemical Behaviour Of Environmentally Friendly Inhibitor Of Aloe Secundiflora Extract In Corrosion Control Of Carbon Steel In Soft Water Media, J Mutasingwa, J Buchweishaija, Jeg Mdoe Dec 2012

Electrochemical Behaviour Of Environmentally Friendly Inhibitor Of Aloe Secundiflora Extract In Corrosion Control Of Carbon Steel In Soft Water Media, J Mutasingwa, J Buchweishaija, Jeg Mdoe

Tanzania Journal of Science

Electrochemical behaviour of Aloe secundiflora on carbon steel corrosion control in neutral and aerated soft water solutions have been investigated using electrochemical impedance spectroscopy and Tafel polarization techniques. The investigation was performed at different inhibitor concentrations under static and dynamic conditions using a Rotating Disk Electrode (RDE). The impedance and polarization results revealed that A. Secundiflora could be a potential corrosion inhibitor for carbon steel undergoing corrosion in fresh water medium. It was found that Aloe secundiflora reduces the electrochemical processes taking place on carbon steel undergoing corrosion. The inhibitor efficiency increases with increase in A. Secundiflora concentration and gradually …


Heavy Metal Content In Some Commonly Consumed Vegetables From Kariakoo Market, Dar Es Salaam, Tanzania, Eb Mubofu Dec 2012

Heavy Metal Content In Some Commonly Consumed Vegetables From Kariakoo Market, Dar Es Salaam, Tanzania, Eb Mubofu

Tanzania Journal of Science

This work reports on the levels of cadmium, lead, copper, manganese and zinc in 174 samples from eight varieties of green vegetables (amaranth, Chinese cabbage, cowpea leaves, green pepper, leafy cabbage, lettuce, okra and pumpkin leaf) commonly grown in Dar es Salaam and marketed at Kariakoo, Tanzania. The amount of cadmium and lead ranged between 3-42 and 11-60 μg/kg respectively. The amount of copper, manganese and zinc ranged between 0.35 - 2.12, 1.01 - 7.57, and 1.19 - 6.33 μg/kg respectively. On average consumption pattern, the contribution of these vegetables to the recommended daily intakes (RDI) for cadmium and lead …


Correlation Between Morphological, Optical And Electrical Properties Of Zno:Al/Zno Double Layers And The Cu(In,Ga)Se2 Solar Cell Efficiencies, Pd Nsimama Jul 2012

Correlation Between Morphological, Optical And Electrical Properties Of Zno:Al/Zno Double Layers And The Cu(In,Ga)Se2 Solar Cell Efficiencies, Pd Nsimama

Tanzania Journal of Science

The morphological, optical and electrical properties of magnetron sputtered ZnO:Al/ZnO double layers are reported and their correlations with their respective Cu(In,Ga)Se2 (CIGS) solar cell efficiencies are presented. The ZnO:Al/ZnO double layers were produced by using the established baseline RF process and plasma emission monitoring (PEM) DC reactive sputtering. The scanning electron microscope (SEM) and atomic force microscope (AFM) were employed for the surface morphological measurements. The charge carrier concentrations, mobilities and AC resistivities were deduced from Drude’s model. The DC resistivities were determined from the four-point probe measurements. Transmittance and reflectance measurements were done by using the UV-VIS-NIR Lambda 900 …


Paleoseismic Investigations Along The Bubu Fault, Dodoma-Tanzania, As Macheyeki, D Delvaux, Md Batist, A Mruma Jul 2012

Paleoseismic Investigations Along The Bubu Fault, Dodoma-Tanzania, As Macheyeki, D Delvaux, Md Batist, A Mruma

Tanzania Journal of Science

The central part of Tanzania, Dodoma, was hit by an Mw= 5.5 earthquake in November 4, 2002. It was part of a swarm of moderate earthquakes that affected the area. This paper, reports the first attempt to investigate significant past earthquakes along one of the known seismically active riftfaults (Bubu fault, Gonga segment) by paleoseimological trenching. The trench revealed over 3 episodes of faulting (2 of which correspond to Mid-Holocene faulting). The magnitude of the largest earthquake illustrated in the trench is estimated at Mw = 6.3-6.4 and the slip rate between two recent faulting events is about 0.11 to …


