Characteristics Of Joints Research Articles

Effects of hurdle height on lower limb joint kinematics and kinetics of male trainee sprinters during hurdle jumps

ABSTRACT Hurdle jumps are frequently practiced in the field of sports training. The present study aimed to clarify the effect of hurdle heights on jumping height and joint kinematics, and kinetics during hurdle jumps. Ten male Japanese trainee sprinters performed at three heights (0.76, 0.91 and 1.06 m) of hurdle jumps and maximum countermovement jump (CMJ). Sagittal plane kinematics and ground reaction force were measured. Jump height significantly increased with hurdle heights (η p 2 = 0.65), but the difference in jump heights was small as compared to the difference in the hurdle heights. The contact time and mechanical work of the lower limb joints did not differ between different hurdle heights. The minimal angles of the knee (η p 2 = 0.47) and hip (η p 2 = 0.70) joints during the flight phase significantly decreased with higher hurdle heights. The load characteristics of the lower limb joint with higher hurdle heights would be similar to those with lower hurdle heights. In higher hurdle heights, since the increase in jump height was smaller than the increase in hurdle height, the legs were more flexed to clear the hurdle. Therefore, the hurdle height which is similar to the maximum CMJ height would be appropriate as a training load.

Dimensional measurement of anti-stress cone of HV cable joints based on 3D point cloud

To solve the problem of automatic measurement of anti-stress cone of high voltage cable joints, a measurement algorithm based on 3D point cloud is proposed. Firstly, denoising and coordinate adjustment of point cloud of a cable joint are realized. Then the characteristic curve model of fitting circle radius indicating structure characteristic of cable joints is constructed by fitting circles with random sample consensus algorithm. After that, the discrete points on the characteristic curve are extracted according to the characteristics such as the fluctuation range of the characteristic curve for straight line fitting and the intersection of the fitted lines is calculated to complete the segmentation of the anti-stress cone area of the cable joint. Finally, the parameter measurement of the anti-stress cone was completed according to the structure of the anti-stress cone, and the error correction post-processing was performed. Two types of cable joint point clouds with standard dimensions and surface defects were used for measurement experiments, the absolute errors of the measurement results are less than 0.2 mm and 1.0 mm respectively, and the relative errors are less than 0.25% and 2% respectively, indicating that the proposed method has high robustness and measurement accuracy, which meet the measurement requirements in engineering practice.

An experimental and simulation study of RGO effects on mechanical behaviour of structural adhesive and lap shear joints strength

The research investigates the effects of adding Reduced Graphene Oxide (RGO) at various weight fractions (0.25, 0.5, 0.75 and 1 wt%) on mechanical properties of high strength structural adhesive Araldite©️ 2011 and lap shear strength of adhesive joints. For uniform dispersion of RGO across adhesive, an extensive solution mixing technique was carefully carried out for the preparation of RGO/Epoxy combinations. Two types of lap joints: single lap joint (SLJ) and double lap strap joint (DLSJ) were fabricated. The joints were fabricated using Al 5083 as adherends. The adherends were treated with phosphoric acid anodization (PAA) before joining. A comparison of the strength properties was made after tensile testing of the adhesive specimens and lap joints. In the case of adhesive samples, an increase in mechanical properties was observed at lower concentrations. A maximum increase of 9.5% in the tensile strength and 128% in toughness characteristics was observed with the addition of 0.25 wt% RGO. A maximum improvement of 24% for SLJ and 25% for DLSJ was observed at the same filler percentage. Chemical analysis was conducted using Fourier-Transform Infrared Spectroscopy (FTIR), while dispersion analysis was carried out using Ultraviolet–Visible Spectroscopy (UV-VIS-Nir). Digital and Scanning Electron Microscopy (SEM) techniques were utilised in close examination of the fracture surface at high magnification. A finite element analysis based on cohesive zone modelling (CZM) was performed to predict the failure load characteristics of lap joints. Finally, a comparison of strength and fracture behaviour of RGO with GNPs and MWCNTs was critically discused.

