development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

the theory of contact mechanics deals with stresses and deformations which arise when the surfaces of two solid bodies are brought into contact. in elastic deformation contact occurs over a finite area. a regular method for determining the dimensions of this area is hertz contact model. appearance of atomic force microscope results in introduction of contact mechanics into biology. low elastici...

this research develops thermo-elastic analysis of a functionally graded cylinder under thermo-mechanical loadings. heat conduction equation in cylindrical coordinate system is solved. thermal conductivity coefficient is graded along the radial direction. by considering a symmetric distribution of temperature, loading and boundary conditions, strain-displacement and stress-strain relations can b...

We fabricate freely suspended nanosheets of molybdenum disulphide (MoS2) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS2 using an atomic force microscope. The Young's modulus and the initial pre-tension of the nanosheets are determined by performing a nanoscopic vers...

The weakness of existing relationships correlating off-axis modulus of elasticity E� to shear mod­ ulus G12 for wood composite panels is demonstrated through presentation of extensive experimental data. A new relationship is proposed that performs better than existing equations found in the literature. This relationship can be manipulated to calculate the shear modulus G12 of orthotropic specim...

Coiled carbon nanotubes were produced catalytically by thermal decomposition of hydrocarbon gas. After deposition on a silicon substrate, the three-dimensional structure of the helix-shaped multiwalled nanotubes can be visualized with atomic force microscopy. Helical structures of both chiralities are present in the nanotube deposits. For larger coil diameters ( >170 nm), force modulation micro...

The purpose of the present work is to analyze the modulus of elasticity of graphene (Gr) sheet-reinforced metal matrix nanocomposites (MMNCs) using a homogenized model based on the Mori-Tanaka micromechanics approach. The main focus is to investigate the effects of Gr sheet agglomeration on the MMNC macroscopic elastic modulus. Also, the role of aligning Gr sheets in the mechanical performance ...