47results about How to "Good air purification function" patented technology

The invention relates to a fresh air purifying system with an intelligent automatic control function. The fresh air purifying system comprises an air inlet device, an air outlet device, an air channel, an air filtering device, a fresh air device and an intelligent control module. The air inlet device is provided with an air inlet and an axial flow fan. The air outlet device is provided with an air outlet and a centrifugal fan. The air inlet device and the air outlet device are connected through the air channel. The air filtering device is arranged in the air channel. The fresh air device is opposite to the air inlet, and comprises a multi-purpose air opening communicating with the outside and an air regulation plate rotationally arranged in the multi-purpose air opening. The intelligent control module is configured to enable the fresh air purifying system to operate in different modes according to received air quality information. The air purifying system can be utilized for lowering noise, dissipating heat and flexibly adjusting the fresh air amount between non-fresh air and pure fresh air, optimum indoor air quality parameters are automatically achieved and maintained in real time, and meanwhile electric energy is saved.

The invention relates to an air purifying device and specifically relates to a split type air-purifying fresh-air draught fan. The whole machine of the split type air-purifying fresh-air draught fan is divided into two parts, namely, an outdoor unit and an indoor unit, wherein a fan is mounted in the outdoor unit; a control panel is arranged on the indoor unit; the control panel is connected with a PM2.5 sensor, a TVOC sensor and a temperature and humidity sensor and is provided with a control and detecting circuit; outdoor air and air discharged from the interior are mixed by an air mixing chamber at an air inlet of the fan of the outdoor unit and then are fed into the interior by the fan; the energy of the indoor air is fully utilized and the energy-saving effect is obvious. The characteristics of an indoor air purifying device and an outdoor fresh air fan are synthesized by the split type air-purifying fresh-air draught fan; the manufacturing cost is lowered; the usage ratio of the energy of the indoor air reaches up to above 95%. The design for an air filtering channel is optimized by the split type air-purifying fresh-air draught fan; the whole machine has an excellent air purifying function; the strainer exchanging and ultraviolet ray maintenance are very convenient; the split type air-purifying fresh-air draught fan has an automatic air monitoring and intelligent control function and is beneficial to popularization and application.

The invention discloses a diatom clay plate. The diatom clay plate comprises, by weight, 5 to 35 parts of diatom minerals, 65 to 95 parts of clay and 0 to 10 parts of tourmaline. The invention also discloses a preparation method of the diatom clay plate. The preparation method comprises mixing the raw materials and water, processing a clay plate according to a clay plate shape and carrying out drying and calcination. Compared with the traditional clay plate product, the diatom clay plate has the advantages of light weight, humidity control, good thermal insulation properties and air purification, is suitable for building inner wall surfaces and solves the problems of the traditional clay plate in interior decoration.

The invention belongs to an air cleanser in the field of environmental protection. The air cleanser is composed of 30-50% of a modified bentonite formaldehyde adsorbent, 5-10% of modified bentonite, 10-20% of modified meerschaum, 10-20% of kaolin, 0.2-1% of a nano-silver base antibacterial agent, 4-8% of titanium dioxide, 5-15% of calcium carbonate, 2-6% of diatomite tailings, 1-5% of methyl cellulose, and 0.3-1% of wooden fiber. The modified bentonite formaldehyde adsorbent, modified bentonite, kaolin, modified meerschaum, the nano-silver base antibacterial agent, titanium dioxide, calcium carbonate, diatomite tailings, methyl cellulose and wooden fiber are put into a mixer to be mixed and stirred uniformly; and a mixture obtained passes through a disc granulator to prepare a granular product with the particle size of 1-6 mm. the defect that existing air purifying materials have low purification efficiency and have hazardness is overcome. The air cleanser provided by the invention has high purification efficiency, has no toxicity, and is pollution-free.

