scholarly journals A Method for Characterising the Influence of Casting Parameters on the Metallurgical Bonding of Copper and Steel Bimetals

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6223
Author(s):  
Simon Kammerloher ◽  
Julika Hoyer ◽  
Philipp Lechner ◽  
Tim Mittler ◽  
Wolfram Volk
Keyword(s):  
Casting Process ◽  
Time Profile ◽  
High Mass ◽  
Maximum Temperature ◽  
Cast Part ◽  
Casting Technology ◽  
Production Route ◽  
Research Activities ◽  
Process Route ◽  
The One

Traditional casting technology offers two mayor drawbacks towards research activities. On the one hand, time and resources needed for every casting are rather high. The mould has to be able to withstand the high temperatures introduced by the melt and provide cooling for the cast part. Preparation and installation of measuring equipment therefore takes time. Additionally, due to the high mass of the mould when compared to the cast part, parameter variations are rather limited in their resulting effect on the temperature-time profile being one of the most prominent factors regarding cast quality. Especially when pouring by hand, variations in casting times and rates superimpose effects created intentionally. Therefore, a different process was advanced and evaluated, allowing to minimise some of the drawbacks mentioned before. The key idea is to drastically reduce casting size to the dimensions of one specimen and to apply a highly automated production route. As such, a mirror furnace was modified as to allow the processing of melt. Due to the specimens size, an adaption of mechanical testing equipment was performed and evaluated. As an example, copper-iron bimetal specimens were examined by light microscopy, micro hardness testing, nanoindentation as well as tensile and torsion testing. As the results were consistent, the newly introduced method can be applied successfully in casting research. This allows for highly reproducible results, reducing the uncertainty of temperature measurements of a specimen due to the distance between them. The possibility of separating influencing variables like maximum temperature and cooling rate allows an analysis of the casting process, which would require different moulds to do so in traditional casting methods. The next steps will be directed at a broader variety of metals processed and at a direct comparison between the new process route and traditional casting technology.

Higher education for sustainable development: stakeholders benefits

2020 ◽  
pp. 121-136 ◽  
Author(s):  
O.V. Kotomina ◽  
A.I. Sazhina
Keyword(s):  
Sustainable Development ◽  
Active Agent ◽  
Education For Sustainable Development ◽  
Special Role ◽  
Stakeholder Approach ◽  
Research Activities ◽  
Academic Activities ◽  
Key Stakeholders ◽  
The One ◽  
Significant Factors

Education is one of the key goals of sustainable development (SD), which establishes the basis for the improvement of the people’s living conditions. In this logic a special role is played by universities that create an institutional framework for educating citizens on sustainable development, offering a new understanding of social problems. On the one hand, universities can create and promote knowledge about SD by their educational, expert and research activities, hence developing relevant values among people. On the other hand, universities can become an active agent in implementing the concept of SD by introducing it into its own academic activities. The article considers stakeholder approach as one of the approaches to the implementation of the concept of education for sustainable development (ESD). Therefore based on this approach, the article explores the benefits of the key stakeholders of the sustainable university. Low awareness among key stakeholders is one of the significant factors that hindering the implementation of the SD concept. Due to the lack of a sufficient research focused on studying the interests of the main stakeholders in the framework of ESD, this article is an attempt to narrow this gap.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals Analytical Determination of the Brake Temperature Mode During Repetitive Short-Term Braking

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1912
Author(s):  
Aleksander Yevtushenko ◽  
Katarzyna Topczewska ◽  
Michal Kuciej
Keyword(s):  
Friction Pair ◽  
Thermal Sensitivity ◽  
Finite Difference Methods ◽  
Temporal Variations ◽  
Frictional Heat ◽  
Maximum Temperature ◽  
Analytical Determination ◽  
Flash Temperature ◽  
Short Term ◽  
The One

