A capacitance standard based directly on the definition of capacitance was built. Single-electron tunneling devices were used to place N electrons of charge e onto a cryogenic capacitor C, and the resulting voltage change DeltaV was measured. Repeated measurements of C = Ne/DeltaV with this method have a relative standard deviation of 0.3 x 10(-6). This standard offers a natural basis for capacitance analogous to the Josephson effect for voltage and the quantum Hall effect for resistance.
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http://dx.doi.org/10.1126/science.285.5434.1706 | DOI Listing |
Sensors (Basel)
January 2025
Department of Clinical and Molecular Biochemistry, Pomeranian Medical University in Szczecin, 72 Powstańców Wlkp. Al., 70-111 Szczecin, Poland.
Biosensors are transforming point-of-care diagnostics by simplifying the detection process and enabling rapid, accurate testing. This study introduces a novel, reusable biosensor designed for direct viral RNA detection from unfiltered saliva, targeting SARS-CoV-2. Unlike conventional methods requiring filtration, our biosensor leverages a unique electrode design that prevents interference from saliva debris, allowing precise measurements.
View Article and Find Full Text PDFMicromachines (Basel)
January 2025
College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China.
High-precision, low-power MEMS accelerometers are extensively utilized across civilian applications. Closed-loop accelerometers employing switched-capacitor (SC) circuit topologies offer notable advantages, including low power consumption, high signal-to-noise ratio (SNR), and excellent linearity. Addressing the critical demand for high-precision, low-power MEMS accelerometers in modern geophones, this work focuses on the design and implementation of closed-loop interface ASICs (Application-Specific Integrated Circuits).
View Article and Find Full Text PDFMagn Reson Imaging
January 2025
Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, TN 37232, USA. Electronic address:
Background: Inductively coupled wireless coils are increasingly used in MRI due to their cost-effectiveness and simplicity, eliminating the need for expensive components like preamplifiers, baluns, coil plugs, and coil ID circuits. Existing tools for predicting component values and electromagnetic (EM) fields are primarily designed for cylindrical volume coils, making them inadequate for irregular volume-type wireless coils.
Purpose: The aim of this study is to introduce and validate a novel magnetic (H-) field probe-based co-simulation method to accurately predict capacitance values and EM fields for irregular volume-type wireless coils, thereby addressing the limitations of current prediction tools.
Biotechnol Prog
January 2025
Amgen, Cambridge, Massachusetts, USA.
The biopharmaceutical industry is shifting toward employing digital analytical tools for improved understanding of systems biology data and production of quality products. The implementation of these technologies can streamline the manufacturing process by enabling faster responses, reducing manual measurements, and building continuous and automated capabilities. This study discusses the use of soft sensor models for prediction of viability and viable cell density (VCD) in CHO cell culture processes by using in-line optical density and permittivity sensors.
View Article and Find Full Text PDFBMC Musculoskelet Disord
January 2025
Department of Physiotherapy, Iranian Center of Excellence in Physiotherapy, Rehabilitation Research Center, School of Rehabilitation Sciences, Iran University of Medical Sciences, Madadkaran All., Shahnazari St., Madar Sq., Mirdamad Blvd., Tehran, Iran.
Introduction: Groin pain is a common issue among athletes. Adductor-related pain is known as the most common cause of groin pain. Although, non-operative treatments have limited efficacy, Capacitive and Resistive Energy Transfer (TECAR), can be used in the treatment of musculoskeletal conditions.
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