scholarly journals Biomass measurement of living Lumbriculus variegatus with impedance spectroscopy

2019 ◽  
Vol 5 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Martina Sammer ◽  
Bob Laarhoven ◽  
Ernest Mejias ◽  
Doekle Yntema ◽  
Elmar C. Fuchs ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Phase Measurement ◽  
Biological Tissues ◽  
Nutritional Composition ◽  
Phase Response ◽  
Lumbriculus Variegatus ◽  
Individual Worm ◽  
Online Biomass Monitoring ◽  
Average Individual ◽  
Measured Phase

Abstract Impedance spectroscopy is a useful tool for non-invasive and real time measurements of cell suspensions and a variety of biological tissues. The objective of this study was the investigation of the dielectric properties of living aquatic worms (Lumbriculus variegatus) using impedance spectroscopy in a frequency range between 100 Hz and 10 MHz. We demonstrate a linear relation between the worm biomass and the phase response of the signal thereby providing a quick and precise method to determine the biomass of aquatic worms in situ. Possible applications for non-destructive online biomass monitoring of aquatic worms and other aqueous organisms are discussed. Furthermore, we show that groups of worms fed different diets can be distinguished by the method presented. These results reveal a close relationship between the nutritional composition of the worms and the measured phase response. We also demonstrate that the phase response at 90 kHz does not depend on the worm size. In contrast, the response function for the signal at 440 Hz reveals a linear correlation of average individual worm size and phase. Therefore, we conclude that the measured phase response at 90 kHz qualifies as a measure of the total amount of worm biomass present in the measuring cell, whereas the phase measurement at 440 Hz can be used to estimate the average individual worm size.

scholarly journals A CMOS Magnitude/Phase Measurement Chip for Impedance Spectroscopy

2013 ◽  
Vol 13 (6) ◽  
pp. 2229-2236 ◽  
Author(s):  
Panagiotis Kassanos ◽  
Iasonas F. Triantis ◽  
Andreas Demosthenous
Keyword(s):  
Impedance Spectroscopy ◽  
Phase Measurement

scholarly journals Phase characterisation of metalenses

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Maoxiong Zhao ◽  
Mu Ku Chen ◽  
Ze-Peng Zhuang ◽  
Yiwen Zhang ◽  
Ang Chen ◽  
...  
Keyword(s):  
Measurement System ◽  
Phase Distribution ◽  
Phase Measurement ◽  
Berry Phase ◽  
Focal Length ◽  
Numerical Aperture ◽  
Superior Performance ◽  
Distribution Analysis ◽  
Interferometric Imaging ◽  
Measured Phase

AbstractMetalenses have emerged as a new optical element or system in recent years, showing superior performance and abundant applications. However, the phase distribution of a metalens has not been measured directly up to now, hindering further quantitative evaluation of its performance. We have developed an interferometric imaging phase measurement system to measure the phase distribution of a metalens by taking only one photo of the interference pattern. Based on the measured phase distribution, we analyse the negative chromatic aberration effect of monochromatic metalenses and propose a feature size of metalenses. Different sensitivities of the phase response to wavelength between the Pancharatnam-Berry phase-based metalens and propagation phase-reliant metalens are directly observed in the experiment. Furthermore, through phase distribution analysis, it is found that the distance between the measured metalens and the brightest spot of focusing will deviate from the focal length when the metalens has a low nominal numerical aperture, even though the metalens is ideal without any fabrication error. We also use the measured phase distribution to quantitatively characterise the imaging performance of the metalens. Our phase measurement system will help not only designers optimise the designs of metalenses but also fabricants distinguish defects to improve the fabrication process, which will pave the way for metalenses in industrial applications.

Non-Destructive Evaluation of the Interface in Reinforced Concrete Using Phase Measurement Interferometry

1997 ◽  
Vol 503 ◽  
Author(s):  
Masoud Ghandehari ◽  
Sridhar Krishnaswamy ◽  
Surendra Shah
Keyword(s):  
Reinforced Concrete ◽  
Phase Measurement ◽  
Crack Opening ◽  
Surface Displacement ◽  
Reinforced Concrete Structures ◽  
Pull Out ◽  
Non Destructive Evaluation ◽  
Non Destructive ◽  
Growth Detection ◽  
Measured Phase

ABSTRACTStudying the behavior of steel and concrete as a composite is of fundamental importance to the understanding of the cracking of reinforced concrete structures. In this article, a technique leading toward the development of a constitutive model for the interaction of steel and concrete is described. Experiments are based on pull-out specimens, where the shear stress and the two displacement components at the interface are measured. Phase Measurement Interferometry is used for accurate surface displacement measurement, and crack growth detection. The normal stress is then deduced using the measured crack length and crack opening displacements, along with a fracture mechanics based numerical simulation.

scholarly journals Comparative Study of AC Signal Analysis Methods for Impedance Spectroscopy Implementation in Embedded Systems

2022 ◽  
Vol 12 (2) ◽  
pp. 591
Author(s):  
Ahmed Yahia Kallel ◽  
Zheng Hu ◽  
Olfa Kanoun
Keyword(s):  
Fourier Transform ◽  
Impedance Spectroscopy ◽  
Signal Analysis ◽  
Measurement Accuracy ◽  
Phase Measurement ◽  
Nonlinear Least Squares ◽  
Hardware Acceleration ◽  
Fitting Method ◽  
Overall Performance ◽  
Memory Constraints

For embedded impedance spectroscopy, a suitable method for analyzing AC signals needs to be carefully chosen to overcome limited processing capability and memory availability. This paper compares various methods, including the fast Fourier transform (FFT), the FFT with barycenter correction, the FFT with windowing, the Goertzel filter, the discrete-time Fourier transform (DTFT), and sine fitting using linear or nonlinear least squares, and cross-correlation, for analyzing AC signals in terms of speed, memory requirements, amplitude measurement accuracy, and phase measurement accuracy. These methods are implemented in reference systems with and without hardware acceleration for validation. The investigation results show that the Goertzel algorithm has the best overall performance when hardware acceleration is excluded or in the case of memory constraints. In implementations with hardware acceleration, the FFT with barycentre correction stands out. The linear sine fitting method provides the most accurate amplitude and phase determinations at the expense of speed and memory requirements.

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections

1972 ◽  
Vol 30 ◽  
pp. 464-465
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Present Report ◽  
Biological Tissues ◽  
Specimen Preparation ◽  
Technical Problems ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.

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