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Item Analysis of carbon dioxide reservoir performance and optimization strategies: a case study of a carbon dioxide plant(Springer, 2025-01-29) Monge, Emmanuel; Kichonge, BarakaThis study aimed at developing an empirical model for estimating and analyzing CO2 reservoir performance. This was achieved by using decline curve analysis (DCA) to determine an accurate empirical decline model for reservoir performance prediction and optimal producing, i.e., time at which the plant recovery build-up (RBU) efficiency has declined to an approximate value of 44.5%. MATLAB R2013b was used for calculating raw gas density whereas Ms Excel 2007 was used in plotting and performing all calculations. Through an examination of real production data, a harmonic decline model with an Arps’ decline constant (d) of 1.0 and a nominal decline rate of approximately 0.035572337/year was identified as the most suitable for characterizing reservoir performance. The study identifies the year 2048 as an optimal opportunity for implementing production optimization strategies to maximize returns while ensuring efficient resource recovery. Acknowledging the limitations of DCA, the study recommends exploring alternative forecasting models such as type curve analysis (TCA), material balance equation (MBE), and well simulation techniques to mitigate uncertainties in reservoir performance prediction. In addition, the study proposes a 5-year model verification and improvement program to refine reservoir descriptions and enhance data acquisition practices, aiming to optimize production efficiency and minimize uncertainties in CO2 reservoir operations.Item Performance of a Wild Sesame (Sesamum Spp) Phytochemical Extract for Water Disinfection(Springer, 2025-01-14) Adeeyo, Adeyemi; Oyetade, Joshua; Msagati, Titus; Colile, Nkosi; Makungo, RachelThe study sampled wild Sesame from open field in South Africa. The samples were pretreated while the extracts were screened for phytochemical compositions and applied for water purification using standard procedures. The physicochemical properties of sampled raw and purified water (pH, total dissolved solids, salinity turbidity and conductivity) were analyzed in situ before and after treatment in the lab, respectively. The plant’s phytochemical extract from the leaves and stem was prepared using selected solvents (methanol, cold water and warm water). The results revealed the presence of phytochemicals including tannins, phenols, flavonoids, steroids, anthraquinone, terpenoids, saponins, and phlobatannins in both the stem and leaf of the wild Sesame plant. The study shows effective percentage reduction of E. coli and total bacteria with extracts of leaf (98.5, 100.0 and 97.2%), (98.8, 100.0 and 95.0%) and stem (94.0, 95.4 and 99.0%), (99.4, 98.6 and 98.4%) using methanol, cold and warm water, respectively, at 5ml of the phytochemical extracts. This study explores the use of wild Sesame phytochemicals for disinfecting river and stream water samples, highlighting the potential for greener and sustainable water treatment. The physicochemical parameters of the treated water were within tolerable limits, especially salinity and the total dissolved solids. Thus, the extract is presented as a potential solution for water purification, aligning with SDG goals 6 (clean water), 9, and 12 (green innovations). It fills the knowledge and product gap in water treatment, causing minimal harm, consistent with the African Union's sustainable development agenda and the African Council on Water's goal for clean water. This innovation meets the criteria for technology readiness levels 2 and 3, making it ready for further development.Item Viability and desirability of financing conservation in Africa through fire management(Nature Sustainability, 2025) Knowles, Tony; Stevens, Nicola; Amoako, Esther Ekua; Mohammed, Armani; Chipilica, Barbosa; Beale, Colin; Bond, William; Chidumayo, Emmanuel; Colin Courtney-Mustaphi; Dintwe, Kebonye; Andy Dobson,; Donaldson, Jason; Dziba, Luthando; Govender, Navashni; Hempson, Gareth; Glynis, Joy Humphrey; Kimuyu, Duncan; Laris, Paul; Aya, Brigitte N’Dri; Parr, Catherine; Probert, James; Gernot,Ruecker; Izak