Agricultural waste management
M. Khoshdel; S. J. Hashemi; S. M. Zabihzadeh; R. Esmaeilzadeh Kenari
Abstract
IntroductionThe use of agricultural waste to produce biodegradable containers is an appropriate option to solve the problem of biomass accumulation resulting from the cultivation of crops such as rice. The highest amount of agricultural waste compared to the area under cultivation is related to wheat ...
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IntroductionThe use of agricultural waste to produce biodegradable containers is an appropriate option to solve the problem of biomass accumulation resulting from the cultivation of crops such as rice. The highest amount of agricultural waste compared to the area under cultivation is related to wheat straw and rice straw, respectively. After wheat, rice is the most important agricultural product in human nutrition. According to the World Food Organization, the area under rice cultivation in the world is about 150 million hectares. The use of rice straw as a raw material for disposable cellulosic dishes can prevent straw residues in paddy fields, improve the deficiency of cellulosic raw materials, and reduce the use of plastic containers and the dangers thereof. Rice straw is a significant source for making cellulosic containers, but after making containers, hydrophobicity and microbial hazards can be among the problems of making these types of containers. The coating technique is one of the best solutions for resolving hydrophobicity and microbial problems. Coverage is very important and necessary to increase the shelf life of agricultural products and maintain their quality. Waxes are the best preventative methods against moisture and water vapor loss, and beeswax is one of the best edible waxes with these properties. The antibacterial properties of coatings with natural antioxidants will help solve the cellulose containers' problem. The main objectives of this study were to evaluate the endurance, hydrophobicity and antimicrobial activity of rice straw degradable cellulosic dishes.Materials and MethodsIn order to obtain the raw material for the manufacture of cellulosic dishes, the straw was digested with 10% and 20% sodium hydroxide, and then to weigh the hydrophobicity tests, tensile strength index and brightness, 120 Gr paper was made. Concentrations of 1, 2, 5 and 10% of the wax solution in ethanol solution were prepared and used as the first coating to improve the hydrophobicity. The nettle extract encapsulated with royal seed gum as the second coating to improve the antibacterial activity. Hydrophobicity and antimicrobial properties of the samples were measured and compared. The cup mold specimen was made of 2-piece steel and made using appropriate rice straw paste and coating with the appropriate concentration of the sample in disposable cellulose.Results and DiscussionThe results showed that increasing the amount of sodium hydroxide in baking conditions increased the tensile strength and the degree of clarity, but it had no effect on hydrophobicity. As the concentration of baking soda (sodium hydroxide) increases, so does the brightness. Increasing the concentration of sodium hydroxide increases the tensile strength, and the increase in tensile strength due to the increase in the percentage of sodium hydroxide can be due to the increase in the ability to form bonds between fibers due to the release of lignin. Honey wax with a 5% concentration was the most optimal coating for hydrophobic cellulose containers. With increasing wax concentrations in ethanol solvents from 1 to 10 percent, water absorption by the paper made from rice straw has decreased by approximately 93 percent. Adding royal seed gum and nettle extract has a positive effect on the diameter of the halo and has antimicrobial properties. Honey wax with 5% and 10% concentration with nano-encapsulated nettle extract with royal seed gum was selected as the most suitable coating to improve antibacterial activity.ConclusionDue to the characteristics of rice straw and the experiments shown, rice straw can be considered as a suitable alternative to oil resources in the production and usage of disposable tableware. Rice straw has the potential to be used as a cellulose source for the production of disposable containers, and honey wax with a 5% concentration and nano-encapsulated nettle extract can improve the hydrophobic and antimicrobial properties as the airtight coating of the dishes.
M. Barzegar Tabrizi; S. J. Hashemi; R. Karimi
Abstract
Introduction Improving the efficiency of all agricultural operations has always been important for farmers and engineers. It is well known that the force required for cutting a soil using narrow blades is a function of soil and environmental physical properties, tool shape geometry and the tool’s ...
