---

  Managerial researches emphasize an organizational contingency elements rule at improving the performance. Although, few theorical and empirical researches were implemented upon the influencing elements at organizational performance. This paper is an effort to fill gaps of corresponding issue. For this, exploration and searching the literature and expert interviews (DELPHI) resulted in formulation of 14 contingent elements which impact the military organization performance. Then, an importance- performance analysis technique based on experts needs and expectations was used to prioritize the elements performance. This technique also presents weakness and strength of influencing performance elements. In this paper, to improve the validity and practical aspects of importance- performance analysis technique, experts and personnel of mentioned organization were interviewed. Then, two quantitative and qualitative techniques multiple regression and DEMATEL final values as integration of implicit and explicit importance respectively are used to extract the importance rates. Finally, the performance rate extracted through interviews based on likert values as well as importance rate applied to build the importance- performance matrix in four quadrants which based on two axes (importance, performance) to analysis the feature of located elements in each quadrant.    

---

Based on the macro-invertebrate community and physico-chemical indices, water quality of the Tajan River in 6 stations along 80 km of the river length was assessed. Monthly sampling was conducted for one year (September 2011 to August 2012), using a surber with 30.5 × 30.5 cm dimensions and a 60μ mesh net for the benthic invertebrates sampling. The identified macro-invertebrates belonged to 31 families, 12 orders and 5 classes, the highest and the lowest abundance of which belonged to Psychodidae and Chironomidae, respectively. Based on Hilsenhoff Family Biotic Index, the research stations were classified into 4 qualitative categories, viz. excellent, good, fair, and fairly poor. Stations 1 and 5, respectively, showed the highest and lowest HFBI index. The highest and the lowest values for the Shannon–Weiner index were recorded in station 1 and station 2, respectively. The results of physicochemical parameters indicated  reduced dissolved oxygen in the stations 2 and 5, and increased TDS in station 2 and 1 and increased nitrite and ammonium in station 3. Results of Spearman correlation coefficients between biotic indices and physicochemical variables revealed significant relationship between DO, TDS, EC, PO₄ and water flow with HFBI and Shannon-Weiner indices. This study showed, generally pollution in stations 2 and 5 has reduced water quality in these station's.

---

---

---

---

One of the important parts of many large dams is flood release chute spillway. Aerators are installed on chute spillways to prevent cavitation phenomenon under very high speed water flow. An aerator consists of a ramp providing a sudden slope change that separates water from the bed and permits air to mix with water. For the study of flow condition in aeration zone and for having an insight knowledge about the aeration, the study of flow condition on the ramp is a prerequisite. The change in the slope of the bed is common in spillways due to the change in the topographical slope and at the connection of the spillway and the stilling basin. In the present study, the flow condition at the place of sudden slope change was numerically simulated by FLUENT software. FLUENT is powerful software in simulation of water flow, in which the effects of turbulent are well considered. In this software, the Navier-Stokes equations are numerically solved. Volume of fluid method is applied to simulate the free surface water accurately. The results of the model in terms of pressure distribution at bed, pressure distribution in depth, velocity profile and water surface profile were compared with the results of an analytical model of streamline method as well as with the available experimental data. The analytical model is a streamline method based on conformal mapping with the basic assumption of ideal flow. The results of the model were compared in various slopes and water velocities. The study showed that numerical model can predict water surface profile and dynamic pressure properly and the results of numerical model are more accurate as compared to analytical model for the two important parameters of pressure distribution at the bed and the velocity profile. The pressure distribution was reasonably predicted by the numerical model at the bed of channel before the ramp for all the studied degrees and at the bed on the ramp for smaller degrees. The maximum error was nearly 5-10 percent. The velocity profile calculated by the numerical model was very close to the experimental data and the maximum error was nearly 5 percent. The analytical method was found quite capable in prediction of dynamic pressure and water surface profile, and less accurate in predicting the velocity profile. The study also showed that before and after the slope change, the influence length, where the dynamic pressures are significant, is dependent on the degree of sudden slope change and also on the amount of normal depth. Furthermore, the water surface profiles calculated by the numerical model and the analytical model were quite coincident, showing that the effects of gravity, viscosity and turbulence parameters on the water surface profile are insignificant.

