44results about How to "Reduce contact surface" patented technology

This invention relates to the field of embryo resuscitation technology and discloses an auxiliary warming device for frozen embryo resuscitation, including a collection plate. A fixing ring is fixedly connected to the side wall of the collection plate, and a forward threaded groove is formed on the side wall of the fixing ring. The cover plate drives the separator ring to rotate clockwise through the contact rod and the fixing plate. Since the reverse threaded groove rotates in the opposite direction to the forward threaded groove, the rotating ring will move upward at this time. The upward rotating ring will drive the separator ring to move upward synchronously, so that the through hole gap coincides with the flow hole. At this time, the new solution on the outer wall of the separator ring flows downward through the flow hole and the through hole gap. Finally, the new solution mixes with the solution inside the collection plate. At this time, the pressure of the dripping will be absorbed by the top of the fixing ring and will not directly contact the solution inside the collection plate. When the operator twists the cover plate to close it, the flow hole and the through hole gap will coincide, and the new solution will mix with the solution inside the collection plate, effectively reducing the damage to the outer wall of the embryo cell membrane when injecting the new solution.

This invention belongs to the technical field of quartz products, and particularly relates to a quartz ring-type product cleaning basket and its working method. A quartz ring-type product cleaning basket includes a basket body, a bottom hook, side hooks, and a position adjustment structure. The basket body is open at the top; the bottom hook is fixedly installed at the bottom of the basket body, and has multiple first positioning grooves along its length; at least two side hooks are provided, symmetrically arranged above both sides of the bottom hook, and have multiple second positioning grooves; the position adjustment structure is used to adjust the distance between the two side hooks and the distance between the side hooks and the bottom hook. This invention, by adjusting the distance between the two side hooks and the distance between the side hooks and the bottom hook through the position adjustment structure, adapts to quartz ring products of different sizes, thereby improving the versatility of this cleaning basket.

This utility model relates to the field of smartwatches, specifically a smartwatch with a replaceable case. It includes a watch body, a first watch strap rotatably connected to one side of the watch body via a pivot, and a second watch strap rotatably connected to the side of the watch body away from the first watch strap via a pivot. A lower housing is located below the watch body, and several sets of connecting components are arranged on the upper part of the lower housing, respectively located on both sides of the lower housing in a symmetrical arrangement. Several sets of limiting components are located below the watch body, and the limiting components are connected to their corresponding connecting components. Compared to existing technologies, this patent, by setting connecting components and limiting components, allows the first and second limiting blocks to clamp the inverted trapezoidal inclined block with increased force via a threaded rod, thus increasing the contact area. The inverted trapezoidal structure of the inclined block becomes increasingly tighter under pressure. The limiting rod is inserted into the limiting hole, forming an anti-shear redundancy design, improving vibration and impact resistance.

The application discloses a non-welding accessory connecting structure of a wind power tower drum, the wind power tower drum and a construction method thereof, and relates to the technical field of wind power generation equipment. Technical scheme points of the application are as follows: the application comprises a rooting piece for connecting with an accessory structure, a structural adhesive layer coated between a mounting surface of the rooting piece and an inner wall of a tower drum body, and a resin fiber composite material coating layer which is cured and formed to wrap a root part of the rooting piece and is fixedly connected with the inner wall of the tower drum body through the structural adhesive layer. The application can effectively disperse stress generated by accessory load, avoid a welding heat affected zone, welding residual stress and stress concentration at a welding toe, eliminate negative effects of welding of the accessory on fatigue strength of a main steel plate of the tower drum, and make the fatigue strength grade of the main steel plate not be reduced due to connecting details.

The present application belongs to the technical field of pharmaceutical preparations, and relates to a combined preparation of ezetimibe and atorvastatin calcium, in particular to a preparation containing ezetimibe and atorvastatin calcium and a preparation method thereof. A double-layer tablet is formed by an ezetimibe layer and an atorvastatin calcium layer, the ezetimibe layer is composed of ezetimibe and a first excipient, and the atorvastatin calcium layer is composed of atorvastatin calcium and a second excipient; the second excipient does not contain an alkaline stabilizer, and kaolin is used as a filler in the second excipient. By adding kaolin as a filler, the present application can not only avoid the addition of an alkaline adjusting agent, but also improve the stability of ezetimibe and atorvastatin calcium.

