Showing papers on "Paddle published in 2022"

Augmented Reality to Assist Skin Paddle Harvesting in Osteomyocutaneous Fibular Flap Reconstructive Surgery: A Pilot Evaluation on a 3D-Printed Leg Phantom

Abstract: Background Augmented Reality (AR) represents an evolution of navigation-assisted surgery, providing surgeons with a virtual aid contextually merged with the real surgical field. We recently reported a case series of AR-assisted fibular flap harvesting for mandibular reconstruction. However, the registration accuracy between the real and the virtual content needs to be systematically evaluated before widely promoting this tool in clinical practice. In this paper, after description of the AR based protocol implemented for both tablet and HoloLens 2 smart glasses, we evaluated in a first test session the achievable registration accuracy with the two display solutions, and in a second test session the success rate in executing the AR-guided skin paddle incision task on a 3D printed leg phantom. Methods From a real computed tomography dataset, 3D virtual models of a human leg, including fibula, arteries and skin with planned paddle profile for harvesting, were obtained. All virtual models were imported into Unity software to develop a marker-less AR application suitable to be used both via tablet and via HoloLens 2 headset. The registration accuracy for both solutions was verified on a 3D printed leg phantom obtained from the virtual models, by repeatedly applying the tracking function and computing pose deviations between the AR-projected virtual skin paddle profile and the real one transferred to the phantom via a CAD/CAM cutting guide. The success rate in completing the AR-guided task of skin paddle harvesting was evaluated using CAD/CAM templates positioned on the phantom model surface. Results On average, the marker-less AR protocol showed comparable registration errors (ranging within 1-5 mm) for tablet-based and HoloLens-based solution. Registration accuracy seems to be quite sensitive to ambient light conditions. We found a good success rate in completing the AR-guided task within an error margin of 4 mm (97% and 100% for tablet and HoloLens, respectively). All subjects reported greater usability and ergonomics for HoloLens 2 solution. Conclusions Results revealed that the proposed marker-less AR based protocol may guarantee a registration error within 1-5 mm for assisting skin paddle harvesting in the clinical setting. Optimal lightening conditions and further improvement of marker-less tracking technologies have the potential to increase the efficiency and precision of this AR-assisted reconstructive surgery.

Rational Design of Carborane-Based Cu2-paddle wheel Coordination Polymers for Increased Hydrolytic Stability

Abstract: A new unsymmetric carborane based dicarboxylic linker provided a 1D Cu2-paddle wheel coordination polymer (2) with much higher hydrolytic stability than the corresponding 2D Cu2-paddle wheel polymer (1), obtained from...

Innovative design and performance test of threshing-separating device for horizontal axial-flow combine harvester

Abstract: Aiming at the problems of high grain entrainment loss rate and impurity rate of traditional horizontal axial-flow combine harvesters, a horizontal axial-flow threshing-separating device with coaxial differential threshing drum, conical cleaning fan, double-layer vibrating screen and spiral plate-tooth re-thresher is designed. Meanwhile, a test-bed with a feeding rate of 2 kg/s is designed to improve the device performance. The test through quadratic orthogonal rotation combination design method is used to inspect the effects of the differential drumspeed combination, conical fan blade taper, and length ratio of the high and low speed sections of the differential drum on the loss rate, crushing rate , impurity rate and threshing power consumption. The regression mathematical models of the loss rate, crushing rate, impurity content and threshing power consumption are established, and the multi-objective optimization calculation of the regression mathematical model is carried out by using MATLAB optimization toolbox. The results show that the order of the three factors affecting the loss rate and impurity content of the horizontal axial-flow threshing-separating device is the differential drumspeed combination, the conical fan bladetaper, and the length ratio of high and low speed sections of the differential drum. The field test results show that the performance index of the horizontal axial-flow separation device is better than the requirements of the national standard.

