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...

Little is known about uranium, U(VI), transport in alkaline and saline solutions. However understanding U(VI) mobility in these conditions is critical due to the storage of U(VI) at high pH and ionic strengths (I). To this end we have studied the geochemical processes taking place in a reservoir, and during transport through quartz sand packed columns. The results show that at pH 10.5 and 11.5 ...

Tidal sandstone reservoirs contain significant intervals of hydrocarbonbearing heterolithic facies, characterized by the presence of tidegenerated sedimentary structures such as flaser, wavy, and lenticular bedding (millimeter to centimeter sand-mud alternations). We have characterized the reservoir properties (sandstone connectivity, effective permeability, and displacement efficiency) of thes...

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...

the sarcheshmeh formation is a shaly sequence of lower cretaceous age (aptian) which is deposited in koppeh-dagh sedimentary basin and conformably overlies and underlies the tirgan and sanghaneh formations respectively in the toos well # 1. lithologically, this formation has a thickness of 177m and consists mainly of marl, shale and shaly limestone. palynological studies resulted in identificat...

Turbidite systems are complex heterogeneous siliciclastic deposits calling for a new approach to geophysical and geostatistical reservoir characterization. The aim of this paper is to demonstrate the integration of seismic amplitude and rock physics data into realistic geological scenarios using a novel geostatistical approach. Avseth (2000, 2001 with others) presented an integrated rock physic...

This case study involves sand distribution prediction for the Gujiazhi and Houwujiahu gas fields in Jilin Province, China. Initial data analysis involved correcting and calibrating the well logs. Log data from 74 wells were available from the Gujiazhi field and the Houwujiahu field. This initial process also established 3-D porosity, permeability and clay volume models for each field. The Gujia...