Postsurcharge secondary compression equation for clays

1988 ◽  
Vol 25 (3) ◽  
pp. 594-599 ◽  
Author(s):  
Eulalio Juárez-Badillo

A general time – volume change equation for soils is used to describe the initial swelling and further secondary compression of clay samples when surcharges are used. The procedure is illustrated by a practical application to México City clay. Key words: clay, secondary compression, secondary consolidation, postsurcharge, time-dependent compression, constitutive equations.

2020 ◽  
pp. 84-89
Author(s):  
Inna Ivanovna Lapkina

Today, around 50 million people worldwide suffer from cataracts, more than a half of them need surgical treatment. High prevalence of this pathology in Ukraine, the need to improve the provision of ophthalmic care to patients, and the reform of the health care system have made the research relevant. Concomitant diseases and special conditions of the eye increase the risk of intra− and postoperative complications, worsen the functional parameters of patients after surgery. In order to develop a unified approach to the treatment of complicated cataracts based on diagnostically related groups of patients, a retrospective analysis of case histories of patients with different variants of complications related to the condition of the lens itself, its ligament apparatus and other structures of the eye was conducted. In each case, the surgeon has to choose the appropriate modification of cataract phacoemulsification surgery. The study proposed the classification of cataract phacoemulsification modifications on the basis of the techniques and the sequence of operation stages, taking into account the classification of the degrees of turbidity of the lens, proposed by L. Buratto. It has been noted that in complicated cases, according to the indications of the patient, surgery may be performed on several modifications of cataract phacoemulsification. The developed classification made it possible to generalize the various variants of pathology and greatly facilitate the choice of tactics of surgical treatment in complicated cataracts. It can be used not only for practical application, but also for improving the qualification of trained professionals. The prospect of further research is to identify contraindications for outpatient treatment of the patients with complicated cataracts. Key words: cataract complication, classification of phacoemulsification modifications, diagnostically related groups.


1993 ◽  
Vol 07 (28) ◽  
pp. 4827-4840 ◽  
Author(s):  
DONALD H. KOBE ◽  
JIONGMING ZHU

The most general time-dependent Hamiltonian for a harmonic oscillator is both linear and quadratic in the coordinate and the canonical momentum. It describes in general a harmonic oscillator with mass, spring “constant,” and friction (or antifriction) “constant,” all of which are time dependent, that is acted on by a time-dependent force. A generalized Hannay angle, which is gauge invariant, is defined by making a distinction between the Hamiltonian and the energy. The generalized Hannay angle is the classical counterpart of the generalized Berry phase in quantum theory. When friction is present the generalized Hannay angle is nonzero. If the Hamiltonian is (incorrectly) chosen to be the energy, the generalized Hannay angle is different. Nevertheless, in the adiabatic case the same total angle is obtained.


1967 ◽  
Vol 45 (24) ◽  
pp. 3143-3151 ◽  
Author(s):  
T. Schaefer ◽  
F. Hruska ◽  
H. M. Hutton

The fluorine and proton chemical shifts in some geminally disubstituted vinylidene fluorides and ethylenes are discussed. For these compounds, at least, there are difficulties with an interpretation based on intramolecular time-dependent electric fields. On the other hand, the shifts correlate with the inverse ionization potentials of the substituents, indicating a paramagnetic effect arising from the second term in Ramsey's expression. It is suggested that the effect operates via the bonds and not across space. Methyl proton shifts in a series of substituted methyl compounds of group IV, V, and VI elements show similar correlations. A practical application of the correlation to spectral analysis problems is given.


1974 ◽  
Vol 41 (3) ◽  
pp. 652-657 ◽  
Author(s):  
Bernard W. Shaffer ◽  
Myron Levitsky

Thermoelastic constitutive equations are derived for a material undergoing solidification or hardening as the result of a chemical reaction. The derivation is based upon a two component model whose composition is determined by the degree of hardening, and makes use of strain-energy considerations. Constitutive equations take the form of stress rate-strain rate relations, in which the coefficients are time-dependent functions of the composition. Specific results are developed for the case of a material of constant bulk modulus which undergoes a transition from an initial liquidlike state into an isotropic elastic solid. Potential applications are discussed.


2018 ◽  
Vol 18 (8) ◽  
pp. 04018088 ◽  
Author(s):  
Abdoreza Fazeli ◽  
Amin Keshavarz ◽  
Mohammadhossein Moradi

Author(s):  
Li-Min Wang ◽  
Xiaokuan Ban ◽  
Zongzi Jin ◽  
Ranran Peng ◽  
Chusheng Chen ◽  
...  

Severe dendrite growth, low Coulombic efficiency and huge volume change have impeded the practical application of Li metal anode, and the construction of porous scaffolds is an effective strategy to...


1997 ◽  
Vol 4 (4) ◽  
pp. 223-235 ◽  
Author(s):  
G. Haller ◽  
A. C. Poje

Abstract. We study the relation between changes in the Eulerian topology of a two dimensional flow and the mixing of fluid particles between qualitatively different regions of the flow. In general time dependent flows, streamlines and particle paths are unrelated. However, for many mesoscale oceanographic features such as detaching rings and meandering jets, the rate at which the Euierian structures evolve is considerably slower than typical advection speeds of Lagrangian tracers. In this note we show that for two-dimensional, adiabatic fluid flows there is a direct relationship between observable changes in the topology of the Eulerian field and the rate of transport of fluid particles. We show that a certain class of flows is amenable to adiabatic or near adiabatic analysis, and, as an example, we use our results to study the chaotic mixing in the Dutkiewicz and Paldor (1994) kinematic model of the interaction of a meandering barotropic jet with a strong eddy.


2003 ◽  
Vol 81 (10) ◽  
pp. 1185-1191
Author(s):  
J -Q Shen ◽  
P Chen ◽  
H Mao

The present paper finds the complete set of exact solutions of the general time-dependent dynamical models for quantum decoherence, by making use of the Lewis–Riesenfeld invariant theory and the invariant-related unitary transformation formulation. Based on this, the general explicit expression for the decoherence factor is then obtained and the adiabatic classical limit of an illustrative example is discussed. The result (i.e., the adiabatic classical limit) obtained in this paper is consistent with what is obtained by other authors, and furthermore we obtain more general results concerning time-dependent nonadiabatic quantum decoherence. It is shown that the invariant theory is appropriate for treating both the time-dependent quantum decoherence and the geometric phase factor. PACS Nos.: 03.65.Ge, 03.65.Bz


Sign in / Sign up

Export Citation Format

Share Document