Abstract: An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer. The emission layer includes at least one doping layer and at least one non-doping layer. The doping layer comprises a first host, a second host, and a dopant.

Abstract: Aspects of the present disclosure relate to compositions and processes suitable for use in forming a lid for a hot food or beverage container, the lid being made from a multi-layer sheet that includes a substrate layer and a cap layer made from polyolefin-based compositions. The lid has a density less than water at 23° C., allowing the lid to be recycled in a recycling stream.

Abstract: A multilayer film (10) having excellent mechanical strength and transparency comprise a core layer (12), at least two skin layers, and at least two sub-skin layers disposed between the core layer (12) and the two skin layers. The core layer (12) comprises at least 60 wt. % linear low density polyethylene (LLDPE). The sub-skin layers comprise at least 60 wt. % low density polyethylene (LDPE). The skin layers comprise at least 80 wt. % of LLDPE wherein the LLDPE comprises C6 LLDPE, C8 LLDPE, or combinations thereof, and each skin layer has a thickness of less than 25% of the overall thickness of the multilayer film (10). The multilayer film (10) comprises at least 0.1 wt. % ultraviolet stabilizer.

Abstract: A transmittance-variable film having a double-cell structure or a single-cell structure capable of suppressing formation of bubbles inside a liquid crystal layer or at the interface between a base film and a pressure-sensitive adhesive layer under high-temperature and high-humidity reliability conditions is provided. An exemplary transmittance-variable film can be applied to various applications, including various construction or automotive materials that require control of transmittance, or eyewear, such as augmented reality experience or sports goggles, sunglasses or helmets.

Abstract: Various enhancements of tabbed seals are provided herein with enhanced tab functionality. Such enhancements include a lacquer coating, such as one-part and two-part coatings, which can help minimize tab sticking to the lower laminate. Further, the lacquer can help decrease air bubbles under the tab and also provide visual enhancements to the tab.

Abstract: Provided is a laminated glass where multiple glass sheets are joined via an interlayer film [J], wherein i) mean density of the laminated glass is 1.2-1.5 g/cm3 at 25° C., ii) the interlayer film [J] has layered structure comprising at least two adhesive layers [G], comprising an adhesive mainly containing a thermoplastic elastomer having an alkoxysilyl group [F]; and at least one rigid resin layer [H] positioned therebetween, iii) storage modulus of the rigid resin layer [H] is higher than that of the adhesive layer [G], iv) storage modulus of the interlayer film [J] calculated from a formula 1 or measured is 2.0×108-1.0×109 Pa at ?20° C. and 1.0×108-8.0×108 Pa at 40° C., G?=(?iti)/(?i(ti/G?i))??(1) where G?: calculated storage modulus of the interlayer film, G?i: storage modulus of an i-th layer of the interlayer film, ti: thickness of the i-th layer, ?i: sum of numerical values of the i-th layer.

Abstract: The purpose of the present invention is to provide a chemically strengthened glass in which reduction in glass surface strength is effectively suppressed even without performing a polishing treatment after a prolonged chemical strengthening treatment has been conducted at a high temperature. The present invention relates to a chemically strengthened glass having a specific glass composition, wherein: the surface roughness (Ra) is a specific value or greater; the compressive stress layer depth of a surface layer is a specific value or greater; by setting the hydrogen concentration in the glass surface layer to be within a specific range, the surface strength of the glass is dramatically improved even without performing an etching treatment using hydrofluoric acid or polishing the glass surface after a prolonged chemical strengthening treatment has been conducted at a high temperature.

Abstract: Provided is an interlayer film for laminated glass that can improve bending rigidity and sound insulating properties of laminated glass and can inhibit the occurrence and growth of foam in the laminated glass. An interlayer film for laminated glass according to the present invention has a single-layer structure or a two or more-layer structure and includes a first layer containing a polyvinyl acetal resin and a plasticizer, in which a glass transition temperature of the first layer is 10° C. or lower, and an elastic modulus of the first layer at 30° C. is 285,000 Pa or greater.

