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The extrusion process is widely used in making aquatic feeds. The aim of this study was to investigate the effects of extrusion on biochemical analysis, removal of phenolic compounds and protein and carbohydrate digestibility of wheat flour in common carp. In treatments 1, 2 and 3 wheat flour was mixed with tap water at the rate of 250, 100 and 200 ml per kg of flour and then extruded by a single-axis extruder under the temperature of 120, 135 and 120 °C, respectively. Treatment 4 (control) was not subjected to the conditions of dough preparation and then extrusion. Extruding had no significant effect on the amount of crude protein and ash of wheat flour (p>0.05) but it significantly decreased the content of crude lipid, total phenolic compounds and non-tannin phenolic compounds and increased the digestibility of carbohydrate and protein (p<0.05). There were no significant differences in the amount of crude protein, crude lipid, ash and non-tannin phenolic compounds in the extruded treatments, but significantly the lowest amount of total phenolic compounds was recorded in treatments 1 and 2. Significantly, the highest carbohydrate digestibility was obtained in treatments 1 and 2, and the highest protein digestibility was observed in treatment 2. In total, treatment 2 (135 °C and 100 ml tap water per kg flour) was recognized as the best extruded wheat flour for common carp.
 

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In this paper, the multi-objective optimization of twist extrusion process is carried out using the artificial neural network model and the genetic algorithm. the target purpose functions are equivalent plastic strain, strain distribution and extrusion force. the design variables are twist angle, friction factor and the loading rate. the FEM model of the process is first created and used to create training cases for the ANN, and the well-trained ANN is used as a quick and exact model of the process. Then the optimization of the design variables is conducted by an integrated genetic algorithm and the ANN model to create a set optimal solutions (pareto front).

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Snacks are amongst popular foods, therefore improving the quality of the snacks is of great importance. Half-products are a kind of cereal based snacks that are sold in the form of dried pellets and then deep-fried for a few minutes by the consumer to form puffed crispy edible snacks. The main aim of this study was to determine the sufficient pellet moisture content in order to reach an appropriate snack quality.  Pellets were produced using a single screw extruder by mixing wheat flour and starch to reach moisture content of 7.5%. The moisture content of the pellets was then adjusted on 5, 10, 12, 14 and 16%. Pellets were deep-fried at 185 °C to reach their maximum volume and then their physical and sensory characteristics were studied. Increasing the moisture content from 5 to 16% reduced the density, increased lightness, reduced redness and yellowness of the snacks. The fracture force to break of snacks reduced with increasing the moisture up to 10% but it reduced with further increase in pellet moisture content. Increasing pellet moisture up to 14% improved the sensory characteristics of the snacks while further increase in the moisture content reduced these properties. Adjustment of the pellet moisture content is a practical solution in the industry to improve the quality of the snacks. The most appropriate moisture content of the pellet was in the range of 10-12%. At higher or lower moisture levels, the sensory characteristics of product were affected, negatively.

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In this paper, a new forward extrusion process is proposed for producing large-diameter tubular components. At the beginning of the process, a round billet is located in the container and then extruded into a preliminary die with three bean-shaped holes forcing a hole in the original billet. The material is then entered into another die with a diverging and converging surfaces designed to weld the material and decrease the tube thickness. Material flow behavior, applied strain and the required process load were predicted using finite element (FE) simulations. The results showed that the new extrusion process had three important advantageous namely a lower process load and a container with a smaller diameter while applying much higher plastic strain compared to the conventional methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . .. . . .. . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . .. . . . . .. . . . . . . . . . . . . . . . . .

