Set Of Tensions Research Articles

A HOUSE WITH EXPOSED BEAMS: INQUIRY‐BASED LEARNING AND HISTORIANS’ ETHICAL RESPONSIBILITIES AS SCHOLAR‐TEACHERS

ABSTRACTThis is an article about the relationship between historical scholarship and pedagogy. The teaching of history can itself be seen as a meaningful form of historical scholarship and poses some of the same methodological, theoretical, and ethical questions as historical research, albeit usually generating quite different answers to the queries. I delve into three sets of questions that are of significance to historians in our roles as researchers and as teachers. In scholarship and in teaching, it pays to consider the relationship between authority and humility. In the library and the classroom, there is a balance to be struck between narrative and analysis. In both settings, one must at times choose between historicist particularity and human universalism. I discuss each set of tensions with reference to such thinkers as Paulo Freire, bell hooks, and Friedrich Nietzsche. In each case, I also draw on my own experience in the classroom, particularly my time teaching tenth‐grade world history. Throughout, I suggest that intellectually and ethically flourishing history classrooms are often “houses with exposed beams,” in which teachers initiate students as junior members in communities of historical inquiry, often, though not always, through collaborative analyses of revealing primary documents.

Hamiltonian Birkhoff Normal Form for Gravity-Capillary Water Waves with Constant Vorticity: Almost Global Existence

We prove an almost global existence result for space periodic solutions of the 1D gravity-capillary water waves equations with constant vorticity. The result holds for any value of gravity, vorticity and depth, a full measure set of surface tensions, and any small and smooth enough initial datum. The proof demands a novel approach—that we call paradifferential Hamiltonian Birkhoff normal form for quasi-linear PDEs—in presence of resonant wave interactions: the normal form is not integrable but it preserves the Sobolev norms thanks to its Hamiltonian nature. A major difficulty is that paradifferential calculus used to prove local well posedness (as the celebrated Alinhac good unknown) breaks the Hamiltonian structure. A major achievement of this paper is to correct (possibly) unbounded paradifferential transformations to symplectic maps, up to an arbitrary degree of homogeneity. Thanks to a deep cancellation, our symplectic correctors are smoothing perturbations of the identity. Thus we are able to preserve both the paradifferential structure and the Hamiltonian nature of the equations. Such Darboux procedure is written in an abstract functional setting applicable also in other contexts.

Genesis and fluid evolution of the Hatu orogenic gold deposit in the West Junggar, Western China

The West Junggar in Xinjiang, western China, represents a significant gold mineralization belt hosting over 200 gold deposits, with the Hatu gold deposit being the largest among them. In this study, ore geology and fluid inclusion assemblages of quartz samples from the Hatu gold deposit were investigated in an effort to clarify the mineralization process and its relationship with the geodynamic settings. The mineralization process is delineated into early (pyrite-albite-quartz veins), middle-a (quartz-ankerite veins), middle-b (quartz-ankerite-sulfide-native gold veins), and late (quartz-calcite veins) stages. The early stage veins suggest a compressional setting while the middle-a and middle-b stage veins suggest a tensional shear setting. The late stage veins are typically filled fissures cutting through earlier veins. Scanning electron microscope-cathodoluminescence (SEM-CL) reveals that early stage quartz (Q1) exhibits concentric CL-oscillatory growth zoning, while middle-a stage quartz (Q2a) displays unidirectional zoning and ranges from CL-bright to CL-dark, middle-b stage quartz (Q2b) is CL-bright and weakly zoned, and late-stage euhedral quartz (Q3) shows sector zoning transitioning from CL-gray to CL-dark. Quartz that formed in these stages developed three types of fluid inclusions: pure CO2 (PC-type), CO2–H2O (C-type), and H2O–NaCl (W-type). The early stage quartz contains C- and W-type fluid inclusions homogenizing at 309–345 °C, while the late stage quartz contains only W-type fluid inclusions with homogenization temperatures of 164–229 °C. Microthermometry of fluid inclusion indicated the evolutionary of the metallogenic fluid from a high-temperature, CO2-rich, and minor CH4 metamorphic fluid to a low-temperature, CO2-poor meteoric fluid. From the early to middle-a stages, fluid boiling caused the unloading of ore-forming elements whereas fluid mixing led to the precipitation of polymetallic sulfides and gold in the middle-b stage. Trapping pressures in the middle-b stage were estimated using C-type inclusions, illustrating that gold mineralization took placed at depth of 8.0 km. We propose classifying the Hatu gold deposit as an orogenic deposit, originating from the collisional orogenesis between the Yili-Kazakhstan and Siberian continents in the Late Carboniferous.