Smit,; Strydom, Tercia; Syampungani, Stephen; Archibald, SallyAdopting early dry season fires in African conservation areas has been proposed as ecologically desired and a means of generating sufficient carbon revenues for their management. We interrogate available peer-reviewed information on the ecology and biogeochemistry of fire in Africa to offer an informed perspective on the full implications of the proposal. We conclude that there is insufficient evidence that a shift to early dry season fires will reduce greenhouse gas emissions, that resultant biodiversity and ecosystem service outcomes may not be desired, and that adopting a single burning regime limits the use of fire to achieve a diverse range of goals.Item Electro-spun transparent film from banana pseudo-stem native cellulose using N-methylmorpholine-N-oxide solvent system(Elservier, 2025-06) Livifile, Silla; Tarus, Bethwel; Kisula, Lydia; Kivevele, Thomas; Jande, YusufuThe study-utilized electrospinning to prepare a transparent film from native cellulose extracted from banana pseudo stems. The process of electrospinning was performed at room temperature conditions, after which the cellulose film was obtained through water coagulation. Dimethyl sulfoxide and dimethylformamide were added to the electrospinning solution to adjust the surface tension, viscosity, and conductivity of the prepared solutions. The formed thin film was characterized using Infrared spectroscopy (IR) and X-ray crystallography tests to confirm the elimination of non-cellulosic materials during extraction. It was revealed that the banana fibers were dominated by crystallinity and converted from cellulose-I to cellulose-II after dissolution in N-methyl morpholine N-oxide (NMMO). Scanning electron microscopy images revealed that fiber and electro-spun film morphologies could be achieved by varying sodium hydroxide solution concentration and solution parameters during fiber treatment and electrospinning. Concentration of 17.5 % (wt./v)of the alkaline solution showed to be more effective in changing the surface morphology of the fiber. The structure and mechanical characteristics of the films were influenced most by the concentration of banana native cellulose, process stability, and the solidification of the electro-spun fibers. The film exhibited an initial degradation temperature of 165°C, a light transmittance of 83.3 % in the visible UV range, and a tensile strength ranged from 5.83 MPa to 8.13 MPa. This performance highlights its potential applications in various fields, including packaging and biomedical engineering.Item Radioactivity distribution in soil, rock and tailings at the Geita Gold Mine in Tanzania(Elsevier, 2025-04-30) Mwimanzi, Jerome; Haneklaus, Nils; Bituh, Tomislav; Brink Hendrik; Katarzyna Kiegiel; Lolila, Farida; Marwa, Janeth; Rwiza, Mwemezi; Mtei, KelvinThis study evaluated the activity concentrations of natural radionuclides in soil, waste rocks and tailings from the Geita gold mining site in Tanzania using high-resolution gamma spectroscopy. A total of 41 samples: 31 soil, 5 waste rock, and 5 tailing samples were collected around the mine to assess their radiological hazards. The average activity concentrations in soil were 54, 45 and 279 Bq kg-1 for 226Ra, 232Th and 40K. In contrast, tailings exhibited higher activity concentrations of 70, 36 Bq kg-1 for 226Ra and 232Th, and significantly elevated levels of 877 Bq kg-1 for 40K, while waste rocks showed intermediate values, with 66, 73 and 660 Bq kg-1 for 226Ra, 232Th and 40K respectively. Radiological hazard indices were calculated to quantify potential risks. In soil, the radium equivalent activity (Raeq) averaged 139 Bq kg-1, the annual effective dose equivalent (AEDE) was 78 μSv y-1, the annual gonadal dose equivalent (AGDE) reached 430 μSv y-1, and the excess lifetime cancer risk (ELCR) was 0.27 × 10-1. Tailings showed a Raeq of 189 Bq kg-1, AEDE of 111 μSv y-1, AGDE of 678 μSv y-1, and ELCR of 0.39 × 10- 1, while waste rocks exhibited a Raeq of 200 Bq kg-1, AEDE of 108 μSv y-1, AGDE of 642 μSv y-1, and ELCR of 0.37 × 10-3. Notably, the ELCR values for tailings and waste rocks exceeded the global average of 0.29 × 10-3, rendering them unsuitable for use as building materials. The absorbed dose rates were 