Scattering measurements on natural and model trees

The acoustical back scattering from a simple scale model of a tree has been experimentally measured. The model consisted of a trunk and six limbs, each with 4 branches; no foliage or twigs were included. The data from the anechoic chamber measurements were then mathematically combined to construct the effective back scattering from groups of trees. Also, initial measurements have been conducted out-of-doors on a single tree in an open field in order to characterize its acoustic scattering as a function of azimuth angle. These measurements were performed in the spring, prior to leaf development. The data support a statistical model of forest scattering; the scattered signal spectrum is highly irregular but with a remarkable general resemblance to the incident signal spectrum. Also, the scattered signal's spectra showed little dependence upon scattering angle

Material Flow Analysis: Outcome Focus (MFA:OF) for Elucidating the Role of Infrastructure in the Development of a Liveable City

Engineered infrastructures (i.e., utilities, transport & digital) underpin modern society. Delivering services via these is especially challenging in cities where differing infrastructures form a web of interdependencies. There must be a step change in how infrastructures deliver services to cities, if those cities are to be liveable in the future (i.e., provide for citizen wellbeing, produce less CO2 & ensure the security of the resources they use). Material Flow Analysis (MFA) is a useful methodology for understanding how infrastructures transfer resources to, within and from cities and contribute to the city’s metabolism. Liveable Cities, a five-year research programme was established to identify & test radical engineering interventions leading to liveable cities of the future. In this paper, the authors propose an outcome-focussed variation on the MFA methodology (MFA: OF), evidenced through work on the resource flows of Birmingham, UK. These flows include water, energy, food & carbon-intensive materials (e.g., steel, paper, glass), as well as their associated waste. The contribution MFA: OF makes to elucidating the interactions & interdependencies between the flows is highlighted and suggestions are made for how it can contribute to the (radical) rethinking of the engineered infrastructure associated with such flow

End-functionalized glycopolymers as mimetics of chondroitin sulfate proteoglycans

Glycosaminoglycans are sulfated polysaccharides that play important roles in fundamental biological processes, such as cell division, viral invasion, cancer and neuroregeneration. The multivalent presentation of multiple glycosaminoglycan chains on proteoglycan scaffolds may profoundly influence their interactions with proteins and subsequent biological activity. However, the importance of this multivalent architecture remains largely unexplored, and few synthetic mimics exist for probing and manipulating glycosaminoglycan activity. Here, we describe a new class of end-functionalized ring-opening metathesis polymerization (ROMP) polymers that mimic the native-like, multivalent architecture found on chondroitin sulfate (CS) proteoglycans. We demonstrate that these glycopolymers can be readily integrated with microarray and surface plasmon resonance technology platforms, where they retain the ability to interact selectively with proteins. ROMP-based glycopolymers are part of a growing arsenal of chemical tools for probing the functions of glycosaminoglycans and for studying their interactions with proteins

Vortices and the entrainment transition in the 2D Kuramoto model

We study synchronization in the two-dimensional lattice of coupled phase oscillators with random intrinsic frequencies. When the coupling $K$ is larger than a threshold $K_E$, there is a macroscopic cluster of frequency-synchronized oscillators. We explain why the macroscopic cluster disappears at $K_E$. We view the system in terms of vortices, since cluster boundaries are delineated by the motion of these topological defects. In the entrained phase ($K>K_E$), vortices move in fixed paths around clusters, while in the unentrained phase ($K<K_E$), vortices sometimes wander off. These deviant vortices are responsible for the disappearance of the macroscopic cluster. The regularity of vortex motion is determined by whether clusters behave as single effective oscillators. The unentrained phase is also characterized by time-dependent cluster structure and the presence of chaos. Thus, the entrainment transition is actually an order-chaos transition. We present an analytical argument for the scaling $K_E\sim K_L$ for small lattices, where $K_L$ is the threshold for phase-locking. By also deriving the scaling $K_L\sim\log N$, we thus show that $K_E\sim\log N$ for small $N$, in agreement with numerics. In addition, we show how to use the linearized model to predict where vortices are generated.Comment: 11 pages, 8 figure

Universality in the one-dimensional chain of phase-coupled oscillators

We apply a recently developed renormalization group (RG) method to study synchronization in a one-dimensional chain of phase-coupled oscillators in the regime of weak randomness. The RG predicts how oscillators with randomly distributed frequencies and couplings form frequency-synchronized clusters. Although the RG was originally intended for strong randomness, i.e. for distributions with long tails, we find good agreement with numerical simulations even in the regime of weak randomness. We use the RG flow to derive how the correlation length scales with the width of the coupling distribution in the limit of large coupling. This leads to the identification of a universality class of distributions with the same critical exponent $\nu$. We also find universal scaling for small coupling. Finally, we show that the RG flow is characterized by a universal approach to the unsynchronized fixed point, which provides physical insight into low-frequency clusters.Comment: 14 pages, 10 figure

