A Fiber Optic RF Resonant Cavity Sensor for Strain Sensing-Forrcs

A fiber optic vibration and strain sensor described by Rogowski et al [1] implemented a radio frequency (rf) phase locked loop in an optical strain gauge bonded to or embedded in a composite structure. A laser is modulated at radio frequency by a voltage controlled oscillator. The phase delay through the optical fiber transmission line is compared to the source oscillator, and the resulting error signal shifts the oscillator, locking the phase. Strain in the specimen (a composite panel) produces a change in optical phase length in the fiber. Tracking the frequency change gives a measure of the integrated strain transduced into the fiber from the strained panel. Strain level sensitivity on the order of 0.1 microstrains has been reported [1]. However, considerable confusion surrounds the performance of the reported sensor, since noise presumed to arise from cladding/core mode interference and splice reflections makes significant filtering necessary, reducing the bandwidth of the sensor, e.g., increasing the response time to detect strains [2]. This limits vibration control applications

UHF Modulation and Fourier Transform Differential Time Domain Techniques for Measuring Strain Via Fiber Optics

The design and manufacture of future space transportation and delivery systems will be strongly driven by safety, cost, maintenance and reliability considerations. Advanced composite structural components are likely to be a key element in realizing these system objectives. Composites have the additional potential of enabling the embedment of sensors for system health monitoring, which supports requirements for low cost safety, maintenance and repair diagnosis

Degradation of Optical Fibers at Carbon-Carbon Pyrolysis Temperatures

The value of having a sensor capable of monitoring the progress of carbon-carbon fabrication has been previously discussed and continues to be an attractive objective [1, 2]. Acoustic emission, when correlated with gas evolution and temperature profile, has been shown to give a strong indication of the internal stresses produced during pyrolysis and the path taken to achieve stress relief under varying process conditions. A challenging aspect of the process is the high temperature at which in situ sensors must function. Distributed physical proximity to the part under fabrication is critical to insure that the data reflects the material condition in real-time

Acceptability and feasibility of peer assisted supervision and support for intervention practitioners: a Q-methodology evaluation

Evidence-based interventions often include quality improvement methods to support fidelity and improve client outcomes. Clinical supervision is promoted as an effective way of developing practitioner confidence and competence in delivery; however, supervision is often inconsistent and embedded in hierarchical line management structures that may limit the opportunity for reflective learning. The Peer Assisted Supervision and Support (PASS) supervision model uses peer relationships to promote the self-regulatory capacity of practitioners to improve intervention delivery. The aim of the present study was to assess the acceptability and feasibility of PASS amongst parenting intervention practitioners. A Q-methodology approach was used to generate data and 30 practitioners volunteered to participate in the study. Data were analyzed and interpreted using standard Q-methodology procedures and by-person factor analysis yielded three factors. There was consensus that PASS was acceptable. Participants shared the view that PASS facilitated an environment of support where negative aspects of interpersonal relationships that might develop in supervision were not evident. Two factors represented the viewpoint that PASS was also a feasible model of supervision. However, the third factor was comprised of practitioners who reported that PASS could be time consuming and difficult to fit into existing work demands. There were differences across the three factors in the extent to which practitioners considered PASS impacted on their intervention delivery. The findings highlight the importance of organizational mechanisms that support practitioner engagement in supervision

Shape memory-based actuators and release mechanisms therefrom

SM-based actuators (110) and release mechanisms (100) therefrom and systems (500) including one or more release mechanisms (100). The actuators (110) comprise a SM member (118) and a deformable member (140) mechanically coupled to the SM member (118) which deforms upon a shape change of the SM member triggered by a phase transition of the SM member. A retaining element (160) is mechanically coupled to the deformable member (140), wherein the retaining element (160) moves upon the shape change. Release mechanism (100) include an actuator, a rotatable mechanism (120) including at least one restraining feature (178) for restraining rotational movement of the retaining element (160) before the shape change, and at least one spring (315) that provides at least one locked spring-loaded position when the retaining element is in the restraining feature and at least one released position that is reached when the retaining element is in a position beyond the restraining feature (178). The rotatable mechanism (120) includes at least one load-bearing protrusion (310). A hitch (400) is for mechanically coupling to the load, wherein the hitch is supported on the load bearing protrusion (310) when the rotatable mechanism is in the locked spring-loaded position

Policy to Implementation: Evidence-Based Practice in Community Mental Health — Study Protocol

