Abstract: To provide a method for producing a ceramic porous material which has a high strength, though it has a high porosity, and which is excellent in permeability without dust generation. In a ceramic porous material having a three-dimensional mesh-like skeleton structure with a large number of substantially spherical adjacent cells communicating with each other via communication holes, the crystal particle size at the rim of each communication hole in the skeleton structure is provided substantially equal to the crystal particle size in the other parts.

Abstract: A process for forming a porous silicon nitride-silicon carbide body, the process comprising (a) forming a plasticizable batch mixture comprising (1) powdered silicon metal; (2) a silicon-containing source selected from the group consisting of silicon carbide, silicon nitride and mixtures thereof; (3) a water soluble crosslinking thermoset resin having a viscosity of about 50-300 centipoise; and, (4) a water soluble thermoplastic temporary binder; (b) shaping the plasticizable batch mixture to form a green body; (c) drying the green body; (d) firing the green body in nitrogen at a temperature of 1400° C. to 1600° C. for a time sufficient to obtain a silicon nitride-silicon carbide structure.

Abstract: The present invention relates to the extrusion freeform fabrication of low cost, in situ, metallic foam components having oriented microstructures and improved mechanical properties such as energy absorption and specific stiffness. The present invention relates to the freeform fabrication of metallic foams to form parts having complex geometry that demonstrate superior mechanical properties and energy absorbing capacity.

Abstract: A sensor element containing a porous layer is provided for detecting a physical magnitude of a measured gas, such as for determining the concentration of a gas component of an exhaust gas of an internal combustion engine. The porous layer includes pores of a first pore type whose diameters correspond to at least half the layer thickness of the porous layer.

Abstract: A method of making a permeable fiber-reinforced ceramic body comprising mixing an organic particulate with silica fiber, alumina fiber, alumina borosilicate fiber, a dispersant, and water to produce a slurry of fibrous ceramic material. The slurry is then placed within a mold and vaccuum pressure is applied thereto to substantially remove the water to form a fibrous ceramic body. The fibrous ceramic body is then dried and sintered to a temperature sufficient to bond the ceramic material together to form a porous ceramic article. Simultaneously, the fibrous ceramic body is heated to a temperature sufficient to generally burn off the organic particulate to create voids interconnecting the pores to form a permeable fiber reinforced porous ceramic article.

Abstract: The invention relates to a device for emitting and/or receiving electromagnetic waves comprising a lens bringing a plurality of directions defined by the radiation space of the lens into correspondence with a plurality of focusing points defining a focusing surface of the lens, the lens comprising a shaped volume of dielectric material. According to the invention, the dielectric material comprises a granular agglomerate defined by a homogeneous or quasi-homogeneous distribution of granules of the same type and of small size with respect to the wavelength (&lgr;R, &lgr;T) of the electromagnetic waves to be received and/or emitted by the said device, the said granules being held under pressure in the said volume by holding means shaped according to the said volume. The invention also relates to a communications terminal comprising a device according to the invention.

Abstract: Ceramic oxide pre-forms comprising substantially continuous, alpha alumina fibers, and methods for making the same. The ceramic oxide pre-forms are useful, for example, as in making metal matrix composites reinforced with substantially continuous, alpha alumina fibers.

Abstract: A ceramic matrix composite part having elongated cooling channels within the wall thereof is manufactured by inserting decomposable inserts within a woven ceramic fiber preform. The inserts are tows of continuous carbon fibers surrounded by a carbonaceous filler, and are inserted where the channels are desired. The preform, with the inserts in place, is disposed within a mold. A ceramic matrix material is added and the fiber preform is consolidated with the ceramic matrix material. The consolidated part is then heated to thermally decompose the inserts to create the elongated channels within the part. The inserts may be flexible and woven into the preform using an automated weaving loom, or they may have limited flexibility and be inserted by machine or by hand.

Abstract: Method for producing highly porus, self-supporting molded part that has a metallic or nonmetallic solid phase and at least one binder. The porosity is 50-90 vol.

