Optical method of registration of kinetics of particle aggregation in turbid suspensions

FIELD: measurement equipment.

SUBSTANCE: invention relates to measurement equipment, namely, to optical methods for registration of particle aggregation during performance of immunochemical reactions, for instance, using particles of micron size with reagents immobilised on them. During the reaction such particles are aggregated, formation of aggregates is recorded by turbidimetric or nephelometric method. Due to large size of initial particles their mutual approaching due to Brownian motion is slow, and formation of aggregates takes place in a non-uniform manner in the reaction volume, therefore to increase speed of aggregation and accuracy of its supervision the suspension of reagents must be mixed. Mixing is carried out by or at the expense of cyclic movement of magnetic particles placed into the mix, or the mix flow in the mode of flooded jet, or by means of reciprocal movement of the mix along the cuvette.

EFFECT: method accelerates the reaction and increases accuracy of measured kinetics.

5 cl, 6 dwg

 

The invention relates to measurement devices, and more specifically to optical methods of registration of aggregation of particles when performing immunochemical reactions, including for the purposes of clinical diagnosis. Such methods are widely used in biology and medicine, as on routine measurement in clinical diagnostic laboratories, and the development and improvement of biomedical technologies. In many problems of interest to determine the kinetics of aggregation (agglutination, precipitation) of micron and submicron particles. Under the kinetics of aggregation refers to the time dependence of the relative degree of aggregation and the relative velocity of aggregation from time to time. Under the relative degree of aggregation is the ratio at a particular point in time of the optical signals to analyze and control samples (control sample is included in a diagnostic kit). Under the relative rate of aggregation refers to the derivative of the relative degree of aggregation over time. Immunological studies, for example, the method of detection of antibodies and antigens based on the agglutination of latex particles sensitized with antigens or antibodies (i.e. containing antigens or antibodies on their surface). Based on this principle many owls the temporal diagnostic kits (test systems), intended for the diagnosis of various diseases and pathologies.

The characteristic size of the particles involved in the processes of aggregation, can be quite a wide range from tens of nanometers to several micrometers, within considerable limits may change the concentration of these particles. Therefore, in many cases it is necessary to investigate the aggregation in a rather turbid medium.

In the study of the processes of aggregation of particles in liquid media used optical methods based on measuring changes in intensity of the transmitted light through the sample cell (the so-called turbidimetry)or scattered by the particles at a certain angle (nephelometry), and measuring the intensity fluctuations of scattered light [2, pp. 80-88], the value of which changes in the aggregation process (the fluctuation nephelometry).

Also widely used visual registration methods, the use of which is primarily due to the simplicity of the setting reaction of aggregation, as well as the challenges of the apparatus registration of optical parameters in muddy and heterogeneous suspensions.

The size and concentration of sensitized particles must be consistent with the method of registration. Currently in kits designed for turbidimetric or values accounting results, use the aggregation of small is astiz (particle size α~0.1λ). Such particles is relatively little scatter light; when particle concentration of 1-10 mg/ml, typical of diagnostic kits, free path length of light L=1/nσ, where n is the number concentration of particles, σ is the cross section for the scattering of one particle in such suspensions is typically of the order of 10 mm, which Is comparable with the length I of the optical path of light in standard cuvettes (usually L≳l). Therefore, suspension of single particles of size α~0.1λ have relatively low turbidity and the formation of small aggregates (for example, the size of two to three particle diameters) turbidity (i.e., the scattering of light mix) increases [3]. Small particles diffuse fast enough, so the speed of the reaction of their aggregation weakly dependent on the availability and parameters of stirring the reaction mixture; diffusion provides a uniform distribution of aggregates and, consequently, a uniform reaction throughout the volume of the mixture. Thus, aggregation of small particles can be registered methods turbidimetry and(or) by nephelometry.

However, from the point of view of information content immunochemical analysis using large particles (α~λ) has the following advantages compared with the use of particles of small size (α~0.1λ).

