Needle Structure Research Articles

Structure of Needle Highlights Ecological Adaptability and Microevolution of Natural Populations of Cedrus atlantica in Morocco

The study of morphological and anatomical characteristics of leaves is important for assessing the geographical variation of species. The ecological adaptability of forty individuals from four populations of Cedrus atlantica were studied, based on analysis of morphological and anatomical traits. The results of the Spearman nonparametric coefficient of correlation showed that the number of stomatal lines (NLS) and the length of the needle (NL) are negatively correlated to altitude and positively to latitude and precipitation sums, while the width of the needle (NW), the thickness of the cuticle (CT), and the number of needles per rosette (NN/R) were negatively related to temperature. In addition, the sum of precipitation is negatively correlated with NW. The first two principal components account for 58.18% of the variation. According to Tukey’s test and Kruskal–Wallis test, all populations had at least three characters separating them at a statistically significant variation. Moreover, the hierarchical classification led us to the individualization of three main groups. All these results show an adaptation of the structure of the needles of C. atlantica from Morocco to the geographical position and the climatic conditions of the populations.

Inherent Minor Conformer of Bordetella Effector BteA Directs Chaperone-Mediated Unfolding.

The pathogen Bordetella pertussis uses a type-3 secretion system (T3SS) to inject its cytotoxic effector BteA into the host cell via a designated needle structure. Prior to injection BteA is bound to its cognate chaperone BtcA presumed to assist in effector unfolding en route to needle passage. We utilized NMR and EPR spectroscopy to uncover the molecular mechanism of BtcA-mediated unfolding of BteA. BtcA induces a global structural change in the effector, which adopts a more extended and partially unfolded conformation. EPR distance measurements further show that the structured helical-bundle form of free BteA exists in conformational equilibrium with a lowly populated minor species. The nature of this equilibrium was probed using NMR relaxation dispersion experiments. At 283 K structural effects are most pronounced for a contiguous surface spanning the A- and B-helices of BteA, extending at 303 K to a second surface including the D- and E-helices. Residues perturbed in the minor conformation coincide with those exhibiting a BtcA-induced increase in flexibility, identifying this conformation as the BtcA-bound form of the effector. Our findings hint at a conformational-selectivity mechanism for the chaperone interaction with the effector, a paradigm that may be common to effector-chaperones secretion complexes in this family of pathogens.

Biomimetic bamboo leaf double-sided microstructure composite surface and its delayed icing performance

The frost phenomenon occurred on the surface of engineering equipment can not only lead to a reduction in the efficiency of equipment but a higher energy consumption. How to effectively inhibit or delay the frost behavior on a material surface and improve the anti-frost property on the surface is of great importance. It is found that the nano needle structure on the surface of bamboo leaves can provide large Laplace pressure to drive droplets to bounce and hence delay the condensation process. In addition, in the frost crystal growth stage, the nano needle structure can reduce the contact area between droplets and the surface of bamboo leaves, and hence limit the phase-change heat transfer of water vapor and increase the thermodynamic barrier when nucleation of water vapor occurs, thereby delaying the frost crystal growth. In this paper, inspired by bamboo leaves, biomimetic structures are constructed on the surface of an aluminum alloy by laser processing and sol-gel method. Results reveal that delayed frost formation on the surface is realized, which is of immense practical value in engineering and many other aspects.

Removal of cadmium ions by magnesium phosphate: Kinetics, isotherm, and mechanism studies

In this study, magnesium phosphate with needle structure has been prepared by simple co-precipitation method. XRD, FTIR and SEM-EDX analyses indicated the successful fabrication of Mg3(PO4)2·5H2O phase. Subsequently, the adsorption performance of the material was tested toward Cd(II) removal from aqueous media. Batch experiments indicated that the solution pH highly influences the removal efficiency of Cd(II) with a maximum uptake observed at pH=3. Besides, the examination of the adsorption kinetics highlights that the data could be fitted by both pseudo 2nd order and Elovich models. This suggests that adsorption/desorption process in the limiting step in the kinetics of Cd(II) uptake. The Langmuir maximum adsorption capacity was 943 mg/g and the calculated energy from Dubinin–Radushkevich model was E=8.75 kJ/mol. This result indicates that the uptake of Cd(II) onto Mg3(PO4)2·5H2O is essentially an ion exchange process. Thermodynamic study suggests spontaneous and exothermic adsorption process. Besides, the XRD diffractogram of the adsorbent after saturation with Cd(II) revealed the presence of characteristic peaks related to Cd5H2(PO4)4·4H2O phase.

