scholarly journals Calendar Aging of Li-Ion Cells—Experimental Investigation and Empirical Correlation

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 28
Author(s):  
Daniel Werner ◽  
Sabine Paarmann ◽  
Thomas Wetzel
Keyword(s):  
Storage Period ◽  
Lithium Ion ◽  
Wide Range ◽  
Different Temperatures ◽  
Battery Degradation ◽  
Operating Lifetime ◽  
Remaining Capacity ◽  
The Subject ◽  
Temperature Levels ◽  
Increasing Temperature

The lifetime of the battery significantly influences the acceptance of electric vehicles. Calendar aging contributes to the limited operating lifetime of lithium-ion batteries. Therefore, its consideration in addition to cyclical aging is essential to understand battery degradation. This study consequently examines the same graphite/NCA pouch cell that was the subject of previously published cyclic aging tests. The cells were aged at different temperatures and states of charge. The self-discharge was continuously monitored, and after each storage period, the remaining capacity and the impedance were measured. The focus of this publication is on the correlation of the measurements. An aging correlation is obtained that is valid for a wide range of temperatures and states of charge. The results show an accelerated capacity fade and impedance rise with increasing temperature, following the law of Arrhenius. However, the obtained data do also indicate that there is no path dependency, i.e., earlier periods at different temperature levels do not affect the present degradation rate. A large impact of the storage state of charge at 100% is evident, whereas the influence is small below 80%. Instead of the commonly applied square root of the time function, our results are in excellent agreement with an exponential function.

scholarly journals Analysis of the impact of quick charge technology on the charging process parameters of the lithium-ion storage at various temperatures

2018 ◽  
Vol 19 ◽  
pp. 01035 ◽  
Author(s):  
Damian Burzyński ◽  
Damian Głuchy ◽  
Maksymilian Godek
Keyword(s):  
Process Parameters ◽  
Lithium Ion ◽  
Cell Parameters ◽  
Lithium Ion Cells ◽  
Lithium Ion Cell ◽  
Ion Storage ◽  
Different Temperatures ◽  
The Subject ◽  
The Impact

The paper deals with the subject of influence of the Quick Charge technology on the parameters of the charging process of lithium-ion cells. Tests of lithium-ion cell parameters during the charging process were performed at three different temperatures using conventional and accelerated charging. Also, the following paper comprises conclusions related to the conducted tests.

Ethen/1-Hexen- und 1-Octadecen-Copolymerisation mit dem stereorigiden Zirkon-Katalysatorsystem iPr(CpFlu)ZrCl2/MAO: Einfluß der Temperatur / Copolym erization of Ethene/1-Hexene and 1-Oetadecen with the Stereorigid Zirconium Catalyst System iPr(CpFlu)ZrCl2/MAO : Influence of the Temperature

1995 ◽  
Vol 50 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Peter H. Mühlenbrock ◽  
Gerhard Fink
Keyword(s):  
Active Center ◽  
Order Statistic ◽  
Catalyst System ◽  
Polymerization Rate ◽  
Side Chain ◽  
Wide Range ◽  
Different Temperatures ◽  
Sterical Hindrance ◽  
Increasing Temperature ◽  
Long Chain

Ethene was copolymerized with 1-hexene and 1-octadecene at different temperatures to study the influence of the temperature. The stereorigid catalyst [2,4-cyclopentadien-1-yliden- (iso-propyliden)fluoren-9-yliden]zirconium dichloride iPr(CpFlu )ZrCl2 1 in combination with methylalumoxane MAO was used. The polymerization rate of ethene depends in a wide range on the temperature and the com onom er content in solution. In each case a large rate enhancem ent at low ratios [com onom er]/[ethene] was observed. A t 25 °C the polymerization rate of ethene increases continuously with increasing [1-hexene]/[ethene]-ratio. At 40 °C the consumption of ethene is nearly independent of the 1-hexene content in solution. Finally, at 60 °C, similar to the ethene/1-octadecene-copolymerisation at different temperatures, the polymerization rate of ethene decreases with increasing [1-hexene]/[ethene]-ratio. It is suggested that this behavior is caused by the mobility of the side chains in the copolym er near the active center, probably for sterical reasons. W ith increasing temperatures, the side chain becomes more and more flexible and thus the sterical hindrance is increased. This effect is even stronger with long chain α-olefins.The microstructure of the copolymer was investigated with respect to Marcovian statistic 1. and 2. order. The experimental triad distribution is described satisfactorily only with the second order statistic. Independent of the temperature the r22 parameter is considerably greater than the r12 parameter, the insertion of an α-olefin thus being more favored for he sequence {R -(α-olefine)-(α-olefine)-Kat.} than for {R -(ethene)-(α-olefine)-Kat.}. It therefore appears that both last inserted monomers influence the insertion of the subsequent monomer, especially at high comonomer contents. Furthermore, the parameters for the α-olefin insertions r22 and r12 are nearly independent of the temperature of polymerization, whereas the r11 and r21 parameters increase with increasing temperature.

