Experimental Plan Research Articles

Research of the combined sowing working body

Today, the issues of ecology, resource conservation and reduction of production costs in agriculture are associated with the development of combined tillage - sowing machines, which make it possible to reduce a number of technological techniques. Taking into account these factors makes it possible to equip agricultural enterprises with means of mechanization adapted to the specific conditions of their production use. Therefore, a promising direction is the development of universal and combined machines, that is, technical means of mechanization capable of performing several technological operations in one working cycle or, after relatively simple retrofits, ensuring the consistent execution of a number of operations. To carry out experimental studies, an installation was developed and manufactured, which is a combined machine that provides pre-sowing tillage, strip spreading sowing, mineral fertilizers and post-sowing rolling. Using the experimental planning method, mathematical models have been developed that link factors such as the speed of the unit, the angle of attack of the coulter's paw, the depth of the coulter's paw when optimizing the degree of soil crumbling, pruning of weeds, changes in soil hardness. Analysis of mathematical models shows that factors in a certain way affect the quality of tillage (crumbling, hardness, pruning of plants). In the first place in terms of significant importance is the speed of movement. The degree of pruning of plants depends on the angle of attack. As for the depth of processing, this factor has practically no effect on the degree of pruning of weeds. This can be explained by the fact that the root system is located at a shallow depth. For other cultures, this factor may play a significant role.

Robust parameter design of the measurement procedure for determining the chemical composition of copper alloys by X-ray fluorescence

A brief overview of contemporary methods for determining the chemical composition of copper alloys and the analytical control methods used is given. It has been shown that to obtain reliable and comparable results of measuring the mass fractions of copper alloys elements in wide ranges of values, the most suitable procedures are based on the X-ray fluorescence method, implemented using portable X-ray fluorescence spectrometers. In order to select the optimal values of the influencing quantities when determining the chemical composition of copper alloys, a robust parameter design of a quantitative chemical analysis procedure was carried out on the X-50 Mobile X-ray fluorescence spectrometer. The use of robust parameter design, as opposed to conducting a full factorial experiment when developing a measurement procedure, makes it possible to optimize measurement conditions and obtain results of the required accuracy with a limited number of experiments and a maximum number of control factors. An example of drawing up an experimental plan for the parameter design of this procedure is given and a statistical analysis of the measurement results is carried out. The optimal measurement conditions (influencing quantities) were analyzed and selected, under which the minimum error in the results of measuring the mass fraction of elements is ensured. The selection of optimal values of the influencing quantities based on the results of robust parameter design of the quantitative chemical analysis procedure made it possible to increase the accuracy of the results of determining the chemical composition of copper alloys and, as a consequence, the reliability of the results of product quality control at relatively low costs for its implementation. This approach can be recommended to analytical laboratories developing procedures of quantitative chemical analysis for metallurgical industry enterprises.

Evaluation of the Depth and Width of Cuts after Controlled-Depth Abrasive Water Jet Machining Using Low Pressure.

The presented paper is focused on the evaluation of material removal during machining via an abrasive water jet with a controlled depth of cut. In the introductory parts of the work, a theoretical analysis of water jet technology and an analysis of the current state of the problem are presented. The experimental part of the work is devoted to testing the effects of technological parameters on material removal from the point of view of the maximum erosion depth and volume loss of material during machining with a low water pressure of 50 MPa. The tested material was a Ti 6Al 4V titanium alloy. The experiments were carried out by changing the traverse speed of the cutting head, the mass flow of the abrasive and the angle of inclination of the cutting head, according to the DoE 33 experiment plan. The obtained values were evaluated using the method of variance (ANOVA) and regression analysis. Furthermore, the values of the width of the erosion track and the maximum and minimum erosion effects for both tested materials were evaluated.

Preliminary Study On the Function-Defining 3D Surface Roughness Parameters in Tangential Turning

The function-defining three-dimensional (3D) surface roughness parameters (which describe an aspect of the surface quality based on areal topography measurements) are studied on tangentially turned surfaces with different technological parameters in this paper. The 23 factorial design is applied in the planning of experiments. Two levels of depth of cut, cutting speed and feed were chosen for the comprehensive analysis of the tangential turning process. The values of Core Roughness, Reduced Peak Height, Reduced Valley Depth, Skewness and Kurtosis are measured by the application of a 3D areal roughness measurement machine. Equations were determined for the calculation of the studied parameters according to the factorial design method. The results were evaluated in two steps: first the functional parameters derived from the Areal Material Ratio curve were analyzed, then the Skewness and Kurtosis of the assessed area were studied. It is found that a two-fold increase in the cutting speed decreases the Core Roughness Depth, Reduced Peak Height, and Reduced Valley Depth 2-4-fold. The increasing feed rate lowers the presence of inordinately extremes, resulting in a smoother surface. In the point of view of Skewness and Kurtosis, lower cutting speeds and higher feeds are more favorable.

