The research was conducted in order to determine the BENDING stress, Young's modulus, shearing stress, and shearing energy of safflower stalk as a function of moisture content and stalk region. The BENDING forces were measured at different moisture contents and the BENDING stress and the Young's modulus were calculated from these data. For measuring the shear forces, the stalk specimens were severed by using a computer aided cutting apparatus. The shear energy was calculated by using the area under the shear force versus displacement curve. The experiments were conducted at four moisture contents (8.61, 16.37, 25.26, and 37.16% wb) and at three stalk regions (bottom, middle, and top). Based on the results obtained, the BENDING stress decreased as the moisture content increased. The value of the BENDING stress obtained at the lowest moisture content was approximately 2 times higher than that of the highest moisture content. BENDING stress values also decreased from top to the bottom of stalks. The average BENDING stress value varied from 21.98 to 59.19 MPa. The Young's modulus in BENDING also decreased as the moisture content and diameter of stalks increased. The average Young's modulus varied between 0.86 and 3.33 GPa. The shear stress and the shear energy increased with increasing moisture content. Values of the shear stress and energy also increased from top to the bottom of stalks due to the structural heterogeneity. The maximum shear stress and shear energy were found to be 11.04 MPa and 938.33 mJ, respectively, both occurring at the bottom region with the moisture content of 37.16%.

Todays, hydrogels have attracted many researchers due to individual response to exterior stimuli. According to the environmental stimuli, these materials absorb a huge amount of water and swell. Due to the vast application of the functionally graded pH sensitive hydrogels, investigation of their mechanical behavior during changing of pH is very important. In this regard, the energy density is decomposed additively to energy of the network stretching, energy of mixing and energy of dissociation. Considering the variation of PROPERTIES along thickness, the semi analytical solution is presented under plane strain condition. Verifying the accuracy of presented method, the result of this method is compared with the finite element method including radius, radial and tangential stresses, BENDING curvature and BENDING semi angle between pH = 2 to 8. In addition, the continuity of stresses and deformation is one of the benefits of using functionally graded hydrogel instead of multi layer ones.

Sandwich structures are widely used in aerospace, high speed trains and marine applications because of lightweight and high in-plane and flexural stiffness.Sandwich structures consist of two thin face sheets and a core. Face sheets usually are made from highly stiff and highly strong materials; In general, the face sheets may be of different metal or composite layers. Both metal and composite face sheets have advantages and disadvantages, and searching for new materials with better PROPERTIES is in progress. In this paper flexural behavior of a new generation sandwich beams with fiber metal laminate (FML) face sheets were investigated experimentally.Three groups of specimens with different layer arrangements of face sheets consist of (Al/GE (0-90) /GE (90-0) /Al), (Al/GE (0-90) /Al/GE (90-0)) and (GE (0-90-0-90-90-0- 90-0)) and 40 kg/m3 polyurethane foam core were made and tested. The results show that sandwich beams with FML face sheets have better resistance against local loads, while composite faces are weak against intense loads. Also, FML faces are lighter than metal face sheets and have better connection to foam core. Also, a simple classical theory was used to predict the force-deflection behaviour of sandwich beams in elastic region. Good agreement between the experimental results and analytical prediction were obtained. Sandwich beams with FML face sheets have larger elastic region than beams with composite face sheets therefore agreement between the analytical and experimental results in these specimens are in larger area.

In this research work, the effects of natural fibers such as date palm fiber (DF) and jute fiber (JF) on BENDING PROPERTIES of polypropylene (PP) / ethylene-propylene-diene-monomer (EPDM) thermoplastic elastomers are investigated. For this purpose, the date palm and jute fibers at five levels of fiber weight fractions (0, 5, 10, 20 and 30 wt. %) are utilized during composite fabrication. Maleic anhydride grafted to polypropylene (MAPP) is used as coupling agent to increase the interfacial adhesion between the polymer and the fibers.Results show that by adding fiber to the matrix, the BENDING PROPERTIES are increased, but elongation at break is decreased.

The purpose of this paper is to investigate mechanical PROPERTIES of Nanocomposite materials reinforced with carbon nano tubes (CNTs). This study considers the mechanical PROPERTIES by three point BENDING test. The technique which is used in this study is one of the methods to calculate fracture toughness value. The specimens with four different mass percentages of carbon nano tubes were made. The mass percentages are 0%, 0. 01%, 0. 05%, 0. 1%, 0. 2% and 0. 3%. An ultrasonic device was used to disperse the CNTs uniformly in the epoxy matrix. So, the agglomeration of the CNT particles decreased in the matrix. In order to investigate the fracture toughness, same size cracks were created in two different directions on the specimens including low CNTs content grade and high CNTs content grade. Three point BENDING test was repeated at least three times for each of specimens. For each crack, there are different values of the fracture toughness and the fracture forces. Furthermore, the fracture surfaces of samples were investigated using scanning electron microscopy (SEM). The results showed that the direction of the crack, CNTs content and dispersion of the carbon nano tubes are important parameters. Also, flexural elasticity modulus that is different from tensile elasticity modulus was considered in this research.

