Circle Loop Research Articles

An ultra‐wideband polarization insensitive frequency selective surface for shielding applications

A dual layer polarization-insensitive frequency selective surface (FSS) with ultra-wideband response for electromagnetic shielding is presented in this article. In the proposed configuration, a single layer FR4 dielectric substrate is used in which the top metallic layer comprises of combined square and circle loop and the bottom metallic layer comprises of combined swastika shape and circle loop. The proposed FSS exhibits a 13.5 GHz ultra-wide stop band response from 2.3 to 15.8 GHz. The proposed FSS has a fractional bandwidth of 148%, and the structure is polarization insensitive for the incident angles up to 450 in both TE and TM modes. The performance of the simulated structure is compared with the fabricated structure and the measured results are in tune with the simulated results. It can be used for shielding applications of Wi-Fi frequency bands 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz, 6 GHz, X band microwave link communication, and aircraft mobile satellite services.

Fabrication of RF elements on thin plastic substrate using laser engraving technique

A novel fabrication process using a laser machining is proposed, allowing for the creation of arbitrary conductor geometries on an ultrathin dielectric substrate. During the engraving process, a thin aluminum layer is removed from a Mylar substrate, leaving a periodic conductive array. This process provides several advantages over existing techniques and may open additional applications due to the ability to economically create ultra-thin, conformal, optically transparent, light weight surfaces. The proposed technique is modelled and validated through experimental measurements of fabricated simple band-stop square and circle loop frequency selective surfaces (FSSs). Good agreement is observed between the simulated and measured results with resonances 9.9 GHz and 10 GHz for the square loop and 14.2 GHz and 14.4 GHz for the circle loop.

Microcrystalline paraffin wax, biogas, carbon particles and aluminum recovery from metallised food packaging plastics using pyrolysis, mechanical and chemical treatments

Abstract Metallised food packaging plastics waste (MFPW) is the most complex part of plastic waste ever with poor recyclability. In order to close the circle loop of MFPWs and to increase their economic and environmental benefits according to the zero waste principle, this research aims to convert MFPWs into energy products (Microcrystalline paraffin wax and biogas) and raw materials (carbon particles and aluminum) using three combined approaches: pyrolysis, mechanical and chemical treatments. The thermal treatment using mini-pyrolysis plant (capacity of 250 g) was applied as the main treatment to convert MFPWs into three main energy products: biooil, biogas, and char mixed with aluminum flakes (Al/char) at 25 °C/min up to 500, 600, and 700 °C, while the mechanical treatment using milling process was used to break the bonds between char and Al flakes, thus liberating Al flakes after sieving process. Finally, the leaching process using hydrochloric acid was employed to extract the remaining Al particles from the milled Al/char and to recover the carbon particles simultaneously, using a density separation method. The experiments were performed on a mixture of five types of equal shares of packages (potato chips, chocolate, bakery, coffee, and biscuits). The obtained energy products and recovered materials were analyzed by GC, FTIR, ICP, and SEM-EDS. The results showed that MFPWs can be decomposed thermally into Al/char (99.4%) only up to 500 °C, while in case of 600 and 700 °C, they can be converted into microcrystalline paraffin wax (19.5%), biogas (63%), and Al/char (17.8%). Also, the mechanical and chemical treatments were succeeded by leaching >90 wt% of Al and extraction of carbon particles on a micro-scale (10–50 μm). Finally, the assessment of economic performance and greenhouse gases showed that application of the developed approach on an industrial scale can provide an economic return up to 610 $/ton of MFPWs and decrease carbon footprint by −984 kg CO2-eq/t of MFPWs.

Unilateral double testicular arteries surround renal vein

Normally male rsquo s testicular arteries are originating from the abdominal aorta In this case we noted that testicular artery variations are related to renal and or aorta arteries The aim of this presentation was to evaluate the testicular arteries in male rsquo s reproductive system and their contribution with renal function in some disorders During routine dissection of abdomen rsquo s retroperitoneal region in a year old male cadaver we observed double variant testicular arteries with circle loop around left renal vein Anatomical variations of testicular and renal vessels must be considered to solve male genital and or renal disorders

Wide band fractal‐based perfect energy absorber and power harvester

In this article, a novel wide band polarization and incident angle independent metamaterial absorber (MA) and energy harvesting applications which operates at C (4GHz-8 GHz) and X (8GHz-12 GHz) is proposed. The unit-cell of the proposed structure based on fractal circle loop. Four lumped resistors are mounted the structure to obtain a broad band absorption characteristics. Resistors increase the absorption characteristic of proposed MA significantly at mentioned frequency ranges. In addition, under favor of the resistors proposed MA can convert absorbed energy from incident wave to appearing power.

Comparison of the strength of two multi-strand tendon repair configurations in a chicken model

We sought to investigate the strength of two multi-strand tendon repair configurations in a chicken model. Fifty-six chicken flexor tendons were repaired with one to two different four-strand configurations: 1) a four-strand repair consisting of a two-strand core modified Kessler suture with a circle loop repair and 2) a four-strand core Kessler suture repair with three separate peripheral suture points. The strength of the repaired tendons were measured 2, 3 and 4 weeks after the surgical repair and were analyzed statistically. The strength of the two repair methods was not statistically different 2 weeks after surgery. The tendons repaired with the four-strand core Kessler suture repair and three separate peripheral suture points were significantly stronger than those repaired with a two-strand core modified Kessler suture and a circle loop repair at 3 weeks (P = 0.033) and 4 weeks (P = 0.039). The four-strand repair with three separate peripheral suture points had greater strength than a two-strand repair with one circle loop suture based on an in vivo chicken flexor tendon model.

NEW LOOP DETECTOR INSTALLATION GUIDELINES FOR REAL-TIME ADAPTIVE SIGNAL CONTROL SYSTEMS

A real-time adaptive signal control system, named COSMOS, generated signal control parameters automatically using collected information from loop detectors. Therefore, the reliability of loop detector information can affect the operational effectiveness of the signal control system. In this paper, a set of practical loop detector installation guidelines was developed through extensive field experiments. Results indicated that a laying depth of 12 cm provided good performance regardless of detector types tested. In addition, a laying depth less than 9 cm should not be selected in practice. The limit lengths of feeder cable were determined as 1,000 m for octagon loop detector and 900 m for circle loop detector, respectively. It was also recommended that the number of soldering should be less than 6 times when the feeder cable length was below 600 m, and 4 times when the length was in a range between 600 m and 1,000 m.

Nilpotent right alternative rings and bol circle loops

We determine the nilpotent right alternative rings of prime power oirder pn n ≥ 4, which are not left alternative. Those which are strongly right alternative become Bol loops under the circle operation. The smallest Bol circle loop has order 16. There are six such loops, all of which appear to be new.

Combined intraocular lens implantation and trabeculectomy: A. Preliminary Report

Artificial lens implantation was combined with trabeculectomy in 18 patients suffering from glaucoma simplex and cataract. Intracapsular ex traction was carried out, and a Medallion lens (circle loop clip) was implanted. The addition of a trabeculectomy was not technically difficult. There were few complications, the most serious being cystoid macular edema. Postoperative visual acuity and intraocular pressure were satisfactory.