798,582 research outputs found
Full-flow fluid filter
Etched-disk filter was developed with fluid passageways in configuration which allows relatively unrestricted flow of fluid and has stagnation areas for collection of impurities. In addition, filter housing without center post was developed to improve flow characteristics
Filter Cleaning Using Gas Injection
A filter cleaning process using gas injection is considered. An estimate for the minimum mass flow rate out of the gas injector and the corresponding injector/filter geometry is found. The estimates are based on a similarity solution for a free turbulent jet. The minimum mass flow rate and geometry is worked out for a specific example
Aerated blast furnace slag filters for enhanced nitrogen and phosphorus removal from small wastewater treatment plants
Rock filters (RF) are a promising alternative technology for natural
wastewater treatment for upgrading WSP effluent. However, the application
of RF in the removal of eutrophic nutrients, nitrogen and phosphorus, is very
limited. Accordingly, the overall objective of this study was to develop a lowcost
RF system for the purpose of enhanced nutrient removal from WSP
effluents, which would be able to produce effluents which comply with the
requirements of the EU Urban Waste Water Treatment Directive (UWWTD)
(911271lEEC) and suitable for small communities. Therefore, a combination
system comprising a primary facultative pond and an aerated rock filter
(ARF) system-either vertically or horizontally loaded-was investigated at
the University of Leeds' experimental station at Esholt Wastewater
Treatment Works, Bradford, UK.
Blast furnace slag (BFS) and limestone were selected for use in the ARF
system owing to their high potential for P removal and their low cost. This
study involved three major qperiments: (1) a comparison of aerated
vertical-flow and horizontal-flow limestone filters for nitrogen removal; (2) a
comparison of aerated limestone + blast furnace slag (BFS) filter and
aerated BFS filters for nitrogen and phosphorus removal; and (3) a
comparison of vertical-flow and horizontal-flow BFS filters for nitrogen and
phosphorus removal.
The vertical upward-flow ARF system was found to be superior to the
horizontal-flow ARF system in terms of nitrogen removal, mostly thiough
bacterial nitrification processes in both the aerated limestone and BFS filter
studies. The BFS filter medium (whieh is low-cost) showed a much higher
potential in removing phosphortls from pond effluent than the limestone
medium. As a result, the combination of a vertical upward-flow ARF system
and an economical and effective P-removal filter medium, such as BFS,
was found to be an ideal optionfor the total nutrient removal of both nitrogen
and phosphorus from wastewater.
In parallel with these experiments, studies on the aerated BFS filter effective
life and major in-filter phosphorus removal pathways were carried out. From
the standard batch experiments of Pmax adsorption capacity of BFS, as well
as six-month data collection of daily average P-removal, it was found that
the effective life of the aerated BFS filter was 6.5 years. Scanning electron
microscopy and X-ray diffraction spectrometric analyses on the surface of
BFS, particulates and sediment samples revealed that the apparent
mechanisms of P-removal in the filter are adsorption on the amorphous
oxide phase of the BFS surface and precipitation within the filter
The geometry of low-rank Kalman filters
An important property of the Kalman filter is that the underlying Riccati
flow is a contraction for the natural metric of the cone of symmetric positive
definite matrices. The present paper studies the geometry of a low-rank version
of the Kalman filter. The underlying Riccati flow evolves on the manifold of
fixed rank symmetric positive semidefinite matrices. Contraction properties of
the low-rank flow are studied by means of a suitable metric recently introduced
by the authors.Comment: Final version published in Matrix Information Geometry, pp53-68,
Springer Verlag, 201
Fiber length and orientation prevent migration in fluid filters
Stainless steel fiber web filter resists fiber migration which causes contamination of filtered fluids. This filter is capable of holding five times more particulate matter before arbitrary cutoff pressure drop and shows excellent retention in fuel flow at high rates
Identification of nonlinear lateral flow immunoassay state-space models via particle filter approach
This is the post-print of the Article. The official published version can be accessed from the link below - Copyright @ 2012 IEEEIn this paper, the particle filtering approach is used, together with the kernel smoothing method, to identify the state-space model for the lateral flow immunoassay through available but short time-series measurement. The lateral flow immunoassay model is viewed as a nonlinear dynamic stochastic model consisting of the equations for the biochemical reaction system as well as the measurement output. The renowned extended Kalman filter is chosen as the importance density of the particle filter for the purpose of modeling the nonlinear lateral flow immunoassay. By using the developed particle filter, both the states and parameters of the nonlinear state-space model can be identified simultaneously. The identified model is of fundamental significance for the development of lateral flow immunoassay quantification. It is shown that the proposed particle filtering approach works well for modeling the lateral flow immunoassay.This work was supported in part by the International Science and Technology
Cooperation Project of China under Grant 2009DFA32050, Natural Science Foundation of China under Grants 61104041, International Science and Technology Cooperation Project of Fujian Province of China under Grant
2009I0016
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