Effect of protein and temperature on cutting time prediction in goats' milk using an optical reflectance sensor

2003 ◽  
Vol 70 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Manuel Castillo ◽  
Fred A Payne ◽  
Clair L Hicks ◽  
José Laencina ◽  
María-Belén López
Keyword(s):  
Protein Concentration ◽  
Near Infrared ◽  
Block Design ◽  
Processing Efficiency ◽  
Time Prediction ◽  
Regression Parameters ◽  
Wide Range ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Reflectance Ratio

An objective method for determining the coagulum cutting time is needed to improve consistency and processing efficiency of goats' cheese. A fibre optic sensor was used to measure the backscatter of near-infrared radiation at 880 nm during the coagulation of skimmed goats' milk for the purpose of predicting coagulum cutting time. A randomised block design, replicated three times, was used to test the effect of three protein concentrations (3, 5 and 7% (w/w)) on diffuse reflectance parameters for cutting time prediction of milk coagulated at five different temperatures (20, 25, 30, 35 and 40°C) to assure a wide range of coagulation rates. The inclusion of a protein term in the existing algorithms was essential to reduce the standard error of prediction to under 6·2 min. An algorithm including a time-based parameter and a protein term, Tcut=β0T2 min (1+γ% Protein) was found to predict cutting time with a SEP of 2·42 min and an R2 of 0·98. γ was considered constant (γ=−0·0674, goats' milk) representing the protein effect on β0. Algorithms using response-based parameters (such as change in reflectance ratio) and the composition parameter protein required additional regression parameters such as temperature and an intercept term to predict the cutting time with the same precision as algorithms using only time-based parameters. Time-based parameters were found to decrease proportionally with increasing temperature and decreasing protein concentration. Response-based and mixed-based parameters were found to decrease with decreasing temperature. Reflectance ratio at cutting time did not significantly change with protein concentration for skimmed goats' milk. The activation energy of κ-casein hydrolysis was calculated based on changes in reflectance profile parameters and was found to be in the range 63–72 kJ mol−1.

The Effect of Temperature on Lithium-Ion Battery Energy Efficiency With Graphite/LiFePO4 Electrodes at Different Nominal Capacities

2018 ◽  
Author(s):  
Ashkan Nazari ◽  
Roja Esmaeeli ◽  
Seyed Reza Hashemi ◽  
Haniph Aliniagerdroudbari ◽  
Siamak Farhad
Keyword(s):  
Energy Efficiency ◽  
Heat Generation ◽  
Lithium Ion ◽  
Effect Of Temperature ◽  
Discharge Rates ◽  
Wide Range ◽  
Different Temperatures ◽  
Lifepo4 Cathode ◽  
Battery Energy ◽  
Charge Discharge

In this work, the energy efficiency of the lithium-ion batteries (LIB) with graphite anode and LiFePO4 cathode (G/LFP) at different nominal capacities and charge/discharge rates is studied through multiphysics modeling and computer simulation. After characterizing all the heat generation sources in the cell, the total heat generation in LIBs is calculated and the charge/discharge efficiency plots at different temperatures are obtained. Since G/LFP LIBs have a wide range of applications in passenger and commercial electric vehicles (EVs), the result of this study assist engineer toward more efficient battery pack design.

