Strength development modelling

HYBOT will compute hydrogen bond donor (SCa) and acceptor (2Ca) factors that describe the donor and acceptor strengths, respectively, of a compound. Using these two parameters, the authors developed models with significant statistical quality (r2 = 0.91, q2 = 0.87) of intestinal absorption. 

Bayles (1989) proposed seven obligations of modelers to clients honesty, candor, competency, diligence, loyalty, fairness, and discretion. Each of these qualities will be briefly discussed. Honesty and candor go hand in hand. Modelers should be truthful with their clients, but candor goes beyond truthfulness requiring modelers to make full disclosure. Clients want a modeler to develop models. When equally plausible models exist, it is the modelers responsibility to present these alternatives to the client along with how these alternatives vary in cost, scope, and time to implementation. The modeler also has a responsibility to explain not only the strengths of a model, but also its inadequacies, in an objective manner without advocacy. Modelers must provide adequate... 

The time-to-failure of a structure or its components is an important issue for structural safety considerations in fire. On the basis of the strength degradation models for FRP materials under elevated and high temperatures developed in Chapter 5, the time-to-failure is predicted for GFRP tubes and laminates under both thermal and mechanical loading in compression. Temperature responses were again calculated using the thermal response model presented in Chapter 6. 

Marshall MG, Metaxas AC. Modeling the radio frequency electric field strength developed during the RE assisted heat pump dr5dng of particulates. Inti. Microwave Power Institute 33(3) 167-177, 1998. 

A remarkable achievement of statistical mechanics is the accurate prediction of gas-phase chemical reaction equilibria from atomic structures. From atomic masses, moments of inertia, bond lengths, and bond strengths, you can calculate partition functions. You can then calculate equilibrium constants and their dependence on temperature and pressure. In Chapter 19, we will apply these ideas to chemical kinetics, which pertains to the rates of reactions. Reactions can be affected by the medium they are in. Next we will develop models of liquids and other condensed phases. 

A strain-energy based reliability model similar to a previously developed model for Sn-Pb assemblies (Ref 16, 44-46) is under development. In lieu of finite element analysis, the model uses strength of materials techniques to capture the deformations of substrates and components. One main item presently under investigation is the selection of an adequate constitutive model for solder in lead-free solder joints (Ref 47, 49). This is a critical part of the model development effort, given significant differences in the mechanical behavior of bulk solder and small size solder joints. 

A study of the hydration of cement and cement compounds in the presence of superplasticizers is useful for theoretical and practical considerations. Many t5 es of thermal techniques including DTA, DSC, TG, DTG, Conduction Calorimetry, and EGA have been used for such studies. They have yielded important results that could be correlated with physical and mechanical characteristics of cement systems. Investigations have included the measurementofheat of hydration, the mechanism of reactions, strength development, microstmcture, permeability, durability aspects, compatibility problems between cement and superplasticizers, the prediction of some properties, material characterization and selection, mathematical modeling of hydration, development of test methods, and cement-superplasticizer interactions. 

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