An Experimental Study of Boiling in Reduced and Zero Gravity Fields

A pool boiling apparatus was mounted on a counterweighted platform which could be dropped a distance of nine feet. By varying the size of the counterweight, the effective gravity field on the equipment was adjusted between zero and unity. A study of boiling burnout in water indicated that a variation in the critical heat flux according to the one quarter power of gravity was reasonable. A consideration of the transient burnout process was necessary in order to properly interpret the data. A photographic study of nucleate boiling showed how the velocity of freely rising vapor bubbles decreased as gravity was reduced. The bubble diameters at the time of breakoff from the heated surface were found to vary inversely as gravity to the 1/3.5 power. Motion pictures were taken to illustrate both nucleate and film boiling in the low gravity range

Bulk Properties of the Oxygen Reduction Catalyst SrCo_(0.9)Nb_(0.1)O_(3-δ)

The perovskite SrCo_(0.9)Nb_(0.1)O_(3−δ) (SCN) has excellent electrochemical activity toward oxygen reduction, and it is also valuable as a possible model material for other state-of-the-art perovskite catalysts based on strontium and cobalt, such as Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ) (BSCF). Here we report thermogravimetric, conductivity, and diffraction measurements from SCN. We find that the thermodynamic stability limits of SCN are slightly more favorable than those reported for BSCF, although both materials exhibit a slow oxidative partial decomposition under likely operating conditions. In SCN, this decomposition is thermodynamically preferred when the average formal oxidation state of cobalt is greater than ∼3.0+, but due to sluggish kinetics, metastable SCN with higher cobalt valence can be observed. The oxygen stoichiometry 3−δ varies from 2.45 to 2.70 under the conditions studied, 500–1000 °C and 10^(–4)–1 bar O_2, which encompass both stable and metastable behavior. The electronic conductivity is p-type and thermally activated, with a value at 600 °C in air of 250 S cm^(–1), comparable to that of La_(0.8)Sr_(0.2)MnO_(3−δ). The polaron migration enthalpy decreases linearly from 0.30 to 0.05 eV as 3−δ increases from 2.52 to 2.64. Thermal and chemical expansivities are also reported

Probing the reaction pathway in (La_(0.8)Sr_(0.2))_(0.95)MnO_(3+δ) using libraries of thin film microelectrodes

Libraries of (La_(0.8)Sr_(0.2))_(0.95)MnO_(3+δ) (LSM) thin film microelectrodes with systematically varied thickness or growth temperature were prepared by pulsed laser deposition, and a novel robotic instrument was used to characterize these libraries in automated fashion by impedance spectroscopy. The measured impedance spectra are found to be described well by an electrochemical model based on a generalized transmission model for a mixed conducting oxide, and all trends are consistent with a reaction pathway involving oxygen reduction over the LSM surface followed by diffusion through the film and into the electrolyte substrate. The surface activity is found to be correlated with the number of exposed grain boundary sites, which decreases with either increasing film thickness (at constant growth temperature) or increasing film growth temperature (at constant thickness). These findings suggest that exposed grain boundaries in LSM films are more active than exposed grains towards the rate-limiting surface process, and that oxygen ion diffusion through polycrystalline LSM films is faster than many prior studies have concluded

Bridging Diversity: Do We Have A Shared Language?