69 nGy h-1 for soil, 91 nGy h-1 for tailings, and 88 nGy h-1 for waste rocks. One-way ANOVA revealed significant differences (p < 0.05) among the matrices. These findings underscore the need for targeted waste management and remediation strategies to mitigate radiological health risks in the investigated mining area as well as other areas with similar characteristicsItem Life cycle assessment and cost analysis of locally made solar powered cooler for vaccine storage(Elsevier, 2025-04-15) Mbugano, Milton; Selemani, Juma; Kichonge, Baraka; Mwaijengo, Grite; Mwema, MwemaStoring vaccines and perishable food in regions without access to the national grid presents significant chal- lenges. Solar power generation technologies have emerged as a viable alternative solution to address these issues. This study conducted a life cycle assessment (LCA) and cost analysis (CA) of the locally developed solar-powered cooler to assess its economic viability and potential environmental impacts. The cooler was designed to preserve vaccines and perishable foods for use, especially in areas with no electricity connectivity, as a cheaper alternative to electricity-powered coolers. The results of LCA show that battery manufacturing was a slightly higher contributor to environmental impacts across various indicators, with terrestrial ecotoxicity identified as the highest impact among other environmental impacts. Cost analysis results further revealed that a solar-powered cooler project demonstrated a positive economic outlook, with the unit manufacturing cost estimated at USD 2682. This quantitative analysis of life cycle and cost will help decision-makers comprehend both the economic aspects and environmental impacts throughout the life cycle of locally manufactured solar-powered coolers. Such insights will be instrumental in enhancing the sustainability of these products.Item Modelling and optimization of different pozzolanic materials in the durability of cement composite by central composite design(Elsevier, 2025-04-19) Fode, Tsion; Jande, Yusufu; Kivevele, ThomasThe production of Ordinary Portland Cement (OPC) requires high temperatures and significant energy con- sumption, leading to environmental pollution and posing challenges to the sustainability of green cementing materials. To address this, numerous researchers have explored replacing cement with various supplementary cementitious materials, such as blast furnace slag, active limestone, and bentonite in concrete or mortar. However, optimizing the combined use of these materials to achieve maximum durability in mortar remains a novel area of study. This research models and optimizes the effects of replacing OPC with blast furnace slag, active limestone, and bentonite in mortar using the central composite design method. The findings reveal that increasing the content of bentonite along with either blast furnace slag or limestone from 0 % to 20 % signifi- cantly minimizes strength degradation due to sulfuric acid exposure, improves heat resistance, and lowers water absorption at 28 days. The optimal substitution levels were found to be 20 % for both blast furnace slag and limestone, and 18.54 % for bentonite. The optumal result reduced damage from sulfate attack by 33.4 %, strength loss under high temperatures by 69.04 %, and water absorption by 98.58 % when compared to the control sample. These outcomes were validated experimentally with a 95 % confidence level. Overall, incor- porating these SCMs not only improves the durability of mortar but also supports environmental sustainability by reducing CO₂ emissions due to OPC production.Item Selective extraction of uranium from nitric acid leachate of Minjingu rock phosphate(2025-04) Kariim, Ishaq; Bakari, Ramadhani; Syed, Muhammad; Park, Ji-Yeon; Lee, In-Gu; Thomas KiveveleA sample of beneficiated rock phosphate from Minjingu Mine and Fertilizer Plant, Tanzania was analysed by energy-dispersive X-ray fluorescence (ED-XRF) spectroscopy and found to contain 15.8 % and 5.30 × 10−2 % w/w P2O5 and U, respectively. The U content of the same sample was estimated to be 3.70 × 10−2 % w/w when the digested mass was analysed by inductively coupled plasma mass spectrometry (ICP-MS). The rock was leached with three different