Abstract: An electrode for secondary battery made of carbon material is provided, which is light in weight while excellent in charge-discharge properties and in durability in repetitive use. A material for electrode is obtained by intermixing a synthetic resin with vapor-phase growth carbon fibers to make the vapor-phase growth carbon fibers uniformly dispersed in the synthetic resin to obtain a mixture, molding the mixture into a predetermined shape to obtain a molded product, and heating the molded product at high temperature to convert it into a carbon-carbon composite material. The electrode for battery is made of thus obtained carbon-carbon composite material.

Abstract: Alpha alumina abrasive grits which are particularly well-suited to medium to low pressure grinding applications wherein the grits comprise uniformly dispersed microvoids.

Abstract: A powder injection molding process involves providing a melt mixture that includes a powder and a binder. The melt mixture is pressurized in an injection molding machine and a gas is injected into the melt mixture. The melt mixture and gas are injected into at least one mold to form a green part and the binder is removed from the green part.

Abstract: According to the present invention, a porous member made of temperature-resistant material for filtering and/or mixing fluids comprises first channels (132) and second channels (138) respectively extending therethrough. The channels extend under an acute angle to the flow direction (D). Fluids flowing through the porous member (101) flow through the channels (132, 138), on the one hand, and, on the other hand, through the porous material between the channels so that a good mixing of the fluids is obtained and a fluid, homogenized over the cross section, exits from an outlet surface (103). The invention further refers to methods of making the porous member (101), wherein, according to the present invention, a foamed plastic material member is formed with channels, the foamed material member is wetted with wetting material and is afterwards removed by evaporation during the curing.

Abstract: A microabrasive tool is formed from a slurry including liquid, abrasive grains, a bonding material, and a polymer—for example, gellan gum. The slurry is cast in a mold, and the polymer is ionically cross-linked. Cross-linking the polymer fixes the structure of the bonding material and the abrasive grains, wherein the abrasive grains are dispersed substantially uniformly within the bonding material. The ionically cross-linked structure of bonding material and abrasive grains can then be fired to form a microabrasive tool.

Abstract: A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Abstract: The invention relates to a process for preparing a porous ceramic body, which process is based on a negative replica method. The invention further relates to a ceramic body obtainable by said method and to its use as a scaffold for tissue engineering.

Abstract: A plasticizable raw material batch mixture for forming a silicon carbide honeycomb structure comprising the following components: (1) powdered silicon metal; (2) a carbon precursor comprising a water soluble crosslinking thermoset resin having a viscosity of less than about 1000 centipoise (cp), and preferably less than about 500 cp; (3) a powdered silicon-containing filler; and, (4) a water soluble thermoplastic binder. Optionally, the batch mixture can include either, or both, an organic fibrous filler and a pore-forming filler comprising either a graphitic or a thermoplastic pore-forming filler.

Abstract: An improved porous article and a method for forming such porous article are provided. A mixture of ceramic or metal particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the particles are bonded such as by sintering, and the organic spheres are eliminated, resulting in a strong porous article having uniformly spaced interconnected voids.

Abstract: A powder injection molding and infiltration process. A powder of a skeleton material having a relatively high melting point is mixed with a composite binder to form a mold mixture. The composite binder is comprised of at least two binder materials. The mold mixture is molded into a desired shape in a mold device to produce a molded part. The composite binder is then removed to produce voids in the molded part and the voids are filled by infiltrating an infiltrant comprised of an infiltrant material having a relatively low melting point to produce a composite molded part. In a preferred embodiment the skeleton material is TiB2 and the infiltrant material is aluminum and the composite binder is comprised of a plastic and a wax. In this embodiment the wax portion of the composite binder is removed using a solvent and the plastic is removed during the infiltration step. The resulting composite part has a TiB2 skeleton with voids substantially filled with aluminum.

Abstract: The invention concerns a method for preparing macro-porous synthetic ceramics designed in particular for bone substitution. The invention also concerns macro-porous synthetic ceramics comprising pores of controlled dimensions, distributed in number and in surface in a predetermined manner, the interconnection between the pores thereof being controlled.

