80results about How to "Electrically insulating" patented technology

The invention provides basalt and polypropylene hybrid fiber reinforced concrete and a preparing method. Basalt fibers accounting for 0.1-0.5 part of the weight of a concrete matrix and polypropylene fibers accounting for 0.01-0.08 part of the weight of the concrete matrix are doped into the concrete matrix. (1) at the normal temperature, sand and stone are put into a blender to be blended for 60 s; (2) cement is put into the blender to be blended for 60 s; (3) water is added into the blender to be blended for 90 s to 120 s, and a concrete matrix is obtained; and (4) two kinds of fibers including the basalt fibers and the polypropylene fibers are mixed, and are scattered into the concrete matrix obtained in the step (3) to be blended for 120 s after the two kinds of fibers are highly scattered, and then the basalt and polypropylene hybrid fiber reinforced concrete is obtained. Compared with traditional concrete, the basalt and polypropylene hybrid fiber reinforced concrete can better adapt to complex environments such as high temperature, high heat, corrosion and the like, can be widely applied to roads, bridges, buildings, undergrounds and oceanographic engineering, and the concrete application scope is greatly expanded.

The invention provides a preparation method of basalt fibers, and relates to the technical field of basalt fibers, and the preparation method comprises the following steps: soaking basalt ore powder in a phosphoric acid solution and a sodium hydroxide solution, and drying at 100-120 DEG C; adding the raw material into a smelting furnace, adding a certain amount of carbon powder, continuously heating to 1,400-1,500 DEG C to obtain a basalt solution, and carrying out high-speed drawing molding by using a wire drawing machine to obtain basalt protofilaments, wherein a filament root cooler is usedfor cooling while a sodium carbonate solution is sprayed in the high-speed drawing molding process; carrying out infiltering modification treatment on the basalt protofilaments by using an infiltering agent, drying the basalt protofilaments subjected to infiltering modification treatment by using a hot-air blower, and carrying out unwinding and doubling twisting to obtain the basalt fibers. Moreover, the basalt fiber also has various excellent properties such as electrical insulation, corrosion resistance, combustion resistance and high temperature resistance, is excellent in mechanical property, and has the tensile strength improved by 15-30% compared with basalt fibers on the market at present.

The invention relates to an optical fiber type two-dimensional wind speed / direction measuring device belonging to the technical field of wind speed / direction measurement, digital image processing, and the like. The optical fiber type two-dimensional wind speed / direction measuring device comprises a base plate, an upper plate and a point light source, wherein the upper plate is parallel to the base plate; the point light source is fixed on the upper plate and is connected to the beginning end of optical fiber; the upper plate is provided with a hole for being penetrated by the optical fiber and fixing the optical fiber; the optical fiber is divided into two parts, one part from the point light source to the upper part is used for leading in the point light source, and a vertical part from the upper plate to bottom is an air flow sensing part; the tail end of the optical fiber is fixed with a camera; the camera comprises a microspur lens group and an area-array photosensitive device; light spots sent by the point light source pass through the optical fiber and then project on the camera; an image acquired by the camera is sent to an image processing and computing unit; and the image processing and computing unit computes wind speed and wind direction according to the light spot image. The invention also provides a two-dimensional wind speed / direction measuring method realized by the optical fiber type two-dimensional wind speed / direction measuring device. The invention has the advantages of simple structure, low cost, little power consumption, high sensitivity, moderate volume, and the like.

Provided are a urethane foam molding having high thermal conductivity and electrical insulating properties, and a method for manufacturing the urethane foam molding. The urethane foam molding has a base material composed of polyurethane foam, and composite particles blended with the base material and aligned so as to be joined with each other, and the composite particles are composed of thermally conductive particles composed of a nonmagnetic substance, and magnetic particles and insulating inorganic particles which are bonded to the surfaces of the thermally conductive particles by a binder. A powder of the composite particles can be manufactured by stirring a powder of the thermally conductive particles, a powder of the magnetic particles, a powder of the insulating inorganic particles, and a raw material powder including the binder, using a mixer granulator. The urethane foam molding is manufactured by injecting a raw material mixture, in which the powder of composite particles and the foam urethane resin raw material are mixed, into the cavity of a foaming die and performing foam molding while applying a magnetic field so that the magnetic flux density in the cavity is made substantially uniform.

