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Applying the reliability concept as a new and profitable design approach can optimize the design and manufacturing of tillage machines. In this study, the Monte Carlo method was used to perform reliability analysis on the whole chassis of a moldboard plow. For this, a complete model of a three-bottom moldboard plow was assumed as the limit mode function. Stochastic soil parameters were applied and the interaction forces of the plow with soil were simulated with finite element method (FEM). The desired output was the soil reaction forces on the plow at the most critical plowing speed and depth. Then, by applying the forces obtained from the FEM model and considering Young's modulus of the chassis as a random variable, chassis static analysis was performed in different iterations and the stress concentration at different locations was determined. The probability of failure (Pf) and reliability index (β) of different locations of chassis were calculated. The results of the Monte Carlo simulation showed that the highest Pf occurred in crossbars, standards, braces and, masts with the values of 1, 0.296, 0.165 and, 0.033, respectively, which indicates the uncertainty of the design in these parts and the needs to strengthen or optimize the aforementioned parts of the moldboard plow chassis. [ABSTRACT FROM AUTHOR]

The current study proposes a novel approach for assessing the effect of storage on potato tuber texture using biospeckle imaging. Agria potato tubers were subjected to biospeckle imaging using three low-power laser diodes and mechanical reference tests including uniaxial compression and creep tests for 6 months. The speckle activity indices of features such as inertia moment, absolute value of differences, autocorrelation function, and energy of wavelet transform were computed from the images. Mechanical and rheological properties were also measured using mechanical tests. An adaptive neuro-fuzzy inference system (ANFIS) coupled with the genetic algorithm was employed to develop models for predicting mechanical properties. The models for retarded compliance, maximum force, and retarded viscosity, with correlation coefficients of 0.812, 0.773, and 0.750, provided the best results. These findings can be used to non-invasively predict the mechanical properties of potatoes. The study demonstrates the potential of biospeckle imaging in assessing the texture of potato tubers during storage. [ABSTRACT FROM AUTHOR]

The aim of the present work was to assess the influence of high-intensity airborne ultrasound application on duration and energetic performance of hot air drying of peppermint leaves. To this end, drying experiments were conducted at constant air flow rate of 1 m s−1 and different temperatures (40, 50, 60 and 70 °C) without and with application of ultrasound power (90, 180, 270 and 360 W). The results showed that the maximum (170.84 MJ kg−1) and the minimum (63.36 MJ kg−1) specific energy consumptions belonged to convective drying at temperature of 40 °C and ultrasonic-assisted drying at 60 °C and 270 W, respectively. Energy efficiency varied from 1.41 to 3.69%. Depending on the power level, application of the ultrasound power at the air temperatures less than 70 °C reduced drying time and improved energetic performance of the process. The obtained findings in this research declare that acoustic power could be effectively used in combination with convective dryers to reduce duration and energy required for drying of heat-sensitive products. • Ultrasound power ability to improve energy efficiency of drying process was studied. • Application of the power reduced the process duration of up to 41%. • At temperatures less than 70 °C, ultrasound power increased the energy efficiency. • The values of energy efficiency ranged from 1.41 to 3.69%. • The power has good ability to reduce the process duration and energy consumption. [ABSTRACT FROM AUTHOR]

The aim of the present work was to assess the influence of high-intensity airborne ultrasound application on duration and energetic performance of hot air drying of peppermint leaves. To this end, drying experiments were conducted at constant air flow rate of 1 m s−1 and different temperatures (40, 50, 60 and 70 °C) without and with application of ultrasound power (90, 180, 270 and 360 W). The results showed that the maximum (170.84 MJ kg−1) and the minimum (63.36 MJ kg−1) specific energy consumptions belonged to convective drying at temperature of 40 °C and ultrasonic-assisted drying at 60 °C and 270 W, respectively. Energy efficiency varied from 1.41 to 3.69%. Depending on the power level, application of the ultrasound power at the air temperatures less than 70 °C reduced drying time and improved energetic performance of the process. The obtained findings in this research declare that acoustic power could be effectively used in combination with convective dryers to reduce duration and energy required for drying of heat-sensitive products. • Ultrasound power ability to improve energy efficiency of drying process was studied. • Application of the power reduced the process duration of up to 41%. • At temperatures less than 70 °C, ultrasound power increased the energy efficiency. • The values of energy efficiency ranged from 1.41 to 3.69%. • The power has good ability to reduce the process duration and energy consumption. [ABSTRACT FROM AUTHOR]

