Understanding air‐gun bubble behavior

Geophysics ◽  
1994 ◽  
Vol 59 (11) ◽  
pp. 1729-1734 ◽  
Author(s):  
Daniel T. Johnson
Keyword(s):  
Seismic Source ◽  
Ideal Gas ◽  
Infinite Volume ◽  
Bubble Motion ◽  
Bubble Behavior ◽  
Ideal Gas Law ◽  
Air Gun ◽  
Higher Order Terms ◽  
Equivalent Mass ◽  
And Mathematics

An air‐gun bubble behaves approximately as a spherical bubble of an ideal gas in an infinite volume of practically incompressible water. With this simplification, the equation of bubble motion and its far‐field signature is more understandable than with the more exact theory commonly cited in the literature. The terms of the equation of bubble motion are explained using elementary physics and mathematics, computation of numerical results is outlined, and an example signature is shown. An air‐gun bubble is analogous to a simple harmonic oscillator consisting of a mass on a spring, with an equivalent mass equal three times that of the water displaced by the bubble, and air pressure following an ideal gas law corresponding to a spring. With this understanding, one is prepared to deal with the effects of interactions among air guns and with the higher‐order terms and other features that must be included to model the air‐gun signature of actual seismic source arrays.

Making sense of sensemaking: using the sensemaking epistemic game to investigate student discourse during a collaborative gas law activity

2021 ◽  
Author(s):  
Kevin H. Hunter ◽  
Jon-Marc G. Rodriguez ◽  
Nicole M. Becker
Keyword(s):  
Problem Solving ◽  
Conceptual Understanding ◽  
Ideal Gas ◽  
Interactive Simulation ◽  
Structural Components ◽  
Student Discourse ◽  
Coding Scheme ◽  
Making Sense ◽  
Ideal Gas Law ◽  
The Ideal

Beyond students’ ability to manipulate variables and solve problems, chemistry instructors are also interested in students developing a deeper conceptual understanding of chemistry, that is, engaging in the process of sensemaking. The concept of sensemaking transcends problem-solving and focuses on students recognizing a gap in knowledge and working to construct an explanation that resolves this gap, leading them to “make sense” of a concept. Here, we focus on adapting and applying sensemaking as a framework to analyze three groups of students working through a collaborative gas law activity. The activity was designed around the learning cycle to aid students in constructing the ideal gas law using an interactive simulation. For this analysis, we characterized student discourse using the structural components of the sensemaking epistemic game using a deductive coding scheme. Next, we further analyzed students’ epistemic form by assessing features of the activity and student discourse related to sensemaking: whether the question was framed in a real-world context, the extent of student engagement in robust explanation building, and analysis of written scientific explanations. Our work provides further insight regarding the application and use of the sensemaking framework for analyzing students’ problem solving by providing a framework for inferring the depth with which students engage in the process of sensemaking.

The shape of things to come — Development and testing of a new marine vibrator source

2019 ◽  
Vol 38 (9) ◽  
pp. 680-690 ◽  
Author(s):  
Benoît Teyssandier ◽  
John J. Sallas
Keyword(s):  
Seismic Source ◽  
Test Facility ◽  
Data Sets ◽  
Far Field ◽  
Ocean Bottom ◽  
Air Gun ◽  
Seismic Image ◽  
Field Radiation ◽  
Technical Issues ◽  
To Come

Ten years ago, CGG launched a project to develop a new concept of marine vibrator (MV) technology. We present our work, concluding with the successful acquisition of a seismic image using an ocean-bottom-node 2D survey. The expectation for MV technology is that it could reduce ocean exposure to seismic source sound, enable new acquisition solutions, and improve seismic data quality. After consideration of our objectives in terms of imaging, productivity, acoustic efficiency, and operational risk, we developed two spectrally complementary prototypes to cover the seismic bandwidth. In practice, an array composed of several MV units is needed for images of comparable quality to those produced from air-gun data sets. Because coupling to the water is invariant, MV signals tend to be repeatable. Since far-field pressure is directly proportional to piston volumetric acceleration, the far-field radiation can be well controlled through accurate piston motion control. These features allow us to shape signals to match precisely a desired spectrum while observing equipment constraints. Over the last few years, an intensive validation process was conducted at our dedicated test facility. The MV units were exposed to 2000 hours of in-sea testing with only minor technical issues.

