1,821 research outputs found

    Let’s Talk About it: Caregivers’ Perspective on Communication About Sexuality with Foster Youth

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    Foster youth are particularly at risk for pregnancy and are 2.5 times more likely to become pregnant by age 19 than their peers that are not in the child welfare system (Comlossy, 2013). Researchers have gathered that parents and children are commonly apprehensive when it comes to discussing sexual health and reproduction. Limited research has been conducted regarding the roles of caregivers as advocates for youth and caregivers’ perceptions of how to carry out this role as an educator. This study aims to further investigate caregivers’ beliefs of their self-efficacy levels in assisting youth with their sexual health and reproduction

    Nonlinear viscoelastic characterization of structural adhesives

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    Measurements of the nonliner viscoelastic behavior of two adhesives, FM-73 and FM-300, are presented and discussed. Analytical methods to quantify the measurements are given and fitted into a framework of an accelerated testing and analysis procedure. The single integral model used is shown to function well and is analogous to a time-temperature stress-superposition procedure (TTSSP). Advantages and disadvantages of the creep power law method used in this study are given

    The nonlinear viscoelastic response of resin matrix composite laminates

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    Possible treatments of the nonlinear viscoelastic behavior of materials are reviewed. A thermodynamic based approach, developed by Schapery, is discussed and used to interpret the nonlinear viscoelastic response of a graphite epoxy laminate, T300/934. Test data to verify the analysis for Fiberite 934 neat resin as well as transverse and shear properties of the unidirectional T300/934 composited are presented. Long time creep characteristics as a function of stress level and temperature are generated. Favorable comparisons between the traditional, graphical, and the current analytical approaches are shown. A free energy based rupture criterion is proposed as a way to estimate the life that remains in a structure at any time

    Numerical solution methods for viscoelastic orthotropic materials

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    Numerical solution methods for viscoelastic orthotropic materials, specifically fiber reinforced composite materials, are examined. The methods include classical lamination theory using time increments, direction solution of the Volterra Integral, Zienkiewicz's linear Prony series method, and a new method called Nonlinear Differential Equation Method (NDEM) which uses a nonlinear Prony series. The criteria used for comparison of the various methods include the stability of the solution technique, time step size stability, computer solution time length, and computer memory storage. The Volterra Integral allowed the implementation of higher order solution techniques but had difficulties solving singular and weakly singular compliance function. The Zienkiewicz solution technique, which requires the viscoelastic response to be modeled by a Prony series, works well for linear viscoelastic isotropic materials and small time steps. The new method, NDEM, uses a modified Prony series which allows nonlinear stress effects to be included and can be used with orthotropic nonlinear viscoelastic materials. The NDEM technique is shown to be accurate and stable for both linear and nonlinear conditions with minimal computer time

    Creep and creep rupture of laminated graphite/epoxy composites

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    An incremental numerical procedure based on lamination theory is developed to predict creep and creep rupture of general laminates. Existing unidirectional creep compliance and delayed failure data is used to develop analytical models for lamina response. The compliance model is based on a procedure proposed by Findley which incorporates the power law for creep into a nonlinear constitutive relationship. The matrix octahedral shear stress is assumed to control the stress interaction effect. A modified superposition principle is used to account for the varying stress level effect on the creep strain. The lamina failure model is based on a modification of the Tsai-Hill theory which includes the time dependent creep rupture strength. A linear cumulative damage law is used to monitor the remaining lifetime in each ply

    Implementation Science and Fidelity Measurement: A Test of the 3-5-7 Model™

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    Children and youths engaged with the child welfare system can experience grief and loss as a result of trauma, broken relationships, and inadequate attachments. Interventionists are often challenged to implement effective strategies that help youths to reestablish trusting relationships and to promote overall psychological well-being. A 5-year federal demonstration project funded by the U.S. Department of Health and Human Services, Children’s Bureau, guided by an implementation science model, sought to increase well-being in youths age 12–21 who were involved in the child welfare system. The 3-5-7 Model™, a strengths-based approach that empowers children, youths, and families to engage in grieving and integrating significant relationships, was studied. A fidelity system was created in order to test the model. Important lessons about implementation science guided the work of the demonstration project. Although definitive conclusions could not be reached, several indicators of psychological well-being were found to be associated with high levels of fidelity to the 3-5-7 ModelTM. Suggestions for future research are offered

    Application of a Geomorphic and Temporal Perspective to Wetland Management

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    The failure of managed wetlands to provide a broad suite of ecosystem services (e.g., carbon storage, wildlife habitat, ground-water recharge, storm-water retention) valuable to society is primarily the result of a lack of consideration of ecosystem processes that maintain productive wetland ecosystems or physical and social forces that restrict a manager’s ability to apply actions that allow those processes to occur. Therefore, we outline a course of action that considers restoration of ecosystem processes in those systems where off-site land use or physical alterations restrict local management. Upon considering a wetland system, or examining a particular management regime, there are several factors that will allow successful restoration of wetland services. An initial step is examination of the political/social factors that have structured the current ecological condition and whether those realities can be addressed. Most successful restorations of wetland ecosystem services involve cooperation among multiple agencies, acquisition of funds from non-traditional sources, seeking of scientific advice on ecosystem processes, and cultivation of good working relationships among biologists, managers, and maintenance staff. Beyond that, in on-site wetland situations, management should examine the existing hydrogeomorphic situation and processes (e.g., climatic variation, tides, riverine flood-pulse events) responsible for maintenance of ecosystem services within a given temporal framework appropriate for that wetland’s hydrologic pattern. We discuss these processes for five major wetland types (depressional, lacustrine, estuarine, riverine, and man-made impoundments) and then provide two case histories in which this approach was applied: Seney National Wildlife Refuge with a restored fen system and Bosque del Apache National Wildlife Refuge where riverine processes have been simulated to restore native habitat. With adequate partnerships and administrative and political support, managers faced with degraded and/or disconnected wetland processes will be able to restore ecosystem services for society in our highly altered landscape by considering wetlands in their given hydrogeomorphic setting and temporal stage

    Identifying the attributes of a profession in the practice and regulation of fire safety engineering

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    Fire Safety Engineering is often implemented within a framework that requires a recognized and recognizable profession. This article reviews the current state of various attributes that define Fire Safety Engineering as a profession. It is argued that: 1) reliance on prescriptive solutions opens the domain to practitioners that do not possess the required specialist knowledge; 2) the fire safety engineering process is often triggered through non-compliances to individual prescriptive provisions, negatively impacting on the discipline's professional authority; 3) the discipline operates in a manner that exposes it to challenges of its ethical code; and 4), the lack of a well-defined accreditation framework challenges the professional culture. The resulting environment favours a customer relationship between those commissioning the work and the Fire Safety Engineer, rather than the client relationship necessary for professional practise. Most engineering disciplines respond to failures by formalisation of the profession around its duty of care to society. Conversely, in Fire Safety Engineering such responses have focused on regulation. Recent incidents are a significant impetus and opportunity for the fire safety profession to better formalize itself
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