Can the splitting joint reproduce the characteristics of the natural joint in the lab? —A comparison study based on the roughness analysis and shear test

Splitting joints have been widely used to study the morphology characteristic and shear behavior of rock joints in the laboratory. There are some differences between the splitting joint and natural joint both in morphology characteristic and shear behavior. To quantitatively compare the differences, the present study used several splitting joints and natural joints to carry out the roughness analysis and direct shear test. Six profiles were extracted from each joint surface with a 30° interval to calculate the 2D roughness parameters (i.e., amplitude roughness parameter, average asperity inclination, root-mean-square of profile slope, and joint roughness coefficient). These parameters of the natural joints have a wide range and have obvious fluctuation. On the contrary, these parameters of the splitting red sandstone joints converge on a small range with tiny fluctuation, even calculated from different joint surfaces. The directional parameter (θ⁎max(C + 1)) was adopted to calculate the 3D roughness with a 5° interval. The directional parameter of the natural joints in range of 0° ∼ 360° forms a peanut, a prolate ellipse, or a gourd shape, presenting significant anisotropy. For the splitting joints, it forms a circle or a roughly circular shape, presenting insignificant anisotropy. The asperity heights of natural joints mainly present an irregular distribution, and they present an approximately normal distribution in few joints. For the splitting joints, the asperity heights generally obey a normal distribution. It indicates that there are huge differences between natural joint and splitting joint in morphology characteristic. To study the shear behavior, two types of joint were reconstructed for repeated test. The mechanical performance and failure characteristic of the splitting joint under different shear directions are similar. On the contrary, those of the natural joints under different shear directions are different, presenting obvious anisotropy. Based on the comparative analysis of the natural joints and the sandstone splitting joints in the present study, there is substantial difference between two types of joints both in morphology characteristic and shear behavior. The splitting joints cannot reproduce the characteristics of the natural joints well.

The administration of methotrexate in patients with Still's disease, “real-life” findings from AIDA Network Still Disease Registry

ObjectivesTo describe clinical characteristics of patients with Still's disease treated with methotrexate (MTX) and to assess drug effectiveness evaluating change in disease activity, reduction of inflammatory markers, and glucocorticoid (GC)-sparing effect. MethodsPatients with Still's disease treated with MTX were assessed among those included in AIDA Network Still Disease Registry. ResultsIn this registry, 171 patients with Still's disease were treated with MTX (males 43.3%, age 37.1 ± 16.0 years). They were mainly characterised by joint features and fever without a prominent multiorgan involvement. MTX was administered with GCs in 68.4% of patients, with other conventional synthetic DMARDs in 6.4%, and with biologic DMARDs in 25.1%. A significant reduction of the modified systemic score was observed, and 38.6% patients were codified as being in clinical remission at the end of follow-up. The concomitant administration of a biologic DMARD resulted a predictor of the clinical remission. Furthermore, a reduction of inflammatory markers and ferritin levels was observed following the administration of MTX. Additionally, a marked reduction of the dosage of concomitant GCs was identified, while 36.7% discontinued such drugs. Male gender appeared as a predictor of GC discontinuation. MTX was discontinued in 12.3% of patients because of adverse effects, and in 12.3% for lack of efficacy. ConclusionsClinical characteristics of patients with Still's disease treated with MTX were described, mainly joint features and fever without a prominent multiorgan involvement. The clinical usefulness of MTX was reported in reducing the disease activity, decreasing the inflammatory markers, and as GC-sparing agent.

Fabrication and performance of Nb3Sn superconducting joints

Nb3Sn superconducting joints were developed, and the joint characteristics were investigated. The joints were prepared by powder metallurgy to sinter the precursor powders that were mechanically alloyed. The optimized parameters were confirmed through x-ray diffraction studies to confirm the stoichiometry of Nb, Sn, and Cu. First, the precursor powders after mechanical alloying were heat treated without the Nb3Sn wires. Electron backscatter diffraction was used to quantify the crystal morphology, phase distribution, grain boundaries, physical grain orientation, and so on. Small equiaxed Nb3Sn grains were formed after heat treatment. The high-angle grain boundaries in Nb3Sn indicated the complete solid-state diffusion reaction. After the Nb3Sn was successfully prepared, and the superconducting characteristics were measured, we introduce the Nb3Sn wires to prepare Nb3Sn joints and measure their electrical properties. To use the space as economically as possible, the joint was tested under different background fields to estimate the joint resistance under various locations in the magnet. The experimental method and the test results are reported in this work. The joint resistance was tested by using the current decay measure method. The electrical resistance of the Nb3Sn–Nb3Sn joints was on the 10−13 Ω level under the 5.5 T magnetic field.

