203 results about "Sediment concentration" patented technology

A method is disclosed for simulating the formation of sedimentary deposits. In one embodiment, this method involves, (a) solving a two-dimensional time-dependent map view system of equations for at least flow momentum, flow height, suspended sediment concentration, and entrainment of overlying water, (b) calculating net sediment deposition at each map view location using the flow properties, (c) recording the time-variability of the net sediment deposition.

A method is disclosed for simulating the formation of sedimentary deposits. In one embodiment, this method involves, (a) solving a two-dimensional time-dependent map view system of equations for at least flow momentum, flow height, suspended sediment concentration, and entrainment of overlying water, (b) calculating net sediment deposition at each map view location using the flow properties, (c) recording the time-variability of the net sediment deposition.

The invention relates to a hydraulic model test method, in particular to a differential density flow model test method suitable for canyon-type reservoirs, belonging to the technical field of hydraulic engineering, and its IPC international patent classification number is E02B 1 / 02. In this test method, tracks are set on both sides of the model, and a sampling bridge that can move upstream and downstream along the track is set on the model. A sampling device composed of a sampling tube and a copper tube is integrated on the probe rod on the sampling bridge. The device is connected, and the negative pressure device includes a water ring pump, an air storage tank and a suction pipe. Through the negative pressure device and the sampling pipes installed at different water depths, it is very convenient and timely to sample multiple sections and different water depths, which improves the sampling efficiency and the validity of the sand content samples, and increases the data volume of the test data. The test accuracy is improved, and the work efficiency is significantly improved.

The invention discloses a silt coast high-turbidity sea area island siltation promotion engineering simulation method. A body-fitted coordinate system is adopted to discretize a study sea area, sediment grain size grouping is considered, wave radiation stress is utilized to calculate the wave influence, a two-dimensional wave current sediment mathematic model is established, the siltation promotion area is calculated, the effective siltation promotion amount is counted, the siltation promotion result is estimated, and mechanism analysis is conducted. By means of the silt coast high-turbidity sea area island siltation promotion engineering simulation method, the wave current sediment mathematic model is established aiming at unique dynamic geomorphologic features of a silt coast island of having numerous curved shorelines, large water depth, complicated underwater topography, strong tides under the effect of rotating flow, high water body turbidity suffering a lot from the weather waves, and sediment movement jointly acted by wave currents; meanwhile, the influence of bottom frictional resistance changing with different underwater topographies and shoreline shapes and sediment concentrations on sand contents in different seasons is considered, and the siltation promotion engineering dynamic geomorphology effect simulation requirements of silt coast high-turbidity sea area islands with different topographic shapes can be adapted to and met.

The invention relates to a river channel water and sediment real-time prediction method based on data assimilation, and belongs to the technical field of water conservancy projects. The method includes the steps of firstly, collecting topographic data of a water channel to be predicated, upstream boundary condition data, downstream boundary condition data and fracture surface data of the river channel, setting up a one-dimensional non-steady-flow and non-balance sediment transport model, and solving the model; secondly, conducting water and sediment model assimilation on real-time observation data while receiving the real-time observation data, and enabling the assimilation value to serve as an initial field for calculation; thirdly, calculating the changes of the future water level, the further flow and the future sediment concentration according to information of the initial field and the boundary condition data. According to the method, the water level and flow speed prediction function, the flood forecast function and other functions are achieved on the basis of data such as the assimilation real-time water level, the flow speed and the sediment concentration, and the method has the advantages of being strong in pertinency, comprehensive in function, convenient to use, practical and the like, can be applied to river channel flood real-time forecasting of great rivers, and provides the decision-making support for the practical flood prevention command work.

The invention discloses a high / low concentration-adaptive sediment movement numerical simulation method. The method comprises the following steps of: (1) establishing a high / low concentration-adaptivesediment movement mathematic model; (2) calculating a boundary condition, a suspended sediment settlement speed, a bed surface shearing stress, a stability function and correction adapted to a high / low concentration sediment condition; (3) solving the high / low concentration-adaptive sediment movement mathematic model; (4) carrying out water flow verification on the sediment movement mathematic model by adoption of practically measured data, verifying a sediment concentration and verifying channel deposit distribution; and (5) analyzing influences, on river-mouth channel sediment deposit, of each factor according to a sediment movement mathematic model result. According to the method, a three-dimensional sediment transportation simulation technology is provided, a sediment movement numerical simulation technology which considers a water-sediment interaction mechanism and a sediment suspension mechanism under high / low concentration sediment conditions is provided, so that numerical simulation research is carried out on engineering problems such as river-mouth channel sediment deposit and the like, action process and mechanism of sediment transportation are analyzed, and scientific and technological support is provided for engineering practice.

