Defining Computational Emissivity Uncertainty Over Large Temperature Scales Due to Surface Evolution

Author(s):  
Humberto Silva ◽  
Brantley Mills ◽  
Benjamin Schroeder ◽  
Ryan Keedy ◽  
Kyle Smith

Abstract There is a dearth in the literature on how to capture the uncertainty generated by material surface evolution in thermal modeling. This leads to inadequate or highly variable uncertainty representations for material properties, specifically emissivity when minimal information is available. Inaccurate understandings of prediction uncertainties may lead decision makers to incorrect conclusions, so best engineering practices should be developed for this domain. In order to mitigate the aforementioned issues, this study explores different strategies to better capture the thermal uncertainty response of engineered systems exposed to fire environments via defensible emissivity uncertainty characterizations that can be easily adapted to a variety of use cases. Two unique formulations (one physics-informed and one mathematically based) are presented. The formulations and methodologies presented herein are not exhaustive but more so are a starting point and give the reader a basis for how to customize their uncertainty definitions for differing fire scenarios and materials. Lastly, the impact of using this approach versus other commonly used strategies and the usefulness of adding rigor to material surface evolution uncertainty is demonstrated.

2010 ◽  
Vol 65 ◽  
pp. 124-129
Author(s):  
Anne-Sophie Andreani ◽  
Francis Rebillat ◽  
Angéline Poulon-Quintin

The solar furnace is a heating system based on concentrated sunrays on the material surface. It is an original method for testing ultra-high-temperature ceramics (UHTC) at very high temperature (above 2200°C) in air with an exposure time of several minutes. In this study, the solar flux is 15.5 MW.m-2 with a homogeneous exposed surface of 10 mm2. A large temperature-time composition parameters space is covered producing a large set of oxidized samples. Massive cylindrical specimens of UHTC materials are prepared by spark plasma sintering at 1900°C under a pressure of 100 MPa for 5 minutes. Then, samples are tested in air from 1750°C up to 2400°C with dwell times varied from 1 to 5 min. During oxidation of ZrB2-SiC (20%vol) material, the formed and known complex oxide scale identified from literature is easily reproduced using this method. It consists of a thin outer silica layer and zirconia columnar layer with a region of SiC depleted zone in ZrB2 phase. The impact of the reduction of Si content is quantified and the coating ZrB2-20%vol SiC is tested as protection on C-C composite.


2014 ◽  
Vol 55 (1-2) ◽  
pp. 131-144
Author(s):  
Suzanne Marie Francis

By the time of his death in 1827, the image of Beethoven as we recognise him today was firmly fixed in the minds of his contemporaries, and the career of Liszt was beginning to flower into that of the virtuosic performer he would be recognised as by the end of the 1830s. By analysing the seminal artwork Liszt at the Piano of 1840 by Josef Danhauser, we can see how a seemingly unremarkable head-and-shoulders bust of Beethoven in fact holds the key to unlocking the layers of commentary on both Liszt and Beethoven beneath the surface of the image. Taking the analysis by Alessandra Comini as a starting point, this paper will look deeper into the subtle connections discernible between the protagonists of the picture. These reveal how the collective identities of the artist and his painted assembly contribute directly to Beethoven’s already iconic status within music history around 1840 and reflect the reception of Liszt at this time. Set against the background of Romanticism predominant in the social and cultural contexts of the mid 1800s, it becomes apparent that it is no longer enough to look at a picture of a composer or performer in isolation to understand its impact on the construction of an overall identity. Each image must be viewed in relation to those that preceded and came after it to gain the maximum benefit from what it can tell us.


2000 ◽  
Vol 151 (12) ◽  
pp. 502-507
Author(s):  
Christian Küchli

Are there any common patterns in the transition processes from traditional and more or less sustainable forest management to exploitative use, which can regularly be observed both in central Europe and in the countries of the South (e.g. India or Indonesia)? Attempts were made with a time-space-model to typify those force fields, in which traditional sustainable forest management is undermined and is then transformed into a modern type of sustainable forest management. Although it is unlikely that the history of the North will become the future of the South, the glimpse into the northern past offers a useful starting point for the understanding of the current situation in the South, which in turn could stimulate the debate on development. For instance, the patterns which stand behind the conflicts on forest use in the Himalayas are very similar to the conflicts in the Alps. In the same way, the impact of socio-economic changes on the environment – key word ‹globalisation› – is often much the same. To recognize comparable patterns can be very valuable because it can act as a stimulant for the search of political, legal and technical solutions adapted to a specific situation. For the global community the realization of the way political-economic alliances work at the head of the ‹globalisationwave›can only signify to carry on trying to find a common language and understanding at the negotiation tables. On the lee side of the destructive breaker it is necessary to conserve and care for what survived. As it was the case in Switzerland these forest islands could once become the germination points for the genesis of a cultural landscape, where close-to-nature managed forests will constitute an essential element.


