Digital Commons Network^™

Study Of The Effects Of Thermal Aging Coupled With Shot-Peening Treatment Of Carbonitrided Din 1.6587 Low Alloy Steel On Retained Austenite And Residual Stresses, Richard J. Katemi

Tanzania Journal of Engineering and Technology (TJET)

This work investigated the effects of thermal aging and shot-peening of carbonitrided 1.6587 steel grade on retained austenite and residual stresses. After carbonitriding samples contained maximum of 0.87% carbon, 0.34% nitrogen and 50 mass. -% retained austenite. Thermal aging conditions investigated were -30°C, 90°C and 150°C while the aging period were 14, 96 and 720 hours. After thermal aging, some of the samples were subjected to shot-peening treatment using standard cut wire shots StD – G3 - 0.6 mm VDFI 8001 with intensity in the range of 0.25 to 0.30 mmA and coverage of 1.00 to 1.24 x 98%. It …

Geological Structure And Possible Mineralized Zones In Ikungi – Manyoni Area, Tanzania: Delineated From High-Resolution Aeromagnetic Data, Raymond K. Pius, Michael M. Msabi

Tanzania Journal of Science

Understanding geological structures is important in mineral exploration. Delineating subsurface geological structures, structural intersections, and complexities of potential geological settings for the formation of hydrothermal mineral deposits, such as gold requires using magnetic data, particularly, high-resolution aeromagnetic data. To define possible targets for mineral exploration, this study used linear detection and the Centre for Exploration Targeting (CET) techniques on high-resolution aeromagnetic data for structural delineation and interpretation. The study's conclusions indicate that the majority of geological features, such as faults, shears, fault intersections, and fracture systems, trend NE-SW, N-S, and occasionally NW-SE. These structures create potentially large areas that have …

Extraction Of Natural Dyes From Delonix Regia Flowers For Cotton Fibres, Lutamyo Nambela, Liberato V Haule

Tanzania Journal of Science

Textile colouration is among the major industry that pollutes the environment with effluents rich in dye chemicals. Most of the dyes used are synthetics which possess health and environmental impacts. Potentially, the use of bio-based dyes and other chemicals can lessen the environmental challenges of the textile effluents. This study reports on sustainable extraction and dyeing of cotton fabric using extract of Delonix regia flowers. The extraction process was done using acidified water as a solvent and the dyeing process was free from hazardous auxiliary chemicals. To improve the dyeing performance, banana sap was used as an affordable and eco-friendly …

Modeling The Transmission Dynamics Of Tuberculosis In Humans, Farida Kisinda, Joshua A. Mwasunda, Mbwiga S. Aloni

Tanzania Journal of Science

Tuberculosis (TB) is a major threat to human health particularly in most of developing countries. In this article, we formulate and analyze a deterministic model for the transmission dynamics of pulmonary and extra-pulmonary tuberculosis. The next generation method is employed to find the basic reproduction number which helps to determine whether TB clears or persists in the human population. Global stability of model equilibria is done through Lyapunov functions whereas the normalized forward sensitivity index method is adopted to determine parameters that drive tuberculosis. Analysis shows that both TB free and endemic equilibria exist. The TB free equilibrium is globally …

Prevalence And Predictors Of Cesarean Delivery In A Tertiary Hospital In Taraba State, Nigeria, Olateju Alao Bamigbala, Ayodeji Oluwatobi Ojetunde, Maza Tanko

Tanzania Journal of Science

A cesarean section (CS) is a surgical technique in which a baby is delivered through an abdomen and uterine incision following fetal viability. It is imperative to identify the factors that influence the use of CS to reduce the needless use of this life-saving procedure and increase its availability for those who need it most. Therefore, this study assesses the prevalence and predictors of cesarean delivery in a tertiary hospital in Taraba state, Nigeria. Information of pregnant women who came for delivery to Federal Medical Center, Jalingo, Taraba state Nigeria from August 2021 to August 2023 was collected. Binary Logistic …

The Effects Of Algal Blooms On Oxygen Levels In Lakes Babati And Eyasi, Tanzania, Amelia S. Buriyo, Nyatwere D. Mganga, Mary Melchiory

Tanzania Journal of Science

Globally aquatic ecosystems are reportedly overwhelmed by algal blooms due to excessive deposition of nutrients which ultimately cause hypoxia, leading to massive fish death. This study aimed at assessing the relationship between algae contents and dissolved oxygen (DO) in Lake Babati which is threatened by anthropogenic activities, whereas Lake Eyasi was used as a control. Algae contents (chlorophyll a), DO and surface water temperature were measured using standard methods. Results revealed that the mean algae content was significantly higher (4.47±0.88 mg/L) in Lake Babati than in Lake Eyasi (1.6±0.45 mg/L) (P < 0.05) and was beyond the standard permissible levels for domestic water supply and healthy ecosystem. Conversely, DO was significantly lower in Lake Babati than in Lake Eyasi (P < 0.05). There was no significant difference in water temperature in the two lakes (P > 0.05). Furthermore, there was an inverse relationship between algae …

Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda

Tanzania Journal of Science

Measurement of angular distribution (AD) of the bremsstrahlung spectral temperature from a full dimension of the Electron Cyclotron Resonance Ion Source (ECRIS) along the beam axis is challenging. To overcome some challenges, this paper presents the AD of the bremsstrahlung spectral temperature measured in a full dimension of the ECRIS along the beam axis using data obtained from the Busan Center of Korea Basic Science Institute (KBSI). The bremsstrahlung spectral temperature from 28-GHz ECR Ion source at the KBSI was measured in six, three, and nine azimuthal angles at the injection, centre, and extraction sides of the ECRIS using three …

Influence Of Stacking Order On The Structural And Optical Properties Of Cu2znsns4 Absorber Layer Prepared From Dc-Sputtered Oxygenated Precursors, January S Gwaydi, Hezekiah B Sawa, Egidius R Rwenyagila, Nathanael R Komba, Talam E Kibona, Nuru R Mlyuka, Margaret E Samiji, Lwitiko P Mwakyusa

Tanzania Journal of Science

Several studies have attempted to overcome the sudden volume expansion of the precursor during sulfurization by the use of oxygen-containing precursors when growing the CZTS absorber. This work demonstrates the influence of precursor stacking orders on the properties of the CZTS thin film absorber layer from DC-sputtered oxygenated precursors for solar cell applications. CZTS absorber layers were prepared from three types of DC-sputtered stacks, namely, Zn-O/Sn/Cu, Sn/Zn-O/Cu, and Sn/Cu/Zn-O. The precursors were sequentially deposited on a soda lime glass (SLG) using DC-magnetron sputtering and annealed in a sulfur and nitrogen ambient. X-ray diffractometry (XRD) and Raman spectroscopy analyses reveal the …

Genetic Characterization Of Water Yam (Dioscorea Alata L.) And Production Constraints Of Yam In Pwani Region And Unguja Island, Tanzania, Gladness E Temu, Veneranda E Mlegi, Nessie D Luambano

Tanzania Journal of Science

Yam (Dioscorea spp.) is a tuber crop cultivated in over 30% of all regions in Tanzania, contributing to the carbohydrate needs of many households. The morphological and genetic diversity of water yam (D. alata L.) local cultivars collected from Pwani region and Unguja Island were evaluated using 26 agro-morphological characters and 10 Short Sequence Repeat (SSR) markers. Cluster analysis using morphological characters classified nine water yam local cultivars into two main clusters with three subclusters. Tuber flesh and leaf colour were the main descriptors for clustering. The genetic diversity of 128 water yam genotypes using ten polymorphic SSR markers generated …

Microbiological Quality Of Irrigation Water And Leafy Vegetables In Dar Es Salaam, Tanzania, Bubelwa L. Kamara, Godwill D. Mrema, Thomas J. Lyimo

Tanzania Journal of Science

The quality of water used for the irrigation of leafy vegetables in urban settings is in doubt due to contamination associated with poor hygiene and water pollution. This study examined the microbiological quality of irrigation water and leafy vegetables at Chang’ombe in Dar es Salaam, Tanzania as well as the perceptions and level of awareness of nearby consumers. Water and leafy vegetable samples were analysed for faecal coliform (FC) using standard techniques. Perception and awareness of consumers were collected using a questionnaire survey. The results showed an average FC count of 406.1 ± 16.40 MPN/100 ml for the irrigation water. …

Effects Of Bending And Re-Bending On Mechanical Properties Of Locally-Manufactured Steel Rebars, Patrick W. Waruhiu, Simon I. Marandu, Mussa I. Mgwatu

Tanzania Journal of Science

Steel rebars experience deformation when subjected to bending and re-bending operations. Subsequently, their microstructures are impaired thus affecting the mechanical properties and leading to failure. This study establishes the effects of bending and re-bending the steel rebars on the mechanical properties. Experiments were conducted to determine the effects of bending and re-bending of the steel rebars. Testing was conducted on Ten virgin and Thirty specimens which were bent and re-bent at 45º, 90º, and 180º, and followed by tensile tests. Yield strength, ultimate tensile strength, elongation, and ultimate tensile strength to yield strength ratio (Rm/Re), were recorded. Results showed the …

