Frequency Values Research Articles

Remarkable Active Site Utilization in Edge-Hosted-N Doped Carbocatalysts for Fenton-Like Reaction.

Improving the utilization of active sites in carbon catalysts is significant for various catalytic reactions, but still challenging, mainly due to the lack of strategies for controllable introduction of active dopants. Herein, a novel "Ar plasma etching-NH3 annealing" strategy is developed to regulate the position of active N sites, while maintaining the same nitrogen species and contents. Theoretical and experimental results reveal that the edge-hosted-N doped carbon nanotubes (E-N-CNT), with only 0.29 at.% N content, show great affinity to peroxymonosulfate (PMS), and exhibit excellent Fenton-like activity by generating singlet oxygen (1O2), which can reach as high as 410 times higher than the pristine CNT. The remarkable utilization of edge-hosted nitrogen atom is further verified by the edge-hosted-N enriched carbocatalyst, which shows superior capability for 4-chlorophenol degradation with a turnover frequency (TOF) value as high as 3.82 min-1, and the impressive TOF value can even surpass those of single-atom catalysts. This work proposes a controllable position regulation of active sites to improve atom utilization, which provides a new insight into the design of excellent Fenton-like catalysts with remarkable atom utilization efficiency.

Tuning ligand-vacancies in Pd-UiO-66 to boost biofuel production from 5-hydroxymethylfurfural hydrodeoxygenation

The hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural (HMF) to biofuel 2,5-dimethylfuran (DMF) serves as a vital reaction in biomass refineries. Herein, Pd-UiO-66 catalysts with controlled contents of ligand-vacancies were developed for the HMF-to-DMF conversion. Strikingly, a volcano-like relationship between defect level and HDO activity was obtained. The DMF yield was promoted ∼3 times, reaching 92.2 % at 160 °C and 15 bar H2, which refers to a high-level turnover frequency value of 42.66 h−1 among the reported candidates. The Pd-UiO-66 catalysts also afforded >80 % yield for the HDO of 5-methyl furfural, furfural, and vanillin. Besides, high HDO activity could be retained in five recycles. Manipulating the contents of ligand-vacancies was confirmed to create more Pd0 species and Bronsted acid sites, leading to remarkable performance. This work provides significant inspiration for tuning structural defects in MOFs to realize the efficient HDO of platform molecules in biomass valorization.

Construction of high‐loading WO3‐x sub‐nanometer clusters via orderly‐anchored top–down strategy boost acidic hydrogen evolution

AbstractExploring a simple, rapid, and scalable synthesis method for the synthesis of high loading nonprecious metal sub‐nanometer clusters (SNCs) electrocatalysts is one of the most promising endeavors today. Herein, an orderly‐anchored top–down strategy is proposed for fabricating a new type of high loading WO3‐x SNCs on O‐functional group‐modified Ketjen black (WO3‐x‐C(O)) to balance the high loading (49.29 wt.%) and sub‐nanometer size. By optimizing the vacancy number, WO2.71‐C(O) has extremely large electrochemically active surface area (402 m2 g−1) and high turnover frequency value of 1.722 s−1 at −50 mV (vs. reversible hydrogen electrode). The overpotential of WO2.71‐C(O) reaches 22 mV at a current density of 10 mA cm−2, which is significantly better than the commercial Pt/C level (32 mV), achieving a breakthrough in the hydrogen evolution reaction (HER) catalytic activity of nonprecious metals in acidic environment. Theoretical calculations and in situ characterization show that this material allows for the enrichment of reactants (H*) and the optimization of intermediate adsorption, which leads to the enhancement of acidic HER catalytic activity.

An experimental and numerical effort on the vibration behavior of additively manufactured recycled polyethylene terephthalate glycol components

AbstractThe importance of recycling engineering components and thus obtaining low‐cost production solutions has become prominent in today's world. In this study, the mechanical and dynamic behaviors of three‐dimensional‐printed recycled polyethylene terephthalate glycol (RePET‐G) beams were investigated numerically and experimentally for the first time in the literature. Initially, the governing equations of the beams were determined according to the Bernoulli–Euler beam theory, and these equations were numerically solved using the differential quadrature method and ANSYS program. Subsequently, to validate the accuracy of the numerical models, the obtained natural frequencies were compared with experimental results. It was observed that the numerical results showed good agreement with the experimental results. Finally, the effects of beam length, infill rate, and building direction on the natural frequencies of RePET‐G beams were investigated. The outcomes showed that as the beam length changed, natural frequencies were significantly affected. Increasing the infill rate, especially for beams with vertical building direction, from 20% to 100% led to a slight decrease in the natural frequency values of the structure. Moreover, it was found that for beams with an infill rate of 100%, the natural frequency values obtained in the horizontal building direction were higher than those obtained in the vertical building direction.Highlights Printable recycled filaments have great potential for vibration applications. Sample length affects the first natural frequency value of RePETG parts. Differential quadrature and ANSYS methods can be utilized for the vibration. For the 3D‐printed samples, rising infill rate causes a natural frequency drop.

