Abstract:
There is provided a method for the fabrication of porous SiC ceramic. The method comprises oxidizing particles of SiC ceramic thereby forming amorphous silica on the surface of the particles. The oxidized SiC particles are then mixed with an additive. Alternatively, layer(s) of the additive is (are) deposited on their surface by sol-gel technique. The oxidized SiC particles mixed or coated with the additive are then mixed with at least one pore-former. Alternatively, the oxidized SiC particles mixed or coated with the additive are coated with layer(s) of a polymer or pore-former by in-situ polymerization. In embodiments where the oxidized SiC particles are mixed with an additive and a pore-former or polymer, a further additive may be used. In each of these embodiments, the resulting product is then compacted into a green body which is heated and sintered to yield the porous SiC ceramic material. There is also provided a porous SiC ceramic fabricated by the method according to the invention.
Abstract:
There is provided a method for the fabrication of porous SiC ceramic. The method comprises oxidizing particles of SiC ceramic thereby forming amorphous silica on the surface of the particles. The oxidized SiC particles are then mixed with an additive. Alternatively, layer(s) of the additive is (are) deposited on their surface by sol-gel technique. The oxidized SiC particles mixed or coated with the additive are then mixed with at least one pore-former. Alternatively, the oxidized SiC particles mixed or coated with the additive are coated with layer(s) of a polymer or pore-former by in-situ polymerization. In embodiments where the oxidized SiC particles are mixed with an additive and a pore-former or polymer, a further additive may be used. In each of these embodiments, the resulting product is then compacted into a green body which is heated and sintered to yield the porous SiC ceramic material. There is also provided a porous SiC ceramic fabricated by the method according to the invention.
Abstract:
An oxygen-enriched gas burner and method of operation thereof for incinerating and/or melting and/or vitrifying and/or performing thermal treatment and/or oxidizing ground/liquid waste materials and particularly, but not exclusively, contaminated waste materials. The burner comprises a body having annular chambers and defining an injection nozzle which is adjustable whereby to adjust the configuration of a flame and wherein the nozzle is provided, at the center thereof with an axial feed port through which the grounded solid/liquid waste material is injected within the flame. The waste material is fed axially within the flame under control pressure with the waste feed and flame configuration being adjusted independently from one another whereby the waste material is substantially incinerated without substantially affecting the combustion of the gas which would otherwise produce undesirable carbon monoxide and hydrocarbons.
Abstract:
The process is conducted in an incinerator installation comprising i) a generally vertical, cylindrical riser pipe, ii) a vertically extending annular chamber surrounding the riser pipe and containing a fluidized bed of granular inert material, and iii) a burner for producing an upwardly extending flame in the lower portion of the riser pipe. Granular solid waste is supplied at a constant flow rate to the bed, directly or through the burner. Granular solid waste and bed material is transferred from the lower portion of the annular chamber to the lower portion of the riser pipe directly in the flame. The flame burns the granular solid waste, heats the inside of the riser pipe to a temperature greater than or equal to 900.degree. C., and produces flue gas that pneumatically transports the granular solid waste and bed material upwardly from the lower portion to the upper end of the riser pipe at a speed of 3-15 m/s to create a high turbulence thereby increasing absorption of heat by the granular solid waste and oxidation of the organic components of the granular solid waste. The granular solid waste and bed material is discharged in the annular chamber through the upper end of the riser pipe, treated granular solid waste is collected from the fluidized bed to maintain the height of granular solid waste and bed material substantially constant, and flue gas is evacuated.
Abstract:
The present document describes a catalyst to initiate microwave pyrolysis of waste, a process for the microwave pyrolysis of waste using the catalyst, as well as a microwave pyrolysis system.
Abstract:
The present document describes a catalyst to initiate microwave pyrolysis of waste, a process for the microwave pyrolysis of waste using the catalyst, as well as a microwave pyrolysis system.
Abstract:
This invention is a novel method for making zirconia ceramic from hybrid composite biomaterials. The inorganic particles of zirconium oxide with a desired size and controlled shape were synthesized in an alcohol solution in the presence of water and a morphologic catalyst. Zirconium alkoxides and/or zirconium oxychloride, Yttrium alkoxide, Yttrium nitrate hexahydrate and Yttrium chloride, were used as the precursor materials for the preparation of zirconium oxide colloidal suspensions. Particle surface modification by the introduction of polymerization precursors was carried out in colloidal suspension. Highly-filled and well dispersed composite biomaterials with thermoplastic and/or thermo-hardening matrices are easily obtained using several polymerization techniques, like catalytic polymerization, controlled free radical polymerization, and polycondensation. This new method makes it possible to prepare composite biomaterials with monodispersed and spherical colloidal particles that are well dispersed and highly compacted in the polymeric matrix and with an easy control of the number of grafted polymeric chains per particle. The obtained biomaterials have the advantage of being sintered isotropically with a weak and controlled shrinkage. These properties offer the possibility of shaping these materials using CAD/CAM technology in the composite state followed by a sintering process leading to TZP (tetragonal zirconia polycrystal) ceramic.
Abstract:
A spout-fluid bed drying system and process is comprised of a spout-fluid bed dryer having a conical shaped lower section provided with a packing of heat exchange particles. A cyclone separator is connected to the top of the dryer with separated particles collected by a receiver connected to the leg of the cyclone. A vapor fan compresses the air-vapor mixture before it goes to the heat recuperator and mixing chamber. A tube-shell type heat exchanger, wherein effluent gases from the vapor fan are preheated with heat exchange with the outcoming high temperature gases. A combustion and incineration chamber wherein a natural gas burner is installed at the top and the high temperature flame is used to incinerate the effluent gases introduced from the annulus channel of the chamber to have the odors and VOCs destroyed. A mixing chamber wherein high temperature stream from the incineration chamber is mixed with low temperature stream from the vapor fan to serve as the drying media with the temperature maintained at around 400.degree. C. A slurry discharge nozzle is disposed below the packing and connected to a slurry container via piping and a slurry pump for releasing slurry to the surface of the particles within the packing. Evaporation of water occurs mostly on the surface of particles by contact with hot drying media. A gas-air mixture is fed to the burner through a feed pipe line wherein fresh air is supplied from an air blower.
Abstract:
A method and a device for simultaneous and quantitative measurement of a carrier composition and a solids volume fraction in a gas/solid, liquid/solid, liquid/liquid, liquid/gas or gas/liquid/solid multiphase systems are presented. A first measurement identifies the phase of the sample and/or the solids fraction of the sample. A second measurement provides a liquid or gaseous chemical composition of the sample. The device comprises a generator of light that propagates through a sample of the multiphase system. A detector obtains a spectrum of absorbance of the light. The spectrum of absorbance is representative of measurements.
Abstract:
The present invention provides an implant system of facilitated use and installation which comprise an implant and a prosthesis support and a method of installation thereof. The prosthesis support disclosed herein includes an abutment and a collar member. Prior art implant systems are mostly made of metallic parts which are assembled with a screw and are shaped to receive a tooth prosthesis. The design of the abutment allows it to be made from highly filled composite materials being of a better optical quality and being easily machinable and further allows its installation without the use of a screwing member. The design of the collar member allows minimization of bacteria growth and tartar formation. The optimization of the implant system proposed herein may reduce stress to the jaw bone and therefore minimize the risk of injury for the patient.