The invention provides a insulation package reinforcement material which is electrically insulation packed by electrical insulation material having high electricity insulation property. A electrical insulation material packing layer is formed by packing conductive reinforcement materials for concrete buried in the concrete such as round steel, steel bar with rib with electrical insulation material, and producing surface of the electrical insulation material packing layer into a coarse surface, and is used as the insulation package reinforcement material buried in the concrete produced by the process.

Provided is a separator which shows excellent performance in electric insulation, electrolyte-holding property and ion- or electron-permeability and which can be stably manufactured. The separator is configured from a laminate non-woven fabric consisting of at least two layers, said layers including a non-woven fabric layer (layer I) that comprises a synthetic fiber having a fiber size of 0.1 mum or greater and less than 4.0 mum and a non-woven fabric layer (layer II) that comprises a thermoplastic resin fiber having a fiber size of 4.0-30.0 mum inclusive, and has a weight per area of 3.0 g / m2 or greater and less than 20.0 g / m2.

The invention provides a solder resist composition and a printed circuit board, concretely a solder resist composition with high reflectivity and high resolution capable of preventing the reflectivity from being reduced due to discoloration deterioration and a printed circuit board obtained by forming a solder film using the solder resist composition. The solder resist composition comprises: (A) carboxyl-containing resin without aromatic ring; (B) bi-acyl phosphine oxide type light polymerization initiator; (C) monoacyl phophine oxide type light polymerization initiator; (D) light polymerization monomer; (E) rutile type titanium oxide; (F) epoxide; (G) organic solvent; and (H) antioxidant.

The invention discloses an insulation coating for the surface of a low-voltage electric appliance and a preparation method thereof, and relates to the technical field of the insulation coating. The insulation coating is prepared from the following raw materials in parts by weight: 20-30 parts of rubber powder, 15-25 parts of epoxy resin, 10-15 parts of organic silicon resin, 6-15 parts of nanosilicon dioxide, 3-8 parts of nano-zinc oxide, 3-8 parts of nano-magnesium oxide, 3-8 parts of nano-aluminium oxide, 8-16 parts of glass fiber, 6-15 parts of attapulgite, 3-8 parts of calcium stearate, 1.2-2.5 parts of dispersant, 0.8-1.5 parts of defoamer, 2-5 parts of anti-aging agent, 1.5-3.2 parts of adhesive force accelerant and 3.6-6.2 parts of curing agent. The insulation coating has the advantages of high insulation performance, high binding force, easiness in even coating, good anti-aging performance, small possibility of oxidative cracking, long service life, high practicality, simple and easily-learnt preparation process, high operability and easiness in mass production and popularization.

The invention relates to a high-intensity electromagnetic shielding material for a new energy electric vehicle and a preparation method thereof. A symmetric multi-layered structure comprises an electromagnetic wave impedance matching layer located on the outermost layer, a wave absorbing layer located on the secondary outer layer and a reflective layer of a three-layer structure located in the middle, wherein the electromagnetic wave impedance matching layer comprises a glass fiber cloth with a layer of magnetic medium wave absorbing filler A modified polymer solution sprayed or brushed on thesurface; the wave absorbing layer comprises a glass fiber cloth with a layer of composite modified polymer solution of a magnetic medium wave absorbing filler A and a conductive wave absorbing fillerB sprayed or brushed on the surface; the reflective layer comprises a c11 layer formed by spraying or brushing a layer of conductive filler C modified polymer solution on the surface of a carbon fiber cloth, a c12 layer formed by spraying or brushing a layer of conductive filler C modified polymer solution on the surface of a carbon fiber felt, and a c13 layer formed by spraying or brushing a layer of conductive filler C modified polymer solution on the surface of the carbon fiber cloth; and the c12 layer is located between the c11 layer and the c13 layer, which solves the defects in the prior art as well as meets the electromagnetic shielding effectiveness and mechanical performance requirements of the material.