Abstract: A wash-off label includes a face film. According to an embodiment the face film is at least uniaxially oriented and comprises at least one of the polyolefins: cyclic olefin copolymer, propylene terpolymer, propylene random copolymer, propylene homopolymer, heterophasic polypropylene and linear low density polyethylene. The face film has density between 0.85 and 0.94 g/cm3 at room temperature (23±2° C.). Further the invention relates to a labelled item comprising the wash-off label.

Abstract: A vehicle floor configured to direct water flow comprising a floor portion that extends front-to-back and side-to-side in the vehicle including a surface that faces the vehicle occupant. The floor portion surface includes one or a plurality of raised rib portions and one or a plurality of web regions in-between said raised rib portions, wherein the one or plurality of web regions provides a downwardly sloping floor surface that is configured to direct water to one or a plurality of desired locations.

Abstract: A material includes a transparent substrate coated with a stack of thin layers including an alternation of three functional silver-based metallic layers. This material makes it possible to obtain a multiple glazing having good thermal performance results, in particular a selectivity greater than 2, excellent color neutrality and low optical sensitivity.

Abstract: This disclosure provides a composition of matter nucleated from a homogenous nucleation to form a self-assembled binder-less mesoporous carbon-based particle. In some implementations, the composition includes: a plurality of electrically conductive 3D aggregates formed of graphene sheets and sintered together to define a 3D hierarchical open porous structure comprising mesoscale structuring with micron-scale fractal structuring and configured to provide an electrical conduction between contact points of the graphene sheets. A porous arrangement is formed in the 3D hierarchical open porous structure and is arranged to contain a liquid electrolyte configured to provide ion transport through a plurality of interconnected porous channels in the 3D hierarchical open porous structure.

Abstract: The present invention relates to a novel plastisol composition that cures at a temperature much lower than conventional plastisols. Also disclosed is a method of applying the composition.

Abstract: A method for making a joint structure including embedding a portion of at least two layers of a third component into a first component and interleaving at least one layer of a second component with an unembedded portion of the at least two layers of the third component, wherein the third component inhibits galvanic corrosion between the first and second components, the first component has a first CTE, the second component has a second CTE that is different from the first CTE, the third component has a third CTE that is between the first CTA and the second CTE, and the third component comprises a mesh component.

Abstract: A multilayer electronic component includes a body including a dielectric layer and an internal electrode; and an external electrode including an electrode layer disposed on the body and connected to the internal electrode and a conductive resin layer disposed on the electrode layer, and the conductive resin layer includes a metal wire, a conductive metal, and a base resin.

Abstract: A glass laminate includes a glass core layer having a core coefficient of thermal expansion (CTE) and a glass cladding layer adjacent to the core layer and having a cladding CTE that is less than the core CTE such that the core layer is in tension and the cladding layer is in compression. A stress profile of the glass laminate includes a compressive peak disposed between an outer surface of the cladding layer and an inner surface of the cladding layer.

Abstract: Methods for regenerating poisoned salt bath comprising providing a salt bath comprising at least one of KNO3 and NaNO3, providing an ion-exchangeable substrate comprising lithium cations, contacting at least a portion of the ion-exchangeable substrate with the salt bath, whereby lithium cations in the salt bath diffuse from the ion-exchangeable substrate and are dissolved in the salt bath, and selectively precipitating dissolved lithium cations from the salt bath using phosphate salt. The methods further include preventing or reducing the formation of surface defects in the ion-exchangeable substrate by preventing or reducing the formation of crystals on the surface of the ion-exchangeable substrate upon removal from the salt bath.

Abstract: A method of producing glass-based articles having sections of different thicknesses is provided, where a maximum central tension in a thinner section is less than that of a thicker section. The method includes reducing the thickness of a region of a glass-based article that includes a compressive stress layer extending from a surface to a depth of compression to form a glass-based article with multiple thickness regions, and then ion exchanging the glass-based article to form a stress profile in the thinner region that has a maximum central tension that is less than a maximum central tension of a stress profile of the thicker region. The glass articles produced by the method are also provided.

Abstract: A polyolefin material that is formed by solid state drawing of a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and nanoinclusion additive is provided. The nanoinclusion additive is dispersed within the continuous phase as discrete nano-scale phase domains. When drawn, the nano-scale phase domains are able to interact with the matrix in a unique manner to create a network of nanopores.

