Glass transition in Ultrathin Polymer Films : A Thermal Expansion Study

Glass transition process gets affected in ultrathin films having thickness comparable to the size of the molecules. We observe systematic broadening of glass transition temperature (Tg) as the thickness of the polymer film reduces below the radius of gyration but the change in the average Tg was found to be very small. Existence of reversible negative and positive thermal expansion below and above Tg increased the sensitivity of our thickness measurements performed using energy dispersive x-ray reflectivity. A simple model of Tg variation as a function of depth expected from sliding motion could explain the results. We observe clear glass transition even for 4 nm polystyrene film that was predicted to be absent from ellipsometry measurements of thicker films.Comment: 11 pages, 5 figure

Extended supernova shock breakout signals from inflated stellar envelopes

Stars close to the Eddington luminosity can have large low-density inflated envelopes. We show that the rise times of shock breakout signals from supernovae can be extended significantly if supernova progenitors have an inflated stellar envelope. If the shock breakout occurs in such inflated envelopes, the shock breakout signals diffuse in them, and their rise time can be significantly extended. Then, the rise times of the shock breakout signals are dominated by the diffusion time in the inflated envelope rather than the light-crossing time of the progenitors. We show that our inflated Wolf-Rayet star models whose radii are of the order of the solar radius can have shock breakout signals which are longer than ~100 sec. The existence of inflated envelopes in Wolf-Rayet supernova progenitors may be related to the mysterious long shock breakout signal observed in Type Ib SN 2008D. Extended shock breakout signals may provide evidence for the existence of inflated stellar envelopes and can be used to constrain the physical properties of these enigmatic structures.Comment: 5 pages, 3 figures, 1 table, accepted by Astronomy & Astrophysics Letters, proofed in v

Generating 3D faces using Convolutional Mesh Autoencoders

Learned 3D representations of human faces are useful for computer vision problems such as 3D face tracking and reconstruction from images, as well as graphics applications such as character generation and animation. Traditional models learn a latent representation of a face using linear subspaces or higher-order tensor generalizations. Due to this linearity, they can not capture extreme deformations and non-linear expressions. To address this, we introduce a versatile model that learns a non-linear representation of a face using spectral convolutions on a mesh surface. We introduce mesh sampling operations that enable a hierarchical mesh representation that captures non-linear variations in shape and expression at multiple scales within the model. In a variational setting, our model samples diverse realistic 3D faces from a multivariate Gaussian distribution. Our training data consists of 20,466 meshes of extreme expressions captured over 12 different subjects. Despite limited training data, our trained model outperforms state-of-the-art face models with 50% lower reconstruction error, while using 75% fewer parameters. We also show that, replacing the expression space of an existing state-of-the-art face model with our autoencoder, achieves a lower reconstruction error. Our data, model and code are available at http://github.com/anuragranj/com

Talent management and developing leadership talent

An important aspect of talent management in the contemporary organization is the investment and development of leaders including leadership development. Developing leadership talent is viewed as a key lever in delivering competitive advantage in business today. Leadership can be viewed from multiple perspectives: as a personality with special traits or characteristics; an act or behavior shown by the leader; the capability, knowledge, and skills demonstrated by the leader; the process used by the leader to bring groups together; or transformative change and the power relationship that exists between leaders and followers. In essence, developing leadership talent is a multi-layered process, ideally involving a blended learning approach that incorporates formal, informal, and experiential learning. The development of the leader as an individual focuses on building and enhancing the individual's capability to undertake the role of a leader. A key aspect of leader development is that “it is ultimately about facilitating an identity transition” to create new leadership options

Evidence on education to career transitions in the financial and accountancy sector

The aim of this pilot project was three-fold: 1) create a learning intervention with the aim of developing priority employability skills for first year undergraduate students as determined within the financial services and accountancy sector; 2) explore the participants’ experience of the programme content; 3) identify recommendations for future schemes. The United Kingdom (UK) Financial and Legal Skills Partnership (FLSP) developed a platform to provide mentoring and skills development across financial services and accountancy. Known as “Get In Get On” (GIGO), the FLSP’S virtual work experience comprises two discreet though interdependent features: 1) skills and knowledge development; 2) e-career mentoring. Between February 2014 and April 2014, twenty eight mentees and mentors (from Middlesex University and supportive organisations/individuals) participated in the scheme. The pilot evaluation suggests that there is reciprocal learning for students and professional mentors within the context of the accounting and finance profession. Students have benefitted from a heighted awareness of the career opportunities available in the sector and how their studies may assist them in developing their key employability attributes. Feedback suggests that the scheme has greatest benefit for students entering higher education, with a view to preparing them for future employment

Two-dimensional Induced Ferromagnetism

Magnetic properties of materials confined to nanometer length scales are providing important information regarding low dimensional physics. Using gadolinium based Langmuir-Blodgett films, we demonstrate that two-dimensional ferromagnetic order can be induced by applying magnetic field along the in-plane (perpendicular to growth) direction. Field dependent exchange coupling is evident in the in-plane magnetization data that exhibit absence of hysteresis loop and show reduction in field required to obtain saturation in measured moment with decreasing temperature.Comment: 4 pages, 3 postscript figures, corrected paper forma