562 results about "H2O2 - Hydrogen peroxide" patented technology

The invention discloses a nano-enzyme-sensitized electrochemical luminescence immune biosensor as well as a construction method and application thereof. The biosensor comprises a three-electrode system of an immune electrode, a reference electrode and a counter electrode, and a solution containing luminol and hydrogen peroxide is taken as an electrolyte solution; the immunoelectrode is obtained by covalently immobilizing a tumor marker antibody and closing a non-specific site on an electrode confined to Co3O4 nano-enzyme. On the basis of an ECL signal of an SNF confinement Co3O4 nano-enzyme sensitization luminol-H2O2 system, an antibody on an immune recognition interface in detection can specifically capture a steric hindrance effect caused by a tumor marker and an immune complex, so that the ECL signal is reduced, and a detection effect is achieved. The Co3O4 nano-enzyme is generated in situ in a nano-channel, the activity of pseudo-peroxidase is enhanced while the Co3O4 nano-enzyme is stabilized, and the Co3O4 nano-enzyme is used as a co-reaction accelerant to sensitize ECL signals. The sensor disclosed by the invention is used for detecting tumor markers and has the advantages of high sensitivity and low detection limit.

The invention relates to the technical field of electrochemistry, in particular to a hypochlorous acid and hydrogen peroxide synergetic electrochemical device, a preparation method and application of the hypochlorous acid and hydrogen peroxide synergetic electrochemical device, and the hypochlorous acid and hydrogen peroxide synergetic electrochemical device comprises a shell, a liquid inlet and a liquid outlet. The shell is provided with an electrolyte cavity, a cathode reaction assembly located in the electrolyte cavity, an anode reaction assembly and a spoiler assembly used for increasing the liquid moving stroke, the cathode reaction assembly is used for generating hydrogen peroxide, the anode reaction assembly is used for generating hypochlorous acid, and the liquid inlet and the liquid outlet are located in the same side of the shell. The hydrogen peroxide and the hypochlorous acid can be directly generated in the electrolyte chamber through the cathode reaction assembly and the anode reaction assembly respectively, and mixing after respective preparation is not needed, so that the process is simplified, the cost is reduced, the synergism of the hypochlorous acid and the hydrogen peroxide is improved, the liquid moving stroke is increased through the spoiler assembly, and the efficiency is improved. The mixing effect is effectively improved, and the electrochemical reaction efficiency and uniformity are improved.

The invention discloses application of iron ruthenium nano-enzyme in preparation of nucleic acid detection products, and belongs to the technical field of biological detection and nano-materials. The RIN has stable peroxidase-like (POD) activity, and can catalyze a chromogenic reaction between 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) and hydrogen peroxide (H2O2). The catalytic activity of the nano-enzyme can be selectively inhibited by pyrophosphate (PPi) generated in a nucleic acid amplification reaction, so that visual colorimetric analysis on whether target nucleic acid exists or not is realized. In combination with a polymerase chain reaction (PCR) system, the invention constructs a new nucleic acid detection strategy which does not need fluorescence labeling, is simple and convenient to operate and has high sensitivity. Through verification, the system can be widely applied to rapid on-site screening and visual interpretation of related nucleic acid of drug-resistant pathogens (such as ESKAPE flora) and the like, and has a good application prospect.

The invention discloses a preparation method of monodisperse nano cerium oxide, and relates to the technical field of rare earth materials. The preparation method of the nano cerium oxide comprises the following steps: S1, adding hydrogen peroxide and a surfactant into a cerium salt solution, and uniformly stirring and mixing to obtain a pre-solution; s2, the pre-solution is adjusted to be in an alkaline environment through an alkaline solution, stirring is conducted for 0.5-1.5 h at the temperature of 60-90 DEG C, slurry is obtained, then suction filtration, washing, drying and calcination are conducted, and cerium oxide powder is obtained. The prepared nano cerium oxide particles are small in particle size, narrow in particle size distribution range and good in dispersity.

