57 results about "Wall shear" patented technology

The invention relates to the technical field of verification optimization, in particular to a color master batch extrusion molding defect prediction method and system based on a rheological model. Comprising the following steps: carrying out rheology test to obtain rheology test data; performing parameter fitting on the rheology model based on the rheology test data to obtain a rheology prediction model; obtaining a solution flow, an extrusion temperature and geometric parameters of the mold; carrying out fluid mechanics calculation to obtain a wall surface shearing rate at the outlet of the mold; inputting the wall surface shear rate into the rheology prediction model to obtain wall surface shear stress; monitoring the processing process to obtain multi-source data; performing time alignment on the wall surface shearing rate, the wall surface shearing stress and multi-source data to obtain a processing time sequence; and performing analysis and prediction based on the processing time sequence to obtain roughness early warning parameters. According to the method, prediction and early warning of the surface roughness are realized through the rheological model.

The invention discloses a high-precision lossless milling method for shear-resistant slotting of a side wall of a hard rock stratum at the bottom of a foundation pit. The method comprises the following steps: step 1, determining a position and a side line of a shear-resistant slot on the side wall of the foundation pit; step 2, sawing a horizontal groove along the side line through a disk saw; step 3, drilling a horizontal hole in the range of the anti-shear groove, and injecting a static expanding agent for controllable pre-splitting; step 4, carrying out mechanical milling on the pre-split rock mass to form a groove body; and step 5, washing the tank body and carrying out secondary milling on the undercut part based on a measurement result so as to realize high-precision forming. According to the method, through laser positioning, guide cutting, rock presplitting, hydraulic milling, high-pressure washing and secondary re-checking, multi-stage progressive control errors are achieved, and the construction quality, efficiency, controllability and environment friendliness of hard rock section shear-resistant slotting are remarkably improved.

The present invention discloses a multiphase erosion and corrosion coupled damage pipeline simulation experimental testing system and method, comprising a screw pump, a pressure measurement module, a high-pressure rubber expansion joint, a gas discharge module, a check valve, a special feeding module, a temperature control measurement module, a wall shear force measurement chamber, a fluid acceleration module, a buffer tank, a pipeline boosting module, a temperature sensor, an electric control cabinet and a copper tube coil cooler arranged on the circulation pipeline; the present invention solves the problem that the gas-liquid / gas-liquid-solid multiphase erosion and corrosion coupled damage law and the damage rate prediction are difficult to test in the harsh environment of high sulfur, high chlorine and high acid in petrochemical production equipment. By designing special feeding, pressurization, acceleration, constant temperature, anti-corrosion, anti-wear, anti-vibration and other structures, as well as temperature, flow, concentration and pressure precise control systems, long-term stable operation and precise measurement of multiphase erosion and corrosion coupled damage are achieved, effectively supporting the safety assessment and risk prevention and control of complex flow-induced damage in petrochemical production equipment.

This invention discloses a composite-structure wall shear-enhanced sintering raw material mixing and granulation device and method, belonging to the field of metallurgical sintering raw material processing technology. The device includes a storage cylinder and a stirring component disposed on its inner wall. The stirring component employs three optimized structures: a trapezoidal composite lifting component, a lifting plate and shear blade synergistic structure, or a lifting plate and inclined baffle synergistic structure. By optimizing the inner wall component structure, this invention can generate a three-dimensional composite force field of radial lifting, axial shearing, and diffusion on the material, significantly improving the mixing uniformity and granulation efficiency of the sintering raw materials, effectively controlling particle residence time, and reducing energy consumption. This invention has a simple structure, is easy to modify based on existing cylindrical equipment, and has extremely high industrial application value.

The invention relates to a static calibration system for a floating element wall surface shear stress sensor. The system comprises an electric precision displacement table, a flexible rod assembly, a micro-force probe, a mass block, a floating element and a signal processing unit, the electric precision displacement table is used for providing target force, and the target force acts on the flexible rod assembly; the flexible rod assembly transmits the received target force to the micro-force probe; the micro-force probe transmits the target force to the floating element through the mass block; the signal processing unit is used for fitting different target forces output by the electric precision displacement table and deformation quantities of the flexible flexible rod corresponding to the target forces into a first straight line, and fitting wall surface shear stresses output by the floating element corresponding to the different target forces and deformation quantity signals of the flexible flexible rod corresponding to the wall surface shear stresses into a second straight line; whether the calibrated wall surface shear stress sensor is qualified or not is judged by judging whether the linear error of the second straight line and the first straight line is within the nominal precision range of the wall surface shear stress sensor or not.