The utility model relates to a rotatable supporting leg column and foot stand assembly of office chair, and relates to an office chair leg and foot assembly with a novel connecting structure. The utility model discloses a chair supporting leg column, and a foot stand which is detachably and fixedly connected with the supporting leg column. The foot stand comprises a central sleeve and a chair foot extending outward. The central sleeve has a leg column hole, and the supporting leg column can be inserted into the leg column hole and tightly matched with the leg column hole. A plurality of axial strip-shaped slot holes are uniformly distributed on the inner surface of the leg column hole. A key groove is also arranged on the inner surface of the leg column hole. A key hole is arranged on the supporting leg column. A key column is also arranged and can be clamped in the key groove. The utility model technical scheme can realize quick, simple and easy disassembly and assembly.

The utility model discloses a water cooling plate integrated turbulence structure relates to water cooling plate technical field, and this turbulence structure includes bottom plate, and the top of bottom plate is provided with turbulence structure, and the top of turbulence structure is provided with upper baffle, still include: sealed outer frame, its setting in the external position of bottom plate, turbulence structure and upper baffle, and the top position of upper baffle is provided with the water pass -through port, and the water pass -through port is provided with two, and the upper end of two water pass -through ports all is provided with the water nozzle, and the socket recess is set up on the bottom end inner wall of upper baffle, and the inside of two socket recesses is provided with two fins, has solved the existing water cooling plate through the built -in fan -shaped flow channel structure and has increased the heat exchange area of water cooling plate, but water cooling plate lacks effective turbulence mechanism, leads to the problem of easy partial overheating.

This invention discloses a polymer antistatic wood-plastic composite flooring, relating to the field of wood-plastic composite flooring, comprising joists and wood-plastic composite panels. At least two joists and wood-plastic composite panels are provided, with the two joists arranged parallel to each other and the two wood-plastic composite panels slidably fitted onto the tops of the two joists. A connecting structure is provided on adjacent sides of the two wood-plastic composite panels. In practical operation, when the wood-plastic composite panels are installed outdoors, rainwater will enter the interior of the moisture-proof ring through the heat dissipation holes during rainy weather and drain out from both ends of the moisture-proof ring, reducing the accumulation and erosion of rainwater on the top of the wood-plastic composite panels, thus improving service life. The addition of multiple sets of heat dissipation holes increases the friction on the top of the wood-plastic composite panels, preventing slippage during rainy weather. Because rainwater drains quickly, it dries rapidly after the rain stops due to wind and temperature variations.

The invention discloses efficient metal plate pickling equipment, and relates to the field of metal plate machining, the efficient metal plate pickling equipment comprises a pickling box, mounting sleeves are fixedly connected to the two sides of the interior of the pickling box, a circular frame is movably sleeved with the mounting sleeves, and a limiting plate is fixedly connected to the middle of the inner side of the circular frame; and a first lead screw is installed in the limiting plate, and the first lead screw is sleeved with a transverse plate in a threaded mode. According to the efficient pickling equipment for the metal plates, the angle of the circular frame is adjusted by starting the first motor, the transverse plates are installed at the upper end and the lower end of the inner side of the circular frame correspondingly, in the rotating process of the first motor, a metal plate can be driven to turn over, the angle of the metal plate can be changed, and during pickling of the metal plate, the comprehensiveness of the pickling equipment during spraying is guaranteed; the problems that the pickling solution cannot be sprayed to the back face and the clamping face of the metal plate, so that the pickling efficiency of the metal plate is reduced, and the convenience and the pickling efficiency are improved during plate overturning and angle adjustment are solved.

This utility model discloses a protective and impact-resistant resin lens, comprising: a lens; a mounting bevel on the edge of the lens, the bevels on both sides facilitating the lens to be secured in the mounting groove of the frame; multiple slots surrounding the edge of the lens, with shock-absorbing pads placed in the slots; an arc-shaped surface between the inner edge of the bevel and the edge of the lens surface; and a wear-resistant layer on the inner and outer surfaces of the lens, the wear-resistant layer comprising a zirconium oxide film layer, a titanium oxide film layer, and a silicon oxide film layer. The shock-absorbing pads on the edge of the lens reduce the fixing force between the frame and the lens edge, reducing the contact area of ​​the rigid connection, thus reducing the probability of damage to the lens edge upon impact. The wear-resistant layers on the front and back surfaces of the lens protect the lens surface from scratches upon impact.