mineral acids at 65–70 °C. The outlet liquid and solid streams were analysed by ICP-MS and ED-XRF, respectively. Maximum leaching of P2O5 and U occurred with 8.9 M HNO3. Their respective concentrations in the leachate were 6.69 % w/w (99.0 g L−1) and 1.80 × 10−2 % w/w (0.27 g L−1). The leachate also contained 1.90 × 10−2 % w/w (0.28 g L−1) rare earth elements (REEs). Selective extraction of U was attempted employing Di-2-ethyl hexyl phosphoric acid (D2EHPA) and Tri-butyl phosphate (TBP) as co-extractants. A 2-stage cross-current solvent extraction (10 g scale; 30 °C) with 1:6 mol ratio of D2EHPA:TBP (0.14 M total extractant concentration; 1:1 w/w organic/aqueous ratio) gave 81–89 % U extraction without co-extraction of REEs. The extraction of U increased to 95.6 % after four stages of solvent extraction but there was a noticeable co-extraction of Y beyond the first two stages. Production of fertilizers from U-free leachate is environmentally safer and the recovered U, in pure form, can be used for fuel production.Item Performance Assessment of Novel Soda Ash Adsorbent Biogas Sweetening: Fixed Bed Studies, Adsorption Kinetics, and Adsorption Isotherms(MDPI, 2025-03-17) Mrosso, Register; Mecha, CleophasThe reliance on greenhouse gas-emitting unrenewable energy sources such as coal, natural gas, and oil, increases climate change. Transitioning to renewable energy, such as biogas, is crucial to reducing environmental degradation and global warming. The existence of impurities such as hydrogen sulfide hampers the application of biogas. Utilizing natural resources for biogas purification is essential to improve access to clean energy for low-income communities. This study used soda ash derived from Lake Natron in Tanzania as a sorbent for H2S removal. Effects of sorbent mass, flow rate, and particle size were investigated. Experimental data were analyzed using kinetic models, adsorption isotherms, and breakthrough curves. Soda ash of 280 μm particle size, a flow rate of 0.03 m3/h, and a mass of 75 g demonstrated the best performance, achieving an efficiency of 94% in removal and a sorption capacity of 0.02 g per 100 g in five repeated cycles. Freundlich and Jovanovich’s isotherms match the data with n = 0.4 and Kj = 0.003, respectively. Adsorption kinetics were best described by the intra-particle model (kid = 0.14, c = 0.59 mg/g, and R2 = 0.972). A breakthrough analysis indicated that the Yoon–Nelson model provided the best fit with an R2 of 0.95. Soda ash from Lake Natron demonstrated great potential in biogas desulphurization, thus contributing to the production and access to clean energy.Item Groundwater recharge assessment under climate change scenarios: a case study of Kiryandongo, Uganda(IWA Publishing, 2025-03-27) Ochwo, Owino; Okwirb, Gustavio; Selemania, Juma; Matabaa, GordianGroundwater recharge is an important element in ensuring the sustainability of groundwater reservoirs. Unfortunately, its spatial distribution patterns and volume are influenced by climate and land use/land cover changes. This article uses the WetSpass-M model to assess the impacts of climate and land use/land cover changes on groundwater recharge in the Kiryandongo area. Long Ashton Research Station Weather Generator-8 (LARS-WG8) model was calibrated and used to downscale the future climatic variables from the Coupled Model Inter comparison Project Phase-6. The downscaled temperature shows an increase in the annual mean temperature of 1.05 and 1.23 °C under the shared socioeconomic pathways (SSPs), SSP126 and SSP245, respectively. However, annual precipitation is projected to increase by 6.7% under SSP126 and 9.3% under SSP245. The WetSpass-M model was calibrated, and coefficients of determination (R2) of 0.83 and Nash Sut cliffe efficiency of 0.82 were obtained. It was then used to simulate groundwater recharge. The simulated groundwater recharge, considering the combined effects of climate and land use/land cover changes, shows an increase of 14.79% under the SSP126 and 13.31% under the SSP245 scenarios. However, if land use/land cover changes are kept constant, recharge would increase by 21.9% under SSP126 and 19.8% under SSP245 compared to the baseline.Item Assessment of rectal dose with thermoluminescent in