Variation, coordination, and trade-offs between needle structures and photosynthetic-related traits across five Picea species: consequences on plant growth

BackgroundPicea species are distributed and planted world-wide due to their great ecological and economic values. It has been reported that Picea species vary widely in growth traits in a given environment, which reflects genetic and phenotypic differences among species. However, key physiological processes underlying tree growth and the influencing factors on them are still unknown.ResultsHere, we examined needle structures, needle chemical components, physiological characteristics and growth traits across five Picea species in a common garden in Tianshui, Gansu province in China: Picea glauca, P. mariana, P. likiangensis, P. koraiensis, and P. crassifolia, among which P. glauca and P. mariana were introduced from North America, P. likiangensis was from Lijiang, Yunan province in China, P. koraiensis was from Yichun, Heilongjiang province in China, and P. crassifolia was native to the experimental site. It was found that nearly all traits varied significantly among species. Tissue-level anatomical characteristics and leaf mass per area (LMA) were affected by needle size, but the variations of them were not associated with the variations in photosynthetic and biochemical capacity among species. Variations in area-based maximum photosynthesis (Pnmax) were affected by stomatal conductance (gs), mesophyll conductance (gm) and biochemical parameters including maximum carboxylation rate (Vcmax), and maximum electron transport rate (Jmax). The fraction of N allocated to different photosynthetic apparatus displayed contrasting values among species, which contributed to the species variations in photosynthetic nitrogen use efficiency (PNUE) and Pnmax. Additionally, all growth traits were positively correlated with Pnmax and PNUE.ConclusionNeedle structures are less important than needle biochemical parameters in determining the variations in photosynthetic capacity across the five Picea species. Pnmax and PNUE are closedly associated with the fraction of N allocated to photosynthetic apparatus (Pphoto) compared with leaf N content per area (Narea). The tremendous growth differences among the five Picea species were substantially related to the interspecies variation in Pnmax and PNUE.

In-Plane Si Microneedles: Fabrication, Characterization, Modeling and Applications.

Microneedles are getting more and more attention in research and commercialization since their advancement in the 1990s due to the advantages over traditional hypodermic needles such as minimum invasiveness, low material and fabrication cost, and precise needle geometry control, etc. The design and fabrication of microneedles depend on various factors such as the type of materials used, fabrication planes and techniques, needle structures, etc. In the past years, in-plane and out-of-plane microneedle technologies made by silicon (Si), polymer, metal, and other materials have been developed for numerous biomedical applications including drug delivery, sample collections, medical diagnostics, and bio-sensing. Among these microneedle technologies, in-plane Si microneedles excel by the inherent properties of Si such as mechanical strength, wear resistance, biocompatibility, and structural advantages of in-plane configuration such as a wide range of length, readiness of integration with other supporting components, and complementary metal-oxide-semiconductor (CMOS) compatible fabrication. This article aims to provide a review of in-plane Si microneedles with a focus on fabrication techniques, theoretical and numerical analysis, experimental characterization of structural and fluidic behaviors, major applications, potential challenges, and future prospects.

Formation of tubular structures and microneedles on silicon surface by doughnut-shaped ultrashort laser pulses

We report on the formation of tubular structures and microneedles on the surface of monocrystalline silicon using ultrashort laser pulses. Highly deterministic surface processing is ensured by single-shot ablative modification of the sample surface using radially polarized doughnut-shaped laser pulses with duration of 70 fs. Under such conditions, well reproducible tubular structures are formed whose height is rising with increasing fluence, culminating by closing the structure on the top with formation of a microneedle with a cavity in its base. Upon multi-pulsed irradiation, the height of the needle structures can further increase as compared to those produced by single pulses and top part of the structure is flattened. However, at a certain number of pulses, melting and ablation cause collapsing the entire structure. The mechanisms responsible for creating the tubular and needle structures are discussed based on the careful analysis of the experimental observations. The generated silicon microtubes and needles can find applications in various fields, such as intracellular delivery of micromolecules, micro/electromechanical systems, photovoltaic devices and silicon-based photonics.

