Structure-property relationship, absorbable

Structural dements resist blast loads by developing an internal resistance based on material stress and section properties. To design or analyze the response of an element it is necessary to determine the relationship between resistance and deflection. In flexural response, stress rises in direct proportion to strain in the member. Because resistance is also a function of material stress, it also rises in proportion to strain. After the stress in the outer fibers reaches the yield limit, (lie relationship between stress and strain, and thus resistance, becomes nonlinear. As the outer fibers of the member continue to yield, stress in the interior of the section also begins to yield and a plastic hinge is formed at the locations of maximum moment in the member. If premature buckling is prevented, deformation continues as llic member absorbs load until rupture strains arc achieved. 

Hales JM (2004) Chemical Structure-Nonlinear Optical Property Relationships for A Series of Two-Photon Absorbing Fluorene Molecules. CREOL and School of Optics, University of Central Florida, Orlando, PhD dissertation... 

The next logical step toward chromophore design was to conduct a spectral survey of commercially available organic compounds in order to learn some general structure-property relationships for minimization of the residual absorbance. As an easily measured figure of merit, the ratio between the minimum and maximum molar absorptivities has been used. In many cases, this ratio (expressed in percent, or more conveniently, as the minimum molar absorptivity per 100,000 L/mol-cm of maximum absorbance) is 5-10% (5000-10,000 per 100,000). (The lower the number the better the dye.) An improved figure of merit would take into account the area under the absorption curve as well as the location of the transparent window relative to the peak in the absorption. This is tantamount to calculating the dispersion from the absorption spectrum, which was too complex for this type of survey. 

Ever since the foundations of spectroscopy were laid the problem of the relationship between the optical spectra emitted or absorbed by matter and the microscopic properties of the matter has been regarded as a fundamental problem. A class of very interesting systems with this regard is provided by non-metallic compounds of rare-earth ions with partially filled 4f shells. Their rich electronic structure is only weakly perturbed by the environment and provides a detailed fingerprint of the surrounding arrangement of atoms and their interactions with the f-electrons. 

Water has a number of unique properties that are essential to life, due largely to its molecular structure and bonding properties. Among the special characteristics of water are the fact that it is an excellent solvent, it has a temperature-density relationship that results in bodies of water becoming stratified in layers, it is transparent, and it has an extraordinary capacity to absorb, retain, and release heat per unit mass of ice, liquid water, or water vapor. 

There are close relationships between the distribution of the degree of substitution fk>, physical properties of cellulose derivatives (CD) we are presently approaching the goal to design the particular molecular structure of CD required for a desired physical property (for example, anti-coagulant activity or solvent absorbing power). 

In 1954 Forster and Kasper reported that in some cases the emission of light following excitation of a molecule can be attributed to fluorescence from a dimer rather than from the individual molecule that initially absorbed the radiation the emitting moiety was termed an excimer , and the determination of the relationship between its structure and emitting properties was a matter of considerable interest (Chandra et al. 1958 Murrell and Tanaka 1964 Smith et al. 1966). 

Connecting the properties on the macro level and the properties on the micro level is also achieved. The focus of the first two modules in HAVO is specifically aimed at this aspect. In unbreakable mugs students learn about the relationship between properties on the macro level (breaking) and the micro/meso scale (meso structure of clay particles). In the second structure in which polymers used to absorb water in diapers is discussed, students learn about the molecular structure of the polymers. 

Assumptions and provide simple geometry and light intensity relationships. Assumption permits neglect of the UV absorber contribution to the system volume and film specific volume. Assumption eliminates the conq>lication of conversion-dependent optical properties. Assumptions , and lead to mathematically simple relations between integrated light flux and polymer structure alteration. We further state that I is the light intensity in the upper film (or topcoat) surface and that... 

Fitch, W.L., McGregor, M Katritzky, A.R., Lomaka, A., Petrukhin, R. and Karelson, M. (2002) Prediction of ultraviolet spectral absorbance using quantitative structure-property relationships. 

Unlike other physicochemical molecular properties affecting environmental behavior, there are no useful guidelines or even empirical relationships for prediction of. Subtle changes In molecular structure, as will be demonstrated In this study, alter the efficiency of competing photochemical and photophysical processes. For most molecules quantum yields are less than 0.01 indicating that the vast majority of electromagnetic energy absorbed does not affect a chemical reaction of the substrate. 

Chatterjee, P. K., Nguyen, H. V., 1985, Mechanism of Liquid Flow and Structure Property Relationships. In Absorbency (P. K. Chatteijee, ed.), Elsevier, Amsterdam, 34. 

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