Computer Simulation of Solid Electrolyte Fuel Cells

1990 ◽  
Vol 112 (2) ◽  
pp. 114-123 ◽  
Author(s):  
W. R. Dunbar ◽  
R. A. Gaggioli

This paper presents the results of mathematical modeling of the performance of solid electrolyte fuel cells. The system of fundamental physical equations has been solved using a computer program which was developed expressly for this purpose, in order to simulate the performance of arrays of fuel cells for which experimental data exists in the literature. The comparison of experimental data and simulated performance is excellent. The results of the simulation show the influence of each irreversible process within the fuel cell, quantitatively; that is, the relative importance of each source of inefficiency—and the consequent voltage loss—is determined. Because certain rate constants (for diffusion and for chemical kinetics) employed in the model were obtained by regression, it cannot be claimed that the ability to fit the experimental data is a definitive test of the model; more work is needed for that purpose. Nevertheless, it is shown that (a) modeling of fuel cells on the basis of basic physical principles is a worthwhile venture, (b) the model presented here simulates performance well and warrants further development, and (c) it not only simulates the overall performance of the cells, but also provides the important breakdown of the effects of each irreversibility in the cells. Furthermore, specific recommendations are made in this paper for improving the model.

2021 ◽  
Vol 2 ◽  
Author(s):  
Fabian Lenartz ◽  
Marie Dury ◽  
Benjamin Bergmans ◽  
Virginie Hutsemékers ◽  
Valéry Broun ◽  
...  

The increasing availability of low-cost sensors and open source projects make it easier than ever for a maker to build his own air quality node. Nonetheless, depending on one’s goal and its related data quality objective, to customize an existing project or to build a specific printed circuit board may still be very useful. In the framework of the Outdoor and Indoor Exposure project, a portable mini-station has been developed, tested and then used in two experiments: exposure assessment and complementary network measurement. The present paper focuses on the description of the equipment that was designed and prototyped, as well as on the tests that were made in the lab and in the field to evaluate its overall performance and that of its different sensors. Finally, we present what we consider to be its main drawbacks and our perspectives for further development and tests.


Author(s):  
Maximilian Wagner ◽  
Oliver Lorenz ◽  
Felix Paul Lohmann-Richters ◽  
Áron Varga ◽  
Bernd Abel

Solid acid fuel cells operate at intermediate temperatures utilizing a solid electrolyte (CsH2PO4, CDP). However, relatively little is known about the degradation mechanism and the topic is rarely addressed. Phosphate...


Author(s):  
Hao Yuan ◽  
Yun Wang

In this paper, we present analysis of air cathode performance, taking into account both electrode passivation and transport resistance raised by insoluble products. Both effects are theoretically evaluated and compared. Validation is carried out against experimental data under low currents. The effects of electrode pore structure, such as porosity and tortuosity, on both the influence of insoluble precipitates and discharge capability are investigated.


2015 ◽  
Vol 370 (1681) ◽  
pp. 20140267 ◽  
Author(s):  
Paul J. Ferraro ◽  
Merlin M. Hanauer

To develop effective protected area policies, scholars and practitioners must better understand the mechanisms through which protected areas affect social and environmental outcomes. With strong evidence about mechanisms, the key elements of success can be strengthened, and the key elements of failure can be eliminated or repaired. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. This essay assesses what mechanisms have been hypothesized, what empirical evidence exists for their relative contributions and what advances have been made in the past decade for estimating mechanism causal effects from non-experimental data. The essay concludes with a proposed agenda for building an evidence base about protected area mechanisms.


2016 ◽  
Vol 25 (12) ◽  
pp. 1650101 ◽  
Author(s):  
Luis Augusto Trevisan

In the present work, the effects of the nonextensivity are considered in a model to obtain the polarized structure function for the proton and neutron, including the strange contribution for each one. Any type of symmetry is made in consequence of the experimental data involved.


2017 ◽  
Vol 9 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Jeffrey H. Barsuk ◽  
Elaine R. Cohen ◽  
Joe Feinglass ◽  
William C. McGaghie ◽  
Diane B. Wayne

ABSTRACT Background Many medical certifying bodies require that a minimum number of clinical procedures be completed during residency training to obtain board eligibility. However, little is known about the relationship between the number of procedures residents perform and their clinical competence. Objective This study evaluated associations between residents' medical procedure skills measured in a simulation laboratory and self-reported procedure experience and year of training. Methods This research synthesis extracted and summarized data from multiple cohorts of internal medicine, emergency medicine, anesthesiology, and neurology resident physicians who performed simulated clinical procedures. The procedures were central venous catheter insertion, lumbar puncture, paracentesis, and thoracentesis. We compared residents' baseline simulated performance to their self-reported procedure experience using data from 7 research reports written by Northwestern University investigators between 2006 and 2016. We also evaluated how performance differed by postgraduate year (PGY). Results A total of 588 simulated procedures were performed during the study period. We found significant associations between passing the skills examinations and higher number of self-reported procedures performed (P = .011) and higher PGY (P < .001). However, performance for all procedures was poor, as only 10% of residents passed the assessments with a mean of 48% of checklist items correct (SD = 24.2). The association between passing the skills examination and year of training was mostly due to differences between PGY-1 and subsequent years of training. Conclusions Despite positive associations between self-reported experience and simulated procedure performance, overall performance was poor. Residents' clinical experience is not a proxy for skill.