Improving Small-Scale Human Action Recognition Performance Using a 3D Heatmap Volume.

In recent years, skeleton-based human action recognition has garnered significant research attention, with proposed recognition or segmentation methods typically validated on large-scale coarse-grained action datasets. However, there remains a lack of research on the recognition of small-scale fine-grained human actions using deep learning methods, which have greater practical significance. To address this gap, we propose a novel approach based on heatmap-based pseudo videos and a unified, general model applicable to all modality datasets. Leveraging anthropometric kinematics as prior information, we extract common human motion features among datasets through an ad hoc pre-trained model. To overcome joint mismatch issues, we partition the human skeleton into five parts, a simple yet effective technique for information sharing. Our approach is evaluated on two datasets, including the public Nursing Activities and our self-built Tai Chi Action dataset. Results from linear evaluation protocol and fine-tuned evaluation demonstrate that our pre-trained model effectively captures common motion features among human actions and achieves steady and precise accuracy across all training settings, while mitigating network overfitting. Notably, our model outperforms state-of-the-art models in recognition accuracy when fusing joint and limb modality features along the channel dimension.

Transforming spatio-temporal self-attention using action embedding for skeleton-based action recognition

Over the past few years, skeleton-based action recognition has attracted great success because the skeleton data is immune to illumination variation, view-point variation, background clutter, scaling, and camera motion. However, effective modeling of the latent information of skeleton data is still a challenging problem. Therefore, in this paper, we propose a novel idea of action embedding with a self-attention Transformer network for skeleton-based action recognition. Our proposed technology mainly comprises of two modules as, (i) action embedding and (ii) self-attention Transformer. The action embedding encodes the relationship between corresponding body joints (e.g., joints of both hands move together for performing clapping action) and thus captures the spatial features of joints. Meanwhile, temporal features and dependencies of body joints are modeled using Transformer architecture. Our method works in a single-stream (end-to-end) fashion, where multiple-layer perceptron (MLP) is used for classification. We carry out an ablation study and evaluate the performance of our model on a small-scale SYSU-3D dataset and large-scale NTU-RGB+D and NTU-RGB+D 120 datasets where the results establish that our method performs better than other state-of-the-art architectures.

Influence of weight-bearing on the 3D movement of lumbar facet joints in the sitting position

ObjectiveTo analyze the motion characteristics of lumbar facet joints and to observe the effect of weight-bearing on lumbar facet joints in the sitting position.MethodsTen normal subjects (5 males and 5 females) were recruited and scanned by CT, and their lumbar 3D models were reconstructed by software. The images of flexion and extension of lumbar facet joints in the sitting position were collected without weight-bearing and weight-bearing 10 kg, and the 2D model was constructed by software. The 2D-3D model was matched to restore the flexion and extension motion changes of the subjects’ lumbar spine in the sitting position. Coordinates were established in the middle of the vertebral body and copied to the facet joints. Measure and record the lumbar facet joint movement distance through coordinate system. The relevant data of facet joints were collected.ResultsIn the L3/4 segment, after weight loading, the displacement of the left facet joint in the X axis became larger, while that in the Y axis and Z axis decreased. The displacement of the right facet joint in the X axis and Y axis increased, and the Z axis displacement decreased. The rotation angle of the bilateral facet joints also decreased. In the L4/5 segment, after loading, the displacements of the X, Y, and Z axis displacements of both sides increase, while the rotation angles of α and β increase, while the rotation angle of γ decreases. In the L5/S1 segment, the displacements of the X, Y, and Z axes on the left side decrease. The displacement of the X and Y axes on the right side decreases, while the displacement on the Z axis increases. The rotation angles of α and γ increase, and the rotation angle of the β axis decreases.ConclusionWhen sitting, the flexion and extension distance and rotational displacement of lumbar facet joints are not affected by weight-bearing. In addition, there is asymmetry in the movement of the left and right facet joints, and weight bearing has no effect on the asymmetry of the motion.

