Rapeseed is one of the important oilseeds, as its oil ranks second in the world after soybean. The rapeseed cultivation has been increased recently in Iran. Drying of seeds to a safe moisture level is necessary for storage of oilseeds before processing. Rapeseed drying conditions affect the seed quality, ...
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Rapeseed is one of the important oilseeds, as its oil ranks second in the world after soybean. The rapeseed cultivation has been increased recently in Iran. Drying of seeds to a safe moisture level is necessary for storage of oilseeds before processing. Rapeseed drying conditions affect the seed quality, total oil and germination capacity. Hence in this research the effects of different temperatures and humidity on the PF variety were studied. Rapeseed samples with different moisture contents at harvesting time (12, 15 and 20% w/w), were dried under 40, 45 and 50ºC temperatures and the rape kernels were dried under 80, 90 and 120ºC temperatures, respectively until reaching final humidity of 8% (w/w). Then the effect of drying conditions were determined on the total oil, free fatty acid (acidity value), peroxide value, and color of extracted oil and the germination capacity of dried seed. The result showed that the optimum drying conditions for rapeseed and rape kernel was obtained at 80ºC temperature with 12% moisture content and 40ºC with 12% moisture content (according to the germination capacity), respectively.
One of the common causes that make unexpectedly low irrigation system efficiency, is temporal variations of soil hydraulic properties. In this study, the effect of saline and sodic irrigation water was investigated on infiltration rate in a clay loam soil. Ten weekly irrigations were carried out using ...
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One of the common causes that make unexpectedly low irrigation system efficiency, is temporal variations of soil hydraulic properties. In this study, the effect of saline and sodic irrigation water was investigated on infiltration rate in a clay loam soil. Ten weekly irrigations were carried out using water with electrical conductivity and SAR of 12dS/m and 32, respectively. The cumulative infiltration rate was measured on the third, sixth and tenth irrigation events using blocked end furrows. Results showed that infiltration rate was significantly decreased during the three irrigations as indicated above. Decreasing in infiltration rate was due to structural disaggregating caused by sodium. The temporal variations of soil hydraulic properties were estimated using inverse option of HYDRUS-1D model. Due to limitation in estimating several parameters simultaneously, we performed a sensitivity analysis and found that saturated hydraulic conductivity (Ks), van Genuchten n, and saturated water content (qs) were the most sensitive soil hydraulic parameters. Therefore, two scenarios were used to estimate the temporal variations of soil properties. First, only Ks and in a second run both Ks and qs were estimated simultaneously. The results showed that optimized Ks values decreased with time and it was somewhat difficult to optimize Ks and qs simultaneously. Agreement between measured and calibrated cumulative infiltration was satisfactory. As a conclusion, with present enough measured data, inverse technique can be a suitable method for estimating soil hydraulic properties. We also used Philip's equation to fit the measured cumulative infiltration data. The agreement between measured and predicted infiltration data by Philip's equation was relatively satisfactory during the third and sixth irrigations and somewhat weak during the tenth irrigation round.
Grape is used in large amounts and different types (fresh, raisin, vinegar, molasses, juice, unriped grape and etc). Remarkable amount also are preserved in stores and cold-rooms to be supplied out of season, that causes quality and weight decrease. This research was conducted to study different ...
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Grape is used in large amounts and different types (fresh, raisin, vinegar, molasses, juice, unriped grape and etc). Remarkable amount also are preserved in stores and cold-rooms to be supplied out of season, that causes quality and weight decrease. This research was conducted to study different factors which affect the grape shelf-life. Obtaining more information about optimum conditions and requirements for preserving grape fruits in cold-room and reduction of losses were the main objectives. For this purpose, two Fakhri and Shast-e-Arous cultivars late-ripen with high preservation ability and were selected as main cultivars in Qazvin. The grape were treated using: sterilization with fungicide solutions before or after harvest, So2 gas before transferring to cold-room and their interaction. Then they were placed in 3 and 6 kg boxes for 30, 60 and 90 days under 0±1°C in cold-room. Some variables such as fresh weight and TSS of each treatment were noted before placing boxes in cold-room. Other factors were also measuread after brining the boxes out from cold-room, such using weight reduction (%) diseased (%) and healthy fruits (%). The experiment was conducted as factorial based on CRD with 3 replications. Mean comparison was carried out by Duncan's multiple range test (DMRT). The results showed that Shast-e-Arous cultivar presented better storable properties than Fakhri. So, it was more suitable for preserving in cold-room and supplying out of season. So2 fumigation was more effective than the other fumigation methods for fungi growth control and also higher healthy and marketable fruit percent preserving. However, treating fruits with fungicide solution after harvest was in second grade, too. 3 kg boxes were more suitable than 6 kg ones because of having higher healthy fruit percent and very low infection to fungi. However, weight reduction was higher in 3 kg boxes than 6 kg ones. Storage period was very effective on all traits. So, fruit quality and quantity decreases as storage period increases.