---

The flow at a channel bifurcation is turbulent, highly three-dimensional (3D) and has many complex features. There is transverse motion accompanying the main flow and an extensive separation zone that develops in the branch channel. There are two complex flow regions along the intake channel: one is the separation zone and the other is the region in which helical motion of water particles forms. This separation occurs because the flow entering the branch channel has considerable momentum in the direction of the main channel flow. This zone causes hydraulic and sedimentation problems that must be known before designing the system. This necessitates a deeper insight into the flow patterns and shear stress distributions near the solid boundaries. In this research, 3D flow patterns at lateral diversion were investigated experimentally and numerically. The experimental investigation was carried out at a T-junction, formed by two channels with rectangular cross-sections. The width of lateral intake to the main channel was 0.4. 3D velocity measurements were obtained using Acoustic Doppler Velocimeter at junction region for 11%, 16% and 21% discharge ratios. Fluent mathematical model was then used to investigate the dividing open-channel flow characteristics. Turbulence was modeled by Two Equation (k-ε, k-ω) and Reynolds Stress (RSM) turbulence models. The predicted flow characteristics were validated using experimental data and the proper model was selected for hydrodynamic and parametric studies. Within the main channel, good agreement was obtained between all models prediction and the experimental measurements, but within the lateral channel, the RSM predictions were in better agreement with the measured data, and k-ω predictions was better than those of k-ε. The comparison of experimental and numerical streamlines at different elevations showed that the selected model is capable to simulate the most important features of flow at diversions. The study of the velocity contours at different elevations showed that the velocity magnitude decreases at main channel, just downstream corner of lateral intake at the near bed levels and this causes the sedimentation in movable beds. The results showed that the width of separation zone at lateral intake will decrease and the distance of dividing stream surface from left bank of the main channel will increase by increasing of the discharge ratio. Investigation of the flow pattern at the entrance of the lateral intake showed that the secondary flow will form at this section. The dimension of the secondary flow at near bed elevation will increase by increasing of the discharge ratio and this causes entering of more bed load into the lateral channel.

---

---

Wastewater treatment with microalgae and its reuse is an effective step toward reducing water consumption and preserving water resources. The possibility of growing spirulina microalga on cattle effluents and the possibility of purifying effluents using microalga were investigated. Different concentrations of standard culture medium (Zaruk)-wastewater were used to measure the optimal algal growth on wastewater and to determine the concentration of effluent-Zaruk for optimal algal growth. The treatments were T1 including 100% Zaruk and no wastewater, T2 including 75% Zaruk and 25% wastewater, T3 including 50% Zaruk and 50% wastewater, T4 including 25% Zaruk and 75% effluent and T5 including 100% effluent without Zaruk. Treatments that had more Zaruk, showed more optimal growth, and those that had a higher concentration of effluent often showed a relatively lower growth of algae biomass. The results showed the high growth of algae on the concentrated effluent. T1 with 0.35 and T2 with 0.3 g/liter of dry biomass had the highest biomass of microalgae. T1, T2, T4, T3, and T5 had the highest to the lowest amount of phycocyanin pigment production in microalgae, respectively. The highest removal of nitrate belonged to T5 and T4 with 82.57% and 78.21% removal respectively, and the lowest nitrate removal belonged to T1 and T2 with 57.17% and 70.94%, respectively. The highest removal of phosphate belonged to T1 and T2 with 94% and 92.11% removal, respectively. The lowest removal of phosphate belonged to T4 with 84% removal. Findings indicated the high potential of microalga for treating cattle wastewater.
 

