Correlation Equations Research Articles

District Office Leadership Supporting Site-Level Teacher Collaborative Teams

Previous researchers examining professional learning communities (PLCs) claim that effective building-level PLCs improve teacher collaboration and student achievement. However, the role of district office leadership in supporting the success of site-level PLC teams is presently underexplored. Using an online survey, we investigated the claim that district office support enhances the success of site-level PLCs. Quantitative data were collected from 596 participants employed at 21 schools within 16 school districts in the north Texas region. Findings derived from correlation and structural equation modeling analyses revealed a significant direct effect of district office leadership support on successful PLC team implementation, suggesting that district leaders play an active role in the districtwide implementation of PLCs.

A non-destructive method using low-field nuclear magnetic resonance for characterizing the molecular weight of PBAT during thermo-oxidative degradation

The molecular weight is an important indicator for assessing the aging of polymers. However, existing methods for characterizing the molecular weight of polymers involve complex procedures and destructive tests. Therefore, efficient, rapid, and non-destructive testing methods would be a key development in material degradability evaluation. In this paper, we studied the thermo-oxidative aging process of polybutylene adipate terephthalate (PBAT) using a low-field nuclear magnetic resonance (LF-NMR) analysis method. The degradation mechanism of PBAT during thermo-oxidative aging is characterized by its low-field nuclear magnetic resonance decay curve and inversion curve. A two-component LF-NMR fitting analysis reveals that the thermo-oxidative degradation of PBAT conforms to a random fracture mechanism. Furthermore, a correlation between number average molecular weight and LF-NMR relaxation time during thermo-oxidative degradation of PBAT was constructed, with a correlation coefficient R2 greater than 0.97. The error between the correlation equation used in the molecular weight detection of PBAT and the actual test is less than 10%, indicating that it is feasible and reliable to characterize the number average molecular weight of materials by applying the LF-NMR relaxation time.

Quantification and correlation analysis of bubble characteristics and heat transfer performance in direct contact heat exchanger

In this work, a combination of morphological processing and watershed algorithm is proposed to measure bubble size, based on which an improved frame difference method is proposed to obtain bubble velocities with an F1 score of 0.96. Empirical equations for the boiling properties of flow in immiscible fluids and their influencing factors are developed. Correlation equations for the Nusselt (Nu) number and Colburn (j) factor are developed, with mean deviations of 5.42% and 5.47%, respectively. The results show that the increase in bubble rise rate and the trend of bubble growth become slower with the increase in the flow rate of the dispersed phase. In contrast, the temperature of the continuous phase has a negative correlation on the bubble growth and almost no effect on the bubble velocity. In addition, the heat transfer coefficient, which increases with the increase of the flow rate of the dispersed phase, has a negative correlation with the initial temperature difference. The main objective of this study is to provide a new method for measuring bubble parameters during direct contact boiling heat transfer and to provide new ideas for studying direct contact boiling heat transfer.

Hotspot Detection and Estimation of Methane Emissions from Landfill Final Cover

The main objectives of this study were to identify methane hotspots through spatial distribution tests of the surface methane concentration above a landfill final cover and to investigate the effects of rainfall, atmospheric pressure, ground temperature, and ambient methane concentration on methane emissions. A portable laser methane detector was used to measure the spatial distribution of methane concentrations. The methane concentration distribution showed a distinct spatial variability. The maximum methane concentration reached 3225 ppm, while 73.0% of the methane concentration values were below 10.0 ppm. Several meteorological factors were found to be associated with the variation in methane emissions. Rainfall limited gas transport in the cover, resulting in more significant methane hotspots. Atmospheric pressure was negatively correlated with methane emission. The ambient methane concentration and methane flux had a significant positive linear correlation. Based on a linear correlation equation, the spatial distribution of methane concentrations in the landfill could be converted into a methane emission distribution. The estimated average value for methane emissions in the test area was approximately 4.3 g m−2 d−1. This study provides an experimental basis for locating methane hotspots and assessing methane emissions in landfill final covers, and proposes supplementary means for detecting geomembrane damage in landfill covers.

