Design and construction of an automatic coefficient of friction measuring device

The need for knowledge of coefficient of friction of agricultural materials on various surfaces has long been recognized by engineers concerned with rational design of grain bins, silos and other storage structures.  In the design of agricultural machinery, however, the need for this information has been recognized rather recently.  Not finding this information in any handbook or published data, it became necessary to set up a friction test apparatus and obtain the information needed.  We know that the internal friction angle metering devices in our laboratories have the low accuracy, thus we decided to design an automatic internal friction angle metering device with high accuracy which the tangent of this angle is equal to the coefficient of friction that be measured and displayed.  This device is made up of one frame, three hinges, one electromotor with gearbox, one DC Adaptor, one wooden plate that can be changed, acceleration measuring sensor, laser transmitter and LDR for detection of movement, electrical circuit, Microcontroller and monitor for display of the angle and other devices for moving of the wooden plate and carrying of the materials

Determination of physical and mechanical properties of Zucchini (summer squash)

Abstract: Several physical and mechanical properties of Zucchini from Kermanshah province of Iran were determined.  The physical and mechanical properties of the zucchini are necessary for the design of automatic equipment for harvesting, processing, transporting, sorting and separating of samples.  At the average moisture content of 94.65% w.b., average of mass, volume, dimensions (big, medium and small diameters), geometric mean diameter, projected area (big, medium and small area), criteria areas, arithmetic means diameter, sphericity, density and surface area were 80.81 g, 85 cm3, 111.7 mm, 34.58 mm, 33.87 mm, 51.74 mm, 3892.52 mm2, 3792.07 mm2, 1126.44 mm2, 2937.02 mm2, 60.05 mm, 45.49%, 0.96 g/cm3 and 8268.20 mm2, respectively, and ratio of weight of rind per weight of fruit was 0.25.  Mechanical properties that measured including elasticity modulus, maximum force which fruit can be supported, work which performed to this force under compression loading, deformation at maximum force and penetration force, their averages were found 0.73 GPa, 167 N, 762.82 N.mm, 8.81 mm and 1.26 N, respectively. Keywords: Zucchini, physical and mechanical properties, compression loading, penetration force

Moisture-dependent physical and mechanical properties of hawthorn (Crataegus aronia)

 In this study, some important physical and mechanical properties of the hawthorn and the effect of moisture on them were investigated.  The effect of moisture at two levels (64.01% and 70.1%, w.b.) on the geometric dimensions (length, width, thickness, arithmetic mean diameter, geometric mean diameter, degree of sphericity, surface area, projected area, criteria projected area, mass, volume and the apparent), true density, porosity, coefficient of static friction and coefficient of rolling on three levels (wood, glass and galvanized) and mechanical properties obtained by impact testing machine using a randomized factorial design was evaluated by software SPSS18.  Results indicate that moisture has an effect on the physical properties of the hawthorn.  The moisture content of 70.1% of all physical properties except the true density and porosity values​​ is greater than 64.01% moisture there.  Coefficient of static friction with increasing moisture increased and coefficient of rolling decreased.  Moisture has an effect on the mechanical properties of hawthorn also.  With increasing moisture, all the mechanical properties except dL in Fmax decreased (dL is changing the shape of the force and Fmax is the maximum force).   Keywords: hawthorn, physical properties, maximum force at impact, mechanical properties, moisture conten

Mass modeling of caper (Capparis spinosa) with some engineering properties

Nomenclature M = fruit mass, g; V = fruit Volume, cm 3 ; Dg = geometric mean diameter, mm; S = surface area, mm 2 ; L = length of fruits, mm; W = width of fruit, mm; T = thickness of fruit, mm; PA1 = first projected area which perpendicular to L direction, mm 2 ; PA2 = second projected area which perpendicular to W direction, mm 2 ; PA3 = third projected area which perpendicular to T direction, mm 2 ; CPA = criteria projected area, mm 2 ; SD = standard deviation; b0, b1, b2 = curve fitting parameters; X = independent parameter. Abstract Introduction Horticultural crops used as food with a similar weight and uniform shape are in high demand in terms of marketing value. Objectives Therefore, an awareness of methods for grading fruits and vegetables based on weight is crucial. A part of this research was aimed at presenting some physical properties of caper. Methods In addition, in this study, the mass of caper was predicted using different physical characteristics in four models that include linear, quadratic, S-curve and power. Results According to the results, all properties considered in the current study were found to be statistically significant at the 1% probability level for the best and the worst models for prediction; the mass of caper was based on volume and second projected area of the caper with determination coefficients of 0.984 and 0.323, respectively. Conclusion Mass model based on first projected area from an economical standpoint is recommended. Lorestani AN, Jaliliantabar F, Gholami R (2012) Mass modeling of caper (Capparis spinosa) with some engineering properties. Quality Assurance and Safety of Crops & Foods, 4

