Electrical capacitance of roots in relation to plant electrodes, measuring frequency and root media

2005 ◽  
Vol 53 (2) ◽  
pp. 197-210 ◽  
Author(s):  
K. Rajkai ◽  
K. R. Végh ◽  
T. Nacsa
Keyword(s):  
Water Saturation ◽  
Electrical Capacitance ◽  
Dielectric Media ◽  
Capacitance Method ◽  
Root Media ◽  
Measuring Frequency ◽  
Living Root ◽  
The Difference ◽  
Whole Plants ◽  
Root Capacitance

The electrical capacitance method was applied for the examination of living root systems in a pot experiment. The measured root capacitances gave an unambiguous indication of the development of root mass and length. The root capacitances measured using needle and clamp plant electrodes were closely similar when the roots of whole plants were placed in water, while increasing differences were observed with a decrease in soil water saturation. The difference in capacitance between the plant electrodes is outlined by interpreting the action mechanism of the clamp electrode. The capacitance and electrical impedance spectra (30 Hz-1 MHz) were determined for roots in soil, for pieces of roots washed free of soil, and for the soil itself. The root capacitance was smaller than that of the soil and higher than that of root pieces at 1 kHz, while the capacitance of the soil became equal to that of roots in soil at about 2 kHz. This calls attention to the importance of the measuring frequency when determining root capacitance. A capacitor model with two dielectric media is proposed besides Dalton's model in order to interpret the behaviour of root and soil capacitances. However, its validity requires further verification.

scholarly journals Application of Electrical Capacitance Method for Prediction of Plant Root Mass and Activity in Field-Grown Crops

2018 ◽  
Vol 9 ◽  
Author(s):  
Imre Cseresnyés ◽  
Katalin Szitár ◽  
Kálmán Rajkai ◽  
Anna Füzy ◽  
Péter Mikó ◽  
...  
Keyword(s):  
Plant Root ◽  
Root Mass ◽  
Electrical Capacitance ◽  
Capacitance Method

A New High Resolution Measurement Technology of D Flip-Flop Output Signals for Measuring Frequency Difference

2013 ◽  
Vol 391 ◽  
pp. 568-571
Author(s):  
Jin Feng Dong ◽  
Wei Yu Zhang ◽  
Hua Liu Liu ◽  
Yong Wei
Keyword(s):  
Absolute Error ◽  
Measurement Technology ◽  
Clock Period ◽  
Flip Flop ◽  
Average Value ◽  
Resolution Measurement ◽  
Measuring Frequency ◽  
The Difference ◽  
Quartz Crystal Resonators ◽  
The Relationship

The output periods of D flip-flop mixer are variable though the periods of two input frequencies are invariable. To measure the output frequency, the conventional method is to calculate the average value of the output periods and the maximum possible absolute error is a clock period. The variation of the output periods has its own pattern of arrangement and it can provide valuable information. Measuring accuracy can be significantly improved by taking into account all the details of output periods changes. A mathematical model that describes the relationship between the input square waves and the output square waves was developed and the difference of two input frequencies can be estimated by the solution of the model. The new method is quite suitable for measuring small frequency increments of quartz crystal resonators.

scholarly journals Liquid-liquid phase separation in particles containing secondary organic material free of inorganic salts

2017 ◽  
Author(s):  
Mijung Song ◽  
Pengfei Liu ◽  
Scot T. Martin ◽  
Allan K. Bertram
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Material ◽  
Water Saturation ◽  
Liquid Phase Separation ◽  
Inorganic Salts ◽  
Photo Oxidation ◽  
Condensation Nucleation ◽  
The Difference ◽  
Liquid Liquid Phase Separation

Abstract. Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid-liquid phase separation (LLPS) occurs at high relative humidities (RH) (greater than ~ 95 %) in α-pinene-derived SOM particles free of inorganic salts while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ~ 95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene at 290 ± 1 K. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the average oxygen-to-carbon elemental ratio (O : C) of the organic material. When the average O : C is between 0.25 and 0.60, LLPS was observed, but when the average O : C was between 0.52 and 1.3, LLPS was not observed. These results help explain the difference between the hygroscopic parameter k of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

scholarly journals Study on the Impacts of Capillary Number and Initial Water Saturation on the Residual Gas Distribution by NMR

