Abstract: Disclosed examples provide gas cells and a method of fabricating a gas cell, including forming a cavity in a first substrate, forming a first conductive material on a sidewall of the cavity, forming a glass layer on the first conductive material, forming a second conductive material on a bottom side of a second substrate, etching the second conductive material to form apertures through the second conductive material, forming conductive coupling structures on a top side of the second substrate, and bonding a portion of the bottom side of the second substrate to a portion of the first side of the first substrate to seal the cavity.

Abstract: A roughened silicon surface is formed by a process including repetitively performed roughening cycles. Each roughening cycles including a step for depositing a non-planar polymeric layer over an area of a silicon body and a step for plasma etching the polymeric layer and the area of the silicon body etch in a non-unidirectional way. As a result, a surface portion of the silicon body is removed, in a non-uniform way, to a depth not greater than 10 nm.

Abstract: The present disclosure relates to a wafer-level package that includes a first thinned die, a multilayer redistribution structure, a first mold compound, and a second mold compound. The first thinned die includes a first device layer formed from glass materials. The multilayer redistribution structure includes redistribution interconnects that connect the first device layer to package contacts on a bottom surface of the multilayer redistribution structure. Herein, the connections between the redistribution interconnects and the first device layer are solder-free. The first mold compound resides over the multilayer redistribution structure and around the first thinned die, and extends beyond a top surface of the first thinned die to define an opening within the first mold compound and over the first thinned die. The second mold compound fills the opening and is in contact with the top surface of the first thinned die.

Abstract: A probe card fits in a system for testing a micro-electro-mechanical device having an element sensitive to a magnetic field. The probe card is formed by a PCB having a through-opening and probe tips for electrically contacting the micro-electro-mechanical device. A housing structure is received within the through-opening. The housing structure includes a planar peripheral region surrounding seats that protrude and extend at least partly into the through-opening. Magnetic elements are arranged in the seats, with the magnetic elements configured to generate a test magnetic field for testing operation of the micro-electro-mechanical device.

Abstract: The nanocomposite system for hydrogen storage is a composite of MgH2 powder with ZrNi5 powder and a combination of Nb2O5, TiC and VC. Preferably, the MgH2 is in nanocrystalline form and the ZrNi5 is significantly in a Friauf-Laves phase. The nanocomposite system is formed by combining the MgH2 powder with the ZrNi5, Nb2O5, TiC and VC, preferably in amounts of 4 wt. % ZrNi5+1 wt. % Nb2O5+0.5 wt. % TiC+0.5 wt. % VC, to form a mixture, and then performing reactive ball milling on the mixture. Preferably, the reactive ball milling is performed for a period of 50 hours.

Abstract: A hydrogen generation system including: a reformer generating hydrogen-containing gas using a raw material and reforming water; a combustor combusting hydrogen-containing gas and air and generating exhaust gas; a first channel passing cooling water; a condenser generating condensed water by heat exchange between exhaust gas and cooling water; a tank storing condensed water as cooling water; a pump supplying cooling water from the tank to the condenser; a second channel branching at a branch between the pump and condenser in the first channel, and passing some cooling water to the reformer as reforming water; a heater provided downstream of the branch, and heating the first channel; a temperature detector detecting the temperature of the first channel; and a controller, in an activation operation mode, determining whether the second channel is filled with reforming water, based on the temperature detected by the temperature detector after the heater has operated.

Abstract: A dual utilization liquid and gaseous fuel CPOX reformer that includes reaction zones for the CPOX reforming of liquid and gaseous reformable fuels. A reforming method is also provided. The method comprises reforming a first gaseous reformable reaction mixture comprising oxygen-containing gas and vaporized liquid fuel and before or after this step, reforming second gaseous reformable reaction mixture comprising oxygen-containing gas and gaseous fuel to produce a hydrogen-rich reformate.