vivo dosimetry in high-dose-rate cobalt-60 intracavitary brachytherapy for cervical cancer: A two-arm cohort study using orthogonal images planning(Journal of Contemporary Brachytherapy, 2025-05-07) Mlawa, Omega; Ngaile, Justin; Chaurasia, Pradumna; Amasi, AloycePurpose: High-dose-rate intracavitary brachytherapy delivers high radiation doses to tumors while minimizing exposure to surrounding normal cells. However, inappropriate administration can lead to radiation-induced toxicity by overdosing organs at risk. This study evaluated and compared the rectum doses planned by treatment planning system and measured using a thermoluminescent dosimeter. Material and methods: Thermoluminescent dosimeters (TLD) were employed to measure radiation dose to the rectum across two patient groups: one treated using first fraction-based planning (FFP), and the other with each fraction planned individually (EFP). Results: The mean dose measured by TLD (3.99 ±1.63 Gy) was higher than the mean dose planned by TPS (3.23 ±1.16 Gy, p < 0.001). The mean dose difference was higher in second fraction (0.87 ±1.89 Gy) for first fraction-based planning group; however, the differences between first and second fractions were not statistically significant in either group. Conclusions: For patients transferred from a brachytherapy couch to a hospital stretcher during applicator insertion and dose delivery, first fraction-based planning is feasible. However, caution is needed to minimize applicator shifts, as these changes can alter the geometric position between fractions.Item Compressive strength optimization of the ambient-cured metakaolin-based geopolymer mortar using the Taguchi design approach(Elsevier, 2025-05-16) Hashimu Hamisi; Chambua, Safiel; Mansouri, Said; Hicham, Majdoubi; Yusufu Abeid; Chande, Jande,; Youssef, Tamraoui; Askwar, HilongaThis study utilized raw natural kaolinite sourced along Pugu hills, Tanzania, as the aluminosilicate source. To optimize the compressive strength, nine (9) metakaolin geopolymer formulations were activated using the Taguchi technique at various Na2SiO3/NaOH mass ratios, NaOH concentrations, and alkaline/binder ratios. The ideal parameters were 12 M, 2.5, and 0.8 Na2SiO3/NaOH mass ratios, NaOH concentration, and alkaline/binder ratios, respectively, resulting in a compressive strength of 70.38 MPa. When the optimized geopolymer was exposed to a higher temperature, its compressive strength increased by 15.57 % at 200°C compared to room temperature. Compressive strength decreased with exposure over 200°C, and weight loss and water absorption were directly correlated with this. The SEM results show that the former lacks a well-linked geopolymer network when comparing weak and superior formulations. High-strength formulations are verified to include higher levels of orthoclase and albite, according to Rietveld refinement and XRD research. The XRD patterns showed the development of sanidine, chrysotile, and nepheline crystalline phases at temperatures higher than 200°C, which may have contributed to the decrease in strength of the geopolymer specimens.Item Optimized Demand Side Management for Refrigeration: Modeling and Case Study Insights from Kenya(MDP, 2025-06-21) Kakande, Josephine; Philipo, Godiana; Krauter , StefanAccording to the International Institute of Refrigeration (IIR), 20% of worldwide electricity consumption is for refrigeration, with domestic refrigeration appliances comprising a fifth of this demand. As the uptake of renewable energy sources for on-grid and isolated electricity supply increases, the need for mechanisms to match demand and supply better and increase power system flexibility has led to enhanced attention on demand-side management (DSM) practices to boost technology, infrastructure, and market efficiencies. Refrigeration requirements will continue to rise with development and climate change. In this work, particle swarm optimization (PSO) is used to evaluate energy saving and load factor improvement possibilities for refrigeration devices at a site in Kenya, using a combination of DSM load shifting and strategic conservation, and based on appliance temperature evolution measurements. Refrigeration energy savings of up to 18% are obtained, and the load factor