سعید گوهری

Self-discipline reflected in the government's criminal policy is one of the forms of decriminalization in order to respond non-criminally to crimes committed by public and government organizations. In the framework of this approach, identifying the manifestations of self-discipline in the plan to liberate the Caspian coast provides the basis for the adaptation of the current policies with the approaches derived from the knowledge of decriminalization. The results of this research, which was conducted with the case study research method, showed that the government has accepted the commission of crimes related to non-compliance with the legal protection of the sea coast by the institutions under the government by introducing the plan to liberate the sea coast. However, it has not considered punishment as a suitable response to deal with criminal behavior. Therefore, non-criminal politics has tried to, on the one hand, by requiring government agencies to respect the legal protection of sea shores within a certain period of time, and on the other hand, by relying on the mass media, to emphasize the requirement of all agencies to comply with the rule of law. have The simultaneous implementation of these two policies, from the perspective of crime prevention knowledge, is considered a form of decriminalization of the criminal behavior of government institutions.

Due to the increasing importance of using clean energy, Hydrodynamic screw turbine has been considered as a small-scale hydropower source. One of the characteristics that makes the mentioned turbine to be unique compared to others is its acceptable performance in low head and flow conditions. Although a lot of research has been done in the world to achieve the best configuration to achieve the maximum output efficiency using numerical and laboratory methods, but the methods of making these types of turbines have rarely been examined. In this research, for the first time in Iran, the construction of a hydrodynamic screw turbine with a traditional method based on common industrial processes has been described. Then, its testing and evaluation have been considered. The installation angle of 24 degrees was obtained as the optimal installation angle.

Preventing crimes related to counterfeit drugs, due to the technologies used in the production and distribution of these drugs, will not have a bright outlook with traditional methods such as field surveillance. Therefore, adopting appropriate preventive measures requires the use of innovative technologies capable of detecting these crimes on a large scale and with high accuracy. In this regard, artificial neural networks such as recurrent neural networks, generative adversarial networks, and convolutional neural networks, inspired by the structure of the human brain, are capable of detecting these crimes. However, each of these networks has its drawbacks, ignoring which makes the legal system face difficulties in preventing these crimes. Therefore, the present study, through a case study method, seeks to identify the most efficient neural network for preventing these crimes. The outcome of this research indicates that the legislature has paid special attention to the monitoring technique in the prevention domain but has not defined the tools for this monitoring. Nevertheless, the Food and Drug Administration, using the Titac system (tracking code), identifies the discovery of crimes in this area. However, due to the non-intelligence of the system, it will not be able to detect all forms of fraud. Therefore, simultaneous use of three networks (recurrent neural networks, generative adversarial networks, and convolutional neural networks) in the form of a composite neural network seems to improve the detection of drug crimes on a large scale.

Fear of the older sibling's position in sibling relationships can lead to various negative consequences, including domestic violence within the family. Therefore, the development of appropriate preventive policies to control and reduce the fear of this position can have a direct impact on reducing domestic violence and strengthening the foundation of the family. This study, conducted in 2022 using the Q-methodology and purposive sampling, aimed to identify the influential factors in the formation of bullying resulting from the fear of the older sibling's position. The findings of this research indicate that nine factors (mental patterns) with a cumulative variance of 34.78% play a key role in creating fear of the risk of bullying from the older sibling. Moreover, the inferential results of factor analysis suggest a significant relationship between bullying resulting from the fear of the older sibling's position and factors such as "intimate relationships, discrimination among siblings, age and gender, culture, power imbalance, vulnerability assumption, lack of self-esteem, instrumental violence, and lack of knowledge and skills."

Due to the increasing human need for electrical energy and the reduction of non-renewable resources for its production, the use of non-fossil and renewable resources and resources that have less environmental damage have been taken into consideration. Archimedes screw turbine is used as a means of producing clean energy in waterways, and many theoretical and experimental studies have been done on it. Most of these studies, in laboratory and numerical form, are in the field of optimization of screw constituent components and their effect on its efficiency including length, inner and outer diameter, installation angle, number of blades and screw pitch. In this research, the most important studies conducted in the field of Archimedes screw turbine performance, which have been published in the last two decades, were reviewed. The results showed that the parameters of screw components have a greater effect on efficiency compared to hydraulic parameters.

A better understanding of the relationship between dowry and women's perceived beauty is of great importance in achieving practical solutions for promoting women's rights and reducing gender discrimination. Therefore, examining women's attitudes about the impact of dowry on their perceived beauty in married life provides important approaches for taking preventive measures. The aim of this study is to identify the factors affecting women's attitudes towards the relationship between dowry and perceived beauty.