The detection limit of the aggregation reaction on the analyte for large particles substantially n the same than for particles of small sizes. It is known that the most efficient formation of aggregates is achieved at a certain ratio of the accounts concentrations sensitized particles and molecules of the analyte [4], therefore lowering the threshold of detection of the analyte is required reducing the number concentration of particles. In this case a reduction of the mass concentration of particles leads to a decrease of the reaction rate and, therefore, increase the time of registration. In the case of large particles, their number concentration is lower than when using small particles of the same mass concentration, respectively, below the threshold of detection of the analyte without loss of expressnet diagnostic test. The use of large particles allows the reaction of aggregation in undiluted biological fluids, often with considerable turbidity. In order to reliably register the aggregation, it is necessary that the light scattering particles was much higher than its own scattering turbid liquid. Since particles of large size (α~λ) effectively scatter light [3], aggregation can be securely even in undiluted or in a weakly diluted biological fluids in contrast to small particles (α~0.1λ), which weakly scatter light [3], resulting for reliable registration of their agregats and often requires a strong dilution of the body fluids high turbidity. The use of large particle size allows the aggregation reaction, for example, whole blood, which has important diagnostic value.

However, the implementation of these advantages of large particles in diagnostic kits fraught with significant difficulties, which are listed below.

Large particles slowly diffuse, so the rate of aggregation is relatively low, in addition, because of the weakness of the diffusion formation of aggregates is uneven in volume of the reaction mixture, especially when a small number concentration of the analyte. Another problem is that when the formation of small aggregates (for example, the size of two to three particle diameters), the intensity of light scattering changes relatively weak [3]. Therefore, to secure such aggregation is possible only in the later stages, when the formation of aggregates consisting of a relatively large number of particles. In addition, suspensions of single particles of size α~λ may have a relatively higher turbidity (usually L≲0.1 mm, i.e. for standard cuvettes L<<l), which limits the use of optical methods, working on the assumption of single scattering of light. Because of these difficulties for diagnostic sets with large particles in real time aggregation is fixed mainly on the endpoint visas is real, including using photoresistive device. For such a large Desk turbidity of the reaction mixture and the uneven distribution of aggregates by volume of the mixture is not an obstacle, in contrast to the Desk with turbidity meters and turbidimeters.

Visually check the degree of aggregation, despite the simplicity and accessibility, has the following disadvantages.

Visual determination of the degree of aggregation is characterized by low accuracy, being essentially qualitative or, at best, semi-quantitative method. Visual reaction accounting complicates the automation of the measurements. The necessary involvement of staff in almost all stages of the reaction increases the frequency of errors. Visual reaction accounting is done only at the end point of the reaction aggregation, since the formation of visible aggregates is possible only at a late stage of the reaction, when the units reach the size resolvable by the human eye (~0.1 mm).

Therefore, attempts optical registration aggregation of large particles.

Known optical method of measuring particle size using multiple-angle light scattering (MALS), which allows us to measure the particle sizes in a wide range (from 50 nm to 100 µm) [5]. The disadvantage of this method that prevents its application to suspensions of high turbidity, Tr is the requirement of a strong dilution of the analyzed suspensions, because this method only works when you register once scattered light. Preliminary dilution of the suspension of sensitized particles would lead to a corresponding reduction in the rate of aggregation and to a huge increase in the time of its registration, i.e. to reduce expressnet a diagnostic kit, which is highly undesirable. The dilution for the purposes of registration after conducting the reaction for a large particle size is undesirable procedure, as may lead to the destruction of aggregates [2, s].

Known optical method of dynamic light scattering (ODCs), which allows to measure the size of particles in a wide range (from 1 nm to 6 µm), allowing the analysis of suspensions of high turbidity [6]. The disadvantage of this method is a great time to obtain a single reference on the kinetic curve (of the order of minutes). In addition, DSU registers scattered light from the region of a mixture of relatively small volume (about 0.1 mm3), the so-called "coherent volume, which leads to an increase in the amplitude of low frequency fluctuations in the detected signal due to the heterogeneity of the distribution of the resulting aggregates by volume of the reaction mixture. A significant disadvantage of the DSU to determine the aggregation of particles is also the impossibility of organizing paramesh is of the sample in the cell to increase the rate of reaction and homogeneous distribution of the resulting aggregates by volume of the reaction mixture. Another disadvantage of the DSU - the high cost of the devices.

Known optical method of registration of aggregation of the particles by changing the intensity of light scattering in a thin layer of the suspension in advance the slide (Multi-well slide) [7, 8]. The disadvantage of this method is the technical difficulty of ensuring mixing of the sample in a thin (thickness of a fraction of a mm) layer in the hole of the slide to increase the rate of reaction (such stirring prevents, in particular, surface tension). Another drawback is the complexity of creating a standard film sample in the area of the sensing beam of light, reproducible from experiment to experiment.