The invention discloses environment-friendly type ocean anticorrosive paint applicable to large ships. The environment-friendly type ocean anticorrosive paint is prepared from the following componentsin percentage by weight: 15 to 25 percent of epoxy resin, 5 to 8 percent of ultrafine barium sulfate, 8 to 12 percent of light calcium carbonate, 1 to 3 percent of a thixotropic agent, 5 to 10 percent of a curing agent, 0.1 to 0.2 percent of a film-forming catalyst, 1 to 3 percent of an alga removing agent, 1 to 2 percent of a dispersant, 25 to 35 percent of amine type resin, 0.05 to 0.1 percentof nano silicon dioxide, 5 to 8 percent of toner and the balance of silicon micro-powder. According to the paint disclosed by the invention, a small amount of the film-forming catalyst lanthanum oxideis added; under the catalysis effect, the strength and impermeability performance of a formed film are remarkably improved; the surface strength and anti-chloride ion permeability performance of thepaint are enhanced; the nano silicon dioxide is highly bound to the surface of the film, so that a nano-grade gap of the film is easy to fill and the strength of the film is enhanced.

The invention discloses a novel table tennis racket base plate which comprises a racket body, wherein the racket body comprises a core board layer and a panel layer; the upper surface and the lower surface of the core board layer are glued through a modified glutinous rice glue layer and the panel layer separately; the core board layer is made of a composite material sheet and the thickness is 3-5mm; the panel layer is made of a bamboo board and the thickness is 0.5-1mm; and the modified glutinous rice glue layer is made of modified glutinous rice glue and the thickness is 0.3-0.8mm. The novel table tennis racket base plate is uniform in density and equal in force reaction rates in various directions, has relatively high stability, high strength and sufficient toughness and has multiple excellent properties, such as electrical insulating property, corrosion resistance, combustion resistance and high-temperature resistance, the service life of a table tennis racket is prolonged, and meanwhile, the production cost is relatively low.

An aluminum nitride (AlN) thin-film is applied over thin-film metallic circuitry such as an environmental sensor, on the side edges of electrode pads, and / or over some or all of the surface area of a substrate. The thin-film acts to protect the encapsulated structures from exposure to oxidation and from reducing and vacuum environments, electrically insulates the encapsulated structures from other structures, and helps to securely adhere the structures to the substrate surface. The AlN thin-film can also enable multiple IC layers to be stacked on top of each other, with AlN thin-film interlayers employed between IC layers such that each IC layer is separated and electrically insulated from adjacent layers.

The invention discloses a heat insulation-type cable, which comprises a cable core. An inner sheath and an outer sheath are extruded outside the cable core; the cable core is composed of a triangular support, three insulated wire cores mutually extruded inside the triangular support and ground wires located at three vertex angles of the triangular support; a ceramic fiber is arranged between the triangular support and the inner sheath; and an elastic buffer layer with a thickness of 2 to 5 mm, a metal armored layer with a thickness of 2 to 4 mm and a rock wool heat insulation layer with a thickness of 3 to 6 mm are sequentially arranged between the inner sheath and the outer sheath. Through arranging multiple heat insulation structures, the cable of the invention has the advantages of good heat insulation performance, high temperature resistance, good heat stability, low heat conductivity and the like.

The invention discloses a temperature-resistant and cold-resistant control cable with a fluoroplastic insulating thermoplastic elastic sheath. The cable comprise conductors, a wrapping tape and a second sheath. The wrapping tape is wound on the outer surface of the side edge of first sheaths; fillers are filled between the first sheaths and the wrapping tape. The outer surface of the side edge ofthe wrapping tape is provided with an armor tape, the outer surface of the side edge of the armor tape is sleeved with the second sheath, the number of the conductors and the number of the first sheaths are respectively seven, the thickness of the second sheath is larger than that of the first sheath, the second sheath and the first sheaths are made of fluoroplastic materials; and the wrapping tape is made of non-woven fabric materials. According to the temperature-resistant and cold-resistant control cable with the fluoroplastic insulating thermoplastic elastic sheath, the control cable hasa double-thermal-insulation structure, the temperature resistance and cold resistance of the cable can be effectively improved, the cable can be suitable for a high-temperature or low-temperature environment, and the application range of the cable is widened.

