هبة علي عباس البو جواد

Estimating groundwater salinity is important for the use of groundwater resources for irrigation purposes and provides a suitable guide for the management of groundwater. In this study, the artificial neural networks (ANNs) were adopted to estimate the salinity of groundwater identified by total dissolved solids (TDS), sodium adsorption ratio (SAR), and sodium (Na+) percent, using electrical conductivity, magnesium (Mg2+), calcium (Ca2+), potassium (K+), and potential of hydrogen (pH) as input elements. Samples of groundwater were brought from 51 wells situated in the plateau of Najaf–Kerbala provinces. The network structure was designed as 6-4-3 and adopted the default scaled conjugate gradient algorithm for training using SPSS V24 software. It was observed that the proposed model with four neurons was exact in estimating the irrigation salinity. It has shown a suitable agreement between experimental and ANN values of irrigation salinity indices for training and testing datasets based on statistical indicators of the relative mean error and determination coefficient R 2 between ANN outputs and experimental data.TDS, SAR, and Na percent predicted output tracked the measured data with an R 2 of 0.96, 0.97, and 0.96 with relative error of 0.038, 0.014, and 0.021, respectively, for testing, and R 2 of 0.95, 0.96, and 0.96 with relative error of 0.053, 0.065, and 0.133, respectively, for training. This is an indication that the designed network was satisfactory. The model could be utilized for new data to predict the groundwater salinity for irrigation purposes at the Najaf–Kerbala plateau in Iraq.

This study includes the effect of using different dosages of integral waterproof Admixture and silica fume on some mechanical properties of concrete. Concrete improved by using different ratios of integral water proof admixture(IWP admixture) to increase strength and durability , this admixture used as percentages from cement weight in each mix ranged from 0.0% to 2% ( 0.0 , 1.0%, 1.2%,1.4%,1.6%,1.8%,and 2%) , compressive strength test done for cubes with (10*10*10) cm for each mix .The flexural strength test was done by (10*10*40) cm beams and tested after 28 days of curing. comparison study was made between silica fume mixes properties and mixes without silica fume. Adding IWP admixture leads to increase mechanical properties of ordinary concrete, the reference mix shows compressive strength equal to 26.38 MPa ,while mixes with 2% IWP gives 38.8 MPa in this study .The study also includes the effect of using 2 main dosages of silica fume to the mixes that contain IWP, the new concrete with two admixtures show better values of compressive , tensile and flexural strength comparing with mixes with only IWP, the compressive strength increased from 38.8 MPa for ordinary IWP mixes to 52.3 MPa for 10% silica fume concrete mixes , and also the flexural strength increased from 4.8 MPa for mixes with only IWP to 7.3 MPa for mixes modified with 10 % silica fume .Study include also using waste glass as fine aggregate in mixes contain IWP and 10% silica fume and that show more increment in mechanical properties also.

This study presents a laboratory experiments for evaluating the local scour depth around S-shape solid non- submerged groynes using different number of these groynes and also different distances between them as two countermeasures to reduce the scour. The study was conducted in non- curved laboratory flume where uniform cohesion-less sand of median size (d50) equal to (0.7 mm) was used as the bed material. The physical hydraulic model of the groynes was made of polystyrene foam with fixed dimensions to operate under steady subcritical flow and clear water conditions. The studied parameters in this study were the number of groynes changed three times (single, double, triple), the distances between them altered also three times (1L, 1.5 L, 2L) and finally the hydraulic conditions (depth and velocity of the mean flow) also changed four times for each parameter. A new empirical equation was derived where its coefficient of determination indicates good agreement between the predicted results and the observed ones experimentally.

Groynes are ban impressive engineered methods that used to diverge the flow away from the banks to protect them from erosion, control the flood situations, improve the navigation and also decrease rivers dredging costs, since, their presence will regulate and increase the sediments transport rate through the river reach at the groynes location. In spite of the many advantages for construction the groynes but their presence lead to develop the local scour phenomena which in time cause a structural failure to the groynes body. This issue presents a need to find solutions that have the ability to lessen the scour process along with maintaining all the above benefits of the groynes. The present study introduced a creative solution which is using groynes having a C-shape that have the ability to reduce the scour around themselves through smoothing the water streamlines paths as much as possible to cause little disturbance and hence, less scour. Also the C-shape groynes are compared with the I-shape groynes. The number of groynes is studied also as a countermeasure for more reducing to the local scour phenomena. The study was performed through a laboratory flume with bed material having a median size (d ) equal to (0.7 mm). A polystyrene foam material was used to manufacture the 50 physical models where they investigated under clear water conditions and steady subcritical flow. The results showed that using the C-shape groynes instead of the I-shape groynes for the same hydraulic conditions will reduce the maximum local scour depth with a great percentage. Based on the experimental data, an empirical formula that give good agreement between the observed results experimentally and the predicted ones from it were derived.

River training structures; such as groynes; are efficient engineered methods utilized to protect eroding river banks. But during groynes design stage; the designers faces one of the most significant issues which is the evaluation of the maximum depth of local scour around groynes. This is due to the flow area constriction in the groyne location itself; which in turn cause increasing in local velocity that consequently causes the scour. In the present study, the maximum scour depth around L-shape groyne was computed based on laboratory experiments where different number of groynes and distances between them were used as sort of countermeasures to reduce the scour around the groynes foundations. The results showed clear decreasing in scour depth at increasing number of groynes and also distance between them in the limitation of this study. A new formula based on experimental data was derived to calculate the local scour depth. This formula gave R2 =0.903 which reflecting good agreement to the results.

The commonly used cross sections of weirs are sharp crested rectangular, trapezoidal and triangular, however; the measurement accuracy of single sharp crested weir is abated in areas where flows exhibits great variability, i.e. the flow ranging from very low flow in dry conditions to very high flow in extreme rainfall events. In top of that, generally the weirs have the problem of accumulation the sedimentation in the weir pond, so to minimize the disadvantage of weirs; it can be merged with gates (which also have the problem of retaining the floating materials) in one device. The main objective of this study is to investigate the coefficient of discharge and the characteristics of the free flow for a compound weir (have rectangular notch over triangular notch with trapezoidal notch between them) and semi circular sluice gate of fixed dimensions. Fifteen combined device models were constructed and tested under various geometrical conditions and constant hydraulic conditions. The results show that Cd increases as the hydraulic parameters (H/D , H1/D , H2/D , H3/D) and (W) increases, while the decreasing in Cd values happen at increasing the parameters (Z & Y). The values of Cd range from (0.358 to 0.426) with an average value of (0.392). A general expression were obtained to estimate Cd for the combined device, the estimated values for Cd from the equation plotted against the calculated values from the experimental data and it was found to be good.