The electromagnetic environment in CFC structures

Extensive measurements of induced voltages and currents were made using a CFC (carbon fiber composites) horizontal stabilizer from the A320 as a test bed. The work was done to investigate the efficacy of various protection schemes to reduce the magnitudes of the induced voltages and validate a computer program INDCAL. Results indicate that a good understanding of the various induced voltage mechanisms including the long wave effect due to current redistribution was obtained

Age and Histamine metabolism

The age carve of histamine in the rat skin exhibits a general, fairly constant level of 10 to 20 microg./g. ap to 500 days. 'I'here are, however, two exceptions, the peak about birth and the peak about weaning. Between these two disturbances values not much above the normal adult figures are obtained. The rise at weaning has been shown to be separable into two parts. Observations on the histamine content of bread and milk (less than 0.5 microg./g.) and of rat cake (about 5 microg./g.) show that these cannot account for the steady rise observed between 16 and 24 days. This may be due to alterations in the intestinal flora on changing from a milk diet to solid food or to hormonal imbalance. These causes probably account, in large measure, for the other irregularities noted in the literature at about this age. Changes in epidermal thickness and tissue fat content may influence the change but are not of prime importance.The peak observed at 22 days in large but not in small litters is ascribed to the shock of premature weaning. Not weaning . a large litter eliminated this peak and the suggestion is further supported by weaning a small litter prematurely and by the results obtained after traumatic stress. These results indicate that the increase in skin histamine after such treatment may be caused by a relative hypocortism.Apart from this theoretical aspect the results reported here indicate that careful consideration should he given to weaning schedules to ensure that all litters are, as far as possible, similar. The practice of some authors of allowing the litter to remain with the mother till thirty days has much to recommend it.The rise before birth may again be related to changes in the thyroid and adrenal glands and forms part of the general metabolic changes at parturition.An important point arising from Section 4. is that shin not affected directly by the stressing agent did show a change in histamine content. The use of unaffected areas as simultaneous controls i should clearly be used with caution.It would appear that, in general, changes in the histamine content of the skin indicate a disturbance! of the hormonal balance of the adrenal and thyroid. These changes may also be an indicator of disturbed protein metabolism (133, 134). The gerontological importance of such disturbances has been pointed out in the Introduction, and theory suggests that work on successive stresses might be informative. The results indicate that animals about 50 days old might show differences in their skin histamine reactions which could be related to their previous experience; Such differences do not appear to exist in adult (330 day) animals

Teachers\u27 Perceptions of Reflective Practices Within an International Baccalaureate Primary Years Programme

The International Baccalaureate (IB) standards recognize reflection as an integral part of the framework and the fabric of the Primary Years Programme school, as it is embedded in the foundational standards and practices of the inquiry-based IB teaching model. However, teachers in an IB Primary Years Programme school located in the southeast United States struggled with being reflective practitioners. Guided by John Dewey\u27s reflective thought, the purpose of this bounded qualitative exploratory case study was to examine teacher perceptions of reflection practices in an IB Primary Years Programme school. Research questions were drafted to ask about teachers\u27 perceptions of their reflective practices, how teachers\u27 perceived reflective practices aligned with IB\u27s teaching model, and beliefs about the school-based support and resources teachers needed to implement reflective practices. The selection criteria included teachers with at least 2 years of teaching experience who had been to at least 1 outside IB training. Ten teachers, chosen through purposeful sampling, completed a 2-week reflective journal and participated in a semistructured interview. Based on the open-coding and inductive analysis patterns emerged, leading to themes; including lesson reflections, planning, time, and training. Based on the findings, a project, a white paper, includes recommendations to address the teachers\u27 perceptions of reflective practices that will be presented to the school as well as the district. This improved instructional change may provide positive social change in the culture of reflection for teachers and help them and to better differentiate instruction for students

Measurements of some parameters of thermal sparks with respect to their ability to ignite aviation fuel/air mixtures

A method used to generate thermal sparks for experimental purposes and methods by which parameters of the sparks, such as speed, size, and temperature, were measured are described. Values are given of the range of such parameters within these spark showers. Titanium sparks were used almost exclusively, since it is particles of this metal which are found to be ejected during simulation tests to carbon fiber composite (CFC) joints. Tests were then carried out in which titanium sparks and spark showers were injected into JP4/(AVTAG F40) mixtures with air. Single large sparks and dense showers of small sparks were found to be capable of causing ignition. Tests were then repeated using ethylene/air mixtures, which were found to be more easily ignited by thermal sparks than the JP4/ air mixtures

A new approach to equipment testing

Considerable controversy has arisen during the recent discussions over a new version of the RTCA DO160C/ED 14C Section 22 document at the European Committee for Aviation Electronics. Section 22 is concerned with lightning waveform tests to equipment. Investigations of some of these controversies with circuit analysis and measurements indicate the impedance characteristics required of the transient generators and the possibility of testing to a voltage limit even for current waveforms

