The horizontal high energy rotor ball mill () is used to break and activate dry solids. It is used for dry-milling and in the vertical mount for wet-milling in leaching processes. Technical electric arc furnace (EAF) dust with high contents of zinc oxide, zinc ferrite and magnetite is efficiently separated by ambient temperature leaching. The process shows promise for industrial application

We investigate the spectral energy distributions (SEDs) of low mass-loss rate O-rich asymptotic giant branch (AGB) stars using the infrared observational data including the Infrared Space Observatory (ISO) data. Comparing the results of detailed radiative transfer model calculations with observations, we find that the dust formation temperature is much lower than 1000 K for standard dust shell models. We find that the superwind model with a density-enhanced region can be a possible alternative dust shell model for LMOA stars.

The main sources of interstellar dust are believed to be dust envelopes around AGB stars. The outflowing envelopes around the long period pulsating variables are very suitable place for massive dust formation. Oxygen-rich silicate dust grains or carbon-rich dust grains form in the envelopes around AGB stars depending on the chemical composition of the stellar surface. The dust grains expelled from AGB stars get mixed up and go through some physical and chemical changes in interstellar medium. There are similarities and differences between interstellar dust and dust grains in AGB stars. The mass cycle in the Galaxy may be best manifested by the fact that the dust grains at various regions have many similarities and understandable differences.

This is a proposal to probe local part of the interplanetary dust (IPD) cloud complex and retrieve mean volume emissivity of the local IPDs at mid-infrared wavelengths. This will be done by monitoring, with Infrared Camera (IRC) aboard the ASTRO-F, the annual modulation of the zodiacal emission. In pointing mode of the ASTRO-F mission the spacecraft can make attitude maneuvering over approximately ±1 ̊ range centered at solar elongation 90 ̊ in the ecliptic plane. The attitude maneuvering combined with high sensitivity of the IRC will provide us with a unique opportunity observationally to take derivatives of the zodiacal emission brightness with respect to the solar elongation. From the resulting differential of the brightness over the ±1̊ range, one can directly determine the mean volume emissivity of the local IPDs with a sufficient accuracy to de-modulate the annual emissivity variations due to the Earth's elliptical motion and the dis-alignment of the maximum IPD density plane with respect to the ecliptic. The non-zero eccentricity (e⊕= 0.0167) of the Earth's orbit combined with the sensitive temperature dependence of the Planck function would bring modulations of amplitude at least 3.34% to the zodiacal emission brightness at mid-infrared wavelengths, with which one may determine the IPD temperature T(r) and mean number density n(r) as functions of heliocentric distance r. This will in turn fix the power-law exponent δ in the relation T(r) = T_o(r/r_o)-δ for the dust temperature and v in n(r) = n_o(r/r_o)-v for the density. We discuss how one may de-couple the notorious degeneracy of cross-section, density, reference temperature To and exponent δ.

Conidia of molds within the Asian dust were captured in the ambient air of mid-west Korea, in springtime of 2000~2002. An eight-stage Cascade impactor and 0.22 μm pore size membrane filters were used for the dust samples. Several kinds of mol

서울시에서 설치하여 운영중인 대기질 측정소의 입자상물질을 대표하는 PM2.5, PM10, TSP와 황사기간 중 고용량고기포집기로 채취한 먼지성분을 분석, 평가하였다. 1990년도부터 2002년 11월까지 서울에서 관측된 황사일수는 2000년 이후 발생빈도가 증가하였으며 황사지속시간도 길어지는 경향을 보였다. PM10/TSP 비율은 황사시 2000년, 2001년도에 각각 52.9%, 59.4%로 비황사시에 비해 PM10의 비율이 약 10% 정도 낮은 것으로 미루어 황사시 10 μm이상의 입경이 큰 입자 영향이 컸던 반면에 2002년 황사시에는 PM10의 영향이 오히려 크게 나타나 PM10이 TSP 중의 71.4%에 달하였다. 황사가 전체 먼지농도에 미치는 기여율은 2002년도에 PM2.5 11.9%, PM10 23.1%, TSP 19%로 가장 높은 기여도를 보여 황사가 전체 면지농도에 미치는 영향이 매우 크다는 것을 알 수 있었다.