This paper aims at presenting a comprehensive perusal on hot air and microwave drying of medicinal herbs through investigating the dehydration behaviour, mathematical modelling, energy characteristics and essential oil yield of peppermint leaves drying. For our study the leaves were dried using microwave at power levels of 200, 400, 600, and 800 W, and hot air at temperatures of 50, 60 and 70 °C. The dehydration process of the leaves in microwave drying method occurred in an accelerating rate period at the start followed by a falling rate period while; convective drying took place in the falling rate period entirely. Six mathematical models were fitted into the experimental data and the Midilli and Kucuk model best described the drying curves. The lowest effective moisture diffusivity (1.809×10 −9 m 2 s −1 ) belonged to hot air drying at 50 °C, while the highest (110.552×10 −9 m 2 s −1 ) belonged to microwave drying at 800 W. The activation energy for microwave and hot air drying was determined to be 1.89 W g −1 and 12.46 K J mol −1 , respectively. Specific energy consumption for microwave and convective drying of the peppermint leaves were ranged from 4.581 to 5.890 M J kg w −1 , and from 42.721 to 64.712 M J kg w −1 , respectively. The maximum and minimum oil yields were obtained from the leaves dried at air temperature of 70 °C and microwave power at 800 W, respectively. [ABSTRACT FROM AUTHOR]

An accurate understanding of moisture transfer parameters, including moisture diffusivity and moisture transfer coefficient, is essential for efficient mass transfer analysis and to design new dryers or improve existing drying equipments. The main objective of the present study was to carry out an experimental and theoretical investigation of mushroom slices drying and determine the mass transfer characteristics of the samples dried under different conditions. The mushroom slices with two thicknesses of 3 and 5 mm were dried at air temperatures of 40, 50 and 60 °C and air flow rates of 1 and 1.5 m s. The Dincer and Dost model was used to determine the moisture transfer parameters and predict the drying curves. It was observed that the entire drying process took place in the falling drying rate period. The obtained lag factor and Biot number indicated that the moisture transfer in the samples was controlled by both internal and external resistance. The effective moisture diffusivity and the moisture transfer coefficient increased with increasing air temperature, air flow rate and samples thickness and varied in the ranges of 6.5175 × 10 to 1.6726 × 10 m s and 2.7715 × 10 to 3.5512 × 10 m s, respectively. The validation of the Dincer and Dost model indicated a good capability of the model to describe the drying curves of the mushroom slices. [ABSTRACT FROM AUTHOR]

To design new dryers or improve existing drying equipments, accurate values of mass transfer parameters is of great importance. In this study, an experimental and theoretical investigation of drying whole lemons was carried out. The whole lemons were dried in a convective hot air dryer at different air temperatures (50, 60 and 75 °C) and a constant air velocity (1 m s). In theoretical consideration, three moisture transfer models including Dincer and Dost model, Bi- G correlation approach and conventional solution of Fick's second law of diffusion were used to determine moisture transfer parameters and predict dimensionless moisture content curves. The predicted results were then compared with the experimental data and the higher degree of prediction accuracy was achieved by the Dincer and Dost model. [ABSTRACT FROM AUTHOR]