In-service property prediction of X80 self-shielded flux-cored (FCAW) girth weld metal based on strain ageing kinetics

ABSTRACT In order to achieve in-service safety evaluation of girth weld, property prediction of X80 self-shielded flux-cored girth weld metal based on strain ageing kinetics was conducted. Strength increment (ΔY) and toughness reduction (ΔCVN) relationship was obtained through tensile and Charpy impact test using specimens before and after strain ageing. 1% prestrain was conducted and then aged at different conditions (150°C/100°C for 1–6 h, 80°C/50°C for 1–120 days). Strain ageing kinetics was investigated based on experiment results, and diffusion activation energy (Q) was calculated as 88.1 kJ/mol. The correlation equation of ageing temperature and period was obtained: , T 1<T 2 <423 K. It is predicted that, since occurrence of 1% prestrain, toughness of girth weld metal would drop down to <80 J after 3.9 years service in the present case, and its service safety should be reconsidered. Other prediction should be based on experimental results of specific consumable and welding parameters.

The Potential Pro-Environmental Behavior Spillover Effects of Specialization in Environmentally Responsible Outdoor Recreation

Outdoor recreationists represent a key population to educate for pro-environmental behavior (PEB). Given that previous research has found a mixed relationship between outdoor recreation and PEB, this research merges several concepts to better understand the social psychological nuances of this relationship. Specifically, this study explores how specialization regarding environmentally responsible outdoor recreation is related to other PEBs through a behavioral spillover framework. A correlational structural equation model was utilized to test this framework within a merged population of individuals from the Leave No Trace organization and general United States citizens. The results suggested that traditional behavioral spillover dynamics held for private PEBs but not public PEBs. However, recreation specialization was significantly related to both PEB types. These results suggest that the current behavioral spillover theory may only explain the relationship between some PEBs. Furthermore, environmentally responsible outdoor recreation specialization may be a promising pathway toward a spillover into encouraging private and public PEBs.

Analysis of heat transfer enhancement of passive methods in tubes with machine learning

This study investigates the efficacy of machine learning techniques and correlation methods for predicting heat transfer performance in a dimpled tube under varying flow conditions, including the presence of nanoparticles. A comprehensive numerical analysis involving 120 cases was conducted to obtain Nusselt numbers and friction factors, considering different dimple depths and velocities for both pure water and water-Al2O3 nanofluid at 1%, 2%, and 3% volume concentrations. Utilizing the data acquired from the numerical simulations, a correlation equation, SVM ANN architectures were developed. The predictive capabilities of the statistical approach, ANN, and SVM models for Nusselt number distribution and friction factor were meticulously assessed through mean average percentage error (MAPE) and correlation coefficients ( R2). The research findings reveal that machine learning techniques offer a highly effective approach for accurately predicting heat transfer performance in a dimpled tube, with results closely aligned with Computational Fluid Dynamics (CFD) simulations. Particularly noteworthy is the superior performance of the ANN model, demonstrating the most precise predictions with an error rate of 2.54% and an impressive R2 value of 0.9978 for Nusselt number prediction. In comparison, the regression model achieved an average error rate of 6.14% with an R2 value of 0.8623, and the SVM model yielded an RMSE value of 2.984% with an R2 value of 0.9154 for Nusselt number prediction. These outcomes underscore the ANN model’s ability to effectively capture complex patterns within the data, resulting in highly accurate predictions. In conclusion, this research showcases the promising potential of machine learning techniques in accurately forecasting heat transfer performance in dimpled tubes. The developed ANN model exhibits notable superiority in predicting Nusselt numbers, making it a valuable tool for enhancing thermal system analyses and engineering design optimization.

Practical Aspects of Correlation Analysis of Compressive Strength from Destructive and Non-Destructive Methods in Different Directions

The research presented here demonstrates the practical aspects of the numerical correlation of the results of the compressive strength test. The destructive test (DT) in a hydraulic press and the non-destructive test (NDT) using a Schmidt hammer in several process variations were evaluated. The aim was to evaluate the real differences between the tool supplier’s curve and testing. Therefore, 150 concrete cube specimens with an edge length of 150 mm were produced using a mixture of three types of concrete classes: C30, C35, and C40. The test was carried out 7 and 28 days of age of the concrete. The Schmidt hammer test was carried out in horizontal (θ = 0) and vertical (θ = 90) directions and using a series of 10 measurements. Furthermore, the tests were performed in two sets: first, the sample was placed on the ground, and second, under a hydraulic jack with a load of 50% of the maximum bearing capacity of specific concrete. Then, regression analysis was performed on the data sets to establish linear mathematical relationships between compressive strength and number of bounces. The results showed that the correlation between the DT and NDT tests has a high value for each group, but the correlation equations are different and must be taken into account.

