A new relation between morphisms in a category is introduced – roughly speaking (accurately in the categories Set and Top), f ‖ g iff morphisms w : dom(f) → dom(g) never map subobjects of fibres of f non-constantly to fibres of g. (In the algebraic setting replace fibre with kernel.) This relation and a slight weakening of it are used to define “connectedness” versus “disconnectedness” for morp...

Four explicit finite difference schemes, including Lax-Friedrichs, Nessyahu-Tadmor, Lax-Wendroff and Lax-Wendroff with a nonlinear filter are applied to solve water hammer equations. The schemes solve the equations in a reservoir-pipe-valve with an instantaneous and gradual closure of the valve boundary. The computational results are compared with those of the method of characteristics (MOC), a...

The main objective of this work is to propose a mathematical model for the differential sticking coefficient of clayey drilling fluids with a lubricant as an additive and evaluate the influence of differential pressure and lubricant content on filter cake thickness and permeability. Tests were carried out on fluids composed of water and 4.86% of active bentonite clay prepared in Hamilton Beach ...

one of the problems in the ground-based circular synthetic aperture radar is the dependence of the azimuth resolution to the antenna rotation radius and operational limitation of increasing it. to enhance the image quality in azimuth, model-based image formation through three methods: matched filter, inverse filter and optimum filter is suggested and analyzed. for the purpose of comparison, thr...

This paper proposes a new method for rejecting the Continuous Wave Interferences (CWI) in the Global Positioning System (GPS) receivers. The proposed filter is made by cascading an adaptive Finite Impulse Response (FIR) filter and a Wavelet Packet Transform (WPT) based filter. Although adaptive FIR filters are easy to implement and have a linear phase, they create self-noise in the rejection of...

In this report, a dual-scale modeling approach is presented to describe turbulent twophase interface dynamics in a Large Eddy Simulation spatial filtering context. To close the unclosed terms related to the phase interface arising from filtering the Navier-Stokes equation, a resolved realization of the phase interface is explicitly filtered. This resolved realization is maintained on a high res...

a chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (cr+6) mist sampling methods. the results of 48 cr+6mist samples collected using the u.s. national institute for occupational safety and health method 7600showed that cr+6concentration was higher: (1) for sampling by closed-face filter cassettes than for sam...