scholarly journals A Brief History of the T4 Radiation Law

2009 ◽  
Author(s):  
John Crepeau
Keyword(s):  
Heat Exchange ◽  
Electromagnetic Radiation ◽  
Far Infrared ◽  
Working Fluid ◽  
Radiative Heat Exchange ◽  
Carnot Cycle ◽  
Max Planck ◽  
University Of Berlin ◽  
The Individual ◽  
The University

Since the 1700s, natural philosophers understood that heat exchange between two bodies was not precisely linearly dependent on the temperature difference, and that at high temperatures the discrepancy became greater. Over the years, many models were developed with varying degrees of success. The lack of success was due to the difficulty obtaining accurate experimental data, and a lack of knowledge of the fundamental mechanisms underlying radiation heat exchange. Josef Stefan, of the University of Vienna, compiled data taken by a number of researchers who used various methods to obtain their data, and in 1879 proposed a unique relation to model the dependence of radiative heat exchange on the temperature: the T4 law. Stefan’s model was met with some skepticism and was not widely accepted by his colleagues. His former student, Ludwig Boltzmann, who by then had taken a position at the University of Graz in Austria, felt that there was some truth to the empirical model proposed by his mentor. Boltzmann proceeded to show in 1884, treating electromagnetic radiation as the working fluid in a Carnot cycle, that in fact the T4 law was correct. By the time that Boltzmann published his thermodynamic derivation of the radiation law, physicists became interested in the fundamental nature of electromagnetic radiation and its relation to energy, specifically determining the frequency distribution of blackbody radiation. Among this group of investigators was Wilhelm Wien, working at Physikalisch-Technische Reichsanstalt in Charlottenburg, Berlin. He proposed a relation stating that the wavelength at which the maximum amount of radiation was emitted occurred when the product of the wavelength and the temperature was equal to a constant. This became known as Wien’s Displacement Law, which he deduced this by imagining an expanding and contracting cavity, filled with radiation. Later, he combined his Displacement Law with the T4 law to give a blackbody spectrum which was accurate over some ranges, but diverged in the far infrared. Max Planck, at the University of Berlin, built on Wien’s model but, as Planck himself stated, “the energy of radiation is distributed in a completely irregular manner among the individual partial vibrations...” This “irregular” or discrete treatment of the radiation became the basis for quantum mechanics and a revolution in physics. This paper will present brief biographies of the four pillars of the T4 radiation law, Stefan, Boltzmann, Wien and Planck, and outline the methodologies used to obtain their results.

Near-Field Radiative Heat Exchange Analysis of a Spacecraft Waste Heat Converter Design

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Laurie Y. Carrillo ◽  
Yildiz Bayazitoglu
Keyword(s):  
Heat Exchange ◽  
Radiative Heat ◽  
Waste Heat ◽  
Thermal Environment ◽  
Near Field ◽  
Electrical Energy ◽  
Radiative Heat Exchange ◽  
Carnot Cycle ◽  
Field Plane ◽  
Cycle Efficiency

This paper presents a new design to convert spacecraft waste heat to electrical energy. The proposed device utilizes near-field radiative heat transfer incorporated with pyroelectric materials. To generate electricity, the pyroelectric materials are cyclically heated using spacecraft waste heat and cooled by the thermal environment of deep space (∼2.7 K). Near-field plane-to-plane radiative heat exchange within the device is calculated using a modified sphere-to-plane asymptotic approximation. This method is superimposed on multiple spheres to approximate a plane-to-plane environment. Silica and lithium fluoride coatings are considered in this study to maximize the near-field heat exchange. The efficiency of the device is 17% and 32% when compared to the Carnot cycle efficiency and the Curzon-Ahlborn efficiency, respectively. Initial results indicate that the device is promising but requires further development before it is manufactured for operational use. Suggestions for possible future developments to enhance the design are presented.

C–O Ring Construction: The Georg Synthesis of Oximidine II

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Max Planck ◽  
Enantiomerically Pure ◽  
Michael Adduct ◽  
University Of Oxford ◽  
Mo Catalyst ◽  
Peking University ◽  
Duke University ◽  
The Individual ◽  
The University ◽  
Academy Of Sciences

