Basic relationships for salinity evaluation from measurements on soil solution

Soil Research ◽  
1980 ◽  
Vol 18 (2) ◽  
pp. 199 ◽  
Author(s):  
DS McIntyre
Keyword(s):  
Electrical Conductivity ◽  
Osmotic Potential ◽  
Large Range ◽  
Ion Concentration ◽  
Graphical Form ◽  
Small Range ◽  
Regression Equations ◽  
The Us ◽  
Best Fit ◽  
Good Agreement

Relationships among total ion concentration, electrical conductivity and osmotic potential have been determined on 137 saturation extracts from Australian soils. The results are presented in graphical form with linear regression equations of best fit, and are compared with results for western U.S.A. soils. If the relationships fitted to the US. data are corrected to the temperature at which the present measurements were made, the differences between the two are less than 20%. As well, the electrical conductivity, and the osmotic potential, have been estimated from the measured compositions of the extracts, and compared with the measured values. Good agreement is found for electrical conductivity over a large range, but only over a small range for osmotic potential.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

scholarly journals Adsorption of Cr6+ Onto Unmodified and Hydrochloric Acid Modified African Nutmeg Pod (Monodora myristica) from Aqueous Solution

2019 ◽  
pp. 1-8
Author(s):  
F. U. Okwunodulu ◽  
H. O. Chukwuemeka-Okorie ◽  
N. M. Mgbemena ◽  
J. B. I. Kalu
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Low Ph ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Particle Sizes ◽  
Monodora Myristica ◽  
Best Fit

The removal of Cr6+ from aqueous solution using unmodified and hydrochloric modified African nutmeg pod was studied. The effects of particle size, pH and initial metal ions concentration adsorbed were investigated. The amount of metal ion adsorbed increased as the initial metal ion concentration increased and also decreased at low pH of 2 for both modified and unmodified African nutmeg pod.  400 µm and 250 µm were the optimum particle sizes for both modified and unmodified African nutmeg pod respectively, values given as 75.8 mg/g for the modified and 93.39 mg/g for the unmodified. Generally, it was observed that the unmodified African nutmeg pod showed greater adsorption capacity than the modified African nutmeg pod. The equilibrium experimental data were examined via Langmuir and Freundlich isotherm models.  Freundlich isotherm model gave the best fit for the data in both unmodified and modified African nutmeg pod based on the correlation coefficients (R2 values) gotten. The results of the study showed that the African nutmeg pod is efficient for the removal of Cr6+ from aqueous solutions especially when unmodified.

scholarly journals Development of Miniaturized Water Quality Monitoring System Using Wireless Communication

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3758
Author(s):  
Hsing-Cheng Yu ◽  
Ming-Yang Tsai ◽  
Yuan-Chih Tsai ◽  
Jhih-Jyun You ◽  
Chun-Lin Cheng ◽  
...  
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Wireless Communication ◽  
Monitoring System ◽  
Industrial Waste ◽  
Continuous Monitoring ◽  
Copper Ion ◽  
Water Quality Monitoring ◽  
Ion Concentration ◽  
Quality Monitoring

Recently, environmental pollution resulting from industrial waste has been emerging in an endless stream. The industrial waste contains chemical materials, heavy metal ions, and other toxic materials. Once the industrial waste is discharged without standards, it might lead to water or environmental pollution. Hence, it has become more important to provide evidence-based water quality monitoring. The use of a multifunctional miniaturized water quality monitoring system (WQMS), that contains continuous monitoring, water quality monitoring, and wireless communication applications, simultaneously, is infrequent. Thus, electrodes integrated with polydimethylsiloxane flow channels were presented in this study to be a compound sensor, and the sensor can be adopted concurrently to measure temperature, pH, electrical conductivity, and copper ion concentration, whose sensitivities are determined as 0.0193 °C/mV, −0.0642 pH/mV, 1.1008 mS/V·cm (from 0 mS/cm to 2 mS/cm) and 1.1975 mS/V·cm (from 2 mS/cm to 5.07 mS/cm), and 0.0111 ppm/mV, respectively. A LoRa shield connected into the system could provide support as a node of long range wide area network (LoRaWAN) for wireless communication application. As mentioned above, the sensors, LoRa, and circuit have been integrated in this study to a continuous monitoring system, WQMS. The advantages of the multifunctional miniaturized WQMS are low cost, small size, easy maintenance, continuous sampling and long-term monitoring for many days. Every tested period is 180 min, and the measured rate is 5 times per 20 min. The feedback signals of the miniaturized WQMS and measured values of the instrument were obtained to compare the difference. In the measured results at three different place-to-place locations the errors of electrical conductivity are 0.051 mS/cm, 0.106 mS/cm, and 0.092 mS/cm, respectively. The errors of pH are 0.68, 0.87, and 0.56, respectively. The errors of temperature are 0.311 °C, 0.252 °C, and 0.304 °C, respectively. The errors of copper ion concentration are 0.051 ppm, 0.058 ppm, 0.050 ppm, respectively.

