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Analysis of bondwires and RF compensation circuits in E-Band
No full textThis article investigates the impact of bondwire interconnections on signal integrity in low and high millimeter-wave (mmWave) applications, emphasizing transmission degradation caused by inductive and parasitic effects. Through detailed measurements and analysis, we demonstrate that transmission loss and impedance mismatches can be effectively reduced by minimizing bondwire length and using multiple wires in parallel. Based on empirical data, we developed an electrical model of bondwire incorporating distributed inductance, capacitance, resistance (L/C/R) , and transmission line characteristics. To further enhance performance, we introduce compact compensation circuits using LC structures and radial stubs optimized for both single and double bondwire configurations. Experimental validation shows that the proposed double-wire LC compensation technique significantly reduces insertion loss—from 5 to 1.5 dB and provides a return loss bandwidth from 70 to 75 GHz. The key novelty of this work lies in integrating multiple bondwires with low complexity, compact LC compensation structures, providing an effective solution for reducing insertion loss and improving impedance matching in mmWave systems. This approach offers a practical and scalable solution for improving chip-to-board and board-to-board interconnect performance in mmWave systems
Piezoelectric-resonator-based power supply for an ozone-generating dielectric barrier discharge reactor
Get PDFIn this work, a dielectric barrier discharge (DBD) reactor power supply designed for operation with a low input voltage is presented. A piezoelectric resonator (PR) is used to provide voltage gain and high efficiency in a small volume for portable (point of use) ozone generation, suitable for the disinfection of surfaces, for example. The power supply was coupled to a small, asymmetrical DBD reactor and achieved an efficiency of 63% and an ozone generation efficacy of 67 g/kWh when operating at 4.4 W. The use of a PR to provide voltage gain has several advantages over, for example, a traditional electromagnetic transformer. The PR has monolithic construction for reliability, is inherently insulated against high voltage due to the ceramic material, can operate up to 300 ∘ C, and its resonant behavior allows the power supply to operate with zero-voltage switching
Rethinking the potential of urban agriculture as a climate resilience strategy:evidence from Accra, Ghana
Get PDFScientific or naïve? Perceptions of direct and indirect realism, and why they matter
Get PDFPhilosophical debates about the nature of perception are standardly informed by an empirical assumption about folk beliefs: They assume there is such a thing as “the” common-sense conception of vision, and that this conception is captured by Direct Realism. This naïve theory is thought to compete with scientifically informed Indirect Realism. This paper discusses how to render these claims empirically tractable and reports a scientific accuracy rating study whose findings suggest instead that both Direct Realism and Indirect Realism capture prescientific conceptions. We discuss two philosophical consequences: “Common sense” is too conflicted about vision to deserve epistemic default status in philosophical debates about perception, and the “problem of perception” needs to be reconceptualized as arising not from a challenge to our ordinary understanding of vision, but from a patent conflict within this understanding. Together, these two upshots facilitate a fresh approach to the problem which can usefully be transferred to further “aporetic” problems that arise from conflicts between beliefs to which we are pretheoretically attracted
Exploring early transition metal coordination: a synthetic and computational study of tripodal ligand complexes
Get PDFXRGait: Immersive Gait Training Visualization with Integrated Sensing
No full textGait training and rehabilitation have traditionally been done through movement observation during in-person sessions with medical professionals and follow-up exercises at home. However, these methods are costly, have low patient adherence, and have a decreased accuracy in assessing and modeling patient gait. We present XRGait, a system that seamlessly integrates wearable sensors with immersive technologies to provide real-time support for gait training and rehabilitation. Our system combines smart insoles and wearable motion tracking sensors with immersive displays to provide the patient with real-time feedback about their gait within an engaging training environment. We conducted two studies that compared various system environments and gait visualizations to inform optimal system usability and user experience. Our findings demonstrate that the level of immersion is a critical factor for user engagement in biofeedback-driven gait training, with immersive VR significantly outperforming mobile AR and non-immersive screen-based displays and participants found the real-time visualizations and feedback very useful, with a preference for the full lower body visualization. We discuss these findings, along with limitations and recommendations for future work
Fluid-structure interactions: one-field monolithic fictitious domain method and its parallelization
No full textIn this paper, we delve into the parallelization of the one-field monolithic fictitious domain (MFD) method, a comprehensive algorithm designed for simulating fluid-structure interactions (FSI). This method treats the velocity fields of both the fluid and solid as a unified field through an L2 projection, enabling synchronous equation solving instead of sequential approaches. Given the computational intensity of 3D domain simulations, parallelizing the algorithm and the linear systems derived from discretization becomes imperative. This parallelization significantly reduces simulation time from several months to just a few days. We focused on parallelizing the algorithm for FSI simulations on uniform meshes. Our primary aim is to develop an efficient and robust algorithm capable of handling complex FSIs, including scenarios involving collisions of multiple immersed solids in fluid. Such scenarios often require high-resolution meshes to accurately resolve phenomena near collision points and fluid-structure interfaces
The structure of the bacterial outer membrane transporter FusA enabled by addition of the native lipid lipopolysaccharide
No full textLipopolysaccharide (LPS) is a glycolipid found uniquely in the outer membrane of diderm bacteria, formed of 4–7 acyl chains covalently linked to an extended polysaccharide chain. While a few examples of the interaction between LPS and outer membrane proteins (OMPs) have been structurally characterised, either experimentally or computationally, the precise nature of LPS-OMP interactions and their functional consequences remains unclear. Here, we show that the addition of LPS facilitated cryoEM structure determination of FusA, a 100 kDa TonB-dependent outer membrane transporter from P. atrosepticum. A 2.8 Å structure combined with molecular dynamics of FusA with different LPS models reveals LPS binding sites with a strong LPS interaction site located adjacent to the β-seam region of the FusA β-barrel. The requirement of lipid binding for successful structure determination indicates a stabilisation of the protein, which in turn suggests a potential method for solving other, small OMPs and membrane proteins. Further, it hints at how LPS may mediate protein conformation and thus how LPS and OMPs can work in concert to maintain a structural and functional OM
Navigating values in decision-making to shape the landscape of Bangkok’s urban waterways
Get PDFUrban waterways are complex and vulnerable landscapes, particularly in rapidly urbanising cities where they are prone to flooding and degradation of cultural heritage. This complexity is reflected in decision-making processes about urban waterways, as they cross administrative boundaries and involve stakeholders from multiple disciplines who value the urban waterways in different ways. This paper aims to examine how fragmented decision-making contributes to the vulnerability of urban waterways. Focusing on the case of Bangkok, the research engaged those government agencies responsible for the city’s waterways in collaborative workshops to collectively explore their values in decision-making processes. Findings show that practitioners and policymakers expressed differences in values about BUW, which explains the inertia of current waterways management in Bangkok. Findings also show that individually expressed expertise and values can be collectively expressed, demonstrating how collaboration can lead to comprehensive solutions to managing complex environmental challenges in vulnerable urban landscapes
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