Modelling The Combined Use Of Long-Lasting Insecticidal Nets And Insecticides Zooprophylaxis Against The Resilience Of Anopheles Arabiensis For Effective Malaria Control, Watson Levens

Tanzania Journal of Science

Malaria is a significant public health concern, especially in tropical regions. It remains endemic in many areas where malaria mosquitoes are prevalent. This study investigates the viability of insecticide zooprophylaxis (IZ) in conjunction with Long Lasting Insecticidal Nets (LLINs) as a strategic approach to combat malaria transmission, particularly in regions dominated by zoophagic vectors. Through the presentation and analysis of a mathematical model that integrates IZ and LLINs for the control of Anopheles arabiensis (An. arabiensis), the research underscores IZ's role in reducing zoophagic vector populations and enhancing malaria control efforts. Notably, the study reveals that achieving comprehensive coverage of …

Green And Blue Water Footprints Of Major Crops In The Wami/Ruvu Basin, Tanzania: Implications For Water Scarcity And Sustainability, Benson Hm Lazaro, Martine M. Hagai, Rubhera Ram Mato

Tanzania Journal of Science

Accurate estimation of the blue and green water requirements of the various crops cultivated in a water basin is essential for planning specific plant/crop irrigation schedules. In this study, the crop water requirements of the major crops grown in the Wami/Ruvu basin were determined using the FAO-CROPWAT model based on meteorological parameters: monthly maximum and minimum temperature, wind speed, mean relative humidity, sunshine hours, rainfall data, and effective rainfall for 23 hydro-meteorological stations distributed in the study area. The studied crops are rice, maize, beans, tomatoes, and sugarcane. The crop reference evapotranspiration (ETo) and actual evapotranspiration (ETc) for each crop …

Modelling And Mapping Of Forest Biodiversity Indicators Using Sentinel-2 And Planetscope Remotely Sensed Data, Diana L. Tesha, Ernest W. Mauya, Sami D. Madundo

Tanzania Journal of Science

Tropical montane forests harbour exceptionally high biodiversity yet face severe threats from human activities. Assessing forest biodiversity over large areas is crucial yet extremely challenging. Remote sensing provides an efficient monitoring solution, but few studies have focused on Tanzania's diverse, montane forests. We collected field data on tree species composition within 159 plots across montane forests in Tanzania's West Usambara region. We calculated species richness, evenness, and Shannon diversity index as indicators of tree diversity. Using Sentinel-2 and PlanetScope satellite imagery, we derived spectral, textural, and vegetation index predictors to model these indices via generalized additive models and extreme gradient …

Dispelling The Malaria-Typhoid Co-Infection Myth In Nigeria. A Literature Review, Olawale Akinola

Dartmouth Library Staff Publications

Malaria and typhoid fever are public health concerns in Nigeria, with high prevalence rates. The perception of a widespread co-infection between these diseases may be misleading, due to limitations in diagnostic methods, particularly the Widal test for typhoid fever. This literature review examines the prevalence of malaria-typhoid co-infection in Nigeria and identifies factors contributing to misdiagnosis, including non-specific symptoms, limited diagnostic resources, and the diagnostic accuracy of tests employed. Additionally, the review discusses the implications of misdiagnosis, such as the overuse of broad-spectrum antibiotics leading to a rising incidence of antimicrobial resistance. Strategies to address this issue are explored, emphasizing …

An Assessment On The Influence Of Aridity And Vegetation Cover On Land Surface Temperatures: Case Of Dodoma Urban District, Tanzania, Carolyne Vincent Mbirika

Research, Papers & Creative Work

This study examines the influence of aridity and vegetation cover on land surface temperature (LST) in Dodoma Urban District, Tanzania, a semi-arid environment experiencing rapid urban growth. Using Landsat 9 satellite imagery (30 m resolution) for October 2023, key environmental variables including the Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), and LST were derived and analyzed using ArcGIS Pro. The study applies remote sensing techniques and spatial analysis to examine the relationships between vegetation, moisture availability, and surface temperature patterns. The results reveal substantial spatial variation across the study area, with NDVI values ranging from -0.17 to …

From The Outside, Looking In: Reflections On The Complex Infrastructures Of African Art History, Joanna Gardner-Huggett

Artl@s Bulletin

This essay engages with the five articles featured in this issue from the perspective of a non-specialist. Each contribution considers challenges facing scholars of African arts when confronted with incomplete and not always reliable historical evidence. The author contends that given the escalating demands for the repatriation of African objects, all art historians— not only art historians focused on African arts—should better understand the important strategies proposed by contributors to this issue. These interventions encourage the development of a more critical audience for African arts and also model ethical research, a slow critical archival practice, and sustainable provenance and digital …

Autumn 2023 Full Issue, The U.S. Naval War College

Naval War College Review

No abstract provided.