The invention relates to the technical field of etching liquid, in particular to a copper metal etching liquid composition. Comprising the following components in percentage by weight: 5-10% of hydrogen peroxide, 0.1-0.3% of a first fluorine source, 1-5% of first inorganic acid, 1-5% of alkali, 0.01-0.8% of a first metal corrosion inhibitor and the balance of deionized water; and the auxiliary agent comprises 2-8% of a second fluorine source, 10-55% of second inorganic acid, 0.1-2% of a second metal corrosion inhibitor and the balance of deionized water. The etching liquid is excellent in etching effect, CD-loss reaches 0.6-0.8 [mu] m, the slope angle reaches 40-50 degrees, the highest copper load reaches 20000 ppm, and meanwhile the problem that when copper is high, due to the fact that the nitric acid concentration is too high, metal etching is abnormal is solved.

The invention provides a preparation method of an organic polymer photocatalyst and application of the organic polymer photocatalyst in the aspect of photocatalytic synthesis of nitric acid (HNO3) by directly taking nitrogen (N2) and oxygen (O2) as raw materials in water, and additional reagents do not need to be added. It is worthy of notice that the organic polymer photocatalyst (PyOP) shows excellent photocatalytic performance. When O2 is subjected to photocatalytic reduction, the yield of hydrogen peroxide (H2O2) reaches 10147.5 [mu] mol g <-1 > cat, and meanwhile, 672.8 [mu] mol g <-1 > cat of HNO3 can be synthesized by directly utilizing N2 and O2. The preparation method of the photocatalyst provided by the invention is simple, the raw materials are easy to obtain, the preparation cost is low, a metal-free photocatalytic platform only using H2O, N2 and O2 is constructed, and the photocatalyst is used for green and sustainable nitric acid production.

The present application belongs to the technical field of rare metal metallurgy, and particularly relates to a method and device for removing arsenic in germanium tetrachloride by hydrogen peroxide oxidation. The arsenic removal device comprises GeCl4, H2O2 and HCl storage containers, the storage containers are connected with a first reactor and a second reactor through pipelines, fourth, fifth, sixth, seventh and eighth valves are arranged on the pipelines, a first constant temperature heater is arranged at the lower part of the first reactor, a first mechanical stirrer is arranged at the top of the first reactor, a first residual liquid collector is connected with the bottom of the first reactor through a pipeline, and ninth and eleventh valves are arranged between the first reactor and the first residual liquid collector. Compared with the traditional chlorine arsenic removal method, the present application uses hydrogen peroxide to remove arsenic in germanium tetrachloride, is more environmentally friendly, safe, low-cost and does not bring new impurity elements, and the arsenic removal effect is very significant.

The invention discloses a special antibacterial and antioxidant biosensing nano-composite preservative film for fermented food in the technical field of biochemistry, GOx and Lac are synergistically loaded on a nano-carrier to construct a multifunctional composite film, the loading capacity and catalytic efficiency of enzyme are remarkably improved by the high specific surface area and surface active sites of the nano-carrier, and the antibacterial and antioxidant biosensing nano-composite preservative film can be applied to the field of biochemistry. Meanwhile, the synergistic effect of the two enzymes endows the composite membrane with multiple functions: GOx catalyzes glucose to oxidize into hydrogen peroxide (H2O2), Lac catalyzes and oxidizes polyphenol substances, and the combination of GOx and Lac can realize antibacterial, antioxidant and biosensing functions at the same time. In addition, due to the introduction of the porous structure and the matrix material of the nano composite membrane, the mechanical property and the biocompatibility of the membrane are further enhanced, and the application potential of the membrane in food packaging, medical dressing and biosensors is widened.

The invention provides a hydrogen peroxide concentration detection method and device for a food packaging production line, and the method comprises the following steps: preparing hydrogen peroxide solution samples with different concentrations, measuring the near infrared spectrum of the hydrogen peroxide solution samples to obtain near infrared spectrum data, forming an original spectrum matrix by the near infrared spectrum data, and calculating the concentration of hydrogen peroxide in the original spectrum matrix; meanwhile, forming an original concentration matrix by corresponding preparation concentration data; removing optical path errors and wave band screening from the original spectrum matrix, and then forming an input matrix with the original concentration matrix; inputting the input matrix into a 1D-CNN regression model for training to obtain a detection data feedback model; the near infrared spectrum data of the hydrogen peroxide solution with the hydrogen peroxide concentration to be detected are obtained, and after optical path errors and wave band screening are removed, the data are input into the detection data feedback model to obtain the hydrogen peroxide concentration value of the hydrogen peroxide solution with the hydrogen peroxide concentration to be detected. The concentration of hydrogen peroxide in the packaging production line is accurately detected.

