Search

The Kosciuszko Bridge carries a 1.8 km long segment of the Brooklyn–Queens Expressway over Newtown Creek between Brooklyn and Queens in New York City, USA. The roadway is a vital link in the region's transportation network, carrying over 170 000 vehicles/day. Owing to structural and operational deficiencies, the existing structure was replaced. The new bridge consists of two parallel structures, one eastbound and one westbound, with main spans mirroring one another. Each structure consists of a single-tower cable-stayed main span over Newtown Creek with unbalanced main and back spans. This was the first cable-stayed bridge to be constructed in New York City, joining the ranks of the city's most iconic bridges. Here, two main span structures are discussed, with the focus primarily on the design and construction of the westbound, phase 2 bridge. Some key design aspects are outlined, including outboard cable anchorages, a concrete-filled counterweight and other details intended to facilitate construction, maintenance and inspection. The eastbound, phase 1 bridge was constructed under a design–build contract, and the westbound, phase 2 bridge as a design–bid–build. The paper also touches on some of the design aspects that were refined during the second phase.

A wideband single-fed circularly polarized (CP) stacked patch antenna with an L-shaped stub is presented. The CP antenna is made up of the bottom gradient microstrip transmission line, middle driven patch and top square radiation patch. The driven patch with an L-shaped stub and opening slot can achieve a wideband CP radiation which is different from a conventional patch. The presented CP stacked patch antenna maintains good directional radiation, while featuring wideband CP radiation. The final tested results indicate that the presented CP antenna has significant performance with a −10 -dB impedance bandwidth of 42.1% (4.26-6.53 GHz), a 3-dB AR bandwidth of 26.0% (4.36-5.66 GHz) and broadside peak gain of 8.6 dBic. Moreover, the fifth-generation (5G) N79 band (4.4-5.0 GHz) and 5G wireless local area network (WLAN) band (5.15-5.35 GHz) can be covered by the operating bandwidth of the presented CPantenna.

In this communication, a dual-polarized filtering magneto-electric dipole (FMED) antenna and arrays are proposed for 5G n258 (24.25-27.5 GHz) operations. The FMED antenna was devised to incorporate filtering mechanisms using a built-in substrate integrated waveguide (SIW) based filter plus slot-and-notch etching on the dipole element. As such, lower and upper radiation cutoffs and nulls were produced and tuned, independently. To overcome the problem of “high selectivity” of a filtering antenna that has not been correctly quantified and thus has no comparison, a new skirt measure metric named as radiation suppression index is initiated here. Design steps of the FMED element and novel feeding techniques are elaborated, where the SIW-based series-parallel slot-coupled feeders and the slot-coupled differential power divider were conceived for large-size array, to combat with the insertion losses. A prototype of the 4×4 FMED array was implemented and tested for experimental verification. A high gain of 16.8±1.4 dBi with a 3-dB gain bandwidth of 24-27.7 GHz and a radiation efficiency of 78% were accomplished.

Advanced microwave absorption (MA) materials have attracted widespread attention to meet the challenges of electromagnetic (EM) pollution. Herein, MgFe2O4/MgO/C fibers were successfully prepared via electrospinning technology and carbonization, and their surfaces were coated by MoS2 via hydrothermal method. The EM wave absorption performance of composites was enhanced due to the introduction of MoS2. The results showed that the EM wave absorption performance of MgFe2O4/MgO/C could not meet the requirements due to low dielectric loss and poor impedance matching. The performance of the composites was improved after coating of MoS2, which showed the strong wave absorption capability and the broad absorption bandwidth. The optimal reflection loss (RL) is −56.94 dB at 9.5 GHz and the effective absorption bandwidth is 3.9 GHz (8.08–11.98 GHz) with a thickness of 2.7 mm. The excellent MA performance can be mainly attributed to excellent synergistic effect between MgFe2O4/MgO/C and MoS2. Furthermore, MoS2 also contributes to dielectric loss and ideal impedance matching. MgFe2O4/MgO/C@MoS2 composites may be utilized for lightweight and high-efficient MA materials.

