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Accurate analysis of bitumen behavior as a viscoelastic material and its natural phenomena such as aging are important issues in pavement engineering. Therefore, controlling the low and high temperature properties of bitumens is essential to prevent low temperature cracking and common high temperature distress in order to provide proper service throughout the pavement life. In this study, the aging phenomenon and its effects on the mechanical properties of bitumens were simulated using the Superpave method, namely the RTFOT method for short-term aging and the PAV method for long-term aging. In order to investigate the effect of repeated PAV cycles on the properties of bitumens, three types of bitumen with different penetration degrees of 40-50 (PG70-16), 60-70 (PG64-22) and 85-100 (PG58-28) were selected and three samples of each were subjected to one to three PAV aging times. The beam shear rheometer (BBR) test was performed at three temperatures from 0 to -12°C and the dynamic shear rheometer (DSR) at seven temperatures from 46 to 82°C. Based on the results obtained, the high temperature performance of the bitumens increased by a maximum of three grades and their low temperature performance increased by a maximum of two grades. In other words, the grading of the triple bitumens, after three times of PAV, became 82-4, 82-10, and 70-16, respectively. Also, the relationship between the high temperature performance properties of the aged bitumens and their chemical changes at different times of aging was investigated and their changes were examined to show the correlation between these properties. The results showed that the high temperature viscoelastic properties and the chemical aging index of the different bitumens had a strong linear relationship with a coefficient of determination (R²) of more than 0.9.

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The pot life of high-energy composites is one of the most important parameters of their manufacturing process. This is mainly influenced by the pot life of the binder system. In this research, the effect of different amounts of two types of curing catalyst (dibutyltin dilaurate (DBTDL) and triphenyl bismuth (TPB)) and different ratios of NCO / OH (R) on the pot life and physical properties of the polyurethane binder system  based on Hydroxyl-terminated polybutadiene (HTPB) was investigated. By increasing the amount of curing catalyst for both types of catalysts, the viscosity build-up of the binder system measured by the rotation viscometer was intensified. Also, increasing the amount of R from 0.8 to 1 increases the viscosity and crosslink density. Isophorone Diisocyanate (IPDI) binder system shows two distinct steps of increasing viscosity with two different rates, which is attributed to the presence of two different isocyanate groups in the molecular structure of IPDI with different reactivity. In the following, the physical properties and swelling of binder samples were investigated. Based on these results, binders with the highest crosslink density have the lowest swelling. The pot life value increases from R of 1 to 1.1, contrary to expectation, with pot life range value between R of 1 to 0.9. When using the DBTDL catalyst, it is clearly identifiable between different reactivity of two groups IPDI isocyanates, but when used with the TPB curing catalyst, this difference was not observed significantly.

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This experiment was conducted to determine the effects of three binding agents, including corn starch, carboxymethyl cellulose (CMC) and urea formaldehyde (UFA) (in diets containing 42% soybean meal) on growth performance, pellet water stability and chemical composition of Litopenaeus vannamei. Shrimps with an average initial weight of 0.73 g stored in polyethylene tanks and fed experimental diets for 52 days (four treatments and three replicates). Biometric measurements of shrimp were carried out in two periods of 15 and 21 days. At the end of experiment results showed that the average final weight of shrimp fed the UFA binder is significantly lower than other treatments (p<0.05). Specific growth rate at three sampling periods (p<0.05) and at the end of experimental (p<0.01) was significantly affected by the type of binder, with the lowest SGR in UFA and highest in shrimps were fed control diet. Statistical analysis showed that chemical body composition of shrimp was not significantly affected by dietary treatments. In general, according to the results of diet stability, growth performance and feed utilization as well as shrimp body composition, corn starch is a good binder for whiteleg shrimp feed.

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Research subject: The binder system based on of hydroxyl-terminated polybutadiene resin (HTPB), consist of dioctyl sebacate as a plasticizer (DOS), and toluene diisocyanate as the curing agent. Reaction between the HTPB hydroxyl resin group and the curing agent isocyanate group produces a polyurethane mesh to produce a rubber with the desired properties. In this research, the rheological and mechanical properties of the binder system were investigated and Physical properties compared in the presence of three chemicals retarder polymerization Polyurethane, oxalic acid, maleic acid and tetracycline.
Research approach: Oxalic acid, maleic acid and tetracycline alter the properties of the binder system by specific mechanisms. Oxalic acid and maleic acid react with the isocyanate group of the curing agent to produce amides and reduce the viscosity of the binder system. Due to its chemical structure, tetracycline reacts with the curing agent and prevents the development of the main reaction between the HTPB resin and the curing agent TDI and reduces the viscosity. Infrared Fourier transform (FT-IR) test was also used to investigate the functional mechanism of these compounds. In this test, the intensities of the spectra related to each sample were compared with each other and the type of function and mechanism of each of the oxalic and maleic substances and tetracycline were determined.
Main results: The structure of the reaction product between HTPB resin and oxalic acid, maleic acid and tetracycline with curing agent was determined and confirmed by FT-IR spectrum. In-situ FT-IR study showed reduction in isocyanate peak intensity after 60/90 min. Chemorheological investigation showed best performance at 0.05% concentration for all retardants, among them tetracycline, oxalic acid and maleic acid depicted 54%, 48% and 47% reduction in viscosity build-up; respectively. Adding 0.05% of tetracycline to binder system resulted in about 20% decrease in cross link density probably due to better interaction with curing agent which emphasized the best performance of 0.05%-tetracycline as retardant.
 

