Characterisation of dielectric 3D-printing materials at microwave frequencies

3D-printer materials are becoming increasingly appealing, especially for high frequency applications. As such, the electromagnetic characterisation of these materials is an important step in evaluating their applicability for new technological devices. We present a measurement method for complex permittivity evaluation based on a dielectric loaded resonator (DR). Comparing the quality factor Q of the DR with a disk-shaped sample placed on a DR base, with Q obtained when the sample is substituted with an air gap, allows a reliable determination of the loss tangent

A Dielectric Loaded Resonator for the Measurement of the Complex Permittivity of Dielectric Substrates

A new configuration of dielectric-loaded resonator (DR), particularly versatile for the complex permittivity measurement of substrates for microwave circuits, even in the presence of back metal plates, is shown here. To test this technique in a wide interval of the values of the complex permittivity, the versatility of 3-D printing is exploited to print samples with different densities, thus artificially changing the effective permittivity in the interval (1.7-3.1) for the real part and (0.02-0.06) for the imaginary part. The designed resonator, tuned at -12 GHz, is experimentally validated by the comparison of measurements obtained on these samples with a split ring resonator (SRR) and standard transmission/reflection waveguide methods. Then, the versatility of the designed resonator is shown in the characterization of FR4-fiberglass and Kapton polyimide samples

Diffused capacitance-based sensing for hydric control and watering optimization

Soil moisture measurements are essential especially in the agricultural field, where it is crucial to guarantee that the optimal amount of water is provided to the cultivations. Most soil moisture measurement systems are local sensors; hence, a multitude of sensors must be distributed all over the field to obtain a comprehensive picture of the soil condition. Starting from these considerations, the present work addresses the feasibility of employing diffused sensing elements (in a wire-like configuration) for sensing soil moisture variations, based on capacitance measurements. To this purpose, for a preliminary validation of the proposed methodology, several experiments were carried out, thus identifying the suitable setup configurations and the potential of the method

Broadband Electromagnetic Sensing for Food Quality Control: A Preliminary Experimental Study

Quality control is of great importance in food industry, both for the evaluation of product characteristics and to avoid the occurrence of foreign bodies contamination in packaged items. With respect to the inspections against possible contaminants inside the product, different technologies are currently adopted along production chain lines. However, the number of accidents involving low density objects remains very large. To overcome this limitation, the use of electromagnetic technologies has been recently proposed. In this work, the synergic use of terahertz and microwaves technologies is proposed, so to provide high resolution images and in-depth inspections of different scenarios, including low density materials. A focus study on sugar samples is considered, reporting both its broadband characterization at microwaves and preliminary terahertz imaging to evaluate the integrity of the packaging. Ongoing research is devoted to the development and validation of a microwave device for monitoring food products along the production line

Identifying Critical Evidence Gaps in Wound Closure and Incision Management After Total Hip Arthroplasty: Delphi Panel Insights

BACKGROUND: In total hip arthroplasty (THA), proper management of surgical incisions is essential for optimal wound healing and patient outcomes. Despite advances in surgical techniques, significant challenges remain in preventing complications and infections. This study aimed to identify evidence gaps in THA wound care, including presurgical preparation, intraoperative practices, and postsurgical complications. METHODS: Using a modified Delphi method, 20 expert orthopedic surgeons from Europe and North America participated in a 3-phase consensus process from April 1 to September 30, 2023. This included a preliminary questionnaire, a remote conference, and a final online survey. The panel reviewed literature and achieved agreement on 18 consensus statements regarding wound care in THA. A secondary aim was to identify critical gaps in current wound care knowledge. RESULTS: Consensus was reached on 18 statements. Key gaps were identified in the effectiveness of mesh-adhesive dressings, optimal closure methods (skin adhesives, staples, sutures), cost benefit of barbed sutures, and appropriate use of negative pressure wound therapy. These findings highlight the need for further research to validate best practices and guide standardized evidence-based protocols. CONCLUSIONS: Addressing these evidence gaps is essential to improve THA wound care methods. Future studies should compare closure techniques and new technologies to develop more efficient patient-centered strategies. Bridging these gaps may reduce complications, enhance outcomes, and lower the burden of wound-related issues in THA