is reduced. Modeling is done for a hybrid system with grid, solar PV, and battery, showing a marginal increase in solar energy supply to the load relative to the no DSM case, while the grid portion of the load supply reduces by almost 25% for DSM relative to No DSM.Item Experimental Study on Physio-Chemical Characteristics of Stinging Nettle Fiber Toward Compatibility for Polymer Composites Used in Wind Turbine Blade Application(Taylor & Francis Group, 2025-06-25) Nsanzumuhire, C.; Daramola, O.; Oladele, I.; Akinwekomi, A.; Aramide, F.; Igadwa, Mwasiagi; Dulo, Ben; Habanabakiz, T.This study investigated the compatibility of stinging nettle (urticadioica) fiber to improve the performance characteristics of wind turbine blade applica tions. The fiber was extracted using the water retting method, and the alkali treatment was performed using 6% NaOH. This concentration was reported to be optimal for the alkaline treatment of many natural fibers. The fiber maximum normal density achieved was 1.213 g/cm3 and 1.229 g/cm3 for raw and alkali-treated samples. Through alkali treatment, the linear density reduced from 12.64 taxes to 11.98 taxes with a decrease of 5.509%, whereas the maximum breaking force increased from 5.51 to 5.82 N, and the breaking elongation increased from 0.63% to 0.71%. It was further observed that the tenacity of the untreated and treated samples was, respectively, 43.67 and 46.12 cN/tex. The maximum cellulose content of 78.736% was achieved with alkali treatment, whereas hemicellulose, lignin, moisture content, extractives, and volatile matter decreased. On the other hand, the ash content, alpha- cellulose, and holocellulose contents increased with alkali treatment. Owing to its properties compared to other natural fibres used for wind turbine blades, the achieved alkali-treated fibre can also be considered a better reinforcement to improve the mechanical characteristics of polymer compo sites for this area. The novelty of this work is to evaluate the compatibility of stinging nettle fibre as a reinforcement material in polymer composites for wind turbine blade applications, given the global push towards more sus tainable and biodegradable alternatives to synthetic fibre-reinforced com posites.Keywords: Chemical characterization, natural fibre-reinforced polymer composites, single fibre tensile strength, stinging nettle fibre, wind turbine blade application, wind energy.Item Green adsorbent from maize biomass for mercury capture: insights from sorption modeling and thermodynamic analysis(Applied Water Science, 2025-07-05) Bayuo, Jonas; Mwemezi, Rwiza; Oyelude, Emmanuel; Mtei, Kelvin; Joon Weon ChoiAdsorption isotherms and kinetics modeling, as well as thermodynamic analysis, are useful in providing insight into the nature and mechanisms of the adsorption process. The present study investigated the interactive behavior and mechanisms of mercury ions removal using activated carbon produced from maize biomass (bio-adsorbent). To determine the mechanism of mercury removal from the aqueous system using the activated carbon, the equilibrium adsorption isotherm, kinetics, and thermodynamic studies were performed using the batch technique. Among all the isotherm models analyzed, the Langmuir isotherm model best correlated with the equilibrium sorption data of Hg(II) attained by the bio-adsorbent with a high correlation coefficient of 0.9998. The Langmuir maximum monolayer sorption capacity attained by the bio-adsorbent was 112.46 mg/g, and the dimensionless separation factor ( RL) was in the range of 0.00 < RL > 1.00 indicating favorable biosorption. The pseudo-second-order model well fitted the experimental data of Hg(II) better than the other kinetic models with a high correlation coefficient of 0.9712, which is close to unity with an uptake capacity of 82.10 mg/g. The negative values of ΔG0 obtained from all the temperature ranges of 283–358 K indicate the spontaneous nature of Hg(II) ions removal from the adsorption system by the bio-adsorbent. The positive value of + 24.86 kJ/mol and + 8.13 kJ/mol attained for ΔH0 and ΔS0 , respectively, indicates endothermic adsorption and an upsurge in disorder during the adsorptive removal of Hg(II) ions. Therefore, the study found that the