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In the production of fuel briquettes, different additives are used in order to improve the technical parameters. In the present study, two types of lignocellulosic binders including nanocellulose and lignin have been used. Due to the different chemical structure and difference in calorific value of each of these two materials (lignin and nanocellulose) and the difference in their mechanism of action on improving the thermal properties of fuel briquettes, in order to evaluate the final product of thermal analysis using calorific value and TGA and DTA diagrams were used. The results show the positive effects of the use of cellulosic binders in improving the thermal behavior of biofuel briquettes. Thermal analysis showed that 9% nanocellulose and 9% lignin treatments with 19.85 MJ / Kg and 25.75 MJ / Kg had the highest calorific value compared to the control sample, respectively. The diagram obtained from thermal analysis (TGA) of the control sample and the samples treated with lignin and nanocellulose show that the treated samples have lower weight loss rate, higher burning rate and higher burning temperature.

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Metal Injection Molding (MIM) is a novel manufacturing technology, used for complex geometric parts at a high production rate. One of the most important parameters in this method is the selection of proper feedstock consisting of optimal powder loading and an optimized binder system. The defects, which appear during the injection process, cannot be removed in later process stages and this is for the reason that the rheological behavior of the feedstock needs to be checked to make sure that it has the required injection properties. In this study, a multi-component wax-based binder system has been selected in order to inject Fe-2Ni powder. For this reason, a multi-component wax-based binder system with different percentages of constituents was used to produce 11 feed modes containing 60% vol. % of the powder. Further, the viscosity and its variation with the shear rate for 11 developed samples have been measured. The results showed that the feedstock consisting of 66 vol. % Paraffin wax, 19 vol. % Polypropylene, 10 vol. % Carnauba wax and 5 vol. % Stearic Acid has the lowest viscosity and lowest sensitivity to the shear rate and this leads to the complete filling of the mold cavity and production of a healthy component for very complex geometries. After achieving the proper binder system, the critical powder loading for the binder system was measured by 58 vol. % using torque rheometer.
 

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Nanomaterials have been used in the recent years to improve rheological properties of the asphalt binders and increase mechanical properties of the asphalt mixtures. The high cost of producing nanomaterials is one of the major obstacles that has limited their application in road pavements. In this research, two methods of producing nanomaterials have been applied to produce nano hydrated lime (NHL). The first method was a mechanical process of milling hydrated lime with the application of a planetary ball mill. The second method was chemical processing of dissolving certain chemical materials (namely, calcium nitrate Ca(NO₃)₂, sodium hydroxide NaOH and sodium dodecyl sulfate SDS) into distilled water. The process resulted in the production of NHL solution that after drying in an oven resulted in NHL particles. The sizes of the NHL products were measured using two methods of Field Emission Scanning Electron Microscope (FE-SEM) and Dynamic Light Scattering (DLS). The size analysis was performed on NHL samples that were produced after different milling periods in the physical method; and, variation of the concentration of the solution, mainly calcium nitrate and SDS, in the chemical method. The average particle sizes in the physical method, after 6 hours of milling, were 211 nm, as measures in DLS and 114 nm as measured in FE-SEM. These in the chemical method, at concentration of 3 ml of calcium nitrate solution (Ca(NO₃)₂), were 379 and 124.615 nm respectively. With the chemical method, the nano particles were formed in the plate form with average thickness of 68.5 nm. In addition, X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis were performed in order to determine the composition of the produced nano materials. These indicated that with the physical method, a higher lime content material was produced. With the aim of assessing the effectiveness of the produced NHL materials to modify asphalt binders, a 60-70 and an 85-100 penetration grade were used and nano modified binders containing 2, 4 and 6% NHL were prepared and were tested under standard bitumen tests and viscosity determination. The results indicated that with adding NHL to the asphalt binders, penetration was reduced and softening point was increased. In addition, the temperature susceptibility of the modified binders were reduced too. Assessing the change of the viscosity of the NHL modified binders, it resulted that 4% NHL would provide the optimum conditions.