Background: Evidence-based treatments (EBTs) are not widely available in community mental health settings. In response to the call for implementation of evidence-based treatments in the United States, states and counties have mandated behavioral health reform through policies and other initiatives. Evaluations of the impact of these policies on implementation are rare. A systems transformation about to occur in Philadelphia, Pennsylvania, offers an important opportunity to prospectively study implementation in response to a policy mandate. Methods/design: Using a prospective sequential mixed-methods design, with observations at multiple points in time, we will investigate the responses of staff from 30 community mental health clinics to a policy from the Department of Behavioral Health encouraging and incentivizing providers to implement evidence-based treatments to treat youth with mental health problems. Study participants will be 30 executive directors, 30 clinical directors, and 240 therapists. Data will be collected prior to the policy implementation, and then at two and four years following policy implementation. Quantitative data will include measures of intervention implementation and potential moderators of implementation (i.e., organizational- and leader-level variables) and will be collected from executive directors, clinical directors, and therapists. Measures include self-reported therapist fidelity to evidence-based treatment techniques as measured by the Organizational Social Context Measurement System and the Implementation Climate Assessment, leader variables as measured by the Multifactor Leadership Questionnaire, attitudes towards EDTs as measured by the Evidence-Based Practice Attitude Scale, and knowledge of EBTs as measured by the knowledge of Evidence-Based Services Questionnaire. Qualitative data will include semi-structured interviews with a subset of the sample to assess the implementation experience of high-, average-, and low-performing agencies. Mixed methods will be integrated through comparing and contrasting results from the two methods for each of the primary hypotheses in this study. Discussion: Findings from the proposed research will inform both future policy mandates around implementation and the support required for the success of these policies, with the ultimate goal of improving the quality of treatment provided to youth in the public sector

First Science Observations with SOFIA/FORCAST: Properties of Intermediate-Luminosity Protostars and Circumstellar Disks in OMC-2

We examine eight young stellar objects in the OMC-2 star forming region based on observations from the SOFIA/FORCAST early science phase, the Spitzer Space Telescope, the Herschel Space Observatory, 2MASS, APEX, and other results in the literature. We show the spectral energy distributions of these objects from near-infrared to millimeter wavelengths, and compare the SEDs with those of sheet collapse models of protostars and circumstellar disks. Four of the objects can be modelled as protostars with infalling envelopes, two as young stars surrounded by disks, and the remaining two objects have double-peaked SEDs. We model the double-peaked sources as binaries containing a young star with a disk and a protostar. The six most luminous sources are found in a dense group within a 0.15 x 0.25 pc region; these sources have luminosities ranging from 300 L_sun to 20 L_sun. The most embedded source (OMC-2 FIR 4) can be fit by a class 0 protostar model having a luminosity of ~50 L_sun and mass infall rate of ~10^-4 solar masses per year.Comment: Accepted by ApJ Letter

A review on silica aerogel-based materials for acoustic applications

Silica aerogels are popular in terms of production volume and real-world applications. Although the current market growth rate is driven exclusively by thermal insulation, aerogels may also be attractive for acoustic applications with the potential in aiding sound absorption/insulation. This paper is a summary of the acoustics related studies of silica aerogel-based products. It introduces silica aerogels, some acoustic characterization methods, and reviews systematically the available data on sound absorption/insulation of silica aerogels, polymer-silica aerogel composites, nonwoven-silica aerogel blankets, and aerogel renders/glazing. The work identifies areas where further research is required, including experimental and theoretical work on the physics of sound absorption in mesoporous materials, and more systematic and standardized evaluations of the acoustic properties of aerogel and aerogel-composites. Aside from this call to action, the opportunities and barriers for the commercialization of silica aerogel products for acoustic applications are presented

The organizational social context of mental health services and clinician attitudes toward evidence-based practice: a United States national study.

UnlabelledABSTBACKGROUND: Evidence-based practices have not been routinely adopted in community mental health organizations despite the support of scientific evidence and in some cases even legislative or regulatory action. We examined the association of clinician attitudes toward evidence-based practice with organizational culture, climate, and other characteristics in a nationally representative sample of mental health organizations in the United States.MethodsIn-person, group-administered surveys were conducted with a sample of 1,112 mental health service providers in a nationwide sample of 100 mental health service institutions in 26 states in the United States. The study examines these associations with a two-level Hierarchical Linear Modeling (HLM) analysis of responses to the Evidence-Based Practice Attitude Scale (EBPAS) at the individual clinician level as a function of the Organizational Social Context (OSC) measure at the organizational level, controlling for other organization and clinician characteristics.ResultsWe found that more proficient organizational cultures and more engaged and less stressful organizational climates were associated with positive clinician attitudes toward adopting evidence-based practice.ConclusionsThe findings suggest that organizational intervention strategies for improving the organizational social context of mental health services may contribute to the success of evidence-based practice dissemination and implementation efforts by influencing clinician attitudes