Control of sedimentation in dam reservoirs is considered to be one of the most important issues in exploitation of dams and increasing the their useful life. Reservoirs act as traps for sediments and prevent transport of sediment to the river. The deposited sediment decreases the capacity of reservoirs ...
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Control of sedimentation in dam reservoirs is considered to be one of the most important issues in exploitation of dams and increasing the their useful life. Reservoirs act as traps for sediments and prevent transport of sediment to the river. The deposited sediment decreases the capacity of reservoirs so that they can not be in use any more. Various methods dealing with removing part of the deposited sediments are discussed in this study. Regarding fact that flow energy is utilized and no need to employ any external source of energy, flushing method has been used extensively in many projects all over the world. In this study, one-dimensional model in which the continuity equation of sediment solved by the finite difference method using the Cranck-Nickolson scheme has been developed. The developed model was capable to compute the variation of the reservoir bed with time. Also, the accumulated flushed sediment volume and reservoir water volume were calculated at different time steps. The Fortran language used for programming the model based on the results obtained from physical models employed by several investigators. Also a comparison with HEC-6 model was conducted. The verification was verified by using data from the natural reservoir of Dashidaira dam in Japan. The results of the proposed model and the HEC-6 ones were compared with practical measurements data and reliable good agreement was noticeable for the model where it wasn’t with HEC-6 ones.
Sewage sludge can be utilized as one of the best and cheapest organic fertilizer in agriculture due to its organic and plant nutrient contents. However, the presence of potentially toxic heavy metals in some sludges can restrict its use in agricultural lands. A greenhouse study was conducted in the college ...
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Sewage sludge can be utilized as one of the best and cheapest organic fertilizer in agriculture due to its organic and plant nutrient contents. However, the presence of potentially toxic heavy metals in some sludges can restrict its use in agricultural lands. A greenhouse study was conducted in the college of Agriculture, Ferdowsi University of Mashhad, to investigate the effects of leaching and sewage sludge application on soil properties, yield and quality of barley. The experiment was carried out using a factorial arrangement with a completely randomized design with three replicates. Sewage sludge was applied at five levels of 0, 50, 100, 200 or 400 t ha-1 while leaching was performed at two levels of 0 and 10%. At the end of growing season, the soil and plant characteristics were assessed. Results showed that increase in sewage sludge application caused a significant (r0.05) increase in all the above mentioned soil characteristics except for the pH which showed a significant (r0.05) decrease. In the case of plant, sign of chlorosis was observed on barley leaves in treatments of 200 and 400 t ha-1 sewage sludge. Moreover, a significant (r0.05) increase in the concentration of Pb and Cd in leaves and stem of barley was indicated due to the increase in sludge application rate. However, the effect of sludge application on the 100 seed weight and plant aerials dry weight was not significant (r<0.05). The effect of leaching factor on soil characteristics was not significant (r<0.05) except on concentrations of Mg and Ca in soil solution. Leaching factor increased plant aerial dry weight significantly (r0.05), but had no effect on the 100 seed weight and concentrations of Pb and Cd. The interaction effects of sludge application rates and leaching levels were not significant.
Concrete is one of the most important construction materials widely using in hydraulic structures, such as lining of irrigation canals. Concrete durability might be decreased due to the environmental or inner factors with physical, chemical or mechanical reactions. Since, the climatologically condition ...
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Concrete is one of the most important construction materials widely using in hydraulic structures, such as lining of irrigation canals. Concrete durability might be decreased due to the environmental or inner factors with physical, chemical or mechanical reactions. Since, the climatologically condition is variable in most part of the country, local studies are needed to evaluate of the weakness and straight of the different concrete component for a given climate. Therefore even thought a large expense is used for lining of irrigation canals, most of these projects have low conveyance and distribution efficiency. This study was conducted for evaluation of failure factors in applied concrete lining in irrigation canals of Hamadan-Bahar plain. The main issue in irrigation canals of the mentioned plain has been destruction of lining, which appeared as cracks and destruction in concrete linings. The main purpose of this research was determination of effective factors for destruction of irrigation canals in four different locations namely, Gondehjin, Bahadorbeig, Abroomand and khooshabe Olia. The data collection were include samples of concrete linings, inflow water in canals and bed soil of lining. Totally, 9 samples of concrete, 12 of water and 78 of bed soil were collected. The samples were tested based on standard methods of ASTM and the results were compared with the primary documentations on design and performance of each irrigation canals as well as Iranian Concrete Code and ACI. According to results, the main causes of cracking and destructing of concrete lining of irrigation canals were: (i) the factors that related to concrete preparation (inner factors) such as improper vibration, wormy holes and low compressive strength, (ii) environmental factors such as temperature variation and freezing and thawing.
