mohammad hashem rahmati

In this study the effect of air temperature, paddy final moisture and variety on degree of whiteness and breakage percentage in fluidized bed dryer were investigated. Three rice varieties (Tarom-domsiah, Hashemi, and Shiroodi); air temperature in four levels (40, 45, 50 and 55°C) and final moisture in three levels (8-10, 10-12, and 12-14%) were considered. Tests were conducted within the factorial design. The results indicated that the degree of whiteness of Shiroodi variety is more than other varieties in different temperatures. Only the degree of whiteness of Tarom-domsiah is increased with increasing the moisture. The average degree of whiteness in moisture 8-10 percent was less than other moistures. Hashemi variety in each temperature indicated the least rice breakage percentage. Breakage percentage of Tarom-domsiah and Shiroodi varieties had no significant difference in any moisture levels. While Breakage percentage of Hashemi variety in 12-14% moisture had a significant difference in its breakage percentage in the moisture of 8-10% and 10-12% and it showed more breakage percentage value.

In no-tillage, the coulters are the best way to cross the plant residues, which, along with the furrow openers, prepare the soil for seed placement. So four available tiller models in front of a mechanical row crop planter were installed and a two factor randomized complete block design using strip plots with four coulters (sweep, nail, narrow chisel and T inverted) as factor A and the three factors related to the speed of tractor (4.8, 7.2 and 9.4 km.h-1) as factor B were performed. The planter units were adjusted on 50 cm distance between rows. The sweep model with 24.4 and 7.3 cm had the highest width and depth of disturbed soil. T inverted tiller at the specified depth with the least amount of standard deviation got the highest uniformity of seed distribution on the row that was 80.4% and did not change depth of seeding by speed increasing but increased the distance between two seeds. Also, the highest quality of feed index (42.7%) and the lowest multiple index (46.8%) were related to this treatment and its miss index (10.5%) has been around other tillers. Although T inverted tiller in the forward speed of 4.8 km h-1 has better performance in terms of planting indices, but the nail tiller is more suitable because of simplicity and performance as well as its low cost compared to other tested tillers and it passes through plant residues more easily.

Three electrode system simulates the human tongue taste system and can be used to assess the quality of food. The sense of taste is one of the five senses and tongue recognizes certain molecules. In recent years, three electrode system with an array of electrodes has been used to identify various molecules. In this research, a three electrode system is used based on voltammetric methods with three graphite electrodes (Pencil Graphite (PG)), Screen Printed (SP) and Glassy Carbon (GC) to identify heavy metals (cadmium , Lead, tin and nickel) in olive oil. Heavy metals are added to the edible oil in three concentrations of 0.05, 0.1 and 0.25 ppm and then the output of the device is classified by chemometric method. According to PCA results, the PG electrode contains 96% of the variance between the data in olive edible oils. Also, SP electrode contains 91% and GC contains 100% of the variance between the data in olive oil. The SVM method showed a high ability to classify heavy metals in edible oils. Also, The PLS method was also able to predict 99% of the data in olive oil for all electrodes. Finally, according to the results, it can be said that the built-in three electrode system has a high accuracy in identifying heavy metals in edible oils.

One of the main goals of drying agricultural crop is reduction of the moisture content and obtain optimum moisture in order to get maximum storage time and reduction of crop losses in the processing stage. Regarding to new science application and different methods of drying, use of new methods such as drying with infrared ray is necessary to be studied. In this study in order to determine effect of air temperature at three levels of 40, 50 and 60 ° C and ultimate paddy moisture at levels of %7-8, % 9-10 and %11-12 (based on dry weight) on drying time and paddy husk percent of Tarom Hashemi was used rotary cylindrical drier of infrared in three replications. Besides, effect in three levels of temperature and moisture and two type crop of paddy and brown rice on some mechanical properties of the dried paddy were determined by instron apparatus in five replications. The results indicated that the studied factors temperature and moisture had a significant effect on drying time. However, temperature and moisture factors hadn’t significant effect on the husk present. Measurement of Mechanical properties of rice paddy after drying indicated that among three factors: type crop (paddy and brown rice), moisture and temperature; two factors of type crop and moisture were more effective on mechanical properties. The obtained results of the research showed that optimum temperature of drying and optimum ultimate moisture (based on dry weight) are 57/68 ° C degree and %7/5 and under such conditions optimum time of drying was 84/76 minutes so that husk percent, break time and force were %21/54, 4/24 sec and 33/92 N respectively, besides size of displacement up to break point was 0/34 mm.

With the development of modern drying paddy in addition to speed up the drying process, and in particular the amount of waste can be reduced to the minimum possible energy consumption. In this study was investigate the effect of input air temperature, input air flow rate and variety also their interaction on energy consumption and drying rate in the fluidized bed dryer. The parameters of input air temperature at 4 levels of 45, 50, 55 and 60 °C, the air flow rate at 3 levels of 0/12, 0/14 and 0/16 m3/s and variety of paddy at 3 levels Tarom, Fajr and Shirudi was considered and tests was done in three replication in form of a 3×3×4 the 3-factor factorial design. The results indicated that In all three varieties tested, by increasing the intake air temperature as well as reduced energy consumption, drying rate also increased significantly. At 45 and 50 ° C, increasing air flow grain drying had no significant effect on the rate But at 55 and 60 ° C by increasing the flow rate of drying significantly increased. The results showed that by increasing air flow, increased energy consumption.