Abstract: A graphite-containing refractory has higher bending strength and fracture energy than known refractories. The graphite-containing refractory has a graphite content of 1% to 80% by mass. 1000 to 300000 carbon fibers with a fiber diameter of 1 to 45 ?m/fiber are bundled. The carbon fiber bundle has a length of 100 mm or more and is placed within the graphite-containing refractory to form the same.

Abstract: An absorbent article is disclosed, including a three-dimensional material formed of a liquid permeable topsheet and an acquisition material. The acquisition material is positioned beneath the topsheet, and both may be formed of nonwoven material. The three dimensional material may have two surfaces and a plurality of protrusions extending in a z-direction from one of the surfaces, each protrusion having side walls defining an opening in the other of the surfaces. One of the topsheet and the acquisition material may include fibers spun of polymer resin pigmented with a first color that differs from a second color of fibers of the other of the topsheet and the acquisition material, and the differing colors are visible when viewing a wearer-facing surface of the absorbent article.

Abstract: In order to solve reduction in strength and rigidity at a weldline which is a problem of an injection molding body, and enable free design such as thin wall molding or complex shape molding of the injection molding body, there is provided an integrally molded body in which a substrate for reinforcement (a) having a discontinuous fiber (a1) and a resin (a2) and an injection molding body (b) having a discontinuous fiber (b1) and a resin (b2) are integrated, in which the substrate for reinforcement (a) has a difference in an orientation angle of the discontinuous fiber (a1) in each of regions obtained by dividing a major axis direction of the substrate for reinforcement (a) into 10 equal parts of within 10°, and the substrate for reinforcement (a) covers a part or all of a weldline of the injection molding body (b) to be integrated with the injection molding body (b).

Abstract: The present disclosure relates generally to vapor retarding building materials and methods for making them. The present inventors have found simple and cost-efficient materials that have low water vapor permeability at low relative humidities and that can be provided as a coating on a building material substrate. Notably, in many embodiments, the materials can have high water vapor permeability at high relative humidities. In one embodiment, the disclosure provides vapor retarding articles comprising a building material substrate; and a polymeric coating layer coated on the building material substrate, the polymeric coating layer comprising an inorganic hydrophilic particulate filler dispersed in a continuous organic phase comprising a hydrophobic polymer, wherein the content of the filler is from about 30% to about 85% by weight of the polymeric coating layer, the vapor retarding article configured to have a water vapor permeance of no more than about 1 Perm at 25% relative humidity.

Abstract: This disclosure provides systems and methods of manufacturing an anode, which can include nucleating a plurality of carbon particles at a first concentration level, forming a first film on a sacrificial substrate based on the first concentration level, each of the carbon particles defined by a plurality of aggregates formed of few layer graphene sheets fused together, defining a porous structure based on the few layer graphene sheets; and infusing a molten lithium (Li) metal into the porous structure. A plurality of interconnected porous channels can be defined based on the plurality of carbon particles. A second film can be formed by nucleating the carbon particles at a second concentration level on the first film. The first film can be configured to provide a first electrical conductivity and the second film can be configured to provide a second electrical conductivity different than the first electrical conductivity.

Abstract: A joint structure of a composite bicycle frame includes a base layer and at least one reinforcing layer. The base layer is made of a first polymeric matrix material doped with a plurality of first fibers. The first fibers have random fiber orientation, and the base layer has a first thickness. The reinforcing layer is adhesively connected to the base layer. The reinforcing layer is made of a second polymeric matrix material doped with a plurality of second fibers. The second fibers have a single fiber orientation. The reinforcing layer has a second thickness which is smaller than the first thickness of the base layer.

Abstract: A multilayer film including a core layer and two skin layers, wherein the core layer is positioned between the two skin layers, wherein the core layer includes a polyethylene composition including a high density polyethylene having a density of 0.930-0.965 g/cc and a melt index of 0.7-10.0 g/10 min, and wherein each skin layer independently includes a polypropylene composition including greater than 50 wt. %, based on the total weight of the polypropylene composition, of a propylene-based polymer.