2010 ◽  
pp. 487-495
Author(s):  
Martin Bruhns ◽  
Peter Glaviè ◽  
Arne Sloth Jensen ◽  
Michael Narodoslawsky ◽  
Giorgio Pezzi ◽  
...  

The paper is based on the results of international project entitled “Towards Sustainable Sugar Industry in Europe (TOSSIE)”. 33 research topics of major importance to the sugar sector are listed and briefly described, and compared with research priorities of the European Technology Platforms: “Food for Life”, “Sustainable Chemistry”, “Biofuels”, and “Plant for the Future”. Most topics are compatible with the research themes included in the COOPERATION part of the 7th Framework Program of the EU (2007-2013). However, some topics may require long-term R&D with the time horizon of up to 15 years. The list of topics is divided into four parts: Sugar manufacturing, Applications of biotechnology and biorefinery processing, Sugarbeet breeding and growing, Horizontal issues. Apart from possible use of the list by policy- and decision makers with an interest in sugarbeet sector, the description of each research topic can be used as a starting point in setting up a research project or other R&D activities.


2020 ◽  
Author(s):  
Helena S. Wisniewski

With companies now recognizing how artificial intelligence (AI), digitalization, the internet of things (IoT), and data science affect value creation and the maintenance of a competitive advantage, their demand for talented individuals with both management skills and a strong understanding of technology will grow dramatically. There is a need to prepare and train our current and future decision makers and leaders to have an understanding of AI and data science, the significant impact these technologies are having on business, how to develop AI strategies, and the impact all of this will have on their employees’ roles. This paper discusses how business schools can fulfill this need by incorporating AI into their business curricula, not only as stand-alone courses but also integrated into traditional business sequences, and establishing interdisciplinary efforts and collaborative industry partnerships. This article describes how the College of Business and Public Policy (CBPP) at the University of Alaska Anchorage is implementing multiple approaches to meet these needs and prepare future leaders and decision makers. These approaches include a detailed description of CBPP’s first AI course and related student successes, the integration of AI into additional business courses such as entrepreneurship and GSCM, and the creation of an AI and Data Science Lab in partnership with the College of Engineering and an investment firm.


Author(s):  
Daniel B. Kelly

This chapter analyzes how law and economics influences private law and how (new) private law is influencing law and economics. It focuses on three generation or “waves” within law and economics and how they approach private law. In the first generation, many scholars took the law as a starting point and attempted to use economic insights to explain, justify, or reform legal doctrines, institutions, and structures. In the second generation, the “law” at times became secondary, with more focus on theory and less focus on doctrines, institutions, and structures. But this generation also relied increasingly on empirical analysis. In the third generation, which includes scholars in the New Private Law (NPL), there has been a resurgence of interest in the law and legal institutions. To be sure, NPL scholars analyze the law using various approaches, with some more and some less predisposed to economic analysis. However, economic analysis will continue to be a major force on private law, including the New Private Law, for the foreseeable future. The chapter considers three foundational private law areas: property, contracts, and torts. For each area, it discusses the major ideas that economic analysis has contributed to private law, and surveys contributions of the NPL. The chapter also looks at the impact of law and economics on advanced private law areas, such as business associations, trusts and estates, and intellectual property.


Author(s):  
Ah-Young Park ◽  
Satish Chaparala ◽  
Seungbae Park

Through-silicon via (TSV) technology is expected to overcome the limitations of I/O density and helps in enhancing system performance of conventional flip chip packages. One of the challenges for producing reliable TSV packages is the stacking and joining of thin wafers or dies. In the case of the conventional solder interconnections, many reliability issues arise at the interface between solder and copper bump. As an alternative solution, Cu-Cu direct thermo-compression bonding (CuDB) is a possible option to enable three-dimension (3D) package integration. CuDB has several advantages over the solder based micro bump joining, such as reduction in soldering process steps, enabling higher interconnect density, enhanced thermal conductivity and decreased concerns about intermetallic compounds (IMC) formation. Critical issue of CuDB is bonding interface condition. After the bonding process, Cu-Cu direct bonding interface is obtained. However, several researchers have reported small voids at the bonded interface. These defects can act as an initial crack which may lead to eventual fracture of the interface. The fracture could happen due to the thermal expansion coefficient (CTE) mismatch between the substrate and the chip during the postbonding process, board level reflow or thermal cycling with large temperature changes. In this study, a quantitative assessment of the energy release rate has been made at the CuDB interface during temperature change finite element method (FEM). A parametric study is conducted to analyze the impact of the initial crack location and the material properties of surrounding materials. Finally, design recommendations are provided to minimize the probability of interfacial delamination in CuDB.