The invention relates to an air-conditioning air purification system with a remote control function. The air-conditioning air purification system with the remote control function comprises an air inlet device, an air outlet device, an air duct, an air filtering device, an air conditioning device and a remote control device, wherein the air inlet device is provided with an air inlet and an axial flow fan, and the air inlet device is used for guiding air into the air-conditioning air purification system; the air outlet device is provided with an air outlet and a centrifugal ventilator, and the air outlet device is used for exhausting air out of the air-conditioning air purification system; the air inlet device and the air outlet device are connected through the air duct, and the air duct is used for guiding air between the air inlet device and the air outlet device; the air filtering device is arranged in the air duct and used for filtering air; an evaporator of the air-conditioning device is arranged in the air duct; and the remote control device is configured to receive a remote control command from a user so that the user can remotely start the air-conditioning air purification system and control the operation of the air-conditioning air purification system. By the adoption of the air-conditioning air purification system, noise can be lowered, heat can be dissipated, the energy utilization rate is increased, and remote control is achieved.

The invention relates to the field of paints, and discloses an air-purification diatomite internal wall decoration powder paint and a preparation method thereof. The powder paint comprises 40-50 parts of diatomite, 10-20 parts of meerschaum, 10-20 parts of air purification particle, 6-10 parts of silica sol, 4-6 parts of Portland cement, 4-6 parts of hyacinth bletilla powder, 1-2 parts of carboxymethyl cellulose, 1-2 parts of phenoxy resin, 0.5-1.5 parts of glutaric dialdehyde, 0.5-1.5 parts of chitosan, 0.5-1.5 parts of defoaming agent and 0.5-1.5 parts of dispersing agent. The air-purification diatomite internal wall decoration powder paint has the advantages of favorable water resistance, high adsorption capacity, long purification time efficiency and favorable air purification effect, and has the air purification function. The powder paint has favorable antibacterial and mildewproof actions.

The invention relates to a convection-type heater with an air purifying function. The convection-type heater comprises a casing and is characterized in that an air outlet louver window is arranged on the upper side wall of the casing; an air return louver window is arranged on the lower side wall, opposite to the air outlet louver window, of the casing; a cross-flow fan and an electric heating unit are arranged in the inner cavity of the casing; an air inlet of the cross-flow fan faces the air return louver window, and an air outlet of the cross-flow fan faces the air outlet louver window to form an air inlet / outlet channel structure; the electric heating unit is arranged between the air outlet of the cross-flow fan and the air outlet louver window to form a convection-type circulating hot air structure; an air filtering layer is arranged at the air return louver window to form a convection-type heater structure with the air purifying function. According to the convection-type heater with the air purifying function, the problems of poor air purification effect and low heating efficiency in the prior art can be solved; the convection-type heater with the air purifying function has the prominent beneficial effects that the air purifying effect is good, the heating efficiency is high, and particularly, the quality and the effect on filtering organic substances, such as bacteria, ozone and formaldehyde, are good.

The invention relates to wood-plastic composite materials, in particular to a nano modified wood-plastic composite plate and a preparation method thereof. The preparation method includes stirring polyvinyl chloride plastic particles, tribasic lead sulfate, nano kaolin, talcum powder, terpene resin, polyolefin elastomer, butyl stearate and oxidic polyethylene, then extruding and pelleting to obtain modified plastic particles; mechanically stirring and mixing the modified plastic particles, azodicarbonamide and wood powder again, and then melting, mixing, extruding and foaming by an extruder to obtain the nano modified wood-plastic composite plate. The nano modified wood-plastic composite plate is convenient to produce and manufacture, is high in mechanization degree and low in required labor during production and low in production cost, and further, is low in plastic usage, environment-friendly, low in density, excellent in impact resistance, long in service life and convenient to mount and maintain, has a certain function of air purifying, and can be widely applied to places such as high-end buildings, homes and offices.

The invention relates to a fresh air purification system. The fresh air purification system comprises an air feeding device, an air exhausting device, an air duct, an air filtering device and a fresh air device. The air feeding device is provided with an air inlet and an axial flow fan and used for introducing air into the fresh air purification system. The air exhausting device is provided with an air outlet and a centrifugal fan and used for exhausting the air from the fresh air purification system. The air duct connects the air feeding device with the air exhausting device and is used for guiding the air between the air feeding device and the air exhausting device. The air filtering device is arranged in the air duct and used for filtering the air. The fresh air device is arranged opposite to the air inlet and comprises a multipurpose air opening communicating with the outdoor and an air volume regulation plate rotationally arranged in the multipurpose air opening. The fresh air purification system can lower noise, dissipate heat and flexibly adjust the fresh air volume between absence of fresh air and pure fresh air.