The invention relates to a method for measuring sediment concentration through density of muddy water. The method comprises the following steps: 1) preparing, namely (1) weighing mass of sediment MS which serves as a sand sample, putting the sediment into a container, measuring volume VW of clear water, pouring the clear water into the container, and stirring to form muddy water; (2) measuring volume V of the muddy water obtained in the step (1), and calculating volume VS of the sediment in the muddy water according to a formula of VS=V-VW; and (3) calculating density of the sediment according to a formula of rhos=Ms / Vs; and 2) testing, namely (1) weighing mass M of muddy water to be measured, and measuring volume V of the muddy water to be measured; (2) calculating density of the muddy water according to a formula of rho=M / V and calculating density of the clear water according to a formula of rhoW=MWVW; and (3) calculating to obtain the volume concentration of the sediment according to a formula of CV=(rho-rhoW)(rhoS-rhoW). The method can be applied to sediment concentration measurement in muddy water rivers, hydropower stations, water pumping stations and the like, sediment concentration measurement in simulation test devices and calibration of various concentration measurement instruments in pressure flow and open-channel flow, as well as solid particle concentration measurement for all solid-liquid two-phase flows comprising solid particles.

The invention relates to a method and a device for measuring sediment group settling velocity and belongs to the field of river model tests. The device comprises a settling barrel, a plurality of pressure measurement devices and a computer, wherein the settling barrel is a cylindrical container which is placed perpendicularly and provided with a cross section of any shape; a plurality of pressure measurement holes are uniformly and perpendicularly formed in one side wall; no less than 3 pressure measurement holes are provided; the pressure measurement devices are perpendicularly mounted in the pressure measurement holes and are sealed with the side wall; centers of sensing elements of the pressure measurement devices are aligned with centers of the pressure measurement holes; the pressure measurement devices are connected with the computer; the pressure intensity is measured under the control of the computer; and a measurement result is returned to the computer for analysis and storage in real time. The method calculates a change process of the sediment concentration by measuring a change process of the pressure intensity, and the sediment group settling velocity is calculated further. According to the method and the device, the sediment group settling velocity in a sandy water body can be measured automatically, without interference and accurately.

The invention discloses an infrared measurement including: 1) first to emit the infrared ray to the water without the sand from the emitter and adjust the carrier wave to zero; 2) the emitter emits some frequency infrared ray to the water with the sand; 3) the infrared receiver collects the infrared signal reflected and dispersed in the water; 4) overlapping the signal with the carrier wave signal and output an adjusted frequency signal changed by the sediment concentration; 5) last to reduce a output voltage after amplifying by the demodulating amplifier, the voltage is the signal relates to the sand concentration. The invention can measure the sand concentration of all kinds of the water because the inferred ray has the small reflectivity in the clean water and it will increase with the sand concentration.

The invention discloses a design method of anti-blockage channel structures of douches of a labyrinth channel structure, which includes five parts of: the drawing of the shape of an original runner structure, drawing of a contour map of sediment concentration with two-phase numerical simulation, redesigning of a boundary line of the runner, sizing of the shape of the runner structure, standardized designing of the boundary line of the runner, etc. The method optimizes parameters of the runner structure of the douche. Compared with the douche in the shape of the original runner structure, in the designed douche, the sediment concentration distribution in the runner is more uniform, thus basically eliminating the phenomenon that a great number of solid particles accumulate at the runner wall. Therefore, the anti-blockage capability of the douche is doubled and the service life reaches twice that of the original service life. The hydraulic performance and prototype of the designed douche remain unchanged and the manufacture technique and material usage of the products are the very same with that of present products.