Abstract: A deposition apparatus including a frame and a cylindrical drum with a cylindrical surface that extends along a central axis. The drum has a first and a second end surface, which extend perpendicularly to the central axis. The drum is rotatably mounted in the frame and includes a plurality of gas zones positioned on the cylindrical surface. The included gas channels extend within the drum. At least a number of the gas zones are in gas connection with at least two channels. The deposition apparatus includes closing elements for closing off all but one of the at least two channels with which a said gas zone is in gas connection so that the type of gas supplied to the various gas zones along the drum surface is programmable.

Abstract: The present invention relates to a secondary battery having the electrode structure and a method of manufacturing therefor, the electrode structure according to an embodiment of the present invention may comprise an electrode assembly including a cathode layer, an anode layer facing the cathode layer, and a separation film disposed between the cathode layer and the anode layer; an exterior body including a upper exterior layer having an outer sealing part of which at least a portion of or whole edges are adhered so as to accommodate the electrode assembly and an electrolyte therein, and a lower exterior layer; a battery penetration part forming openings from the upper exterior layer to the lower exterior layer; and an inner sealing part in which facing portions of the upper exterior layer and the lower exterior layer of external periphery of the battery penetration part are adhered each other.

Abstract: In color reproduction for a dental restorative material, in order to achieve a color that closely matches the color of the natural tooth, one technique that is used is to form a mill blank by laminating layers of materials having different colors. However, misidentification of layers frequently occurs. The present invention is a dental mill blank having a plurality of layers and the dental mill blank has a visual identifying portion by which the plurality of layers are visually identifiable. The visual identifying portion may be provided by color or by structure. Providing the visual identifying portion by color refers to coloring the surface of a layer of the dental mill blank and providing the visual identifying portion by structure refers to forming microscopic or macroscopic irregularities in the entire periphery or part of a layer surface.

Abstract: A connection structure: a first electronic component having a terminal pattern in which a plurality of terminals are arranged side by side in a radial form and a second electronic component having a terminal pattern corresponding to the terminal pattern of the first electronic component are anisotropically conductively connected using an anisotropic conductive film, (i) the effective connection area per terminal is 3000 ?m2 or more, and the number density of conductive particles in the anisotropic conductive film is 2000 particles/mm2 or more and 20000 particles/mm2 or less, (ii) as the anisotropic conductive film, adopted is an anisotropic conductive film in which the conductive particles are arranged in a lattice form, and the arrangement pitch and the arrangement direction are configured such that each terminal captures three or more conductive particles, or (iii) as the anisotropic conductive film, adopted is an anisotropic conductive film having a multiple circular region.

Abstract: A multilayer film includes an outer foam layer and a gas barrier layer. The multilayer film may also include at least one tie layer and at least one inner layer, and can be configured to have various film layer constructions. For example, the multilayer film can be configured as a five-layer, six-layer, or seven-layer films. The multilayer film can provide unique texture, softness, quietness, gas barrier properties, light weight and low cost per volume. Further, one or more layers of the multilayer film can contain a vinyl-bond rich triblock copolymer to provide sound absorbing properties.

Abstract: A paper product has a plurality of individual paper sheets with a moist center section impregnated with a liquid and dry outer sections that bound the moist center section. The paper product includes a core element and the plurality of individual paper sheets that are wound around the core element. Each paper sheet has a top surface, a bottom surface, the moist center section impregnated with the liquid, a first dry outer section bounding a first edge of the moist center section, a second dry outer section bounding a second edge of the moist center section, a first moisture impermeable barrier at the first edge of the moist center section, a second moisture impermeable barrier at the second edge of the moist center section, and a water impermeable membrane extending laterally between the first and second moisture impermeable barriers for dividing the moist center section into a first region and a second region.