Metal deposited nanoparticles as “bridge materials” for lead-free solder nanocomposites

An influence of carbon nanotubes and carbon nanospheres coated by Au–Pd and Pt on the microstructure of solder/copper joints at room temperature and after aging at sub-zero temperature. The carbon nanosized admixtures were mixed with ternary Sn3.0Ag0.5Cu matrix to prepare a composite solder. The microstructure of the solder joints between the nanocomposite solders and a copper substrate was studied by scanning electron microscopy. It was found that minor (0.05 wt. %) admixtures of both the carbon nanospheres and nanotubes increase the shear strength of the solder joints and reduce the growth rate of the intermetallic Cu6Sn5 layer, formed at the interface between solder and copper. This effect may be related to the adsorption of nanoinclusions on the grain surface during the solidification process. Comparative analysis suggests that exposure for 2 months at 253 K does not lead to deterioration of such an important mechanical characteristic of the solder joint as shear strength, indicating the possibility of using these nanocomposite solders in microelectronic equipment even at temperatures below 0 ℃.

Influences of various parameters on shear stiffness of bolted joints subjected to shear load

Parameters which affect shear stiffness characteristics of bolted joints subjected to shear load should be elucidated in order to design mechanical structures for functionality focusing not only on their strength and self-loosening but also on their shear stiffness. In this study, we have both experimentally and analytically investigated the behaviors of a bolted joint subjected to shear load and primary parameters which determine the shear stiffness characteristics of bolted joints. The experiments have been conducted applying the shear load four times repeatedly on clamped plates of a bolt/nut assembly with washers. We measured the shear stiffness of bolted joints and the shear load at which the slippage started to occur between the clamped plates. Four types of washers were used in the experiments with different contact areas on the clamped plates in order to reveal the effect of contact area of washers. We also conducted FE analysis under the same conditions. As the results, it was seen that the shear stiffness slightly increased with an increase in the clamp force of bolted joint. The shear stiffness was not influenced by the number of loading cycles. It was also seen that the amount of rotational deformation in the bolted joint depended on the slippage between the clamped plates. Although the rotation deformation was very small until the slippage occurrence, the rotational deformation remarkably increased after the slippage occurred. In general, it is well-known that the joining portion of lap jointed plates by spot welding, for example, slightly and rotationally deformed, but it has never been elucidated that the inclination angle due to the rotational deformation depends on the slippage between the clamped plates in the bolted joint. It was also seen that the shear stiffness until the slippage occurrence increased with an increase in the contacting surface area between the clamped plates. Although we investigated the effect of surface roughness of the clamped plates only in the experiments, we cannot clearly reveal its effect on the shear stiffness. But it is seen from the FE analysis result that the friction coefficient between clamped plates had a slight influence on the shear stiffness. The result shows that the shear stiffness of bolted joint mainly depends not only on the slip resistance between the clamped plates but also on increase of the contact surface between the washers and clamped plates. The results can be applied in order to control the shear stiffness of lap-jointed plates by spot welding and so on.

Analysis of Rigid-Flexible Coupling Characteristics of Pneumatic Modular Soft Joints with Variable Stiffness

Analysis of Rigid-Flexible Coupling Characteristics of Pneumatic Modular Soft Joints with Variable Stiffness

Insights into the microstructure evolution and mechanical behavior of dissimilar friction stir welded joints of additively manufactured AlSi10Mg and conventional 7075-T651 aluminum alloys

Metal 3D printing through laser powder bed fusion (L-PBF) has revolutionised the manufacturing industry. However, size limitations and production costs persist as challenges for the 3D printing of metallic alloys. Thus, joining L-PBF components to other parts becomes a vital aspect to produce composite structures for engineering applications. Among the dissimilar joining of various non-ferrous alloys, the integration of L-PBF components with difficult-to-join materials, such as aerospace-grade AA-7XXX aluminum alloys, still remains an unaddressed industrial problem. To address this problem, the current study was carried out to investigate the feasibility of joining L-PBF manufactured AlSi10Mg alloy with a traditionally rolled AA7075-T651 alloy using friction stir welding process. In this study, the influence of the base material positioning and heat input on the mechanical and metallurgical characteristics of welded joints was examined, followed by their interrelationships for more efficient adoption of this technology. The results revealed that the base material placement significantly influenced the joint strength at low heat input but showed negligible impact at high heat input. The joints fabricated at high heat input exhibited higher hardness within the nugget zone owing to the higher concentration of MgZn2 and β-Mg2Si secondary-phase particles as compared to the joints fabricated at low heat input. Texture analysis of welds showed that the C {001} <110> shear component dominated the nugget zone when AA7075-T651 was placed on the retracting side. Whereas, the A1*/ A2* {111} <1‾12‾ >/{111} <112‾ > simple shear component was prominent when AA7075-T651 was placed on the advancing side of the joint. Finer grains and high dislocation density in the nugget zone at low heat input resulted in the maximum joint efficiency of 77% with respect to the AlSi10Mg alloy. In contrast, a coarse grain structure at high heat input reduced the joint efficiency to 74%. The findings from this research suggest friction sir welding to be an efficient method for dissimilar joining of additive components with conventionally manufactured parts.

