Parallel Strips Research Articles

A Bandpass Filter–Polarizer Based on a Dielectric Multilayer with Strip Conductor Gratings

A new design of a multilayer bandpass filter is proposed, in which each resonator consists of two identical dielectric layers with parallel strip conductor gratings on their outer surfaces and an orthogonal strip conductor grating between the layers. The filter designed on the basis of crossed gratings works simultaneously as a polarizer transparent in a specified frequency band if the electric field vector of a wave is parallel to the outer strip conductors but reflects waves with an orthogonal polarization. The data from a numerical electrodynamic analysis of a 3D model of the proposed device agree well with the results of the measurements performed on the fifth-order filter–polarizer prototype with a relative bandwidth of 14% and a central frequency of 13.4 GHz. The microwave power loss in the filter passband is ~1.2 dB under parallel polarization of the electromagnetic wave and more than 40 dB under orthogonal polarization.

The effects of an auxiliary axle on forwarder rut development – a Norwegian field study

ABSTRACT The goal of this study was to compare wheel-rut development between a conventional 8-wheel forwarder and a 10-wheel forwarder. Two Ponsse Buffalo forwarders with 14 metric ton load capacity were compared; one with a standard double-bogie undercarriage and one with double-bogies plus an auxiliary back axle. Both forwarders were equipped with bogie-tracks front and back; the 8-wheeler with standard traction tracks on the rear bogie, the 10-wheeler with combi-tracks. The comparison was set up with two parallel forwarding trails leading down from the landing over marine sediments (coarse sand) to four parallel strip roads over a 4 m deep bog. Seven blocks with three transects per block were laid out to follow the breakdown of the harvest residue layer (above the humus surface) and development of rut depth (below the humus surface) after each loaded pass. Ruts deeper than 10 cm were found on 19% and 31% of transects after 5–10 and 15–20 passes for the 8-wheel forwarder, respectively. The corresponding figures for the 10-wheel forwarder were 7% and 12%, respectively. Using linear regression, 79% of the variation in rut depth could be explained by pass interval, forwarder type, and pre-harvest soil moisture content. The auxiliary axle with suitable bogie-tracks offers increased site availability in moderate terrain during frost-free periods.

Diffraction in grating optical filters with angular-selective light transmission

The effect of diffraction on the directional light transmittance of grating optical filters designed for smart windows is studied. The filter has an angular selective light transmission due to two thin-film gratings formed by "non-transmissive" (absorptive, reflective or scattering) parallel strips on the surfaces of a single or double glazed window. Methods are considered for calculating the op-timal slope angle of two filter’s gratings, their relative position on the opposite window surfaces and the widths of the strips of both gratings to minimize light transmission on a specific date and time of day for a given latitude and longitude of the building and azimuth of the window. A meth-od has been developed for calculating the diffraction at the input and output gratings of the filter with regard for a complex movement of the Sun relative to the window and a corresponding change in the incidence angle of the solar beams on the gratings. To evaluate a decrease in the light transmittance of the filter due to diffraction, an additional factor is introduced into the calcu-lation equation. Geometric parameters of the filters and diffraction are calculated. The values of the diffraction factor are 0.9999992 and 0.9999998 for single or double glazed windows, respec-tively, i.e., the influence of diffraction on the light transmittance of the grating filter can be ne-glected.

Sediment Enrichment Ratio and Nutrient Leached by Runoff and Soil Erosion on Cacao Plantation

Soil consevation management system is an activity for diminishing sediment enrichment ratio and nutrient leacheds by water run off and soil erosion processes. The research was aimed to study sediment enrichment ratio and nutrient leached by run off and soil erosion on cacao plantations. Arachis pintoi with strips parallel contour and multiple strip cropping of upland rice or soybean (Glycine max) were planted to improve soil physical characterictic on cacao plantation as a main plant. The expriment were conducted with treatments as 10-15% and 40-45% slopes, 5-7 months and 25-27 months cacao ages (as main plants). As sub plots are T1 as a monoculture which to be cleaning under the plant canopy, T2 as a multiple strip cropping of upland rice or soybean, T3 as a combination of T2 and A. Pintoi strip. The results showed that total N, P2O5, and K2O and organic-C contents in water run off and soil sediments indicated that T3 >T2 >T1 treatment, with the contents of each nutrient: T3 (total N 0.18%; 24.87 mg 100 g-1 P2O5: K2O 15.16 mg 100 g-1), T1 (total N 0.16%, 22.39 mg 100g-1 P2O5, K2O 11.50 mg 100g-1). The total N, P2O5, K2O and organic-C soil contents < accumulation nutrient contents of total water run off and soil sediment transport. All of treathments have sediment enrichment ratios > 1.

