An Array-Type System Applied to Complex Surfaces in Nuclear Pollution Detection

[EN] Radioactive pollution detection plays a key role in nuclear technology application. In this paper, an array-type of nuclear pollution detection system is designed for the detection scenario of complex surfaces. Firstly, to get the three-dimensional point cloud of the surface, a complex surface was modeled based on the geometric ranging model of a two-dimensional laser profilometer and the motion model of a two-degree-of-freedom displacement platform. Secondly, an 'S' type scanning scheme of profilometer was developed to overcome the problem of limited scanning area of the profilometer. Thirdly, Euclidean distance weighted median filtering was used to solve the impulsive noise that may occur during the point cloud acquisition process. Finally, the 3D point cloud information of the complex surface was used for controlling the movement of the 6 x 6 array channel pollution detector to complete the alpha and beta particle measurement tasks. A mechanical platform was constructed for experiments, the results are as follows. The working range of this system is from -5 cm to 5 cm in elevation difference of surfaces, and the accuracy is 12 mu m in surface height measuring. It takes 26.13 s to perform a detection task including surface scanning and the detector moving, and scanning accuracy is 0.35 x 0.35 mm(2). The maximum control error of the surface contamination detector is 0.4 mm. Specifically, the detection area of the system reaches 240 x 240 mm(2). The results show that the system acquires three-dimensional terrain information, and realizes control over the movement of the pollution detector accurately and then completes the detection of alpha and beta particles effectively.This work is supported by National Natural Science Foundation (NSFC) of China under Grant No.61601382, Sichuan Provincial Science and Technology Support Project No.2019YJ0325, the Doctoral Fund of Southwest University of Science and Technology No.16zx7148, No.19zx7123, Longshan academic talent research supporting program of SWUST No.18LZX632 and the Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province No.13zxtk08.Chu, H.; Chang, Z.; Shao, Y.; Zhang, X.; Lloret, J. (2020). An Array-Type System Applied to Complex Surfaces in Nuclear Pollution Detection. Electronics. 9(11):1-21. https://doi.org/10.3390/electronics9111870S12191

A Vision to Smart Radio Environment: Surface Wave Communication Superhighways

Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart radio environment by using software-defined materials or programmable metasurfaces for establishing favourable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on "smart surfaces" for future smart radio environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off radio waves intelligently towards intended user terminals. In this vision, energy efficiency will be ultra-high, due to much less pathloss compared to free space propagation, and the fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-free data access. We shall outline the opportunities and associated challenges arisen from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.Comment: 7 pages, 6 figure

Taxonomic notes on eleven species of the subfamily Cteninae (Araneae, Ctenidae) from Asia

The spider family Ctenidae Keyserling, 1877 has a worldwide distribution with 584 species belonging to 49 genera. Amongst these, 141 species are from Asia, including 130 species assigned to Cteninae Keyserling, 1877.Nine new species belonging to three genera of Cteninae are reported from Asia: Amauropelma krabi sp. n. (female; Krabi, Thailand), Am. phangnga sp. n. (male; Phang Nga, Thailand), Am. saraburi sp. n. (male and female; Saraburi, Thailand); Anahita medog sp. n. (male and female; Tibet, China); Bowie ninhbinh sp. n. (male; Ninh Binh, Vietnam) and B. vinhphuc sp. n. (male and female; Vinh Phuc, Vietnam) from the robustus-species group; B. borneo sp. n. (male; Sabah, Malaysia) from the chinagirl-species group; B. engkilili sp. n. (female; Engkilili, Malaysia); B. sabah sp. n. (male and female; Sabah, Malaysia) from the scarymonsters-species group. The male of An. popa Jäger & Minn, 2015 and the female of B. fascination Jäger, 2022 (robustus-species group) are described for the first time. B. fascination Jäger, 2022 is reported from China for the first time. In addition, the DNA barcodes of all the species in this study were obtained, except for B. vinhphuc sp. n

Path Loss and Surface Impedance Models for Surface Wave-Assisted Wireless Communication System

Surface wave-assisted wireless communication systems have recently emerged as a promising complementary solution for creating a smart radio environment, particularly in the context of beyond-fifth generation (5G) and sixth generation (6G) networks. Unlike traditional approaches that rely solely on space waves or use passive elements on a large surface to reflect space waves, the incorporation of surface waves can effectively address challenges such as blockage and severe path loss, which are prevalent at extremely high frequencies, including millimeter wave (mmWave) and terahertz (THz) bands. Recent advances in metasurface properties have enabled the propagation of electromagnetic waves on a surface without re-radiation. Motivated by these developments, in this paper, we develop a path loss model and two surface impedance models for surface wave-assisted wireless communication systems. We demonstrate that the signal-to-noise ratio (SNR) of this system can be significantly higher than that of traditional wireless communication systems because the path loss for a surface wave is proportional to the propagation distance, whereas the path loss for a space wave is proportional to the square of the propagation distance. Furthermore, we explore how the metasurface should be designed in terms of its materials and structures, considering that the incident space wave must be aligned with Brewster’s angle to excite a surface wave