Grain discoloration (caused by fungal agents) is a complex disease and in the crop seasons when mature grain stage coincides with successive rain falls, it spreads and causes many damages. In this research the effects of paddy discoloration in three varieties (Hashemi, Gohar and Khazar) as well as disease index (high vs. low disease index levels) on grain apparent quality, milling PROPERTIES and grain BENDING strength were investigated. The experiment was conducted in a factorial layout based on a randomized complete design of three replications. The milling recovery, degree of whitening, BENDING strength, length and thickness of the grains (brown rice) in the case of high disease index were lower than those in low disease index. Also it was shown that the broken grains in the three varieties of Hashemi, Gohar and Khazar (in high disease index) increased by 5.33, 1.53 and 2.52% as compared with those of low disease index. Therefore it becomes evident that grain discoloration reduces the BENDING strength and grain size resulting in lower milling recovery, head rice yield degree of whitening of rice.

In this study, the strain rate effect on the BENDING PROPERTIES of fiber reinforced composites for three types of polymer composites namely phenolic resin reinforced by woven basalt fibers, woven carbon fibers, and woven basalt/ woven carbon fibers at a total volume fraction of approximately 35% has been determined. Flexural tests have been conducted at low range of strain rates included 0.03 min-1, 0.06 min-1 and 0.09 min-1. Specimens with identical geometry have been used in all the tests. Experimental results showed that the strain rate has a significant effect on the material response in BENDING. Results showed that, both the flexural modulus and the ultimate flexural strength of the three types of composites are increased with the increasing in the strain rate. Also, the BENDING PROPERTIES of composites reinforced with woven carbon fibers are very sensitive to the strain rate during the test.

Sluggish Cognitive Tempo is used to describe a particular type of attention deficit, concentration, and slowness in information processing. The aim of this study was to investigate the psychometric PROPERTIES of the Sluggish Cognitive Tempo Scale (SCTS) of the parent form among Iranian children. The present study is a descriptive study. A sample of 1700 people was selected from the provinces of Tehran, East Azerbaijan, West Azerbaijan, Kurdistan, Fars and Khorasan using cluster sampling method. 122 subjects were excluded from statistical analysis due to incomplete answers to the questionnaires and thus the final sample was reduced to 1578 parents. The confirmatory factor analysis method and internal consistency were used to compute the Sluggish Cognitive Tempo Scale factorial validity and reliability, respectively. Also, in order to examine the construct validity of the Sluggish Cognitive Tempo Scale, we computed correlations between different dimensions of Sluggish Cognitive Tempo Scale with Attention Deficit Subscale of Mental Health Assessment Questionnaire for Children and Adolescents. The results of statistical results showed that this scale has structural validity, criterion and convergence in Iranian society. The results indicate that the scale is three factors and also the validity of the scale using Cronbach's alpha method and retest test after Approved two weeks. According to the findings of the present study, the parent form of the Sluggish Cognitive Tempo Scale (SCTS) has a good validity and reliability and it can be used in research related to slow cognitive multiplication in Iranian society.

In this study, the effect of nano-wollastonite addition on strength and fire resistance characteristics of wood flour/polypropylene composite was investigated. The composites samples were manufactured using a dry blend/hot press method. In this study, beech dried wood flour was used as the filler for poly propylene as the matrix. Composite sample were prepared using 60% polypropylene, 37% wood flour and 3% polypropylene grafted with maleic anhydride as the coupling agent. Nano-wollastonite was used in four levels ( 0, 1, 3 and 5% based on dried wood flour). Nominal density and dimensions of the composites were one g/cm3 and 1*20*25 cm, respectively. BENDING strength was measured according to ASTM standard test methods and fire resistance characteristics including flammability, duration of flame and glow after removing the burner, and mass reduction were measured according to ISO 11925. Results indicated that by increasing the nano-wollastonite the BENDING strength, MOE and flammability increased but mass reduction, duration of flame and glow decreased. The dispersion of nano-wollastonite in composites was evaluated by Filed Emission Scanning Electron Microscopy (FE-SEM).

Metal orthopedic plaques can cause problems such as osteoporosis in the area under the plaque, the release of unwanted corrosion products in the body due to the wear of metal plaque and as a result of infection, as well as surgery to remove the hard metal plaque. Therefore, polymer plaques and composite plaques can be a good substitute for metal plaques. In the current research, the effect of polymeric material type on the mechanical PROPERTIES of two bone stabilizing plaques, one flat and the other curved, both with a row of holes and high clinical application, is investigated using the three-point BENDING test. For this purpose, samples were made of ABS, PLA and PETG using additive manufacturing method of 3D printing and FDM melt deposition method. The test results showed that the highest strength and flexural modulus for both models of orthopedic plaque samples is related to PLA material. For the flat plaque, the BENDING strength and BENDING modulus of PLA compared to PETG are 58% and 100% higher, respectively. For the curved plaque, the BENDING strength and BENDING modulus of PLA compared to PETG are 49% and 100% higher, respectively. It was also seen that although the strength and flexural modulus depend on the dimensions and geometry of the models, but the ratio of changes in these PROPERTIES, especially the flexural modulus, is almost constant.