Abstract: There is provided a method of producing a metal/ceramic composite, comprising the steps of adding starch to a ceramic slurry; casting the slurry into a water-nonabsorptive mold; heating the slurry to harden it to obtain a hardened body; demolding the hardened body out of the mold; and drying the hardened body to obtain a molded body; and then impregnating pores of the molded body or pores of a porous ceramic body produced by firing the molded body with a metal. The method can produce a metal/ceramic composite having a narrow metal distribution at a low cost, while freely controlling metal content as designed for complex shapes, or products with varying thickness or highly thick products, to say nothing of simple shapes.

Abstract: A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Abstract: A plasticizable raw material mixture for use in preparing a substrate having cordierite as its primary phase with the mixture comprised of a chemical composition, percent by weight, of 11 to 17% MgO, 33 to 41% Al2O3 and, 46 to 53% SiO2. The raw material mixture specifically comprises the following: (1) one source of Al2O3 and SiO2 comprising a clay mixture having less than about 22%, by weight based on the total raw materials in the plasticizable mixture, of calcined clay; (2) an alumina yielding precursor comprising alumina having an average particle diameter of about 1 &mgr;m or less; and, (3) at least one source of magnesia having an average particle diameter of between about 3 to 15 microns.

Abstract: The invention concerns a process for the preparation of an insulated soft magnetic powder comprising the steps of mixing particles of a soft magnetic iron base powder with an acidic, aqueous insulating-layer forming solution, in which MgO has been dissolved; and drying the obtained mixture to obtain an electrically insulating Mg containing layer on the particle surfaces. The invention also concerns the powder per se as well as compressed soft magnetic powder cores prepared from the powder.

Abstract: The present method of manufacturing a ceramic composite material, composed of matrix and reinforcing materials and an intermediate weak interfice material, creates a composite material particuarly intended for use at temperatures above 1400° C. and in an oxidizing environment. The matrix and reinforcing materials consist of the same or different ceramic oxides having a melting point above 1600° C. The interface material provides in combination with the matrix and reinforcing materials a stress field liable to micro aciding. The reinforcing material is immersed into a powder slurry containing carbon (C) and ZrO2 so as to be coated thereby and then dried. After which, the thus created composite material is subjected to green forming and densifying steps. Finally, the composite material undergoes a heat-treatment in air leaving a porous structure of the interface material.

Abstract: A process for producing a biocompatible implant material which can be suitably shaped into a variety of forms. A binder is added to a mixture of hydroxylapatite powder and calcium phosphate glass frit (5 wt. %), to thereby prepare a slurry, and the resultant slurry is granulated, to prepare spherical raw material granules. Separately, spherical polyisobutyl methacrylate particles are prepared, and the particles are dry-mixed with the above-prepared granules, to thereby obtain a powder mixture. The powder mixture is compacted using a mold press, to thereby form a cuboid sample. The resultant compact is heated in a drier at 170° C. for three hours, to thereby melt spherical polyisobutyl methacrylate particles. Thereafter, the compact is allowed to cool, to thereby bind the raw material granules together via the polyisobutyl methacrylate that solidifies after melting. After the compact is allowed to cool, the compact is subjected to shaping by use of a copy machining machine and also to drilling.

Abstract: A porous composite product comprised of a network of fibers is produced by forming an unsintered preformed network of fibers and a gasifiable structure forming agent, followed by gasification of the structure forming agent prior to sintering of the fibers at appropriate junction points. The preferred structure forming agent is a cellulosic material.

Abstract: A method and composition for combining ceramic powder and binder to form green elements suitable for shaping and firing uses dry blending techniques. The binder includes a particulate wax component that is not melted in order to combine it with the ceramic powder, but rather, the wax component is combined in particulate form with the ceramic powder. The particulate wax is mixed in conventional blender apparatus in a relatively short time period. The binder composition may also include a lubricity enhancer or slip agent and a dispersion or colloidal binder.

