Modeling salmonellosis transmission dynamics in humans and dairy cattle with optimal controls

This research article was published in the journal of Applied Mathematical Modelling, Volume 138, 2025In this paper, we develop a mathematical model to examine the transmission dynamics and control analysis of salmonellosis in humans and dairy cattle. The model considers three time-dependent controls (improving hygiene, vaccination, and organic acid disinfectants), human and dairy cattle populations, and Salmonella typhimurium bacteria in the environments and dairy products. The next generation matrix technique is applied to compute the effective reproduction number that gauges the persistence and extinction of salmonellosis while adopting the proposed control interventions. The stability behavior of the equilibrium states is examined using the Lypunov function method based on the effective reproduction number . The Latin hypercube sampling and the partial rank correlation coefficient methods are used to investigate the sensitivity and uncertainty of input parameters against model outputs. The results indicate that improving hygiene and vaccination can eliminate salmonellosis. Improving hygiene habits at a rate of at least 0.9 per day is recommended to eliminate salmonellosis. An efficacious vaccine that can immunize at least 85% of the vaccinated dairy cattle is also recommended to eradicate salmonellosis if it can be implemented to vaccinate susceptible dairy cattle at a rate of at least 0.45 per day for the first 30 days of the salmonellosis outbreak. The use of all three controls is recommended to eliminate salmonellosis quickly and at the lowest cost

Dynamical modeling of Salmonellosis in humans and dairy cattle with temperature and pH effects

This research article was published in the journal of Research in Veterinary Science, Volume 184, 2025Approximately 20 million cases and 0.15 million human fatalities worldwide each year are caused by Salmonellosis. A mechanistic compartmental model based on ordinary differential equations is proposed to evaluate the effects of temperature and pH on the transmission dynamics of Salmonellosis. The transmission potential of the disease in areas with temperature and pH stresses is examined. The next-generation matrix method is applied to compute the temperature-pH-dependent reproduction number . The dynamical regimes of the system are examined using Lyapunov stability theory and backward bifurcation analysis. The uncertainty and global sensitivity analysis are examined using the Latin Hypercube Sampling (LHS) and Partial Rank Correlation Coefficient (PRCC) methods. The numerical simulations of the proposed model under favorable and unfavorable temperatures are performed with a confidence interval (CI) for the reliability assessment of the model parameters. The analysis shows that the ingestion rates of Salmonella enterica subsp. enterica serovar Typhimurium bacteria in humans and dairy cattle, human-to-human transmission rate, cattle-to-cattle transmission rate, human shedding rate, dairy cattle shedding rate, and the rate of producing contaminated dairy products are directly proportional to the number of infected humans and infected dairy cattle. The temperature ranges of and and pHs greater than 3.8 have a significant effect on the dynamics of Salmonellosis. In order to eliminate Salmonellosis, the study recommends treating natural water bodies using the recommended chemical disinfectants during summer seasons and in areas with temperature ranges of , cooking food at the hottest temperatures, and storing food at the lowest temperatures for all pHs

Hermetia illucens pupae casings and biogas slurry activated carbon electrodes for Cd2 + removal from aqueous solutions using capacitive deionization

This research article was published Desalination and Water Treatment Volume 322, 2025This study examined capacitive deionisation’s effectiveness for recovering Cd2+ from water using novel carbon-based electrodes derived from Hermetia illucens pupae casings (PC) and biogas slurry (BG). Activated carbon (AC) was produced through carbonization at 500 °C and chemical activation (KOH) at 700 °C. The Brunauer-Emmett-Teller method, Scanning Electron Microscope, X-ray diffractometer, Fourier transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy, and contact angle measurement were performed on AC. Electrochemical impedance spectroscopy and cyclic voltammetry were used to test the electrochemical properties of carbons. Prepared AC possessed high specific surface areas of 549 m2/g and 927 m2/g for pupae casings and biogas slurry. Electrochemical tests revealed that PC-700 has a high specific capacitance of 271.9 Fg−1 and 105.8 Fg−1 for BG-700. Two concentrations of CdCl2 (5 mg/L and 10 mg/L) were used in a batch mode for the CDI test. Electrodes show an impressive cadmium removal efficiency of approximately 91 % and 56 % for PC and BG electrodes, respectively. Electro-sorption capacity was 10.9 mgg−1 and 2.1 mgg−1 for PC and BG electrodes, respectively. This work demonstrates the potential of PC-derived electrodes in CDI technology for recovering heavy metals from water