An algorithm to determine the maximum temperature of brake systems during repetitive short-term (RST) braking mode has been proposed. For this purpose, the intermittent mode of braking was given in the form of a few cyclic stages consisting of subsequent braking and acceleration processes. Based on the Chichinadze’s hypothesis of temperature summation, the evolutions of the maximum temperature during each cycle were calculated as the sum of the mean temperature on the nominal contact surface of the friction pair elements and temperature attained on the real contact areas (flash temperature). In order to find the first component, the analytical solution to the one-dimensional thermal problem of friction for two semi-spaces taking into account frictional heat generation was adapted. To find the flash temperature, the solution to the problem for the semi-infinite rod sliding with variable velocity against a smooth surface was used. In both solutions, the temperature-dependent coefficient of friction and thermal sensitivity of materials were taken into account. Numerical calculations were carried out for disc and drum brake systems. The obtained temporal variations of sliding velocity, friction power and temperature were investigated on each stage of braking. It was found that the obtained results agree well with the corresponding data established by finite element and finite-difference methods.

Buddhist art in the museum as a source base of scientific research

2019 ◽  
Author(s):  
Светлана Гарриевна Батырева
Keyword(s):  
Art Criticism ◽  
Traditional Culture ◽  
Museum Collection ◽  
Buddhist Art ◽  
Scientific Center ◽  
Research Activities ◽  
The People ◽  
Initial Work ◽  
The One ◽  
Academy Of Sciences

В настоящей статье рассматривается проблема изучения музейной коллекции буддийского изобразительного искусства Калмыкии, а также сохранения художественного наследия в условиях глобализации культур. Автор ставит цель создать научно обоснованные информационные ресурсы на базе исследования музейных коллекций и экспонатов. Информация составляет суть музейного дела, в основе которого лежит научно-исследовательская деятельность, объединяющая сферы комплектования, учета и хранения фондов, с одной стороны, с другой коммуникативная, связанная с экспозиционно-выставочной деятельностью. Исходными в работе музея являются не только сохраняемый фонд, но и сведения об экспонатах, собираемые в процессе комплектования фонда и создания каталога музейного собрания, состоящего из коллекций. Основываясь на богатой традиции описания и каталогизации предметов искусства, а также применяя современные технологии и искусствоведческие методы, стало возможным подготовить и издать научный каталог коллекций основного фонда Музея традиционной культуры имени Зая-пандиты Калмыцкого научного центра РАН. This article discusses the problem of studying the museum collection of Buddhist fine art in Kalmykia, as well as preserving the artistic heritage in the context of globalization of cultures. The author aims to create scientifically based information resources that include research on museum collections and exhibits. Information is the essence of museum business, which is based on research activities that combine the fields of acquisition, accounting and storage of funds, on the one hand, and on the other hand, communicative activities related to exposition and exhibition activities. The initial work of the museum is not only the preserved fund, but also information about the exhibits collected in the process of acquiring the fund and creating a museum collection catalog consisting of collections. The Zaya-Pandita Museum of Traditional Culture of the Kalmyk Scientific Center of the Russian Academy of Sciences stores and presents in the educational sphere multidisciplinary and largely unique information about the cultural heritage of the people. Based on a rich tradition of describing and cataloging objects of art, as well as using modern technologies and art criticism methods, it has become possible to prepare and publish a scientific catalog of the collections of the main fund of the Zaya-Pandita Museum of Traditional Culture.

I nuovi scambi tra medici e pazienti: le parole della medicina

2021 ◽  
Vol 9788879169776 ◽  
pp. 35-45
Author(s):  
Antonio M. Carrassi
Keyword(s):  
Search Engines ◽  
Health Workers ◽  
Medical Knowledge ◽  
Medical Field ◽  
Average Life ◽  
Average Life Span ◽  
Research Activities ◽  
Field Information ◽  
The One ◽  
The Individual