Presentation at ECARTE : 13th European arts therapies conference [16 Sep 2015 - 19 Sep 2015] How is qualitative and quantitative patient experience linked, and what language do we use to describe the arts therapist’s role in that change process? ICAPT, in collaboration with the University of Hertfordshire will present phase 1 of the ‘Horizons Project’. Phase 1 mapped the language used by arts therapists to respond to the patient’s relational experience. Arts therapists were interviewed using a repertory grid technique to map the therapist’s personal perspectives in the context of clinical scenarios. The hypothesis being tested was that there were different theories that influenced each arts therapy in such a way that language was contingent on context and profession. The initial results collated by the categorising process suggested there was specific terminology that could capture generalised actions across the arts therapies. A focus group was established to examine the outcomes further and the results demonstrated that only a few of the constructs were interpreted differently according to different professional groups. The process and the surprising results of the repertory grid process will be presented, and how a shared language was further refined in a research collaboration between therapists and patients. The implications for this type of work are numerous. Whilst this project was examining clinical practice within a specific range of mental health services in London, the method that was developed offered a tool for establishing a ‘map of descriptors for clinical actions’. From this further work can be conducted about the occurrence, timing and impact of clinical actions in specific therapeutic contexts. This first stage of research suggests that there could be underlying ideas about therapeutic change across the arts therapies. A challenge to the researcher’s hypothesis, this first step of the Horizons Project unexpectedly bridged diversity. Biography Dominik Havsteen-Franklin is Consultant in Arts Psychotherapies (CNWL) and Head of ICAPT. Since 1999 roles undertaken have included team manager/clinical lead and interim head of profession. As Consultant he is responsible for developing and implementing arts therapy clinical training, leading on research and development for arts psychotherapists within, and external to, the trust plus leading the research arm of ICAPT. His research interests centre on severe mental health disorders and psychological therapies in the NHS. He is currently engaged in doctoral research studying the relationship between in-session interventions and occurrences of metaphor in art psychotherapy, supervised by Prof. Robert Hinshelwood at the University of Essex. Philippa Brown is Programme Leader MA Art Therapy and Professional Lead Arts Therapies at the University of Hertfordshire. She has extensive experience as a consultant and academic in art therapy education and training across the UK and Europe. Her research interests extend to the qualitative and experiential research approaches that address the nature of artistic practice in relationship to art therapy. Miriam Usiskin is Senior Lecturer on the MA Art Therapy and Programme Leader for the Foundation Certificate Art Therapies at the University of Hertfordshire. She worked for a number of years in the NHS as a Head Art Therapist in adult mental health with particular clinical focus on working with PTSD in Children and Adolescents. Research projects include collaborative project work with CNWL trust on the Horizons Project and the efficacy of art therapy in treating PTSD and domestic violence

Examining arts psychotherapies practice elements: Early findings from the Horizons Project

Background: Arts Psychotherapies (art, music, drama and dance/movement) have been integral to mental health care services for several decades, however consensus and transparency about the clinical process is still being established. This study investigates practice with a team of six arts psychotherapists working with severe mental illnesses in London, inpatient and community services. The study examines what in-session practice elements are used, whether there is consensus about what the practice elements are and why the arts therapists use them. Method: The methods employed in the first phase of the project are interview-based with thematic analysis; repertory grid technique and nominal group techniques are used to analyse the data with the aim of triangulating results to establish greater validity. Results: The results showed that there is scope for developing a shared language about in-session practice elements within a mental health context. However the research examining the timing and reasons for employing those practice elements is still being undertaken. In this study the first results from an extract of the interviews illustrates a complex relationship between theory and practice. Conclusion: From the findings so far it would appear that within this specific context it is possible to see that there are ways of categorising the therapist’s actions that become comparable across the arts psychotherapies. From the therapist’s personal descriptions of his or her own practice, there also appears to be a close correlation between arts psychotherapies in a mental health community and inpatient context. Additionally, evidence-based practice models such as mentalisation-based therapies appear to have a close correlation

Platinum-decorated carbon nanotubes for hydrogen oxidation and proton reduction in solid acid electrochemical cells

Pt-decorated carbon nanotubes (Pt-CNTs) were used to enhance proton reduction and hydrogen evolution in solid acid electrochemical cells based on the proton-conducting electrolyte CsH_2PO_4. The carbon nanotubes served as interconnects to the current collector and as a platform for interaction between the Pt and CsH_2PO_4, ensuring minimal catalyst isolation and a large number density of active sites. Particle size matching was achieved by using electrospray deposition to form sub-micron to nanometric CsH_2PO_4. A porous composite electrode was fabricated from electrospray deposition of a solution of Pt-CNTs and CsH_2PO_4. Using AC impedance spectroscopy and cyclic voltammetry, the total electrode overpotential corresponding to proton reduction and hydrogen oxidation of the most active electrodes containing just 0.014 mg cm^(−1) of Pt was found to be 0.1 V (or 0.05 V per electrode) at a current density of 42 mA cm^(−2) for a measurement temperature of 240 °C and a hydrogen-steam atmosphere. The zero bias electrode impedance was 1.2 Ω cm2, corresponding to a Pt utilization of 61 S mg^(−1), a 3-fold improvement over state-of-the-art electrodes with a 50× decrease in Pt loading