Evaluation of pre-service teachers' views on STEM education

This study aimed to evaluate pre-service science teachers' views on STEM education. Data were collected at the end of each activity and the end of the training with evaluation sheets. The collected data were analyzed with the content analysis method and interpreted with percentage and frequency values. The research method is a case study. Participants received four weeks of practical training, including STEM activities. Based on the data collected, it was determined that teacher candidates did not have a negative perception of STEM activities, that they had difficulty in activities that required handcraft, and that it contributed positively to their interdisciplinary perspectives. They also stated that the training was enjoyable and creative; developed imagination and handicraft skills; increased productivity, self-confidence, design skills, problem-solving skills, and group work; provided practical thinking; ensured permanent learning and field cooperation; and contributed to analytical thinking. Most of the participants stated that they did not find STEM education at their universities sufficient, would apply STEM activities to their students when they became teachers, and wanted to improve themselves in STEM education. Participants stated that they most needed development in the subject of academic knowledge, utilization of technology, handcraft and creativity. In addition, it was determined that positive perceptions and opinions about STEM education were observed.

Addressing the multiplicity of optimal solutions to the Clonal Deconvolution and Evolution Problem

The Clonal Deconvolution and Evolution Problem consists on unraveling the clonal structure and phylogeny of a tumor using estimated mutation frequency values obtained from multiple biopsies containing mixtures of tumor clones. In this article, we tackle the problem from an optimization perspective and we explore the number of optimal solutions for a given instance. Even in ideal scenarios without noise, we demonstrate that the Clonal Deconvolution and Evolution Problem is highly under-determined, leading to multiple solutions. Through a comprehensive analysis, we examine the factors contributing to the multiplicity of solutions. We find that as the number of samples increases, the number of optimal solutions decreases. Additionally, we explore how this phenomenon operates across various tumor topology scenarios. To address the issue of the existence of multiple solutions, we present sufficient conditions under which the problem can have a unique solution, and we propose a linear programming-based algorithm that leverages mutation orderings to generate instances with a single solution for a given topology. This algorithm encounters numerical challenges when applied to large instance sizes so, to overcome this, we propose a heuristic adaptation that enables the algorithm’s use for instances of any size.

The broad study of blade cascade under controlled torsional flutter: Dynamics of the flow and stability analysis

The experimental and numerical investigation of the flow instabilities acting on rigid blades and vice versa was conducted for both compressor and turbine configuration. The blade cascade consisted of five rectangular NACA 0010 blades, with three middle blades capable of performing harmonic motion with one degree of freedom (pitching) using force excitation. The base case (all blades fixed) and excited regime were examined. The influence of various angles of attack, harmonic frequency values, amplitude values, inter-blade phase angles and Reynolds numbers (Re) were tested. The mean flow properties as well as the fluid - structure interaction (FSI) were studied using Particle Image Velocimetry (PIV), Reynolds-averaged Navier-Stokes (RANS) CFD methods and using force measurement. Additionally, two different approaches, namely traveling wave mode (TWM) and aerodynamic influence coefficient (AIC), were adopted to estimate the aeroelastic stability of the blade cascade, and the results were compared. The results show significant aeroelastic coupling between the blades in both compressor and turbine configuration. However, the aerodynamic coupling effect for torsional flutter is more prominent in turbine configuration.

