270 results about "Chemical solution" patented technology

A solution applicator assembly comprises an upper body defining an upper channel. The upper body further includes a primary inlet fluidly connected to the upper channel. A lower body defines a lower channel being fluidly connectable to the upper channel to define a central channel. The lower body further defines a primary outlet fluidly connected to the lower channel. A flow control insert is removeably receivable in the central channel for receiving a chemical solution from the upper channel and releasing the solution into the lower channel. The upper body and the lower body are removeably connectable to one another to selectively allow the flow control insert to be removed and positioned in the central channel.

The invention relates to the field of integrated circuit manufacturing, in particular to the technical field of manufacturing of semiconductor device special equipment such as a photoetching machine and an etching machine special for production, and provides a through hole filling electroplating method and system for a printed circuit board. The method comprises the following steps: carrying out laser micro-through-hole processing on the printed circuit board; carrying out glue removal treatment on the printed circuit board with the micro through hole; carrying out black hole treatment or direct electroplating treatment on the degummed printed circuit board; performing porefilling electroplating on the treated printed circuit board by using an acidic copper plating porefilling special liquid medicine; in the hole filling electroplating process, a multi-stage electroplating current parameter program is adopted, in-hole pre-plating is carried out at low current density in the initial stage, it is ensured that hole walls are evenly covered, after the main hole filling stage is started, pulse or periodic reverse current is adopted, the current density is increased in a stepped mode, and through holes are filled with acid copper plating hole filling special liquid medicine; and parameters are adjusted at the last stage of filling to ensure that the copper thickness of the hole surface is uniform, and dished pits or excessive recesses are avoided.

This utility model relates to the field of water treatment technology, and in particular to an intelligent control dosing device, including a mixing tank. The inner wall of the mixing tank is equipped with dosing components, and a mounting plate is installed on one side wall of the mixing tank. This utility model controls the lifting stroke of a metering cylinder via an electric actuator. When the metering cylinder descends below the water level, it draws the chemical solution by gravity. After rising to a specific position, the chemical solution is again discharged under gravity through a corresponding cylindrical groove, a circular hole, and an outlet pipe, achieving quantitative dosing. Three sets of dosing components are arranged side-by-side on the crossbeam. According to actual needs, all three sets can be selected for simultaneous dosing, significantly improving work efficiency and meeting the needs of large-scale production scenarios. Alternatively, designated valves can be flexibly closed, allowing for individual dosing through designated outlet pipes, enhancing the device's versatility and practicality. The inlet pipe and dosing pipe independently transport water and chemicals. Combined with a bottom motor-driven stirring shaft, this ensures thorough mixing of the chemical solution within the mixing tank, effectively avoiding localized uneven concentrations.

The invention discloses a method for treating a metal surface through ethylene glycol butyl ether after a fire disaster. The treatment method comprises the following steps that modified ethylene glycol butyl ether is prepared; sequentially adding modified ethylene glycol butyl ether serving as a main chemical solution into the reaction kettle according to the quantitative percentage, and carrying out mixed reaction; standing the mixed chemical solution in the step S2 for 10-20 minutes, and adding water to dilute the mixed solution according to the remaining percentage of the volume of the reaction kettle; the ethylene glycol butyl ether is modified and serves as a main component of the cleaning solution, the sodium phosphate, the epichlorohydrin, the sodium pyrophosphate and the trichloroethylene are mixed according to a proper proportion, a proper amount of water is added for dilution, and the cleaning solution is obtained. Dirt formed by fire disasters on the metal surface can be effectively removed, and metal objects cannot be damaged.

To provide a chemical storage tank that is simple and inexpensive to construct, yet can adequately maintain the properties of the chemical solution. [Solution] A chemical storage tank comprising a chemical tank 1 for containing a separable chemical solution, a bubble discharge unit 2 for discharging bubbles into the chemical tank 1 to agitate the chemical solution, a gas supply means 3 for supplying gas to the bubble discharge unit 2, and a chemical injection means 4. The gas supply means 3 comprises a tube 6, a pressure regulating device 7, and a solenoid valve 8. The chemical injection means 4 comprises a suction pipe 11, a tube 12, and a chemical injection pump 13.

