جستجوی مقالات مرتبط با کلیدواژه « پایداری » در نشریات گروه « مکانیزاسیون کشاورزی »

The purpose of this study was to investigate changes in energy consumption and environmental indicators in the production of crops, including sugarcane, wheat, canola and sunflower during the years 2018 to 2022. Relevant information was collected through statistics recorded in planning management of Imam Khomeini Sugarcane Agro-Industrial Company in Khuzestan province. Using these statistics and sources, the production situation of agriculture and industry products was investigated. Based on the obtained results, in sugarcane fields, energy consumption in the years 2018 to 2022 was calculated as 131.05, 142.47, 152.16, 155.45 and 161.71 GJ ha-1 respectively. Also, energy consumption was equal to 30.49, 32.70, 35.10, 36.52, and 38.02 GJ ha-1 in wheat fields in the considered period. On the other hand, for the production of canola in the years 2018 to 2022, it varied and was equal to 19.44, 20.81, 22.68, 23.83 and 24.86 GJ ha-1 respectively. Also, in sunflower fields in the same period of time, it was estimated as 44.19, 82.14, 61.15, 20.16 and 76.16 GJ ha-1 respectively. The results of environmental effects showed that the highest amount of pollution caused by the effect of resources in sugarcane production is in the mentioned years of 12.08, 12.64, 12.91, 12.40 and 12.47 USD2013. Also, in wheat production this index increased from 61.96 to 68.23, in canola production increased from 79.86 to 85.51, and finally, in sunflower production increased from 61.82 to 65.73. Based on the ranking of the by-products, sunflower, wheat and canola are prioritized for cultivation from the first to the third place respectively. Optimal use of electricity inputs, diesel fuel and chemical fertilizers can help reduce energy consumption and environmental pollution. In order to reduce energy consumption in the production of agricultural and industrial products, it is recommended to use renewable energy sources such as electricity produced from solar sources by photovoltaic systems.

Agricultural residues and wastes are the main source of biomass for use in bioenergy production and animal and poultry feed production industries. These biomasses in their original form have a large volume and low energy (per unit volume) and require a lot of space and extensive movement. Therefore, one of the methods of optimal use of these biomasses is to transform them into pellets, which have more mass and energy per unit volume and enable their easier use and transportation. Currently, biomass has the fourth place in energy supply after oil, natural gas and coal and provides approximately 14% of the world's energy needs. The use of biomass, especially in European Union countries, as an attractive source for replacing fossil fuels is developing and expanding. The use of biomass as fuel has significantly reduced the amount of environmental pollutants, so that the amount of CO2 absorbed from the atmosphere during biomass growth is similar to the amount produced during combustion, followed by a net cycle of production.

 The raw materials for making pellets were prepared from spruce wood sawdust (collected from a sawmill in Sari) as well as corn stalk and soybean residues in the fields of Dasht Naz in Sari. The desired materials were transferred to the laboratory in the necessary amount and kept at ambient temperature until the experiments. The samples were first crushed into 20 mm sizes and then powdered using a grain mill (Mehr Tehiz company, Iran) and passed through 18 mesh sieves in the range of 1 mm to make pellets. A palletization mechanism was used to compress the pellet. This system was designed and built in biosystem mechanics of Sari University of Agricultural Sciences and Natural Resources. The material was placed inside a steel mold with a cylinder inner diameter of 8.05 mm and a height of 150 mm with a blocked end. A piston with a diameter of 8 mm connected to the driving arm of the tension-compression test machine was used to compress the material. Loading by a piston with a quasi-static speed of 5 mm per minute is compressed to a pressure of 1300 N.

