Selection of Equations-of-State for Blast Attenuation

1971 ◽  
Vol 38 (1) ◽  
pp. 253-261 ◽  
Author(s):  
P. Lieberman
Keyword(s):  
Boundary Condition ◽  
Equations Of State ◽  
Rear Surface ◽  
Applied Pressure ◽  
Rigid Boundary ◽  
One Dimensional ◽  
Number Of Layers ◽  
State Boundary ◽  
Analytical Expressions ◽  
Selection Of

Blast shield materials are described by idealized equations-of-state in both one-dimensional loading and one-dimensional unloading. A square-wave applied pressure history is one boundary condition at the impingement surface of the material and, at the rear surface of the material(s), there is a stationary boundary condition. The objective is to select the equations-of-state that yield the greatest reduction in reflected stress at the rigid-boundary condition, for the smallest overall length, for application to a blast shield. One and two layers of material are considered. Idealizations of the equations-of-state, boundary conditions, length of each layer, and number of layers are arranged to yield simple analytical expressions for the relation of reflected stress to the overall length of the blast shield.

Study on One Dimensional Mathematical Model for Unsteady Flow Sediment and Water Quality in Channel with a Sluice

2013 ◽  
Vol 444-445 ◽  
pp. 1830-1836
Author(s):  
Jin Qiong Zhao
Keyword(s):  
Mathematical Model ◽  
Water Quality ◽  
Boundary Condition ◽  
Unsteady Flow ◽  
River Channel ◽  
One Dimensional ◽  
Local Erosion ◽  
Operational Modes ◽  
Calculation Software ◽  
Selection Of

Based on existing mathematical model for one-dimensional unsteady flow and non-uniform water-sediment, the inside boundary condition of sluice has been introduced to establish a mathematical model which is suitable for sediment and water quality in nontidal river channel with sluice, in combination with empirical model of local erosion-deposition and one-dimensional mathematical model for water quality. It can be used to simulate motion of water flow, sediment and pollutant under different operational modes of sluice in tidal reaches. In addition, a mathematical model calculation software for water-sediment and water quality has been developed on this basis after sluice has been built, which is also being used to study the influence of different application solution of sluice in Yongding New River on the motion of sediment and pollutant, so as to provide a basis for the selection of sluice operational modes.

Preliminary evaluation of the influence of surfactant injection on the mechanical behaviour of a compacted till

1995 ◽  
Vol 32 (3) ◽  
pp. 539-544
Author(s):  
Alexandre R. Cabral ◽  
Guy Lefebvre ◽  
Pascal Collette
Keyword(s):  
Mechanical Properties ◽  
Applied Pressure ◽  
Soil Mass ◽  
Preliminary Evaluation ◽  
Test Results ◽  
One Dimensional ◽  
Surfactant Solutions ◽  
Significant Compression ◽  
Soil Behaviour ◽  
Selection Of

One-dimensional consolidation tests were performed with till samples compacted dry of optimum to 85% of the modified Proctor density. When the applied pressure reached 200 kPa, the samples were saturated (submerged) and then flushed with two types of surfactant solutions, under a hydraulic gradient varying from 35 to 40. Significant compression occurred during submergence and as a result of flushing with a 2% solution of an anionic surfactant. Only minor additional compression resulted from flushing with a 2% solution of a nonionic surfactant. While only preliminary conclusions could be drawn from the limited test results, this study highlighted the importance of considering, in the early stages of remediation procedure design (including the selection of the surfactant), the possible deleterious effects of surfactant injection on the mechanical properties of the soil mass, particularly when it is in a loose to moderately loose state. Key words : surfactants, adsorption, hydrocarbon remediation, compression, mechanical properties, soil behaviour.

