130 results about "Spectral emission" patented technology

The invention discloses a temperature and emissivity joint inversion method for multispectral temperature measurement, and relates to the field of non-contact temperature measurement of high-temperature targets. In order to solve the defect that in the prior art, combined inversion of the emissivity cannot be realized under the condition that the emissivity does not need to be known in advance, the technical scheme provided by the invention comprises the following steps: establishing a multispectral temperature measurement model, constructing a temperature calculation model under each channel, and outputting a plurality of sub-objective functions for optimization; constructing a weighted objective function used for optimization solution; outputting a global optimal solution as an initial point; constructing an optimization model with a penalty function, and outputting the target temperature and the spectral emissivity; and performing simulation verification based on the inversion result, performing error evaluation by setting a typical emissivity curve and a real temperature, and outputting an algorithm precision index. The method is suitable for non-contact high-precision temperature and emissivity combined measurement of a high-temperature target in a complex spectrum environment.

The invention discloses an LIBS (laser-induced breakdown spectroscopy) heterogeneous sample detection and analysis system and method based on 3D (three-dimensional) mapping. The system comprises a laser spectrum emission device for providing carrier waves required by LIBS, and a sample positioning and ablation point control and adjustment device for adjusting a heterogeneous sample detection position and accurately positioning a laser ablation position, the sample positioning and ablation point control adjusting device comprises a 3D scanning mechanism used for scanning the surface of a heterogeneous sample to obtain a three-dimensional model of the sample, and an electronic adjustable lens used for receiving laser emitted by the laser spectrum module and adjusting the focusing position. The electronic adjustable platform is used for adjusting an ablation point on the surface of the sample in cooperation with the electronic adjustable lens, LIBS and space mapping are combined, accurate detection and analysis of all position areas on the surface of the irregular heterogeneous sample are achieved through the electronic adjustable platform and the electronic adjustable lens, the consistency of laser focusing at all positions can be guaranteed, and the detection accuracy is improved. The accuracy of detection and analysis data is ensured.

Some aspects of the present disclosure provide methods and devices that enable a framework for selection or configuration, or both, of a waveform for use in integrated sensing and communications (ISAC). Use of the framework provides a new waveform, based in part on various criteria, which provides a trade-off among different ISAC requirements. Therefore, when different criteria are important for a particular implementation, a waveform that best meets the requirement of those criteria may be used. The various criteria may include factors such as hardware constraints at the UE, radio frequency (RF) chirp generation or detections capability at the UE, spectral emission or leakage such as OOBE, sensing performance, and sensing complexity. In some embodiments, a cyclic prefix (CP) is provided to use the chirp-based sensing waveforms as a demodulated reference signal (DMRS). In some embodiments, the CP enables alignment with a communication signal frame.

The invention discloses a boron-nitrogen compound, a preparation method thereof and an organic electroluminescent device prepared from the boron-nitrogen compound. The structural formula of the boron-nitrogen compound is # imgabs0, R1 to R8 are independently one of H, alkyl of C1 to C16, naphthenic base of C3 to C20, aryl of C6 to C30, aryl of C6 to C18 substituted by single or multiple Ra, heteroaryl of 5 to 18 membered and heteroaryl of 5 to 18 membered substituted by single or multiple Ra, and Ra is one of deuterium, fluorine, alkyl of C1 to C12, alkoxy of C1 to C12, naphthenic base of C3 to C12 and aryl of C6 to C14. The electroluminescent device made of the boron-nitrogen compound as a luminescent layer material can realize narrow spectrum emission, the electroluminescent external quantum efficiency of the device exceeds 10%, the service life of the device exceeds 300 h, the luminous efficiency and the stability are greatly improved, and the boron-nitrogen compound is suitable for an OLED (Organic Light Emitting Diode) display.

The invention relates to the technical field of image processing, and discloses a tea maturity detection method and system, and the method comprises the steps: obtaining an original image of tea in a natural illumination imaging environment; generating a global illumination difference chart representing an ambient illumination state, and performing illumination compensation on the to-be-detected area of the tea in the original image to obtain a compensated image of the tea; performing gray scale range adjustment on the compensated image of the tea leaves to obtain an enhanced spectral image of the tea leaves; integrating the color and spectral characteristics of the specific spectral reflection characteristics of the tea leaves with different maturity degrees in the enhanced spectral image and the three-dimensional morphological characteristics reflecting the spreading degree and thickness of the tea leaves into the fusion image characteristics of the tea leaves; mapping the color spectrum emission characteristics and texture characteristics of the tea leaves in the enhanced spectrum image to a maturity discrimination knowledge base of the tea leaves to obtain a preliminary maturity result; performing confidence coefficient weighting on the preliminary maturity result to obtain a target maturity; according to the invention, the tea maturity detection efficiency can be improved.

