Thermodynamics-Inspired Macroscopic States of Bounded Swarms

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Hossein Haeri ◽  
Kshitij Jerath ◽  
Jacob Leachman
Keyword(s):  
Collective Behavior ◽  
Ideal Gas ◽  
Virial Equation ◽  
Collective Behaviors ◽  
Robotic Swarms ◽  
Agent Interactions ◽  
Ideal Gas Law ◽  
Macroscopic Properties ◽  
Macroscopic States ◽  
Small Set

Abstract The collective behavior of swarms is extremely difficult to estimate or predict, even when the local agent rules are known and simple. The presented work seeks to leverage the similarities between fluids and swarm systems to generate a thermodynamics-inspired characterization of the collective behavior of robotic swarms. While prior works have borrowed tools from fluid dynamics to design swarming behaviors, they have usually avoided the task of generating a fluids-inspired macroscopic state (or macrostate) description of the swarm. This work will bridge the gap by seeking to answer the following question: is it possible to generate a small set of thermodynamics-inspired macroscopic properties that may later be used to quantify all possible collective behaviors of swarm systems? In this paper, we present three macroscopic properties analogous to pressure, temperature, and density of a gas to describe the behavior of a swarm that is governed by only attractive and repulsive agent interactions. These properties are made to satisfy an equation similar to the ideal gas law and also generalized to satisfy the virial equation of state for real gases. Finally, we investigate how swarm specifications such as density and average agent velocity affect the system macrostate.

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.

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.

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.

Enthalpy Calculation of Flue Gas from Pressurized Oxy-Coal Combustion Based on Real Gases

2013 ◽  
Vol 325-326 ◽  
pp. 340-345
Author(s):  
Jing Lan Dong ◽  
Wei Ping Yan ◽  
Chao Hui Zhang
Keyword(s):  
Flue Gas ◽  
Atmospheric Pressure ◽  
Coal Combustion ◽  
Function Method ◽  
Ideal Gas ◽  
Virial Equation ◽  
Flow Sheet ◽  
Fuel Gas ◽  
Deviation Function ◽  
Classic Approach

The oxy-fuel combustion is recognizing one of the most promising available technologies that zero emission accomplishment may be in the offing. With coal burned at the pressure of 6MPa and oxygen-enriched conditions, the high temperature and high pressure gaseous combustion product is composed of mainly CO2and water-vapor that belonging to real gases. However, once lauded as classic approach of resolving fuel gas enthalpy calculation pertaining to ideal gas at atmospheric pressure was restrained by pressure limitations. In this paper, the flue gas was assumed as an ideal mixture of real gases system, and the equations for calculating the flue gas enthalpy were derived by using deviation function method based on the virial equation. Consequently, comparing with the results simulated by the flow-sheet simulation 2éÕÒ: software" software-ASPEN PLUS, it showed that calculation method on the basis of virial equation appears to be a reasonable enthalpy values for the pressurized oxygen-enriched coal combustion.

Bending Behavior of Plain-Woven Fabric Air Beams: Fluid-Structure Interaction Approach

2006 ◽  
Author(s):  
Paul V. Cavallaro ◽  
Ali M. Sadegh ◽  
Claudia J. Quigley
Keyword(s):  
Finite Element ◽  
Ideal Gas ◽  
Woven Fabric ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Ideal Gas Law ◽  
Biaxial Tests ◽  
Structural Responses ◽  
Bending Behavior ◽  
Interaction Approach

A swatch of plain-woven fabric was subjected to biaxial tests and its material characterization was performed. The stress-strain relations of the fabric were determined and directly used in finite element models of an air beam, assumed constructed with the same fabric, subjected to inflation and bending events. The structural responses to these events were obtained using the ABAQUS-Explicit[1] finite element solver for a range of pressures including those considered typical in safe operations of air inflated structures. The models accounted for the fluid-structure interactions between the air and the fabric. The air was treated as a compressible fluid in accordance with the Ideal Gas Law and was subjected to adiabatic constraints during bending. The fabric was represented with membrane elements and several constitutive cases including linear elasticity and hyperelasticity were studied. The bending behavior for each constitutive case is presented and discussions for their use and limitations follow.

scholarly journals Gas flow through a bore-piston ring contact

2020 ◽  
pp. 146808742097112
Author(s):  
Baptiste Hallouin ◽  
Didier Lasseux ◽  
Gerald Senger
Keyword(s):  
Gas Flow ◽  
Piston Ring ◽  
Practical Interest ◽  
Contact Length ◽  
Ideal Gas ◽  
Ideal Gas Law ◽  
Thermodynamic Conditions ◽  
Sinusoidal Shape ◽  
Flow Through ◽  
Ic Engines

This work reports on the derivation of simplified but accurate models to describe gas flow through a bore-piston ring contact in reciprocating machines like compressors or IC engines. On the basis of the aperture field of a contact deduced from real measurements carried out on an expanding ring in a bore, a scale analysis on the complete compressible flow model is performed, assuming ideal gas law. It is shown that the flow can be treated as stationary and three distinct flow regimes can be identified (namely incompressible, compressible creeping, and compressible inertial regimes). Three dimensionless parameters characterizing these regimes are identified. While for the two former regimes, classical analytical Poiseuille type of models are derived, an Oseen approximation is further employed for the latter, yielding a quasi-analytical solution. The models are successfully compared to direct numerical simulations (DNS) of the complete initial set of balance equations in their steady form performed on an aperture field of sinusoidal shape. These simplified models are of particular practical interest since they allow an accurate gas flow-rate estimate through a real contact using the aperture field as the geometrical input datum, together with the thermodynamic conditions (pressure and temperature). This represents an enormous advantage as DNS is still very challenging in practice due to the extremely small value of the contact aperture to contact length ratio.

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