scholarly journals H. B. Reitlinger and the origins of the efficiency at maximum power formula for heat engines

Author(s):  
Alexandre Vaudrey ◽  
François Lanzetta ◽  
Michel Feidt

AbstractEven if not so ancient, the history of the heat engine efficiency at maximum power expression has been yet turbulent. More than a decade after the publication of the seminal article by Curzon and Ahlborn in 1975, two older works by Chambadal and Novikov were rediscovered, both dating from 1957. Then, some years ago, the name of Yvon arose from a textual reference to this famous relation in a conference article published in 1955. Thanks to a historical study of French-written books not published for a long time, and since never translated into other languages, we bring to light in this paper that this relation was actually first proposed by Henri B. Reitlinger in 1929.

2018 ◽  
Vol 98 (5) ◽  
Author(s):  
Sang Hoon Lee ◽  
Jaegon Um ◽  
Hyunggyu Park

1960 ◽  
Vol 28 (4) ◽  
pp. 324-326 ◽  
Author(s):  
C. Finfgeld ◽  
S. Machlup

2016 ◽  
Vol 90 (1-2) ◽  
pp. 1-27
Author(s):  
Giulia Bonacci

Twenty-eight years ago, F.J. van Dijk published in the New West Indian Guide what remained for a long time the only scholarly paper on the Twelve Tribes of Israel. Undoubtedly the largest Rastafari organization both in terms of membership and international expansion, the Twelve Tribes of Israel remains little known in public and academic circles. This article fills two major but closely related gaps in Van Dijk’s seminal article. The first is information on the formation and history of the Twelve Tribes, and the second is how the organization mobilized the return of members to Africa, a cornerstone of Rastafari belief. This article argues that the issue of return to the continent determined the very genesis of the organization and subsequently the development of its eighteen international branches. In its turn, this focus on return to Africa offers another perspective on the internal dynamics of the Rastafari movement, namely the structuring role of Rastafari organizations, a role which challenges the common image of Rastafari as an “acephalous” movement. Exploring the tangible relationship of Rastafari with Ethiopia, through the return to Ethiopia of members of the Twelve Tribes of Israel, offers new insight into the history of the Rastafari movement.


