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Tanzania Journal of Science
Number of Followers: 4  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0856-1761
Published by African Journals Online Homepage  [261 journals]
  • Pulsed Lased Deposition of Single-Crystalline (001) Oriented
           Pb(Zr0.5T0.5)O3 Thin Film on PrScO3 Substrate

    • Authors: Mahamudu H. Mtebwa, Nava Setter
      Pages: 528 - 536
      Abstract: High quality thin films are important for domain engineering applications such as on-volatile memory applications. Single crystalline (001) oriented Pb (Zr0.5T0.5)O3 thin films have been grown by pulsed laser deposition on PrScO3 with strontium ruthenate (SRO) electrodes. Thin films were prepared from PZT ceramic targets with 15% excess PbO to compensate for lead loss at high deposition temperature. Layer by layer/step flow growth mode observed on AFM images has been realised by using a single terminated PrScO3 substrate as well as optimized deposition parameters. XRD measurements have confirmed the highly (001) oriented tetragonal symmetry. Furthermore, analysis conducted using piezoresponse force microscopy has shown that the thin films are monodomain with spontaneous ferroelectric polarization preferentially pointing upwards, i.e., away from the substrate. The absence of ferroelastic domains and the observed single ferroelectric domain structure are the results of both relatively small compressive misfit strain as well as favourable electrical boundary conditions. Keywords:    PZT; Pulsed Laser Deposition; Epitax; Thin film
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.
      Issue No: Vol. 48, No. 3 (2022)
       
  • Evaluation of Natural Antifungal Compounds from Artemisia afra and its
           Effectiveness on Prevention of Aflatoxins

    • Authors: Noela G. Kilenga, Daniel Maeda, Oscar Kibazohi, Lilian D. Kaale
      Pages: 537 - 547
      Abstract: Artemisia afra is a medicinal plant with antimicrobial activities, known to treat tuberculosis, measles, cough, and influenza. In consequence, its applications have increasingly become pivotal to control various microbes which cause different diseases. This study therefore, evaluated the chemical composition and the antifungal activity of A. afra essential oil. The extraction of essential oil was done using steam distillation. The essential oil chemical composition was analysed by GC-MS. The analysis revealed 19 compounds from A. afra. The main compounds were borneol (71.529%), terpinen-4-ol (8.582%), β-thujone (3.283%), β-terpineol (2.590%), α-terpineol (1.791%), chrysanthenone (1.507%), myrtenal (1.393%), eucalyptol (1,8-cineole) (1.263%), cis-sabinene hydrate (1.172%) and trans-carane, 4,5-epoxy (1.088%). The growth and aflatoxin production inhibitions against A. flavus were determined via antifungal and antiaflatoxigenic bioassays of the A. afra essential oil at the concentration range of 10–50 µL/mL using a poisoned-food method. The quantification of the aflatoxins production was carried out using high-performance liquid chromatography. The antifungal activity of A. afra essential oil was effective against A. flavus with growth inhibition of 99.97–99.99% and controlled aflatoxins production by 99.25–99.63%. The results indicated that A. afra essential oil can become an alternative natural fungicide for the control of A. flavus growth and aflatoxins production. Keywords: Artemisia afra; essential oil; A. flavus; aflatoxins; GC-MS
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.2
      Issue No: Vol. 48, No. 3 (2022)
       
  • Phytochemical Investigation, Anti-inflammatory and Analgesic Activities of
           Ethyl Acetate Extract of Pride of Barbados Pod (Caesalpinia pulcherrima)

