http://ir.mu.ac.ke:8080/jspui/handle/123456789/65 2026-08-30T03:56:51Z 2026-08-30T03:56:51Z Maritim, Joseph K. http://ir.mu.ac.ke:8080/jspui/handle/123456789/10475 2026-08-27T08:56:55Z 2026-08-01T00:00:00Z

Energetic particles in space and earth science: propagation, interaction, and atmospheric effects Maritim, Joseph K. Energetic particles, originating from galactic cosmic rays (GCRs), solar energetic particles (SEPs), and trapped radiation belt populations, play a crucial role in shaping planetary environments. These high-energy protons, electrons, and heavy ions traverse the heliosphere, interact with interplanetary magnetic fields, and produce complex cascades when colliding with Earth’s atmosphere. This paper combines theoretical modeling, Monte Carlo–inspired GEANT4-like yield tables, and simulation of Bethe–Bloch stopping power to investigate energetic particle propagation, atmospheric ionization, and implications for space weather. Our findings reveal that density-effect corrections and shell corrections significantly alter proton energy loss curves, while GEANT4-like lookup yields realistic ionization profiles vs altitude. These results advance predictive models of radiation hazards, ionospheric variability, and space weather event

2026-08-01T00:00:00Z Kibet, Tabitha Githinji, David N. Nziu, Patrick http://ir.mu.ac.ke:8080/jspui/handle/123456789/10470 2026-08-27T08:04:14Z 2026-02-01T00:00:00Z

Natural fibre–reinforced starch biocomposites and their effects on the material mechanical properties: a review Kibet, Tabitha; Githinji, David N.; Nziu, Patrick Research on biodegradable materials has gained significant attention due to increasing environmental awareness. Starch, as a biodegradable polymer readily available from agricultural resources, is a promising candidate for biocomposite production. Starch-based films, though exhibiting low mechanical strength, can be enhanced using various plasticizers at elevated temperatures with shear, resulting in a deformable thermoplastic material known as thermoplastic starches. The tensile properties of these starch-based composites can be further improved by incorporating fibres, making them more suitable for a range of applications. This review highlights the significance of biodegradable materials as sustainable alternatives to synthetic plastics, driven by environmental concerns. It focuses on natural fibre–reinforced biopolymer composites, particularly those based on starch, which exhibit improved properties. The review also covers natural fibres as reinforcement, starch as a biopolymer component and potential applications of these composites and suggests directions for future research. The results of this compilation show that natural fibres have a significant influence on the characteristic of the fabricated composites.

2026-02-01T00:00:00Z Bett, Kipchumba Chemweno, Peter Nganyi, Eric Ochola, Jerry http://ir.mu.ac.ke:8080/jspui/handle/123456789/10447 2026-08-12T06:49:20Z 2023-08-01T00:00:00Z

Analyzing incoherence and inconsistencies in data utilization within maintenance operations for critical equipment in the weaving section of textile manufacturing processes Bett, Kipchumba; Chemweno, Peter; Nganyi, Eric; Ochola, Jerry In the context of textile manufacturing’s weaving section, efficient maintenance operations play a pivotal role in upholding critical equipment’s peak performance and longevity. However, inconsistencies in data utilization during maintenance can lead to equipment failures, downtimes, and decreased efficiency. To address this, this study endeavors to scrutinize these data dis parities, focusing on the weaving section’s essential machinery. The objective encompasses identifying failure patterns, gauging parameter impacts on system components, and proposing personalized maintenance strategies based on failure characteris tics. The study employed the Weibull distribution plot to analyze data from 19 distinctive components, with shape (β) and scale (η) parameters elucidating failure trends, distinguishing early-life and wear-out failures. The Anderson-Darling (AD) statistic validated Weibull fitting. Visual aids and charts presented findings effectively. Analysis showcased distinct failure patterns across system components, where shape parameters exceeding 1 denoted wear-out failures, and scale parameters re vealed equipment lifespans. The study emphasized the necessity of bespoke maintenance approaches in response to equipment failure traits. Tailoring strategies for early-life and wear-out failures is essential. The Weibull analysis aids in pinpointing crucial maintenance junctures, optimizing schedules, and enhancing equipment reliability. This study’s contribution lies in ele vating equipment dependability, curbing downtimes, and augmenting operational efficiency in textile manufacturing processes. Recommendations encompass tailored maintenance strategies, prioritized preventive measures for wear-out-prone components, comprehensive craftsman training, and exploring predictive techniques leveraging sensor data and AI.

2023-08-01T00:00:00Z Okumu, Victoria Akoth Shitote, Stanley Muse Koteng, David Otieno Myamba, Yohakimu Jinifa http://ir.mu.ac.ke:8080/jspui/handle/123456789/10445 2026-08-12T06:00:32Z 2026-08-01T00:00:00Z

Mechanical and durability properties of concrete with limestone calcined clay cement: assessing the suitability of Tanzanian kaolinite clay Okumu, Victoria Akoth; Shitote, Stanley Muse; Koteng, David Otieno; Myamba, Yohakimu Jinifa In most African countries, supplementary cementitious materials (SCMs), such as silica fume, slag, and fly ash, are scarce, creating a need for alternative low-clinker cement that utilises locally abundant resources. Given the limited availability of SCMs, the development of Limestone Calcined Clay Cement (LC3) has emerged as an attractive solution. LC3 is a blended binder composed of ground limestone, calcined kaolinite clay, and ordinary Portland cement clinker. This research assessed the mechanical and durability properties of LC3 binders formulated using raw materials obtained from selected deposits in Tanzania. Two samples of clay from the Pugu deposit were selected: Pugu hard clay (PH) and Pugu soft clay (PS). Limestone and gypsum were sourced from Dar es Salaam. LC3 mixes containing 58% CEM I/42.5N were produced and used to make concrete with a water/binder ratio of 0.4. Two control mixes were made, a mix with 100% Portland cement CEM I/42.5 N and a mix with 100% Portland pozzolana CEM II/P-B 42.5 N. In addition, four concrete mixes were designed for the study: LC3-PH, LC3-PS, CEM I + PH (CC-PH), and CEM I + PS (CC-PS). The mechanical properties evaluated included compressive strength, splitting tensile strength, and flexural strength, whilst durability performance was assessed through sulfuric acid resistance, water sorptivity, and absorption. The results demonstrated the superiority of LC3 concrete compared to CEM I and CEM II concretes. For instance, the LC3-PS mix achieved a 90-day compressive strength of 63 ± 2.1 MPa, compared with 62 ± 1.8 MPa for CEM I. Similarly, water absorption was 1.35% and 1.1% for CEM I and LC3 concretes, respectively. Under sulfuric acid exposure, LC3 concrete exhibited the lowest mass loss (1.6%) and strength loss (17.9%) compared with 2.4% and 23% for CEM I and 2.1% and 21% for CEM II, respectively. The enhanced performance of LC3 concrete was attributed to its denser and more refined microstructure, which reduced pore connectivity and improved resistance to the ingress of aggressive agents.

2026-08-01T00:00:00Z