The invention relates to a temperature field imaging method based on free energy minimization, and belongs to the technical field of temperature field temperature distribution monitoring. Comprising the following steps: acquiring a multispectral image of a to-be-measured temperature field; wherein each pixel point in the multispectral image comprises a plurality of wavelengths and corresponding gray values; the pixel points comprise background pixel points and object pixel points; based on each wavelength and the corresponding gray value of each object pixel point, using pre-calibrated gray value-spectral radiation brightness corresponding data to obtain spectral radiation brightness corresponding to each wavelength of each object pixel point in the multispectral image; based on each wavelength of each object pixel point and the corresponding spectral radiation brightness, obtaining the temperature of each object pixel point by using a spectral emissivity temperature separation inversion method based on free energy minimization; and obtaining a temperature distribution diagram of the temperature field based on the temperature of each object pixel point. The accurate and efficient inversion of the temperature distribution state of the temperature field is realized.

A method for estimating process characteristics is provided. The method can include collecting process data from a spectral emitter and a spectral sensor during a substrate processing operation, and generating a calibrated model for the process data. Generating a calibrated model can include selecting a calibration option from a set of calibration options, based on a degree of freedom associated with a given calibration option, and calibrating a base model to generate the calibrated model. The base model is calibrated using the selected calibration option and a portion of the first process data.

The invention provides a light-emitting composition film material and application thereof.The light-emitting composition film material comprises a main material and a doping material, the doping material is a compound with the structure shown in the formula I. The main material comprises a first main material and a second main material, the first host material comprises at least one carbazole derivative having a structure represented by any one of formulas (H-1) to (H-4), the second host material comprises at least one compound represented by a formula Ph-2CN-1, Ph-2CN-2, Ph-2CN-3, Ph-2CN-4, Ph-2CN-5 or Ph-2CN-6, or the second host material comprises at least one phosphorescent compound containing metal Ir. The light-emitting film material of the composition has a narrow spectrum and is used for an organic electroluminescent device, so that the device realizes narrow-spectrum TADF emission, the electroluminescent external quantum efficiency of the device reaches up to 35% or above, and the service life of the device is 500 h or above.

The invention provides a seven-membered ring-containing boron-nitrogen compound and application thereof, the seven-membered ring-containing boron-nitrogen compound has a structure as shown in formula I. According to the boron-nitrogen compound disclosed by the invention, through extension conjugation and introduction of nitrogen atoms, not only is fine adjustment of a spectrum realized, but also the luminous efficiency is further improved. The boron-nitrogen compound has a narrow spectrum and is used as a narrow-spectrum luminescent material for preparing a luminescent layer of an organic electroluminescent device, the prepared organic electroluminescent device realizes narrow-spectrum TADF emission, the electroluminescent spectrum is in a green light-red light region, the half-peak width is less than 50nm, and the boron-nitrogen compound has a wide application prospect. And the highest external quantum efficiency of electroluminescence of the device is up to 24% or above.

The invention relates to the technical field of radiation temperature measurement, and discloses a multispectral radiation temperature measurement temperature inversion method and device and a storage medium, and the method comprises the steps: constructing a radiation equation set according to N spectrum channels of a multi-wavelength pyrometer; substituting the exponential polynomial model into a radiation equation set, constructing an equation set under different wavelength combinations, and introducing a conjugate gradient least square algorithm to solve and obtain multiple groups of temperature predicted values; modeling the probability density distribution of the temperature prediction value by using an adaptive kernel density estimation method, screening the temperature values of which the normalized probability density is greater than or equal to a preset threshold value, and calculating a weighted average value as a temperature prediction result; according to the method, multiple iterations are carried out through cross validation, the temperature value with the minimum prediction error is finally selected as the final temperature prediction result, the normal spectral emissivity of the sample is inversed according to the final temperature prediction result, and the accuracy of the temperature result can be further improved while the calculation efficiency is guaranteed.

