bluuebunny/crossref_metadata_2025_split huggingface dataset:
An α‐variable model‐free prescribed‐time control for nonlinear system with uncertainties and disturbances
Authors: He Dingxin , Wang Haoping , Tian Yang 
Published: March 2022

AbstractIn this article, an ‐variable model‐free prescribed‐time controller (‐MFPTC) is proposed for a nonlinear system with uncertainties and disturbances. First, an ultra‐local model is employed to formulate the plant dynamic by using input and output data. Second, to observe the state variables and compensate for the lumped uncertainties, a linear extended state observer (LESO) is designed. Then, a corresponding LESO‐based ‐fixed model‐free controller (LESO‐iPD) is proposed. Third, based on LESO‐iPD, a prescribed‐time sub‐controller (PTC) is adopted to converge tracking error within a prescribed finite time. Furthermore, an adaptive RBF neural network compensator is constructed to approximate and compensate for LESO error. Correspondingly, an ‐fixed model‐free prescribed‐time controller (‐MFPTC) is proposed. Fourth, based on ‐MFPTC, a tracking error‐based ‐variable method is applied to improve the controller performance, and an ‐variable model‐free prescribed‐time controller (‐MFPTC) is subsequently proposed. Moreover, stability and prescribed‐time convergence of closed‐loop system with ‐MFPTC are analyzed by using the Lyapunov theorem. Ultimately, to demonstrate the performance and effectiveness of the proposed control strategy, the numerical simulation with sliding mode control, LESO‐iPD, ‐MFPTC, and ‐MFPTC and co‐simulation results on quadrotor have been obtained.
Comparison of Colorimetric Methods to Detect Malondialdehyde, A Biomarker of Reactive Oxygen Species
Authors: Islayem Deema , Fakih Fatima Ba , Lee Sungmun 
Published: March 2022

AbstractExcessive production of reactive oxygen species (ROS) is implicated in the pathogenesis of aging‐related disorders such as cardiovascular diseases. However, monitoring of ROS in vivo remains elusive due to the short half‐lives. ROS level can be assessed by measuring the level of malondialdehyde (MDA), a biomarker of lipid oxidation induced by ROS. Although there are many techniques to measure MDA, colorimetric analysis has advantages such as lower costs and simple instruments required. Here, three colorimetric methods, p‐anisidine, Schiff reagent and methyl‐2‐phenylindole (MPI), were compared in specificity and sensitivity of MDA. Both MPI and p‐anisidine generated specific peaks for MDA, an aldehyde, which were different from peaks for acetone, a ketone. For the sensitivity, three chemicals were reacted with MDA at normal (0.2 μM) and diseased (0.6 μM and 1 μM) saliva conditions, and healthy (1 μM) and diseased (2 μM) serum conditions. Only MPI was sensitive enough to identify MDA in diseased conditions. MPI method was also able to detect extracellular MDA produced by RAW264.7 macrophages treated with H2O2. Based on the results in this study, we anticipate numerous applications of MPI for the detection of ROS overproduced.
Polysaccharides‐Based Nano‐Hybrid Biomaterial Platforms for Tissue Engineering, Drug Delivery, and Food Packaging Applications
Authors: Shahbaz Areej , Hussain Nazim , Basra Muhammad Asim Raza , Bilal Muhammad 
Published: March 2022

AbstractPolysaccharides have received immense interest in recent years for outstanding properties, including biocompatibility, biodegradability, renewable origin, and ease of modification. Owing to their considerable bioactivities, natural abundance, immunoactivity, and chemical modifiability in a variety of applications, they are considered potential biomaterials for the biomedical, biotechnological, and industrial sectors of the modern world. Polysaccharide‐based novel nanocomposites from starch, chitin and chitosan, alginates, cellulose, dextran, and hyaluronic acid with unique functional and structural attributes have been the subject of extensive study to promote their usage in a variety of fields, including biomedicine, food industry, and nonbiological sectors. Furthermore, polysaccharide‐based metal and nonmetal oxides, graphene, and carbon nanotubes have been used with various combinations in diverse fields of research. This review spotlights the application prospects of polysaccharides‐based hybrid nano‐biomaterials in tissue engineering, drug delivery, and food packaging concerning the biological and chemical properties, cross‐linking membranes, and focuses on the relationship between their composition and properties.
TESOL Teachers’ Writing to Support Developing Understandings of Translanguaging Theory and Praxis in Neoliberal Times
Authors: Pontier Ryan W. , Deroo Matthew R. 
Published: March 2022

