1,445 research outputs found

    An optimized tuned mass damper/harvester device

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    Much work has been conducted on vibration absorbers, such as tuned mass dampers (TMD), where significant energy is extracted from a structure. Traditionally, this energy is dissipated through the devices as heat. In this paper, the concept of recovering some of this energy electrically and reuse it for structural control or health monitoring is investigated. The energy-dissipating damper of a TMD is replaced with an electromagnetic device in order to transform mechanical vibration into electrical energy. That gives the possibility of controlled damping force whilst generating useful electrical energy. Both analytical and experimental results from an adaptive and a semi-active tuned mass damper/harvester are presented. The obtained results suggest that sufficient energy might be harvested for the device to tune itself to optimise vibration suppression

    Life story resources in dementia care: a review.

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    PURPOSE: Life story work has a relatively long tradition in the caring sciences and is recognised as an important component of dementia care and practice. However, to date, there has not been a review of accessible life story resources. The paper aims to discuss these issues. DESIGN/METHODOLOGY/APPROACH: Following a systematic approach to identification and inclusion, 11 life story resources were reviewed to ascertain areas of commonality and divergence between the materials. FINDINGS: The authors were able to group the analysis under eight areas and at the end of this process, it was uncertain if life story work is a formal staff intervention or an informal activity that people with dementia and their families could engage in. Resources also varied in terms of whether the life story information was organised in a chronological way, or with topics of interest/discussion or with a combination of both. Life story evaluation and its impact on the life of the person with dementia is in need of development. PRACTICAL IMPLICATIONS: Across the resources the authors identified four reasons to do life story work which the authors have named as: emotional connections; interactional connections; building new connections and practical care connections. SOCIAL IMPLICATIONS: There was limited guidance aimed at helping people with dementia to develop and compile their own life story. ORIGINALITY/VALUE: This paper provides new insights into the usefulness, future directions and content of life story resources in dementia care. It will be of interest to those in health and social care as well as people living with dementia

    An experimental and theoretical study of transient negative ions in Mg, Zn, Cd and Hg

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    A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states

    Racial Identity: Toward an Integrated Developmental Psychological Perspective

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    This article outlines current knowledge and lines of research regarding racial identity and, in particular, African American racial identity. A developmental psychological framework is proposed as a means of integrating and synthesizing 2 lines of racial identity research that have emerged within the existing literature: (a) the developmental line of research and (b) the adjustment outcome line of research. The proposed integration of the current racial identity research will emphasize the interdependency of developmental mechanisms, outcome processes, and identity trajectories among minority individuals, and highlight the significance of those identities for individuals across their life spans. Potential benefits of integrating these 2 lines of research within a developmental psychological framework are discussed regarding both scientific theory and practice-related applications

    Using Proanthocyanidin as a Root Dentin Conditioner for GIC Restorations

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    Glass ionomer cements (GICs) are considered the material of choice for restoration of root carious lesions (RCLs). When bonding to demineralized dentin, the collapse of dentinal collagen during restorative treatment may pose challenges. Considering its acidic nature and collagen biomodification effects, proanthocyanidin (PAC) could be potentially used as a dentin conditioner to remove the smear layer while simultaneously acting to biomodify the dentinal collagen involved in the bonding interface. In this study, 6.5% w/v PAC was used as a conditioner for sound (SD) and laboratory demineralized (DD) root dentin before bonding to resin-modified GIC (FII), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified GIC (FVII), or a high-viscosity GIC (FIX). Root dentin conditioned with deionized distilled water (DDW) or polyacrylic acid (PAA) served as controls. Results indicated FII showed higher shear bond strength (SBS) on SD than the other 2 GICs, especially in PAA-conditioned samples; FIX showed significantly higher SBS than FII and FVII on PAA- or PAC-conditioned DD. In each category of GIC, PAA and PAC did not have a significant influence on SBS in most cases compared to DDW except for a significant decrease in PAC-conditioned SD bonded to FII and a significant increase in PAA-conditioned DD bonded to FIX. The bonding interface between GIC and SD was generally more resistant to the acid-base challenge than DD. Although the alterations in failure modes indicated a compromised interfacial interaction between GICs and PAC-treated root dentin, biomodification effects of PAC on dentin were observed from Raman microspectroscopy analysis in terms of the changes in mineral-to-matrix ratio and hydroxyproline-to-proline ratio of dentin adjacent to the bonding interface, especially of DD. Results from this study also indicated the possibility of using in situ characterization such as Raman microspectroscopy as a complementary approach to SBS test to investigate the integrity of the bonding interface