The invention discloses a remote-sensing calculation method of long-term variation of suspended sediments of a strong-tide high-turbidity estuary. The method comprises the following steps: step S1, receiving Landsat satellite remote-sensing data in different years and the same hydrological condition; step S2, processing the remote-sensing data; step S3, carrying out spectral measurement above spring / neap-tide water surfaces, carrying out synchronous surface layer suspended-sediment sampling, obtaining remote-sensing reflectivity, analyzing wavebands where spectral curve peak values are located, selecting waveband data which are of different sensors on Landsat and correspond to reflectivity peak values, establishing a statistical regression model between surface layer suspended-sediment concentration and remote-sensing reflectivity corresponding to sensitive wavebands, and then obtaining an optimal calculation mode of quantitative remote sensing through accuracy verification calculation, wherein wavebands corresponding to the peak values are the sediment sensitive-wavebands; and step S4, applying the optimal calculation mode, which is of quantitative remote-sensing and is obtained in the step S3, to the remote-sensing data after processing in the step S2, obtaining remote-sensing data of the suspended sediments of all regions in the different years and the same hydrological condition, and carrying out analysis of long-term variation of the suspended sediments.

The invention discloses a fluid-solid interface wave based sediment concentration detection device and a detection method, and belongs to the technical field of ultrasonic detection and analysis. Fluid-solid Schotle waves are generated by a signal sending module at an excitation measurement side of an excitation signal module and are propagated along a bed, and fluid-solid Schotle wave signals are received by a signal receiving module; the received signals pass through a signal processing module, and then the average velocity of the Scholte waves is extracted and is processed by an algorithmmodule to obtain the average sediment concentration in a measurement range of the bottom of the detected river. The detection method provided by the invention has a large one-time detection range, and an average effect in a wave propagation range is detected by the fluid-solid Schotle waves because the sediment concentration of small regions is possibly different, accordingly, the overall macro detection and analysis are favorable; the method provided by the invention is favorable for real-time detection without sampling for re-detecting; and the relative amplitude of fluid-solid interface waves is large, so that the measurement accuracy of ultrasound can be relatively improved.

The invention provides a flocculation kinetics-based cohesive sediment movement numerical simulation method. The method comprises the steps of (1) according to a river bed topography, generating un-structured triangular grids, comprising a main river channel and a beach part; (2) according to a water flow control equation, calculating hydraulic elements of the grids, and giving out upstream and downstream boundary conditions and river channel roughness in the calculation process; (3) calculating out change situations of particle size distribution and sediment settling velocity of cohesive sediment after flocculation; (4) obtaining sediment concentration and river bed erosion and deposition change situations of the corresponding grids; and (5) repeating the steps (2) to (4) until calculation of the whole time period is finished, simulating the whole movement process of the cohesive sediment, and giving out river channel sediment field distribution and river bed erosion and deposition change. The method simulatively calculates particle size distribution change of the cohesive sediment and sediment distribution fields under different hydrodynamic conditions, solves the problem of ignoring or simplification of flocculation influence in cohesive sediment transport simulation, and provides an important technical means for accurate simulation of cohesive sediment movement.

The invention relates to an apparatus and process for disposing waste water containing organics, nitrogen and phosphor, wherein the apparatus comprises, an anaerobic rotting tank for separating solid substance from the sewage water and waste water, a flow capacity adjustment tank for controlling the load variation of flowing-in waste water, a first, second and third intermittent aeration reaction tank for treating organics, nitrogen and phosphor, a sediment concentration tank for concentrating the solid body and microorganism in the backwashed exhaust, and a drainage tank for sterilizing and draining the water treated by the reaction tank.

Characters of the test unit are that the test unit is composed of feeding reservoir, water pump, motor, nozzles of water flow, mechanism of adding sand, bracket for test piece, sand basin, and flowmeter. Water pump is connected to motor. Through pipes, feeding reservoir, pump, control valve, and nozzle is connected in sequence. Nozzle is extended to sand basin. Mechanism of adding sand is located above exit of nozzle. The bracket for test piece is positioned in front of the nozzle of water flow in sand basin. The flowmeter is on outlet pipe of the sand basin. Since test section being as free flow, the invention obtains condition of experiment including synthetical ablation, cavitation corrosion, and aeration more near to engineering practice. Features are: simple structure design, easy of manufacturing, easy of adjusting water flow and sediment concentration, wide application, reaching to 50m / s of maximum flow rate, and no ablation on nozzle.