The invention relates to the field of coating and discloses a water-resistant net-flavor waterborne ceramic simulating coating and a preparation method thereof. The coating comprises the following components in parts by mass: 10-20 parts of calcite powder, 10-20 parts of heavy calcium carbonate powder, 8-12 parts of calcium carbonate, 2-4 parts of bletilla striata powder, 1-3 parts of corn starch, 0.5-1.5 parts of carboxymethyl cellulose, 0.5-1.5 parts of phenoxy resin, 0.5-1.5 parts of glutaraldehyde, 1-3 parts of air purifying particles and 45-55 parts of water. The water-resistant net-flavor waterborne ceramic simulating coating provided by the invention has the advantages of relatively good water resistance, air purifying function, large adsorption capacity, long purifying time and good air purifying effect.

The invention relates to the field of coatings, and discloses environment-friendly polyvinyl acetate emulsion paint and a preparation method thereof. The emulsion paint comprises the following components in parts by mass: 40-50 parts of polyvinyl acetate emulsion, 4-6 parts of kaolin, 1-2 parts of phenoxy resin, 2-4 parts of bletilla striata powder, 1-3 parts of corn starch, 0.25-0.75 part of glutaraldehyde, 2-4 parts of air purification particles, 0.04-0.06 part of a thickening agent, 0.04-0.06 part of a defoaming agent, 0.04-0.06 part of a dispersing agent and 35-45 parts of water. The environment-friendly polyvinyl acetate emulsion paint provided by the invention has an air purification function, is large in adsorption capacity, long in water purification lasting time and good in air purification effect, and meanwhile is relatively good in filming property, water resistance and soiling resistance.

The invention discloses air purifying putty and preparation and application methods thereof and belongs to the technical field of building functional decoration materials. The air purifying putty comprises, by weight, 40-70 parts of shell powder, 10-20 parts of ground calcium carbonate powder, 5-15 parts of talcum powder, 1-5 parts of guar gum, 1-5 parts of basalt fiber, 0.5-2 parts of hydroxypropyl methyl cellulose ester and 1-5 parts of expanded vermiculite. The air purifying putty has the advantages that the air purifying putty replaces traditional putty, and the air purifying putty does not contain toxic and harmful substances, can absorb and decompose toxic gas, can purify air and regulate indoor humidity and can provide a safe, healthy and fresh working and living environment for people.

The invention provides a multifunctional anti-influenza solid aromatic agent. The solid aromatic agent is characterized by being prepared from the following components in parts by weight: 1-5 parts of gelatin, 0.5-2 parts of carrageenan, 0.5-2 parts of sodium alginate, 0.5-2 parts of agar, 0.5-5 parts of spice, 0.01-1 part of bactericide, 10-20 parts of absolute ethanol, 0.01-10 parts of bamboo vinegar and 0.01-0.5 part of defoaming agent, as well as aqueous extracts of the following components in parts by weight: 1-20 parts of lonicera japonica, 1-20 parts of wild chrysanthemum flower, 1-20 parts of licorice root, 2-6 parts of black bean, 0.3-0.7 part of fresh ginger, 2-7 parts of kudzu vine root, 0.1-0.8 part of pinellia ternata and 1-3 parts of pericarpium citri reticulatae, wherein the concentration of effective component contents of the aqueous extracts of lonicera japonica, wild chrysanthemum flower, licorice root, black bean, raw ginger, kudzu vine root, pinellia ternata and pericarpium citri reticulatae are 2-3 percent, and the balance of water. The multifunctional anti-influenza solid aromatic agent has the characteristics of high transparency, high gel strength, stable performance and long storing and using time, and is capable of absorbing foreign odor and foul smell in the air and killing influenza germs in the air, so that the air quality can be completely improved.

The invention relates to a fresh air purification system with a remote control function. The fresh air purification system with the remote control function comprises an air inlet device which is provided with an air inlet and an axial flow fan, an air outlet device which is provided with an air outlet and a centrifugal fan, an air duct connecting the air inlet device with the air outlet device and used for guiding air between the air inlet device and the air outlet device, an air filtering device arranged in the air duct and used for filtering air, a fresh air device opposite to the air inlet and comprising a multipurpose air port and an air amount adjusting plate rotationally arranged in the multipurpose air port, and a remote control device configured to receive a remote control command from a user. By means of the fresh air purification system, noise can be reduced, heat can be dissipated, the fresh air amount is flexibly adjusted between zero fresh air and pure fresh air, and the fresh air purification system is further allowed to be remotely controlled.