This invention discloses a fluid wall shear and compressive stress composite array sensor chip, belonging to the field of MEMS sensor technology. It includes several shear stress sensors and compressive stress sensors integrated on the chip. The shear stress sensors are arranged in a cross-shaped array, while the compressive stress sensors are arranged in a zigzag shape. These two arrays are concentrically superimposed to obtain a grid array layout. A pressure sensor is positioned at the center of the grid array. Several shear stress sensors are arranged radiating outwards along the cross-shaped direction with the central pressure sensor as the radiation center, used to measure two-dimensional shear stress. Several compressive stress sensors are arranged radiating outwards along the zigzag direction with the central pressure sensor as the radiation center, used to measure gradient pressure. This invention solves the problem that single-point measurements are insufficient to fully reflect the actual flow field stress distribution in complex fluid environments.

A high-robustness capacitance floating unit friction resistance stress chip belongs to the field of friction resistance chips, the chip utilizes capacitance comb teeth to detect the size of wall surface friction resistance stress due to the fact that fluid wall surface shear stress acts on a floating unit, and the chip comprises an electrode, a capacitance sensitive layer, a shielding layer and a shear stress sensitive layer from top to bottom. According to the chip, the vibration resistance of the chip is improved by regulating and controlling the inertial mass of the shear stress sensitive layer, the influence of complex flow field pollution particles and liquid drops on the capacitance sensitive structure is avoided through the buried design, and the high-robustness friction resistance stress chip can be formed by combining inverted leadless packaging. The friction stress chip has the advantages of strong robustness, strong long-term stability, high sensitivity and excellent performance, and can realize long-term detection of friction stress in a complex flow field environment.

The invention relates to the technical field of train aerodynamics optimization, in particular to a train surface bionic microstructure partition arrangement and drag reduction optimization method and system.The method comprises the steps that the train surface is divided into design partitions which are geometrically continuous and relatively consistent in near-wall flow form according to train appearance geometric parameters and external flow field characteristics; resistance mechanisms in the same subarea tend to be the same; a turbulent flow correction model is adopted for the design partition where the bionic microstructure is arranged, geometric parameters of the bionic microstructure are mapped into near-wall dissipation correction, and the wall surface shear stress is equivalently changed; an initial turbulence model is adopted for the non-arranged partition, and physical quantity continuity is kept at the junction through data exchange of a virtual grid; and a stable and comparable aerodynamic resistance evaluation result is obtained, and a target partition arrangement scheme is screened from candidate arrangement schemes, so that the reliability of resistance reduction optimization is improved at relatively low calculation cost.

The invention discloses a method and a system for measuring Klebanoff fringes in a boundary layer, and belongs to the technical field of aerodynamic experimental measurement. According to the method, a quasi wall surface shearing force thermal film array composed of a plurality of measuring units is laid on a to-be-measured wall surface, two groups of orthogonally arranged thermal film sensing parts in each measuring unit are utilized to synchronously measure the distribution of flow direction quasi wall surface shearing force and spanwise quasi wall surface shearing force, and the thickness of a boundary layer, the dynamic viscosity and the normal reference height of the wall surface are combined. A two-dimensional velocity field near the wall surface is obtained through inversion based on a boundary layer velocity distribution model, a wall surface normal vorticity field is solved through spatial difference, and then the transient space structure and the dynamic evolution process of Klebanoff stripes are represented. The method is suitable for boundary layer transition measurement and analysis in a wind tunnel experiment, a blade profile experiment and a blade cascade experiment, and can improve the synchronism, reliability and engineering applicability of near-wall small-scale disturbance structure measurement under a complex flow channel condition.

