Ultrasonic metal sheet thickness measurement without prior wave speed calibration

Conventional ultrasonic mensuration of sample thickness from one side only requires the bulk wave reverberation time and a calibration speed. This speed changes with temperature, stress, and microstructure, limiting thickness measurement accuracy. Often, only one side of a sample is accessible, making in situ calibration impossible. Non-contact ultrasound can generate multiple shear horizontal guided wave modes on one side of a metal plate. Measuring propagation times of each mode at different transducer separations, allows sheet thickness to be calculated to better than 1% accuracy for sheets of at least 1.5 mm thickness, without any calibration

Early years safeguarding and child protection in practice : an enquiry into the experiences of newly qualified practitioners

Much has been written about challenges facing early years practitioners in a time of rapid policy implementation affecting the children’s workforce, and the introduction of graduate professional accreditation (NCTL, 2013) for those tasked with leading quality developments in the early years sector. Tensions have emerged across the children’s workforce particularly in the fields of health and social care, concerning the implications for safeguarding and child protection (Munro, 2011; Lumsden, 2012). Whilst research illuminates workforce challenges, as policy is imposed on professional practice, little is known about the actual experiences of safeguarding and child protection from the perspectives of those practitioners with Early Years Teacher Status (EYTS) who are new to the sector. This small-scale research project sought to examine the safeguarding and child protection experiences of ‘change of career’ Graduate Entry (GE) EYTS trainees in their first year of employment in an early years setting. The study took an empirical phenomenological approach (Schütz, 1962) to reveal the lived experiences of Early Years Teachers (EYTs) in the context of their settings. It revealed that notions of safeguarding and child protection were conceptualised as interrelated but different elements of practice that affected confidence as EYTs experienced situations over time. This was related to emotions that inhabited and affected behaviours as EYTs experienced tensions between statutory policy, procedural requirements, partnership working and what they considered to be appropriate practice for working with young children. The conclusions suggested the need for further policy developments in safeguarding and child protection in the early years sector, so that EYTs might not be compromised in their practice. New ways of educating GE EYTs in safeguarding and child protection were identified to better enable contextualisation of their learning and to develop personal and emotional agency in order for them to confidently navigate this complex aspect of professional practice

Group Interaction Modelling of PETN

Group Interaction Modelling (GIM) is a relatively simple model developed to predict the properties of polymers based upon the interaction of a potential function between two adjacent molecules, and a thermodynamic energy balance equation relating the various energy contributions to an ensemble of molecular units. GIM has seen limited application to predicting the properties of explosives, but has not previously been applied to PETN; as result the required GIM parameters to model PETN have not been measured or derived. Here we use single point measurements of a number of PETN properties to fit the GIM parameters, and then validate this fitting process by predicting the temperature dependent response of PETN and comparing these results to experimental data from the literature.Crown copyright

Hybodont sharks of the English Bathonian and Callovian (Middle Jurassic).

Recent bulk sampling and study of museum collections has revealed a high diversity of hybodont sharks from the English Bathonian, with 15 species being recognised. In addition, study of dental and skeletal material from the English Callovian has allowed the diagnosis of a new genus and species, Planohybodus peterboroughensis gen. et sp. nov., allowing the Bathonian species Hybodus grossiconus Agassiz to be referred to Planohybodus. Two additional new genera, Secarodus and Frangerodus, are erected for the Bathonian taxa Hybodus polyprion Agassiz and Strophodus lingualis Woodward, respectively. Egertonodus duffini sp. nov. is described and the diagnosis of Egertonodus based on dental material is discussed. The previously unrecorded Hybodus sp., Parvodus sp., and Lonchidion sp. are recognised but left in open nomenclature. Asteracanthus medius (Owen) is recorded in the British Bathonian for the first time, and the status of Bathonian nominal species of Asteracanthus are assessed. Bathonian hybodonts showed great diversity in trophic ecology and many of the species are specific to particular palaeoenvironments

Experience in Imaging Medullary Thyroid Carcinoma Using 99mTc (V) Dimercaptosuccinic Acid (DMSA)

99mTc (V) dimercaptosuccinic acid (DMSA) is a new tumor imaging agent that has been successfully used to image patients with medullary thyroid carcinoma (MTC). Since 1986, studies have been performed in 32 patients with histologically proven MTC at Guy\u27s Hospital, London, England. Five patients with primary tumor were studied prior lo surgery, four patients were studied after successful removal of the primary tumor, and 26 patients with biochemical evidence of recurrence were studied. Eight patients were studied serially to assess progression of disease, and four patients were studied before and after surgery. Twenty-one of the 26 patients with disease had positive scans with four false negative scans and three true negative scans. One patient had a false-positive scan (sensitivity 80%, specificity 75%). Two of the false-negative scans were obtained in patients with moderate but stable elevations of calcitonin but no other evidence of recurrence. One false-negative scan was obtained in a patient who was discovered on screening to have an abnormal pentagastrin response, and a small 1 cm tumor was subsequently removed. Uptake in local neck recurrence was frequently intense, but uptake at sites of bone metastases was less marked. 99mTc (V) DMSA is an inexpensive radiopharmaceutical which produces good quality images and has been shown to have an acceptable sensitivity and specificity in the follow-up of patients with MTC and thereby contributes significantly to the management of these patients