This study was conducted using the Q method, and all married female students of Zabol University were considered as the statistical population. 30 students were selected as the sample size. 28 factor arrays were provided to the participants, along with a Q diagram, using 28 question cards for each participant, in which they marked their level of agreement or disagreement with each proposition. The reliability of the Q table was calculated as 73%. Factor analysis was used to analyze the data.

The results of factor analysis showed that there is a significant relationship between dowry and women's perceived beauty. The instrumental approach to dowry, cultural differences in determining and receiving dowry, the inability of men to pay dowry, and the linkage of dowry with the status and position of women are among the most important factors that can play a stimulating role in women's perceived beauty.Keywords: Dowry, Women's perceived beauty, Attitude measurement, Factor analysis, Q method.

Punishment reflected in judicial rulings is considered as one of the tools of government governance in the field of water resources management in the crisis-stricken region of Sistan. Therefore, identifying the philosophical goals and social influences of this institution reveals the strengths and weaknesses of the judicial procedure. The results of this study, which was conducted by descriptive-inferential analysis, showed that some courts in Sistan area follow the approach of utilitarian philosophy and others follow the approach of punishment. This philosophical dichotomy renders the justice system's policies in protecting water resources ineffective. On the other hand, judges' attention to the cultural, religious, social and identity structures of Sistan society in the sentencing stage can prevent the destructive social effects of punishment at the individual and social levels. Sociological analysis of examples of votes suggests that inappropriate response leads to the formation of a criminal identity resulting from social stigma in the convict and de-sensitizes the importance of these crimes.Keywords: water crimes,sociolegy, social effects of punishment, water rights

Spur dikes are structures that constructed for protection of the river walls against the erosion. Spur dikes are generally built perpendicular or at an angle to the river bank or revetment, protruding into the watercourse. The effect of the geometrical characteristics of the hockey spur dikes on formation developing of scour hole has been rarely studied. Spur dikes. The current study aims to evaluate the effect of the length of the hockey spur dike on the formation and development of scour hole and comparing with that effect in L-shaped spur dike. In this direction, all experiments were done in clear water conditions using the spur dikes in length of 8 cm and 12 cm and in a laboratory flume. The results asserted that the dimensions of the scour hole and the length and thickness of the sedimentary hill were increased by raising the length of the spur dike. However, this increment was lower in hockey spur dike than the L-shaped spur dike. The maximum depth, area and the volume of the scour hole were also increased by raising the length of the spur dikes. This increment in-average was equal to 57.5 and 67.7 per cent in L-shaped spur dikes and equal to 33.3 and 42 per cent in hockey spur dikes for two different lengths of spur dikes. Furthermore, no scouring was observed in downstream section of the hockey spur dikes near the wall. Therefore, the dimensions of the scour hole around the hockey spur dike was lower than those in the L-shaped spur dikes.

Spur dikes are river training structures that developed from the natural river banks with proper length and angle from the flow dominant direction, cause to divert the flow attack at the riverside and the critical regions and directs the flow to the river central axis. There are several researchers focused on the effect of the spur dikes angles on the flow pattern however there is not any study on hockey spur dikes angle on scouring patterns. In present study, the effects of the hockey spur dikes angle on scouring and the bed topography was carried out experimentally while the results were compared to those provided for L-shape. The experiments were conducted on a series of hockey spur dikes also the L-shape in three various angles equal to ,  and  (towards the downstream channel lateral walls) inside a laboratory flume in 10.5m length, 0.5 width and 0.5m height under the clear water conditions. The results revealed the scour hole parameters including the length and thickness of the sediment hill are lower in hockey spur dikes than the L- shape by increasing the spur dikes angle. Furthermore, the maximum scour depth, mean area and volume of scouring are increased by 41.4, 41 and 75.5 percent in hockey and by 33.8, 39 and 73 percent in L-shape through increasing the angle from   to , respectively. Also, no scouring was taken place in the vicinity of the channel lateral walls downstream the hockey spur dikes, hence, those beter act against the destruction also in protection of river beaches against the erosion, with respect to the L-shape.

Punishment reflected in judicial rulings is one of the tools of government governance in the field of protection and management of water resources in the new irrigation plan of the crisis-stricken plain of Sistan. In this regard, the explanation and analysis of the philosophical approach of the penitentiary institution clearly shows the strengths and weaknesses of the judiciary in dealing with water crimes. The results of this study, which was conducted by descriptive-inferential analysis, indicate that some courts have used the utilitarian approach and others the punitive approach in the prescribed punishments. However, the consequence of this dichotomy in the philosophical approach has rendered the policies of the justice system in the protection of water resources ineffective. The results of this study show that any amount of punishments determined by the general expectations of the local community and the capacity for a culture of compromise in resolving disputes between water resources stakeholders in this project, in addition to the capacity of religious teachings to pay less attention to the inefficiency of punishment. Will lead to water crimes.