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2714
Author(s):  
Tao Li ◽  
Ying Wang ◽  
Min Li ◽  
Jiahao Ji ◽  
Lin Chang ◽  
...  
Keyword(s):  
Capillary Number ◽  
Water Saturation ◽  
Transverse Relaxation Time ◽  
Spontaneous Imbibition ◽  
Trapping Efficiency ◽  
Gas Distribution ◽  
Initial Water ◽  
Capillary Trapping ◽  
Residual Gas ◽  
The Difference

The determination of microscopic residual gas distribution is beneficial for exploiting reservoirs to their maximum potential. In this work, both forced and spontaneous imbibition (waterflooding) experiments were performed on a high-pressure displacement experimental setup, which was integrated with nuclear magnetic resonance (NMR) to reveal the impacts of capillary number (Ca) and initial water saturation (Swi) on the residual gas distribution over four magnitudes of injection rates (Q = 0.001, 0.01, 0.1 and 1 mL/min), expressed as Ca (logCa = −8.68, −7.68, −6.68 and −5.68), and three different Swi (Swi = 0%, 39.34% and 62.98%). The NMR amplitude is dependent on pore volumes while the NMR transverse relaxation time (T2) spectrum reflects the characteristics of pore size distribution, which is determined based on a mercury injection (MI) experiment. Using this method, the residual gas distribution was quantified by comparing the T2 spectrum of the sample measured after imbibition with the sample fully saturated by brine before imbibition. The results showed that capillary trapping efficiency increased with increasing Swi, and above 90% of residual gas existed in pores larger than 1 μm in the spontaneous imbibition experiments. The residual gas was trapped in pores by different capillary trapping mechanisms under different Ca, leading to the difference of residual gas distribution. The flow channels were mainly composed of micropores (pore radius, r < 1 μm) and mesopores (r = 1–10 μm) at logCa = −8.68 and −7.68, while of mesopores and macropores (r > 10 μm) at logCa = −5.68. At both Swi= 0% and 39.34%, residual gas distribution in macropores significantly decreased while that in micropores slightly increased with logCa increasing to −6.68 and −5.68, respectively.

scholarly journals Research on Application of Wax Deposition Detection in the Nonmetallic Pipeline Based on Electrical Capacitance Tomography

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nan Li ◽  
Kui Liu ◽  
Xiangdong Yang ◽  
Mingchen Cao
Keyword(s):  
Experimental Results ◽  
Projection Algorithm ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Wax Deposition ◽  
Binary Images ◽  
Profile Distribution ◽  
The Difference ◽  
Research On Application ◽  
Capacitance Tomography

Wax deposition detection in nonmetallic pipelines is an important requirement in the oil industry. In this paper, an ECT (electrical capacitance tomography) sensor is developed for wax deposition detection in nonmetallic pipelines. Four wax models with different concentrations were established for detection. These models were analyzed through simulations and practical experiments simultaneously and data were compared. A linear back projection algorithm is applied to reconstruct the image with both simulated and experimental data. A comparison of binary images with different concentration of stratified flow was demonstrated; this illustrates that the difference in concentration between the experimental results and profile distribution is less than 1.2%. The experimental results indicate that the ECT system is valid and feasible for detecting the degree of wax deposition in the nonmetallic pipelines.

scholarly journals Improved water saturation estimation in shaly sandstone through variable cementation factor

2021 ◽  
Author(s):  
Wan Zairani Wan Bakar ◽  
Ismail Mohd Saaid ◽  
Mohd Riduan Ahmad ◽  
Zulhelmi Amir ◽  
Nur Shuhadah Japperi ◽  
...  
Keyword(s):  
Water Saturation ◽  
Percentage Error ◽  
Saturation Model ◽  
Formation Factor ◽  
Archie’S Law ◽  
Straight Line ◽  
The Difference ◽  
Shaly Sandstone ◽  
Cementation Factor ◽  
Surface Conduction

AbstractEstimation of water saturation, Sw, in shaly sandstone is an intricate process. The surface conduction of clay minerals adds up to the electrolyte conduction in the pore spaces, thus generating high formation conductivity that overshadows the hydrocarbon effect. In each resistivity-based water saturation model, the key parameter is formation factor, F, which is typically derived from Archie’s Law. Referring to a log–log plot between formation factor and porosity, cementation factor reflects the slope of the straight line abiding Archie’s Law. In the case of shaly sandstone, derivation based on Archie’s Law in combination with Waxman–Smits equation leads to higher cementation factor, m*. In the shaly parts of the reservoir, high m* is counterbalanced by clay conductivity. Nonetheless, high m* used in clean parts increases Sw estimation. In this study, the variable cementation factor equation is introduced into the standard correlation of Sw versus Resistivity Index, RI, to develop a water saturation model with shaly sandstone parameters. Data retrieved from two fields that yielded mean arctangent absolute percentage error (MAAPE) were analysed to determine the difference between calculated and measured data within the 0.01–0.15 range for variable cementation factor method. The conventional method yielded maximum MAAPE at 0.46.