On the Behaviour-Altering Effect of Horses and Dogs in theTherapy of Attention-Deficit/ Hyperactivity Disorders

The effects of horses and dogs on disorder-specific behavior were examined in amovement-oriented behavioral training for children and adolescents with attention-deficit/hyperactivity disorders. This was done using two behavioral experiments, a two-group experimental plan and a three-group experimental plan, in a within-subject design. In small group settings (3-4 subjects), a total sample of N = 13 was examined in two experiments. In Experiment I, an equineassisted therapy session was compared to a therapy session using an additional person as a control condition (the horse is replaced by a sports student).This experiment was carried out three times in a small group setting with a total of nine subjects (n = 9). In Experiment II, an equineassisted therapy session was compared to a dog-assisted therapy session, using an additional person as a control condition (sports student). Experiment II (n = 4) was carried out once with a small group. In both experiments, symptom-oriented behavior was assessed by Conner's scales and by physical activity measured using accelerometry. As a control variable, the attitudes towards horses, dogs, and sports teachers were recorded by drawings and verbal statements.The results show that in both experiments, the equine-assisted therapy session reduced symptom behavior.The results of accelerometry indicate a superiority of equine-assisted interventions, as physical activity in the equine-assisted setting was lower than in the settings assisted by dog or human, which is considered a desired behavior change in hyperactivity.

Dosimetric feasibility analysis and presentation of an isotoxic dose-escalated radiation therapy concept for glioblastoma used in the PRIDE trial (NOA-28; ARO-2022-12)

Background and purposeThe PRIDE trial (NOA-28; ARO-2022-12; NCT05871021) is scheduled to start recruitment in October 2023. Its primary objective is to enhance median overall survival (OS), compared to historical median OS rates, in patients with methylguanine methlyltransferase (MGMT) promotor unmethylated glioblastoma by incorporating isotoxic dose escalation to 75 Gy in 30 fractions. To achieve isotoxicity and counteract the elevated risk of radiation necrosis (RN) associated with dose-escalated regimens, the addition of protective concurrent bevacizumab (BEV) serves as an innovative approach. The current study aims to assess the dosimetric feasibility of the proposed concept. Materials and methodsA total of ten patients diagnosed with glioblastoma were included in this dosimetric analysis. Delineation of target volumes for the reference plans adhered to the ESTRO-EANO 2023 guideline. The experimental plans included an additional volume for the integrated boost. Additionally, the 60 Gy-volume was reduced by using a margin of 1.0 cm instead of 1.5 cm. To assess the risk of symptomatic RN, the Normal Tissue Complication Probability (NTCP) was calculated and compared between the reference and experimental plans. ResultsMedian NTCP of the reference plan (NTCPref) and of the experimental plan (NTCPex) were 0.24 (range 0.11–0.29) and 0.42 (range 0.18–0.54), respectively. NTCPex was a median of 1.77 (range 1.60–1.99) times as high as the NTXPref. In a logarithmic comparison, the risk of RN is enhanced by a factor of median 2.00 (range 1.66–2.35). The defined constraints for the organs at risk were feasible. ConclusionWhen considering the potential protective effect of BEV, which we hypothesized might reduce the risk of RN by approximately two-fold, achieving isotoxicity with the proposed dose-escalated experimental plan for the PRIDE trial seems feasible.