In this study, a hybrid model was developed in order to approximate the discharge coefficient of side weirs located on converging channels for first time. In other words, the ANFIS network was optimized by means of the Firefly Algorithm (FA). After that, six ANFIS and ANFIS-FA models were defined by input parameters. In addition, in this study, the Monte Carlo simulation was employed to study the modeling accuracy. Furthermore, the k-fold cross validation approach was implemented for validating the modeling results. By analyzing the modeling results, it was concluded that hybrid models are more accurate than ANFIS models. The superior model simulated the discharge coefficient values with reasonable accuracy. For example, the values of R2, MAE and RMSE for the superior model were calculated 0.003, 0.011 and 0.015, respectively. Also, about 98% of the superior model results have an error less than 12%. According to the uncertainty analysis results, the superior model had an overestimated performance. A sensitivity analysis indicated that the flow Froude number at the side weir downstream is the most effective input parameter.

The role of floods in sediment transport and river morphology has been proven. In this study, the effect of different parameters on the transfer of sediment bed load under flash flood has been investigated. The input flood hydrograph of the symmetric triangular type with the base time of 90 sec and peak flow rate 30 and 45 lit/s were considered. Sediment particles of quartz type with a moderate diameter of 1.2 and 3 mm and two bed slopes of 0.006 and 0.014 were tested. In this study, changes in water surface profile, rate of bed load in steady and unsteady conditions, and unsteadiness parameter relative to total work done of flow and sediment rate were investigated. By using dimensional analysis, the parameters affecting sediment transport were determined and evaluated in experiments. The results showed that the unsteadiness parameter in unsteady flow had a significant effect on sediment transport. On the other hand, the work done by the flow has a greater impact on sediment transport than the unsteadiness number. In this regard, the effect of channel slope on sediment transport should be considered. The role of channel slope in the transfer of bed load is very important so that by doubling the bed slope, the total amount of sediment transferred to the downstream increases almost 5 times. Also, with increasing the sediment flow rate, the unsteadiness parameter increases and it plays an effective role in the whole work. In general, in high-value hydrographs, the amount of transfer sediment increases and there is a large relationship between the amount of transfer sediment and the total flow work. Reducing the time of the rising arm of the hydrograph shows the effect of increasing the flow rate, which is effective in these waterways, so that with the faster the flood peak time, the more sediment is transferred and the probability of damage and destruction increases.

Culvert is one of the main structures in drainage systems at crossing with railways and roads. Flood flows, along with the transport of sediments and floating debris, can cause blockages and backwater, thereby reducing flood flow capacity. The main purpose of this study was to physically model and numerically simulate the effects of different percentages of blockages on culvert hydraulic characteristics. Blockage effects investigated in 21 laboratory experiments. Complementary tests were carried out with the use of OpenFOAM numerical tool box. Three blockage scenarios have been numerically simulated with 20, 40 and 60 percent coverage of inlet area. The numerical model was calibrated using the experimental data. The simulation results of OpenFOAM in different culvert inlet blockages indicated that the LES turbulent model is more adaptive than RAS models. The main flow characteristics were compared with the corresponding simulation results from the trademark FLOW-3D model, and showed good agreement for verification purpose. Results for different flows (i.e. 40, 60 and 100 percent of the design discharge) showed that the increasing rate of upstream water level is not identical, and is higher for the lower discharges. Blockage also intensifies turbulence and shear stress levels in the outlet section. For design discharge, the 40 percent blockage resulted in the increase of shear stresses up to 10 times, which cause severe scour in downstream channel.

Bridge scour is one of the most important challenges in river engineering. Every year, thousands of bridges around the world are destroyed due to scouring. Hence, the accurate prediction of maximum scour depth for saving financial resources and the safety of human lives is of paramount importance. One way to reduce scouring is to use slot at the pier of the bridge. Research on the effect of the slots, in reducing scour around the bridge pier, has been done bed sediments of uniform type and in most cases the depth of flow have been considered as a constant factor. The aim of the present study is to investigate the effect of sediment non-uniformity in the presence or absence of slots in the bridge pier and the relative effect of increasing the depth of flow (with increasing flow rate) on the scour depth around the cylindrical pier.

The present experiments have been conducted in hydraulic laboratory at Bu-Ali Sina University, Hamadan (Iran). The pier model with a diameter of 4 cm was put inside a rectangular flume with dimensions of 0.5 m wide, 10.5 m long and 0.5 m height. Three different types of slots were used along with the pier without slot. In order to obtain the effect of sediments on scour depth, two types of bed were used. The bed of the first and second types had uniform and non-uniform sediments, respectively. In this experiment, flow rates of 8, 10 and 12 l/s were used with corresponding flow depths of 5.7, 6.6 and 7.4 cm, respectively, Melville and Chiew (1999) chose a time as equilibrium after which scour depth changes of less than 0.5% of the pier diameter over a 24-hour period. According to this criterion, the time of all experiments was considered to be 6 hours.