Correlation and pathways of behavioral activation systems mediating physical activity level and depressive symptoms among college students.

Depression is a common mental disorder among college students. The main symptoms include being persistent low mood, sad emotional experiences, lack of pleasure, listlessness, and impaired cognitive function accompanied by tendencies of self-harm and suicide. To clarify the pathways and effects of the behavioral activation system between physical activity and depressive symptoms in college students with depressive symptoms. This cross-sectional research screened 3047 college students. Of these, 472 had depressive symptoms, with a depression detection rate of 15.49%. Furthermore, 442 college students with depressive symptoms were analyzed. A one-way analysis of variance and Pearson's correlation, linear regression, and structural equation modeling analyses were used to explore the correlations and pathways of the interactions between the variables. Depressive symptoms were significantly negatively correlated with physical activity (r = -0.175, P < 0.001), the behavioral activation system (r = -0.197, P < 0.001), and drive (r = -0.113, P = 0.017). Furthermore, it was negatively correlated with fun-seeking (FS) (r = -0.055, P = 0.251); however, it was not significant. Physical activity was significantly positively correlated with reward responsiveness (RR) (r = 0.141, P = 0.003) and drive (r = 0.124, P = 0.009) and not significantly positively correlated with FS (r = 0.090, P = 0.058). The mediating effect of RR between physical activity and depressive symptoms was significant [B = -0.025, 95% confidence interval (95%CI): -0.051 to -0.008, P = 0.001]. The direct and total effects of physical activity on depressive symptoms and were significant (B = -0.150, 95%CI: -0.233 to -0.073, P < 0.001; B = -0.175, 95%CI: -0.260 to -0.099, P < 0.001), respectively. As physical activity levels increased, depression scores among college students decreased. The mediating effect of RR between physical activity and depressive symptoms was significant. Therefore, colleges and universities should encourage college students with depression to increase their physical activity and improve their behavioral activation system. Particular attention should be paid to RR, which may reduce the prevalence of depressive symptoms.

Compilation of a Structural Model of Body Image Based on the Attitude towards Eating with the Mediation of Dysfunctional Beliefs in People with Body Deformity Disorder Referring to Beauty Clinics

Background and Objective: Body image is a multidimensional structure broadly defining the mental and internal manifestations of physical appearance and bodily experiences. It is associated with weak self-esteem, weak gender identity, and depression. Therefore, the current research aims to develop a structural model of body image based on the attitude towards eating with the mediation of dysfunctional beliefs in people with body deformity disorder referring to the beauty clinics of Mazandaran province. Materials and Methods: The current research method is correlation and structural equation modeling (SEM). The statistical population of the research was made up of people who were referred to the beauty clinics of Mazandaran province (the cities of Amol, Babol, Sari, and Qaem Shahr). According to Klein's opinion, the sample size was 330 cases selected in a purposeful and random way. The data collection tools included Sooto and Garcia's (2002) body image satisfaction scale, Connor et al.'s (1979) eating attitude scale, and Wiseman and Beck's (1982) dysfunctional beliefs scale. In this research, SPSS (version 22) and Amose (version 23) software packages were used to analyze the information obtained from structural regression equation modeling. Results: The results of the research demonstrated a relationship between attitude toward eating and body image with the mediation of ineffective beliefs in people with body deformities. Moreover, the data analysis showed the appropriateness of the indicators and indicated a very good fit for the research model at a significant level. Conclusions: One of the prerequisites of behavior is attitude; in other words, every behavior that comes from a person is associated with some kind of attitude. According to this point of view, any particular attitude towards a special subject or phenomenon creates a certain readiness in people to perform behavior. Many diseases, including body image disorder, are directly or indirectly caused by a person's attitude towards eating or are affected by it, or at least, a person's attitude plays a role in its aggravation and durability.