The invention discloses a system for dynamically detecting slope runoff sediment concentration. The system comprises a weighing sensor (1), an overflow cylinder (2) arranged at the top of the weighing sensor (1) and a cylinder cover (3) arranged at the top of the overflow cylinder (2), wherein an arc groove (17) is formed at the bottom of the overflow cylinder (2), a screw rod (10) is rotatably installed in the arc groove (17), a shaft neck of the screw rod (10) is connected with a motor (11); an inclined pipe (12) is connected with an electromagnetic valve (13); the system further comprises a computer (16) which is connected with the electromagnetic valve (13), a check valve (5), the weighing sensor (1), a water pump (8), the motor (11), a zero liquid level sensor (15), and a liquid level switch (14). The invention further discloses a detection method. The system disclosed by the invention has the advantages that the slope runoff sediment concentration can be fast, continuously and dynamically measure in real time, the detection period is shortened, the measurement precision is improved, and the operation is simplified.

The invention relates to a sediment accumulation forecasting method aiming at a trenchless harbor basin channel. The sediment accumulation forecasting method aiming at the trenchless harbor basin channel comprises the steps of collecting environmental parameters of the targeted trenchless harbor basin channel, wherein the environmental parameters comprise the sediment concentration S of the water body, the sediment median diameter d 50, the average flow rate V1 of the water body before the construction of the harbor basin channel, and the average flow rate V2 of the water body after the construction of the harbor basin channel; calculating the dry density gamma 0 of the sedimentation body and the sedimentation settling velocity omega according to the sediment median diameter d 50; calculating the sedimentation volume PB which is the forecasting result within a predetermined sedimentation time t. The method is capable of better forecasting sediment accumulation of the trenchless harbor basin channel, reasonable and reliable in forecasting result, and playing a role in guiding port site selection, channel route selection and port and channel continuous running cost calculation.

The invention discloses a field observation-based construction method of a sediment resuspension model. The method includes the main steps of: acquiring observation data reflecting water body sediments and hydrodynamic features, and carrying out data preprocessing; calculating high-frequency sediment concentration data and wave feature parameters; calculating bottom shear stress, and determining critical shear stress; determining sediment settlement speed under different concentrations; and constructing the sediment resuspension flux simulation prediction model. Mainly used instruments includemeasurement equipment measuring water body hydrodynamics and silt, and field observation and a laboratory experiment result need to be combined. According to the method, an observation process is combined, the sediment resuspension prediction model which is acquired by field data and closer to reality is established, and the defect that previously a method of systematically establishing a sediment resuspension prediction model of accurate prediction does not exist is overcome. The method of the invention is simple, is convenient to implement, and provides a basis for the scientifically and reasonably established model.

The invention provides a method and device for measuring sediment concentrations of multiple points on a model through a laser, and belongs to the field of hydraulic model experiments. The method comprises the steps of water body sediment concentration and laser photo relationship calibration, water body sediment concentration measurement, water body sediment concentration calculation and water body sediment movement speed calculation; the device comprises an image acquisition module, a synchronization module, a laser device and a reflector, and the image acquisition module comprises an endoscope and an exposer. The method and device have the advantages that water disturbance is eliminated, and vertical distribution characteristics of sediments are obtained; the efficiency of measuring the sediment concentrations in the model experiments is improved; the sediment movement speed can be obtained; a brand-new sediment concentration measurement solution is provided.

The invention discloses an estuary suspended sediment concentration real-time measuring method based on sound attenuation. The estuary suspended sediment concentration real-time measuring method basedon the sound attenuation comprises the steps that an underwater sound signal sending end and a receiving end are arranged in an estuary, sound attenuation is calculated, acoustic attenuation disturbance caused by suspended sediment is calculated, and the suspended sediment concentration is iteratively calculated. According to the estuary suspended sediment concentration real-time measuring methodbased on the sound attenuation, covering areas are wide, the expandability is high, obtained parameters are more continuous in space, the detecting instantaneity is good, and the measuring precisionis high. Sound propagation technology is adopted for measuring, and the performance is better and development and application potentiality are more achieved compared with light, electromagnetic wave and other modes.