The percentage of scour depth reduction varies according to the height of the slot and its location. Comparison of S1 and S2 models for two slot models in the same dimensions showed that the closer the slot is to the bed, the greater its effect in reducing scour depth. Also, increasing the height of the slot under the bed (S3 compared to S2) is more effective in reducing the scour depth. Comparison of the first and second beds showed that by converting uniform to non-uniform sediments under constant particle diameter conditions, the maximum scour depth in models S0,S1,S2 and S3 at a flow rate of 8 l/s was 76, 78, 76 and 79%, is respectively reduced. The reason for this can be the formation and expansion of a layer of coarse particles on the bed surface (armor layer). As the flow rate increases due to the increase in flow depth, the scour dimensions increases. According to the obtained results, the scour hole in the non-uniform bed reaches equilibrium with less time than the uniform bed. The formation of an armor layer in a non-uniform bed is the reason for less equilibrium time in similar conditions than in a uniform bed. With increasing the Froude number of flow in all base models, the depth and dimensions of the scour hole have increased. Increasing the Froude number makes the downflow current stronger, and as a result, horseshoe vortices are formed and act with less time. In clear water conditions, the maximum scouring depth will occur in the state u/〖 u〗_c =1 (Melville and Chiew 1999.( The results showed that with increasing the ratio u/〖 u〗_c of clear water scouring conditions, scouring depth increases in a variety of models and beds. According to Guo (2012) if the ratio of flow depth to pier diameter is less than 6. By increasing this ratio, the scour depth in uniform and non-uniform sediments increases.

The results of this research showed that the use of slots in Cylindrical bridge pier was more effective in reducing scouring than the use of bridge piers. With the conversion of uniform to non-uniform bed due to the formation of the armor layer, the scour depth has decreased by an average of 77% in different base models and also the time to reach the scour equilibrium has been reduced. Scour depth has increased with increasing flow rate, Froude number and ratio u/〖 u〗_c in different pier and bed models. In general, the closer the slot is to the bed, the more it reduces the scouring depth and the non-uniformity of sediments due to the formation of an armor layer around the pier causes a significant reduction in scouring depth.

In regard to wide piers, the pile group rather than single pile is used frequently to bear the loading of the structure in a particular arrangement; piles group composed of only one column of piles in the flow direction has a great effect on supporting the bridge deck. In this study, local scour at a single column arrangement of the piles group made up of four rows of piles characterized by different piles spacing was studied for clear-water conditions with two flow discharges of 20 and 35 l/s (the effect of increasing the flow depth with the same flow intensity). The results indicated that an increase in the flow depth not only greatly enhanced the scour depth and the width of the scour hole. Besides, the investigation of the relative flow depth on scour extent showed the need for revision in deep water conditions, as reported in the literature. The results of the pile group experiments revealed the noticeable impacts of piles spacing on the local scour. The bigger pile spacing caused a feeble interaction of wake-horseshoe vortices, leading to a decrease of the scour depth; the separate view of the scour holes was generated at individual piles. Finally, the results were compared with commonly used comprehensive models. The findings of this study can be applied for the appropriate selection and positioning for the countermeasure of the scour at bridge piers.

Culverts are common structures for runoff drainage system in the design and construction of roads and railways, in both urban and rural areas. Due to the nature of runoff flow, large amount of sediments, foliage, urban waste and debris materials may accumulate in the entrance of culverts, particularly in flood events. Blockage in the culvert’s entrance can result in a significant increase in flood risk, through elevated flood levels and diverted flow paths through the urban or rural areas (Rigby et al., 2002). Sudden blockage in a runoff system is also one of the common problems. The study of culvert’s blockage would be useful in the prediction and prevention of flood hazard in the vicinity of drainage systems. Current study deals with this problem in box culverts. Blockage effects on the upstream water level were investigated using both experimental and numerical modeling. The FLOW-3D model was chosen, because the sufficiency of this model for such flow conditions was already reported by several studies such as Abad et al. (2008), Ayaseh (2010), Brethour and Brunham (2009) and Gunal et al. (2019).