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In this paper, an upper bound analysis for novel backward extrusion has been presented. Initially deformation zone has been divided to four separated regions and an admissible velocity field for them has been suggested. Then total power in this process has been calculated for every region and extrusion force has been gained. Moreover investigation of relevance of extrusion force and process powers (friction, deformation, velocity discontinuity) with process parameters has been revealed better understanding in load estimation and process efficiency in this method. Finite element analysis by DEFORMTM3D has been done for validation of upper bound results. Upper bound analysis showed, increasing of initial billet diameter enhances extrusion force by nonlinear relation. In addition big billet size remodels novel backward extrusion to conventional backward extrusion and it proves lower requirement extrusion load in novel backward extrusion in comparison with conventional backward extrusion. Moreover Increasing of first region’s thickness in this process diminishes extrusion force by exponential relation and no considerable change in extrusion force can be seen in a particular thickness domain. Investigation of process parameters in power efficiency shows that bigger extruded part’s diameter creates critical condition in process efficiency because of high friction power. But increasing of thickness enhances power efficiency. Finally upper bound analysis results have a good agreement with FEM.

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In the extrusion of sections with a multi-hole flat-faced die, the proper positioning of the die holes is of critical importance in avoiding the appearance of geometrical defects. In this paper, a methodology has been presented for radial positioning of the die holes in multi-hole extrusion process. A die with two non-symmetric T-shaped holes has been chosen as the computational example. A kinematically admissible velocity field at deformation zone has been obtained. The effects of dead metal zone formation have been considered in prediction of the velocity field. To measure the exit profile curvature a deviation function has been suggested. Using the proposed function, the velocity field has been used for prediction of the exit profile curvature and accordingly positioning of the die holes. It was found that a balanced metal flow at the exit of extrusion die could be achieved if the position of holes is near the centroid of the die area. In order to validate the results, finite element simulation has been used. The proposed methodology can be extended to dies with greater number of holes and more complex shapes. This methodology helps the die designer to have a better quality extrusion process.

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Spaghetti samples were prepared by replacing wheat flour with defatted soy flour (DSF) at 0, 10, and 20% levels (w/w). Each sample had 4% gluten. In addition, xanthan gum was added at three levels (0.0, 0.2, and 0.4%) to spaghetti dough containing 20% soy flour as a modifying agent. Samples were extruded at 35 or 50^oC and dried at, respectively, 52^oC for 21h or 72^oC for 6 hours. The color, protein content, cooking loss, cooked weight, and firmness of all spaghetti samples were measured. A trained sensory group evaluated chewiness, firmness, stickiness, color, and flavor. The overall results showed that increasing protein level in spaghetti caused an increase in the firmness and cooking loss with a decrease in cooked weight and consumer acceptance. However, when xanthan gum was added to spaghetti dough containing 20% DSF, the positive properties of spaghetti, including cooked weight and consumer acceptances, were improved significantly and its negative aspects, including firmness and cooking loss, were reduced noticeably. When xanthan gum and DSF levels reached, respectively, 0.4 and 20%, and the spaghetti dough was extruded at 50^oC followed by drying at average temperature of 72^oC, the best spaghetti in terms of physico-chemical and organoleptic properties was obtained.

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In this research the abrasive flow finishing process (AFF) of AISI H13 hot work steel was studied and the effects of various process parameters such as flow pressure (extrusion pressure), abrasive particles densities, abrasive particles sizes and the first quality of surfaces on variations of surface roughness and material removal have been investigated. The results showed that increasing the density of abrasive particles leads to increase in variations of surface roughness and material removal. Increase of extrusion pressure from 4 to 6 MPa causes the increase in variations of surface roughness and material removal and from 6 to 8 Mpa leads to decrease in the two latter. Electron microscopic results showed that increase of finishing process time over 4 hours causes a detrimental effect on the surface of the specimens, as a result of penetration and stabilization of abrasive particles in the form of broken particles. Also according the results of this paper, increasing the size of abrasive particles leads to higher variations of surface roughness and material removal, and this process is more effective in finishing of rougher surfaces.