A flexible triboelectric nanogenerator based on PVA/PTT/LiCl conductive hydrogel for gait monitoring in basketball

Recently, wearable flexible sensors for intelligent sports monitoring have attracted much attention. In this work, we designed the polyvinyl alcohol (PVA)/polytrimethylene terephthalate (PTT)/LiCl hydrogel to act as the flexible conductive of triboelectric nanogenerator (PPL-TENG). Significantly, the PPL-TENG device has high transparency and stretchability, demonstrating excellent ability in complex mechanical energy harvesting. From the results, the PPL-TENG achieve the maximum power density of 159.6 µW cm−2. In addition, the PVA/PTT/LiCl hydrogel exhibits good mechanical properties, thus endowing PPL-TENG devices with excellent application value. Also, the electrical output of PPL-TENG exhibits good stability and excellent fast charging capability. In addition to mechanical energy harvesting, PPL-TENG also has excellent sensing performance and can be used as a self-powered sensor for basketball motion monitoring. After experimental testing, PPL-TENG can recognize the characteristics of body joints and gait in basketball, which will play an auxiliary role in basketball sports. This research will promote the development of intelligent wearable sports devices.

Automatic identification of rock discontinuity and stability analysis of tunnel rock blocks using terrestrial laser scanning

Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels. This study demonstrates the integration of terrestrial laser scanning (TLS) with distinct element method for rock mass characterization and stability analysis in tunnels. TLS records detailed geometric information of the surrounding rock mass by scanning and collecting the positions of millions of rock surface points without contact. By conducting a fuzzy K-means method, a discontinuity automatic identification algorithm was developed, and a method for obtaining the geometric parameters of discontinuities was proposed. This method permits the user to visually identify each discontinuity and acquire its spatial distribution features (e.g. occurrences, spacings, trace lengths) in great detail. Compared with hand mapping in conventional geotechnical surveys, the geometric information of discontinuities obtained by this approach is more accurate and the identification is more efficient. Then, a discrete fracture network with the same statistical characteristics as the actual discontinuities was generated with the distinct element method, and a representative numerical model of the jointed surrounding rock mass was established. By means of numerical simulation, potential unstable rock blocks were assessed, and failure mechanisms were analyzed. This method was applied to detection and assessment of unstable rock blocks in the spillway and sand flushing tunnel of the Hongshiyan hydropower project after a collapse. The results show that the noncontact detection of blocks was more labor-saving with lower safety risks compared with manual surveys, and the stability assessment was more reliable since the numerical model built by this method was more consistent with the distribution characteristics of actual joints. This study can provide a reference for geological survey and unstable rock block hazard mitigation in tunnels subjected to complex geology and active rockfalls.

Cerebrovascular segmentation in phase-contrast magnetic resonance angiography by a Radon projection composition network.

Cerebrovascular segmentation based on phase-contrast magnetic resonance angiography (PC-MRA) provides patient-specific intracranial vascular structures for neurosurgery planning. However, the vascular complex topology and spatial sparsity make the task challenging. Inspired by the computed tomography reconstruction, this paper proposes a Radon Projection Composition Network (RPC-Net) for cerebrovascular segmentation in PC-MRA, aiming to enhance distribution probability of vessels and fully obtain the vascular topological information. Multi-directional Radon projections of the images are introduced and a two-stream network is used to learn the features of the 3D images and projections. The projection domain features are remapped to the 3D image domain by filtered back-projection transform to obtain the image-projection joint features for predicting vessel voxels. A four-fold cross-validation experiment was performed on a local dataset containing 128 PC-MRA scans. The average Dice similarity coefficient, precision and recall of the RPC-Net achieved 86.12%, 85.91% and 86.50%, respectively, while the average completeness and validity of the vessel structure were 85.50% and 92.38%, respectively. The proposed method outperformed the existing methods, especially with significant improvement on the extraction of small and low-intensity vessels. Moreover, the applicability of the segmentation for electrode trajectory planning was also validated. The results demonstrate that the RPC-Net realizes an accurate and complete cerebrovascular segmentation and has potential applications in assisting neurosurgery preoperative planning.

