New York State Superintendents and Social Media

Little is understood or has been researched regarding which social media tools New York State public school superintendents use in their jobs, how they use those tools, and what challenges they face using social media in their jobs. The purpose of this quantitative study was to examine and understand the challenges that superintendents face on a daily basis and to explain how social media is impacting the superintendencies of superintendents, ages 30 to over 65 years. A survey was sent to over 720 public school superintendents in New York State. Participants were drawn from urban, suburban, and rural school districts across the state. The data that were collected through research, interviews, and a survey and were analyzed to identify categories, themes, and perspectives across the participant responses. The data were disaggregated to reveal emergent themes and grouped into different ways of looking at all the themes. The research identified the types of social media that superintendents use in the areas of professional development and decision making in policy development, and social media use with boards of education, professional organizations, and school districts. Recommendations for additional research and initiatives to help superintendents succeed with social media tools are included, and recommendations are also identified as to what social media tools superintendents should be using and the major social media tools superintendents should be looking at daily in their districts

Scanning laser source and scanning laser detection techniques for different surface crack geometries

Standard test samples typically contain simulated defects such as slots machined normal to the surface. However, real defects will not always propagate in this manner; for example, rolling contact fatigue on rails propagates at around 25º to the surface, and corrosion cracking can grow in a branched manner. Therefore, there is a need to understand how ultrasonic surface waves interact with different crack geometries. We present measurements of machined slots inclined at an angle to the surface normal, or with simple branched geometries, using laser ultrasound. Recently, Rayleigh wave enhancements observed when using the scanning laser source technique, where a generation laser is scanned along a sample, have been highlighted for their potential in detecting surface cracks. We show that the enhancement measured with laser detector scanning can give a more significant enhancement when different crack geometries are considered. We discuss the behaviour of an incident Rayleigh wave in the region of an angled defect, and consider mode-conversions which lead to a very large enhancement when the detector is close to the opening of a shallow defect. This process could be used in characterising defects, as well as being an excellent fingerprint of their presence

Non-contact ultrasonic detection of angled surface defects

Non-destructive testing is an important technique, and improvements are constantly needed. Surface defects in metals are not necessarily confined to orientations normal to the sample surface; however, much of the previous work investigating the interaction of ultrasonic surface waves with surface-breaking defects has assumed cracks inclined at 90° to the surface. This paper explores the interaction of Rayleigh waves with cracks which have a wide range of angles and depths relative to the surface, using a non-contact laser generation and detection system. Additional insight is acquired using a 3D model generated using finite element method software. A clear variation of the reflection and transmission coefficients with both crack angle and length is found, in both the out-of-plane and in-plane components. The 3D model is further used to understand the contributions of different wavemodes to B-Scans produced when scanning a sample, to enable understanding of the reflection and transmission behaviour, and help identify angled defects. Knowledge of these effects is essential to correctly gauge the severity of surface cracking

Vapor phase growth technique and system for several 3-5 compound semiconductors Quarterly technical report

Vapor phase growth technique and system for group 3A and 5A compound semiconductor

Interaction of laser generated ultrasonic waves with wedge-shaped samples

Wedge-shaped samples can be used as a model of acoustic interactions with samples ranging from ocean wedges, to angled defects such as rolling contact fatigue, to thickness measurements of samples with non-parallel faces. We present work on laser generated ultrasonic waves on metal samples; one can measure the dominant Rayleigh-wave mode, but longitudinal and shear waves are also generated. We present calculations, models, and measurements giving the dependence of the arrival times and amplitudes of these modes on the wedge apex angle and the separation of generation and detection points, and hence give a measure of the wedge characteristics

Reproducible Acoustic Emission Signatures by Indentation in Steels

Creating reproducible signals from defects is of great importance for quantitative studies of acoustic emission (AE). A method of doing so is presented here which consists of indentation of hardened steel plates. A survey was made of a variety of steels, including A533B pressure vessel steel with an embrittled weld as well as embrittled Wl, 01 and 02 tool steels. Regions in these steels with a Rockwell C hardness greater than about 50 produced detectable AE during indentation. In many cases the signals were reproducible over an appreciable range and appeared to be the same for epicenter measurements as those produced by sudden unloading. However, monitoring on the same surface as the crack in some cases produced sets of two different but reproducible signals which gradually evolved with repeated loading which could be due to crack branching or zigzag motion. Regions in the steels with a hardness less than about 40 on the Rockwell C scale produced no detectable AE, even with appreciable plastic deformation. Examination with scanning electron microscopy indicated that the AE signals were produced by the nucleation and incremental growth of subsurface cracks, generally penny-shaped, less than a millimeter in size. A typical fracture toughness value for such cracks in an embrittled 02 tool steel was calculated to be about 19MNm-3/2. AE was also produced in as-received A533B steel by indentation fatique. The method suggests itself for materials studies of AE as well as a nondestructive method for in situ examination of structures for embrittlement

Pre-Pandemic Ethics: Triage and Discrimination

UK COVID-19 death rates are disproportionately high among Black African, Black Caribbean, Bangladeshi, Pakistani, and Indian people in the UK, as well as among care home residents, carers, essential workers, and people living with disabilities and pre-existing conditions. The effects of the pandemic demonstrate the systemic social disparities of life and death in the UK. This is the context in which the authors consider Christian pandemic ethics, and this calls for a shift of focus away from pandemic ethics to what we term ‘pre-pandemic ethics’

Theoretical Elements of Acoustic Emission Spectra

I will be describing an acoustic emission program at the National Bureau of Standards sponsored jointly by NBS and the Electric Power Research Institute. This is part of a larger comprehensive NDE program at NBS. The acoustic emission program uses the spectral analysis approach for the characterization of moving defects and, as I will point out, includes the development of an acoustic emission transducer calibration facility as well as the experimental study of crack motion in glass and pressure vessel steels. These require a quantitative theory which serves to guide the experimental design as well as to interpret the results