Nanodesigning of Multifunctional Ceramic Composites

1989 ◽  
Vol 175 ◽  
Author(s):  
J. Liu ◽  
M. Sarikaya ◽  
W. Y. Shih ◽  
W.-H. Shih ◽  
I. A. Aksay
Keyword(s):  
Packing Density ◽  
Binary Systems ◽  
Bond Formation ◽  
Particle Interaction ◽  
Ceramic Composites ◽  
Point Of View ◽  
Primary Concern ◽  
Multicomponent Systems ◽  
Fundamental Point ◽  
Component Systems

AbstractNanodesigning of multifunctional ceramic composites with colloids is discussed from a fundamental point of view. We start with one-component systems, where packing density is the primary concern. Then we extend the discussion to binary systems and deal with the problem of homogeneity. We show that the structure is controlled by the nature of bonding between the particles and by the particle-particle interaction. Surfactants are used to modiy these properties, by, first, protecting the active particle surfaces to prevent solid bond formation, and, second, altering the interparticle interaction to provide a “lubricating” effect. In weakly attractive multicomponent systems, not only are we able to achieve high-density packing through restructuring, but we can also control the scale of homogeneity.

Radiation Damage in Ceramics

1982 ◽  
Vol 40 ◽  
pp. 600-603
Author(s):  
T. E. Mitchell ◽  
M. R. Pascucci ◽  
R. A. Youngman
Keyword(s):  
Radiation Damage ◽  
Outer Space ◽  
Point Of View ◽  
Nuclear Waste Storage ◽  
Waste Storage ◽  
Storage Media ◽  
Transmission Electron ◽  
Fundamental Point ◽  
Small Defect ◽  
Present Understanding

1. Introduction. Studies of radiation damage in ceramics are of interest not only from a fundamental point of view but also because it is important to understand the behavior of ceramics in various practical radiation enyironments- fission and fusion reactors, nuclear waste storage media, ion-implantation devices, outer space, etc. A great deal of work has been done on the spectroscopy of point defects and small defect clusters in ceramics, but relatively little has been performed on defect agglomeration using transmission electron microscopy (TEM) in the same kind of detail that has been so successful in metals. This article will assess our present understanding of radiation damage in ceramics with illustrations using results obtained from the authors' work.

Determination of vapor—liquid equilibrium diagrams of multicomponent systems

2016 ◽  
Vol 70 (12) ◽  
Author(s):  
Leonid Serafimov ◽  
Anastasia Frolkova
Keyword(s):  
Phase Diagram ◽  
Multicomponent Systems ◽  
Liquid Equilibrium ◽  
Vapor Liquid Equilibrium ◽  
Equilibrium Modeling ◽  
Component Systems ◽  
Full Structure ◽  
Concentration Simplex ◽  
Vapor Liquid

AbstractA method for the determination of vapor–liquid phase diagram structure of five-component systems based on the analysis of types and Poincare indexes of singular points of the geometric scan and full structure of the concentration simplex is proposed. Validity of the proposed method was demonstrated by vapor–liquid equilibrium modeling in five-component mixtures: ethanol + water + toluene + butanol + chlorbenzene and acetone + chloroform + ethanol + cyclohexane + water.

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Concentration Dependence ◽  
Experimental Error ◽  
Binary Systems ◽  
Experimental Studies ◽  
Study Results ◽  
Component Systems ◽  
Minimum Depth ◽  
Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

scholarly journals Control Systems and Number Theory

2012 ◽  
Vol 2012 ◽  
pp. 1-28
Author(s):  
Fuhuo Li
Keyword(s):  
Zeta Functions ◽  
Feedback System ◽  
State Equation ◽  
The State ◽  
Point Of View ◽  
Pid Controllers ◽  
Primary Concern ◽  
Feedback Connection ◽  
Proper Understanding ◽  
Natural Way

We try to pave a smooth road to a proper understanding of control problems in terms of mathematical disciplines, and partially show how to number-theorize some practical problems. Our primary concern is linear systems from the point of view of our principle of visualization of the state, an interface between the past and the present. We view all the systems as embedded in the state equation, thus visualizing the state. Then we go on to treat the chain-scattering representation of the plant of Kimura 1997, which includes the feedback connection in a natural way, and we consider theH∞-control problem in this framework. We may view in particular the unit feedback system as accommodated in the chain-scattering representation, giving a better insight into the structure of the system. Its homographic transformation works as the action of the symplectic group on the Siegel upper half-space in the case of constant matrices. Both ofH∞- and PID-controllers are applied successfully in the EV control by J.-Y. Cao and B.-G. Cao 2006 and Cao et al. 2007, which we may unify in our framework. Finally, we mention some similarities between control theory and zeta-functions.

