ABSTRACT: Experiments were conducted at the Natural Energy Laboratory of Hawaii to determine the effectiveness of non-chemical techniques to control biofouling. The two techniques investigated were ultrasonic and ultraviolet. The colonization of microorganisms attracts higher order organisms; therefore, deactivation of microorganisms to prevent colony should reduce the fouling propensity. The m...

Fog droplets in the atmosphere are first produced by the activation of cloud condensation nuclei (CCN), which are originally some ionic compound. Subsequently, the nuclei grow by vapor diffusion. Fog droplets are polluted through the activation process and successive diffusion growth and residence (post activation). We cannot distinguish the effects of the two pollution processes of natural fog...

Abstract A coupled process of ultrasonic spray pyrolysis and lyophilisation was used for the synthesis dried gold nanoparticles. Two methods were applied determining their melting temperature: uniaxial microcompression differential scanning calorimetry (DSC) analysis. Uniaxial resulted in sintering nanoparticles at room temperature with an activation energy 26–32.5 J/g, which made it impossible...

The physical aging of amorphous polymers induces changes in material properties, which are challenging to detect situ industrial settings. Here, we present a nondestructive nonlinear ultrasonic evaluation technique that enables localized measurements the combined effects temperature and time polymers, without needing remove materials. proposed is demonstrated using commercial grade poly(vinyl c...

The removal of nitroaromatics from polluted water is difficult due to their high stability to conventional treatment methods. This paper presents a method for the destruction of 1,3-dinitrobenzene and 2,4-dinitrotoluene in aqueous solutions. The compounds are shown to be stable to reaction with ozone, even under ultrasonic activation. The use of ultrasound enhances the rate of electrochemical r...

In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas th...

Thin films, consisting of a sol–gel Nb2O5 matrix doped with zeolite Na-X synthesized from fly ash through ultrasonic-assisted double-stage fusion-hydrothermal alkaline activation, were deposited by the spin-coating method. In order to improve optical quality and sensing properties thin zeolites wet milled for 60, 120 540 s prior incorporation in film. The liquid adsorption ability films was tes...

Densities, ρ, viscosities, η, and ultrasonic sound velocities u of pure methyl isobutylketone, diethylketone, cyclopentanone, cyclohexanone, 2-methyl cyclohexanone and those of their binary mixtures with N-methyl aniline were measured at 303.15 K over the entire composition range. These experimental data have been used to calculate the excess volume (VE), deviation in ultrasonic sound velocity ...

Commercially pure nickel was processed by equal channel angular pressing (ECAP) through route Bc for 12 passes to obtain an ultrafine grained (UFG) microstructure and further subjected to an ultrasonic treatment (UST) which introduced a maximum amplitude equivalent to anormal stresses of 100 MPa in a steady state regime. It was observed that the microstructure of UFG Ni can be differently alter...

Both the spectrum and correlation characteristics are important in constructing excitation sequences to realize the multichannel ultrasonic sensors working together. For LFM excitation sequence, there should not be too many simultaneously fired ultrasonic sensors, because of the limited available frequency band of the ultrasonic ranging system. The optimized CFM excitation sequences are propose...