scholarly journals Characterizing and modeling of low twist yarn mechanics

2019 ◽  
Vol 14 ◽  
pp. 155892501986694
Author(s):  
Benjamin K O Cheung ◽  
Jason P Carey
Keyword(s):  
Linear Regression ◽  
Standard Error ◽  
Prediction Models ◽  
Large Range ◽  
Short Fiber ◽  
Regenerated Cellulose ◽  
Small Range ◽  
Longitudinal Stiffness ◽  
Simple Linear Relationship ◽  
Multifilament Yarns

Twist in yarns can be used for handling or testing purposes, but it is not necessary when using continuous multifilament yarns as compared to the spinning required for a short fiber yarn. Small amounts of twist have shown to increase the strength of the yarn while decreasing the longitudinal stiffness. Previous models, including Gegauff’s cos2 θ model and Rao and Farris’ model, are compared and discussed. A para-aramid (Kevlar 49) and a regenerated cellulose (BioMid) yarn are tested at various levels of twist to compare with these models. Twist is manually applied, and the samples are tested under continuous rate of extension to determine chord modulus, breaking tenacity, and elongation and break. The results are then fit to existing prediction models using a minimization of the standard error of the regression. Finally, a linear regression is also applied to the data to contrast the fit compared to traditional models. It was found that while the Gegauff model and the Rao and Farris model may capture the overall trend and decrease in longitudinal stiffness over a large range of twist, the small range over which twist can practically be used is not well represented by these models and is better represented by a simple linear relationship.

Comparison of dye-dilution and flowmeter estimates of pulmonary valve incompetence in dogs

1960 ◽  
Vol 15 (3) ◽  
pp. 465-472 ◽  
Author(s):  
P. I. Korner ◽  
J. B. Uther ◽  
J. P. Chalmers ◽  
R. Nicks
Keyword(s):  
Distribution Curve ◽  
Pulmonary Valve ◽  
Regression Equations ◽  
Forward Flow ◽  
Pooled Data ◽  
Quantitative Estimates ◽  
Single Determination ◽  
Frequency Distribution Curve ◽  
Good Agreement

Quantitative estimates of backflow were obtained in dogs with experimental pulmonary valve incompetence by means of a bristle flowmeter and the dye curve variance method. The variance of the curve was found to be the best index of indicator dispersion and is calculated from analogy to a frequency distribution curve. The method postulates that (forward flow + backflow)/forward flow = variance observed during incompetence/Vx(F; V), where Vx(F; V) is the expected variance for the same forward flow and volume between injection and sampling sites and is determined from regression equations calculated from data of normal dogs. There was good agreement between dye and flowmeter results, provided that Vx(F2;V) was estimated for the specific regression equations obtained from individual dogs. Three or four successive dye curves, obtained while the animal was in a steady state, permitted quantitation of backflow with the accuracy of a single determination of forward flow by the direct Fick or dye method. When Vx(F;V) was estimated from regression equations obtained from the pooled data and normal dogs, agreement with the flowmeter estimates was poor. Submitted on October 28, 1959

Thermal-Electric Finite Element Analysis of Electrosurgical Cautery Process

2007 ◽  
Author(s):  
Robert E. Dodde ◽  
Scott F. Miller ◽  
Albert J. Shih ◽  
James D. Geiger
Keyword(s):  
Heat Transfer ◽  
Electrical Conductivity ◽  
Finite Element ◽  
Biological Tissue ◽  
Tissue Temperature ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Temperature Dependent Thermal Conductivity ◽  
Insight Into ◽  
Good Agreement