The invention discloses a global dynamic measurement device and method for a flow field in a confined space of a turbomachine, and belongs to the technical field of internal flow testing of the turbomachine. A dynamic probe and a hot-wire probe are matched with a surface hot film measurement unit and an oil flow visual measurement unit to obtain the pressure and the flow direction of a main flow area between turbomachinery stages, the blade normal near-wall boundary layer speed, the blade surface quasi-wall surface shear force and an end wall near-boundary layer streamline topological structure; sweeping measurement in a limited blade channel section is realized through a displacement control mechanism, and a synchronous phase locking module and a multi-channel data acquisition and processing module which take a dynamic probe periodic pressure signal as a reference are adopted. After phase sensitive detection and low-pass filtering are carried out on hot line and hot film signals, high signal-to-noise ratio extraction and strict synchronization with a rotor phase are realized, spatial and temporal distribution of a turbomachinery boundary layer is reconstructed, boundary layer separation, reattachment and transition characteristics are identified, and global dynamic measurement of a flow field in a limited space is realized.

Aspects of this disclosure are directed to optical probes for collecting images of a region of interest for determining wall shear stress. The optical probe includes an imager with a line of sight and a light guide configured to steer light from a light source to the region of interest. The optical probe includes an objective configured to focus light reflected off of the region of interest to the line of sight of the imager. The optical probe can include a micro-lens array at the objective. The micro-lens array can focus light from the objective onto the imager. The imager can collect images from the light from the micro-lens array for determining wall shear stress at the region of interest.

Ventricular catheters and their methods of use are disclosed. In some embodiments, the disclosed ventricular catheters may reduce, or substantially prevent, obstruction of the catheter by astrocytes or other brain tissue due to adhesion and / or growth within the catheter. For example, in some embodiments, the holes and internal lumen of a ventricular catheter may be constructed such that the wall shear stresses applied within the holes and internal lumen of the catheter are greater than a threshold shear stress to prevent cell adhesion and growth within the catheter.

The invention relates to a fluid wall shear pressure stress composite sensor chip and a manufacturing method thereof, and belongs to the technical field of MEMS sensors. Comprising a bottom electrode layer, a conductive substrate layer, an insulating supporting layer, a pressure sensitive layer, a metal bonding layer and a shear stress sensitive layer which are sequentially integrated in the lamination direction. The bottom electrode layer is provided with an independent pressure measuring electrode and an independent shear stress measuring electrode; the conductive substrate layer is divided into a plurality of conductive areas through the isolation grooves; the insulating support layer is provided with a vertically through electrode through hole and a double-cavity structure, and double cavities comprise a top cavity and a bottom cavity which are arranged in a through manner; the pressure sensitive layer is positioned between the top concave cavity and the bottom concave cavity; the metal bonding layer is divided into a plurality of bonding areas through the isolation grooves; the shear stress sensitive layer is connected with the insulating supporting layer through the metal bonding layer. According to the invention, in-situ synchronous measurement of fluid wall shear stress and pressure is realized, and the spatial resolution of the sensor is improved.

The application provides a tunneling and complex underground space combined ventilation characteristic numerical simulation method, a tunneling and complex underground space combined ventilation physical model is set, a ventilation characteristic numerical simulation model is established, and the flow velocity, pressure and wall shear stress distribution of the tunneling and complex underground space combined space, the pressure boosting reduction coefficient of the jet fan and the ventilation resistance are solved to realize the analysis of the jet fan arrangement and the flow field characteristics of the tunneling and complex underground space combined space, solve the pain points of the ventilation setting of the tunneling and complex underground engineering, provide the ventilation condition analysis for the tunneling and complex underground engineering, and optimize the fan layout setting.

A wall-column integrated steel structure building comprises wall stand columns and floor horizontal beams, the wall stand columns and the floor horizontal beams in the same vertical face are fixedly connected to form bearing frames, a set of parallel bearing frames are connected through shear-resisting pieces in the horizontal direction to form a three-dimensional bearing structure, and the shear-resisting pieces comprise wall shear-resisting pieces and floor shear-resisting pieces. The wall body stand columns and the wall body shear-resisting pieces are fixedly connected to form a wall body framework, and the wall body framework is compounded with the fireproof heat insulation layer to form a wall body. The floor slab horizontal beam and the floor slab anti-shearing piece are fixedly connected to form a floor slab framework, and the floor slab framework is compounded with a fireproof heat insulation layer to form a floor slab. The wall bodies and the floor slabs of the building work cooperatively, the anti-seismic capacity is high, and industrial production can be achieved.