Gold particle-modified glassy carbon electrode: an advanced electrochemical sensor for dipyrone monitoring

This study presents the development and optimization of a gold particle-modified glassy carbon electrode (Au/GCE) as an advanced electrochemical sensor for monitoring dipyrone (DIP), a commonly used pharmaceutical compound. The objective of this study was to enhance the sensitivity and accuracy of DIP quantification through efficient experimental planning and the incorporation of gold particles onto the surface of the GCE. The electrodeposition of gold particles onto the GCE significantly improved the response of DIP in a 0.5 mol L−1 H2SO4 solution. By employing a design of experiments (DoE) approach, we optimized the differential pulse voltammetric (DPV) method, resulting in enhanced performance, including the achievement of a remarkably low limit of detection (0.15 µmol L−1). To assess the accuracy of the electroanalytical method, we conducted extensive recovery tests, which yielded recovery values ranging from 98.9% to 104% for DIP concentration in pharmaceutical formulations. These results emphasize the selectivity and robustness of the developed electroanalytical method, positioning it as a reliable tool for monitoring DIP. The comprehensive account of experimental procedures, optimization strategies, and analytical validation presented in this study establish the efficacy and potential applications of the developed sensor in pharmaceutical analysis. Overall, this research contributes valuable insights into the field of electrochemical sensing and offers promising prospects for its application in various pharmaceutical and clinical settings.

Increased durability of glass composites

Composite materials based on cement binders are currently among the widely used for the construction of transport structures. In accordance with regulatory requirements, concrete for transport construction must have improved physical, mechanical and operational properties. One of the areas that makes it possible to obtain materials with improved properties is the use of various fillers, including waste from industrial enterprises. Among the variety of man-made waste, a significant part is broken glass, which is an effective secondary resource and can be used in the construction industry to produce binders, fillers, composites and structures based on them. The article presents the results of research aimed at increasing the durability of composite materials based on cement binders filled with cullet. Effective additives have been proposed to reduce the reactivity of broken glass with binders. Processing of experimental data was carried out using experimental planning methods. The study of the experimental design showed that it is possible to reduce the number of factors previously involved in the formation of the experimental planning matrix. It was established that the reduction in the number of factors is carried out with a confidence probability of at least 0,95. Experimental studies were carried out on the biological resistance of composites filled with broken glass and their components under the influence of filamentous fungi. It has been established that pre-treatment of the filler surface with a 1, 3, 5 % solution of potassium permanganate helps impart fungicidal properties to the composites, and treatment with a 7,5 % solution makes it possible to obtain filled materials with fungicidal properties.

Reinventing ecolabels in the era of augmented reality: An experimental study on the case of fair-trade coffee

This research is interested in the effect of augmented reality (AR) technology on ecolabels’ effectiveness. Based on a conceptual model, including control variables, the authors tested the effect of augmented and enriched information on evaluating messages around ecolabels and purchase intention for eco-labeled products. A between-subject experiment on fair-trade coffee involving 264 Canadian consumers was conducted. The experimental plan includes five cells: 2 (augmented reality: absence vs. presence) × 2 (information richness: low vs. high) + 1 control group (absence of ecolabel). The results confirm that AR and enriched information significantly increase the perceived quality and credibility of information around ecolabels, as well as purchase intention for eco-labeled products. Moreover, a significant interaction effect between the medium and the level of information detail was noted for purchase intention. This effect is influenced by the perceived novelty and coolness of the packaging, the degree of the perceived complexity of AR, the level of consumer involvement with the product, and income.

Pharmacology of a CpG-Linked Anti-Mir-126 Oligonucleotide Targeting Acute Myeloid Leukemia (AML) in Rats and Non-Human Primates (NHP)

