Study of Post-World War II French Aeronautical Aluminium Alloy and Coatings: Historical and Materials Science Approach

ABSTRACT

In many countries, collections of historic aircraft, conserved in Air and Space museums or local associations, reflect the importance of a national or local history. Mostly parked outdoors, aircraft suffer from significant corrosion requiring conservation operations. During renovation, metallic parts are often replaced by association members. This can lead to a major loss of information since industrial archives dealing with materials and processes do not always survive. However, if these elements can be considered, they could be a fundamental source of information on the materials originally used and of the technical history of aeronautics. This work reports a thorough study of aluminium-based alloy parts collected on a Breguet aeroplane dating from the 1950s, during its recent renovation. Thanks to an approach coupling multi-scale material characterisation and research in archives, information on the industrial knowledge is revealed. Several historic grades of aluminium-based alloys were found, namely A-U4G, A-U4G1, and A-U3G, depending on the role of the part. Similarly, different protective coatings were identified (anodic oxidation, primers, and paintings), depending on the role of the metallic part and its location in the plane. Knowledge of the materials from bulk metal to the coated surface is necessary for good conservation practices regarding aeronautical heritage artefacts. Related documents and archives also fundamentally help in understanding such complex artefacts.     

Complementing subjective with objective data in analysing expertise: A machine-learning approach applied to badminton

ABSTRACT

This study aimed to assess which combination of subjective and empirical data might help to identify the expertise level. A group of 10 expert coaches classified 40 participants in 5 different expertise groups based on the video footage of the rallies. The expertise levels were determined using a typology based on a continuum of 5 conative stages: (1) structural, (2) functional, (3) technical, (4) contextual, and (5) expertise. The video allowed empirical measurement of the duration of the rallies, and tri-axial accelerometers measured the intensity of the player’s involvement. A principal component analysis showed that two dimensions explained 54.9% of the total variance in the data and that conative stage and empirical parameters during rallies (duration, intensity of the game) were correlated with axis 1, whereas duration and acceleration data between rallies were correlated with axis 2. A random forest algorithm showed that among the parameters considered, acceleration, duration of the rallies, and time between rallies could predict conative stages with a prediction accuracy above possibility.

This study suggests that performance analysis benefits from the confrontation of subjective and objective data in order to design training plans according to the expertise level of the participants.     

Library Management in Trivandrum,India

ABSTRACT

The authors present assessment strategies, research results, and decision making in the process of building a website and formalizing management procedures for a library in Kerala, India serving a significant number of deaf students. The strategies include user interviews and developing user experience personas, collecting and incorporating examples from other library sites in building a new website, and communicating new methods of managing and promoting library resources to the university community. The co-presenters encountered difficulties and some resistance regarding their suggestions for changes in the website as well as the public and technical services offered by the library due to differences in infrastructure and expectations in academic culture.     

Reintegrating Janus: Eclectics and dialectics in counselling and psychotherapy

The history of science reveals a number of significant shifts in the conception of the universe. Recently, 20th century physics with its new discoveries has broken away from the traditional view of the universe to seeing it as interrelated, holistic, and emergent. This version of reality is complementary with the concept of dialectics. Dialectics is defined accordingly and its flexibility is suited to guide the present eclectic stance in counselling psychology and psychotherapy. Counselling psychology and psychotherapy are discussed within Kuhn's (1970) framework of normal science, crisis, and revolution. The normal science phase demonstrates variations of the subject/object dichotomy, and active/passive therapeutic orientations. Eclecticism reflects the crisis stage. Eclecticism is a multiple perspective that does not usually guide metatheory. The revolution and resolution phase for therapeutic psychology is manifested in a new paradigm based on dialectics. Dialectics makes eclecticism legitimate and comments towards that end are presented.     

Design,validation, and use of an evaluation instrument for monitoring systemic reform

Over the past decade, state and national policymakers have promoted systemic reform as a way to achieve high‐quality science education for all students. However, few instruments are available to measure changes in key dimensions relevant to systemic reform such as teaching practices, student attitudes, or home and peer support. Furthermore, Rasch methods of analysis are needed to permit valid comparison of different cohorts of students during different years of a reform effort. This article describes the design, development, validation, and use of an instrument that measures student attitudes and several environment dimensions (standards‐based teaching, home support, and peer support) using a three‐step process that incorporated expert opinion, factor analysis, and item response theory. The instrument was validated with over 8,000 science and mathematics students, taught by more than 1,000 teachers in over 200 schools as part of a comprehensive assessment of the effectiveness of Ohio's systemic reform initiative. When the new four‐factor, 20‐item questionnaire was used to explore the relative influence of the class, home, and peer environment on student achievement and attitudes, findings were remarkably consistent across 3 years and different units and methods of analysis. All three environments accounted for unique variance in student attitudes, but only the environment of the class accounted for unique variance in student achievement. However, the class environment (standards‐based teaching practices) was the strongest independent predictor of both achievement and attitude, and appreciable amounts of the total variance in attitudes were common to the three environments. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 646–662, 2001     

How do parenting concepts vary within and between the families?