The invention discloses a method for determining the flux of sediment passing through a turbine of a pumped storage power station for heavily silt-carrying rivers. The method is characterized in that a plane two-dimensional unsteady flow-sediment mathematical model is established, the reservoir area terrain of each year in the running process of the pumped storage power station is obtained through analog calculation, the flow-sediment mathematical model is adopted to establish a relationship between the storage sediment concentration and the sediment concentration at an intake during pumping on the basis of the reservoir area terrain of each year, a sediment concentration change model of a reservoir of the pumped storage power station is established by theoretical analysis, a relationship between the sediment concentration at the intake during power generation and the sediment concentration at the intake during pumping is established, and a method for calculating the flux of sediment passing through the turbine of the pumped storage power station is comprehensively established in combination of the two relationships according to definition of the flux of sediment passing through the turbine of the pumped storage power station. The method provided by the invention can be adopted to determine the flux of sediment passing through the turbine of the pumped storage power station and provides references for selecting the model of the turbine of the pumped storage power station, formulating deposition promotion of sediment in the pumped power generation process and choosing the pumping time.

The present invention relates to an in-situ automatic monitoring method and system for the vertical distribution of sediment concentration in seawater. The steps of the monitoring method are as follows: 1) first establish a standard curve of the corresponding relationship between suspended sediment concentration and conductivity value, 2) Then measure the resistivity value corresponding to each point in the vertical direction of the sediment concentration in seawater through the resistivity probe rod, and obtain the corresponding sediment concentration value according to the standard curve established in 1), wherein the electrode spacing of the resistivity probe rod is 1.5 cm. The system includes a power supply, a central control unit, a resistivity probe rod, a digital signal collector, a memory, GPRS and a data processing module, and is characterized in that the electrode spacing of the resistivity probe rod is 1.5 cm. The invention uses a resistivity probe rod to monitor the vertical distribution of sediment concentration in seawater. The resistivity probe rod used can perform continuous and real-time monitoring of sediment concentration under any sea conditions, and can measure the suspended sediment concentration of high and low concentrations. Both are better.

The invention discloses a method for building a relation model between turbidity and single sand. The method adopts a water turbidity meter, and comprises the following steps: step 1, selecting a site as a monitoring point according to the following requirements: 1) the reach of the site is straight and has no branch flow, flow cannot ice, and silt in the flow is only suspended sediment; 2) a monitoring section is U-shaped or V-shaped; 3) a water level approaches to the historical lowest level; 4) the monitoring point is 5 to 10 meters away from water; step 2, carrying out comparing measurement, that is, on an original measurement single sand section, averaging single sand with a vertical line of mixture of a water sample being 0.2 in position relative to an original measurement single sand vertical line and another water sample being 0.8 in position relative to the original measurement single sand vertical line, wherein the water turbidity meter is arranged on a selected vertical line fixing point, a probe of the water turbidity meter is fixed on a point being 0.5m underwater for comparing measurement, and comparing measurement is carried out for 31 times or more; step 3, building the relation model between turbidity and single sand, wherein the relational expression is CS equal to KRC. The built relation model can be used for monitoring suspended load index sediment concentration automatically, the monitoring precision and the efficiency are high, and the technical problem of slow and less hydrological information sources is solved.

Depth-averaged flow simulation systems and methods provided herein employ parameterized templates for dynamical depth profiling for at least one step of a simulation. In one illustrative computer-based embodiment, the simulation method includes, for each map point at one given time step: determining a flow template and a sediment concentration template based on depth-averaged flow velocity and depth-averaged sediment concentrations of different classes of grain size for that map point; employing the templates to construct a vertically-distributed flow velocity profile and vertically-distributed sediment concentration profiles for associated classes of grain size for that map point, thereby obtaining 3D flow velocity and 3D sediment concentration fields; using the 3D fields to calculate fluid and sediment fluxes; updating the flow velocity and sediment concentration profiles based on the divergence of the fluxes; integrating the profiles to compute updated depth-averaged flow velocity and sediment concentrations and center of gravity; and solving the depth-averaged flow equations for the next time step.

The invention discloses a water tank three-dimensional topographic measurement device based on a camera image processing technology and a measurement method based on the device. The device at least comprises two sets of photographing devices and two laser emission devices, and a uniform-speed movement device of the laser emission devices. The method comprises the following steps of: photographing a water tank sediment bed surface picture by the photographing device through a wireless remote control manner; then copying the photographed picture or a recorded video into a computer; and calculating by utilizing image processing software and a calculation procedure to obtain a three-dimensional bed surface topography. The water tank three-dimensional topographic measurement device is economical and practical, and the obtained three-dimensional topography has high reliability and precision; furthermore, the measurement of a bed surface two-dimensional topography in a video mode is changed along time; the topography is measured in a non-contact manner and the movement of water flow and sediment is not interfered; and the water tank three-dimensional topographic measurement device can also be used for measuring a river bed topography with middle sediment concentration and low sediment concentration, and an experiment does not need to be paused.

