Improved Performance of Electrical Transmission Tower Structure Using Connected Foundation in Soft Ground

A connected foundation is an effective foundation type that can improve the structural performance of electrical transmission towers in soft ground as a resilient energy supply system with improved stability. In the present study, the performance of a connected foundation for transmission towers was investigated, focusing on the effect of connection beam properties and soil conditions. For this purpose, a finite element analysis was performed for various foundation and soil conditions. In order to validate the finite element analysis, the calculated results were compared with measured results obtained from field load tests. The use of connection beams was more effective for uplift foundations that usually control the design of transmission tower foundations. For the effect of soil condition, the use of connected foundation is more effective in soft clays with lower undrained shear strength (su). Smaller amounts of differential settlement were observed in all soil conditions for both unconnected and connected foundations when a bearing rock layer was present. When the foundation was not reinforced by connection beams, the values of lateral load capacity of tower structure (Hu) were similar for both with- and without-rock layers. It was confirmed that introducing haunch-shaped connection beams is effective for increasing connection beam stability

Diagnostic imaging of adnexal masses in pregnancy

Adnexal masses detected during pregnancy require a prompt and accurate diagnosis to ensure fetal safety and good oncological outcomes. Computed tomography is the most common and useful diagnostic imaging modality for diagnosing adnexal masses; however, it is contraindicated in pregnant women because of the teratogenic effect of radiation on the fetus. Therefore, ultrasonography (US) is commonly used as the main alternative for the differential diagnosis of adnexal masses during pregnancy. Additionally, magnetic resonance imaging (MRI) can assist in the diagnosis when US findings are inconclusive. As each disease has characteristic US and MRI findings, understanding these features is important for the initial diagnosis and subsequent treatment. Thus, we thoroughly reviewed the literature and summarized the key findings of US and MRI to apply these in real-world clinical practice for various adnexal masses detected during pregnancy

Optimized End Functionality of Silane-Terminated Liquid Butadiene Rubber for Silica-Filled Rubber Compounds

As the world is shifting from internal combustion engine vehicles to electric vehicles in response to environmental pollution, the tire industry has been conducting research on tire performance to meet the requirements of electric vehicles. In this experiment, functionalized liquid butadiene rubber (F-LqBR) with triethoxysilyl groups at both ends was introduced into a silica-filled rubber compound as a substitute for treated distillate aromatic extract (TDAE) oil, and comparative evaluation was conducted according to the number of triethoxysilyl groups. The results showed that F-LqBRs improved silica dispersion in the rubber matrix through the formation of chemical bonds between silanol groups and the base rubber, and reduced rolling resistance by limiting chain end mobility and improving filler–rubber interaction. However, when the number of triethoxysilyl groups in F-LqBR was increased from two to four, self-condensation increased, the reactivity of the silanol groups decreased, and the improvement of properties was reduced. As a result, the optimized end functionality of triethoxysilyl groups for F-LqBR in silica-filled rubber compound was two. The 2-Azo-LqBR with the optimized functionality showed an improvement of 10% in rolling resistance, 16% in snow traction, and 17% in abrasion resistance when 10 phr of TDAE oil was substituted

Spontaneous Generation of Molecular Thin Hydrophobic Skin Layer on Sub-20 nm, High-k Polymer Dielectric for Extremely Stable Organic Thin-Film Transistor (OTFT) Operation

Polymer dielectric materials with hydroxyl functionalities such as poly(4-vinylphenol) and poly(vinyl alcohol) been utilized widely in organic thin-film transistors (OTFTs) because of their excellent insulating performance gained by hydroxyl-mediated cross-linking. However, the polar hydroxyl functionality also deleteriously affects the performance of OTFTs and significantly impairs the device stability. In this study, a sub-20 nm, high-k copolymer dielectric with hydroxyl functionality, poly(2-hydroxyethyl acrylate-co-di(ethylene glycol) divinyl ether), was synthesized in the vapor phase via initiated chemical vapor deposition. The inherently dry environment offered by the vapor phase polymer synthesis prompted the snuggling of polar hydroxyl functionalities into the bulk polymer film to form a molecular thin hydrophobic skin layer at its surface, verified by near-edge X-ray absorption fine structure analysis. The chemical composition of the copolymer dielectric was optimized systematically to achieve high dielectric constant (k approximate to 6.2) as well as extremely low leakage current densities (less than 3 X 10(-8) A/cm(2) in the range of +/- 2 MV/cm) even with sub-20 nm thickness, leading to one of the highest capacitance (higher than 300 nF/cm(2)) achieved by a single polymer dielectric to date. Exploiting the structural advantage of the cross-linked high-k polymer dielectric, high-performance OTFTs were obtained. Notably, the spontaneously formed molecular thin, hydrophobic skin layer in the copolymer film substantially suppressed the hysteresis in the transistor operation. The trap analysis also suggested the formation of bulk trap with a high energy barrier and sufficiently low trap densities at the semiconductor/dielectric interface, owing to the surface skin layer. Furthermore, the OTFTs with the OH-containing copolymer dielectric showed an unprecedentedly excellent operational stability. No apparent OTFT degradation was observed up to 50 000 s of high constant voltage stress (corresponding to the applied electric field of 1.4 MV/cm) because of the markedly suppressed interfacial trap density by the hydrophobic skin layer, together with the current compensation by the bulk hydroxyl functionalities. We believe that the surface modification-free, one-step polymer dielectric synthetic strategy will provide a new insight into the design of polymer dielectric materials for high-performance, low-power soft electronic devices with high operational stability.11Nsciescopu

Soft, full Wheatstone bridge 3D pressure sensors for cardiovascular monitoring

Abstract Variations in parameters associated with the ambient environment can introduce noise in soft, body-worn sensors. For example, many piezoresistive pressure sensors exhibit a high degree of sensitivity to fluctuations in temperature, thereby requiring active compensation strategies. The research presented here addresses this challenge with a multilayered 3D microsystem design that integrates four piezoresistive sensors in a full-Wheatstone bridge configuration. An optimized layout of the sensors relative to the neutral mechanical plane leads to both an insensitivity to temperature and an increased sensitivity to pressure, relative to previously reported devices that rely on similar operating principles. Integrating this 3D pressure sensor into a soft, flexible electronics platform yields a system capable of real-time, wireless measurements from the surface of the skin. Placement above the radial and carotid arteries yields high-quality waveforms associated with pulsatile blood flow, with quantitative correlations to blood pressure. The results establish the materials and engineering aspects of a technology with broad potential in remote health monitoring