The invention relates to an arc wind tunnel conduit test wall surface shear force determination method, and belongs to the field of aircraft ground aerodynamic heat test research, the conduit test wall surface shear force determination method provided by the invention can rapidly and accurately obtain the wall surface shear force of an arc wind rectangular conduit test based on actually measured heat flow and pressure; according to the correction method based on development, rapid evaluation of the arc wind tunnel rectangular conduit test wall surface shear force can be realized, and shear force determination of a typical aerodynamic heating environment can be realized within seconds; based on heat flow and pressure measurement, a developed correction method is combined, the wall shear force of the arc wind tunnel rectangular conduit test can be evaluated more accurately, and the error is increased by at least one time compared with that of a conventional engineering method.

An adaptive adjustment method for cleaning pressure of a pleated sintered plastic plate dust collector used in mines under humid conditions is disclosed. The method includes the following steps: defining dimensionless geometric parameters to characterize the pleated structure; constructing a dimensionless correlation function between the pleated structure parameters and the wind speed field based on the wind speed field distribution on the windward side of the sintered plastic plate in the confined underground space; constructing a mathematical model to predict dust deposition distribution in the pleated region of the sintered plastic plate based on the dimensionless correlation function; constructing a cleaning resistance correction model coupling the pleated structure and the flow field, and calculating the critical peeling stress considering the pleated structure effect; establishing a fluid-structure interaction response function covering pulse jet pressure and wall shear stress, and inverting the minimum pulse jet pressure; and implementing an adaptive graded control strategy for cleaning pressure based on the inverted minimum pulse jet pressure and the allowable equivalent stress of the coating. This invention comprehensively considers the influence of multiple factors on cleaning pressure, achieving adaptive adjustment of cleaning pressure for a pleated sintered plastic plate dust collector used in mines under humid conditions.

The invention relates to the technical field of vacuum coating deposition and metal material surface treatment, and discloses a magnetron sputtering deposition preparation method and application of a turbine rotor blade surface quasi wall surface shear force sensor. According to the method, an insulating layer is sprayed or deposited on the surface of the turbine rotor blade to achieve the electrical isolation effect, and then cleaning, ion beam bombardment and vacuum drying are sequentially conducted to activate a deposition interface; the method comprises the following steps: designing and assembling a flexible mask based on blade curved surface morphology data, and depositing a nickel or platinum thin film in situ in a mask opening limiting area by adopting magnetron sputtering to form a substrate-free thin film quasi-wall surface shearing force sensitive element; after the wire mask is replaced, a copper film is sputtered in situ to form a film-coated wire which is electrically connected with the sensitive element in a lap joint manner; and finally, carrying out electrical continuity detection and insulation integrity detection on the prepared quasi wall surface shearing force sensitive element and the coated wire. Substrate step disturbance can be eliminated, film-substrate combination and high-temperature service stability are improved, and the method is suitable for turbine boundary layer shear stress testing.

Embodiments of the present application disclose a method for detecting wall shear parameter of a blood vessel, an ultrasonic imaging system and a computer readable storage medium. The method comprises: acquiring, by an ultrasonic probe, a first wall shear stress or a first wall shear rate of a to-be-detected position on a longitudinal section and a second wall shear stress or a second wall shear rate of the to-be-detected position on a transverse section; synthesizing a three-dimensional wall shear stress at the to-be-detected position according to the first wall shear stress and the second wall shear stress, or determining a three-dimensional wall shear rate of the to-be-detected position according to the first wall shear rate and the second wall shear rate; and displaying the three-dimensional wall shear stress or the three-dimensional wall shear rate of the to-be-detected position of the blood vessel wall. In this way, a user can perform clinical evaluation related to arteriosclerosis according to the size and direction of the displayed three-dimensional wall shear stress or three-dimensional wall shear rate, thereby improving the accuracy and repeatability of detection.

The invention provides an anti-vibration interference optical wall shear stress microsensor and a measuring system thereof, and belongs to the technical field of MEMS sensors. Comprising an MEMS chip module, a four-quadrant vibration sensitive film and a dynamic anti-interference shear stress correction module, the four-quadrant vibration sensitive film and the dynamic anti-interference shear stress correction module are installed on the MEMS chip module, and the four-quadrant vibration sensitive film is arranged on the lower surface of a floating element of the MEMS chip module in a quaternary orthogonal circumferential array mode and located on the periphery of a movable grating film on the lower surface of the floating element; the dynamic anti-interference shear stress correction module projects a vibration vector of a four-quadrant vibration sensitive film to a sensitive axis direction of the shear stress microsensor, extracts a vibration interference component along a shear stress measurement direction, and compensates a vibration coupling error in a shear stress signal in real time in combination with a low-pass filtering algorithm. And completing anti-interference calculation of the shear stress. The problems of limitation and vibration interference of traditional single parameter detection are solved.

