Sökning: "Electrical impedance"

Visar resultat 16 - 20 av 240 avhandlingar innehållade orden Electrical impedance.

1. 16. Planar-Goubau-line components for terahertz applications

   Författare :Juan Cabello Sánchez; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; planar Goubau line; Through-Reflect-Line TRL calibration; stopband filter; on-wafer measurements; vector network analyzers VNA ; silicon membrane; power divider; Impedance-matched load; terahertz spectroscopy; microfluidic channels;

   Sammanfattning : Terahertz-wave technology has a broad range of applications, including radio astronomy, telecommunications, security, medical applications, pharmaceutical quality control, and biological sensing. However, the sources, detectors, and components are less efficient at this frequency band due to parasitic effects and increased total losses, which hinder the performance of terahertz systems. LÄS MER

3. 17. Pulmonary ventilation and perfusion assessed by electrical impedance tomography - Experimental studies in pigs

   Författare :Anneli Fagerberg; Göteborgs universitet; []
   Nyckelord :electrical impedance tomography; V Q matching; pig; endotoxinaemic ALI; ACE inhibitor;

   Sammanfattning : Pulmonary ventilation and perfusion and ventilation/perfusion (V/Q) matching determine gas exchange in every lung unit in the healthy state and in the pathologically altered lung. Mismatch of V and Q lead to hypoxaemia and hypercapnia and monitoring of V/Q relations are thus important in critical illness. LÄS MER

4. 18. Active Transmitter Antenna Array Modeling for MIMO Applications

   Författare :Parastoo Taghikhani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; beam steering; Active antenna array; active impedance; hybrid beamforming transmitter; MIMO transmitter; far-field nonlinear distortion; millimeter wave; modeling.;

   Sammanfattning : The rapid growth of data traffic in mobile communications has attracted interests to the Multiple-Input-Multiple-Output (MIMO) communication systems at millimeter-wave (mmWave) frequencies.  MIMO systems exploit active transmitter antenna arrays for higher energy efficiency and providing beamforming flexibility. LÄS MER

5. 19. Effects of the environment on quantum systems: decoherence, bound states and high impedance in superconducting circuits

   Författare :Marco Scigliuzzo; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TLS; atom photon bound state; circuit QED; quantum thermodynamics; two-level systems; surface acoustic wave; high impedance; superconducting circuits; SAW;

   Sammanfattning : Superconducting circuits in the quantum regime represent a viable platform for microwave quantum optics, quantum simulations and quantum computing. In the last two decades, a large effort brought this architecture from an academic curiosity to concrete technology. LÄS MER

7. 20. Studies of changes in volume in right ventricle with electrical bio impedance

   Författare :Karin Järverud; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :intracardiac impedance;

   Sammanfattning : In intracardiac impedance, electrical bio-impedance is measured inside the heart. This signal is known to reflect the volume of blood passing in and out of the ventricles. In transthoracic impedance the measurement current and voltage sensing is connected on the subject’s chest. LÄS MER