scholarly journals A new system for measuring electrical conductivity of water as a function of admittance

2019 ◽  
Vol 2 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Haval Y. Yacoob Aldosky ◽  
Suzan M. H. Shamdeen
Keyword(s):  
Tap Water ◽  
Water Sources ◽  
Electrode System ◽  
Electrode Impedance ◽  
Water Conductivity ◽  
Plastic Tube ◽  
Low Frequencies ◽  
Good Operation ◽  
New System ◽  
Four Electrodes

Abstract This paper presents a new system for measuring water conductivity as a function of electrophysical property (admittance). The system is cheap and its manufacturing is easy. In addition, it does not require any sort of electrolysis and calibration. The system consists of four electrodes made of silver (Ag 92.5 g to Cu 7.5 g) fixed in a plastic tube filled by water which allows the use of two and four electrode setups. The admittance (reciprocal of impedance) was measured for different water sources (distilled, rainfall, mineral, river and tap water) using different frequencies between 50 Hz and 100 kHz. These measurements were taken twice, first with four electrodes and then with two electrodes of two modes (inner and outer electrodes). The results showed good correlation between the measured admittance and the conductivity of all the water sources and the best correlation was found at low frequencies between 50 Hz and 20 kHz. The highest efficiency can be achieved by using the four electrode system which allows circumventing the effect of the electrode impedance. This result makes the system efficient compared to traditional conductivity meters which usually require high frequencies for good operation.

scholarly journals Heavy metal levels in drinking water sources of Chingola District, Zambia

2020 ◽  
Author(s):  
Francis Hamwiinga ◽  
Chisala D. Meki ◽  
Patricia Mubita ◽  
Hikabasa Halwiindi
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Drinking Water ◽  
Ground Water ◽  
Water Samples ◽  
Tap Water ◽  
Water Sources ◽  
Wet Season ◽  
Drinking Water Sources ◽  
Metal Levels

Abstract Background: One of the factors impeding access to safe water is water pollution. Of particular concern is heavy metal contamination of water bodies. This study was aimed at determining the levels of heavy metals in drinking water sources of Chingola District of Zambia. Methods: A cross sectional study was employed. A total of 60 water samples were collected. Thirsty (30) samples were collected in the dry season in the month of October 2016 and another 30 in the wet season in the months of February and March, 2017. For each season 10 water samples were collected from each of the three water sources. i.e. Tap water, Urban ground water sources and Rural ground water sources. Heavy metal analysis was done using Atomic Absorption Spectrophotometer (AAS).Results: This study revealed that the concentrations of Iron, Manganese, Lead, Nickel and Arsenic were beyond maximum permissible levels in various water sources. Combined averages for both dry and wet seasons were as follows: Iron: 2.3, Copper: 0.63, Cobalt: 0.02, Manganese: 0.36, Lead: 0.04, Zinc:3.2, Nickel: 0.03, Arsenic: 0.05. Chromium and Cadmium were below detection limit in all water samples. The median concentrations of iron, arsenic, copper, manganese in drinking water from the Tap, rural and urban ground water sources were different, and this difference was statistically significant (p<0.05). The median concentrations of arsenic, nickel, manganese and cobalt were different between dry and wet season, and this difference was statistically significant (p<0.05).Conclusions: Sources of heavy metals in water seems to be both natural and from human activities. The concentration of heavy metals in different water sources in this study was found to be above the recommended levels. This calls for improvement in water monitoring to protect the health of the public. Therefore, there is need for continuous monitoring of heavy metals in drinking water sources by regulatory authorities.

scholarly journals Predicting neural recording performance of implantable electrodes

The Analyst ◽  
2019 ◽  
Vol 144 (9) ◽  
pp. 2973-2983 ◽  
Author(s):  
Alexander R. Harris ◽  
Ben J. Allitt ◽  
Antonio G. Paolini
Keyword(s):  
Neural Recording ◽  
Electrode Impedance ◽  
Low Frequencies ◽  
Implantable Electrodes

Electrode impedance at low frequencies was a stronger predictor of electrophysiological performance than the typically reported impedance at 1 kHz.

scholarly journals 927. Tap Water Avoidance Decreases Rates of Nontuberculous Mycobacteria in Intensive Care Units

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S29-S30 ◽  
Author(s):  
Arthur W Baker ◽  
Becky Smith ◽  
Daniel J Sexton ◽  
Kirk Huslage ◽  
Jason E Stout ◽  
...  
Keyword(s):  
Patient Care ◽  
Nontuberculous Mycobacteria ◽  
Tap Water ◽  
Positive Culture ◽  
Water Sources ◽  
Incidence Rates ◽  
Sterile Water ◽  
Intervention Period ◽  
Symptomatic Infection ◽  
Outbreak Period

