Ultra fine particles

Fe Ultra fine particle Decomposition of metallocene 1060 Benzene 21... 

Ultra fine particle Decomposition of metal carbonyl 800 Acetylene 24... 

Co Ultra fine particle Laser etching of Co thin film 1000 Triazine 26... 

VGCFs have typical diameters of 100 nm - 100 pm with hollow cores [9]. Thus VGCFs are 10 - lO times thicker than CNTs. A preparation method for VGCFs was first developed by Endo [10,11] wbo decomposed benzene at 1150-1.300°C in an electric furnace in the presence of H2 (99.9% pure) as the carrier gas (see Fig. 1). Ultra-fine particles of Fe (ca. 10 nm diameter) or its compounds, such as Fe(N03)3 or ferrocene, were introduced into the chamber as a catalyst. 

To avoid explosion, the compounds can be decomposed via hydrolysis in liquid solution. Ultra-fine particles are obtained in water and water-ammonia media. Hydrolysis in HC1 and HN03 solutions leads to the precipitation of an agglomerated powder of both tantalum and niobium oxides. Agglomerates obtained are up to 12 pm in diameter, while the estimated diameter of the smallest ciystalline particles varies in the range of 0.01-0.5 pm [512]. 

ULTRA-FINE PARTICLES edited by Chikara Hayashi, R. Ueda and A. Tasaki... 

Sawadaishi, T. and Shimomura, M. (2005) Two-dimensional patterns of ultra-fine particles prepared by self-organization. Colloid. Surf. A, 257-258, 71-74. 

A recently commercialized U.L.V. (ultra-low volume) -type aerosol sprays a fixed volume of ultra-fine particles into the room and retains effectiveness for 12 h with one spray. The mechanism of the effectiveness was considered to be the contact of pyrethroid particles with mosquitoes in the air at the initial stage followed by re-volatilization into the air of pyrethroids attached to walls and floors however, according to experiments by the present author et al., it was confirmed that mosquitoes are knocked down by contact with pyrethroid particles in the air during the first 1 h and then the lethal effect on mosquitoes is achieved by their contact with pyrethroids adhering to walls. 

Esaki H, Namhu T, Morinaga M, Udaka M, Kawasaki K (1996) Development of low hydrogen overpotential electrodes utilizing metal ultra-fine particles. Int J Hydrogen Energy 21 877-881... 

The sol is made of a stable suspended solution of metal salts or solvated metal precursors containing solid particles of nanometer diameter. Polycondensation or polyesterification results in the appearance of particles in a new phase called the gel . Aging, drying and dehydration are steps required to achieve solid-form ultra-fine particles. Coarsening and phase transformation occur simultaneously with aging. Gel drying is associated with the... 

One of the excellent characteristics of Raney catalyst is a porous skeletal structure composed of ultra fine particles. 

Figure 16. Dispersion of ultra-fine particles by heating a primary leached particle in electron beam in vacuum...

These fine particles were not newly formed but already existed as skeletal particles. Similar dispersion of ultra fine particles may occur in SPS by heating in vacuum. Each particle was composed of a single crystal as shown in high resolution transmission microscopy (Fig. 17). 

The discussions summarized in Sections 4.4.2-4.4.S relate to the morphologies of crystals of size down to a few millimeters. Will extremely tiny crystals of sizes ranging from a few to 100 nm take polyhedral forms bounded by flat faces, or will they show forms bounded by curved faces due to the size effect It was theoretically predicted that, as the size of solid materials decreases, a change is expected to occur in the physical properties. Also, considering the presence of ultra-fine particles in the cosmos, the morphology exhibited by ultra-fine particles attracts a special concern. 

Aluminium and magnesium hydroxides are difficult to produce directly in any useable form from their natural ores. Filler grade calcium carbonate is widely produced from natural sources, but grinding costs appear to become prohibitive when ultra-fine particles are required and precipitation procedures then become competitive. Further details of precipitation procedures will be found under the specific filler types. 

Its nominal compn is ultra-fine particle PETN, 20—50 60% AN soln, 0—80 diethyleneglycol, 0—25 guar gum or polyacrylamide, 0.1 —0.3 and w to make 100%. A cross-linking agent (Ti tetraisopropoxide) is added as required... 

Pey J, Querol X, Alastuey A, Rodriguez S, Putaud JP, Van Dingenen R (2009) Source apportionment of urban fine and ultra-fine particle number concentration in a Western Mediterranean city. Atmos Environ 43 4407 (415... 

Kumar P, Fennell P, Langley D, Britter R (2008) Pseudo-simultaneous measurements for the vertical variation of coarse, fine and ultra fine particles in an urban street canyon. Atmos Environ 42 4304 -319... 

Shi PJ, Khan AA, Harrison RM (1999) Measurements of ultra fine particle concentration and size distribution in the urban atmosphere. Sci Total Environ 235 51-64... 

Wensing, M., Schripp, T., Uhde, E. and Salthammer, T. (2008) Ultra-fine particles... 

Ultra-Fine Particle Emission from Office Devices 425... 

Uhde, E., He, C. and Wensing, M. (2006) Characterization of ultra-fine particle emissions from a laser printer. Proceedings of Healthy Buildings, Lisboa, pp. 479-82. 

Heat Treatment of AuSn Particles. Differential Scanning Calorimetry. Heat treatment of these ultra-fine particles caused the expected increase in crystallite... 

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