The surface defects of a hot-rolled strip will adversely affect the appearance and quality of industrial products. Therefore, the timely identification of hot-rolled strip surface defects is of great ...significance. In order to improve the efficiency and accuracy of surface defect detection, a lightweight network based on coordinate attention and self-interaction (CASI-Net), which integrates channel domain, spatial information, and a self-interaction module, is proposed to automatically identify six kinds of hot-rolled steel strip surface defects. In this paper, we use coordinate attention to embed location information into channel attention, which enables the CASI-Net to locate the region of defects more accurately, thus contributing to better recognition and classification. In addition, features are converted into aggregation features from the horizontal and vertical direction attention. Furthermore, a self-interaction module is proposed to interactively fuse the extracted feature information to improve the classification accuracy. The experimental results show that CASI-Net can achieve accurate defect classification with reduced parameters and computation.
This article discusses the design of the beam-steerable aperiodic linear array antenna with improved sidelobe level (SLL), using the strip-projection method. The strip projection method uses the area ...of rotated higher-dimensional lattice and projects it to lower dimensions to generate an aperiodic array. This article describes the modeling and analysis of such an array and its optimization for the desired far-field performance. The aperiodic arrays are also generated using various evolutionary optimization algorithms, namely genetic algorithm (GA), particle swarm optimization (PSO), and Jaya algorithms. The far-field performance of the generated aperiodic arrays is compared with the conventional periodic array. The proposed 21-element aperiodic array is also populated with a X-band electromagnetically coupled patch antenna and phase shifter designed using varying width of the high dielectric material. The aperiodic patch array antenna is also developed and characterized for various beam scan angles. A significant improvement of 5.72 dB in peak SLL is achieved at ±30° beam scan angle.
A two-phase Eulerian-Eulerian volume-averaged model was used to predict the outcome of the twin-roll casting process for inoculated Al-4 wt.% Cu alloys. The model is able to address the deformation ...of the mush during hot rolling by treating the solid/liquid mixture as a viscoplastic skeleton saturated with liquid. A parameter measuring the mean absolute deviation around the nominal composition was applied to the normalized macrosegregation distribution and the results were then used to determine an optimal process window where minimal compositional variation is achieved in the final strip. In the case of casting an 8 mm thick Al-4%Cu strip with rolls of 800 mm diameter, casting speeds between 40 and 42 mm/s and heat transfer rates given by HTCs between 5000 and 5250 W/m2/K minimize the macrosegregation deviations in the strip and thus predict an optimal strip quality.
Quality control of the surfaces of rolled products has received wide attention due to the crucial role that these products play in the manufacture of various car bodies, planes, ships, and trains. ...The process of quality control has undergone remarkable development. Previously, it was based on the human eye and characterized by slowness, fatigue, and error. To overcome these problems, nowadays the quality control is based mainly on computer vision. In this context, we propose in this work to develop an intelligent recognition system of surface defects for hot-rolled steel strips images using modified AlexNet convolution neural network and support vector machine model. Furthermore, we conducted a study on the effect of layers selection on classification accuracy. We have trained and tested our classification model using a public database of Northeastern University composed of 1800 images of defects. The results showed that our classifier model can be used easily for effective screening of surface defects for hot-rolled steel strips with very a high classification accuracy up to 99.7%, using only 7% of the total extracted features for each image with activations on the fully connected layer “FC7.” In addition, we addressed through this research a comparative study between the proposed classification model and the well-known modern classification models. This study highlighted the efficiency and effectiveness of our proposed model for the classification of surface defects.
Functionally similar to the tight junctions present in animal guts, plant roots have evolved a lignified Casparian strip as an extracellular diffusion barrier in the endodermis to seal the root ...apoplast and maintain nutrient homeostasis. How this diffusion barrier is structured has been partially defined, but its lignin polymerization and assembly steps remain elusive. Here, we characterize a family of dirigent proteins (DPs) essential for both the localized polymerization of lignin required for Casparian strip biogenesis in the cell wall and for attachment of the strip to the plasma membrane to seal the apoplast. We reveal a Casparian strip lignification mechanism that requires cooperation between DPs and the Schengen pathway. Furthermore, we demonstrate that DPs directly mediate lignin polymerization as part of this mechanism.