In this research, the mechanical and thermal properties of pellets made from the combination of spruce sawdust and corn and soybean residues were evaluated. In the present study, the effect of four combinations of agricultural and forest materials at two moisture levels (12% and 18% based on fresh weight) on the indices of density, compressibility, Hausner ratio, strength and calorific value of the produced pellets were investigated and evaluated. it placed. The results showed that the pellet density at 18% humidity was lower than the density at 12% humidity. The highest density related to the combination of 60% spruce wood sawdust-40% corn stalks was obtained with a value of about 149 kg/m3 and the lowest value related to 100% soybean stalks was about 110 kg/m3. Also, the ratio of Hanser and CI in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the permissible range. The highest pellet strength was 23.8 N/cm corresponding to 100% sawdust at 18% humidity and the lowest was 15.4 N/cm corresponding to 100% soybean stalk at 12% humidity. The calorific value of the pellets is in the range of 14.37 to 18.52 MJ/kg, which is the minimum value for the pellet made from 100% soybean stalk at 18% humidity and the maximum value for the pellet made from 100% fir wood sawdust and It was obtained at a humidity of 12%. Therefore, the use of agricultural wastes and their proper combination is a good option for the production of biofuels due to their density and strength.

 The type of biological waste and moisture percentage affect the physical and mechanical properties of the produced pellets. In general, the combination of spruce wood sawdust with corn stalks and soybean improved the mechanical and thermal properties of the pellet. Hanser's ratio and compressibility in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the standard range. Also, in the compositions that have a higher proportion of spruce wood sawdust and lower moisture, the density and strength factors of the pellet increase. The highest and lowest calorific values were obtained in a higher ratio of sawdust and a higher ratio of corn, respectively. Therefore, it is possible to make pellets from the waste of garden and agricultural products that have good density and strength and high calorific value.

The development of mechanization and machine technology can have positive and negative effects on the economic, social, and environmental conditions of a region. Conflicts in these areas complicate the selection and optimization of sustainable mechanization systems. One of the basic questions in the selection of a sustainable agricultural mechanization system is how and with what methodology would it be possible to propose the closest mechanization model that will overcome the simultaneous contradictions between the three pillars of sustainability; taking into account the natural and technical limitations in agricultural production. What is the appropriate approach considering the economic, environmental, and social aspects? The current research aims to provide a framework for an optimal mechanization model to achieve the goals of agricultural sustainability so that it can be implemented and applied practically. It is possible to provide a model that addresses the conflicting economic, social, and environmental aspects by quantitatively optimizing the level of mechanization.

In this study, a framework is applied whereby contradictory goals of agricultural sustainability can be achieved simultaneously. After selecting the indices and data collection, by combining Shannon entropy and TOPSIS, the similarity index was obtained for each objective. The similarity indices and values of the Benefit-Cost Ratio calculated for each system were considered as coefficients of three objective (economic, social, and environmental) functions in multi-objective optimization. The multi-objective optimization model was applied to achieve sustainable mechanization patterns and was solved using the NSGA-II algorithm. For framework validation, paddy production mechanization systems in the Ramhormoz region located in southwestern Iran were analyzed with constraints: land, water, and machinery. The five mechanization systems of paddy production included puddled transplanted, un-puddled transplanted, water seeded, dry seeded, and, no-till.

Pareto-optimal solutions of different scenarios with water and machine constraints showed that this framework cannot only meet the sustainable goals, but also the optimal allocation of mechanization systems is identified and the effect of different scenarios under different constraints can be examined. The sustainability goals between the no-tillage and planting with puddling systems are highly contradictory. The no-tillage system has the highest score in the environmental aspect and the lowest score in the social and economic aspects. This modern system was developed in Ramhormoz three years ago and has faced technical, economic, and social challenges ever since. The cultivated area using this system was 43 hectares in 2019. Despite the speed and ease of planting with this system, and its direct environmental benefits, the possibility of fungal outbreaks is raised due to the presence of wheat residues from previous cultivation and the warm and humid environment of cultivation. Additionally, weed outbreaks caused by periodic irrigation have greatly affected the satisfaction and profitability of this system, leading to the highest amount of pesticides consumed among the studied systems. The results of multi-objective optimization of sustainable rice mechanization systems in Ramhormoz city showed that the total surface area of optimal point systems is in the range of 2700 to 3200 hectares, which is close to the area under rice cultivation in Ramhormoz (3310 hectares) and it indicates that the output of the model is according to the applied restrictions and close to reality. The limitation of machinery and water has made the two planting systems of un-puddled transplanting and dry-seeding better than other systems. Removing only the machinery restriction can lead to an increase in the area under rice cultivation by about 700 hectares. This means that the requirement for the development of sustainable rice cultivation in Ramhormoz is to strengthen and support modern mechanized systems of no-tillage, dry-seeding, and planting with puddling, with a focus on systems with less water consumption which are the systems with higher levels of mechanization. Without water limitation, if the model is subject to the current machinery limitations, the optimal mechanization systems are the more traditional ones such as transplanting without puddling and wet-seeding.

