This paper introduces an innovated plate anchor, increasing its bearing section area during uplift. In this experimental study, the influences of embedment depth of plate anchor and soil surface condition (restricted or free) on sand deformation field during uplift test are investigated. In order to study the soil deformation around the anchor, Particle Image Velocimetry (PIV) is used. The experimental setup consists of a camera, a new designed box, load cell, encoder and computer. During the uplift test on physical models, images are captured and used by PIV to depict the soil displacement field. Based on this study, it is found that pullout capacity and sand deformation zone are significantly influenced by anchor embedment depth. In shallow anchors, sand deformation zone lines are similar to a curve and cross the soil surface; however, in deep anchors, sand deformation zone is a bulb-shaped zone that extends from anchor to a distance of approximately two times its diameter above. Soil surface restriction increases anchor pullout capacity in shallow anchors up to 37 %, but in deep ones, there is no significant difference. Soil surface restriction changes shallow anchor behavior to deep anchors; however, it has no notable influence on deep anchors.
A comparison of photosynthetic nitrogen (N) use efficiency between C3 and C4 species within the genus Cyperus was made at a range of available nitráte levels. Net photosynthetic rates (P^) of both types increased with N content but CO2 assimilation on a leaf area basis was consistently higher in C4 species in comparison to the C3 species. C4 plants had a higher photosynthetic N use efficiency than C3 plants, and achieved higher Pn at lower N and protein levels. The higher leaf photosynthetic N use efficiency (PNUE) in C4 plants is due to their high raťher than low N and protein contents. Because C^ leaves contain less N than C3 leaves for a given Py^, PNUE is significantly higher in C4 than C3 plants. Nitrogen supply had highly significant effect on the leaf N concentration, but had no significant influence on the CO2 compensation concentration. Carboxylation efficiency was significantly higher in C4 leaves than C3 leaves of Cyperus species, due to the CO2 concentrating mechanism of C4 photosynthesis.