Accurate prediction of dam breach parameters in embankment dams is an essential step in the risk management plan. Overtopping and piping are the leading causes of embankment failure in the world. The failure of this type of dam is typically proposed by hydrological and hydraulic computational models of the dam (Wahl, 1998). The relationships for assessing the breach and flow characteristics are generally obtained by artificial intelligence and regression analysis from case studies of historical dam failure. These models relate the input parameters such as the dam height (Hw) and the flow volume through the breach (Vw) to the observed breach parameters resulting from the actual failures. Several relationships have been proposed to calculate Qp as a function of Hw and Vw (De Lorenzo & Macchione, 2014; Hagen, 1982; Kirkpatrick, 1977; Singh & Snorrason, 1984; Hakimzadeh et al., 2014). Downstream sediment transport studies show that breach geometry directly affects the output hydrograph. Investigations on historical records for Qp determination show that Hw and Vw could provide more accurate results than El and Ew. Moreover, the combination of these parameters significantly increases computational accuracy (Thornton et al., 2011; Wang et al., 2018). Several laboratory and field studies have been performed to investigate the hydraulic properties of the breach and the output hydrograph in overtopping failure cases (Dhiman & Patra, 2017; Sadeghi et al., 2020; Vaskinn et al., 2004). Determination of the average breach width (Bave) is an essential factor in determining progressive erosion (Von Thun & Gillette, 1990; Froehlich, 1995) as well as the height of breach (Hb). The range of variation in Bave as a function of the dam height (Hd) is an important issue in the breach lateral evolution process (Johnson & Illes, 1976; Singh & Snorrason, 1984).

Introduction: The present study is conducted with the aim of studying the efficacy of metacognition training and perception of spatial relationship on improvement of mathematical operation of the students with mathematics learning disabilities.Method: The statistical population of the study included the students of grade three, primary school, with mathematics learning deficiencies in Isfahan between the years1389-90. To do this study 20 classes were sampled randomly. The applied instruments included Wechsler Intellectual Scale for Children 4, the test of recognizing mathematics deficiencies and the test of mathematics function. From among the students who were recognized with mathematics deficiencies, 45 were selected randomly for metacognition training, perception of spatial relationship training, and control groups.Experimental research design was in pre-test/post-test with a control group. Data were analyzed by statistical covariance.Results: The covariance analysis represented a significant difference between the two groups: (F2, 41=18/12, h=0/47, P<0/0001) the test revealed the least significant difference between metacognitive training group (p<0.0001) and perception of spatial relationship group (p<0.0001) and control group, while there was no significant difference between the experimental groups (P=0.991).Conclusion: Based on the findings of this study, both metacognitive methods and perception of spatial relationship methods of training are useful in treatment of mathematics learning disorders.Findings of the present study may conclude that it is useful to apply metacognition and perception of spatial relationship in teaching mathematics to the students.

hypothesis: The physical properties of electrospun nanofibrous mats have a significant effect on the behavior of electrospun mat in interaction with other surfaces, as well as on its efficiency in various applications. Therefore, determining and predicting these structural properties using controllable factors in the electrospinning process are of particular importance. On this basis, in the present research each of the structural properties of nanofibrous mat, including mat porosity, diameter and porosity of fiber, were estimated using mathematical relationships. Also, the prediction and optimization of input factors and the porosity of the mat and fibers were performed using the response surface methodology (RSM). Methods: Poly(lactic-glycolic acid) was used to produce nanofibrous mats. After the determination and optimization of the electrospinning process factors, which influence the structural properties of nanofibrous mats, 18 types of mats were prepared. Considering the combined effect of three electrospinning factors, including solution concentration, humidity and collector linear speed, RSM and regression methods were used to optimize and model the relationship between variables and mat properties, respectively. Findings: Based on the mathematical relationships between the input factors and the structural characteristics of the mat, it can be revealed that the concentration is the most effective factor on the fiber diameter and mat porosity, and the collection speed is the most effective factor on the fiber porosity. According to the RSM models, the optimized values for the initial factors of concentration, humidity and collection speed based on the model designed for fiber porosity are 2% (w/v), 45% and 0. 4 m/s, and based on the model designed for mat porosity are 3% (w/v), 45% and 2. 4 m/s, respectively. The predicted optimized values of fiber porosity and mat porosity are 0. 342% and 0. 989%, respectively, which are not much different from the experimental values obtained from these points. The nanofibrous mat introduced by each of these models has created the most porosity.

Water measurements play a pivotal role in the irrigation and drainage networks.Due to effective limitations of simple sharp crested weirs, compound sharp crested weirs have attracted the attention of scientists and civil engineers recently. With this kind of weirs, flow discharge is measured with a reasonable sensitivity over a wide flow range. In this paper, by assumption of flow similarity between compound sharp crested weirs and compound open channels, a new method based on numerical solution of a quasi-two-dimensional mathematical model has been proposed for discharge calculation of compound weir. The numerical results were compared with the experimental data of Jan et al. (2006) and the traditional method (theoretical equations of simple weirs). These comparisons revealed that the proposed method had nearly 1 percent error while the traditional method had more than 8 percent error.

Introduction: Surface irrigation is still the most used method. For accessing to high efficiency, irrigation requires careful design and correct implementation. In addition, the design and evaluation of these systems require the identification of the advance, recession, and infiltration curves. Infiltration is the most important and difficult parameter to evaluate surface irrigation systems. The objective of this study was to evaluate five different methods to estimate infiltration parameters (two-point method of Elliott and Walker, recycling furrow infiltrometer, Singh and Yu method, Shepard one-point method and modified Shepard et al. two-point method) and to determine the most compatible method with design and evaluation models of furrow irrigation (hydrodynamic, kinematic wave and zero inertia) by applying SIRMOD software. …

The present paper studies the possibility of translating “ sense relations” in the level of sentences into formal expressions. In so doing, it applies the mathematical logic, especially the logic of propositions within the constraints of sufficient Farsi examples. That is, firstly, a definition for each relation in sentence level is presented. Secondly, using the tools of propositional logic, a formal translation for each relation is offered. Then, each of the proposed relation is shown to be in accordance with its corresponding sense relation; finally, the efficiency of the formal expression is tested by examples from Farsi. The sense relations discussed are as follows: entailment, contradiction, inference, and presupposition. The author concluded that the sense relation of “ synonymy” is, basically, impossible to be translated into formal expression since there are no two sentences in any language that can be considered “ synonymous” . Thus, no formal translation can be proposed for “ synonymy” in the sentence level.