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This study presents a quad-band stub-incorporated split octagonal ring antenna specifically designed for wireless applications that rely on satellite communication. The antenna is fabricated on an FR4 substrate with dimensions of 26×21×1.6 mm³ and its performance is simulated using the CST EM Studio software. The device operates in the frequency range from 2.15 GHz to 6.35 GHz, using stub integration and gap modification to achieve resonant bands. The antenna has resonant frequencies of 2.23 GHz, 3.28 GHz, 4.77 GHz, and 5.89 GHz, with corresponding bandwidths of 153 MHz, 9011 MHz, 7692 MHz, and 6813 MHz, respectively. The parametric analysis optimizes the values of the design parameters, while the experimental validation shows the consistency between the measured and simulated results. The antenna is characterized by a small size, a consistent radiation pattern and a wide range of applications including ISM, WIFI, WLAN, WIMAX, 5G, and C-Band Satellite. The device is capable of operating in two frequency bands and consistently maintains a gain of over 1 dBi across its resonating range.

Background Prognostically meaningful tricuspid regurgitation (TR) is not well‐defined in the mitral transcatheter edge‐to‐edge repair arena. We aimed to explore the prevalence, correlates, and consequences of TR grades and postprocedural trends in this setting. Methods and Results A single‐center registry of isolated, first‐time interventions was retrospectively assessed for pre‐, intra‐, and postprocedural aspects up to 1 year, of them the primary composite outcome of all‐cause deaths or heart failure (HF) hospitalizations, all according to TR severity at baseline and at 1 month following mitral transcatheter edge‐to‐edge repair. Overall, 1287 individuals (60.3% men, age 78 [interquartile range, 69–85] years, 52.9% with functional mitral regurgitation) were included. Below‐moderate, moderate, and above‐moderate TR affected 48.4%, 29.5%, and 22.1% of patients, respectively. Increasing TR severity was accompanied by higher rates of functional, severe mitral regurgitation, greater comorbidity, and more advanced heart failure. Although not affecting technical and echocardiographic procedural success, moderate‐and‐above TR degrees were associated with higher incidence of mortality, heart failure admissions, and functional class III to IV postprocedure, with moderate‐to‐severe and greater TR independently conferring increased risk for the various outcomes (primary end point; HR, 1.36 [95% CI, 1.21–1.80]; P=0.027). One‐month postprocedural TR severity directly correlated with, and was mostly similar to or worse than, its baseline counterpart. Rather than the change between the two, moderate‐and‐above grade at 1 month, observed in 37.1% of eligible cases, emerged as predictive of the primary outcome's risk. Conclusions Among patients undergoing mitral transcatheter edge‐to‐edge repair, above‐moderate TR at baseline and the closely related moderate‐and‐above TR at 1 month postprocedure are highly prevalent and signal a suboptimal course.

This study introduces an innovative photonic crystal fiber (PCF) surface plasmon resonance (SPR) biosensor, notable for its sophisticated design and exceptional performance, utilizing gold as the plasmonic material. The sensor offers an expanded detection range and outstanding sensitivity, operating within a refractive index range of 1.27 to 1.43. It achieves a remarkable wavelength sensitivity of 157,000 nm/RIU with a resolution of 6.37 × 10⁻⁷ RIU and an amplitude sensitivity of 1263 RIU⁻¹ with a resolution of 7.92 × 10⁻⁵ RIU. Additionally, it boasts a figure of merit (FOM) of 1648, underscoring its superior capability in detecting biomolecular interactions. The suggested design is numerically analysed using the finite element method (FEM) of a gold-coated PCF-based SPR sensor designed for detecting changes in the refractive index (RI) within the range of 1.27 to 1.43. This range is related to various biological and chemical samples, including proteins, DNA, and biochemical analytes typically used in biomedical diagnostics and environmental monitoring. The integration of gold plasmonic elements enhances the sensor's sensitivity and stability while extending its detection capabilities across a broader range, allowing for versatile applications in biomedicine, environmental monitoring, and beyond. This research significantly advances optical biosensing technologies by offering a robust platform for high-precision detection across diverse domains. The sensor's advanced design and performance make it an invaluable tool for applications requiring accurate and reliable detection, driving innovations in areas such as biomedical diagnostics, environmental monitoring, food safety, and pharmaceutical quality control.