activated carbon not only interacted well with the Hg(II) species in the aqueous solutions but also had a high uptake capacity. Hence, the bio-adsorbent is promising and could efficiently be applied for heavy metal remediation in aquatic environments.Item Unraveling the potential of sisal fiber in sustainable innovation: A bibliometric perspective(Taylor and Fransis, 2025) Kahigi, Nickson; Mkunda, Josephine; Mwema, Mwema; Machunda, RevocatusSisal fiber has increasingly attracted attention as a sustainable bio-based material due to its biodegradability, availability, and relevance to circular economy initiatives. Given its underutilization in high-impact applications and the limited integration of East African contributions, there is a growing need to assess the global research dynamics surrounding sisal fiber. This study hypothesizes that a bibliometric approach can reveal critical patterns, emerging themes, and collaboration gaps in sisal fiber research over the past decade. Using 59 curated articles from the Dimensions database (2012–2024), the study employed VOSviewer and Excel to analyze thematic evolution, citation patterns, and co-authorship networks. Findings show a rapid growth in publications from 2021 to 2024 (67.8%), led by Brazil and India, with emerging focus areas including waste valorization, biocomposites, and LCA-based sustainability assessments. The study concludes that targeted research investment, policy support, and international collaboration are essen-tial to enhancing sisal fiber’s role in global sustainability transitions.Item Synthesis, characterization, and photocatalytic degradation of Reactive Blue dye 171 using copper-based metal organic framework(Sage Journals, 2025-06) Kiteto, Moses; Vidija, Beryl; Achisa, Cleophas; Mrosso, Register; Chollom, MarthaThe presence of organic dyes in wastewater, particularly the azo chromophore based reactive dyes, is a formidable challenge to existing water treatment technologies. Advanced methods such as the use of metal-organic frameworks (MOFs) are a promising solution. The MOFs are versatile and encompass applications in adsorption, photocatalysis, and membrane separation processes. The present study investigated photocatalytic degradation of Reactive Blue dye 171 using copper (II) dipyridyl chloride MOF under visible light (sunlight). The MOF was synthesized via the hydrothermal method and characterized by Light microscopy, UV–vis diffuse reflectance spectroscopy, and Fourier Transform Infrared spectroscopy (FTIR). The effect of photocatalyst mass (0.1 to 0.3 g) and use of hydrogen peroxide as an electron acceptor was evaluated. The MOF had uniform well defined hexagonal crystals, and a 3.30 eV band gap energy indicating visible light absorption. The photocatalytic degradation efficiency of reactive blue dye increased as the photocatalyst mass increased, reaching 76%, 83%, and 93% for 0.1 g, 0.2 g and 0.3 g, respectively. The addition of hydrogen peroxide as an electron acceptor accelerated the process resulting in a 99% degradation efficiency and a fourfold increase in the first order reaction rate constants from 0.0231 min−1 (MOF) to 0.094 min−1 (MOF + H2O2). The study demonstrated that solar photocatalytic MOFs are a promising material for the degradation of organic pollutants such as dyes from water.Item Valorization of invasive sickle bush plant (Dichrostachys cinerea L.) and evaluation of its water treatment potentials(Elsevier Inc., 2025-08-16) Adeeyo, Adeyemi; Makungo, Rachel; Mothapo, Eva; Oyetade, Joshua; Msagati, TitusThe study investigates the valorization of invasive plant (Dichrostachys cinerea L.), using its calcinated product (550 oC for 5 h) as a treatment and disinfection agent, especially for E. coli and total coliform count in water samples. The methods compare the use of the derived ash and potash alum in their pristine form and when combined using a dosage range of 0.01g-0.05 g at 0, 6 hrs and 24 hrs treatment time for 100 mL of respective water samples. The treatment with the volarized product resulted in a pH range of 8.03–9.07, which is in tandem with the limits set by the regulatory bodies for drinking water. The conductivity of the treated water increased with increased dosage and treatment time. The