Designing novel applications for emerging multimedia technology

Current R&D in media technologies such as Multimedia, Semantic Web and Sensor Web technologies are advancing in a fierce rate and will sure to become part of our important regular items in a 'conventional' technology inventory in near future. While the R&D nature of these technologies means their accuracy, reliability and robustness are not sufficient enough to be used in real world yet, we want to envision now the near-future where these technologies will have matured and used in real applications in order to explore and start shaping many possible new ways these novel technologies could be utilised. In this talk, some of this effort in designing novel applications that incorporate various media technologies as their backend will be presented. Examples include novel scenarios of LifeLogging application that incorporate automatic structuring of millions of photos passively captured from a SenseCam (wearable digital camera that automatically takes photos triggered by environmental sensors) and an interactive TV application incorporating a number of multimedia tools yet extremely simple and easy to use with a remote control in a lean-back position. The talk will conclude with remarks on how the design of novel applications that have no precedence or existing user base should require somewhat different approach from those suggested and practiced in conventional usability engineering methodology

Adjustments and Uncertainty Quantification for SLS Aerodynamic Sectional Loads

This paper presents a method for adjusting sectional loads to match target values for integrated force and moment coefficients. In a typical application, the sectional load profile for one flight condition is calculated from Computational Fluid Dynamics (CFD) while the integrated forces and moments are measured in a wind tunnel experiment. These two methods do not generally result in identical predictions, and this leads to an inherent inconsistency between different data products. This paper aims to provide a procedure to remove that inconsistency. A sectional load profile for a launch vehicle splits the rocket into slices along its length and calculates the aerodynamic loading on each slice, which leads to a one-dimensional aerodynamic load profile that is used for structural analysis. Adjusting sectional loads, also known as line loads, is a nontrivial matter due to several consistency constraints. For example, the adjusted sectional normal force profile must be consistent with both the integrated normal force and pitching moment. To avoid such inconsistency issues, this paper presents a method using a Proper Orthogonal Decomposition (POD) to generate basis functions to adjust the sectional load profiles. As a corollary, this correction method enables the creation of an uncertainty quantification for sectional loads that is consistent with the dispersed integrated force and moment database and its uncertainty quantification. Several extensions to this technique, such as applying the method to the surface pressures, are considered

Inviscid and Viscous CFD Analysis of Booster Separation for the Space Launch System Vehicle

This paper presents details of Computational Fluid Dynamic (CFD) simulations of the Space Launch System during solid-rocket booster separation using the Cart3D inviscid and Overflow viscous CFD codes. The discussion addresses the use of multiple data sources of computational aerodynamics, experimental aerodynamics, and trajectory simulations for this critical phase of flight. Comparisons are shown between Cart3D simulations and a wind tunnel test performed at NASA Langley Research Center's Unitary Plan Wind Tunnel, and further comparisons are shown between Cart3D and viscous Overflow solutions for the flight vehicle. The Space Launch System (SLS) is a new exploration-class launch vehicle currently in development that includes two Solid Rocket Boosters (SRBs) modified from Space Shuttle hardware. These SRBs must separate from the SLS core during a phase of flight where aerodynamic loads are nontrivial. The main challenges for creating a separation aerodynamic database are the large number of independent variables (including orientation of the core, relative position and orientation of the boosters, and rocket thrust levels) and the complex flow caused by exhaust plumes of the booster separation motors (BSMs), which are small rockets designed to push the boosters away from the core by firing partially in the direction opposite to the motion of the vehicle

What Makes a City Liveable? Implications for Next-Generation Infrastructure Services

Abstract: Infrastructure forms the framework within which modern societies operate both at the physical and social level. It includes (amongst others) digital, green and social infrastructures, emergency services and food networks, water, energy, waste and transport. Infrastructure, by its very nature, locks in behaviours. The Liveable Cities research consortium aims to identify and test radical engineering interventions that will lead to future low carbon, resource secure cities in which societal wellbeing is prioritised, and these will necessarily influence the shape of infrastructure provision. This paper presents a discussion of what comprises a liveable city and how it might be achieved. It presents the City Design Framework, a technique for the analysis of city strategies that establishes a hierarchy of needs relevant to successfully achieving a liveable city. The framework supports changing perceptions of infrastructure since the necessary future changes have the potential to radically alter people’s lifestyle and wellbeing. Citation: Leach, J.M., Lee, S.E., Braithwaite, P.A., Bouch, C.J., Grayson, N. & Rogers, C.D.F. (2014). What Makes a City Liveable? Implications for Next-Generation Infrastructure Services. In: Campbell P. and Perez P. (Eds), Proceedings of the International Symposium of Next Generation Infrastructure, 1-4 October 2013, SMART Infrastructure Facility, University of Wollongong, Australia