Author(s):  
Т.А. Коныратбай

На протяжении всего ХХ века в фольклористике доминировал так называемый поэтический метод, который занимался определением художественной системы героического эпоса. Вместе с тем все чаще ставился вопрос об отношении эпоса к историческим событиям прошлого. Многие фольклористы и историки, в лице С. Н. Азбелева, Л. И. Емельянова, Н. И. Кравцова, А. А. Петросяна, М. М. Плисецкого, Б. А. Рыбакова начали разрабатывать проблемы историзма в русских былинах. На этой почве в середине 1960-х гг. вспыхнули научные дебаты вокруг этой проблемы – историзма героического эпоса. Несмотря на полемический характер,суждения многих фольклористов оказались на стороне исторического изучения былин. Такая постановка вопроса, с учетом посмертно изданного труда «Экскурсы в теорию и историю славянского эпоса» (1999), оказалась не чуждой самому Б. Н. Путилову, который усердно разрабатывал типологическую теорию. В своих поздних изысканиях автор несколько отошёл от изначальной позиции. На широком фоне исторического изучения былин фольклористы пошли ещё дальше, вычленяя сведения этнического порядка в героическом эпосе. Цель настоящего исследования – определение этнического характера героического эпоса с учетом методологических достижений фольклористики конца ХХ и начала ХХI веков. Актуальность данного направления заключается в том, что несмотря на многочисленные этнонимы, топонимы, гидронимы, антропонимы и т. д., отражённые в героическом эпосе, они долгое время оставались в тени. Историки, опиравшиеся только на достоверные факты, игнорировали подобные сведения, а фольклористы, в свою очередь, считали их объектом историков. Поэтому научно-познавательный процесс подменялся суждением о личном вкладе эпических сказителей, якобы вносивших этническую номенклатуру в героический эпос. С распадом СССР были сняты многие идеологические запреты, связанные с этнической природой казахского эпоса. Это позволило отдельным учёным постсоветского пространства приступить к разработке этнических истоков героического эпоса. Были опубликованы соответствующие материалы, в том числе на страницах настоящего журнала, направленные на изучение этнических сведений в казахском эпосе. Отныне этнический характер эпоса не вызывает больших разногласий. В казахском эпосоведении эта проблема стала разрабатываться более глубже, с использованием методов исследования фольклористики, этнографии и этнологии. В статье приводятся новые сведения и суждения отдельных исследователей методологического порядка. Наряду с общеизвестными трудами вышеуказанных фольклористов в научный обиход вовлекаются герменевтические суждения А. М. Эткинда. Обращено внимание на информативную сущность героического эпоса, определены познавательные возможности синхронного и диахронного методов исследования. Подытоживая материал, автор приходит к заключению, что без этноса нет героического эпоса, а без этнического процесса – эпической традиции. Throughout the 20th century, folkloristics was dominated by the so-called poetic method, which was engaged in determining the artistic system of the heroic epic. At the same time, the question of the attitude of the epic to the historical events of the past was increasingly raised. Many folklorists and historians, represented by S. N. Azbelev, L. I. Emelyanov, N. I. Kravtsov, A. A. Petrosyan, M. M. Plisetsky, B. A. Rybakov, began to develop the problems of historicism in Russian epics. On this ground in the mid-1960s, a scholarly debate broke out around this problem: the historicism of the heroic epic. Despite the polemical nature of the judgment of many folklorists, they were on the side of the historical study of epics. Such a statement of the question, taking into account the posthumously published work “Excursions into the theory and history of the Slavic epic” (1999), turned out to be no stranger to B. N. Putilov himself, who diligently developed typological theory. In his later research, the author somewhat moved away from the original position. Against the broad background of the historical study of epics, folklorists went even further, distinguishing information of the ethnic order in the heroic epic. The purpose of this study was to determine the ethnic nature of the heroic epic, taking into account the methodological achievements of folkloristics of the late 20th and early 21st centuries. The relevance of this direction is that despite the numerous ethnonyms, toponyms, hydronyms, anthroponyms, etc., reflected in the heroic epic, they remained in the shadows for a long time. Historians, relying only on reliable facts, ignored such information, and folklorists, in turn, considered the object of historians. Therefore, the scholarly and cognitive process was replaced by a judgment on the personal contribution of epic storytellers who allegedly contributed ethnic nomenclature to the heroic epic. With the collapse of the USSR, many ideological prohibitions related to the ethnic nature of the Kazakh epic were lifted. This allowed individual scientists of the post-Soviet space to begin developing the ethnic origins of the heroic epic. Relevant materials were published, including on the pages of this publication, aimed at studying ethnic information in the Kazakh epic. From now on, the ethnic nature of the epic does not cause much disagreement. In Kazakh epic studies, this problem began to be developed more deeply, using methods of studying folkloristics, ethnography and ethnology. The article provides new information and judgments of individual researchers of the methodological order. Along with the well-known works of the above folklorists, hermeneutic judgments of A. M. Etkind are involved in scholarly use. Attention was drawn to the informative essence of the heroic epic, the cognitive possibilities of synchronous and diachronic research methods were determined. Summing up the material, the author concludes that without an ethnic group there is no heroic epic, and without an ethnic process – no epic tradition.


Author(s):  
Preety Aneja ◽  

This review aims to study the various theoretical and numerical investigations in the optimization of heat engines. The main focus is to discuss the procedures to derive the efficiency of heat engines under different operating regimes (or optimization criteria) for different models of heat engines such as endreversible models, stochastic models, low-dissipation models, quantum models etc. Both maximum power and maximum efficiency operational regimes are desirable but not economical, so to meet the thermo-ecological considerations, some other compromise-based criteria have been proposed such as Ω criterion (ecological criterion) and efficient power criterion. Thus, heat engines can be optimized to work at an efficiency which may not be the maximum (Carnot) efficiency. The optimization efficiency obtained under each criterion shows a striking universal behaviour in the near-equilibrium regime. We also discussed a multi-parameter combined objective function of heat engines. The optimization efficiency derived from the multi-parameter combined objective function includes a variety of optimization efficiencies, such as the efficiency at the maximum power, efficiency at the maximum efficiency-power state, efficiency at the maximum criterion, and Carnot efficiency. Thus, a comparison of optimization of heat engines under different criteria enables to choose the suitable one for the best performance of heat engine under different conditions.


