A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built s...A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built self-adjustment of flow rates among the filters assisted with downstream orifice for flow control with limited flexibility for further adjustment. The proposed design allows the control of flow level and flow rates in individual filters, the water level in the over flow distributor tank and offers increased flexibility in responding to changes in filtration variables and optimising the overall performance of the filters. The design set up can also operate as constant rate filter through setting the water level in the distributor tank to the maximum.展开更多
A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate...A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.展开更多
A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determine...A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determined using either row wise or column wise operations and are demonstrated to be sums of permutation products of the Gauss pivot row multipliers. These sums of permutation products can be constructed using a tree structure that can be easily memorized or alternatively computed using matrix products. The method requires only storage of the L matrix which is half in size compared to storage of the elements in the LU decomposition. Equivalence of the proposed method with both the Gauss elimination and LU decomposition is also shown in this paper.展开更多
文摘A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built self-adjustment of flow rates among the filters assisted with downstream orifice for flow control with limited flexibility for further adjustment. The proposed design allows the control of flow level and flow rates in individual filters, the water level in the over flow distributor tank and offers increased flexibility in responding to changes in filtration variables and optimising the overall performance of the filters. The design set up can also operate as constant rate filter through setting the water level in the distributor tank to the maximum.
文摘A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.
文摘A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determined using either row wise or column wise operations and are demonstrated to be sums of permutation products of the Gauss pivot row multipliers. These sums of permutation products can be constructed using a tree structure that can be easily memorized or alternatively computed using matrix products. The method requires only storage of the L matrix which is half in size compared to storage of the elements in the LU decomposition. Equivalence of the proposed method with both the Gauss elimination and LU decomposition is also shown in this paper.
