Gazor H.R.,Agricultural Engineering Research Institute
International Journal of Food Science and Technology | Year: 2010
The equilibrium moisture contents of saffron (Crocus sativus L.) stigmas were determined experimentally using the standard gravimetric method at temperatures 30, 45 and 60 °C and water activity ranging from 11% to 83%. The sorption isotherm curves of saffron were sigmoidal in shape and decreased with increased temperature at constant relative humidity. Five selected isotherm models GAB, modified Henderson, modified Chung-Pfost, modified Halsaey and modified Oswin were tested to fit the experimental isotherm data. Modified Oswin and modified Henderson models were found acceptable for predicting desorption moisture isotherms and fitting to the experimental data, respectively. The isosteric heats of desorption, determined from equilibrium data using the Clausius-Clapeyron equation, were found to be a function of moisture content. The net isosteric heat of desorption of saffron varied between 1.38 and 5.38 kJ mol-1 at moisture content varying between 2% and 20% (d.b). © 2010 Institute of Food Science and Technology.
Karimi P.,SRI International |
Qureshi A.S.,International Water Management Institute |
Bahramloo R.,Agricultural Engineering Research Institute |
Molden D.,SRI International
Agricultural Water Management | Year: 2012
Groundwater irrigation consumes considerable energy as well as water resources across the globe. Using a case study from Iran, this paper explores how enhanced farm water management can help in reducing groundwater exploitation and subsequently limiting energy consumption and the carbon footprint of the groundwater economy. Groundwater use for irrigated agriculture in Iran has increased vastly over the last three decades. We estimate that groundwater pumping consumes 20.5. billion. kWh electricity and 2 billion liters of diesel and contributes to 3.6% of the total carbon emission of the country. Thus there is an opportunity to reduce energy use and carbon emissions by pumping less water. However, groundwater use remains important for food security. To identify opportunities for water conservation within agricultural fields, the SWAP model was applied to simulate crop growth and field water balance for three major irrigated crops, i.e. wheat, maize, and sugar beet in the Gamasiab River Basin, one of the highest groundwater using irrigated areas of Iran. The model simulations showed that by adopting improved irrigation schedules and improving farm application efficiencies, water productivity will increase, and irrigation water withdrawals from groundwater can be reduced significantly with no reduction in yields. While these improvements may or may not result in water saving and retarding the ground water decline, depending on the fate of excess application, they will have significant water quality, energy, and carbon implications. Such reduction in irrigation application can result in 40% decline in energy consumption and subsequently carbon emission of groundwater use. © 2011 Elsevier B.V.
Bagheri N.,Agricultural Engineering Research Institute |
Bordbar M.,Islamic Azad University at Marvdasht
Agricultural Engineering International: CIGR Journal | Year: 2014
A descriptive survey research was undertaken in order to assess challenges facing agricultural mechanization development in Iran. The research population included agricultural mechanization experts, managers and specialists in private and governmental sections. Using proportional stratified sampling, a sample of 119 was constituted out of a total population of 809 based on the Cochran formula. Data were collected using questionnaire on which the statements were collected after literature review of research and interviews with mechanization specialists. The questionnaire was validated by a panel of experts and its reliability index was established by a Cronbach's coefficient. A pilot study was conducted with 30 questionnaires (not included in the sample population) to determine the reliability of the questionnaire. Computed Cronbach's alpha score was 75%, which indicated that the questionnaire was highly reliable. All survey data were analyzed using the Statistical Package for Social Sciences (SPSS 16.0). The results of factor analysis indicated that 69% of the variances of the challenges could be classified in seven groups, namely: programming, technical, infrastructural, managerial, economical, research and extension, and content area. From each group the most important challenges facing agricultural mechanization development in Iran include: inefficiency of subside payment methods for buying agricultural machinery, large number of time-worn agricultural machinery, incomplete collection of agricultural equipments for power generator machinery (tractor), slow trend of beneficiaries in accepting new technologies, financial weakness of agricultural beneficiaries, inefficiency of agricultural extension and education methods, and weakness of agricultural machinery producers and operators in protecting their guild benefits.