Simulating the Hydrodynamic Conditions of the Human Ascending Colon: A Digital Twin of the Dynamic Colon Model

Abstract: The performance of solid oral dosage forms targeting the colon is typically evaluated using standardised pharmacopeial dissolution apparatuses. However, these fail to replicate colonic hydrodynamics. This study develops a digital twin of the Dynamic Colon Model; a physiologically representative in vitro model of the human proximal colon. Magnetic resonance imaging of the Dynamic Colon Model verified that the digital twin robustly replicated flow patterns under different physiological conditions (media viscosity, volume, and peristaltic wave speed). During local contractile activity, antegrade flows of 0.06–0.78 cm s−1 and backflows of −2.16–−0.21 cm s−1 were measured. Mean wall shear rates were strongly time and viscosity dependent although peaks were measured between 3.05–10.12 s−1 and 5.11–20.34 s−1 in the Dynamic Colon Model and its digital twin respectively, comparable to previous estimates of the USPII with paddle speeds of 25 and 50 rpm. It is recommended that viscosity and shear rates are considered when designing future dissolution test methodologies for colon-targeted formulations. In the USPII, paddle speeds >50 rpm may not recreate physiologically relevant shear rates. These findings demonstrate how the combination of biorelevant in vitro and in silico models can provide new insights for dissolution testing beyond established pharmacopeial methods.

Crescent‐shaped skin paddle for a fibular flap: Avoiding skin grafting at the donor site

Abstract: A fibular osteocutaneous flap is the mainstay of oromandibular reconstruction. This report aimed to present a crescent‐shaped skin paddle, a novel fibular skin paddle designed to achieve both sufficient intraoral lining and primary closure of the donor site. A 3–5‐cm‐wide crescent‐shaped skin paddle was harvested according to the locations of the distal septocutaneous perforators on preoperative color Doppler sonography. This narrow skin paddle fits well morphologically into the mucosal defect, enabling a reliable intraoral lining. This advantage becomes more evident when the mandibular defect crosses the midline or extends posteriorly to the maxillary tuberosity as the shape of the mucosal defect becomes arcuate. Primary closure of the donor site is easier to achieve because the required width of the crescent‐shaped skin paddle is minimized. This method reduces donor‐site morbidity associated with skin grafting while ensuring safe intraoral closure with a fibular osteocutaneous flap.

Reconstruction of Complex Soft Tissue Defects of the Heel With Versatile Double Skin Paddle Anterolateral Thigh Perforator Flaps: An Innovative Way to Restore Heel Shape

Abstract: Background Complex heel defects constitute a significant challenge for plastic surgeons. Objectives In this study, versatilities of free double skin paddle ALT flaps in the reconstruction of complex soft tissue defects of heels were explored. Methods From January 2010 to December 2019, 16 patients (13 male and 3 females) aged 16–74 years underwent double skin paddle ALT flap reconstruction in our department. All the patients had large defects located at the heel, and 5 had a dead space. Underlying structures such as vessels, bones, and tendons were exposed in all cases. Results Flap survival rate was 100% after the reconstruction. Eleven double skin paddle ALT flaps and 5 vastus lateralis muscle-chimeric double skin paddle ALT flaps were used. The size of the skin flap ranged from 9.5 × 4.5 cm2 to 22 × 10 cm2, and the size of a muscle segment ranged from 6 × 3 × 1 cm3 to 10 × 3 × 2 cm3. The mean follow-up was 22.6 months (range: 10–81 months). The wounds healed well, providing reliable soft tissue coverage and good heel contour. All the patients ambulated independently during the follow-up period. Most of them regained protective sensation. The average two-point discrimination was 32.7 mm (range: 27–37 mm). Conclusion Double skin paddle ALT flaps are a feasible option for the reconstruction of complex heel defects, with good functional and aesthetic results. Nonetheless, further studies comparing double skin paddle ALT flaps to other flap techniques are needed.

Revision and Replacement of Spinal Cord Stimulator Paddle Leads.

