Abstract: A hot-press formed product can be achieved which has regions corresponding to a shock resistant portion and an energy absorption portion within a single formed product without applying a welding method and achieves the balance of high strength and elongation with a high level according to each region by means of having a first forming region exhibiting a metal structure containing martensite: 80-97 area % and retained austenite: 3-20 area % respectively, the remaining structure being 5 area % or less, and a second forming region exhibiting a metal structure containing annealed martensite or annealed bainite: 30-97 area %, martensite as quenched: 0-67 area %, and retained austenite: 3-20 area %.

Abstract: The present application is generally directed to separation and recovery of rare earths using biomass, liposomes, and/or other materials. In some embodiments, a composition comprising rare earths is exposed to biomass, where some of the rare earths are transferred to the biomass, e.g., via absorption. The composition may then be separated from the biomass. A solution may be exposed to the biomass thereby enriching the solution in one or more rare earths, relative to other rare earths in the biomass. The solution and the biomass may then be separated, and the rare earths recovered from the solution. In some cases, this process may be repeated with different solutions, which may result in different solutions enriched in various rare earths. Similar processes may be used to separate the rare earths from thorium and uranium. Liposomes may be used instead of and/or in addition to biomass.

Abstract: New heat treatable aluminum alloys having magnesium and zinc are disclosed. The new aluminum alloys generally contain 3.0-6.0 wt. % Mg, 2.5-5.0 wt. % Zn, where (wt. % Mg)/(wt. % Zn) is from 0.60 to 2.40.

Abstract: A cermet contains hard phase particles containing Ti and a binding phase containing at least one of Ni and Co. 70% or more of the hard phase particles have a cored structure containing a core and a peripheral portion around the core. The core is composed mainly of at least one of Ti carbide, Ti nitride, and Ti carbonitride. The peripheral portion is composed mainly of a Ti composite compound containing Ti and at least one selected from W, Mo, Ta, Nb, and Cr. The core has an average particle size ?, the peripheral portion has an average particle size ?, and ? and ? satisfy 1.1??/??1.7. The hard phase particles in the cermet have an average particle size of more than 1.0 ?m.

Abstract: A cermet contains hard phase particles containing Ti and a binding phase containing at least one of Ni and Co, and 70% or more (by number) of the hard phase particles have a cored structure containing a core and a peripheral portion around the core. The core is composed mainly of at least one of Ti carbide, Ti nitride, and Ti carbonitride, and the peripheral portion is composed mainly of a Ti composite compound containing Ti and at least one selected from W, Mo, Ta, Nb, and Cr. The core has an average particle size ?, the peripheral portion has an average particle size ?, and ? and ? satisfy 1.1??/??1.7.

Abstract: The present invention provides a permanent magnet suitable as a variable flux magnet for a variable magnetic flux motor. A permanent magnet comprising R (R is composed of 75 at % or more of Nd and 25 at % or less of at least one element selected from the group consisting of Y, Ce, La, Pr, Sm, Eu, Gd, Er, Tm, Yb and Lu), Fe and B as the main component, wherein, said permanent magnet is composed of a main phase of a crystal structure represented by R2Fe14B, a ratio of the element R to all constituent element satisfies 11.8 at %?R?12.2 at %, a cross-sectional area ratio Are of the sub-phase with a higher concentration of R than that of the main phase to the whole magnet structure satisfies 0%<Are?1.3%, and a cross-sectional area ratio Ama of the main phase to the whole magnet structure is 97%?Ama.

Abstract: A steel for wheel contains, in mass %, C: 0.65 to 0.84%, Si: 0.4 to 1.0%, Mn: 0.50 to 1.40%, Cr: 0.02 to 0.13%, S: 0.04% or less and V: 0.02 to 0.12%, wherein Fn1 expressed by formula (1) is 32 to 43, and Fn2 expressed by formula (2) is 25 or less, the balance being Fe and impurities. P, Cu and Ni as impurities are P: 0.05% or less, Cu: 0.20% or less and Ni: 0.20% or less: Fn1=2.7+29.5'C+2.9'Si+6.9'Mn+10.8'Cr+30.3'Mo+44.3'V?? (1) Fn2=exp(0.76)'exp(0.05'C)'exp(1.35'Si)'exp(0.38'Mn)'exp(0.77'Cr)'exp(3.0'Mo)'exp(4.6'V)??(2). The steel has excellent properties for use as a wheel.

