Tanzania Journal of Science最新文献_第3页

Wind Speed Forecasting Using Wavelet Analysis and Recurrent Artificial Neural Networks Based on Local Measurements in Singida Region, Tanzania 基于小波分析和递归神经网络的坦桑尼亚辛吉达地区风速预报

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.17

Rajabu J. Mangara, Mwingereza J. Kumwenda

引用次数: 0

Evaluation of the Inhibitive Properties of Silver Nanoparticles in Senna occidentalis Root Extract as Corrosion Inhibitor of Mild Steel 西泻根提取物中纳米银对低碳钢缓蚀性能的评价

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.9

Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo

{"title":"Evaluation of the Inhibitive Properties of Silver Nanoparticles in Senna occidentalis Root Extract as Corrosion Inhibitor of Mild Steel","authors":"Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo","doi":"10.4314/tjs.v49i3.9","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.9","url":null,"abstract":"The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased corrosion efficiency due to increase surface to volume ratio. Nanoparticles which undergo physisorption/chemisorption to the corrosion metal surface and inhibit the corrosion efficiently also have low toxicity, low cost and easy production. In this research work, weight lost method was applied to study the inhibitive properties of silver nanoparticles (AgNPs) synthesized using Senna occidentalis root extract as environmentally benign corrosion inhibitor of mild steel in 0.5 M H2SO4 medium at 298 K and 308 K. It was observed that the corrosion rate of the steel sample decreases with increase in concentration of the silver nanoparticles but increased with rise in temperature. The highest inhibition efficiency of 65.59% was obtained at 308 K at the concentration of 5 gdm-3 and the least of 10.58% at the concentration of 1 gdm-3 at 308 K. The decrease in inhibition efficiency with rise in temperature is suggestive of physical adsorption mechanism. The surface coverage was observed to increase with increasing concentration of the nanoparticles and decreased with increase in temperature. This could be as a result of physical adsorption mechanism. The evaluated activation energy was found to be higher for the inhibited process than for the uninhibited process. The increase in apparent activation energy in the presence of the nanoparticles denotes physical adsorption mechanism, while the reverse is usually attributed to chemical adsorption. The negative values of heat of adsorption Qads suggest that the adsorption phenomenon is exothermic.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mineralogy and Geochemical Characteristics of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications for Industrial Applications 坦桑尼亚西南部njombe地区Matamba高岭土矿床的矿物学和地球化学特征:对工业应用的影响

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.12

Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi

{"title":"Mineralogy and Geochemical Characteristics of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications for Industrial Applications","authors":"Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi","doi":"10.4314/tjs.v49i3.12","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.12","url":null,"abstract":"Kaolin is a commercial clay material composed of hydrated aluminosilicate mineral kaolinite and used in various industrial applications such as ceramics, paper, paints, refractories, fiberglass, plastics, cosmetics and pharmaceuticals. It is formed as a result of strong chemical weathering of crystalline and feldspar-rich rocks or hydrothermal alteration of granitic rocks at relatively low temperature and pressure conditions. The kaolin deposit of Matamba originated from the weathering of leucogabbro rock during the development of the African land surface. In view of highlighted properties, the mineralogy and chemical characteristics of the Matamba kaolin deposit were investigated to determine its industrial applications. As part of the study approach, forty-six (46) samples were collected and analyzed for major oxides using X-ray fluorescence (XRF) and mineralogical composition using X-ray diffraction (XRD). The XRD results indicated that the Matamba kaolin is dominantly composed of kaolinite (10.1–100%) with other phases such as albite (1.2–56.8%), oligoclase (10.1–54.3%), quartz (1.2–33.9%), goethite (1.0–9.4%) and muscovite (1.1–29.5%). The dominant major oxides are SiO2 (39.78–67.96 wt.%), Al2O3 (14.60–38.07 wt.%) and subordinate amounts of Fe2O3 (0.93–6.37 wt.%), MgO (1.42–4.74 wt.%), Na2O (0.10–1.09 wt.%), K2O (0.14–2.01 wt.%), CaO (0.08–0.99 wt.%), TiO2 (0.07–1.66 wt.%), P2O5 (0.36–1.77 wt.%) and LOI (1.91–13.97 wt.%). These major oxides correlate with the mineralogical composition supporting kaolinite dominance. Consequently, compared with some industrial specifications, these results indicate that Matamba kaolin deposit may be useful for ceramic products, refractories such as fireclay crucibles and electrolytic production of aluminium and its alloys. However, it should be beneficiated and upgraded to improve some technical properties to qualify for other industrial applications.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ethnobotanical Survey on the Knowledge and Use of Medicinal Plants for Malaria Management among University Students 大学生疟疾防治中药用植物知识与利用的民族植物学调查