Flame Retardancy and Properties of Thermoplastic Vulcanizates from Dibutyl Phosphate-Bound Natural Rubber/Ethylene Vinyl Acetate Blends

ABSTRACT Dibutyl phosphate-bound epoxidized natural rubber (DBNR) was synthesized from natural rubber latex via epoxidation using a 20 mol% intermediate. Successful formation of epoxidized natural rubber (ENR-20) and DBNR was confirmed by FTIR analysis. Thermoplastic vulcanizates (TPVs) were prepared by dynamically vulcanizing blends of DBNR and ethylene-vinyl acetate copolymer (EVA). The 50/50 DBNR/EVA TPV exhibited higher mixing torque during vulcanization, indicative of increased shear stress, shear rate, and tensile strength. This was attributed to finer dispersion of vulcanized rubber domains in the EVA matrix, leading to enhanced interfacial adhesion. Elongation at break decreased with increasing EVA content, while hardness and tension set increased, suggesting reduced elasticity at higher EVA proportions. Under heat aging, TPVs experienced degradation of mechanical properties and increased tension set, indicating loss of elastomeric behavior. Significantly, DBNR exhibited a low burning rate of 0.2 mm/s, imparting inherent flame retardancy. The burning rate of DBNR/EVA TPVs decreased with increasing DBNR content, demonstrating improved flame retardancy. Overall, DBNR/EVA TPVs exhibited favorable mechanical properties and flame retardancy, making them suitable for applications requiring flame-retardant elastomeric materials.

A trio-autoethnographic analysis of the experiences and wellbeing of part-time doctoral students with full-time academic roles

ABSTRACT This study highlights the needs and potentialities of an often-overlooked group: Part-Time Doctoral Students who are Full-Time Academics at their institutions (PTSFTAs). Such students are rarely considered in the research literature, yet they face a unique set of tensions as their roles and identities evolve. This study contributes fresh understanding of PTSFTAs’ experiences and wellbeing through a thematic analysis of a series of five open conversations reflecting on the supervisory process. Three PTSFTAs who studied and work at the same institution engaged in a series of trio-autoethnographic dialogues. These dialogues were structured around five doctoral supervision concepts. Tensions are identified that have the potential to affect PTSFTA wellbeing and identity. The study concludes that a student-centred doctoral supervision process can enable PTSFAs to develop multifaceted personal and professional identities and rich personal epistemologies.

Experimental Behaviour of Tensioner for Rigid Hangers of Arch Bridges

In steel tied arch bridges where the hangers are made of rigid bars, the replacement of damaged hangers is rather complex. In fact, while generally the cable hangers are already prepared with anchors at the ends and their replacement traces the initial stages of construction with their prestressing, on the contrary, the rigid bars are welded to the arch and the deck, so their replacement must include the design of a new suspension system that allows the insertion of a pretension where this had never been considered. To check the reliability of this new system, a prototype of tensioner was studied for the case of a steel arch bridge in which the high level of corrosion made it necessary to replace all the original hangers with new ones. This entailed the need to test the tensioner performance with the aim of ensuring the axial force transmission between the two hanger segments without slippage in the threads, as well as to test the correct tension setting before construction and putting into service the hangers to be replaced. For this reason, a predictive experimental campaign was carried out on a prototype by means of tests for the mechanical characterization of the materials used, tensile tests of the system, and tensioning tests under load, measuring the displacements and strains of the system elements. The results of the tests, with slippage in the threads limited to the 2% of total elongation, and the turnaround-stressing curves were useful for the definition of the pieces to be assembled during on-site work and for addressing the operating procedures of the tensioning phases on-site during hanger replacement. Validation with the on-site monitoring of stressing operation was conducted at the end; the monitoring of tension through dynamic tests confirmed the agreement of on-site results with the predictive loading tests of the experimental campaign on the tensioner prototype.