Estimating root mass in maize genotypes using the electrical capacitance method

2008 ◽  
Vol 54 (2) ◽  
pp. 215-226 ◽  
Author(s):  
Raymond McBride ◽  
Michael Candido ◽  
James Ferguson
Keyword(s):  
Root Mass ◽  
Electrical Capacitance ◽  
Maize Genotypes ◽  
Capacitance Method

scholarly journals Empirical determination of water saturation of porous materials in the process of long duration imbibition

2019 ◽  
Vol 109 ◽  
pp. 00117
Author(s):  
Volodymyr Yelisieiev ◽  
Vasyl Lutsenko ◽  
Tetiana Demchenko ◽  
Vitalii Ruban
Keyword(s):  
Good Accuracy ◽  
Water Saturation ◽  
Process Time ◽  
Saturation Curve ◽  
Porous Bodies ◽  
Theoretical Approaches ◽  
Long Duration ◽  
Empirical Determination ◽  
The Difference

The paper presents the results of an experimental study of the process of imbibition of porous bodies with a long stay in the impregnating medium. Experiments have confirmed, that at time of the order of 100 min there is a significant slowdown in the rise of the saturation curve, which can be taken as the end of the process. However, for the final completion of the process time is needed in the hundreds of times greater and the water saturation can increase more than twice. Experiments showed that with an increase in porosity, the length of the region of a significant deceleration of the impregnation rate tends to decrease. Regardless of the difference in the structures of the tested samples, it was possible to obtain a general analytical expression for describing the process of water saturation, which indicates similarity in the movement of fluid in the system of pore channels. The approximation of the experimental data by a logarithmic function gives a good result of an analytical representation of the process. It is also shown that the theoretical approaches used make it possible to obtain water saturation curves over long periods with good accuracy.

scholarly journals Liquid–liquid phase separation in particles containing secondary organic material free of inorganic salts

2017 ◽  
Vol 17 (18) ◽  
pp. 11261-11271 ◽  
Author(s):  
Mijung Song ◽  
Pengfei Liu ◽  
Scot T. Martin ◽  
Allan K. Bertram
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Material ◽  
Water Saturation ◽  
Liquid Phase Separation ◽  
Inorganic Salts ◽  
Photo Oxidation ◽  
Condensation Nucleation ◽  
The Difference ◽  
Liquid Liquid Phase Separation

Abstract. Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid–liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than  ∼  95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than  ∼  95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

scholarly journals The Discourse on Measuring Frequency of Tongue Strength

2019 ◽  
pp. 03-07 ◽  
Author(s):  
Chun Hao Lin ◽  
Shu-Ying Chung ◽  
Yueh-Juen Hwu
Keyword(s):  
Repeated Measurements ◽  
Analysis Of Covariance ◽  
Standard Protocol ◽  
Tongue Strength ◽  
Oral Performance ◽  
Research Subjects ◽  
Measuring Frequency ◽  
The Difference ◽  
Intraoral Pressure ◽  
Posterior Tongue

Iowa Oral Performance Instrument (IOPI) is an instrument used to measure tongue strength. The standard protocol of operating IOPI is three trials separated by 10-15 seconds of rest. The highest pressure of these three trials is recorded as the tongue strength. The purpose of this study was to investigate the difference of three trials. Forty-one healthy adults were taken as research subjects. Repeated-measurements analysis of covariance (RANCOVAs) was used to analyze the anterior and posterior tongue strength under four conditions: maximum isometric pressure, dry swallowing, 5c.c. and 10c.c. of water swallowing. The results showed that there were no statistically significant differences among three trials of anterior and posterior tongue strength. It is suggested that before measuring the tongue strength, the participants should be provided with the opportunity to practice, and one or two trials in formal measurements can be adopted to reduce their fatigue. Keywords: Intraoral pressure; Swallowing; Dysphagia

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