Comparative analysis of exhaust gases from MF285 and U650 tractors under field conditions

Agricultural machinery is an important source of emission of air pollutant in rural locations.  This work deals with the effects of types of tractors and operation conditions on engine emission.  The values of some exhaust gases (HC, CO, CO2, O2 and NO) from two common tractors (MF285 and U650) at three situations (use of ditcher, plowing and cultivator) were evaluated in the West of IRAN (Kermanshah).  In addition, engine oil temperature at operation conditions was measured.  Also results showed the values of exhaust HC and O2 of MF285 are lower than U650, while the other exhausts gases (CO, CO2, and NO) of MF285 are higher than U650.  Value of NO emission increased as engine oil temperature increased.  All of exhaust gases except CO have a significant relationship with type of tractors, while all of measured gases have a significant relationship with installed instruments at 1%.   Keywords: environmental pollution, exhaust gases, tracto

Measurement and Analysis of Vibration of Operator in Universal 650, Massey Ferguson 285 & MF 299 Tractors

Abstract Since healthy human is basis of permanent development in any society, and safety & health subject have special importance, then examination and investigation is necessary about of risks working for the purpose of recognition danger and guiding to eliminate them. In this study, object is to compare effect of change engine rotation and ground type on operator of tractors and implements that utilized. In other words, the goal is to measurement and analysis of transmitted vibration on different parts of human body. In this investigation universal tractor and ferguson285 &299 tractors with moldboard plough and disk are used. Hand-Arm vibration's operator in 1300, 1500 and 1700 rpm and in ploughing field and unploughing field with hand-arm vibration meter are measured. After statistical analysis, appeared that effective vibration difference on hand and arm's operator in examined tractors is significant and engine rotation is significant too

Effect of harvesting time and cultivar on barley quality and predict the nutrient composition

The present study was conducted in response to the lack of information on effects of cultivar and harvesting time on nutritional value of barley grown in Iran. The objective of this study was to determine the detailed chemical composition of barley in different cultivar and harvesting time and predict the nutrient composition. Three barley cultivars (Ansar, Abidar and Sahand), were harvested at two stages of growth (ripening of grain GS-91 and forage barley GS-83) and nutrition indices of treatments were determined in the advanced nutrition lab. The results of analysis showed that the effect of harvesting time and cultivar were significant on minerals and crude protein of barley, also the effect of harvesting time was significant on gross energy and crud fat. The highest percentage of minerals was in Sahand cultivar with an average of 7.13%, also the mineral of forage barley (GS-83) was higher than barley in the ripening of grain (GS-91). Sahand cultivar with the mean of 15.3% and GS-83 with a mean of 13.4% had the highest crude protein. The highest amount of gross energy was related to Abidar cultivar at GS-83 with an average of 6416 cal/gr. The mean of GS-83 with 2.1% of crude fat was more than GS-91 with the mean of 1.5%. The result of linear regression model showed that harvesting time and cultivar were effective parameter in prediction of crud protein and mineral content, but only harvesting time could be used in prediction of crud fat and gross energy

Investigation the effect of outlet air flow and chamber temperature on some bio-char properties of wheat straw in a fixed-bed oxidative pyrolysis

Soil plays an important role in the sustainability of ecosystems. In recent years, the increasing growth in the degradation of soil resources has drawn attention to management strategies for maintaining the soil quality. Researchers have recently studied the impact of using biochar on physical and chemical properties of soil. It has been found that adding biochar improves the soil quality. Some factors such as pyrolysis chamber conditions, pyrolysis peak temperature and air flow rate affect the physical and chemical properties of biochar including the density, pH, ash content, and so on. In this study, the effect of changes in the air flow rate and chamber temperature in the fixed-bed oxidative pyrolysis on the biochar yield, ash content, density and pH were investigated. For this purpose, a fixed-bed biochar production apparatus with varying chamber temperature and flow rate of outlet air was designed and manufactured. The experiments were performed at four air flow rates of 20, 25, 30 and 35 L min-1 and four temperatures of 350, 400, 450 and 500 °C for wheat straw. The results showed that increasing the temperature and flow rate of the outlet air from the chamber increased the ash content and pH. However, increasing these parameters decreased the biochar bulk density and yield