Abstract: Paddle leads for spinal cord stimulation (SCS) offer more efficient energy delivery and advantages in some patients. However, there is concern for how safely SCS paddles can be replaced once previously implanted because of scar tissue and the relative vulnerability of the thoracic cord. In this study, we share our experience on SCS paddle replacement.Participants who underwent SCS replacement at Albany Medical Center between 2011 and 2020 were identified. The medical records were reviewed for demographic data and information regarding initial complications, reason for removal or revision, subsequent complications of replacement surgery and its timing, and whether the implant was ultimately removed. Percutaneous lead replacement cases performed over the same period were used as a comparison group.A total of 1265 patients were identified to have had an SCS-related procedure based on billing codes. Of these, 73 involved replacement of epidural leads (51 paddles, 22 percutaneous). Most paddles (48/51) were replaced at the time of removal. A total of 30 of the 51 paddle replacements required additional lamina removal. Re-operations that occurred more than one year after initial implant were significantly more likely to require additional bone removal (p < 0.001). Paddle re-operations lasted in general 1.7 ± 0.2 hours and had 35 ± 5 mL of blood loss, whereas percutaneous operations lasted 1.3 ± 0.2 hours and had 12.5 ± 2 mL of blood loss. Despite the invasive nature of paddle replacement, there was no difference in complications (p = 0.23) compared with that in percutaneous leads.This study characterizes the safety profile of SCS paddle replacement surgeries. Here, we demonstrate that the replacement of paddle leads at the time of removal, with additional lamina removal if needed because of scar, is associated with low rates of complications. This validates the feasibility and low-risk profile of replacing paddle leads when clinically indicated for experienced surgeons with specialization in SCS.

High-Resolution Spinal Motor Mapping Using Thoracic Spinal Cord Stimulation in Patients With Chronic Pain

Abstract: BACKGROUND: High-resolution spinal cord stimulation (HR-SCS) paddle can stimulate medial-dorsal columns and extend stimulation coverage to the laterally positioned spinal targets. OBJECTIVE: To investigate the medio-lateral selectivity of an HR-SCS paddle in patients with chronic pain. METHODS: During standard-of-care spinal cord stimulation (SCS) placement, epidurally evoked electromyography and antidromic dorsal column–evoked potentials were recorded in 12 subjects using an HR-SCS paddle with 8 medio-lateral sites spanning the full epidural width at thoracic T9-12 and a commercial paddle consecutively. RESULTS: Recruitment maps were aligned with respect to physiological midline which was overlapping with anatomic midline in 10 of 11 cases. Overlapping contacts between the HR-SCS and commercial paddles exhibited similar patterns while HR-SCS demonstrated higher precision targeting of certain dermatomes. Spinal motor maps showed that the lateral contacts triggered stronger responses in medial gastrocnemius, adductor magnus, and tibialis anterior while the medial contacts triggered stronger responses in gluteus maximus and adductor hallucis. The time-locked popliteal fossa responses indicated ipsilateral activation by HR-SCS at the lateral contacts and bilateral activation at the medial contacts with stronger ipsilateral responses. CONCLUSION: This study is the first to perform high-resolution medio-lateral SCS mapping in patients with chronic pain. These results show promise that HR-SCS may provide additional ipsilateral recruitment within the extremities which improve targeting of focal pain in the lower extremities. Furthermore, this study supports the functional use of intraoperative neuromonitoring as a decision tool to determine physiological midline in thoracic SCS surgeries and provides a full methodological framework.

Paddle propulsive force and power balance: a new approach to performance assessment in flatwater kayaking.

