Friction Coefficient Calibration of Sunflower Seeds for Discrete Element Modeling Simulation

Sunflower(Helianthus annuus L.)is one of the four major oil crops in the world and has high economic value.However,the lack of discrete element method(DEM)models and parameters for sunflower seeds hinders the application of DEM for computer simulation in the key working processes of sunflower seed sowing and harvesting.The present study was conducted on two varieties of sunflower,and the DEM model of sunflower seeds was established by using 3D scanning technology based on the distribution of triaxial dimensions and volumes of the geometric model of sunflower seeds.Similarly,the physical characteristics parameters of sunflower seeds were determined by physical tests and the simulation parameters were screened for significance based on the Plackett-Burman test.Our results show that the coefficient of static friction between sunflower seeds and the coefficient of rolling friction have significant effects on the repose angle of the simulation test.Furthermore,the optimal range of the significance parameters was further determined by the steepest climb test,and the second-order regression model of the significance parameters and the repose angle was obtained according to the Box-Behnken design test and Response Surface Methodology(RSM),with the repose angle measured by the physical test as the optimized target value to obtain the optimal parameter combination.Finally,a two-sample t-test for the repose angle of the physical test and the repose angle of the simulation test yielded P>0.05.Our results confirms that the repose angle obtained from simulation is not significantly different from the physical test value,and the relative errors between the repose angle of the simulation test and the physical test are 1.43%and 0.40%,respectively,for the optimal combination of parameters.Based on these results it can be concluded that the optimal parameters obtained from the calibration can be used for DEM simulation experiments related to the sunflower seed sowing and harvesting process.

Profiling and geographical distribution of seed oil content of sunflower in Ukraine

The sunflower has the potential to be a highly competitive crop owing to its diversity market and the valuable oil it produces.Nevertheless,the amount of sunflower seed oil-a key factor for the crushing industry-is affected by genotype and environment,which sometimes is difficult to predict.The paper analyzes the theoretical principles of sunflower growth in Ukraine,highlights the current trends in the sowing of this crop,the influence of climatic factors of the environment on the prospects of the oilseed sunflower yield.The results of the research are presented for 3 years(2014-2016),during the authors conducted a grain quality observatory at the regional level,taking into account the climatic conditions of sunflower growth in different natural zones of Ukraine(from 45
to 51
north latitude and from 22
to 37
east longitude).Additionally,the research includes the coefficient of significance of the deviation from long-term climatic indicators,which makes it possible to forecast sunflower yield in the future.The analyzed data was obtained from the commercial fields with a minimum area of 40 ha in all Ukrainian regions except Crimea peninsula,Donetsk and Luhansk regions.The results obtained in research show the great diversity of oil content index as per both latitude and longitude meaning.If we consider the entire country,this survey shows that the seed oil content can change dramatically from year to year:e.g.47.5%in one year versus 45.7%in another year.Regionally,these changes have a completely different dynamic with a gradual decrease in seed oil content in the southern part of the country.The main goal of the research was to identify the best sunflower growing areas in Ukraine according to the oil content index.

Mechanical Properties of Sunflower Seed and Its Kernel, Azargol Variety as a Case Study, under Compressive Loading

The objective of this study was to investigate the effect of moisture content, size and loading orientation on mechanical properties such as force, deformation and energy absorbed per unit volume for fracturing Iranian sunflower seed and its kernel （Azargol as a case study） under quasi-static loading. Sunflower seeds and their kernels were quasi-statically loaded in horizontal and vertical orientations with moisture content in three levels： 3%, 7% and 14%, and size category in three levels： small, medium and large. The obtained results showed that rupture force for both sunflower seed and its kernel decreased with increasing moisture content while the absorbed energy and deformation at rupture point increased for all size categories in both horizontal and vertical loading orientations. Also, seeds in the vertical orientation developed hull cracks at a higher level of force than those loaded in the horizontal orientation. However, for the kernels it was the opposite. In addition, the average forces required to cause kernel rupture were lower （11.64-39.9 N） than those required to rupture the seed （30.06-117.46 N） in both orientations. Seeds loaded in a vertical orientation absorbed more energy （87.67 mJ） prior to rupture than those loaded in the horizontal （46.60 mJ） orientation. However, for the kernels it was the opposite.