Abstract: A catalyst for decomposing high-concentration hydrogen peroxide comprises an active layer on a carrier comprising gamma-phase alumina. The carrier can also comprise aluminum, with the gamma-phase alumina forming a passivating layer on the surface of the aluminum. The active layer can comprise platinum. Apparatus for decomposing hydrogen peroxide can include the catalyst in a decomposition chamber arranged to receive hydrogen peroxide. The apparatus can be used as a thruster, comprising a nozzle arranged to generate thrust by directing exhaust gases in a specific direction. For example, the thruster can be a monopropellant, bipropellant, or hybrid thruster. In other embodiments, the apparatus can be used as a gas generator or a fuel cell.

Abstract: Particle production apparatus 1 including processing section 3 in which a processing liquid is adhered to a surface of each of inorganic particles contained in a powder material, chamber 4 connected to processing section 3 at a downstream side thereof in which the powder material is separated from gas carrying the material, powder material supply device 50 with supply portion 5 and supply unit 6 for supplying the powder material into processing section 3, and processing liquid spraying device 70 having a nozzle 7, a pump 8, a supply unit 9 for supplying the processing liquid, and a high-pressure gas (air) generating unit 11. Processing liquid spraying device 70 is configured to spray processing liquid as droplets onto the powder material just after the powder material being supplied into the processing section 3. Preferably, a volume of the processing section 3 is smaller than a volume of the chamber 4.

Abstract: Particle production apparatus 1 including processing section 3 in which a processing liquid is adhered to a surface of each of inorganic particles contained in a powder material, chamber 4 connected to processing section 3 at a downstream side thereof in which the powder material is separated from gas carrying the material, powder material supply device 50 with supply portion 5 and supply unit 6 for supplying the powder material into processing section 3, and processing liquid spraying device 70 having a nozzle 7, a pump 8, a supply unit 9 for supplying the processing liquid, and a high-pressure gas (air) generating unit 11. Processing liquid spraying device 70 is configured to spray processing liquid as droplets onto the powder material just after the powder material being supplied into the processing section 3. Preferably, a volume of the processing section 3 is smaller than a volume of the chamber 4.

Abstract: Methods and systems for cost effectively transforming lower quality sands into higher quality sands for use as proppants in fracking operations. One or more of an attrition process, a microwaving process and a tumbling process, and systems therefor, are disclosed and shown to be applied to sands having inferior physical properties in order to increase the performance of those sands as proppants in hydrocarbon formation fracturing.

Abstract: A method of removing hydrous silica from bentonite includes irradiating an ultrasonic wave after preparing slurry by putting the bentonite and a sodium compound into distilled water or deionized water, adding the distilled water or the deionized water to the slurry, into which the ultrasonic wave is irradiated, to dilute and centrifugate the slurry, and drying a supernatant obtained through the centrifugation.

Abstract: The present invention provides a process for producing high purity hydromagnesite from a source of magnesium chloride. The process involves preparation of a magnesium chloride brine of a specific concentration, which is ammoniated at a specific temperature range, followed by carbonation, while maintaining the reaction at a specific temperature range to form a hydromagnesite precipitate. The product can be calcined to generate high purity magnesium oxide compounds.

Abstract: The present invention provides a process for producing high purity hydromagnesite from a source of magnesium chloride. The process involves preparation of a magnesium chloride brine of a specific concentration and reacting with sodium carbonate, while maintaining the reaction at a specific temperature range to form a hydromagnesite precipitate. The product can be calcined to generate high purity magnesium oxide compounds.

Abstract: An amorphous mesoporous alumina having a connectivity (Z) greater than 2.7 is described. The present invention also relates to the process for preparing the said alumina, comprising at least one precipitation step of at least one aluminum salt, at least one heating step of the suspension obtained, a thermal treatment step to form the alumina gel, a gentle drying step or spray drying step, a moulding step of the powder obtained, and a final thermal treatment step in order to obtain the alumina.

Abstract: Processes for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof. Systems for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof.

Abstract: A method for producing a potassium titanate easily produces a potassium titanate having a high single phase ratio and a significantly reduced fibrous potassium titanate content in high yield. The method for producing a potassium titanate includes: a mixing step that mixes a titanium raw material with a potassium raw material, the titanium raw material including 0 to 60 mass % of titanium oxide having a specific surface area of 1 to 2 m2/g, 40 to 100 mass % of titanium oxide having a specific surface area of 7 to 200 m2/g, and 0 to 4.5 mass % in total of one or more materials selected from titanium metal and titanium hydride, and the potassium raw material including a potassium compound; a calcination step that calcines a raw material mixture obtained by the mixing step at a calcination temperature of 950 to 990° C.; and a grinding step that grinds a calcined powder obtained by the calcination step using one or more means selected from a vibrating mill and an impact pulverizer.