Electrical Properties Of Dc Reactive Magnetron Sputtered Zno:Al Films From Optical Spectra, Pd Nsimama, Me Samiji Jul 2012

Electrical Properties Of Dc Reactive Magnetron Sputtered Zno:Al Films From Optical Spectra, Pd Nsimama, Me Samiji

Tanzania Journal of Science

Reactive direct current (DC) sputtered ZnO:Al films were prepared using the plasma emission monitoring (PEM) system. Films were deposited using PEM setpoints ranging from 50 to 80%. Transmittance and reflectance of the films were measured by using the UV-VIS-NIR Lambda 900 double beam spectrophotometer. The sheet resistance was measured using the four-point probe. Films optical spectra were fitted with the Drude model to determine their charge carrier concentration, mobility and the alternating current (AC) resistivity. The highest values of mobility and charge carrier concentration were 8.31cm2/Vs and 2.14 x 1021cm-3 respectively. The lowest value of the AC resistivity was given …


Wet Oxidation Of Maleic Acid By A Pumice Supported Copper (Ii) Shiff Base Catalyst, Jeg Mdoe, Raj Minja, L Daniel Jul 2012

Wet Oxidation Of Maleic Acid By A Pumice Supported Copper (Ii) Shiff Base Catalyst, Jeg Mdoe, Raj Minja, L Daniel

Tanzania Journal of Science

Pumice supported Cu (II) Schiff base catalysts were prepared by surface chemical modification followed by complexation with Cu (II) acetate. The resulting materials were characterised by Diffuse Reflectance Fourier Transform Spectroscopy (DRIFTS) to confirm the modification. The materials were tested in a wet oxidation of maleic acid using air or hydrogen peroxide as an oxidant. Results indicate that up to 80% degradation of maleic acid could  be achieved in the presence of the catalyst using hydrogen peroxide as an oxidant. The degradation was found to depend on the type of oxidant, temperature and whether the parent pumice was acid pre-treated …


Ni Mineralization And Pge Characterization In The Kabanga And Luhuma Ni-Cu Sulfide Deposits, North West Tanzania, As Macheyeki Jul 2012

Ni Mineralization And Pge Characterization In The Kabanga And Luhuma Ni-Cu Sulfide Deposits, North West Tanzania, As Macheyeki

Tanzania Journal of Science

Nickel mineralization in the Kabanga sulfide ores is found associated with (1) peripheral veins in the country-rock metapelites, (2) contact type massive sulfide mineralization, and (3) disseminated and vein mineralization. This work, apart from giving general highlight of the Ni mineralization (and other associated elements) in the Kabanga and Luhuma, intends to assess the PGE content in both areas. Cores (mafic-ultramafic and metasedimentary rocks as well as ore sections) from both Kabanga and Luhuma areas were sampled, cut, crushed, pulverized and analyzed for both major and trace elements. Results show that all the Iridium Platimum Group Elements (IPGEs) have very …


Spatial-Temporal Variation In Sex Ratio And Group Size Of Ostriches (Struthio Namelus) In The Serengeti National Park And Environs In Northern Tanzania, Fj Magige Mar 2012

Spatial-Temporal Variation In Sex Ratio And Group Size Of Ostriches (Struthio Namelus) In The Serengeti National Park And Environs In Northern Tanzania, Fj Magige

Tanzania Journal of Science

A study was conducted on variation in sex ratio and group size of ostriches (Struthio camelus) in Serengeti National Park and adjacent partially protected areas in northern Tanzania. Data were collected for two years (2005- 2006), along 388 km of roads. The two areas were compared with respect to ostrich sex ratio (male: female) and group size. Seasonal variation of these variables (sex ratio and group size) was also determined. Repetitive sampling showed an overall femaleskewed sex ratio, which was significantly different from unity. The sex ratio inside the National Park was also significantly skewed towards females, whereas that in …