    • Authors: Osahon K. Ogbeide, Efosa D. Omono, Precious O. Ehizojie, Anthony E. Aiwonegbe , Jeremiah O. Uadia
      Pages: 548 - 558
      Abstract: Pride of Barbados is a therapeutic herb which has wide traditional applications in the treatments and management of diverse ailments. Diseases pose great threats to human race. This research was aimed at evaluating the phytochemicals, proximate composition, acute toxicity, anti-inflammatory, and analgesic activities of the pod extract of Pride of Barbados in order to provide a scientific validation for its use as a therapeutic herb. All analyses were carried out using already established methods; the antioxidant potential was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, while the formalin-induced inflammation and acetic acid-induced writhing techniques were used to evaluate the anti-inflammatory and analgesic activities, respectively. Phytochemicals detected were alkaloids, tannins, saponins, flavonoids and phenolic compounds. The moisture content, crude fibre, acid insoluble ash, water soluble ash and total ash were 9.02 ± 0.02%, 9.04 ± 0.01%, 2.78 ± 0.02%, 1.20 ± 0.00% and 4.35 ± 0.13%, respectively. The IC50 values for the DPPH radical scavenging capacity of the pod extract and ascorbic acid (standard) were 50.05 ± 0.50 and 5.20 ± 0.85 µg/mL, respectively. The oral administration of crude ethyl acetate pod extract of Pride of Barbados to Swiss mice was not toxic even up to a dose of 5,000 mg/kg. The pod extract showed a significant decrease (p < 0.05) in the formation of formalin-induced oedema and the number of writhes in the acetic acid-induced writhing test in a concentration (dose) dependent manner. This study confirms the phytomedicinal use of the pod extract of Pride of Barbados with rich pharmacological and antioxidant properties. Keywords:  Pride of Barbados; Caesalpinia pulcherrima; Anti-inflammatory; Analgesic; Phytochemicals
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.
      Issue No: Vol. 48, No. 3 (2022)
       
  • Urinary Schistosomiasis and Its Potential for Cancer and Hepato-Renal
           Function Alterations among the Residents of Asejire Dam, South-Western
           Nigeria

    • Authors: Omowumi O. Adewale, Monsurat O. Odebode, Maryam O. Mustapha, Oluwatosin A. Adetuyi, Monsuru A. Adeleke
      Pages: 559 - 568
      Abstract: Urinary schistosomiasis is of public health significance in sub-Saharan Africa with its prevalence being linked to carcinogenesis. However, there is a paucity of data to support this relationship. This study explored the prevalence and intensity of Schistosoma haematobium infections and its associations with cancer and hepatorenal function alterations in villages along the Asejire dam in the State of Osun, Nigeria. Urine samples from 152 consented participants (aged 18–75 years) from four communities were collected and examined for Schistosoma haematobium using the microscopy method. The blood serum of randomly selected infected and non-infected individuals (10 per group) was screened for tumor, inflammatory and hepato-renal function biomarkers. From the results, only one out of the four communities recorded cases of schistosomiasis with a prevalence of 26.5% (22/83) and overall infection prevalence was 14.47% (22/152). There was no statistical difference (p ˃ 0.05) in kidney, liver antioxidants, and lipid peroxidation markers in the infected and non–infected participants. The concentrations of antioxidants, inflammatory, and tumor markers were higher in Schistosoma infected individuals as compared with non-infected individuals. This justifies the need to monitor schistosomiasis-infected individuals for tumor, inflammatory and hepato-renal function biomarkers before they develop into cancer, liver, and kidney failure. Keywords:    Urinary Schistosomiasis; tumor; and inflammatory markers; antioxidants; hepato-renal function; Asejire dam Nigeria
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.
      Issue No: Vol. 48, No. 3 (2022)
       
  • Modelling the Impacts of Immigrants on COVID 19 Transmission Dynamics with
           Control Measures

    • Authors: Alfred K. Hugo, Goodluck M. Mlay, Moses B. Kabigi
      Pages: 569 - 584
      Abstract: The COVID-19 pandemic began in Wuhan City in the Hubei province of China in December 2019. The disease spread quickly in many countries around the world due to mobility of people from one location to another. As a result, a COVID-19 mathematical model with the impacts on immigrants was proposed to study its transmission dynamics and possible control measures. The reproduction number was determined by using the next-generation technique and found to be 0.636, indicating that the transmission could be minimized in the community if all immigrants were effectively controlled. The Pontryagin's Maximum Principle was applied in analysing control strategies which are screening of immigrants, provision of public education to raise community awareness, and treatment of infected individuals. The simulated results revealed that a combination of public education, screening of all immigrants, and treatment of infected individuals plays a significant role in reducing COVID-19 transmission in the community. Keywords: COVID-19; Immigrants; Optimal control theory;
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.5
      Issue No: Vol. 48, No. 3 (2022)
       
  • Population Characteristics of Selected Small Pelagic Fish Species along
           the Tanzanian Coast