AbstractThis study highlights Masters‐level TESOL students’ meaning‐making about translanguaging theory and pedagogy through writing in response to course readings and conversations. To gain deeper insight into shifting understandings of languaging that seek to move from monoglossic orientations to heteroglossic framing of language learning as connected to dynamic bilingualism, we drew on both translanguaging (García & Li, 2014) and reflective writing as a mechanism for supporting teacher learning (Hoover, 1994; Kelley 2006; Zeichner, 1987). Our inductive and deductive approach to analyze 12 students’ 132 journal entries during a TESOL methods class showed developing understandings of translanguaging theory and pedagogy influenced by (a) experience with theories of bilingualism grounded in language separation as historically understood in TESOL, (b) tensions regarding the application of translanguaging theory to praxis (Li, 2017), and (c) tensions between language and testing within the context of neoliberalism (Zeichner, 2014) guiding language teaching and learning in the K‐16 context. We conclude by providing suggestions to help teacher educators who engage in teacher language education to better support teacher‐learning about translanguaging.
Power of stochastic kinetic models: From biological signaling and antibiotic activities to T cell activation and cancer initiation dynamics
Authors: Teimouri Hamid , Kolomeisky Anatoly B. 
Published: March 2022

AbstractAll chemical processes exhibit two main universal features. They are stochastic because chemical reactions might happen only after random successful collisions of reacting species, and they are dynamic because the amount of reactants and products changes with time. Since biological processes rely heavily on specific chemical reactions, the stochasticity and dynamics are also crucial features for all living systems. To understand the molecular mechanisms of chemical and biological processes, it is important to develop and apply theoretical methods that fully incorporate the randomness and dynamic nature of these systems. In recent years, there have been significant advances in formulating and exploring such theoretical methods. As an illustration of such developments, in this review the recent applications of stochastic kinetic models for various biological processes are discussed. Specifically, we focus on applying these theoretical approaches to investigate the biological signaling, clearance of bacteria under antibiotics, T cells activation in the immune system, and cancer initiation dynamics. The main advantage of the presented stochastic kinetic models is that they generally can be solved analytically, allowing to clarify the underlying microscopic picture, as well as to explain the existing experimental observations and to make new testable predictions. This theoretical approach becomes a powerful tool in uncovering the molecular mechanisms of complex natural phenomena.This article is categorized under:
Molecular and Statistical Mechanics > Free Energy Methods
Structure and Mechanism > Computational Biochemistry and Biophysics
Theoretical and Physical Chemistry > Statistical Mechanics
Shockley: Queisser detailed balance limit after 60 years
Authors: Markvart Tom 
Published: March 2022

AbstractThe year 2021 marks the 60th anniversary of the Shockley–Queisser paper which laid the theoretical foundations for the fundamentals of solar cell operation. This article reviews the principal results of the Shockley‐Queisser paper and the developments that followed. Starting with links to the earlier radiative balance laws of Kirchhoff and Planck, we discuss the nature of the detailed balance between the incident and emitted photon beams. The resulting efficiency limit is juxtaposed with another popular limit due to Trivich and Flinn. The dependence of the Shockley–Queisser limit on the intensity and sizes (étendues) of the two beams—in other words, on the concentration of sunlight—is discussed in some detail. This article then takes a broader view of the detailed balance with the help of the generalized Planck law and the refinements that this implies for the efficiency and the current–voltage characteristic of the cell. A natural extension of the Shockley–Queisser detailed balance into the realms of thermodynamics is outlined by considering the photon entropy in the two beams. This produces the detailed balance limit in a typical thermodynamic form, similar to the result for a heat engine, where the efficiency losses are expressed in terms of entropy generation. The paper concludes with a brief discussion of how the results can be extended to the operation of practical solar cells with a more realistic description of light absorption and nonradiative recombination. A brief overview is also given of mechanisms for how the Shockley–Queisser limit can be exceeded.This article is categorized under:
Sustainable Energy > Solar Energy
Emerging Technologies > Materials
Alternative methods for cleaning membranes in water and wastewater treatment
Authors: Terán Hilares Ruly , Singh Imman , Tejada Meza Kevin , Colina Andrade Gilberto J. , Pacheco Tanaka David Alfredo 
Published: March 2022