Combination therapies with agents targeting the DNA damage response (DDR) offer an opportunity to selectively enhance the therapeutic index of chemoradiation or eliminate use of chemotherapy altogether. The successful translation of DDR inhibitors to clinical use requires investigating both their direct actions as (chemo)radiosensitizers and their potential to stimulate tumor immunogenicity. Beginning with high-throughput screening using both viability and DNA damage-reporter assays, followed by validation in gold-standard radiation colony-forming assays and in vitro assessment of mechanistic effects on the DDR, we describe proven strategies and methods leading to the clinical development of DDR inhibitors both with radiation alone and in combination with chemoradiation. Beyond these in vitro studies, we discuss the impact of key features of human xenograft and syngeneic mouse models on the relevance of in vivo tumor efficacy studies, particularly with regard to the immunogenic effects of combined therapy with radiation and DDR inhibitors. Finally, we describe recent technological advances in radiation delivery (using the small animal radiation research platform) that allow for conformal, clinically relevant radiation therapy in mouse models. This overall approach is critical to the successful clinical development and ultimate Food and Drug Administration approval of DDR inhibitors as (chemo)radiation sensitizers.

Nowadays, ferrites/carbon fibers have attracted considerable attention as microwave absorption materials (MA) due to the synergistic effect between dielectric and magnetic loss. Herein, the ZnFe2O4/C fibers were fabricated via electrospinning and calcination methods, and then polypyrrole (PPy) successfully coated on the fibers via oxidative polymerization. The ZnFe2O4/C@PPy composites exhibit enhanced EM wave absorption performance with the loading of 25 wt%. The optimal reflection loss (RL) value is up to −66.34 dB (13.80 GHz) and effective absorption bandwidth (EAB) is 5.74 GHz (11.78–17.52 GHz) with a matching thickness of 1.93 mm. Besides, high-efficient absorption performance of the ZnFe2O4/C@PPy composites is mainly attributed to the dielectric loss and ideal impedance matching. This study reveals a novel approach to development of ferrites/carbon fibers coated with PPy, and the ZnFe2O4/C@PPy composites exhibit great potential application as the materials with high-efficient absorption properties.

Metal-organic framework (MOF) materials have caused widespread concerns in the field of microwave absorption, due to the unique microstructure and electronic state. Herein, the CoZn/C@MoS2@polypyrrole (PPy) composites were prepared through MOF self-template method. The MoS2 sheets and PPy shell incorporated for optimizing impedance matching of two-dimensional (2D) CoZn/C composites. The introduction of MoS2 sheets and PPy shell endowed the composites with enhanced microwave absorption. The as-prepared CoZn/C@MoS2@PPy composites showed a minimum reflection loss (RL) of −49.18 dB with the thickness of 1.5 mm. In addition, the effective absorption bandwidth (EAB, RL values exceeding −10 dB) covered 4.56 GHz, which showed greater performances than CoZn/C composites under a lower thickness (

In this work, one-dimensional (1D) ZnFe2O4@carbon@MoS2/FeS2 composites were synthesized by hydrothermal method, magnetic-field-induced distillation-precipitation polymerization and high-temperature carbonization. The structure, morphology, composition, magnetic performance and electromagnetic (EM) wave absorbing properties of the composites were systematically studied. The composites show strong microwave absorption (MA) capacity with a minimum reflection loss (RLmin) value of −52.5 dB at 13.2 GHz, and have an effective absorption frequency range of 10.10–15.08 GHz with a bandwidth of 4.98 GHz when the thickness is 2.23 mm. It is expected that as-synthesized 1D ZnFe2O4@carbon@MoS2/FeS2 composites can be a promising EM wave absorption material.