Baby Warmer to Improve Neonatal Resuscitation Training

Objectives To enhance realism in neonatal simulations, a modification to a commercial infant warmer was desired. The ideal modification must allow use of existing controls and alarm functions, as well as work with any manikin to display temperature, and to provide feedback to learners about patient condition. Methods A Panda BNT-1000 radiant baby warmer was used for this warmer unit modification. The radiant warmer’s heat lamps were disconnected from the control board. Then the 120 VAC heat lamp output was connected to a low voltage (12VDC 2A) transformer to power LED lights. Two parallel strips of LEDs, with a color-temperature of 2000K, were run along the parabolic reflector. Ordinarily, the front temperature sensor is controlled by a thermistor. We internally disconnected the thermistor, and replaced it with a fixed resistor in series with a correctly proportioned potentiometer. This modification allows the front-panel temperature readout to be altered without any actual change in temperature. Results The resistance of the thermistor at physiologic temperature was 12.6K-Ohm. A 10K-Ohm resistor and a 10K-Ohm potentiometer applied in series across this terminal provides controllable temperature readouts on the front panel, producing a fully functional-appearing radiant warmer with standard operation and alarms. The improved warmer design allows simulation of hypo- and hyper-thermic conditions that previously could not be accomplished. Conclusion Color-temperature matched LED light strips are a visually similar alternative to thermal heating elements in an infant warmer. User control (via potentiometer) of the front-panel temperature display allows training of temperature physiology while preserving system alarms. Additionally, simulation equipment will no longer experience damaging heat or UV exposure.

Effect of enzyme-induced collagen crosslinking on porcine sclera

This study aims to evaluate the effect of a new type of collagen crosslinking (CXL) mediated by microbial transglutaminases (Tgases) on sclera. Porcine eyes were divided into two groups according to the different crosslinking procedures used: the double-sided CXL group (D-CXL group) and the single-sided CXL group (S-CXL group). In the D-CXL group, 4.0 × 14.0 mm scleral strips harvested from 40 porcine eyeballs were incubated with 1 U/ml Tgases for 30 min at 37 °C. Parallel scleral strips from the same eyeball were incubated with PBS under the same conditions as the controls. In the S-CXL group, 80 whole globes were directly incubated with 1 U/ml Tgases and PBS as the controls for 30 min at 37 °C. After incubation, 4.0 × 14.0 mm scleral strips were cut from each eyeball. Biomechanical testing and light microscopy were used. In the D-CXL group, the general elastic modulus of the Tgases-treated scleral strips was 14.89 ± 6.05 MPa, and the controls was 6.72 ± 2.58 MPa, indicating an increase of 121% with Tgases treatment. In the S-CXL group, the general elastic modulus of the Tgases-treated scleral strips was 12.88 ± 4.29 MPa, and the controls was 7.00 ± 2.45 MPa, indicating an increase of 84% with Tgases treatment. In both the D-CXL and S-CXL groups, significant increases in scleral rigidity were observed compared to that of the respective controls (P < 0.05). The histology indicated increased collagen bundle density, decreased interfibrillar spaces and increased interlamellar spaces after CXL. In conclusion, scleral collagen crosslinking mediated by Tgases produced a significant increase in biomechanical strength.

Manipulation of shear horizontal guided wave with arbitrary wave fronts by using metasurfaces

In this work, we proposed a general method to manipulate the fundamental shear horizontal wave (SH0) in plates with arbitrary wave fronts by using metasurfaces consisting of multiple parallel strips. Firstly, the guided waves in infinitely long rectangular strips with different widths were analyzed. The transmission characteristic of the fundamental shear horizontal wave in infinitely long rectangular strips (quasi-SH0) was calculated and the relationship between the phase shift and the frequency-width product is obtained. Secondly, the mode conversion was analyzed for the oblique incidence of SH0 wave from a large plate to a strip, and it was found that the Lamb wave S0 also appeared. Then, the design method for metasurfaces under the incidence of SH0 wave with arbitrary wave fronts was proposed. Two types of metasurfaces, i.e. the flat lenses and the ring-type source illusion devices, were designed to validate the proposed design method. Both simulations and experiments were conducted in which the thickness-shear d15 piezoelectric rings and strips were used as the SH0 wave exciters and the d24 face-shear wafers were used as the wave receiver. Results showed that using the proposed method, different functional metasurfaces can be designed and work well under arbitrary wave fronts incidence. The proposed metasurface design method is potentially useful for practical applications such as nondestructive testing, advanced signal modulation and seismic wave controlling.

