Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

the aim of this study was to investigate the effect of different amounts of hydrogen peroxide and iron resources in refining petroleum (kerosene) contaminated soils using fenton reaction. for this, ten complex soil samples around tehran oil refinery were collected and after preparations were contaminated with two levels of 10 and 20% of petroleum (kerosene) in triplicate. after reaching equilib...

The high inertia, i.e. high mass and low speed, of a landing spacecraft has the potential to drive a penetrometer into the subsurface without the need for a dedicated deployment mechanism, e.g., during Huygens landing on Titan. Such a method could complement focused subsurface exploration missions, particularly in the low gravity environments of comets and asteroids, as it is conducive to condu...

A laboratory study to optimize a low cost technology for small scale drinking water treatment in rural Bangladesh Harmen van der Laan Abstract High concentrations of arsenic in drinking water form a major threat for public health in more than 70 countries worldwide. The situation is Bangladesh is seen as the worst incidence of arsenic poisoning: it is believed that 30 million people in Banglade...

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a 'precompetent' period in which they do no...

In this work, the Fe3O4 nanoparticles from natural iron sand were combined with active carbon (AC) and polyaniline (PANI) to obtain Fe3O4/AC/PANI nanocomposites with mass variations of the AC of 0.1, 0.2, 0.3, 0.4, and 0.5 g. The crystalline phase of Fe3O4/AC/PANI nanocomposites formed from Fe3O4 with PANI h...

This study aims to analyze the content of magnetic mineral compound natural iron sand on beach Lombok Island. uses experimental method by taking primary data which is carried out in three locations, namely at Ijobalit Beach (East Lombok), Cemara (West and Telindung Lombok). The stage begins with a separation sand, then obtain Fe3O4 powder. last testing Fe using AAS (atomic absorption spectropho...

This article presents the results of a research on recycling wastes from metallurgical plants in city Pavlodar at steel smelting plant KSP Steel. The pellets were produced with aspiration dust and mixed steelmaking (white) slag, ferrous sand, scale. fired temperature 600 ° C. experience use 20% white sand 10% mill scale shows, after burning furnace, quite satisfactory strength, which is 80 kg /...