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.2

Felista W. Mwingira, Deokary J. Matiya, Neema G. Mogha

引用次数: 0

Design of a Cooling System Integrated with Ultraviolet Light for Preservation of Fruits and Vegetables at Variable Tropical Weather Conditions: A Case Study of Arusha, Tanzania 在多变的热带气候条件下保存水果和蔬菜的综合紫外线冷却系统的设计:以坦桑尼亚阿鲁沙为例

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.16

John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge

{"title":"Design of a Cooling System Integrated with Ultraviolet Light for Preservation of Fruits and Vegetables at Variable Tropical Weather Conditions: A Case Study of Arusha, Tanzania","authors":"John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge","doi":"10.4314/tjs.v49i3.16","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.16","url":null,"abstract":"Post-harvest losses of fruits and vegetables pose significant challenges, especially in tropical climates. This study introduces the development and performance evaluation of a solar-powered evaporative cooling storage system integrated with ultraviolet light (UV) designed for preservation of perishable fruits and vegetables. The cooling chamber supplied with ultraviolet lamp was developed using locally available materials such as sisal, sponge, and bricks. The performance of the system was evaluated in terms of air temperature decrease, relative humidity increase, and evaporative cooling power capacity both for sunny and cloudy tropical weather conditions. The study reveals that activating the UV light considerably extends the shelf life of fruits and vegetables. The system was able to extend the shelf life of perishable products by up to 21 days when exposed to ultraviolet light and by 9 days when not exposed to ultraviolet light. On sunny days, active system operation leads to an average temperature reduction of 5.0 °C, along with a relative humidity increase of 23%. On the contrary, on cloudy days, the cooling impact diminishes slightly, resulting in temperature decrease of approximately 3.5 °C and relative humidity increase of 18%. These findings emphasize the potential of the solar-powered evaporative cooling system, combined with UV light treatment, as a viable approach to combat post-harvest losses in tropical environments.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effective Enhancement of Post-Harvest Tomato Storage through Wrapping Using Deacetylated Chitin Nanofibril-Plasticized Honey Films 脱乙酰几丁质纳米原纤维塑化蜂蜜膜有效增强番茄采后贮藏

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.14

Ngesa Ezekiel Mushi, Edina Meela, Divina Kaombe

{"title":"Effective Enhancement of Post-Harvest Tomato Storage through Wrapping Using Deacetylated Chitin Nanofibril-Plasticized Honey Films","authors":"Ngesa Ezekiel Mushi, Edina Meela, Divina Kaombe","doi":"10.4314/tjs.v49i3.14","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.14","url":null,"abstract":"As one of the most grown seasonal fruit, tomato is widely consumed for making food products, drugs and ornaments. However, poor post-harvest handling system, transport and storage facilities deteriorate the quality of tomato fruits resulting into post-harvest losses. These problems have been addressed by the use of nanotechnology in this study. The combination of a chitosan surface and the core shell chitin results into novel deacetylated chitin nanofibril (DeChNF) with good biological activity and mechanical strength. The effectiveness of the DeChNF films for food preservation as an alternative material to chitosan is investigated. The DeChNF with degree of acetylation (DA) = 60.2% and chitosan (DA = 7.1%) were obtained from crab shells. Two appraches were employed to store freshly matured tomatoes harvested at a breaker stage. The tomatoes were coated with the colloidal suspension and wrapped in the films. Flexible wrapping films were prepared from the colloidal suspension through solution casting using bees honey (35%) and compared to those with glycerol (25%) as plastisizers. The main output storage parameters analysed include colour development, surface spoilage, and weight loss over 20 days at a 73% relative humidity. Tomatoes covered with DeChNF-honey and chitosan-honey films remained in good condition after 20 days, while the coated samples lasted for up to 15 days, except those coated with DeChNF, and those covered with a polyethylene films or stored in a refrigerator at 9 °C. The samples covered with DeChNF films plasticized with honey showed the best resistance against weight loss. The tensile strength of the DeChNF-honey films (strength = 21.32 MPa) and the chitosan-honey films (strength = 21.86 MPa) were higher than the polyethylene films (10.9 MPa). The current work increases understanding on DeChNF as an alternative material, with additional of honey as a plasticizer, over the superior chitosan, or commercial films based on fossil resources.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of the Offline Setup Correction Protocol and Thermoplastic Mask Use for Head and Neck Cancer Radiotherapy: A Single Institution Experience 评估脱机设置校正方案和热塑性口罩用于头颈癌放疗:单一机构经验