Introduction: Acute myeloid leukemia (AML) is a lethal hematopoietic malignancy, characterized by the accumulation of clonal myeloid progenitor cells arrested in development. AML patients have dismal outcomes with a 5-year overall survival (2011 - 2017) of 29.5% (SEER). The persistence of leukemia stem cells (LSCs), a treatment-resistant primitive cell population able to inititiate and maintain AML, is thought to underlie relapse. Even newly approved drugs do not target LSCs efficiently. MicroRNA (miR)-126 is a non-coding regulatory RNA that contributes to LSC homeostasis in the bone marrow niche. Several lines of evidence validate miR-126 as a target in AML. Thus, we designed and made a novel anti-miR-126 oligonucleotide (oligo) linked to a CpG moiety, termed miRisten. miRisten incorporates modifications such as 2'-fluoro and phosphorothioate substituting phosphodiester in the sugar moiety of the nucleotide to enhance in vivo stability. miRisten eradicates LSCs in mouse models of AML and synergizes with FDA-approved AML drugs (PMID: 29505034, 34372909). Here, the results of IND-enabling toxicokinetic (TK) studies of miRisten in rats and NHP are presented. Objective: To investigate the pharmacological properties of miRisten to establish a safe dosing strategy to achieve prolonged knockdown of miR-126 for a first-in-human trial. Experimental Plan and Results: Good laboratory practice (GLP) TK studies were carried out in Sprague-Dawley rats. miRisten was given IV b.i.d. for 19 days at human equivalent doses (HED) of 1.6 and 4 mg/kg. miRisten was measured in plasma after the first dose. Plasma miRisten C max average was 3622 ± 335 and 6010 ± 175 nM post first doses of 1.6 and 4mg/kg, respectively. Plasma t 1/2 averaged 20.0 ± 3.8 minutes across both doses. The area under the curve (AUC 0 - ¥) were 638.9 ± 32 nMxhr (1.6 mg/kg) and 1313.5 ± 439 (4 mg/kg). A parallel toxicology study was undertaken documenting cage-side observations and body weight; complement activation, blood chemistries, urine and hematology were also evaluated. There were no unscheduled deaths in the toxicology segment. Four single NHP exploratory studies were also carried out (Fig. 1: Treatment schema). In each study, miRisten was given IV as a slow bolus (~5') b.i.d. and PK parameters evaluated in plasma. Study #1 & #2: 1 wk at 4mg/kg; #3: 1 wk at 5 mg/kg; #4: 18 days at 4 mg/kg. In all studies, miRisten dosage was ramped up (1, 2, 4 mg/kg for all and 5 mg/kg at dose 4 for Study #3). Solumedrol was given as premedication for the first 3 doses in all studies to prevent known phosphorothioate-mediated complement activation and cytokine release syndrome. Blood draws for PK were carried out immediately following doses 3 and 12 (Studies 1 - 3) and after the last dose on Day 18 (Study 4). The average area under the curve AUC was 3860 ± 1189 (4 mg/kg) and 3954 ± 1569 nMxhr (5 mg/kg) which was greater than observed in mice given the equivalent HED in bolus doses (~6x, 465.0). The t 1/2 of plasma miRisten was 11.7 min on Day 3 and 12.0 min on Day 7, comparable to mouse (9.6 min) and rat (20 min). Cage-side observations, body weight, complement activation, blood chemistries, urine and hematology were also evaluated. There was no terminal sacrifice of NHP however, all animals tolerated the treatment without observable adverse events. Conclusion: The dose ramp-up in NHP combined with pre-medication with solumedrol were undertaken to prevent possible acute inflammatory reactivity leading potentially to death. There were no unscheduled deaths in any species studied. These data are consistent with the safety of miRisten given IV with a dose ramping regimen combined with solumedrol. The greater AUC in NHP may predict better potency in humans. In mice, miRisten at 1.6 mg/kg HED q.d. effectively eradicated LSCs [PMID 29505034].

Algorithm for a simulation model for the selection of a rational type of vans on technological routes of the transport and recycling system for recycling of a metallurgical enterprise

The article presents an algorithm of the simulation model for selecting the rational type of trucks on the technological routes of the transport and production system of waste transportation in the conditions of a metallurgical enterprise. The study was conducted on the basis of formalized models and queuing systems theory. In the simulation, a discrete-event model of a closed queuing system was chosen as the basic model. In this model, cars are represented as requests that go through the following phases of service: loading at the temporary waste storage dump; movement to the unloading point (crushing and sorting complex); unloading raw materials to the crushing and sorting complex; returning to the loading point along the same route; servicing of vehicle breakdowns. The following data were used to build the simulation model through statistical studies of the transportation process on technological routes: vehicle loading time, vehicle unloading time, and time determined by the duration of vehicle failure. When constructing the algorithm of the simulation model, the duration of one experiment and the number of simulation experiments were determined using the methods of mathematical statistics and the theory of experiment planning. The modeling process begins with the input of the following initial data: the number of vehicle units, the average vehicle travel time, the current amount of raw materials in the crushing and sorting complex, the vehicle carrying capacity, the intensity of raw material supply to the crushing and sorting complex, the vehicle unloading time, the intensity of minor vehicle breakdowns, and the intensity of vehicle repair. The algorithm is built in accordance with the principles of special states and meets the requirements for discrete-event models. As a result of the algorithm development, it will be possible to determine the required number (types) of vehicles necessary to ensure the smooth functioning of this transport and production system, to determine the idle time coefficient and the coefficient of time losses due to technological delays of vehicles.
 Key words: modeling, simulation model, dump truck, carrying capacity, metallurgical slag, crushing and screening equipment.