Provided are a catalytic ceramic membrane, and a preparation method therefor and the use thereof. The catalytic ceramic membrane comprises a ceramic base membrane and a catalyst loaded on the ceramic membrane, wherein the catalyst comprises metal elements of Ti, Mn and Fe, and the ceramic base membrane comprises at least one of metal elements of Zr, Ti and Al. The catalytic ceramic membrane is used for the preparation of H2O2, has relatively high capability of utilizing oxygen in the air for activation, and generates hydrogen peroxide by means of air aeration without the need for inputting an additional energy (such as light and electricity), such that the generation efficiency of H2O2 is high.

The invention belongs to the cross technical field of environmental catalysis and green chemical industry, and particularly relates to a PDI / PMSO-based composite photocatalytic system and a method for producing hydrogen peroxide by using organic wastewater. According to the invention, a PDI / PMSO composite photocatalytic system is obtained by coupling a PDI supramolecular photocatalyst with methyl phenyl sulfoxide (PMSO) wastewater according to a specific concentration ratio. According to the PDI / PMSO composite photocatalytic system, the yield of H2O2 can be remarkably increased, and when the concentration of PMSO is 10 mM, the yield of H2O2 reaches 137.28 [mu] M.g <-1 >. H <-1 > and is increased by 4.3 times compared with a pure water system. The system promotes photo-induced electron-hole pair separation (steady-state fluorescence intensity is reduced by 37%) through a synergistic effect, enhances electron conduction efficiency (photocurrent is improved by 1.8 times), and keeps excellent cycle stability (the yield is kept above 80% after 10 cycles) and practical water body applicability. The method is simple in process and low in cost, and an integrated solution is provided for recycling of organic wastewater and green synthesis and application of H2O2.

The invention discloses a hydrogen peroxide sensing electrode, a preparation method thereof, a hydrogen peroxide electrochemical sensor and a monitoring method. The hydrogen peroxide sensing electrode comprises a tube body, the tube body is provided with a first end and a second end, the first end is provided with a first opening, the second end is a tip, the tip is provided with a second opening, the first opening is communicated with the second opening, and the caliber of the second opening is smaller than that of the first opening; the tip is filled with solid hydrogel embedded with catalase, and the aperture of the solid hydrogel is 20-50 nm; the tube body is filled with an electrolyte, and the electrolyte is a solution with ionic conductivity; the electrolyte is in contact with the solid hydrogel. According to the invention, nano confinement hydrogel and electrophoresis-like technologies are combined, oxygen nano bubbles are used as a signal transduction mechanism, ultrasensitive detection of intracellular H2O2 is realized through ionization sensing, and dynamic change of intracellular hydrogen peroxide can be monitored in situ in real time.

The utility model provides a hydrogen peroxide preparation device and ceiling equipment with the same. The hydrogen peroxide preparation device comprises a hydrogen peroxide preparation assembly, wherein the hydrogen peroxide preparation assembly at least comprises an electrolysis assembly and a refrigeration assembly; and the pressing assembly is provided with a pressing space, the pressing space is used for containing the hydrogen peroxide preparation assembly, and the height of the pressing space is adjustable so that the hydrogen peroxide preparation assembly can be pressed to the target thickness. By applying the scheme, the refrigeration assembly can condense moisture in air, the electrolysis assembly electrolyzes condensed water to generate hydrogen peroxide, and the pressing space of the pressing assembly is used for containing the hydrogen peroxide preparation assembly and pressing the hydrogen peroxide preparation assembly to the target thickness, so that the internal resistance of the hydrogen peroxide preparation assembly is adjusted to the target size; therefore, the electrolysis assembly can generate large electrolysis current only through a small amount of condensate water, the hydrogen peroxide generation efficiency is higher, and the problem that in the prior art, the hydrogen peroxide preparation efficiency is low is solved.

