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This study explores the correlation between thermal, electrical, and structural properties of metals, alloys, and single-crystal semiconductors using photothermal techniques, electrical methods, and X-ray diffraction. Polycrystalline metals (Al, Pt, Ti, Cu, AISI 1030 steel, α-brass) and semiconductors (Si, GaSb-Te) were systematically analyzed. Thermal diffusivity was measured using Frequency Domain Photoacoustic (FDPA), and thermal conductivity and volumetric heat capacity using the Thermal Relaxation Method (TRM). A thermal diffusivity image for a Si sample was taken to show the influence of mechanical damage on the thermal transport properties. The structural properties were determined using X-ray diffraction, while the electrical properties were evaluated using the Van der Pauw method. The results show a strong correlation between the thermal, electrical, and structural properties of the materials, specifically with respect to crystallite size and space group. The thermal conductivity is influenced by the crystallite size, while electrical conductivity varies due to extrinsic factors, especially for polycrystalline metals. These results suggest that the Wiedemann-Franz theory needs to be re-evaluated by considering both intrinsic and extrinsic influences on material behavior.

This study explores the impact of ohmic heating, a non-chemical, electric field-driven thermal process, on sorghum starch. Two sorghum genotypes with different amylose contents (85P20: 35.6%, 81G67: 24.5%) were subjected to various electric field strengths (25–70 V/cm) to assess physicochemical changes and the formation of resistant starch (RS). Techniques like FTIR and XRD revealed that ohmic heating induced partial gelatinization, disrupted crystallinity, and caused molecular reorganization, even at low moisture levels (1:1 w/w). FTIR showed shifts in O–H and water-associated bands, suggesting reconfiguration of hydrogen bonds, while XRD confirmed reduced starch crystallinity. Significantly, RS content increased with higher field intensity, indicating enhanced retrogradation and amylose-inclusion complex formation. This method produces resistant starch without chemical additives, offering a sustainable approach to developing functional starches for health-oriented food applications. By adjusting electric field parameters, starch digestibility and functionality can be tailored for clean-label products.