colloidal nanosilica is currently being produced by various methods which are mainly high energy intensive and/or not environmentally friendly. it is therefore essential to develop new energy-efficient and environmentally friendly technologies. this paper introduces a new ultrasound assisted route based on alkali leaching of silica fume for synthesis of colloidal silica nanoparticles. the ef...

Since the mass of the electron is very small relative to atomic masses, Thomson scattering of low-energy photons (hν ≪ mec) produces thermal Doppler frequency shifts that are much larger than atomic Doppler widths. A method is developed here to evaluate the electron scattering emissivity from a given radiation field which is considerably faster than previous methods based on straightforward eva...

We have studied purified preparations of murine mammary tumor virus (MuMTV), Rous sarcoma virus (RSV; Prague strain), and feline leukemia virus (FeLV) by laser beat frequency light-scattering spectroscopy, ultra-centrifugation, and electron microscopy. The laser beat frequency light-scattering spectroscopy measurements yield the light-scattering intensity, weighted diffusion coefficients. The c...

We investigate the effects of electron and acoustic phonon confinements on the low-field electron mobility of thin, gated, square silicon nanowires SiNWs , surrounded by SiO2. We employ a self-consistent Poisson–Schrödinger–Monte Carlo solver that accounts for scattering due to acoustic phonons confined and bulk , intervalley phonons, and the Si /SiO2 surface roughness. The wires considered hav...

A high quality Keck spectrum of the Hα line in NGC 4395 reveals symmetric exponential wings, fv ∝ e, with σ ≃ 500 km s. The wings extend out to > ∼ 2500 km s from the line core, and down to a flux density of < ∼ 10 of the peak flux density. Numerical and analytic calculations indicate that exponential wings are expected for optically thin, isotropic, thermal electron scattering. Such scattering...