2021 ◽  
pp. 194277862110000
Author(s):  
Sheila Margaret McGregor

This article looks at Engels’s writings to show that his ideas about the role of labour in the evolution of human beings in a dialectical relationship between human beings and nature is a crucial starting point for understanding human society and is correct in its essentials. It is important for understanding that we developed as a species on the basis of social cooperation. The way human beings produce and reproduce themselves, the method of historical materialism, provides the basis for understanding how class and women’s oppression arose and how that can explain LGBTQ oppression. Although Engels’s analysis was once widely accepted by the socialist movement, it has mainly been ignored or opposed by academic researchers and others, including geographers, and more recently by Marxist feminists. However, anthropological research from the 1960s and 1970s as well as more recent anthropological and archaeological research provide overwhelming evidence for the validity of Engels’s argument that there were egalitarian, pre-class societies without women’s oppression. However, much remains to be explained about the transition to class societies. Engels’s analysis of the impact of industrial capitalism on gender roles shows how society shapes our behaviour. Engels’s method needs to be constantly reasserted against those who would argue that we are a competitive, aggressive species who require rules to suppress our true nature, and that social development is driven by ideas, not by changes in the way we produce and reproduce ourselves.


Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 468
Author(s):  
Krzysztof Piasecki ◽  
Anna Łyczkowska-Hanćkowiak

In general, the present value (PV) concept is ambiguous. Therefore, behavioural factors may influence on the PV evaluation. The main aim of our paper is to propose some method of soft computing PV evaluated under the impact of behavioural factors. The starting point for our discussion is the notion of the Behavioural PV (BPV) defined as an imprecisely real-valued function of distinguished variables which can be evaluated using objective financial knowledge or subjective behavioural premises. In our paper, a BPV is supplemented with a forecast of the asset price closest to changes. Such BPV is called the oriented BPV (O-BPV). We propose to evaluate an O-BPV by oriented fuzzy numbers which are more useful for portfolio analysis than fuzzy numbers. This fact determines the significance of the research described in this article. O-BPV may be applied as input signal for systems supporting invest-making. We consider here six cases of O-BPV: overvalued asset with the prediction of a rise in its price, overvalued asset with the prediction of a fall in its price, undervalued asset with the prediction of a rise in its price, undervalued asset with the prediction of a fall in its price, fully valued asset with the prediction of a rise in its rice and fully valued asset with the prediction of a fall in its rice. All our considerations are illustrated by numerical examples. Presented examples show the way in which we transform superposition of objective market knowledge and subjective investment opinion into simple return rate.


2021 ◽  
Vol 11 (10) ◽  
pp. 4635
Author(s):  
Marcel Ulrich Ahrens ◽  
Maximilian Loth ◽  
Ignat Tolstorebrov ◽  
Armin Hafner ◽  
Stephan Kabelac ◽  
...  

Decarbonization of the industrial sector is one of the most important keys to reducing global warming. Energy demands and associated emissions in the industrial sector are continuously increasing. The utilization of high temperature heat pumps (HTHPs) operating with natural fluids presents an environmentally friendly solution with great potential to increase energy efficiency and reduce emissions in industrial processes. Ammonia-water absorption–compression heat pumps (ACHPs) combine the technologies of an absorption and vapor compression heat pump using a zeotropic mixture of ammonia and water as working fluid. The given characteristics, such as the ability to achieve high sink temperatures with comparably large temperature lifts and high coefficient of performance (COP) make the ACHP interesting for utilization in various industrial high temperature applications. This work reviews the state of technology and identifies existing challenges based on conducted experimental investigations. In this context, 23 references with capacities ranging from 1.4 kW to 4500 kW are evaluated, achieving sink outlet temperatures from 45 °C to 115 °C and COPs from 1.4 to 11.3. Existing challenges are identified for the compressor concerning discharge temperature and lubrication, for the absorber and desorber design for operation and liquid–vapor mixing and distribution and the choice of solution pump. Recent developments and promising solutions are then highlighted and presented in a comprehensive overview. Finally, future trends for further studies are discussed. The purpose of this study is to serve as a starting point for further research by connecting theoretical approaches, possible solutions and experimental results as a resource for further developments of ammonia-water ACHP systems at high temperature operation.


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