Abstract: An Fe-based nano-crystalline alloy formed from an alloy composition of (FeE)(100-X-Y-Z)BXPYCuZ having an amorphous phase as a main phase, wherein 79?100-X-Y-Z?86 atomic %, 4?X?9 atomic %, 1?Y?10 atomic %, and 0.5?Z<1.2 atomic %, and wherein (FeE) includes Fe and at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Al, Mn, Ag, Zn, Sn, As, Sb, Bi, Y, N, O and a rare-earth element, wherein a combined total of said at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Al, Mn, Ag, Zn, Sn, As, Sb, Bi, Y, N, O and a rare-earth element is in an amount of 3 atomic % or less relative to the whole composition.

Abstract: Producing a Ni superalloy component in which the superalloy has a ? phase matrix containing intermetallic ?? precipitates. Providing a Ni superalloy casting of the component; solutioning the component by heat treating the casting under vacuum and/or in an inert atmosphere at a temperature above the ?? solvus to homogenize the ? phase; quenching and ageing the solutioned component to grow intermetallic ?? precipitates in the homogenized ? phase. Before the solutioning step: heat treating the casting to produce a thermally grown oxide on the surface, oxide adherent to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. Performing the solutioning step under a Ni vapor pressure which is sufficient to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. During the solutioning heat treatment the component is encapsulated in a container protecting the casting from Si-doped contaminants.

Abstract: A high-strength ?+? type hot-rolled titanium alloy sheet containing 0.8 to 1.5 mass % Fe, 4.8 to 5.5 mass % Al, 0.030 mass % N, O and N, wherein cracks are prevented from spreading, wherein: (a) ND represents normal direction of a hot-rolled sheet; RD represents hot rolling direction; TD represents hot rolling width direction; ? represents the angle formed between c axis and ND; ? represents angle formed between plane including c axis and ND, and a plane including ND and TD; (b1) XND represents highest (0002) relative intensity of X-ray reflection by grains when ? is from 0° to 30° ; (b2) XTD represents the highest (0002) relative intensity of the X-ray reflection caused by grains when ? is from 80° to 100° and ? is ±10° . (c) The high-strength ?+? type hot-rolled titanium alloy sheet has a value for XTD/XND of at least 4.0. Q(%)=[O]+2.77·[N].

Abstract: A galvannealed steel sheet includes: a scale-removed rolled steel sheet; and a galvannealed layer arranged on the scale-removed rolled steel sheet. When ten measurement points of the galvannealed steel sheet are set in a transverse direction by equally dividing a line-segment having a reference length of 50 mm by 10, a minimum P content of the galvannealed layer in the ten measurement points is 50% or more as compared with a maximum P content therein.

Abstract: The invention relates to a coating system for a component of a turbomachine, which includes at least two different base powders. Each of the at least two different base powders has an individual predetermined distribution within the coating system. Further, each of the at least two different base powders is responsible for a specific property of the coating system.

Abstract: Provided is a hard coating having, in particular, excellent oxidation resistance, high hardness, and excellent abrasion resistance as compared with conventional hard coatings such as TiSiN, TiAlSiN, TiCrAlSiN, and AlCrSiN coatings. The hard coating according to the present invention has a compositional formula of (Ti?Cr1-?)1-aGea(C1-xNx), where the atomic ratios of the elements satisfy the expressions: 0???1, 0.010?a?0.20, and 0.5?x?1.

Abstract: An article comprises a body and at least one protective layer on at least one surface of the body. The at least one protective layer is a thin film having a thickness of less than approximately 20 microns that comprises a ceramic selected from a group consisting of Y3Al5O12, Y4Al2O9, Er2O3, Gd2O3, Er3Al5O12, Gd3Al5O12 and a ceramic compound comprising Y4Al2O9 and a solid-solution of Y2O3—ZrO2.

Abstract: A method of forming a superconductor tape, includes depositing a superconductor layer on a substrate, forming a metal layer comprising a first metal on a surface of the superconductor layer, and implanting an alloy species into the metal layer where the first metal forms a metal alloy after the implanting the alloy species.