Use of Sunflower Cake in the Diet of ISA Brown Pullets

Recently, feed ingredient prices and availability concerns have resulted in the examination of diet formulations using alternative, locally available, high protein feed ingredients. An experiment was carried out to evaluate sunflower cake （SC） dietary effect on the performance of ISA brown pullets. The duration of the experiment was 20 weeks. A total of 48 one-day-old pullets were randomly allocated in three groups （C, SC6.25 and SC12.5） with four replications. The pullets of the control group （C） were given proper full rations without sunflower cake for the 1 st, 2nd and 3rd rearing ages, whereas in the treatment groups 5C6.25 sunflower cake was added at 6.25% of rations and in group SC12.5 at 12.5% of rations. The pullets were housed in floor pens with litter and were offered feed and water ad libitum. According to the results of statistical analysis, the addition of 6.25% sunflower cake in the diet significantly （P 〈 0.05） affected body weight gain and feed conversion ratio. The results of this study showed that sunflower cake can be added to the ration of ISA brown pullets of 0-20 weeks of age up to 12.5% without any adverse effect on their performance.

Some Engineering Properties of Sunflower Seed and Its Kernel

Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small）. With increase of moisture content from 3 to 14% d.b., all the main dimensions （length, width and thickness）, geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher （47.1-94.72 N） than those required to rupture the kernel （8.5-13.4 N） in both orientations.

Frictional Behavior of Sunflower Seed and its Kernel as a Function of Moisture Content, Variety and Size

The object of this study was to investigate the frictional properties （repose angles and friction coefficient） of Iranian sunflower seed and its kernel （Fandoghi, Azargol and Shahroodi） as a function of moisture content, size and variety. The static coefficient of friction were determined on five structural surfaces including aluminium, plywood, galvanized iron, polyethylene and rubber when moisture content varied between 3 and 14 % d.b. The obtained results showed that static coefficient of friction on five studied surfaces increase linearly as moisture content increase from 3 to 14% for both seed and kernel. Among the applied surfaces, rubber showed the highest value of friction coefficient for both sunflower seed and kernel followed by plywood, polyethylene, galvanized iron and aluminium. The obtained values of emptying and filling angles of repose increase linearly with an increase in moisture content. Furthermore, the values of empting and filling angles of repose for small sizes were higher than big sizes in all levels of moisture content for both seed and kernel. Also, the emptying angle of repose assumed higher values than the filling angle of repose for all varieties and categories.

Multiparameter collaborative optimization of the vibrating screen based on the behavior of oil sunflower seed penetrating screen holes

The behavior of oil sunflower seeds penetrating screen holes is an important factor that affects the screening performance of oil sunflower seeds.In this study,a double-deck reverse-motion vibrating screening device for oil sunflower seed screening was designed.The force condition and motion law of the oil sunflower seeds on the screen surface were analyzed.This study compared the effect of particle filling amount of discrete element model of oil sunflower seeds on the simulation effects.The screening process was numerically simulated using the coupled Discrete Element Method and Multibody Dynamics(DEM-MBD)technique with the screening percentage of oil sunflower seeds as the index.The influence of the operating parameters of the vibrating screen on the screening effect was analyzed using a multiparameter collaborative optimization scheme.The results of this study can provide a reference for the numerical simulation of crop screening behavior and the development of screening devices.

The preparation,characterization, and catalytic performance of porous fibrous LaFeO3 perovskite made from a sunflower seed shell template

LaFe03 perovskite with a porous fibrous structure was successfully synthesized using a sunflower seed shell as a template.To investigate the effects of this template,a sample was prepared without a template via the same procedure.Through various characterization techniques,such as X-ray diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,N2 adsorption-desorption analysis,X-ray photoelectron spectroscopy,oxygen temperature programed desorption,and hydrogen temperature programed reduction,the physiochemical properties of the samples were investigated.The results showed that the sample made with a template had a larger surface area and a larger amount of adsorbed oxygen,which further illustrated that the sunflower seed shell template had a significant impact on the physiochemical properties of the samples.Furthermore,we explored the catalytic activity for nitric oxide(NO)oxidation,and studied the factors affecting it,which highlighted its potential application in automobile exhausts.