Bandgap and visible-light-induced photocatalytic performance and dye degradation of silver doped HAp/TiO2 nanocomposite by sol-gel method and its antimicrobial activity

Silver doped hydroxyapatite and titanium oxide nanocomposites have been obtained by sol-gel techniques with novel antimicrobial activities for biomedical applications. The synthesis of Ca10-X AgX (PO4)6(OH)2 along with titanium oxide nanoparticles with XAg = 0 (HAp/TiO2), 0.1, 0.25 and 0.5 (Ag:HAp/TiO2-NCS) was performed. The developed crystalline phase was characterized via X-ray diffraction (XRD), and the morphological features were executed via scanning and transmission electron microscopy (SEM/TEM). The HAp/TiO2 and silver doped HAp/TiO2 nanocomposites were spherical grains, with needle and flower-like structures. XRD examination revealed the crystalline phases of HAp/TiO2 and Ag-doped HAp/TiO2 nanocomposites. The crystallite size of HAp/TiO2 and Ag-doped HAp/TiO2 nanocomposites determined from the XRD pattern was ranged between 16 nm and 20 nm. The FTIR analysis confirms the presence of stretching and vibrational peaks for the presence of silver doped HAp/TiO2. The EDAX analysis showed the existence of major elements of HAp/TiO2 and Ag-HAp/TiO2 nanostructured composites. HAp/TiO2 and silver doped HAp/TiO2 were active against both Gram-positive and Gram-negative bacteria such as, E. coli (MTCC 443), S. typhi (MTCC 733), and S. aureus (MTCC 3160). The photocatalytic absorption spectrum implied an increased absorption rate of methylene blue by HAp/TiO2 and silver doped HAp/TiO2 nanocomposites. The photocatalytic activity revealed that 50% Ag doped HAp/TiO2 optimally improved photocatalytic activity.

The coordination of displacement and conduction currents to boost the instantaneous power output of a water-tube triboelectric nanogenerator

Liquid-solid based triboelectric nanogenerator (L-S TENG) has aroused great attention in blue energy harvesting. Although these classical L-S TENG can achieve good performance by using the gradually changed displacement current, the further improvement of instantaneous power is limited. People can improve the output with external management circuits and transistor-like architecture, but the complex structure and fabrication process of devices make the practicality of TENG very difficult. Here, by developing the structure of charge collector needle to introduce conduction current into the traditional architecture of TENG, we designed a new water tube TENG (DcCc-TENG) with high instantaneous power. By establishing a detailed physical process model, we revealed that the physical nature of DcCc-TENG with high instantaneous power output is based on the synergistic enhancement mechanism of displacement and conduction currents. We also used the different device structures to further clarify the contribution of these two currents. Finally, a single device shows high instantaneous volumetric power density of 16.6 W/m3, which is capable to power more than 120 LEDs. A ship attitude sensor based on DcCc-TENG further proves its potential application in sensing.

Effects of decompressing carbonization on the preparation of needle coke from FCC decant oil

More efficient treatments of FCC decant oil (FDO) were developed to convert this common by-product in refineries to high-value-added carbonaceous materials, such as needle coke. The performance of the produced needle coke was determined by the properties of raw materials and the carbonization process based on the theories of carbonaceous mesophase. The preparation of needle coke can generally be divided into two stages before calcination and graphitization: liquid carbonization and solidification stage. Pressure in both stages, especially the pressure in the solidification stage, showed great effects on the properties of the products. The microstructure of semi-coke can hardly be the preferred needle structure with carbonization without decompressing operation, although the raw material satisfies the preparation requirement of needle coke. A new method for evaluating the order degree of microstructure (ODM) of semi-cokes was developed, enabling semi-cokes with preferable axial orientation to be further efficiently distinguished. The ODM value can also be used as an index to evaluate whether a semi-coke can be used as a precursor for further preparation of high-quality needle coke. The evolution of product gases can provide external force to the orientation of mesophase into the preferred needle structure in the product. This improvement can be achieved through decompressing operations in the second stage of carbonization and optimized when the pressure is at 0.5 MPa.

Bioinspired Self-Powered Piezoresistive Sensors for Simultaneous Monitoring of Human Health and Outdoor UV Light Intensity.