    • Authors: Godfrey Fabiani, Leonard J. Chauka, Christopher A. Muhando
      Pages: 585 - 595
      Abstract: Although small pelagic fishing in Tanzania is rising, lack of information on population structure has been a significant concern in its management. This study aimed to determine the species composition, length-weight relationship and length at first maturity of Amblygaster sirm, Encrasicholina heteroloba, Encrasicholina punctifer, Stolephorus commersonii, and Spratelloides gracilis landed at Kilwa Kivinje, Kipumbwi and Shangani along the Tanzanian coast. These landing sites were chosen because of their locations and importance in the small pelagic fishery. Sampling was done monthly from October 2018 to June 2020. The catch composition was site specific such that  E. heteroloba dominated at Kilwa Kivinje and Shangani, while E. punctifer dominated at the Kipumbwi site. Further analysis shows allometric coefficient to be greater than 3 for A. sirm and E. punctifer, indicating positive allometric growth, while for S. commersonii and S. gracilis, the allometric coefficient was less than 3, indicating negative allometric growth. Our findings showed that length at first maturity (L50) differed, implying that these species start spawning at different sizes, an essential biological reference for sustainable small pelagic fish exploitation. We recommend seasonal closure of the fishery to maintain reproductive seasons since many species are multiple spawners. Keywords: Population; Small pelagic; Maturity; Tanzania
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.6
      Issue No: Vol. 48, No. 3 (2022)
       
  • Anxiolytic Effects, Antioxidant and Anti-inflammatory Activities of the
           Methanol Extract of Jatropha tanjorensis Leaf

    • Authors: Anthony E. Aiwonegbe , Uwaila Omoruyi, Osahon K. Ogbeide, Blessing O. Imoukhuede, Benjamin O. Gabrielsson
      Pages: 596 - 606
      Abstract: The methanol leaf extract of Jatropha tanjorensis was analyzed for its bioactive components, in-vitro antioxidant, antidepressant, anxiolytic and anti-inflammatory activities using established methods. The phytochemicals detected were saponins, tannins, terpenoids, phenolic compounds, alkaloids, flavonoids and eugenols. The total phenolic content (TPC) was 36.48 mgGAE/g, while the total flavonoid content (TFC) was 145.92 mgQE/g of the extract. 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity gave an IC50 of 185.02 and 5.15 µg/mL for the extract and ascorbic acid (standard), respectively. The 50% lethal dose (LD50) was greater than 5000 mg/kg, while graded doses of 50, 100 and 200 mg/kg of the plant extract relieved depression in mice to 93.3, 100 and 80.8%, respectively when compared with 10 mg/kg amitriptyline (positive control). A significant anxiety reduction, exemplified by a decrease in the frequency of head dip, was observed for animals administered with the plant extract compared with untreated control (p < 0.05). The reduction of formalin-induced paw edema was significant (p < 0.01) at 50 mg/kg of the plant extract, when compared with the control. The methanol extract of J. tanjorensis leaf is therefore a potential source of plant medicine with remarkable pharmacological activities. Keywords:    Jatropha tanjorensis; anxiolytic; antidepressant; anti-inflammatory; antioxidant; phytochemicals
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.7
      Issue No: Vol. 48, No. 3 (2022)
       
  • Characterisation and Antimicrobial Potential of Actinobacteria Isolated
           from Momela Soda Lakes, Tanzania

    • Authors: Witness S. Lema, Ally Mahadhy, Modester Damas, Joan J.E. Munissi, Thomas J. Lyimo
      Pages: 607 - 622
      Abstract: Extreme environments such as soda lakes are potential sources of microbes with biotechnological applications in different sectors. This study aimed at isolation, characterization and investigation of antibacterial potential of actinobacteria from Momela Soda Lakes, at Arusha National Park in Tanzania. One hundred and twenty (120) isolates were recovered from soil and water samples using the dilution plate technique. The isolates were morphologically and biochemically characterized, and further, screened for antimicrobial activity by disc diffusion method as well as the micro dilution technique. Cytotoxic effects were determined using the brine shrimp lethality test. Results showed that, all 120 isolates were Gram-positive rod-coccus shaped. Forty-four out of them showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The Streptomyces (101TI) and Dietzia (56BI) strains exhibited exceptionally higher antibacterial activity compared to the rest with inhibition zones of 16.25 and 21.00 mm, respectively. These two strains were toxic against brine shrimp-larvae. Microbacterium (5LI), Hoyosella (113BI), Streptomyces (62BI), Dietzia (117SI), Hoyosella (37SI) and Microbacterium (3BI) strains had low antibacterial and cytotoxic activities. This study therefore revealed that Momela Soda Lakes harbour actinobacteria with antimicrobial potential. Keywords: Actinobacteria; antimicrobial activity; extremophiles; Momela soda lakes
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.8
      Issue No: Vol. 48, No. 3 (2022)
       