Field vaccination of locally-owned cattle against malignant catarrhal fever under environmentally challenging conditions in Tanzania

This research article was published by Vaccine Volume 45, 25 January 2025Malignant catarrhal fever (MCF), caused by alcelaphine herpesvirus-1 (AIHV-1) transmitted from wildebeest, is a lethal cattle disease with significant impacts on East African pastoralists. Development of a live attenuated MCF vaccine has prompted research into its use in communities at risk. This study reports results from the first utilisation of the MCF vaccine in locally-owned cattle under field conditions. The study involved a primary two-dose course vaccination of 1634 cattle, followed a year later, by boost vaccination of 385 of these cattle. It aimed to: (a) evaluate the antibody response to a two-dose AlHV-1 primary vaccination course, including initial response, antibody levels after one year, and clinical events post-vaccination; (b) assess how factors like age, reproductive status, body condition, and breed influence the initial response; and (c) compare antibody responses to single- and two-dose booster protocols one year after primary vaccination. Analyses were carried out using linear mixed-effects models and paired t-tests. Clinical incidents were reported in 11/1634 cattle vaccinated during the primary course and in 0/385 cattle during the boost regimens. The primary vaccination resulted in a 9-fold increase in comparison to pre-vaccination antibody levels and the response was consistent across animals of different ages, reproductive statuses and body conditions. While antibody levels declined 11 months after primary vaccination, they remained high, and a single-dose booster vaccination was sufficient to elicit a strong immune response, with only marginal increases after a second booster. The study provides evidence of high immunogenicity and low incidences of clinical events of the vaccine in cattle across individual host factors and immunologically vulnerable groups, under prevailing environmental conditions. It also indicates the utility of a single-dose booster regimen. These findings will support progress towards commercial production and larger-scale adoption which could generate important benefits for the livelihoods, and sustainability of pastoral livestock systems

Kinetics and energetics of biodiesel oxidation stability: The impact of Uapaca kirkiana-derived natural antioxidants

This research article was published by Biofuels, Bioproducts and Biorefining Volume19, 2025Despite considerable progress in understanding biodiesel autoxidation inhibition, the kinetics and energetics of the inhibition reactions involving natural antioxidants remain underexplored. Most existing research on natural antioxidants has focused on enhancing oxidation stability and other fuel properties. This study aimed to investigate the oxidative stability of croton biodiesel (CBD) and assess the kinetics and energetics of natural antioxidants derived from the roots, pulp, and fruit peels of the Uapaca kirkiana plant. The oxidation stability of biodiesel samples was assessed using the OXITEST method at temperatures of 90, 100, 110, and 120 °C. These tests enabled the calculation of kinetic parameters such as reaction rates and activation energies, crucial for understanding the inhibition role of antioxidants during oxidative degradation. Activation energy for antioxidant consumption, determined using the Arrhenius equation, was found to be 81.39 kJ mol−1 for fruit peel extracts, 77.73 kJ mol−1 for pulp extracts, and 63.85 kJ mol−1 for root bark extracts. The higher activation energy for fruit peel extracts suggests that they are more effective at preventing oxidation, especially under high-temperature conditions. Enthalpy, entropy, and Gibbs free energy parameters were calculated using the Eyring equation, indicating a nonspontaneous endothermic process for the antioxidant samples. The study found an inverse relationship between antioxidant concentration and rate constants, demonstrating the antioxidants' effectiveness in slowing down the oxidation process. These kinetics and energetics analyses provide detailed insights into how antioxidants function, facilitating the optimization, selection, and validation of their efficiency in stabilizing biodiesel

Effects of different lengths and doses of raw and treated sisal fibers in the cement composite material