Experimental tests were conducted in Hydraulic Laboratory of Water Engineering Department in Bu Ali Sina University, Hamedan, Iran. The box culvert models made of glass and smooth water pipes used as circular culvert models. The experimental setup includes a glass wall flume with 10m length, 0.5m width and 0.6m deep. Rectangular plates in different sizes were used in order to make sudden blockage into the culverts. An extensive experiment tests was conducted under different flow condition and blockage scenarios, and 21 experimental data sets were provided. The FLOW-3D model, Version 11.3, was performed on the main server of Water Institute at the University of Tehran, and adapted to the experimental data sets from this study. The stability and sensitivity of this model have been tested according to: mesh cell size, simulation time step, turbulent model, and culvert hydraulic characteristics such as wall roughness. The simulation convergence was achived with an efficient simulation time step of 80 seconds. Three different mesh blocks were used for pre-simulation cases, and a block in block with 1.0 cm and 0.5 cm mesh cell sizes were chosen as the best meshing senario. The RNG was found to be an apropriate turbulence model. The slope of culvert barrel was changed from horizontal to 0.005 in the flow direction, and the roughness coefficient modified from 0.00085 m to 0.001 m in the culvert barrel. The relative error of simulated water levels and discharge for calibrated model were to be in the order of acceptance ranges, and the simulation FLOW-3D model was adjusted as an efficient and reliable tool. The FLOW-3D model was then calibrated and verified using the experimental data sets, and was used to simulate different flow conditions into the culverts, under different entrance-blockage scenarios.

Effect of the inlet blockage on upstream water level was tested for three flow rates (the design discharge of 27.5 lit/s, and two lower discharges of 10.5 lit/s and 16.5 lit/s), in four different sizes of inlet blockage (B). Simulation results showed a good agreement in upstream backwater level in all cases. In the case of flow with 16.5 lit/s, upstream water level raised from 28.5 cm in non-blocked inlet to 31.4, 34.2 and 38.5 cm in presence of 20% ,40% and 60% blocked inlet area, respectively. The rate of the upstream water level increase (DHu) against the reduced inlet area (1-B) represents a higher rate for discharges smaller than the culvert-design discharge. The evaluated equations for upstream water level enhancement were : DH_u=-0.48(1-B)+45.089 (1) DH_u=-0.82(1-B)+75.663 (2) in which, Eq. (1) is for design discharge and Eq. (2) for the smaller discharges. Blokage has been affected flow in the barrel and in the downstream of the culvert. Investigation of turbulent characteristics and shear velocity values in both the barrel and downstrem indicated the impact of blocked inlet. Turbulent enrgy of flow in the 60% blocked-inlet area was 5 times greater than that of non-blocked inlet for the design discharge. Also shear velocity in the same blockage situation increased by 2 times in downstream which results in a greater scouring power of the flow downstream. Sorourian et al. (2015) rep[orted this phenomenon with even higher scour downstream of bocked cualverts. Maximum value of shear velocity increased with the increase level of blockage in the all flow condition, however in the design discharge it seems to be constant for blockages greather than 40%.

The FLOW-3D model was calibrated and validated to simulate the flow into the culverts. Influence of inlet obstruction on the upstream water level and flow characteristics into the barrel and downstream of the culvert was investigated. The results show a linear increase in the upstream water level by decreasing the percentage of culvert inlet. The upstream water level for the design discharge was lower than the other tested discharges. Changes in turbulent flow properties and shear velocity inside the barrel and downstream were also investigated in the presence of obstruction. Shear velocity increased 3 times in the presence of 80% blockage for 10.5 lit/s. and for the design discharge (27.5 lit/s) with 60% inlet blockage increased 2 times. The turbulence energy for the design discharge has also increased by about 5 times. The present results confirm the previous studies on the effect of the culvert inlet obstruction on the geometry of the scour hole downstream of culverts.

Local scouring around the pier is one of the main reasons for the instability of the bridges. Providing appropriate methods for predicting and controlling scour depth is one of the important issues that have been considered. Various methods have been proposed to control the scouring around the bridge pier. In this study, the effect of using the bed sill on scouring around the cylindrical bridge pier under clear water conditions has been investigated and compared in non-cohesive sediments. The bed sill has been placed at the downstream of the pier and its effect on reducing the scouring has been evaluated by changing distance between and the pier and sill geometry. In this research, a pier with 50 mm diameter was used. The results showed that bed sill setting has effect on scour reducing. Also, the distance and the shape of the sill have the greatest effect on reducing the scour. The placement of the straight and oblique bed sill at the backside of the pier resulted in a decrease of 11% and 16%, respectively, in the maximum of scour depth. By increasing the distance of sill to the oblique pier, its protective effect was reduced. Also the oblique bed sill more reduces the amount of scour around the pier relative to the straight bed sill and prevents the scour hole from developing to upwards.