highest reported values were 564.00, 567.00, 569.00 µS/cm for the upper stream of Pond and 577.00, 585.00, 592.00 µS/cm for the lower stream of the Pond, although within the set limit for drinking water (1700 mS/cm). Salinity and Total dissolved solids (TDS) were in a similar manner at the respective sampling points. The blended product presents a greener alternative to synthetic alum and showed excellent antimicrobial potential, with a 100 % reduction efficiency, especially using a 0.03 and 0.05 g dosage for 24 hrs.Item Late Quaternary Montane Forest Dynamics From Equatorial East Africa: A Biome Perspective(Wiley Online Library, 2025-06-09) Githumb, Esther; Finch, Jemma; Finch, Jemma; Courtney-Mustaphi , Colin; Musili, Paul; Rucina, Stephen; Lejju, Julius; Liljenberg, Peter; Marchant, RobAim: Understanding environmental change over large spatial and temporal scales requires working at a broad ecological scale to enable cross-site comparisons. This allows data-based comparisons to dynamic vegetation model outputs, with utility for cli- mate and land cover modelling. We synthesise multisite pollen data at the biome level to understand Equatorial Afromontane ecosystem response to climate change over the last 50,000 years and quantitatively document the timing, character and spatial patterns of ecosystem transitions. Location: Mountains of Equatorial East Africa.Time Period: Late Quaternary (50,000 cal year BP–present). Taxon: Angiosperms (trees, shrubs and grasses), gymnosperms (conifers), pteridophytes (ferns) and bryophytes (clubmosses). Methods: A literature review revealed 58 available published pollen sites from Equatorial East African Mountains. Original ge- ochronological and palynological data were collated from 34 sites from the African Pollen Database (APD) and directly from au- thors. Pollen taxonomies were updated and harmonised using the African Plant Database. The geochronologies were reanalysed and radiocarbon data (n = 219) were IntCal20 calibrated to develop linearly interpolated age-depth models. The 636 pollen taxa were grouped into 21 plant functional types and combined into seven biomes that represent the range of montane ecosystems. A rate of change analysis at each site provided a scale of the change through time at each site. Results: Mesic montane forest biomes were present throughout the 50,000 cal year BP. Cold and dry montane biomes expanded during and after the Last Glacial Maximum (LGM). Warm and wet forest biomes expanded from the early Holocene and more open biomes expanded in the Late Holocene. Regional differences were observed, such as the Eastern Arc Mountain sitesItem Techno-economic analysis and life cycle assessment of locally made solar-powered cooler for storage of vaccine and perishable food stuff(NM-AIST, 2025-06) Mbugano,MiltonStorage of vaccines and perishable food in regions without access to the national grid electricity presents ongoing challenges, especially in remote regions. Solar-powered system offers a reliable and sustainable alternative. This study presents a techno-economic analysis (TEA) and life cycle assessment (LCA) of a locally developed solar-powered cooler designed for such conditions. The cooler serves as a lower-cost alternative to conventional electric-powered refrigeration units, especially where grid access is unreliable or unavailable. The analysis was performed using ReCiPe2016 midpoint indicators with SimaPro software and Microsoft Excel 2019 to assess both environmental and economic factors. Results from the LCA show that battery production contributes the most to environmental impacts, followed by solar panel. Terrestrial ecotoxicity was the highest environmental concern, with human non-carcinogenic toxicity also notable. The TEA indicates strong economic performance, with an initial investment of USD 2682, a payback period of one year, and a return on investment of 98.8%. These results support the cooler’s potential for use in off-grid health and food supply chains. These quantitative analyses provide valuable insights for decision-makers, aiding in understanding both economic aspects and environmental impacts throughout the life cycle of locally manufactured solar-powered coolers, thereby enhancing their sustainability.