Abstract: This study aims to determine the propulsive force (Fp) and its timing of application during the paddle stroke confirming the dynamic balance between propulsive and drag powers (Pp = Pd) in kayaking performance. Ten male sub-elite paddlers participated in the study. The athletes carried out three trials of 50 m at three different velocity ranges: 2.70 - 3.00 m/ s; 3.01 - 3.50 m/s and 3.51 - 4.00 m/ s. A constant velocity during each trial was maintained and the section between 15 and 40 m of the total pool length was considered for further analysis. Data were collected using the E-kayak system provided of an instrumented paddle and 2D video analysis. It was observed that the propulsive force increases in intensity (up to 90% of the peak force) as the velocity increases. The dynamic balance between Pd and Pp was confirmed with a Bland and Altman plot (estimated bias: 0.2; LoA: 12.8 and 13.3 W). The related comparisons between the power parameters showed no significant difference (p > 0.050) in each of the considered velocity. By applying the dynamic balance theory between Pp = Pd on the data obtained from the interaction among GPS, force on the paddle and 2D video analysis, it is possible to acquire essential information (Fp, Pp) to monitor the flatwater kayaking performance.

Investigation of Mixing Non-Spherical Particles in a Double Paddle Blender via Experiments and GPU-Based DEM Modeling

Abstract: : In this study, we have investigated the mixing kinetics and flow patterns of non-spherical particles in a horizontal double paddle blender using both experiments and the discrete element method (DEM). The experimental data were obtained using image analysis from a rotary drum containing cubical and cylindrical particles. Then, the experimental data were used in order to calibrate the DEM model. Using the calibrated DEM model, the effects of operating parameters such as vessel fill level, particle loading arrangement, and impeller rotational speed on the mixing performance were examined. The diffusivity coefficient was calculated to assess the mixing performance.

The Effect of Paddle Stroke Variables Measured by Trainesense SmartPaddle® on the Velocity of the Kayak

Abstract: (1) Background: This study aimed to compare key variables of paddle stroke measured by a commercial Trainesense SmartPaddle® against the strain-gauge shaft and investigate how these variables are associated with the velocity of the boat among national-level canoe polo players. (2) Methods: This study involved 14 Finnish national-level canoe polo players. The measurement protocol consisted of three different paddling velocities, which were performed in indoor swimming pools. The velocity of the boat was calculated based on the performance time measured with the laser photocell gate. Canoe polo equipment was used in the study and a SmartPaddle sensor was attached to the paddle blade. A strain-gauge paddle shaft was used as a reference method to examine the validity of SmartPaddle. (3) Results: The stroke rate, force production time, mean and maximal force measured with the strain-gauge paddle shaft correlated strongly (r = 0.84–0.95, p < 0.01) with SmartPaddle. However, the SmartPaddle overestimated the maximum force compared to the strain-gauge shaft. Stroke rate (r = 0.86, p < 0.01), mean force (r = 0.79, p < 0.01), maximal force (r = 0.78, p < 0.01) and total absolute impulse (r = 0.70, p < 0.01) correlated positively and force production time negatively (r = −0.76, p < 0.01) with the velocity of the boat. (4) Conclusions: We conclude that the SmartPaddle provides promising information on stroke key variables when compared to the strain-gauge paddle shaft. The SmartPaddle is a new and interesting tool for biomechanical research and daily kayaking coaching in real open water conditions. However, more research and algorithm development are needed before the SmartPaddle can be used in everyday coaching sessions in kayaking.

Win or lose. Physical and physiological responses in paddle tennis competition according to the game result

Abstract: ABSTRACT Sports success can be determined by technical level, physical condition, but also with behaviour and decision-making in competition. The main aim of this study was to compare the different physiological and physical responses of professional male paddle-tennis players as a function of the game result. Sixty sets and twenty-four players were analysed in the Spanish National Championships. Heart rate (HR), lactate concentrations, rating of perceived exertion (RPE), covered distance and speed and sprints were measured. Comparative tests were performed to compare winners and losers, and RPE was analysed using the Receiver Operating Characteristic (ROC) curve test through Logit model. Losers showed greater results in the mean HR (154.1±15.6 beats·min−1) than winners (144.2±19.1 beats·min−1, p<0.01). A score of 6–10 or 16–20 points in RPE, entailed a high or low probability of winning the set (72–92% or 6–23%, respectively). Physical responses were higher in losers, e.g. higher distances, mean velocity, sprints number between 2.1–9.0 km·h−1. As conclusions, players who finally lose the match demand greater physical and physiological responses in general. It is established, as in other racket sports, that the player’s position on the court is key to determining victory in this sport.