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.13

Furahini Yoram, Nazima Dharsee, Khamza Maunda, Jumaa D. Kisukari, Geofrey F. Soko

{"title":"Assessment of the Offline Setup Correction Protocol and Thermoplastic Mask Use for Head and Neck Cancer Radiotherapy: A Single Institution Experience","authors":"Furahini Yoram, Nazima Dharsee, Khamza Maunda, Jumaa D. Kisukari, Geofrey F. Soko","doi":"10.4314/tjs.v49i3.13","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.13","url":null,"abstract":"This study assessed the efficiency of offline setup correction protocol and the use of a thermoplastic mask for head and neck cancer (HNC) patients treated with three-dimensional conformal radiotherapy at Ocean Road Cancer Institute. A prospective study was conducted from April to August 2021 to verify 62 patients’ treatment setup using an offline setup correction protocol while immobilized with a thermoplastic mask. Megavoltage images were matched with digitally reconstructed radiographs obtained during CT simulation to determine the gross set-up deviations. Box plots were used to show the deviations on three consecutive days of the first week and a successive weekly set-up verification in lateral, longitudinal, and vertical directions. The associations between thermoplastic mask types and weekly deviations were analyzed using repeated test ANOVA. A p-value ˂ 0.05 was considered statistically significant. The observed deviations after the use of correction protocol were lower in all three translational directions. There was no statistical significance between types of thermoplastic mask and setup deviations in lateral (p < 0.65), longitudinal (p = 0.19), and vertical (p = 0.12) directions. The offline correction protocol can be used in settings with limited resources and high workloads of patients. Both types of thermoplastic masks are effective in immobilizing HNC patients.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Overlapped Sub-array Hybrid Beamforming Architecture with Successive Interference Cancellation and Water-filling in Massive MIMO Systems 大规模MIMO系统中具有连续干扰抵消和注水的重叠子阵列混合波束形成结构

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.5

Godwin Mruma Gadiel

{"title":"An Overlapped Sub-array Hybrid Beamforming Architecture with Successive Interference Cancellation and Water-filling in Massive MIMO Systems","authors":"Godwin Mruma Gadiel","doi":"10.4314/tjs.v49i3.5","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.5","url":null,"abstract":"Over the years, wireless communication has significantly improved the data rate of mobile users. The key drive behind this success is the technological advancement in wireless communication. In the physical layer, hybrid beamforming has revolutionized the way signal reaches the user by constructively adding the signal at the destination thus improving the performance. Many researchers works have proposed different algorithms to solve for optimal hybrid beamforming. However, there is no single algorithm that can achieve both high spectral efficiency and energy efficiency at the same time. This work proposes a hybrid algorithm that combines successive interference cancellation and water filling and applies this algorithm in overlapped sub-array architecture (OSA). The former can successfully optimize for analog precoding in a subarray environment as it eliminates the interference between the successive sub-arrays. While the latter can allocate the power in each data stream proportionally, thus improving the spectral efficiency. The simulation results show that the proposed algorithm with OSA can achieve a near optimal performance in comparison to fully connected hybrid beamforming (FCH) and significantly larger performance in comparison to partially connected hybrid beamforming (PCH). Moreover, the proposed algorithm achieves 89.2% energy efficiency in comparison to PCH architecture. These results show that an OSA system with the proposed algorithm provides a better tradeoff between achieved spectral efficiency (SE) and energy efficiency (EE).","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135083032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Public Perceptions of Water Quality in the Lake Bunyonyi Sub-Catchment, Western Uganda 公众对乌干达西部Bunyonyi湖分集水区水质的看法