Paleostress Analysis Using Fracture Data, a Case Study of Kewa Charmula Anticline, Kurdistan Region, Northeastern Iraq

Fracture analysis was carried out through three adjacent traverses. The study area is considered a part of the Arabian Plate and geologically falls within the boundary between the Low Folded Zone and the High Folded Zone of the Western Zagros Fold-Thrust Belt in the Iraqi Kurdistan Region. Five formations are cropped out in this anticline, extending from the Late Oligocene up to the Late Miocene – Pliocene. Those formations are (Anah, Jeribe, Fatha, Injana, and Mukdadiya). In addition, identify an Oligocene unit the Kirkuk Group, represented by the (Anah Fn.) that no other studies have previously referred to, in addition, to observing the Jeribe Formation along Tilyan Gorge. About 350 fracture planes were measured for the study and classified into sets and systems concerning their relations to the three mutually perpendicular geometrical axes (tectonic axes). Tension sets are (ac), which are formed by extension along the fold axis accompanying direct compression perpendicular to the fold trend, whereas the (bc) set is supposed to be the product of relaxation that motivated the primary compressional stress. The shear systems are each of hk0, h0l, and 0kl developed successively during direct compression and subsequent relaxation episodes of each tectonic stress. The results of the paleostress analyses showed that there is a general coincidence in the direction of the major stress axis (σ1) and the minor stress axis (σ3), which were derived from the joints (fracture planes). Joints are presented as sets and systems. The analysis of joint attitudes revealed that the joints might be due to the influence of the main horizontal compression paleostress in the direction NE – SW that is responsible for folding, or they might be caused by the stretching of the outer arc for the folded layers. According to field observations and paleostress studies, the region experienced four stress stages. The first is a main compressive tectonic phase in the NE – SW direction. The second phase is the second compressive tectonic stress in the direction NW – SE. The third was a NE – SW extension tectonic phase that originated during the final uplift stage of folding and it is representative of the major fold trend. The fourth is the NW – SE extension face considered as the extension stress connected to the principal NE – SW compressive stress.

Closing of the east Palaeo‐Tethys Ocean: Source–sink records from Middle Triassic sediments, Hainan Island, China

During the Late Palaeozoic to Early Mesozoic, the eastern segment of the Palaeo–Tethys Ocean closed, resulting in the collision and amalgamation of the South and North Hainan Islands. However, the exact location of the collision and amalgamation remains controversial. The main collision locations are the Baisha, Jiusuo–Lingshui and Changjiang–Qionghai faults. The U–Pb age of detrital zircons was used to determine the main source area of the Middle Triassic basin in the eastern part of Hainan Island and the closed position of the eastern section of the Palaeo‐Tethys Ocean. The U–Pb dating of detrital zircons revealed that the Middle Triassic Lingwen Formation contains four age groups: 235–258, 335–446, 766–986 and >1000 Ma. Notably, rock masses aged 248–252 Ma that were formed in a post‐orogenic tension setting have been identified in the western region of Hainan Island, whereas no igneous rocks from this period have been discovered in the eastern region. The detrital zircon samples from the Lingwen Formation revealed a peak at 249 ± 2 Ma U–Pb age, which is important evidence indicating that the Changjiang–Qionghai Fault is the product of collision between the southern and northern Hainan terranes. Affected by the bipolar subduction of the eastern segment of the Palaeo‐Tethys Ocean, the collision and amalgamation of the South and North Hainan terranes occurred, and experienced a post‐collision (extensional) process at ca. 249 ± 2 Ma.

Tensions between inclusion and change in worldview education: can Joe F. Kincheloe’s bricolage help teachers navigate them?