  • Chemical Composition and Bioactive Potential of Extracts from Diospyros
           capricornuta F. White against Aspergillus flavus and Aspergillus
           parasiticus

    • Authors: Princess W. Ngowi, Juma A. Mmongoyo, Lilian D. Kaale
      Pages: 623 - 632
      Abstract: Diospyros capricornuta is an endemic species widely distributed along the coast of Tanzania that is used as food condiments and traditional medicine. The chemical compositions of Diospyros capricornuta leaves, stem-bark, and root-bark extracts; and their bioactive potentials against Aspergillus flavus and Aspergillus parasiticus were investigated. The leaves, stem-bark, and root-bark samples of D. capricornuta were extracted using Soxhlet apparatus and the resultant extracts were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). A total of 14 compounds were identified from the extracts, whereby 2,4-di-tert-butylphenol was the most abundant compound in all extracts. The growth and aflatoxin production inhibitions against A. flavus and A. parasiticus were determined via antifungal and antiaflatoxigenic bioassays of the extracts at the concentrations of 0.0, 62.5, 125.0, and 250.0 µg/mL using a poisoned-food method. The High-Performance Liquid Chromatography (HPLC) technique was used to quantify the aflatoxins after bioassays to evaluate aflatoxin inhibitions. The stem-bark extracts at the highest dose of 250.0 µg/mL inhibited aflatoxin production by A. flavus for over 99% and A. parasiticus for over 94%. Overall, the results show that the leaves, stem-bark, and root-bark extracts of D. capricornuta are potential inhibitors against A. flavus and A. parasiticus-the producers of aflatoxins. Keywords: Diospyros capricornuta; Growth inhibitions; Aflatoxin inhibitions; Aspergillus flavus; and Aspergillus parasiticus.
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.9
      Issue No: Vol. 48, No. 3 (2022)
       
  • Pulse-Field Analysis Diversity of Extended Spectrum Beta Lactamases
           Producing Gram Negative Bacteria Isolated from Periplaneta americana
           (Cockroaches)

    • Authors: Omolara D. Popoola, Moses O. Efuntoye, Georgia C. Agu , Benjamin T. Thomas
      Pages: 633 - 639
      Abstract: Extended spectrum beta lactamase (ESBL) producing bacteria are organisms of public health significance that have been implicated in prolonged hospital stay, treatment failures and higher fatalities. These organisms were originally thought to be widely distributed in hospital, but have since grown in terms of their epidemiological coverage. This study was therefore aimed at using pulse-field gel electrophoresis (PFGE) to understand the diversity of ESBL producing organisms originating from cockroaches in Ago-Iwoye, Nigeria. The diversity was determined by using a set of twenty six (26) ESBL producing bacterial strains isolated from cockroaches sampled in Ago-Iwoye community, Ogun State, Nigeria. PFGE analysis revealed three pulsotypes (distinct profile) with no distinct isolates present on a pulsotype. It was however observed that no pulsotype had less than two (2) isolates in any case, while isolates from different communities displayed identical profiles. In conclusion, clonal distributions of ESBL producing organisms on cockroaches are without bias to specimens and/or the community sampled. Keywords: ESBL; Gram negative bacteria; PFGE; Diversity;
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.10
      Issue No: Vol. 48, No. 3 (2022)
       
  • Knowledge, Attitudes and Practices towards the Use of Iron and Folic Acid
           Supplements among Pregnant and Lactating Women in Dar es Salaam