New types of electromagnetic (EM) wave absorption materials with a light weight, strong absorption ability and wide absorption frequency have been widely explored. Nevertheless, it is still an intractable challenge to design the structure of the materials and rationalize multiple components. In this work, one-dimensional (1D) CoFe2/C@MoS2 composites were prepared via electrospinning technology, high-temperature carbonization and hydrothermal method. SEM and TEM images reveal that the as-prepared CoFe2/C fibers with a 1D structure are well coated with MoS2. The excellent absorption performance of the composites is mainly attributed to the 1D structure and the ideal impedance matching. CoFe2/C@MoS2 composites show strong absorption ability with an optimal reflection loss (RL) of -66.8 dB (13.28 GHz) at a matching thickness of 2.12 mm. Meanwhile, the composite possesses an effective absorption frequency range between 10.70 and 16.02 GHz with a bandwidth of 5.32 GHz. These results indicate that CoFe2/C@MoS2 composites will become promising lightweight and highly efficient MA materials.

A dual circularly polarized (CP) magnetoelectric dipole antenna is presented in this article. The dual-CP antenna was devised to form a circular ring shape and fabricated using 3-D printing technology. To overcome the conflict between high (broadside) gain and wide (half-power) beamwidth, a new beamwidth broadening technique was proposed. Twelve meta-columns were placed evenly along the circumference close to the ring-shaped dipole. A design approach is elaborated, where the number and size of meta-columns were decided according to the design curves. Symmetrical beamwidth of 108° in orthogonal planes with a broadside gain of 6 dBic was achieved across a wide effective bandwidth from 3.2 to 5.4 GHz (51%), sufficiently covering the 5G new radio (NR) bands: $n77, n78, n79$ . The antenna owns a compact size of $0.83 \times 0.83 \times 0.18\lambda ^{3}$ at 4.15 GHz. A planar subarray composed of four dual-CP elements was also investigated and compared with the existing arrays.

In this paper, we propose a newly developed impedance method to gauge the variations of multidirectional strain using a near-circular-patch based sensor. A novel three-dimensional (3D) feeding mechanism realized by a 90-deg bended microstrip line is devised for allowing strain detection along any direction in the azimuth plane of a metallic surface. The simulated results, verified by experimental results, demonstrate that there is a linear relationship between normalized impedance and multi-directional strain with high sensitivities of about 100 ppm/μe. The relationship between sensitivity and sensor orientation is derived as a cosine function, which is a useful feature for estimating principal strain direction.

A compact wideband circularly polarized (CP) magneto-electric (ME) dipole antenna array is proposed. In order to achieve compact size and wideband characteristics, a novel substrate integrated waveguide (SIW) to coaxial transition (SCT) was designed to connect the lightning-shaped ME-dipole antenna element and an SIW feeding network. Particularly, an SCT-based power divider network together with the sequential-rotation (SR) technique was employed to improve the axial ratio (AR) bandwidth of the $4\times 4$ antenna array. The antenna array prototype was fabricated to verify the design. Measured results show that an impedance bandwidth of 27.7% (23.3–30.8 GHz) and 3 dB gain bandwidth of 25.3% (23.5–30.3 GHz) were achieved. Moreover, a 3 dB AR bandwidth of 27.8% (23.2–30.8 GHz) with a peak gain of 20.2 dBic was also recorded. Therefore, it is a good candidate for the fifth-generation (5G) millimeter-wave (mm-wave) communications.

In this paper, a tri-band unidirectional printed antenna is presented. By employing a torch-shaped structure to cooperate with a pair of side-by-side rectangular patches, triple band characteristics are realized. Simulation results show that the working frequency bands are 806-960 MHz, 1.71-2.7 GHz and 3.3-3.7 GHz, respectively, which cover the LTE700/ GSM850/ GSM900, S-band and WLAN frequency bands. A compact and simple structure with good radiation characteristics is achieved by the proposed antenna, which is suitable for multi-frequency wireless communications.

This paper presents a correlation study into a circularly-polarized multiple-input-multiple-output (CP-MIMO) antenna array of Chinese-character-shaped patch antennas. Isolation between CP Zhong- and Guo-shaped patch antenna elements are first examined. Our results indicate that the non-identical elements exhibit linear isolation increment against the element separation. The envelope correlation coefficient is then computed using the S-parameter method, which provides a fast estimation. At 2.5 GHz, the ECC is obtained better than -30 dB at a separation of 80 mm. An average reduction rate of -2.7 dB/cm is deduced.

