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In this article, a dual-mode, dual-polarized antenna designed using characteristic mode analysis (CMA) is described. An elliptical-shaped patch radiator is chosen with double slits on its minor axis. This design is based on mode separation from the circular patch into the elliptical patch. The suggested antenna geometry has a footprint of 60 mm × 60 mm × 1.6 mm. To design and fabricate the antenna, an FR-4 substrate with a relative permittivity of 4.3 is used, along with copper sheets 0.035 mm thick for the ground plane and the radiating plane. The circular patch has the resonating mode at 1.8 GHz, whereas the elliptical radiator gives different resonant modes at 1.8 GHz and 3.5 GHz. An orthogonal mode is excited with a 50-Ω coaxial feed line at 3.5 GHz by applying a full-wave approach. The antenna gives a −10dB bandwidth of 51 MHz (1.77–1.82 GHz) centered at 1.8 GHz and a bandwidth of 210 MHz (3.37–3.58 GHz) centered at 3.5 GHz. The working principle is explained through modal analysis and characteristic angles. This dual-band antenna covers a 1.8 GHz GSM band with horizontal polarization and a 3.5 GHz 5G service with vertical polarization. Peak gain attained with these bands is 5.9 dBi and 7.1 dBi, respectively. A CST full-wave simulator is used for the simulations. As a result of the antenna, radiation is stable and enhanced. Compared to measured results, simulation results are close to reality. The characteristic mode analysis (CMA) provides an in-depth look into different operating modes on the antenna in contrast with the conventional method, which relies on the simulated current distribution to verify functionality.

The present work investigates the thermal performance of a domestic refrigerator integrated with the phase change material (PCM) and Nanoparticle Enhanced phase change material (NEPCM) based thermal energy storage system (TES). The materials such as Paraffin wax and Multi Walled Carbon Nano Tube (MWCNT) Dispersed Paraffin Wax are used as TES on condenser side. The experiments are conducted to analyze the performance of the refrigerator by placing the PCM and NEPCM based TES system on the condenser side, and to predict the possible energy saving potential. The integration of PCM and NEPCM based TES system over the condenser results in lowering the ratio of on cycle time to the total cycle time of the refrigerator by 8.26% and 17.95% respectively. The Subcooling of refrigerant takes place due to effective absorption of heat on the condenser side using TES in an isothermal manner. The decrease in the ratio of on cycle time to the total cycle time of the refrigerator and sub cooling of refrigerant lead to an energy saving potential. This potential is estimated as 13.06% with PCM and 18% with NEPCM based TES systems.

An Al₂O₃–13% TiO₂ coating was applied to M2 high-speed steel using the d-gun process. The surface properties were compared between uncoated samples, coated samples before cryogenic treatment (CBCT), and coated samples after cryogenic treatment (CACT). The mean particle size was ~17.07 μm, with average coating thicknesses of 212 μm for CBCT and 196 μm for CACT. CACT exhibited 3.19% and 24.65% higher microhardness than CBCT and uncoated samples, respectively. All samples exhibited hydrophilic wettability, with CBCT showing 59.41% and 67.43% higher Ra values, along with 56.03% and 59.70% higher Rz values than CACT and uncoated samples. CBCT also exhibited 32.96% and 98.14% higher porosity than CACT and uncoated samples. CACT showed reduced abrasion loss by 54.05% and 36.25% compared to CBCT and uncoated samples. CBCT has better corrosion resistance of 90.25% and 95.89% than CACT and uncoated samples. The Raman shift revealed increased particle size formation in CACT than other samples. [ABSTRACT FROM AUTHOR]

In this study, the optimization of printing parameters in fused deposition modeling (FDM) is addressed, focusing on their impact on energy absorption and vibration behaviour of triply periodic minimal surface (TPMS) lattice structures, specifically Pseudo-periodic-based Schwarz P and Schoen Gyroid designs. The experimental design employs a Taguchi L9 orthogonal array involving layer height (0.15 mm, 0.30 mm, 0.45 mm), build orientation (0°, 45°, 90°), and extruder temperature (190°C, 200°C, 210°C) as inputs. These lattice structures are generated through Math Mod and simulated using Blender, with Autodesk Mesh mixer refining the STL file. The lattice fabrication employs PLA (polylactic acid). Comparative analysis is conducted against a high-density solid structure lacking lattice design. Optimal parameters for Schwarz P lattice are found to be 0.45 mm layer height, 0° build orientation, and 200°C extruder temperature, while for Schoen Gyroid lattice, 0.30 mm layer height, 0° build orientation, and 210°C extruder temperature. Solid structure optimization yields 0.30 mm layer height, 90° build orientation, and 190°C extruder temperature. Solid structures outperform Schwarz-P and Schoen-Gyroid in energy absorption and vibration behaviour, with Schwarz P showing superior properties over Schoen Gyroid. [ABSTRACT FROM AUTHOR]

There is great enthusiasm for using loop-mediated isothermal amplification (LAMP) in point-of-care nucleic acid amplification tests (POC NAATs), as an alternative to PCR. While isothermal amplification techniques like LAMP eliminate the need for rapid temperature cycling in a portable format, these systems are still plagued by requirements for dedicated optical detection apparatus for analysis and manual off-chip sample processing. Here, we developed a new microfluidic system for LAMP-based POC NAATs to address these limitations. The new system combines digital microfluidics (DMF) with distance-based detection (DBD) for direct signal readout. This is the first report of the use of (i) LAMP or (ii) DMF with DBD – thus, we describe a number of characterization steps taken to determine optimal combinations of reagents, materials, and processes for reliable operation. For example, DBD was found to be quite sensitive to background signals from low molecular weight LAMP products; thus, a Capto™ adhere bead-based clean-up procedure was developed to isolate the desirable high-molecular-weight products for analysis. The new method was validated by application to detection of SARS-CoV-2 in saliva. The method was able to distinguish between saliva containing no virus, saliva containing a low viral load (104 genome copies per mL), and saliva containing a high viral load (108 copies per mL), all in an automated system that does not require detection apparatus for analysis. We propose that the combination of DMF with distance-based detection may be a powerful one for implementing a variety of POC NAATs or for other applications in the future. [ABSTRACT FROM AUTHOR]