A Low-Profile and High-isolated MIMO Antenna for 5G Mobile Terminal.

An eight-element multiple-input multiple-output (MIMO) frame antenna array in the 3.5 GHz band (3400–3600 MHz) for 5G mobile terminal systems was presented. By using the adjacent grounding and electromagnetic coupling feeding technology, the loop antenna element could generate two resonant frequencies, thus effectively expanding its bandwidth. By adopting double-sided parallel strip line (DSPSL) technology, the electromagnetic coupling inside the loop antenna could be adjusted, and the size of the loop antenna could be effectively reduced so that the MIMO antenna array could obtain a low-profile structure. The total size of the MIMO array was 150 mm × 75 mm × 5.3 mm. Without additional isolation measures, the measured −6 dB impedance bandwidth (BW) was 3400–3660 MHz, and the minimum isolation between antenna elements was better than −20 dB. The proposed antenna was expected to be applied to 5G mobile terminals based on its low-profile, high-isolated characteristics, and good MIMO performance.

Cities of the future: a building typology with optimal daylighting

A novel building typology consisting in the use of optical filters in smart windows to achieve comfortable conditions of natural lighting and insolation indoors is presented. Thin-film chromogenic parallel strips on two surfaces of pane(s) of the window form two gratings providing the angular-selective light transmission. The design and principle of operation of the smart window and methods for calculating filter parameters are briefly described. The principles of using smart windows with optical filters are demonstrated on an example of a complex of three buildings.

Influence of inlet/outlet arrangement on flow boiling of a parallel strip fin heat sink

This paper experimentally investigates a parallel strip fin heat sink (PSFHS) with various types of inlet/outlet arrangements (IOAs) including I-type, L-type, and U-type. The heat sink contains 150 fins 1 mm wide and 5.5 mm high on a square in-line configuration with a 1 mm pitch. Nine thermocouples are placed inside the base plate of the heat sink to map the temperature distribution in it. Because of the difference in IOAs, the resultant temperature distributions are different. The corresponding boiling curves and flow pattern are discussed in detail. In addition, the two-phase thermal resistance and temperature uniformity are utilized to evaluate the thermal performance of the heat sink. The experiment results show that the inlet/outlet arrangements have a significant influence on local dry out and temperature distribution, both of which are also affected by the discontinuous passage configuration. It is found that L-type PSFHS has relatively small thermal resistance with a moderated temperature uniformity, and I-type PSFHS has the worst performance in temperature distribution.

Design of capacitance sensor for two phase flow monitoring based on finite element models

Monitoring water-oil two-phase flow is of great industrial significance. In this work, an electrical capacitance sensor was designed and tested to monitor the two-phase flow. In order to optimise the capacitance sensor for two-phase flow monitoring, it is necessary to analyse capacitance sensors with different geometries. In this paper, the capacitance sensors with concave plates, double ring electrodes, helical electrodes, parallel strips and perpendicular strips are proposed and briefly introduced. The Finite Element (FE) models for capacitance sensors were constructed in COMSOL Multiphysics, and the preliminary experiments were carried out. Both simulation and experimental results show that the capacitance of the sensor tends to increase with the decreased oil content. The measurement sensitivity distributions obtained from FE models vary with different electrode geometries, based on which design parameters can then be selected to address different requirements.

Switchable Slant Polarization Filtering Antenna Using Two Inverted Resonator Structures for 5G Application

This study presents a novel design of two filtering antennas with a +45° and −45° slant polarization, using the co-design of a third-order filter and a rectangular patch antenna. Slant polarization is obtained by directing the surface current that flows to the radiator by applying two parallel inverted resonators in the transmission line. The resonators consist of two parallel strips with alternate open and short circuits at each end and the 45° and −45° polarization is determined from these short circuit positions. The rectangular patch antenna is fed using proximity coupling, and it is parallel to the resonators. The filtering antennas provide not only 45° slant polarization, a flat gain response but also a controllable bandwidth. Operating at 4.65 GHz for 5G application, the antennas have a controllable bandwidth range from 5.9% to 8.4% without affecting the polarization and center frequency. The gain responses are filter like and attain the maximum value of 6.82 and 6.69 dBi at 4.7 GHz. This design needs no extra component or rotation of the radiator and transmission line because the inverted resonators can switch the polarization to be +45° and −45°. The results of the 45° and −45° polarization filtering antenna simulation and experiments are consistent with each other.