Abstract: A ceramic material has a composition represented by the formula: La1-x-yAEyMnO3 in which AE is at least one of Ca and Sr; x satisfies 0<x?about 0.20; and y satisfies 0<y?about 0.10.

Abstract: A system and a method for treating salt-containing glycerin wastewater are provided, wherein the system for treating the salt-containing glycerin wastewater includes a mixing tank, a filtering device, a distillation column, and a water supply device. The mixing tank is adapted to mix salt-containing glycerin wastewater with a concentrated hydrochloric acid to obtain a mixture. The filtering device communicates with the mixing tank and filters the mixture to obtain an acidic filtrate and a precipitated salt. The distillation column communicates with the filtering device and receives the acidic filtrate from the filtering device. The water supply device supplies water to the acidic filtrate. The system and method for treating the salt-containing glycerin wastewater can effectively recycle hydrochloric acid.

Abstract: Synthesis, fabrication, and application of nanocomposite polymers in different form (as membrane/filter coatings, as beads, or as porous sponges) for the removal of microorganisms, heavy metals, organic, and inorganic chemicals from different contaminated water sources.

Abstract: Cross-linked polymeric resins from anilines linked together with polyamine alkyl chains. A process for producing the cross-linked polymeric resins by Mannich-type polycondensation of anilines and diaminoalkanes linked together by an aldehyde and subsequent basification. In addition, a method for removing heavy metals, such as Pb (II) and As (V) from aqueous solution via contacting and treatment with the cross-linked polymeric resins.

Abstract: The present invention provides a method for generating hydroxyl radicals and removing organic pollutants in water by utilizing an organic membrane. The inventive method generates hydroxyl radicals by adopting a nitrocellulose membrane as a photocatalytic material, placing the nitrocellulose membrane in water, illuminating with the sun or a sunlamp having a wavelength above 280 nm as a light source, and causing the nitrocellulose membrane to undergo a photochemical reaction at the membrane surface, and the generation rate of hydroxyl radicals can be achieved by adjusting the surface area of the membrane and a light intensity. The generated hydroxyl radicals can remove phenol, bisphenol A, thiamphenicol and other typical organic pollutants in water very well.

Abstract: An UV-irradiation apparatus of an embodiment is provided with an irradiation unit, a measuring unit, a detecting unit, a calculator and a display. The irradiation unit irradiates treatment water as a treatment target with treating ultraviolet rays. The measuring unit measures ultraviolet ray intensity of ultraviolet rays transmitted through the treatment water. The detecting unit detects a deterioration of the irradiation unit in accordance with the ultraviolet ray intensity measured by the measuring unit. The calculator calculates the ultraviolet ray permeability of the treatment water, on the basis of the ultraviolet ray intensity of ultraviolet rays emitted from the irradiation unit depending on a preset setting value and the ultraviolet ray intensity measured by the measuring unit. The display displays the detection result of the deterioration of the irradiation unit by the detecting unit, and the ultraviolet ray permeability calculated by the calculator.

Abstract: Disclosed herein are methods and systems for achieving degradation of ethers.

Abstract: The present invention relates to a water purification process carried out in an electrochemical cell in which the content of nitrate ions of an aqueous solution is reduced providing a resulting aqueous solution having a concentration of nitrate concentration lower than 100 ppm, an ammonium concentration lower than 50 ppm and a combined chlorine concentration lower than 2 ppm. The invention also provides a method for designing an electrochemical cell suitable for carrying out said water purification process.

Abstract: The disclosure generally relates to reactive electrochemical membranes (REMs); and in particular, to asymmetric reactive electrochemical membranes to be used for aqueous separations and membrane fouling regeneration.