Chun-Bao Miao and Hai-Tao Yang of Changzhou University constructed (J. Org. Chem. 2011, 76, 9809) the oxetane 2 by exposing the Michael adduct 1 to I2 and air. Huanfeng Jiang of the South China University of Science and Technology carboxylated (Org. Lett. 2011, 13, 5520) the alkyne 3 in the presence of a nitrile to give the three-component coupled product 4. Alois Fürstner of the Max-Planck-Institut Mülheim cyclized (Angew. Chem. Int. Ed. 2011, 50, 7829) 5 with a Mo catalyst, released in situ from a stable precursor, to give 6 in high ee. Hiromichi Fujioka of Osaka University rearranged (Chem. Commun. 2011, 47, 9197) 7 to the cyclic aldehyde, largely as the less stable diastereomer 8. Edward A. Anderson of the University of Oxford cyclized (Angew. Chem. Int. Ed. 2011, 50, 11506) 9 to 10 with excellent stereochemical fidelity. Similarly, Michal Hocek of the Academy of Sciences of the Czech Republic, Andrei V. Malkov, now at Loughborough University, and Pavel Kocovsky of the University of Glasgow combined (J. Org. Chem. 2011, 76, 7781) the individual enantiomers of 11 and 12 to give 13 as single enantiomerically pure diastereomers. Daniel Romo of Texas A&M University cyclized (Angew. Chem. Int. Ed. 2011, 50, 7537) the bromo ester 14 to the lactone 15. Xin-Shan Ye of Peking University condensed (Synlett 2011, 2410) the sulfone 16 with 17 to give the sulfone 18, with high diastereocontrol. Jiyong Hong of Duke University found (Org. Lett. 2011, 13, 5816) that 19 could be cyclized to either diastereomer of 20 by judicious optimization of the reaction conditions. Stacey E. Brenner-Moyer of Brooklyn College showed (Org. Lett. 2011, 13, 6460) that cyclization of racemic 21 in the presence of 22 and the Hayashi catalyst delivered an ~1:1 mixture of 23 and 24, each with good stereocontrol. Kyoko Nakagawa-Goto of the University of North Carolina showed (Synlett 2011, 1413) that the MOM ether 25, prepared in high de by Evans alkylation, cyclized efficiently to 26. Armen Zakarian of the University of California Santa Barbara cyclized (Org. Lett. 2011, 13, 3636) 27, readily prepared in high ee by asymmetric Henry addition, to the enone 28.

‘A Routh O’ Auld Nick-Nackets’ – the antiquarian collection of John Rae

2015 ◽  
Vol 36-37 (1) ◽  
pp. 163-183
Author(s):  
Paul Taylor
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
Social Context ◽  
Moral Education ◽  
The United States ◽  
Representative Case ◽  
National Museums ◽  
The Individual ◽  
The University

John Rae, a Scottish antiquarian collector and spirit merchant, played a highly prominent role in the local natural history societies and exhibitions of nineteenth-century Aberdeen. While he modestly described his collection of archaeological lithics and other artefacts, principally drawn from Aberdeenshire but including some items from as far afield as the United States, as a mere ‘routh o’ auld nick-nackets' (abundance of old knick-knacks), a contemporary singled it out as ‘the best known in private hands' (Daily Free Press 4/5/91). After Rae's death, Glasgow Museums, National Museums Scotland, the University of Aberdeen Museum and the Pitt Rivers Museum in Oxford, as well as numerous individual private collectors, purchased items from the collection. Making use of historical and archive materials to explore the individual biography of Rae and his collection, this article examines how Rae's collecting and other antiquarian activities represent and mirror wider developments in both the ‘amateur’ antiquarianism carried out by Rae and his fellow collectors for reasons of self-improvement and moral education, and the ‘professional’ antiquarianism of the museums which purchased his artefacts. Considered in its wider nineteenth-century context, this is a representative case study of the early development of archaeology in the wider intellectual, scientific and social context of the era.

IMAGERY AND EMOTIONS IN THE PIANO PIECE „THE SICK DOLL“ FROM CHILDREN’S ALBUM OF P . I TCHAIKOVSKY

2020 ◽  
Vol 11 (1) ◽  
pp. 110-113
Author(s):  
Smilena Smilkova ◽  
Keyword(s):  
At Risk ◽  
Social Work ◽  
Short Story ◽  
Special Educational Needs ◽  
Social Pedagogy ◽  
Sound Image ◽  
The Individual ◽  
The Right ◽  
The University ◽  
Art Pedagogy

The proposed material examines the creative task of students majoring in Social Pedagogy at the University „Prof. Dr. Assen Zlatarov“ in Burgas, and studying the discipline Art Pedagogy – Part 1 – Music. In the course of the lecture course students get acquainted with the elements of musical expression, as a means of figurative representations and impact of music, with different techniques concerning individual musical activities, with the endless and diverse opportunities that music provides in the use of art pedagogy for social work teachers.Verbal interpretation of music is a necessary component when working with children with special educational needs, at risk and in the norm. Looking at Tchaikovsky’s short and extremely figurative piano piece „The Sick Doll“ from his charming „Children’s Album“, in the form of a short story, tale or essay, students express their personal vision, feeling and transformation of the musical image. The aim of the task is to transcribe the sound image into a verbal one. This requires speed, flexibility and logic in thinking, through imagination and creativity in its manifestation. Children love to listen, especially when they are involved. In search of the right way to solve problems and situations, future social educators could successfully benefit from the conversion of sound into words, according to the needs and deficits of the individual or group.

