The utilization of dredged material in dike construction as a substitute for traditionally used materials is considered as an option to preserve natural resources such as marsh sediments. As a prerequisite for this application, the equivalency with respect to soil physical and mechanical properties of the materials must be assessed. Previous investigations have shown pronounced differences in shrinkage behavior and desiccation cracking between sediments and dredged material. The key objective of the study was to assess whether shrinkage of processed dredged material can be reduced by further processing, i.e., dewatering, which can be referred to as ripening.
Materials and methods
To compare the shrinkage behavior of the materials, three different methods of different scales were applied. Small-scale methods conducted were the standard procedure for the determination of the shrinkage limit and the determination of the coefficient of linear extensibility (COLErod). Large-scale shrink-swell experiments were carried out in a specially constructed test system with 90 l capacity for a period of up to 385 days. Here the materials were ripened, i.e., air-dried, until shrinkage almost ceased, and a rewetting-air-drying cycle was conducted. Shrinkage and swelling were determined during the processes by measuring the changes in volume. On the ripened materials, COLErod was determined.
Results and discussion
The experiments show that the shrinkage behavior of processed dredged material can be ameliorated by ripening. COLErod of the ripened materials were about 20–80% lower than COLErod of the un-ripened materials. The large-scale shrink-swell experiments showed that shrinkage in the second drying cycle amounted to less volume than in the first drying cycle and that shrinkage behavior in contrast to the first drying cycle, where pronounced proportional shrinkage was observed, was dominated by structural and residual shrinkage in this cycle.
Conclusions
Ripening of processed dredged material is considered a useful pre-treatment option to ameliorate the shrink-swell behavior of processed dredged material and to obtain a better functional equivalency with traditionally used dike construction materials such as fine-grained marsh sediments.
Journal of Soils and Sediments - Pesticide contamination of river waters is a global problem, and therefore, authorities regularly monitor the water quality status. Especially, flood events might... 相似文献
Ohne Zusammenfassung
f. f?chf. Dberforftmeifter.
f. bahr. Regierungs- und Forftrath von Mürzburg.
f. preuk. Dberforftmeifter aus Breslau.
f. f?chf. Dberforftmeifter.
f. bahr. Regierungs- und Forftrath von Augsburg.
f. bahr. Regierungs- und Forftrath aus Regensburg.
Dberj?germeifter von Braunfchweig.
f. bahr. Regierungs- und Forftrath aus München.
f. f?chf. Dberf?rfter.
f. f?chf. Dberforftmeifter.
f. f?chf. Dberforftrath.
herz. braunfchweig. Forftmeifter von Blanfenburg.
Direftor der fürftlich Cfterhazh’fchen Herrfchaft Spoly Parsto.
fürftl. fondershauf. Dberfortmeifter.
f. bahr. Redierf?rfter don Schmarzenbach.
f. preuk. Dberf?rfter.
f. f. Forftrath aus Brekburg.
f. preuk. Dberf?rfter von Altruppin.
f. hann?v. Forftmeifter von Rienburg.
Forftmeifter in preuk. Schleften.
f. preuk. Dberforftmeifter von Berlin.
herz. aftenburg. Dberfortmeifter.
f. preuk. Dberf?rfter.
f. f?chf. Dberf?rfter.
f. ruff. Forftfomiff?r aus Marfchau.
f. preuk. Forftinfpeftor.
f. f?chf. Forftinfpeftor.
grokh. meimar. Forftinfpeftor von Martfuhl.
f. mürttb. Dberf?rfter und Brofeffor aus Hohenheim.
f. hannov. Forftmeifter aus Hammeln.