Male and Female Mitochondria Respond Differently after Exercising in Acute Hypoxia.

The use of hypoxic devices among athletes who train in normobaric hypoxia has become increasingly popular; however, the acute effects on heart and brain metabolism are not yet fully understood. This study aimed to investigate the mitochondrial bioenergetics in trained male and female Wistar rats after acute hypoxia training. The experimental plan included exercising for 30 min on a treadmill in a Plexiglas cage connected to a hypoxic generator set at 12.5% O2 or in normoxia. After the exercise, the rats were sacrificed, and their mitochondria were isolated from their brains and hearts. The bioenergetics for each complex of the electron transport chain was tested using a Clark-type electrode. The results showed that following hypoxia training, females experienced impaired oxidative phosphorylation through complex II in heart subsarcolemmal mitochondria, while males had an altered ADP/O in heart interfibrillar mitochondria, without any change in oxidative capacity. No differences from controls were evident in the brain, but an increased electron transport system efficiency was observed with complex I and IV substrates in males. Therefore, the study's findings suggest that hypoxia training affects the heart mitochondria of females more than males. This raises a cautionary flag for female athletes who use hypoxic devices.

Analysis of the results of field testing of the spring-wave roller

BACKGROUND: Surface tillage is very important in agriculture, because it helps to increase the quantity and quality of the yield. One of the types of surface tillage is packing. It is carried out in order to improve the contact of seeds with the soil, as well as to create optimal soil porosity, in which the pores contain the necessary amount of water and air for good plant development. AIMS: Improvement the quality of surface tillage based on the development of a highly efficient spring-wave roller, which ensures meeting the agricultural requirements, reducing operating costs and increasing crop yields. METHODS: The new design of the spring-wave roller capable of packing the soil in compliance with the agrotechnical requirements has been proposed. RESULTS: As a result of the conducted field studies of the spring-wave roller, a regression equation describing the influence of all independent factors of the packing process on the optimization criterion KPI was obtained. The adequacy of the mathematical model was evaluated according to the Fisher criterion, the calculated value of which was 1.001 with a tabular value of Ft = 2.46, which indicates its adequacy. The analysis of the deviations of the experimental results from the results obtained by calculating the resulting equation showed that at all points of the experimental plan, the data obtained fit into the confidence interval, which indicates the high quality of the experiments. CONCLUSIONS: The maximum value of the coefficient of approximation to the KPI standard when using the spring-wave roller is 0.81 at the motion velocity v = 11 km/ h, the total force generated by compression springs C = 1750 N and the weight of the ballast m = 70 kg. The maximum KPI value achieved during operation of the commercially produced KKZ-6 roller is 0.57, which is 42.1% better than the proposed spring-wave roller has.

Wire electrical discharge machining characteristics of rare earth oxides reinforced AZ91D magnesium alloy hybrid composite using Taguchi-grey relational analysis approach

The objective of the present study was to investigate the influence of machining parameters on performance for Wire Electrical Discharge Machining (WEDM) of Rare Earth (RE) oxides (Y2O3 and CeO2) particles reinforced AZ91D hybrid metal matrix composites. Taguchi's plan of experiments was implemented for the conduction of experimental trials. Pulse on, pulse off and peak current were considered as process parameters with each varied at 3 levels. Material removal rate, surface roughness and electrode wear were studied as responses. The ANOVA analysis revealed that, individual effect of parameters on responses was significant. In addition, pulse-on with pulse-off interaction effect on response was also remarkable. The main effect plots shown that, MRR and surface roughness and electrode wear studied were found to increase with the increase of pulse on and peak current and decreased with increase of pulse off. Further, regression models were developed to correlate the machining parameters with responses. The R-Sq. and R-Sq. (adj.) values of models were >85 %, which suggests that models are feasible to predict the responses within the studied range of parameters. The surface impurities like, recast layer, surface void, globule and craters were observed on the machined surface under higher cutting conditions.