A University Education

2017 ◽  
Author(s):  
David Willetts
Keyword(s):  
Higher Education ◽  
Modern Society ◽  
University Education ◽  
Modern World ◽  
Controversial Issues ◽  
The Us ◽  
The Individual ◽  
The University ◽  
First Time ◽  
The Relationship

Universities have a crucial role in the modern world. In England, entrance to universities is by nation-wide competition which means English universities have an exceptional influence on schools--a striking theme of the book. This important book first investigates the university as an institution and then tracks the individual on their journey to and through university. In A University Education, David Willetts presents a compelling case for the ongoing importance of the university, both as one of the great institutions of modern society and as a transformational experience for the individual. The book also makes illuminating comparisons with higher education in other countries, especially the US and Germany. Drawing on his experience as UK Minister for Universities and Science from 2010 to 2014, the author offers a powerful account of the value of higher education and the case for more expansion. He covers controversial issues in which he was involved from access for disadvantaged students to the introduction of L9,000 fees. The final section addresses some of the big questions for the future, such as the the relationship between universities and business, especially in promoting innovation.. He argues that the two great contemporary trends of globalisation and technological innovation will both change the university significantly. This is an authoritative account of English universities setting them for the first time in their new legal and regulatory framework.

scholarly journals Action and Entropy in Heat Engines: An Action Revision of the Carnot Cycle

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 860
Author(s):  
Ivan R. Kennedy ◽  
Migdat Hodzic
Keyword(s):  
Heat Engine ◽  
Working Fluid ◽  
Field Energy ◽  
Carnot Cycle ◽  
Gibbs Potential ◽  
Atmospheric Gases ◽  
Temperature Dependent ◽  
Expansion Phase ◽  
Heat Engines ◽  
The Difference

Despite the remarkable success of Carnot’s heat engine cycle in founding the discipline of thermodynamics two centuries ago, false viewpoints of his use of the caloric theory in the cycle linger, limiting his legacy. An action revision of the Carnot cycle can correct this, showing that the heat flow powering external mechanical work is compensated internally with configurational changes in the thermodynamic or Gibbs potential of the working fluid, differing in each stage of the cycle quantified by Carnot as caloric. Action (@) is a property of state having the same physical dimensions as angular momentum (mrv = mr2ω). However, this property is scalar rather than vectorial, including a dimensionless phase angle (@ = mr2ωδφ). We have recently confirmed with atmospheric gases that their entropy is a logarithmic function of the relative vibrational, rotational, and translational action ratios with Planck’s quantum of action ħ. The Carnot principle shows that the maximum rate of work (puissance motrice) possible from the reversible cycle is controlled by the difference in temperature of the hot source and the cold sink: the colder the better. This temperature difference between the source and the sink also controls the isothermal variations of the Gibbs potential of the working fluid, which Carnot identified as reversible temperature-dependent but unequal caloric exchanges. Importantly, the engine’s inertia ensures that heat from work performed adiabatically in the expansion phase is all restored to the working fluid during the adiabatic recompression, less the net work performed. This allows both the energy and the thermodynamic potential to return to the same values at the beginning of each cycle, which is a point strongly emphasized by Carnot. Our action revision equates Carnot’s calorique, or the non-sensible heat later described by Clausius as ‘work-heat’, exclusively to negative Gibbs energy (−G) or quantum field energy. This action field complements the sensible energy or vis-viva heat as molecular kinetic motion, and its recognition should have significance for designing more efficient heat engines or better understanding of the heat engine powering the Earth’s climates.

Schleiermachers Vorlesungen über das Leben Jesu – Die Einleitungen der Kollegien von 1819/20 und 1829/30. Zwei Teileditionen von Hörernachschriften

2020 ◽  
Vol 27 (2) ◽  
pp. 262-310
Author(s):  
Matthias Hofmann
Keyword(s):  
Critical Edition ◽  
Friedrich Schleiermacher ◽  
University Of Berlin ◽  
The University

Abstract Between 1819 and 1832 Friedrich Schleiermacher was giving lectures on the life of Jesus at the University of Berlin. The following article includes two partial editions, which document the introductory parts of the lectures from 1819/20 and 1829/30. Both are based on manuscripts written by Schleiermacher’s listeners. Especially to explore the development of Schleiermacher’s conceptual considerations this two partial editions should be a useful addition to the new critical edition of Schleiermacher’s Vorlesungen über das Leben Jesu published in 2018 by Walter Jaeschke (KGA II/15).