The invention discloses a corrosion-resistance and energy-conservation water pump for agricultural water conservancy. The water pump comprises a water pump body, a permanent magnet motor, a water current driving power generation device and an accumulator; a portable handle is arranged at the upper end of the water pump body; a detachable sealing connection buckle is arranged between the portable handle and the water pump body; a metal severe corrosion resisting paint layer is arranged on the outer surface of the water pump body; a fixed base is arranged at the lower end of the water pump body;and a water inlet is formed between the fixed base and the water pump body. The corrosion-resistance and energy-conservation water pump for agricultural water conservancy is provided with the metal severe corrosion resisting paint layer, the permanent magnet motor and the water current driving power generation device, has the characteristics of rust resistance, chemical medium corrosion resistance, acid and alkali resistance, water resistance and heat dissipation, can adjust the frequency along with the operation demands, meanwhile, can generate electricity for the permanent magnet motor in the operating process, is suitable for different working conditions, and achieves better application prospect.

The present invention provides a chemical pump casing, and material formula and manufacturing method thereof, and belongs to the technical field of composite materials. The chemical pump casing material formula comprises the following components by weight: 20-50 parts of a PET powder, 10-40 parts of a UV glue and 30-50 parts of glass fiber. The manufacturing method of the chemical pump casing comprises the steps of: A, material preparation: uniformly stirring 20-50 parts of a PET powder, 10-40 parts of a UV glue and 30-50 parts of glass fiber to form a paste composite material; B, injection molding: injecting the composite material obtained in the step A into a pump casing mold by an injection molding machine, and releasing to obtain a pump casing blank; and C, UV curing: curing the pump casing blank under ultraviolet light to obtain the casing. The pump casing of the present invention has the advantages of stiffness, high temperature resistance and corrosion resistance, and the manufacturing method of the pump casing is simple and easy to implement.

The invention relates to the technical field of three-element material power batteries, and particularly provides a high-temperature three-element material power battery which comprises a positive pole, a diaphragm, a negative pole, an electrolyte, a cover plate and a shell, wherein the active substance of the positive pole is a three-element positive pole material of which the nickel:cobalt:manganese ratio is 1:1:1. The positive pole current collector is carbon-coated aluminum foil. The diaphragm is a coated diaphragm, the diaphragm matrix is polypropylene, and the coating is ceramic. The negative pole is natural flaky graphite powder. The electrolyte comprises an organic solvent and an additive; the organic solvent is a mixed solution composed of 30-35 wt% of ethylene carbonate, 35-40 wt% of methylethyl carbonate and 30-35 wt% of diethyl carbonate; and the additive is a mixed solution composed of vinylene carbonate which accounts for 2-2.5 wt% of the organic solvent, 1,3-propenyl carbonate which accounts for 2-2.5 wt% of the organic solvent and propenyl sulfite which accounts for 2-2.5 wt% of the organic solvent; and 0.3-0.5mu m silica gel is coated inside the shell. The test on the product under the condition of 3000 cycles or above at high temperature is passed. In the pin-prick test period, no naked fire is seen, the shell does not explode, and thus, the power battery has higher safety.

The invention discloses a preparation method for enhancing interface performance of basalt. Firstly, a PAN-basalt nano-coated fiber is prepared by using the electrospinning technology; then the prepared PAN-basalt nano-coated fiber is carbonized to obtain a core-structured basalt carbonized nano-material with enhanced interface performance; finally the prepared core-structured basalt carbonized nano-material and resin matrix are solidified to form a composite with enhanced interface performance. The composite has the advantages of a large surface area, relatively high electrical conductivity,complete structure and good absorption performance of a cortical carbon nano-material, excellent mechanical properties of a core layer basalt fiber, and can simultaneously exert the advantages of thetwo materials. The preparation method for enhancing the interface performance of the basalt has the advantages that less pollution to environment is generated, can be widely applied to the field of fiber reinforcement materials, and solves the problem of poor interfacial adhesion of the basalt fiber reinforced resin matrix composites in the prior art, further optimizes the performance of the composites, and can promote design of the new fiber composites, which facilitates better application and development.

The invention discloses a flame-retardant PBT / PA alloy material and a preparation method thereof. The alloy material comprises the following raw materials in parts by mass: 30-42 parts of a PBT resin, 8-15 parts of a transparent PA resin, 6-12 parts of a glow wire temperature increasing agent, 7-12 parts of brominated polystyrene, 2-5 parts of antimonide, 20-35 parts of glass fibers, 3-5 parts of a compatilizer, 0.1-1 part of an antioxidant and 0.1-1 part of a lubricating agent. The PBT / PA alloy material disclosed by the invention is enhanced by the glass fibers and is excellent in mechanical property, a novel glow wire temperature increasing agent is adopted, the material can reach the level V0, high glow wire temperature and high CTI of the material can be obtained, and the alloy material can be used for preparing contactors and circuit breakers.