The invention belongs to the technical field of optical ceramics and functional ceramic materials, and discloses a spinel ceramic material with high-temperature extinction and broadband high emissivity as well as a preparation method and application thereof. The chemical formula of the material is Cu (0.7-x) Ni (x) Cr (1.5) Mn (0.8-y) MyO4, M is Co and Fe, x is more than or equal to 0 and less than or equal to 0.5, y is more than or equal to 0 and less than or equal to 0.5, and different-valence or variable-valence metal elements (Ni, Co and Fe) and Mn are co-doped with copper-chromium spinel. The spectral emissivity of the ceramic material in the infrared band of 2.5-25 microns is gt; the emissivity spectrum curve is flat, the material has the characteristics of wide band, high emissivity and the like, and the emissivity of a coating prepared from the material is the spectral emissivity gt of the infrared band of 2.5-25 microns; and 0.95, the method has good application prospects in the fields of aerospace thermal control, aerospace craft thermal protection, industrial kiln energy saving, high-temperature extinction black bodies, optical camera extinction coatings and the like.

The invention belongs to the technical field of quantitative remote sensing, and relates to a mid-infrared hyperspectral emission and reflection characteristic integrated inversion method, which comprises the following steps: acquiring mid-infrared hyperspectral satellite remote sensing data, and optimizing sensing entrance pupil radiance data to obtain optimized entrance pupil radiance data; the intermediate infrared hyperspectral satellite remote sensing data comprises sensing entrance pupil radiance data; performing atmospheric correction on the optimized entrance pupil radiance data by using a radiation transfer model to obtain surface brightness temperature and atmospheric downward radiation, and calculating solar irradiance reaching the surface; constructing a mid-infrared hyperspectral earth surface bi-directional reflectivity inversion framework, and performing earth surface bi-directional reflectivity inversion based on the mid-infrared hyperspectral earth surface bi-directional reflectivity inversion framework to obtain earth surface bi-directional reflectivity and earth surface equivalent radiance; constructing a scene self-adaptive framework, and performing inversion based on the scene self-adaptive framework to obtain the surface temperature and the surface emissivity; therefore, accurate separation of surface emission radiation and surface reflection radiation is completed.

The invention discloses a multi-spectral radiation temperature measurement method and system for improving a quantum particle swarm, relates to the field of radiation temperature measurement and photoelectric signal processing, and solves the problems that when an existing standard PSO algorithm is applied to high-dimensional and nonlinear multi-spectral inversion, local extreme values are likely to be trapped, and the self-adaptive capacity is poor. Setting parameters, generating an initial particle position by using Tent chaotic mapping, calculating the particle fitness of an initialized population, updating initial individual optimum and global optimum, and calculating an average optimal particle position; updating the optimal particle position through a Levy flight mechanism; and repeating the steps, calculating the multispectral radiation temperature measurement target function value of the updated position, updating the initial individual optimum and the global optimum, and if an error threshold value or the maximum number of iterations is met, outputting the global optimum solution. The method is also suitable for the application field of inverting the real temperature and the spectral emissivity of the target from the multi-channel spectral radiation signals and the like.

The present invention belongs to the technical field of on-line detection of gaseous substances, and particularly relates to a system device and method for spectroscopically co-detecting gaseous substances. The system device for spectroscopically co-detecting gaseous substances has a simple structure, is modular, and has a relatively high degree of information integration, and can realize in-situ, rapid, comprehensive, and continuous qualitative and quantitative identification and detection. A system device for spectroscopically co-detecting gaseous substances includes: a pipeline; the spectroscopic co-detection structure includes a hyperspectral component, a terahertz time-domain spectroscopy component, and a laser-induced breakdown spectroscopy component; the hyperspectral component includes a hyperspectral imager and a hyperspectral data acquisition and analysis module; the terahertz time-domain spectroscopy component includes a terahertz time-domain spectroscopy emitter, a terahertz time-domain spectroscopy receiver, and a terahertz time-domain spectroscopy data acquisition and analysis module; the laser-induced breakdown spectroscopy component includes a laser-induced breakdown spectroscopy emission module, a laser-induced breakdown spectroscopy reception module, and a laser-induced breakdown spectroscopy data acquisition and analysis module.