    The Skits, Sketches, and Stories of MotherScholars

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    “MotherScholars” are those who creatively weave their maternal identities into their scholarly spaces. With this article we invite readers along a collaborative friendship study of our own participatory arts-based journey to understand, reclaim, and identify personal and professional benefits only realized once we acknowledged and embraced the blended reality of Mother Scholarhood. Our work is presented as a curation of individual skits, sketches, and short stories that were created during a collective 8-week time span in a shared virtual space. We open our story to interpretation and interaction through the lenses of our readers

    Quarantine Mothering and Working at Home: How Institutions of Higher Education Supported (or Failed to Support) Academic Mothers

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    This mixed methods study explores whether and how explicit policies, implicit practices, and internal communication from university administrators about aca-demic mothers’ work lives and expectations were impacted by the 2020 COVID-19 quarantine protocols. As this was a large study focussing on university policies addressing the presence of children on campus and the ways in which their enforcement or nonenforcement affected the personal and professional lives of faculty, we used purposive sampling (Palys) and snowball sampling (Patton) to distribute a survey in academic social media groups and to professional organization listservs (Palys). Among other things, the survey asked participants to report how well they thought their university was handling the COVID-19 pandemic and invited them to participate in an in-depth interview. As a result of the survey responses, we subsequently interviewed nineteen academic mothers from a range of academic disciplines, ages, and types of institutions, until we reached theoretical saturation (Strauss and Corbin). The semi-structured interview protocol included questions about the impact of COVID-19-related policies, practices, and messaging regarding children on participants’ job satisfaction, mental and physical health, as well as work-life balance. We used open and axial coding (Strauss and Corbin) and the constant comparative method (Glaser and Strauss) to analyze the data. We then triangulated the data by comparing interview and survey findings, engaging multiple researchers in the analysis, and conducting peer debriefings (Denzin and Lincoln; Lincoln and Guba). Findings highlight institutional policies and practices that serve or fail to serve faculty in terms of supporting their professional advancement in teaching, research, and service

    Remineralising effects of fluoride varnishes containing calcium phosphate on artificial root caries lesions with adjunctive application of proanthocyanidin

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    Objectives: To evaluate the remineralising effects of fluoride (F) varnishes containing bioavailable calcium-phosphate compound (Ca-P) based remineralisation systems and 5000 ppm F toothpaste (FTP) on root caries lesions (RCLs) and the potential effects of proanthocyanidin (PA) for the treatments of RCLs when used as an adjunct to F regimens. Methods: Demineralised root dentine and a pH-cycling model were used to mimic RCLs and the oral environment. Remineralising effects of MI VarnishTM (MIV) containing casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) and Clinpro™ White Varnish (CPWV) containing tri-calcium phosphate (TCP) along with FTP and PA were evaluated regarding the birefringence, elemental composition, mechanical properties and mineral density of remineralised dentine with DuraphatTM as a comparison. Results: MIV, CPWV and DuraphatTM promoted the incorporation of F into RCLs and increased mineral density but did not change microhardness of root dentine significantly. Surface microhardness increased significantly when MIV or CPWV was used with 5000 ppm FTP. Application of PA with F regimens significantly increased subsurface mineral density. When PA was applied with MIV or CPWV along with FTP, the highest ion uptake and relative mineral gain (%ΔZ) was achieved, and significant increase of microhardness was up to 30 μm depth. Generally, MIV was associated with a higher mineral content gain than CPWV. Significance: Treatment of carious root surfaces remains challenging due to the complex pathological processes and difficulty in restoring the highly organised structure of root dentine. Treatment strategies targeting both remineralisation and preservation of the dentinal organic matrix have the potential to improve the fluoride-mediated remineralisation approaches

    New Information on Culmacanthus (Acanthodii: Diplacanthiformes) from the ?Early–Middle Devonian of Southeastern Australia

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    A new articulated acanthodian from the Devonian Bunga Beds on the south coast of New South Wales is assigned to Culmacanthus sp., and reveals that this diplacanthiform has smooth dental plates on the occlusal surfaces of the lower jaws. Within the Acanthodii, this type of element was first identified in “Gladiobranchus” probaton from the earliest Devonian MOTH locality, Northwest Territories, Canada, and has now also been identified in “Euthacanthus” curtus (Lochkovian, Lower Old Red Sandstone, Scotland) and Diplacanthus spp. (Givetian, Scotland and Frasnian, Canada). The dental plates in Culmacanthus have the same morphology as those of “Gladiobranchus” probaton and “Euthacanthus” curtus. Reexamination of type specimens of Culmacanthus shows that its pectoral fin spines do not have long insertions, and the purported lack of prepectoral, admedian and prepelvic fin spines could be due to loss of the elements before burial rather than morphological absence
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