A passive probe for electrostatic charge density measurements

1990 ◽  
Vol 61 (11) ◽  
pp. 3416-3420 ◽  
Author(s):  
Ioannis N. Miaoulis ◽  
Behrouz Abedian
Keyword(s):  
Charge Density ◽  
Electrostatic Charge ◽  
Density Measurements

Characterisation of natural organic matter (NOM) removed by magnetic ion exchange resin (MIEX® Resin)

2009 ◽  
Vol 9 (2) ◽  
pp. 199-205 ◽  
Author(s):  
M. R. D. Mergen ◽  
B. J. Adams ◽  
G. M. Vero ◽  
T. A. Price ◽  
S. A. Parsons ◽  
...  
Keyword(s):  
Charge Density ◽  
Natural Organic Matter ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Low Molecular Weight ◽  
Raw Water ◽  
Density Measurements ◽  
Organic Species ◽  
Magnetic Ion ◽  
Insight Into

The aim of the research presented in this paper was to gain greater insight into the characteristics of NOM removed by MIEX® Resin. Previous studies have shown that MIEX® Resin increases the level of removable DOC when used in combination with coagulation, suggesting that these two processes target a different type of organics. Initially the characteristics of DOC in regenerant solutions from four different MIEX® Resin treatment plants were analysed and compared to DOC in the respective raw water. Following this the raw water and the regenerant solutions were coagulated and the characteristics of the residual DOC analysed and compared to the regenerant solutions prior to coagulation. From the regenerant solutions it was seen that MIEX® Resin targets DOC of increased UV254 absorbance, increased charge density and of mid to low molecular weight (5 to 2 kDa). In terms of hydrophobicity no preference of MIEX® Resin for a specific NOM type was seen. The presence of hydrophilic neutral acids in the regenerant solution was unexpected since the removal of only highly charged organic species was expected. Charge density measurements however revealed the presence of functional groups, allowing hydrophilic neutrals to be removed by anion exchange. Comparative coagulation of the raw water and regenerant solution showed that both a residual DOC of similar hydrophobicity in the sub 3 kDa area. Considering that this DOC fraction was present in the regenerant it was concluded that MIEX® Resin removes organics recalcitrant to coagulation from raw water and therefore increases DOC removal when both methods are combined.

scholarly journals Three dimensional charge density measurements at surfaces

2005 ◽  
Vol 61 (a1) ◽  
pp. c96-c96 ◽  
Author(s):  
R. Feidenhans'l ◽  
O. Bunk ◽  
J. Ciston ◽  
L. D. Marks
Keyword(s):  
Charge Density ◽  
Three Dimensional ◽  
Density Measurements

scholarly journals Simulations of 3D charge density measurements for commissioning of the PolariX-TDS

2018 ◽  
Vol 1067 ◽  
pp. 072012 ◽  
Author(s):  
D Marx ◽  
R Assmann ◽  
R D’Arcy ◽  
B Marchetti
Keyword(s):  
Charge Density ◽  
Density Measurements

Oscillating probe for charge density measurements

1976 ◽  
Vol 2 (1) ◽  
pp. 91-95 ◽  
Author(s):  
F. Nordhage ◽  
G. Bäckström
Keyword(s):  
Charge Density ◽  
Density Measurements

Surface charge density measurements with a controlled growth mercury electrode

1996 ◽  
Vol 8 (8-9) ◽  
pp. 742-747 ◽  
Author(s):  
John J. O'Dea ◽  
Malgorzata Ciszkowska ◽  
Robert A. Osteryoung
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Mercury Electrode ◽  
Controlled Growth ◽  
Density Measurements

scholarly journals Assessment of N95 and K95 respirator decontamination: fiber integrity, filtration efficiency, and dipole charge density.

2020 ◽  
Author(s):  
Wonjun Yim ◽  
Diyi Cheng ◽  
Shiv Patel ◽  
Rui Kui ◽  
Ying Shirley Meng ◽  
...  
Keyword(s):  
Charge Density ◽  
Science Studies ◽  
Materials Science ◽  
Electrostatic Charge ◽  
Filtration Efficiency ◽  
Protective Equipment ◽  
Before And After ◽  
Physical Changes ◽  
N95 Respirators ◽  
Filter Layer

Personal protective equipment (PPE) including N95 respirators are critical for persons exposed to SARS-CoV-2. KN95 respirators and N95 decontamination protocols have been described as solutions to a lack of such PPE. However, there are a few materials science studies that characterize the charge distribution and physical changes accompanying disinfection treatments particularly heating. Here, we report the filtration efficiency, dipole charge density, and fiber integrity of pristine N95 and KN95 respirators before and after various decontamination methods. We found that the filter layer of N95 is 8-fold thicker than that of KN95, which explains its 10% higher filtration efficiency (97.03 %) versus KN95 (87.76 %) under pristines condition. After 60 minutes of 70 °C treatment, the filtration efficiency and dipole charge density of N95 became 97.16% and 12.48 µC/m2, while those of KN95 were 83.64% and 1.48 µC/m2 ; moreover, fit factor of N95 was 55 and that of KN95 was 2.7. In conclusion, the KN95 respirator is an inferior alternative of N95 respirator. In both systems, a loss of electrostatic charge does not directly correlate to a decrease in performance.

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