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Number of results: 87
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Abstract

The article presents a zero-dimensional mathematical model of a tubular fuel cell and its verification on four experiments. Despite the fact that fuel cells are still rarely used in commercial applications, their use has become increasingly more common. Computational Flow Mechanics codes allow to predict basic parameters of a cell such as current, voltage, combustion composition, exhaust temperature, etc. Precise models are particularly important for a complex energy system, where fuel cells cooperate with gas, gas-steam cycles or ORCs and their thermodynamic parameters affect those systems. The proposed model employs extended Nernst equation to determine the fuel cell voltage and steadystate shifting reaction equilibrium to calculate the exhaust composition. Additionally, the reaction of methane reforming and the electrochemical reaction of hydrogen and oxygen have been implemented into the model. The numerical simulation results were compared with available experiment results and the differences, with the exception of the Tomlin experiment, are below 5%. It has been proven that the increase in current density lowers the electrical efficiency of SOFCs, hence fuel cells typically work at low current density, with a corresponding efficiency of 45–50% and with a low emission level (zero emissions in case of hydrogen combustion).
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Authors and Affiliations

Janusz Badur
Marcin Lemański
Tomasz Kowalczyk
Paweł Ziółkowski
Sebastian Kornet
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Abstract

With widespread use of pesticides in modern agriculture, the impacts of spray drift have become a topic of considerable interest. The drifting of sprays is a highly complex process influenced by many factors. The paper presents results of experimental research on a drifting cloud of droplets dispersing from aircraft. Experiments were conducted to quantify spray drift from aerial applications of pesticide. Parallel to the blowing wind, the measurement line 800 m long was disposed. The relationships between the relative dose and the distance of drift as well as spray density and its structure on the measuring length have been established.

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Authors and Affiliations

Tomasz Seredyn
Robert Rowiński
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Abstract

What kind of contamination poses the greatest hindrance to our experience of the world? Do the most important cognitive faculties in epistemology – reason and the senses – truly cooperate with one another? What might be getting in the way, polluting and contaminating our image of the world, effectively keeping us unable to ever directly access the truth that we assume exists somewhere out there?
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Authors and Affiliations

Katarzyna Kasia
1

  1. Department of Culture Theory, Faculty of Management of Visual Culture, Academy of Fine Arts in Warsaw
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Abstract

The article presents a phenomenological description of existential experience, one of the fundamental issues in the philosophy of existence. At the outset, it is worth emphasizing that showing the specifics of this experience seems to be a difficult, or even an impossible task – due to its individual, subjective and inexpressible nature, and, as a consequence, its elimination from the academic, schematic, scientific reflection. The problem of existential experience is so interesting, however, and philosophically so important that – despite those disheartening limitations – it seems worthwhile to take a closer look at it. The article shows the phenomenon of human existence in the context of its intra‑world situation, exposing its ontic uniqueness.
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Authors and Affiliations

Marek Błaszczyk
1
ORCID: ORCID

  1. Uniwersytet Mikołaja Kopernika, Instytut Literaturoznawstwa, ul. Fosa Staromiejska 3, 87‑100 Toruń
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Abstract

Consumer experiences as a driver of contemporary brand and marketing management are taken up nowadays by many researchers and academics. It’s merely compelled by bored with generic products and services consumers who much more than ever look for intensive, personalized experiences. However, there is a significant gap in knowledge how to transfer these global changes to the needs of effective tourist product management. The article presents a brand-new approach called ‘the experience key’ for discovering, grouping and converting common, dedicated to a certain destination customers experiences into clear and desirable tourist offer with meaningful competitive impact. One of most important advantages of the methodology is its simplicity and ease-of-use for any professionals involved in destination product management by using well-know research methods and apparent applicability into the process of building and selling tourist offer of a place. The Experience Key can be regarded as a missing link between theoretical considerations led by academics and expectations of tourism industry representatives in the context of applying customer experience to place brand and product management.

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Authors and Affiliations

Piotr Lutek
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Abstract

There is a growing body of research investigating the relationships among gratitude, self-esteem, and subjective well-being. However, there remains a scarcity of research examining the impact of self-esteem on the relationship between gratitude and subjective well-being within Arabic context. In this study, 300 Arabic speaking adults completed measurements of gratitude, self-esteem, satisfaction with life, and positive and negative experiences. Participants’ ages ranged between 18 and 54 years with a mean age of 29.67 years (SD = 8.91). The correlation results revealed that there were significant positive relationships between gratitude, self-esteem, satisfaction with life, and positive experience, while there were significant negative relationships between gratitude, self-esteem, satisfaction with life, and negative experience. The results also showed that gratitude and self-esteem directly predicted subjective well-being. Additionally, using structural equation modeling, self-esteem exerted a mediation effect on the relationship between gratitude and subjective well-being. The results suggest that enhancing self-esteem could assist adults who have gratitude to experience greater subjective well-being. Using the source of self-esteem, researchers and professionals could improve one’s subjective wellbeing by employing various gratitude activities.