Synthesis Of Organoamine-Silica Hybrids Using Cashew Nut Shell Liquid Components As Templates For The Catalysis Of A Model Henry Reaction, Sc Msigala, Jeg Mdoe Mar 2012

Synthesis Of Organoamine-Silica Hybrids Using Cashew Nut Shell Liquid Components As Templates For The Catalysis Of A Model Henry Reaction, Sc Msigala, Jeg Mdoe

Tanzania Journal of Science

Organoamine-silica hybrids were prepared by a co-condensation of tetraethoxysilane (TEOS) and different aminoalkoxysilanes, namely, 3-aminopropyltrimethoxysilane, N-(3(trimethoxysilyl)propyl)-ethylenediamine and 3[2(2-amino)ethylamino]propyl trimethoxysilane, at different ratios using cashew nut shell liquid (CNSL) components as templates. Of the major components of CNSL tested, only cardanol was found to be efficient as a template as it yielded 66% of the hybrid. The prepared materials were characterized by diffuse reflectance Fourier Transform Infrared (FTIR), Atomic Force Microscopy and acid titration. Results indicated that indeed the organoamine groups were attached onto the silica surface, with a maximum loading of 2.9 mmol organic group per g silica. The materials …


Mg-Rich Metabasalts From The Southern Musoma –Mara Greenstone Belt: Possible Evidence For Mantle Plume Activity In The Tanzania Craton?, S Manya Mar 2012

Mg-Rich Metabasalts From The Southern Musoma –Mara Greenstone Belt: Possible Evidence For Mantle Plume Activity In The Tanzania Craton?, S Manya

Tanzania Journal of Science

Mg-rich metabasalts from the Simba Sirori to Majimoto segment of the southern Musoma-Mara greenstone belt are the most magnesian lavas reported in the Archaean Tanzania Craton. The lavas yielded a Sm-Nd isochron age of 2768 ± 38 Ma (MSWD = 1.2) and corresponding !Nd(2.7 Ga) values in the range of + 0.66 to + 2.81. The lavas exhibit high MgO contents of up to 16 wt %, Cr (140 – 1590 ppm), Ni (80 – 510 ppm), values which are higher than those of primitive NMORB, but are comparable with those of Archaean komatiitic basalts and modern oceanic plateau basalts. …


The Influence Of Aliphatic Side Chain Of Anacardic Acid On Molecular Recognition Properties Of Imprinted Polymers, Jyn Philip, J Buchweishaija, Ll Mkayula, L Ye Mar 2012

The Influence Of Aliphatic Side Chain Of Anacardic Acid On Molecular Recognition Properties Of Imprinted Polymers, Jyn Philip, J Buchweishaija, Ll Mkayula, L Ye

Tanzania Journal of Science

The objective of this work was to determine the influence of the aliphatic side chain of anacardic acid on molecular recognition properties of imprinted polymers made from anacardanyl methacrylate (AnMcr). Salicylic methacrylate (SaMcr), a structural analog of AnMcr, was synthesized and used as a functional monomer to prepare imprinted polymers for comparison with AnMcr-based polymers. Using divinylbenzene (DVB) as a cross linker and racemic propranolol as a model template, irregular monolithic particles of poly(SaMcr-co-DVB)m were synthesized in toluene, and spherical beads of poly(SaMcr-co-DVB)b and poly(AnMcr-co-DVB)b weresynthesized in acetonitrile by precipitation polymerization. Although imprinted irregular monolithic particles, poly(SaMcr-co-DVB)m, tested in toluene …


Spectral Analysis Of Ground Magnetic Data In Magadi Area, Southern Kenya Rift, Jg Githiri, Jp Patel, Jo Barongo, Pk Karanja Mar 2012

Spectral Analysis Of Ground Magnetic Data In Magadi Area, Southern Kenya Rift, Jg Githiri, Jp Patel, Jo Barongo, Pk Karanja

