scholarly journals Research the hardness of polymer materials after turning

2020 ◽  
Vol 329 ◽  
pp. 03041
Author(s):  
Oleg Erenkov ◽  
Elena Yavorskaya
Keyword(s):  
Experimental Studies ◽  
Polymer Materials ◽  
Experimental Methodology ◽  
Elastic Aftereffect

The paper presents the results of experimental studies to determine the hardness of the treated surface depending on the conditions and machining type of workpieces made of textolite, caprolon and fluoroplastic. The experimental methodology and explanation of the reasons for changing the hardness of the treated surface for the investigated variants of machining the materials are under study. The results of studying the influence of the phenomenon of elastic aftereffect of the polymer materials after workpieces machining are obtained.

scholarly journals Thermal Inertia Characterization of Multilayer Lightweight Walls: Numerical Analysis and Experimental Validation

2021 ◽  
Vol 11 (11) ◽  
pp. 5008
Author(s):  
Juan José del Coz-Díaz ◽  
Felipe Pedro Álvarez-Rabanal ◽  
Mar Alonso-Martínez ◽  
Juan Enrique Martínez-Martínez
Keyword(s):  
Lightweight Concrete ◽  
Thermal Flux ◽  
Experimental Studies ◽  
Thermal Inertia ◽  
Transient State ◽  
Experimental Tests ◽  
Building Design ◽  
Experimental Methodology ◽  
Improve Energy Efficiency ◽  
Concrete Blocks

The thermal inertia properties of construction elements have gained a great deal of importance in building design over the last few years. Many investigations have shown that this is the key factor to improve energy efficiency and obtain optimal comfort conditions in buildings. However, experimental tests are expensive and time consuming and the development of new products requires shorter analysis times. In this sense, the goal of this research is to analyze the thermal behavior of a wall made up of lightweight concrete blocks covered with layers of insulating materials in steady- and transient-state conditions. For this, numerical and experimental studies were done, taking outdoor temperature and relative humidity as a function of time into account. Furthermore, multi-criteria optimization based on the design of the experimental methodology is used to minimize errors in thermal material properties and to understand the main parameters that influence the numerical simulation of thermal inertia. Numerical Finite Element Models (FEM) will take conduction, convection and radiation phenomena in the recesses of lightweight concrete blocks into account, as well as the film conditions established in the UNE-EN ISO 6946 standard. Finally, the numerical ISO-13786 standard and the experimental results are compared in terms of wall thermal transmittance, thermal flux, and temperature evolution, as well as the dynamic thermal inertia parameters, showing a good agreement in some cases, allowing builders, architects, and engineers to develop new construction elements in a short time with the new proposed methodology.

scholarly journals The influence of a country’s brands and industry on its image

2020 ◽  
Vol 55 (1) ◽  
pp. 27-62
Author(s):  
Carmen Lopez ◽  
George Balabanis
Keyword(s):  
Experimental Studies ◽  
Place Branding ◽  
Product Category ◽  
Schema Theory ◽  
Experimental Methodology ◽  
Cross Sectional ◽  
Economic Dimension ◽  
Content Type ◽  
The Uk

Purpose Extant research has largely treated country image (CI) as an exogenous variable, focusing mostly on its consequences for consumers’ evaluations and purchases of products or brands originating from a country. Scant research has examined the instrumental role of a country’s brands and products in the evaluations of CI. This study aims to investigate how the brands of a country contribute to CI ratings and the conditions underlying their effect on CI. Design/methodology/approach Three experimental studies test the hypotheses, one pertaining to the effect of brands on CI (N = 227), the second to the effect of products on CI (N = 116) and the third to the effect of brands and products on industry image (N = 215). The experimental approach overcomes the limitations of cross-sectional surveys commonly used in CI studies to detect the direction of the observed effects. Furthermore, respondents (British consumers) were allowed to determine the brands and products associated with a country. Findings Drawing on memory schema theory, across three studies, the authors identify two types of reverse inferences: from brand to CI and from product category to CI. The reverse inference from a brand to a superordinate image is stronger for industry image than for CI. Research limitations/implications This research focuses on consumers’ evaluations from only one country (the UK). Further research could replicate the studies across different countries and with different countries of origin (COOs). Researchers could also examine the influence of brands misidentified with the wrong COO and mistakenly stored as such in consumers’ memories. Practical implications The results are relevant for managers and consultants working with country- (place-) branding campaigns. Brands and industries can help strengthen the evaluations of the economic dimension of different countries; however, these assets are underdeveloped in country-branding campaigns. Linking countries with brands and industries in campaigns could result in positive associations, which, in turn, could enhance the reputational rating of the countries. Originality/value This research extends previous studies on the effects of a country’s products and brands on CI by incorporating the mediating role of industry image between brands/products and CI, separating the effects of brand and product category on CI, allowing consumers to determine, which brands and products are associated with a country and adopting an experimental methodology to ascertain the causal direction of the effects.