Vortex formation and quantum turbulence with rotating paddle potentials in a two-dimensional binary Bose-Einstein condensate

Abstract: We conduct a theoretical study of the creation and dynamics of vortices in a two-dimensional binary Bose-Einstein condensate with a mass imbalance between the species. To initiate the dynamics, we use one or two rotating paddle potentials in one species, while the other species is influenced only via the interspecies interaction. In both species, the number and the dominant sign of the vortices are determined by the rotation frequency of the paddle potential. Clusters of positive and negative vortices form at a low rotation frequency comparable to that of the trap when using the single paddle potential. In contrast, vortices of the same sign tend to dominate as the rotation frequency of the paddle increases, and the angular momentum reaches a maximum value at a paddle frequency, where the paddle velocity becomes equal to the sound velocity of the condensate. When the rotation frequency is sufficiently high, the rapid annihilation of vortex-antivortex pairs significantly reduces the number of vortices and antivortices in the system. For two paddle potentials rotating in the same direction, the vortex dynamics phenomenon is similar to that of a single paddle. However, when the paddle potentials are rotated in the opposite direction, both positive and negative signed vortices occur at all rotational frequencies. At the low rotation frequencies, the cluster of like-signed vortices produces the $k^{-5/3}$ and $k^{-3}$ power laws in the incompressible kinetic energy spectrum at low and high wavenumbers, respectively, a hallmark of the quantum turbulent flows.

Estimation of Heat Transfer Coefficient in Turbulent Regime during Agitation by Two-blade Wide Paddle Impellers

Abstract: This work proposed a new equation to estimate heat transfer coefficients in a turbulent regime during the agitation by two-blade wide paddle impellers. The equation includes Nusselt number, Prandtl number, Reynolds number based on energy dissipation rate, a ratio of impeller diameter to vessel diameter, and a ratio of blade width to vessel diameter. The representative length related to the heat transfer, proposed by Hiraoka and Ito (1973), was adopted for the equation. The proposed correlation equation successfully estimated the heat transfer coefficient during the agitation by two-blade wide paddle impellers (Maxblend impeller, Fullzone impeller, Sanmeler impeller, MR210, and MR 203). The proposed equation is also applicable for the agitation by conventional impellers (disk turbine, flat paddle, and pitch paddle).

A Bow‐Drill Structured Triboelectric Nanogenerator for Marine Ranching Monitoring

Abstract: Triboelectric nanogenerator (TENG) is one promising method of wave energy harvesting for marine ranching monitoring. Different from previous studies with complex structures (gears, racks, worm gears, or screw‐nut), a bow‐drill structured TENG (BS‐TENG) with a simple, cheap but effective rope‐roller structure is proposed and investigated to magnify the wave motion frequency. Inspired by the bow‐drill for carpentry, the proposed structure only simply needs a rope and roller to transfer the random wave motion into regular rotary motion with higher frequency. Results show that the structure parameters (flexible paddle number NP flexible paddle length L, electrode number NE and shaft side length D) have a great influence on the working performance of the BS‐TENG. The maximum frequency magnification ration (Rm) is 74 under the condition of 130 mm wave height (Hw); the maximum output power (P) is 450 µW. Demonstration experiments verify that the BS‐TENG is able to charge the thermo‐hygrometer and light emitting diode lights for marine ranching. Combined with the Internet of Things and 5G technologies, the BS‐TENG could be applied in the offshore sensor system for the monitoring of marine ranching information.

