The effect of mechanical deformation on the movement of water in foods.
This study has shown the importance of relating NMR spectroscopic information on the water in model food structures to the mechanical properties of those structures. Analysis of the NMR relaxation data can be used to examine the distribution of water domain sizes, and this has been related to the mechanical properties of the samples. A novel NMR probe-head has been designed, which allows both the NMR and the mechanical data to be simultaneously measured during compression of the sample. This probe-head allows compressive stress/strain data to be obtained directly from the NMR sample, allowing changes in the distribution of the water to be directly correlated to changes in mechanical properties.
FEM-based simulation of the mechanical behavior of grapefruit under compressive loading
Abstract Bruising in fresh crops is a major challenge of the horticulture industry, which can cause quality degradation and losses throughout the pre-harvest to the post-harvest stages. A visual understanding and/or detailed description of the mechanical behavior of fruits under different loading scenarios using analytical and physical experiments are complicated topics. This is particularly more complicated in fruits with a thicker peel. Vulnerability of grapefruits to mechanical damage under an external compression force was predicted in this study using the finite element method. The simulation results showed that the internal texture reach the yield point at 9.55 and 13.7 mm of longitudinal and transverse displacements, respectively, although the peel showed no sign of damage under these displacement values. However, according to the experimental data, the samples needed 29.47 and 36.55 mm displacements at the both longitudinal and transverse directions before reaching the complete yield and failure limits. Based on Newton’s second law, a total of 25 and 31 grapefruits in the longitudinal and transverse directions were needed to create the forces (60 and 75 N) required for developing the yield displacements in the fruit pulp. Finite element results showed that the method is capable of contributing to the prediction and knowledge of internal mechanical damages of grapefruits and equally other horticultural products.
Experimental Study on Acoustic Agglomeration of Fine Particles from Coal Combustion
The removal of fine particles in coal-fired fumes was experimentally studied based on acoustic agglomeration. An experiment facility was designed and set up. In this facility, a fluidized bed coal combustor was used as fume generator, and an Electrical Low Pressure Impact or (ELPI) was used to measure the fine particle concentration and size distribution in the fumes. The results show that under the effect of high intensity sound waves, there is good performance to remove fine particles in coal-fired fumes, which with a number mean diameter of 0.07μm. Especially, under the conditions of the frequency of 1 000Hz and the sound intensity of 161.5dB, the number concentration of 0.0233~9.314μm particles decreased by 85.2%, and their mass concentration decreased by 92.5%.