We present a mathematical analysis of the speciation model for food-web structure, which had in previous work been shown to yield a good description of empirical data of food-web topology. The degree distributions of the network are derived. The properties of the speciation model are compared to those of other models that successfully describe empirical data. It is argued that the speciation mo...

We present a mathematical analysis of the speciation model for food-web structure, which had in previous work been shown to yield a good description of empirical data of food-web topology. The degree distributions of the network are derived. Properties of the speciation model are compared to those of other models that successfully describe empirical data. It is argued that the speciation model ...

The objective of this article is to review the spectrum of mathematical models that have been developed to describe drug release from hydroxypropyl methylcellulose (HPMC)-based pharmaceutical devices. The major advantages of these models are: (i) the elucidation of the underlying mass transport mechanisms; and (ii) the possibility to predict the effect of the device design parameters (e.g., sha...

In recent years, mechanistic-empirical (M-E) design methods are preferred in the of flexible pavements instead empirical using equations based on road performance tests. However, calibration transfer that convert mechanical responses to pavement life and definition layer materials used M-E have great importance for methods. this study, analyzes a cross-section designed with AASHTO-93 method wer...

Flexible pavement structure design is a complex task because of the variability input parameters and failure mechanisms. Therefore, aim this study to develop implement simplified Mechanistic-Empirical (M-E) method based on 1993 American Association State Highway Transportation Officials (AASHTO), National Cooperative Research Program (NCHRP) 9-22, NCHRP 1-37A 1-40D projects. This methodology im...

The establishment of research protocol for horticultural substrates must include the measurements of physical and hydraulic properties. Both empirical and mechanistic approaches must be utilized in protocol development. The steps in establishing a protocol should be: 1) the development of standard definitions for properties and terms, 2) development of a mechanistic framework based on modeling,...