The invention provides a multi-size sample emissivity measuring system and measuring method based on a co-heating mechanism, the system comprises the co-heating mechanism, a heating chamber is arranged in the co-heating mechanism, a blackbody cavity and a sample cavity are arranged in the heating chamber in parallel, and the internal temperature of the blackbody cavity and the sample cavity is controlled through the same electric heating assembly; the replaceable positioning assembly is arranged in the sample cavity and is used for adapting to the to-be-tested samples with different sizes; a light path of the spectrograph is switchably aligned with an outlet of the blackbody cavity or the sample cavity; and the positioning adjusting mechanism is used for adjusting the relative position of the co-heating mechanism and the spectrograph, so that the optical axes of the blackbody cavity and the sample cavity coincide with the optical axis of the spectrograph. According to the measuring system, the blackbody cavity and the sample cavity can be heated simultaneously through the co-heating system, temperature consistency is guaranteed, the replaceable positioning assembly is adopted to adapt to samples of different sizes, and high-precision spectral emissivity measurement of the samples of multiple sizes is achieved.

A method of analyzing an interference peak of a sample spectrum generated using a detector of an optical spectrometer is provided. The interference peak is produced by a plurality of spectral emissions of different wavelengths. The method includes generating, based on a model of expected curve parameters of the optical spectrometer and a location of the sample peak on the detector of the optical spectrometer, interference curve parameters representing a shape of each spectral emission in the interference peak. The method further includes fitting a plurality of curves to the interference peak, each curve corresponding to one of the plurality of spectral emissions of different wavelengths that form the interference peak, wherein each curve is fitted using the interference curve parameters provided by the model of expected peak parameters. The plurality of curves are output for further analysis.

Offset illumination using multiple emitters in a fluorescence imaging system is described. The system includes an emitter to emit pulses of electromagnetic radiation and an image sensor including an array of pixels to sense reflected electromagnetic radiation. The emitter includes a first emitter and a second emitter to emit electromagnetic radiation of different wavelengths. The system causes at least a portion of the pulses of electromagnetic radiation emitted by the emitter to include one or more of a hyperspectral emission, a fluorescence emission, or a laser mapping mode.

This solution relates to the coatings field and proposes an aqueous nano-dispersion of far-infrared negative oxygen ion material. By weight, it comprises: 300-350 parts water; 35-45 parts wetting agent; 40-60 parts dispersant; 25-35 parts defoamer; 35-45 parts multifunctional additive; 5-7 parts thickener; 400-600 parts activated far-infrared negative oxygen ion material; 1-3 parts accelerator; and 3-5 parts shielding agent. This solution designs a multi-component synergistically promoting activated far-infrared negative oxygen ion material, which can improve the hemispherical spectral emissivity in the 4-14μm band, even reaching above 0.95 in the key 8-12μm band, effectively promoting formaldehyde decomposition with a long-lasting effect, while also improving antibacterial properties.

Disclosed is a vicarious radiometric calibration system. More specifically, disclosed is a ground reference target for calibrating a digital signal that is obtained through a sensor when a landmark is observed from a satellite or an airplane by using a spectral reflection factor or spectral emissivity of the ground reference target and a vicarious radiometric calibration system including the same. It is possible to derive accurate measurement results for the MWIR region by installing a ground reference target having predetermined reflectance or emissivity and having a special form on the ground with respect to the calibration of a sensor for remote exploration, such as aviation, space, and astronomy, and performing absolute radiometric calibration by using images that are obtained through the ground reference target.

The invention belongs to the technical field of lasers, and particularly relates to a laser for achieving high-power pumping stable output based on temperature gradient spectrum broadening. Comprising a total reflection mirror, a gain medium, an output mirror, a vapor chamber, a right trapezoid prism heat sink, a bar module, a first temperature probe, a second temperature probe, a first TEC, a second TEC, an environment temperature detector, a wire, an information processing module, a regulation and control module and a driving power supply, wherein the total reflection mirror and the output mirror form an optical resonant cavity. Through the temperature gradient distribution of the right trapezoid prism heat sink, the bar module is induced to generate a thermally induced spectrum broadening effect, and the temperature gradient range of the laser during high-power working is regulated and controlled through the TEC, so that the broad spectrum emission of pump light is realized, a plurality of characteristic absorption peaks can be covered at the same time, and the high-power pumping efficiency of the laser is improved during high-power pumping. And efficient energy conversion and stable laser output are realized.