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Friction Stir Extrusion (FSE) is a modern one step process with high efficiency for conversion and recycling of materials which capable of producing Nano-engineered material via production with good deformability, mechanical and physical properties. Novelty of this production technique is utilization of frictional heat and severe plastic deformation for material flowing, mechanical alloying and finally amendment of powder, chips and other recyclable scraps directly to useful products. Sample’s microstructure was revealed and average grain size was gained for 18 samples. Experimental parameters by use of design of experiments for two factors and analysis of variance were investigated and by the use of experimental results were validated. In this study, the effect of rotational speed in 3 levels and plunge rate in 2 levels were examined on microstructure of produced wires via FSE process. Based on process parameters, there is an equation for grain size prediction was presented by using full factorial design of experiment. Furthermore, normal possibility diagram and residual versus order based on residual theorem were evaluated for systematic error entry and reliability to experimental results. The efficient region on contour diagram reveals that suitable condition of minimum grain size and maximum strength occurred at 250 rpm for rotational speed and 14 mm/min for feed rate. It should be noted that analysis of variance showed that rotational speed, feed rate and interaction of rotational speed and feed rate respectively have a meaningful effect on the grain size of produced wire.

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"DEFORM" three-dimensional finite element software is used to describe the behavior of plastic deformation of Ti-6Al-4V workpiece during blade preform extrusion process. Under different conditions of extrusion, numerical analysis of the process force parameter during extrusion process is presented. The relative effects of billet temperature, friction coefficient and die temperature on process force were investigated. To determine the process friction coefficient, the ring compression test of Ti-6Al-4V alloy with glass lubrication was performed. Also experimental tests were successfully done in order to manufacture blade preform. It was observed that billet temperature has much effect on force of Ti-6Al-4V alloy blade preform extrusion process. Die temperature has effect on the process force but its effect is not as much as the effect of the billet temperature. By increasing of the die temperature, the process force decreases. Experimental tests showed that the billet transfer process from the furnace to die has important effect on done or not done of the extrusion process because the billet transfer process from the furnace to die is cause of alters the billet initial temperature just before extrusion process. By reducing of the placing and transfer time of billet from the furnace to die, due to the vicinity of the billet and air, billet temperature have less reduction and therefore it becomes easier to shape. Also by increasing the friction coefficient, the force required for extrusion of Ti-6Al-4V alloy blades preform increased.

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In food products packed in hot filling mode, the use of probiotic bacteria is very limited due to thermal sensitivity. The microencapsulation of probiotic bacteria is suggested as a suitable method for reducing thermal damage. Dual layer extrusion using high molecular weight hydrocolloids, such as zedo gum, can prevent thermal damage. In this research, microencapsulation by two layers extrusion method was performed on Lactobacillus rhamnosus. The first layer was sodium alginate and the second was zedo gum at 0.2, 0.4, 0.6, 0.8%., was used. Microencapsulation was followed by light microscopy, texture and color analysis. Thermal stability, acid and salt stability, acid production tests and the growth of microencapsulated bacteria during storage conditions in MRS medium were investigated. The results showed that 0.8% zedo gum used as the second layer could significantly change the outer layer diameter. However, the increase of zedo concentration did not increase the hardness component. Only at 0.2% zedo gum had a significant difference with the rest (p<0.05). At 0.6% and 0.8% zedo gum increase in gumminess component wasobserved. At 72 ° C, the number of microencapsulated bacteria remained stable for 10 minutes, and at the 5th minute their count was about 5 log CFU‌/‌ml higher than free bacteria (p <0.05). The amount of acid production was lower and bacterial growth in the microencapsulated bacteria was slower than free bacteria. The microencapsulated bacteria had microbial survival of 2 log CFU/ml more than free bacteria the of 15% (pH = 1.5).

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Combined shear extrusion (CSE) is a new severe plastic deformation (SPD) technique to produce bulk ultra-fine grained materials. CSE is obtained by the combination of simple and pure shear extrusion. This technique is based on definitions of pure and simple shear. In the present work, the nonlinear (large) deformation elasticity theory is used for obtaining the shear strain applied to the sample under pure shear extrusion with various angles of distortion. Also plastic deformation characteristics of CSE method were analyzed with finite element analysis using commercial Deform 3D software. Shear strain and effective strain applied to the sample, the load required to carry out the process and the final shape of the cross-sectional area were studied for different angles of distortion. Analytical results and finite element analysis shows by increasing the angles of distortion, shear strain and increased rate of shear strain applied to the sample increased so the effective strain and load required to carry out the process increases. Analysis of finite element and geometry of the die shows that distribution of shear strain and effective strain is inhomogeneously and symmetrical in specimen’s cross section which increases from the center to the corners and by increasing the angles of distortion, distribution of strain becomes more inhomogeneously, also the final shape of the cross-sectional area deforms more.