Abstract: A stretch-modified elastomeric multilayer film comprising a core layer comprising a first ethylene-?-olefin block copolymer, wherein the first ethylene-?-olefin block copolymer comprises at least 50 mol. % ethylene, has a melt index (I2) from 0.5 g/10 min to 5 g/10 min, and has a density of 0.850 g/cc to 0.890 g/cc, and at least one outer layer independently comprising a second ethylene-?-olefin block copolymer and from 2.5 to 30 wt. % of an antiblock agent, wherein the second ethylene-?-olefin block copolymer comprises at least 50 mol. % ethylene, has a melt index (I2) from 0.5 g/10 min to 25 g/10 min, and has a density of 0.850 g/cc to 0.890 g/cc, wherein the density of the first ethylene-?-olefin block copolymer is equal to or greater than the density of the second ethylene-?-olefin block copolymer.

Abstract: The present disclosure relates to graphene. In particular, the present disclosure relates to a method for continuously preparing thermally conductive graphene films. A graphite oxide containing 40-60 wt % of moisture is directly stripped at a high temperature; and then, procedures such as dispersion, defoaming, coating, stripping, trimming, and reduction are performed to prepare thermally conductive graphene films with high thermal conductivity coefficient and strong electromagnetic shielding effectiveness. In the method, because of directly stripping the graphite oxide containing 40-60 wt % of moisture at a high temperature, the procedure of drying the graphite oxide is omitted, achieving low energy consumption and low manufacturing costs. Compared with preparing slurry by directly dispersing the graphite oxide, the concentration of the slurry after high temperature stripping is higher, and can reach 3-20 wt %.

Abstract: Improved dental appliances and polymeric sheet compositions are disclosed. The polymeric sheet compositions are useful for making dental appliances having outer layers comprised of a material having a modulus of from about 1,000 MPA to 2,500 MPA (“hard”) and an inner core comprised of elastomeric material or materials having a modulus of from about 50 MPa to 500 MPa (“soft”), which exhibit improved flexibility and strength, and better stain and tear resistance than currently available materials and dental appliances.

Abstract: Provided is a mountain-shaped structure material being excellent in stiffness and lightness. The present invention is a structure material including a resin, reinforced fibers and voids. The structure material has a specific bending stiffness represented as Ec1/3·??1 being 2.5 or more where a bending modulus is Ec and a density is ?. The structure material has a mountain shape.

Abstract: An optical film for a cover plate of a flexible display, which is disposed on the display side of the flexible display, is disclosed. The optical film sequentially includes an optical substrate layer adjacent to the flexible display, a first adhesive layer, a polarizing layer, a second adhesive layer and a surface functional film which is disposed on the folding side of the flexible display. The optical film having excellent bending resistance and recovery property can be obtained by adjusting the ratio of the integrated bending modulus of the optical substrate layer, the polarizing layer, and the surface functional film to the total thickness of the optical film.

Abstract: A shaped glass article is provided that is ultrathin, has two surfaces and one or more edges joining the two surfaces, and a thickness between the two surfaces. The shaped ultrathin glass article has at least one curved area with a non-vanishing surface curvature with a minimal curvature radius R if no external forces are applied. A method for producing a shaped glass article is also provided that includes providing an ultrathin glass with two surfaces and one or more edges joining the two surfaces, having a thickness between the two surfaces and shaping the ultrathin glass to a shaped ultrathin glass article by forming at least one curved area having a non-vanishing surface curvature with a minimal curvature radius R if no external forces are applied to the shaped ultrathin glass article.

Abstract: A bending actuator and methods for making and using the same. A beam of anisotropic polymer material, such as nylon, characterized by a greater degree of molecular orientation along a longitudinal axis than transverse to the longitudinal axis, has a heating element in thermal contact with at least one of a pair of opposing faces parallel to the longitudinal axis of the beam. The heating element in certain embodiments provides for photothermal activation of the bending actuator.

Abstract: One or more aspects of the present disclosure provide optical element transfer structures that include an optical element releasably coupled with a transfer medium and methods of making and using the optical element transfer structures. The optical element transfer structures can be used to dispose an optical element onto an article, whereby the optical element imparts a structural color to the article.

Abstract: A laminate-type power storage element includes a flat plate-shaped electrode body and an exterior body. The electrode body is configured by stacking a sheet-shaped positive electrode and a sheet-shaped negative electrode on either side of a separator. The exterior body is formed in a flattened bag-shape by thermocompression bonding peripheral edge regions of two opposing laminated films, to seal the electrode body inside the flattened bag-shape of the exterior body together with an electrolyte. The separator has a sheet-shaped substrate and at least one bonding layer formed on at least one surface of the substrate. A peripheral edge portion of the separator is sandwiched between and bonded by the two laminated films at a peripheral inside of the peripheral edge regions of the two laminated films.