Abstract: The use of non-mass analyzed ion implanter is advantageous in such application as it generates ion implanting at different depth depending on the ions energy and mass. This allows for gaining advantage from lubricity offered as a result of the very light deposition on the surface, and at the same time the hardness provided by the intercalated ions implanted below it, providing benefits for cover glass, low E enhancement, and other similar materials. In further aspects, ion implantation is used to create other desirable film properties such anti-microbial and corrosion resistance.

Abstract: The invention belongs to the technical field of inorganic compounds, and particularly, relates to a method for directly preparing graphene by taking CBr4 as a source material and using methods such as molecular-beam epitaxy (MBE) or chemical vapor deposition (CVD). A method for preparing graphene comprises the following steps: selecting a proper material as a substrate; directly depositing a catalyst and CBr4 on a surface of the substrate; and performing annealing treatment on the sample obtained through deposition. Compared with other technologies, an innovative point of the method in the invention is that the catalyst and CBr4 source can be quantitatively and controllably deposited on any substrate, and the catalyst and CBr4 source react on the surface of the substrate to form the graphene, so that the dependence of the graphene growth on a substrate material can be reduced to a great extent, and different substrate materials can be selected according to different application backgrounds.

Abstract: The present invention proposes a production method for obtainment of three-dimensional closed graphene-based nano-/microstructures (10) using a coaxial multilayer core-shell production process (1000) comprising a coaxial flow system (100) having a first flow path (101) and a first fluid exit (1011) at an end of said first flow path; and a second flow path (102) circumferentially surrounding said first flow path (101), said second flow path having a second fluid exit (1021); wherein a first fluid (1) flows through the first flow path and exits through the first fluid exit (1011); and a second fluid (2) which is immiscible with the first fluid (1) under the conditions where said production method is conducted, flows through the second flow path (102) and exits through the second fluid exit (1021) such that the second fluid (2) circumferentially covers the first fluid (1) upon leaving the coaxial flow system (100); said second fluid (2) comprises a graphene-based material, a polymeric material and solvent.

Abstract: Described herein is a method of depositing a plasma resistant ceramic coating onto a surface of a chamber component using a non-line-of-sight (NLOS) deposition process, such as atomic layer deposition (ALD) and chemical vapor deposition (CVD). The plasma resistant ceramic coating consists of an erbium containing oxide, an erbium containing oxy-fluoride, or an erbium containing fluoride. Also described are chamber components having a plasma resistant ceramic coating of an erbium containing oxide, an erbium containing oxy-fluoride, or an erbium containing fluoride.

Abstract: A low-k dielectric porous silicon oxycarbon layer is formed within an integrated circuit. In one embodiment, a porogen and bulk layer containing silicon oxycarbon layer is deposited, the porogens are selectively removed from the formed layer without simultaneously cross-linking the bulk layer, and then the bulk layer material is cross-linked. In other embodiments, multiple silicon oxycarbon sublayers are deposited, porogens from each sub-layer are selectively removed without simultaneously cross-linking the bulk material of the sub-layer, and the sub-layers are cross-linked separately.

Abstract: Atomic layer deposition (ALD) type processes for producing metal containing thin films comprise feeding into a reaction space vapor phase pulses of metal containing cyclopentadienyl precursors as a metal source material. In preferred embodiments the metal containing cyclopentadienyl reactant comprises a metal atom that is not directly bonded to an oxygen or halide atom. In other embodiments the metal atom is bonded to a cyclopentadienyl compound and separately bonded to at least one ligand via a nitrogen atom. In still other embodiments the metal containing cyclopentadienyl compound comprises a nitrogen-bridged ligand.

Abstract: Embodiments of the present invention generally relate to apparatus for reducing arcing and parasitic plasma in substrate processing chambers. The apparatus generally include a processing chamber having a substrate support, a backing plate, and a showerhead disposed therein. A showerhead suspension electrically couples the backing plate to the showerhead. An electrically conductive bracket is coupled to the backing plate and spaced apart from the showerhead. The electrically conductive bracket may include a plate, a lower portion, an upper portion, and a vertical extension. The electrically conductive bracket contacts an electrical isolator.