Abstract: An improved porous ceramic article and a method for forming such porous ceramic article. A mixture of ceramic particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the ceramic particles are bonded such as by sintering, and the organic spheres are burned off, resulting in a strong porous ceramic article having uniformly spaced interconnected voids.

Abstract: A process for making a low volume fraction preform for a metal matrix composite including the steps of: mixing a reinforcement with a binder and sacrificial fillers to provide a castable slurry; placing the slurry in a mold to provide a green cast preform; drying the green casting to remove any water and/or solvent; firing the green preform at a relatively low temperature to burn off the sacrificial fillers; firing the green preform at an elevated temperature to sinter the binder to bond the reinforcement together. The firing steps include particular combinations of temperature and time to ensure decomposition of the sacrificial filler and sintering without destruction or cracking of the green preform.

Abstract: In a process for stabilizing a foamed starting slip material, the starting slip material which is foamed comprises the following constituents: a. inorganic sinterable material, b. a source of blowing gas, c. a framework former which forms a framework when the pH of the starting slip material is changed, d. pH control material, e. liquid, f. if desired, one or more of the following materials: dispersant binder viscosity modifier, and the pH of the starting slip material is changed to initiate or accelerate the formation of the framework from the framework former.

Abstract: An alumina-based porous support with uniform physical properties is obtained in a rapid sintering process. An alumina raw material including a raw alumina powder and an inorganic binder is molded into an article, and the article is then sintered for 5 to 8 hours at 1520 to 1560.degree. C. using a roller hearth kiln.

Abstract: The invention relates to a one-part, fire resistant ceramic composite structure consisting of at least two adjacent layers. The substantial mass portion of the layers consists of an identical, fire-resistant ceramic material, and the remaining mass portion is selected in relation to each layer in such a manner that at least one layer couples inductively subject to the influence of a magnetic field, whereas at least one other layer does not couple subject to the influence of said electromagnetic field. However, all layers have the same thermal coefficient of expansion.

Abstract: A ceramic contact sheet and setter tile with controlled porosity is introduced, along with the method for making the same. The amount of porosity is controlled by the volume percentage, particle size, and particle shape of a fugitive phase which can be added to the original refractory material slurry used to fabricate setter tiles and contact sheets. The fugitive phase can be used independently to introduce porosity in setter tiles and contact sheets or in conjunction with partial densification. Since porosity is not solely dependent upon partial sintering, higher porosity levels can be achieved with less impact on subsequent mechanical properties of the resultant refractory material.

Abstract: A microcapsule includes a shape memory resin shell wall formed with fissures that do not completely pass through the shell wall, and a dye encapsulated in the shell wall. The shell wall exhibits a temperature/pressure characteristic such that the fissures open, when the shell wall is squashed and compacted under a predetermined pressure at a predetermined temperature, whereby a seepage of the dye frog the squashed and compacted shell wall through the opened fissures is adjustable.

Abstract: Prills of ammonium dinitramide (ADN) are prepared by melting this salt with a stabilizer and, by dry nitrogen pressure, injecting the molten salt i an inert, perfluorinated carrier liquid of greater specific gravity which, initially, is above the solidification temperature of the salt. The molten salt and carrier liquid pass together in turbulent flow through a heated conduit in which stationary vanes disperse the salt into droplets. The liquid and salt then pass in turbulent flow through a cooled conduit for solidification of the salt into prills without agglomeration. The prills are then separated from the liquid by flotation and any liquid carried with the prills recycled. The main flow of carrier liquid is pumped through a preheater and then back to the molten salt injector. The cooled conduit is provided with compression refrigeration, the refrigerant passing in parallel flow along the conduit and the compressed refrigerant passing to the preheater before condensation.

Abstract: High concentration drag reducing agents may be prepared by microencapsulating polymer drag reducing agent. The microencapsulation may be performed prior to, during, or after the polymerization of monomer into effective drag reducing polymer. If encapsulation is done before or during polymerization, a catalyst may be present, but little or no solvent is required. The result is very small scale bulk polymerization within the microcapsule. The inert capsule or shell may be removed before, during or after introduction of the microencapsulated drag reducer into a flowing liquid. No injection probes or other special equipment is expected to be required to introduce the drag reducing slurry into the liquid stream, nor is grinding (cryogenic otherwise) of the polymer necessary to form a suitable drag reducing agent.

