scholarly journals COMPRESSIBILITY BEHAVIOUR OF COMPACTED SOILS – HYPERBOLIC MODELLING

2020 ◽  
Author(s):  
U. Venkata Ratnam ◽  
K. Nagendra Prasad
Keyword(s):  
Void Ratio ◽  
Model Parameters ◽  
Initial State ◽  
Compacted Soils ◽  
One Dimensional ◽  
Initial Void Ratio ◽  
Two Samples ◽  
Earth Structures ◽  
Hyperbolic Behavior ◽  
Engineering Projects

Compacted soils constitute most engineering projects such as earth dams,embankments, pavements, and engineered slopes because of their high shear strengthand low compressibility. The compressibility behavior of compacted soils is a key soilparameter in the design of earth structures but it is not determined correctly owing topartly saturated state. The compressibility of compacted soils can be better evaluatedunder the framework of hyperbolic behavior. One dimensional Consolidation tests oncompacted specimens were conducted using conventional oedometer apparatus underconstant water content condition. Tests were conducted by compact the soil specimensat respective optimum moisture contents for eight different soil samples, of varyinggrain size characteristics and consistency limits, collected from Tirupati Region. Themain objective of this study is to examine the compressibility behavior of compactedsoils to propose a phenomenological model. It is observed that the compressibilitybehavior can be captured by hyperbolic modeling with model parameters involved inthe behavior being initial void ratio, e0, representing the initial state of soil and otherhyperbolic constants linked to this state. The data of 6 samples were used fordeveloping the model and the data of remaining two samples were used for predictingthe observed response from the model proposed. The data of published literature hasalso been used to predict the experimental behavior to bring out the merits of themodel proposed.

The Duncan-Chang Model Parameters for Municipal Solid Waste

2011 ◽  
Vol 48-49 ◽  
pp. 1235-1240
Author(s):  
Zhen Ying Zhang ◽  
Da Zhi Wu
Keyword(s):  
Theoretical Analysis ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Void Ratio ◽  
Practical Method ◽  
Model Parameters ◽  
Mechanical Parameters ◽  
Initial Void Ratio ◽  
The Relationship ◽  
Chang Model

By theoretical analysis and laboratory test, the model parameters of Duncan-Chang for municipal solid waste have been studied. To obtain the mechanical parameters, a new simple and practical method has been established. Research results show that the damage ratio is 0.6, parameter n is about 1.05, parameter F varies between 0 and 0.1, and parameter G varies between 0.3 and 0.4. Besides, the relationship between parameter k and the initial void ratio is linear, and the slope of the line is 5.0.

scholarly journals Undecidability in quantum thermalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoto Shiraishi ◽  
Keiji Matsumoto
Keyword(s):  
Turing Machine ◽  
Thermal Equilibrium ◽  
General Theorem ◽  
Nearest Neighbour ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Universal Turing Machine ◽  
Many Body Systems ◽  
Neighbour Interaction

AbstractThe investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.

A Theoretical Analysis of CO2 Absorption in Sun Versus Shade Leaves

1978 ◽  
Vol 100 (1) ◽  
pp. 20-24 ◽  
Author(s):  
R. H. Rand
Keyword(s):  
Experimental Data ◽  
Quantitative Estimate ◽  
Geometric Model ◽  
Model Parameters ◽  
Co2 Absorption ◽  
Temperature Model ◽  
Spongy Mesophyll ◽  
One Dimensional ◽  
Mesophyll Tissue ◽  
Shade Leaves

A one-dimensional, steady-state, constant temperature model of diffusion and absorption of CO2 in the intercellular air spaces of a leaf is presented. The model includes two geometrically distinct regions of the leaf interior, corresponding to palisade and spongy mesophyll tissue, respectively. Sun, shade, and intermediate light leaves are modeled by varying the thicknesses of these two regions. Values of the geometric model parameters are obtained by comparing geometric properties of the model with experimental data of other investigators found from dissection of real leaves. The model provides a quantitative estimate of the extent to which the concentration of gaseous CO2 varies locally within the leaf interior.

scholarly journals Post-liquefaction reconsolidation of sand

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150745 ◽  
Author(s):  
O. Adamidis ◽  
G. S. P. Madabhushi
Keyword(s):  
Void Ratio ◽  
One Dimensional ◽  
Geotechnical Centrifuge ◽  
Significant Damage ◽  
Pore Water Pressures ◽  
The One ◽  
Crucial Parameter ◽  
Excess Pore ◽  
Good Agreement ◽  
Made In

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

Discrete-Time Memristor Model for Enhancing Chaotic Complexity and Application in Secure Communication

