A dual-band semi-circular patch antenna for WiMAX and WiFi-5/6 applications

A semi-circular patch antenna (SCPA) is designed for WiMAX and WiFi-5/6 communications. The footprint of the proposed SCPA is only 30 × 40 × 1.575 mm³, which is composed of a semi-circular patch and a partial ground plane. The main strength of this work is that the estimated wide dual-frequency span of 2.39–3.75 GHz and 5.39–7.18 GHz are contributed with two sharp resonances at 2.77 and 6.46 GHz, respectively. The proposed SCPA has been practically tested after fabrication. The measured results confirm that the designed antenna achieved the bandwidth necessity for WiMAX 1.5 (2.5–2.69 GHz), WiMAX 2 (3.4–3.6 GHz), WiFi-5 (5.15–5.85 GHz) and WiFi-6 (5.925–7.125 GHz). In the two resonance frequencies of 2.77 and 6.46 GHz, the designed antenna achieved a gain of 2.558 and 4.109 dB, respectively. In addition, the SCPA also manifests good radiation properties and achieves an average efficiency of more than 90%. A professional version of the 3D electromagnetic simulator is utilized to examine the effect of diffident parameters and model the tested antenna.     

Preclinical study probing primary stability of dental implants in synthetic and natural bones

The natural bone is a biological example of a polymer–ceramic composite with a higher volume fraction of nanosized ceramic (around 65% hydroxyapatite) dispersed in polymer (collagenous) matrix. The loading of a dental implant involves the biomechanical interactions of the implant with such natural composites in the jaw bones of human subjects. In particular, the insertion torque responses of the dental implant are related to the implant design, in particular the external thread morphology, which influences the primary stability of the implant. In this study, the effect of the bone properties (polyurethane-based synthetic bone, porcine and human cadaver lumbar bone) and clinically relevant implant driving protocols on the insertion and removal torques of newly designed implant variants (hybrid threads with macro- and micro-threads) were assessed, quantitatively and qualitatively. It was observed that torque response increased with an increase in bone density, irrespective of the implant designs. The torque response of the implants in both synthetic and natural bones was benchmarked with the commercially available implant. The implants with bone cutting partial macro-threads at the apical end without inter thread gap exhibited comparable clinically relevant results with respect to control implants and were found to be most suitable for implantation into natural bone.     

Adaptive dewarping of severely warped camera-captured document images based on document map generation

International Journal on Document Analysis and Recognition (IJDAR) - Automated dewarping of camera-captured handwritten documents is a challenging research problem in Computer Vision and Pattern...     

Charge Storage Capabilities of Fractal Porous Silicon Obtained Using Simple Metal Assisted Porosification Method

Silicon - Simpler methods for fabricating electrodes for charge storage applications are required because electrode materials have appreciable significance to enhance the electrochemical...