---

Abstract- Forward speed is perhaps the most important parameter in the design of a planing hull. The speed strongly influences the drag and thus the energy supplied by the engine of the ship. Employment of an appropriate drag reduction strategy plays an important role in the design of these hulls. The flow around a Cougar high-speed planing hull was numerically simulated and the results were compared against experiments available in the literature. To reduce the total drag, two tunnels were introduced at the bottom section of the original Cougar hull. The weight and center of gravity of both hulls remained the same. An unstructured mesh was generated in the computational domain around the hull and a Re-Normalization Group K-ε formulation was used to model the turbulence. To capture the free-surface of the flow around the hull, the volume of fluid model was applied. The drag forces of both the original and modified Cougar hulls were obtained for various forward speeds, corresponding to the original hull length based Froude numbers ranging from 1.00 to 5.62. The results show reduction in total drag for the modified hull at the forward speed of 60 knot.

---

Shortage of irrigation water is a crucial problem especially in arid and semiarid regions; therefore, application of wastewater in agriculture in such regions seems to be an indispensable solution. A field experiment was conducted in non-agricultural soil to investigate the effect of Treated Municipal Wastewater (TMW) on the yield and fiber quality of cotton (Gossypium hirsutum L.) crop. The treatments consisted of surface irrigation by different mixtures and as well, through different intervals of freshwater plus TMW. Two additional treatments, namely, irrigation with freshwater and with TMW were considered as control. The experimental design was a randomized complete block one with eight treatments and three replications. The results indicated that cotton yield, number of bolls per m², Leaf Area Index (LAI) and plant height were significantly higher when the crop irrigated with TMW rather than with freshwater. The crop yields in TMW vs. freshwater treatments were about 2,200 and 780 kg lint ha^-1, respectively. There were no significant differences observed between interval and mixture treatments when the same percentages of freshwater and TMW applied. Also there was no significant detrimental effect observed on the characteristics of cotton fiber quality when the crop irrigated with TMW.

---

In this paper, the Lagrangian tracking of individual particles was performed at the straight channel and the lateral intake. This study is conducted for the aim of investigation of Discrete Phase Model )DPM (for simulation of tracking of individual sediment particles and also estimation of the rate of bed load at the entrance of intake related to the main channel. The Reynolds stress transport model )RSM) of the FLUENT software was used for evaluating the turbulent flow characteristics. The study was conducted in two parts. At the first part, the particle movement was simulated in the straight channel for evaluating of the model operation. The comparison of numerical results (predicted) and experimental data (measured), which were done for this purpose, confirmed numerical simulation. In the second part, sediments movement pattern in lateral intake from straight direction investigated from quantitative and qualitative views and compared with available experimental data. The qualitative analysis of sediments movement showed a shape of wedge liked sand bar forms by bed load at the entrance of lateral intake. The quantitative comparison of the predicted and measured Qs (ratio of the bed load discharge in lateral intake to the bed load in main channel) shows predicted values were more than the measured values. In this paper, the Lagrangian tracking of individual particles was performed at the straight channel and the lateral intake. This study is conducted for the aim of investigation of Discrete Phase Model )DPM (for simulation of tracking of individual sediment particles and also estimation of the rate of bed load at the entrance of intake related to the main channel. The Reynolds stress transport model )RSM) of the FLUENT software was used for evaluating the turbulent flow characteristics. The study was conducted in two parts. At the first part, the particle movement was simulated in the straight channel for evaluating of the model operation. The comparison of numerical results (predicted) and experimental data (measured), which were done for this purpose, confirmed numerical simulation. In the second part, sediments movement pattern in lateral intake from straight direction investigated from quantitative and qualitative views and compared with available experimental data. The qualitative analysis of sediments movement showed a shape of wedge liked sand bar forms by bed load at the entrance of lateral intake. The quantitative comparison of the predicted and measured Qs (ratio of the bed load discharge in lateral intake to the bed load in main channel) shows predicted values were more than the measured values. from quantitative and qualitative views and compared with available experimental data. The qualitative analysis of sediments movement showed a shape of wedge liked sand bar forms by bed load at the entrance of lateral intake. The quantitative comparison of the predicted and measured Qs (ratio of the bed load discharge in lateral intake to the bed load in main channel) shows predicted values were more than the measured values.