Bridge scour is one of the most important challenges in river engineering. Research into local scour has primarily focused on investigating the impact of different hydrodynamic conditions on scour in a bed of uniformly graded material. However, local scour investigations in a bed of uniformly well-graded material provided knowledge of the underlying processes, field sediment beds are much more complex consisting of non-uniform sediment mixtures ("σ" _"g" ">1.4" ). In the case of complex sediment beds, selective transport of the finer particles due to unequal mobility can make the bed surface to be armored. There have been relatively few studies reported in the literature relating to scour in complex sediment beds, and most of these relate to quite specific situations. With regards to natural river materials (non-uniform sediments) and its great effects on the dimension and the time evolution of scour hole, the interaction of flow-structures with non-uniform sediments is very crucial due to armor layer development. The aim of this study is to improve understanding of scour development and armoring evolution in non-uniform sediment beds for estimating the scour depth in more realistic field conditions. Therefore, the rate of variation of erosion over time around single cylindrical pier is investigated in different bed sediment types. The armored layer due to selective transport of the finer particles in non-uniform sediments causes complexity for predicting equilibrium scour depth. The present experiments on local bridge scour were conducted in hydraulic laboratory of the Bu-Ali Sina University (Hamadan, Iran). The pier model with a diameter of 4 cm was put inside a 0.5 m wide, 10.5 m long and 0.5 m depth rectangular tilting flume. In this study, the number of 15 experiments were organized at five different sediment beds, uniform and non-uniform in two steady flow condition (20 and 35 l/s with the same flow intensity of u/uc~0.9) along with an unsteady flow. The duration of tests was fixed at 8 hours in all runs based on the empirical method given by Ettema (1980). The experimental results revealed that with increasing flow rate from 20 to 35 l/s (increasing follow shallowness, h/b) at the same sediment bed, not only larger scour depths were recorded, but also the armor layer became coarser. The comparison between the bed configurations with uniform and non-uniform sediments represented dramatical reduction of the scour depth regards with increasing sediment non-uniformity. The effect of non-uniform sediments on scour in a current clear water conditions showed that maximum scour depth was less than scour depth in a uniform sand with the same d50 value. The comparison between these two mentioned bed configurations showed that the change in geometric standard deviation ("σ" _"g" ) from 1.4 to 2 (altering the uniform bed to non-uniform), decreased the maximum depth of scour by 70% and 60% in two corresponding experiments. As the armor layer coarser grains remains at upstream flow bed and at the vicinity of scour hole in the same flow intensity, the scour depth was decreased. Otherwise, there was not remarkable decrease on the scour depth by increasing non-uniformity index, since two sediment beds types were non-uniform. Also, a slight increase on scour depth has been observed by reduction of median grain size in the beds with non-uniform sediments at the same geometric standard deviation. By taking into account of the grain size of the armor layer and ice cover roughness, Wu et al. (2014) analyzed the dimensionless maximum scour depth and they found out that with an increase in grain size of the armor layer, the dimensionless maximum scour depth decreases. Singh et al. (2018) investigated the incipient motion for gravel particles in cohesionless sediment mixtures having silt and sand. The visual observations of the channel bed after the end of incipient motion indicated appearance of gravel particles at the top surface of the sediment bed. The critical shear stress for the gravel particles was found to be lower in the presence of silt. Presence of silt in the mixture affects the critical shear stress for gravel particles. They concluded from the present study that high silt content in the mixture leads to the higher deviation of critical shear stress from the revised Shields curve. They proposed an equation for the determination of critical shear stress of gravel particles in the non-uniform sediment mixture. The results showed that scour depths were reduced dramatically as sediment non-uniformity index ("σ" _"g" ) increase in clear water conditions. The larger particles form an armor layer protecting the bed from eroding. Also, the observation indicated that with increasing flow depth, the armor layer coarsens, and larger scour depths were recorded. However, scour depth increase rate was very different for the various bed sediment types.

The floodplains are relatively flat lands in the vicinity of the rivers with the residential, industrial or agricultural usage. The sudden breakdown of large dams leads to the formation and propagation of devastating flood waves over the downstream. The flood propagation occurs over the floodplains due to the topographic variations and in-stream obstacles such as bridges. These waves are developed one and two dimensional over a small reach of the river and floodplains, respectively. In the hydrodynamic simulations, two-dimensional characteristics of the dam-break flow over the floodplains have been studied scarcely. Therefore, the combined effects of the floodplains obstacles, constriction and the bottom barriers are calculated over the dam-break flow characteristics.

In the present study, the moving particle semi-implicit (MPS) method was used to the numerical study of the dam-break flow characteristics over the floodplain. From advantages of this method are including the incompressibility, the particle-based and using of powerful models of gradients and Laplacian in velocity-pressure corrections without any complex smoothing functions. Hence, the effects of the reservoir initial water level, the shapes of the obstacles - lateral transitions as well as the bottom barriers on the hydraulic parameters were studied in 15 various cases. The floodplain obstacles are cylindrical, cubic, rhomboidal and asymmetric, and the bottom barriers are cubic. At first, the sensitivity analysis was carried out on three particles diameters including the 0.01, 0.015 and 0.20 m. Finally, the diameter of the particles equal to 0.015m was adopted as the water particles size in the model. The simulations carried out through more than 280000 spherical particles, with the second order spatial and temporal accuracy.