AbstractMembrane fouling is caused by foulant deposition or adsorption through physical or chemical interactions on the membrane surface, causing the reduction of flux through the membrane. The main drawbacks of chemical agents used for cleaning are cost, damage caused on the membrane, and waste stream making the process unattractive. Alternative, methods such as ultrasound, enzymatic process, and osmotic backwashing were explored for membrane cleaning. Among all mentioned methods, micronanobubbles have been reported as a promising and emergent method for membrane surface cleaning; unfortunately, the information is limited, but preliminary studies have shown it as an efficient, cheap, and environmentally friendly technique. Other methods like electrically and vibratory‐enhanced membrane cleaning also could be interesting but currently are unexplored and information is limited.Practitioner Points
Chemical cleaning is an efficient option; however, from an environmental point of view, it is not attractive, and high concentrations could cause damage to the membrane.
Micronanobubbles are an emergent and suitable technology for membrane and surface cleaning.
Membrane modification and functionalization avoid membrane fast fouling, and the cleaning process is easier, but the manufacture cost could be expensive.
Are “Weak Ties” Really Weak? Social Capital Reliance Among Second Generation Turkish Lawyers in Paris
Authors: Keskiner Elif , Waldring Ismintha 
Published: March 2022

AbstractThe chapter studies social capital development and application among highly educated Turkish second generation working in the law sector in Paris. Previously we have demonstrated how social capital was a crucial resource in the professional pathways of Turkish second generation lawyers in Sweden, the Netherlands, France and Germany. In this chapter we take our inquiry a step further analyzing the strong and weak ties that descendants of migrants relied upon in their professional pathways. We use biographical interviews conducted with descendants of migrants in France in which they explicate their entire educational and professional trajectories. We concentrate on Turkish second generation with low-educated parents hence young people who did not receive direct professional resources from their parents.We see for this group the development of professional networks already begins in tertiary education and continues into their labour market careers. The paper aims to make contributions to several strands of the literature. Firstly, it contributes to the debate on temporality of networks by showing how distinct forms of social capital became crucial in different phases of their careers and how they relied on both weak and strong ties strategically to overcome the glass ceilings in their sectors and move upwards in their pathways. Secondly, we aim to problematize the concepts of “strong” and “weak” ties in relation to their ethnic connotations. Our study shows that second generation lawyers were able to develop relations of trust with their so-called “weak ties” while the ethnic “strong ties” represented useful clientele.
Context Matters: The Varying Roles of Social Ties for Professional Careers of Immigrants’ Descendants
Authors: Lang Christine , Pott Andreas , Schneider Jens 
Published: March 2022

AbstractResearch on social networks of immigrants and their descendants usually starts from the distinction between ‘ethnic’ ties and ties to members of the population without migration background. In migration studies ‘ethnic’ ties are repeatedly associated with ‘strong ties’, whereas ‘weak ties’ – that are found to be essential for the access to jobs in the wider society – are associated with contacts to members of the ‘majority population’. Building on existing criticism of this narrowing dichotomy and looking at upward social mobility careers of immigrants’ descendants we question this group-related understanding of weak and strong ties. Examining professional trajectories of immigrants’ descendants in Germany, this chapter suggests shifting the focus to occupational contexts in order to understand better how and why different types of social ties can play an important role for their professional mobility. We argue that both the quality of ties and their ‘ethnic dimension’ are dependent on the occupational context with its specific institutionalized modes of access and recruitment. Moreover, different forms of ‘ethnic’ or ‘cross-ethnic’ ties develop a changing significance in the course of a career and over time; this makes it necessary to also look at the dynamics in careers and the occupational contexts. The chapter compares the role of social ties for the inclusion into two occupational fields: law and public administration. It draws on interviews with (mainly Turkish) immigrants’ descendants working in these sectors. While in the law sector mainly ‘weak ties’, which had been built up during university studies and in the course of later careers, proved important, in public administration ‘strong ties’ to relatives and friends were most crucial for the access to jobs. In both sectors, we can observe that ties to ‘co-ethnics’ become increasingly relevant for professional careers as people of immigrant descent gradually achieve higher positions.
Networks in Migration Processes
Authors: Eve Michael 
Published: March 2022