Discrete element method (DEM) is a suitable technique for simulation of stress propagation in soils, particularly with freshly tilled or aggregated structures. Measurement of true stress, in the absence of a stress-measuring probe inserted in the soil, is not experimentally possible. Stress probes may therefore under- or over-estimate true soil stress. Building on previous work simulating vertical stress propagation under plate sinkage loading, the study modelled stress propagation under a moving rigid wheel. The aim was to determine how vertical stress, with and without a probe, at a given depth may differ under dynamic loading vs. static plate sinkage loading and with varying wheel speed. DEM parameters of the hysteretic spring-linear cohesion contact model were calibrated by a cone penetration test which was validated by wheel sinkage into the soil. Two tests were conducted in a soil bin at a water content of 11% d.b; at a bulk density of 1200 kg m−3 and a wheel loading of 600 N, and at a bulk density of 1350 kg m−3 and wheel loading of 1200 N. Vertical soil stress was measured at 0.15 m depth using a cylindrical load cell probe. The DEM simulation underestimated the measured stress by an average 13%. Average stress overestimation ratio (with/without probe stress) was found to be 1.12, which agreed with measurements beneath the plate during plate sinkage loading. Increasing wheel speed from 0.2 to 6 m s−1 showed a 7% increase in DEM-simulated with-probe stress. • Development of a DEM model of stress propagation in soil under wheel pass. • Development of a soil bin wheel tester for stress measurements under a rigid wheel. • Similar ratio of with-probe to without-probe stress under wheel and plate loading. • Minor impact of wheel speed (loading time) on simulated soil stress. [ABSTRACT FROM AUTHOR]

Highlights: [•] Apple bruising is an important issue. [•] Three methods were used to measure modulus of elasticity. [•] Apple handling is considered. [•] Hooke’s, Hertz’s and Boussinesq’s theories were addressed. [Copyright &y& Elsevier]

Pre-compression stress (σ pc ) has been widely used as a criterion for assessing the susceptibility of soil to compaction. Confined compression (CCT), semi-confined compression (SCCT) and plate sinkage (PST) tests are the most practical procedures to estimate σ pc . Discrepant estimates of σ pc may be obtained from the above tests mainly due to differences in boundary conditions. The aim of this study was to simulate these compaction tests using the finite element method (FEM) to compare σ pc estimated from stress-strain curves with the simulated yield stress. It was hypothesized that for a given simulated yield stress, σ pc estimated either at the point of maximum curvature or the point of Casagrande's method is not the same as simulated yield stress for different tests. FEM models were developed in ABAQUS with elastic-perfectly plastic law and Drucker-Prager yield criterion for the soil material. Yield stresses of 20, 50, 75, 100, 125, 150, 200 and 300 kPa were examined. The results showed that the stress at the point of maximum curvature was close to the simulated yield stress in CCT but smaller than that in SCCT and PST. Casagrande's method overestimated σ pc (averagely by 40%) for all the tests. A more precise estimate of σ pc was obtained at the point of maximum curvature than the Casagrande’s method in experimental CCT and PST on remolded soils. Cyclic loading-unloading CCT and PST to different stress levels showed that a safe threshold for preventing a severe plastic strain is significantly smaller (with a factor of 0.5 and 0.8 for CCT and PST, respectively) than σ pc in either of the tests. [ABSTRACT FROM AUTHOR]

Pre-compression stress (σ pc ) has been widely used as a criterion for assessing the susceptibility of soil to compaction. Confined compression (CCT), semi-confined compression (SCCT) and plate sinkage (PST) tests are the most practical procedures to estimate σ pc . Discrepant estimates of σ pc may be obtained from the above tests mainly due to differences in boundary conditions. The aim of this study was to simulate these compaction tests using the finite element method (FEM) to compare σ pc estimated from stress-strain curves with the simulated yield stress. It was hypothesized that for a given simulated yield stress, σ pc estimated either at the point of maximum curvature or the point of Casagrande's method is not the same as simulated yield stress for different tests. FEM models were developed in ABAQUS with elastic-perfectly plastic law and Drucker-Prager yield criterion for the soil material. Yield stresses of 20, 50, 75, 100, 125, 150, 200 and 300 kPa were examined. The results showed that the stress at the point of maximum curvature was close to the simulated yield stress in CCT but smaller than that in SCCT and PST. Casagrande's method overestimated σ pc (averagely by 40%) for all the tests. A more precise estimate of σ pc was obtained at the point of maximum curvature than the Casagrande’s method in experimental CCT and PST on remolded soils. Cyclic loading-unloading CCT and PST to different stress levels showed that a safe threshold for preventing a severe plastic strain is significantly smaller (with a factor of 0.5 and 0.8 for CCT and PST, respectively) than σ pc in either of the tests. [ABSTRACT FROM AUTHOR]

