scholarly journals Determination of the zeta potential for highly charged colloidal suspensions

2011 ◽  
Vol 369 (1945) ◽  
pp. 2546-2554 ◽  
Author(s):  
Giovanni Giupponi ◽  
Ignacio Pagonabarraga
Keyword(s):  
Steady State ◽  
Charged Particle ◽  
Zeta Potential ◽  
Electric Fields ◽  
Electrostatic Potential ◽  
Colloidal Suspension ◽  
Colloidal Suspensions ◽  
Ion Concentration ◽  
Lattice Resolution

We compute the electrostatic potential at the surface, or zeta potential ζ , of a charged particle embedded in a colloidal suspension using a hybrid mesoscopic model. We show that, for weakly perturbing electric fields, the value of ζ obtained at steady state during electrophoresis is statistically indistinguishable from ζ in thermodynamic equilibrium. We quantify the effect of counter-ion concentration on ζ . We also evaluate the relevance of the lattice resolution for the calculation of ζ and discuss how to identify the effective electrostatic radius.

scholarly journals Highly Sensitive Optical Sensor for Selective Detection of Fluoride Level in Drinking Water: Methodology to Fabrication of Prototype Device

2021 ◽  
Author(s):  
Arka Chatterjee ◽  
Nivedita Pan ◽  
Tuhin Kumar Maji ◽  
Sheik Saleem Pasha ◽  
Soumendra Singh ◽  
...  
Keyword(s):  
Drinking Water ◽  
Steady State ◽  
Detection Limit ◽  
Aqueous Media ◽  
Ion Concentration ◽  
Fluoride Ion ◽  
Selective Detection ◽  
Highly Sensitive ◽  
Prototype Device

<p><b>Excess consumption of fluoride through drinking water and its detrimental effects on human health have been a serious global concern. Therefore, frequent monitoring as well as quantitative determination of fluoride ion (F<sup>-</sup>) concentration in aqueous media is of vital importance. Herein, we have developed a facile</b> <b>and</b> <b>highly sensitive spectroscopic technique for selective detection of F<sup>-</sup> in aqueous media using aluminium phthalocyanine chloride (AlPc-Cl) as a sensor. The absorbance as well as steady-state fluorescence intensity of AlPc-Cl has been found to decrease in presence of F<sup>-</sup> which has been used as a marker for the determination of fluoride ion concentration in water. The structural change in AlPc-Cl after addition of F<sup>-</sup> has been thoroughly studied by using <sup>19</sup>F NMR (Nuclear Magnetic Resonance) spectroscopy. Our detailed steady-state as well as time-resolved fluorescence studies reveal that the quenching mechanism is static in nature due to ground state complexation in between F<sup>-</sup> and AlPc-Cl molecules. The response of the sensor is found to be linear over the F<sup>-</sup> concentration regime from 0 to 6 parts per million (ppm) with a detection limit of 0.05 ppm. Additionally, it shows an excellent selectivity as well as an insignificant change in sensitivity even in the presence of interfering iron and aluminium ions. Based on the detailed photophysical study, we have further developed a low cost and portable prototype device which shows an excellent sensitivity with the detection limit of 0.10 ppm. This prototype device has a high prospect for real-time monitoring of fluoride ion concentration especially in remote areas.</b></p>

scholarly journals Highly Sensitive Optical Sensor for Selective Detection of Fluoride Level in Drinking Water: Methodology to Fabrication of Prototype Device

2021 ◽  
Author(s):  
Arka Chatterjee ◽  
Nivedita Pan ◽  
Tuhin Kumar Maji ◽  
Sheik Saleem Pasha ◽  
Soumendra Singh ◽  
...  
Keyword(s):  
Drinking Water ◽  
Steady State ◽  
Detection Limit ◽  
Aqueous Media ◽  
Ion Concentration ◽  
Fluoride Ion ◽  
Selective Detection ◽  
Highly Sensitive ◽  
Prototype Device

<p><b>Excess consumption of fluoride through drinking water and its detrimental effects on human health have been a serious global concern. Therefore, frequent monitoring as well as quantitative determination of fluoride ion (F<sup>-</sup>) concentration in aqueous media is of vital importance. Herein, we have developed a facile</b> <b>and</b> <b>highly sensitive spectroscopic technique for selective detection of F<sup>-</sup> in aqueous media using aluminium phthalocyanine chloride (AlPc-Cl) as a sensor. The absorbance as well as steady-state fluorescence intensity of AlPc-Cl has been found to decrease in presence of F<sup>-</sup> which has been used as a marker for the determination of fluoride ion concentration in water. The structural change in AlPc-Cl after addition of F<sup>-</sup> has been thoroughly studied by using <sup>19</sup>F NMR (Nuclear Magnetic Resonance) spectroscopy. Our detailed steady-state as well as time-resolved fluorescence studies reveal that the quenching mechanism is static in nature due to ground state complexation in between F<sup>-</sup> and AlPc-Cl molecules. The response of the sensor is found to be linear over the F<sup>-</sup> concentration regime from 0 to 6 parts per million (ppm) with a detection limit of 0.05 ppm. Additionally, it shows an excellent selectivity as well as an insignificant change in sensitivity even in the presence of interfering iron and aluminium ions. Based on the detailed photophysical study, we have further developed a low cost and portable prototype device which shows an excellent sensitivity with the detection limit of 0.10 ppm. This prototype device has a high prospect for real-time monitoring of fluoride ion concentration especially in remote areas.</b></p>