ABSTRACT This paper delineates tensions that arguably are inherent to integrative Worldview Education in plural societies, due to the subject’s dual commitment to imperatives of inclusion and change. The imperative of inclusion stems from the subject’s mandate to integrate the whole plurality of pupils in society, whereas the imperative of change stems from the subject’s mandate to promote certain aims and values over others. The task of handling such tensions can be daunting, and teachers need resources that enable them to do so. The main aim of this paper is thus to provide a critical examination of the metaphor of bricolage, as it was conceptualised by Joe L. Kincheloe, in search of such resources. The examination points to the following chain of argument: (1) Kincheloe’s bricolage contains its own tensions between inclusion and change, due to its application of multiple methods, methodologies, and perspectives, combined with a desire to promote social change. (2) There is a strong overlap between the two sets of tensions. (3) Teachers should be aware of the distinct political and philosophical underpinnings of Kincheloe’s bricolage, and how these can create new tensions, possibly productive ones, if teaching and learning in Worldview Education is framed as bricolage work.

Hypoxia and Hypoxia Mimetic Agents As Potential Priming Approaches to Empower Mesenchymal Stem Cells.

Mesenchymal stem cells (MSC) exhibit self-renewal capacity and multilineage differentiation potential, making them attractive for research and clinical application. The properties of MSC can vary depending on specific micro-environmental factors. MSC resides in specific niches with low oxygen concentrations, where oxygen functions as a metabolic substrate and a signaling molecule. Conventional physical incubators or chemically hypoxia mimetic agents are applied in cultures to mimic the original low oxygen tension settings where MSC originated. This review aims to focus on the current knowledge of the effects of various physical hypoxic conditions and widely used hypoxia-mimetic agents-PHD inhibitors on mesenchymal stem cells at a cellular and molecular level, including proliferation, stemness, differentiation, viability, apoptosis, senescence, migration, immunomodulation behaviors, as well as epigenetic changes.

Research on Innovative Mechanical Structure Design in Carbon Fiber Ingot Winding Technology

Abstract Carbon fiber ingot winding, the final step in the production of carbon fiber, is a crucial process that directly influences the quality of the final product, ensuring the quality of carbon fiber and facilitating smooth processing in the subsequent process. This paper describes the principle of carbon fiber ingot winding, summarises the difficulties of winding carbon fiber ingots, and designs a winding machine that can wind different specifications of carbon fiber ingots. It figures out the folding curve and spiral rise angle in the winding movement of carbon fiber spindles using theoretical knowledge of physical kinematics. It then builds an experimental test platform, prepares the experimental samples, and, based on the needs of the experiment, analyses the process of carbon fiber spindle winding technology. The results demonstrate that the error value between the measurement on the experimental platform and the actual manual measurement remains within 0.01 g, the carbon fiber spindle becomes compact at a tension setting scale value of 5, and the winding end surface remains flat. Furthermore, we find that a larger spiral angle, ranging from 51.7° to 208.5°, enhances the winding’s overlapping effect. The innovative mechanical structure design scheme proposed in this paper has been proven to be effective in process simulation.

The potato vine crusher: a new tool for harvest weed seed control

Harvest weed seed control (HWSC), an evolving strategy in weed management, is highly effective for the control of a variety of weed species in North American cropping systems. Previous devices for weed seed devitalization at harvest have been limited to tow behind and integrated combine systems. The potato vine crusher (PVC) is a harvester-mounted set of rollers originally designed for crushing and control of Ostrinia nubilalis (Hübner) larvae during potato ( Solanum tuberosum L.) harvest. To evaluate the potential of the PVC for HWSC, we conducted stationary testing of spring tension and roller speed settings to maximize devitalization of lambsquarters ( Chenopodium album L.), the most problematic weed species in Canadian potato production. In addition, we evaluated the efficacy of the PVC for the devitalization of several pernicious weed species under controlled conditions and during a simulated harvest. Increasing PVC spring tension reduced the devitalization of lambsquarters seed, whereas roller speed had minimal effect. In contrast, maximized spring tension and minimized roller speed reduced lambsquarters emergence (53%) in soil. Hypocotyl and radicle elongation was observed from lambsquarters seed fragments under controlled conditions, potentially contributing to increased control in soil through fatal germination. High levels of seed devitalization (65%–94%) were observed for all species under controlled conditions. During simulated harvest, control of large weed seeds (50%–63%) was observed, whereas smaller seeds were not impacted, signifying the importance of seed size for PVC efficacy. These studies demonstrate the PVC as a promising new tool for HWSC in Canadian potato production systems.