Abstract: A metal plating apparatus for plating metal with zinc is provided with a rotating device and a plurality of stirring devices. The rotating device has a driving assembly and a rotating assembly. The driving assembly has a driving gear. The rotating assembly is connected with and controlled by the driving assembly. The rotating assembly has a sustaining pillar. A rotating seat is mounted on the sustaining pillar and engaged with the driving gear. The stirring devices is mounted on the rotating seat radially and spaced from each other. The metal plating apparatus improves productivity through an automatic process which shifts locations of the stirring devices by the rotating device and plates metal with a cooperation of peripheral supporting apparatus, and improves working efficiency through decreasing occupied space and the number of operating personnel.

Abstract: Shielding coatings are applied to polymer substrates for selective metallization of the substrates. The shielding coatings include a primer component and a hydrophobic top coat. The primer is first applied to the polymer substrate followed by application of the top coat component. The shielding coating is then selectively etched to form an outline of a desired current pattern. A catalyst is applied to the patterned polymer substrate followed by electroless metal plating in the etched portions. The portions of the polymer substrate which contain the shielding coating inhibit electroless metal plating. The primers contain five-membered heterocyclic nitrogen compounds and the top coat contains hydrophobic alky organic compounds.

Abstract: A feedstock for a cold spray process includes a plurality of globule bodies. The globule bodies include a plurality of discrete particles bonded to one another to define porous globule bodies. The bonds between the particles are of sufficient strength such that the globule bodies can retain both the body integrity as well as the body shape when the body experiences acceleration from a conveying gas in a cold spray technique. Methods of making the feedstock and globule bodies are also described.

Abstract: Alloy composition for the manufacture of protective coatings, comprising cobalt, nickel, chromium, aluminum, yttrium and iridium in amounts so as to obtain the phases ?, ? and ?, in particular for coating a super-alloy article. Preferably, such super-alloy article is a turbine component.

Abstract: A coating of niobium oxide, zirconium titanate, or nickel titanate is formed on at least a part of a surface of a jet pump member constituting a jet pump serving as a reactor internal structure of a boiling water reactor. Further, a solution containing, e.g., a niobium compound is applied to at least a part of the surface of the jet pump member constituting the jet pump, and the jet pump member coated with the solution is heat-treated to form a coating of, e.g., niobium oxide. With this configuration, the jet pump member constituting the jet pump of the boiling water reactor is provided such that deposition of crud can be sufficiently suppressed on the jet pump member.

Abstract: A surface that includes a three-dimensional surface, wherein a notch is present in said three-dimensional surface. The surface further includes a metal edge inserted into the notch and attached to the three-dimensional surface.

Abstract: Disclosed is an apparatus and method for forming lubricant recesses having minute configurations by applying a photolithograph method in a curved inner surface, such as a cylinder bore surface of a cylinder block, the inside of a cylinder liner, the inside of a compressor cylinder, a big end of a connecting rod, a big end bearing, a shaft insertion hole of a rocker arm, or the like in an internal combustion engine.

Abstract: An anode assembly is disclosed for use in a cathodic protection system. The anode assembly includes an elongated housing, an electrical cable, an anode, and electrically conductive backfill. The housing has a leading end and a trailing end through which the electrical cable extends. The anode is located within the housing and is in the form of a plurality of electrically conductive segments which are spaced apart from each other and which are electrically connected to the electrical cable at respective electrically conductive joints. The backfill surrounds the anode and cable within the housing.

Abstract: A process of using an electrochemical cell to generate aluminum hydride (AlH3) and other high capacity hydrides is provided. The electrolytic cell uses an electro-catalytic-additive within a polar non-salt containing solvent to solubilize an ionic hydride such as NaAlH4 or LiAlH4. The resulting electrochemical process results in the formation of AlH3 adduct. AlH3 is obtained from the adduct by heating under vacuum. The AlH3 can be recovered and used as a source of hydrogen for the automotive industry. The resulting spent aluminum can be regenerated into NaAlH4 or LiAlH4 as part of a closed loop process of AlH3 generation.

Abstract: The invention provides a lining for an aluminium electrolyzer having inert anodes and is enclosed in a cathode casing comprising a bottom formed from taller blocks having projections and shorter bottom blocks. The shorter bottom blocks are mounted at the ends of the bottom of the cathode device. The shorter bottom blocks alternate with the taller bottom blocks having projections. Vertical channels are provided in the projections of the blocks over the entire thickness of the block for the mounting of conductive elements formed from aluminium and are attached in the lower part to a current-carrying collector that is in the form of a plate which extends out of the ends of the bottom blocks and through the longitudinal sides of the cathode casing.

