This research project is designed to study the feasibility of removing or remediating nitrate/atrazine in groundwater using iron powder treatment. Iron powder was selected because it is cheap and nontoxic. Three different types of iron powders were used in this research. They were lab grade iron powder (about 0.02 micron in size), industrial grade iron powder (about 0.5 micron in size), and rus...

An increase in intracellular Ca2+ concentration ([Ca2+]) and morphological were simultaneously observed by epifluorescence and differential interference contrast (DIC) microscopy during fertilization of the sand dollar, Clypeaster japonicus. [Ca2+], which was detected by a Ca2+ indicator, Fluo-3, initially increased just beneath the sperm-attached site on the egg surface 8.6 sec after attachmen...

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 ...

Background & objectives: In recent years, iron nanoparticles have been successfully used to remove water pollutants. Fecal coliform is one of the parameters that reduces water quality and its removal is essential. The aim of the present study is using nanoscale zerovalent iron particles to enhance the usual sand filters in removal of fecal coliform of groundwater in Ilam city. Methods: Water s...

Short-term performance of permeable sand cap test cells, installed over sediment containing liquid coal tar was monitored on the Grand Calumet River (Hammond, Indiana, USA). The sand cap test cells included two sand-only cells, two test cells containing a sand/peat mixed layer, two test cells containing a sand/organoclay mixed layer, and two sediment control cells. In each test cell, six monocy...

Astronaut observations and photographs of color variations in the Western Desert of Egypt are related to both iron oxide coalings on individual grains and the presence of locally derived material in the sand deposits. The results of four field trips, to Baharîya Oasis, Sîwa Oasis, Khârga and Dakhla Oases, and the Great Sand Sea, enable more detailed interpretations of colors photographed during...