Factors Affecting Lung Function in Preschool Children with a History of Transient Tachypnea of the Newborn

Background: Transient tachypnea of the newborn (TTN) is a common cause of self-limiting respiratory distress in neonates. Increasing data suggest that TTN may be a risk factor for developing childhood wheezing attacks or asthma. Objectives: The aim was to evaluate lung functions in preschool children diagnosed with TTN in the neonatal period using an Impulse Oscillometry System (IOS) to assess the presence of respiratory morbidity and its contributing factors. Methods: In this prospective study, preschool children diagnosed with TTN in the neonatal period and healthy age-matched children were defined as the TTN group and control group, respectively. Impulse Oscillometry System values for resistance (R5-R20), reactance (X5-X20), resonant frequency (Z5), and reactance area (AX) were compared between both groups and within the TTN subgroups. Asthma diagnosis was determined following IOS testing using the Modified Asthma Predictive Index/ International Study of Asthma and Allergies in Childhood (ISAAC). Results: A total of 52 preschool children and 101 healthy controls participated in the study. R5 minus R20 was significantly higher, and X10 and X15 values were significantly lower in the TTN group compared to the controls. Additionally, higher R values and AX values were observed in TTN subgroups with a history of late preterm birth, noninvasive respiratory support, and maternal asthma. The rates of variable respiratory symptoms and ≥ 4 wheezing attacks in one year were 20.5% and 18%, respectively. By the end of the study, the rate of newly diagnosed asthma in the TTN group was 30.8%. Moreover, R values and Z5 were significantly higher, and X values were significantly lower in the TTN subgroup exposed to passive smoking (PS) compared to the TTN subgroup not exposed. Conclusions: Our study showed that preschool children diagnosed with TTN in the neonatal period may have peripheral airway obstruction, a known characteristic of asthma. In addition to TTN-related factors, exposure to cigarette smoke appears to negatively impact their lung function. These findings suggest that long-term medical care should be provided for these children.

Anti-sulfatide antibodies in neurological disorders: should we test?

Neurological autoimmune peripheral and central nervous system disorders can be associated with anti-sulfatide antibodies. These antibodies are considered potential diagnostic biomarkers, although their additional diagnostic value in neurological fields has been increasingly questioned. Given the little evidence of anti-sulfatide antibodies' frequency and diagnostic value in neurology, we aimed to fill this knowledge gap by investigating 10years of data. This retrospective study analyzed the results of the anti-ganglioside dot kits (GA Generic Assays GmbH) from 1318 serum samples and 462 cerebrospinal fluid (CSF) samples for the frequency, sensitivity, and specificity of anti-sulfatide antibodies in neurological disorders. Although anti-sulfatide antibodies are rarely present in neurological autoimmune disorders (serum IgM 2.5%, IgG 4.6%), they are also present in non-autoimmune diseases (serum IgM 1.2%, IgG 2.5%) and lack sensitivity and specificity towards being a diagnostic marker. Furthermore, anti-sulfatide antibodies are rarely found in CSF (e.g., no positive results for IgM), and including so-called borderline results ((+)) increases sensitivity and the false-positive rate in serum and CSF. While anti-sulfatide antibodies appear more frequently in neurological autoimmune diseases, they are rare overall and provide very limited diagnostic value in determining specific neurological diseases and-more importantly-if a neurological disease has a potential autoimmune etiology.

Bi2O2CO3/g‐C3N4 Catalyst for Photocatalytic Coupling of Benzylamine under Mild Conditions

AbstractThe photocatalytic conversion of benzylamine into imine is promising for industrial production and environmental protection. To develop photocatalysts with desirable compositions and microstructures is key to achieve high activity and selectivity. Here we propose the immobilization of Bi2O2CO3 on g‐C3N4 for the photocatalytic conversion of benzylamine. The Bi2O2CO3/g‐C3N4 catalyst possesses improved light absorption capacity, electron transmission rate and reduced electron‐hole recombination than pure Bi2O2CO3. It can efficiently catalyze benzylamine coupling reaction under mild conditions, i. e., at room temperature, with air as oxidant and no additional oxidant involved. The maximum turnover frequency value of N‐benzylbenzaldimine reaches 1555.3 μmol g−1 h−1 under this condition. The Bi2O2CO3/g‐C3N4 catalyst has potential in other photocatalytic reactions.

How Do Off-Season Cover Crops Affect Soybean Weed Communities?

