Processing of engineering ceramics with high power CO2 lasers

The hardness and brittleness of high performance engineering ceramics such as zirconia, aluminia, silicon carbide and silicon nitride makes traditional processing very expensive and time consuming. Efforts have been made to cut thick commercial ceramics with a continuous wave CO₂ laser. The results obtained so far are very promising and materials up to 10 mm in thickness have been cut successfully.     

A review on improving the autonomy of unmanned surface vehicles through intelligent collision avoidance manoeuvres

In recent years unmanned vehicles have grown in popularity, with an ever increasing number of applications in industry, the military and research within air, ground and marine domains. In particular, the challenges posed by unmanned marine vehicles in order to increase the level of autonomy include automatic obstacle avoidance and conformance with the Rules of the Road when navigating in the presence of other maritime traffic. The USV Master Plan which has been established for the US Navy outlines a list of objectives for improving autonomy in order to increase mission diversity and reduce the amount of supervisory intervention. This paper addresses the specific development needs based on notable research carried out to date, primarily with regard to navigation, guidance, control and motion planning. The integration of the International Regulations for Avoiding Collisions at Sea within the obstacle avoidance protocols seeks to prevent maritime accidents attributed to human error. The addition of these critical safety measures may be key to a future growth in demand for USVs, as they serve to pave the way for establishing legal policies for unmanned vessels.     

Superfluid-insulator transition in disordered boson systems

We review the localization problem in two dimensions for interacting bosons in a random potential. This problem is intimately related to the study of ⁴ He adsorbed in porous media, Josephson junction arrays, disordered superconducting films and vortex glasses. Using path integral Monte Carlo techniques, we find a superfluid, a localized or Bose glass insulator with gapless excitations, and (at commensurate densities) a Mott insulator with a finite gap to excitations.     

Advances in Applying Computer-Aided Drug Design for Neurodegenerative Diseases

Neurodegenerative diseases (NDs) including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and Huntington’s disease are incurable and affect millions of people worldwide. The development of treatments for this unmet clinical need is a major global research challenge. Computer-aided drug design (CADD) methods minimize the huge number of ligands that could be screened in biological assays, reducing the cost, time, and effort required to develop new drugs. In this review, we provide an introduction to CADD and examine the progress in applying CADD and other molecular docking studies to NDs. We provide an updated overview of potential therapeutic targets for various NDs and discuss some of the advantages and disadvantages of these tools.     

Coupling granule properties and granulation rates in high-shear granulation

It is possible to link granulation rates to granule properties. The linkage is by multiple dimension population balance equations that, by means of simplifying assumptions, can be reduced to multiple one-dimensional (1-D) population balance equations (PBEs). Using simple physically based models, this paper demonstrates how multiple one-dimensional population balance equations can describe the results of high-shear granulation experiments of two different materials, calcium carbonate and lactose. Good agreement between experimental and simulated results was achieved enabling the granulation rates to be defined by two model parameters: the critical binder volume fraction and the aggregation rate constant. The modelling framework presented in this paper also provides a basis for the kinetic analysis of granulation experiments so that with further work, it is possible to determine the effect of process conditions and material properties on the model parameters.     

Non-uniformity of binder distribution in high-shear granulation

Further experimental investigation based on a microscopic, or single granule, scale has been conducted to investigate the uniformity of binder composition within a given size class for high shear melt granulation. This work assesses whether there is significant non-uniformity of binder composition within size classes to warrant considering this level of detail to improving population balance modelling of high shear granulation. It is concluded that at early times in a batch granulation process there is a broad variation in binder content between individual granules and that this variation persists in granules of small size.     

3D Simulation Research on Urea-SCR DeNO<em>x Catalyst for Diesel Engine

In order to reduce oxides of nitrogen (NOx) emanated from a diesel eng ine, a comprehensive urea selective catalyst reduction (SCR) DeNOx catalys t was modeled in which numerical simulations were used as a complementary tool f or the experimental investigations to make the design decisions, and hence short en the development process. In this approach, relevant conversion reactions were studied in 1D model, and the parameters obtained in this way were transferred t o 3D simulations. According to the results ...     

Delay-dependent anti-windup synthesis for stability of constrained state delay systems using pole-constraints

This paper proposes the design of anti-windup compensator gain for stability of actuator input constrained state delay systems using constrained pole-position of the closed-loop. Based on Delay-Dependent Lyapunov-Krasovskii functionals and local sector conditions, a new LMI characterization is derived that ensures closed-loop asymptotic stability of constrained state delay systems while accounting upper bound fixed state delay and largest lower bound of the system’s pole-position in the formulation of anti-windup gain. Besides, at saturation, the method significantly nullifies the inherent slow dynamics present in the system. It is shown in the comparative numerical examples that the LMI formulation draws stability with improved time-domain performance.