STEADY-STATE DETERMINATION OF FUEL-BOND NITROGEN IN DIESEL AND INDUSTRIAL GAS OIL

Clean Air ◽  
2007 ◽  
Vol 8 (4) ◽  
pp. 359-371
Author(s):  
A. Medeiros ◽  
R. Edenhofer ◽  
K. Lucka ◽  
H. Kohne
Keyword(s):  
Steady State ◽  
Gas Oil ◽  
State Determination

Fluctuations of Annual Precipitation and Water Resources Quality in Ukraine

2016 ◽  
Vol 10 (4s) ◽  
pp. 621-629
Author(s):  
Valentina Pidlisnyuk ◽  
◽  
John Harrington JR ◽  
Yulia Melnyk ◽  
Yuliya Vystavna ◽  
...  
Keyword(s):  
Water Resources ◽  
Surface Waters ◽  
Precipitation Amount ◽  
Ion Concentration ◽  
Annual Precipitation ◽  
Resource Quality ◽  
Phosphate Ion ◽  
Regional Trends

The article focuses on examining the influence of fluctuations in annual precipitation amount on the quality of surface waters. Water quality was estimated with data on BOD, COD and phosphate–ion concentration within five selected regions of Ukraine. Analysis of the precipitation data (1991 – 2010) showed different regional trends. Using the statistics, determination of the interconnection between precipitation amount and water resources quality were done. The obtained regularities and associated uncertainties can be used for prediction of changes in water resource quality and as a guide for future adaptation to possible climate change.

Calcium Budgets for Catchments as Interpreted by Strontium Isotopes

1989 ◽  
Vol 20 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Gunnar Jacks ◽  
Göran Åberg ◽  
P. Joseph Hamilton
Keyword(s):  
Steady State ◽  
Forest Ecosystem ◽  
Coniferous Forest ◽  
Strontium Isotopes ◽  
Runoff Water ◽  
Weathering Rate ◽  
Weathering Rates ◽  
Exchangeable Calcium

Strontium isotopes in precipitation, soil and runoff water can be used to establish a ratio of wet plus dry deposited Sr to Sr released by weathering. This ratio is especially enhanced in areas with old acid Proterozoic rocks (0.6-2.5 Ga) and Archean rocks (&gt;2.5 Ga). Since Sr and Ca behave in an analogous way in the coniferous forest ecosystem the results for Sr can be used for the determination of Ca. If the deposition of calcium can be calculated reasonably accurately the weathering rate can also be estimated. Five catchments have been investigated using this approach. Three of them seem to be close to a steady state, wherein the losses and gains of calcium to the system are equal. In the two southern-most catchments there seems to be an ongoing loss of exchangeable calcium. The loss by runoff occurs with sulphate being the dominant anion. Weathering rates of 1.5 to 4.8 kg Ca/ha year have been estimated.

A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

1996 ◽  
Vol 27 (4) ◽  
pp. 247-254 ◽  
Author(s):  
Zekâi Şen
Keyword(s):  
Steady State ◽  
Graphical Method ◽  
Pumping Test ◽  
Quasi Steady State ◽  
Flow Data ◽  
Steady State Flow ◽  
Storage Coefficient ◽  
State Flow ◽  
Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

Operational Determination of the Activated Sludge Process Using Neural Networks

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2461-2464 ◽  
Author(s):  
R. D. Tyagi ◽  
Y. G. Du
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Steady State ◽  
Activated Sludge ◽  
Feedforward Neural Network ◽  
Training Data ◽  
Activated Sludge Process

A steady-statemathematical model of an activated sludgeprocess with a secondary settler was developed. With a limited number of training data samples obtained from the simulation at steady state, a feedforward neural network was established which exhibits an excellent capability for the operational prediction and determination.

scholarly journals Determination of the Zeta Potential of Planar Solids in Nonpolar Liquids

2021 ◽  
Author(s):  
Dennis C. Prieve ◽  
Benjamin A. Yezer ◽  
Keyi Xu ◽  
Aditya S. Khair ◽  
James W. Schneider ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Nonpolar Liquids
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