Cautery is a process to coagulate tissues and seal blood vessels using the heat. In this study, finite element modeling (FEM) was performed to analyze temperature distribution in biological tissue subject to cautery electrosurgical technique. FEM can provide detailed insight into the heat transfer in biological tissue to reduce the collateral thermal damage and improve the safety of cautery surgical procedure. A coupled thermal-electric FEM module was applied with temperature-dependent electrical and thermal properties for the tissue. Tissue temperature was measured at different locations during the electrosurgical experiments and compared to FEM results with good agreement. The temperature-dependent electrical conductivity has demonstrated to be critical. In comparison, the temperature-dependent thermal conductivity does not impact heat transfer as much as the electrical conductivity. FEM results show that the thermal effects can be varied with the electrode geometry that focuses the current density at the midline of the instrument profile.

scholarly journals The Correlation and Regression Analysis of Physicochemical Parameters of River Water for the Evaluation of Percentage Contribution to Electrical Conductivity

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Arun Kumar Shrestha ◽  
Nabin Basnet
Keyword(s):  
Electrical Conductivity ◽  
Correlation Coefficients ◽  
Quality Standards ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Regression Equations ◽  
Water Quality Standards ◽  
Percentage Contribution ◽  
Correlation And Regression Analysis ◽  
Standard Procedures

Ten different water samples were collected from Ratuwa River and its tributaries. The laboratory test was carried out by standard procedures (APHA methods), and the measured values were compared with the Nepal standard recommended by Nepal Drinking Water Quality Standards (NDWQS). Statistical analysis also had been used to calculate the correlation coefficients and to plot the regression equations of various parameters with electrical conductivity. The aim of the study was to identify the parameters that affect the electrical conductivity and evaluate the percentage contribution of these parameters. The correlation matrix shows that color, total dissolved solids (TDS), chloride (Cl), fluoride (F), total phosphorus (TP), total alkalinity (TA), calcium (Ca), magnesium (Mg), sodium (Na), and dissolved oxygen (DO) have a significant effect on the electrical conductivity (EC). Among these parameters, TDS has the highest contribution (39.65%) followed by total alkalinity (23.5%), total hardness (19.9%), chlorine (6.5%), and calcium (5.5%) ions, respectively. However, color, TP, fluoride, and DO have almost 1.45% contribution to the electrical conductivity.

X-Ray Fluorescence Minor- and Trace-Element Analyses Silicate Rocks in the Presence of Large Interelement Effects

1977 ◽  
Vol 21 ◽  
pp. 75-88
Author(s):  
B. S. King ◽  
L. F. Espos ◽  
B. P. Fabbi
Keyword(s):  
Matrix Effects ◽  
Dilution Method ◽  
Regression Equations ◽  
X Ray ◽  
Geological Materials ◽  
Accuracy And Precision ◽  
Binder Ratio ◽  
Silicate Rocks ◽  
Good Agreement

An X-ray fluorescence (XRF) method has been devised for the rapid quantitative determination of 16 minor and trace elements in geological materials. This method, a modification of a direct dilution method (1, 2, 3), uses a sample-to-binder ratio of 85:15 for sample preparation. Pellets prepared by this method are durable and do not deteriorate rapidly when exposed to high X-ray irradiation. Interferences and matrix effects are successfully corrected in actual analyses by employment of multiple linear regression equations.Accuracy and precision have been improved over the method previously used in this laboratory. Detection limits have been lowered for Zn, Rb, Y and Zn approximately by the factor of 2. When interelement corrections are made, the XRF values are found to be in good agreement with the preferred chemical values for the 19 international silicate-rock standards.

Post-Test Investigations of BFBT Critical Power Tests With Trace

2009 ◽  
Author(s):  
Marc Thieme ◽  
Wolfgang Tietsch ◽  
Rafael Macian ◽  
Victor Hugo Sanchez Espinoza
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Critical Power ◽  
The Core ◽  
Fine Mesh ◽  
The Us ◽  
Post Test ◽  
Trace Model ◽  
Good Agreement ◽  
Transfer Models

The validation of heat transfer models of safety analysis codes such as TRACE is very important due to the strong interaction of the thermal hydraulics parameters with the core neutronics. TRACE is the reference system code of the US NRC for LWR. It is being developed and extensively validated within the international CAMP-program. In this paper, the validation of heat transfer models of TRACE related to the prediction of the critical power is presented. The validation is based on a large number of critical power tests performed in the NUPEC BFBT (BWR Full-Size Fine-Mesh Bundle Tests) facility in Japan. These tests were analysed with the TRACE Version 5 RC 2. The comparison of predictions with the experimental data shows good agreement. The developed TRACE model and the comparison of experimental data with code results will be presented and discussed.

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