scholarly journals Ionic Strength and Drag Reduction of Polymers in Straight Pipes – An Experimental Investigation

2021 ◽  
Vol 10 (2) ◽  
pp. 23
Author(s):  
Ahmed Kamel
Keyword(s):  
Ionic Strength ◽  
Drag Reduction ◽  
Polymer Solutions ◽  
Salt Content ◽  
Small Scale ◽  
Flow Loop ◽  
Reduction Behavior ◽  
Reduced Salt ◽  
Reduction Characteristics ◽  
The Relationship

Previous work has tied the drag reduction properties of polymer solutions to type and concentration of salts, rather than its ionic strength, although it is a more extensive parameter to investigate the effects of salt contents on fluids behavior. The current study aims at investigating the relationship between ionic strength and drag reduction characteristics of polymer solutions when flowing in straight tubing. Nalco ASP-700 and ASP-820, two common anionic AMPS copolymers, are examined with various salts (2% KCl, 4% KCl, and synthetic seawater). Flow tests were conducted using a small-scale flow loop that includes a straight tubing with an outside diameter of 1.27 cm and a length of 4.57 m. It has been found that drag reduction performance of polymer solutions is well correlated with ionic strength, rather than salt type and/or concentration. With high ionic strength, lower drag reduction is noticed despite of the reduced salt concentration. Nevertheless, at higher Reynolds number, the effects of ionic strength minimizes. Both polymer solutions exhibit effective drag reduction characteristics and their behavior is greatly affected by polymer type, shear rate, and salt content. Correlations, with acceptable confidence level, between drag reduction ratio and solutions ionic strength are proposed. The correlations are strongly recommended to investigate the effects of salt types and/or concentrations, represented by its ionic strength on drag reduction behavior of polymer solutions in straight tubing.

Titration of sulphates and lead using lead ion selective electrode

1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý
Keyword(s):  
Ionic Strength ◽  
Electrode Surface ◽  
Salt Content ◽  
Ion Selective Electrode ◽  
Lead Ion ◽  
Selective Electrode ◽  
Limit Of Determination ◽  
Total Salt Content ◽  
Automatic Titration

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.

Consumer preferences for low-salt foods - a Danish case study based on a comprehensive supermarket intervention

2021 ◽  
pp. 1-26
Author(s):  
Sigrid Denver ◽  
Tove Christensen ◽  
Jonas Nordström
Keyword(s):  
Consumer Preferences ◽  
Salt Content ◽  
Dietary Advice ◽  
Scanner Data ◽  
Statistical Regression ◽  
Salt Consumption ◽  
Dietary Choices ◽  
Low Salt ◽  
Reduced Salt

Abstract Objective: The objective is to analyze Danish consumers’ attitudes to buying food with reduced salt content. Design: The study is based on a comprehensive store intervention that included 114 stores belonging to the same supermarket chain. Three different salt claims were tested for eight weeks on six test products within the categories bread, cornflakes and frozen pizzas. Scanner data were supplemented with 134 brief interviews with consumers in nine selected stores. Setting: Stores spread across Denmark. Participants: Consumers who buy food in the stores. Results: Statistical regression analyses of the scanner data indicated that none of the three claims significantly affected demand for any of the test products. The interviews confirmed that many consumers were more focused on other elements of the official dietary advice than reduced salt consumption, such as eating plenty of vegetables, choosing products with whole grains and reducing their intake of sugar and fat. Conclusions: Overall, both the scanner data and the interviews pointed in the same direction, toward the conclusion that salt content is often a secondary factor when Danish consumers make dietary choices.

scholarly journals Maternal toxoplasmosis and the risk of childhood autism: serological and molecular small-scale studies

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jamila S. Al Malki ◽  
Nahed Ahmed Hussien ◽  
Fuad Al Malki
Keyword(s):  
Neurodevelopmental Disorders ◽  
Repetitive Behavior ◽  
Saudi Arabian ◽  
Childhood Autism ◽  
Small Scale ◽  
Autistic Children ◽  
High Prevalence ◽  
Life Threatening ◽  
The Relationship ◽  
Delayed Language Development

Abstract Background Toxoplasmosis resulting from infection with the Toxoplasma parasite has become an endemic disease worldwide. Recently, a few studies have reported a high prevalence of Toxoplasmosis infections among Saudi Arabian women. This disease could become life threatening for pregnant women and for immunodeficient people. There is evidence that infections during pregnancy, especially in the early stages, are associated with neurodevelopmental disorders. Autism disorder represents one of the most common neurodevelopmental disorders worldwide; it is associated with delayed language development, weak communication interaction, and repetitive behavior. The relationship between prenatal toxoplasmosis and autism in childhood remains unclear. The present study aims to report a link between maternal toxoplasmosis and autistic offspring among Saudi Arabian women. Method Blood samples (36 maternal, 36 from their non-autistic children, and 36 from their autistic children) were collected for serological and molecular evaluation. Results A toxoplasmosis infection was reported for 33.34% of participants using an ELISA assay (5.56% IgG+/IgM+, 11.11% IgG−/IgM+, and 16.67% IgG+/IgM-); however, a nested PCR assay targeting B1 toxoplasmosis specific genes recorded positive tests for 80.56% of the samples. In addition, the present study detected several points of mutation of mtDNA including NADH dehydrogenase (ND1, ND4) and Cyt B genes and the nDNA pyruvate kinase (PK) gene for autistic children infected with toxoplasmosis. Conclusion Considering previous assumptions, we suggest that a maternal toxoplasmosis infection could have a role in the development of childhood autism linked to mtDNA and nDNA impairment.

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