Water contamination resulting from the presence of organic dye pollutants in the ecosystem is a significant issue in the 21st century, that requires urgent resolution. Utilizing an effective nanocatalyst for the removal of dyes from water is a viable solution to address this problem. In this study, we proposed two distinct approaches for synthesizing δ-MnO2 nanostructures: an environmentally friendly, “green” method (MG) and a “cost-effective” hydrothermal method (MH). The leaf extract of Clinacanthus nutans was used for the preparation of MG, while MnSO4 was used for MH as a reducing agent, along with KMnO4, with the reaction time fixed at 90 °C. X-ray diffraction analysis confirmed that both approaches yielded δ-MnO2 nanostructures with a monoclinic Birnessite phase. The MG sample displayed a coagulated nanoflake-like morphology, as observed in FESEM images. On the other hand, the MH sample exhibited a distinct nanoflower morphology. The materials' optical properties were investigated using UV–visible spectra analysis, revealing direct bandgap energies of 2.2 eV and 2.58 eV for the MG and MH, respectively. The surface area of the MG sample was found to be higher as compared to the MH nanoflower, showcasing a mesoporous structure. XPS analysis was employed to determine the oxidation states of the elements. The effect of varying pH levels on the degradation of Methyl Orange dye by the two nanocatalysts was investigated. The results demonstrated that acidic pH led to higher decolouration efficiency, particularly notable for the MG nanocatalyst. Consequently, this study illustrates that the green δ-MnO2 nanocatalyst effectively degrades methyl orange dye under acidic conditions through photocatalysis.

The increasing scarcity of natural materials and rising construction costs have prompted the need for alternative materials that can match the performance of conventional aggregates. This study explores the use of recycled aggregate concrete (RAC) as a sustainable alternative, supplemented with natural and synthetic fibers to overcome the inherent strength limitations caused by the residual cement paste on the aggregate surface. To enhance the mechanical and thermal stability of RAC, steel, polypropylene, and coconut fibers were incorporated. The rheological, hardened, and post-fire properties of fiber-reinforced RAC were thoroughly investigated. After 28 days, the porosity of RAC with fiber reinforcement was observed to be less than 2 %. The concrete was also exposed to elevated temperatures as per ISO 834 guidelines to assess its thermal performance. Key parameters such as mass loss, crack width, porosity, and strength degradation were analyzed. Image analysis was used to track surface modifications and measure surface porosity after heating. Among the fiber types, steel fiber reinforced concrete exhibited superior mechanical and thermal performance, followed by coconut fiber reinforced concrete, making coconut fibers a viable natural alternative to synthetic fibers. RAC without fibers displayed the highest porosity (20 % and 32 %) after exposure to 821 °C and 1029 °C, respectively. Strength degradation ranged from 40 to 50 % after heating to 821 °C, increasing to 74–80 % at 1029 °C, irrespective of fiber type. This research highlights the potential of fiber-reinforced RAC for structural applications, offering a sustainable solution with comparable strength and durability to conventional concrete.

Fires occurring within buildings present a grave concern, as they entail substantial risks to human lives, property, and the environment. Implementing appropriate fire safety measures becomes imperative to mitigate the occurrence of fires and ensure efficient response in the event of an incident. The primary aim of the study is to examine the performance of various coatings on the residual strengths of the reinforced normal strength self-compacting geopolymer concrete (NSGC) and high strength self-compacting geopolymer concrete (HSGC) columns subjected to standard temperature exposure in accordance with ISO 834 guidelines. The design compressive strength of the concretes was 36.12, 57.06 and 52.8 MPa. Two types of coating were employed in the present investigation namely ceramic wool wrapping and high alumina cement. A computerized electric furnace is used to heat the column specimens. Amongst the forty-two columns developed, six specimens tested without temperature exposure and protective coating as a reference specimen. Twelve specimens were heated as per ISO fire curve and tested to assess the residual axial strength performance and twenty-four specimens were coated with protective layers, then heated and tested to assess the post fire performance. It is exemplified that the composite protective coating offers effective resistance to concrete, gaining optimum axial strength performance. The findings show that these fire protecting composites have a high potential for utilizing as new strengthening techniques for reinforced concrete (RC) columns.