Abstract: To provide a trivalent chromium plating film, in which the generation of cracks penetrating from the film surface to a substrate interface is suppressed, and a sliding member coated with the trivalent chromium plating film, plating is conducted with a chromium plating bath containing trivalent chromium as a chromium source, with a second phase dispersed in a planar and/or fibrous form, such that the second phase in a planar and/or fibrous form is dispersed in the hard chromium plating film to prevent or deflect the propagation of cracks, and to suppress the increase of the crack width, thereby suppressing the propagation of cracks in the hard chromium plating film.

Abstract: Acid bismuth electroplating baths are stable and have high current efficiency over the life of the baths. The bismuth baths are easy to control because of the reduced number of bath components.

Abstract: A system and methods are provided for electrochemical grinding a workpiece. In one embodiment, a method includes controlling potentials to grinding tool and the workpiece, controlling applying electrolyte, and controlling grinding of the workpiece by the grinding tool. The method may also include determining screen replacement when there is sufficient metal plated.

Abstract: Provided is an anodized aluminum film formed on a surface of a substrate that comprises aluminum or an aluminum alloy, the anodized aluminum film having a structure constituted of a single anodized film layer or a structure composed of superposed anodized film layers of two or more different kinds, wherein the outermost anodized film has a degree of film formation, defined by equation (1), of 1.3 or more and the proportion of the thickness of this anodized film in the entire film thickness is 3% or higher. Thus, the anodized aluminum film is inhibited from cracking in bent portions. As a result, the substrate is inhibited from corroding in corrosive-gas atmospheres, and a decrease in withstand voltage characteristics due to film cracking is inhibited. With this anodized aluminum film, enhanced withstand voltage characteristics can hence be attained: Degree of film formation=(thickness of anodized film)/(substrate thickness loss by anodization)??(1).

Abstract: To manufacture a chamber component for a processing chamber, an aluminum coating is formed on an article comprising impurities, the aluminum coating being substantially free from impurities.

Abstract: Provided is a method of forming a complex plating film using multi-layer graphene metal particles. The method of forming the plating film may include preparing a powder with a metal particle structure coated with multi-layer graphene, and forming a plating film by adding the powder to a plating solution through electric plating.

Abstract: Quantum dots and methods of making quantum dots are provided.

Abstract: Boron-doped diamond and methods for making it are provided. The doped diamond is made using an ultra-thin film of heavily boron-doped silicon as a dopant carrying material in a low temperature thermal diffusion doping process.

Abstract: A method for a heat treatment of a silicon single crystal wafer in an oxidizing ambient, including: performing the heat treatment based on a condition determined by a tripartite correlation between a heat treatment temperature during the heat treatment, an oxygen concentration in the silicon single crystal wafer before the heat treatment, and a growth condition of a silicon single crystal from which the silicon single crystal wafer is cut out. This provides a method for a heat treatment of a silicon single crystal wafer which can annihilate void defects or micro oxide precipitate nuclei in a silicon single crystal wafer with low cost, efficiently, and securely by a heat treatment in an oxidizing ambient.

Abstract: The present invention relates to composites comprising rigid-rod polymers and graphene nanoparticles, processes for the preparation thereof, nanocomposite films and fibers comprising such composites and articles containing such nanocomposite films and fibers.

Abstract: An apparatus for forming a leno selvage, in particular for a loom, includes a fixed-position housing, a support having the shape of a circular ring or of a circular disk and rotatably supported in the housing by a bearing and having two diagonally oppositely disposed thread eyelets for guiding leno threads in the region of the inner race of the bearing. At least two ring gears of magnetizable material extending in parallel with one another are arranged on the outer periphery of the support. A plurality of magnets are arranged on the outer periphery of the support in the region of the ring gears. A stator sheet package of circular ring shape having a plurality of coils arranged thereat has segments each having a toothed arrangement associated with the toothed arrangement of the ring gears in the region of the coils.