STUDENT EVALUATION OF COURSES: PERCEPTIONS, ENGAGEMENT AND MOTIVATION

Live lectures and frequent, clear communications are key factors for keeping students engaged and motivated in online courses (Brew, 2008; Dixson, 2015; Murphy & Stewart, 2017). One area that has received less attention is that of inviting students to be partners in learning: of asking their opinions on the course and actively responding to this feedback during the teaching period to improve their online learning experience. This project aims to investigate how students perceive being asked for feedback in an online course and if this intervention increases their engagement with the course. Taking a phenomenographic approach to investigating students’ experiences and perceptions of giving feedback, a cohort of first-year chemistry students at The University of New South Wales were asked to evaluate their course twice during the teaching period via online questionnaires, with feedback summarised for lecturers to make course improvements. Qualitative questions on perceptions of evaluation and engagement were built into the questionnaires. At the end of the term, students were invited to participate in interviews to further understand their experiences of evaluating courses and being engaged as learning partners. Preliminary results from this study will be presented, with a focus on students’ understanding of engagement and evaluation, and their perceptions of how this intervention affected their engagement with an online course. REFERENCES Murphy, C. A., & Stewart, J. C. (2017). On-campus students taking online courses: Factors associated with unsuccessful course completion. Internet and Higher Education, 34, 1-9. Dixson, M. D. (2015). Measuring Student Engagement in the Online Course: The Online Student Engagement Scale (OSE). 2015, 19(4). doi:10.24059/olj.v19i4.561 Brew, L. S. (2008). The role of student feedback in evaluating and revising a blended learning course. The Internet and Higher Education, 11(2), 98-105

Alguns restos de peixes fósseis do Devoniano Médio (Eifeliano-Givetiano) da Formação Pimenteira da Bacia do Parnaíba, Nordeste do Brasil

Some Middle Devonian (late Eifelian-early Givetian) fossil fish remains are described from an outcrop of the Pimenteira Formation on the eastern border of the Parnaíba Basin (Picos area, State of Piauí, northeast Brazil). These remains include a fin spine with ribbed ornament, a bicuspid shark tooth similar to those of xenacanths and omalodontids, a badly-preserved Machaeracanthus spine, and small indeterminate scales and fragments of what may be prismatically calcified cartilage. The bicuspid tooth is the first record of its kind from the Devonian of Brazil and the first unequivocal Devonian record from South America. Its principal cusps have widely spaced cristae, like teeth of the Gondwanan Devonian elasmobranch Antarctilamna, but small intermediate cusps are absent (as in Leonodus). The fin spine has comparable ornament to those of Ctenacanthus, Antarctilamna, and Doliodus, but is too poorly preserved for accurate determination. Machaeracanthus is the most widespread Devonian vertebrate in the Malvinokaffric Realm, and its spines are also known from the Old World and Eastern Americas realms, although scales referred to the genus are reported from outside these three regions. The occurrences of Machaeracanthus spines in the Parnaíba and Amazon basins lends support to an earlier proposal based on the distribution of invertebrate fossils that these basins provided maritime connections existed between the Malvinokaffric and the Old World/Eastern Americas realms during the late Eifelian - early Givetian.Restos de peixes fósseis do Devoniano Médio (Neo-eifeliano - Eogivetiano) são descritos da Formação Pimenteira, em sua faixa aflorante na margem oriental da Bacia do Parnaíba (região de Picos, PI, nordeste do Brasil). Os fósseis incluem um espinho de nadadeira ornamentado com costelas, um dente bicúspide de tubarão similar aos dos xenacantos e omalodôntidas, e um espinho mal preservado de Machaeracanthus. Além disso, registram-se pequenas escamas indeterminadas e possíveis fragmentos de cartilagem com calcificação prismática. O dente bicúspide constitui o primeiro achado dessa natureza no Devoniano do Brasil, sendo também o primeiro com registro inequívoco no Devoniano da América do Sul. Suas cúspides principais possuem cristas bem espaçadas entre si (tal como se verifica nos dentes de Antarctilamna, um elasmobrânquio devoniano do Gondwana), porém inexistem pequenas cúspides intermediárias (como em Leonodus). O espinho da nadadeira possui ornamentação comparável à de Ctenacanthus, Antarctilamna e Doliodus, porém a sua má preservacão não permite uma determinação segura. Machaeracanthus é o vertebrado devoniano com a mais ampla distribuição no Reino Malvinocáfrico, e seus espinhos são também conhecidos nos reinos do Velho Mundo e América Oriental, embora escamas referidas ao gênero tenham sido assinaladas fora dessas três regiões. A ocorrência de espinhos de Machaeracanthus nas bacias do Parnaíba e Amazonas reforça uma proposta anterior (baseada na distribuição de certos invertebrados fósseis) de conexões marinhas entre essas duas bacias e os reinos Malvinocáfrico, do Velho Mundo e da América Oriental durante o Neo-eifeliano - Eogivetiano