Iranian Journal of Biosystems Engineering
Year:2015 | Volume:46 | Issue:1|Papers Count:11

Fresh peels of three dominant Iranian pomegranate cultivars were taken to be extracted through soxhlet extraction method via four different solvents. The extracts were analyzed by use of High Performance Liquid Chromatography (HPLC), using ultraviolet-visible spectrometric detection. The extraction yields and presence of seven phytoestrogenic compounds, two tannic acids along with their quantities in the extracts were determined. The compounds were identified and quantified according to their retention times in comparison with those in standard samples. A comparison of fresh pomegranate peel of some three cultivars indicated that the yield of extraction from Poost Goliye Malase Saveh variety was more than the yields of the other two cultivars and the yield of extraction of extracts obtained through a mix of the solvents was more than that through any single solvent (p≤0.05). HPLC analysis indicated besides ellagic and syringic acids, some of such phytoestrogens as Esteriol (up to 7.45 mg/100 g fresh peel), Testosteron and a-Estradiol (up to 8.43 mg/100 g fresh peel) were also found in the extracts of the pomegranate peels. The results show that, of the two tannic acids, a high value of ellagic acid (up to 103.0 mg/100g fresh peel of Poost Siyahe-Ardestan) was detected in any of the extracts.

A survey intended to determine the spring and damper settings of ITM285 tractor’s cabin that ensured the optimal ride comfort of the tractor operator was conducted. Analysis was done in terms of Root Mean Square Acceleration Response (RMSAR) within one-third-octave band and International Standard Organization (ISO). Optimization was performed using Particle Swarm Optimization (PSO) method on a 2 DOF modeled in MatLab software for frequencies ranging from 1 to 10 Hz. The obtained figures for C1, C2, K1 and K2 were 943 (Ns/m), 850 (Ns/m), 3927 (N/m) and 26199 (N/m), respectively. Modeling tractor cabin, applying optimized parameters according to ISO 2631-1985, showed 16.7, 10.1, 11.5 and 12.2 % reduction in rise time, peak time, settling time and max. overshoot of the tractor cabin displacement. Therefore, the transmitted vibration was diminished, and and improvement in the ride comfort of the tractor operator achieved.

A portable and light pneumatic branch shake system was designed and manufactured in this research for harvesting fruits that can be harvested by shaking branch. Required air flow and electric current are provided for operating system from category containing electrical generator and air compressor on wheelbarrows and portable chassis. Vibration is equipped by programmable logic controller (PLC) for controlling frequency and it is equipped by pantograph system to change amplitude. First farm test was done on olive with three levels of frequency (8, 12 and 16 Hertz) and three times to shaking (5, 10 and 15 seconds) and in constant amplitude of oscillation 5 cm in completely randomized design with four reduplications and second farm test was performed on olive with three levels of frequency (8, 12 and 16 Hertz) and three amplitudes of oscillation (50, 80 and 100 mm) for a fixed period of 5 s in completely randomized design with four reduplication for determining application of branch shake. Some experiments were done for determining static force separating fruit from branch and for comparing it with dynamic force due to performing vibration, as well. The results showed that oscillatory frequency and duration of shaking out have meaningful effect on one percent level on efficiency of shaking system whereas their interaction was not meaningful effect. Comparison of averages showed that increase of the time of vibration didn''t have meaningful effect on percent of harvesting olive in constant oscillation but increase of oscillation in constant time of vibration had meaningful effect on percent of harvesting. Also the result of indicator was based on meaningful effect of amplitude of oscillation on falling olive. And by comparing averages, it was given that falling olive is increased with increasing frequency in constant amplitudes of oscillation. Also, it was not observed meaningful differences between percent of falling olive with increasing amplitude of oscillation from 50 mm to 80 mm in constant frequencies. But when amplitude of oscillation increases from 80 mm to 100 mm, the percent of falling olive meaningfully increases. Finally, concerning by performing 16 Hz frequency and 100 mm amplitude of oscillation for 5 s, 90 percents of olive were separated from branches, therefore they were selected as the best amplitude, frequency and time of vibration.

A combined solar dryer of a specific mechanism to be adjusted for the tilted angle of the collector was utilized to get the following needed information. The efficiency of the dryers is low because of such various reasons as heat loss of air occurred in an open flow circuit. Getting air back toward the air inlet of a dryer can increase the efficiency of the dryer while decreasing the drying process period. A new mechanism was considered for a dryer in which, the percentage of air recirculation is controlled. It contains two dampers embedded in return air channel of the dryer. In order to investigate the effect of air recirculation on energy consumption of drying and dryer efficiency, thin layers of tomato slices are dried at three levels of air flow rate (0.018, 0.036 and 0.054 m3/s) and at four levels of air recirculation percentage (0, 50, 75 and 87.5%). The experiments were carried out, starting with the beginning of the autumn when the moisture content of the samples reaches 12% (w.b.). The results indicated that a minimum of energy consumption and a maximum of efficiency were achieved when 75% of air flow was forced back to the inlet of the dryer.