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The most successful ‘‘top–down’’ approach to produce bulk ultra-fine grained or nanostructured materials involves the use of severe plastic deformation (SPD) processing. The amount of higher effective plastic strain per pass plays a key role on the final microstructure of SPD processed samples. In the present study the numerical experiments of the combination of the equal channel angular pressing (ECAP) and simple shear extrusion (SSE) as a new process entitled “planar twist channel angular extrusion (PTCAE)” was performed based on the Response Surface Methodology (RSM), as a statistical design of experiment approach, in order to investigate the effect of parameters on the response variations, achieving the mathematical equations, predicting the results to impose higher effective plastic strain values. Α and ϕ angles, radius and friction coefficient was imposed as the input parameters while average, minimum and maximum effective strain and maximum load was imposed as the output parameters. Governing regression equations obtained after analysis of the simulation data by Minitab software. Optimum process parameters are: α=450, Φ =450, r=2 mm and µ=0.1. Verification of the optimum results using simulation experiment was done. Good agreement between simulation, experimental and optimization was occurred.

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Metallic alloys exhibit rheological behavior similar to non-Newtonian fluids in the semi-solid temperature range. This behavior can be described using rheological models. In this study, the viscosity of semi-solid 7075 aluminum alloy was measured by using the results of load-displacement signals obtained from two different experiments: parallel plate compression and backward extrusion. The obtained data were used to determine the parameters of the Cross model in a wide range of shear rates. The effects of temperature (solid fraction) and shear rate were studied on the viscosity of the alloy. The results showed that with increasing temperature and decreasing the solid fraction the resistance to flow decreases, resulting in a reduced amount of applied forces. This reduction in applied forces results in reducing the viscosity. It was observed that the behavior of semi-solid alloy is shear thinning in which the viscosity decreases with increasing shear rate. Also, the calculated viscosity values of the four parameters Cross model were in good agreement with the obtained experimental results in a wide range of shear rates. The simulation results showed a good agreement of the presented model for predicting the rheological properties and flow behavior of the semi-solid alloy in a wide range of shear rates.

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In recent years, Mg alloys have received much attention as a promising candidate for raw material in biodegradable vascular stent. Forming of Mg alloys is difficult because of poor workability of them at room temperature. Hence this presents a technological barrier to the fabrication of initial micro-tube for a biodegradable stent. With regard to high biodegradability of the magnesium alloy WE43 to manufacture biodegradable stent, it has been selected as initial with casted structure. In this study, for enhancing mechanical properties and attaining micro tube a combination of equal channel angular pressing (ECAP) with extrusion and micro extrusion was used and Mg bars were fabricated to high-quality micro-tubes with refined microstructure. Fine-grained size billets of the WE43 alloy were obtained by one-pass of ECAP. The processed Mg bar was extruded into a bar with 5 mm in diameter. Finally, a UFG and high strength micro tubes with an outside diameter of 3.4mm and a wall thickness of 0.25mm were successfully produced by micro extrusion process. Mentioned processes were simulated using finite element (FE) simulations. The result shows the grain size of Mg incredibly reduced after this combined method and mechanical properties were significantly improved.