The invention relates to the field of semiconductor manufacturing, and discloses a semiconductor wafer wet etching device which comprises a shell, a working chamber and an inner chamber are arranged in the shell, an etching tank is fixedly installed in the inner chamber, a pump is installed at the bottom of the etching tank in a communicating mode, and a filter box is installed in an inner cavity of the inner chamber. And the water outlet end of the pump communicates with the filter box, and four sets of backflow pipes are fixedly connected to the bottom of the outer surface of the filter box. According to the device, through redesign, a chemical solution flowing back into the etching tank enters along the tangential direction of the etching tank and forms an anticlockwise vortex in the etching tank, and at the moment, the chemical solution in the whole etching tank starts to rotate, so that the chemical solution continuously passes through the surfaces of a plurality of groups of wafer bodies in a moving form; and the vortex accelerates the combination of the gas and forms bubbles to be discharged, so that the chemical solution can be more fully contacted and reacted with the surface of the wafer body.

The utility model relates to the technical field of knitting needle surface treatment, and discloses a knitting needle surface and corner angle high-precision chemical polishing device which comprises a working box, the inner wall of the working box is connected with a supporting frame in a sliding mode, the lower surface of the supporting frame is fixedly connected with a fixing sleeve, the upper surface of the fixing sleeve is fixedly connected with a stepping motor, and the stepping motor is connected with the working box in a sliding mode. And the output end of the stepping motor penetrates through the interior of the fixing sleeve and is fixedly provided with a fixing seat, the lower surface of the fixing seat is fixedly connected with a fixing plate, the outer wall of the fixing plate is fixedly connected with an electric push rod, and the output end of the electric push rod is fixedly connected with an L-shaped block. According to the knitting needle polishing device, the fixing base, the fixing plate, the electric push rod, the L-shaped block, the U-shaped frame, the L-shaped frame and the clamping block are matched with one another, the knitting needle body is clamped and fixed, the polishing stability of the knitting needle body in a chemical solution is improved, uniform chemical polishing of the surface and edges and corners of the knitting needle is achieved, and scratches and excessive abrasion are avoided.

The present application relates to the technical field of chemical experiment, and specifically relates to a chemical experiment table with chemical solution treatment function, which comprises a chemical experiment table composed of a table body, a water tank and a storage rack, a controller is arranged on the table body, the controller is signal connected with a touch display screen, neutralization cavities are symmetrically arranged in the middle of the table body, a PH sensor is arranged in each neutralization cavity, a fixing block is fixedly connected to the side wall of each neutralization cavity, vibration grooves are formed in the two sides of the inner wall of the table body, a neutralization pipe is slidably arranged in the middle of each neutralization cavity, a plurality of through holes are formed in the neutralization pipe, a waste liquid pipe is connected to the top of each neutralization cavity, a three-way pipe is connected to the bottom of each neutralization cavity, a collecting assembly and a sewage assembly are arranged at the other two ends of the three-way pipe respectively, and an auxiliary assembly is arranged in the vibration groove. The structure for preliminary neutralization treatment of chemical solution arranged below the chemical experiment table can avoid the leakage risk and high subsequent treatment cost caused by the temporary storage of the traditional experiment table relying on the collecting barrel.

This invention discloses a water quality detection and treatment device based on intelligent water management, relating to the field of water technology. It includes a treatment tank, a detector, and a mixing assembly. The treatment tank is internally divided into a mixing chamber and a detection chamber by a partition hopper. The invention employs a transmission mechanism where a second electric actuator drives a first transmission assembly, which in turn drives a second transmission assembly upwards to seal the discharge port of the partition hopper. Water from the detection chamber flows into the mixing chamber. After a suitable amount of chemical solution is added through a dosing pipe, the first electric actuator drives a third transmission assembly, which in turn drives the mixing assembly to stir the water in the mixing chamber, ensuring thorough mixing of the water and chemical solution. After sealing the discharge port of the partition hopper, when cleaning water is added to the detection chamber, the second transmission assembly drives a cleaning assembly to clean the inner wall of the partition hopper, preventing residual substances in the water from affecting subsequent test data.