The utility model provides a novel lifting upper pull rod fixing structure which comprises an upper pull rod and a pull plate arranged on a rear transverse support of a tractor, a pin shaft is arranged at one end, close to the rear transverse support of the tractor, of the pull plate, one end, close to the upper pull rod, of the pull plate is of a U-shaped structure, and a hook is arranged on the upper pull rod and corresponds to the pull plate. A lock pin is arranged between the pulling plate and the hook, the lock pin comprises a shaft body and a stop lever, the shaft body corresponds to the hook, a clamping structure is arranged on the pulling plate, and the clamping structure corresponds to the stop lever. According to the utility model, the pulling plate is arranged on the rear transverse support of the tractor, the pin shaft is arranged at one end, close to the rear transverse support of the tractor, of the pulling plate, the lock pin is arranged between the pulling plate and the hook and can be fixed through the lock pin, and the upper pulling rod, the pulling plate and the vehicle body form a stable triangular structure, so that the shaking of the upper pulling rod is reduced, and the stability is ensured; and the U-shaped structure of the pulling plate can be used for connection, so that the strength is ensured, and breakage is prevented.

The utility model discloses a feeding device of a bottle blowing machine, which comprises a base, an inclined bottle blank slide way is fixedly mounted on the base, an outlet of the bottle blank slide way is connected with a blank separating mechanism, the blank separating mechanism comprises a blank separating block horizontally mounted on the base in a sliding manner, and a plurality of bottle blank clamping grooves are formed in the blank separating block. A bottle blank clamping groove of the blank separating block faces one side and is connected with an outlet of the bottle blank sliding way, the blank separating block is driven by a horizontal reciprocating driving device, an auxiliary limiting device and an auxiliary backup plate horizontally sliding on the limiting device are installed on the side, located on the blank separating block, of the base, and the auxiliary backup plate is driven by an auxiliary linear power device. The auxiliary backup plate leans against the bottle blanks in the bottle blank clamping grooves when approaching the blank separation blocks; a bottle blank clamping and overturning mechanism is installed on the base and located on the other side of the blank separating block, and a feeding blocking device used for blocking the bottle blanks, close to the outlet, of the bottle blank sliding way is further installed on the base. The feeding device is simpler in structure and can more accurately achieve feeding of the bottle blanks.

The utility model relates to the technical field of vibration conveying, and discloses a vibration conveying device which comprises two side plates, vibration exciters are installed on the outer sides of the two side plates, noise reduction assemblies are installed at the tops of the two side plates, and dust filtering assemblies are installed at the bottoms of the two side plates. The noise reduction assembly comprises two clamping seats and a plurality of protection plates, the two clamping seats are fixedly installed on the outer sides of the two side plates correspondingly, a plurality of limiting grooves are formed in the tops of the clamping seats, the protection plates are arranged and installed between the tops of the two clamping seats, and handles are fixedly installed on the tops of the protection plates. Through a rubber sleeve and a protection plate, outward diffusion of noise generated during vibration sliding of materials is reduced, meanwhile, outward diffusion of fine particles is reduced, and internal protection is improved; and through the material groove and the filtering holes, the contact surface of the materials is reduced, the materials can slide better, and fine particles in the materials can be filtered out.

The application relates to a high-efficiency roughening milling head for a glass surface, which comprises a base body, a milling head and a vane wheel; the bottom end of the milling head is provided with a grinding ring, the milling head is provided with a horn-shaped water inlet end, a water storage area and a water flow channel, the vane wheel is arranged below the water storage area, the ratio of atomized water of the vane wheel can be reduced, the cooling water flow is improved, the outer side wall of the grinding ring is provided with a chip removal groove, the inner side wall is provided with a water passage, and the milling head is internally provided with a water flow channel; when the vane wheel transmits a torsion and rotates simultaneously with the milling head, the vane pushes the cooling water to the end face of the grinding ring, then the water is affected by the water passage and applied to the grinding area, and the outer cooling mode is changed into the inner cooling mode; the chip removal speed is improved through the densely arranged outer chip removal groove and the water passage; the problem that the roughness of the roughened glass surface is too low due to the high passivation rate of diamond caused by the grinding heat and the poor self-sharpening property of the milling head is solved through the water passage, the contact area with the glass is reduced, and the problem that the thin glass is softened or broken due to the excessively large applied pressure is avoided.

