Electrical impedance studies of stem tissue of Solanum clones during cooling

1972 ◽  
Vol 50 (7) ◽  
pp. 1547-1554 ◽  
Author(s):  
R. E. Hayden ◽  
L. Dionne ◽  
D. S. Fensom
Keyword(s):  
Electrical Impedance ◽  
Freezing Point ◽  
Specific Resistance ◽  
Frost Hardiness ◽  
Cooling Curves ◽  
Stem Tissue ◽  
Impedance Measurements ◽  
Recovery Curve ◽  
Temperature Recovery ◽  
Selection Of

Specific electrical impedance measurements made on the stems or petioles of four varieties of Solanum were found to discriminate various clones when the plants were grown and tested under carefully controlled conditions. Frost hardiness of clones was related to the depression of the freezing point in the absence of supercooling, to the specific resistance at 4.4 °C, to the slope of the log impedance – temperature cooling curves, and to the position of the temperature recovery curve after chilling. The technique appears to be potentially useful for selection of frost resistant clones in breeding for this property.

Prediction of Frost Hardiness in Douglas Fir Seedlings by Measuring Electrical Impedance in Stems at Different Frequencies

1973 ◽  
Vol 3 (2) ◽  
pp. 256-264 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Survival Data ◽  
Electrical Impedance ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Impedance Measurements ◽  
Temperature Regimes ◽  
Before And After ◽  
Post Test ◽  
Different Levels ◽  
Short Days

Frost hardiness of Douglas fir (Pseudotsugamenziesii Mirb. Franco.) plants was assessed by a range of freezing tests in three experiments. In experiments 1 and 2 plants were grown in different temperature regimes, under short days, for 8 weeks to induce different levels of frost hardiness. In experiment 3, plants remained in the open and were sampled on 21 occasions through one year.Comparison of stem impedance measurements made at 1 kHz, 4.5 kHz, and 1 MHz, before and after freezing tests in experiments 1 and 2, indicated survival of individual plants was well predicted by post test measurements. The postfreezing test 1 kHz/1 MHz ratio distinguished between dead and surviving plants with the smallest number of measurements. Both this ratio and 4.5 kHz impedance provided similar conclusions about treatment effects, which agreed satisfactorily with conclusions from survival data. Impedance ratios of 1 kHz/1 MHz measured in stems after freezing tests accurately predicted survival in experiment 3. Seasonal changes in ratio, determined after freezing to a particular temperature, paralleled seasonal change in plant frost hardiness and was significantly correlated with exposure to cold during 14 days prior to measurement.

scholarly journals ELECTRIC IMPEDANCE OF THE FROG EGG

1942 ◽  
Vol 25 (5) ◽  
pp. 765-775 ◽  
Author(s):  
Kenneth S. Cole ◽  
Rita M. Guttman
Keyword(s):  
Plasma Membrane ◽  
Electrical Impedance ◽  
Rana Pipiens ◽  
Specific Resistance ◽  
Membrane Resistance ◽  
Leopard Frog ◽  
Electric Impedance ◽  
Frequency Range ◽  
Impedance Measurements ◽  
Membrane Capacity

Electrical impedance measurements were made upon unfertilized and fertilized eggs of the leopard frog, Rana pipiens, over a frequency range of 0.05 to 10 kc. Average values of 170 ohm cm.2 were obtained for the plasma membrane resistance of the egg, 2.0 µf/cm.2 for the plasma membrane capacity, 86° for the phase angle of the membrane, and 570 ohm cm. for the specific resistance of the interior. These values did not change upon fertilization. No spontaneous rhythmical impedance changes such as have been found by Hubbard and Rothschild in the trout egg were found in frog eggs.