scholarly journals Induction of Changes in Internal Gas Pressure of Bulky Plant Organs by Temperature Gradients

1990 ◽  
Vol 115 (2) ◽  
pp. 308-312 ◽  
Author(s):  
Kenneth A. Corey ◽  
Zhi-Yi Tan
Keyword(s):  
Bath Temperature ◽  
Ideal Gas ◽  
Gas Pressure ◽  
Temperature Gradients ◽  
Maximum Pressure ◽  
Plant Organs ◽  
Ideal Gas Law ◽  
Increasing Temperature ◽  
Pressure Changes

Water manometers were connected to fruits of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and then fruits were submerged in water baths providing initial temperature gradients between fruit and water of 0 to 19C. Apple (Malus domestics Borkh.) fruits, carrot (Daucus carota L.) roots, witloof chicory (Cichorium intybus L.) roots, rhubarb Rheum rhabarbarum L.) petioles, and pokeweed (Phytolacca americana L.) stems were subjected to water bath temperature gradients of 5C. Internal partial vacuums developed in all organs within minutes of imposing the gradients. The maximum partial vacuums in tomato and pepper fruits increased with increasing temperature gradients. Uptake of water accompanied changes in internal pressure reaching maxima of 17% (w/w) and 2% (w/w) of pepper and tomato fruits, respectively, after 22 hours. Maximum pressure changes achieved in bulky organs deviated from those predicted by the ideal gas law, possibly due to concomitant changes in gas pressure upon replacement of intercellular spaces with water and dissolution of CO2. Partial vacuums also developed in pepper fruits, rhubarb petioles, and pokeweed stems following exposure to air 15C cooler than initial organ temperatures. Results point to the role of temperature gradients in the transport of liquids and gases in plant organs.

Some notes on air-gun development as a marine seismic source

2009 ◽  
Vol 28 (11) ◽  
pp. 1334-1335 ◽  
Author(s):  
Ben F. Giles
Keyword(s):  
Seismic Source ◽  
Air Gun ◽  
Marine Seismic

Design of Near-orthogonal Air-gun Sequences for Marine Seismic Source Encoding

2016 ◽  
Author(s):  
M.B. Mueller ◽  
D.F. Halliday ◽  
D.J. van Manen ◽  
J.O.A. Robertsson
Keyword(s):  
Seismic Source ◽  
Air Gun ◽  
Marine Seismic ◽  
Source Encoding

What Happens When We have Winter Heating of Our Rooms?

2020 ◽  
Vol 02 (01) ◽  
pp. 2020001
Author(s):  
Dulli C. Agrawal
Keyword(s):  
Internal Energy ◽  
Old Age ◽  
Ideal Gas ◽  
Van Der Waals Gas ◽  
Constant Weight ◽  
Gas Laws ◽  
Ideal Gas Law ◽  
Marginal Change ◽  
Three Stages ◽  
The Ideal

The illustrious question by German Astrophysicist R. Emden, “Why do we have winter heating?” has been re-examined for air following both the ideal and imperfect gas laws; the internal energy of the air in the room remains unaffected in the former case whereas it increases marginally for the latter one. The findings corresponding to ideal gas law were correlated by Emden with the mass of a person which does not change even though food is constantly consumed. This example corresponds to adulthood when the mass of a person remains more or less constant. But the marginal change of internal energy in the case of van der Waals gas is consistent with three stages of a person — initially a person grows during childhood followed by adulthood when he has more or less constant weight and finally in old age, it deteriorates.

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