The utility model belongs to the technical field of valves, and provides an agricultural valve which comprises a valve body, one end of the valve body is provided with a connecting port, the other end of the valve body is provided with a water outlet, the top of the valve body is provided with a limiting pipe, a spherical protection plate is arranged in the valve body, the top of the spherical protection plate is provided with an imbedding hole, and a rotating assembly is arranged in the spherical protection plate. The rotating assembly comprises a rotating shaft rotationally connected into the placement hole, a handle is fixedly connected to the top of the rotating shaft, a protruding block is fixedly connected to the handle, and a flow guide component is arranged at the bottom of the rotating shaft; according to the utility model, by arranging the upwarped guide plate, when water flow passes through, the guide plate changes the laminar flow of the water flow into turbulent flow, and the water flow is guided and the direction of part of the water flow is changed, so that the water flow washes a sediment precipitation area in the valve, the valve can effectively avoid impurity precipitation during irrigation, the self-cleaning effect is achieved, and the interior of the valve body is prevented from being blocked; the normal opening and closing of the valve are influenced, even the valve is blocked, and the irrigation efficiency is improved.

The utility model discloses an automobile rear cover hinge structure, which is applied to the technical field of automobile rear covers and comprises an arch-shaped arm, a fixing seat is arranged at the top of the arch-shaped arm, a rotating shaft in bolted connection with the fixing seat is rotatably connected to one end, close to the fixing seat, of the arch-shaped arm in a penetrating manner, and an oil injection hole is formed in one side of the interior of the fixing seat. And a connecting hole communicating with the oil injection hole is formed in the rotating shaft. The oil injection hole is opened by pressing the conical plug, so that lubricating oil can be extruded from the surface of the rotating shaft through the oil injection hole and the connecting hole. And therefore, the lubricating oil is uniformly coated between the rotating shaft and the arch-shaped arm, the coating uniformity of the lubricating oil is improved, and it is guaranteed that the automobile rear cover can be smoothly opened and closed through the hinge structure. When the torsion spring rotates in the clamping sleeve and the clamping groove, the torsion spring is in contact friction with the tooth-shaped protruding block, and therefore abrasion between the torsion spring and the interior of the clamping sleeve and the clamping groove is avoided. And meanwhile, the tooth-shaped convex blocks can reduce the contact surface with the torsion spring, so that the friction abnormal sound generated when the torsion spring rotates is reduced.

This utility model relates to the field of electric curtain technology, specifically to an electric curtain guide rail, including a guide rail body, multiple mounting mechanisms, multiple recessed plates, and multiple connecting plates. The interior of the guide rail body has a corrugated texture. In use, a slider is placed inside the guide rail body and fixed in place by the multiple connecting plates. The added recessed plates make it easier and tighter to assemble the guide rail body, solving the problem of guide rail jamming and excessive noise caused by improper assembly after transporting in sections. The innovative symmetrical design of the guide rail body allows the motor to be installed vertically or upside down, meeting personalized installation needs. Furthermore, the corrugated texture inside the guide rail body reduces the contact area between the transmission belt and the guide rail body during sliding, reducing friction and noise.

The utility model relates to the technical field of lightning arrester provides a lightning arrester with wind -resisting structure, include: mounting seat, the center place fixed setting of mounting seat has lightning rod main part, still include: stable subassembly, set up in the outer surface of mounting seat, stable subassembly includes: a plurality of rectangular boards, all fixed settings in the outer surface of mounting seat, the outer surface movable arrangement of rectangular board has adjusting screw rod, carousel, fixed setting in one end of adjusting screw rod, the outer surface of carousel is set up with a plurality of positioning hole, a plurality of sliding slot, all set up in the outer surface of mounting seat, the inside fixed setting of sliding slot has guide rod, rotary adjusting screw rod pushes away arc plate movement through ring cover, arc plate improves its stability under the action of sliding block, makes arc plate better and the lower end of lightning rod main part is pasted together, a plurality of arc plate relative movement supports the lower end of lightning rod main part, improves the connecting effect of lightning rod main part and mounting seat.