The invention relates to the technical field of sewage treatment, in particular to a gravel processing wastewater treatment system and method.The gravel processing wastewater treatment system comprises a sewage tank, a dosing pool and a control module, a water inlet pipe and a water outlet pipe are arranged on the sewage tank, the dosing pool is communicated with the sewage tank through a dosing pipe, and a dosing pump is arranged on the dosing pipe; a third detection unit, a fourth detection unit, a mixing cavity and a premixing chamber are arranged on the dosing tank. The premixing chamber and the mixing cavity are arranged on the dosing tank, after high-concentration liquid medicine is diluted to the preset concentration through the mixing cavity, new liquid medicine is continuously supplemented into the dosing tank, stirring and mixing actions in the dosing tank are omitted, continuous liquid supplementing is conducted on the dosing tank under the working condition, and the dosing efficiency is improved. The continuous automatic dosing work of one dosing pool in cooperation with the sewage tank is achieved, the dosing amount in the dosing work is matched with the wastewater treatment demand amount, and the production cost, the operation cost and the maintenance cost of the gravel processing wastewater treatment system are effectively reduced.

A handheld reactive electrochemical application system is provided. The handheld reactive electrochemical application system includes a power supply configured to be electrically coupled to a substrate and a hydrogel electrically coupled to the power supply. The hydrogel includes a reactive chemical solution. The hydrogel is configured to contact the substrate, the power supply is configured to pass a current through the hydrogel and the substrate, and the reactive chemical solution is configured to treat the substrate when the current is passed through the hydrogel and the substrate.

The invention provides a substrate processing apparatus capable of separating a chemical solution from a mixed solution of the chemical solution and an organic solvent with low energy. The substrate processing apparatus includes a processing unit, a recovery pipe (60a), and a recovery unit (6). The processing unit causes a mixed solution of the chemical solution and the organic solvent to act on the main surface of the substrate. The recovery pipe (60a) has an upstream end connected to the processing unit. The mixed liquid from the processing unit flows into a recovery pipe (60a). The recovery unit (6) includes a separation membrane (72c) that separates the chemical solution from the liquid mixture supplied through the recovery pipe (60a) and increases the concentration of the organic solvent in the liquid mixture.

An increase in voltage of a light-emitting device manufactured through a step of forming an aluminum oxide film in contact with an organic compound layer is inhibited. An organic compound film is formed over a first electrode. An organic mask film containing an organic compound which has low solubility to water or a chemical solution including water as a solvent is formed over the organic compound film. An inorganic mask layer is formed over the organic mask film. Shapes of the organic mask film and the organic compound film are processed with the use of the inorganic mask layer, whereby an organic mask layer and an organic compound layer are formed. At least parts of the inorganic mask layer and the organic mask layer are removed with the use of water or a liquid including water as a solvent.

The invention relates to the technical field of water treatment, in particular to a sludge dewatering agent preparing and adding system which comprises a tank body, a water inlet pipe and a water outlet pipe. The jacket is arranged on the outer side of the tank body, and a closed cavity is formed between the jacket and the tank body; the feeding device is arranged at the top of the tank body; the jet head is arranged on the inner wall of the tank body; the jet head is communicated with the closed cavity; the stirring device comprises a driving mechanism, a dispersing disc and a stirring rod; the driving mechanism is fixedly arranged at the top of the tank body; a driving shaft of the driving mechanism extends into the tank body; the top of the dispersion disc is of a circular truncated cone structure; diversion trenches are uniformly distributed on the inclined surface of the circular truncated cone structure; the diversion trench extends along the generatrix of the circular truncated cone structure; the dispersing disc is sleeved on the driving shaft, and the stirring rod is fixedly arranged at the bottom of the dispersing disc; the aeration device is arranged at the bottom of the inner side of the tank body; and the aeration device is communicated with the closed cavity. By adopting the chemical mixing device, the chemical mixing efficiency can be improved, the mixing uniformity and the chemical solution concentration stability are improved, and accurate chemical supply is guaranteed.

This invention discloses a high-temperature chemical solution supply system for cleaning substrates. The system includes a solution tank for containing a chemical solution; a first pump, the inlet of which is connected to the solution tank, and the outlet of which is connected to a buffer tank; a buffer tank including a tank body, an exhaust pipe, and a needle valve, one end of which is connected to the tank body and the other end to the solution tank, and the needle valve mounted on the exhaust pipe for regulating the pressure within the buffer tank; and a second pump, the inlet of which is connected to the buffer tank, and the outlet of which is connected to a cleaning chamber for cleaning the substrate. When the second pump is in the open state, the first pump and the needle valve are also in the open state. The pressure within the buffer tank is regulated by the needle valve and the first pump, causing the chemical solution in the buffer tank to be forced into the inlet of the second pump. This invention also provides a substrate cleaning apparatus including a high-temperature chemical solution supply system and an ultrasonic / megasonite device, as well as a method for cleaning substrates.