The invention relates to an air purification system with an air-conditioning device. The air purification system with the air-conditioning device comprises an air feeding device, an air exhausting device, an air duct, an air filtering device and the air-conditioning device. The air feeding device is provided with an air inlet and an axial flow fan and used for introducing air into the fresh air purification system. The air exhausting device is provided with an air outlet and a centrifugal fan and used for exhausting the air from the fresh air purification system. The air duct connects the air feeding device with the air exhausting device and is used for guiding the air between the air feeding device and the air exhausting device. The air filtering device is arranged in the air duct and used for filtering the air. An evaporator of the air-conditioning device is arranged in the air duct. The air purification system with the air-conditioning device can lower noise, dissipate heat and improve energy utilization efficiency.

The invention discloses a nanometer anion function material for wallpaper and a preparation method thereof. The nanometer anion function material is prepared from, by weight, 20-30 parts of hydromica, 18-26 parts of magnetic wave stone, 10-20 parts of palygorskite, 14-22 parts of schorlite, 15-25 parts of montmorillonoid, 5-10 parts of titanium dioxide, 21-29 parts of Huangshan ballstone, 10-15 parts of periporate konilite and 5-10 parts of heavy calcium powder. According to the nanometer anion function material for the wallpaper, the magnetic wave stone, the schorlite, the Huangshan ballstone and the like serve as main raw materials, the prepared anion function material has a function of permanently releasing anions, can release a large number of anions and has a removing effect on methanal, ammonia, benzene, TVOC and other poisonous and harmful gases released by various kinds of indoor decorative materials and harmful gases produced by smoking, cooking oil fume and the like, the elimination rate is larger than 95%, the air purification function is superior, and the nanometer anion function material also has sterilization and disinfection effects, enables bacteria and viruses to have structural changes or energy transfer and leads the bacteria and the viruses to death.

The invention discloses a ventilation sound proof window which comprises a window frame. The window frame comprises a ventilation portion and a sound proof transparent portion. The front face and the back face of the ventilation portion are each provided with a sound proof steel plate. The front face and the back face of the sound proof transparent portion are each provided with tempered glass. One end of the sound proof steel plate on the front face of the ventilation portion is provided with a waterproof shutter ventilation opening. The other end of the sound proof steel plate on the back face of the ventilation portion is provided with a waterproof shutter ventilation opening. The window frame is formed by combining square pipes filled with flame retardant sponge, and an air exchange fan is arranged in the ventilation portion. The ventilation sound proof window keeps the good sound proof effect while having the good ventilation performance, perfectly combines the ventilation function and the sound proof function, further has the good air purification function, and can improve indoor air quality and improve living environment.

The invention discloses a preparation method of a composite material for high-efficiency purification of indoor air. The preparation method comprises the following steps: uniformly stirring tourmalinepowder, nano-vermiculite powder, nano-diatomite and talcum powder, adding modified fir powder, uniformly mixing, calcining, grinding and then adding alumina powder, oxidized starch, microcrystallinecellulose, bamboo charcoal fibers, polyurethane resin and natural perfumes, uniformly mixing and granulating to obtain the composite material for the high-efficiency purification of the indoor air. The composite material obtained by the invention can remove organic volatiles such as formaldehyde, toluene, xylene, sulfur dioxide and VOC, has a very good air purifying function, can be applied to automobile air filter element particles, an air purifying particle packet or a refrigerator deodorant, and is high in purification efficiency, free of toxicity and pollution, can be recycled and is low in cost.

The invention discloses a nano-photocatalyst aluminum alloy air supply outlet which comprises a purifying device aluminum alloy outer frame and aluminum alloy air supply outlet shutters. Special-shaped groove aluminum frames are further connected to the four inner corners of the purifying device aluminum alloy outer frame. Nano-photocatalyst honeycomb filters are arranged in the special-shaped groove aluminum frames. An ultraviolet lamp tube is further arranged between every two nano-photocatalyst honeycomb filters. The bottoms of the ultraviolet lamp tubes are connected to an ultraviolet lamp tube socket bracket. The ultraviolet lamp tube socket bracket is connected with the purifying device aluminum alloy outer frame. The aluminum alloy air supply outlet shutters are further arranged on the right sides of the nano-photocatalyst honeycomb filters. An aluminum alloy air supply outlet flange frame is further connected to an air port of the purifying device aluminum alloy outer frame. The nano-photocatalyst aluminum alloy air supply outlet is reasonable in structure, has powerful bactericidal ability, enables the cleanliness of discharged air to be quite high, and also has powerful deodorization, mould-proof, antifouling, self-cleaning and air purification functions.