Editor’s summary
Plant roots contain a lignin-based diffusion barrier called the Casparian strip that controls nutrient balance. Gao
et al
. found that a family of dirigent proteins controls the synthesis of lignin at the Casparian strip. The authors established a two-stage process of synthesis in which the dirigent proteins initiate lignin biosynthesis in plasma membrane patches. After this, gaps between the patches are filled in by the previously described Schengen pathway. The work extends our understanding of complex polysaccharide patterning in the plant extracellular space. —Madeleine Seale
Dirigent proteins mediate lignin polymerization in the Casparian strip to seal the root.
The hydraulic performance of grass swales as a highway stormwater control measure was evaluated in a field-scale study adjacent to a Maryland highway. Two common swale design alternatives, ...pretreatment grass filter strips and vegetated check dams, were compared during 52 storm events over 4.5 years. Swale performance is described via three regimes, dependent on the relative size of the rainfall event. Overall, half of the events were small enough that the entire flow was stored, infiltrated, and evapotranspirated by the swales, resulting in no net swale discharge. Swales significantly reduced total volume and flow magnitudes generally during events with rainfall less than 3 cm. While the majority of improvement can be attributed to the swales, inclusion of check dams increases swale effectiveness. Pretreatment grass filter strips produced mixed effects. The swales demonstrated essentially no volumetric reduction during large storm events, functioning instead as conveyance, and smoothing fluctuations in flow.
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► The hydraulic performance of grass swales was evaluated in a field-scale study. ► Swale performance is described via three regimes, dependent on the rainfall size. ► Half of the events were small enough that there was no net swale discharge. ► Inclusion of check dams increases swale effectiveness. ► Swales demonstrated minimal volumetric reduction during large storm events.
Screening asymptomatic organisms (humans, animals, plants) with a high‐diagnostic accuracy using point‐of‐care‐testing (POCT) technologies, though still visionary holds great potential. Convenient ...surveillance requires easy‐to‐use, cost‐effective, ultra‐portable but highly reliable, in‐vitro‐diagnostic devices that are ready for use wherever they are needed. Currently, there are not yet such devices available on the market, but there are a couple more promising technologies developed at readiness‐level 5: the Clustered‐Regularly‐Interspaced‐Short‐Palindromic‐Repeats (CRISPR) lateral‐flow‐strip tests and the Single‐Molecule‐with‐a‐large‐Transistor (SiMoT) bioelectronic palmar devices. They both hold key features delineated by the World‐Health‐Organization for POCT systems and an occurrence of false‐positive and false‐negative errors <1–5% resulting in diagnostic‐selectivity and sensitivity >95–99%, while limit‐of‐detections are of few markers. CRISPR‐strip is a molecular assay that, can detect down to few copies of DNA/RNA markers in blood while SiMoT immunometric and molecular test can detect down to a single oligonucleotide, protein marker, or pathogens in 0.1mL of blood, saliva, and olive‐sap. These technologies can prospectively enable the systematic and reliable surveillance of asymptomatic ones prior to worsening/proliferation of illnesses allowing for timely diagnosis and swift prognosis. This could establish a proactive healthcare ecosystem that results in effective treatments for all living organisms generating diffuse and well‐being at efficient costs.
CRISPR lateral‐flow‐strip tests, combined with enzymatic amplification, and the SiMoT bioelectronic palmar devices, review as highly performing point‐of‐care testing technologies that have reached technology readiness level 5, are capable of single‐molecule detections (10−20 m in 0.1 mL) and exhibit extremely high reliability (diagnostic sensitivity and selectivity > 95–99%). Moreover, they are multipurpose and can also be effectively utilized in resource‐constrained settings.