---

Qaboosnameh is one of the valuable works of Persian prose in the fifth century and is the result of the experiences of Amir Rantul-Maali to his son Gilan Shah, in which the narrator taught his son about various issues of life, arts and professions in forty-four chapters. This work, which is also known as "Advice" and "Pandnameh", is a moral narrative with unique narrative structures, the most important of which is the existence of counter-discourses in the form of anecdotes. These anti-discourses are in support of the narrator's speech and aligned and in interaction with his moral-educational discourse, so that the optimistic narrator with deep insights and wise observations and embellishing and armed his words with supporting anti-dots such as: appropriate anecdotes, verses of the Quran, the speech of scholars and poems of poets, the wall It has created a strong defense and a strong support umbrella in the discourse system of the book, which has led to more persuasion of the narrative heard. The results of the present research show that anti-discourses in Qaboosnameh have been involved in persuasiveness of Shenu's narrative with roles such as instructiveness, influence, incitement, threat, experienceability and easy understanding and highlighting.

1. Introduction
In Qaboos, the narrator's letter is written by himself, and he is interested in such factors as: Quranic verses, the words of the elders, poems, appropriate stories, the frequency of great use of women and etc. It focuses its discourse on only one area (educational literature) and closes the way for other interpretations.  It hinders the plurality of discourse, and this has led all actions to jointly serve a primary purpose, which is advice and advice. This is the focus of discourse on a purpose and message through supporting elements, in semantics theories of discourse. The role of anti-speech is called and means to use a solution as a ploy from the word processor to highlight part of the statement, to influence the audience more, to support the statement. Repairing scarred relationships and instilling a particular sense of audience in discourse
Research Question(s)
The results of the present study show that the anti-discourses in the script with roles such as lesson, influence, persuasion, and threat. Easy experience and understanding and highlighting have been involved in persuading the Shenu narrative.

2. Literature Review
The present research has been conducted in a descriptive-analytical manner using library resources and the basis of the work has been based on the semiotics theory of discourse.

3. Methodology
In any discourse belonging to a particular genre, Blashk also has elements and themes specific to that genre, so that the mere existence of these elements and themes leads to the creation and durability of a general system with ideology. It becomes a specific structure and theme that can be considered a discourse. Every discourse in the following genre, including epic, educational, mystical, and rich, though powerful and dominant. It needs support to prove its legitimacy so that these protections, like a shadowy halo, return to the circle of discourses and support their legitimacy and existence under a particular genre they do. For example, in the Shahnameh, which belongs to the genre of epic and discourse, certain elements and themes such as Salakhshuri, Shabbakhon, Warrior, Courage, Exaggeration, Ranting, Weaponry, Wrestling, Forcefulness, Difference، Resonant cheques and...In all the text, as a supportive umbrella, it has helped to the durability and consistency of discourse. Also, in a text such as Qaboos, which belongs to educational discourse, elements and themes such as poems, appropriate anecdotes, admonition, beingware, persuading, encouraging, Quranic verses, hadiths, and proverbs. It has played a role in arming the text with supportive tools and has preserved it in a particular purpose, ideology, and structure. In this work “Hayt and Temask to Story” along with other elements, one of the important ways of communicating is where we witness the narrator's efforts to have more impact on the audience. This state of discourse supported by other discourses or elements that lead to the proof and support of the original discourse is called «pad discourse». In fact, the status of anti-speech means the same supportive and covering function that a discourse has in common with another discourse within a dialogue space, Moghaddam et al. (1396). The pods are set in a discourse based on a reliance on a central nucleus that embraces the meaning, message, and primary purpose of the narrative and serves a given purpose. Now that we accept that every discourse is armed with support pods.  We believe that this theoretical framework is covered by the text of the script and, while describing the role of anti-discourses in creating a supportive halo around the main purpose of the narrative، they also describe their various roles in how to persuade the Shenu (Ambud) narrative.