The precision of the numerical results was calculated using the NRMSE normal error through the comparison with the previous experimental one. The results demonstrated that evacuation of the reservoir occurs in numerical solutions faster than the experimental. Therefore, the MPS model under and overestimates the values of the free-surface profile height and the flow propagation velocity, respectively. The impact of flow to the floodplain obstacles leads to the rising up and the formation of a three-dimensional flow at the obstacles place, the lateral constrictions and the bottom obstacles. Further, the shape of the obstacles represents a crucial factor in the free surface profile deformations, the horizontal component of the surface velocity, and the drag resistance forces applied to the flow.

Normal error values showed that the accuracy of the MPS method in the calculation of the free surface longitudinal profile deformations are variable between 88 and 91 percent.

Conveyance and Water distribution irrigation canals are hydraulic structures that transport water supplied from sources such as diversion dams for drinking, agricultural, industry or other purposes. These canals are usually lined by materials such as: concrete, stone with sand cement mortar, asphalt, to prevent water seepage losses along the flow path. Concrete lining that is used in irrigation canals is an unreinforced concrete with a thickness of 5 to 10 cm. Basic requirements of good hardened concrete are: satisfactory compressive strength and sufficient durability (Aba, 2005). After the implementation of each engineering structure, it is necessary to evaluate the project to determine the optimal performance and quality of implementation. Evaluation of the quality of irrigation canal linings is often carried out by the destructive and costly method of coring and carried out various experiments in the laboratory. Although destructive method yields relatively exact and straightforward results from the desired parameters, it also has some side problems that are sometimes difficult to recover. The problems of destructive test (DT) method with coring and destructive method are associated with damage of project, high cost, need the expert group and equipment, time-consuming and sometimes stoppage of project operation. Non-destructive testing (NDT) methods can be used to prevent these complications. Electrical, ultrasonic and Schmidt hammer tests are among non-destructive testing. Nowadays, non-destructive testing of concrete has an effective and practical function in the repair of concrete structures. Non-destructive testing of concrete by providing data on various existing structures allows experts to judge and decide on the performance, needs and methods of repair and restoration of concrete structures. The indicator of evaluation of the quality of concrete lining in irrigation canals in different environmental conditions is the same as the other structures based on the amount of compressive strength (Anon., 2014). The failure of hardened concrete due to repeated cycles of thawing- freezing in cold air in hydraulic structures (such as irrigation canals that can absorb water and saturated) is more probable than other concrete structures (Ramazanianpour and Shahnazari, 1988).

In this study, in order to establish a relationship between non-destructive testing (NDT) of Schmidt's Hammer number with destructive testing (DT) of compressive strength and water absorption parameters, 13 sections from 3 main conveyance canals were studied in Nahre Shaban irrigation network in Nahavand City. At all sections, non-destructive testing of Schmidt's Hammer accomplished for determining the rebound number, then from the same points, 12 and totally 156 cores were provided from 3 canals. Next relationship between rebound numbers (RN) with each of the parameters of laboratory experiments on the linings was investigated. The study area in this study was 6 km from the main canal of the irrigation network of Nahre Shaban in 3 sections of Ghaleqabad, Shaban and Jahanabad in Nahavand City. This canal is divided by diversion dam of Sha'ban with height of 3.5 m which was constructed in a section with coordinates of (X = 262862, Y= 3775625) during 1985 and 2001. Table 1 presents the characteristics of the main canal at the location of the Ghaleh Ghobad river section on the Shaban network. The coordinates of each section of the canal intended for coring were determined using GPS; these coordinates are presented for the 13 points in the selected canals in Table 2.

In this study, the effect of different amounts of AEA and amount of cement on the capillary water absorption of concrete was studied. For this purpose, 15 concrete mix designs with w/c of 0.45, Dmax=19mm and 4 levels of cement: 275, 325, 350, 375 and 400 kg/m3, and three levels of AEA( zero, 0.01% and 0.03% of cement weight) was considered. Various experiments included: total air, density and slump on fresh concrete and capillary water absorption on specimens of hardened concrete were studied. The results showed that in non-AEA mixtures, the total air content decreased and the density increased with increasing cement content. By increasing the amount of AEA, in mixtures with 275 and 325 kg/m3 of cement, the amount of total air of mixture decreased and the density increased, but for mixtures with higher than that, the total amount of air was increased and the density decreased. The results on specimens hardened concrete showed that increasing the cement content increased the amount of capillary water absorption. Also, for concrete samples with cement of 275 and 325, by increasing the amount of AEA, the amount of capillary water absorption increased, while for concrete samples with cement of 350, 375 and 400 kg/m3, decreased. Based on results, it was found that in concrete lining in conveyance canals, amount of cement should not be less than 330 kg/ m3. There is not difference between 0.01% and 0.03% of AEA, and therefore, an amount of 0.01% cement weight is recommended.