Medicine showed enormous progresses since the middle of the last century and, thanks to the overwhelming research activities, which characterized that period, the average life span of people has increased extraordinarily. Many diseases that once were considered incurable are now being successfully treated. However, the disease has often been placed at the core of the clinical process rather than the person, the individual, the patient. Even in recent years, the patient doesn’t always find in his doctor the appropriate degree of empathy, and the level of communication that would be desirable. Moreover, today we are living an extraordinary development and spreading use of digital resources and search engines. Patients exploit these tools to obtain any kind of information, included the one in the medical field. Information technology and search engines play an extremely important role in medicine, and they can be seen a pivotal communication instrument between clinicians and patients, although they can also provide inaccurate or incorrect feedback to laypeople looking for answers to health questions, who do not have enough medical knowledge to evaluate the reliability of the source. This problem has been raised by clinicians and, more generally, by health workers, who today operate with a view to greater psychological proximity to the patient, passing from a so-called Disease Centred Medicine to a clinical practice much more sensitive to the needs of the patient, to his experience, to the context in which he lives, thus achieving a Patient Centred Medicine. Listening, attention, empathy and the words that a clinician is required to use towards each patient, during the clinical routine, take on more and more value for a correct doctor-patient exchange and alliance.

scholarly journals Stellar Winds in Massive X-ray Binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 355-358
Author(s):  
Peter Kretschmar ◽  
Silvia Martínez-Núñez ◽  
Enrico Bozzo ◽  
Lidia M. Oskinova ◽  
Joachim Puls ◽  
...  
Keyword(s):  
Compact Object ◽  
High Mass ◽  
Stellar Winds ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Wide Range ◽  
Strong Winds ◽  
The One ◽  
X Ray Binaries

AbstractStrong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the varying properties of the emitted X-rays; but on the other side the accretor’s gravity and ionizing radiation can strongly influence the wind flow. Based on a collaborative effort of astronomers both from the stellar wind and the X-ray community, this presentation attempts to review our current state of knowledge and indicate avenues for future progress.

scholarly journals ISOCAM and DENIS Survey of 0.5 square degrees in the Bar of the LMC. Detection of the whole TP-AGB Star Population

1999 ◽  
Vol 191 ◽  
pp. 561-566
Author(s):  
C. Loup ◽  
E. Josselin ◽  
M.-R. Cioni ◽  
H.J. Habing ◽  
J.A.D.L. Blommaert ◽  
...  
Keyword(s):  
Mass Loss ◽  
High Mass ◽  
Evolutionary Models ◽  
Agb Stars ◽  
Complete Sample ◽  
High Mass Loss ◽  
Low Mass ◽  
The One ◽  
Good Agreement ◽  
Loss Rates

We surveyed 0.5 square degrees in the Bar of the LMC with ISOCAM at 4.5 and 12 μm, and with DENIS in the I, J, and Ks bands. Our goal was to build a complete sample of Thermally-Pulsing AGB stars. Here we present the first analysis of 0.14 square degrees. In total we find about 300 TP-AGB stars. Among these TP-AGB stars, 9% are obscured AGB stars (high mass-loss rates); 9 of them were detected by IRAS, and only 1 was previously identified. Their luminosities range from 2 500 to 14 000 L⊙, with a distribution very similar to the one of optical TP-AGB stars (i.e. those with low mass-loss rates). Such a luminosity distribution, as well as the percentage of obscured stars among TP-AGB stars, is in very good agreement with the evolutionary models of Vassiliadis & Wood (1993) if most of the TP-AGB stars that we find have initial masses smaller than 1.5 to 2 M⊙.

The Arch Support Construction and Hydration Heat Analysis of the First Bridge over Yangtze River in Hejiang

2013 ◽  
Vol 291-294 ◽  
pp. 1122-1127
Author(s):  
Yan Feng Luo ◽  
Da Yan Qin ◽  
Yun Zhang
Keyword(s):  
Yangtze River ◽  
Casting Process ◽  
Hydration Heat ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Element Analysis ◽  
Early Hydration ◽  
Mix Proportion ◽  
Arch Support ◽  
Heat Preservation