Abstract: Devices and systems for electromagnetic treatment of fluids are provided. In various embodiments, an electromagnetic fluid treatment apparatus comprises a first rod spacer, a second rod spacer, and at least one conductive rod. In various embodiments, the first rod spacer comprises a fluid pipe aperture and at least one rod aperture, and the second rod spacer comprises a fluid pipe aperture and at least one rod aperture wherein the rod aperture of the first rod spacer and the rod aperture of the second rod spacer are circumferentially aligned about a centerline axis. In various embodiments, the conductive rod comprises a first attachment portion and a second attachment portion, wherein the first attachment portion is disposed in the rod aperture of the first rod spacer, the second attachment portion is disposed in the rod aperture of the second rod spacer, and the conductive rod extends therebetween.

Abstract: A media bed reactor may be used to remove selenium from water. An exemplary reactor has a fluid injection system with one or more outlets located within the media bed. The fluid injection system may be connected to a source of gas, liquid or both. In a selenium treatment process, a denitrification zone forms above a selenium-reducing zone in the media bed. Operation of the reactor includes a step of flowing a fluid upwards through only an upper part of the bed. This upper part of the bed preferably contains at least most of the denitrification zone.

Abstract: The invention relates to wastewater treatment systems, in particular to biosorbers for wastewater treatment, comprising a bioreactor with a fluidized bed of charge and a layer of filtering charge, a system for saturating the water with air or oxygen, a sewage treatment pipeline, a purified water discharge line and a recirculated flow line with a circulating pump. According to the invention, the biosorber includes a receiving and dispensing chamber connected via a metering pump to the chamber with a coal removal trap that is connected to the fluidized bed bioreactor through a circulation pump, the biosorber including an automated biosorber control module, the bioreactor being provided with a convex reflector for activated coal, installed in the upper part of the bioreactor, designed to provide laminar upward movement of liquid along the walls of the bioreactor. The technical result achieved is to increase the degree of wastewater treatment while ensuring high reliability of operation.

Abstract: A wastewater treatment system is disclosed that includes a desanding hydrocyclone, a deoiling hydrocyclone, an electrocoagulation apparatus that is adapted to receive a flow of treated wastewater from the desanding and deoiling hydrocyclones, a floc separator that is adapted to receive a flow of a first effluent from the electrocoagulation apparatus, and an ultrafiltration membrane apparatus that is adapted to receive at least a portion of a flow of a second effluent from the floc separator.

Abstract: Glass furnace regenerators having opposed pairs of side and end walls formed of refractory blocks, wherein at last one of the side and end walls of the regenerator comprise an interlocking plurality of refractory blocks, and wherein the refractory blocks are self-supporting and load-bearing one-piece pre-cast structures of a refractory material. Tie back bars may be provided to operatively connect a wall formed of the refractory blocks to externally provided buckstays to allow relative movement between the refractor blocks forming the wall and the buckstays (e.g., as may be required due to the blocks undergoing thermal expansion during use).

Abstract: A method for producing a shaped glass article may include heating at least a portion of a mold-facing surface of the glass article to a forming temperature, shaping the glass article in a mold, and removing the multilayer coating from the glass article. The glass article may be coated with a multi-layer removable coating including an inner layer in contact with the glass article and an outer layer disposed over the inner layer. The mold may be in direct contact with the outer layer during shaping. The inner layer may include a first glass having a softening point of at least about 50° C. less than a softening point of the glass article. The outer layer may include a second glass having a softening point of at least about 50° C. greater than the softening point of the glass article.

Abstract: A glass precursor gel and methods of melting the glass precursor gel are disclosed. The glass precursor gel contains a bulk amorphous oxide-based matrix that contains one or more synthesis byproducts. One method includes obtaining the glass precursor gel with the bulk amorphous oxide-based matrix having one or more synthesis byproducts, exposing the glass precursor gel to microwave radiation, and heating and/or melting the glass precursor gel into a molten glass with the microwave radiation by way of the one or more synthesis byproducts.

Abstract: Described herein are alkali-free, boroalumino silicate glasses exhibiting desirable physical and chemical properties for use as substrates in flat panel display devices, such as, active matrix liquid crystal displays (AMLCDs). In accordance with certain of its aspects, the glasses possess good dimensional stability as a function of temperature.