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Introduction Improving the efficiency of all agricultural operations has always been important for farmers and engineers. It is well known that the force required for cutting a soil using narrow blades is a function of soil and environmental physical properties, tool shape geometry and the tool’s surface characteristics like soil-tool adhesion and friction. Soil tool adhesion can reduce ploughing efficiency and quality. It may also halt the movement of tillage machines in more severe conditions. Adhesion can also disable some machine abilities, which can result in a significant reduction of machine performance. Adhesion of the soil to seed-bed preparation tools like furrowers can significantly affect the germination rate. Reducing soil tool adhesion of furrowers can reduce draft force and improve ploughing efficiency. Many researchers have worked on methods of reducing draft force by modifying the surface material and/or surface texture of the plough tools. A good prediction on draft force of a tool before producing it has always been important for farmers and engineers. There are some models for predicting the draft force of narrow blades in soil. McKyes-Ali’s model is widely used because of its accuracy and simplicity. Ultra-high molecular weight polythene (UHMW-PE) is a polymer with ultra-high weight and long molecular chains and is well known for its outstanding physical and chemical properties and self-cleaning abilities, which reduce soil-tool adhesion. The aim of this study was to investigate usability of UHMW-PE coated furrower tines for draft force. Analytical and experimental investigations were carried out during the research. A comparison was conducted between the analytical and the experimental method. The results of this comparison can be used to determine reliability of the analytical model for predicting the draft force improvement caused by the surface modification on tines using different surface coatings. Materials and Methods Eight tines have been built. Four of them had a thick coating layer of UHMW-PE, and the other four were made of pure mild steel. Each set of the tines have been installed on a four shanked chisel plough chassis and then attached to a tractor. The draft force required for pulling the furrowers attached to the tractor has been measured by a simple load meter mechanism connecting two tractors. Draft force has been measured in two different speeds. Slip ratio of the tractor has been recorded. Each test has been repeated three times.McKyes-Ali’s proposed model for evaluating the draft force of narrow blades has been chosen to predict draft force of the traditional steel furrower tines and the surface coated ones. To drive the model, a computer program has been coded in the script environment of Matlab software. The model required some of the mechanical properties of the soil and the tool to operate. Specific gravity, cohesion and internal friction angle of the soil have been measured by routine laboratory methods. Soil-tool adhesion and friction of the mild steel and the UHMW-PE plates have been measured using the direct shear apparatus. Results and Discussions MkKyes-Ali’s model has predicted draft forces with an accuracy of 90%. According to the results of the driven model, applying a UHMW-PE coating layer to the surface of the tines can improve draft force by 13%. The change of tractor speed from 3.5 km h-1 to 5.5 km h-1 have no significant effect on the predicted draft forces. The model also predicted different angles of the soil failure zone for coated and uncoated tines. On the other hand, the improvement of the draft force for the UHMW-PE coated tine in the field test was about 27%. According to The results obtained from the field test, the draft force of the furrower tines had significant correlation with the speed. Conclusion The UHMW-PE coated tines required significantly less draft force to work in compare with the steel tines. McKyes-Ali’s model predicted a significant improvement (13%) in draft force for the UHMW-PE coated tines. According to the experimental results, the improvement of the draft force was about 27%, which was almost twice as predicted. Although the McKyes-Ali’s model could predict an improvement for draft force of the UHMW-PE coated tine, but the actual improvement was about twice of the prediction. According to analytical and experimental results, applying a layer of UHMW-PE plastic on furrower tines can improve the draft force significantly.
R. Tabatabaei koloor; A. Kolouri; S. J. Hashemi; R. Hadipour Rokni
Abstract
Apple fruits are subjected to different loading from harvesting to supermarket shelf. Bruising has been attracted many researchers as one of the most important damage criteria. In this research, the effects of some factors such as contact surface material, drop height and linear velocity of apples were ...
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Apple fruits are subjected to different loading from harvesting to supermarket shelf. Bruising has been attracted many researchers as one of the most important damage criteria. In this research, the effects of some factors such as contact surface material, drop height and linear velocity of apples were investigated. Influence of these factors on bruising of “Golden Delicious” variety was analyzed by a Completely Randomized Design (CRD) with factorial test at three level of drop height (10, 20 and 30 cm), linear velocity (0.05, 0.1 and 0.15 ms-1) and four contact surface (wooden, steel, plastic and cardboard). Tests were conducted at three replications with 108 treatments. Analysis of variance results showed that the effects of drop height and contact surface material on bruising area at 1% level was significant while bruising volume only affected by contact surface material (meaningful difference at 1% level). Mean comparison test indicated that there significant difference between levels of drop height on the bruise area. Also, there was a meaningful difference between contact surface of cardboard with steel, wood and plastic. There was a significant difference between surface materials of steel and wooden with cardboard and plastic. Therefore, drop height and contact surface material must be considered in designing the apple processing systems.