New types of electromagnetic (EM) wave absorption materials with a light weight, strong absorption ability and wide absorption frequency have been widely explored. Nevertheless, it is still an intractable challenge to design the structure of the materials and rationalize multiple components. In this work, one-dimensional (1D) CoFe

Early determination of correct cement dosage for concrete mixes and prediction of their compressive strengths are very valuable in construction industry. This article presents a few compressive-strength prediction models for ordinary concrete using early-age measurements of relative complex permittivity. Both the dielectric constant and loss factor of the first-seven-day concrete with four types of mix proportions were measured for building the mathematical models composed of exponential functions at 6 GHz, whereas the measured dielectric data at 28 d were used for model validations. The proposed models not only have high regression accuracy with R2-values of greater than 0.97 but also the low prediction errors of within 10%, which significantly outperform the existing models of the same kind. Through Cole–Cole plot analysis, this article reveals an interesting finding that a minimum loss factor was located at 3 GHz regardless of the age of concrete, which would be useful for wireless network design and planning inside a building. The average loss tangents of various concrete mixes have also been verified to have the same value (~ 0.33) regardless of concrete age, which explains the confidence in use of early-age dielectric properties. Moreover, this article also initiates a precise prediction method of using loss factor and dielectric constant simultaneously in a 3-dimensional plot, wherein no explicit mathematical model is required.

Advanced microwave absorption (MA) materials have attracted widespread attention to meet the challenges of electromagnetic (EM) pollution. Herein, MgFe

This contribution presents a novel design of a circularly polarized (CP) array antenna composed of the Chinese character-shaped artistic patches: Zhong and Guo . Namely, the CP Zhong-shaped patch and the Guo-shaped patch join together via a feeding network to form a two-element antenna array. This is the Chinese country name of China printed in the boldfaced SimHei font. Attributed to its artistic nature, this is the first design that breaks the design principles of CP antenna array, wherein, first, nonidentical radiating elements are used, and second, nonrotated elements are excited with quadrature phases. The experimental results in combination with simulations validate that the Zhong–Guo artistic antenna exhibits a unidirectional gain of 8.2 dBic with an operating bandwidth of 0.72 GHz. The achieved bandwidth sufficiently covers the 14 channels of IEEE 802.11 at 2.4 GHz wireless local area network band.

This contribution presents a novel 3-D circular conformal MIMO antenna system composed of three magneto-electric dipoles (MED) antennas. The single MED element was delicately designed to include one main (lower-band) dipole and two auxiliaries (upper-band) dipoles in order to achieve the dual-band radiation. The proposed MED owns a low-profile conformal geometry but features a wide H-plane beamwidth (minimum 103°). By embedding the metamaterial of the broadside-coupled E-shaped unit cells into the magnetic dipole, the height of MED can be dramatically reduced by 37.2% as compared with the conventional ones. Meanwhile, the two U-shaped notches together with a rectangular notch were included onto the E-dipole to create a band-notch, which offers the anti-interference capability to the ubiquitous 2.4-GHz signal of the wireless local area network. According to the measurement results, the MED element exhibits an impedance bandwidth of 54.2% (1.68-2.93 GHz) with a stable gain of 6.05± 1.15 dBi in the lower band and 9.2% (3.32-3.64 GHz) with 5.71 ± 0.7 dBi in the upper band, respectively. Moreover, the three-element MIMO system provides quasi-omnidirectional coverage in the H-plane from 1.68 to 3.64 GHz. The outstanding performance metrics validate the proposed ME dipole antenna that is well suited for the future sub-6-GHz fifth-generation MIMO mobile base stations.