Abstract: A silicate glass that is tough and scratch resistant. The toughness is increased by minimizing the number of non-bridging oxygen atoms in the glass. In one embodiment, the silicate glass is an aluminoborosilicate glass in which ?15 mol %?(R2O+R?O?Al2O3?ZrO2)?B2O3?4 mol %, where R is one of Li, Na, K, Rb, and Cs, and R? is one of Mg, Ca, Sr, and Ba.

Abstract: A method for manufacturing a glass cliché using laser etching includes a dipping step for dipping a glass cliché, which will be etched, into an etching solution, a patterning step for irradiating laser to the glass cliché dipped in the etching solution to form a pattern therein, and a washing step for washing the patterned glass cliché. This method allows making a cliché with a high aspect ratio and fine line widths in comparison to a conventional cliché manufacturing method using photoresist for etching, and also ensures more efficient energy consumption and higher etching efficiency rather than an etching method using laser only.

Abstract: An apparatus for producing anti-glare surfaces includes an etching cream dipping tank and a sub-tank arranged to receive a slurry of etching cream. A pumping unit is fluidly coupled to the etching cream dipping tank and the sub-tank such that the pumping unit is operable to selectively self-circulate the slurry of etching cream in the sub-tank to improve homogeneity of the etching cream and transfer a volume of the homogenized etching cream from the sub-tank to the etching cream dipping tank.

Abstract: An antimicrobial article having a substrate, and a coating on a surface of the substrate. The coating includes a silver-containing alkali silicate. The antimicrobial article has an antimicrobial efficacy of greater than or equal to about 90.0% according to EPA Test Method for Efficacy of Copper Alloy Surfaces as a Sanitizer. The coating may further include at least one of a boron-containing compound and an aluminum-containing compound. A method for forming antimicrobial articles includes coating a substrate with a mixture comprising an alkali silicate; curing the coating at a temperature from greater than or equal to about 300° C. to less than or equal to about 620° C. for a duration of greater than or equal to about 15 minutes to less than or equal to about 120 minutes; and contacting the coating with an antimicrobial medium comprising silver nitrate and an alkali nitrate.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than 0.7·t, comprise a tangent that is less than about ?0.1 MPa/micrometers or greater than about 0.1 MPa/micrometers, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness.

Abstract: The invention relates to a process for the preparation of a shaped composite, comprising the preparation of a mixture into which fragments of mineral wool comprising a size comprising a sugar, a non-cement silica carrier distinct from the wool, a non-cement alkali metal carrier distinct from the wool, and water, are introduced, the non-cement silica carrier and the non-cement alkali metal carrier forming, with the water, a mineral binder which gradually solidifies around the solid particles present in the mixture, and then the shaping of the mixture into a shaped composite, in particular into briquettes. The invention also relates to a process for the manufacture of mineral wool, in which a molten mass is produced which is converted into mineral wool by means of a fiberizing device, the shaped composite being introduced as vitrifiable charge into a melting chamber, such as a cupola furnace.

Abstract: A manufacturing method of a big-model low-permeability microcrack core includes: (1) determining the size of a microcrack core to be manufactured; (2) placing stones in a baking oven to bake for 24h under 120° C., placing the stones into a mixer, mixing and spraying oil, enabling the oil to seep into the stone, evenly forming a thin oil film on stone's surface; (3) mixing the oil sprayed stone with quartz sand and cement, adding water to mix evenly to obtain cement paste; (4) spreading butter on core mold's inner surface to form a thin butter film, pouring the cement paste into the core mold to obtain a cement sample; (5) loading confining pressure outside the core according to the requirements of porosity and permeability of the mold to adjust a pore permeability value; (6) obtaining the big-model core with microcrack after the cement sample is dried and formed.

Abstract: Light-weight, fire-resistant “mineral foam” includes an inorganic cementitious matrix and at least one metal hydrate that is a “super hydrate” substance, in which water is present with the substance in an amount of at least about ten moieties of water of hydration per formula unit of the substance. As a cured solid, that “mineral foam,” or another mineral foam composition including an inorganic cementitious matrix, can be provided as a structural member in part of an assembly that has at least one open web, thermally insulating support member at least partially embedded in the cured solid. Also, the cured “mineral foam” may be a solid foam in a form of a panel, panel block or tile, which may have a tongue provision and/or a groove provision.