Design of capacitance sensor for two phase flow monitoring based on finite element models

Monitoring water-oil two-phase flow is of great industrial significance. In this work, an electrical capacitance sensor was designed and tested to monitor the two-phase flow. In order to optimise the capacitance sensor for two-phase flow monitoring, it is necessary to analyse capacitance sensors with different geometries. In this paper, the capacitance sensors with concave plates, double ring electrodes, helical electrodes, parallel strips and perpendicular strips are proposed and briefly introduced. The Finite Element (FE) models for capacitance sensors were constructed in COMSOL Multiphysics, and the preliminary experiments were carried out. Both simulation and experimental results show that the capacitance of the sensor tends to increase with the decreased oil content. The measurement sensitivity distributions obtained from FE models vary with different electrode geometries, based on which design parameters can then be selected to address different requirements.

Studija slučaja uređenja i korišćenja zemljišta za određivanje načina upravljanja zemljištem koji se može primeniti u poljoprivrednoj praksi za sprečavanje erozije i gubitka plodnog zemljišta

The Büyük Melen river in the Melen Basin meets Istanbul's drinking water needs. Protecting the basin against nutrient pollution is vital in this regard as well. This study focuses on the best possible management practice (BMPs) in the Melen Basin to reduce the export of nutrients from the agricultural areas. A region comprising industrial, farming, and residential zones is the Melen basin. There is a forecast of global climate change in Turkey, and scientists and also governors must know which areas are no longer farming zones and which will be more appropriate for agriculture. Turkey's territory is a high-risk desertification area. In Melen Basin, the soil type and land use properties have been determined and mapped using GIS and Soil and Water Assessment Tool (SWAT). Buffer BMP filter strips can be used effectively for nutrient protection that can be carried from residential areas and motorways by runoff. The region in the basin is steep, and its clay and sandy soil structures are ideal for parallel terraces, grade stabilization, strip, and contour cultivation. Unless the ground can not retain or store water, the soil can undergo sudden floods, causing an erosion of the soil's productive surface layer. When we protect the land, this condition is reduced. The land type and land use mapping should be drawn up as soon as possible for the remaining Turkish basins by scientific methods. This research is intended to be an illustration for researches on other agricultural basins in Turkey and the world for this reason.

Pollen-derived porous carbon decorated with cobalt/iron sulfide hybrids as cathode catalysts for flexible all-solid-state rechargeable Zn-air batteries.

The development of flexible all-solid-state rechargeable Zn-air batteries (FS-ZABs) for wearable applications faces challenges from the balance between performance and flexibility of the battery; efficient cathode catalyst and reasonable electrode construction design are key factors. Herein, a low-cost pollen derived N,S co-doped porous carbon decorated with Co9S8/Fe3S4 nanoparticle hybrids (Co-Fe-S@NSRPC) has been synthesized. Owing to the active Co9S8/Fe3S4 nanoparticles, N,S co-doping, and large specific area of the pollen derived porous carbon matrix, the Co-Fe-S@NSRPC composite exhibits an excellent bifunctional catalytic activity with a small potential gap (ΔE = 0.80 V) between the half-wave potential for the ORR (0.80 V) and the potential at 10 mA cm-2 for the OER (1.60 V), and endows a liquid Zn-air battery with a high power density of 138 mW cm-2, a larger specific capacity of 891 mA h g-1 and a stable rechargeability of up to 331 cycles. Based on the Co-Fe-S@NSRPC cathode catalyst, a 2D coplanar FS-ZAB has been fabricated with specially designed parallel narrow strip electrodes alternately arrayed on a polyacrylamide polyacrylic acid copolymer hydrogel solid electrolyte. The presented FS-ZAB exhibits excellent battery performance with high open-circuit-voltage (1.415 V), competitive peak power density (78 mW cm-2), large specific capacity (785 mA h g-1) and stable rechargeability (150 cycles), offers robust flexibility to maintain stable charge/discharge capacity under different bending deformations, and provides convenient coplanar integrability to realize parallel or series connection of multiple cells in a relatively small area.

Modular Design for a Stacked SIW Antenna Array at Ka-Band

This article presents a modular substrate-integrated waveguide (SIW) antenna array based on H-plane aperture structures for Ka-band. The unitary antenna is based on a SIW aperture antenna with an improved H-plane radiation pattern by means of the implementation of metallic vias in the wave propagation along the H-plane antenna. The inner metallic vias are introduced to form four different sub-apertures at the end of the H-plane aperture antenna, dividing the field from the feeding into four in-phase wavefronts. In that manner, a flatter wavefront is generated to achieve high directivity. Additionally, some periodic parallel strips are printed at the end of the antenna aperture to improve the impedance matching with the air. The H-plane antenna is used as the constituting element for an E-plane array antenna, using four H-plane elements. The E-plane array antenna increases the antenna directivity, providing a pencil-shape beam, based on a series coaxial feeding structure. This feeding strategy favours the antenna modularity at the expense of suffering from a slight beam steering with frequency in the working bandwidth. The proposed antenna has an impedance matching below -10 dB from 32.9 to 37.0 GHz (equivalent to 11.73% bandwidth) with a nearly stable gain of almost 10 dBi for the H-plane unitary element and 14 dBi for the E-plane array. Prototypes of both antennas are manufactured to validate the proposed unitary antenna and array designs.