Abstract: A formulation of a poly(propylene-co-ethylene) elastomer copolymer and a poly(ethylene-co-1-octene) block copolymer; a method of making the formulation; a manufactured article comprising or made from the formulation; and a method of using the manufactured article.

Abstract: Disclosed are multilayer films with high toughness performance, where the films have an elastic ethylene copolymer in the core layer.

Abstract: Various embodiments of multilayer polymer films and multilayer structures with enhanced tear strength are provided. Also disclosed are processes and systems for producing the disclosed multilayer polymer films. The disclosed films comprise a first polymer that may be cross-linkable upon exposure to radiation, and a second polymer that is cleaved or broken when exposed to irradiation. Layers comprising the first polymer are referred to as bulk layers, and layers comprising the second polymer are referred to as scission layers. Scission layers are positioned between bulk layers. The bulk and scission layers may comprise one or more sublayers.

Abstract: A composite film material usable in a data carrier card body includes a first outer plastic layer, an inner plastic layer and a second outer plastic layer, all the layers together forming a co-extruded composite. The plastic material of the first outer layer is a polyethylene terephthalate glycol copolymer (PETG) or contains a PETG, the plastic material of the inner layer is a thermoplastic copolyester elastomer (TPC) or contains a TPC, and the plastic material of the second outer layer is a PETG or contains a PETG.

Abstract: A method for manufacturing a structural assembly comprising at least two assembly components interconnected by means of a thermoplastic plastics material, and useful in the field of aviation or space travel. First, a first assembly component and a second assembly component are provided and arranged so as to form an arrangement. Second, the arrangement is subjected to creep forming at a temperature which is selected in such a way that the thermoplastic plastics material melts at least in part during the creep forming so as to connect the first assembly component and the second assembly component. The invention further relates to structural assemblies, in particular for an aircraft or spacecraft, and to an aircraft or spacecraft comprising a structural assembly of this type.

Abstract: A resin supply material is used for molding a fiber-reinforced resin and includes a continuous porous material and a resin. The continuous porous material has a bending resistance Grt of 10 mN·cm or more at 23° C., and a bending resistance ratio Gr of 0.7 or less, the bending resistance ratio Gr being expressed by the formula: Gr=Gmt/Grt Gmt: bending resistance of continuous porous material at 70° C.

Abstract: The invention provides a high strength stone plastic floor and manufacturing method thereof. The stone plastic floor comprises a PVC substrate and a surface layer on a surface of the PVC substrate. Compositions of PVC substrate comprise: PVC powder from 20 to 35 weight percent, calcium carbonate from 60 to 70 weight percent, stabilizer from 1 to 3 weight percent, flexibilizer from 1 to 3 weight percent, lubricants from 0.4 to 1 weight percent, and colorant from 0.4 to 1 weight percent. The high strength stone plastic floor does not contain plasticizer so environmental risks are completely avoided. The contractility is good. The high strength stone plastic floor is resistant to high temperature and direct sunlight. Compared with conventional stone plastic floor, lifespan of the present invention is prolonged. The PVC substrate of the floor can be combined with different layers and can integrate different advantages of other floors.

Abstract: A method and apparatus for a continuous compression molding machine. The continuous compression molding machine comprises a tooling die, extending through a heating zone and a cooling zone, a tooling sleeve, and a biasing system. The tooling sleeve corresponds to the tooling die and is for use in forming a thermoplastic composite part from a thermoplastic composite charge when the tooling sleeve with the thermoplastic composite charge is moved with respect to the tooling die through the heating zone and the cooling zone. The biasing system is configured to hold the thermoplastic charge at a first angle within the heating zone and hold the thermoplastic composite charge at a second angle within the cooling zone, as the tooling sleeve moves through the heating zone and the cooling zone with the thermoplastic composite charge. The first angle is different from the second angle.

Abstract: The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa·m1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m° C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.