Abstract: Disclosed herein are novel electrophoretic displays and materials useful in fabricating such displays. In particular, novel encapsulated displays are disclosed. Particles encapsulated therein are dispersed within a suspending, or electrophoretic, fluid. This fluid may be a mixture of two or more fluids or may be a single fluid. The displays may further comprise particles dispersed in a suspending fluid, wherein the particles contain a liquid. In either case, the suspending fluid may have a density or refractive index substantially matched to that of the particles dispersed therein. Finally, also disclosed herein are electro-osmotic displays. These displays comprise at least one capsule containing either a cellulosic or gel-like internal phase and a liquid phase, or containing two or more immiscible fluids. Application of electric fields to any of the electrophoretic displays described herein affects an optical property of the display.

Abstract: The present invention is based, in part, on a method for combining a mixture of hydroxide and hydride functional siloxanes to form a polysiloxane polymer foam, that leaves no residue (zero char yield) upon thermal decomposition, with ceramic and/or metal powders and appropriate catalysts to produce porous foam structures having compositions, densities, porosities and structures not previously attainable. The siloxanes are mixed with the ceramic and/or metal powder, wherein the powder has a particle size of about 400 .mu.m or less, a catalyst is added causing the siloxanes to foam and crosslink, thereby forming a polysiloxane polymer foam having the metal or ceramic powder dispersed therein. The polymer foam is heated to thermally decompose the polymer foam and sinter the powder particles together. Because the system is completely nonaqueous, this method further provides for incorporating reactive metals such as magnesium and aluminum, which can be further processed, into the foam structure.

Abstract: A pollutant-reducing catalytic converter for an internal combustion engine. The catalytic converter is of ceramic and operates at higher temperatures for increased efficiency. A ceramic foam is used as the substrate for the catalyst. The foam is an open-celled foam and the substrate is deposited on the walls of the cells. Thus, there is a maximum area of catalyst with a minimum amount of catalyst required. The catalytic converter can be placed in the engine compartment adjacent the engine for maximum efficiency without causing temperature problems within the engine compartment.

Abstract: A porous ceramic body having a ceramic framework is produced having a surface roughness of about 40 microns or less. The ceramic body has a plurality of pores where each pore is interconnected with at least one adjacent pore. The ceramic body is made from a powdered ceramic component and a pore-forming polymeric component such as polymeric beads. The ceramic component is alumina which can contain at least one other component selected from the group consisting of calcium oxide, silicon oxide, magnesium oxide, barium oxide, titanium dioxide, and zirconium dioxide. The pore-forming polymeric beads, such as polymethylmethacrylate beads, each having a particle size of 100 microns or less, are mixed with the ceramic powder. The powdered mixture is compressed under pressure and heated to form a porous ceramic body. A coating of an aqueous dispersion of a metal oxide can be applied to the surface of the ceramic body and heated to produce a smooth and durable coating.

Abstract: One aspect of the invention relates to an interconnect for an SOFC wherein the interconnect is made from a cermet including partially stabilized tetragonal zirconia and a superalloy that is resistant to oxidizing and reducing conditions. Another aspect of the invention relates to an SOFC having vias for carrying fuel and an oxidant and at least one patterned feature in the anode, electrolyte, cathode and/or interconnect for laterally distributing the fuel or oxidant.

Abstract: Disclosed is a method of making a solid oxide fuel cell with controlled porosity by varying the size of the ceramic particles, the type of organics, the sintering cycle and the amount of catalyst.

Abstract: A method for preparing a light metal or light metal alloy composite product, wherein (a) an aqueous slurry containing water, a reinforcement powder, a metal powder and an alumina sol binder is prepared; (b) a preform is prepared from the slurry; (c) the preform is sintered; and (d) the sintered preform is impregnated with a melt of a light metal or a light metal alloy to produce a light metal or a light metal alloy based composite product.

