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The GMA Techline

February 1st, 2021

Moderated by George R. Koerner BIOLOGICAL DEGRADATION OF PE AND PP Q: Can you please enlighten me on the biological degradation of polyolefin polyethylene (PE) and polypropylene (PP)? A: Within the various plant forms of biological life, i.e., bacteria, actinomycetes, fungi and algae, polymer degradation is essentially nonexistent due to high molecular weight of the common […]

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The GMA Techline

February 1st, 2020

Moderated by George R. Koerner and Y. “Grace” Hsuan DARCIAN PERMEABILITY Q: I am aware of the section in your book regarding geomembrane “permeability” and get from it that it aims to calculate an equivalent Darcian permeability using vapor diffusion via Fick’s law. Can one use the derived permeability then when calculating flow using Darcy’s […]

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The GMA Techline

October 1st, 2018

Toxicity of nonwovens? Q: Are there any comprehensive tests (or a general synopsis) of the environmental toxicity of leachate from nonwoven polypropylene fabrics when aged in a freshwater or saltwater solution? Regulatory and municipal bodies in Europe and New Zealand are requesting more info about products that are used in riparian and coastal environments. A: […]

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The GMA Techline answers all

August 1st, 2018

UV Weathering of Geotextiles Q: My firm is providing construction quality assurance services for a landfill cell expansion. We are having an issue with our contractor and are going to be in a position of having 8 ounces/square yard (271 g/m2) of nonwoven geotextile exposed for a period of time, which exceeds the seven-day limit […]

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