The exact fabrication of precise three-dimensional structures for piezoresistive sensors necessitates superior manufacturing methods or tooling, which are accompanied by time-consuming processes and the potential for environmental harm. Herein, we demonstrated a method for in situ synthesis of zinc oxide nanorod (ZnO NR) arrays on graphene-treated cotton and paper substrates and constructed highly sensitive, flexible, wearable, and chemically stable strain sensors. Based on the structure of pine trees and needles in nature, the hybrid sensing layer consisted of graphene-attached cotton or paper fibers and ZnO NRs, and the results showed a high sensitivity of 0.389, 0.095, and 0.029 kPa-1 and an ultra-wide linear range of 0-100 kPa of this sensor under optimal conditions. Our study found that water absorption and swelling of graphene fibers and the associated reduction of pore size and growth of zinc oxide were detrimental to pressure sensor performance. A random line model was developed to examine the effects of different hydrothermal times on sensor performance. Meanwhile, pulse detection, respiration detection, speech recognition, and motion detection, including finger movements, walking, and throat movements, were used to show their practical application in human health activity monitoring. In addition, monolithically grown ZnO NRs on graphene cotton sheets had been integrated into a flexible sensing platform for outdoor UV photo-indication, which is, to our knowledge, the first successful case of an integrated UV photo-detector and motion sensor. Due to its excellent strain detection and UV detection abilities, these strategies are a step forward in developing wearable sensors that are cost-controllable and high-performance.

Effect of the nickel coated precipitated calcium carbonate addition on microstructure, phase and wettability of Sn-9Zn solder

This paper presents the effect of nickel-coated precipitated calcium carbonate (Ni-coated PCC) on the wettability, microstructure and phase change of Sn-9Zn solder. The microstructure and phase analysis of the material plays a very important role as it determines the physical and mechanical behavior of materials. Both Sn-9Zn and Ni-coated PCC/Sn-9Zn produced almost similar microstructure, which contain needle-like, dark phase Zn-rich phase and distributed evenly in beta-Sn rich matrix. However, compared to pure Sn-9Zn, the addition of Ni-coated PCC produce finer size of Zn rich phase needle-like structure. The presence of new phases of nickel tin and calcium carbonate compounds was also found with the addition of Ni-coated PCC. This believed to help in refining the size of Zn-rich needle structure, while retaining the original phases of Sn and Zn of the Sn-9Zn solder, Furthermore, Ni-coated PCC/Sn-9Zn have a smaller contact angle compared to pure Sn-9Zn. This can be explained that, Ni-coated PCC reinforced particle was the interfacial active element and decrease the interfacial energy between the solid and liquid. The microstructure and phase analysis of the material plays a very important role as it determines the wettability behavior of the material

Light microscopic structure of needle in Pinus sibirica, P. pumila, and their hybrids

Needle structure in Pinus sibirica, P. pumila, and their hybrids was studied by light microscopy. The examined hybrids primarily had mtDNA of P. pumila and cpDNA of P. sibirica. The species differed by all measured traits including needle dimensions, number and position of resin ducts, and mesophyll folding. A hybrid index was calculated by qualitative traits and traits not correlated with needle length, namely closeness of abaxial resin ducts and number of additional cells in the hypodermis. On average, the hybrid index was 3.04, 48.05, and 29.07 in P. sibirica, P. pumila, and hybrids, respectively. The hybrids were characterized by the largest area of the resin ducts compared to the parental species. The most differentiation of the species and hybrids was obtained with discriminant analysis based on needle length, needle width, needle thickness, hybrid index, and resin duct total area. The squared Mahalanobis distance was 114 between the species, 37 between P. sibirica and hybrids, and 24 between P. pumila and hybrids. The greater similarity between hybrids and P. pumila could be the result of maternal effect.

Investigation of the Erosion Characteristics in the Distribution Parts of Pelton Turbine

Pelton turbine, as its working principle, can perform in the high head condition especially in the southwest mountainous region in China. When the flow contains silt, it will induce the erosion in the bucket and needle structure which affects the efficiency and furthermore the service life. This paper performs unsteady air-liquid-solid three-phases simulation focusing on the distribution tube and needle parts. Volume of Fluid (VOF) method is used for capturing the free surface flow, at the same time, silt particle is simplified as the sphere particle and simulated through the Discrete Particle Model (DPM). Furthermore, flow detail and erosion information are obtained by conjugating both the former methodologies. Finally, particle size is analyzed in order to investigate the effect of erosion characteristic to the flow passage of Pelton turbine which aims to improve the turbine efficiency.