Weeds compete for environmental resources, leading to reduced soybean yield. In this context, integrated weed management strategies related to cultural control with the use of cover crops are necessary. Our aim was to evaluate weed occurrence in soybean systems with different cover crops. Field studies were conducted at Júlio de Castilhos, Santa Maria, Capão do Leão, Barra do Ribeiro, and Santo Ângelo, Rio Grande do Sul, Brazil. A randomized complete block design with four replications was used. Treatments consisted of black oats (Avena strigosa Schreb.), white oats (Avena sativa L.), rye (Secale cereale L.), hairy vetch (Vicia sativa L.), forage turnip (Raphanus sativus L.), and white clover (Trifolium repens L.) in pure stands or in mixtures. The analyzed variables were relative frequency, density, abundance, and importance value index, similarity index of weeds, dry shoot mass of cover crop, and soybean yield. Cover crops containing white or black oats reduced the relative importance value index of weeds, such as Lollium multiforum, Conyza spp., and Bidens pilosa. Forage turnip, hairy vetch, and white clover showed distinct responses. Black oats and forage turnip did not differ from cover crop mixtures in terms of dry shoot mass and grain yield, being superior to fallow, white clover, and hairy vetch.

Effect of PGV/PGA ratio on seismic-induced vibrations of structures equipped with parallel tuned mass dampers considering SSI

Tuned mass damper is one of the effective methods used to reduce dynamic loads in structures under the influence of environmental loads such as earthquakes, wind, and traffic loads. In the current TMD design, the fixed base approach is mostly considered when determining the dynamic properties of the structure. However, in cases where the structure-soil interaction (SSI) is important, the frequency values of the structure are significantly different from those obtained for the fixed foundation approach. This situation negatively affects the performance of TMD operating in a narrow frequency range. Therefore, using a control system consisting of multiple TMDs connected in parallel (MTMD) instead of a single TMD may be a promising solution for the control of structural vibrations. In this study, a parameter design and efficiency assessment of MTMD for reducing the seismic responses of the structure considering SSI is studied. The particle swarm optimization (PSO) algorithm is adopted to obtain the optimum parameters (i.e., damping ratio, frequency ratio, and frequency bandwidth) of the MTMD. The effects of different support conditions, number of TMD units, and peak ground velocity (PGV) / peak ground acceleration (PGA) ratio on the performance of MTMD are also evaluated comprehensively. The dynamic responses of the structure are obtained under 42 near -fault ground motions from the time history analysis. The results reveal that ground motions with low PGV/PGA ratio can significantly increase the responses of the structure for both with and without SSI cases. Moreover, it has been observed that optimized TMDs placed parallel to the top floor of the structure are effective in reducing the seismic responses of a ten-story building considering SSI.

Promoting C-Cl Bond Activation via a Preoccupied Anchoring Strategy on Vanadia-Based Catalysts for Multi-Pollutant Control of NOx and Chlorinated Aromatics.

Regulating vanadia-based oxides has been widely utilized for fabricating effective difunctional catalysts for the simultaneous elimination of NOx and chlorobenzene (CB). However, the notorious accumulation of polychlorinated species and excessively strong NH3 adsorption on the catalysts lead to the deterioration of multipollutant control (MPC) activity. Herein, protonated sulfate (-HSO4) supported on vanadium-titanium catalysts via a preoccupied anchoring strategy are designed to prevent polychlorinated species and alleviate NH3 adsorption for the multipollutant control. The obtained catalysts with -HSO4 modification achieve an excellent NOx and CB conversion with turnover frequency values of ∼ 3.63 and 17.7 times higher than those of the pristine, respectively. The protonated sulfate promotes the formation of polymeric vanadyl with a higher chemical state and d-band center of V. The modulated catalysts not only substantially alleviate the competitive adsorption of multipollutant via the "V 3d-O 2p-S 3p" network, but also distinctly strengthen the Brønsted acid sites. Besides, the introduced proton donor of the -HSO4 connecting polymeric structure could markedly reduce the reaction barrier of breaking the C-Cl bond. This work paves an advanced way for low-loading vanadium SCR catalysts to achieve highly efficient NOx and CB oxidation at a low temperature.

Chicks produce consonant, sometimes jazzy, sounds.

Several animal species prefer consonant over dissonant sounds, a building block of musical scales and harmony. Could consonance and dissonance be linked, beyond music, to the emotional valence of vocalizations? We extracted the fundamental frequency from calls of young chickens with either positive or negative emotional valence, i.e. contact, brood and food calls. For each call, we calculated the frequency ratio between the maximum and the minimum values of the fundamental frequency, and we investigated which frequency ratios occurred with higher probability. We found that, for all call types, the most frequent ratios matched perfect consonance, like an arpeggio in pop music. These music-like intervals, based on the auditory frequency resolution of chicks, cannot be miscategorized into contiguous dissonant intervals. When we analysed frequency ratio distributions at a finer-grained level, we found some dissonant ratios in the contact calls produced during distress only, thus sounding a bit jazzy. Complementing the empirical data, our computational simulations suggest that physiological constraints can only partly explain both consonances and dissonances in chicks' phonation. Our data add to the mounting evidence that the building blocks of human musical traits can be found in several species, even phylogenetically distant from us.