Experimental investigation and optimization of cutting parameters during dry turning process of copper alloy

Increasing the quality and productivity of machined components are the main issues of machining operations in metalworking industries. The copper alloys CuZr and CuCrZr generally find applications for current-carrying structural components, seam welder wheels, shafts, and bearings flash. The manufacturing of these components is still facing challenges in the form of machining process characteristics. One of the most common machining operations for removing material is turning that produces reasonably good surface finish quality, which is influenced by different factors (speed of cut, rate of feed, tool geometry, cutting fluid, cutting tool, etc.). This research has focused on experimental study and optimization of the cutting parameters viz. cutting speed, depth of cut, and feed, for best surface finish, material removal rate, tool tip temperature as well as surface morphology during dry turning of C15000 and C18150 copper alloy using High-Speed Steel (HSS) tool The plan and design of experiment has been performed through orthogonal Taguchi L9. array. The optimum cutting settings were discovered by using the Taguchi technique and using the performance index by applying a Grey Relational Grade (GRG). The best cutting parameters for both materials were a cutting speed 1200 rpm, feed rate 0.06 mm/rev, and depth of cut 1.25 mm. The optimum factors obtained from GRA for all responses (surface roughness, MRR, and tool temperature) at the best level of cutting parameters are the same for both materials. These cutting parameters values yielded the experimental result for each response like surface roughness, MRR, and tool tip temperature (2.5 µm,12,475 mm3/min, and 74 °C) for grade C15000 whereas (2.39 µm, 2590mm3/min and 68 °C) for grade C18150. The optimization of cutting parameters plays a vital role in the improvement of surface finish which minimizes mechanical failures caused by wear, corrosion, and thereby increasing the productivity of the products. This investigation is expected to help all researchers working in this area of applications.

Study of the influence of the current distortion power of the secondary winding of a transformer on the level of losses in it using the method of experiment planning

Purpose. Detection the relationship between the level of losses of a three-phase transformer and the power of distortion caused by current harmonics.. Methodology. During the research, the methods of determining power losses and additional losses in the elements of the electrical system from higher current and voltage harmonics, the visual programming method, the experiment planning method, and the orthogonal central composite plan method were used. Findings. An analysis of the indicators characterizing voltage and current distortions was carried out, and it was found that these distortions are most fully characterized by the current distortion power and voltage distortion power. These indicators are used to analyze the transmission of electric energy by a transformer of a traction substation. It is noted that the order of harmonics in the distortion power is not eliminated, and higher harmonics are taken into account by the corresponding effective current of higher harmonics. The specifics of the transformer secondary winding connections to the consumer, namely the grounding of one of the secondary winding phases, were taken into account. A number of combinations of current harmonics were used to simulate current distortions. The experiment was carried out using the planning method. The coefficients of the quadratic regression equation that relates power losses to the level of load current harmonics of the third, fifth, and seventh orders are obtaine To determine the significance of the obtained coefficients of the regression equation, the variances and the corresponding values of the Student's criterion were calculated, as a result, factors that do not affect the process and can be excluded from the regression equation were identified. The adequacy of the obtained regression equation was checked by Fisher's criterion. The analysis of the effects and their interaction showed that the standard error of the sample does not exceed 1.66%. As a result of analyzing the combinations of current harmonics that were set during the experiment, it was noted that some of them lead to the same effective phase current, while the power of current distortion is different. The greatest significance of the level of the third harmonic of the current is determined. The constant level of active power on the high voltage side of the transformer is noted, which is due to the absence of voltage distortions on it. Originality. Cases of combinations of current harmonic levels at which the current distortion power index remains unchanged, while the level of transformer power losses caused by current harmonics changes, have been identified. Practical value. This research can be used to assess and reduce the level of power losses in a transformer by filtering certain current harmonics.

Effects of the Mixing Process on the Rheological Properties of Waste PET-Modified Bitumen

