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In this study the herdel effects of heating time, basil seed mucilage and Sodium Nitrite during preservating time on qualitative characteristics of 40% sausage by RSM method were investigated in order to decrease using nitrite at sausage. At first section the effect of different herdels on qualitative characteristics of sausage including residual nitrite, color and the number of Clostridium Perfringens and texure were investigated. In the second part, the optimization and the validity of developed model were performed. The results indicated that by increasing nitrite, the residual nitrite amount increased and by increasing of preservation time the nitrite amount was decreased. Overall changes are influenced by nitrite amount, basil seed mucilage, and heating time. Chlorostidium number was influenced by nitrite square and preservation time, so that the lowest Clostridium Perfringens amount was acquired at the highest nitrite concentration. Also only effective parameter on the sausage texture was basil seed mucilage. By increasing of mucilage content hardness of sausage was decreased by optimization the amounts of 95.38 ppm nitrite, 0.76% basil seed mucilage, the heating time of 112.15 minute at the preservation time of (24 days) were selected- which this formula lead to decrease at about 30ppm of the added nitrite- based on Iran national standard. The theoretical and the experimental results were in great agreement so RSM could be used for modeling and optimization of such processes.

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Rivers have been always the main source of water for human kind and the basic element of population development. Study of the interaction between flow structure and bedforms is one way to understand the behavior of the rivers. Moreover,vegetation in natural rivers increases roughness of the main channel and flood plains which affects the geometry of channels, flow structure, bed resistance and consequently the pattern of sediment transport. Considering the role of bedforms on sediment transport, turbulence production and flow resistance, investigations on details of flow-bedforms interaction, vegetated banks and flow structure seem to be essential. In this study, the influence of straight crested gravel bedforms and vegetation of the banks of channels on flow turbulent characteristics are investigated based on model experimentation. For this purpose, seven fixed artificial 2-D straight crested bedforms were built inside a rectangular flume of 8 m long, 0.4 m wide and 0.6 m deep. The graded gravel particles used to create the bedforms had an average diameter of d50 = 10 mm. Johnson grasses with a diameter of 2.8 mm were used to simulate vegetation cover on the flume side-walls. Since, the fully developed flow was just observed after the fifth dune, experimental measurements were performed over the fifth and sixth dunes. Overall, three runs were performed over the dunes with a wave length, height, angle of repose and flow depth of 0.96 m, 0.04 m, 28 degrees and 0.28 m, respectively. In the first case 17 velocity profiles and in the second and the third cases 21 velocity profiles were measured. All the tests were performed with a constant discharge of 0.024 m3/s. The instantaneous three-dimensional velocity components were measured using a down-looking Acoustic Doppler Velocimeter ADV. Velocities were recorded for each point with a sampling rate of 200 Hz and the sampling volume of 5 mm. The sampling duration was at least 120 seconds. Overall, about 45400000 velocity data were collected, filtered by WinADV software. Results indicated no negative velocities for both cases of with and without vegetation cover. For no vegetation case, the least value of velocity was zero at a small region on the lee side of the dune. Whereas, for the case of vegetating the side-walls, the zero value of velocity was located at the dune's trough. Negative vertical velocity value in both cases of with and without vegetation along a dune confirmed that separation is not dominant for the case of straight crested dunes compared to the corresponding sharp-crested bedforms. The Reynolds stresses increase for the case of vegetating the side-walls compared to the case of without vegetation cover. This is in part due to the increase of flow resistance, while the side-walls are vegetated. Rivers have been always the main source of water for human kind and the basic element of population development. Study of the interaction between flow structure and bedforms is one way to understand the behavior of the rivers. Moreover,vegetation in natural rivers increases roughness of the main channel and flood plains which affects the geometry of channels, flow structure, bed resistance and consequently the pattern of sediment transport. Considering the role of bedforms on sediment transport, turbulence production and flow resistance, investigations on details of flow-bedforms interaction, vegetated banks and flow structure seem to be essential.

