scholarly journals Effect of vegetation cover and sediment type on 3D subsurface structure and shear strength in saltmarshes

2021 ◽  
Author(s):  
Clementine Chirol ◽  
Kate L. Spencer ◽  
Simon J. Carr ◽  
Iris Möller ◽  
Ben Evans ◽  
...  
Keyword(s):  
Shear Strength ◽  
Vegetation Cover ◽  
Sediment Type ◽  
Subsurface Structure

Resource Partitioning in Two Coexisting Sunfish: Pumpkinseed (Lepomis gibbosus) and Northern Longear Sunfish (Lepomis megalotis peltastes)

1980 ◽  
Vol 37 (9) ◽  
pp. 1411-1420 ◽  
Author(s):  
Dennis R. Laughlin ◽  
Earl E. Werner
Keyword(s):  
Habitat Use ◽  
Vegetation Cover ◽  
Plant Cover ◽  
Lepomis Gibbosus ◽  
Sediment Type ◽  
Vegetation Density ◽  
Sympatric Populations ◽  
Sparse Vegetation ◽  
Lepomis Megalotis ◽  
Longear Sunfish

Qualitative surveys of 22 lakes in southern Michigan indicated that relative abundances of the northern longear sunfish (Lepomis megalotis peltastes) and pumpkinseed (L. gibbosus) depended upon amount of plant cover and sediment type. The longear sunfish occurred only in lakes with marl sediments and regions of sparse vegetation cover. The pumpkinseed occurred in all lakes surveyed and increased in abundance in lakes with greater vegetation density and/or more organic sediments. Quantitative measurements of habitat and food use were made in five lakes with sympatric populations. Data from underwater transects indicated that large (> 75 mm standard length) longear sunfish occurred primarily in shallow regions containing moderate to low vegetation cover whereas large pumpkinseeds were concentrated in deeper areas with heavy vegetation cover. The smaller size-classes of both species occupied the vegetation in deeper areas of the littoral zone. Large longears consumed predominantly large, sediment-dwelling mayfly or odonate nymphs regardless of the lake or habitat types. Pumpkinseeds consumed mainly gastropods and other prey from the vegetation. Preliminary studies of seasonal food use indicated that the pumpkinseed and longear sunfish both consumed more food in the spring and exhibited greater overlap in diet during this period. The relationship between foraging behaviors of these two species and the types of prey consumed is discussed as well as the complications of assessing competition between species when food and habitat use are dependent on size.Key words: Habitat use, size-class, lake types, food overlap, competition, Lepomis, Michigan

scholarly journals ON THE DEPOSITIONS PROPERTIES OF ESTUARINE SEDIMENTS

1974 ◽  
Vol 1 (14) ◽  
pp. 72
Author(s):  
Ashish J. Mehta ◽  
Emmanuel Partheniades
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Steady State ◽  
Flow Field ◽  
Annular Channel ◽  
Estuarine Sediments ◽  
Sediment Type ◽  
Cohesive Sediments ◽  
Analytic Treatment ◽  
Turbulent Flow Field

The depositional characteristics of floes of fine cohesive sediments in a turbulent flow field differ distinctly from those of a cohesionless material such as sand. This difference exists because the floe size and shear strength distributions depend on the sediment type as well as the flow condition itself; consequently, the problem of the depositional behavior of these floes is rather complex, and not easily amenable to analytic treatment. The present basic experimental study was carried out in a specially designed annular channel. The derived laws of deposition in relation to the time-rates as well as the steady-state concentrations are described and discussed. The reanalyzed results of other limited investigations agree well with the result of the study.

Holding Power of Orthopaedic Screws in Metacarpal and Metatarsal Bones of Young Calves

1992 ◽  
Vol 05 (03) ◽  
pp. 100-103 ◽  
Author(s):  
G. Jean ◽  
J. K. Roush ◽  
R. M. DeBowes ◽  
E. M. Gaughan ◽  
J. Kirpensteijn
Keyword(s):  
Shear Strength ◽  
Tensile Load ◽  
Young Female ◽  
Limiting Factor ◽  
Holding Power ◽  
Metatarsal Bones ◽  
Bone Width ◽  
Load To Failure ◽  
Holstein Calves

SummaryThe holding power and holding power per mm bone width of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws were obtained by tensile load-to-failure studies in excised metacarpal and metatarsal bones of young female Holstein calves. Holding power and holding power per mm bone width of 6.5 mm orthopaedic screws were significantly greater than those of 4.5 and 5.5 mm orthopaedic screws in the diaphysis and metaphysis. Significant differences were not detected between holding power and holding power per mm bone width of 4.5 and 5.5 mm orthopaedic screws. The holding power was not different between metacarpi and metatarsi. The limiting factor in all tests of holding power was the shear strength of the bone. We found that 6.5 mm orthopaedic screws have the greatest holding power in the metacarpal and metatarsal bones of young calves.This study compares the holding power of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws in excised metacarpal and metatarsal bones from young female Holstein calves. We found that 6.5 mm orthopaedic screws have the greatest holding power.

The Fully Softened Shear Strength of Lake Agassiz Clays

2020 ◽  
Author(s):  
Iván A. Contreras ◽  
Jed D. Greenwood ◽  
Aaron T. Grosser
Keyword(s):  
Shear Strength ◽  
Lake Agassiz ◽  
Fully Softened Shear Strength

Influence of anatomy on the adhesion performance of four wood species

2020 ◽  
Vol 9 (4) ◽  
pp. e31942727
Author(s):  
João Gabriel Missia da Silva ◽  
Pedro Nicó de Medeiros ◽  
Denise Ransolin Soranso ◽  
Vinicius Peixoto Tinti ◽  
José Tarcísio da Silva Oliveira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Specific Gravity ◽  
Wood Species ◽  
Tectona Grandis ◽  
Glue Line ◽  
Anatomical Characteristics ◽  
Ray Cells ◽  
Adhesion Performance ◽  
Adhesion Process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

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