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Authors and Affiliations

Murat Yildirim
Nouf Abdullah Alshehri
Izaddin Ahmad Aziz
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Abstract

The aim of this article is to research the psychological trauma of a person who has experienced extreme events and gained psychotraumatic experience. Modern humanities understand the problem of injury in several aspects. One of the topical issues is the representation of psychotraumatic events through the involvement of aesthetic experience. The relevance of this paper is due to the fact that an important component of safe human life is to solve problems related to experiencing mental trauma and healing a person from it. The leading research method was the method of analysis of research sources. Also, in the research, the authors used the method of synthesis, observation, modeling. To describe the narrative of psychological trauma, the authors set out the theoretical foundations of the toolkit. The authors' view on the negative consequences of the traumas of war in their further psychological, physiological, and social development was presented. The main ways of reflecting individual and collective traumas were also analyzed, and artistic strategies of detraumatization were pointed out. As a result of the study, generalized conclusions were formed about the role of narrative practices in the formation of the historical and individual experiences of overcoming psychological trauma.
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Authors and Affiliations

Oleksandr M. Kyrylchuk
1
Liubomyr O. Krupka
1
Myroslava A. Krupka
1

  1. Rivne State University of Humanities, Rivne, Ukraine
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Abstract

This paper describes the p-diagram (parameter-diagram) and its application in planning a DoE (Design of Experiments). A case study describing an actual problem from industry is presented where the planning phase started to go wrong as difficulties in selecting the right variables for the DoE were discovered. Furthermore, running these experiments became prohibitively expensive, due to the large number of such experiments that would be needed, and though the exploitation of a p-diagram it was then possible to come up with a feasible DoE.
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Authors and Affiliations

Matthew Barsalou
ORCID: ORCID
Karolina WILCYNSKA
Pedro Manuel SARAIVA
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Abstract

Brasilia. A city that is a utopia. An experiment. A political act. A city that is a symbol and a manifesto. Built because of an idea and boldly cast deep inland. And although it was built in the 1960’s, it still elicits strong emotions. This masterfully planned city was meant to be a model centre and an aesthetic symbol of new modernist thought, as well as the key to the success of Brazil’s young society. Over sixty years have passed since signing the founding act of the city by the socialist and populist Juscelino Kubitschek. How is this urban masterwork, the symbol of Brazilian postmodernism, that once surprised and enchanted the entire world, developing today? What is left of the imaginings and assumptions of functionalists? Can we state that this globally unique experiment was successful?
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Authors and Affiliations

Beata Malinowska-Petelenz
Mariusz Twardowski
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Abstract

An evaluation method is developed for single blow experiments with liquids on heat exchangers. The method is based on the unity Mach number dispersion model. The evaluation of one experiment yields merely one equation for the two unknowns, the number of transfer units and the dispersive Peclet number. Calculations on an example confirm that one single blow test alone cannot provide reliable values of the unknowns. A second test with a liquid of differing heat capacity is required, or a tracer experiment for the measurement of the Peclet number. A modified method is developed for gases. One experiment yields the effective number of transfer units and approximate values of the two unknowns. The numerical evaluation of calculated experiments demonstrates the applicability of the evaluation methods.
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Authors and Affiliations

Wilfried Roetzel
Chakkrit Na Ranong
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Abstract

The recently developed special unity Mach number dispersion model prescribes the corrections to heat transfer coefficients which are simple functions of the dispersive Peclet numbers. They can be determined through the residence time measurements. An evaluation method is described in which the measured input and response concentration profiles are numerically Laplace transformed and evaluated in the frequency domain. A characteristic mean Peclet number is defined. The method is also applied to the parabolic dispersion model and the cascade model. A calculated example of a tube bundle with maldistribution and backflow demonstrates the suitability of the evaluation method.

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Authors and Affiliations

Wilfried Roetzel
Chakkrit Na Ranong
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Abstract

An evaluation method is developed for temperature oscillation experiments in heat exchangers. The unity Mach number dispersion model is applied. For the consideration of lateral wall heat conduction an effective wall thickness is introduced together with a wall heat transfer coefficient. The evaluation method may also be applied to single blow experiments with pulse signals. A sensitivity analysis describes and discusses the accuracy of different evaluation procedures.