4. Results
The word processor is trying to do as best as possible. Convince the audience and convey their advice to him with linguistic-narrative techniques so that he is not in a position of power and the audience in a position of weakness. Text in this genre is a central core with a specific message and meaning that maintaining, expanding, and transmitting to the audience requires solidifying elements.  It is a pleasant and supportive person who is referred to as «pad» in the sign of discourse and narrative, and in discourse because they are defensive and expanding towards the central nucleus. They are known as anti-discourses. Qaboos letter from important Persian educational texts has such a structure, and the element of theologian in one text has given his son advice, and it is decided that in forty-four, Bob has a central nucleus (the title of Bob) extend, support, and convey; accordingly, his discourse has several supporting layers (pods of discourse) which include verses and hadiths, the words of the elders, proverbs, its proper poems, and anecdotes. Together, these pods are supported by halos in the form of appropriate anecdotes and form a pernicious discourse, with roles such as learnability, avoidance, easy understanding of the transmission of experience, influence، delivering, and threatening an important role in persuading and acclimating the audience within the text of Leele and Biruni audience and today's readers are responsible.
 

---

Outlet conduits are one of the important parts of dams. Due to the high flow rate and pressure drop, problems such as cavitation can affect these structures. Considering these problems, detailed design is necessary. Laboratory studies are usually carried out which are expensive, thus, numerical models for determining complex flow characteristics have attracted the attention of the designers. In this study, the numerical simulation of Jegin dam outlet conduit in south of Iran with the scale of 1:10 is provided and the results are verified by experimental information taken from physical model built and tested at Water Research Institute. Gate opening in this research is always 70% and the water head is the constant value of 38.6m. The research is focused on the intake gate and not the service one, so the service gate is always fully opened. FLUENT computer code is considered for the numerical model studies. In the numerical simulation the Finite volume mixture two phase flow scheme is used together with k–e turbulence model. The flow discharge and air supply from the air vent downstream of the gate is then computed by 3D numerical model for different channel geometries. Reasonable agreement between the numerical model and experimental results shows reliable performance of the numerical model. This study showed the ability of the numerical model to simulate the complex air water flow in high speed gated tunnels. This study also includes the effect of the height to width ratio of the conduit on flow discharge and aeration downstream of the gate. To do this, different numerical models are simulated among which the difference is the height to width ratio of the conduit. Height and width of the conduit are measured at the gate section and changes are applied in two cases of constant height (depth) and variable width, and constant width and variable height. Results show more aeration and more flow discharge while heightening and widening of the outlet. Flow discharge has also been determined as function of the height to width ratio of the conduit at gate section of the channels. One of the important results is that in comparison with the width changes, height changes of the channel affect hydraulic characteristics of flow more and the diagram rates vary more sharply. Researches show that 1.5 to 2 ranges for height to width ratio is the best range hydraulically and other ranges have effect on reducing aeration and Air demand ratio β (β in this research agrees more with the relation Kalinske and Robertson presented), so the pressure in a conduit may fall considerably below atmospheric pressure which results in cavitation and vibration. To avoid these problems, suggests not to heightening the conduit more than a specific value.