Effects of cutting parameters on drilling performance of carbon black–reinforced polymer composite

2016 ◽  
Vol 232 (7) ◽  
pp. 1133-1142 ◽  
Author(s):  
Alper Uysal
Keyword(s):  
Surface Roughness ◽  
Composite Materials ◽  
Carbon Black ◽  
Polymer Composite ◽  
Experimental Studies ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Polymer Materials ◽  
Drill Point

Polymer composite materials can be produced by reinforcing carbon black, carbon fiber, graphite, graphene, metals and metal oxides, nanotubes, and so on. These types of composite materials can be employed in applications demanding electrical conductivity besides high specific strength and stiffness properties of polymer materials. In the literature, there is a lack of knowledge on the examination of drilling of particle-reinforced composite materials. In this study, drilling of pure polypropylene and carbon black–reinforced polypropylene composite material was investigated at different drill point angles, cutting speeds, and feeds. The cutting temperature of drill point and surface roughness of holes were examined. The experimental studies were designed by L27 full-factorial design, and analysis of variance statistical method was performed. According to the results, cutting temperature increased and surface roughness decreased with the increase in the cutting speed and feed and decrease in the drill point angle.

scholarly journals Research the chip formation process thermoplastic turning

2020 ◽  
pp. 46-48
Author(s):  
O. YU. Erenkov
Keyword(s):  
Formation Process ◽  
Chip Formation ◽  
Experimental Studies ◽  
Polymer Materials ◽  
Cutting Depth ◽  
The Relationship ◽  
Cutting Modes

The article presents the results of experimental studies of the relationship between the characteristics of cutting modes and nature of chip formation for thermoplastics blanks. Caprolon and fl uoroplast-4 were used as the studied materials. It has been experimentally proved that the cutting depth has the maximum eff ect on the chip formation character when turning blanks from the studied polymer materials.

scholarly journals Mediated Generalization and Stimulus Equivalence

2021 ◽  
Vol 44 (1) ◽  
pp. 1-27
Author(s):  
Christoffer Eilifsen ◽  
Erik Arntzen
Keyword(s):  
Stimulus Equivalence ◽  
Experimental Studies ◽  
Early Research ◽  
Experimental Methodology ◽  
Inferential Statistics ◽  
Publication Trends ◽  
Explanatory Variables ◽  
Research Tradition ◽  
Current Article ◽  
Human Participants

AbstractFrom the 1930s to the 1970s a large number of experimental studies on mediated generalization were published, and this research tradition provided an important context for early research on stimulus equivalence. Mediated generalization and stimulus equivalence have several characteristics in common, notably that both traditions seek to experimentally investigate derived responding among arbitrarily related stimuli in human participants. Although studies of stimulus equivalence are currently being regularly published, few studies investigate mediated generalization in humans today, and the research tradition is mainly of historical interest. The current article will give an account of the origin, the development, and the demise of research on mediated generalization, including a presentation of publication trends, experimental methodology, and the conceptual context research on mediated generalization took place within. Finally, some thoughts on the demise of mediated generalization and its relevance for modern research on stimulus equivalence and other types of derived responding are presented, including reflections on the observability of explanatory variables and the use of inferential statistics.

scholarly journals Impact assessment of silting on pipeline capacity

Vestnik MGSU ◽  
2021 ◽  
pp. 360-369
Author(s):  
Andrey E. Ten ◽  
Nazira T. Dzhumagulova ◽  
Yuliya V. Bryanskaya
Keyword(s):  
Hydraulic Resistance ◽  
Research University ◽  
Complex Structure ◽  
Experimental Studies ◽  
Drainage System ◽  
Resistance Coefficient ◽  
Polymer Materials ◽  
Roughness Coefficient ◽  
Flow Rates ◽  
Average Flow