Theoretical study of the prestressing strand's stress by computer modeling methods

2020 ◽  
Vol 76 (11) ◽  
pp. 1139-1148
Author(s):  
A. G. Korchunov ◽  
E. M. Medvedeva ◽  
E. M. Golubchik
Keyword(s):  
Residual Stresses ◽  
High Strength ◽  
Pearlitic Steel ◽  
Internal Stresses ◽  
Steel Microstructure ◽  
Compressive Stresses ◽  
Wide Range ◽  
Prestressing Strands ◽  
Increasing Temperature ◽  
Wire Strand

The modern construction industry widely uses reinforced concrete structures, where high-strength prestressing strands are used. Key parameters determining strength and relaxation resistance are a steel microstructure and internal stresses. The aim of the work was a computer research of a stage-by-stage formation of internal stresses during production of prestressing strands of structure 1х7(1+6), 12.5 mm diameter, 1770 MPa strength grade, made of pearlitic steel, as well as study of various modes of mechanical and thermal treatment (MTT) influence on their distribution. To study the effect of every strand manufacturing operation on internal stresses of its wires, the authors developed three models: stranding and reducing a 7-wire strand; straightening of a laid strand, stranding and MTT of a 7-wire strand. It was shown that absolute values of residual stresses and their distribution in a wire used for strands of a specified structure significantly influence performance properties of strands. The use of MTT makes it possible to control in a wide range a redistribution of residual stresses in steel resulting from drawing and strand laying processes. It was established that during drawing of up to 80% degree, compressive stresses of 1100-1200 MPa degree are generated in the central layers of wire. The residual stresses on the wire surface accounted for 450-500 MPa and were tension in nature. The tension within a range of 70 kN to 82 kN combined with a temperature range of 360-380°С contributes to a two-fold decrease in residual stresses both in the central and surface layers of wire. When increasing temperature up to 400°С and maintaining the tension, it is possible to achieve maximum balance of residual stresses. Stranding stresses, whose high values entail failure of lay length and geometry of the studied strand may be fully eliminated only at tension of 82 kN and temperature of 400°С. Otherwise, stranding stresses result in opening of strands.

Typologization of security regulation

2020 ◽  
pp. 20-27
Author(s):  
Denis Tikhomirov
Keyword(s):  
Social Relations ◽  
Scientific Literature ◽  
Legal Regulation ◽  
Procedural Understanding ◽  
Limited Ability ◽  
Methodological Basis ◽  
Wide Range ◽  
The Subject ◽  
Definition Of ◽  
Legal Understanding

The purpose of the article is to typologize terminological definitions of security, to find out the general, to identify the originality of their interpretations depending on the subject of legal regulation. The methodological basis of the study is the methods that made it possible to obtain valid conclusions, in particular, the method of comparison, through which it became possible to correlate different interpretations of the term "security"; method of hermeneutics, which allowed to elaborate texts of normative legal acts of Ukraine, method of typologization, which made it possible to create typologization groups of variants of understanding of the term "security". Scientific novelty. The article analyzes the understanding of the term "security" in various regulatory acts in force in Ukraine. Typological groups were understood to understand the term "security". Conclusions. The analysis of the legal material makes it possible to confirm that the issues of security are within the scope of both legislative regulation and various specialized by-laws. However, today there is no single conception on how to interpret security terminology. This is due both to the wide range of social relations that are the subject of legal regulation and to the relativity of the notion of security itself and the lack of coherence of views on its definition in legal acts and in the scientific literature. The multiplicity of definitions is explained by combinations of material and procedural understanding, static - dynamic, and conditioned by the peculiarities of a particular branch of legal regulation, limited ability to use methods of one or another branch, the inter-branch nature of some variations of security, etc. Separation, common and different in the definition of "security" can be used to further standardize, in fact, the regulatory legal understanding of security to more effectively implement the legal regulation of the security direction.

History of the Study of Apocrypha in Early Medieval England

2020 ◽  
Vol 48 (3-4) ◽  
pp. 13-26
Author(s):  
Brandon W. Hawk
Keyword(s):  
Old Testament ◽  
Medieval England ◽  
Medieval Period ◽  
Early Medieval ◽  
Future Directions ◽  
Early Judaism ◽  
Wide Range ◽  
History Of ◽  
The Subject ◽  
Early English

Literature written in England between about 500 and 1100 CE attests to a wide range of traditions, although it is clear that Christian sources were the most influential. Biblical apocrypha feature prominently across this corpus of literature, as early English authors clearly relied on a range of extra-biblical texts and traditions related to works under the umbrella of what have been called “Old Testament Pseudepigrapha” and “New Testament/Christian Apocrypha." While scholars of pseudepigrapha and apocrypha have long trained their eyes upon literature from the first few centuries of early Judaism and early Christianity, the medieval period has much to offer. This article presents a survey of significant developments and key threads in the history of scholarship on apocrypha in early medieval England. My purpose is not to offer a comprehensive bibliography, but to highlight major studies that have focused on the transmission of specific apocrypha, contributed to knowledge about medieval uses of apocrypha, and shaped the field from the nineteenth century up to the present. Bringing together major publications on the subject presents a striking picture of the state of the field as well as future directions.