Known optical method of counting and measuring the size of particles and their aggregates [9], or the degree of aggregation of the particles [7, 8] by recording the light scattered by the particles and their aggregates in microfluidic cuvette. The disadvantage of this method is the impossibility of recording the kinetics of aggregation - registered education units on one particular stage of the reaction, since the reaction is carried out outside the optical reception prior to placing the mixture in a microchannel. It is connected by the complexity of mixing in microchannel to accelerate aggregation. Also the disadvantage of this method is the high technical complexity of it " is.

Closest to the claimed is "a Method of analysis of platelet aggregation and device for its implementation" [10, prototype]. In this method, the luminous flux passes through the sample containing platelets and(or) their units, provided they move through the formed optical channel, which allows to measure the average intensity and at the same time the standard deviation of the intensity transmitted through the sample luminous flux from the average intensity, caused by fluctuations in the number of platelets or their aggregates in the optical channel, which set the average radius and the concentration of the number of platelets or their aggregates in the optical channel.

The specified prototype has the following disadvantages. The application of this method to register aggregation sensitized particles of large size (α~λ) is difficult, because the movement of the particles or their aggregates via the optical channel in the specified method is carried out by mixing the liquid in the cuvette using a magnetic stirrer. However, this stirring of the reaction mixture are only circular laminar flows in a ditch because of aggregometry [10] at the maximum rotational speed of magnetic stirrer Reynolds number Remax≈500, and turbulent flows in the system cuvette-magnetic whom I stirrer develop at Reynolds numbers of order Re kr≈10000 [11]. Due to the lack of turbulent flow does not significantly increase the speed of the relative motion of fluid particles in comparison with the speed of diffusion. The result is not a significant increase in the number of collisions and the reaction rate, therefore, requires a large time for the registration of aggregation of particles. For example, in the case of the use of the diagnostic kit of reagents MAH-Endotox spp. [12] the analysis time exceeds 20 minutes, the Set of MAH-Endotox spp. used for the rapid diagnosis of surgical infections and infectious complications, and therefore expressnet is of the utmost importance when applying it. Also, when using this method the signal change which is judged on the kinetics of the reaction, greatly fluctuates due to poor mixing of aggregates, which reduces the accuracy of registration of the kinetics of the reaction because of the resulting discontinuities. This intensification of mixing by increasing the rotation speed of the agitator is not valid, because it leads to the destruction of the formed aggregates in the zone of interaction with the rotating magnetic stirrer rod.

The aim of the invention is to overcome these disadvantages, namely reducing the time of registration reactions aggregation and increase the accuracy of observation of the kinetics reactivate is achieved by providing intensive turbulent mixing volume of the reaction mixture, what contributes to the relative motion of the reacting particles even at their relatively large sizes with speeds exceeding Brownian because turbulent flow have a high potential for rapid spread of chemical reactions and the ability to carry and transmit particles [13]. This greatly increases the reaction speed and accuracy of her observations of the kinetics due to the acceleration of the redistribution of the formed aggregates by volume of the mixture. In this case there is destruction of the formed aggregates as the main energy flows contained in microturbulence and there is no significant relative movement of the liquid layers in the scale of macroaggregates.

The method is illustrated by the 6 figures.

Figure 1 shows the implementation of the method in the conical cell, where 1 is the source of probing radiation, for example laser, 2 - cell with a test specimen, 3 - detector intensity of the transmitted radiation, 4 - detector intensity of the scattered radiation, 5 - channel registration fluctuations of the intensity of scattered radiation, 6 - reciprocating pump.

Figure 2 shows the implementation of the method using submerged jet, where 7 - a thin tube.

Figure 3 shows the implementation of the method using magnetic particles, where 8 is the mechanism of creation of periodically is anyone's magnetic field, for example, a rotating magnet.

Figure 4 shows experimental data on the measurement of the reaction kinetics of aggregation in cone cell under different methods of mixing, where 9 is the recorded signal without mechanical mixing environment, 10 - mixing environment of the magnetic particles 11 - mixing medium pump, 12 - mixing pump and magnetic particles. Hereinafter, the abscissa axis is time in seconds, y-axis is the logarithm of the intensity of the recorded signal.

Figure 5 shows the experimental data for the cell constant cross section, where the 13 - mixing environment by the pump submerged jet mode.