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Authors and Affiliations

Wilfried Roetzel
Na Ranong Chakkrit
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Abstract

The exudation layer seriously affects the properties and the surface finish of the tin bronze alloy. The effective control of the exudation thickness is important measure for improving the properties of the alloy. In order to study the influence of process parameters on the thickness of exudate layer, the tin bronze alloy was prepared by continuous unidirectional solidification technology at different process parameters. The microstructure of the continuous unidirectional solidification tin bronze alloy was analyzed. The effect of process parameters on microstructure and chemical compositions was studied by orthogonal experiment. The results show that there exists an exudation layer on the surface of the continuous unidirectional solidification tin bronze alloy, and the exudation is mainly composed of a tin-rich precipitated phase. It indicates that the continuous casting speed is the main factor affecting the thickness of exudation layer, followed by mold temperature, melt temperature, cooling water temperature and cooling distance.

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Authors and Affiliations

Jihui Luo
Fang He
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Abstract

The research was concerned with the influence of chemical composition of austenitic steels on their mechanical properties. Resulting properties of castings from austenitic steels are significantly influenced by the solidification time that affects the size of the primary grain as well as the layout of elements within the dendrite and its parts with regard to the last solidification points in the interdendritic melt. During solidification an intensive segregation of all admixtures occurs in the melt, which causes a whole range of serious metallurgical defects and it has also a significant influence on subsequent precipitation of carbides and intermetallic phases. Chemical heterogeneity then affects the structure and mechanical properties of the casting. In a planned experiment, we cast melted steels containing 18 to 28 % Cr and 8 to 28 % Ni with variable carbon and nitrogen contents. Testing the tensile strength of the cast specimens we could determine the Rp0.2, Rm, and A5 values. The dependence of the mechanical properties on the chemical content was described by regression equations. The planned experiment results allow us to control the chemical content for the given austenitic steel quality to achieve the required values of the mechanical properties.

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Authors and Affiliations

A. Záděra
V. Kaňa
B. Maroš
P. Blažík
J. Čech
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Abstract

Technical system for condition monitoring and failure diagnostics of gear driver with roller bearings was tested in situ. The experimental measurement data of rotors shaft vibration displacements were introduced into physical model of gear teeth meshing dynamics. The modelling and simulation of teeth failures in gear driver with roller bearings was performed by finite element method. The experimental and simulation results were used in identification and elimination of sources of gear teeth damages and bearings failures.

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Authors and Affiliations

Vytautas Barzdaitis
Vytautas Zemaitis
Pranas Mazeika
Rimantas Didziokas
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Abstract

Numerical simulation is an economical and effective method in the field of marine engineering. The dynamics of mooring cables has been analysed by a numerical simulation code that was created on a basis of a new element frame. This paper aims at verifying the accuracy of the numerical simulation code through comparisons with both the real experiments and a commercial simulation code. The real experiments are carried out with a catenary chain mooring in a water tank. The experimental results match the simulation results by the numerical simulation code well. Additionally, a virtual simulation of a large size chain mooring in ocean is carried out by both the numerical simulation code and a commercial simulation code. The simulation results by the numerical simulation code match those by the commercial simulation code well. Thus, the accuracy of the numerical simulation code for underwater chain mooring is verified by both the real experiments and commercial simulation code.

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Authors and Affiliations

Xiangqian Zhu
Wansuk Yoo
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Abstract

In multi-stage wire drawing machines productivity growth can be achieved at higher drawing speeds by preventing wire breakage during the process. One disadvantage of high-speed wire drawing is the requirement imposed by machine dynamics in terms of its stability and reliability during operation. Tensile forces in the wire must maintained by fast synchronization of all capstans speed. In this process, the displacement sensors play the main role in providing the control system with feedback information about the wire condition. In this study, the influences between the sensors and actuator driven capstans have been studied, and tuner roll concept of a wire drawing machine was experimentally investigated. To this aim, measurements were carried out on two drawing stages at different drawing speeds and obtained results were presented. These results clearly show the fast changes of the capstans speed and the angular displacements of the rollers that tighten the wire, which only confirms the high dynamics of the wire drawing machine.