Abstract: Dry mortar mixture characterized by a glass mixture of expanded glass beads with a grain size d/D 0/8, mixed in a ratio of between 1:1 and 1:3, for example 1:2 with a dust poor or dust free binding mixture of hydraulic binders and stone granules in the weight ratio of 1:2 to 1:4. The glass has a discontinuous grain distribution. For the glass mixture the fractions 0.5/1.0 and 2.0/4.0 are present while the fractions 0.25/0.5 and 1.0/2.0 are absent. For the glass mixture preferably all grain sizes between 1.0 and 2.0 mm are absent and the grain size distribution is around an average, so that an open structure is obtained.

Abstract: A jamb spray mix comprising: 0.1% to 10% phosphate by weight based on total weight of dry ingredients in the mix, 5% to 15% plasticizer by weight based on total weight of dry ingredients in the mix, the balance of dry ingredients including fused silica particles and impurities, and at least 20% water by weight based on total weight of the mix. In certain non-limiting embodiments, a coating of the jamb spray mix is applied to a refractory brick surface region in a coke oven using an air pressurized applicator and associated nozzle.

Abstract: A composition for a refractory material comprising a base mixture having a composition in oxide (mol %) as follows: SiO2 between 69% and 73%; Al2O3 between 22% and 28%; TiO2 between 0.4% and 1%; Fe2O3 between 0.2% and 1%; CaO between 0.1% and 1%; MgO between 0.1% and 1%; K2O between 0.5% and 2%; Na2O between 0.1% and 0.5%; and comprising a filler mixture comprising at least one from between a schamotte and a smelting agent.

Abstract: Methods for forming ceramic cores are disclosed. A ceramic core formed using the method of the present application includes a silica depletion zone encapsulating an inner zone. The inner zone includes mullite and the silica depletion zone includes alumina. The method includes heat-treating a ceramic body in a non-oxidizing atmospheric condition for an effective temperature and time combination at a pressure less than 10?2 atmosphere to form the silica depletion zone at a surface of the ceramic core.

Abstract: A method of producing a component of a composite of diamond and a binder, wherein a Hot Isostatic gas Pressure process (HIP) is used, includes the step of enclosing a de-bound green body having compacted diamond particles in an infiltrant. The method includes the further steps of enclosing the de-bound green body and the infiltrant in a Zr-capsule that has Zirconium as a main constituent and sealing the Zr-capsule, and applying a predetermined pressure-temperature cycle on the unit formed by the de-bound green body, infiltrant and capsule in which the infiltrant infiltrates the de-bound green body and the de-bound green body is further densified in the sense that the volume thereof is decreased.

Abstract: A method of forming silicon carbide by spark plasma sintering comprises loading a powder comprising silicon carbide into a die and exposing the powder to a pulsed current to heat the powder at a rate of between about 50° C./min and about 200° C./min to a peak temperature while applying a pressure to the powder. The powder is exposed to the peak temperature for between about 30 seconds and about 5 minutes to form a sintered silicon carbide material and the sintered silicon carbide material is cooled. Related structures and methods are disclosed.

Abstract: A Ca—SiAlON ceramic with enhanced mechanical properties and a method employing micron-sized and submicron precursors to form the Ca—SiAlON ceramic. The Ca—SiAlON ceramic comprises not more than 42 wt % silicon, relative to the total weight of the Ca—SiAlON ceramic. The method employs submicron particles and also allows for substituting a portion of aluminum nitride with aluminum to form the Ca—SiAlON ceramic with enhanced mechanical properties.

Abstract: A method for synthesizing high-purity ultrafine ZrC—SiC composite powder is provided. The high-purity ultrafine ZrC—SiC composite powder is prepared by utilizing zirconium silicate only or zirconium silicate with one or both of zirconium oxide or silica sol as a zirconium source and a silicon source material, utilizing sucrose or glucose as a carbon source material, and utilizing acrylamide monomer and N,N?-methylene diacrylamide cross-linking agent as a gel material.