Dberforftmeifter aus Sotha.
herz. altenburg. Dberf?rfter aus Hummelshain.
herz. altenburg. Revierf?rfter aus Milchwig.
herz. altenburg. geheimer Finanzrath und Dberforftmeifter.
herz. altenb. Dberforftmeifter aus Hummelshain.
grokh. f?chf. geheimer Dberforftrath aus Qifenach.
herz. naffau. Dberforftrath aus Miesbaden.
grokh. heff. Dberforftfefret?r aus Darmftadt.
f. f?chf. Dberforftmeifter. 相似文献
Ohne Zusammenfassung
(Borgetragen in der Societ?t der Wiffenfchaften zu Helfingfors am 29. April 1850.) Ueberfekt aus Notises ur S?llskapets pro
Fauna et Flora Fennica F?rhandlingar; Andra H?ffes, Helsingfors 1852 von dem Dberforftrath von Berg. 相似文献
Staphylococcus aureus and coagulase-negative staphylococci (CNS) isolated from bovine mastitis were examined for their ability to interact with 125I-labelled fibronectin, fibrinogen and type II collagen. Their relative surface hydrophobicity and production of extracellular capsule were also investigated. Almost all S. aureus strains bound fibronectin (mean value 23%), fibrinogen (mean value 12%) and type II collagen (mean value 16%). CNS bound fibronectin (mean value 6%) and type II collagen (mean value 7%), but not fibrinogen (mean value 2%). The specificity of binding of these proteins to S. aureus strain F1440 and to coagulase-negative Staphylococcus chromogenes strain BO52 was studied by adding an excess of unlabelled proteins. Fibronectin and collagen binding were observed to be specific, varying between 50 and 75%, whereas the specificity of fibrinogen binding to S. aureus strain F1440 was lower (26%). Most of the S. aureus strains (63%) showed very high surface hydrophobicity (autoaggregation) or lower hydrophobicity (29% of the strains) and the rest were hydrophilic. None of the CNS strains autoaggregated, 44% were classified as hydrophilic strains. Hydrophilic strains (except the reference strains) did not show extracellular capsule production. However, the encapsulated (reference) strains showed low binding to these proteins as compared to their unencapsulated variants. Pre-treatment of S. aureus strain F1440 and S. chromogenes strain BO52 with trypsin decreased their fibronectin binding capacity and surface hydrophobicity, whereas pre-treatment with bovine milk (except on collagen binding to strain F1440) did not significantly affect binding to these proteins. These data indicate that S. aureus and CNS isolated from bovine udder infection have the ability to bind to tissue matrix and plasma proteins which may be exposed in the traumatized or toxin-damaged udder epithelial lesions. 相似文献
Hypertrophic scarring and poor intrinsic axon growth capacity constitute major obstacles for spinal cord repair. These processes are tightly regulated by microtubule dynamics. Here, moderate microtubule stabilization decreased scar formation after spinal cord injury in rodents through various cellular mechanisms, including dampening of transforming growth factor-β signaling. It prevented accumulation of chondroitin sulfate proteoglycans and rendered the lesion site permissive for axon regeneration of growth-competent sensory neurons. Microtubule stabilization also promoted growth of central nervous system axons of the Raphe-spinal tract and led to functional improvement. Thus, microtubule stabilization reduces fibrotic scarring and enhances the capacity of axons to grow. 相似文献
The current study investigated the effects of oyster mushroom Pleurotus ostreatus, extract on immunological and hematological parameters of rainbow trout, Oncorhynchus mykiss. The fish were fed diets containing 0 (control), 1, and 2% supplementation of the oyster mushroom extract for 6 wk. Blood samples were collected weekly for the first 6 weeks. After 6 wk of feeding, the fish were challenged with Lactococcus garvieae and mortality was recorded. The results of this study showed that feeding rainbow trout an oyster mushroom extract–supplemented diet stimulated phagocytic activity of phagocytic cells, lysozyme activity, and myeloperoxidase activity in serum, but it did not significantly affect the total serum immunoglobulin level. At the same time, a significant increase was found in the number of neutrophils, monocytes, and total white blood cells. Fish fed the diet supplemented with oyster mushroom extract showed reduced mortalities following L. garvieae infection compared with controls. These results show that supplementation of fish diets with oyster mushroom extract at 1 and 2% concentrations significantly imrpoves hematological parameters and modulates the immune response against L. garvieae in rainbow trout. 相似文献
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