The present invention addresses the problem of providing a chemical solution that, when used for cleaning a semiconductor substrate which contains a copper-containing material and which has been subjected to a chemical-mechanical polishing treatment, exhibits excellent corrosion-inhibiting properties with respect to copper and excellent removability of residue on the copper-containing material. The present invention also addresses the problem of providing a method for cleaning a semiconductor substrate and a method for producing an electronic device which use the chemical solution.　A chemical solution according to the present invention comprises: an alkali source; at least one specific phosphorus-atom-containing compound selected from the group consisting of phosphorus-atom-containing acids and salts thereof; at least one specific compound selected from the group consisting of a first compound and a second compound; and water, wherein pH is not more than 11.50, the first compound has at least two groups selected from the group consisting of an amino group and a hydroxyl group, and the second compound has at least two groups selected from the group consisting of a thiol group and a thioether group.

This invention relates to the field of dental chair water system disinfection equipment, and discloses a modular integrated dental chair water system cleaning and disinfection device, including a device shell and internally detachably connected modules for clean water supply, chemical solution supply, water system switching, control, and monitoring. Each module is an independent detachable unit, connected via standardized fluid interfaces and electrical connectors; the clean water and chemical solution modules have independent fluid branches and standardized output interfaces connected to the water system switching module; the water system switching module has a built-in solenoid valve group, with its input end connected to the former two and its output end having a total output interface for the dental chair water system; the control module is electrically connected to each module, and the monitoring module includes a pipeline sensing unit. This invention effectively solves the problems of low integration, lack of modularity, inconsistent interfaces, and cumbersome maintenance in existing equipment, achieving fully automated cleaning and disinfection of the dental chair water system, while also possessing the advantages of strong adaptability and stable operation, significantly improving cleaning efficiency and hygiene safety.

This invention relates to a method for amplifying the polarization ratio of a photodetector based on a two-dimensional semi-metallic material and a heterostructure, belonging to the field of photodetection technology. Based on a strategy combining a two-dimensional semi-metallic material and a heterostructure, a BP / MoS2 / WTe2 heterojunction is constructed, where BP is the light-absorbing layer, MoS2 is the barrier layer, and WTe2 is the contact layer. This invention not only achieves selective carrier transport and reduces dark current, but also allows WTe2 to reduce contact resistance and provide a fast carrier extraction channel, realizing asymmetric amplification of the photocurrent, thereby achieving active amplification of the polarization ratio even at zero bias. This invention breaks the limitation of the inherent anisotropy of materials on the magnitude of the polarization ratio, and uses a completely dry transfer process to fabricate polarization detection photodetectors, eliminating the need for additional polarization elements and chemical solution treatment. It boasts advantages such as simple process, low cost, high repeatability, and no pollution.

The present invention provides: a chemical solution that can selectively remove a SiGe-containing substance having a high Ge concentration more than a SiGe-containing substance having a low Ge concentration from a material to be treated which contains two SiGe-containing substances having differing Ge concentrations; a method for treating a material to be treated with the chemical solution; and a method for producing a semiconductor device. A chemical solution according to the present invention is used with respect to a material to be treated that contains two silicon-germanium-containing substances having differing germanium concentrations, said chemical solution comprising water, hydrogen chloride, and hydrogen peroxide, wherein the mass ratio of the hydrogen peroxide content to the hydrogen chloride content is not less than 0.20, and the mass ratio of the water content to the hydrogen chloride content is 130-560.

The application provides a high-porosity Raney nickel electrode and a preparation method thereof, and relates to the technical field of Raney nickel electrodes and preparation thereof. The preparation method of the high-porosity Raney nickel electrode effectively controls the dealuminization rate and the pore uniformity through a preparation process of'sintering treatment + special electrochemical dealloying treatment', and stably prepares the high-porosity Raney nickel electrode. A new process for preparing the high-porosity Raney nickel electrode in an environmentally friendly manner is provided, which replaces the traditional corrosion pore-forming process of a strong alkaline chemical solution and reduces pollution. The prepared high-porosity Raney nickel electrode has a high porosity of up to 52%, and the pore structure is stable, so that the catalytic activity and mechanical stability of the electrode are effectively improved.