Abstract Background We recently investigated a clonal outbreak of Mycobacterium abscessus molecularly linked to a colonized water supply at a new hospital addition. Use of sterile water instead of tap water for patient care in ICUs successfully mitigated the respiratory phase of the outbreak. We hypothesized that avoidance of tap water would also be associated with decreased respiratory isolation of other nontuberculous mycobacteria (NTM). Methods We analyzed all positive cultures for NTM obtained at our hospital from August 2013 through December 2015. The pre-intervention outbreak period was defined as August 2013 through May 2014; the tap water avoidance intervention period was defined as June 2014 through December 2015. NTM isolation was defined as a positive culture from a respiratory specimen obtained from an ICU patient on day 3 or later of hospitalization. We also performed AFB cultures of biofilms obtained from ICU water sources. Results NTM were isolated from 137 patients during 70,168 patient-days (figure). NTM isolation decreased from 41.0 patients/10,000 patient-days in the outbreak period to 9.9 patients/10,000 patient-days in the intervention period (IRR, 0.24; 95% CI, 0.17–0.34; P &lt; .0001) (table). Incidence rates of the 4 most common NTM (M. abscessus, M. chelonae/immunogenum, M. avium complex, and M. gordonae) also markedly decreased. Biofilm cultures were positive for at least 1 NTM isolate in 25 of 33 (76%) ICU water sources, including M. abscessus (n = 11, 33%), M. chelonae/immunogenum (n = 11, 33%), and M. gordonae (n = 11, 33%). Conclusion The use of sterile water for ICU patient care substantially decreased NTM isolation from patient respiratory specimens, presumably reducing risk of symptomatic infection. Hospitals with endemic NTM should consider tap water avoidance for high-risk patients. Disclosures All authors: No reported disclosures.

A Study of Hot Corrosion of Fe-Cr Alloys Induced by a Thin Film of Fused (Na,K)2SO4 by Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 32 (5) ◽  
pp. 493-501
Author(s):  
S.N. Liu ◽  
W. Su ◽  
W.Y. Lu ◽  
Z.F. Wei ◽  
C.L. Zeng
Keyword(s):  
Thin Film ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Hot Corrosion ◽  
Electrochemical Impedance ◽  
Diffusion Flux ◽  
Electrode System ◽  
Corrosion Mechanism ◽  
Low Frequencies ◽  
Nyquist Plots

AbstractTo understand the hot corrosion mechanism of materials it is of significance to establish electrochemical measurements under a thin film of fused salts. In this paper, the hot corrosion behavior of Fe-Cr alloys containing 5, 10 and 25wt% Cr, respectively, in the presence of a fused film of 0.9Na2SO4-0.1K2SO4 (mole fraction) at 1173 K in air has been investigated by electrochemical impedance spectroscopy using a two-electrode system. The Nyquist plots for the corrosion of both Fe-5Cr and Fe-10Cr are composed of a very small semicircle at high frequencies and a line at low frequencies indicating that the corrosion is controlled by the diffusion of oxidants in the fused salt film. The alloys were severely corroded, forming a thick porous corrosion layer containing large amounts of non-protective precipitated Fe oxide particles. Conversely, the Nyquist plots for the corrosion of Fe-25Cr are composed of double capacitive loops, with significantly larger impedance values, which are associated with the formation of a protective Cr2O3 scale. Based on the experimental diffusion impedance results and the theoretic solubility and diffusion coefficient of oxygen in molten salts, respectively, a theoretical value of the diffusion flux of molecular O2 has been calculated.

scholarly journals Effects of Water Quality on Dissolution of Yerba Mate Extract Powders

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Wen-Ying Huang ◽  
Pei-Chi Lee ◽  
Jaw-Cherng Hsu ◽  
Yu-Ru Lin ◽  
Hui-Ju Chen ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Tap Water ◽  
Reducing Power ◽  
Water Sources ◽  
Total Phenol Content ◽  
Yerba Mate ◽  
Scavenging Capacity ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging ◽  
Mate Tea

Yerba mate tea is known as one of the most popular nonalcoholic beverages favoured by South Americans due to its nutrition facts and medicinal properties. The processing of yerba mate tea is found to affect the properties of its final forms. This study presents an investigation into the effects of water sources on the dissolution of yerba mate extract powders. Comparisons were conducted between yerba mate teas prepared by dissolving yerba mate extract powders into tap water and deionized water. Topics to be explored in this work are the major compositions and antioxidant activities, including total phenol content, reducing power, DPPH scavenging activity, and ABTS+• scavenging capacity. It is indicated that there is little difference for antioxidant activities and major constituents of yerba mate teas between both water sources. However, a deeper color is seen in the tap water case, resulting from the reaction between tannic acid and ions. This research finding can be treated as a way to benefit the yerba mate tea processing for applications.

