The effects of layering on reflection coefficient and transmission measurements from a sand/water interface at the Sediment Acoustics Experiment 2004 (SAX04)

2006 ◽  
Vol 120 (5) ◽  
pp. 3142-3142
Author(s):  
Marcia Isakson
Keyword(s):  
Reflection Coefficient ◽  
Water Interface ◽  
Transmission Measurements

Trial for Monitoring the Water Temperature Utilizing the Frequency Dependence of Reflection Coefficient of Ultrasound Passing Through Thin Layer

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Hironori Tohmyoh ◽  
Shu Terashima
Keyword(s):  
Thin Film ◽  
Reflection Coefficient ◽  
Thin Layer ◽  
Water Temperature ◽  
Acoustic Impedance ◽  
Amplitude Spectrum ◽  
Acoustic Resonance ◽  
Water Interface ◽  
Amplitude Spectra ◽  
The Difference

This paper describes a new concept to monitor the temperature of water utilizing the acoustic resonance, which occurs when ultrasound passes through a thin layer. In the ultrasonic transmission system that comprises of the reflection plate, thin film, and water, the reflection coefficient of the ultrasound at the plate/film/water interface depends on the frequency and takes its minimum value at the resonant frequency. Notably, this is closely related to the acoustic impedance of the water; moreover, it is a known fact that the acoustic impedance of the water demonstrates temperature dependence. Against this background, the present study aims to develop a technique in order to monitor the temperature of water utilizing the aforementioned correlation between the reflection coefficient and water temperature. First, a theoretical model was developed to determine the acoustic impedance of water from the difference in the amplitude spectra of echoes reflected at the back of the plate in the cases both with and without the film. It was found that the ratio of the amplitude spectrum of the echo recorded in the case with the film to that in the case without the film clearly decreased with a drop in water temperature. From this, we obtained the equation for determining water temperature experimentally. Finally, the temperature of water, which was brought down by air or ice cooling, was monitored by the proposed method. It was found that the behavior of temperature determined by the proposed method was congruent with that which was measured by a thermocouple.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Porous materials from cellulose nanocrystal and mxene surfactants at the oil/water interface

2020 ◽  
Author(s):  
Bingqing qian ◽  
Haiqiao Wang ◽  
Dong Wang ◽  
Hao-Bin Zhang ◽  
Jessica Wu ◽  
...  
Keyword(s):  
Porous Materials ◽  
Cellulose Nanocrystal ◽  
Water Interface ◽  
Oil Water
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