The embodiment of the utility model discloses a burning bearing jig for a complex structural part. The burning bearing jig comprises a jig body, a fixing groove formed in the longitudinal direction of the jig body, positioning grooves formed in the two sides of the fixing groove at intervals, a receding groove formed in the center of the bottom of the fixing groove, and the front-back distance between the positioning grooves is 3 mm. According to the sintering jig for the complex structural part, the contact face between a product and the sintering jig in the sintering process can be reduced, friction between the product and the sintering jig can be reduced, the deformation amount of the product in the sintering shrinkage process is reduced to the minimum, product deformation caused by sintering is greatly reduced, the production cost is effectively reduced, and the production efficiency of the product is improved.

This utility model provides a foldable stool, relating to the field of portable seating, and solves the technical problem of large bolt shearing forces during opening and closing of foldable stools, leading to damage. The foldable stool includes a webbing, a pivot fastener, and at least two stool leg frames that can pivot to switch between an unfolded and folded state. The two ends of the webbing are detachably fixed to the two stool leg frames. In the area where the stool leg frames pivot and contact each other, a protruding structure with a through hole is provided on the stool leg frame. The protruding structures on different stool leg frames abut against each other, and the pivot fastener passes through the through holes on the two protruding structures, thereby hinged the two stool leg frames. When the two stool leg frames pivot, only the protruding structures contact each other, while a gap is maintained between the main body parts of the stool leg frames. This reduces the contact area during pivoting, greatly reducing the friction area, improving shear resistance, and enhancing durability.

This utility model discloses a cleaning and loading rack for medical devices, including a support member with multiple support slots along its length; a positioning member having a support surface and a positioning surface connected to the support surface, wherein the support surface is positioned closer to the support slots than the positioning surface, a clearance area is provided between the support member and the support surface, and the support slots are positioned higher than the support surface, with the positioning surface extending upward from the support surface; and a connecting member for connecting the support member and the positioning member. This utility model achieves oblique placement of the device by utilizing the height difference between the support slots and the support surface for coordinated support of the device, and by using the positioning surface to limit the device's tail end, allowing water to quickly slide off the device and accelerate subsequent drying. Furthermore, the clearance area minimizes the contact area between the water and the cleaning and loading rack, allowing water to drain quickly from the rack, which is beneficial for rapid drying of the device.

The utility model belongs to the technical field of fiber textile fabrics, and particularly relates to an anti-pilling fabric. By arranging the three-layer structure and additionally arranging the static electricity connecting fiber clusters connected with the static electricity generating fiber clusters on the anti-pilling layer, electrons on the surfaces of high-static-electricity materials such as regenerated fibers can be transferred, and the situation that short and small regenerated cellulose formed by breakage under the static electricity effect is separated from original plied yarn is avoided; the pilling phenomenon on the surface of the electrostatic generation fiber cluster is relieved. By arranging the static dispersing fiber clusters which are connected with the static connecting fiber clusters and are partially arranged outside the protective layer, static electricity can be transferred from the inside of the fabric to the outside along the electron generating end, the static electricity inside clothes is reduced, and meanwhile, the static electricity inside the clothes is reduced. The electronic divergence ends formed by winding and interweaving the electric divergence fiber clusters can also achieve the physical isolation effect between the surfaces of the fabric, friction between the electronic divergence ends and the protective layer is reduced, and the fuzzing and pilling problems are solved through static conduction and physical isolation.

The utility model discloses a ladder type PTFE sealing element structure, including the shell of setting up the pivot piece still including the main seal of setting up in the outer side of pivot piece and the inner ring is provided with the lip, is equipped with the strip hole of symmetrical arrangement on the side wall of main seal, still including the vice seal of sticking to the side wall of main seal, the ring strip of inserting in the strip hole is fixedly installed on the vice seal, is equipped with the air cavity in main seal. The ladder type PTFE sealing element structure provided by the utility model increases the main seal and vice seal connection contact surface and friction force through the ring strip of rubber material quality, makes two not easy to slip off through temperature difference change, reduces the generation of gap, and the air cavity is accompanied by the pressure of cavity edge to strip hole position in the heating process and makes the connection more fastening, simultaneously accompanied by the lip far away from pivot piece side wall far away, the purpose is that the contact surface between rubber deformation and pivot piece can be reduced under high temperature environment, reduces the abrasion of pivot piece to main seal, improves ladder type PTFE sealing element use efficiency.