Nowadays, ferrites/carbon fibers have attracted considerable attention as microwave absorption materials (MA) due to the synergistic effect between dielectric and magnetic loss. Herein, the ZnFe

Metal-organic framework (MOF) materials have caused widespread concerns in the field of microwave absorption, due to the unique microstructure and electronic state. Herein, the CoZn/C@MoS

In this work, one-dimensional (1D) ZnFe

As a newly invented technology, ionizing radiation acoustic imaging (iRAI) provides a potential solution for in vivo dosimetry and real-time online monitoring of radiation beam position during external beam radiotherapy, including both conventional and FLASH radiotherapy. In this study, the dose resolution as low as 1% from a single pulse was achieved, demonstrating a clinically acceptable sensitivity of iRAI in mapping the dose deposition. The relative displacement of the radiation beam with respect to the target tissue can be visualized in real time by our clinically ready iRAI and ultrasound (US) dual-modality imaging system.

This paper introduces a Chanel-logo shaped antenna. By characteristic mode analysis (CMA), modal significance and modal radiation patterns of different modes were studied and find the suitable mode that can be easily excited. The Y-shaped feeding structure was chosen to excite the desired modes and have a good impedance matching. The simulation results indicated that the 10-dB return loss bandwidth of 2.5-4 GHz (46.2%) is obtained. This work demonstrates feasibility of future application in product advertisement.

In this paper, a metasurfaced circularly-polarized (CP) antenna with a double-layer structure is proposed for the electronic toll collection (ETC) system. The antenna composed of dual layer of printed circuit board (PCB) with an overall height of 6 mm. The top-layer (Layer 2) is a metasurface that made with 4×4 unit-cells of chamfered square patches. The driven patch is printed with a U-slot at the bottom layer (Layer 1). The addition of metasurface helps to achieve narrow beam width with a high gain. The simulation results demonstrate that the proposed metasurfaced CP antenna exhibits a mandated right-hand narrow beamwidth in the desired ETC frequency band, whereas its broadside gain is obtained greater than 6.5 dBic. In addition, both the achieved impedance bandwidth and axial ratio bandwidth are sufficient to cover the entire ETC band (5.75 GHz-5.9 GHz).

In order to solve the scarcity problem of microwave spectrum resources, this paper proposed a tri-band Wilkinson power divider(WPD) based on a triple section stepped impedance resonator. The tri-band WPD introduces a triple section stepped impedance resonator and an open stub to achieve tri-band making the power divider have filtering properties. The board size of WPD is 25×20mm2. The simulated results show that the center frequencies of the tri-band WPD is 2.45 GHz, 4.41 GHz and 6.11 GHz respectively, the reflection is less than -10dB, the isolation is less than -15dB, and the insertion loss is less than 4dB.

We propose a newly developed “phase-area method” to gauge the variations of multidirectional strain using a circularly-polarized (CP) patch antenna sensor excited by a proximity-coupled microstrip line in this paper. In order to minimize the physical size of sensor, high-dielectric-constant RO3010 dielectric laminate is used as the substrate for the antenna sensor, thus the sensor owns a small patch size of 17.66mm×18.46mm. A proof-of-concept prototype has been conducted to reveal the principle of multidirectional strain detecting through the concept of orthogonal modes (TM10 & TM01). Very high sensitivities of −106.8 and +71.2 ppm/μe have been achieved for the x- and y-directional strain, respectively.

This paper presents a 1x3 circularly-polarized patch antenna array designated as the Chinese dream antenna array. The three-element array was implemented by using Chinese character-shaped artistic patch antennas (APAs): Zhong-Guo-Meng. The individual patch antennas radiate right-handed circular polarization (RHCP) in the broadside direction, and excited by a one-to-three power divider with equal-power distributions as its feeding network. The CP antenna array exhibits an axial ratio bandwidth and an impedance bandwidth of 310 MHz and 835 MHz, respectively, at a center frequency of 2400 MHz.

This paper presents the results of mutual coupling study into Chinese-character-shaped patch antennas. A number of two-element arrays composed of side-by-side identical and non-identical circularly polarized (CP) antenna elements are investigated. Our results reveal that the Guo-Meng array of nonidentical elements exhibit better coupling reduction with less fluctuation versus frequency as compared with the Guo-Guo and Meng-Guo scenarios. A new reduction technique is also introduced here to suppress the mutual coupling below −20 dB at, and beyond, the separation of 0.75 wavelengths at 2.5 GHz.