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There are instances in which it is desirable to determine relationships among fruit physical attributes. For example, fruits are often graded on the basis of size and projected area, but it may be more suitable and/or economical to develop a machine which grades by mass. Therefore, a relationship between mass and dimensions or projected areas and/ or volume of fruits is needed. Various grading systems, size fruits on the basis of specific parameters. Sizing parameter depends on fruit and machine characteristics.Models for predicting mass of orange from its dimensions and projected areas were identified. Models were divided into three classifications: 1- Single and multiple variable regression of orange dimensions (1st classification). 2- Single and multiple variable regression of projected areas (2nd classification). 3- Estimation of orange shape; ellipsoid or spheroid based on volume (3rd classification). Ten Iranian varieties of oranges were selected for the study. 3rd classification models had the highest performance followed by 2nd and 1st classifications respectively, with R2close to unity. The 2nd classification models need electronic systems with cameras for projection whereas, 1st classification models are used in the simple mechanical systems, except multiple variable ones, of and 3rd classification models need more complex mechanical systems. Among the systems that sorted oranges based on one dimension (Model 2), system that applies intermediate diameter suited better with nonlinear relationship as: M = 0.07b2 – 2.95 b + 39.15 with R2= 0.97.

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A non-linear finite element model could be a useful tool in the development of a method of predicting soil pressure-sinkage behaviour, and can be used to investigate and analyze soil compaction. This study was undertaken to emphasize that the finite element method (FEM) is a proper technique to model soil pressure-sinkage behaviour. For this purpose, the finite element method was used to model soil pressure-sinkage behaviour and a two-dimensional finite element program was developed to perform the required numerical calculations. This program was written in FORTRAN. The soil material was considered as an elastoplastic material and the Mohr-Coulomb elastoplastic material model was adopted with the flow rule of associated plasticity. In order to deal with material non-linearity, incremental method was adopted to gradually load the soil and a total Lagran-gian formulation was used to allow for the geometric non-linear behaviour in this study. The FEM model was verified against previously developed models for one circular footing problem and one strip footing problem and the finite element program was used to pre-dict the pressure-sinkage behaviour of the footing surfaces. Statistical analysis of the veri-fication confirmed the validity of the finite element model and demonstrated the potential use of the FEM in predicting soil pressure-sinkage behaviour. However, experimental verification of the model is necessary before the method can be recommended for exten-sive use.