The utility model relates to the technical field of hydrogen peroxide detection devices, and discloses a residual hydrogen peroxide sampling and detection device, comprising a sampling module, a reaction module, a cleaning and degassing module, a detection module and a waste liquid collection module which are connected in sequence, wherein the sampling module comprises a wiping sampling part and a gas-liquid sampling part and an extraction part which are connected to the wiping sampling part, wherein the wiping sampling part comprises a wiping sample container; the gas-liquid sampling part comprises a collecting pump and a gas collecting pipe and a liquid collecting pipe on the collecting pump and a collector which is connected to the wiping sample container; the reaction module comprises a reaction container which is connected to the cleaning and degassing module and a color changing part which is connected to the reaction container; the device can quickly collect, color and test residual hydrogen peroxide in engineering equipment, can quickly obtain results on site, can avoid the problem of decomposition of collected materials caused by discontinuity between the collecting process and the detecting process, so that the test results are more real and accurate, can perform multi-channel detection, and can process multiple samples at the same time to further improve the detection efficiency.

The invention provides a generating device for electrochemically generating hydrogen peroxide integrated in a drum of a washing machine and the washing machine. The device serves as a functional inner component, is tightly attached to the inner wall of an outer barrel of the washing machine or in a barrel gap, does not need to be connected with an external water path, achieves high integration with the roller, and reduces occupation of the effective washing volume of the roller to the maximum extent. A first shell and a second shell are combined to form a reaction space, and a difunctional anode electrode and a difunctional cathode electrode are integrated in the reaction space and are electrically connected with a positive electrode and a negative electrode of an external power supply respectively to form a complete electrochemical loop. When water flow naturally flows through the reaction space in the washing process, a specific working potential is applied to the difunctional anode electrode under constant potential control, so that hydrogen peroxide (H2O2) and / or hydroxyl radicals (OH) are / is generated on the surface of the difunctional anode electrode in an in-situ electrochemical mode.

The application discloses a preparation method of a molybdenum-nickel hydroxyl oxide catalyst and application thereof, and the preparation method comprises the following steps: firstly, a precursor MoNi LDH material is obtained through a hydrothermal reaction; and then, the MoNi LDH material is electrochemically oxidized to obtain the molybdenum-nickel hydroxyl oxide material; and the electrochemical oxidation time is 10-60 minutes. The molybdenum-nickel hydroxyl oxide material has excellent urea catalytic activity and stability. When the molybdenum-nickel hydroxyl oxide material is applied as an anode catalyst, urea removal and hydrogen peroxide preparation can be realized, the problem of activity reduction caused by the lack of OH- in a traditional electrocatalytic process is solved, the urea removal rate in water can reach 100%, 28 g / L of hydrogen peroxide is obtained at the same time, the Faraday efficiency of H2O2 generation is maintained at 80%-90%, the device can maintain stable urea removal and H2O2 generation performance in a long running time, the activity of the generated H2O2 is high, and the H2O2 can be used for Fenton treatment of sulfamethoxazole pollutants in water, and the removal rate of sulfamethoxazole is more than 90%.

The invention belongs to the technical field of biosensing of organic electrochemical transistors, and particularly relates to an organic electrochemical transistor based on a spirobifluorene polymer as well as a preparation method and application of the organic electrochemical transistor. An active layer of the organic electrochemical transistor is composed of poly [benzo [2, 1, 3] thiadiazole-4, 7-diyl-[5-[3, 6-bis (octyloxy)-9, 9 '-spirobis [9H-fluorene]-2-yl]-1, 3-phenylene]], an ionic gel layer is prepared by mixing PVDF-HFP, EMIM TFSI and Li TFSI, and a gate electrode is modified with MnO2 nanoparticles and poly [benzo [2, 1, 3] thiadiazole-4, 7-diyl-[5-[3, 6-bis (octyloxy)-9, 9'-spirobis [9H-fluorene]-2-yl]-1, 3-phenylene]-1, 3] thiadiazole-4, 7-diyl-[5 and 2, 3-phenylene]]. The organic electrochemical transistor can be used for detection of hydrogen peroxide, is high in detection sensitivity, good in selectivity and wide in application range, and provides a new solution for detection of hydrogen peroxide.

The present invention relates to a process for bleaching keratin fibers, in particular human keratin fibers such as hair, comprising sequentially: a) applying to said keratin fibers at least one composition C comprising: i) at least one alkaline agent AA1; ii) at least one peroxygenated salt S1; and iii) hydrogen peroxide; and b) applying to said keratin fibers at least one composition F comprising: i) hydrogen peroxide; ii) optionally at least one peroxygenated salt S2; and wherein composition F is devoid of an alkaline agent, it being understood that step a) may be followed by step b) or step a) may be preceded by step b), preferably step a) is followed by step b).

