Turboprop aircraft may face a variety of harsh flight environments during flight, and various foreign objects may be sucked into the engine, among which the inhalation of sand can lead to erosion of the blades of the compressor. Such ingestion often results in compressor blade erosion, which can lead to engine surge and power loss. Therefore, this study explores the aerodynamic and sand separation characteristics of the inlet channel with a bypass channel through numerical simulation methods. ANSYS Fluent software is used to simulate the six-bladed propeller rotation based on the slip-grid technique by combining the unsteady Reynolds-averaged Navier-Stokes equations (URANS) and shear stress transport (SST) turbulence model. A Lagrangian discrete phase model (DPM) is applied to track the motion of standard coarse sand. The focus is on analyzing the mechanism of different propeller speeds and scavenge ratio (SCR) on the separation efficiency (η).
The goal of this water treatment study was to evaluate the effects of ozonated water and ultraviolet light (100–280 nm) on the efficacy of Bacillus subtilis spores. These water treatments are based on the current research for sanitizing bio-contaminated water. However, this study focused on small-scale water treatment units that could be modified or custom-built for a mobile sanitation system used for cleaning field equipment. The factorial study included four factors, resulting in a total of 16 water treatments. The ultraviolet light water treatment (UVC + UVC), with a total exposure time of 60 minutes, resulted in a log10 reduction of 3.51, equivalent to a 99.9% reduction in viable spores. The average spore reduction from UVC treatment increases with exposure time, then reaches an asymptotic plateau between 30 and 60 minutes. The combination of ozonated water with UV radiation yielded promising results in reducing spores. Wastewater technology, based on UVC systems, may be implemented with both mobile power washing systems. Additionally, larger units are required to effectively sterilize bio-contaminated wastewater within farms and storage facilities in the agricultural industry.
In this paper, we systematically develop the theory of bipolar-valued fuzzy sets in the setting of Sheffer stroke BG-algebras (SBG-algebras) by introducing and characterizing bipolar fuzzy SBG-subalgebras and SBG-ideals. Necessary and sufficient conditions for these structures are established via sss-cuts and ttt-cuts, along with explicit algorithms for their verification. We further investigate the relationship between bipolar-valued fuzzy sets and their crisp counterparts through constructive examples. It is shown that the intersection of bipolar fuzzy SBG-ideals preserves the ideal structure, and that the combination of the positive membership function with the complement of the negative membership function yields fuzzy SBG-ideals and subalgebras. These findings extend the algebraic framework of fuzzy logic and provide practical tools for modeling and analyzing bipolar uncertainty in algebraic systems.
In January 2020, we published a paper [1] showing that the Intergovernmental Panel on Climate Change (IPCC) claimed that Earth’s temperature would reach 1.5 °C above pre-industrial days by 2030. At the same time, those who study the Sun, such as Valentina Zharkov, indicated that by 2030, the Earth's temperature would be much lower and close to pre-industrial times. The satellite temperature measurements of the Earth’s temperature are the best because they cover the whole Earth and minimize the urban heat island effect. This record shows that from January 2019 to January 2023, the temperatures dropped by approximately 0.5 °C, which indicates that the Earth is cooling. On January 15, 2022, the Hunga Tonga submarine volcano violently erupted, sending approximately 146 million tonnes of water into the stratosphere. This water reduced the heat flow to space. It increased the Earth’s temperature to a peak in April 2024 of approximately 0.45 °C above the safe upper limit of 1.5 °C above pre-industrial levels, as promoted by the IPCC. There was no disastrous effect. We are halfway to 2030, and there are serious problems with the IPCC estimate. It is recommended that the IPCC consider revising its estimates of the impact of CO2 on warming the Earth’s atmosphere.
In this work, an elastic elbow wrap is developed to press a cotton ball against the skin after a blood draw during an annual medical checkup, helping to stop bleeding. The wrap is made entirely from elastic material and incorporates an auxetic structure with hollow, re-entrant patterns that produce a negative Poisson’s ratio. Consequently, when stretched, the wrap becomes wider rather than thinner, which helps prevent buckling and maintains a smooth surface. Combined with its elasticity, this design ensures the cotton ball remains in firm contact with the skin. In this work, the internal geometry of the auxetic structure is first designed based on geometric constraints. To link the two ends of the wrap around an elbow, a self-locking mechanism is then developed that relies on both friction and the material’s elasticity. Finally, the prototype is fabricated using resin 3D printing. Testing results demonstrate that the wrap effectively resolves the issues of loose contact and over-tightening, which are frequently observed when conventional bandages or adhesive tapes are employed to secure a cotton ball following venipuncture.