The Contribution of the Predicted Sorting Platform Component HrcQ to Type III Secretion in Xanthomonas campestris pv. vesicatoria Depends on an Internal Translation Start Site.

Pathogenicity of the Gram-negative bacterium Xanthomonas campestris pv. vesicatoria depends on a type III secretion (T3S) system which translocates effector proteins into plant cells. T3S systems are conserved in plant- and animal-pathogenic bacteria and consist of at least nine structural core components, which are designated Sct (secretion and cellular translocation) in animal-pathogenic bacteria. Sct proteins are involved in the assembly of the membrane-spanning secretion apparatus which is associated with an extracellular needle structure and a cytoplasmic sorting platform. Components of the sorting platform include the ATPase SctN, its regulator SctL, and pod-like structures at the periphery of the sorting platform consisting of SctQ proteins. Members of the SctQ family form a complex with the C-terminal protein domain, SctQC, which is translated as separate protein and likely acts either as a structural component of the sorting platform or as a chaperone for SctQ. The sorting platform has been intensively studied in animal-pathogenic bacteria but has not yet been visualized in plant pathogens. We previously showed that the SctQ homolog HrcQ from X. campestris pv. vesicatoria assembles into complexes which associate with the T3S system and interact with components of the ATPase complex. Here, we report the presence of an internal alternative translation start site in hrcQ leading to the separate synthesis of the C-terminal protein region (HrcQC). The analysis of genomic hrcQ mutants showed that HrcQC is essential for pathogenicity and T3S. Increased expression levels of hrcQ or the T3S genes, however, compensated the lack of HrcQC. Interaction studies and protein analyses suggest that HrcQC forms a complex with HrcQ and promotes HrcQ stability. Furthermore, HrcQC colocalizes with HrcQ as was shown by fluorescence microscopy, suggesting that it is part of the predicted cytoplasmic sorting platform. In agreement with this finding, HrcQC interacts with the inner membrane ring protein HrcD and the SctK-like linker protein HrpB4 which contributes to the docking of the HrcQ complex to the membrane-spanning T3S apparatus. Taken together, our data suggest that HrcQC acts as a chaperone for HrcQ and as a structural component of the predicted sorting platform.

Effect of composite coating on insertion mechanics of needle structure in soft materials

This research aims to study the effect of a composite coating comprised of polydopamine (PDA), polytetrafluoroethylene (PTFE), and activated Carbon on the insertion mechanics of surgical needles in tissues i.e., polyvinyl chloride (PVC) tissue phantom and bovine kidney. A needle insertion and extraction test system was designed and constructed to measure the insertion and extraction forces. It was found that the composite coating on the needle surface decreases the maximum average insertion and extraction forces by 62% and 64%, respectively, when tested in PVC tissue phantom and by 49% and 30%, respectively, in bovine kidney tissue. Additionally, an Atomic Force Microscope study was performed to characterize the surface properties of the coated needles. It was found that the composite coating reduced the friction force on the needle surface by 65.7%. The decrease in these forces is critical in minimizing tissue damage and decreasing needle path deviation or deflection during percutaneous procedures.

Numerical study for bioconvection transport of micropolar nanofluid over a thin needle with thermal and exponential space-based heat source

Nanomaterials are the latest technique to upgrade thermal conduction of base liquids. The submerging of these nanomaterials in base liquid is known as nanofluid. In recent time the nanofluids are more useful in mechanical engineering, nanotechnology, bioscience, biotechnology and in many sectors. This analysis deals with the bio-convection transport of micropolar liquid containing nanomaterial's and gyrotactic motile microorganisms past a needle moving in parallel flow in occurrence of thermally radiation and activation-energy. Modeling of needle structure for bioconvection flow of micropolar nanofluid is developed. The behavior of temperature and exponential space-based heat source is considered. The boundary layer flow expressions for developed transport issue are represented by PDEs. Suitable similarity variables are used to change transport expressions in nondimensional nonlinear ordinary differential ones. The bvp4c algorithm has been used to numerically tackle dimensionless nonlinear differential equations (ODEs). All results are described by employing bvp4c tool in MATLAB. Impacts of active numbers on flow distributions are examined with sketches and tables. Temperature field and heat transfer rate are quite opposite for exponential space-based heat source sink parameter and heat sink/source parameter. The concentration of nanoparticles is reduced for larger amount of Brownian motion parameter while uplifts for thermophoresis parameter. Concentration is enriched for the growing magnitudes of thermophoresis number. Higher Peclet parameter decayed the microorganism's field.