One of the most fundamental challenges in the development of mechanization is identifying systems that can best balance the economic, social, and environmental aspects of sustainability and minimize environmental damage whilst maximizing economic and social benefits. Using the framework for sustainable mechanization will not only accomplish sustainable goals in identifying the optimum agricultural mechanization level, but it will also allow researchers and implementers in the agricultural sector to examine the outcome of various scenarios under different constraints. This framework can be used to find the optimal model for mechanization of all stages of tillage, planting, harvesting, and post-harvest in diverse geographical areas.

Applying agricultural operations under different mechanization systems has different economic, social, and environmental consequences. Conflicts among these dimensions complicate the selection and allocation of sustainable mechanization systems. In this study, a method was used to allocate optimal patterns of spraying and harvesting systems in the Ramhormoz region to achieve agricultural sustainability. Indices included satisfaction, ease of work, health and safety, employment in the machine sector, labor force, diesel fuel consumption, pesticide consumption, farm load intensity, and operating costs. Three spraying systems namely backpack, tractor, and unmanned aerial vehicle (UAV), and three harvesting systems namely two-stage (harvesting and manual feeding to grain combine), direct harvesting with a grain combine harvester, and harvesting with rice combine harvester were included in the model. Combining AHP and TOPSIS methods, the similarity index for social and environmental dimensions was calculated and this value along with the cost of each system was used as coefficients of objective functions. The multi-objective optimization model to achieve sustainable agricultural mechanization was analyzed using a genetic algorithm. Pareto optimal results showed that in the absence of existing machine constraints, the development of the operational capacity of modern systems like spraying with UAV up to 2000 hectares and direct harvesting with rice harvesters up to 1000 hectares will be optimal scenarios for agricultural sustainability. Using the proposed method, not only can sustainable goals be achieved in identifying the best patterns of mechanization systems, but it is also possible to examine the effect of different scenarios under different constraints.

In this paper the effect of different milling processes (high shear blender, ceramic mill and ball mill, and stone mill) on the structure and size distribution of sesame paste particles was investigated and rheological properties of the resulting paste samples were analyzed. Sesame paste was a fluid suspension of protein–oil. The results indicated that the stone mill for 10 min in comparison to other mill processing can significantly affect on size reduction of the particles in sesame paste, improving the rheological properties and stability of the product. The results indicated that the colloidal stability of sesame paste was improved by decreasing the median particle size to values below 5 µm. Shear thinning behaviors were observed for different sesame paste samples. Creep test showed that the elastic structure of sesame paste changed to a viscous behavior with decreasing particle size that was also related to the milling method. Whiteness (L-values) of sesame paste decreased with the reduction of particle size.