Influence of microwave power on dehydration kinetics as well as quantity, chemical composition and antioxidant potential of peppermint essential oil was evaluated. The leaves were dried using microwave powers of 200, 400 and 800 W, and the essential oils extracted by hydro-distillation. The antioxidant potential of the essential oils was quantified by DPPH radical-scavenging activity method. The obtained results showed that increasing microwave power caused significant decrement (p ≤ 0.01) in drying duration. Drying over the considered microwave powers reduced essential oil yield significantly (p ≤ 0.01). In total, 36 compounds were identified in the essential oils belonging mainly to oxygenated monoterpenes. The main constituents namely menthol, menthone and menthyl acetate showed significant variation (p ≤ 0.01 or p ≤ 0.05) with the drying process. Antioxidant assaying indicated significant effect (p ≤ 0.05) on radical scavenging activity of the essential oil by drying and essential oil concentration. Compared to the fresh samples (with an IC50 of 103 μg/ml), the leaves dried at microwave power levels of 200, 400 and 800 W resulted in significant lower antioxidant activities with IC50 values of 201, 291 and 615 μg/ml, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse input-output energy and economical assessment of almond production in three age groups of orchards (group I 6-10, group II 11-15 and group III 16-20 years old) in Chahrmahal-Va-Bakhtiari province, Iran. Data for almond production were collected by administering questionnaire in face-to-face interviews from the orchards selected based on random sampling method during a 3-year period. The results showed that 57,027.13, 60,341.14 and 61,640.43 MJ ha energy was consumed by group I, group II and group III, respectively. The most energy input was consumed by electricity, followed by chemical fertilizer. Energy indices were calculated, and the results revealed that energy efficiency was 0.62, 1.12 and 0.81 in the triple groups of orchards, respectively. Economical assessment showed that total production cost of almond in group I, II and III was $4547.54, $5799.26 and $5687.05 ha, respectively. In all orchard groups, the shares of variable and fixed production costs found to be same nearly. Net return for almond production was $14,516.22, $30,735.19 and $21,395.57ha, respectively. According to the research results, it was concluded that although almond production in the study region was not an efficient process in terms of energy consumption, it was a profitable agricultural operation. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine the energy consumption and evaluation of inputs for honey production in Shahrekord city in the Chaharmahal Va Bakhtiary province, Iran to investigate the efficiency of energy consumption and to make an economic analysis of honey production. Data used in this study were obtained from 80 beekeepers using a face to face questionnaire method. The sample bee keepings were selected through a stratified random sampling technique. The following results were obtained at the end of the study: with 54.43% the input of sugar is the highest within the energy equivalences of input used in honey production. This is followed by electricity and transportation with 14.02% and 13.84%, respectively. The total energy inputs, total energy outputs, input–output energy ratio and productivities were 28941.51 MJ hive −1 , 15264 MJ hive −1 , 0.54 and 0.04, respectively. The results indicated that all of the inputs affected the yield significantly, except electricity. The fuel (2815.5 MJ hive −1 ) and sugar (15292.2 MJ hive −1 ) were affected significantly with 0.547 and 0.459 coefficients, respectively. The input–output energy ratio shows that the inputs used in the production of honey are not used efficiently. Extension activities are needed to improve the efficiency of energy consumption in honey production and to employ environmentally friendly agricultural management practices and production methods. [ABSTRACT FROM AUTHOR]