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In this research, the effects of Konjac gum (0.2-0.6%), Fat content (18-25%) and Homogenization pressure (100-200 bar) on rheological properties of low fat cream were investigated. The results of the back extrusion test indicated that increasing konjac gum, fat content and homogenization pressure, significantly increased hardness, consistency and adhesiveness. The simultaneous increasing of homogenization pressure and fat content also led to increasing adhesiveness of the samples, which showed their synergistic effect of them on the adhesiveness. The results of the steady shear test showed that the flow behavior index (n) of all samples was less than one which indicates a shear thinning behavior (pseudoplastic) of all samples. Also increasing fat content, significantly decreased the flow behavior index of the samples and increased the consistency. konjac gum and homogenization pressure had no significant effect on the flow behavior. The optimum processing conditions for producing low fat cream with the high hardness, consistency, consistency coefficient and low flow behavior index for response variables were 146/51 bar homogenization pressure،18/01% Fat content and 0.59% konjac gum.

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Adding Fiber supplement to beverages can be a suitable choice for consumers to compensate for the lack of DF and have a positive impact on their health. Wheat bran, a by-product of wheat milling process is due to DF and its nutritional value is concerned. But it requires processing, because of nutritional and technological problems. There are some methods for wheat bran processing to reduce anti-nutritional compounds and increase its functional properties e.g. Fermentaion & Extrusion food extrusion. The objective of this study was to investigate the effects of adding 0.5, 0.7 and 1% of fiber supplements including fermented and extruded wheat bran compared to the commercial sample of orange fiber on the physicochemical properties of pineapple beverage. The results showed that adding different levels of fiber supplements and storage conditions over time led to a significant increase (P≤0.05) in specific gravity, turbidity, ash, brix and reducing sugar content and total sugar content, as well as brightness (L*), yellowness (b*) and redness (a*). However, there was no significant difference between the acidity of different treatments by adding three types of fiber supplementation (P≥0.05). The organoleptic properties of beverage treatment in this study also showed that, increas the amount of extruded wheat bran, led to promote the color index, flavor, and overall acceptance and its score was in an acceptable range. Due to the nutritional composition of extruded wheat bran and application modifying in comparison with fermented and non-extruded, its use in the formulation of beverages leads to a new functional beverage

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There has been much interest in recent years in improving material properties by grain refinements using severe plastic deformation (SPD). With applying severe plastic deformation to metals, the structure changes and nanostructure produce. In this study, ultra-fine grained pure titanium fabricate by combination of Equal channel angular pressing and Extrusion process in different passes (1, 2, 4 and 6 pass). ECAP and Extrusion processes were carried out at 400°C. Then, mechanical and microstructural properties of UFG pure titanium billets produced b combination process of ECAP and extrusion process were examined and the effect of passes on mechanical and microstructural properties was investigated. The results showed that mechanical properties were improved significantly. Ultimate strength increased up to 941MPa, in the best state, while for initial sample was 505MPa, in other word ultimate stress increased about 86.3%. With this combinational method, ultimate stress increased about 60.8% for 1 pass sample, 78.8% for 2 pass sample, 86.3% for 4 pass sample and 80.8% for 6 pass sample rather than initial state. In higher passes the rate of increase are reduced due to the grains size saturation. Hardness increased from 81.85 Hv to 216.65 Hv; In other words, hardness increased 164% from initial value. Further passes of the process only have a minor effect on increasing of billet hardness. Scanning Electron Microscope also revealed that brittle fracture were takeplaced in all sample with shallow dimples.

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Blends of sorghum and soybean flours were processed in a co-rotating twin screw extruder to prepare expanded product. Response surface methodology (RSM) was used to study the effect of soya level (SL), feed moisture (FM), barrel temperature (BT) and screw speed (SS) on extruder system parameters and physical properties of the extrudate. Response variables were product temperature (PT), motor torque (MT), specific mechanical energy (SME), expansion ratio (ER), bulk density (BD), hardness (H), crispness (C), water absorption index (WAI), and water solubility index (WSI). Second order polynomial models were developed to determine the responses as a function of process variables. FM, BT, and SS had a significant effect on all the responses except BT on WAI, while SL considerably affected ER, BD, H, C, and WAI.  All the models were found to be statistically significant (R²> 0.85; insignificant lack of fit). Sorghum-soya extruded product was found to be feasible and the optimum values of processing variables were: SL: 14 per cent; FM: 14 per cent wb; BT: 129°C; and SS: 422 rpm.