Estimation of total landfill surface methane emissions using geospatial approach combined with measured surface ambient air methane concentrations

ABSTRACT The concentration of surface air methane (CH4) measured in parts per million by volume (ppmv) near the soil/atmosphere interface should, in theory, have a positive correlation with surface methane emissions fluxes, measured in grams per square meter per day (gm−2d−1). Some researchers suggest that CH4 flux can be reasonably inferred from simple measurements of CH4 concentrations near the landfill surface. Ground-based and drone-based surface emissions monitoring (SEMs) were performed at several municipal solid waste landfills as tracer correlation method (TCM) testing was being used to measure total methane emissions from the same landfills. The TCM data and SEM data were used to establish a new simple correlation to convert surface methane concentrations in ppmv to localized surface methane emission flux in gm−2d−1. The SEM data obtained from ten ground and drone monitoring campaigns were log-transformed and geospatially treated using inverse distance weighting to the power of 2 to predict methane surface concentrations in the entire footprint of the SEM measurements area. The developed new correlation equation was then used to convert every predicted surface methane concentration to an emissions flux. The total estimate of surface emissions from the entire landfill was obtained by integrating the predicted fluxes over the area of the footprint of the SEM measurement area. The use of the new developed correlation resulted in higher total emissions estimates than other correlations reported in the literature and should be considered more conservative. Not including other factors, the proposed approach provides estimate of total methane emissions with a coefficient of variation of 20%. This study introduces a novel approach that utilizes a developed correlation between surface methane concentrations and surface emissions fluxes to estimate total methane emissions from municipal solid waste landfills or from a specified area. This study provides an additional use of the quarterly SEM data. Implications: The proposed approach provides an occasion for additional use of the easily obtainable quarterly SEMs data that can be performed by most landfills. The SEMs data are the most abundant landfill methane concentrations data. This approach gives them more benefit for the user. It is intended to convert ambient air concentrations to some estimates of surface emissions that can help landfill owners with decision making such as remediation activities or adjustments of their gas collection a systems.

Assessment of water quality ions in brackish water on drip irrigation system performance applied in saline areas

Utilizing brackish water with drip irrigation technology, due to its precise water control alleviates the secondary soil salinization, and improves crop yield and quality, which offers sustainable agricultural development opportunities in saline areas. However, the complex characteristics of brackish water increase the risk of drip irrigation emitter clogging, which inhibit its promotion and adoption. It is necessary to find out the dominant water quality ions that lead to emitter clogging under multiple ion interactions when using brackish water under multiple ion coexistence conditions. Thus, the in-situ pilot research was conducted to study the emitter clogging mechanism using brackish water collected from 16 different salt-alkaline regions. A comprehensive evaluation with the consideration of 11 water quality ions on emitter clogging were conducted. Results showed that the degree of emitter clogging gradually increased in the first 40 days of irrigation, hereafter started an accelerated reduction until the days 64 of brackish water application. Spearman correlation and structural equation modelling were used to identify the main factors contribute to emitter clogging. And results indicated that calcium fouling (CF) and silica fouling (SF) were the major fouling minerals in the emitter flow channels. Ca2+, CO32-+HCO3-, pH, total hardness (TH), and zeta potential (ZP) were the key water characteristics leading to emitter clogging. These factors directly affected CF and SF, while also affecting the Mg2+, Mn2+, Cu2+, and other water quality factors which indirectly enhanced the CF and SF. Thereafter a few water quality control strategies were proposed based on emitter clogging and soil salinization mitigation. This study identified the key water quality ions that induce drip irrigation emitter clogging when using brackish water, provided solid support for solving the clogging issue, and promoted the high-efficient utilization of brackish water in saline areas.

Evaluate the use of Mehlich-III compared to Mehlich-I as a soil test in Northeast Florida

Soil laboratories throughout the United States have widely integrated the Mehlich-III (M-III), derived from Mehlich-I (M-I), methodologies to extract soil nutrients. However, there have been concerns regarding its precision. The University of Florida's Hastings Agricultural and Extension Center (HAEC) conducted a soil sampling during the spring of 2021. This research aimed to rigorously compare the extraction efficiencies of M-I and M-III, specifically focusing on critical soil nutrients like phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). From forty-six meticulously chosen fields, 276 composite soil samples derived from two distinct depth strata (0–15 ​cm and 15–50 ​cm) were analyzed using both methods. Our findings highlighted the superior extraction prowess of M-III, which showcased an efficiency almost threefold compared to M-I. Intriguingly, the correlation between M-I and M-III extraction efficiencies weakened with escalating soil nutrient concentrations. The coefficient of determination (r2) between M-I and M-III had a high correlation value and was statistically significant (p<0.05) for all macro- and micronutrients. We found that the correlation between M-I and M-III became more robust with an increase in sample size and a higher correlation coefficient. It is noteworthy to mention that the M-III method has the propensity to provide slightly inflated soil nutrient estimations. Since soil labs worldwide use M-III equations derived from M-I, this study proposes that soil labs reinvestigate and possibly adopt new correlation equations to estimate soil nutrients using M-III.