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Spillways and bottom outlets are the common hydraulic structures in dam engineering to convey excess water from the reservoir toward the downstream river. Economy and operation are the major factors affecting the type of spillway and its’ crest shape to avoid unfavorable hydraulic phenomena. An appropriate spillway crest results in increasing the discharge coefficient and distributing a uniform pressure inside the conveying conduits. One of the most common types of spillways in dam engineering is shaft spillways with morning glory inlet. Generation of swirling flow at the entrance of the shaft spillways and entraining air into the conduits is an unfavorable phenomenon. Air-entrainment into the system leads to different depressing effects on system operation including reduction of the discharge coefficient and can cause severe damages. To control the swirling flow phenomenon one way is the application of anti-vortex devices. Applying certain shape of inlets e.g. installing a Daisy (Marguerite)-shape inlet over the shaft entrance is another alternation to avoid the swirling flow effects thereby to increase the discharge coefficient. Marguerite-shape inlet has been used in different existing dam projects. Marguerite inlet is a unique inlet compared to other shapes of spillway crests for a constant head. This is in part due to spatially varied flow inside the marguerite inlet which makes it capable of passing greater discharge. Although different types of dam spillways have been the subject of different investigations, there is a lack of study on these types of spillways.
In this study, the effects of Daisy (Marguerite)-shape inlet on free-flow through shaft spillways have been investigated based on model experimentation. Dimensional analysis has been used to determine the effective dimensionless parameters. Experiments were conducted in a cylindrical model of 2 m diameter with two shafts of 10 and 12.5 cm diameters on the tank bottom. The tests have been performed based on a wide range of geometric and hydraulic parameters to study the effects of each dimensionless parameter on flow hydraulics. Finally, applying SPSS software and nonlinear regression analyses empirical correlations were obtained for estimating the discharge coefficient and the threshold depth of orifice flow over Daisy-shape inlets. To validate these correlations, the normalized root-mean-square error (NRMSE), the weighted quadratic deviation (WQD) and the coefficient of determination R2 were applied. Contrary to R2, both NRMSE and WQD must be small to have the best correlations.
Spillways and bottom outlets are the common hydraulic structures in dam engineering to convey excess water from the reservoir toward the downstream river. Economy and operation are the major factors affecting the type of spillway and its’ crest shape to avoid unfavorable hydraulic phenomena. An appropriate spillway crest results in increasing the discharge coefficient and distributing a uniform pressure inside the conveying conduits. One of the most common types of spillways in dam engineering is shaft spillways with morning glory inlet. Generation of swirling flow at the entrance of the shaft spillways and entraining air into the conduits is an unfavorable phenomenon. Air-entrainment into the system leads to different depressing effects on system operation including reduction of the discharge coefficient and can cause severe damages.

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The present study is subjected to analytical, numerical, and experimental simulation of hydraulic characteristics of flow over the streamlined weirs. Numerical simulations were performed using an open source software namely OpenFoam. According to the objectives of the present study, to evaluate the results of numerical modeling, experimental investigation was conducted, studying different models of streamlined weirs, experimentally. The profiles of the experimental models as well as the simulated numerical models were designed based on the Joukowsky transform function. By analyzing the results of different turbulence models including standard k-ε model, realized k-ε model, RNG k-ε model, k-ω SST model and Reynolds stress LRR model, the k-ω SST model was chosen as the most accurate numerical turbulence model for the simulation of flow over the streamlined weirs. The results of the numerical simulations for different flow discharges and different geometrical characteristics, indicated that, increasing the flow discharge and the relative eccentricity in Joukowsky transform function, tends to increase the velocity and consequently decrease the pressure over the weir crest. Therefore, the lowest pressure and the most probable potential of cavitation belongs to the circular-crested weirs with λ = 1 and high flow discharges. Furthermore, the results show that the greatest bed shear stresses and the compressive forces occur at the downstream end of the circular-crested weirs, thus the downstream zone of the circular-crested weirs is responsible to large values of bed erosion. This is partly due to formation of shock waves, reduction of the flow depth and enhanced velocity of flow downstream of the circular-crested weirs. Furthermore, the lowest bed shear stresses occur at the upstream end of the circular-crested weirs. Therefore, potential of sedimentation upstream of the circular-crested weirs increases. Accordingly, by employing streamlined weirs with λ< 1, and an appropriate curvature, unfavorable flow conditions would be improved, leading to a more safe and economic hydraulic structure. The present study is subjected to analytical, numerical, and experimental simulation of hydraulic characteristics of flow over the streamlined weirs. Numerical simulations were performed using an open source software namely OpenFoam. According to the objectives of the present study, to evaluate the results of numerical modeling, experimental investigation was conducted, studying different models of streamlined weirs, experimentally. The profiles of the experimental models as well as the simulated numerical models were designed based on the Joukowsky transform function. By analyzing the results of different turbulence models including standard k-ε model, realized k-ε model, RNG k-ε model, k-ω SST model and Reynolds stress LRR model, the k-ω SST model was chosen as the most accurate numerical turbulence model for the simulation of flow over the streamlined weirs. The results of the numerical simulations for different flow discharges and different geometrical characteristics, indicated that, increasing the flow discharge and the relative eccentricity in Joukowsky transform function, tends to increase the velocity and consequently decrease the pressure over the weir crest. Therefore, the lowest pressure and the most probable potential of cavitation belongs to the circular-crested weirs with λ = 1 and high flow discharges. Furthermore, the results show that the greatest bed shear stresses and the compressive forces occur at the downstream end of the circular-crested weirs, thus the downstream zone of the circular-crested weirs is responsible to large values of bed erosion. This is partly due to formation of shock waves, reduction of the flow depth and enhanced velocity of flow downstream of the circular-crested weirs. Furthermore, the lowest bed shear stresses occur at the upstream end of the circular-crested weirs. Therefore, potential of sedimentation upstream of the circular-crested weirs increases. Accordingly, by employing streamlined weirs with λ< 1, and an appropriate curvature, unfavorable flow conditions would be improved, leading to a more safe and economic hydraulic structure.