Economic value of the rice product is determined by the quality of rice after paddy conversion operation to white rice. Conversion Coefficient and crack percent are two important indices for determining the quality of rice after conversion operation that type of dryer used is effective on level of these indices. In this study effect of air temperature was studied in four levels (40, 45, 50 and 55°C); final moisture in three levels (8-10, 10-12, and 12-14%) and rice variety in three levels (Tarom-domsiah, Hashemy, Shirudy) on crack percent and conversion coefficient during the drying in a fluidized bed dryer. Experiments were conducted in the factorial design with three replications and three factors 3×3×4. Results showed that conversion coefficient of Tarom-domsiah, Hashemi and Shiroodi varieties reduced with increasing of moisture at all four temperature levels. In order to dry rice, temperatures 40°C and 50°C for Tarom-domsiah variety and temperature 55°C for Shiroodi variety lead to the best conversion coefficient. Crack percent of Hashemi variety increases with rising of drying temperature but crack percent of Shiroodi variety is reduced. Minimal crack percent of Tarom-domsiah, Hashemi and Shiroodi varieties is gained at temperatures (45°C and 50°C), 45°C and 55°C respectively. Hence, it is recommended to use temperatures mentioned for drying of these varieties in order to obtain minimal crack content.

In this research, the effect of air temperature and and air flow rate was investigated on the broken grains percent, milling recovery and paddy drying time of three rice varieties dried in fluidized bed dryer. The experiment was carried out as factorial in completely randomized design with three replications and the experimental factors were including air temperature at four levels (45, 50, 55 and 60 °C), air flow rate at three levels (0.12, 0.14 and 0.16 m3.s-1) and three rice varieties (Tarom, Fajr and Shirudi). Results indicated that increasing temperature from 55 to 60°C increased the broken grains percent of Shirudi, Fajr and Tarom from 19.10 to 35.97%, 43.30 to 51.36% and 19.82 to 29.06%, respectively. The lowest broken percent (17.17%) was obtained from the air rate 0.12 m3.s-1 and the temperature 45°C and the highest broken percent (40.54%) was registered from the rate 0.16 m3.s-1 and the temperature 60°C. The milling recovery of Shirudi variety at the air rate 0.12 to 0.16 m3.s-1 decreased from 72.37% to 71.74%, but in Fajr and Tarom varieties was not observed significant variation in the milling recovery. Increasing the air temperature from 45 to 60°C at the rate 0.16 m3.s-1 reduced drying time from 13.45 to 5.37 h, respectively, however increasing the air rate from 0.12 to 0.16 m3.s-1 at the air temperature 60°C reduced drying time only from 6.37 to 5.37 h.

Rice is a main food for Iranian people and has an important role in providing food security. Regarding the population growth، increase of rice production and reduction of losses have special importance in prevention of rice import. Rice losses in the harvest stage are the highest through the whole production period of this crop and hence the reduction of these losses is necessary. Provision of this purpose depends on on-time harvesting and separation of grains from chaff with the least grain losses، and choosing a suitable harvesting method. The choice of harvesting method depends on various factors in each region; thus، different harvest methods in each region must be compared while conducted in the same conditions. In order to recommend the beast harvest method in Shivan-Chardavol region، three harvesting methods (manually، rice-specific combine harvester and conventional cereals combine harvester) were considered as three experimental treatments and four different parts of this region considered as experimental blocks. The experimental design was randomized complete block design. This study was carried out on Anbarboo variety and the measured factors were: effective farm capacity، percent of total losses، percent of harvesting losses، number of workers and harvesting cost. The results of this study indicated that the total difference of factors was significant at the 1% error level among all treatments. The effective farm capacity in harvesting by cereals combine harvester was more than other treatments. The lowest percent of loss was observed for harvesting by rice-specific combine harvester (2. 32%) and the highest percent of loss was obtained for cereals combine harvester (3. 816%). The manual harvesting method had the highest harvesting cost and the lowest cost was found to be associated with the rice specific combine harvester. Therefore، from the results of this study، the use of this combine harvester is recommended for rice harvesting in this region.

Wheat as the most main food for the world and a strategic product has a major role in people's food supply. Average of wheat growing areas in Iran is 6.65 million hectares and more than 374 thousand hectares of wheat annually in Lorestan province is planted. In this study, conventional methods in the measurement of crop losses, John Deere and Behroozi-Lar method as proposed approaches was considered and the real waste of dry land wheat harvest, in 2011 in central part of the Khorramabad Township, in the center of Lorestan province, was measured. Using three Factors-factorial design, in field sampling, pre-harvest losses (normal), cutting platform Losses, unit pounding Losses, the unit separate and distinguishable Losses (end of combine) was measured and total farm losses were also determined. For statistical analysis of data, SPSS software was employed and for comparison of means, Duncan's test was used. The results showed that the average wheat harvest losses in Khorramabad has been 5.21% including 0.65% normal losses and 4./56% losses of combine.

Terminal velocity and drag coefficient are the most important aerodynamic properties of agricultural products like soya in the designing of machines and processing equipment. In this study, these properties were evaluated for three soybean varieties (Sahar, Viliyams and Dpx) and five moisture content levels (4, 8, 12, 16 and 20% d.b.). First, relation of the terminal velocity and the drag coefficient with the moisture content was mathematically formulated, and then, in fluidized bed dryer was practically investigated. The results showed, with the changing of the moisture content of three varieties (Sahar, Viliyams and DPX) from 4% to 20%, the terminal velocity of three varieties increased respectively from 4.42 to 5.1, 5.12 to 5.94 and 4.71 to 5.5 (m/s) while at the same moisture content the drag coefficient decreased from 0.45 to 0.389, 0.53 to 0.452 and 0.512 to 0.444. The diagrams of the terminal velocity and the drag coefficient revealed that the terminal velocity and the drag coefficient values have a linear relationship with the moisture content, but with increasing the moisture content, terminal velocity values increased whilist drag coefficient ones decreased.