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Bibliography

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Authors and Affiliations

Goce Tasevski
Kocho Angjushev
Zlatko Petreski
Dejan Shishkovski

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Abstract

This work attempts to reconstruct the culture that contributed to the philosophical way of thinking. My goal is to extract two important factors: religion carrying individual experience and the importance of certain ideas which are present in that culture. Sources of philosophical thinking can be found in the structure of polis. Only on its basis could the idea of the wise man and citizen as well as religion-oriented individual experience be raised. Greek polis paves the way for a new style of thinking by creating the conditions for its citizens to follow the ideal, regardless of the position they occupy in society. Sustainability, which should be a feature of a good citizen, is also the essence of society. Highly positioned wisdom as moral reflection tinged with religiosity allows thinking according to the laws of logos. Finally, the experience offered by the mystery cults leads to the transformation of their own existence and the emergence of a way of recognition of reality different than before. Undeniably, all the elements related to structure policies with its ideals contribute to the emergence of a new way of thinking in the form of philosophy. One could say that the philosophical objectivity is preceded by the subjectivity and rationality of its roots dating back to irrationality.

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Authors and Affiliations

Jadwiga Skrzypek-Faluszczak
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Abstract

The article presents scientific achievements of Alfred Nobel Memorial Prize Laureates in economic sciences in 2019: Esther Duflo, Abhijit Banerjee, and Michael Kremer. The paper describes their contribution to the research on the sources of poverty in the world and the ways of alleviating it, and their contribution to the development of experimental research in social sciences using randomized control trials (RCT). In this context, the authors explain the reasons for growing popularity of this approach in development economics and discuss its strengths and weaknesses.

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Authors and Affiliations

Dominik Buttler
Jan Szambelańczyk
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Abstract

A series of steps taken to determine a kinetic equation that describes hydrogenation of propene on nickel catalyst is presented in this study. Mixed factorial design approach, belongs to designing of experiments methods was used to plane experiments. The investigations showed that the method applied makes possible determination of the kinetic equation in a relatively fast and cheap manner since only a few measurement points is required. The equation obtained was verified experimentally and statistically. Both tests showed satisfactory precision of anticipated values of the process rate.
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Bibliography

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Authors and Affiliations

Adrian Szałek
1
Mirosław Szukiewicz
1
Elżbieta Chmiel-Szukiewicz
1

  1. Rzeszów University of Technology, Faculty of Chemistry, al. Powstańców Warszawy 6, 35-959 Rzeszów, Poland
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Abstract

Boiling produces vapor with a phase change by absorbing a consistent amount of heat. Experimentation and modeling can help us better understand this phenomenon. The present study is focused on the heat transfer during the nucleate pool boiling of refrigerant R141b on the surface of a horizontal copper tube. The results of the experiment were compared with four correlations drawn from the literature, and the critical heat flux was examined for different pressures and also compared with the predicted values. Simulating boiling with two-phase models allowed us to infer the plot of the temperature distribution around the tube and compared it to results from other work.
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Bibliography

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Authors and Affiliations

Touhami Baki
1
ORCID: ORCID
Abdelkader Aris
2
Mohamed Tebbal
1

  1. Faculty of Mechanics, Gaseous Fuels and Environment Laboratory, University of Sciences andTechnology of Oran Mohamed Boudiaf (USTO-MB), El Mnaouer, Oran, Algeria.
  2. ENP. Oran, Laboratoire de Recherche en Technologie de Fabrication Mécanique, Algeria
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Abstract

The research presented in detail in this scientific paper refers to the modelling of process parameters for natural gas transmission in a centralized system. The method of the factorial experiment was used to model some parameters considered to be vital, namely the gas temperature, the air temperature as well as a certain correction factor on the flow delivered to the population. The study was conducted by accessing information provided by a regulation-measurement station that delivers gas to an important locality in a locality in central Romania. Experimental data collected over 24 hours on a summer day but also on a winter day were used. After a previous study with classical experimental research methods, the factorial experiment was used, which allows the delivery of much more detailed information and the graphical representations are much more precise and detailed, in other words, relevant and useful conclusions can be obtained on objective studied in the research approached.
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Authors and Affiliations

Mihail Aurel Țîțu
ORCID: ORCID
A.B. Pop
1
ORCID: ORCID
M. Nabiałek
2
ORCID: ORCID

  1. Technical University of Cluj-Napoca, Northern University Centre of Baia Mare, Faculty of Engineering – Department of Engineering and Technology Management, 62A, Victor Babes Street, 430083, Baia Mare, Maramures, Romania
  2. Częstochowa University of Technology, Department of Physics, Armii Krajowej 19 Av., 42-200 Częstochowa, Poland

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