The invention discloses a gas analyzer based on infrared spectrum and an indication error calibration method. The method comprises the following steps: respectively mounting a spectrum transmitting end and a spectrum receiving end on two sides of a calibration tube; standard gas with the same concentration and different injection operation parameters is injected into each calibration pipe, infrared light is emitted into the calibration pipes at the same time, the light intensity of the infrared light passing through the gas in the calibration pipes and received by a spectrum receiving end is analyzed, and the measurement and calculation value of the concentration of the standard gas is obtained in combination with the absorption law; constructing a calibration model between the concentration measurement and calculation value and the injection operation parameters; injecting to-be-detected gas into each calibration pipe according to the same injection operation parameters, and correcting the measured concentration of the to-be-detected gas based on the injection operation parameters and the calibration model; based on the influence coefficient of the injection operation parameters on gas concentration measurement, the measurement concentration of the to-be-measured gas with unknown concentration is corrected, and the measurement accuracy of the gas concentration is improved.

A method for characterization of metallic powder including presenting a metallic powder sample to a laser and detector system, wherein the metallic powder sample passes through the laser and detector system via a sample introducer; applying a pulsed laser beam to a first location in the metallic powder sample to provide a first micro-plasma at the first location in the metallic powder sample when the pulsed laser beam terminates, the micro-plasma cools to provide spectral emissions at the first location; collecting the spectral emissions at the first location in the metallic powder sample with a detector; analyzing the spectral emissions at the first location to provide a spectral analysis dataset; and identifying inclusions at the first location in the metallic powder sample.

This application provides a method and system for detecting smoke in fires, relating to the field of emergency fire protection technology. The smoke detection system includes a dual-spectrum transmitter and a multispectral receiver. The method includes: the dual-spectrum transmitter transmitting a first beam of a first band and a second beam of a second band to the area to be detected according to a preset transmission cycle. The multispectral receiver receives and determines a first spectral response signal corresponding to the first beam and a second spectral response signal corresponding to the second beam. Based on the first spectral response signal and a pre-calculated first reference spectral response signal, the multispectral receiver determines a first attenuation rate corresponding to the first beam, and based on the second spectral response signal and a pre-calculated second reference spectral response signal, determines a second attenuation rate corresponding to the second beam. The multispectral receiver outputs a smoke alarm signal based on each attenuation rate and an attenuation rate threshold. Using this application can avoid false smoke alarms caused by false alarm sources such as dust and water vapor.

The invention discloses an OLED equipment fault diagnosis system based on artificial intelligence, and relates to the technical field of fault diagnosis, and the system comprises the following steps: capturing OLED pixel-level brightness distribution in real time through a microscopic camera, synchronously collecting driving current, voltage and spectral emission data, and aligning all spatio-temporal data by taking a driving signal rising edge as a reference; a defect area is segmented and positioned by adopting a self-adaptive threshold value, topological features are extracted, and a defect distribution tensor containing spatial attributes is constructed; fusing space-time and electro-optical parameters to construct a fourth-order degradation tensor, and coupling a space attenuation weight and a time sensitive function through a space-time convolution operator; microdefect evolution is analyzed by using a 3D-CNN branch, a macroscopic degradation track is learned by using an LSTM branch, and dual-scale features are interactively fused through a mask matrix; and calculating fault probability distribution, generating a fault positioning thermodynamic diagram and residual life prediction, and outputting a diagnosis report. According to the method, the tensor degradation model based on spatial-temporal feature fusion is constructed, so that the sensitivity of the system to hidden faults is enhanced.

A field portable device for determining the unconfined compressive strength of a soil sample includes a sample holder, a heating device, a scale, a spectrometer, and a microprocessor. The sample holder receives a soil sample. The heating device dries the soil sample for a specified time. The scale measures a weight of the soil sample and a dried weight of the soil sample. The spectrometer performs laser induced breakdown spectroscopy on the soil sample and generates spectral emission intensities of the soil sample. The microprocessor calculates a bulk density and a water content of the soil sample, actuates the spectrometer to generate the spectral emission intensities. The microprocessor applies the spectral emission intensities, the bulk density and the water content to a trained machine learning regressor combined with an adaptive boosting classifier to predict the unconfined compressive strength of the soil sample.