---

The treatment of wastewater generated from acrylonitrile butadiene styrene (ABS) resin manufacturing industry have a great importance due to its high chemical oxygen demand (COD) and some other toxic substances. Activated carbon adsorption, chemical oxidation and biodegradation are the most conventional methods to the treatment of ABS effluents. Among them, the biological treatment as an environmentally friendly technology is highly regarded in the bio treatment and biotransformation of the toxic compounds of ABS wastewater to the intermediate and final compounds such as CO2 and water. This study was conducted to evaluate the performance of an activated sludge system for pretreating ABS manufacturing effluents. The wastewater pretreatment plant is consisted of 3 fine screens, a grit chamber, an equalization basin, dissolved air floatation (DAF) system, an activated sludge reactor and a final clarifier. This system was operated to reduce the TSS and COD values in the effluent in order to obtain to interior discharge permits to the central wastewater treatment utility operated by Tabriz petrochemical complex. Four runs weighed average sampling was conducted during 6 months according to the standard methods of the examination of water and wastewater. The parameters including COD, BOD5, TSS, TDS, sulfate, total kjeldahl nitrogen (TKN), ammonia-N, nitrate-N, alkalinity, cyanide, phosphate and pH were measured in wastewater samples according to the standard methods. The concentrations of acrylonitrile, acrylamide and acrylic acid in wastewater samples were determined using gas chromatography (GC) equipped with flame ionization detector (FID) with capillary column. Microbial structure of activated sludge was also evaluated using R2A, PCA and Nutrient Agar culture media as well the biochemical standard tests. According to the results, at surface loading rate of 2.76 m3/m2.h applied to DAF, the COD and TSS removal efficiencies of 24 and 43% were obtained, respectively. The ratio of BOD5/COD in the influent was 0.57 indicated the moderate biodegradability of ABS wastewater. In addition, the COD and BOD5 removal efficiencies in biological reactor were 59 and 68% respectively, at the organic loading rates (OLR) of 0.79 ± 0.06 kgCOD/m3.d. Totally, the COD, BOD5 and TSS removal efficiencies in the pretreatment system were 80, 90 and 88%, respectively. In addition, at the acrylonitrile loading rates of 0.067 ± 0.008 kg ACN/ m3.d, the removal efficiency of acrylonitrile was 91% which 26% of that has occurred in the biological reactor. Also, the removal efficiency of cyanide was 97% which only 4% of that has occurred in the biological reactor. Twenty bacterial strains were isolated and identified from the activated sludge samples. Among the isolated bacterial strains, four strains include Alcaligenes sp. Pseudomonas sp. Bacillus sp. and Moraxella sp. were identified as heterotrophic nitrifiers. Based on the results, the nitrifier bacteria have played an important role in the degradation of acrylonitrile in the biological activated sludge system. The results of parameters analysis, performance evaluation and microbial assessment revealed the satisfactory performance of COD removal as well nitrification. However, it seems that a significant portion of the volatile organic compounds (VOCs) are removed from the influent wastewater by stripping.

---

The purpose of this study was to investigate the factors affecting the fermentation process in the production of bacteriosin by two commercial probiotic bacteria in dairy factories effluents as a culture medium. Therefore, the effect of independent variables, including incubation temperature (30, 34 and 38 °C), initial pH (5, 6 and 7), duration of incubation (12, 30 and 48 hours), yeast extract concentration (0, 2 and 4 %), probiotic bacterial species (L. acidophilus LA5 and B. animalis subsp. lactis BB12) and culture medium (cheese whey and milk permeate) was studied using a completely randomized design with two-level factorial arrangement. The results showed that the temperature and time of incubation as well as the culture medium had a significant effect on bacteriosin production (p<0.05). Also, temperature, yeast extract concentration, culture medium type and culture of bacteria had a significant effect on biomass (p<0.05). Initial pH and culture medium had a significant effect on total protein content (p<0.05). Based on the results of incubation temperature, duration of incubation, yeast extract concentration, type of culture medium and type of probiotic bacteria had a significant effect on the titratable acidity (p<0.05). The levels of bacteriosin activity, biomass, total protein, and titratable acidity were in the range of 1000 to 5000 AU/mL, 0.80 to 8.67 g/L, 107.75 to 351.92 mg/L and 0.25 to 1.41 g/L, respectively. In general, the results showed that cheese whey and L. acidophilus LA5 is the suitable culture medium and bacterium for producing bacteriosin, respectively.
 

