Papers by Keyword: Agglomeration

Abstract: In article questions of receiving high-strength ceramics on the aluminum oxide and zirconium dioxide nanopowders basis are considered. As questions of strength properties increase of a ceramic samples surface are studied by ionic implantation methods.

Abstract: The NiCu nanoparticles were synthesized from Ni_xCu_1-x (20 at. % < x < 80 at. %) bulk alloys with arc plasma technique. The experimental results indicated that the crystal structure of the powders is face centered cubic structure, the same as the bulk raw materials. The composition between the prepared powders and the bulk alloys altered with the content of the nickel and copper. With Scherrer equation, the average crystallite size was determined to be 50 nm, which is consistent with the results achieved from the TEM (transmission electron microscopy) images. Also the TEM images showed that some of the nanoparticles could aggregate and grew into micro-size particles at room temperature. The largest size of the grown particle at room temperature was about 1 μm.

Abstract: Catalysts of Ni/MgO-ZrO2 were synthesized by the impregnation method and co-precipitation. They were characterized by X-ray diffraction (XRD), Scanning electron microcopy (SEM). It was observed that the monoclinic ZrO2 turned to tetragonal ZrO2 with the Mg2+ mixed. The tetragonal phase ZrO2 is considered as the desired phase which exhibits both acidity and basicity, and active in many heterogeneous catalytic systems. The NiO-MgO solid solution is also discovered on the surface of catalysts. Since the formation of carbon deposit needs a certain size of metal Ni, so the solid solution inhibited the reduced state Ni agglomeration .

Abstract: This article expound that, piece of historical buildings which witness urban developmental venation are facing the questions in nowadays urban development, although historical buildings embody corporality, but they contain spirit speciality, they regard something according with the trend of social development as the gist, put forward that historical buildings’ criterion and form to be reserved. Of course it is important to reserve the historical buildings, but it is not the only way to reserve them, the deep-seated meanings to reserve is in order to continue, so it is the key and soul to continue the connotation of piece of historical buildings. This article expound with example that there are two side in continuing content, those are physical layer and psychic layer, and the form to continue which is look for the jumping-off point of continuing from history, by this way we can obtain logistic extend in physical layer. This is an open system, this article summarize several sides about it and to prove them with example, and to exploit point of view and manner of thinking in urban construction and development.

Abstract: Rheological properties of semi-solid alloys are closely knit to the solid-phase microstructure. Parameters such as particle size distribution are commonly determined by 2D cross section analysis. The determination of mechanisms such as particle deagglomeration with increasing shear rate however, requires information on the 3D spatial distribution. By means of synchrotron radiation tomography and SEM on AlCu samples, particle size distributions and the not yet microscopically observed interrelation of shear rate and particle agglomeration in thixo-material is investigated.

Abstract: Experiments were carried out to investigate the characteristic of kaolin on agglomeration mechanism of the black liquor combusted in a bench-scale fluidized bed. The combustion experiments were focused on the influence of different operating conditions at three temperatures (700°C, 750°C and 800°C), and at three kaolin additive dosages(0, 10% and 30%). Sinter of the bed material collected after experiments were analysed by scanning electron microscope (SEM) and X-ray diffractometry (XRD). The results show that kaolin is a significant additive in improving the black liquor combustion in a fluidized bed. With the kaolin dosage increases, the degree of agglomeration decreases.

Abstract: The characteristics of dry ice particles produced by expanding liquid carbon dioxide and its application for surface cleaning have been studied experimentally. The production of the dry ice particles was based on the Joule-Thomson effect. The ejected dry ice particles were observed using a high-speed microscope camera. Through digital image processing, the particle size and particle velocity in the jet were analyzed. To in-situ measure the size distribution of the dry ice particles, a laser diffraction method was used. The experimental results showed that the primary dry ice particles ejected from the expansion nozzle were about 1 μm in mass median diameter. The presence of a thermally insulated tube at the outlet of the nozzle enhanced the agglomeration of the particles, whereby agglomerates of about 100 μm in mass median diameter were formed. The performance of dry ice jet for removing fine particles adhering to surfaces was also evaluated using microscopic observation. It was found that the particle removal process consists of two stagesslow removal stage and rapid removal stagethat are related to the jet temperature.

Abstract: This article simulated the collision and agglomeration between bipolarly charged particles in an electrostatic agglomerator. The EHD turbulent flow was solved and the flow parameters were extracted a priori. The particle initial charge was obtained by tracking particles with a certain diameter in the charging zone. When simulating collision and agglomeration in the agglomerating zone, the initial charge on a particle was sampled from the charge distribution by statistical analysis. The classical stochastic model for calculating collision between neutral particles was extended to calculate collision between charged particles, and the effect of particle charge on collision and agglomeration was embodied in the agglomeration criteria. The effect of an external DC and AC electric field on the collision and agglomeration was investigated.

Abstract: The texture of thin films, originating from a solid state reaction between a deposited film and a single crystal substrate is investigated. The relation between the phase formation and texture is analyzed for a number of these systems, such as Co/Si, Ni/Si or Co/Ge, where a metal film is allowed to react with a semiconductor single crystal substrate during heating and a summary of these results in presented in this article. It was found that the texture of the resulting films can be very complex, consisting of a variety of simultaneously occurring texture components such as epitaxy, fiber and axiotaxy texture. The close connection between the phase formation and texture is demonstrated by the fact that even a small intervention in either one, can have a huge effect on the resulting phase and/or its texture. From this, we show that the effect of the addition of ternary elements (e.g. Pt, W, C) to the thin films can only be understood if one considers its effects on both the kinetics and the thermodynamics of the reactions, as well as on the texture of the phases. We show how this can be used to influence technologically important properties of the films, such of formation temperature or stability.

Abstract: Antimony doped tin oxide (ATO) nanoparticles were synthesized via complex-homogeneous coprecipitation. Then different drying methods (such as azeotropic distillation, infrared drying and microwave drying, etc.) were used to eliminate the agglomeration. The nanoparticles were characterized by thermal analysis, X-ray diffraction (XRD), and Brunauer-Emmett-Teller measurements (BET). The result shows that ATO nanopaticles with tetragonal rutile phase structure are all well crystallized after the drying processes above, and the average grain size is between 29.30 nm and 71.52 nm. The grain size estimated by BET method is similar to the result of Scherrer equation, and the nanoparticles prepared by azeotropic distillation have better crystallinity comparing to other methods. With the extension of the distillation time, the grain size increases, and the colour changes from grey blue to light grey. Moreover, the combination of azeotropic distillation and infrared drying can prepare smaller and better crystalline ATO nanoparticles.