System for determining the angle of impact of an object on a structure

A method for determining the angle of impact of an object on a thin-walled structure which determines the angle of impact through analysis of the acoustic waves which result when an object impacts a structure is presented. Transducers are placed on and in the surface of the structure which sense the wave caused in the structure by impact. The waves are recorded and saved for analysis. For source motion normal to the surface, the antisymmetric mode has a large amplitude while that of the symmetric mode is very small. As the source angle increases with respect to the surface normal, the symmetric mode amplitude increases while the antisymmetric mode amplitude decreases. Thus, the angle of impact is determined by measuring the relative amplitudes of these two lowest order modes

Methods of determining loads and fiber orientations in anisotropic non-crystalline materials using energy flux deviation

An ultrasonic wave is applied to an anisotropic sample material in an initial direction and an angle of flux deviation of the ultrasonic wave front is measured from this initial direction. This flux deviation angle is induced by the unknown applied load. The flux shift is determined between this flux deviation angle and a previously determined angle of flux deviation of an ultrasonic wave applied to a similar anisotropic reference material under an initial known load condition. This determined flux shift is then compared to a plurality of flux shifts of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift

A Short History of New Hope Church

A short history of New Hope Church.https://digitalcommons.georgiasouthern.edu/bchs-pubs/1034/thumbnail.jp

An Asynchronous, Virtual Lab Course Model using the Framework to Reshape Student Responses to Media Narratives

This chapter describes a lab course redesigned by two librarians in a small liberal arts college. The course is tied to an undergraduate methods course, Research, Media, Culture, in a Critical Media & Cultural Studies program. The lab had previously been taught as a synchronous course over three weeks. As a response to lower enrollments in the major, as well as the virtual teaching mode for the main course, we adapted the lab component into a six-week asynchronous course pilot with a goal of delving more deeply into information literacy pedagogy than the previous course format allowed. We also embedded ourselves in the main course over those six weeks, joining discussions of documentaries and readings and answering questions on research and analysis. We designed the new course around the ACRL Framework for Information Literacy for Higher Education and each week focused on one of the six frames, with readings and online discussion questions in Canvas, some involving search exercises. The final assignment for the lab course was a short reflective essay (300–500 words). In this chapter, we describe the coursework, the discussion prompts, and an assessment of the pilot based on student responses to discussion board questions, in which we clarified certain misunderstandings of concepts; as well as excerpts from the reflective essays and the students’ evaluations of the course, anonymized and selected for relevance to the transformative educational aims of the course. We present this asynchronous course pilot as a model for other courses that seek to help students engage in transformative learning, with the discussion questions and readings included for reuse or adaptation

Hagin - Beasley Letters 1854 -1895

Family correspondence saved by Julia Ann Beasley. Includes letters from family members who fought in the Confederate Armyhttps://digitalcommons.georgiasouthern.edu/bchs-pubs/1015/thumbnail.jp

Space Shuttle Program (SSP) Orbiter Main Propulsion System (MPS) Gaseous Hydrogen (GH2) Flow Control Valve (FCV) Poppet Eddy Current (EC) Inspection Probability of Detection (POD) Study

The Director of the NASA Engineering and Safety Center (NESC), requested an independent assessment of the anomalous gaseous hydrogen (GH2) flow incident on the Space Shuttle Program (SSP) Orbiter Vehicle (OV)-105 during the Space Transportation System (STS)-126 mission. The main propulsion system (MPS) engine #2 GH2 flow control valve (FCV) LV-57 transition from low towards high flow position without being commanded. Post-flight examination revealed that the FCV LV-57 poppet had experienced a fatigue failure that liberated a section of the poppet flange. The NESC assessment provided a peer review of the computational fluid dynamics (CFD), stress analysis, and impact testing. A probability of detection (POD) study was requested by the SSP Orbiter Project for the eddy current (EC) nondestructive evaluation (NDE) techniques that were developed to inspect the flight FCV poppets. This report contains the findings and recommendations from the NESC assessment

Development and Certification of Ultrasonic Background Noise Test (UBNT) System for use on the International Space Station (ISS)

As a next step in the development and implementation of an on-board leak detection and localization system on the International Space Station (ISS), there is a documented need to obtain measurements of the ultrasonic background noise levels that exist within the ISS. This need is documented in the ISS Integrated Risk Management System (IRMA), Watch Item #4669. To address this, scientists and engineers from the Langley Research Center (LaRC) and the Johnson Space Center (JSC), proposed to the NASA Engineering and Safety Center (NESC) and the ISS Vehicle Office a joint assessment to develop a flight package as a Station Development Test Objective (SDTO) that would perform ultrasonic background noise measurements within the United States (US) controlled ISS structure. This document contains the results of the assessmen

Comparison of tide-gauge data and a saltmarsh-derived reconstruction of mean sea-level for the Mersey Estuary

Using saltmarsh sediment cores, Mills (2011) reconstructed the historic trend of mean sea-level in the Mersey over a period since 1975. The analysis is based on the foraminifera species identified at different levels within the sediment core; each species being associated with a tidal elevation (for example, mean high water neap) identified from present-day vertical distribution of saltmarsh foraminifera at the coring sites. While the reconstruction at Decoy Marsh matched the tide gauge record at Gladstone Dock, the reconstruction at Oglet Bay for the period 1993 and 2003 disagreed. During this period the reconstruction suggested an initial drop in mean tidal level (MTL) of 50 cm followed by a 50 cm rise back to the underlying trend after 2002. Because a local drop in sea-level (SL) is unlikely, and the foraminifera fossils used in the reconstruction are unlikely to have changed their tolerance to inundation, another factor must account for this sea-level anomaly. Here using the 3D hydrodynamic Proudman Oceanographic Laboratory Coastal Ocean modelling System (POLCOMS), the impact of the position of the main estuarine channel and historic sea-level elevations on the tidal dynamics are investigated relative to the conditions in 2008. Changes in the proportion of time that certain elevations at the saltmarsh coring sites are inundated could explain the deviation observed in the reconstruction. Such an effect is hypothesised to occur in response to local changes in the tidal dynamics, i.e. changes in tidal range or asymmetry in tidal elevation. It is found that in response to changes in channel configuration to test the scenario of a northern channel migrating up-estuary through Oglet Bay, a change in inundation characteristics caused by a change in the bank drying phase of the tidal cycle, may well have contributed to the anomalous reconstruction