The invention provides a manufacturing method for a spray pipe of a propeller. The method includes the following steps that (1) phenolic aldehyde glass fiber reinforced moulding compound is weighed and placed in an oven to be baked; (2) a spray pipe mould is heated and evenly coated with release agents; (3) the moulding compound is placed in an upper mould cavity of the mould, the mould is closed, and pressure is injected into the mould; (4) when the moulding compound is softened in the upper mould cavity, the mould is pressurized, and after the moulding compound is completely injected into the mould cavity, the mould is subjected to air bleeding, low-temperature vulcanization and pressurization; (5) turn-on and turn-off of a thermostat and air bleeding of the mould are controlled; (6) after the mould is cooled, the mould is opened; and (7) a product is taken out and placed in a cold mold to be subjected to positioning treatment, after the product is cooled, burrs are removed, powder is blown off, and the spray pipe is obtained. The manufacturing method for the spray pipe of the propeller has the advantages that operation is simple and convenient and the application range is wide. The spray pipe obtained through the manufacturing method has the characteristics of high-temperature resistance, corrosion resistance and insulativity. Various technical indexes are superior to technical indexes in common processes.

The invention discloses a novel neodymium iron boron magnet. The novel neodymium iron boron magnet comprises a neodymium iron boron substrate, wherein the outer surface of the neodymium iron boron substrate is sequentially provided with an electric insulation coating, an anticorrosion layer and a galvanized layer from inside to outside, wherein the electric insulation coating is a nano silicon nitride coating, the thickness of the electric insulation coating is 5 to 10 micrometers, and the anticorrosion layer is an epoxy resin coating. The thickness of the epoxy resin coating is 30 to 50 micrometers. The novel neodymium iron boron magnet has technical effects that the outer surface of the neodymium iron boron substrate is sequentially provided with the electric insulation coating, the anticorrosion layer and the galvanized layer from inside to outside, by adopting the nano silicon nitride, the novel neodymium iron boron magnet is insulated to electricity, the epoxy resin coating improves the corrosion resistance, and the novel neodymium ion boron magnet which can be insulated to the electricity and also can resist the corrosion can be obtained.

The invention discloses a crosslinked polyethylene insulated multi-core flame retardant cable, which comprises a cable core. The gap of the cable core is provided with an inorganic mineral oxygen barrier layer; the cable core is wrapped with a first polyester tape; a semi-conductive shielding layer is extruded outside the polyester tape; a steel strip armored layer is arranged outside the inner semi-conductive shielding layer; a rock wool heat insulation layer is extruded outside the steel strip armored layer; and the outermost layer of the cable is provided with a silica fireproof sleeve; the cable core is formed by stranding a ground wire and two insulated wire cores arranged symmetrically with the ground wire as an axial center in a horizontal mode; and the cable core is internally provided with a group of through holes symmetrically with the ground wire as the axial center. The crosslinked polyethylene insulated multi-core flame retardant cable has the advantages of good flame retardancy, high temperature resistance, good cooling performance, fire resistance, good insulated performance and the like.

The invention discloses a halogen-free phosphorus-free flame-retardant thermoplastic alloy and a preparation method thereof. The halogen-free phosphorus-free flame-retardant thermoplastic alloy is prepared from the following components in parts by weight: 50 to 70 parts of polyolefin, 25 to 40 parts of a thermoplastic elastomer, 5 to 10 parts of a compatilizer, 30 to 50 parts of calcium gluconate,10 to 15 parts of melamine cyanuric acid, 5 to 10 parts of hydrotalcite, 3 to 5 parts of zinc stannate, 0.1 to 0.5 part of an antioxidant and 3 to 5 parts of a silicone lubricant. According to the invention, the thermoplastic alloy is prepared by adding calcium gluconate; after combustion of calcium gluconate, calcium carbonate and carbon dioxide are produced, calcium carbonate can rapidly expandto form porous calcium carbonate under the action of carbon dioxide, the good flame-retardant synergistic effect is achieved, the high mechanical property and the high flame-retardant effect of the thermoplastic alloy are ensured, meanwhile, the smoke generation amount can be reduced, emission of toxic substances is effectively reduced, the environment is protected, and the mechanical property and the chemical property of the alloy are not affected.