How do parenting concepts vary within and between the families? The present study regards parenting as a complex family process by considering three concepts of parenting: styles, differential treatment and coparenting consistency. A main question was addressed: whether and how these parenting concepts vary within the families towards siblings or between the two parents, and between the families according to the child's, the parent's and the family's characteristics? The parenting concepts were computed from the EPEP questionnaire (Meunier &; Roskam, 2007) in a sample of 101 non-divorced families: 101 mothers and 101 fathers of two siblings from 6- to 12-years-old. The parenting concepts were found to vary within the families towards two siblings and between the mother and the father. They were also found to vary between the families according to the child's age and personality traits as well as a function of the parent's educational level and the number of siblings.     

Comparison of two methodological approaches for the mechanical analysis of single-joint isoinertial movement using a customised isokinetic dynamometer*

Compared to isokinetic and isometric tests, isoinertial movements have been poorly used to assess single-joint performance. Two calculation procedures were developed to estimate mechanical performance during single-joint isoinertial movements performed on a customised isokinetic dynamometer. The results were also compared to appreciate the effects of measurement systems and calculation procedures. Five participants performed maximal knee extensions at four levels of resistance (30, 50, 70 and 90% of the one-repetition maximum, 1-RM). Joint angular velocity and torque were assessed from customised isokinetic dynamometer measures (method A) and from weight stack kinematic (method B). Bland–Altman plots and mean percent differences (M_diff) were used to assess the level of agreement for mean and peak angular velocity and torque. A Passing–Bablok regression was performed to compare the angular velocity-angle and torque-angle relationships computed from the two analysis methods. The results showed a high level of agreement for all mechanical parameters (M_diff < 6% for all parameters). No statistically significant differences were observed between methods A and B in terms of angular velocity-angle and torque-angle relationships except at 30% of 1-RM for the torque-angle relationship. Both methodologies provide comparable values of angular velocity and torque, offering alternative approaches to assess neuromuscular function from single-joint isoinertial movements.     

Mutual point-winning probabilities (MPW): a new performance measure for table tennis

ABSTRACT

We propose a new performance measure for table tennis players: the mutual point-winning probabilities (MPW) as server and receiver. The MPWs quantify a player’s chances to win a point against a given opponent, and hence nicely complement the classical match statistics history between two players. These new quantities are based on a Bradley-Terry-type statistical model taking into account the importance of individual points, since a rally at 8–2 in the first set is less crucial than a rally at the score of 9–9 in the final set. The MPWs hence reveal a player’s strength on his/her service against a given opponent as well as his/her capacity of scoring crucial points. We estimate the MPWs by means of maximum likelihood estimation and show via a Monte Carlo simulation study that our estimation procedure works well. In order to illustrate the MPWs’ versatile use, we have organized two round-robin tournaments of ten respectively eleven table tennis players from the Belgian table tennis federation. We compare the classical final ranking to the ranking based on MPWs, and we highlight how the MPWs shed new light on strengths and weaknesses of the players.     

Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor

In this paper, the characteristics of fluid mixing time in a novel extra-loop fluidized bed were studied. The results showed that the mixing time was shortened with the increase of fluid velocity. All the discrete numbers of the reactor were above 0.2. The serial number n was 2.5 -3.0. It was judged accordingly that the reactor fluid state was continous stirred tank reactor （CSTR） mainly. When the inspiratory capacity increased the mixing time of the reactor was shortened. Thus the air input was beneficial for the fluid mixing. During the three phases mixing process, the mixing time of the reactor could be decreased by the n increase of carrier and air loading together, but the change was not significant. The parameters affecting the reactor fluid state were fluid velocity, inspiratory capacity and carrier. KLa could be increased with the air loading increase, and at the same gas/liquid ratio when the pressure drop was high, KL~ value was increased. The amount of carrier complex influence on KLa. As the carrier loading continued to increase, its value had been dropped but the changes was not significant, and optimization condition was found at above 800 1 000 g carrier loading （pouzzolane） or 600 g PVC. Under gas/liquid ratio of 0.8% -5.2%, KLa was （0.62-1.37）×10^-2· s^-1.     

Poly(vinyl alcohol)-heparin biosynthetic microspheres produced by microfluidics and ultraviolet photopolymerisation

Biosynthetic microspheres have the potential to address some of the limitations in cell microencapsulation; however, the generation of biosynthetic hydrogel microspheres has not been investigated or applied to cell encapsulation. Droplet microfluidics has the potential to produce more uniform microspheres under conditions compatible with cell encapsulation. Therefore, the aim of this study was to understand the effect of process parameters on biosynthetic microsphere formation, size, and morphology with a co-flow microfluidic method. Poly(vinyl alcohol) (PVA), a synthetic hydrogel and heparin, a glycosaminoglycan were chosen as the hydrogels for this study. A capillary-based microfluidic droplet generation device was used, and by varying the flow rates of both the polymer and oil phases, the viscosity of the continuous oil phase, and the interfacial surface tension, monodisperse spheres were produced from ∼200 to 800 μm. The size and morphology were unaffected by the addition of heparin. The modulus of spheres was 397 and 335 kPa for PVA and PVA/heparin, respectively, and this was not different from the bulk gel modulus (312 and 365 for PVA and PVA/heparin, respectively). Mammalian cells encapsulated in the spheres had over 90% viability after 24 h in both PVA and PVA/heparin microspheres. After 28 days, viability was still over 90% for PVA-heparin spheres and was significantly higher than in PVA only spheres. The use of biosynthetic hydrogels with microfluidic and UV polymerisation methods offers an improved approach to long-term cell encapsulation.