Characteristics of fluctuations in the equatorial and polar directions of a compact dipole plasma driven at steady state

The fluctuations in the plasma potential (Vs̃) and electron density (Nẽ) are measured in the steady-state dipole plasma confined in a spherical vacuum chamber using a single permanent dipole magnet. Measurements are made from a radial distance r = 0.5–17 cm, from the surface of the magnet in the equatorial (θ=90°) and polar (θ=180°) directions, using a 4-pin probe setup, and have been characterized by power spectra, cross-phase, cross-coherence, induced transport, and energy spectra. The fluctuations are stronger near the surface of the dipole magnet for θ=90°, thereafter their magnitude decreases gradually with the radial distance. However, a peaked profile of potential fluctuations with the peak around r = 9 cm is observed for θ=180°. The locations of strong fluctuations are around the locations of smaller values of the electron neutral collision frequency. Frequency-resolved power spectra show that the fluctuations in the dipole plasma, predominantly, belong to the very low-frequency range. The values of cross-phase (≤45°) and |Vs̃/Te|/|Nẽ/Ne|≤1 indicate the presence of drift wave instability in both planes, where Te and Ne are equilibrium values of the electron temperature and density. The radial variation of fluctuation-induced electron flux (Γr) verifies the “inward diffusion” of electrons in the equatorial plane.

Equivalent circuit technique for designing split ring resonator based metasurfaces

Metasurfaces are two-dimensional artificially engineered structures capable of manipulating the phase, direction and orientation of electromagnetic waves by exhibiting simultaneously negative values of permittivity and permeability. These unconventional properties have been tailored and explored in many applications such as in bio-sensors, waveguides and antennas. The split ring resonators are the commonly used constituent meta-atoms of metasurfaces whose design and analysis rely on commercially available numerical electromagnetic fields (EM) solvers and experimental analysis. These numerical EM solvers are based on meshing and partitioning of graphical structures into the desire grids or patches to solve Maxwell equations in discrete form. However, graphical rendering and meshing of 3D objects requires significant space-time computational resources to analyze the structure. With the cost of licenses of EM solvers being very expensive, analytical solution were explored. The use of LC resonant frequency analytical formula provides an approximate value of resonant frequency which is less accurate and does not gives information about the current characteristics induced on the constinuent meta-atom of a metasurface. This paper presents an analytical approach to the design and analysis of a doubly split double rings (DSRR) using lumped element equivalent circuit that can be solved by mesh network analysis. The resonant frequency is extracted from the induced current characteristics which agrees with simulations and experimental results. The resonant frequency errors for a single DSRR unit cell ranged from1.05% to 7%, and for two coupled DSRR unit cells, they ranged from 1.4% to 11%.

Prosthetic Maintenance Assessment for Two Implant- Retained Overdentures Reinforced with PEKK Versus Co-Cr Framework: A Randomized Controlled Clinical Trial.

The primary challenge associated with implant overdentures lies in the occurrence of denture fractures around the attachments. Hence, it is recommended to enhance flexural strength through reinforcement frameworks. This study aimed to assess and compare the prosthetic maintenance of mandibular implant overdentures reinforced with Co-Cr and PEKK frameworks. Twenty-four participants with completely edentulous ridges were selected, and two implants were placed at the mandibular canine areas. After osseointegration period, ball attachments were installed. Participants were randomly assigned into two groups: Group I received a mandibular implant overdenture reinforced with a Co-Cr framework, while Group II received a mandibular implant overdenture reinforced with a PEKK framework. Prosthetic maintenance evaluations were conducted in both groups twelve months post-denture insertion. Categorical data were analyzed, and results were presented as frequency and percentage values. Group II exhibited a significantly higher percentage of cases with screw looseness, denture relining, and tooth separation compared to Group I. Although Group II cases showed a non-significant increase in the percentage of insert wear and retention loss. Within the limitations of this study, the findings suggest that Co-Cr, in contrast to PEKK frameworks, offers a more reliable reinforcement of the implant-retained overdentures.