Museum Preserves in the Sphere of “Cultural Tourism”: Through the Example of the Cultural Preserves of Tatarstan

2019 ◽  
Vol 9 (4) ◽  
pp. 193-198
Author(s):  
Lyudmila S. Timofeeva ◽  
Albina R. Akhmetova ◽  
Liliya R. Galimzyanova ◽  
Roman R. Nizaev ◽  
Svetlana E. Nikitina
Keyword(s):  
19Th Century ◽  
Art Museum ◽  
Medium Size ◽  
Business Elite ◽  
Wide Range ◽  
The Subject ◽  
Tourist Center ◽  
Regional Authorities ◽  
The 19Th Century ◽  
The City

Abstract The article studies the existence experience of historical cities as centers of tourism development as in the case of Elabuga. The city of Elabuga is among the historical cities of Russia. The major role in the development of the city as a tourist center is played by the Elabuga State Historical-Architectural and Art Museum-Reserve. The object of the research in the article is Elabuga as a medium-size historical city. The subject of the research is the activity of the museum-reserve which contributes to the preservation and development of the historical look of Elabuga and increases its attractiveness to tourists. The tourism attractiveness of Elabuga is obtained primarily through the presence of the perfectly preserved historical center of the city with the blocks of integral buildings of the 19th century. The Elabuga State Historical-Architectural and Art Museum-Reserve, which emerged in 1989, is currently an object of historical and cultural heritage of federal importance. Museum-reserves with their significant territories and rich historical, cultural and natural heritage have unique resources for the implementation of large partnership projects. Such projects are not only aimed at attracting a wide range of tourists, but also stimulate interest in the reserve from the business elite, municipal and regional authorities. The most famous example is the Spasskaya Fair which revived in 2008 in Elabuga. It was held in the city since the second half of the 19th century, and was widely known throughout Russia. The process of the revival and successful development of the fair can be viewed as the creation of a special tourist event contributing to the formation of new and currently important tourism products.

A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

2018 ◽  
Vol 7 (4) ◽  
pp. 13-21
Author(s):  
Todd Backes ◽  
Charlene Takacs
Keyword(s):  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Cardiopulmonary Exercise Testing ◽  
Mean Value ◽  
The Self ◽  
Mixing Chamber ◽  
Wide Range ◽  
The Subject ◽  
The Mean ◽  
Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

Features of optative modality in Macedonian language (with emphasis on the functionalities of independent da-construction)

2020 ◽  
pp. 301-323
Author(s):  
Natalya I. Kikilo ◽  
Keyword(s):  
Detailed Analysis ◽  
Present Article ◽  
Literary Language ◽  
Natural Context ◽  
Wide Range ◽  
Verb Forms ◽  
Text Types ◽  
The Future ◽  
The Subject ◽  
Ritual Context

In the Macedonian literary language the analytic da-construction used in an independent clause has a wide range of possible modal meanings, the most common of which are imperative and optative. The present article offers a detailed analysis of the semantics and functions of the Macedonian optative da-construction based on fiction and journalistic texts. The first part of the article deals with the specificities of the optative as a category which primarily considers the subject of a wish. In accordance with the semantic characteristics of this category, optative constructions are used in those discourse text types where the speakers are explicitly designated (the most natural context for the optative is the dialogue). The analysis of the Macedonian material includes instances of atypical usage of the optative da-construction, in which the wish of the subject is not apparent and thereby produces new emotional tonalities perceptible to the reader of a fiction/journalistic text. The study describes Macedonian constructions involving two different verb forms: 1) present tense form (da + praes) and 2) imperfective form (da + impf). These constructions formally designate the hypothetical and counterfactual status of the optative situation, respectively. Thus, the examples in the analysis are ordered according to two types of constructions, which reflect the speaker’s view on the probability of the realisation of his/her wish. Unrealistic wishes can be communicated through the present da-construction, while the imperfective construction denotes situations in which the wish can be realised in the future. The second part of the article is devoted to performative optative da-constructions, which express formulas of speech etiquette, wishes and curses. The analysis demonstrates that these constructions lose their magical functions, when used outside of the ritual context, and begin to function as interjections.

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