Occurrence of perchlorate in drinking water sources in Korea

2009 ◽  
Vol 9 (2) ◽  
pp. 133-139 ◽  
Author(s):  
H. K. Kim ◽  
J. H. Kim ◽  
B. C. Lee ◽  
S. J. Yu ◽  
H. J. Kim
Keyword(s):  
Waste Water ◽  
Drinking Water ◽  
Water Treatment ◽  
River Basin ◽  
Tap Water ◽  
Water Sources ◽  
Nakdong River ◽  
Nakdong River Basin ◽  
Perchlorate Concentration ◽  
The Nakdong River

Perchlorate is an unregulated contaminant, and recently, many cases of perchlorate contamination have been reported in the US. Unregulated contaminants (e.g. perchlorate) in drinking water are also of significant concern in Korea. We investigated perchlorate levels in tap water, river water, and sewerage water at 4 major water sources in Korea from June 2006. Tap water samples in the Nakdong River basin contained high perchlorate levels. Of the other sampling sites, one at Daegu showed the highest perchlorate level, 22.3 μg/L. The first 2 investigations of raw water sources for drinking water in the Nakdong River basin, found relatively high perchlorate concentration, 18.7–95.6 μg/L and 4.0–25.6 μg/L. The high perchlorate concentration in the Nakdong River basin was possibly derived from waste water discharged by an LCD (liquid crystal display) manufacturing factory in Gumi. The perchlorate concentration of waste water from the nearby sewerage water treatment plant was 730–1,858 μg/L. We modified the waste water treatment operation system at the LCD factory to reduce the perchlorate emissions from this source. The modified treatment system reduced the perchlorate concentration in the final effluent to 40–70 μg/L. Source reduction was successfully achieved by the modified treatment process and by using a perchlorate-free etching reagent.

scholarly journals Determination of Radon-222 in Natural Drinking Water Sources in Outskirts of Yekaterinburg

2014 ◽  
pp. 95-101
Author(s):  
Keyword(s):  
Drinking Water ◽  
Specific Activity ◽  
Tap Water ◽  
Water Source ◽  
Water Sources ◽  
Drinking Water Source ◽  
Drinking Water Sources ◽  
Radon Content

Analysis of the 222Rn specific activity in water of three springs situated in Western outskirts of Yekaterinburg, out of the well that is the main drinking water source in the Palkinsky Torfyanning community, as well as the Yekaterinburg tap water has been carried out. Assessment of the radon content fluctuations over the period from January to November, 2013 in water of one of the sources under study has been done.

scholarly journals Failure to detect Helicobacter pylori in tap water sources in Al- Najaf and Babylon provinces by using PCR based on ureB gene.

2013 ◽  
Vol 12 (1) ◽  
pp. 162
Author(s):  
O.M. Hadi
Keyword(s):  
Helicobacter Pylori ◽  
Failure Mode ◽  
Tap Water ◽  
Water Sources ◽  
Free Chlorine ◽  
The Other ◽  
Free Chloride

500) sample collected from the study area, divided into (250) from the province of Najaf and (250) from the province of Babylon, and distributed by two models for each sample. I use the first model to estimate the level of free chloride , pH, dissolved substances college and temperature, while the use the other form of the same sample to check for the presence of bacteria in tap water in a PCR study showed a large disparity in the levels of pH, free chlorine, dissolved substances college and the temperature you two provinces were the highest percentages for the Abbasia in Najaf Ashraf and the least in the Alhaidariya in the same province study also demonstrated the existence of significant correlation between the level of free chloride each of the temperature, dissolved substances College and the pH while the highest in the region of Mahaweel in the province of Babylon, and the least in Jordan in the same area of the province and which should be mentioned to him the failure mode (PCR) in detecting the presence of Helicobacter pylori bacteria in tap water in the both provinces

scholarly journals Drinking Water and Diarrheal Characteristic Cases in Darbendikhan City

2020 ◽  
Author(s):  
Sabah Shareef Mohammed ◽  
Yadgar Hussien Hama-karim ◽  
Mohammed Ibrahim Mohialdeen Gubari
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Water Source ◽  
Water Sources ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Pipe System ◽  
Software Application ◽  
Drinking Water Sources

Water pollution in Iraq has been extended disaster edge; this pollution is caused by wastes and sewages into soil and rivers, pollutant water sources influence the outbreak and serious epidemic status among the population.. The aim of this study is to determine the bacteriological quality of drinking water sources and characteristics of water-borne diseases especially diarrheal cases in Darbandikhan city. 166 water samples, collected from the different sources and areas, were tested for the presences of coliform bacteria as an indicator for pathogen contamination. Most probable number index was used for coliform enumeration. 161 diarrheal cases were taken as a sample from the patients were admitted to the general hospital in Darbandikhan district.. The questionnaire form was planned to view characteristics of diarrheal cases and patients were interviewed directly, the data was analyzed by STATA software application. 46% of the diarrheal cases used tap water for drinking. On the other hand, the reminder (54%) used other sources for the same purpose. All the risk factor such as type of water source, sufficiency of the water, duration of water storage and chlorination were associated with diarrhea. Almost half of the cases were children and three quarters were single. The data was analyzed by STATA version 13.1.This study indicated that the majority of drinking water sources in Darbandikhan city are not suitable for drinking, although net pipe system supplied chlorine significantly it has been proven that the tap water from the homes is not suitable for consumption.

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