The utility model relates to the technical field of high-density HDPE pipe polishing, and discloses a high-density HDPE pipe polishing device which comprises a base, a platform is fixedly assembled on the top of the base, a chemical solution box is installed on the outer wall of one side of the platform, and a supporting block is installed on the outer wall of the other side of the platform. A controller and a servo motor are fixedly installed on the outer wall of the platform. The high-density HDPE pipe is placed above the bottom plate, the two ends of a high-density HDPE pipe body are clamped through the limiting plates, the surface of the high-density HDPE pipe body can be mechanically polished through the polishing wheel, meanwhile, a connecting rod can drive a right-angle frame to rotate with the virtual center line of a fixing frame as the axis, and therefore the purpose of polishing the surface of the high-density HDPE pipe body is achieved. According to the chemical polishing device, the polishing liquid can be located on the inner wall of the chemical solution box after being polished, the surface of the chemical solution on the inner wall of the chemical solution box is treated, protruding parts on the surface can be dissolved away, the purpose of chemical polishing is achieved, and the polishing effect is better.

The invention provides a full-automatic liquid preparation device, a liquid preparation method and a computer readable storage medium, and belongs to the technical field of chemical liquid preparation. The device comprises a main rack and an operation surface system integrated on the main rack, wherein a solution storage unit, a solution mixing unit, a conveying unit, a detection unit, a valve unit, a control unit and a pipeline system are integrated on the operation surface system; the solution storage unit comprises a standard barrel for storing a solution; the liquid mixing unit comprises a liquid mixing box, and a magnetic pump for stirring mixed liquid is arranged in the liquid mixing box; the conveying unit comprises a diaphragm pump for extracting the high-concentration stock solution, and the diaphragm pump is connected with the standard barrel and the liquid mixing box through a pipeline system; the detection unit comprises a pulse type liquid level sensor and a PH meter; the valve unit comprises a water inlet valve and a drain valve; the control unit is used for inputting liquid preparation parameters and controlling all the components to work cooperatively. The full-process liquid preparation is automatic, manual intervention is not needed, the safety risk of manual liquid preparation is avoided, and meanwhile the liquid preparation efficiency is improved.

The utility model provides a liquid medicine mixing device for sewage treatment, which comprises a sewage pipe, the inner wall of the sewage pipe is provided with a liquid tank, the top of the liquid tank is provided with a drainage bin, the drainage bin is arranged in the sewage pipe, and two sides of the drainage bin are provided with connecting grooves. The sewage treatment device is reasonable in design, liquid medicine used for sewage treatment can be mixed through the arranged mixing shell, and the interior of the mixed liquid medicine is pressurized through the pressure pump, so that the mixed liquid medicine can enter the guide pipe through the flow dividing pipe and then is mixed with sewage through the water outlet formed in the outer wall of the guide pipe; a plurality of guide pipes and water outlets formed in different positions can be used for fully mixing the liquid medicine with the sewage, so that the liquid medicine is prevented from being accumulated in the sewage.

Surface treatment process for a gallium oxide-based semiconductor substrate (10), comprising: Flattening a surface (12s) of a gallium oxide-based semiconductor substrate (10) by dry etching with a bias voltage of 150 V or more; and Exposure of a step-terrace structure on the surface (12s) of the gallium oxide-based semiconductor substrate (10) by washing the surface (12s) of the gallium oxide-based semiconductor substrate (10) with a chemical solution containing H2SO4 after the surface (12s) of the gallium oxide-based semiconductor substrate (10) has been flattened.

The present disclosure provides a technology of reducing waviness of a carrying width of a catalyst metal carrying portion in an exhaust gas purification catalyst. A method disclosed herein includes: preparing a base material having an exhaust gas passage; preparing a catalyst metal solution containing a catalyst metal oxidizing or reducing exhaust gas component; supplying the catalyst metal solution to a chemical solution plate so that a bottom surface of the chemical solution plate is not exposed; immersing an end of the base material in the catalyst metal solution supplied to the chemical solution plate; and firing the base material. The bottom surface of the chemical solution plate is provided with grooves in a predetermined pattern, and an average of depths of the grooves is from 1.2 mm to 3 mm inclusive, and an average of widths of the grooves is from 1.6 mm to 3 mm inclusive.

