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The river's bends are a major feature of rivers as a result of their hydraulic and morphological characteristics where the flow pattern has a three-dimensional (3D) nature. The aim of this research is to study the flow pattern induced morphological changes in river bends, evaluation of secondary currents in the different scenarios of flow, and develop a new equation for estimating the bend scour depth for the Nile River. Twenty bends in the Damietta branch (Nile River) in Egypt were selected where the study was done by conducting a bathymetric survey and 3D velocity measurements by an ADCP. A numerical model (Delft 3D) was applied to simulate the flow pattern in different flow scenarios. In addition, a Geographic information system (GIS) was used to analyze the morphological changes and bend scour depths. Statistical correlation between morphometric and hydraulic characteristics and morphological changes ratios was determined, as the results showed a significant correlation between these parameters. Four equations were selected for predicting bend scour depths. The results showed that the agreement between equations values and measured values is not reliable. Therefore, a new equation was derived to predict bend scour depth in the Nile River where it provides a more accurate prediction. [ABSTRACT FROM AUTHOR]

Background: Pterygium is a fibrovascular growth of an abnormal conjunctival tissue that progressively encroaches the limbus and then onto the cornea invading its superficial layers. It is a common ophthalmic condition seen mostly in dry, dusty areas. Objective: The aim of the current study was to evaluate the sutureless glueless conjunctival autograft for primary pterygium surgery as regard technique, complications and success rate. Patients and methods: This prospective study included a total of 30 patients with primary nasal pterygium, attending at Outpatient Clinic of Ophthalmology Department, Al-Azhar University, Damietta. This study was conducted between March 2017 to March 2018. Results: When comparing post-operative values at the end of third month with the first month we have found no difference in corneal state for all patients. The patient with corneal opacity was as the first month and had no difference in corneal state or BCVA. We detected one patient (3.3%) having recurrent pterygium. Finally when comparing post-operative values at the sixth month with the third month, we have found another patient who was reported with recurrent pterygium. Thus, the recurrence rate was 2 patients (6.7%) among all studied patients and the other values were approximately the same. Conclusion: This study suggests that sutureless glueless conjunctival autograft technique is a safe, simple, easy of performance, has less surgical time and very effective for the management of primary pterygium. [ABSTRACT FROM AUTHOR]