Review of top of rail friction modifier tribology

© 2016 Informa UK Limited, trading as Taylor & Francis Group.The aim of this paper was to review the current state of research for top of rail friction modifiers (TORFM). In the railway industry, friction modifiers is a catch all term for a wide range of products applied for different purposes which has led to confusion. It is hoped that recently published definitions will aid industry to a better understanding of the different products and how they function. The benefits of friction modifiers are well understood with a large body of research supporting the benefits. Comparatively, there is a lot less knowledge of the optimum amount of product to achieve the benefits or how far down the track from an application site the benefit will be seen. Modelling of the products is another area where there is little research, with most of the modelling papers found focussing on dry wheel–rail contact due to the complexity of introducing a third-body layer to a friction force model. Furthermore, only one paper was found which relates how friction modifiers are affected by contaminants or other applied products such as lubricants. With many different products applied to wheels and rail for different purposes, understanding their interaction is key. At the time of this review, there are currently no standards that prescribe how TORFM should behave although the European Committee for Standardisation is currently developing them at the moment. This review has also attempted to appraise the research against a set of criteria. Depending on how many of the criteria the piece of research filled, it was categorised as A, B or C. It was found that most of the research was of category, this was mainly due to only one test method being used or the scale presented. Category A research incorporated modelling or multiple test-scales to support the results presented

New laboratory methodologies to analyse the top of rail friction modifier performance across different test scales

Test methodologies originally developed for greases have been adapted to be used for top of rail friction modifiers (TORFMs). This has included: a small-scale benchtop tribometer to measure the tackiness of different TORFMs, attaching an applicator bar to a section of rail and rolling a scaled-wheel through the TORFM applied to the rail head to analyse the effect of different variables on pick-up, and applying TORFM to a full-scale test facility to analyse the scaling effects and the effect of slip, load and speed on pick-up. These methods can be used to measure the relative performance of different TORFMs with respect to how much product is picked up by the wheel. The results have shown that the relative ranking of different TORFMs is the same across the three test scales. This shows that these small-scale test methods that are more suitable for inclusion in test standards could be used to reduce the need for the more time-consuming and expensive larger scale tests, as the relative performance is the same

Low cost, SPF aluminum cryogenic tank structure for ALS

Past production work has shown that cryogenic tank structure for the Shuttle Booster Rockets and the Titan system have very high life cycle costs for the fuel tank structure. The tanks are machined stiffener-skin combination that are subsequently formed into the required contour after machining. The material scrap rate for these configurations are usually high, and the loss of a tank panel due to forming or heat treatment problems is very costly. The idea of reducing the amount of scrap material and scrapped structural members has prompted the introduction of built-up structure for cryogenic tanks to be explored on the ALS program. A build-up structure approach that has shown improvements in life cycle cost over the conventional built-up approach is the use of superplastically formed (SPF) stiffened panels (reducing the overall part count and weight for the tank) resistance spot welded (RSW) to outer tank skin material. The stiffeners provide for general stability of the tank, while the skin material provides hoop direction continuity for the loads

Redefining Multicultural Education and Its Applications in the General Music Classroom

Understanding music in relation to history and culture is the ninth standard for music education developed by the National Association for Music Educators (MENC) in 1994 (Mark, 1996, p. 50). This principle is very broad and it is up to individual teachers to make sure they include history and multiculturalism in their curriculum. The term multicultural education is extensive and because many teachers do not understand what all it entails, some students do not get a comprehensive multicultural education. In the general music class for example, teaching students a Japanese folk song is a typical multicultural lesson. I do not believe this would be an adequate multicultural lesson unless the students learned about Japanese culture and how it relates to our own culture in the post- industrial world we live in. The purpose of education is to produce citizens that can function in our society. Due to our rapidly changing international society and the globalization occurring, we should have different goals for our students, and multiculturalism should be included in those goals. This restructuring of our society is why I chose this topic. It is almost impossible to live without contact with someone from another culture. Many of our future graduates will become professionals who work with people from many different cultures and many of them will have to travel internationally as part of their jobs. Interaction with other cultures is inevitable in this day and age and we should prepare our students for this in every school subject, including music. The purpose of this project is practical and I wanted the use of this project to be practical too. I intend to implement the research and lessons plans in my own classroom, and hopefully other music educators will as well. Multicultural music is so broad. There are countless numbers of cultures from all times periods that students should know about and it seems impossible to integrate them into a music class, but it is not impossible. The research that attributed to this project and the lesson plans provided prove that multicultural music is necessary and easily applied to music education

A comparison of friction modifier performance using two laboratory test scales

This paper describes two methods, carried out at two different test scales, for assessing the friction modifier performance. Study A used the wear data from a full-scale rig test at the voestalpine Schienen GmbH and compared it with the wear data from twin disc tests using the SUROS test machine at the University of Sheffield. Study B compared the ‘retentivity’ data, from a full-scale rig at the University of Sheffield, with the data from the SUROS tests. Study A concluded that a good correlation existed between the two scales although assumptions made in the full-scale contact calculation introduce a large spread into the results. There was a greater correlation between the two data sets at more severe contact conditions. Study B showed a different baseline coefficient of traction between the two scales and that a longer test length is required to fully evaluate the ‘retention’ of the friction modifier on the full-scale rig. The paper expands on a previous conference presentation on the same subject. Additional information on the test procedure and test rigs is included here. Surface and subsurface analyses of the SUROS test samples have also been added. The analyses have shown that applying the friction modifier leads to a similar wear mechanism as for the dry contact, but the wear is less severe and there is less subsurface deformation. A discussion describing the differences in test scales and comparing lab tests to field operation is also included