We summarize information concerning Recent and Pleistocene-Holocene Uruguayan sand dollars (Mellitidae), as well as Miocene taxa (Monophorasteridae). Recent and Pleistocene-Holocene species (Encope emarginata, Mellita quinquiesperforata, and Leodia sexisperforata) are at their southernmost limits of distribution, with only E. emarginata recorded further south than Uruguay. Lower temperatures to...

Many larvae and other plankton have complex and variable morphologies of unknown functional significance. We experimentally and theoretically investigated the functional consequences of the complex morphologies of larval sand dollars, Dendraster excentricus (Eschscholtz), for hydrodynamic interactions between swimming and turbulent water motion. Vertical shearing flows (horizontal gradients of ...

Sand dripping in 1 dimensional Sand Pile Model is rst studied. Patterns and signals appear. Their behaviors and interactions are explained and asymptotic approximations are made. The total collapsing time of a single stack of sand is linear in function of the number of grains.

Constructed wetlands are an attractive choice for removing arsenic (As) within water resources used for drinking water production. The role of substrate and vegetation in As removal processes is still poorly understood. In this study, gravel, zeolite (microporous aluminosilicate mineral), ceramsite (lightweight expanded clay aggregate) and manganese sand were tested as prospective substrates wh...

the main objective of this study is to swing krull intersection theorem in primary decomposition of rings and modules to the primary decomposition of soft rings and soft modules. to fulfill this aim several notions like soft prime ideals, soft maximal ideals, soft primary ideals, and soft radical ideals are introduced for a soft ring over a given unitary commutative ring. consequently, the p...

We analyze the end-point region of the photon spectrum in semi-inclusive radiative decays of very heavy quarkonium (mαs ≫ ΛQCD). We discuss the interplay of the scales arising in the Soft-Collinear Effective Theory, m, m(1 − z) and m(1 − z) for z close to 1, with the scales of heavy quarkonium systems in the weak coupling regime, m, mαs and mα 2 s . For 1 − z ∼ αs only collinear and (ultra)soft...

In this study, the performances of sand piles in Istanbul's Bağcılar and Zeytinburnu districts has been analyzed using Finite Element Method (FEM). Single group (triple) with various length/diameter ratios (L/D) were placed water-saturated soft clay soil. Sand modeled L/D (10, 5.71, 8.57). The distance between was chosen as 2 meters effect also investigated. A uniformly distributed load 162 kN/...

The models that were analyzed using FLAC version 4.0 (FLAC, 2000) are shown on Figure 5.1. The models have different soil types: loose silty sand with 20% fines content (Figures 5.1a and 5.1b), soft clay (Figure 5.1c), and silt (Figure 5.1d). Hence, the determination of the parameters is different for each model. The following sections discuss the determination of the parameters used in the ana...