ANALISIS BEBAN PENDINGINAN PADA COLD STORAGE UNTUK PENYIMPANAN DAGING

2019 ◽  
Vol 7 (1) ◽  
pp. 12-22
Author(s):  
Ratu Mutia Fajarani ◽  
Yopi Handoyo ◽  
Raden Hengki Rahmanto
Keyword(s):  
Experimental Method ◽  
Cold Storage ◽  
Freezing Point ◽  
Cooling Load ◽  
Internal Factors ◽  
External Cooling ◽  
Preservation Method ◽  
Load Calculation ◽  
Selection Of

Cooling is the best preservation method than others because the food that has been cooled will remain fresh and will not experience a change in taste, color and aroma, besides all the activities that cause decay will stop so that the cooled food will last longer. (Hartanto, 1984). With the proper cooling engine planning, it can help with spatial adjustments, adjustments to loading, estimation of the power to be used, and budget plans. That is what is commonly called the cooling load calculation. Calculation of cooling load needs to be carried out before planning. This is necessary because the magnitude of the pending load is very influential on the selection of the cooling engine so that the freezing point for preserving food can be accurate. Pendiginan burden is influenced by external and internal factors. With the experimental method, it is obtained the results of the external cooling load as the external cooling load is 11.6 kW, the inner cooling load is 138.8 kW and the performance work coefficient (COP) is 2.

scholarly journals Dry Film Resist Laminated Microfluidic System for Electrical Impedance Measurements

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 632
Author(s):  
Yuan Cao ◽  
Julia Floehr ◽  
Sven Ingebrandt ◽  
Uwe Schnakenberg
Keyword(s):  
Microfluidic Chip ◽  
Electrical Impedance ◽  
Microfluidic System ◽  
Equivalent Circuits ◽  
Proof Of Concept ◽  
Impedance Measurements ◽  
Close Match ◽  
Aspect Ratios ◽  
Lamination Process ◽  
Dry Film

In micro-electrical-mechanical systems (MEMS), thick structures with high aspect ratios are often required. Dry film photoresist (DFR) in various thicknesses can be easily laminated and patterned using standard UV lithography. Here, we present a three-level DFR lamination process of SUEX for a microfluidic chip with embedded, vertically arranged microelectrodes for electrical impedance measurements. To trap and fix the object under test to the electrodes, an aperture is formed in the center of the ring-shaped electrodes in combination with a microfluidic suction channel underneath. In a proof-of-concept, the setup is characterized by electrical impedance measurements with polystyrene and ZrO2 spheres. The electrical impedance is most sensitive at approximately 2 kHz, and its magnitudes reveal around 200% higher values when a sphere is trapped. The magnitude values depend on the sizes of the spheres. Electrical equivalent circuits are applied to simulate the experimental results with a close match.

Electrical impedance measurements for pulmonary disease diagnosis

1992 ◽  
Vol 13 (A) ◽  
pp. 171-174 ◽  
Author(s):  
J N Sahalos ◽  
E Vlachogiannis ◽  
C Koukourlis ◽  
G Kyriacou ◽  
K Batas
Keyword(s):  
Pulmonary Disease ◽  
Electrical Impedance ◽  
Disease Diagnosis ◽  
Impedance Measurements

scholarly journals Low Cost Instrumentation for Electrical Impedance Tomography in Biomedical Applications

2015 ◽  
Author(s):  
Stewart Smith ◽  
Hancong Wu ◽  
Jiabin Jia
Keyword(s):  
Electrical Impedance Tomography ◽  
Integrated Circuit ◽  
Biomedical Applications ◽  
Electrical Impedance ◽  
Low Cost ◽  
Impedance Measurement ◽  
Impedance Tomography ◽  
Impedance Measurements ◽  
Additional Circuitry ◽  
Initial Results

This poster reports the design, implementation and testing of a portable and inexpensive bio-impedance measurement system intended for electrical impedance tomography (EIT) in cell cultures. The system is based on the AD5933 impedance analyser integrated circuit with additional circuitry to enable four-terminal measurement. Initial results of impedance measurements are reported along with an EIT image reconstructed using the open source EIDORS package.

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