scholarly journals The development of the concept of uniform convergence in Karl Weierstrass’s lectures and publications between 1861 and 1886

2020 ◽  
Author(s):  
Klaus Viertel
Keyword(s):  
Uniform Convergence ◽  
Present Article ◽  
Elliptic Functions ◽  
Continuity Theorem ◽  
University Of Berlin ◽  
Lecture Notes ◽  
History Of ◽  
Lecture Courses ◽  
The University ◽  
Independent Branch

AbstractThe history of uniform convergence is typically focused on the contributions of Cauchy, Seidel, Stokes, and Björling. While the mathematical contributions of these individuals to the concept of uniform convergence have been much discussed, Weierstrass is considered to be the actual inventor of today’s concept. This view is often based on his well-known article from 1841. However, Weierstrass’s works on a rigorous foundation of analytic and elliptic functions date primarily from his lecture courses at the University of Berlin up to the mid-1880s. For the history of uniform convergence, these lectures open up an independent branch of development that is disconnected from the approaches of the previously mentioned authors; to my knowledge, Weierstraß never explicitly referred to Cauchy’s continuity theorem (1821 or 1853) or to Seidel’s or Stokes’s contributions (1847). In the present article, Weierstrass’s contributions to the development of uniform convergence will be discussed, mainly based on lecture notes made by Weierstrass’s students between 1861 and the mid-1880s. The emphasis is on the notation and the mathematical rigor of the introductions to the concept, leading to the proposal to re-date the famous 1841 article and thus Weierstrass’s first introduction of uniform convergence.

Canada’s changing innovation landscape

2021 ◽  
Author(s):  
Md. Razib Alam ◽  
Bonwoo Koo ◽  
Brian Paul Cozzarin
Keyword(s):  
The United States ◽  
Destination Country ◽  
Firm Level ◽  
Individual Level ◽  
Patent Classification ◽  
The Usa ◽  
The Government ◽  
The Individual ◽  
The University ◽  
Over Time

Abstract Our objective is to study Canada’s patenting activity over time in aggregate terms by destination country, by assignee and destination country, and by diversification by country of destination. We collect bibliographic patent data from the Canadian Intellectual Property Office and the United States Patent and Trademark Office. We identify 19,957 matched Canada–US patents, 34,032 Canada-only patents, and 43,656 US-only patents from 1980 to 2014. Telecommunications dominates in terms of International Patent Classification technologies for US-only and Canada–US patents. At the firm level, the greatest number of matched Canada–US patents were granted in the field of telecommunications, at the university level in pharmaceuticals, at the government level in control and instrumentation technology, and at the individual level in civil engineering. We use entropy to quantify technological diversification and find that diversification indices decline over time for Canada and the USA; however, all US indices decline at a faster rate.

Round Table Discussion

PEDIATRICS ◽  
1952 ◽  
Vol 9 (3) ◽  
pp. 343-355
Author(s):  
HARLAN BLOOMER ◽  
CHARLES STROTHER ◽  
BURTIS B. BREESE ◽  
A. L. GLEASON
Keyword(s):  
Round Table ◽  
Speech Disorders ◽  
Child Growth ◽  
Speech Pathology ◽  
Round Table Discussion ◽  
General Plan ◽  
Close Relationship ◽  
The Individual ◽  
General Aspects ◽  
The University

Chairman Bloomer: In leading this round table I have with me Dr. Charles Strother, Professor of Clinical Psychology in the College of Medicine of the University of Washington at Seattle. I am from the University of Michigan Speech Clinic in Ann Arbor. We are very glad to be with you at this round table because it suggests the close relationship between the fields of speech pathology and pediatrics. We come to the American Academy of Pediatrics as representatives of the American Speech and Hearing Association which is the national organization for professional people interested in the study of speech disorders, their causes and their methods of treatment. Perhaps you are familiar with the official publication of the Association, the Journal of Speech and Hearing Disorders. We bring you greetings from the Association. I think you may be interested in a brief outline of our general plan of discussion for the afternoon. The first part of our discussion will review the importance of a knowledge of speech disorders to specialists in pediatrics. Next we shall discuss in some detail the nature of these disorders and the etiologic factors which are frequently encountered, and then we shall suggest methods for handling the speech problems which the individual child may present. We shall be glad to have your participation, your questions, and your comments at any time during our discussion. We feel that this subject is particularly timely because of the steadily increasing interest of pediatricians in the general aspects of child growth and development rather than in only the medical care of children.

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