‘There’s Divinity in Everything Here’

Contemporary Pagan nature sanctuaries across the United States feature practices such as ecosystem restoration, species preservation, and green burial. Pagans ritualize these practices in ways that both express and constitute reverential or intimate relations between humans, soil, plants, rocks, nonhuman animals, and spiritual beings. Their nature sanctuaries also express particular relationships with the more-than-human world through creating various kinds of sacred spaces, including shrines and altars. Because they are separated from most visitors’ daily lives, these sanctuaries work for many visitors as portals to a different state of consciousness in which human and nonhuman nature are experienced in powerful ways. This paper will explore the ritualized ways that environmentally conscious practices are promoted and engaged with at these sanctuaries. I will focus particularly on two sets of tensions: 1) leaving spaces wild and domesticating them and 2) natural burial and ecosystem restoration that brings species back to life. These varied practices reveal different ways of understanding ‘nature’ and ‘the wild’.

Theology and Economy ‘after’ Barth

AbstractThe relation of theology and economy is a perennial theological challenge. Many contemporary theologians' understanding of this challenge is shaped by Karl Barth's attempt to resolve a set of tensions problematising this relation inherited from figures like Kant and Feuerbach. Barth ‘identified’ God's decision to be God with God's decision to be human. Further, he inconsistently but insistently claimed that the ‘form’ in which God reveals Godself in the person of Jesus somewhat isomorphically corresponds to God in Godself. The brilliance and yet instability of Barth's approach spawned a number of construals of theology and economy which depart from him in significant ways. I label these contemporary trajectories the post‐Barthian temptation, Barthian revisionism, Barthian Balthasarianism, and Barthian catholicism and critically evaluate them, suggesting that Barthian catholicism is the most promising.

Between norms and margins: The “Norms–Fringe–Margins” model. A dynamic model of psychosocial self-construction through an expanded notion of working

This article addresses the new forms and relationships to work currently developing, in line with the upheavals of the Anthropocene. Occupational and counseling psychology are developing models that increasingly integrate systemic and contextual dimensions to understand careers and work-related issues. We propose a theoretical model “Norms–Fringe–Margins” to approach these new forms of work as hybrid constructs, sources of both personal and social innovation. We argue that these new ways of relating to work can contribute to sustainable and just commitments to citizenship, both at the individual and social levels. The model distinguishes three interrelated spaces of psychosocial self-construction through work: a normed space (Norm), a space on the margin (Margin), and an intermediate space (Fringe). To analyze the psychosocial construction of a person, we study the dynamic interactions of these three psychosocial spaces as a presence supported by a set of tensions to overcome.

Tensions in Data Journey Activities: Mobilising, Processing, Producing, and Re-purposing Data in Environmental Assessment Practice

Digital data shape work practices as they travel through space, time, and social situations. In turn, workers shape the materiality of data through different data-oriented activities. In this paper, we draw on theory of data journeys to develop and present a conceptual framework of four data-intensive activities: Producing, mobilising, processing, and re-purposing. Together, those activities capture entanglements of data transformations and data-intensive practices. We develop the framework through a qualitative study of digitisation in Environmental Assessment (EA) practice. EA practitioners reflect on their experiences working with digital environmental data through ten semi-structured and two interactive interviews. The paper offers two main contributions. First, we develop a data journey theoretical framework and show that it is useful as a unit of analysis for uncovering tensions in data-oriented activities. Second, we use these insights to outline a set of tensions for future design activities in the area of data work practices.

Tectonically assisted emplacement of oceanic intraplate volcanoes: The Bathymetrists Seamounts, central Atlantic

