Experimental and theoretical analysis of (water) permeability variation of nonwoven textiles subjected to compression

This paper presents the experimental determination of permeability for unidirectional in-plane flow through a thin layer of nonwoven porous textile subjected to various rates of compression. The experiments were made on an original device that allows the variation of porous layer compression and pressure differential. The permeability was calculated assuming the validity of Darcy law and, in parallel, Darcy-Forchheimer model. The preliminary results obtained with water show that pressure gradient does not influence sensibly the resistance to flow of the material and Darcy’s law is applicable. For permeability-porosity correlation the experimental results were fitted using the well-known Kozeny-Carman equation. Also good correlation was found with other two models derived from Kozeny-Carman.

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Flow-through electrochemistry in the analysis of wine

Nova Biotechnologica et Chimica ◽

10.36547/nbc.1365 ◽

2022 ◽

Vol 7 (1) ◽

pp. 101-106

Author(s):

Ernest Beinrohr ◽

Stanislava Hlubikova ◽

Jarka Lastincova

Keyword(s):

Heavy Metals ◽

Thin Layer ◽

Coulometric Titration ◽

Ethanol Content ◽

Low Concentrations ◽

Stripping Chronopotentiometry ◽

Flow Through

Flow through coulometry is used for analysis of wine samples for the determination of some heavy metals, sulphites, acidity and ethanol content. Low concentrations of heavy metals and sulphite contents are determined by making use of stripping chronopotentiometry. For the measurement of acid and ethanol content thin-layer coulometric titration is used.

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Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2a.627 ◽

2019 ◽

Vol 7 (2A) ◽

Author(s):

Camilo Fuentes Serrano ◽

Juan Reinaldo Estevez Alvares ◽

Alfredo Montero Alvarez ◽

Ivan Pupo Gonzales ◽

Zahily Herrero Fernandez ◽

...

Keyword(s):

Thin Layer ◽

Expanded Uncertainty ◽

Considerable Decrease ◽

X Ray ◽

Precipitation Efficiency ◽

Method Of Determination ◽

Sensitivity Curves ◽

Order Of Magnitude ◽

Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

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