Long-Term Changes in Thecal Sac Compression and Decreased Cerebrospinal Fluid Space Following Paddle Lead Spinal Cord Stimulation at T9: A Long-Term Follow-Up via Three-Dimensional Myelographic Computed Tomography

Abstract: To investigate the long-term changes in thecal sac compression following T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography (CT).Seventeen patients with five-column paddle lead SCS at T9 underwent three-dimensional myelographic CT scans preoperatively, immediately after surgery, and after an average of 11 months. The cross-sectional areas of thecal sac and spinal cord and the widths of anterior and posterior CSF spaces were repeatedly measured and compared. The contact angle of the lead with long-term pain relief was assessed.The cross-sectional areas of thecal sac and spinal cord decreased significantly after lead placement (30.47 ± 9.21% and 4.71 ± 9.84%, respectively). Even after 11 months, a significant reduction was found with the preoperative values (17.97 ± 12.32% and 2.88 ± 7.09%). The widths of anterior and posterior CSF spaces decreased significantly after surgery (43.53 ± 13.17% and 57.13 ± 13.17%, respectively) and the severe decrease persisted long-term (29.13 ± 21.54% and 50.99 ± 16.07%). The average pain relief was 42.27 ± 17.50% with no correlation between the rate of reduction in cross-sectional areas of thecal sac and the widths of CSF spaces.Significant early reduction and late partial restoration occurred in the thecal sac and spinal cord and the width of the anterior and posterior CSF spaces in the T9 5-column paddle lead SCS. Thecal sac compromise was expected to some extent after paddle lead implantation, but the degree is significant, and the cross-sectional area of the spinal cord as well as the thecal sac is affected. Fortunately, these anatomical changes did not cause any clinical problems except for intercostal root irritation. The shape and flat contours of the five-column paddle leads clearly affected the results.

The impact of rehabilitation sport on breast cancer-related lymphoedema and quality of life

Abstract: Surgery and radiotherapy as part of breast cancer treatment can lead to lymphoedema of the upper extremities (breast cancer-related lymphoedema = BCRL) and reduce the quality of life (health-related quality of life = HRQoL). The aim of the present study was to investigate the influence of paddling in a dragon boat (PP) on HRQoL and BCRL in breast cancer survivors (BCS).Between April and October 2017, a prospective case-control study evaluated the effects of PP compared to a control group. In the paddle group (n = 28), weekly arm circumference measurements were taken at four defined anatomic areas of the arm before and after training; in the control group (n = 70), the measurements were taken once a month. At the beginning and end of the study, questionnaires from both groups (SF 36, EORTC QLQ C30) were evaluated to understand the differences in HRQoL.The paddle group started with a higher HRQoL compared to the control group. Most interesting, whether the affected or unaffected arm, whether before or after training-the arm circumference decreased over time in the paddling group. A pre-existing lymphoedema was not negatively influenced by paddling. In the paddle group, the physical health was constant over the season, while the physical health of the control group decreased significantly over time.PP in a dragon boat does not lead to the development or worsening of pre-existing lymphoedema due to breast cancer therapy, and seems to have a positive effect on the quality of life.

A Control Design for Paddle Juggling based on Discrete System with Racket Tracking Errors

Abstract: This paper considers the stabilization of the paddle juggling, i.e. the hitting task of a ball with a table tennis racket. The rebound phenomenon between the ball and the racket is firstly shown in 2-dimensional space. The continuous trajectory design for the racket is secondly introduced to realize the iterative hitting the ball. With the assumption where the trajectory tracking is achieved, the discrete phenomenon at the rebound is thirdly modelled with the parameters of the continuous trajectories as the new input. The LQ servo controller is then designed which stabilizes the hitting task with reducing the disturbances due to the tracking errors. Numerical simulations are shown to verify the effectiveness of the proposed controller that consists of the regulations of the hitting position and apex.