Tanzania Journal of Science

The area surrounding Lake Magadi in the southern Kenya rift is characterized by hot springs that issue from fractures distributed along the shores of the lake. Presence of earthquake swarms that cluster in northern margin of Lake Magadi strongly indicate magmatic activity in the area. This study was done as a follow-up to investigate depth to the heat source possibly causing high seismic activity and high heat flow in the area. A ground magnetic survey was conducted to investigate geothermal potential of the area and a magnetic anomaly contour map prepared. Spectral analysis involving determining power spectrum was applied to …


Characterisation Of Rapeseed Oil Based Resins Using Infrared And Thermogravimetry Techniques, L. Y. Mwaikambo Dec 2011

Characterisation Of Rapeseed Oil Based Resins Using Infrared And Thermogravimetry Techniques, L. Y. Mwaikambo

Tanzania Journal of Science

Rapeseed oil which is a triglyceride had undergone chemical modification on its structure to obtain hydroxyl groups. The hydroxylated chemical structure was crosslinked using methylene-pphenyl diisocyanate to produce a thermoset rapeseed oil resin. The cross linking process was monitored in situ using the Attenuated Total Internal Reflectance Fourier Transform-Infrared spectroscopy and the thermogravimetric analysis techniques. The infrared technique was also used to monitor chemical groups of the unmodified rapeseed oil. A reduction of the absorption band around 3300 cm-1 which is due to the presence of hydroxyl groups was observed indicating the occurrence of the reaction between the hydroxylated rapeseed …


Landsat Remote Sensing Data As An Alternative Approach For Geological Mapping In Tanzania: A Case Study In The Rungwe Volcanic Province, South-Western Tanzania, E. E. Mshiu Dec 2011

Landsat Remote Sensing Data As An Alternative Approach For Geological Mapping In Tanzania: A Case Study In The Rungwe Volcanic Province, South-Western Tanzania, E. E. Mshiu

Tanzania Journal of Science

Rungwe Volcanic Province (RVP) is mostly covered by extrusive rocks that overlain the Precambrian basement. The use of Landsat data in this area has revealed the need of effective use of these data in geological mapping programs in Tanzania. Landsat band ratios 5/1, 3/7, 5/7 and 5/4 as well as R: G: B composite images 7:4:1, 7:5:4, 1/3:5/7:3/5 and 4/5:6/7:4/6 played an important role in identifying different rock types in the study area. Ratio images managed clearly to distinguish between mafic and felsic rocks whereby two lithological blocks were identified, Block 1 covers a combination of intrusive and metamorphic rocks …


Variability In Parasites’ Community Structure And Composition In Cat Fish With Respect To Level Of Pollution In Mwanza Gulf, Lake Victoria, Tanzania, C. J. Mwita Dec 2011

Variability In Parasites’ Community Structure And Composition In Cat Fish With Respect To Level Of Pollution In Mwanza Gulf, Lake Victoria, Tanzania, C. J. Mwita

Tanzania Journal of Science

This study investigated the composition and structure of the parasite communities in Cat fish with respect to levels of water pollution in Lake Victoria. A total of 1071 Clarias gariepinus with mean TL range of 19 to 27 cm were analyzed from three localities in Mwanza Gulf (Kirumba, 298 fish infected with 15 parasite species), Nyegezi (376 fish, with 15 parasites species) and Malimbe (397 fish, with 16 parasites species). Trematodes and nematodes dominated the population with six (35.3%) and five (29.4%) species, respectively. Mean species richness and heteroxenous/monoxenous ratio showed significant changes (Fr = 8.000; p = 0.0046), being …


Petrography And Geochemistry Of Mafic Granulites Of The Ubendian Belt: Contribution To Insights Into The Lower Continental Crust Of The Paleoproterozoic, N. Boniface Dec 2011

Petrography And Geochemistry Of Mafic Granulites Of The Ubendian Belt: Contribution To Insights Into The Lower Continental Crust Of The Paleoproterozoic, N. Boniface