In this study, the effect of drying temperature on drying behaviour and mass transfer parameters of lemon slices was investigated. The drying experiments were conducted in a laboratory air ventilated oven dryer at temperatures of 50, 60 and 75 °C. It was observed that the drying temperature affected the drying time and drying rate significantly. Drying rate curves revealed that the process at the temperature levels taken place in the falling rate period entirely. The usefulness of eight thin layer models to simulate the drying kinetics was evaluated and the Midilli and Kucuk model showed the best fit to experimental drying curves. The effective moisture diffusivity was determined on the basis of Fick's second law and obtained to be 1.62 × 10, 3.25 × 10 and 8.11 × 10 m s for the temperatures of 50, 60 and 75 °C, respectively. The activation energy and Arrhenius constant were calculated to be 60.08 kJ mol and 0.08511 m s, respectively. The average value of convective mass transfer coefficient for the drying temperatures of 50, 60 and 75 °C was calculated to be 5.71 × 10, 1.62 × 10 and 2.53 × 10 m s, respectively. [ABSTRACT FROM AUTHOR]

Stress propagation in soil under vehicular traffic can be simulated either analytically based on the laws of continuum mechanics or numerically using finite element (FEM) and discrete element methods (DEM). Soil stress measured by a stress probe may differ from the "true" stress (i.e. the stress without the probe), as probes under- or over-estimate soil stress. No instrument has yet been developed to enable true stress measurement, while simulated stress can only be validated by comparing with measured stress. Hence, it is important to model the interaction of soil with a load cell probe to understand the difference between "with probe" and "without probe" soil stress. This study aimed at modelling the interaction of a load cell stress probe and soil under circular surface loading (i.e. by plate sinkage test) using FEM and DEM to understand the differences of the two methods, and to address whether arable soil is a continuum or a discrete media with regard to stress propagation. Simulated stress was compared with experimental stress (i.e. the stress measured by the probe). Experimental stress measurements were made in a clay loam soil at a gravimetric water content of 11% (corresponding to 0.5 PL, the lower plastic limit) and bulk densities of 1000 and 1150 kg m−3 corresponding to loose to slightly compacted soil, respectively. The load cell probe was installed at 0.15 m depth within a soil column, and varying surface loads were applied by a circular plate. The measured stress as a function of applied load was compared with simulated stress using either FEM or DEM. Simulations underestimated the measured stress, with an RMSE of 22.8 kPa for DEM and 40.1 kPa for FEM. The difference in soil stress between simulations with and without a probe were small for DEM, but significant for FEM. For FEM simulations, embedding a stress probe into the soil resulted in an overestimation of the "true" stress by 94% for the soil and boundary conditions tested. For DEM, the average overestimation was only 11%. Differences between FEM and DEM simulations with and without a probe were discussed and attributed to the sponge effect in FEM, and to differences in stress distribution at the soil-loading plate interface caused by the arching effect. Simulations showed that increasing the ratio of probe housing diameter to sensing surface decreased the stress overestimation for both DEM and FEM methods. More research is needed to address how stress propagation and the stress readings by a sensor probe are influenced in continuum and granular media, and how soil stress should be best modelled (as a continuum or granular material) depending on soil properties and characteristics. • Comparison of stress propagation in FEM and DEM with measured stress. • Simulations using DEM resulted in higher soil stress than simulations using FEM. • DEM-simulated stress agreed better with measured stress than FEM-simulated stress. • Stress distribution below the loading plate was more acurate in FEM than DEM. • Stress overestimation is affected by the ratio of probe housing diameter to sensing diameter. [ABSTRACT FROM AUTHOR]