This invention belongs to the field of stool technology, specifically relating to a height-adjustable stool for assisting standing, comprising: a Y-shaped base including three supporting arms; the upper surface of each supporting arm is a supporting plane; chamfered edges are present on opposite sides of the supporting plane; the width of the extended end of the supporting plane is greater than the width at its base; a base; and a support assembly including a movable rod and a fixed sleeve; the movable rod is movably mounted on the fixed sleeve; the upper end of the movable rod is connected to a connection port at the center of the Y-shaped base, and the lower end of the fixed sleeve is fixedly connected to the base. The height-adjustable stool in this design allows for straddle use and height adjustment as needed, assisting workers who stand for long periods, alleviating lower limb swelling and varicose veins; when made of metal, it is more robust and durable, and absorbs static electricity. Height control is unnecessary, reducing bacterial transmission and cross-infection among mobile users.

The utility model discloses an improved health insole, including insole body, the insole body is set gradually as the forefoot, midfoot and heel from front to back, the lower surface of midfoot and heel department is pasted together with hard support piece, the hardness of hard support piece is greater than the hardness of insole body, the outer periphery of heel department is connected with the side wall for the cladding human foot, the middle position of the upper surface of heel department is provided with support convex part no.

The utility model belongs to the technical field of cooking ranges, and particularly relates to a commercial gas hearth and cooking range suitable for cookware in different shapes, which comprises a hearth body in a flaring shape from bottom to top, and is characterized in that the hearth body is detachably provided with an adjusting ring, and the top end of the adjusting ring is arranged to exceed the top end of the hearth body; more than two supporting arms extending inwards are arranged on the adjusting ring, first supporting parts are arranged on the supporting arms, and the top ends of the first supporting parts are flush with the top end of the adjusting ring. According to the hearth, the hearth body can be suitable for cookware with arc-shaped pot bottoms of different sizes, after the adjusting ring is installed on the hearth body, the hearth can be suitable for pans of different sizes, and therefore the same hearth can be suitable for the arc-shaped pot and the pans, the use range of the hearth is enlarged, and the utilization rate of the hearth is increased.

The application relates to the technical field of modified plastics, and particularly discloses a polystyrene composition, a preparation method and application thereof. The polystyrene composition comprises the following components in parts by weight: polystyrene 60-80 parts, a toughening agent 10-25 parts, a self-cleaning agent 2-30 parts, a hydrophobic agent 0.1-0.5 parts, a hydrophobic synergist 2-10 parts and a lubricant 0.1-1 part; the self-cleaning agent is polyethylene; and the hydrophobic synergist is a two-dimensional sheet-shaped inorganic material. The four, namely the self-cleaning agent, the hydrophobic agent with the function of reducing the surface energy of the material, the hydrophobic synergist and the lubricant, are mutually synergistic, so that the contact angle of the polystyrene composition is increased, the polystyrene composition has excellent self-cleaning performance and hydrophobic performance, and oil stains are difficult to remain on the surface. In actual application, the polystyrene composition has good waterproof and dirt-proof performance, and can maintain a good appearance for a long time in use.

The present invention provides an electroplating apparatus and method for prolonging the service life of a circulating electroplating solution by isolating external oxygen. The apparatus includes: an open electroplating tank; a sealed liquid storage tank with electroplating solution stored therein, injected with N2 and maintained at a preset pressure; a liquid injection, reflux and overflow pipeline connecting the electroplating tank and the liquid storage tank, with U-shaped liquid seals provided on both the reflux and overflow pipelines; an N2 pipeline for providing an oxygen-isolated environment for the electroplating solution reflux channel; a bypass pneumatic valve for opening after the N2 pipeline releases N2 to balance the N2 pressure in the liquid storage tank. The present invention innovatively proposes a brand-new open electroplating tank body device structure and electroplating solution circulation system. By controlling the N2 pipeline and using the U-shaped liquid seal, the air in the reflux and overflow pipelines can be discharged and the overall system can be helped to isolate air and oxygen. With the help of the bypass pneumatic valve, etc., the pressure generated by the input of N2 into the liquid storage tank can be balanced, enabling the reflux electroplating solution to flow back to the liquid storage tank by gravity. Moreover, the maintenance of the N2 pressure in the liquid storage tank can maintain a zero or low oxygen environment.