Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the remov...

In this paper we provide a common framework for different stratified $LM$-convergence spaces introduced recently. To this end, we slightly alter the definition of a stratified $LMN$-convergence tower space. We briefly discuss the categorical properties and show that the category of these spaces is a Cartesian closed and extensional topological category. We also study the relationship of our cat...

This paper addresses the problem of obtaining an explicit expression of all real FIR paraunitary filters. In this work, we present a general parameterization of 2-channel FIR orthogonal filters. Unlike other approaches which make use of a lattice structure, we show that our technique designs any orthogonal filter directly, with no need of iteration procedures. Moreover, in order to design an L-...

The notion of pseudo-annulets is introduced in Stone lattices and characterized in terms of prime filters. Two operator α and β are introduced and obtained that their composition β ◦α is a closure operator on the class of all filters of a Stone lattice. A congruence θ is introduced on a Stone lattice L and proved that the quotient lattice L/θ is a Boolean algebra.

This paper addresses the problem of obtaining an explicit expression of all real FIR paraunitary filters. In this work, we present a general parameterization of 2-channel FIR orthogonal filters. Unlike other approaches which make use of a lattice structure, we show that our technique designs any orthogonal filter directly, with no need of iteration procedures. Moreover, in order to design an L-...

This paper explores the design and use of Quadrature-Mirror-Filters (QMF) and Conjugate-Quadrature-Filters (CQF) within a two-dimensional framework for digital video applications, an example of which is the transmission system proposed by Schmidt [I]. The principles of subband coding are well known [2,3] and involve splitting an input signal into M-channel " a l l y decimated subbands, which in...

here, we propose an add-drop and a channel drop filter based on two-dimensional photonic crystal all circular ring resonators. these structures are made of a square lattice of silicon rods with the refractive index n1=3.464 surrounded by air (with refractive index n2=1). the broadest photonic band gap occurs at the filling ratio of r/a = 0.17. two linear defect w1 waveguides couple to the ring....

Here, we propose an add-drop and a channel drop filter based on two-dimensional photonic crystal all circular ring resonators. These structures are made of a square lattice of silicon rods with the refractive index n1=3.464 surrounded by air (with refractive index n2=1). The broadest photonic band gap occurs at the filling ratio of r/a = 0.17. Two linear defect W1 waveguides couple to the ring....