scholarly journals A Direct Entropic Approach to Uniform and Spatially Continuous Dynamical Models of Thermoelectric Devices

2014 ◽  
Vol 1 (3-4) ◽  
Author(s):  
Hans U. Fuchs

AbstractIf we accept temperature and entropy as primitive quantities, we can construct a direct approach to a dynamical thermal theory of spatially continuous and uniform processes. The theory of uniform models serves as a simple entry point for learners of modern thermodynamics. Such models can be applied fruitfully to an understanding of (the dynamics of) thermoelectric processes and devices. Entropy, temperature, charge, and voltage allow us to describe the role of energy concisely, and constitutive quantities can be given their natural entropic interpretation. In this paper, aggregate dynamical models of a Peltier device will be created and simulations will be compared to non-steady-state experimental data. Such overall models give us a simple image of the transport of charge and transport, production, and storage of entropy and can be easily extended to the spatially continuous case. Process diagrams for a uniform model can be used to visualize these processes and the role of energy. Device efficiency can be easily read from the model. Apart from external parameters such as load resistances or temperature differences, it depends upon three parameters of the device: internal electric resistance, entropy conductance, and Seebeck coefficient. The Second Law efficiency of a generator suggests how to define the figure of merit (

Author(s):  
Lidiya Derbenyova

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.


2021 ◽  
Author(s):  
Fabrice Cognasse ◽  
Kathryn Hally ◽  
Sebastien Fauteux-Daniel ◽  
Marie-Ange Eyraud ◽  
Charles-Antoine Arthaud ◽  
...  

AbstractAside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 450
Author(s):  
Chao Wang ◽  
Ravi P. Agarwal

As an effective tool to unify discrete and continuous analysis, time scale calculus have been widely applied to study dynamic systems in both theoretical and practical aspects. In addition to such a classical role of unification, the dynamic equations on time scales have their own unique features which the difference and differential equations do not possess and these advantages have been highlighted in describing some complicated dynamical behavior in the hybrid time process. In this review article, we conduct a survey of abstract analysis and applied dynamic equations on hybrid time scales, some recent main results and the related developments on hybrid time scales will be reported and the future research related to this research field is discussed. The results presented in this article can be extended and generalized to study both pure mathematical analysis and real applications such as mathematical physics, biological dynamical models and neural networks, etc.


2021 ◽  
Vol 26 (3) ◽  
pp. 2626-2630
Author(s):  
EVELINA MILCHEVA MARINOVA ◽  
◽  
DIMITAR STOIMENOV DABOV ◽  
YANI TODOROV ZDRAVKOV ◽  
EMILIA KRASIMIROVA NASEVA ◽  
...  

Objective: The purpose of our research is to emphasize the role of underestimated predisposing conditions for microbial keratitis in contact lens users, to draw attention to the complications of wearing contact lenses without ophthalmic examination, and to offer a short questionnaire for fast and easy estimation of the risk factors for bacterial keratitis. Methods: A series of 23 cases of healthy young individuals, treated for bacterial keratitis, provoked а research on the predisposing factors for its development. Results: 55% of the patients had started to wear contact lenses without specific examination. 75% had made mistakes in the hygiene and storage of the lenses. We identified risk factors for development of bacterial keratitis in all cases. Conclusions: A thorough anamnesis and ophthalmic examination are crucial in decision making about contact lens wearing because they could reveal some of the predisposing conditions for the occurrence of ocular complications. The usage of contact lenses without a prescription poses health risks and could have a negative impact on the social and healthcare system.


1997 ◽  
Vol 60 (9) ◽  
pp. 1029-1033 ◽  
Author(s):  
NORMA S. LÁZARO ◽  
ANITA TIBANA ◽  
ERNESTO HOFER

Tonsils and inguinal, mesenteric, and prescapular lymph node samples collected from 115 swine carcasses from two abattoirs and a family-run operation in the State of Rio de Janeiro, Brazil, were cultured for the presence of Salmonella species. Salmonella spp. were detected in 40 (34.8%) of the swine samples with the following distribution; tonsils (31/40, 77.5%), mesenteric lymph nodes (16/40, 40.0%), inguinal lymph nodes, (9/40, 22.5%), and prescapular lymph nodes (7/40, 17.5%), Scalding tank water and environmental swabs collected from the abattoirs were also analyzed. Salmonella spp. were recovered from 13 of 51 (22.5%) of the environmental samples from one of the two abattoirs, none from those from the other abattoir. Salmonella spp. were recovered from the evisceration tables (5/11, 45.5%), the killing room (3/10, 30.0%), the holding pen (2/10, 20.0%), the butchering saw (2/10, 20.0%), and the scalding tank (1/10, 10.0%). The most frequently detected serovar was Salmonella Muenster. The results show the necessity of adopting more effective hygienic measures in the abattoirs as well as in the areas where swine are raised in order to reduce the role of abattoirs and storage facilities in the spread of Salmonella contamination.


2001 ◽  
Vol 24 (1) ◽  
pp. 132-133
Author(s):  
Sergio Morra

I compare the concepts of “activation” and “storage” as foundations of short-term memory, and suggest that an attention-based view of STM does not need to posit specialized short-term stores. In particular, no compelling evidence supports the hypothesis of time-limited stores. Identifying sources of activation, examining the role of activated procedural knowledge, and studying working memory development are central issues in modelling capacity-limited focal attention.


2009 ◽  
Vol 28 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Petros Sountoulides ◽  
Marleen M. van Dijk ◽  
Hessel Wijkstra ◽  
Jean J. M. C. H. de la Rosette ◽  
Martin Christian Michel

2003 ◽  
Vol 763 ◽  
Author(s):  
U. Rau ◽  
M. Turcu

AbstractNumerical simulations are used to investigate the role of the Cu-poor surface defect layer on Cu(In, Ga)Se2 thin-films for the photovoltaic performance of ZnO/CdS/Cu(In, Ga)Se2 heterojunction solar cells. We model the surface layer either as a material which is n-type doped, or as a material which is type-inverted due to Fermi-level pinning by donor-like defects at the interface with CdS. We further assume a band gap widening of this layer with respect to the Cu(In, Ga)Se2 bulk. This feature turns out to represent the key quality of the Cu(In, Ga)Se2 surface as it prevents recombination at the absorber/CdS buffer interface. Whether the type inversion results from n-type doping or from Fermi-level pinning is only of minor importance as long as the surface layer does not imply a too large number of excess defects in its bulk or at its interface with the normal absorber. With increasing number of those defects an n-type layer proofs to be less sensitive to material deterioration when compared to the type-inversion by Fermi-level pinning. For wide gap chalcopyrite solar cells the internal valence band offset between the surface layer and the chalcopyrite appears equally vital for the device efficiency. However, the unfavorable band-offsets of the ZnO/CdS/Cu(In, Ga)Se2 heterojunction limit the device efficiency because of the deterioration of the fill factor.


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