The origin of broad intraplate volcanic provinces has been related to deep mantle plumes or shallow lithospheric processes, e.g., underlying large fault systems. One example of an understudied intraplate volcanic province is the Bathymetrists Seamounts (BSM) in the central-eastern Atlantic, an area with dense and extended fracture zones, but the BSM has been associated with a mantle plume origin. Extensive bathymetric mapping and seafloor sampling show that most BSM-seamounts resemble flat-topped guyots capped by carbonate platforms. Vesicular, volcanoclastic samples imply that their tops formed near sea level, followed by reef formation during cessation of volcanism and crustal subsidence. Erosion determines the seamount irregularity proportional to their sizes. Strong ellipticity of some seamounts is related to multiple vents that erupted along fractures. The orientation of the volcanoes, carbonate platforms, and morphological lineaments of the BSM show particular trends that reveal information on their origin and formation mechanisms. Geomorphological analyses indicate a structural control on volcano emplacement related to underlying lithospheric faults resembling a Riedel shear pattern. The stress field corresponding to their orientations is related to a NE-SW tensional setting, fitting to the prevalent tectonic setting ~56–38 Ma years ago that coincides with the BSM formation and an increase in spreading rates. A change in movement of the African plate during this time, together with the reactivation of fracture zones of the strongly sheared equatorial Atlantic, created pathways in the lithosphere and possibly enhanced magmatism. The seamounts do not show distinct differences in erosion state, morphology, carbonate platform depth, or Mn-crust thickness, in contrast to what would be expected for an age progression within the seamount chain. Our observations, therefore, do not support a plume mantle source. While the magmatic source remains undefined, we show that tectonic pathways determined the shape of the seamounts and enabled the broad emplacement of the Bathymetrists seamount chain.

Control methodology for tensioned web considering thermal behavior in roll-to-roll manufacturing systems

The roll-to-roll manufacturing system is utilized for processing flexible webs into functional films, offering high productivity through continuous multi-stage processing. In the converting span, which encompasses coating, printing, and drying processes, precise tension control and appropriate tension settings are crucial to ensure the quality of the final product. Particularly during the drying process, where solvent removal occurs, thermal deformation of the web induces additional elongation, amplifying the impact of tension on coating layer quality and printing patterns. Consequently, the drying process necessitates more accurate tension control compared to other span, necessitating the application of feedforward control that considers web thermal deformation. However, the current tension control logic employs an imprecise temperature distribution within the dry span as an input, resulting in inadequate tension control performance and defects such as uneven coating layers and registration errors. This research presents the development of a feedforward tension controller that employs Finite Element Method (FEM)-based web temperature distribution inputs to enhance tension control performance during the drying span. The tension control performance was compared and analyzed based on the drying span web temperature prediction method, affirming that higher accuracy in predicting the web temperature distribution leads to improved tension control performance. Experimental results from an industrial-scale roll-to-roll system demonstrate that the proposed model enhances tension control accuracy during the drying process by 27.76% compared to the existing control logic. Furthermore, the effectiveness of the tension control logic in enhancing the surface quality of functional layers was confirmed through surface quality analysis using solid oxide fuel cell (SOFC) electrolyte layers.

Doing Laundry with the TERF

TERF, or trans-exclusionary radical feminist, is a contemporary configuration that has gained traction in this feminist political moment to encapsulate an imagined set of generational tensions among feminists and queers with respect to gender's essential and/or expansive possibilities. It is also loaded with negative affect. This essay traces the ways that TERF travels in feminist dialogue—often alongside “lesbian”—and argues that loud disavowals of TERFs accumulate into discursive routines that present as anti-anti-trans, but (and) primarily function to preserve a sense of the threatened status of lesbians.

Mechanical Aging Test and Sealing Performance of Thermoplastic Vulcanizate as Sealing Gasket in Automotive Fuel Cell Applications.

Ethylene-propylene-diene monomer (EPDM) rubber is one of the rapidly developing synthetic rubbers for use as a gasket material in proton exchange membrane (PEM) fuel cell applications. Despite its excellent elastic and sealing properties, EPDM faces challenges such as molding processability and recycling ability. To overcome these challenges, thermoplastic vulcanizate (TPV), which comprises vulcanized EPDM in polypropylene matrix, was investigated as a gasket material for PEM fuel cell applications. TPV showed better long-term stability in terms of tension and compression set behaviors under accelerated aging conditions than EPDM. Additionally, TPV exhibited significantly higher crosslinking density and surface hardness than EPDM, regardless of the test temperature and aging time. TPV and EPDM showed similar leakage rates for the entire range of test inlet pressure values, regardless of the applied temperature. Therefore, we can conclude that TPV exhibits a similar sealing capability with more stable mechanical properties compared with commercialized EPDM gaskets in terms of He leakage performance.