Tanzania Journal of Science

Mafic granulites of the Ubendian Belt have geochemical signature, trace and REE patterns, similar to that of the lower continental crustal rocks. A SHRIMP U-Pb single zircon date at 1977±40 Ma indicates that these rocks belong to the Paleoproterozoic Ubendian orogenic cycle, which was followed by the Mesoproterozoic tectonic disturbance that contributed to their exhumation. Orthopyroxene, clinopyroxene, garnet, hornblende, plagioclase and quartz is a frequent mineral assemblage for the mafic granulites of the Ubendian Belt, and garnet frequently form corona between plagioclase and clinopyroxene. Geothermobarometric calculations have revealed the equilibration of these rocks at a temperature range between 650 and …


Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface Dec 2011

Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface

Tanzania Journal of Science

Biotite-granite intrusions in meta-ironstones at Geita Hills and the Bukoli alkali-granite intrusion in metabasites at Mawemeru area produced heat that baked the respective country rocks through epidote-amphibolite- to amphibolite-facies. Critical and informative mineral assemblages in the metairostones of Geita Hills are garnet-grunerite-epidote-quartz and garnetferrogedrite- biotite-quartz and in the metabasites of Mawemeru is ferrotschermakite-(Naplagioclase)- quartz. Peak temperatures ranging between 438°C and 544°C were calculated from the above mineral assemblages and a pressure not exceeding 3 kbar was inferred to from the composition of magnesium-iron amphiboles (grunerite with XFe ratio of 0.83, i.e. Gru83). Hornfels textures in the metaironstones are suggested by …


Identification Of Clay Minerals Of The Eastern Southern Region Of Lake Victoria By Ethylene Glycol And Heat: X-Ray Diffraction And Infrared Spectroscopy Studies, E. H. J. Lugwisha Dec 2011

Identification Of Clay Minerals Of The Eastern Southern Region Of Lake Victoria By Ethylene Glycol And Heat: X-Ray Diffraction And Infrared Spectroscopy Studies, E. H. J. Lugwisha

Tanzania Journal of Science

The effect of glycol and heat on some clay minerals of the eastern southern region of Lake Victoria in Tanzania has been studied. First, Whole Rock Powder mount XRD analysis was carried out at the measuring range 2 # ranging between 2o – 65o. Four non-clay minerals found in samples were Na-feldspar, K-feldspar, pyrope and quartz. Oriented clay mineral XRD analysis diffractograms were developed when the air-dried samples were diffracted in measuring range 2# between 2oo – 32o. Main clay mineral groups found in the samples were kaolinite, illite and montmorillonite. After glycolating the samples, it was evident that kaolinite …


Implementation Of A Tabu Search Heuristic For The Examinations Timetabling Problem, A. R. Mushi Dec 2011

Implementation Of A Tabu Search Heuristic For The Examinations Timetabling Problem, A. R. Mushi

Tanzania Journal of Science

This paper reports on the design and implementation of an algorithm for the construction of an examinations timetable. The Examinations Timetabling Problem is the problem of assigning examinations and candidates to time periods and examination rooms while satisfying a set of specific constraints. Every University has a different set of constraints and structure of examinations. Generally, timetabling problems are NP-Hard and therefore very difficult to solve. However, they are of great interest due to their important practical application in educational institutions. This paper discusses a heuristic algorithm basing on the examinations timetabling at the University of Dar es salaam. The …


Classification Of Plants According To Their Heavy Metal Content Around North Mara Gold Mine, Tanzania: Implication For Phytoremediation, N. Mganga, Mlk Manoko, Z. K. Rulangaranga Dec 2011

Classification Of Plants According To Their Heavy Metal Content Around North Mara Gold Mine, Tanzania: Implication For Phytoremediation, N. Mganga, Mlk Manoko, Z. K. Rulangaranga