Figure 6 shows experimental data on the measurement of the kinetics of the same reaction under stirring environment existing method - a magnetic stir bar.

The proposed method can be implemented in different ways; possible options for implementation are explained in the examples below describe the device.

The proposed method can be implemented by using a tapered cuvette (figure 1). Radiation, for example, the laser source 1 is passed through the sample cell 2 and register the photodetector 3, the intensity of the previous radiation and/or scattered radiation sensor 4 and/or fluctuations in this radiation on channel 5 using one or more photodetectors. For treason is, s (increase of all three signals in case the original large mutota) signals from photodetectors judge the reaction. The increase in signal associated with a decrease in turbidity of the medium in the process of formation of aggregates due to the reduction of multiple scattering on the particles of the medium and reduce the total cross section of scattering of all particles in the formation of large aggregates (≳10α) [3]. In the case of large initial mutota the scheme of registration of radiation is not significant and can be chosen based on the particular design of the device. For example, in the case of low ditch (conical plastic tip pipetochnoe dispenser) it is convenient to use the fluctuation nephelometry (channel 5), because it is not sensitive to constant illumination.

The analyzed mixture moves along the cell, for example, the piston 6, the reciprocating movement and the hydrodynamically connected with the mixture. To prevent contamination of the mixture between the piston and the mixture may be an air gap and/or separating the flexible membrane. During the flow of the reaction mixture in the conical cell in the direction of its extension (the so-called flow in the diffuser), the formation of turbulent flows at low Reynolds numbers [14, p.113-118], which leads to an increase of the reaction rate and accelerates the redistribution of the formed aggregates by volume of the mixture.

Also the proposed method can be implemented according to the scheme in which turbulent flows implement is described by a so-called submerged jet in the reaction volume (figure 2). Diagram check this similar to Fig 1. In the analyzed mixture is placed a thin tube 7, the hydrodynamically connected with the piston 6, resulting in part of the volume of the mixture periodically drawn into the pipe/is popped from it. To prevent contamination of the mixture between the piston and the mixture may be an air gap and/or separating the flexible membranes. While pulling the reaction mixture from the tube into the cell formed by the so-called submerged jet, which provides a turbulent flow in the reaction mixture [14, pp.118-121]. This leads to an increase of the reaction rate and accelerates the redistribution of the formed aggregates by volume of the mixture.

Also the proposed method can be implemented by a location in the reaction mixture of magnetic particles, driven periodic magnetic field. In the analyzed mixture is placed magnetic particles, the surface of which is inert to the components of the reaction mixture. The source of the periodic magnetic field 8, for example, a rotating permanent magnet, causes the formation of chains of magnetic particles and their cyclic motion in the liquid, which act as a set of micromagnetic mixers, creating microturbulence, which leads to an increase of the reaction rate and accelerates the redistribution of the resulting aggregates is about the volume of the mixture [15]. The concentration and/or size of the magnetic particles is chosen much smaller concentration and/or size of the aggregate particles to the scattering of light at the operating wavelength of the added particles was significantly less scattering of the reaction mixture. Due to the high turbidity of the reaction mixture, this requirement is quite real.

The advantages of the proposed method are illustrated by the following experiments. The reaction of the aggregation of activated particles of a diagnostic kit MAH-Endotox spp. [12] conducted in a commercial device for analysis of platelet aggregation [10] (aggregometry) and install that implements this method. In the case of aggregometry used a cylindrical glass cuvette internal diameter of 6 mm, the volume of the sample was 320 mm. For the implementation of this method used 2 types of cells: standard tips to pipetochnoe dispensers 200 μl and standard photometric polystyrene cuvettes (10×4×25 mm3), the volume of the samples was 120 and 520 μl, respectively. 20 μl of diagnosticum MAH-Endotox spp. [12] were diluted with the buffer solution, forming part of a diagnostic kit (in the case of mixing magnetic particles also contributed suspension of particles), then added a control serum in the same proportion that all reactions the concentration of the situation of the lipopolysaccharide of gram-negative bacteria (LPS) was 100 PG/ml

Figs.4-6 presents the curves aggregation of diagnosticum MAH-Endotox spp. adding control sera with different types of mixing and optical methods of registration. The abscissa axis represents time in seconds, y-axis is the logarithm of the signal intensity or the intensity fluctuations in the case of values the sign-up method or fluctuation method nephelometry [1] respectively). The reaction mixture was thermostatically at 37°C, the addition of control sera was performed at time 0.