AbstractMuch of the work on the networks of migrants and their descendants concentrates mainly on the ethnicity of the persons in the network; however, if we are interested in the way networks reinforce ethnic inequalities or foster social mobility, other dimensions may be at least as important as the ethnic composition. In this chapter I describe how migration itself, rather than ethnic identification, shapes social networks. Even in times of electronic communication, space has effects on social relationships, for many social transactions (from child care to commensality) fundamental for maintaining social relationships are difficult or impossible at a distance. Migration is age-selective and this has effects on ties formed in the place of immigration. Labour migration has strong effects on the neighbourhoods migrant families end up in, and these in turn affect the schools their children go to and who they play with outside the home. Most migration is class-selective, forming networks more class-homogeneous in the place of immigration than in the place of departure. So a series of factors linked specifically to ‘the migration process’ have structural effects on the social networks of migrants and their descendants. In this chapter I draw on studies of internal and international migration to show that these effects are important even where citizenship is not at issue. I argue that there are, in fact, marked similarities in the networks of internal and international labour migrants, for example, in the tendency (under certain conditions) to form networks made up primarily of persons from the same place of origin. So I suggest that “the migration process” may affect migrants’ social networks as much as ethnic dynamics. And that this throws light on the social mechanisms behind the forms of inequality documented in many migration contexts. Drawing on qualitative interviews with different types of (internal and international) migrants, I show that the initial social ties used to achieve one’s transfer from one place to another (e.g. a classic migration chain, or professional contacts) have lasting effects, and that these explain some differences between the networks formed by “skilled” and “unskilled” migrants (more work-based in the former case, more kin-based in the latter). I also show how the networks formed by children of migrants are shaped by the specific conditions (net of class) of labour migration.
Formulare der Indiskretion: Interview und Literaturwissenschaft
Authors: Geitner Ursula 
Published: March 2022

ZusammenfassungDer Beitrag Ursula Geitners untersucht das intrikate Verhältnis von Interview und Literaturwissenschaft mithilfe des Formularbegriffs. Das kurrente auto-biografisierende Frage-Antwort-Formular steuert literaturwissenschaftliches Basiswissen und methodisches Vorgehen bis in einschlägige Praktiken und usuelle Operationen hinein. Das macht epistemologische Zugewinne der im 20. Jahrhundert fortgeschrittenen Verwissenschaftlichung von Literaturgeschichte und Literaturwissenschaft obsolet, die mit einer Problematisierung und Neupositionierung der Autorschaftskategorie einherging.
Stahlhartes Gehäuse? Zur Ästhetik des Formulars
Authors: Drügh Heinz 
Published: March 2022

ZusammenfassungFormulare stehen mit ihren Verfahren der Standardisierung, Nüchternheit und Rationalität prototypisch für eine „Logik der Allgemeinheit“ (Reckwitz), also für das Gegenteil jener Einzigartigkeit, Delikatesse und Besonderheit als Domänen des Ästhetischen. Dennoch herrscht nicht etwa Funkstille zwischen Formular und Ästhetik. Künstlerische Darstellungen scheinen von Formularen und ihrem Formklima als von ihrem anderen geradezu angezogen zu werden. Das erklärt sich daraus, dass sich Kunst in der Auseinandersetzung mit der Logik des Formulars selbst befragen kann – auch und nicht zuletzt, so die These des Aufsatzes, mit Blick auf Standardisierungen und Routinen, die im Mythos der ästhetischen Autonomie verborgen liegen.
Telegraphie im Formularstil
Authors: Brändle Stephan 
Published: March 2022

ZusammenfassungWas sind Telegramme? Sind es die Zwanzig-Wörter-Botschaften, die zum Geburtstag oder zur Hochzeit gratulieren; Ankunft, Geburt oder Tod melden; Bestellung oder Kauf tätigen respektive bestätigen? Oder sind es die Papierformulare, die am Aufgabeort vom Absender, am Zielort von einem Telegraphisten ausgefüllt und anschließend an die Adressaten ausgeliefert werden? Während im Fall des Briefes der materielle Träger und die auf ihm geschriebene Botschaft in eins fallen, als transzendental-empirische Dublette untrennbar miteinander verknüpft sind, verkompliziert sich der Sachverhalt im Falle des Telegramms. Ein Telegramm ist viele Telegramm(formular)e: Wie Theseus’ Schiff in der Werft vermehren sich die papiernen Träger des Telegramms in den Telegraphenbüros auf wundersame Weise, während die Botschaft des Telegramms ein und dieselbe bleibt – oder zumindest bleiben soll.
Zum Formular der Moderne
Authors: Werber Niels 
Published: March 2022