The arch support of the First Bridge over Yangtze River in Hejiang used the stratified and graded casting process in mass concrete pouring process. By means of optimizing the concrete mix proportion design, using high mixing amount of fly ash concrete, reducing heat release rate of concrete early hydration heat, delaying the time of maximum temperature rise, and combining turn-over forms and water storage and other surface heat preservation measures, the temperature difference between inside and outside concrete was reduced and the cracking of mass concrete was avoided. Finite element analysis of hydration heat was done to verify the feasibility of the construction scheme.

scholarly journals Magnesium Permanent Mold Castings Optimization

2011 ◽  
Vol 690 ◽  
pp. 65-68 ◽  
Author(s):  
Fady Refaat Elsayed ◽  
Norbert Hort ◽  
Mario Alberto Salgado Ordorica ◽  
Karl Ulrich Kainer
Keyword(s):  
Magnesium Alloys ◽  
Casting Process ◽  
Mold Temperature ◽  
Holding Time ◽  
Permanent Mold ◽  
Melt Temperature ◽  
Cast Part ◽  
Mold Casting ◽  
Permanent Mold Castings ◽  
Inhomogeneous Properties

Permanent mold casting is a well-established route for casting large magnesium alloys components. Casting parameters like superheat, mold temperature, and holding time can often result in inhomogeneous properties, porosity, and segregation problems in the cast part. In order to optimize the casting process, control of the casting parameters including mold temperatures and holding times is essential to promote directional solidification, and ensure defect free homogenous structure. Binary Mg-9wt.%Al and Mg-10wt.%Gd alloys were used to investigate the effect of casting parameters such as melt temperature and holding time on the part macro and microstructure.

scholarly journals The Most Massive galaxy Clusters (M2C) across cosmic time: link between radial total mass distribution and dynamical state

2019 ◽  
Vol 628 ◽  
pp. A86 ◽  
Author(s):  
I. Bartalucci ◽  
M. Arnaud ◽  
G. W. Pratt ◽  
J. Démoclès ◽  
L. Lovisari
Keyword(s):  
Total Mass ◽  
Large Scale ◽  
Cosmic Time ◽  
High Mass ◽  
Shift Parameter ◽  
Dynamical State ◽  
Centroid Shift ◽  
Mass Profile ◽  
The One ◽  
Mass Profiles

We study the dynamical state and the integrated total mass profiles of 75 massive (M500 > 5 × 1014 M⊙) Sunyaev–Zeldovich(SZ)-selected clusters at 0.08 <  z <  1.1. The sample is built from the Planck catalogue, with the addition of four SPT clusters at z >  0.9. Using XMM-Newton imaging observations, we characterise the dynamical state with the centroid shift ⟨w⟩, the concentration CSB, and their combination, M, which simultaneously probes the core and the large-scale gas morphology. Using spatially resolved spectroscopy and assuming hydrostatic equilibrium, we derive the total integrated mass profiles. The mass profile shape is quantified by the sparsity, that is the ratio of M500 to M2500, the masses at density contrasts of 500 and 2500, respectively. We study the correlations between the various parameters and their dependence on redshift. We confirm that SZ-selected samples, thought to most accurately reflect the underlying cluster population, are dominated by disturbed and non-cool core objects at all redshifts. There is no significant evolution or mass dependence of either the cool core fraction or the centroid shift parameter. The M parameter evolves slightly with z, having a correlation coefficient of ρ = −0.2 ± 0.1 and a null hypothesis p-value of 0.01. In the high-mass regime considered here, the sparsity evolves minimally with redshift, increasing by 10% between z <  0.2 and z >  0.55, an effect that is significant at less than 2σ. In contrast, the dependence of the sparsity on dynamical state is much stronger, increasing by a factor of ∼60% from the one third most relaxed to the one third most disturbed objects, an effect that is significant at more than 3σ. This is the first observational evidence that the shape of the integrated total mass profile in massive clusters is principally governed by the dynamical state and is only mildly dependent on redshift. We discuss the consequences for the comparison between observations and theoretical predictions.

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