To utilize fully the excellent mechanical properties of bamboo, thin-walled steel, and carbon fiber-reinforced polymer (CFRP), a CFRP-confined composite member composed of bamboo strips and a ...thin-walled steel tube (CBSC) was proposed to design a bamboo member with high-bearing capacity and ductility. The axial compressive tests were conducted on 26 CBSC members. Based on the validated finite-element (FE) model, a parametric analysis was performed to investigate the effects of different parameters on the axial compressive mechanical behaviors of CBSC members. Finally, the predictions of the ultimate axial compressive bearing capacity derived from the unified theory of concrete-filled steel tube columns agreed well with the test and FE results. The results showed that the failure mode of short CBSC members was strength failure, including material damage in the middle of the member, and end-crushing failure. However, the slender CBSC members exhibited typical global buckling failure. CBSC members can fully utilize the mechanical characteristics of the three materials to exert their combined effects. In terms of improving the bearing capacity, the recommended number of CFRP layers for all CBSC members is one except for the short CFRP-confined bamboo strip, thin-walled, circular steel-tube composite members, which is equal to two. The critical slenderness ratios of the CBCSC specimens and CBSSC specimens for distinguishing strength failure and global buckling are 19 and 36, respectively. The proposed predicted equations can accurately estimate the ultimate bearing capacity of CBSC members under axial compression.
•A composite bamboo member with high-bearing capacity and ductility was designed.•Effects of parameters on the compressive behaviors of the CBSC members were studied.•Theory-based predictions agreed with experimental and simulation FE results.
The activity of leukocyte esterase (LE) is a proxy for the presence of leukocytes in the diagnosis of infection, a common cause of patient morbidity and mortality. Here, the ability of commercial ...glucose test strips to detect hydroquinone (HQ) down to 1.0 μM was explored for the determination of LE in human synovial (joint) fluid and urine samples. To this end, the HQ-releasing substrate (HQS) for LE was synthesized and tested by chronocoulometry at a glucose strip linked to a laboratory potentiostat. The latter was used, rather than a glucometer, to improve the limit of detection. In the presence of LE in a sample, the HQS discharged HQ that was detected at a glucose strip covering a clinically relevant range from 20 μg L−1 (0.64 nM) to 750 μg L−1 LE (R2, 0.973, N = 8). Such a coulometric assay was selective with respect to human LE and required a 20-min sample incubation with HQS, which is much shorter than the current hours-long immunoassays for LE. The assay relied on a differential signal, which circumvented the interferences including those from endogenous glucose and provided a direct measure of infection regardless of the complexity of sample matrix. The scaled-up synthesis of HQS along with the wide availability of glucose strips provides a prospect for the commercialization of such an infection assay.
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•Selective detection of infection enzyme leukocyte esterase (LE)•Commercial glucose strip as a coulometric sensor for hydroquinone (LOD, 1.0 μM)•Hydroquinone-releasing synthetic substrate for human LE•Elimination of matrix effects in the analysis of urine and synovial (joint) fluid
In this paper, a horizontally meandered strip (HMS) feed technique is proposed to achieve good impedance matching and symmetrical broadside radiation patterns for a single-fed broadband circularly ...polarized stacked patch antenna, which is suitable for universal ultrahigh frequency (UHF) RF identification (RFID) applications. The antenna is composed of two corner truncated patches and an HMS, all of which are printed on the upper side of the FR4 substrates. One end of the HMS is connected to the main patch by a probe, while the other end is connected to an SMA connector. Simulation results are compared with the measurements, and a good agreement is obtained. The measurements show that the antenna has an impedance bandwidth (VSWR <; 1.5) of about 25.8% (758-983 MHz), a 3-dB axial ratio (AR) bandwidth of about 13.5% (838-959 MHz), and a gain level of about 8.6 dBic or larger within the 3-dB AR bandwidth. Therefore, the proposed antenna can be a good candidate for universal UHF RFID readers operating at the UHF band of 840-955 MHz. In addition, a parametric study and a design guideline of the proposed antenna are presented to provide the engineers with information for designing, modifying, and optimizing such an antenna. At last, the proposed antenna is validated in RFID system applications.
