The purpose of this research was to investigate and compare the performance of a synthetic drainage envelope material with a granular envelope material vastly used in drainage projects of the region. This study was conducted in the soil and water research laboratory of Chamran University. Upward flow cylinder infiltrometers was used in these experiments. Granular envelope was designed according to USBR recommenedations, and synthetic the envelope used was PP450. Drain outlet discharge variation, soil-envelope hydraulic conductivity under fixed hydraulic head and gradient ratio (GR) in the two envelopes were measured and compared. The results of GR test indicated that clogging potential was greater in the synthetic envelope. In regard to hydraulic conductivity, the performance of both envelopes was acceptable and could be used as drainage envelope material satisfactorily. Under all hydrylic heads used in these experiments, drain outlet discharge for the granular envelope was higher than synthetic envelope material.

Background and Objectives: The effect of mineral clogging by soil particles is one of the main factors affecting the performance of drainage systems. Many drainage systems designs do not pay attention to laboratory and local studies on certain important parameters and some of them use to be specific for a given conditions. Several studies carried out in The Netherlands have shown that nearly 80% of drainage projects’ failure happens as a result of inappropriate performance of drain filters. Since field studies in order to evaluate drain envelopes is not economical from viewpoint of time and cost. Therefore laboratory evaluation is proper for envelopes. The main goal of this study was obtaining a set of empirical equations in order to estimate hydraulic and clogging parameters using hydraulic head and discharge through drains which are easy to measure. Removing the effect of piezometers installed the Permeameter was another goal.Materials and Methods: To conduct this research, The Permeameter which designed and was made according to ASTM-5101 standard, was used PP-450 and gravel envelope were evaluated according to USBR standard. Required soil for this experiment was collected from a drainage project in the north of Khorramshahr at 1.65 m depth. The test was conducted in laboratory using Permeameter by producing 4 different hydraulic pressure head (25, 50, 75, 100 cm). In this study, special parameters (envelope hydraulic conductivity, soil hydraulic conductivity, soil-envelope hydraulic conductivity, gradient ratio) were calculated by measurement of outflow changes in soil envelope system and hydraulic pressure head of manometer.Results: After the tests were completed, the values of hydraulic conductivity for soil-envelope system, soil and geotextile envelope were estimated as functions of hydraulic head and outflow values. Furthermore, other relations were proposed for gradient ratio. The relations between different parameters were analyzed by Sigma Plot software and proper relations were proposed. The errors of the fitting equations and the difference between measured and estimated values were analyzed using the statistic indices. Results showed that these models are accuracy estimation of assessed parameters.Conclusion: Correlation coefficient of these equations for pp450 envelope for soil-envelope hydraulic conductivity, soil hydraulic conductivity, envelope hydraulic conductivity and gradient ratio are 0.96, 0.96, 0.62 and 0.96 respectively and for gravel envelope for soil-envelope hydraulic conductivity, soil hydraulic conductivity and envelope hydraulic conductivity are 0.98, 0.98 and 0.63 respectively. Low correlation coefficient for estimation of envelope hydraulic conductivity is related to envelope clogging during experiment time. Using of proposed equations can be estimate clogging and hydraulic performance of drainage envelopes in different conditions.

Let R be a commutative ring with identity and M a unitary R-module. The concept of prime submodule of an R-module M has been discussed. In this paper, we investigate the concept of semiprime submodule of an R-module M. We also, consider relation between the semiprime submodule N of an r-module M and the semiprime ideal (N: M) of R and we focus our attention on relation between E (N) and N.

Activity-based costing since it's introduction has attracted so much attention. There are, however, practical problems in implementing this costing system, which, in spite of the computational superiority of activity-based costing compared to traditional costing, organizations and companies are still not interested in using this costing method. In the present study, implementation problems that are practically related to implementation of activity-based costing have been investigated and artificial neural networks have been used to solve the problem of estimating the cost-activity relationship (CER) as well as reducing the costs of doing timing in organizations. The statistical population of the research is all branches of Maskan Bank which has been clustered using CI-DEA Data Envelopment Analysis (CI-DEA) and based on performance similarity in 1395. 450 branches were selected as samples and used to train and test the model of neural networks. The distinctive feature of this pattern is to consider non-linear relationship between cost-activity and other patterns. The proposed architecture of network makes it possible, in addition to the cost-of-activity forecast, to be extrapolated from the model, the amount of cost-driven input (time) used as a cost-sharing actuator to the activity in the conventional executive model. The results of the RMSE and MAE models showed that the proposed model has the capability to estimate the cost-activity relationship.

A characteristic of Data Envelopment Analysis (DEA) is to allow individual decision making units (DMUs) to select the factor weights which are the most advantageous for them in calculating their efficiency scores. This flexibility in selecting the weights, on the other hand, deters the comparison among DMUs on a common base. For dealing with this difficulty and assessing all the DMUs on the same scale, this paper proposes using a multiple objective linear programming (MOLP) approach based on scalarizing function for generating common set of weights under the DEA framework. This is an advantageous of the proposed approach against general approaches in the literature which are based on multiple objective nonlinear programming.

Argerami and Farenick have found conditions for the injective envelope of a separable C∗-algebra to be a von Neumann algebra. In this paper, we introduce an equivalent version of this result by finding conditions for the G-injective envelope of a separable G-C∗-algebra A to be a von Neumann algebra, when G is a discrete group acting on A.