Matching Characteristics of CTHP Circulation Systems

Cogeneration can not only reduce the use of primary energy, but also reduce the pollution to the environment; the article selects a 1200kW low-pressure stage turbine as an example to give an analysis, calculates the variation of parameters such as heat production, heat production coefficient, flow rate of cold water and hot water of this turbine, and proposes and analyzes the circulation characteristics of the CTHP system, determines the matching relationship between the steam engine driven heat pump that the system needs to meet, and fits the relationship between the steam engine efficiency and power of the heat pump. The correlation equation of steam engine efficiency and power is regressed, and the relationship of circulating cooling water flow rate with turbine discharge temperature is fitted. It is found that the heat production performance coefficients of the high and low pressure stages of the heat pump increase by 27.6% and 29.3% respectively when the discharge temperature increases from 160°C to 220°C, and the system can realize better economic and social benefits compared with the conventional CHP system.

The Prediction of Landslide Slip Surface Based on the Correlation Between Relative Density and Dynamic Cone Penetration Test

Relative density is one of the most important properties indicating the strength and state of compaction of the soil. The dynamic cone penetration test is considered one of the fastest field tests for evaluating the relative strength of soil layers, including density. In this study, an attempt is made to correlate the relative density of the landslide soil with the dynamic cone penetration results. The aim of this study was to delineate the boundary between moving and in-situ soil for the prediction of slip surfaces and finally to conceptualise the underlying mechanism behind the initiation of a landslide. The results of the penetration tests give an increasing index of 1.9 - 2.4 cm/blow, 2.8 - 3 cm/blow and 3.2 cm/blow for the upper, middle and lower parts (toe), respectively. Using the correlation equation, the calculated relative density in the field was found to agree well with the relative density measured in the laboratory with a standard deviation of ±1.5%. The relationship between the relative density and the penetration index shows an inverse relationship where the resistance of the soil to dynamic penetration increases as the relative density of the soil increases, thus decreasing the penetration index. This result can be used to accurately conceptualize the mechanism behind a landslide using a simple and rapid field device.

In Situ, Real-Time Temperature Mapping and Thermal FE Simulations of Large-Format 3D Printed PETG/CF Vertical Wall.

This work focuses on simulating the thermal history of a vertical wall consisting of a thermoplastic composite material, poly(ethylene terephthalate) glycol (PETG) with short carbon fiber reinforcement, manufactured using a Big Area Additive Manufacturing (BAAM) system. The incremental deposition process used in additive manufacturing, which corresponds to the repeated deposition of hot material onto cooler material, contributes to the presence of residual stresses and part warping. The prediction of these mechanisms is dependent on thermal history of the part, and the major motivation of this work was to improve the accuracy of finite element (FE) models used to quantify the thermal history of large-format additively manufactured parts. Thermocouples were placed throughout the part at varying heights to measure temperature as a function of time. The FE model developed found a thermal contact conductance between the printed part and the bed of 10 W/m2K and convection coefficient values that linearly varied from 3 to 15 W/m2K through the wall height when making a temperature comparison with the output from the thermocouples. It is also demonstrated that the FE model with a constant convection coefficient under-predicts model temperature at the beginning of the manufacturing process when compared against the model with a variable convection coefficient. The impact of this difference was seen in the stress values, which were larger for the model with a constant convection coefficient. Finally, a correlation equation was derived which allows the findings to be generalized to other vertical structures manufactured on the BAAM. In summary, this work offers valuable insights on material characterization, real-time thermocouple placement, and FE modeling of large-format additively manufactured parts.

The potential role of executive functions in prediction of psychological outcomes and cognitive performance among Thai teachers during the Covid-19 pandemic