Tanzania Journal of Science

Plants like other living organisms respond differently under different environmental conditions. An elevated level of heavy metals is one of the stresses which results into three classes of plants depending on their heavy metal content. The classes of plant species according to their accumulated heavy metals around North Mara Gold Mine were not known. To study such classes, a line transect of 700m long was established opposite the gold mine wastes. A total of eight sampling points were systematically established each after every 100m in that transect. Fifteen plant species were sampled; at least one species per sampling point. Approximately …


Evaluation Of Single-Step Steam Pyrolysis-Activated Carbons From Lesotho Agro-Forestry Residues, I. Hapazari, V. Ntuli, W. Parawira Dec 2011

Evaluation Of Single-Step Steam Pyrolysis-Activated Carbons From Lesotho Agro-Forestry Residues, I. Hapazari, V. Ntuli, W. Parawira

Tanzania Journal of Science

Activated carbon has been widely used worldwide as an effective filtration or adsorption material for removing biological and chemical contaminants from drinking water. The potential of producing activated carbon (AC) from local agroforestry residues by single-step steam pyrolysis processes was investigated. The research aims to promote innovative use of local raw materials and relatively low-cost techniques in production of activated carbon. Four varieties of activated carbons from four different agroforestry residues, pine (Pinus contorta) cones (PC), Abies (Abies cilicica) seeds (AS), maple (Acer ginnala) seeds (MS) and peach (Prunus persica) stones (PS), were prepared and evaluated. The ACs were evaluated …


Heavy Metal Levels In Paddy Soils And Rice (Oryza Sativa (L)) From Wetlands Of Lake Victoria Basin, Tanzania, J. F. Machiwa Dec 2010

Heavy Metal Levels In Paddy Soils And Rice (Oryza Sativa (L)) From Wetlands Of Lake Victoria Basin, Tanzania, J. F. Machiwa

Tanzania Journal of Science

A survey of paddy fields in Lake Victoria Basin (LVB) wetlands was conducted at a wider scale in different locations including closer to mining and within urbanized areas in Tanzania. The objective of the study was mainly to assess the present situation with regard to levels of heavy metals in O. sativa grains harvested locally as well as to set the baseline levels of some heavy metals in paddy fields. The results showed that the levels of Cadmium, Chromium, Copper, Lead, Zinc and total Mercury in brown rice are generally within the acceptable levels for human food. However, higher concentration …


The Major Cause Of Observed Erosion Surge On The Beaches North Of Dar Es Salaam City, N. Nyandwi Dec 2010

The Major Cause Of Observed Erosion Surge On The Beaches North Of Dar Es Salaam City, N. Nyandwi

Tanzania Journal of Science

Surges in coastal erosion north of Dar es Salaam city have been documented from 1977 to the early 1980s and around 1997/98. Analysis of the wind data shows that the documented increase in coastal erosion coincided with increased wind speeds. Extreme winds in excess of 10-11 m s-1 were experienced during 1976-78, 1984 and after 1996. Their coincidence with extreme high tides produced the high erosion rates. Using beach profile data for the years 1998-2000 the evolution of the beach profile with the changing monsoon winds and sediment input by rivers could be demonstrated. The beach erosion took place during …


Geomorphological Potential Of Coelacanth Habitat Across Mozambique-Tanzania Border, N. Nyandwi Dec 2010

Geomorphological Potential Of Coelacanth Habitat Across Mozambique-Tanzania Border, N. Nyandwi

Tanzania Journal of Science

The coelacanth is a new fish in Tanzania. It was first discovered in September 2003 after it was spotted by a tourist in a fish market. It was caught by fishermen in the deep waters off Songo Mnara Island offshore of Kilwa Masoko Town in Southern Tanzania. The find potentially added southern Tanzania to the list of known coelacanth areas of the southern Western Indian Ocean Region. Observed current conditions indicate that the waters are swept by strong (2 m/sec) northward flowing current. This suggests that there must exist hideouts for the fish, such as caves in canyons and overhangs. …


