排序方式: 共有34条查询结果,搜索用时 15 毫秒
1.
Pui David Y.H. Biswas Pratim Fissan Heinz Schoonman Joop 《Journal of nanoparticle research》2000,2(4):425-426
Journal of Nanoparticle Research - 相似文献
2.
Jing Wang Christof Asbach Heinz Fissan Tim Hülser Thomas A. J. Kuhlbusch Drew Thompson David Y. H. Pui 《Journal of nanoparticle research》2011,13(4):1373-1387
Nanotechnology has great potential to transform science and industry in the fields of energy, material, environment, and medicine.
At the same time, more concerns are being raised about the occupational health and safety of nanomaterials in the workplace
and the implications of nanotechnology on the environment and living systems. Studies on environmental, health, and safety
(EHS) issues of nanomaterials have a strong influence on public acceptance of nanotechnology and, eventually, affect its sustainability.
Oversight and regulation by government agencies and non-governmental organizations (NGOs) play significant roles in ensuring
responsible and environmentally friendly development of nanotechnology. The EHS studies of nanomaterials can provide data
and information to help the development of regulations and guidelines. We present research results on three aspects of EHS
studies: physico-chemical characterization and measurement of nanomaterials; emission, exposure, and toxicity of nanomaterials;
and control and abatement of nanomaterial releases using filtration technology. Measurement of nanoparticle agglomerates using
a newly developed instrument, the Universal NanoParticle Analyzer (UNPA), is discussed. Exposure measurement results for silicon
nanoparticles in a pilot scale production plant are presented, as well as exposure measurement and toxicity study of carbon
nanotubes (CNTs). Filtration studies of nanoparticle agglomerates are also presented as an example of emission control methods. 相似文献
3.
4.
Burkhard Stahlmecke Sandra Wagener Christof Asbach Heinz Kaminski Heinz Fissan Thomas A. J. Kuhlbusch 《Journal of nanoparticle research》2009,11(7):1625-1635
The stability of agglomerates is not only an important material parameter of powders but also of interest for estimating the
particle size upon accidental release into the atmosphere. This is especially important when the size of primary particles
is well below the agglomerate size, which is usually the case when the size of primary particles is below 100 nm. During production
or airborne transportation in pipes, high particle concentrations lead to particle coagulation and the formation of agglomerates
in a size range of up to some micrometers. Binding between the primary particles in the agglomerates is usually due to van
der Waals forces. In the case of a leak in a pressurized vessel (e.g. reactor, transport pipe, etc.), these agglomerates can
be emitted and shear forces within the leak can cause agglomerates to breakup. In order to simulate such shear forces and
study their effect on agglomerate stability within the airborne state, a method was developed where agglomerate powders can
be aerosolized and passed through an orifice under various differential pressure conditions. First results show that a higher
differential pressure across the orifice causes a stronger fragmentation of the agglomerates, which furthermore seems to be
material dependent. 相似文献
5.
Particle penetrations through commercially available, electrically charged fibrous filters have been measured. The particles were monodisperse and in charge equilibrium. Tests were conducted for several particle sizes in the range 0.02 μm ≤ x ≤ 1 μm. The face velocity was varied in the range of 2 cm/s to 30 cm/s. The penetration has a bimodal dependence on particle size. This behaviour is not found for uncharged filters. The reduction in penetration and bimodal dependence is attributed to electrical collection effects. As the face velocity is increased, the electrostatic collection effects are significantly reduced. The results agree quantitatively with a model for particle penetration through charged fibrous filters recently presented in the literature by the authors. 相似文献
6.
Journal of Nanoparticle Research - 相似文献
7.
Journal of Nanoparticle Research - 相似文献
8.
9.
Eckhard Otto Frank Stratmann Heinz Fissan Srinivas Vemury Sotiris E. Pratsinis 《Particle & Particle Systems Characterization》1994,11(5):359-366
A log-normal model, based on the extended SIMPLER-algorithm utilizing the Modal Aerosol Dynamics Modelling Technique, and a sectional model are compared for Brownian coagulation in the transition regime. The models are in good agreement with respect to the calculated particle size distribution moments. Applying the log-normal model a simple coagulation model consisting of a closed set of five equations is developed that does not require the solution of ordinary diferential equations. 相似文献
10.
Higher surface energy of free nanoparticles 总被引:1,自引:0,他引:1
We present an accurate online method for the study of size-dependent evaporation of free nanoparticles allowing us to detect a size change of 0.1 nm. This method is applied to Ag nanoparticles. The linear relation between the onset temperature of evaporation and the inverse of the particle size verifies the Kelvin effect and predicts a surface energy of 7.2 J/m(2) for free Ag nanoparticles. The surface energy of nanoparticles is significantly higher as compared to that of the bulk and is essential for processes such as melting, coalescence, evaporation, growth, etc., of nanoparticles. 相似文献