Figure 2 presents the experimental curves of aggregation of particles of diagnosticum MAH-Endotox spp. in conical tip for pipetochnoe dosing in the absence of mixing (9), while stirring the magnetic particles according to scheme 3 (10), under stirring piston 6 according to scheme 1 (11), and while stirring under these schemes (12). When this was recorded fluctuations of the intensity of scattered reaction mixture is light scheme 5 figure 1. You can see different behavior education units over time under different methods of mixing, and that their combined use results in the most efficient formation of aggregates throughout the reaction.

Figure 5 presents the curves of particle aggregation in the photometric cuvette in the absence of premesis the tion (9), when mixing the magnetic particles according to scheme 3 (10) and submerged jet scheme 2 (13). When this is detected the intensity of scattering reaction mixture is light (nephelometry).

For comparison, figure 6 presents the curve aggregation of diagnosticum MAH-Endotox spp. in aggregometry under stirring with a magnetic stirrer under the scheme of the prototype, the rotation speed of 800 rpm

Examples of reactions demonstrate the benefits of registration reactions aggregation of large (α~λ) particles in turbulent mixing. It is shown that turbulent mixing one or two orders of magnitude increases the rate of reaction of aggregation and registration accuracy of its kinetics.

Thus, the proposed method industrial implement and allows to achieve the stated objectives, namely a significant reduction of registration time reactions aggregation and increase the accuracy of observation of the kinetics of the reactions.

References

1. US 7209231. Optical detection of particles in liquid medium.

2. Latex immunoagglutination assays. J.A. Molina-Bolivar, F. Galisteo-Gonzalez. Polym. Rev.45 (2005) 59-98.

3. An experiment to measure the Mie and Rayleigh total scattering cross sections. Cox, A.J.; Deweerd, Alan J.; Linden, Jennifer. American Journal of Physics, Volume 70, Issue 6, pp.620-625 (2002), p.621.

4. TechNote 304. Light-Scattering Assays. Bangs Laboratories, Inc. Rev. #002, Active: 11/April/2008, p.2.

5. Analysis of Aggregates and Particles in Protein Pharmaceuticals, Wiley, New Jersey, 2012, p.p.37-60, 305-334.

6. Modulated 3D cross-correlation light scattering: Improving turbid sample Charcterization. Ian D. Block and Frank Scheffold. REVIEW OF SCIENTIFIC INSTRUMENTS 81, 123107 (2010).

7. Sensitive Mie scattering immunoagglutination assay of porcine reproductive and respiratory syndrome virus (PRRSV) from lung tissue samples in a microfluidic chip. Jae-Young Songa, Chang-HeeLeea, Eun-Jin Choia, KeesungKimb, Jeong-YeolYoonc. Journal of Virological Methods 178 (2011) 31-38.

8. Nanoparticle immunoagglutination Rayleigh scatter assay to complement microparticleimmunoagglutination Mie scatter assay in a microfluidic device. Brian C.Heinze, Jeong-Yeol Yoon. Colloids and Surfaces B: Biointerfaces 85 (2011) 168-173.

9. Counting and sizing of particles and particle agglomerates in a microfluidic device using laser light scattering: application to a particle-enhanced immunoassay. Pamme N, Koyama R, Manz A. Lab Chip. 2003 Aug; 3(3): 187-92. Epub 2003 May 30.

10. WO 8910562. The method of analysis of platelet aggregation and device for its implementation.

11. Similitude in Stirred-Tank Reactors: Laminar Feed. L.J. Forney. AIChE Journal, Vol.49, No.10, pages 2655-2661, October 2003, p.2661.

12. WO 2009/04835. Diagnosticum for determining the presence of total endotoxin (lipopolysaccharide-LPS) of gram-negative bacteria and also the genus and type of gram-negative bacteria producing endotoxin, method for producing said diagnosticum and a set.

13. The great Soviet encyclopedia: [30 so]/ CH. Ed. by A.M. Prokhorov. Issue 3-E. - M.: Owls. day., 1969-1978, t., with 324.