• Set up and parametrization of a DEM model of plate sinkage test in cohesive soils. • Particle yield strength was calibrated using confined compression test. • A strong correlation between particle yield strength and precompression stress. Discrete element method (DEM) has presented promising advantages in simulation of soil-machine/tool interaction. To develop reliable DEM simulations, selection and parametrization of a suitable contact model is crucial. The plate sinkage test is widely applied to characterize the soil behavior during compaction. This study aimed at setting up a DEM model for plate sinkage test using the hysteretic spring-linear cohesion contact model to (i) find the key parameters of the model which need to be calibrated and (ii) develop a calibration method for DEM parameters of the model for varying soil water content and bulk density of a cohesive soil. It was tested whether confined compression tests in combination with direct shear tests could be used to calibrate DEM parameters of the contact model. Soil cohesion and internal coefficient of friction were directly obtained and used from experimental direct shear test whereas particle yield strength was estimated by matching the stress-sinkage relationship of experimental and DEM-simulated confined compression tests. A clay loam soil at two water contents (11 and 16 %) and two dry bulk densities (1000 and 1150 kg m−3) was used to test the calibration method. Simulations using the parameterization obtained from the combination of confined compression and direct shear tests resulted in remarkable underestimation of plate sinkage. A satisfactory agreement with measurements was only found when the simulated cohesion and internal coefficient of friction were several times higher than measured. The factors were indicated to be constant with changes in soil water content and bulk density. A strong correlation was found between the particle yield strength and precompression stress estimated from confined compression tests. Using the factors obtained for increasing the cohesion and internal coefficient of friction and estimation of particle yield strength from precompression stress, a viable method for calibration of plate sinkage test could be proposed. [ABSTRACT FROM AUTHOR]

Rapid and non-destructive adulteration detection is of particular importance to oil industries. This paper presents an application of visible and near-infrared (VNIR) spectroscopy for detection of adulteration levels in olive oil. Sunflower oil was used as an adulterant to olive oil, and the adulteration samples with different levels ranging from 0% to 40% were prepared and used for the experiments. The spectra were first considered in the range of 500-900 nm and then smoothened and normalized to reduce the light scattering effects. Principal component analysis (PCA) was performed on the spectra to have a primary data visualization and feature extraction. The extracted PCA scores were used to calculate the Mahalanobis distances of the adulterated samples from the pure sample. Further, the PCA scores were fed to the multi-class support vector machine (SVM) model to perform classification on the basis of different adulteration levels. The results showed that the spectral normalization highlighted different regions over the spectrum affected due to the adulteration. The PCA score biplots showed differences in the samples based on the different amounts of the adulteration. Moreover, the Mahalanobis distance provided a quantitative measure of the differences between the adulterated oil and the pure oil samples. The SVM modelling further supported the classification of the different levels of the adulteration. Consequently, the VNIR spectroscopy in combination with the SVM could support the development of the classification protocols for detection of adulteration in olive oils. [ABSTRACT FROM AUTHOR]

Food adulteration is a widespread illegitimate procedure involving contamination of food with chemical and physical substances. The adulterated food products are not only of decreased quality but also may cause pathogenic effects that jeopardize the human health. Adulteration of liquid foods is majorly performed for economic gains by utilizing cheap adulterants which do not necessarily change the color, taste and appearance of the food to be easily detectable by human senses. In the present study, two different dielectric spectroscopy sensors (parallel plate capacitor (PPC) and cylindrical stub resonator (CSR)) were examined and compared for detection of adulteration in grape syrup. The aim was to address which sensor could be a more precise instrument for detecting the type and level of a variety of common adulterants in grape syrup. The different adulterants tested were the date syrup, grape paste and sugar-water solution mixed at 5, 10, 15, 20, 25 and 30% with pure grape syrup. The multivariate dielectric spectral data were visualized with principal component analysis (PCA). Furthermore, similarity between different adulterants and their levels was identified with the hierarchal cluster analysis (HCA). To perform classification analysis, two different classification techniques i.e., linear discriminant analysis (LDA) and multi-class support vector machines (SVM) were utilized and compared. The results showed that PCA provided clear visualization identifying different types of adulterants over the score plots. Classification of adulteration type using SVM and LDA resulted in 100% accuracy for either of the sensors. For classifying the level of adulteration, PPC sensor associated with SVM classifier resulted in the highest accuracy (100%). In conclusion, the adulteration detection in grape syrup was satisfactorily addressed by the dielectric spectroscopy techniques. As diagnosistic tools, both the instruments could be implemented with standards executed for food security assessments. [ABSTRACT FROM AUTHOR]