Higher-Order Multilevel Solvers for the EHL Line and Point Contact Problem

1994 ◽  
Vol 116 (4) ◽  
pp. 741-750 ◽  
Author(s):  
C. H. Venner
Keyword(s):  
Contact Problem ◽  
Computing Time ◽  
Point Contact ◽  
Higher Order ◽  
Second Order ◽  
Point Of View ◽  
First Order ◽  
Fundamental Point ◽  
Numerical Solver ◽  
Circular Contact

This paper addresses the development of efficient numerical solvers for EHL problems from a rather fundamental point of view. A work-accuracy exchange criterion is derived, that can be interpreted as setting a limit to the price paid in terms of computing time for a solution of a given accuracy. The criterion can serve as a guideline when reviewing or selecting a numerical solver and a discretization. Earlier developed multilevel solvers for the EHL line and circular contact problem are tested against this criterion. This test shows that, to satisfy the criterion a second-order accurate solver is needed for the point contact problem whereas the solver developed earlier used a first-order discretization. This situation arises more often in numerical analysis, i.e., a higher order discretization is desired when a lower order solver already exists. It is explained how in such a case the multigrid methodology provides an easy and straightforward way to obtain the desired higher order of approximation. This higher order is obtained at almost negligible extra work and without loss of stability. The approach was tested out by raising an existing first order multilevel solver for the EHL line contact problem to second order. Subsequently, it was used to obtain a second-order solver for the EHL circular contact problem. Results for both the line and circular contact problem are presented.

A METAMAGNETIC QUANTUM CRITICAL ENDPOINT IN Sr3Ru2O7

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3258-3264 ◽  
Author(s):  
S. A. GRIGERA ◽  
A. P. MACKENZIE ◽  
A. J. SCHOFIELD ◽  
S. R. JULIAN ◽  
G. G. LONZARICH
Keyword(s):  
Quantum Critical Point ◽  
Point Of View ◽  
Zero Temperature ◽  
Tuning Parameters ◽  
First Order ◽  
End Point ◽  
Fundamental Point ◽  
New Type ◽  
Quantum Critical ◽  
The Magnetic Field

In this paper, we discuss the concept of a metamagnetic quantum critical end-point, consequence of the depression to zero temperature of a critical end-point terminating a line of first order first transitions. This new type of quantum critical point (QCP) is interesting both from a fundamental point of view: a study of a symmetry conserving QCP, and because it opens the possibility of the use of symmetry breaking tuning parameters, notably the magnetic field. In addition, we discuss the experimental evidence for the existence of such a QCP in the bilayer ruthenate Sr3Ru2O7.

scholarly journals Fluorescent Artificial Receptor-Based Membrane Assay (FARMA) for Spatiotemporally Resolved Monitoring of Biomembrane Permeability

2019 ◽  
Author(s):  
Frank Biedermann ◽  
Garima Ghale, Ghale ◽  
Andreas Hennig ◽  
Werner M. Nau
Keyword(s):  
High Throughput Screening ◽  
High Sensitivity ◽  
Point Of View ◽  
Phospholipid Bilayer ◽  
Label Free ◽  
Microscopy Imaging ◽  
Biophysical Models ◽  
Fundamental Point ◽  
Artificial Receptor ◽  
Microplate Reader