A Novel Intervention: Stand Up Paddle Boarding Aquatic Therapy (SUPAT) for Pediatric Patients With Cerebral Palsy: 2 Case Studies

Abstract: Background and Purpose: Cerebral palsy (CP) is a nonprogressive neurological condition that typically causes motor dysfunction. Children with CP often have decreased endurance, balance, and strength. This leads to decreased physical activity and difficulty performing sports with their age-related peers. The purpose of these case studies was to determine whether stand up paddle boarding aquatic therapy (SUPAT) improves gross motor function and decreases the number of falls experienced by 2 children with spastic CP. Case Description: Participants included 2 adolescent girls diagnosed with spastic CP categorized as Gross Motor Function Classification System (GMFCS) level II. Intervention: Over 10 weeks, the patients attended seven 1-hour SUPAT sessions. The sessions included a 10-minute warm-up and a variety of paddle boarding skills. Both participants completed Gross Motor Function Measure-88 (GMFM-88) and reported the average number of falls before and after the SUPAT intervention. During each session, a trial run (the total duration a child could maintain balance on the paddle board) was also measured. Outcomes: Participant 1 increased GMFM-88 scores from 92.5% to 95.5% and trial run duration from 1 minute 24 seconds to 6 minutes 14 seconds. Participant 2 increased GMFM-88 scores from 91.6% to 92.9% and trial run duration from 1 minute 12 seconds to 3 minutes 7 seconds. Both participants reported a reduction in the number of falls. Discussion: These case studies indicated the SUPAT program was beneficial for pediatric patients with CP. Following the SUPAT intervention, both participants improved scores on the GMFM-88 and increased their ability to maintain balance on the board (trial run). These findings support the notion that the SUPAT program is beneficial for increasing gross motor function, improving balance, and decreasing the number of falls. SUPAT could be a viable alternative therapeutic intervention to traditional aquatic therapy and an opportunity to participate in an outdoor sport.

Change in concentration of the key component of the mixture during mixing in the transverse direction in dual shaft mixer with rods installed in front of the blade

Abstract: In the construction materials industry, twin-shaft paddle mixers are common in the preparation of both dry and plastic mixes. When the blade rotates in a mixed medium, a compacted zone of mixed components is formed immediately in front of its working surface. This compaction negatively affects the quality of the mixture preparation, characterized by the homogeneity of the resulting mixture. In order to influence the compacted area, to intensify the mixing process, cylindrical rods are installed in front of the working surface of the blade. A mathematical description of the process of dry mixing of two components in a horizontal paddle mixer is obtained. It allows, depending on the design and technological parameters that most affect this process, to calculate the concentration of the key com-ponent in a certain volume of the mixture, both when installing cylindrical rods in front of the working surface of the blade, and without rods. Studies of changes in the concentration of a key component for a mixer with rods have been carried out with varying values of its design and technological parame-ters. Regularities of the influence of design and technological parameters on the change in the con-centration of the key component in a certain volume of the mixture and their rational values have been determined for a mixer with rods. When comparing the values of the concentrations of the key compo-nent obtained using the mathematical description for mixtures prepared in mixers with and without rods, it was found that the mixer with rods allows you to obtain a mixture of higher quality with the concentration values of the key component closer to the ideal value.

Canoeing and kayaking

Abstract: Canoe disciplines include canoe sprint, canoe slalom, canoe ocean racing, canoe marathon, canoe polo and canoe freestyle. Since 2009, paracanoeing has also been a recognised event by the International Canoe Federation and a Paralympic Games event since 2016. Canoe sprint is one of the canoeing Olympic events with athlete teams or individuals racing head-to-head on a flat-water course over a set distance in either a canoe. Canoe slalom, also an Olympic event, requires athletes to race through rapids and pass through suspended poles above the water in the correct order and direction, avoiding a touch with any part of the boat, paddle or body. An adaptation of the swimming pool anaerobic testing can also be performed outdoors in the natural training environment.