Updating of the complete joint characteristics of finite element model via FRF-based substructuring of complex structures

Updating of the complete joint characteristics of finite element model via FRF-based substructuring of complex structures

Investigation of Joint Quality 980 MPa Grade GA Steel Sheet and 5052 Aluminum Alloy by Electromagnetic Self-Piercing Riveting

Generally, an approximately 1% weight reduction in a 200 kg automobile improves the fuel economy by 20~26% and acceleration performance by 8%. Hence, various techniques for automotive lightweighting have been developed to satisfy environmental regulations of the automotive industry. The joining of dissimilar materials is critical for assembling lightweight body structures, but fusion welding is inapplicable owing to the difference in mechanical properties between materials. Thus, the development of an appropriate dissimilar material-joining process is required to produce high-quality joints. Self-piercing riveting is a representative joining process that is applied by pressure punching without prehole piercing. Operationally, this process is widely used for joining because it can produce joints with high shear strengths. However, the development of lighter and higher-strength materials indicates that the required force for SPR machines to form high-quality joints is increasing. Thus, high-speed E-SPR has been developed for joining ultrahigh tensile steels. In this study, SGAFC980/A5052-H34 was applied to the E-SPR process, and the joint characteristics were analyzed via cross-sectional analysis and shear strength tests. With an increase in the fastening speed, the interlock distance and the tensile shear load increased.

Anatomical study of stifle joint in dogs

The stifler is one of the hindlimb joints, described as complicated join consisting of many structures that organized in accurate way to support and stabilize body and hindlimb during the movement. The stifle joint of dogs, equivalent to the knee joint in the human, is a complex composition comprising the tibia, patella femur, menisci, caudal and cranial cruciate ligaments, lateral and medial collateral ligament, also surrounding muscles like hamstring and quadriceps muscles. The long bones (tibia and femur) form this joint, while patella sits in front of it to protect it. The two C-shaped menisci act as shock absorbers, and the supporting ligaments including collateral and cruciate provide stability to the joint. The surrounding muscles, including the quadriceps and hamstring muscles, help to extend and flex the joint, respectively. Together, these structures work in harmony to allow for the complex movement of dogs’ stifle joint.&#x0D; Understanding the anatomical features of the stifle joint in dogs is important for diagnosing and treating injuries or conditions that affect this complex joint

Strengthening of friction surfaces by using geomodifiers based on serpentines from the Dashukivka deposit

The object of research is the process of improving the tribological characteristics of friction joints, in particular anti-wear and anti-burr properties. There is a practice of using serpentines, so-called "friction geomodifiers" (FGM), as special repair and restoration additives. Their use leads to a decrease in the coefficient of friction and temperatures in the contact zone; an increase in the mass of parts is observed, which indicates the restoration of worn surfaces. The mechanism of formation of new structures is still unclear. There are hypotheses that severe friction conditions initiate micrometallurgical processes at the atomic-crystalline level, as a result of which modified layers with unique tribological characteristics are formed on the surfaces. A comparative analysis of the main indicators of serpentines of the Dashukivka deposit in terms of chemical composition and structure showed their correspondence to widely known analogs but they were never used in such a capacity. According to the results of the tests, the additives have shown their effectiveness as geomodifiers of friction. Addition of 4 % serpentine to the lubricating composition based on I-20 A oil reduced the wear rate by 2–3 times, the friction moment by 15 %, compared to I-20 A without additives. An increase in surface microhardness was observed, from 6 GPa for the basic variant to 10 GPa, for the variant with FGM additives. It has been established that the use is most effective for heavily loaded friction pairs (ship fittings, hatch closures, etc.) as it increases the clamping load (from 600 to 1400 N for a pair of steel 45/ShKh15); with increasing load, the coefficient of friction and the rate of wear decrease. The results confirm the need to expand research into this area to solve the complex problem of increasing the reliability of tribojunctions. Keywords: repair and restoration technologies, friction geomodifiers, serpentine, heavily loaded friction pairs