ZusammenfassungWelche Formulare zu benutzen und was aus einemformular Titelbuchabzuschreiben ist, hängt primär von der Zugehörigkeit des Menschen zu einer der Schichten der Gesellschaft ab. Formulare managen die Rangunterschiede in einer stratifikatorisch differenzierten Gesellschaft und ermöglich so, dass die Kommunikation von Ungleichen gelingen kann und für beide Seiten so erwartbar wird, dass Selektionsofferten unterbreitet und angenommen werden. Auch um 1800 und um 1900 inkludieren Formulare und strukturieren Anschlusskommunikation, doch sind hier auch Unterschiede zu betonen, die vor allem dann auffallen, wenn man hinter die kulturkritische Rhetorik Schillers zurücktritt und seine Diagnosen (Entfremdung, Zersplitterung, Mechanisierung) nicht auf seinen Vergleich der idealisierten „Griechen“ mit „uns“ defizitären „Neuern“ bezieht, sondern seine Ausführungen zum Formular auf die epochalen Umbrüche der Gesellschaftsstruktur bezieht, die in der Semantik ihren Niederschlag finden.
Bürokratische Symbiose
Authors: Lehmann Maren 
Published: March 2022

ZusammenfassungBegriff und Problem der Formalisierung – und als eine von deren möglichen Materialitäten soll das Formular im Folgenden verstanden werden – sind soziologische Klassiker, und sie sind es im Modus des Vorbehalts. Dieser Vorbehalt verdankt sich einer Gleichsetzung: Formalisierung gilt als Verwaltungstechnik, als Machtinstrument lebensängstlicher Bürokraten, die sich mit Ärmelschonern und Schreibmaschinen hinter Aktenschränken verschanzen, wo sie mit Haut und Haar ihrem staubigen Interesse verfallen, alles Lebendige zu entsaften, in anschlussfähige Siglen einzufassen und in Hängemappen aufzuknüpfen. (Der Computernerd, der diese ganze Assemblage in einem aktendeckelflachen Laptop unterzubringen vermag, ist nur deren pubertärer Verwandter; der Vorbehalt trifft ihn genauso.) Die Reserve gilt nicht der Arbeit an der Forschungsfrage selbst, sondern ihrer historisch-empirischen Wirklichkeit, den Rollen, Architekturen und Materialisationen.
Facta sunt servanda. Zu Form/Formel/Format/Formular an Schnittstellen der Kontingenz
Authors: Plener Peter 
Published: March 2022

ZusammenfassungIm europäischen 15., 16. Jahrhundert wurde »Literatur« – wesentlich ausgehend von Spanien – durch administrative Schriftsetzungen von der Zumutung der Realitätsansprüche (und deren Unannehmlichkeiten respektive Zwängen) ansatzweise entlastet und gewissermaßen zugunsten der neu systematisierten Repräsentationsordnung vom Fakt zu Fiktion verschoben. Verwaltungsschriften und Aktenbestände erschienen zunehmend als allein gültige Bestandsaufnahmen in das ihnen damit eigentümliche Recht gesetzt (ihre Verarbeitungslogik geht in die Körpergedächtnisse über und lässt sie derart adjustiert die Welt erobern). Eine neue Form organisierter Verwaltung entsteht.
Die Lücke, die die Vorschrift lässt. Heimrad Bäckers nachschrift und die Formulare des Totalitarismus
Authors: Wolf Burkhardt 
Published: March 2022

ZusammenfassungFormulare sind Lückentexte. Vor Augen stellen sie einen Mangel, der beseitigt werden will: Leerstellen und Leerflächen, die nach ihrer Füllung verlangen. Werden Formulare von Amts wegen ausgegeben, verschärft sich dieser Appell. Dann nämlich handelt es sich um Vorschriften im doppelten Sinne, um offizielle Aufforderungen in Gestalt schriftlicher und diagrammatischer Vorgaben.