The Experts below are selected from a list of 645 Experts worldwide ranked by ideXlab platform
John T. Kevern - One of the best experts on this subject based on the ideXlab platform.
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Resistance of Portland Cement Pervious Concrete to Deicing Chemicals
Transportation Research Record, 2010Co-Authors: Heath E Cutler, Kejin Wang, Vernon R. Schaefer, John T. KevernAbstract:The damaging impact of Deicing Chemicals on portland cement pervious concrete materials was investigated. Two concrete mixes (with and without latex modification) were subjected to three Deicing Chemicals (sodium chloride, calcium chloride, and calcium-magnesium acetate) under a freezing-thawing or drying-wetting condition. Two Deicing Chemical application methods (saturated and drained) were employed. The impact of Deicing Chemicals on the concrete was evaluated based on concrete mass and strength losses. Of the Deicing Chemicals studied, the calcium chloride solution caused the most damage, while the calcium magnesium acetate caused the least. The saturated scaling test method, followed according to ASTM C672, provided much higher mass loss of tested concrete samples when compared with a modified, more realistic drained test method.
Askar Zhussupbekov - One of the best experts on this subject based on the ideXlab platform.
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experimental study of Deicing Chemical redistribution and moisture mass transfer in highway subsoils during the unidirectional freezing
Transportation geotechnics, 2021Co-Authors: Assel Sarsembayeva, Askar ZhussupbekovAbstract:Abstract Deicing Chemicals, when applied to pavement surfaces, occasionally deposited on the ground beyond the road pavement, thus lead to their accumulation in roadside soils and producing secondary salinisation of the ground water. In order to explore moisture and Chemical mass transfer in highway subsoils during the winter period, 9 non-saline soil samples of 1 m length were subject to simultaneously freeze–thaw cycles with freezing rate 2 °C/day. To monitor the dependence of mass transfer from the soil density, each further column was packed with increased dry density than the previous one and supplied with 22 g/L of NaCl solution from the base. The results show that soil columns with loose density were consolidated throughout the sample length with the maximum in its lower part. Whilst in the dense soil samples, only the top 10 cm was loosened and attracted a large amount of water to form ice lenses. Chemical mass transfer to the freezing front was observed along the entire length of the samples regardless of density and void ratio. The concentration of de-icing Chemicals in the pore water exceeded the supplied solution by 2–2.5 times at the capillary raise zone. In this study, Chemical mass transfer is considered in terms of the driving forces and the system equilibrium. The driving force was explained as a cryosuction force, effected to the hygroscopic water in a liquid state with dissolved de-icing Chemical ions in it, which migrated towards the freezing front. The continuous secondary salinisation, lasting in the highway subsoils for years, requires an accurate protection as the use of plastic membrane or silicone gel insulation.
Hans-christian Teien - One of the best experts on this subject based on the ideXlab platform.
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Transcriptional changes in Atlantic salmon (Salmo salar) after embryonic exposure to road salt.
Aquatic toxicology (Amsterdam Netherlands), 2015Co-Authors: Knut Erik Tollefsen, You Song, Merethe Kleiven, Urma Mahrosh, Sondre Meland, Bjørn Olav Rosseland, Hans-christian TeienAbstract:Road salt is extensively used as a Deicing Chemical in road maintenance during winter and has in certain areas of the world led to density stratifications in lakes and ponds, and adversely impacted aquatic organisms in the recipients of the road run-off. Aquatic vertebrates such as fish have been particularly sensitive during fertilisation, as the fertilisation of eggs involves rapid uptake of the surrounding water, reduction in egg swelling and in ovo exposure to high road salt concentrations. The present study aimed to identify the persistent molecular changes occurring in Atlantic salmon (Salmo salar) eggs after 24h exposure to high concentrations (5000 mg/L) of road salt at fertilisation. The global transcriptional changes were monitored by a 60k salmonid microarray at the eyed egg stage (cleavage stage, 255 degree days after fertilisation) and identified a high number of transcripts being differentially regulated. Functional enrichment, pathway and gene-gene interaction analysis identified that the differentially expressed genes (DEGs) were mainly associated with toxiciologically relevant processes involved in osmoregulation, ionregulation, oxidative stress, metabolism (energy turnover), renal function and developmental in the embryos. Quantitative rtPCR analysis of selected biomarkers, identified by global transcriptomics, were monitored in the eggs for an extended range of road salt concentrations (0, 50, 100, 500 and 5000 mg/L) and revealed a positive concentration-dependent increase in cypa14, a gene involved in lipid turnover and renal function, and nav1, a gene involved in neuraxonal development. Biomarkers for osmoregulatory responses such as atp1a2, the gene encoding the main sodium/potassium ATP-fueled transporter for chloride ions, and txdc9, a gene involved in regulation of cell redox homeostasis (oxidative stress), displayed apparent concentration-dependency with exposure, although large variance in the control group precluded robust statistical discrimination between the groups. A No Transcriptional Effect Level (NOTEL) of 50mg/L road salt was found to be several orders of magnitude lower than the adverse effects documented in developing fish embryos elsewhere, albeit at concentrations realistic in lotic systems receiving run-off from road salt. It remains to be determined whether these transcriptional changes may cause adverse effects in fish at ecologically relevant exposure concentrations of road salt.