On Propagation Loss for Reconfigurable Surface Wave Communications

Surface wave communication (SWC) is an emerging technology garnering significant interest for its diverse potential applications in communications. However, accurately computing electromagnetic field strength, which is related to the path loss, in reconfigurable surface structures, particularly for long-distance transmission, presents an ongoing challenge. To address this, we introduce a novel analytical model employing surface wave ray tracing. Unlike conventional simulations, our analytical approach enables precise computation of the electromagnetic field strength attenuation in both short and long-distance transmissions, providing invaluable insights for practical SWC implementations. Our proposed model takes into account key system parameters such as surface material, thickness, cavity porosity, and other variables influencing propagation performance. This facilitates analysis of optimal reconfigurable structures. Simulation results validate the model’s accuracy in short-distance transmission, thereby endorsing its effectiveness in studying surface wave path loss over longer distances. Furthermore, our study demonstrates the SWC superiority over traditional coaxial cable and space-wave communication in mitigating path loss. Additionally, we explore the impacts of various factors such as different dielectric layers, wall materials, leakage, and pathway width on SWC performance, providing deeper insights into designing optimal reconfigurable structures for SWC applications

MIMO Evolution Beyond 5G Through Reconfigurable Intelligent Surfaces and Fluid Antenna Systems

With massive deployment, multiple-input-multiple-output (MIMO) systems continue to take mobile communications to new heights, but the ever-increasing demands mean that there is a need to look beyond MIMO and pursue the next disruptive wireless technologies. Reconfigurable intelligent surface (RIS) is widely considered a key candidate technology block to provide the next generational leap. The first part of this article provides an updated overview of the conventional reflection-based RIS technology, which complements the existing literature to include active and semiactive RIS, and the synergies with cell-free massive MIMO (CF mMIMO). Then, we widen the scope to discuss the surface-wave-assisted RIS that represents a different design dimension in utilizing metasurface technologies. This goes beyond being a passive reflector and can use the surface as an intelligent propagation medium for superb radio propagation efficiency. The third part of this article turns the attention to the fluid antenna, a novel antenna technology that enables a diverse form of reconfigurability that can combine with RIS for ultrahigh capacity, power efficiency, and scalability. This article concludes with a discussion of the potential synergies that can be exploited between MIMO, RIS, and fluid antennas

Mesenchymal stromal cells pretreated with pro‐inflammatory cytokines promote skin wound healing through VEGFC ‐mediated angiogenesis

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Arterial stiffness and obesity as predictors of diabetes: Longitudinal cohort study

BACKGROUND: Previous studies have confirmed the separate effect of arterial stiffness and obesity on type 2 diabetes; however, the joint effect of arterial stiffness and obesity on diabetes onset remains unclear. OBJECTIVE: This study aimed to propose the concept of arterial stiffness obesity phenotype and explore the risk stratification capacity for diabetes. METHODS: This longitudinal cohort study used baseline data of 12,298 participants from Beijing Xiaotangshan Examination Center between 2008 and 2013 and then annually followed them until incident diabetes or 2019. BMI (waist circumference) and brachial-ankle pulse wave velocity were measured to define arterial stiffness abdominal obesity phenotype. The Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% CI. RESULTS: Of the 12,298 participants, the mean baseline age was 51.2 (SD 13.6) years, and 8448 (68.7%) were male. After a median follow-up of 5.0 (IQR 2.0-8.0) years, 1240 (10.1%) participants developed diabetes. Compared with the ideal vascular function and nonobese group, the highest risk of diabetes was observed in the elevated arterial stiffness and obese group (HR 1.94, 95% CI 1.60-2.35). Those with exclusive arterial stiffness or obesity exhibited a similar risk of diabetes, and the adjusted HRs were 1.63 (95% CI 1.37-1.94) and 1.64 (95% CI 1.32-2.04), respectively. Consistent results were observed in multiple sensitivity analyses, among subgroups of age and fasting glucose level, and alternatively using arterial stiffness abdominal obesity phenotype. CONCLUSIONS: This study proposed the concept of arterial stiffness abdominal obesity phenotype, which could improve the risk stratification and management of diabetes. The clinical significance of arterial stiffness abdominal obesity phenotype needs further validation for other cardiometabolic disorders

A life-threatening, massive subcutaneous hematoma caused by trauma in a patient with neurofibromatosis type 1: a case report and literature review

BackgroundNeurofibromatosis type 1 (NF1) is an autosomal dominant disease that can give rise to the formation of vascular lesions in affected individuals. These lesions, whether occurring spontaneously or as a result of trauma, have the potential to cause severe and even fatal hemorrhage.Case descriptionWe presented a case demonstrating the most extensive hematoma ever documented in a patient with NF1, resulting from a minor trauma. He experienced hemodynamic instability due to severe anemia. Arteriography revealed a rupture in the intercostal artery, which was successfully treated through interventional embolization to stop the hemorrhage. Additionally, we implemented a refined surgical approach, beginning with suturing, followed by the meticulous resection of necrotic and aberrant tissues, thereby markedly diminishing bleeding.ConclusionMinor trauma may cause severe bleeding in patients with NF1, which can be life-threatening. Timely diagnosis of NF1 and effective hemostatic techniques are key to successful treatment