Boosting the active sites of Cu/Ce0.8Zr0.2O2 catalysts through tailored precipitation method

A reverse co-precipitation method was employed to increase the surface area of Ce0.8Zr0.2O2, resulting in boosting the active sites of Cu catalysts in the water–gas shift reaction (WGS). Active Cu sites and oxygen vacancy have been systematically controlled through the modification of physical properties and geometric configuration via a reverse co-precipitation of Ce0.8Zr0.2O2 support. The catalytic activity in WGS is primarily dependent on the number of active Cu species and is partially on the oxygen storage capacity. The kinetic results with Cu loadings revealed that the efficiency of active metal utilization was effectively enhanced by a reverse co-precipitation method, compared to the normal precipitation method, owing to the moderate metal–support interactions. The turnover frequency values were independent of Cu dispersion, highlighting the structure-insensitivity of Cu/Ce0.8Zr0.2O2 catalysts. This work suggests the possibility of controlling metal–support interactions through support synthesis methods.

Stanovenie mukociliárneho klírensu u pacientov so symptómami laryngofaryngeálneho refl uxu – preliminárne výsledky

Summary: Introduction: Mucociliary clearance represents an important protective mechanism of the respiratory tract. Results of multiple studies indicate that gastroesophageal reflux can participate in worsening mucociliary clearance leading to laryngopharyngeal reflux symptoms including recurrent upper respiratory tract infections. Thereby, we decided to provide ciliary beat frequency of the upper respiratory tract epithelium in patients with laryngopharyngeal reflux. Materials and methods: We enrolled 23 patients with laryngopharyngeal reflux symptoms. Control group consisted of 9 healthy volunteers. Patients were enrolled upon a positive questionnaire reflux symptom index (RSI >13 points), with no proton pump inhibitor treatment. We obtained a nasopharyngeal swab and evaluated ciliary beat frequency of the respiratory epithelium using highspeed videomicroscopy and special sofware Ciliary Analysis. We compared the values of ciliary beat frequency with values from healthy volunteers. Results: We provided median, minimal and maximum values of ciliary beat frequency. Median ciliary beat frequency in healthy volunteers was significantly higher than in patients with laryngopharyngeal reflux symptomatology (10.86 ± 1.67 vs. 6.6 ± 2.2; P <0.001). Maximum ciliary beat frequency was also significantly higher in healthy volunteers than in patients with LPR (17.9 ± 0.95 vs. 15.3 ± 2.39; P <0.001). Minimal value had no significant difference. Correlation analysis showed an inverse correlation between median ciliary beat frequency of the respiratory epithelium and LPR symptoms (RSI value) (P <0.04). Conclusion: Patients with laryngopharyngeal reflux symptoms had lower ciliary beat frequency compared to healthy volunteers. The degree of frequency defect correlates with the degree of their laryngopharyngeal symptoms. More studies are needed to confirm direct evidence of gastroesophageal reflux etiology in mucociliary clearance worsening. Key words: mucociliary clearance – laryngopharyngeal reflux – cilia

Modeling the critical rotation speed of a bladed rotor with bent blades in a circulation mixer of feed mixtures

The purpose of the research is to substantiate the critical rotation speed of a rotor with bent blades based on force analysis and modeling the movement of mixture particles in a horizontal loader of a circulation mixer. The research method[1]ology included the substantiation of the highest rotation frequency of the loader blade rotor based on a force analysis of moving particles of forces when they were moved by the bent blades of the loader and compliance with the conditions for the entry of flying particles into the tray. The numerical analysis performed on the basis of the obtained expressions using the Mathcad mathematical package made it possible to establish the critical values of the rotation speed of the rotor-loader with bent blades based on the condition of the material coming off the blade and the condition of the flight of particles from the blade into the receiving tray. With radial blades, the limitation is the entry of particles into the receiving tray at a critical frequency of 43 min-1 , then for a blade bend of 30° – about 60 min-1 , for a blade bend of 45° – about 70 min-1, for a blade bend of 60° – about 80 min-1. The lowest critical values of the rotor-loader rotation frequency from the condition of particle movement along the blade correspond to the blade bend angle of 27–60° and are determined by the friction coefficient of the material, amounting to 83–78 min-1. With an increase in material friction, the critical values of the rotor rotation speed from the condition of material coming off the blade decrease slightly, and the bend angle for the rotation speed extremum increases. The highest rotation speed of the rotor - loader with a radius of 0.12 m is limited to 78 min-1 at a blade bending angle of the order of 30–60°, determined by the friction of the material on the blade.