The invention discloses a monatomic doped M-B-C material and a preparation method and application thereof.The preparation method comprises the following steps that metal boride, hydrogen peroxide and graphene are mixed according to a certain proportion, and the obtained mixture serves as a monatomic doped M-B-C precursor; and placing the precursor in a tubular furnace, carrying out annealing reduction in an Ar-H2 atmosphere, heating to a set temperature, carrying out heat preservation, and finally cooling to obtain the monatomic doped M-B-C material. The monatomic doped M-B-C material has a layered structure, and metal atoms are highly dispersed, so that the monatomic doped M-B-C material shows excellent battery performance.

The application belongs to the technical field of environmental catalysis and green chemical industry, and particularly relates to a PDI / PMSO composite photocatalytic system and a method for producing hydrogen peroxide by using organic wastewater. The PDI / PMSO composite photocatalytic system can significantly improve the yield of H2O2, and when the concentration of PMSO is 10 mM, the yield of H2O2 reaches 137.28 muM.g ‑1 ·h ‑1 -1.h-1, which is 4.3 times higher than that of a pure water system. The system can promote the separation of photo-generated electron-hole pairs (the steady-state fluorescence intensity is reduced by 37%) and enhance the electron conduction efficiency (the photocurrent is increased by 1.8 times) through synergistic effect, and has excellent cycle stability (the yield is maintained above 80% after 10 cycles) and practical water body applicability. The process is simple and low in cost, and provides an integrated solution for the resource utilization of organic wastewater and the green synthesis and application of H2O2.

The invention relates to the technical field of hydrogen peroxide supply, in particular to an extrusion type hydrogen peroxide supply system for a long-time test, which comprises a hydrogen peroxide supply unit, an extrusion unit, a pneumatic control unit and a blowdown unit, comprising a hydrogen peroxide storage tank I and a hydrogen peroxide storage tank II, liquid outlet pipelines at the bottoms of the hydrogen peroxide storage tank I and the hydrogen peroxide storage tank II are jointly communicated with a converging pipeline communicated with a hydrogen peroxide outlet, and the extrusion unit is used for providing extrusion gas for the hydrogen peroxide supply unit. The device is formed by connecting a plurality of storage tanks with relatively small volumes in parallel, liquid is supplied in sequence, the long-time test requirement is met, the extrusion type system extrudes dangerous liquid through inert gas, operation is safe, the structure is simple, the situation that test resources are wasted during short-time test is avoided, the hydrogen peroxide supply problem of long-time test is effectively solved, and the test efficiency is improved. And the safety in the liquid supply process is improved.

The invention discloses a control method of a hydrogen peroxide device, a control device of the hydrogen peroxide device, the hydrogen peroxide device and ceiling equipment. The method comprises the following steps that refrigeration sheet specification information and working condition information of the hydrogen peroxide device are obtained, the refrigeration sheet specification information at least comprises refrigeration sheet rated voltage and refrigeration sheet rated current, and the working condition information at least comprises electrolytic current; according to the specification information and the working condition information of the refrigeration sheet, the target working state of the refrigeration sheet is determined, and the target working state at least comprises target working voltage and target working current; based on the target working state, a control strategy set is generated, and the control strategy set is at least used for adjusting the working voltage of the refrigeration sheet to the target working voltage and adjusting the working current of the refrigeration sheet to the target working current. The technical problems of electrolyte loss and safety risk caused by the fact that water flows out of a hydrogen peroxide device due to the fact that the condensate water amount is too large in the prior art are solved.

The invention relates to a silver-nitrate recovery method comprising the process steps of preparing a nitric-acid solution in a reactor tank and feeding silver sludge into the prepared acid solution to obtain an intermediate product. The silver-nitrate recovery method further comprises introducing N2 onto the intermediate product, sweeping the resulting NOx gases with the introduced N2 and reacting them with H2O2 so as to eliminate them, and collecting the silver nitrate formed in a vessel.