Combating Terrorism To Promote National Security In Nigeria: Libraries And Information Centres To The Rescue, Udemezue Joseph Ogugua, Jovita Amarachi Ikeagwuani Mrs

Library Philosophy and Practice (e-journal)

Terrorism is a hydra-headed monster and should be stamped out for the benefit of humanity. Fighting terrorism to enthrone national security should be at the front burner of government stakeholders especially this time that non-state actors operate with impunity. The paper discusses the role of libraries and information centres in combating terrorism and promoting national security in Nigeria. Specifically, the paper examines terrorism and national security, terrorism in Nigeria, the role of libraries and information centres in the fight against terrorism to promote national security. It also looks at the challenges encountered by libraries and information centres in the fight …

Socioecological Assessment Of Birds In Ngezi-Vumawimbi Nature Forest Reserve, Eli Taub

Independent Study Project (ISP) Collection

Effective management of natural resources requires consideration of the environment through both a physical and a sociological lens. In this study, the birds in Ngezi-Vumawimbi Nature Forest Reserve were examined through both a biological mist-net survey and a socioecological series of interviews with people living in the surrounding villages. The mist-net survey compared the understory species in undisturbed and disturbed area of the forest, as well as analyzing birds caught for biologically meaningful information on subspecies and sexual dimorphism. While the mist-net survey was largely unsuccessful, highlighting the need for alternative bird capture methods in Ngezi, it found a decrease …

2024 Otterbein University Commencement Program, Otterbein University

Commencement Programs

Program for the 2024 Otterbein University Commencement Ceremony.

Joint Environmental And Social Benefits From Diversified Agriculture, Laura Vang Rasmussen, Ingo Grass

Earth and Environmental Sciences Faculty Publications

Agricultural simplification continues to expand at the expense of more diverse forms of agriculture. This simplification, for example, in the form of intensively managed monocultures, poses a risk to keeping the world within safe and just Earth system boundaries. Here, we estimated how agricultural diversification simultaneously affects social and environmental outcomes. Drawing from 24 studies in 11 countries across 2655 farms, we show how five diversification strategies focusing on livestock, crops, soils, noncrop plantings, and water conservation benefit social (e.g., human well-being, yields, and food security) and environmental (e.g., biodiversity, ecosystem services, and reduced environmental externalities) outcomes. We found that …

Incidental Actinomycosis In A 44-Year-Old Female During Total Abdominal Hysterectomy For Abnormal Uterine Bleeding: A Case Report, Willbroad Kyejo, Ally Zain Ismail, Abduel Kitua, Gregory Ntiyakunze, Munawar Kaguta, Ally Mwawnga

Family Medicine, East Africa

Actinomycosis, a rare chronic bacterial infection caused by Actinomyces species, presents diagnostic challenges due to diverse clinical presentations. This report presents a case of peritoneal actinomycosis incidentally discovered during a total abdominal hysterectomy in a 44-year-old female with refractory abnormal uterine bleeding and a history of long-term intrauterine contraceptive device use. The patient presented with persistent abnormal uterine bleeding despite conservative management. Intraoperative findings during total abdominal hysterectomy revealed peritoneal involvement, prompting histopathological evaluation confirming actinomycosis. This case highlights diagnostic complexities associated with actinomycosis, emphasizing the significance of histopathological confirmation. Postoperative management with antibiotics demonstrated favorable outcomes, supporting their efficacy …

Incidental Actinomycosis In A 44-Year-Old Female During Total Abdominal Hysterectomy For Abnormal Uterine Bleeding: A Case Report, Willbroad Kyejo, Allyzain Ismail, Abduel Kitua, Brenda Moshi, Gregory Ntiyakunze, Munawar Kaguta, Ally Mwanga

Internal Medicine, East Africa

Actinomycosis, a rare chronic bacterial infection caused by Actinomyces species, presents diagnostic challenges due to diverse clinical presentations. This report presents a case of peritoneal actinomycosis incidentally discovered during a total abdominal hysterectomy in a 44-year-old female with refractory abnormal uterine bleeding and a history of long-term intrauterine contraceptive device use. The patient presented with persistent abnormal uterine bleeding despite conservative management. Intraoperative findings during total abdominal hysterectomy revealed peritoneal involvement, prompting histopathological evaluation confirming actinomycosis. This case highlights diagnostic complexities associated with actinomycosis, emphasizing the significance of histopathological confirmation. Postoperative management with antibiotics demonstrated favorable outcomes, supporting their efficacy …

Leveraging Ai And Machine Learning To Develop And Evaluate A Contextualized User-Friendly Cough Audio Classifier For Detecting Respiratory Diseases: Protocol For A Diagnostic Study In Rural Tanzania, Kahabi Isangula, Rogers John Haule

School of Nursing & Midwifery, East Africa

Background:

Respiratory diseases, including active tuberculosis (TB), asthma, and chronic obstructive pulmonary disease (COPD), constitute substantial global health challenges, necessitating timely and accurate diagnosis for effective treatment and management.