The invention relates to the field of coatings and discloses a water-tolerant flavor purification type polyvinyl alcohol water-soluble coating and a preparation method thereof. The coating comprises the following components in parts by mass: 5-15 parts of polyvinyl alcohol, 10-20 parts of calcium carbonate, 4-6 parts of talcum powder, 1-3 parts of phenoxy resin, 2-4 parts of rhizoma bletillae powder, 1-3 parts of corn starch, 0.5-1.5 parts of glutaraldehyde, 1-3 parts of air purification particles and 55-65 parts of water. The water-tolerant flavor purification type polyvinyl alcohol water-soluble coating has an air purification function and a good air purification effect and is relatively good in water tolerance, large in adsorption capacity and long in purification timeliness.

The invention discloses a protective environment-friendly mask. The protective environment-friendly mask comprises a mask frame, a silicone pad, an inhalation valve, an exhalation valve and fixing belts; the mask frame is provided with a first accommodating groove and a second accommodating groove; the first accommodating groove is located above the second accommodating groove; the silicone pad is arranged on the mask frame and provided with a folding portion; the inhalation valve is arranged in the first accommodating groove and comprises a filter box, a mucous membrane filter and a mucous membrane filter cover; the filter box comprises a casing, a first filter and a second filter; the mucous membrane filter is arranged on the inner side of the casing; the mucous membrane filter cover covers the mucous membrane filter; the exhalation valve is arranged in the second accommodating groove and comprises an exhalation adjustment plate and an exhalation cover; the exhalation adjustment plate is arranged in the second accommodating groove in a floatable mode; the exhalation cover is arranged on the outer side of the second accommodating groove; the fixing belts are connected with the bilateral sides of the mask frame respectively. Accordingly, the inhaled air is purified through the silicone pad, the inhalation valve and the exhalation valve which are arranged in the mask and accordingly the physical health of people is guaranteed.

The invention discloses an epidemic prevention type intelligent induction disinfection closestool which comprises a closestool body, a flushing structure is installed on one side wall of the closestool body, a closestool ring and a closestool cover are hinged to the top of one side of the closestool body, a first ultraviolet germicidal lamp is installed on one side wall of the closestool cover, and a second ultraviolet germicidal lamp is installed on the side wall, away from the first ultraviolet germicidal lamp, of the closestool cover. An infrared detector is installed on one side wall of the can cover, a controller is installed on one side wall of the can body, a driven gear is installed on one side wall of the can cover, a protection box is installed on one side wall of the can body, and a servo motor is installed in the protection box. Through the arrangement of a barrel cover, a first ultraviolet sterilization lamp, a second ultraviolet sterilization lamp, a driven gear, a protection box, a servo motor, a driving gear, a disinfectant box, a first water pump, a spray head, an infrared detector and a controller, intelligent induction disinfection can be conducted on the whole, so that bacteria and virus residues are effectively prevented, and the whole use is more sanitary; and the safety is improved.

The invention belongs to the technical field of air purification, and particularly relates to an air freshener containing natural substances, and a preparation method thereof. The preparation method comprises the following steps: crushing dry petals of iris tectorum maxim, dispersing the crushed petals in water, carrying out heating extraction, naturally cooling to room temperature after extraction, filtering to obtain an iris tectorum maxim extracting solution, adding ethanol, adding chlorite, dichloroisocyanurate, lemon eucalyptus oil, tetramethrin and cocoanut fatty acid diethanolamide, anduniformly mixing to obtain the air freshener.

The invention discloses air purifying putty and preparation and application methods thereof and belongs to the technical field of building functional decoration materials. The air purifying putty comprises, by weight, 40-70 parts of shell powder, 10-20 parts of ground calcium carbonate powder, 5-15 parts of talcum powder, 1-5 parts of guar gum, 1-5 parts of basalt fiber, 0.5-2 parts of hydroxypropyl methyl cellulose ester and 1-5 parts of expanded vermiculite. The air purifying putty has the advantages that the air purifying putty replaces traditional putty, and the air purifying putty does not contain toxic and harmful substances, can absorb and decompose toxic gas, can purify air and regulate indoor humidity and can provide a safe, healthy and fresh working and living environment for people.

