A model for the high-frequency backscatter angular response of gassy sediments is proposed. For the interface backscatter contribution we adopted the model developed by Jackson et al. [J. Acoust. Soc. Am. 79, 1410-1422 (1986)], but added modifications to accommodate gas bubbles. The model parameters that are affected by gas content are the density ratio, the sound speed ratio, and the loss para...

The term "black shale" is a common expression widely used to describe any dark~olored, fine-grained sedimentary rock relatively rich in organic matter. As defined by Weissert (1981), the range of organic carbon in black shales is between 1 and 30%, but values outside this range exist. The term usually connotes at least partial lithification, yet this may not be true in young, shallow sediments....

Although large loads of potentially toxic constituents are discharged from coastal urban watersheds, very little is known about the fates and eventual impacts of these stormwater inputs once they enter the ocean. The goal of this study was to examine the effects of stormwater discharges on the benthic marine environment of Santa Monica Bay. Sediment samples were collected across a gradient of s...

In this paper, a design of an ADALINE adaptive filter based noise cancellation based on fine-grained pipelines is presented. The circuit is implemented from 32-bit floatingpoint arithmetic function units which are partitioned into proper fine-grained pipeline stages. Fine-grained pipeline resource-sharing is performed to minimize the circuit size. The ADALINE adaptive filter is implemented on a...

water resources throughout human history have always been an important factor in attracting human settlement. the main purpose of this paper was to investigate what is the role of shadchay river in the location of two prehistoric settlements that are called tepe meymon abad. in this research by field studies and also to investigate the characteristics of the sediments, samples were taken from t...

Sedimentation in the dune fields of the Sistan Plain of Iran is the result of deposition of fine-grained sediment downstream of the Helmand River. Due to poor adhesion and low moisture content of soil particles, and the strong renowned Levar wind, dune fields mostly of Barchan and Nebkha types are created. This study aims to assess the physical, morphological and mineralogical characteristics o...

The microbial community in eutrophic freshwater sediment was investigated from a 67-cm-deep sediment core collected from the Daechung Reservoir in South Korea, where cyanobacterial blooms have occurred annually for the past 30 years. The majority of core sediments were characterized by dark-grayish, fine-grained mud with abundant gas-escaped and thinly laminated layers. Intervals of summer and ...