2022 ◽  
Author(s):  
Wenhao Yan ◽  
Zijing Jiang ◽  
Qun Ding
Keyword(s):  
Fixed Points ◽  
Discrete Time ◽  
Dynamic Characteristics ◽  
Secure Communication ◽  
Chaotic Systems ◽  
Two Dimensional ◽  
Initial State ◽  
One Dimensional ◽  
Backward Euler ◽  
Short Period

Abstract The physical implementation of continuoustime memristor makes it widely used in chaotic circuits, whereas discrete-time memristor has not received much attention. In this paper, the backward-Euler method is used to discretize TiO2 memristor model, and the discretized model also meets the three fingerprinter characteristics of the generalized memristor. The short period phenomenon and uneven output distribution of one-dimensional chaotic systems affect their applications in some fields, so it is necessary to improve the dynamic characteristics of one-dimensional chaotic systems. In this paper, a two-dimensional discrete-time memristor model is obtained by linear coupling the proposed TiO2 memristor model and one-dimensional chaotic systems. Since the two-dimensional model has infinite fixed points, the stability of these fixed points depends on the coupling parameters and the initial state of the discrete TiO2 memristor model. Furthermore, the dynamic characteristics of one-dimensional chaotic systems can be enhanced by the proposed method. Finally, we apply the generated chaotic sequence to secure communication.

scholarly journals Probing non-thermal density fluctuations in the one-dimensional Bose gas

2017 ◽  
Vol 3 (3) ◽  
Author(s):  
Jacopo De Nardis ◽  
Milosz Panfil ◽  
Andrea Gambassi ◽  
Leticia Cugliandolo ◽  
Robert Konik ◽  
...  
Keyword(s):  
Spatial Dimension ◽  
Bose Gas ◽  
Density Fluctuations ◽  
Dynamical Structure ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Fluctuation Dissipation ◽  
Quantum Integrable Models ◽  
The One

Quantum integrable models display a rich variety of non-thermal excited states with unusual properties. The most common way to probe them is by performing a quantum quench, i.e., by letting a many-body initial state unitarily evolve with an integrable Hamiltonian. At late times these systems are locally described by a generalized Gibbs ensemble with as many effective temperatures as their local conserved quantities. The experimental measurement of this macroscopic number of temperatures remains elusive. Here we show that they can be obtained for the Bose gas in one spatial dimension by probing the dynamical structure factor of the system after the quench and by employing a generalized fluctuation-dissipation theorem that we provide. Our procedure allows us to completely reconstruct the stationary state of a quantum integrable system from state-of-the-art experimental observations.

Extreme-value properties of the explosion-time distribution in a pure birth process

1982 ◽  
Vol 19 (3) ◽  
pp. 500-509 ◽  
Author(s):  
Paul D. Feigin ◽  
Emmanuel Yashchin
Keyword(s):  
Saddlepoint Approximation ◽  
Value Theory ◽  
Extreme Value ◽  
Model Parameters ◽  
Theory Analysis ◽  
Initial State ◽  
Birth Process ◽  
Failure Times ◽  
Time Between Failures ◽  
Breakdown Mechanism

In each of a large number N of independent cells a breakdown mechanism is under way and proceeds until the first of the cells actually fails. At such a time, in each cell, the situation reverts to some initial state and the mechanism restarts. In this paper we consider those mechanisms for which breakdown may be modelled as the explosion of a pure birth process. Of interest is the distribution of time between failures and the possibility of estimating N and/or model parameters by observing a sequence of failure times. Saddlepoint approximation methods are used in the relevant extreme-value theory analysis for two important cases.

Variable Angle of Incidence Spectroscopic Ellipsometric Measurement of the Franz-Keloysh Effect in Modfet Structures

1986 ◽  
Vol 77 ◽  
Author(s):  
P. G. Snyder ◽  
J. E. Oh ◽  
J. A. Woollam
Keyword(s):  
Electric Field ◽  
Bandgap Energy ◽  
Model Parameters ◽  
Angle Of Incidence ◽  
Internal Electric Field ◽  
Ellipsometric Measurement ◽  
Band Bending ◽  
Variable Angle ◽  
Two Samples ◽  
Franz Keldysh Effect

ABSTRACTIt has been shown recently that variable angle of incidence spectroscopie ellipsometry (VASE) is a sensitive technique for determining semiconductor multilayer model parameters, e.g. layer thicknesses and ternary compositions. In this paper we show that VASE is, in addition, sensitive to the Franz-Keldysh effect induced by band bending in the barrier layer of a GaAs-AlGaAs-GaAs (MODFET) structure. VASE measurements differ from electro-reflectance and photoreflectance, in that the internal heterojunction region electric field is directly probed, without the application of a modulating field. The Franz-Keldysh effect appears in the VASE spectra near the AlGaAs bandgap energy. Data for two samples, with different doping profiles, are quantitatively modeled to determine the internal electric field amplitudes.

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