The utility model discloses a kind of hydrogen peroxide precision liquid-adding control devices of loop disinfection machine, belong to the technical field of hydrogen peroxide liquid-adding, its technical scheme main point includes storage component, liquid-adding component and base, the storage component is set in the top of base, the liquid-adding component is set in the front side of storage component, by the setting of storage component, storage component can reach the effect of connecting liquid-adding component, and storage component can also play the effect of storing hydrogen peroxide liquid, by the setting of liquid-adding component, liquid-adding component can reach the effect of accurately dosing hydrogen peroxide liquid, to play the effect of hydrogen peroxide precision liquid-adding control, to make storage component cooperate with liquid-adding component use, can solve the problem that existing loop disinfection machine is not accurate when using hydrogen peroxide to disinfect, to possibly lead to unstable disinfection effect, even possibly because of excessive hydrogen peroxide to cause damage to equipment or environment.

Improved methods for reducing and preventing nosocomial infections is provide comprising installing one or more dry hydrogen peroxide (DHP) generating devices into a healthcare treatment area, producing DHP, and maintaining the concentration between 1.0 parts-per-billion (ppb) and 200 ppb.

A substrate processing method includes processing a surface of silicon with an oxidizing aqueous solution containing a hydrogen peroxide solution and an alkaline liquid to form an oxide film on the surface of the silicon, to form a channel region of a transistor; and forming a gate insulating film of the transistor on a surface of the oxide film.

This invention discloses an upflow electrochemical treatment device and method for treating wastewater containing hexavalent chromium. The device includes a cylindrical inner reaction chamber and a double-layer reaction chamber. The inner reaction chamber contains a mesh-like ruthenium-iridium-titanium anode and a carbon fiber felt membrane cathode. The double-layer reaction chamber includes an external overflow chamber and an internal upflow chamber. The method includes the following steps: S1, preliminary preparation; S2, wastewater injection; S3, continuous wastewater treatment; S4, detection. This invention mainly uses an upflow electrochemical water purification membrane for wastewater treatment, which can efficiently reduce highly toxic hexavalent chromium to less toxic trivalent chromium, effectively reducing the toxicity of the wastewater. Simultaneously, it utilizes the oxygen released during the reduction of hexavalent chromium to achieve the simultaneous generation of hydrogen peroxide, improving resource utilization and reducing treatment costs.

The application discloses a paper pulp chlorine-free bleaching method, which comprises the following steps: 1) ozone bleaching to obtain ozone-bleached paper pulp; 2) hydrogen peroxide bleaching to obtain hydrogen peroxide-bleached paper pulp; 3) chelation treatment to obtain chelation-treated paper pulp; and 4) hydrogen peroxide bleaching to obtain bleached pulp. The paper pulp chlorine-free bleaching method has the advantages of low temperature, normal pressure, low energy consumption, low cost, high efficiency, suitability for various paper pulp systems, green environmental protection and the like, and the bleached paper pulp has high whiteness, high viscosity, low Kappa number and no AOX; and the method is suitable for large-scale industrial application.

The present invention relates to a method for reducing emissions from manure, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7-3.5 g of hydrogen peroxide (H2O2) per 1 kg manure. The invention also relates to a method for improving plant growth. Furthermore, the invention relates to a manure additive for reducing emissions from manure and improving plant growth comprising H2O2 and biochar. Furthermore, the invention relates to an organic fertilizer comprising manure and the manure additive.

The invention relates to the technical field of food detection, in particular to a method for determining the iodine content in formula food for special medical purposes. The determination method comprises the following steps: (1) weighing potassium iodide, and adding water for dissolving to obtain a reference substance working solution; (2) adding water into a test sample to obtain a sample suspension, and performing alkali ashing treatment to obtain a sample solution; (3) adding a sulfuric acid solution and a reagent adopted for alkali ashing treatment into the reference substance working solution, and respectively performing derivatization treatment and organic solvent extraction on the reference substance working solution and the sample solution to obtain a reference substance solution and a test solution; (4) testing by adopting a gas chromatographic method, and calculating the iodine content; reagents adopted in the alkali ashing treatment are a potassium hydroxide solution, a potassium nitrate solution and a potassium permanganate solution (or manganese dioxide); the derivatization treatment comprises the steps of adding a sodium sulfite solution, standing, and adding a ketone reagent and a hydrogen peroxide solution to carry out a derivatization reaction. The method has the advantages of being low in cost, high in safety and high in accuracy.