Brain executive functions (EFs) play a key role in both positive and negative impact on human psychological outcomes. This present study investigated the potential effects of executive impairment (EI) on stress, burnout, well-being, and working memory among teachers during Covid-19 pandemic. We recruited 448 male and female teachers from eastern regions of Thailand using multistage sampling technique. Data were collected at schools with research instruments, including Teacher Primarily Data Questionnaire, Ryff Scales of Psychological Well-Being, Suanprung Stress Test-20 (SPST-20), Maslach Burnout Inventory for Educators (MBI-ES), Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A), and Letter Number Sequencing (LNS). Statistical analyses were performed with descriptive statistics, bivariate correlation, and structural equation analysis (SEM). Results showed that dysfunctions in EFs could predict stress (21.9%). EI and stress could predict burnout (44.8%). EI with stress and burnout could predict working memory (11.9%) and well-being (48.7%). Problems related to EFs showed the direct effect on stress, burnout, working memory, and well-being at the statistical level (p &lt; .001) with the direct effects of .47, .23, -.38, and -.30, respectively. Furthermore, problems related to EFs showed the indirect effect on burnout, working memory, and well-being at the statistical level (p &lt; .001) with the indirect effects of .24, -.24, and .12, respectively. Therefore, EFs could predict psychological outcomes and cognitive performance, for example working memory. In conclusion, EFs play the key role in psychological and behavioral management during the pandemic. This data can be used for planning and designing the effective EFs training program to subsequently promote psychological outcomes and cognition among teachers.

The differential roles of shame and guilt in the relationship between self-discrepancy and psychological maladjustment.

The self-discrepancy theory proposes that having inconsistent self-representations can trigger feelings of shame and guilt, leading to experiences of depression and anxiety. The aim of this study was to determine the distinct characteristics of each shame and guilt in relation to the connection between actual/ideal self-discrepancy and depression, as well as actual/ought self-discrepancy and anxiety. A total of 403 participants completed an online questionnaire assessing their self-discrepancy, shame, guilt, depression, and anxiety. Correlational analysis and structural equation modeling (SEM) analysis were used to assess the goodness of fit of the proposed model and the structural relationships between the variables. The key findings were as follows: (1) There were positive correlations among actual/ideal self-discrepancy, actual/ought self-discrepancy, shame, guilt, depression, and anxiety; (2) Shame partially mediated the association between actual/ideal self-discrepancy and depression; and (3) Guilt fully mediated the association between actual/ought self-discrepancy and anxiety. These outcomes uphold the self-discrepancy theory by confirming a distinct intra-psychological process involving shame and guilt. Each type of self-discrepancy was related to experiences of depression and anxiety. Our data suggest that researchers and practitioners should prioritize shame and guilt when examining individuals' self-discrepancy and related mental health challenges.

Fluctuation analysis and spatial distribution model of particle concentration in a lab-scale scrubbing-cooling chamber

The motion and distribution of ash from coal gasification during the scrubbing and cooling process are crucial for revealing the fluid flow pattern and improving the efficiency of multiphase separation. Experimental measurements of the local solid holdup (εs) in the liquid pool of a laboratory-scale gas-liquid-solid three-phase scrubbing-cooling chamber were carried out using an optical fiber probe. The fluctuations of εs in time and frequency domains under different operating conditions were discussed. The axial and radial distribution of εs was quantitatively analyzed. The results showed that inter-particle collision and particle-fluid interaction are the key factors leading to a fluctuation in particle concentration. Axial uniformity of particle concentration can be quantified by solid-phase volume fraction, particle Reynolds number, Archimedes number, and Morton number; εs in different regions is expressed according to the degree of influence of bubble wake as a correlation equation consisting only of cross-sectional average solid holdup and dimensionless radial position; a dimensionless expression for εs concerning operating conditions was established.

Mixing tank hydrodynamics and mixing efficiency for propeller impellers

In this study, the distribution of axial and radial velocities with the use of a PIV laser system was determined and the mixing power in a mixing tank with narrow and wide propeller impellers was measured. The pumping capacity and secondary circulation values in the mixing tank were calculated and on this basis, the energy efficiency of the operation of both types of propeller impellers was determined and compared with the efficiency of turbine impellers with inclined blades. It turned out that propeller impellers with wide blades are most effective as regards the amount of energy that should be supplied to the mixing tank to achieve the required mixing time. It was found that the share of pumping capacity in the total secondary circulation is almost twice as high as the share of induced circulation. Correlation equations for the dependence of the mixing power and dimensionless flow numbers on the pitch of the propeller blade were also formulated. All the results obtained were compared with the works of other authors. The paper also found that propeller impellers with a variable angle of inclination of the blade α depending on the current radius do not meet the theoretical assumption of a constant axial velocity of the liquid flowing out from of the impeller zone. For small radii of the impeller the explanation for this observation is the presence of the hub and shaft in the axis of the mixer and the effect of liquid slip for the steep agitator blades near the hub. For radii close to the radius of the stirrer, the reason is generation of induced circulation as the expense of the kinetic energy of the liquid flowing out of the impeller area.