---

Development in engineering knowledge, methods and techniques in the construction industry has provided the possibility of establishing structures that are significantly light, high and flexible. The sensitivity of high buildings against wind power is more than other ordinary buildings. Basically, wind power has an important role in the design of high buildings. Therefore, it is essential to study more carefully the effects of wind forces in the design of these structures. An important issue that must be considered in all tall building studies in the field of wind engineering is study of atmospheric boundary layer around the structures. Atmospheric boundary layer is a layer of air around the surface of the earth that at a height above the earth surface, friction has not effect on the natural flow of wind. In the present experimental research a wind tunnel was used. It generally consisted of a huge duct in collaboration with a fan in the middle. By switching on the fan, air blows into the duct. Different measurement devices were installed along the wind tunnel which made it possible to consider different test sections in width, height and longitude. In the present research a wind tunnel with 2 meter long, 1.2 meter height and 1 meter width was used with an open wind circulation system. To check every structure in the wind tunnel environment at first the atmospheric boundary in that environment should be simulated. After this stage, any structure can be placed in a wind tunnel and be examined. In this study, two buildings with the same height and cross sectional area but different in plan were examined experimentally. Both Buildings were modeled with scale of 1:600 as a fifteen floors structure with twenty cm height. Buildings had square and circular plans. Speed, pressure and turbulence at any point of the tunnel test section can be measured directly. In this study the rate of percentage of turbulence is provided in different parts of the front and back of the building. In the recent years, numerical models specially finite volume methods have been developed in the fluid sciences. In the present research, all models were simulated in Fluent software numerically. A comparison between numerical and experimental data could help one to see the ability of numerical models. Moreover, by using the numerical model many points which are not accessible in the experimental model can be recorded and analyzed. In different sides of each model the turbulence percent was measured and analyzed. Results showed that by increasing the side walls the percent of turbulence increased. The reason can be more effect of wind impact on the building surface which caused to increase the friction meaningfully. It was also concluded that covering the ground surface around the considered tall building with canopy and trees or other buildings caused more percent of turbulence. It was also observed that from a certain height of building to up, the turbulence percent was went to zero which means non friction along the wind towards the structure. The results of this study helps to provide a better understanding of the effect of plan shape of a tall building in view of wind impact.

---

A large number of flows encountered in nature and technology are a mixture of phases. Advances in computational fluid mechanics have provided the basis for further insight into the dynamics of multiphase flows. Currently there are two approaches for the numerical calculation of multiphase flows: the Euler-Euler approach and the Euler-Lagrange approach
In the Euler-Euler approach, the different phases are treated mathematically as interpenetrating continua. In FLUENT, three different Euler-Euler multiphase models are available: the volume of fluid (VOF) model, the mixture model, and the Eulerian model. For sedimentation, we must use the Eulerian model. The Eulerian multiphase model in FLUENT allows for the modeling of multiple separate, yet interacting phases. The phases can be liquids, gases, or solids in nearly any combination. The Lagrangian discrete phase model (DPM) in FLUENT follows the Euler-Lagrange approach. The fluid phase is treated as a continuum by solving the time-averaged Navier-Stokes equations, while the dispersed phase is solved by tracking a large number of particles through the calculated flow field.
Sediment transport by fluid flow is one of the most important two phase flow in the nature. Due to existence of secondary current in channel bends, the mechanism of flow and sediment transport in these channels is much complex and locationg lateral intake at outer bank of the bens decreases this compelexity.
In this paper, mechanisms of sediments transport into the intake in a 180 degree bend channel with lateral intake have been simulated whit the Eulerian and Discrete phases models in fluent software. The intake is located at the outer bank of an 180o bend at position 115° with 45° diversion angle. The effect of diversion discharge rate and diversion angle on mechanism of sediment entry to the intake was considered.
The turbulence model is k-ε model. Model҆s in different time has performed and the result compared with laboratory result.The results show in Qr=40%, the mechanism of sediment entry was consist of continues entrance from downstream edge of intake and periodic entrance from upstream of the intake, however in Qr=25%, the mechanism of sediment entry was only consist of continues entrance from downstream edge of intake. The two models (Eulerian and Discrete phases) have shown good results. The rout mean square errors for outer boundary of the path of the particle at the channel ҆s bed for two discharges (25% and 40%) have measured.
The number of particle in discrete phases is limited; therefore this model cannot be display the depth of sediment. The Eulerian model displays the bed topography very well. Measuring mean square errors show that the model operation for topography simulation is very well. This model shows the location of intermittent dune and location of sediment accumulation very well. The discrete phase model can be shown the particle trapped place better than the Eulerian model.
Due to increase in intake discharge, dimension of sediment accumulation is decrease. the mechanism of sediment entry to lateral intake is affected by diversion angle of intake. the minimum sediment is entered to lateral intake at diversion angle equal to 50 degree.