Objective:

This research seeks to develop and evaluate a noninvasive user-friendly artificial intelligence (AI)–powered cough audio classifier for detecting these respiratory conditions in rural Tanzania.

Methods:

This is a nonexperimental cross-sectional research with the primary objective of collection and analysis of cough sounds from patients with active TB, asthma, and COPD in outpatient clinics to generate and evaluate a noninvasive cough audio classifier. Specialized cough sound recording devices, designed to be …

Mushroom Composition Across An Elevational Gradient During The 2024 Wet Season In Mazumbai Forest Reserve, Tanzania, Christopher Brady

Independent Study Project (ISP) Collection

Mushrooms are key bioindicators that contribute greatly to ecological health, and their diversity is indicative of a healthy ecosystem. However, even with the vital role they play in ecological health, there are few studies which measure the diversity of mushrooms in Mazumbai Forest Reserve (MFR), Tanzania, Africa, and none which focus on diversity along the elevational gradient within the reserve (1300-1900m). This study measures the diversity and equitability of mushrooms growing in six elevational zones within MFR during the rainy season of 2024. A species checklist of mushrooms growing in MFR during the 2024 rainy season was created, tracking the …

Early Report Of A Microcosm Of The Fourth Major Global Bleaching Event: A Comprehensive Survey Of Coral Bleaching At Chumbe Island Coral Park, Zanzibar, Christian Boudreaux

Independent Study Project (ISP) Collection

Coral reefs harbor a wealth of the biodiversity present in the ocean. They provide an array of ecological and economic services that make them crucial to the function of a healthy ocean and prosperous coastal communities. Due to an array of anthropogenic stressors, including an increase in ocean temperatures as a result of climate change, reefs have been devastated worldwide. This is, in large part, due to the process of coral bleaching, the expelling of symbiont algae which the coral needs to produce energy, for an extended period until death. This study surveyed bleaching and death at a deeper and …

A Study Of Anthropogenic Impacts On Echinoderms In The Jambiani Intertidal Area, Zanzibar, Amaury O. Halley

Independent Study Project (ISP) Collection

The coastal region of Jambiani, Unguja, hosts a rich diversity of marine life within its extensive intertidal zones. Despite its ecological significance, this area is increasingly exposed to anthropogenic disturbances due to increased human activities. This study examines the impacts of these disturbances on the biodiversity, zonation, and species abundance of echinoderms in the intertidal habitats of Jambiani. Through a comprehensive field study involving fifteen transects and detailed substrate analysis, the project evaluated the distribution and abundance of echinoderm species and assessed the influence of human activities such as seaweed farming, anchor damage, and beach trampling on these communities. The …

How Has Us Foreign Policy Militarization Affected Political Stability In Africa?, Christopher Korkor

Graduate Program in International Studies Theses & Dissertations

US foreign policy toward Africa was minimal during the Cold War. US engagement in the continent was centered on spheres of influence politics, and compared to other regions in the global system, the continent was viewed as a backwater and neglected for several decades despite historical relations between the country and the continent. Scholars of political science, international studies, international relations, and history also relegated the study of US foreign policy toward Africa to a low-level status, instead prioritizing scholarship that focused on traditional security, particularly states in Western and Eastern Europe and the North Atlantic Treaty Organization (NATO). US …

Efficiency Analysis And Benchmarking Of Container Ports Operating In Lower-Middle-Income Countries: A Dea Approach, Caleb Danladi, Sarah Tuck, Panagiotis Tziogkidis, Lijun Tang, Chukwuneke Okorie

Plymouth Business School

Container ports play a pivotal role in international trade, facilitating the movement of goods and fostering economic development. While much attention has been given to the efficiency of ports in high-income countries, container ports in lower-middle-income (LMI) countries have received less attention. This paper addresses this research gap by assessing container ports' operational efficiency across diverse LMI countries and determining ways for their efficiency enhancement and management optimization. The cross-sectional data for the year 2012 was collected for 53 container ports in LMI countries. This research utilizes data envelopment analysis, which offers the advantage of considering multiple inputs and outputs. …