This research article was published by Scientific Reports , volume 15, (2025)Sisal fiber moisture sensitivity and degradation are treated by alkaline and pozzolanic methods, such as silica fume and kaolin surface coating. However, it is novel that the treatment of sisal fiber by calcined bentonite slurry can coat sisal fiber from moisture and protect it from cement hydration by consuming free lime and reducing cement matrix alkalinity. Therefore, the present study treated sisal fibers with calcined bentonite slurry and investigated the effect of using different lengths and doses of treated and raw sisal fibers in a mortar. The results indicate that the treatment of sisal fiber with bentonite slurry improved the roughness of the fiber, reduced fresh bulk density, improved resistance in acid, salt, and alkaline conditions, and increased compressive and flexural strength at 28 and 56 days compared to the control mixture and raw sisal fiber-employed mortar. Therefore, TS1L10 improved compressive strength by 30.62% and 1.8% at 28 and 56 days, respectively. Also, TS1L10 enhanced strength and residual strength in 5% HCl by 54.54% and 72.25%, respectively, compared to the control mixture at 56 days. Generally, the present study revealed the importance of calcined bentonite-treated sisal fibers in a mortar mixture for improved durability, physical and mechanical properties

Impacts of Nonlinear Loads on the Power Quality of Solar Microgrids and Proposed Mitigation Strategies

This research article was published by Energy Science & Engineering, 2025The integration of solar energy into microgrids poses significant challenges in maintaining power quality due to the variable nature of solar generation and the presence of nonlinear loads such as uninterruptible power supplies (UPS), variable frequency drives (VFDs), rectifiers, and power electronic components. Active power filters are often used to mitigate harmonics; however, these solutions are complex due to the use of control techniques like the synchronous reference frame and can introduce additional harmonic currents during compensation within electrical systems. This study investigates the effects of different nonlinear loads on the power quality of solar microgrids and explores the reduction of harmonics from VFDs through the application of passive harmonic filters (PHFs). The objective was achieved by measuring harmonics generated by nonlinear loads and simulating a modeled VFD circuit using MATLAB/Simulink R2021b software, considering the demand side. Analysis of current harmonics measurements at the point of common coupling revealed that the total harmonic current distortion (THCD) for UPS, VFDs, and rectifiers was 20.64%, 42.82%, and 22.59%, respectively, while the total harmonic voltage distortion (THVD) for UPS, VFDs, and rectifiers was 27.83%, 31.55%, and 29.16%, respectively. Moreover, the total losses caused by harmonic distortion from these nonlinear loads is 860 Watts. Among these loads, VFDs were the dominant source of harmonics. Therefore, the application of passive harmonic filters (PHFs) was proposed to minimize harmonics in solar microgrids, adhering to the standards set by the Institution of Electrical and Electronics Engineers (IEEE) and the International Electro‐Technical Commission (IEC). Simulation of the VFD revealed that the THCD was reduced by 89.4% and the THVD was minimized by 89.9% due to the connection of passive harmonic filters. These filters have the capability to minimize harmonics to within IEEE 519 standard limit

Towards Efficient Video Codec for 360-degree Video Streaming over Broadband Network