Experimental and numerical study of scouring pattern on the direct and polo-shaped groynes have been investigated in this paper. In this study, direct and polo-shaped groynes models with a length of 0.12 meter have been used in discharges of 10.5, 15, 20 liters per second in a direct flume. The results showed that the maximum scour depth formed around the groyne head of direct and polo-shaped types has increased with augmentation of flow discharge, which was 0.095 and 0.104 meter in the case of 20 L/s discharge respectively. Also, the width of scour hole was 2.25 and 2 times of effective length of the groyne in direct and polo-shaped groynes respectively. In this regards, maximum scour depth around the head of groyne was seen 0.87 and 0.79 times of the effective length of the groyne. Sand form located at downstream of the direct groyne at the distance of 0.09 and 0.15 meters from the side wall of direct groyne was stretched and extended to about 1.3 times of the channel width as well. While the length of the sand form for direct groyne was 1.15 times of the channel width. Overall, the dimensions of the scour hole around the polo-shaped groyne, was less than the direct groyne. In addition to understanding the hydraulic behaviour around the groyne, Flow3D software was used. Statistical survey of the results obtained by experimental and numerical models attested that the relative error of the numerical model could be about 20%, which shows an appropriate performance of using Flow3D for predicting the maximum scour depth.

One of the regular methods for stabilizing and protecting the riverbanks is use of groyne structure. Groynes alter flow direction to the main axis of the river resulting sediment deposition and stabilization of river sides. Therefore, scour around the groyne and the effect of nose on scour are important parameters in river engineering. It should be noted that change of flow pattern in river side is an affective factor on the rate of scouring around the groyne nose. In this study, the effects of the hockey groyne length (L) on scour in straight channel has been investigated through experimental tests. The results showed that there was a direct relation between scour hole dimensions (including the maximum scour depth (ds), the length of scour hole in up and downstream and the maximum scour width) and hockey groyne length. Also, scour hole distance the from channel wall was longer in hockey groyne comparing to that in straight groyne which prevent from scour in river bank and stabilizing the groyne structure. Thus, maximum scour around the hockey groyne was less than that straight groyne around due to suitable flow direction to the downstream.

Labyrinth weirs can be used to increase outlet capacity for a given spillway crest elevation and length or to increase storage by raising the crest while maintaining spillway capacity. Downstream scour dimensions of spillway are important parameters in designing of this structures. By combining the spillway and the gate, two major problems of sedimentation on upstream of spillway and the accumulation of waste materials can be solved. In this study, totally 12 experiments were carried out in 3 different discharges, 10, 15 and 20 liters per second. In this study overflow and flow simultaneously from top of weir and gate for two linear and labyrinth spillway were explored. A layer sand with d50=1 mm and thickness of 15 cm were covered at downstream apron to make a mobile bed. Results showed that by increasing the particle Froude for a constant depth, the maximum scour depth and scour hole length increased. Also it was found that when the flow passed through the spillway and gate simultaneously, in both labyrinth and linear spillway, the maximum scour depth and scour hole length increased with respect to discharge. Transverse profiles at the maximum scour depth also showed that there was a relative symmetry in the case of a linear spillway without a gate, and in this case the bottom profile could be considered as two-dimensional. The maximum scour depth and scour hole length increased with increasing discharge, and its magnitude in labyrinth spillways, was less than that in linear spillways.

Friction factor as an index for flow resistance depends on grain size and bed forms in coarse-bed rivers. A wide range of particle sizes located in these rivers causes development of the armor layer and cluster structures, which have great effects on friction factor. In this study, coupling effects between the armoring process and the friction factor due to an armor layer have been investigated. Therefore, considering logarithmic velocity distribution characteristics, the total friction factor was determined. Then, grain friction factor was determined by the Keulegan and the Shields parameter methods and results were compared. Finally, form friction factor was determined by subtracting the grain friction factor from the total one. Analysis of results showed that the friction factor is rather independent of grain-size distribution of the material forming the bed and the major controlling parameter is the slope of the energy grade line. These unexpected results are due to the coupling of the friction factor with the incipient motion problem and the rearrangement of the grains of the coarsest fraction in the armor layer. Also, the results showed that making and development of the armor layer accompanied with clusters of particles caused an increase in the relative roughness of the bed and a reduction in the relative submergence resulting an augmentation in flow resistance and bed stability. Field observations demonstrated that rivers could change the critical Shields stress due to making equal mobility of coarse and fine sediments.