Introduction. Currently, in the construction of engineering systems for various purposes, pipelines made of polymer materials are often used. The ACO Qmax corrugated pipeline was developed as a drainage system for the drainage of surface runoff. The widespread use in practice of corrugated pipes, which have a significantly higher roughness than technically smooth ones, has caused the need to perform a number of calculations that take into account the features of their hydraulic operation. The purpose of the work is to compare the pipeline capacity in the case of partial silting within the corrugation and in the absence of it. Materials and methods. Due to the complex structure of the inner surface, the resistance of the described polymer pipeline can only be determined experimentally. The hydraulic characteristics of the ACO Qmax corrugated pipeline with partial silting were determined experimentally in the Laboratory of Hydraulics and Hydromechanics of the Moscow State University of ­Civil Engineering (National Research University). Results. The experiments were carried out under the following conditions: at flow rates Q (from 13.9 to 79.1 m3/h) and the slope of the bottom of the tray i = 0.005; at flow rates Q (from 14 to 89.1 m3/h) and the slope of the bottom of the tray i = 0.01. According to the experimental data obtained, the values of the hydraulic resistance coefficient, the Shezi coefficient, the Manning roughness, and the average flow velocity were calculated. The roughness obtained in a “clean” and partially silted pipeline is compared. Conclusions. According to the results of the conducted experimental studies, it is concluded that the partial silting of the pipeline within the corrugation of the tray part practically does not affect its hydraulic resistance. A comparison of the experimental values of the average flow velocities in a silted and non-silted pipeline shows that they practically do not differ. Thus, the obtained values of the roughness coefficient can be assumed to be constant for this pipeline.

scholarly journals Use of Causal Language in Studies on the Relationship between Spiritually-Based Treatments and Substance Abuse and Relapse Prevention

Religions ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1075
Author(s):  
Iván Sánchez-Iglesias ◽  
Marta González-Castaño ◽  
Antonio J. Molina
Keyword(s):  
Substance Abuse ◽  
Behavioral Problems ◽  
Relapse Prevention ◽  
Experimental Studies ◽  
Internal Validity ◽  
Experimental Methodology ◽  
Health Improvement ◽  
Causal Explanations ◽  
Quasi Experimental ◽  
The Relationship

The main goal of scientific research is to explain what causes a phenomenon. However, only well-controlled studies guarantee sufficient internal validity to support causal explanations (i.e., experimental and some quasi-experimental designs). The use of causal claims in non-experimental studies can mislead readers into assuming a cause–effect relationship when alternative explanations have not been ruled out, undermining the principle of scientific rigor and the credibility of scientific findings. Although spiritual practices form part of some interventions for health and behavioral problems, their effectiveness cannot often be assessed via experimental methodology. This paper assesses the validity of causal inferences in published non-experimental studies, and more specifically in studies on the relationship between spiritually based treatments and substance abuse improvement and relapse prevention. We conducted a systematic review using Scopus, Pubmed, and several databases included in ProQuest, for the period 2015 to 2020. Out of 16 studies selected, six studies (37.5%) used correct language in the title, abstract, and discussion sections; 10 studies (68.8%) used tendentious or incorrect language in at least one section. Spiritually based treatments show promising results in some health improvement outcomes. Most studies show transparency when reporting results. However, researchers should be careful not to make causal assertions unless the internal validity of the research is sound.

scholarly journals VIBRATION FREQUENCY DENSITY CONTROL METHOD IN VIBRATION CONDITIONS

2019 ◽  
pp. 41-47
Author(s):  
O. Yu. Oliinyk
Keyword(s):  
Vibration Frequency ◽  
Vibrational Frequency ◽  
Control Method ◽  
Experimental Studies ◽  
Approximation Error ◽  
Frequency Characteristics ◽  
Organic Glass ◽  
Experimental Methodology ◽  
Measuring Instruments ◽  
Density Control