14. Landau L.D., Lifshitz E.M. Theoretical physics - vol. 5-E. - 2006 .VI. Hydrodynamics. §23.

15. Effective mixing in a microfluidic chip using magnetic particles. Lee et al. Lab on a Chip. 2009 Feb 7; 9(3):479-82.

1. Optical method for detecting aggregation of sensitized particles in turbid suspensions, including turbulent mixing of the investigated mixtures, lighting probing optical radiation, the registration of the time-dependent intense is vnesti and/or fluctuations of the intensity transmitted through the sample cell and/or scattered radiation and the determination of the kinetics of aggregation of particles by changing the intensity fluctuations of intensity), characterized in that the mixing in the mixture is placed in the magnetic particles, and stirring is carried out due to the circular motion of particles in a fluid under the action of an alternating magnetic field.

2. The method according to claim 1, characterized in that the surface of the magnetic particles are inert, i.e. it does not interact with components of the reaction mixture.

3. The method according to claim 1, characterized in that the concentration and/or size of the magnetic particles are selected much lower concentration and/or size of the aggregation of particles.

4. Optical method for detecting aggregation of sensitized particles in turbid suspensions, including turbulent mixing of the investigated mixtures, lighting probing optical radiation, the registration of a time-dependent intensity and/or fluctuations of the intensity transmitted through the sample cell and/or scattered radiation and the determination of the kinetics of aggregation of particles by changing the intensity fluctuations of intensity), characterized in that the mixture is stirred by the flow of the mixture in the submerged jet mode, while moving the mixture is performed by means of a pump operating in a reciprocating mode.

5. Optical method for detecting aggregation of sensitized particles in turbid suspensions, including turbulent mixing investigated sm is si, the lighting of the probing optical radiation, the registration of a time-dependent intensity and/or fluctuations of the intensity transmitted through the sample cell and/or scattered radiation and the determination of the kinetics of aggregation of particles by changing the intensity fluctuations of intensity), characterized in that the mixture is placed in a conical cell, and the stirring of the mixture is carried out by reciprocating movement of the mixture along the cell, while moving the mixture is performed by means of a pump operating in a reciprocating mode.



 

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2 ex

FIELD: medicine.

SUBSTANCE: method for the clinical outcome assessment in severe and moderate acute pancreatitis with predominant pancreatic head and isthmus involvement consists in computed tomography angiography of the abdominal organs with bolus contrast enhancement, including: pancreatic involvement volume, %; necrosis depth in a sagittal plane, %; inflammatory infiltrate of the peripancreatic mass; fluid collection in the peripancreatic mass; biliary hypertension signs; free fluid in the abdominal cavity; a complete blood count is measured to determine a neutrophil response; a biochemical blood assay and a urine analysis are used to determine blood amylase, total bilirubin; each sign is certainly scored; if total score is 9 and more, an unfavourable clinical outcome of acute pancreatitis with the predominant pactreatic head and isthmus involvement is considered to be likely.

EFFECT: higher assessment accuracy.

6 tbl, 3 ex

FIELD: physics, atomic power.

SUBSTANCE: invention relates to nuclear power engineering and can be used in making fuel elements for nuclear reactors. The method involves scanning the image of spherical particles with a circular optical spot and determining the area of projections thereof. The diameter of the spot is selected to be less than the lower bound of the range of diameters of the image of the particles. Regions where the area of intersection of the scanning spot with images of particles is equal to the area of the scanning spot are selected. The area of the projection of each particle is defined as the area of the circle whose diameter is equal to the sum of the diameter of the scanning spot and the diameter of the region selected in said particle.

EFFECT: elimination of the operator and automation of image processing.

3 dwg

FIELD: physics.

SUBSTANCE: system and method for ground material characterisation in a grinding system use an irradiation section through which at least a part of the ground material stream is fed and with irradiation means for irradiating the particles in the part of the stream with electromagnetic radiation; and a detection section for passage, having a detection means for detecting electromagnetic radiation emitted from the particles of the part of the ground material stream fed through the irradiation section The detection means comprises an imaging system and a colour image sensor for imaging the particles thereon using the electromagnetic radiation emitted by the particles. The colour image sensor comprises image elements for spectrally selective detection of the electromagnetic radiation imaged on the sensor image elements. The detection section comprises a luminous means or is made and arranged to detect particles of the ground material using a combination of transmitted and incident light.

EFFECT: high rate and accuracy of detecting properties of a stream of a grinding product.

26 cl, 3 dwg

FIELD: instrumentation.