The invention relates to the field of coatings and discloses a water-tolerant flavor purification type polyvinyl alcohol water-soluble coating and a preparation method thereof. The coating comprises the following components in parts by mass: 5-15 parts of polyvinyl alcohol, 10-20 parts of calcium carbonate, 4-6 parts of talcum powder, 1-3 parts of phenoxy resin, 2-4 parts of rhizoma bletillae powder, 1-3 parts of corn starch, 0.5-1.5 parts of glutaraldehyde, 1-3 parts of air purification particles and 55-65 parts of water. The water-tolerant flavor purification type polyvinyl alcohol water-soluble coating has an air purification function and a good air purification effect and is relatively good in water tolerance, large in adsorption capacity and long in purification timeliness.

The invention discloses an emergency traffic light capable of purifying air in the technical field of traffic lights. A transverse plate is arranged in the middle of an inner cavity of the base. A storage battery pack is arranged at the top of the transverse plate. A charging port is formed in the top of the left side of the base. A vertical rod is arranged at the top of the base. A purification device is arranged at the top of the vertical rod. A lamp box is arranged at the top of the purification device. The emergency traffic light is high in practicability and has a good air purification function. Tail gas and air exhausted by passing vehicles are sucked into an inner cavity of the purification device through the exhaust fan. Tail gas and air enter an inner cavity of the exhaust pipe and then are primarily purified through the carbon film layer. The preliminarily purified tail gas and air enter the inner cavity of the water tank through the connecting pipe and are secondarily purified through the activated carbon particles and the water source in the inner cavity of the water tank, the purified tail gas and air are exhausted through the exhaust pipe, convenience and quickness are achieved, the air quality is greatly improved, and the breathing requirements of traffic guidance personnel are met.

The invention discloses an energy-saving ventilator. An air adjusting plate is arranged at an air inlet, so that the ventilation quantity of the ventilator can be naturally adjusted along with the change of external wind power, and the excessive energy consumption does not need to be increased. Natural ventilation is adopted, the power consumption is not needed except for control, start and stop, other power consumption items are avoided, and the consumption of electric energy is greatly reduced. A dust and bacterium adsorption device is arranged at an air outlet, so that the air entering from the outside can be effectively purified, and the purification effect is good. Noise reduction cotton is arranged at related parts in the interior, so that the ventilation noise can be effectively reduced.

The invention discloses an automobile solar semiconductor cooling device including a shell; an outer cover is fixed to the outer wall of one side of the shell through bolts. A same cold end air outletfan is fixed to the inner walls of two sides of the outer cover through bolts. An air outlet is formed in the outer wall of the side, away from the shell, of the outer cover; a filter screen is fixedto the inner wall of the air outlet through screws, an activated carbon layer is fixed to the inner wall of the side, close to the outer cover, of the shell through bolts, and semiconductor cooling plates are fixed to the inner wall of the top end and the inner wall of the bottom end of the shell through bolts. The semiconductor cooling plate is arranged, and solar energy is used for generating electricity in work; the problem that the temperature in an automobile is too high when the automobile is parked can be solved, and the activated carbon layer and the filter screen can purify air in the automobile; a heat conduction plate, a radiator and a cooling fan are arranged, the refrigerating efficiency is improved, energy is saved, the good cooling and air purifying functions are achieved,and the social requirements are met.

The invention provides an air-purifying functional water-based coating, which is characterized in that it is made of the following components in parts by weight: 55-65 parts of film-forming polymer, 5-10 parts of heterogeneously doped titanium dioxide, and 10-15 parts of titanium dioxide , 1-3 parts of wetting agent, 1-3 parts of dispersant, 1-4 parts of defoamer, 20-30 parts of water. The invention also discloses a preparation method of the water-based paint with air purification function. The water-based paint with air purification function prepared by the invention has the advantages of low cost, high hardness, excellent chemical resistance, wear resistance and comprehensive performance, and has air purification function, has little impact on the environment, and has the advantages of safety and environmental protection.