This research article was published in the Indian Journal of Science and Technology, Volume: 18, Issue: 5, 2025Objectives: This study presents the compression efficiency analysis of AV1, H.265/HEVC, and VVenc based on the Peak Signal-to-Noise Ratio (PSNR) and Video Multimethod Assessment Fusion (VMAF) objective quality metrics. Methods: The study utilizes video sets from publicly available databases and YouTube. The video sets were compressed using High Efficient Video Codec (HEVC/H.265) and Versatile Video Encoder (VVenc) based on Common Test Conditions (CTC) for fixed-quality encoding at different rates. For STV-AV1, we use quantization parameters which result in the rate nearly the same as that of CTC. The encoders’ performance was evaluated using PSNR and VMAF objective metrics. Rate-distortion curves were constructed, and Bjøntegaard delta metric was computed to obtain bitrate saving/overhead between encoders. Findings: The superiority of the Versatile Video Encoder (VVenc) over STV-AV1 was unchallenged in eight out of twelve encoded 360-degree videos. The maximum bitrate saving of 72.6% and minimum of 12.8% is attained by the VVenc encoder compared to SVT-AV1. For the case of the HEVC encoder, the maximum and minimum bitrate overhead of 89.5% and 19.2% is required for it to achieve video quality similar to that of VVenc encoded video. Based on bit-rate saving, the SVT-AV1 encoder is the second most performing, especially for 6K and 5K resolution videos. It is further observed that the HEVC encoder outperforms VVenc and SVT-AV1 only in two video scenes, with average bitrate savings of 34.1% and 1.3%, respectively. Even though the popularity of HEVC still exists in most encoded 360-degree videos, the open-source STV-AV1 showed better results by outshining the HEVC in eleven out of twelve 360-degree video sets. The VVenc, an open-source version of H.266 surpasses other encoders, however, up to this moment, most of the Virtual reality platforms do not support the H.266 format. Novelty: High-resolution 360-degree video requires high-speed network infrastructure to transmit video packets. Therefore, a bandwidth-efficient video encoder must be selected to ensure an adequate immersive experience. It is well known that the HEVC encoder performance is far better than its predecessor X.264 yet, most publicly available 360-degree databases and published research works are based on video sequences encoded by using X.264 and few utilize the HEVC encoder. However, based on findings, STV-AV1 outshines HEVC with average bitrate saving of 11.6%, 34.9%, and 58% in 8K, 6K, and 4K resolution respectively making it a suitable candidate for encoding high-resolution 360-degree videos

Applications of Natural Rocks as Heat-Storage Materials for Food Drying in Sub-Saharan Africa

This research article was published by Advances in Science and Technology Volume 160, 2025Natural rocks are emerging as a viable solution for solar heat storage in Sub-Saharan Africa due to their low cost and accessibility, as well as their ability to reduce energy costs and reliance on solar energy. This study review research on applications of natural rocks as heat-storage materials for food drying in Sub-Saharan Africa. Findings of this study indicate that current research on the combination of drying systems with thermal energy storage systems using natural rocks as storage material focuses on indirect solar dryers (66.67%), mixed mode solar dryers (16.67%), and solar-assisted heat pump dryers (16.67%). These dryers perform admirably, particularly in extreme weather conditions and when there is no sunlight. The findings show that using natural rocks as a storage medium can increase the efficiency of dryers by up to 17.48%, reduce drying time by as much as 50%, and extend the drying operation by 2 to 4 hours after sunset. This study also identifies and proposes key areas for further research. In particular, more attention is needed to characterize the thermal properties of the storage materials used, as this aspect is often underexplored in African studies. Understanding these properties is essential for optimizing the performance of solar dryers and making informed choices about which materials to use. In addition, the techno-economic analysis of all these dryers is neglected, making it difficult to assess the economic impacts of these technologies and facilitate their adoption in communities. Exergoeconomic analysis should also be carried out in order to facilitate optimization and understand the actual efficiency of these dryers

Stumbling blocks for solar social enterprises: Unveiling the barriers facing enterprises serving the base of the pyramid solar market in Tanzania

This research article was published by Energy Research & Social Science Volume 119, January 2025Despite the initially favourable environment for solar PV investments, the relevant literature increasingly emphasizes the emerging barriers that threaten the growth and sustainability of solar PV enterprises. This has led scholars to examine challenges in East Africa's solar energy subsector, with a focus on the evolving institutional environment. However, we discovered that, within the ongoing discourse surrounding this sector, relatively limited scholarly attention has been given to solar energy service social enterprises (SEs). In response to this gap, we have conducted a specific study to explore the barriers facing the performance of solar energy service SEs in Tanzania. Drawing on institutional theory, we unveil the formative, normative and cognitive factors that influence the performance of SEs. Data were gathered through semi-structured interviews with ten solar SEs in Tanzania, supplemented by a review of the literature. The study revealed that regulatory barriers such as an unfavourable policy environment, grid arrival regulations, uncertainties over tariff policies, the prevalence of counterfeit products and limited access to finance and capital, as well as normative constraints such as limited partnerships and networking, are key barriers to operating at the base of the pyramid (BoP). The study underscores the need for collaborative efforts between the government, investors and SEs to create an enabling environment to continue serving the BoP market