Tip timing techniques for turbomachinery HCF condition monitoring

High Cycle Fatigue (HCF) has been established as the major common failure mode in the US Air Force large fleet of aero-engines. Corrective measures for this failure mode in themselves deliver additional technical, managerial and cost pressures. Two responses are in place to address this problem; risk mitigation through accelerated engine development fixes and technology transition through targeted and focussed R&D studies. It is the latter that is of interests and is discussed in this paper. Aero-engine blade vibrations of sufficient amplitude cause High Cycle Fatigue, which reduces blade life. In order to observe this vibration a non-intrusive monitoring system is sought. The vibration can be detected by measuring blade tip timing since in the presence of vibration the blade timing will differ slightly from the passing time calculated from rotor speed. Work done to investigate the suitability of a commercially available capacitance probe tip clearance measurement system for application as a non-intrusive turbomachinery blade tip timing measurement device is reported. Capacitance probe results are correlated with simultaneously measure strain gauge results and the performance of the capacitance system in measuring blade vibration is analysed. The growing interest in blade high cycle fatigue within the aerospace industry, and an approach to monitoring their condition are discussed as an extension to the above study. The suggested approach is based upon the tip-timing method, using non-contact optical probes located around the engine’s casing. Two current tip-timing techniques are suggested for the purpose. The techniques are summarised, the experimental validation of both methods outlined, and the approach taken to investigate the potential use as a condition monitoring tool described. The paper is concluded with a discussion of the future use of tiptiming as a condition monitoring tool

Exercises for Preparing Singers to Perform Contemporary Choral Music

This treatise has been prepared largely because of an increasing interest in contemporary music and an awareness on the part of many music educators of its merits in the curriculum of public schools and colleges. Since contemporary music is a controversial subject among directors, it has become necessary to search for specific, positive approaches to the teaching of contemporary music in high school

Test of Ideational Praxis (TIP): Preliminary Findings and Interrater and Test–Retest Reliability With Preschoolers

Praxis is the ability of the brain to develop an idea for action and plan, organize, and execute unfamiliar motor actions. It enables purposeful interaction with people and things in the environment. Ideation is central to praxis but has been little researched. This study investigated the reliability of the Test of Ideational Praxis (TIP) and examined ideational praxis in typical preschoolers. TIP performance for 78 preschoolers ages 3, 4, and 5 yr was videotaped and scored by two trained raters. The TIP has strong interrater reliability, supporting earlier findings. Further, we documented test–retest stability over 2 wk. As a group, preschoolers identified 10.6 affordances (ideas) for action on the TIP; no age differences were found. Training is required for accurate scoring of the TIP; following training, clinicians and researchers may find the TIP a useful tool to screen motor ideational abilities in young children

Predicting peak daily maximum 8 h ozone and linkages to emissions and meteorology in Southern California using machine learning methods (SoCAB-8HR V1.0)

The growing abundance of data is conducive to using numerical methods to relate air quality, meteorology and emissions to address which factors impact pollutant concentrations. Often, it is the extreme values that are of interest for health and regulatory purposes (e.g., the National Ambient Air Quality Standard for ozone uses the annual maximum daily fourth highest 8 h average (MDA8) ozone), though such values are the most challenging to predict using empirical models. We developed four different computational models, including the generalized additive model (GAM), multivariate adaptive regression splines, random forest, and support vector regression, to develop observation-based relationships between the fourth highest MDA8 ozone in the South Coast Air Basin and precursor emissions, meteorological factors and large-scale climate patterns. All models had similar predictive performance, though the GAM showed a relatively higher R2 value (0.96) with a lower root mean square error and mean bias.</p