Abstract: This invention relates to a method for treating various kinds of drain water and waste liquid which treatment now becomes a problem, for example, drain water and waste liquid containing hardly removable phosphorus and nitrogen, waste liquid containing organochlorine compounds such as tetrachloroethylene, etc., excretive drain water from a piggery containing organonitrogen compounds at a high level, waste liquid containing heavy metals such as lead, hexavalent chromium, cadmium and the like, drain water from dairy product plants, fishery processing plates, slaughterhouses, etc. which contains water soluble protein at a high level, drain water from pulp plants, photo developing waste liquid, car wash drain water containing a mixture of car polishing wax and detergent and the like by the use of porous ceramics provided with amorphous pore surfaces.

Abstract: An implant component adapted for bone attachment or replacement is molded from a feed stock which contains a soluble major binder, a backbone binder and structural powder material. After the feed stock is injection molded to form a compact or preform, the major binder is removed from the green article, leaving a structure of interconnected porosity or texture, while the backbone binder remains until the component is sintered. Preferably, the amount of the soluble binder is set to increase the porosity, or reduce the stiffness, of the finished component, thus introducing a biocompatible or growth-enhancing level of porosity or stiffness during the molding process. In further or alternative embodiments, the component may be injection molded onto or about a solvent-leachable spacer preform and/or adjacent to another injected or molded portion of the component which serves as a structural body, frame or shell.

Abstract: A porous, flow-through molded body, designed specifically for use in the removal of diesel soot particles from the exhaust gas of diesel engines. It includes a reciprocally closed honeycombed body made of silicon carbide and possessing the following features.wall thickness: 1.25.+-.0.5 mm;porosity: 55 to 60%;average pore diameter: 25 to 70 .mu.m;specific permeability: 20 to 100 nPm.In the production method, a starting powder of silicon or a mixture of silicon with portions of silicon carbide and/or carbon is combined with an organic binding agent that can be coked and molded into a green body. This is then subjected to a coking fire in an inert-gas atmosphere; the molded body obtained in this manner is then heated in the presence of nitrogen or a nitrogenous inert gas to a temperature where free silicon is converted with the carbon, in a reaction firing, to silicon carbide. Additionally, a recrystallization firing at greater than 2000.degree. C. is implemented.

Abstract: Disclosed herein are novel electrophoretic displays and materials useful in fabricating such displays. In particular, novel encapsulated displays are disclosed. Particles encapsulated therein are dispersed within a suspending, or electrophoretic, fluid. This fluid may be a mixture of two or more fluids or may be a single fluid. The displays may further comprise particles dispersed in a suspending fluid, wherein the particles contain a liquid. In either case, the suspending fluid may have a density or refractive index substantially matched to that of the particles dispersed therein. Finally, also disclosed herein are electro-osmotic displays. These displays comprise at least one capsule containing either a cellulosic or gel-like internal phase and a liquid phase, or containing two or more immiscible fluids. Application of electric fields to any of the electrophoretic displays described herein affects an optical property of the display.

Abstract: A ceramic contact sheet and setter tile with controlled porosity is introduced, along with the method for making the same. The amount of porosity is controlled by the volume percentage, particle size, and particle shape of a fugitive phase which can be added to the original refractory material slurry used to fabricate setter tiles and contact sheets. The fugitive phase can be used independently to introduce porosity in setter tiles and contact sheets or in conjunction with partial densification. Since porosity is not solely dependent upon partial sintering, higher porosity levels can be achieved with less impact on subsequent mechanical properties of the resultant refractory material.

Abstract: Microcapsules are prepared by a process comprising the steps of (i) spray-drying a solution or dispersion of a wall-forming material in order to obtain intermediate microcapsules and (ii) reducing the water-solubility of at least the outside of the intermediate microcaspsules.Suitable wall-forming materials include proteins such as albumin and gelatin.The microcapsules have walls of 40-500 nm thick and are useful in ultrasonic imaging. The control of median size, size distribution and degree of insolubilization and cross-linking of the wall-forming material allows novel microsphere preparations to be produced.