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Different Empirical Models (different + empirical_models)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	50%

Selected Abstracts

Empirical Modeling of Butyl Acrylate/Vinyl Acetate/Acrylic Acid Emulsion-Based Pressure-Sensitive Adhesives

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 5 2004
Renata Jovanovic
Abstract Summary: Butyl acrylate/vinyl acetate/acrylic acid (BA/VAc/AA) emulsion latexes were produced in a semi-batch mode. The objective was to generate polymers with properties favoring their application as pressure-sensitive adhesives. The influence of the individual monomer concentrations on final properties such as glass transition temperature (Tg), peel strength, shear strength and tack was investigated. To obtain the maximum amount of information in a reasonable number of runs, a constrained three-component mixture design was used to define the experimental conditions. Latexes were coated onto a polyethylene terephthalate carrier and dried. Different empirical models (e.g. linear, quadratic and cubic mixture models) governing the individual properties (i.e. Tg, peel adhesion, shear resistance and tack) were developed and evaluated. In the given experimental region, no single model was found to fit all of the responses (i.e. the final properties). However, in all models the most significant factor affecting the final properties was the AA concentration, followed by the VAc concentration. Shear strength contour lines over the investigated region. [source]

DEHYDRATION CHARACTERISTICS OF PAPAYA (CARICA PUBENSCENS): DETERMINATION OF EQUILIBRIUM MOISTURE CONTENT AND DIFFUSION COEFFICIENT

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2009
R. LEMUS-MONDACA
ABSTRACT This study determined the drying kinetics behavior of papaya at different temperatures (40, 50, 60, 70 and 80C). Desorption isotherms were determined at 5, 20 and 50C over a relative humidity range of 10,95%. The Guggenheim, Anderson and de Boer models were found to be suitable for description of the sorption data. The samples reached equilibrium moisture of 0.10 ± 0.01 g water/g dry matter. Fick's second law model was used to calculate the effective diffusivity (6.25,24.32 × 10 - 10 m2/s). In addition, experimental data were fitted by means of seven mathematical models. The kinetic parameters and the diffusion coefficient were temperature-dependent and were evaluated by an Arrhenius-type equation. The modified Page model obtained the best-fit quality on experimental data according to statistical tests applied. PRACTICAL APPLICATIONS The main utility of this study is the application of both different empirical models and the diffusional model in tropical fruits' dehydration, which can be considered a basis for a very accurate estimation of drying time and the optimization of the same process. Two newly mathematical models are proposed in this study, through which a good fit on the data of experimental moisture content was achieved. The study of drying of papaya cultivated in Chile engages a great technological interest, because this product is widely used in the development of different products such as candying, canning, juice, syrup and marmalade. In addition, papayas cultivated in Chile, along with other tropical fruits cultivated in Brazil, Colombia and the Caribbean, have become especially important in the exportations of these countries. The major markets for these products include the U.S.A., the European Community and Asia. [source]

An Empirical Analysis of Strike Durations in Ghana from 1980 to 2004

LABOUR, Issue 3 2009
Anthony Y. Baah
The empirical approach uses a set of well-known parametric accelerated failure time strike duration models. There is a broad consensus among the different empirical models about the role exerted on average strike duration by strike size, the rate of inflation, enterprise ownership, and political governance. However, evidence on the relationship between strike durations and business cycle activity in Ghana is less clear-cut. [source]

Fiscal Coordination and Financial Dependence of State Governments in Mexico

PUBLIC BUDGETING AND FINANCE, Issue 3 2010
JORGE IBARRA-SALAZAR
This paper presents evidence of the effects on subnational financial dependence of the intergovernmental fiscal agreement implemented in 1980. In contrast with a previous study that uses annual time series national data, we use a panel of annual time series (1975,1995) of 31 Mexican states. We propose and estimate three different empirical models using the fixed effects panel data approach. In concordance with previous literature, we find strong statistical evidence that the implementation of the agreement increased financial dependence. The main contribution of this paper is to distinguish the effect of the 1980 fiscal arrangement on every state's degree of financial dependence. [source]