    • Authors: Cecilia N. Mshanga, Elina J. Maseta
      Pages: 640 - 648
      Abstract: The current study investigated knowledge, attitudes and practices (KAP) regarding the use of iron and folic acid (IFA) supplements among pregnant and lactating women living with Human Immunodeficiency Virus (HIV) in Dar es Salaam. A cross-sectional survey involved 294 pregnant and lactating women attending Prevention of Mother-To Child Transmission (PMTCT) clinics. A semi-structured questionnaire was used to collect data from the subjects. The data were analysed using SPSS. Multivariate regression analysis was carried out to determine factors associated with IFA supplement use among the study subjects. The findings indicated that knowledge of IFA supplement use among the subjects was good (92.2%). Most of the respondents (89.8%) had appropriate perceptions of IFA supplements. The subjects also showed positive attitudes towards the use of IFA supplements during pregnancy and lactation. However, practices towards the use of supplements were not satisfactory. It was further revealed that only 15.2% of the women received supplements during pregnancy and a few weeks after delivery as recommended. Women claimed the main barriers towards using the supplements were bad taste (46.7%) and nausea (45.2%). The multivariate logistic regression model showed that factors like being a businesswoman, comfortable use of the supplements and experiencing any barriers were significantly associated with practices on the use of the supplements.  Thus, healthcare workers should clear up the misconceptions about using the supplements and instruct women on how to manage their potential side effects as they have been doing with other conditions or illnesses.  Keywords:     Iron, folic acid, anaemia, supplements, knowledge, attitude, practice, pregnant, lactating women
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.11
      Issue No: Vol. 48, No. 3 (2022)
       
  • Bed II Phytolith Palaeolandscapes (1.5-1.1 Ma) at Oldupai Gorge, Tanzania

    • Authors: Makarius P. Itambu
      Pages: 649 - 659
      Abstract: The primary approach for reconstructing ancient plant landscapes is normally through the analysis of environmental proxy data and ultimately the application of the data from plant micro-remains to infer the vegetation patterns, distribution, and nature of past environments. Phytolith analyses serve as an important tool for identifying different micro-ecological niches in which human activities occurred. They are indicative of certain plant types and vegetation patterns, and the way in which plant landscapes respond to regional climate changes. Hence, in order to understand the ancient plant landscape of the Pleistocene Bed II sites of Oldupai Gorge 1.5 to 1.1 million years ago (Ma), a location inhabited by our early ancestors, the phytoliths research was conducted in order to reconstruct the ancient plant environments of Oldupai’s Bed II sites, namely Sam Howard Korongo (SHK), Thiongo Korongo (TK), and Bell’s Korongo (BK) because there is no enough phytolith data from these upper sections of Bed II. The preliminary results from this study indicate that TK and BK sites’ plant landscape was dominated by arboreal plants. Keywords:   Phytolith, hominin, palaeoecology, palaeoenvironments, palaeolandscape
      PubDate: 2022-09-30
      DOI: 10.4314/tjs.v48i3.12
      Issue No: Vol. 48, No. 3 (2022)
       
  • Effects of Multilayer Structure on the Microstructure and Optical
           Properties of the DC Sputtered Chromium Thin Films for Selective Solar
           Absorber Applications

    • Authors: Justine J Tibaijuka, Margaret E Samiji, Mmantsae Diale, Nuru R Mlyuka
      Pages: 660 - 667
      Abstract: Chromium thin films exhibit several properties that make them potential for solar thermal applications. In this work the effect of film thickness and sputtering power based multilayer structure on the optical properties of DC sputtered chromium thin films is reported. The structural, topological, and optical properties of these films were determined by X-ray diffractometer, Atomic Force Microscopy, and Ultraviolet-Visible-Near Infrared spectrophotometer, respectively. XRD spectra revealed a single peak with preferential orientation of (200) and (210) for single layer and multilayer chromium films, respectively. The grain size and roughness were relatively higher for the multilayer compared to single layer Chromium films. Spectral transmittance showed very high sensitivity to film thickness with average peak of 69% and 5% at a wavelength range of 250-2500 nm for the film thickness of 12 nm and 94 nm, respectively. Spectral transmittance was also found to be higher in single layered films than multi-layered films. Findings from this study suggest that multilayer structure have the potential of tuning the microstructure and optical properties of low thickness Cr films, hence, extending its potential applications in selective solar absorber applications. Keywords: Multilayer, Chromium, Sputtering, Optical constants  
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.13
      Issue No: Vol. 48, No. 3 (2022)
       