---

Given the key importance of the bridges in transportation system lifelines and due to their high initial cost, there is a constant need for the study and monitoring of such structures. The FRP composites, due to their special characteristics including high specific modulus, high specific strength, corrosion resistance, low mass density, and modular construction, can be a good alternative for common bridge deck systems. Too much effort is devoted to implement FRP materials as a whole or in part in bridge construction. There have been several different methods of using FRP materials in bridges, including FRP stay-in-place forms for concrete decks and whole FRP bridge decks. Bridges constantly bear moving mass loads while due to technological progress the moving speeds are approaching higher and higher thresholds, so in this study, effects of moving mass on the dynamic response of steel-FRP and steel-concrete bridges are studied and compared. The deck and moving mass inertia substantially affect the dynamic response of the bridge system. To compare the effect of moving mass on both bridge types, at first, the multi layered beam method (MLB) for determining the FRP beam characteristics is reviewed and its applicability on determining the mechanical properties of laminated beams is investigated through comparison of this method results with numerical and experimental data. It is shown that by using the MLB method very good estimates of the mechanical properties of FRP composite can be achieved. Consequently, the problem of moving mass and its governing differential equations is reviewed and the numerical procedure for solving the set of governing PDEs of the moving mass problem is verified against experimental data. Comparing the theoretical results with the experimental data reveals that the presented methodology correctly estimates the dynamic response of beams subjected to moving masses. After setting up the theoretical framework for the moving mass problem on steel-FRP bridges, the effect of moving mass loading on the dynamic response of steel-FRP and steel-concrete bridge systems is investigated. The results indicate that the mass per length and the stiffness of the deck significantly affect the response of the bridge subjected to moving mass. These effects are captured through two different main parameters which characterize the dynamic behavior of beams subjected to moving masses. The first parameter is the Critical Influential Speed (CIS) at which the maximum deflection of deck at certain location happens. The calculated CIS through the aforementioned methodology indicate that the CIS for steel-FRP system is significantly higher than steel-concrete system. The second important parameter which is determined is the Dynamic Amplification Factor (DAF) which is defined as the ratio of maximum dynamics deflection at the midspan of the beam to its static value. The corresponding results of the DAF indicate that the steel-FRP bridges are less influenced by the moving masses than steel-concrete bridges of the same stiffness. It is shown that the values of DAF are lower in the case of steel-FRP bridge. It can be concluded that this will result in lower vibration amplitudes, which will contribute to higher fatigue life of the bridge system. Regarding these results, this system can be advised in the cases of high and ordinary speed transportation.

---

The quality of water available to humans has been seriously threatened due to population growth and the resulting increase in urban and industrial wastewater. To evaluate changes in the water quality of the Karun River in the urban area of Ahvaz, a simulation model was developed and used to assess the river's water quality based on existing standards. Results show that the quality variables of the river are highly dependent on the season of the year, with the largest changes in dissolved oxygen occurring during the driest and wettest seasons. Comparison of the river's current situation with national and international standards indicates that the water quality does not meet most standards, except during the autumn season when the flow rate is highest. Even if all effluents entering the river comply with existing discharge standards, the quality of the river does not meet desired standards. This highlights the importance of considering specific hydraulic conditions and the effect of time on river quality when updating existing standards.