Hopf-cyclic cohomology of the Connes-Moscovici Hopf algebras with infinite dimensional coefficients

We discuss a new strategy for the computation of the Hopf-cyclic cohomology of the Connes-Moscovici Hopf algebra $\mathcal{H}_n$. More precisely, we introduce a multiplicative structure on the Hopf-cyclic complex of $\mathcal{H}_n$, and we show that the van Est type characteristic homomorphism from the Hopf-cyclic complex of $\mathcal{H}_n$ to the Gelfand-Fuks cohomology of the Lie algebra $W_n$ of formal vector fields on $\mathbb{R}^n$ respects this multiplicative structure. We then illustrate the machinery for $n=1$.Comment: Minor revisions to highlight the main result

Bearing damage characteristics of fibre-reinforced countersunk composite bolted joints subjected to quasi-static shear loading

This paper studies the progression of damage in carbon fibre-reinforced polymer (CFRP) countersunk composite bolted joints (CBJs) with neat-fit clearance, subjected to quasi-static loading. Damage mechanisms, comprising of fibre buckling and breakage, matrix damage, shear damage and inter-laminar delamination within the CFRP composite parts of the joints have been studied. Load-displacement curves, X-ray and optical microscopic images in single- and three-bolt CBJs were used to investigate damage and deformation characteristics. The observations were then employed to further investigate the type of failure and the extent of damage. The evolution of damage within the composite parts was correlated to the failure characteristics of the joints: It was found that the type and extension of damage is strongly correlated with the ultimate failure load point of the joint in single-bolt CBJs. A combined inter/intra-laminar damage consisting of fibre cluster breakage, extensive fibre buckling, debonding and delamination was observed at the ultimate failure load. This study was then extended to three-bolt CBJ where damage surrounding each bolt and its corresponding failure load was strongly correlated: The final study showed that the ultimate failure point in single-bolt CBJ and the first-bolt-failure point in three-bolt CBJ correspond to the composite plies undergoing intra-laminar damage with the size reaching to the edge of the countersunk head. This damage developed extensively through the thickness of the composite parts underneath the countersink, and in the direction opposite to the loading direction. Outside the countersunk head, debonding and delamination were found to be the dominant damage driving mechanisms. Finally, a new design rule has been proposed to predict the response of multi-bolt joints (damage area and failure load) by using the response in single-bolt CBJ as an initial baseline

The Majorana spin in magnetic atomic chain systems

In this paper, we establish that Majorana zero modes emerging from a topological band structure of a chain of magnetic atoms embedded in a superconductor can be distinguished from trivial localized zero energy states that may accidentally form in this system using spin resolved measurements. To demonstrate this key Majorana diagnostics, we study the spin composition of magnetic impurity induced in-gap Shiba states in a superconductor using a quantum impurity model (at the mean-field level). By examining the spin and spectral densities in the context of the Bogoliubov-de Gennes (BdG) particle-hole symmetry, we derive a sum rule that relates the spin densities of localized Shiba states with those in the normal state without superconductivity. Extending our investigations to ferromagnetic chain of magnetic impurities, we identify key features of the spin properties of the extended Shiba state bands, as well as those associated with a localized Majorana end mode when the effect of spin-orbit interaction is included. We then formulate a phenomenological theory for the measurement of the local spin densities with spin-polarized scanning tunneling microscopy (STM) techniques. By combining the calculated spin densities and the measurement theory, we show that spin-polarized STM measurements can reveal a sharp contrast in spin polarization between an accidentally-zero-energy trivial Shiba state and a Majorana zero mode in a topological superconducting phase in atomic chains. We further confirm our results with numerical simulations that address generic parameter settings.Comment: 22 pages, 12 figures (references updated

Analysing the effect of lean on the performance of NPD projects using system dynamics modelling

To be able to survive in today’s fast-changing market environment companies are looking for innovative ways to improve the performance of their new product development (NPD) processes. However, uncertainty and rework are among characteristics of NPD which make them difficult to manage. Implementing lean in NPD is an innovative approach to address this issue. Using system dynamics approach to model set-based concurrent engineering as a fundamental element of lean product development, this paper shows the positive effect on of adopting this strategy on the time, cost and quality of NPD projects, in comparison with the traditional point-based design

The effect of Lean implementation on the efficiency and effectiveness of new product development processes

Although increasing the new product development speed and improving its cost effectiveness as well as enhancing the process quality have been at the centre of attention of many companies, there is still significant opposition to the 'better, faster and cheaper' paradigm. Improvement of new product development processes using Lean principles has been claimed to be an effective way to reach to this goal. In this conceptual paper, first the efficiency and effectiveness in new product development processes and the key components of Lean product development has been defined, then, an introduction to modelling the process based on System Dynamics, to develop the interrelationships between Lean components and performance measures, has been discussed

The activities and impact of personalisation in a UK business school

The aim of this study is to consider the activities and impact of Personalisation in a UK higher education setting. It will consider how personalisation has affected outputs in terms of progression, achievement, internship, enterprise project and international placement uptake within the Nottingham Business School at Nottingham Trent University. The Methodology comprised of using qualitative and quantitative data. Semi-structured interviews were carried out with members of the Personalisation team and those in the delivery of Personalisation. The quantitative data pertains to outputs in terms of success rates, particularly with regard to when the Personalisation project began in 2015/16. The findings suggest that the Personalisation process involves engagement, interaction and reflection to meet the needs and requirements of the learner, as well as providing them options. This contributes to success rates with the outputs, particularly when the Personalisation project began

Cd3As2 is Centrosymmetric

This is a revised version of a manuscript that was originally posted here in February of 2014. It has been accepted at the journal Inorganic Chemistry after reviews that included those of two crystallographers who made sure all the t's were crossed and the i's were dotted. The old work (from 1968) that said that Cd3As2 was noncentrosymmetric was mistaken, with the authors of that study making a type of error that in the 1980s became infamous in crystallography. As a result of the increased scrutiny of the issue of centrosymmetricity of the 1980's, there are now much better analysis tools to resolve the issue fully, and its important to understand that not just our crystals are centrosymmetric, even the old guy's crystals were centrosymmetric (and by implication everyone's are). There is no shame in having made that error back in the day and those authors would not find the current centrosymmetric result controversial; their paper is excellent in all other aspects. This manuscript describes how the structure is determined, explains the structure schematically, calculates the electronic structure based on the correct centrosymmetric crystal structure, and gives the structural details that should be used for future analysis and modeling.Comment: Accepted by ACS Inorganic Chemistr