Introduction: Drying is one of the important stages after harvesting of plants and agricultural products, which plays an important role in the quantity and quality of the active ingredients. The purpose of drying is to reduce water to a certain level for low and stop the microbial activity. Therefore, in laboratories the effects of different levels of temperature and time are investigated on different plant properties during drying operations with laboratory dryers and ovens. It can be said that the principled and thorough drying of medicinal plants is necessary in order to reduce moisture, increase the shelf-life and increase the quantity and quality of the active ingredients.
Today, many control algorithms are used to control temperature, which is much more efficient than the on-off. Fuzzy control is suitable for fast control and high accuracy of proper nonlinear processes. Likewise, the type of ventilation and the placement of thermal elements are also very influential on the heating system and the temperature of the chamber. Today as foreign companies, in addition to focusing on the type of control system and intelligence ovens, many studies have been done on how the element is placed, on its type, the shape of the fan, its type, and the design of the air channels. Materials and Methods: The dryer was designed with software Solid Works and constructed in manufacturing workshop of the Bio-System Mechanics Engineering Department of the Natural Resources and the Agricultural Sciences University of Gorgan, Iran. The device has a fuzzy control system, a ventilation, and fan system. The built-in dryer has two mechanical and electrical parts. This dryer has an external chamber with dimensions of 74 × 50 × 60 cm and internal chamber dimensions of 40 × 35 × 50 cm. The device was insulated with thermal spray foam. The electronic circuit was designed using Proteus simulation software and implemented on the board. The main piece of information processing and controlling the algorithm in the dryer control system is the microcontroller. The microcontroller programming was written by C software and transmitted to the microcontroller with the Code Vision software. The tests were performed at three levels of 60, 80, 90 °C. The programmability of the device was also evaluated simultaneously for four different temperatures and times. The device was evaluated at 4 levels of 90, 70, 50 and 30 °C and four levels of the time were done respectively 10, 10, 10, and 20 min. Also, in the process of increasing temperature, the temperatures of 40, 60, 80 and 90 °C respectively were tested. Also, the stability function and the time to reach the temperature were compared with two samples of the laboratory dryer (oven) imported Memmert and Bender models which had a fuzzy control system and a ventilation system and a built-in oven model in the interior. Results and Discussion: Because exactly as wasted, the temperature of the chamber walls is applied to the chamber, the device is capable of maintaining the temperature of the chamber at the set point. The result of the evaluation in the energy waste from the wall of the device showed that after about 200 min, the temperature of the internal chamber (which was at 80 ° C) was equal to the outside temperature of the chamber. The results showed that during temperature stability, the difference in temperature between different points of the compartment (places where laboratory samples are placed) is less than ±0.5. The programmability of the device was evaluated at 4 levels of 90, 70, 50 and 30 °C; after reaching the temperature of 90 °C, and at the end of the scheduled time, the temperature is reduced to a minimum, reaching the next temperature. Reducing the temperature for other temperatures was also done according to the program. The results of the programmability of the device were shown in the incremental step of the temperature; in the incremental process, as the temperature decreases, the temperature difference between the points is very small and reaches the temperature stability as soon as it reaches the regulated temperature. The control system used can properly maintain the temperature in a stable state. The results of the comparison of the performance of the dryer control system made with other experimental dryers at a temperature of 80 ° C showed that the dryer was able to stabilize the inside of the compartment at the desired point, in comparison with other ovens. The built-in dryer function is compatible with the Memmert UFE500 and the Binder FE53 ovens. Due to the cost of the device, its use will be very useful for conducting research in research centers. Conclusion: The fuzzy control system used in the dryer was able to properly control the temperature of the chamber according to the program. The control system of the device was able to control the temperature of the chamber at a regulated point with a minimum temperature variation (less than half a °C). The built-in dryer was able to reduce and increase the temperature step by step in a given temperature range according to the given program. The performance of the dryer, compared with other ovens, showed that it could match the best of imported ovens.

As a native fermented dairy drink, doogh is an important industrial product in Iran. However, its characteristics have not been completely evaluated. This study evaluated the flow behavior, particle size distribution and stability of non-fat doogh as affected by the row material employed (fresh skim milk or skim milk powder) and the total solids (TS) content of the final drink. The viscosity of samples produced using fresh skim milk was 1.73 ± 0.24cPs. Those produced using skim milk powder exhibited higher viscosity resulting from bigger particle size. Increasing the TS content caused the viscosity of the doogh to increase, but the volume of the separated serum was reduced. Flow behavior became non-Newtonian at higher TS contents. Evaluations indicated that the colloidal particles existing in doogh were distributed among a wide range of sizes. Different particle shapes with complex structures were observed.

Stability of ten pre-release rice cultivars (genotypes) were determined by sowing them in Randomized Complete Block Design (RCBD) with 4 replications at 3 locations (Rasht, Roudsar and Masal) and three consecutive years (2004-2006). In current study, traits such as grain yield, panicle number, 100-grain weight, plant height, panicle length, days to maturity, amylose content, gelatinization temperature, gel consistency and total rice recovery were measured. Combined analysis over all the three locations and years revealed high significant differences for studied genotypes. The genotype × location × year (G×L×Y) interaction was significant for all characters. Stability analysis revealed that promising line No 6 (IR75479-199-3-3) is the most stable genotype, since it showed the lowest coefficient of variation and mean square within each of the location. This stable high yielding cultivar with moderate amylase content is comparable with Iranian traditional land races. There fore it is suitable for releasing as a new cultivar for Guilan province conditions.