An experimental model based on plasma synthetic jet array excitation is provided to promote the enhancement of cavity mixing. A wall shear stress sensor is arranged upstream of the leading edge of the cavity, a wall shear stress sensor is arranged on the rear vertical surface of the cavity, and a dynamic pressure sensor is arranged on the bottom surface of the cavity. By applying amplitude and phase modulation to different rows or columns of plasma synthetic jet exciters, a traveling wave standing wave excitation method is realized to intelligently enhance the mixing of the cavity. First, a plurality of groups of excitation parameters are randomly initialized and the flow control benefits are evaluated; second, a proxy model is constructed to predict the best combination of excitation parameters by means of an intelligent optimization algorithm; finally, the discharge trigger signal sequence of the power supply is solved in reverse, and the benefits are improved through iterative testing. The plasma synthetic jet traveling wave standing wave excitation method has higher penetration depth, stronger mixing ability, better adaptability, and is more intelligent, and can better meet the needs of flame stable combustion under the wide working boundary of a scramjet engine.

This invention discloses a roadway sidewall support design method based on shear failure theory. Addressing the problem that existing suspension theories cannot explain the sidewall failure mechanism, it proposes that sidewall failure is essentially shear slip; by establishing shear angle... θ =45°- Φ / 2. Height of loose material in the tunnel roof h 1=( B +2 H tan θ ) / (2 f ), width of loose body in the side J = H tan θ, Determine the number of anchor bolts per row N = K ( G 1+ G 2) / ( T tan θ This method employs a core formula system to accurately calculate the number, spacing, and length of rock bolts in the ribbed wall. All parameters in this method are directly related to the mechanical properties of the surrounding rock. Through the principle of mechanical equilibrium, it accurately calculates the rock bolt support parameters for the roadway ribbed wall, conforming to the ribbed wall shear failure mechanism. The design results are consistent with engineering practice. This method not only explains the ribbed wall failure mechanism but also provides calculation results that are highly consistent with reality, demonstrating significant safety and economic benefits.

The present application relates to the technical field of flow distribution disc, and particularly relates to a high-pressure flow distribution disc three-section flow groove anti-cavitation structure, which comprises a flow distribution disc, the flow distribution disc comprises two centrally-symmetrically arranged large waist-shaped grooves, small waist-shaped grooves are symmetrically arranged on the two sides of the large waist-shaped grooves, the small waist-shaped grooves are arranged through the flow distribution disc, three-section flow grooves and a second single-section flow groove are respectively arranged at the two ends of the large waist-shaped grooves, and the two three-section flow grooves are centrally symmetrically arranged; the three-section flow groove comprises three triangular grooves which are completely identical in structure, the three triangular grooves are arranged at equal intervals, and one end of a same circular-arc groove is communicated with the end portions of the three triangular grooves, and the other end of the circular-arc groove is communicated with the large waist-shaped groove. The present application can increase the flow area, reduce the jet velocity, weaken the influence of wall shear force, thereby inhibit vortex production, further inhibit cavitation phenomenon of the flow distribution disc of the axial plunger pump under high-pressure working condition, reduce flow pressure pulsation and cavitation, and improve the efficiency and service life of the axial plunger pump.

The invention discloses a coke tower switching control method, device and equipment in delayed coking and a storage medium. The method comprises the following steps: respectively generating a three-dimensional thermodynamic model when each coke tower is in a coke forming state, and meshing the three-dimensional thermodynamic models; according to the three-dimensional thermodynamic model, a lumped kinetics model is introduced, the physical significance of the adhesion phenomenon of the free coke and the wall surface in the coking process is mathematized, and reaction kinetics and stress analysis related to the free coke in the coking process are further defined by calculating the change condition of multiphase flow in a coke tower. Therefore, the coking data in the coke tower can be quickly and accurately acquired by acquiring the theoretical coking amount of reaction kinetics, analyzing the adhesion force of the free coke to the wall surface, the interphase drag force of gas, liquid and solid, the gravity and the shear stress of the wall surface, and blowing the flowing fluid; therefore, the coke towers can be timely switched under the condition that the pyrolysis space of the coke towers is fully utilized, so that the treatment efficiency of the device is effectively improved, and the redundant waste of the treatment capacity of the coke towers is reduced.