2015 ◽  
Vol 29 (14) ◽  
pp. 1550086 ◽  
Author(s):  
X. Y. Niu ◽  
X. L. Huang ◽  
Y. F. Shang ◽  
X. Y. Wang

Superposition principle plays a crucial role in quantum mechanics, thus its effects on thermodynamics is an interesting topic. Here, the effects of superpositions of quantum states on isoenergetic cycle are studied. We find superposition can improve the heat engine efficiency and release the positive work condition in general case. In the finite time process, we find the efficiency at maximum power output in superposition case is lower than the nonsuperposition case. This efficiency depends on one index of the energy spectrum of the working substance. This result does not mean the superposition discourages the heat engine performance. For fixed efficiency or fixed power, the superposition improves the power or efficiency respectively. These results show how quantum mechanical properties affect the thermodynamical cycle.


1993 ◽  
Vol 21 (4) ◽  
pp. 337-346 ◽  
Author(s):  
C. Wu ◽  
R. L. Kiang ◽  
V. J. Lopardo ◽  
G. N. Karpouzian

An endoreversible heat engine is an internally reversible and externally irreversible cyclic device which exchanges heat and power with its surroundings. Classical engineering thermodynamics is based on the concept of equilibrium. Time is not considered in the energy interactions between the heat engine and its environment. On the other hand, although rate of energy transfer is taught in heat transfer, the course does not cover heat engines. The finite-time thermodynamics is a newly developing field to fill in the gap between thermodynamics and heat transfer. Two types of engines are modelled in this paper—a reciprocating and a steady flow—with results obtained for maximum power output and efficiency at maximum power. It is shown that the latter is the same for both types of engines but that the maximum value of power production is different.


2000 ◽  
Vol 22 (2) ◽  
pp. 191-216 ◽  
Author(s):  
Matthias Klaes

According to the folk history of transaction costs, the concept is due to a seminal article by Ronald H. Coase, written in the 1930s. Failing to provide an operational framework, Coase's article was neglected for a long time, or so the story continues. In the 1970s, after the limits of the Arrow-Debreu paradigm had become obvious, several authors, including Oliver E. Williamson, Kenneth J. Arrow, Armen A. Alchian, and Harold Demsetz, took up the notion of transaction costs and turned it into a useful analytical tool. Partly responsible for this sudden upsurge of interest was an article by Coase in which he allegedly proposed the now famous “Coase Theorem.”


Migration and Modernities recovers a comparative literary history of migration by bringing together scholars from the US and Europe to explore the connections between migrant experiences and the uneven emergence of modernity. The collection initiates transnational, transcultural and interdisciplinary conversations about migration in the eighteenth and nineteenth centuries, demonstrating how mobility unsettles the geographic boundaries, temporal periodization, and racial categories we often use to organize literary and historical study. Migrants are by definition liminal, and many have existed historically in the spaces between nations, regions or ethnicities. In exploring these spaces, Migration and Modernities also investigates the origins of current debates about belonging, rights, and citizenship. Its chapters traverse the globe, revealing the experiences — real or imagined — of eighteenth- and nineteenth-century migrants, from dispossessed Native Americans to soldiers in South America, Turkish refugees to Scottish settlers. They explore the aesthetic and rhetorical frameworks used to represent migrant experiences during a time when imperial expansion and technological developments made the fortunes of some migrants and made exiles out of others. These frameworks continue to influence the narratives we tell ourselves about migration today and were crucial in producing a distinctively modern subjectivity in which mobility and rootlessness have become normative.


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