One-Dimensional Fin-Tip Boundary Condition Correction II

2001 ◽  
Vol 22 (5) ◽  
pp. 35-40 ◽  
Author(s):  
D. C. Look Jr ◽  
Arvind Krishnan
Keyword(s):  
Boundary Condition ◽  
One Dimensional

Selection of one-dimensional sedimentation: models for on-line use

1995 ◽  
Vol 31 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Koen Grijspeerdt ◽  
Peter Vanrolleghem ◽  
Willy Verstraete
Keyword(s):  
Steady State ◽  
Selection Criteria ◽  
Data Sets ◽  
Concentration Profiles ◽  
A Posteriori ◽  
One Dimensional ◽  
On Line ◽  
Dynamic Concentration ◽  
Selection Of ◽  
Modelling Task

A comparative study of several recently proposed one-dimensional sedimentation models has been made. This has been achieved by fitting these models to steady-state and dynamic concentration profiles obtained in a down-scaled secondary decanter. The models were evaluated with several a posteriori model selection criteria. Since the purpose of the modelling task is to do on-line simulations, the calculation time was used as one of the selection criteria. Finally, the practical identifiability of the models for the available data sets was also investigated. It could be concluded that the model of Takács et al. (1991) gave the most reliable results.

scholarly journals AN ANALYTIC SOLUTION FOR ONE-DIMENSIONAL DISSIPATIONAL STRAIN-GRADIENT PLASTICITY

2009 ◽  
Vol 50 (3) ◽  
pp. 407-420
Author(s):  
ROGER YOUNG
Keyword(s):  
Boundary Condition ◽  
Strain Gradient ◽  
Analytic Solution ◽  
Strain Gradient Plasticity ◽  
Numerical Results ◽  
Gradient Plasticity ◽  
One Dimensional ◽  
Numerical Result ◽  
Formulation Analysis ◽  
The One

AbstractAn analytic solution is developed for the one-dimensional dissipational slip gradient equation first described by Gurtin [“On the plasticity of single crystals: free energy, microforces, plastic strain-gradients”, J. Mech. Phys. Solids48 (2000) 989–1036] and then investigated numerically by Anand et al. [“A one-dimensional theory of strain-gradient plasticity: formulation, analysis, numerical results”, J. Mech. Phys. Solids53 (2005) 1798–1826]. However we find that the analytic solution is incompatible with the zero-sliprate boundary condition (“clamped boundary condition”) postulated by these authors, and is in fact excluded by the theory. As a consequence the analytic solution agrees with the numerical results except near the boundary. The equation also admits a series of higher mode solutions where the numerical result corresponds to (a particular case of) the fundamental mode. Anand et al. also established that the one-dimensional dissipational gradients strengthen the material, but this proposition only holds if zero-sliprate boundary conditions can be imposed, which we have shown cannot be done. Hence the possibility remains open that dissipational gradient weakening may also occur.

A short ethnography of twenty-first century consumers: On retail rage and one-dimensionality

2021 ◽  
pp. 146954052110396
Author(s):  
Kevin P. Bingham
Keyword(s):  
Consumer Culture ◽  
Retail Trade ◽  
First Century ◽  
One Dimensional ◽  
Unique Position ◽  
Material Goods ◽  
Twenty First Century ◽  
Selection Of ◽  
Sociological Interpretation ◽  
The Way

This article begins with two central ideas – that feelings of rage appear to be on the increase in present modernity and that one of the main sources of rage is directly linked to consumer culture and the retail experience it fosters. Although retail trade allows twenty-first century individuals to spend their money on material goods and experiences which provide structure and a sense of meaning and belonging, what it also causes is ambivalence, insecurity and anxiety. These are formidable feelings that cause irritation, frustration and anger to gradually fester until it accumulates into something violent that distorts the way an individual thinks, acts and treats other people. With these points in mind, what this article provides is a thorough sociological interpretation of twenty-first century retail rage. Veering away from existing interpretations of rage by drawing on Herbert Marcuse’s analysis and image of a one-dimensional society, what this article explores is the idea that retail experiences turn people into individuals who are bound and controlled by a consumer duty. As I contend, based on my unique position as a researcher turned retail worker, it is this administered, one-dimensional kind of lifestyle that cultivates rage. To support my argument and understand more comprehensively how and why retail breeds frustration and anger, I use a selection of narrative episodes to unpack three key sources of consumer rage in the twenty-first century. These sources have been labelled instantaneity, performativity and unfulfillment.

Analysis for the Effect of Inverter Ripple Current on Fuel Cell Operating Condition

2001 ◽  
Author(s):  
Randall S. Gemmen
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Mass Transport ◽  
Transient Behavior ◽  
Mechanical State ◽  
Dimensional Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
A Cell ◽  
The Impact

Abstract The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical state of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches help to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.

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