periodic noises are unwished and spurious signals that create repetitive pattern on images and decreased the visual quality. firstly, this paper investigates various methods for reducing the effects of the periodic noise in digital images. then an adaptive optimum notch filter is proposed. in the proposed method, the regions of noise frequencies are determined by analyzing the spectral of noisy...

The aim of this study was to investigate the importance of surface potential in microbial deposition onto modified granular surfaces. Recent experimental and theoretical work has indicated that surfaces coated with metal oxides and hydroxide rich oxide/hydroxide mixtures ((hydr)oxides) have the potential to increase the capture efficiencies of commercial filtration systems. This study quantitat...

Nasal filter efficiency for particles has been described by several authors as showing large individual variations, probably somehow related to airflow resistance. Twelve children, aged 5.5-11.5 yrs and 8 aged 12-15 yrs were compared to a group of ten adults. Deposition of polystyrene beads (1, 2.05, 2.8 microns mass median aerodynamic diameter (MMAD] was measured by comparing inhaled aerosols ...

The incidence of Legionnaires' disease (LD) in European countries and the USA has been constantly increasing since 1998. Infection of humans occurs through aerosol inhalation. To bridge the existing gap between the concentration of Legionella in a water network and the deposition of bacteria within the thoracic region (assessment of the number of viable Legionella), we validated a model mimicki...

Chemical vapor deposition (CVD) is an important step in integrated circuit fabrication and is a dynamic process that is complex and subject to unmeasured disturbances. Currently in semiconductor industry the main form of advanced process control for CVD is run-to-run (R2R) control. R2R control is a form of discrete process control in which the processing recipe is modified ex situ based on post...

A helicon antenna that sits remotely outside the vacuum system is attached to a magnetron sputtering system. This increases the electron temperature, which increases the ionization of the sputter flux for achieving ionized physical vapor deposition (IPVD). There are no shadowing and contamination problems, unlike other IPVD devices with immersed coils, since the helicon antenna is outside the v...

Two opposite design strategies for ultrafiltration/microfiltration filters, (1) reduction of concentration polarization and particle deposition to increase permeate velocity and (2) utilization of particle deposition on membrane surface to produce an additional (to permeate) volume of clarified water, are analyzed. It is shown that the first strategy is always associated with additional expendi...

Raingardens are becoming an increasingly popular technology for urban stormwater treatment, however, their hydraulic performance is known to reduce due to clogging from deposition of finegrained sediments on the surface. This impacts on their capacity to treat urban runoff. It has been recently hypothesised that plants can help to mitigate the effect of surface clogging on infiltration. A conce...

In this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. Currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

Nowadays, in the after-treatment of diesel exhaust gas, a diesel particulate filter (DPF) has been used to trap nano-particles of the diesel soot. However, as there are more particles inside the filter, the pressure which corresponds to the filter backpressure increases, which worsens the fuel consumption rate, together with the abatement of the available torque. Thus, a filter with lower backp...