Systematic review of high-intensity focused ultrasound ablation in the treatment of breast cancer

Background A systematic review was undertaken to assess the clinical efficacy of non-invasive high-intensity focused ultrasound (HIFU) ablation in the treatment of breast cancer. Methods MEDLINE/PubMed library databases were used to identify all studies published up to December 2013 that evaluated the role of HIFU ablation in the treatment of breast cancer. Studies were eligible if they were performed on patients with breast cancer and objectively recorded at least one clinical outcome measure of response (imaging, histopathological or cosmetic) to HIFU treatment. Results Nine studies fulfilled the inclusion criteria. The absence of tumour or residual tumour after treatment was reported for 95·8 per cent of patients (160 of 167). No residual tumour was found in 46·2 per cent (55 of 119; range 17-100 per cent), less than 10 per cent residual tumour in 29·4 per cent (35 of 119; range 0-53 per cent), and between 10 and 90 per cent residual tumour in 22·7 per cent (27 of 119; range 0-60 per cent). The most common complication associated with HIFU ablation was pain (40·1 per cent) and less frequently oedema (16·8 per cent), skin burn (4·2 per cent) and pectoralis major injury (3·6 per cent). MRI showed an absence of contrast enhancement after treatment in 82 per cent of patients (31 of 38; range 50-100 per cent), indicative of coagulative necrosis. Correlation of contrast enhancement on pretreatment and post-treatment MRI successfully predicted the presence of residual disease. Conclusion HIFU treatment can induce coagulative necrosis in breast cancers. Complete ablation has not been reported consistently on histopathology and no imaging modality has been able confidently to predict the percentage of complete ablation. Consistent tumour and margin necrosis with reliable follow-up imaging are required before HIFU ablation can be evaluated within large, prospective clinical trials. Many questions remai

Early Geometrical Thinking in the Environment of Patterns, Mosaics and Isometries

This book discusses the learning and teaching of geometry, with a special focus on kindergarten and primary education. It examines important new trends and developments in research and practice, and emphasizes theoretical, empirical and developmental issues. Further, it discusses various topics, including curriculum studies and implementation, spatial abilities and geometric reasoning, as well as the psychological roots of geometrical thinking and teacher preparation in geometry education. It considers these issues from historical, epistemological, cognitive semiotic and educational points of view in the context of students' difficulties and the design of teaching and curricula

El Uso de Las Letras como Fuente de Errores de Estudiantes Universitarios en la Resolución de Tareas Algebraicas

La presente investigación es un estudio realizado con 194 estudiantes del Centro Universitario de la Costa Sur, en Autlán, México, cuyo objetivo es analizar los errores más comunes que los alumnos de primer semestre presentan en las producciones, al operar con los distintos significados que pueden tener las letras en álgebra y con base a esos resultados, establecer su ubicación dentro de alguna de las cuatro categorías de entendimiento en el uso y significado de las letras en álgebra que propone Küchemann (1980). Los resultados muestran que más de la mitad de los estudiantes de este nivel educativo no manifiestan dificultades al evaluar las letras, manejarlas como objetos o considerar su presencia, sin embargo, sí revelan deficiencias en el discernimiento para comprender el uso y significado de las letras como incógnitas de valor especifico, números generalizados y como variables

Research on Teaching and Learning Mathematics at the Tertiary Level:State-of-the-art and Looking Ahead

This topical survey focuses on research in tertiary mathematics education, a field that has experienced considerable growth over the last 10 years. Drawing on the most recent journal publication as well as the latest advances from recent high quality conference proceedings, our review culls out the following five emergent areas of interest: mathematics teaching at the tertiary level; the role of mathematics in other disciplines; textbooks, assessment and students’ studying practices; transition to the tertiary level; and theoretical-methodological advances. We conclude the survey with a discussion of some potential ways forward for future research in this new and rapidly developing domain of inquiry