  • Generation of Geochemical Exploration Targets from Regional Stream
           Sediment Data Using Principal Component and Factor Ana

    • Authors: Yusto J Shine, Charles D Moye, Godfrey J Mallya, Ambaliche L Tamambele
      Pages: 668 - 679
      Abstract: A regional-scale stream sediment geochemical sampling was carried out with an average
      sampling density of one sample per nine square-kilometre in Kiteto District, Manyara Region.
      A total of 358 stream sediment samples were collected and analysed for major and trace
      elements by X-ray fluorescence (XRF) and fire assay with atomic absorption spectrometry
      (AAS) finish methods. In this study, Factor and Principal Component Multivariate (FPCM)
      analyses have been used to the stream geochemical data to delineate potential mineralization
      zones by plotting correlated factors as geochemical anomaly maps. Four factors that account
      for 73.7% of the total variance of the stream sediment geochemical data were established.
      Factor 1: Ni–Ba–Co–Cu–Sr which possibly defines the underlying metamorphosed granitic
      units with some contribution from mafic and ultramafic rocks. Factor 2: Cr–Zn–Mn which
      defines crustal forming elements reflecting the mafic rocks. Factor 3 which entails Rb and Pb
      probably attributed to metamorphosed granitic lithology. Factor 4 is arsenic, a chalcophile
      element with affinity to sulfide phases. The FPCM analyses have been successfully in
      delineating potential target areas for gold, nickel and copper exploration in the study area. Keywords: Stream sediment; principal component; factor analysis; exploration targets;
      Kibaya-Kiteto, Manyara.
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.14
      Issue No: Vol. 48, No. 3 (2022)
       
  • Dynamical Analysis and Control Strategies for Capturing the Spread of
           COVID-19

    • Authors: Mutairu K. Kolawole, Kazeem A. Odeyemi, Adedapo I. Alaje, Asimuyu O. Oladapo, Kehinde A. Bashiru
      Pages: 680 - 690
      Abstract: In this paper, a study of preventive measures capable of curbing the spread of COVID 19
      pandemic to avoid its second wave was carried out. The existence and uniqueness of the
      proposed mathematical model is assured, the basic reproduction number is established, the
      local and global stability of the disease free equilibrium are well obtained and the variational
      iteration method is applied to solve the mathematical model. Numerical simulation of the
      included control parameters are carried out. The obtained results and outcomes are presented
      graphically. It was revealed that enlightenment to vaccination awareness should be encouraged
      as vaccination is a good strategy of capturing the spread of the disease. Keywords: Covid-19, Basic Reproduction Number, Local stability, Global Stability,
      variational Iteration Method
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.15
      Issue No: Vol. 48, No. 3 (2022)
       
  • Mineralogy and Geochemistry of the Asanje Iron Ore Deposit within the
           Mayamaya-Hombolo Belt, Dodoma Region, Central Tanzania

    • Authors: Yusto J Shine, Michael M Msabi, Jagarlamudi Seetharamaiah
      Pages: 691 - 702
      Abstract: This paper presents the mineralogy and chemical composition including iron ore impurities to ascertain its suitability for industrial applications. The Asanje iron ore deposit is hosted in Precambrian volcano-sedimentary rocks in the Mayamaya-Hombolo Belt in Dodoma region, within the Lake Nyanza Superterrane. Iron ores are found in two parallel ridges trending NW-SE. Ridge I occurs as vein and banded hematite-type ore and Ridge II as massive-type ore. A total of 24 ore samples were analysed for major and trace elements by XRF and petrographic studies by optical microscopy and XRD. The XRD results revealed that hematite and goethite are the main components and quartz is the gangue mineral in the iron ores. The XRF data shows the Fe2O3t content ranges from 20.8 to 87.3 wt% with an average of 52.7 wt%. The average concentrations in wt% of impurities such as SiO2, Al2O3, P2O5 and S are 37.9, 0.9, 1.2, and 0.2, respectively. By comparison, Ridge II has greater iron content (30.5–87.3 = Avg. 64.66 wt% Fe2O3t), whereas Ridge I (20.8–78.22 = Avg. 48.68 wt% Fe2O3t). Based on the chemical composition, the quality of iron ore is categorised as low to medium grade, and can be used in metallurgical and cement industries. Keywords:    Mineralogy, Geochemistry, Asanje Iron ore deposit, Mayamaya-Hombolo Belt, Tanzania
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.16
      Issue No: Vol. 48, No. 3 (2022)
       