The invention discloses a refractory material for a building wall and a preparation method thereof. The refractory material is prepared from the following components in parts by weight: 6 to 10 parts of cement, 3 to 6 parts of quick lime, 1 to 4 parts of silica gel powder, 3 to 8 parts of coal-ash powder, 2 to 6 parts of cellulose ether, 1 to 4 parts of a hydrophobic agent, 1 to 5 parts of short-cut fiber and 18 to 35 parts of water. The preparation method comprises the following steps: adding cement, quick lime, silica gel powder and coal-ash powder according to the above-mentioned parts by weight into a stirrer, carrying out mixing under stirring for 6 to 8 minutes so as to obtain a mixed material, then adding cellulose ether, the hydrophobic agent and the short-cut fiber into the mixed material, carrying out stirring for 4 to 8 minutes, adding water, and carrying out stirring for 15 to 35 minutes so as to be able to obtain the refractory material for use. The refractory material provided by the invention has the advantages of good toughness, excellent fire resistance, etc.

The invention belongs to the technical field of table tennis bats, and particularly relates to a novel table tennis bat base plate of a basalt composite material. The novel table tennis bat base plate is mainly formed by processing multi-layer basalt fiber cloth through a technique of resin and rubber mixed liquid soaking and integral mold pressing, wherein the basalt fiber cloth is subjected to degreasing treatment before being soaked by resin and rubber mixed liquid. The basalt fiber cloth is firstly dried and degreased, a basalt fiber and a resin fiber are crosslinked through a combining bond through resin and rubber mixed liquid soaking to form relatively high tenacity and strength. After the table tennis bat base plate is processed, the whole table tennis bat is uniform in density; the force reaction speeds in various directions are the same; the novel table tennis bat base plate has relatively high stability, high strength and sufficient tenacity and also has excellent properties of electric insulating property, corrosion resistance, combustion resistance, high temperature resistance and the like; the service life of the table tennis bat is prolonged; meanwhile, the production cost is relatively low; the problems that a carbon fiber product is overhigh in price and the market share is over-low are solved; and the economic benefits are significant.

The invention discloses a compound sound insulation material and a preparation method thereof. The compound sound insulation material contains the following materials by weight percent: 40% of vinyl chloride acetate resin, 10-20% of low-density polyethylene, 20-30% of methyl vinyl silicone rubber, 5-10% of a high molecular compatilizer, 2-3% of a diluent, 1-5% of superfine fiber, and 1-2% of an antioxidant. The preparation method comprises the following steps: S1, weighing and preparing materials: weighing the materials according to weight percentage and marking for storage; S2, feeding and blending; S3, plastifying; and S4, performing extrusion molding. According to the invention, due to the setting of components including vinyl chloride acetate resin, low-density polyethylene, methyl vinyl silicone rubber, high molecular compatilizer, diluent, superfine fiber and antioxidant, so that the sound insulation effect of the compound sound insulation material is improved; and due to the setting of preparation procedures of weighing and preparing materials, feeding and blending, plastifying and performing extrusion molding. Therefore, the quality of the sound insulation material is promoted, and further the market competitiveness of the product is promoted.

Disclosed is a solder resist composition with high reflectivity and high resolution that includes (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) melamine or a derivative thereof, (D) a photopolymerizable monomer, (E) rutile titanium dioxide, (F) an epoxy compound, and (G) an organic solvent, and that prevents decreases in reflectivity that are attributable to discoloration and deterioration. Also disclosed is a printed circuit board obtained by forming a solder resist using the solder resist composition.

The invention provides a high-voltage LED panel lamp. The high-voltage LED panel lamp comprises a lighting assembly which includes a light guide board, LED lamp strips and light transmission insulation medium parts. LED lamps of the LED lamp strips are arranged in the manner of facing the light guide board. The light transmission insulation medium parts are arranged between the LED lamps and the end surface of the light guide board. The light transmission insulation medium parts enjoy electric isolation performance. Therefore, an insulating property is improved. As a result, a same low-voltagerequirement is met without adopting a driving power source with the same level of electric isolation performance or a housing with same insulation performance in the prior art. A driving power sourcewith lower cost is adopted so that cost is lowered.