The application relates to the field of semiconductor cleaning and recovery, and discloses a multiple-chemical-classification-discharge-recovery system, which comprises a base, and a plurality of groups of through holes are equidistantly arranged in the middle part of the circumference of the base. The reaction liquid is continuously provided into the inner cavity of the inner shell through the spray head mechanism until the chemical solution no longer generates heavy metal calcium class precipitates, at which time the heavy metal ions in the chemical solution are consumed, at which time the gravity of the adhesion mechanism no longer increases, and the adhesion mechanism no longer provides the reaction liquid into the inner cavity of the inner shell through the extrusion liquid supply mechanism, so that the problem that, before the existing chemical classification discharge recovery system is used, the volume, weight and concentration of the chemical solution and other parameters need to be detected and calculated in detail and complicatedly, and then the chemical solution is added with appropriate reaction liquid, so that when the chemical solution is treated, a large amount of time and manpower cost need to be consumed, and high-end detection equipment needs to be used, and the cost is sharply increased, is solved.

Provided in the embodiments of the present application are a wafer drying method and device. After a wafer is cleaned with a cleaning solution, the surface of the wafer has a residue of the cleaning solution. The method comprises: spraying a first liquid mutually soluble with the cleaning solution onto the wafer until the cleaning solution on the surface of the wafer is cleaned, resulting in the surface of the wafer having a residue of the first liquid; introducing a set amount of a first drying gas into a cavity, and spraying a modifying chemical solution onto the wafer at the same time, wherein the modifying chemical solution is mutually soluble with the first liquid and changes the surface of the wafer into a hydrophobic surface; and spraying a second drying gas onto the wafer. The wafer drying method and device of the present application can dry a wafer.

The utility model belongs to the technical field of cloth crystallization, and particularly relates to a distributed cloth crystallization conveying device which comprises a workbench used for bearing and supporting operation of the whole device and providing a stable operation platform for cloth conveying and processing. The spraying assembly is arranged on the workbench and used for spraying a chemical solution to the cloth; the driven roller is mounted on one side of the workbench and is used for winding the cloth to be sprayed with the chemical solution; the driving roller is mounted on the other side of the workbench and used for unfolding the cloth wound on the driven roller on the workbench and winding the cloth sprayed with the chemical solution; the first motor is mounted at one end of the driving roller; the controller is used for controlling the operation of the device; the rotating speed sensor is mounted on the driving roller, the output end of the rotating speed sensor is connected with the signal input end of the controller, and the rotating speed sensor is used for providing a rotating speed signal of the driving roller for the controller; and the controller adjusts the operation parameters of the spraying assembly according to the rotating speed signal of the driving roller.

The present invention provides a method and apparatus for adjusting the concentration of a chemical solution that allows for high-precision concentration adjustment with fewer control items and without requiring a long time for adjustment. [Solution] The concentration adjustment method is a method for adjusting a chemical solution of a predetermined concentration by mixing a stock solution containing any component with pure water, and includes the steps of: (A) mixing a predetermined amount of stock solution and pure water to obtain a mixed solution with a concentration in the range of 50% to 200% of a preset target concentration; (B) stirring the obtained mixed solution for a predetermined time and measuring the conductivity and liquid temperature of the mixed solution in the system to obtain a concentration value; and (C) calculating the amount of stock solution or pure water required to make the concentration value obtained in step (B) the median concentration between the concentration value and the target concentration, and supplying the calculated amount of stock solution or pure water to the mixed solution, and repeating steps (B) and (C) until the obtained concentration value is within a predetermined range of the preset target concentration.

This invention relates to a substrate processing method and apparatus for removing organic films from a substrate, providing a substrate processing method and apparatus capable of reducing the burden of chemical solutions and wastewater treatment, and efficiently removing organic films from a substrate. The substrate processing method for removing organic films from a substrate includes: a) a step of introducing ozone-containing gas into a substrate processing chamber, thereby filling the space above the substrate within the substrate processing chamber with ozone-containing gas; b) after step a), a step of starting a spray of a heated chemical solution containing sulfuric acid onto the substrate via the space; c) a step of continuing the spraying initiated in step b); and d) a step of stopping the spraying that continued in step c).