This paper analyses the key findings of a study devoted to PET-modified bitumen. The research program was run according to the D-optimal experimental plan based on a factorial design. Five factors, i.e., the type of polymer (source), the type of bitumen (qualitative factors), PET amount, mixing rate, and mixing temperature (quantitative factors), controlled the bitumen–polymer mixing process. The experiment included a series of determinations of bitumen’s rheological characteristics obtained by MSCR (Jnr, R) and G*/sin(δ) at 50 °C, 60 °C, and 70 °C. The low-temperature properties of the composite (critical temperature) were evaluated using a BBR test. The findings showed that bitumen modification with PET primarily reduced the creep susceptibility of the bituminous–polymer mixture. The low-temperature characteristics of the modified bitumen played a secondary but essential role. The amount of polymer and the mixing rate interacted with the temperature, significantly reducing the stiffness of the composite, while the type and amount of bitumen had a substantial effect on the results obtained in the BBR test. It is worth noting that when combining bitumen and plastomer, special attention should be paid to ensuring a high level of homogeneity of the mixture by controlling the parameters of the mixing process accordingly. The tests and analyses provided crucial models (GLM), which allowed for the prediction of the plastomer-modified bitumen’s low- and high-temperature properties. The resulting relationships between factors and the identification of their impact on the bitumen properties enable a better understanding of the process of bitumen modification with PET. The conclusions presented here serve as a basis for future optimisation of the modified bitumen composition. The performed studies indicate that the use of >3% plastomer in bitumen 70/100 allows for a reduction in its susceptibility (MSCR) to below 0.5 kPa−1, making it suitable for bituminous mixtures for high-traffic roads. No significant increase in critical temperature (BBR) was observed.

Call your Mothers! Sámi Culture-Based Curriculum Development Based on Mathematics Teachers, Students and Mothers in Joint Research Actions

This paper describes the collaboration between home and school during the planning of a mathematics teaching experiment involving ruvden, a Sámi braiding procedure. The experiment was conducted in a Sámi lower secondary school. In Sámi schools, Sámi language and culture shall constitute the basis for the teaching, but no cultural implementation usually takes place in the mathematics teaching. The teachers’ investigations of ruvden took place in collaboration with researchers and students during workshops, meetings and math days. The participants investigated the braiding procedure with different numbers of yarns; during one workshop, two girls’ mothers were invited to participate. The contributions of these new participants opened up for research questions with a focus on home-and-school cooperation. The first research question is: How did the mothers experience their involvement in the development of the Sámi culture-based teaching experiment? Analyses of that question prepared for another research question: How may home-and-school collaboration contribute to culture-based curriculum development? The mothers experienced their involvement positive, and the home-and-school cooperation had even implications for the content of the teaching experiment. The home-and-school collaboration took part on the basis of the perspective of shared responsibilities.

Avaliação do Emprego de Cloreto Férrico e Tanino como Coagulantes na Remoção de Sólidos de Efluentes Industriais

The circular economy has generated a lot of interest in the industrial sector, and one of the proposed principles is the reuse of waste generated by the industry. Considering this, it is important to apply adequate treatments for their reuse, thus avoiding inappropriate disposal, and to bringing economic advantages to the sector. The present proposal applied the alternative coagulants ferric chloride and tannin aiming at the removal of solids from the effluent generated in the painting booth of liquefied petroleum gas (LPG) containers of the company Supergasbras, located in Londrina-PR, considering it uses the iron sulfate. The experimental planning for the tests followed by varying two factors, sedimentation time and coagulant dosage, subdivided into 3 coded levels (+1, 0 -1), hence totalizing 9 experiments in duplicate. After the experiment, analyzes of pH, apparent color, turbidity and COD indicators were perfomed. Ferric chloride proved to be extremely efficient for turbidity removal and chemical oxygen demand, with values exceeding 90% of removal, in addition, the apparent color indicator also obtained a good result. However, in relation to the pH, all the tests with ferric chloride acquired an acid character, consequently it is necessary to use lime to correct the acidity. The application of the tannin organic coagulant, provided excellent efficiency in removing apparent color and turbidity, in addition to obtaining adequate pH values that comply with current legislation. Regarding the removal of the chemical demand for oxygen, it is approximately 90% for all tests using tannin as a coagulant.

The effective integration assessment of life skills education for students in teaching physical education at high schools in Buon Ma Thuot city

Physical education contributes to forming key qualities and general abilities for students; In addition, through equipping students with knowledge about health, health management, and training, physical education helps students form and develop physical capacity physical culture, and a sense of responsibility towards others. with the health of oneself, famifamilyn,d community; know how to choose a sport that suits your physical ability to practice; know how to adapt to living conditions, be optimistic and share with otothershav a healthy life physically and mentally. Through commonly used scientific research methods, the paper has formulated an experimental plan for three high schools in Buon Ma Thuot City for the academic year 2022 - 2023. Based on this, the effectiveness of integrating life skills education for students in teaching physical education at high schools in Buon Ma Thuot City is assessed.