For non-Darcy flow in submerged porous media a one- dimensional mathematical model has been developed. Rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. In this research the focus ...
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For non-Darcy flow in submerged porous media a one- dimensional mathematical model has been developed. Rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. In this research the focus was on the rockfill detention dams in submerged condition. The existence of overtopping rockfill dams flow, seepage flow and the potential momentum of material made investigation through and overtopping phenomena very complicated. Flow through and over rockfill detention dams can be investigated in three zones including open channel flow (main channel), normal seepage zone (non-Darcy seepage low) and transition zone. In this research, at first the governing equation in each zone has been developed individually. These equations combines with boundary condition and then the main governing equation in rockfill detention dams in submerged condition was achieved. A comparison between computed and experimental results was then made on the basis of two physical model performances in the hydraulic laboratory of the University of Tarbiat Modares. The physical model were collected from a rockfill dam of 300×300×600mm dimension (width×depth×length) with rock average diameters of 10-20mm installed in atilting flume of the hydraulic laboratory. At the end an investigation between another researcher's relation and results was made on the basis of amount of flow through rockfill detention dams and the best relation was selected.
There are different methods used for threshing of grain crops. Usual threshers operate based on the impact force (in threshing unit) that may damage the grains. In another method named axial-flow, grain damage is less so these types of the harvesting machines are being used more than before. In this ...
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There are different methods used for threshing of grain crops. Usual threshers operate based on the impact force (in threshing unit) that may damage the grains. In another method named axial-flow, grain damage is less so these types of the harvesting machines are being used more than before. In this study one of the common rice threshers (model T30) locally made in Ashtad Company was modified to an axial flow thresher. For converting the cross flow unit to an axial flow, the cover of T30 thresher was replaced by IRRI axial flow thresher cover design. The thresher feature has also been changed. Then the machine was tested and evaluated on two rice varieties. The numbers of treatments were twenty and each experiment was carried out in four replications. Independent factors were grain moisture contents (two levels), varieties (Khazar and Hashemi) and drum speeds (five levels). Depended factors were the percentage of damaged grain, unthreshed grain and straw/grain ratio. The trials carried out in split plot based on Randomized Completely Block Design (RCBD) and Duncan’s Multiple Range Test (DMRT) was used for mean comparison of samples. The results revealed that drum speeds had significant effect (P<0.01) on percentage of damaged grain. The varieties had no significant effect on threshing loss. Its valve was zero for Khazar but remarkable for Hashemi. The moisture contents had no significant effect on depended variables in all experiments.
The glass transition temperature (Tg) and the melting temperature (Tm) of gelatin at water contents between 7 and 14% were measured using differential scanning calorimetry. The plasticisation of the polymer by water led to a decrease in Tg and Tm. The Tg of partially crystalline gelatin was higher ...
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The glass transition temperature (Tg) and the melting temperature (Tm) of gelatin at water contents between 7 and 14% were measured using differential scanning calorimetry. The plasticisation of the polymer by water led to a decrease in Tg and Tm. The Tg of partially crystalline gelatin was higher than that of the amorphous one obtained by quenching from the melt. The enthalpy relaxation occuring during the ageing of gelatin in the glassy state was studied for different structures (partially crystalline or amorphous), water contents and ageing temperature (Ta). The extent and rate of this relaxation associated with physical ageing were found to increase when the shifted temperature parameter (Ta-Tg) increased. This parameter was able to account for the effects of structure, water content and ageing temperature.
Sorting and classification of agricultural products by machine vision system reduce costs and increase quality and accuracy. This research was performed to develop an algorithm and machine vision system for separating dirty and defects eggs and classifying by volume and weight. This machine installed ...
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Sorting and classification of agricultural products by machine vision system reduce costs and increase quality and accuracy. This research was performed to develop an algorithm and machine vision system for separating dirty and defects eggs and classifying by volume and weight. This machine installed on transport line egg in agriculture included a digital camera, computer and mechanical device for applying commands. After prospecting images by software on computer, proportion commands sent to mechanical device. These commands were based on the dirty and size percent of eggs. The results showed that software was suitable to discern 100% dirty eggs and 1% errors for volume and weight estimation.