Achieving Teaching, Scholarship, and Service through Community Engagement

Occupational therapy faculty currently face enormous challenges in meeting teaching load expectations, while also under pressure to participate in scholarly projects and to make administrative and service contributions. Community engagement projects may provide opportunities for faculty to effectively and efficiently meet the goals in each of these areas while imparting benefits to students and community partners as well. Faculty at the Department of Occupational Therapy (OT) at Virginia Commonwealth University (VCU) embraced this idea as consistent with the university’s mission and strategic plan, and recognized its benefits in assisting faculty to meet workload demands. Four community partnerships reflecting the range and diversity of populations currently involved are highlighted: the Children’s Museum of Richmond, Rebuilding Together-Richmond, the William Nelson Bland Literacy Center, and Gateway Homes of Richmond. The developmental process and resulting benefits are described for each of these partnerships, and the paper concludes with lessons learned from these collaborative efforts. From these examples, it appears important to be proactive about developing community partnerships and realistic about the challenges of collaboration, but also to be aware of the role community engagement plays in creatively blending the potentially conflicting demands on faculty time

Variability in plasma concentrations of methylprednisolone 6 days after intrasynovial injection of methylprednisolone acetate in racing horses: A field study

Background: Methylprednisolone (MP) acetate is a commonly used corticosteroid for suppression of inflammation in synovial structures in horses. Its use is often regulated in equine sports by plasma MP concentrations. Objectives: To describe variability in MP plasma concentrations after MP acetate injection in different synovial structures and with co-administration with hyaluronic acid (HA). Study design: Field study in actively racing horses in three disciplines (Thoroughbred, Standardbred and Quarter Horse). Methods: Seventy-six horses (15 Thoroughbreds, 20 Standardbreds and 41 Quarter Horses) were included in the study. Injection of any synovial structure with a total body dose of 100 mg MP acetate was permitted, data were grouped according to the synovial structure injected and coadministration with HA. Plasma was collected before injection and at 6 days post-injection. Per cent censored data (below the limit of quantification) for each synovial structure were determined, and summary statistics generated by Robust Regression on Order. Differences between synovial structures and co-administration with HA were identified by ANOVA with Tukey’s post hoc testing. Results: Metacarpophalangeal (MCP) plasma concentrations contained 86% censored data and could not be included in the statistical analysis. The carpal joints (CJO) group had a lower plasma MP concentration (P \u3c 0.05) than the distal tarsal joints (DTJ) or medial femorotibial (MFT), the no HA (NHA) group had a lower plasma MP concentration (P \u3c 0.05) than HA. Main limitations: The synovial structures injected varied by racing discipline, so this study was unable to identify any differences between disciplines. Conclusions: Practitioners should be aware that injection of DTJ, CS and MFT joints, and combining MP acetate with HA may prolong its clearance, and withdrawal times for competition in regulated equine sports

Evaluating academic and media nongovernmental organization partnerships for participatory data gathering

This article discusses participatory methods for data gathering in the context of a partnership between a Swiss-based media development organization, Fondation Hirondelle, and a research team at the University of Sheffield. In 2018–2019, the partnership conducted fieldwork which focused on the impact of radio on women listeners in Niger. The project used participatory methods of data gathering in the form of workshops and focus group discussions (FGDs). The article examines the advantages and limitations of combining the practical experience of international development organizations and the in-depth research capabilities of academia. To triangulate this collaboration and to navigate the limitations of FGDs, the use of workshops is discussed as an important method for providing feedback among the radio practitioners and experts in Niger. The article examines the usefulness of combining these methods and reshaping their application to promote participatory research with radio audiences and practitioners

A new doubly discrete analogue of smoke ring flow and the real time simulation of fluid flow

Modelling incompressible ideal fluids as a finite collection of vortex filaments is important in physics (super-fluidity, models for the onset of turbulence) as well as for numerical algorithms used in computer graphics for the real time simulation of smoke. Here we introduce a time-discrete evolution equation for arbitrary closed polygons in 3-space that is a discretisation of the localised induction approximation of filament motion. This discretisation shares with its continuum limit the property that it is a completely integrable system. We apply this polygon evolution to a significant improvement of the numerical algorithms used in Computer Graphics.Comment: 15 pages, 3 figure