<p>The spatiotemporally resolved monitoring of membrane translocation, <i>e.g.,</i> of drugs or toxins, has been a long-standing goal. Herein, we introduce the fluorescent artificial receptor-based membrane assay (FARMA), a facile, label-free method. With FARMA, the permeation of more than hundred organic compounds (drugs, toxins, pesticides, neurotransmitters, peptides, etc.) through vesicular phospholipid bilayer membranes has been monitored in real time (µs-h time scale) and with high sensitivity (nM-µM concentration), affording permeability coefficients across an exceptionally large range from 10<sup>–9</sup>‑10<sup>–3</sup> cm s<sup>–1</sup>. From a fundamental point of view, FARMA constitutes a powerful tool to assess structure-permeability relationships and to test biophysical models for membrane passage. From an applied perspective, FARMA can be extended to high-throughput screening by adaption of the microplate reader format, to spatial monitoring of membrane permeation by microscopy imaging, and to the compartmentalized monitoring of enzymatic activity.<b></b></p>

Gaseous Solutions

1993 ◽  
Author(s):  
Greg M. Anderson ◽  
David A. Crerar
Keyword(s):  
Equations Of State ◽  
Intermolecular Forces ◽  
Point Of View ◽  
Alternative Methods ◽  
Gaseous Species ◽  
Fugacity Coefficient ◽  
Ideal Gases ◽  
Component Systems ◽  
Liquid Solutions ◽  
History Of

The procedures described in Chapter 15 are well suited to solid and liquid solutions and could also be applied to gases, but in fact, other approaches are generally used. The main reason for this is partly historical; much work was done early in the history of physical chemistry on the behavior of gases, and these methods have continued to evolve to the present day. We have also just seen that the Margules equations become very unwieldy with multi-component systems. Because true gases are completely miscible, natural gases often contain many different components, so the Margules approach is not very suitable. Unfortunately, the most successful alternative methods described in this section are also quite unwieldy; however, they do not become much more complicated for multi-component gases than they are for the pure gases themselves, and this is a definite advantage. We have seen that with real, non-ideal gases, all the thermodynamic properties are described if we know the T, P, and the fugacity coefficient. For gaseous solutions, the fugacity coefficient for each component generally depends on the concentrations and types of other gaseous species in the same mixture. All gases, whether pure or multi-component, should approach ideality at higher T and lower P; conversely, non-ideality is most pronounced in dense, low-temperature gases where intermolecular forces are strongest. The challenge here is to find an equation of state that can adequately cover this range of conditions for gases of many different constituents. In the following discussion we first briefly outline some of the equations of state used to describe pure gases. We will introduce these from the molecular point of view since this helps understand the physical basis (and limitations) of each model. Each of these equations of state can then be applied to mixtures of gases using a set of rules which we describe at the end of this section.

Reproducibility of core temperature threshold for sweating onset in humans

1994 ◽  
Vol 77 (4) ◽  
pp. 1671-1677 ◽  
Author(s):  
G. L. Brengelmann ◽  
M. V. Savage ◽  
D. H. Avery
Keyword(s):  
Sweat Rate ◽  
Practical Method ◽  
Rate Of Change ◽  
Point Of View ◽  
Temperature Threshold ◽  
Small Magnitude ◽  
Fundamental Point ◽  
Downward Displacement ◽  
The Relationship ◽  
Second Period

The control of sweating in humans has been described quantitatively in terms of skin and core temperatures (Tsk and Tcore, respectively). However, the precision with which features of the relationship between sweat rate and Tcore at a given Tsk can be reproduced in the short term is not known. We focused on the threshold Tcore. We held Tsk at 38 degrees C until sweating began for two periods separated by a period of cooling with Tsk at 32 degrees C in six men and three women. The esophageal temperature (Tes) at which sweating began was invariably lower in the second period of heating (average difference 0.09 degree C; maximum 0.17 degree C). Also, the rate of rise in Tes was invariably higher (average 148%) during the second period of heating. Thus, although a threshold cannot be reproduced within the error of Tes measurement, the consistency and small magnitude of the downward shift recommend our protocol as a practical method for evaluating other influences on thermoregulation, provided that the effects are big enough to be seen against a background of an expected small decrease. From the fundamental point of view, the consistency of the downward displacement has provocative implications, e.g., the rate of change in Tcore influences sweating or thermosensitive units in slow-responding thermal compartments contribute to the Tcore input signal.

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