In this paper the energy and exergy analyses in chamber drying process of thin layer drying of tomato in a forced solar drying was investigated. The experiments were carried out with two thicknesses of 5 and 7 and two airflows 0.5 m.s-1 and 1 m.s-1. During the experimental process, ambient temperature was between 22 and 36, air relative humidity between was 14 and 50, and solar radiation ranged from 150 to 850 W.m-2. The effects of drying variables on energy utilization, energy utilization ratio, exergy loss and exergy efficiency were studied by applying the first law of thermodynamics. In chamber drying at airflow of 1 m.s-1 and thickness of 5mm,the values of energy utilization, energy utilization ratio, exergy loss and exergy efficiency varied from 6.62 to 152.72W, 0.02 to 0.45, 2.42 to 32W and 32 to 80, Respectively. In addition, the results showed that both energy utilization rate and exergy loss efficiency of the drying chamber decreased with increasing drying mass flow rate and drying thickness while the exergetic efficiency and energy utilization of the drying chamber increased.

Mechanical damages in the processes of harvest and post-harvest form the most important causes of loss in Cucurbits. They cause tissue destruction and consequent fruit’s decay. Because of the difference between the mechanical strength of cantaloupe flesh vs. that of the skin of cantaloupe, internal bruising’s constitute the more usual damages with no visibility. This type of injuryis hard to predict through analytical methods. Throughout the present study,the mechanical properties of skin vs. flesh were determined through individual experiments and then Finite Element Model (FEM) was developed through ABAQUS software. The applied displacements on the model were equal to 5.5, 11 and 16.5 mm or 10, 20 and 30% of the final deformation, respectively. The analytical results showed that the internal tissue of fruit reached the yield point at 20%of whole displacementor in 90N force, with the internal failure occurring as not visible on the surface of the fruit. The model was verified by a comparison of force-displacement graph from the experimental data and FEM results. A high correlation (R2=0.983) between the predicted vs. the actual force indicated the validity in use of FEM model.

The effect of two thickening agents, namely Carboxy Methyl Cellulose (CMC) and Guar, on the rheological properties of set fruit yogurt was investigated. Viscoelasticity moduli (G’, G”), apparent and complex viscosities increased while loss factor getting decreased by increase in Carboxy Methyl Cellulose and Guar contents up to 0.2% and 0.06% respectively. However, in concentrations exceeding these, some contradictory results were observed. Also it was observed that, by adding CMC and Guar to fruit yogurt, syneresis and water holding capacity decreased and increased respectively. In spite of positive effect of the two thikening agents on the rheological properties, addition of a mixture of the two exerted negative effects on the properties. By increase in different proportions of CMC in constant concentrations of Guar (0.02% and 0.04%) no improving synergistic effect on the three-dimensional yogurt structure was observed, the rheological properties and water holding capacity being weakened, while the syneresis getting increased.

In modern agriculture, image processing technique is employed in mechanization and in its related intelligent machines to replace humans. One application of the technique is an identification of varieties of plants and fruits. Identifying plant varieties is essential in plant eugenic programs. Visual examination of plant leaves and fruit is the common procedur towards the aim. Identification and classification of plants while using machine vision techniques can be more quickly and accurately performed. Throughout the present study, four varieties of apple namely Granny Smith, Golab Kohans, Gala, and Delbar-astyval were studied. Following a collection of leaf samples, the images of leaves were captured and subsequently color, texture, as well as morphological properties from each image were extracted. Adaptive Neuro - Fuzzy Inference System (ANFIS) was made use of for classification. The results indicated that it was possible through ANFIS to successfully classify leaves with respective linear and triangular input and output membership functions, along with hybrid learning method, in grid partitioning FIS mood. An accuracy of 95-83% was finally estimated for the method.

Low density polyethylene films incorporating different types of organically modified nanoclays were prepared. Physical, surface morphology and mechanical properties of the films were analyzed through x-ray diffraction pattern, scanning electron microscopy, Tensile Strength (TS), and length increase until fracture point (E) parameters, respectively. Colony counting method was applied to investigate anti-microbial activity of the resulting films. X-ray diffraction pattern showed layered structures for most of the produced films. It was found that Cloisite 20A nanoclay produce a smooth and uniform surface in films, due to a proper compatibility with low density poly ethylene matrix. Mechanical properties of the films were not significantly influenced by the addition of nanoclays into the polymeric matrix, although there was a little improvement observed. Microbial results revealed that Cloisite 15Aand 20Afilms at their concentrations of 6% exhibited a good anti-microbial activity. All the nanoclays at any concentration tested throughout the study showed anti-microbial activity against E. coli.

One of the most practical applications of automated navigation systems is the use in automatic steering systems in agricultural vehicles. Throughout the present research, a machine vision algorithm was designed as based on image acquisition from a camera mounted on the front of a combine harvester cab for detection of its forward path. Following filtration and optimization of the image, Hough Transform was utilized for extracting the path as a line. Then the lateral and angular deviations from the path were obtained as the main inputs for the automatic guidance system of the combine harvester. The algorithm was tested in 7 lateral and 7 angular deviation treatments of three replications. The tests were carried out under different conditions of daylight. A Comparison of the values of angles and deviations extracted from the image processing algorithm with those manually obtained indicates that it is possible to detect the path of the combine, through the algorithm, with an accuracy of 98%.