SUBSTANCE: proposed method comprises conversion of pulse voltage into light flux for analysed medium area to be probed therewith. Measuring channel containing analysed medium and extra channel filled with gas mix cleaned of gas mix are used. Said light flux is splitted in said channels to wide and narrow fluxes to be converted into electric signals while signal proportional to reference channel narrow light flux is subtracted from measuring channel narrow light flux. Obtained signal is synchronously detected and processed by microcontroller. Besides, signal proportional to reference channel wide light flux is subtracted from signal proportional to measuring channel wide flux. Obtained signal is synchronously detected and processed by microcontroller to define total concentration of dust and dust particle size.

EFFECT: higher precision of measurement.

2 dwg

FIELD: instrumentation.

SUBSTANCE: device for measurement of dielectric particle geometrical size comprises radiation source, detector and amplifier and, additionally, it incorporates circulator, horn receiving antenna, low-pass filter and microcontroller. Radiation source output is connected with circulator first arm. Circulator second arm is connected to transceiver horn antenna. Circulator third arm is connected to detector input. Detector output is connected via low-pass filter to amplifier input. Amplifier output is connected with microcontroller input.

EFFECT: higher precision.

1 dwg

FIELD: instrumentation.

SUBSTANCE: flow of particles is illuminated by light flux to record light signal parameters (amplitude-time analysis and analysis of modulation duration or depth) generated by particles in their transit through isolated area. Photoelectric pulse flux is subjected to primary amplitude discrimination with upper and lower threshold levels. Then, pulse selector allows transit of pulses with length exceeding aforesaid threshold. This allows extra suppression of 20% of dark current pulses. Device for correction of multiple coincidences subjects photoelectric pulses to forced interruption in intervals equal to transit of particles through counting volume. Additionally added are two DACs: one for control over air blower and forced pulse interruption duration and another for changing the illuminator radiation amplitude and adjustment of upper amplitude discrimination threshold. Besides, it incorporates extra ADC, PC for amplitude analysis, count of incoming pulses and control over DACs.

EFFECT: higher precision of measurements, ruled out errors.

6 dwg

FIELD: measurement equipment.

SUBSTANCE: device is designed to calibrate optical equipment that measures average diameter of dispersed particles and comprises a cuvette with a transparent liquid, a measurement channel comprising a microscope and a photorecorder and a lighting channel comprising two sources of light with different wavelengths. Additionally an ultrasonic generator is introduced, as well as an ultrasonic emitter, a pulse block of power supply of light sources, a synchroniser and calibrated equipment, at the same time directions of optical axes of the measurement channel and calibrated equipment cross in the illuminated zone of the cuvette, one source of light is installed on the optical axis of the measurement channel, and the second source has an optical axis matched with the optical axis of calibrated equipment, the outlet of the ultrasonic generator is connected to the inlet of the ultrasonic emitter, and the latter is placed into the cuvette with the liquid and is fixed in close proximity to the illuminated zone, sources of light are connected to the outlet of the pulse power supply block, the inlet of the synchroniser is connected to the outlet of the ultrasonic generator, and outlets of the synchroniser with control inlets of the calibrated equipment recorder, photorecorder and the pulse power supply block of the sources of light. At the same time cavitation bubbles in the cuvette produces as a result of action of the ultrasonic generator perform the function of dispersed particles for calibration. The device may have the following versions of design: the optical axis of the second source of light matches with the optical axis of calibrated equipment; calibrated equipment and the second source of light are fixed as capable of separate displacement in the plane perpendicular to the optical axis of the measurement channel.

EFFECT: simplified calibration of measurement systems as a result of replacement of sample suspensions with a dispersed system with controlled average diameter of particles and synchronisation of processes of management and measurement.

2 dwg, 3 cl

FIELD: measuring equipment.

SUBSTANCE: method of determining the size and concentration of suspended particles comprises probing the flow of the medium under study with the light beam, as well as the registration of signals of probing beam interaction with the particles. Also, the method comprises measuring the amplitude and number of photoelectric pulses of these signals, according to which the size and concentration of particles are respectively determined. At that the flow of photoelectric pulses is subjected to primary amplitude discrimination with upper and lower thresholds, and then pulse selector provides the passage of pulses with a duration exceeding a certain threshold, the device of correction of multiple coincidences subjects the photoelectric pulses to the forced interruption through the time equal to the duration of the particles flight through the counting volume. The photoelectric pulses are subjected to forced interruption through the time equal to the duration of the particles flight through the counting volume and depending on the pulses coming to the PC, the blower and the duration of pulse of forced interruption is operated, as well as the amplitude of the laser radiation and the upper threshold level of the amplitude discrimination.