Serotonin Immunoreactive Cells And Nerve Fibers In The Mucosa Of The Rat Stomach, A P Gesase Jul 2009

Serotonin Immunoreactive Cells And Nerve Fibers In The Mucosa Of The Rat Stomach, A P Gesase

Tanzania Journal of Science

The current study has showed the morphological features of serotonin (5-hydroxytryptamine) immunoreactivity in the pyloric mucosa of the rat stomach. The immunoreactive elements included the endocrine cells, mast cells and mucosal nerve fibers in the lamina propria. The immunopositive endocrine cells were oval in shape and located mostly in the basal part of the gastric glands. The cell contained a central non-staining area and the peripheral staining zone. The mast cells stained homogenously and appeared to be oval-round in shape. They were located in the upper, middle and basal parts of the mucosa. Serotonin immunoreactive nerve fibers with varicosities were …


Physico-Chemical Characteristics Of Storage-Ripened Mango (Mangifera Indica L.) Fruits Varieties Of Eastern Tanzania, O C Othman, G P Mbogo Jul 2009

Physico-Chemical Characteristics Of Storage-Ripened Mango (Mangifera Indica L.) Fruits Varieties Of Eastern Tanzania, O C Othman, G P Mbogo

Tanzania Journal of Science

Two mango (Mangifera indica L.) fruit varieties, Dodo and Viringe, from two localities of Eastern Tanzania, (Muheza in Tanga and Ifakara in Morogoro), were harvested as mature green fruits during early, mid and late season and allowed to ripen while stored at room temperature. The fruits were analyzed for their proximate composition (ash, titratable acidity, crude fat, crude fibre, moisture), reducing and total sugars content, ascorbic acid and total soluble solids content, concentration of four macro elements (Ca, Mg, K, Na) and seven heavy metals (Al, Cd, Cu, Fe, Mn, Pb, Zn). The results showed that the mango fruits had …


Physical And Chemical Composition Of Storage-Ripened Papaya (Carica Papaya L.) Fruits Of Eastern Tanzania, O C Othman Jul 2009

Physical And Chemical Composition Of Storage-Ripened Papaya (Carica Papaya L.) Fruits Of Eastern Tanzania, O C Othman

Tanzania Journal of Science

The proximate composition (ash, titratable acidity, crude fat, crude fibre, moisture and sugars), soluble solids, ascorbic acid, polyphenol oxidase activity, macro-nutrients and heavy metal contents of storage-ripened papaya (Carica papaya L.) fruits from Mbezi, Dar es Salaam, Tanzania were determined. The determinations were repeated for early, middle and late-season papaya fruits. The fruits were always harvested at the mature green stage and allowed to ripen during room temperature storage. The results showed that papaya fruits had high moisture content (>85.5%), low acidity (<0.18% c.a.), low crude fat (0.10 g/100 g-edible portion), moderate crude fibre (1.45 g/100 g-edible portion), high ascorbic acid content (>84.5 mg/100 g- fw), moderate total sugars (>13.0%) and soluble solids (>12.9%) content. Early-season …


Monitoring Of Heavy Metal Loading Into The Wetlands South Of Lake Victoria Basin, Nothern Tanzania, M K D Mutakyahwa, J R Ikingura, G Y S Mtui Jul 2009

Monitoring Of Heavy Metal Loading Into The Wetlands South Of Lake Victoria Basin, Nothern Tanzania, M K D Mutakyahwa, J R Ikingura, G Y S Mtui

Tanzania Journal of Science

The paper discusses sources, concentrations and physicochemical parameters of heavy metals of environmental concern in the wetlands of Lake Victoria basin in Tanzania. The metals investigated include copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), nickel (Ni), arsenic (As), manganese (Mn), cobalt (Co) and mercury (Hg). These metals are released into the wetlands via weathering and erosion of rock formations, mining operations and industrial activities, discharge of municipal and domestic waste, and use of agrochemicals. The levels of these heavy metals in soil, sediment, water, and biota differ. Wetlands impacted by gold mining activities in the South Lake …