2020 ◽  
Vol 202 ◽  
pp. 08007
Author(s):  
Wahyu Zuli Pratiwi ◽  
Hadiyanto Hadiyanto ◽  
Purwanto Purwanto ◽  
Muthi’ah Nur Fadlilah

Microalgae-Microbial Fuel Cells (MMFCs) are very popular to be used to treat organic waste. MMFCs can function as an energy-producing wastewater pre-treatment system. Wastewater can provide an adequate supply of nutrients, support the large capacity of biofuel production, and can be integrated with existing wastewater treatment infrastructure. The reduced content of Chemical Oxygen Demand (COD) is one way to measure the efficiency of wastewater treatment. MMFCs reactors are made in the form of two chambers (anode and cathode) both of which are connected by a salt bridge. Tofu wastewater as an anode and Spirulina sp as a cathode. To improve MFCs performance which is to obtain maximum COD removal and electricity generation, nutrient NaHCO3 as the nutrient carbon source for Spirulina sp was varied. The system running phase on 12 days. The results were Spirulina sp treated with MFCs technology has better growth than non-MFCs. The MMFC generated a maximum power density of 21.728 mW/cm2 and achieved 57.37% COD removal. These results showed that the combined process was effective in treating tofu wastewater.


2021 ◽  
Author(s):  
Konstantin Pogorelko

The information system “Scientific Heritage of Russia” has been created in stages since 2007. Currently, the existing software does not meet the needs of the system and complicates its further development. It was decided to implement the new version of the software in the asp.net core crossplatform environment. The article describes the decisions made in the implementation of software and modernization of the data structure. Particular attention is paid to the development of information retrieval tools.


Author(s):  
Michael H. Gelting

One sentence in the Prologue of the Law of Jutland (1241) has caused much scholarlydiscussion since the nineteenth century. Did it say that “the law which the king givesand the land adopts, he [i.e. the king] may not change or abolish without the consentof the land, unless he [i.e. the king] is manifestly contrary to God” – or “unless it [i.e.the law] is manifestly contrary to God”? In this article it is argued that scholarly conjectures about the original sense of the text at this point have paid insufficient attentionto the textual history of the law-book.On the basis of Per Andersen’s recent study of the early manuscripts of the Lawof Jutland, it is shown that the two earliest surviving manuscripts both have a readingthat leaves little doubt that the original text stated that the king could not change thelaw without the consent of the land unless the law was manifestly contrary to God. Theequivocal reading that has caused the scholarly controversy was introduced by a conservativerevision of the law-book (known as the AB text), which is likely to have originatedin the aftermath of the great charter of 1282, which sealed the defeat of the jurisdictionalpretensions of King Erik V. A more radical reading, leaving no doubt that the kingwould be acting contrary to God in changing the law without consent, occurs in an earlyfourteenth-century manuscript and sporadically throughout the fifteenth century, butit never became the generally accepted text. On the contrary, an official revision of thelaw-book (the I text), probably from the first decade of the fourteenth century, sought toeliminate the ambiguity by adding “and he may still not do it against the will of the land”,thus making it clear that it was the law that might be contrary to God.Due to the collapse of the Danish monarchy in the second quarter of the fourteenthcentury, the I text never superseded the AB text. The two versions coexistedthroughout the fourteenth and fifteenth centuries and soon produced a number ofhybrid versions. One of these gained particular importance, since it was the text thatwas used for the first printed editions of the Law of Jutland in 1504 and 1508. Thus itbecame the standard text of the law-book in the sixteenth century. The early printededitions also included the medieval Latin translation of the Law of Jutland and theLatin glosses to the text. The glosses are known to be the work of Knud Mikkelsen,bishop of Viborg from 1451 to 1478. Based on a close comparison of the three texts, itis argued here that Bishop Knud was also the author of the revised Danish and Latintexts of the law-book that are included in the early printed editions, and that the wholework was probably finished in or shortly after 1466. Bishop Knud included the I text’saddition to the sentence about the king’s legislative powers.An effort to distribute Bishop Knud’s work as a new authoritative text seems tohave been made in 1488, but rather than replacing the earlier versions of the Lawof Jutland, this effort appears to have triggered a spate of new versions of the medievaltext, each of them based upon critical collation of several different manuscripts.In some of these new versions, a further development in the sentence on the king’slegislative power brought the sentence in line with the political realities of the late fifteenthcentury. Instead of having “he” [i.e. the king] as the agent of legal change, theyattribute the initiative to the indefinite personal pronoun man: at the time, any suchinitiative would require the agreement of the Council of the Realm.Only the printing press brought this phase of creative confusion to an end in theearly sixteenth century.Finally, it is argued that the present article’s interpretation of the original senseof this particular passage in the Prologue is in accordance with the nature of Danishlegislation in the period from c.1170 to the 1240s, when most major legislation happenedin response to papal decretals and changes in canon law.


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