Light absorption by aerosols contributes to solar radiative forcing through absorption of solar radiation and heating of the absorbing aerosol layer. Besides the direct radiative effect, the heating can evaporate clouds and change the atmospheric dynamics. Aerosol light absorption in the atmosphere is dominated by black carbon (BC) with additional, significant contributions from the still poorl...

introdouction: the major demand for orthodontic treatment is associated with esthetic complaints rather than with the severity of occlusal irregularities. this study evaluated the relationship between orthodontic treatment need based on index of complexity, outcome, and need (icon) and orthodontic- specific quality of life (qol) among high school students in shiraz. materials and methods: based...

The use of pollen shape (spiked sphere) particles for dry powder inhalation is studied. Pollen shape hydroxyapatite (HA) particles are synthesized to cover both size ranges of typical drug and carrier particles for pulmonary drug delivery. The HA particles produced have geometric diameter range from 5-50 μm and effective density range from 0.2-0.72 g/cm. The flow properties of the powders are c...

We demonstrate that a laser beam converging from a specific transverse mode is a bottle beam, as described in J. Opt. Soc. Am. B 20, 1220 (2003). To our knowledge, this is the first time that a bottle beam has been generated directly from a laser. By calculating the radiation forces on a dielectric Rayleigh sphere in the bottle beam, we show that the single beam can trap high-refractive-index p...

In this article, we introduce a novel geometrical index δagg, which is associated with the Euler number and is obtained by an image processing procedure for a given digital picture of aggregated particles such that δagg exhibits the degree of the agglomerations of the particles. In the previous work (Matsutani, Shimosako, Wang, Appl. Math. Modeling 37 (2013), 4007–4022), we proposed an algorith...

Through a series of numerical simulations we explore some scatter effects due to nonspherical particles. Specifically, we examine the link between the aspect ratio of randomly oriented, prolate spheroidal particles and the resulting linear depolarization of the scattered light in the forward and backscatter directions. The particular objective is to detect the presence of randomly oriented part...

Aerosol particles experience hygroscopic growth at enhanced relative humidity (RH), which leads to changes in their optical properties. We developed the white-light humidified optical particle spectrometer (WHOPS), a new instrument to investigate the particles’ hygroscopic growth. Here we present a detailed technical description and characterization of the WHOPS in laboratory and field experime...

Particles moving on crystalline surfaces and driven by external forces or flow fields can acquire velocities along directions that deviate from that of the external force. This effect depends upon the characteristics of the particles, most notably particle size or particle index of refraction, and can therefore be (and has been) used to sort different particles. We introduce a simple model for ...

The data on the far-ultraviolet extinction of starlight in our galaxy and in external galaxies is interpreted in terms of the widespread occurrence of organic particles of optical refractive index 1.4 and radii less than or equal to 20 nm. Such particles are candidates for nanobacteria such as recently been found in abundance on the Earth.

abstract the aim of this study is laboratory investigation of nitrate reduction in water using fe/cu nano particles. in this regards, nano fe0 (54±4 nm) and fe/cu particles (75±3 nm) was synthesized and characterized by x-ray diffraction pattern (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) photographs. the effects of coating load of nano-fe0 by cu (0, 5, ...