The use of existing vibration frequency measuring instruments for monitoring technological parameters inside apparatus and equipment is limited due to the presence of vibrations and industrial noise. The lack of data on the use of part of the technological apparatus as flow resonators through the unexplored basic analytical equations for determining the amplitude-frequency characteristics of such resonators determined the direction of these studies. The article is devoted to studies aimed at establishing the relationship between the vibrational field of the resonator, which is used as part of the technological apparatus with a controlled environment, and its reaction in the form of a change in the frequency or amplitude of the resonator’s own vibrations, which carries information about the properties of the substance in the apparatus. The experimental setup diagram, experimental methodology, and data on determining the oscillation frequency of the resonator under vibration conditions for metallic (corrosion-resistant steel) and non-metallic (organic glass) resonators are presented. The curves obtained from the experimental values were approximated using linear and hyperbolic approximations. It was found that the use of hyperbolic approximation reduces the average approximation error by more than six times. It was found that the error of the hyperbolic approximation error does not exceed 0.022% for a metal resonator and 0.05% for an organic glass resonator. The conducted experimental studies confirm the presence of a determinate coupling of the measured frequency characteristics of the resonator with the density, which was measured inside the equipment. The obtained data was used to develop the scientific and methodological foundations of the vibrational frequency control method in conditions of vibration using a part of the device as a resonator of the vibrational frequency sensor.

Dose Dependences of the Mechanical Strength of Polymer Materials

2018 ◽  
Vol 781 ◽  
pp. 25-29 ◽  
Author(s):  
Anatoliy I. Kupchishin ◽  
Buvkhan G. Taipova ◽  
Nataliya A. Voronova ◽  
Alexander A. Kupchishin ◽  
Kuanysh Shakhanov
Keyword(s):  
Radiation Dose ◽  
Mechanical Strength ◽  
Electron Irradiation ◽  
Experimental Studies ◽  
Polymer Materials ◽  
Exponential Models

Experimental studies on the effect of electron irradiation with energy of 4 MeV to the mechanical strength of the film of Mylar type were conducted. It is found that the strain and stress dependences on the radiation dose are satisfactorily described by the proposed exponential models.

scholarly journals Heavy Oil Residues: Application as a Low-Cost Filler in Polymeric Materials

2019 ◽  
Vol 5 (12) ◽  
pp. 2554-2568 ◽  
Author(s):  
Yulia Yurevna Borisova ◽  
Alsu M. Minzagirova ◽  
Alfina R. Gilmanova ◽  
Mansur F. Galikhanov ◽  
Dmitry N. Borisov ◽  
...  
Keyword(s):  
Composite Materials ◽  
Heavy Oil ◽  
Low Cost ◽  
Experimental Studies ◽  
Polymeric Materials ◽  
Physicomechanical Properties ◽  
Polymer Materials ◽  
Thermal Oxidative Degradation ◽  
Polyethylene Matrix ◽  
Heavy Oil Residues

Deposits of oil sands, bitumen, extra-heavy oil, and heavy oil appear in more than 70 countries all over the world and the fraction of oil recovered gradually increases. High content of poly-condensed high molecular weight oil components (PHMOCs), which may amount up to 50-60% depending on conditions of oil formation, is the main difference of heavy oil and bitumen from conventional oil. PHMOCs can lay the foundation for the preparation of a large number of valuable materials due to their structural manifold and their potential still not discovered to full extent. This work is devoted to the study of the effect of PHMOCs on properties of the composition materials prepared from polyethylene matrix. An «asphalt» – industrial product of deasphalting of tar, as well as asphaltenes and resins isolated from heavy oil, were used as a source of PHMOCs. HDPE and fillers were characterized using MALDI, FTIR, DSC and TGA. For the new composite materials we evaluated the physicomechanical properties, the thermal decomposition characteristics (by TGA), and the accumulation rate of carbonyl groups in the oxidized polymer (on FTIR). Studies of new composite materials showed that the introduction of filler in an amount of up to 4% in a polyethylene matrix does not lead to a significant change in the physicomechanical properties, but for a number of parameters they are improved. It also figured out that the addition of PHMOCs to polyethylene makes it unnecessary to stabilize the resulting compositions with stabilizers of thermal oxidative degradation. Results of experimental studies indicate that industrial residue - «asphalt» is a promising filler and low cost of this stock renders it perfect source for the industry of polymer materials.

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