EFFECT: improving the accuracy of measurement of concentration and size of the particles.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: suspended matter is illuminated with a light beam, and an image of matter is recorded, using which the size and shape of the matter is determined. The light beam after passage of the flow is turned in respect to the initial beam and is again sent via the flow, where the image of the matter is recorded from four angles of the light flow. Therefore, there are four projections of the matter in the recording plane. Using the produced images, they decide on the size and shape of the matter of complex shape.

EFFECT: higher information value of data for assessment of non-spherical particles of complex shape and their orientation in space.

2 dwg

FIELD: nanotechnology.

SUBSTANCE: reference samples with the predetermined initial concentration of nanoparticles are produced. Infrared spectra of the reference samples are recorded, the characteristic absorption peaks are identified. The infrared spectra of the reference samples are recorded during the coagulation process, the experimental dependence of the transmission coefficient of infrared radiation is created on the basis of the coagulation time. The infrared spectra of the reference samples are recorded and the concentrations C and the size of the nanoparticles d are determined according to the relations C(T)=C01+C0τ(T)K,d(T)=αχln(1+KC0τ(T))ln(ξ),C0=ρcVcNAMcVsol,K=4kT3ηψ, where C0 is the initial concentration of the nanoparticles in the sol, K is the coagulation constant determined by the sol composition; ρc is the density of the sol component forming the nanoparticles; Vc is the volume of the sol component forming the nanoparticles; NA is the Avogadro's number; Mc is the molar mass of the sol component forming the nanoparticles; Usol is the amount of the sol; k is the Boltzmann constant; T=29S K is the temperature; η is the dynamic viscosity of the solution; ψ=10-9 is the parameter characterising the effective probability of collision of the nanoparticles with each other; α is the size of the molecule forming the nanoparticle; χ=3 is growth coefficient in the diameter of the nanoparticle in the coagulation process; ξ=13 is the constant related to the fractality of the nanoparticle; τ(T) is the approximation of the experimental dependence of the transmission coefficient of infrared radiation through the sol on the basis of time.

EFFECT: creation of the method of determining the concentration and the average size of nanoparticles in sol undergoing coagulation by IR-spectroscopy.

14 dwg

FIELD: measurement equipment.

SUBSTANCE: measurements of characteristics of a disperse system are carried out with calibrated equipment and a photorecording device with subsequent determination of dependence between the signal of the calibrated equipment and the average diameter of particles identified visually, at the same time the liquid is exposed to ultrasound, thus a disperse system is created, it is illuminated with periodical pulses of light with duration of Tp≤0.1Tuo (where Tuo - period of ultrasonic oscillations), synchronised with ultrasonic oscillations, during light pulses they measure the average diameter of dispersed particles with calibrated equipment and determine it on the basis of photorecording results (dav.e and dav.p accordingly), the phase shift is changed between light pulses and ultrasonic oscillations, as well as ultrasound capacity, afterwards the measurements and photorecording are continued until the necessary quantity of the calibration levels is obtained, the calibration characteristic is determined as dependence of the value dav.e on dav.p.

EFFECT: simplified calibration due to exclusion of operations related to usage of reference powders, expansion of area of application due to calibration of instruments that realise integral methods of optics in disperse systems.

2 cl, 3 dwg

FIELD: measurement of concentration of non-conducting particles, for example particles of therapeutical breathing mixture.

SUBSTANCE: proposed method includes preliminary charge of particles of aerosol flow in first charging chamber of DC corona discharge which is performed before saturation charge of opposite sign in second charging chamber of unipolar pulse corona discharge. Flow of alternating aerosol of alternating sign from outlet of second chamber passes area of supplied external permanent magnetic field whose magnetic induction vector is perpendicular to flow. Particles of opposite charge passing the area of action of external permanent magnetic field shift to opposite sides relative to initial axis of flow under action of Lorentz force. Areas of volumetric positive and negative charges separated in space induce emf of different signs, each in its measuring electrode. Each measuring electrode is connected with its input of instrumental amplifier whose output signal is proportional to total surface concentration of aerosol particles. Electromagnetic radiation from pulse corona unipolar discharge induce similar emf at measuring electrodes which are co-phasing signals for instrumental amplifier suppressed by it.

EFFECT: enhanced accuracy of measurement due to compensation of induction on measuring electrode.

3 cl, 1 dwg

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