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Now showing 1 - 5 of 14

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Simultaneous polarization-based fiber sensor and 10 Gbps data transmission over 75 km SMF for mining safety application
(Optics Communications, 2026) W.K. Nyarangi; E.K. Rotich Kipnoo; F.W. Wekesa; J. Jena; D.W. Waswa
In this paper, we present a novel approach to enhancing safety and communication in mining environments by integrating a fiber optic sensor with high-speed data transmission capabilities. For the first time to our knowledge, we propose a fiber sensor design that also serves as communication hub to enhance safety in a mining environment. This design employed different light sources; WDM, MZM and DFB. Each of the light sources was modulated using a 10 Gbps Pseudorandom Binary Sequence (PRBS 29 -1) signal onto a fiber for data transmission. Among them, the MZM source demonstrated superior performance, enabling transmission over 75 km of single-mode fiber (SMF) while maintaining signal integrity. WDM and DFB attained a maximum of 50 km. Concurrently, the system monitored both the signal’s power and state of polarization (SOP). Mechanical disturbances were applied to the fiber by incrementally loading 2 kg masses at 10-s intervals, up to a total of 18 kg, to simulate real-world environmental stresses. This incremental mechanical loading of up to 18 kg caused a measurable power loss of 0.43 dB and an average SOP rotation of 613◦ over 120 s, corresponding to a strain sensitivity of 0.024 dB/kg and SOP speed of 5.108◦/s. The system demonstrated high sensitivity to changes in the polarization state and power, allowing for real-time detection of mechanical faults or anomalies. This dual-purpose system not only ensure reliable communication but also provides real-time safety monitoring, showing significant potential for improving both operational efficiency and safety in mining applications. Additionally, the architecture supports bi-directional communication using distinct upstream (1310 nm) and downstream (1550 nm) optical windows, enabling twoway interaction between underground personnel and external monitoring systems.
Comparative analysis of different fiber types for strain sensing application under simulated mine conditions
(sciencedirect, 2025-06) W.K. Nyarangi; E.K. Rotich Kipnoo; F.W. Masinde; D.W. Waswa; J. Jena
The recent advances in technology have provided deeper insights into hazard detection for mine safety. This study proposes an optical fiber sensor for mining applications. The performance of four fiber types—G652 Corning, G655 OFS, G655 Corning, and PMF Corning—was evaluated when subjected to controlled strain, simulating potential failure conditions. Additionally, the effectiveness of three laser sources—DFB, MZM, and WDM—was assessed to determine the most suitable laser for strain sensing. Constant input powers were used for strain measurements (Fig. 2), with the power recovering to approximately the same values after unloading (Fig. 3), confirming that no permanent deformation occurred in the fibers. In contrast, a fixed input power of 0.49 dBm was maintained across each of the three laser sources during performance evaluation (Fig. 4to ensure consistency in the comparisons. The optimal combination of the MZM laser source and G655 OFS fiber was found to be the best for mining applications. A strain sensitivity of 0.0041 dB/N and an SOP speed of 5.125 0 /s is achieved. The data obtained from these experiments offer valuable insights into the behaviour of mine structures under stress and can contribute to the development of reliable early warning systems.
The Ecological Effects of Wood Fuel Extraction on the Gazetted Forests within Koibatek Zone, Mau Forests Complex, Kenya
(International Journal of Innovative Research & Development, 2019) Keith Kipng’etich Rono; Raphael Achola Kapiyo; Esnah Kerubo Bosire
Despite the importance of woodfuel in Kenya’s economic development, the ecological effects of its extraction on forests (particularly gazette forests) remain unclear. Studies contradicts each other on effects of woodfuel extraction on for ests with some indicating that it leads to loss of biodiversity and forest degradation while othersstating that woodfuel extraction is a forest cleaning activity and a part of good forest management. Little has been done to establish the area of forests lost due to woodfuel extraction as well as changes in distribution of preferred tree species from gazette forests in Kenya. The objective of this paper was to establish the ecological effects of woodfuel extraction on the gazette forests within Koibatek Zone, Mau Forests Complex-Kenya.Cross-sectional descriptive research design was adopted with all the 8 gazetteblocks within the Zone purposely selected. Stratified random sampling was used to select 384 woodfuel extractors and 8 FGDs were conducted each comprising of 10 participants. World Bank (2009) was used to convert volumes of woodfuel to equivalent forest cover required/ consumed in gazetted forests from 2006-2014. Forest cover change for 2006-2014 was examined by analyzing satellite images acquired from the United States Geological Survey Global Visualization viewer.The estimated volume of woodfuel from gazetted forests between 2006 and 2014 was 260,746.1m3 out of which 113,289.59m3was firewood and 147,456m3 was charcoal. The forest cover lost due to woodfuel was equivalent mature trees contained in 3902.6ha of closedcanopy forests. This is equivalent to 7.6% of closed forests of the gazette blocks within Koibatek Forests Zone. About 13 tree species were preferred for woodfuel; 8 indigenous species and 5 exotic species. Indigenous trees preferred had reduced as indicated by 89% of extractors while distribution of exotic species remained constant as reported by 68% of extractor s
Matrices of the Zero Divisor Graphs of Classes of 3-Radical Zero Completely Primary Finite Rings
(SCIENCE MUNDI, 2024) Frank Omondi Ndago; Maurice Owino Oduor; Michael Onyango Ojiema
The study of finite completely primary rings through the zero divisor graphs, the unit groups and their associated matrices, and the automorphism groups have attracted much attention in the recent past. For the Galois ring R ′ and the 2-radical zero finite rings, the mentioned algebraic structures are well understood. Studies on the 3-radical zero finite rings have also been done for the unit groups and the zero divisor graphs Γ(R). However, the characterization of the matrices associated with these graphs has not been exhausted. It is well known that proper understanding of the classification of zero divisor graphs with diameter 2 and girth 3 can provide insights into the structure of commutative rings and their zero divisors. In this study, we consider a class of 3-radical zero completely primary finite rings whose diameter and girth are 2 and 3 respectively. We enhance the understanding of the structure of such rings by investigating their Adjacency, Laplacian and Distance matrices.
On the Structure of a Class of Galois Ring Module Idealization
(2024) Owino Maurice Oduor
Let Ro be a Galois ring and U is a finitely generated Ro− module. Consider an idealization of U expressed as R = Ro ⊕U endowed with a suitable multiplication. We explore the structure of R through its group of units R × and the graph of its zero divisors Γ(R). The study involves an investigation on the overarching interplay between the ring theoretical properties of R, the group theoretic properties of R × and the graph theoretic properties of Γ(R). Since R is a finite ring with identity, the convention that each element of R is either a unit or a zero divisor has been extensively used to drive the concept of classification of the elements of R. The units of R have been classified, the automorphisms of R have been determined and the zero divisors of R have been characterized.