Предпосевная обработка семян озимой пшеницы поверхностным разрядом

The experimental results of the surface barrier discharge plasma products effect on soft winter wheat seeds in electrode configurations consisted of the parallel strips at a distance of 5 and 10 mm from each other are shown. In each electrode system, the seed treatment was carried out for 10, 60, 120 and 180 s at the sinusoidal voltages of 1.8, 2.1, 2.4 or 2.7 kV with the frequency of 4.4 kHz applied to the electrodes. The seeds were placed in one layer on the grounded plane at the distance of 10 mm from the dielectric barrier surface. The treatment effect was estimated by the morphological characteristics of 3-day seedlings. To control the airflow in the gap, the particle imaging visualization method was used. It is shown that treatment modes are divided into two principal groups. The first group represents the modes when the airflow reaches the plane on which the seeds are located, the second group represents the modes when the airflow does not reach this plane. In the first case (the distance between the strips is 10 mm, the voltage is 2.4−2.7 kV at all exposures), it is possible to achieve modes that stimulate germination. Seed germinating ability did not change and maintained high values at all considered modes.

A Multi-Frequency Patch Antenna With Double Sided Parallel Strip Line Periodic Structure

A multi-frequency patch antenna with double-sided parallel-strip line (DSPSL) periodic offset structure is proposed. The designed antenna consists of a simple rectangular patch as well as an embedded one-dimensional DSPSL periodic offset structure, which is employed to replace the traditional rectangular microstrip patch antenna. The periodic DSPSL structure is characterized leaky wave structure. After the periodic DSPSL structure is embedded, the resonance frequency of rectangular patch is offset, and the leaky wave characteristics can determine the number and position of new operating frequencies. As an application, a tri-band antenna is manufactured and these three operating frequencies can be calculated by the derived formulas studied in this communication. Experiment results suggest that the antenna can work at 4.28, 4.78, and 6.42 GHz, respectively. The results of simulated, measured and calculated show high consistency.

Evaluation of the dielectric rod attenuation using the modified parallel strips that provide a relatively reasonable field environment

A thin film is often coated on the dielectric rods used in traveling wave tubes to provide microwave attenuation. The quality of the thin film will affect the performance of the traveling wave tube. To evaluate the quality of the thin-film by measuring the attenuation performance of the dielectric rod, modified parallel strips with a sample hole are designed to provide a relatively reasonable field working environment for the attenuation evaluation. After analyzing the field distribution of the parallel strips, a sample hole is designed on the side of parallel strips, which is tangent with the outer edge of the strip. An arcuate taper is introduced into the parallel strips to reduce the impedance mismatching. Finally, two unqualified and qualified dielectric rods are measured using the modified parallel strips at frequencies 12 GHz and 18 GHz. The measured results indicate that it is feasible to evaluate whether the thin-film coated on the dielectric rod is qualified or not.

Low-Cost Inkjet-Printed RFID Tag Antenna Design for Remote Healthcare Applications

This paper presents a low-cost, inkjet printed radio frequency identification (RFID) tag antenna for remote healthcare applications. The electrically small tag consists of nested-slot configuration and parallel strips. The tag antenna is exploited as a sensor by modifying its equivalent circuit to mitigate the effects of water, blood sample phantom, and the human body. As a result, the proposed RFID tag antenna with compact dimensions of 40 × 14 mm2, features a conjugate match with Impinj R6 RFID chip ranging from 890 to 937 MHz. Moreover, this tag has a read range of 3 m, 2.5 m, and 1.5 m on the water bottle, intravenous (IV) solution and blood bag, respectively. However, the read range of RFID tag on an empty water bottle or IV solution bag is 0.5 m. By comparing the read range of tag on empty and solution filled IV bags, the proposed tag was used as a water proximity sensor. Experimental testing of the tag is performed for sensing the level of the IV solution. Also, this tag is tested after mounting on the liquid mixture (a mixture of salt and sugar is used as a phantom to mimic the blood) filled plastic bags, which leads to a low-cost solution for blood storage management. Experimental results show a good agreement of the proposed tag toward its use in healthcare applications, which leads to better healthcare facilitation regarding cost, time, and care.