Effect of moisture on the physical properties of three varieties of kenaf seeds

Abstract

The physical properties of three kenaf varieties were evaluated as a function of moisture contents varying from 7.67 to 26.21, 7.35 to 25.96 and 7.27 to 25.53 % (dry basis) for cv. Everglades, Tainung and SF-459, respectively. The results showed that the increase in the moisture content of the kenaf seeds linearly decreased the bulk density, true density and rupture force, whereas it linearly increased the length, width, thickness, arithmetic mean diameter, geometric mean diameter, sphericity, surface area, seed volume, thousand seed mass, porosity, angle of repose and terminal velocity. Among the three varieties, maximum values for most selected physical properties of kenaf seeds were obtained for the Everglades seeds. At all moisture contents, the highest static coefficient of friction was found on the plywood surface followed by rubber, then galvanized iron, aluminum, glass and finally stainless steel. This study was conducted to investigate some moisturedependent physical properties of kenaf seeds. These physical properties are necessary for the design of equipments for harvesting, processing, transportation, sorting, separating and packing.

Determining and modeling the physical, thermal and aerodynamic properties of Pinto beans with different water contents

“…It is shown in Table 6 that the linear model, adjusted itself properly to the data of the experimental terminal speed, with a good determination coefficient (R²), and low relative average error (P), below 10%, the same tendency was found by other authors working with other grains, such as the ones observed by Ahmadi and Siahsar (2011) and Izli (2015).…”

“…According to Table 1, a decrease of 8.49, 10.39 and 6.49% for axis length (a axis), width (b axis) and density (c axis) can be observed for beans grains, respectively, in relation to its initial dimensions, with water content reduction of 32.89 up to 13.62 (%d.b.). This way, it can be verified that beans grains presented disuniform variations in the various axes, as verified in other studies (Siqueira et al, 2012b;Oliveira et al, 2014;Ren et al, 2014;Izli, 2015). From the determination of these variants of the product with water content reduction, the work performed by drier devisors is optimized, and it is feasible for them to enhance the drying system, taking into account factors such as air flow direction, product movement into drier, among other parameters and related processes (Araujo et al, 2015).…”

Chemistry, phytotechnology, pharmacology and nutraceutical functions of kenaf ( Hibiscus cannabinus L.) and roselle ( Hibiscus sabdariffa L.) seed oil: An overview

“…The results also showed negative correlation of the true density and bulk density with moisture content. Moisture content of the kenaf seeds was negatively associated with bulk density, true density and rupture force, while it linearly increased the length, width, thickness, arithmetic mean diameter, geometric mean diameter, sphericity, surface area, seed volume, thousand seed mass, porosity, angle of repose and terminal velocity (Izli, 2015). The static coefficient of friction, filling and emptying angle of repose of kenaf seed increased linearly against the various surfaces like stainless steel, aluminum and glass in the same moisture range.…”

The Impact of Moisture and Number of Contact Points on the Process of Friction in Plant Granular Materials

“…In order to correctly design technical means to process, transport, and store these materials, it is necessary to understand their physical properties [7][8][9]. One of the most relevant physical properties of these materials which impacts the course of these technical processes is the external friction of the materials [10][11][12][13][14]. External friction in these types of materials means the friction which occurs between the construction material and the granular material [4].…”

“…The main factor which has been studied up to this point has been the water content of the materials. The impact of moisture on the value of the force of friction in plant granular materials has been studied by numerous researchers [10][11][12][13][16][17][18][19][20]. All of these studies have indicated an increase in static and kinetic friction along with an increase in moisture for plant granular materials.…”