  • Effects of Small-Scale Mining Activities on Fisheries and Livelihoods in
           the Birim River in Atiwa District, Eastern Region of Ghana

    • Authors: Elliot Haruna Alhassan, Samuel Opoku Dandi, Sandra Akugpoka Atindana
      Pages: 703 - 717
      Abstract: The socioeconomic importance of small-scale mining in Ghana is of great interest to the country. It provides employment, supports the livelihood of poor rural areas, and also contributes to national income. Despite all these importance, it has a great influence on the surroundings, with surface and groundwater bodies being the most affected. The study was conducted to determine the effects of small-scale mining activities on fisheries and livelihoods along the Birim River in Atiwa District of Ghana, and also, to ascertain the nature of mining in the catchment and the current status of fisheries in the river. Data were collected with a help of open and closed ended questionnaire and fishers were sampled using purposive sampling method. Findings revealed that fishing activity was vibrant before 2010, but declined afterward. Respondents indicated that the number of fishers who went fishing daily before 2010 decreased drastically after 2010. Also, before 2010, most of the fishers (62%) used fishing nets compared to that after 2010. About 74% of respondents revealed that they could harvest at most 5 crates of fish a day before 2010, while about 38.6% of respondents indicated they could harvest 5 crates after 2010; thus 25 kg per day before 2010. It was revealed that 34% of respondents indicated they could make above $10 daily before 2010 as against 2% making $10 per day after 2010. About 90% of the respondents attributed their levels of harvest and average income per day to the effects of mining, with the reason being that miners wash their products in the river (52%), thus polluting the waterbody. Mining in water locally and commonly known as “changfan” was the main type of mining in the study area. From the findings, it is concluded that small-scale mining has detrimental effects on aquatic ecology and has resulted in the creation of deep pits which destroy gears, increasing the costs of gear repairs, fishing effort, and pollutes water (physical and chemical factors). Hence, it is recommended that there should be a ban on all small-scale mining in and around water bodies as this has detrimental effects on water quality and reduce fishing in the area. Keywords: Pollution; small-scale mining; Birim River; Changfan; Atiwa; Ghana
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.17
      Issue No: Vol. 48, No. 3 (2022)
       
  • Evaluation of Enzymatic Activity during Growth of Pleurotus HK 37 on Saba
           comorensis Exocarp

    • Authors: Isse I. Molobele, Rose J. Masalu, Prosper R. Mosha, Cyprian B. Mpinda
      Pages: 718 - 727
      Abstract: Mushrooms degrade lignocellulosic biomass by releasing lignolytic and hydrolytic enzymes which convert lignocellulosic material into soluble and low molecular weight compounds which are then absorbed as nutrients. In the present study, enzymatic activities of Pleurotus HK 37 during growth on Saba comorensis exocarps were evaluated. It was observed that, Pleurotus HK 37 has ability to produce lignolytic enzyme (Laccase) and hydrolytic enzymes (Carboxymethyl cellulase, xylanase and filterpaperase). Maximum laccase activity of 3.33 ± 0 UmL-1 was observed during colonization period and the activity dropped during fruitification phase. Similar to hydrolytic enzymes, the activity was observed during colonization period and decreased during fruitification. However, higher filterpaperase activity of 0.93 ± 0.13 UmL–1 was observed compared to other hydrolytic enzymes (CMCase 0.78 ± 0.13 UmL–1, and Xylanase 0.56 ± 0.07 UmL–1). Pleurotus HK 37 showed ability to degrade Saba comorensis exocarps and to release enzymes which can be used in biotechnological industries. Keywords:          Mushroom, Lignolytic, Hydrolytic, Enzyme, Saba comorensis
      PubDate: 2022-10-07
      DOI: 10.4314/tjs.v48i3.18
      Issue No: Vol. 48, No. 3 (2022)
       
 
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