The application relates to a virtual reality-based intangible cultural heritage immersive experience method, device, equipment and medium. The method comprises the following steps: acquiring multidimensional data of a target intangible cultural heritage scene; performing grid processing on original three-dimensional point cloud data to obtain an initial three-dimensional geometric model; performing spatial registration on a spectral reflection curve and the initial three-dimensional geometric model to obtain a three-dimensional geometric model containing material spectral properties; analyzing a facet spectral emission curve in combination with a scene space-time cultural database to generate a parameterized physical material library; generating a basic light image in combination with the parameterized physical material library and the scene space-time cultural database according to experience space-time information selected by a user; fusing environmental special effect physical description parameters and the basic light image to obtain a synthesized visual picture result; and generating an immersive experience instruction based on the synthesized visual picture result and environmental special effect data. The method can dynamically adapt to material characteristics and space-time changes of different intangible cultural heritage scenes, and improves the restoration degree of the intangible cultural heritage scene and the user immersion.

The invention provides a boron-nitrogen compound and application thereof, the boron-nitrogen compound has a structure as shown in a formula I and a formula II, the boron-nitrogen compound not only realizes fine adjustment of a spectrum, but also further improves luminous efficiency through extension conjugation and introduction of double B atoms. The boron-nitrogen compound has a narrow spectrum and is used as a narrow-spectrum luminescent material for preparing a luminescent layer of an organic electroluminescent device, the prepared organic electroluminescent device realizes narrow-spectrum TADF emission, the electroluminescent spectrum is in a green light-yellow light area, the half-peak width is less than 40nm, and the boron-nitrogen compound has a wide application prospect. And the highest external quantum efficiency of electroluminescence of the device reaches up to 30% or above.

The present application relates to the technical field of image processing, and discloses a tea maturity detection method and system, the method comprising: acquiring an original image of tea under an imaging environment of natural light; generating a global light difference map representing the state of the ambient light, and performing light compensation on a tea region to be detected in the original image to obtain a compensated image of the tea; adjusting the gray scale range of the compensated image of the tea to obtain an enhanced spectral image of the tea; integrating the color and spectral features of the specific spectral reflection characteristics of tea leaves of different maturity in the enhanced spectral image with three-dimensional morphological features reflecting the spread and thickness of tea leaves into a fusion image feature of the tea; mapping the color and spectral emission characteristics and texture features of the tea in the enhanced spectral image to a maturity discrimination knowledge base of the tea to obtain a preliminary maturity result; and performing confidence weighting on the preliminary maturity result to obtain a target maturity; the present application can improve the efficiency of tea maturity detection.

The invention relates to a converter roughing slag detection method, belongs to the field of material thermophysical property testing and data processing, and solves the problem of low judgment accuracy of a steel slag condition in a converter tapping process in the prior art. The method comprises the following steps: when a tapping signal of a converter is monitored, acquiring a plurality of wavelengths and corresponding gray values of molten steel at a tapping hole of the converter; based on each wavelength and the gray value thereof, obtaining spectral radiation brightness corresponding to each wavelength by using pre-calibrated data; obtaining the spectral emissivity of the molten steel in the current converter by using a material spectral emissivity temperature separation inversion method based on each wavelength and the spectral radiance thereof; and when the spectral emissivity of the molten steel in the converter is larger than a set threshold value, it is judged that the slag content in the molten steel exceeds a normal value, and the converter is controlled to stop tapping. The spectral emissivity and the temperature of the material can be obtained through separated calculation only depending on the heat capacity function of the material, calculation is simple, and reliability is high.

A field portable device for determining the unconfined compressive strength of a soil sample includes a sample holder, a heating device, a scale, a spectrometer, and a microprocessor. The sample holder receives a soil sample. The heating device dries the soil sample for a specified time. The scale measures a weight of the soil sample and a dried weight of the soil sample. The spectrometer performs laser induced breakdown spectroscopy on the soil sample and generates spectral emission intensities of the soil sample. The microprocessor calculates a bulk density and a water content of the soil sample, actuates the spectrometer to generate the spectral emission intensities. The microprocessor applies the spectral emission intensities, the bulk density and the 10 water content to a trained machine learning regressor combined with an adaptive boosting classifier to predict the unconfined compressive strength of the soil sample.