The invention provides a method for separating suspended sediment concentration in a process of resuspension of submarine sediment. The method comprises the following steps of collecting one or a group of suspended sediment concentration time sequence observation data by utilizing a seabed base, carrying out pretreatment on the obtained mixed suspended sediment concentration observation data, separating mixed suspended sediment concentration by utilizing a blind source separation method, and carrying out character matching and identification on a suspended sediment concentration separation result to obtain the resuspension suspended sediment concentration of the submarine sediment. According to the method for separating the suspended sediment concentration in the process of the resuspension of the submarine sediment, which is disclosed by the invention, the suspended sediment concentration generated by advection and diffusion functions in suspended sediment concentration observation data can be separated, the resuspension suspended sediment concentration data is more accurate, the error of the observation result of the sediment resuspension process is reduced, a new manner is provided for the research on the sediment resuspension, and a new way is also provided for the source apportionment of multiple-source suspended sediment concentration.

The invention relates to a river hydrological monitoring device which comprises a monitoring bench and a base. The bottom surface of the monitoring bench is provided with a floating plate and a telescoping rod. The other end of the telescoping rod connected to the monitoring bench is connected to the base. The upper end face of the monitoring bench is equipped with a solar cell, a lightning rod, an anemometer, a rainfall measuring instrument. The side wall of the monitoring bench is equipped with a supersonic wave liquid level instrument, a sediment concentration measurer, and a water quality measurer. The monitoring bench is internally provided with a controller and a storage battery. The above measurers are connected to the controller through conductive wires. The storage battery is connected to the solar cell and the controller through conductive wires. The controller is also connected to wireless communication equipment and a memory. The device has the advantages that through installing the floating plate and the telescoping rod under the monitoring bench, the monitoring equipment of the monitoring bench can be in good contact with river water in river water rise and fall, and the normal monitoring of the monitoring bench is guaranteed.

The present invention relates to a runoff sediment content measuring equipment system and its measuring method. The measuring equipment system includes a flow measuring device, a filter weighing device and a muddy water volume measuring device connected in sequence; it also includes a microprocessor, a clock module and A storage module, the clock module and the storage module are electrically connected to the microprocessor respectively; the muddy water volume measuring device is provided with a sensor for measuring the sediment concentration in the muddy water, and the sensor is connected with the microprocessor, so The filter weighing device and the muddy water volume measuring device are respectively connected with the microprocessor. The measurement equipment system of the present invention is for automatic measurement without human intervention in the middle, saving labor costs, long-term local storage and real-time upload of data, and multiple backups; because there is no artificial sampling error, the actual measurement effect is more accurate.

The invention relates to a sampling device of sediment concentration for vertical measuring points. The sampling device comprises a plurality of sampling tubes, wherein the water inlets of the sampling tubes are arranged in different heights on the same vertical line; the upper ends of the sampling tubes are fixed on a fixing device; the upper end outlet of each sampling tube is connected with an independent conduit; a valve is arranged at the part, extending out of a testing water tank, of each conduit; a bidirectional air pressure valve is connected onto the side wall of the conduit at the upper part of each valve; an independent on-line tester of sediment concentration is connected with the tail end of each conduit; a longitudinal adjusting bolt and a transversal adjusting lead screw are arranged on the fixing device. The sampling device can greatly improve accuracy and efficiency of sediment concentration sampling of multiple vertical measuring points on the same section in a model test, greatly promotes accuracy and integrity of testing data, and is of great significance.

The invention discloses an extracting and purifying method of dysprosium oxide. Existing roughly machined collected low-purity dysprosium oxide is re-purified through the steps of to-be-purified solution preparation, intermediate agent preparation, separation column preparation, elution column transformation, adsorption operation, eluent ion exchange operation, sampling analysis according to a collected solution in volume, sediment concentration, merging and collection, liquid waste treatment and the like, so that the purity of the dysprosium oxide is up to 99.998 to 99.99999 percent.