Teien Hans-christian - One of the best experts on this subject based on the ideXlab platform.
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Transcriptional changes in Atlantic salmon (Salmo salar) after embryonic exposure to road salt
'Elsevier BV', 2015Co-Authors: Tollefsen, Knut Erik, Song You, Kleiven Merethe, Mahrosh Urma, Meland Sondre, Rosseland, Bjørn Olav, Teien Hans-christianAbstract:Road salt is extensively used as a Deicing Chemical in road maintenance during winter and has in certain areas of the world led to density stratifications in lakes and ponds, and adversely impacted aquatic organisms in the recipients of the road run-off. Aquatic vertebrates such as fish have been particularly sensitive during fertilisation, as the fertilisation of eggs involves rapid uptake of the surrounding water, reduction in egg swelling and in ovo exposure to high road salt concentrations. The present study aimed to identify the persistent molecular changes occurring in Atlantic salmon (Salmo salar) eggs after 24 h exposure to high concentrations (5000 mg/L) of road salt at fertilisation. The global transcriptional changes were monitored by a 60 k salmonid microarray at the eyed egg stage (cleavage stage, 255 degree days after fertilisation) and identified a high number of transcripts being differentially regulated. Functional enrichment, pathway and gene–gene interaction analysis identified that the differentially expressed genes (DEGs) were mainly associated with toxiciologically relevant processes involved in osmoregulation, ionregulation, oxidative stress, metabolism (energy turnover), renal function and developmental in the embryos. Quantitative rtPCR analysis of selected biomarkers, identified by global transcriptomics, were monitored in the eggs for an extended range of road salt concentrations (0, 50, 100, 500 and 5000 mg/L) and revealed a positive concentration-dependent increase in cypa14, a gene involved in lipid turnover and renal function, and nav1, a gene involved in neuraxonal development. Biomarkers for osmoregulatory responses such as atp1a2, the gene encoding the main sodium/potassium ATP-fueled transporter for chloride ions, and txdc9, a gene involved in regulation of cell redox homeostasis (oxidative stress), displayed apparent concentration-dependency with exposure, although large variance in the control group precluded robust statistical discrimination between the groups. A No Transcriptional Effect Level (NOTEL) of 50 mg/L road salt was found to be several orders of magnitude lower than the adverse effects documented in developing fish embryos elsewhere, albeit at concentrations realistic in lotic systems receiving run-off from road salt. It remains to be determined whether these transcriptional changes may cause adverse effects in fish at ecologically relevant exposure concentrations of road salt.acceptedVersio
Heath E Cutler - One of the best experts on this subject based on the ideXlab platform.
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Resistance of Portland Cement Pervious Concrete to Deicing Chemicals
Transportation Research Record, 2010Co-Authors: Heath E Cutler, Kejin Wang, Vernon R. Schaefer, John T. KevernAbstract:The damaging impact of Deicing Chemicals on portland cement pervious concrete materials was investigated. Two concrete mixes (with and without latex modification) were subjected to three Deicing Chemicals (sodium chloride, calcium chloride, and calcium-magnesium acetate) under a freezing-thawing or drying-wetting condition. Two Deicing Chemical application methods (saturated and drained) were employed. The impact of Deicing Chemicals on the concrete was evaluated based on concrete mass and strength losses. Of the Deicing Chemicals studied, the calcium chloride solution caused the most damage, while the calcium magnesium acetate caused the least. The saturated scaling test method, followed according to ASTM C672, provided much higher mass loss of tested concrete samples when compared with a modified, more realistic drained test method.