Mousavi Nezhad M.,University of Exeter |
Javadi A.A.,University of Exeter |
Abbasi F.,Agricultural Engineering Research Institute
International Journal for Numerical and Analytical Methods in Geomechanics | Year: 2011
Water flow is greatly influenced by the characteristics of the domain through which the process occurs. It is generally accepted that earth materials have extreme variations from point to point in space. Consequently, this heterogeneity results in high variation in hydraulic properties of soil. In order to develop an accurate predictive model for transport processes in soil, the effects of this variability should be considered. In this study a two-dimensional stochastic finite element flow model was developed for simulation of water flow through unsaturated soils. In this model, the stochastic partial differential governing equation of water flow, obtained from implementation of the perturbation-spectral stochastic method on classical Richard's equation, was solved using a finite element method in the space domain and a finite difference scheme in the time domain. The effective hydrological parameters embedded in the mathematical model depend on time derivatives of capillary tension head; this makes possible to consider the hysteresis due to large-scale variability of soil hydrological properties. The model is also capable of simulating infiltration and evaporation events and rapid change in the land surface boundary condition from one type event to another, based on a scheme used in the model for implementation of land surface boundary condition. The model was validated with the data obtained from a layered lysimeter test. The model was also used to simulate water flow under a long irrigation furrow. The results obtained with this model show better agreement with experimental measurements in comparison with a deterministic model. The possible reason for this agreement is that in the developed model, the influence of the variability of the properties of soil and effects of parameter hysteresis on water flow and water content redistribution are considered. © 2010 John Wiley & Sons, Ltd..
Bagheri N.,Agricultural Engineering Research Institute
International Journal of Remote Sensing | Year: 2016
An autonomous unmanned aerial vehicle (UAV)-based aerial remote-sensing system was developed for multispectral imaging of agricultural farms. This system consists of on-board and ground-station subsystems. The on-board subsystem was equipped with body and wings, eight DC brushless motors and eight speed controls, an inertial measurement unit (IMU), a global positioning system (GPS), a rechargeable three-cell lithium-polymer battery, a high-resolution multispectral camera, camera mount, and autopilot intelligent navigation system. The ground station was equipped with a radio control, TV monitor, laptop, and flight monitor software. In addition, a telemetry system was used to communicate between the on-board and ground-station subsystems. To investigate the performance of the UAV, several flight tests were carried out in wheat farms, and some technical features of the system were investigated. The acquired imageries were processed and evaluated. The spatial resolution of the imagery obtained from a height of 10–250 m was 3.6 –95 mm/pixel, respectively. Based on the results, the UAV remote-sensing system proved to be extremely promising for monitoring the temporal changes in the studied farm. The supervised classification map with 94% overall accuracy and kappa coefficient of 0.9 emphasized the conclusions. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Gazor H.R.,Agricultural Engineering Research Institute |
Mohsenimanesh A.,Agricultural Engineering Research Institute
Czech Journal of Food Sciences | Year: 2010
Canola, one of the new oil seeds in Iran, is investigated for drying in Batch fluidised beds. Experiments were conducted to assess the kinetics of drying in the temperature range of 30-100°C. The drying rate was found to increase significantly with increasing temperature. The drying rate was compared with various exponential time decay models and the model parameters were evaluated. The approximate diffusion and logarithmic models were found to match the experimental data very closely with the maximum Root Mean Square Error (RMSE) less than 0.02. Considering fewer differences in the model evaluation factors and friendly use, logarithmic model was recommended for modelling canola drying. The experimental data were also modelled using Fick's diffusion equation, the effective diffusivity coefficients having been found to be from 3.76 × 10-11 m2/s to 8.46 × 10-11 m2/s in the range of experimental data covered in the present study. For the process, the activation energy was calculated to be 11.03 kJ/mol assuming an Arrhenius type temperature reliance.