Surface layer of 40Kh steel after electromechanical treatment with dynamic force impact

The paper presents the results of complex studies of the structure, microhardness and depth of the hardened surface layer of 40Kh steel formed as a result of electromechanical treatment with dynamic application of a deforming force (EMT with impact). The research was carried out using optical microscopy, X-ray diffraction analysis, and microhardness methods. The method of electromechanical treatment with dynamic force impact consisted in simultaneous transmission of electric current pulses and deforming force through the contact zone of the tool with the part. As a result of shock-thermal effects with different current densities (j = 100 A/mm2; 300 A/mm2; 600 A/mm2), segments of the hardened layer of different sizes and structure composition are formed on the steel surface in cross-section. Analysis of structural and phase transformations in the surface layer of 40Kh steel subjected to dynamic electromechanical treatment indicates the formation of a specific structure of the white layer, the structure and properties close to the amorphous state of the metal with a maximum hardness HV = 8.0 – 8.5 GPa. As you move away from the surface, a transition zone is formed behind the segment of the white layer with a structure that does not have the characteristic needle structure of martensite. It was found that with an increase in the current density during shock electromechanical treatment, the depth of hardening increases by 4 – 5 times with a simultaneous increase in the heterogeneity of strength properties; the level of micro-stresses increases by 25 %. Experimental data on the structural state, microhardness and depth of the surface layer of 40Kh steel show that electromechanical treatment with dynamic (shock) application of the deforming force causes deeper transformations in the steel structure compared to traditional static EMT. The results obtained show that as a result of electro-mechanical processing with impact, the intensity of the temperature-force effect on the steel surface layer increases, which allows you to open the internal reserves of 40Kh steel and control the process of forming its structure and phase states.

Surfactant assisted spectroscopic application of cadmium oxide nanoparticles prepared via co-precipitation method

Cadmium oxide is one of the captivating nanomaterials possess semiconductor and piezoelectric characteristics which has diverse applications. Most of the nanoparticles synthesis methods are expensive and complex and also difficulty in controlling their shapes and uniformity. The present research work focus on synthesis and characterization of pure and surfactants (SDS) assisted cadmium oxide nanoparticles through co-precipitation method. SDS was used as a stabilizer below its critical micelle concentration. The synthesized nanomaterials were characterized using XRD, SEM, FTIR and photoluminescence spectroscopy. XRD pattern reveal the presence of well indexed CdO nanoparticles with cubic structure. Pure cadmium oxide nanoparticles exhibited ixora flower with needle structure and SDS assisted nanoparticles displayed rosette shaped structure. Optical properties of prepared samples were analyzed using UV and Photoluminescence spectra and the energy gap for pure and surfactants (SDS) assisted cadmium oxide nanoparticles were found to be 3.74 and 3.52 eV. FTIR spectra showed the presence of functional groups in the pure and surfactants (SDS) assisted cadmium oxide nanoparticles. Furthermore, the authors examined the influence of surfactants on size and morphology of nanoparticles.

APPLICATION OF MODELING IN THE QFORM VX 8.2 SOFTWARE PACKAGE FOR DETERMINATION OF RATIONAL COOLING SPEEDS OF RAILWAY RIMS

The tests were performed on ER7 steel according to EN 13262. Based on the hardenability test (GOST 5657) by the method of end hardening (Jomen) the distance from the surface from which unilateral cooling was performed, where the hardness met the requirements of regulatory documentation for wheels of test steel, and the distance where the formation of needle structures, including bainite and otmanshtette, no longer took place. Simulation was applied in the software package QForm VX 8.2, as a result, a model was developed, for the adaptation of which the results of the experiment were used. Confirmed the high convergence of the results of the calculation and the experiment. At the same time, the model allowed to obtain an instantaneous cooling rate in a form that is more in line with the physical meaning of the process and to avoid the scatter of actual values associated with the discreteness of data capture. It is established that the instantaneous cooling rate changes in the process of continuous uniform supply of the cooler. The developed model can be used to build thermokinetic diagrams under continuous cooling and to develop recommendations for heat treatment modes to achieve the specified mechanical properties under a certain structural state.