The present application relates to the technical field of vacuum coating deposition and metal material surface treatment, and discloses a method for preparing a quasi-wall shear stress sensor on the surface of a turbine rotor blade by magnetron sputtering deposition and application. The method sprays or deposits an insulating layer on the surface of the turbine rotor blade to achieve an electrical isolation effect, and then sequentially performs cleaning, ion beam bombardment and vacuum drying to activate the deposition interface; a flexible mask is designed and assembled based on the blade surface topography data, and a nickel or platinum thin film is deposited in situ in the mask opening limited area by magnetron sputtering to form a substrate-free thin film quasi-wall shear stress sensitive element; after replacing the wire mask, a copper thin film is sputtered in situ to form a plated wire electrically connected to the sensitive element; finally, the prepared quasi-wall shear stress sensitive element and plated wire are subjected to electrical continuity detection and insulation integrity detection. The present application can eliminate substrate step disturbance, improve film-substrate adhesion and high-temperature service stability, and is suitable for turbine boundary layer shear stress testing.

This application discloses a method for detecting the wall shear parameters of blood vessels, an ultrasound imaging system, and a computer-readable storage medium. The detection method includes acquiring a first wall shear stress or a first wall shear rate on a longitudinal section and a second wall shear stress or a second wall shear rate on a cross section at a test location using an ultrasound probe; synthesizing a three-dimensional wall shear stress at the test location based on the first and second wall shear stresses, or determining the three-dimensional wall shear rate at the test location based on the first and second wall shear rates; and displaying the three-dimensional wall shear stress or three-dimensional wall shear rate at the test location of the blood vessel wall. Thus, users can perform clinical assessments related to arteriosclerosis by observing the magnitude and direction of the displayed three-dimensional wall shear stress or three-dimensional wall shear rate, improving the accuracy and repeatability of the detection.

This invention discloses an internal wave prediction method based on wall sensors. First, it acquires parameters such as the thickness of the density cascade layer, the location of the density cascade center, the density values ​​of the upper and lower layers, wave amplitude, and buoyancy frequency. These parameters are then used in a numerical solver to solve the DJL equations, constructing the initial flow field for the internal wave. Calculation settings are configured in Fluent. Sensor measurement points are placed on the wall of the vehicle and data is transmitted. In Fluent, the pressure and wall shear stress data at the nodes are stored in ASCII format. A convolutional neural network is used to convert the input data into a dual-channel image format, with one channel storing pressure data and the other storing wall shear stress data. The coordinates and amplitude of the vehicle relative to the wave trough are used as labels. Finally, the convolutional neural network is trained, enabling the prediction of internal waves. This invention enables real-time prediction of internal isolated waves using sensors, which has significant engineering application value for ensuring the safe operation of vehicles.

A method for delivering a therapeutic agent to a tumor through a target vessel includes delivering the therapeutic agent through a lumen of a catheter which has been coated or otherwise structured to reduce the wall shear stress during delivery of the immunotherapy and by generating turbulent flow during the delivery of the therapeutic agent.

The invention relates to the technical field of dust removal control, in particular to a surface dust removal control system for powder compression molding, which comprises a dust removal control module, a dust feature acquisition module, a dust removal performance judgment module, a dust removal working condition acquisition module, a dust removal working condition judgment module and a dust removal process correction module, the dust characteristic acquisition module acquires wall surface shear force, purging coverage rate and airflow dead zone residual value in a powder compression molding demolding purging period, and analyzes dust particle size characteristic characterization value; the dust removal performance judgment module determines whether the momentum transfer effectiveness of the dust removal pulse injection device meets the standard or not; in response to the non-compliance with the standard, the dust removal working condition acquisition module acquires the airflow pressure attenuation rate and the local airflow backflow amplitude in the same purging period, and analyzes the feature representation value of the dust removal pulse valve; the dust removal working condition judgment module determines whether the stability of the airflow pressure field of the dust removal pulse injection device meets the standard or not so as to determine a treatment strategy. The surface dust removal control efficiency is improved.