Abstract: A multi-layer ballistic woven fabric, including an upper woven layer having upper warp yarns and upper weft yarns that are interwoven together to form the upper woven layer. The multi-layer ballistic woven fabric also includes a lower woven layer having lower warp yarns and lower weft yarns that are interwoven together, and a plurality of securing yarns, each securing yarn interwoven with at least some of the upper yarns and some of the lower yarns so as to secure the upper and lower woven layers together. At least one of the securing yarns is woven underneath a first lower weft yarn, then above a second upper weft yarn adjacent the first lower weft yarn, then underneath a third lower weft yarn adjacent the second upper weft yarn and then above a fourth upper weft yarn adjacent the third lower weft yarn. The multi-layer ballistic woven fabric is formed by interweaving the securing yarns with the warp yarns and weft yarns as the upper woven layer and lower woven layer are made.

Abstract: Described is a controlled weight distribution woven terry fabric that includes a body having a first end and a second end, wherein the first and second ends are opposite one another and a first side edge 34 and a second side edge, wherein the first and second side edges are opposite one another and generally perpendicular to the first and second opposite ends. The terry fabric further includes a plurality of zones extending across the fabric between one of the first and second opposite ends or the first and second opposite edges. Each zone of the plurality of zones has a pile with a pile height and the pile height in a zone differs from the pile height in an adjacent zone and the difference between the pile heights in adjacent zones is in a range between about 0.1 mm and about 2 mm. Also described are articles, such as towels, wash cloths, and bath mats, made from the controlled weight distribution woven terry fabric.

Abstract: This invention includes improved IP sensors that both have improved sensitivity, performance, and other properties and are multifunctional. The improved IP sensors have IP sensor conductors with waveforms having legs that are substantially parallel throughout the operating range of stretch. The multifunctional IP sensors include, in addition to IP sensors, accessory conductors, additional sensors, and other compatible modules. This inventions also includes embodiments of apparel incorporating the improved IP sensors. This apparel can range from band-like to shirt-like, and so forth, and include one or more IP sensors sensitive to expansions and contractions of underlying regions of a monitored subject.

Abstract: A knitted athletic performance garment includes a seamless panel to cover a portion of a wearer's body, a first performance zone and a second performance zone formed in the seamless panel, wherein the first performance zone is formed of a first warp knit stitch construction and has a first modulus, wherein the second performance zone is formed of a second warp knit stitch construction and has a second modulus, wherein the first warp knit stitch construction is different from the second warp knit stitch construction, wherein the first modulus is different from the second modulus, and wherein the difference in modulus between the first performance zone and the second performance zone is due to the difference in stitch construction between the first performance zone and the second performance zone.

Abstract: Disclosed is a braiding disk handle for holding a kumihimo braiding disk. The braiding disk handle includes a tubular grip having a proximal end, a distal end, and a chamber extending between and through the proximal and distal ends. The grip is configured and adapted to receive a length of yarn through the extent of the chamber. The handle further includes a hollow shank attached to the distal end of the grip such that the chamber of the grip is in communication with the hollow of the shank. The shank is configured and adapted to cooperatively and detachably mate with an opening of a braiding disk. The handle further includes a shoulder formed at the distal end of the grip adjacent and perpendicular to the shank. The shoulder is configured and adapted to support at least a portion of the braiding disk while the shank is mated with braiding disk.

Abstract: A nonwoven fabric comprising a meltspun fiber of a lignin compound. Also claimed a laminated fabric comprising the nonwoven fabric, a nonwoven fabric product comprising the nonwoven fabric, a structured multicomponent fiber comprising a lignin compound, a web comprising a meltspun fiber of a lignin compound and a method of producing a nonwoven fabric by forming a web of meltspun fiber comprising a lignin compound and bonding at least a portion of the fiber in the web to form the nonwoven fabric.

Abstract: The present invention relates to a nonwoven material for use as an absorbent wiping material produced by hydroentangling of a substrate web comprising at least one layer of fibers selected from amongst synthetic fibers, regenerated fibers and natural fibers, wherein the nonwoven material (1) has a base level h0 with protuberances (2, 3) on one side, wherein the protuberances (2, 3) form at least a first and a second surface structure respectively in the form of first (2) and second (3) protuberances from the base level h0, wherein the first protuberances (2) have a height h1 from the base level h0 and the second protuberances (3) have a height h2 from the base level h0, where h2 is higher than h1, and each of the second protuberances (3) occupies an area of the surface of the base level at least 4 times greater than each of the first protuberances (2).