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.15

Alex Saturday, Thomas J. Lyimo, Siajali Pamba, Susan Kangume, Jeniffer Turyatemba

{"title":"Public Perceptions of Water Quality in the Lake Bunyonyi Sub-Catchment, Western Uganda","authors":"Alex Saturday, Thomas J. Lyimo, Siajali Pamba, Susan Kangume, Jeniffer Turyatemba","doi":"10.4314/tjs.v49i3.15","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.15","url":null,"abstract":"Lake Bunyonyi ecosystem plays vital roles in water resource conservancy and tourism. Nevertheless, the rapid increase in human population and the unrelenting human activities are threatening the values, functions, and ecological integrity of the lake. In this study, the public perceptions of drinking water quality and its health implications in the Lake Bunyonyi Sub-catchment, Western Uganda are presented. A closed-ended questionnaire was administered to 267 respondents living within one Kilometre away from the lake shores. Besides, observation and interview methods were used to complement data collected by the questionnaire method. Results indicate that the prominent activities around the lake are peasantry and small-scale businesses attributed to soil fertility and rural tourism. Despite the lake being a popular source of drinking water in the sub-catchment, the quality of its water suffers from diffuse pollution and little has been done to avert it. This study recommends regular surveillance and water quality testing to increase people’s awareness of water quality. Besides, the local authorities should train people the alternative environmentally-friendly farming practices like afforestation with correct tree species and agro-forestry practices to increase vegetation cover and reduce soil erosion debris washed into the lake system. Environmental-friendly household water treatment methods (biosand filtration and solar disinfection) should be promoted to improve the quality of drinking water.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing Service Restoration in Tanzanian Power Grid using Internet of Things Sensors and Renewable Energy Sources 利用物联网传感器和可再生能源加强坦桑尼亚电网的服务恢复

Tanzania Journal of Science Pub Date : 2023-09-30 DOI: 10.4314/tjs.v49i3.10

Rukia J. Mwifunyi, Daudi C. Mnyanghwalo, Shamte J. Kawambwa

{"title":"Enhancing Service Restoration in Tanzanian Power Grid using Internet of Things Sensors and Renewable Energy Sources","authors":"Rukia J. Mwifunyi, Daudi C. Mnyanghwalo, Shamte J. Kawambwa","doi":"10.4314/tjs.v49i3.10","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.10","url":null,"abstract":"The increased dependence on the electric power grid, coupled with the increasing number of new customers, motivates the need to improve the reliability and resilience of the electric distribution systems. Modern distribution systems are becoming more resilient against power outages due to the increasing integration of Distributed Energy Resources (DERs) and the availability of efficient mechanisms for load shedding. Several studies considered fault detection and Service Restoration (SR) as separate problems without considering the implementation feasibility of integrating both solutions. To ensure the resiliency in the power system, it is important to have proper mechanisms which integrate sensing, detection, and SR as one problem while considering the load shedding and DER for improved capacity. Hence, this study proposed an IoT-based-sensor network framework with an enhanced algorithm coupled with a Binary Bat metaheuristic algorithm for SR integrating sensing, detection, and restoration. The proposed algorithms have been tested in Tanzania's electrical distribution network, considering the inclusion of DERs and load shedding. The results showed that DERs' size and locations significantly impact restoration schemes' performance with a power loss reduction of 74%. Therefore, efficient SR schemes should consider optimal DERs placement and a combination of load shedding and DERs integration for improved performance.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0