Sharifi A.,Agricultural Engineering Research Institute |
Mohsenimanesh A.,Agricultural Engineering Research Institute
International Agrophysics | Year: 2012
A multi-tips horizontal sensor was developed and mounted horizontally on a tine face by shafts. The length of shafts was reduced from top to down the tine. The developed system was evaluated in the controlled soil bin laboratory conditions with clay loam soil and uniform soil moisture content. The experiment was designed with soil compaction at three levels of uniform and non- uniform soil compaction in completely randomized block design with four replications. Vertical standard penetrometer was also used to compare with horizontal sensor data at whole working depth of 0 to 400 mm. The results indicated that there is a correla- tion with R 2 = 0.86 between soil cone penetrometer values and the horizontal soil mechanical resistance measurement system data. It can be concluded that the idea of reducing the length of the tips from top to down the tine face would give promising results. © 2012 Institute of Agrophysics, Polish Academy of Sciences.
Tajeddin B.,Agricultural Engineering Research Institute
Polymers and Polymer Composites | Year: 2015
A viable solution for replacing petroleum-based materials is to combine petroleum and bioresources materials to produce biocomposites having the requisite properties for packaging applications. Although biocomposites have many applications in different purposes such as building construction and aircraft industries, their applications in the packaging engineering are still novel. Therefore, in this study, a biocomposite consisting of low-density polyethylene (LDPE), wheat straw (WS) and the compatibilizers Maleic Anhydride Polyethylene (MAPE) and Polyethylene Glycol (PEG) with molecular weights of 400 and 600, was produced based on the requirements of the packaging industry. By performing different mechanical tests such as tensile, flexure and impact, the effects of the compatibilizing agents was determined. The ratios of the matrix to the filling phase applied to the compound were 70/30, 60/40, 50/50, and 40/60, and the compatibilizers were used at the levels of 0, 7, and 10% respectively. The MAPE compatibilizer improved the tensile properties. The compatibilizer type had no effect on the impact strength properties of the biocomposites. The flexural strength of all compounds was higher than that of the control.
Tajeddin B.,Agricultural Engineering Research Institute
Advanced Structured Materials | Year: 2015
Natural nanoscale materials can be used in many applications like packaging industry. The main reason is to provide packaging which would protect the food from dust, gases, light, pathogens, and moisture. These materials are mainly safe, inert, cheap to produce, easy to dispose, and reuse. In addition, the characteristics of these nanocomposites such as mechanical, electrical, thermal, optical, and electrochemical properties will differ markedly from that of the component materials. One of the most practical uses of nanocomposites in the food packaging is adding the nanosized components to the traditional packaging materials such as metal, glass, paper, various synthetic plastics like PE, PP, PS, PVC. Also, the use of nanofiller materials in the biofilm preparation has been subjected in the many recent studies. Therefore, this chapter is an attempt to introduce various bionanocomposites to readers and provide a general overview of these natural nanopolymer applications in the food packaging industry as well as some practical examples. In effect, nanopackaging materials were developed by clay minerals, e.g., montmorriolonite, in 1986 and are still being grown using many different natural polymers. However, natural nanopolymer applications in the packaging industry can be organized around the main topics, to introduce nanocomposite organic/inorganic materials and to introduce some good examples to produce films, coatings, etc. Detailed discussions about each of these topics are also considered in this chapter. © Springer India 2015.
Sharifi A.,Agricultural Engineering Research Institute
Agricultural Engineering International: CIGR Journal | Year: 2016
Soil mechanical resistance induced by compaction of agricultural soils is one of the main concerns as it restricts crop yield. In this study two cone and prismatic tips were compared to measure soil mechanical resistance by a multi-tips horizontal sensor. The horizontal sensor equipped with S-shaped load cells was mounted on the backside of each tip. A factorial experiment was designed with two types of tip and three levels of soil compaction. Experiments conducted in the soil bin laboratory. Comparison results between the two cone and prismatic tips of horizontal sensor showed that soil mechanical resistance measured by the sensor had significant differences with each other and also with vertical cone penetrometer data. Cone tip had greater values than prismatic tip at all levels of soil compaction. It can be concluded that the horizontal sensor can be used for measuring soil mechanical resistance with both tips. However, the results of prismatic tip had better linear correlation with vertical penetrometer data. © 2016, Int. Comm. of Agricultural and Biosystems Engineering. All rights reserved.