Quantum dynamics of thermalizing systems

We introduce a method "DMT" for approximating density operators of 1D systems that, when combined with a standard framework for time evolution (TEBD), makes possible simulation of the dynamics of strongly thermalizing systems to arbitrary times. We demonstrate that the method performs well for both near-equilibrium initial states (Gibbs states with spatially varying temperatures) and far-from-equilibrium initial states, including quenches across phase transitions and pure states

Weak Gravitational Lensing and Cluster Mass Estimates

Hierarchical theories of structure formation predict that clusters of galaxies should be embedded in a web like structure, with filaments emanating from them to large distances. The amount of mass contained within such filaments near a cluster can be comparable to the collapsed mass of the cluster itself. Diffuse infalling material also contains a large amount of mass. Both these components can contribute to the cluster weak lensing signal. This ``projection bias'' is maximized if a filament lies close to the line-of-sight to a cluster. Using large--scale numerical simulations of structure formation in a cosmological constant dominated cold dark matter model, we show that the projected mass typically exceeds the actual mass by several tens of percent. This effect is significant for attempts to estimate cluster masses through weak lensing observations, and will affect weak lensing surveys aimed at constructing the cluster mass function.Comment: 4 pages, 3 figures. LaTeX2e, uses emulateapj.sty and onecolfloat.sty. To be submitted to the Astrophysical Journal Letter

Risky Behavior: A Three-Factor Adoption Model

This study seeks to understand the convenience versus privacy risk debate that many consumers knowingly and unknowingly participate in every day, as well as the impacts of these information privacy and trust concerns on innovation adoption. We investigate the relationship between the motivation, perception, and intention-to-use of reputation-aware applications, particularly regarding possible privacy threats. Our theoretical model presents a unique and novel interpretation of technology acceptance of reputation-aware systems that have high privacy risks. Specifically, we combine PMT and TAM to propose a three-factor technology adoption model to evaluate the risk, coping, and benefit calculus of technology adoption. We pose two research questions: (1) What are the factors influencing a user’s assessment of the benefits and threats adopting reputation-aware applications?; and (2) Does a three-factor adoption model present greater predictive power to assess behavioral intentions? The results of our empirical evaluation reveal that behavioral intent regarding the adoption of reputation-aware applications can be predicted using a three-factor adoption model, with the findings significant and reliable across all three factors. Additionally, the results show that the conceptual model has improved predictive power over existing acceptance models in the context of reputation-aware applications. The TAM/TPB components were able to predict approximately 62% of the variance of behavioral intention, whereas the PMT and TPB model was able to predict 74% of the variance of behavioral intention

The function, significance and limitations of 'globalisation' in the new labour discourse.

This thesis critically examines the idea of 'globalisation' in the New Labour discourse over the period 1996- 2001, challenging the version articulated by key members of the party. This task involves contesting and reinterpreting the implications imputed to the process both at the domestic and international levels. The understanding and implications of 'globalisation' have changed over time. It herefore distinguish two phases. The first phase I associate exclusively with Tony Blair. This understanding focuses on the domestic significance of globalisation, and conflates the process with liberalisation. In this phase globalisation functions to de-politicise a 'third way' agenda, which is presented as if it were the only logical alternative for a party of the centre left. A second phase, the chief contributors to which are Tony Blair and Robin Cook, concentrates on the international significance of globalisation. Both argue for a move beyond traditional realist approaches to foreign policy, stressing instead the role globalisation plays in creating a 'global interest'. Drawing upon developments in the literature, the thesis challenges the New Labour position firstly by questioning the implications of globalisation drawn out by them, as empirically untenable. Globalisation does not necessarily limit the room for manoeuvre in the way suggested by Blair, nor does it imply an increased harmony of interests forming around the idea of a global interest. However, in offering an alternative interpretation this study highlights that globalisation should not merely be understood in terms of whether its usage is right or wrong. In addition, the thesis argues for a critical hermeneutic approach to be taken on the topic. It is argued that the current form globalisation takes is reproduced because it functions in particular contexts to serve a political agenda within the party. This reveals an ideological dimension in the discourse, drawing attention to the ways in which the meaning of globalisation is manipulated in order to serve an alternative set of interests not declared in the discourse itself, thereby manifesting itself in a particular form over time

Determining SUSY model parameters and masses at the LHC using cross-sections, kinematic edges and other observables

We address the problem of mass measurements of supersymmetric particles\ud at the Large Hadron Collider, using the ATLAS detector as an example. By\ud using Markov Chain sampling techniques to combine standard measurements of kinematic\ud edges in the invariant mass distributions of decay products with a measurement\ud of a missing pT cross-section, we show that the precision of mass measurements at\ud the LHC can be dramatically improved, even when we do not assume that we have\ud measured the kinematic endpoints precisely, or that we have identified exactly which\ud particles are involved in the decay chain causing the endpoints. The generality of the\ud technique is demonstrated in a preliminary investigation of a non-universal SUGRA\ud model, in which we relax the requirements of mSUGRA by breaking the degeneracy\ud of the GUT scale gaugino masses. The model studied is compatible with the WMAP\ud limits on dark matter relic density

Three body kinematic endpoints in SUSY models with non-universal Higgs masses.

We derive and present expressions for the kinematic endpoints that arise in the invariant mass distributions of visible decay products of cascade decays featuring a two body decay followed by a three body decay. This is an extension of a current technique that addresses chains of successive two body decays. We then apply these to a supergravity model with Non-Universal Higgs Masses (NUHM), having simulated a data set using the ATLFAST detector simulation. We find that, should such a model be chosen by nature, the endpoints will be visible in ATLAS data, and we discuss the problems associated with mass reconstruction in models with a similar phenomenology

Characterisation of commercially CVD grown multi-walled carbon nanotubes for paint applications

AbstractCommercially grown, multi-walled carbon nanotubes (MWNTs), available in kilogram quantities from three commercial suppliers have been characterised using a number of analytical techniques. The catalysts used in the growth of the MWNTs are identified by energy dispersive X-ray spectroscopy (EDX) and different growth mechanisms are postulated to explain the various structures present in the MWNT stock in its as-supplied form. A tightening of the agglomerate structures during purification and functionalisation is shown using scanning electron microscopy (SEM) and confirmed more qualitatively using pore-size distributions obtained using the Brunauer–Emmett–Teller (BET) method and non-local density functional theory (NLDFT) calculations. Differences in thermal stability are shown using thermogravimetric analysis (TGA) and are related back to the residual catalysts present. X-ray photoelectron spectroscopy (XPS) is used to confirm functionalisation of certain grades and Raman spectroscopy is used to investigate the level of defects present

A procedure for developing an acceptance test for airborne bathymetric lidar data application to NOAA charts in shallow waters

National Oceanic and Atmospheric Administration (NOAA) hydrographic data is typically acquired using sonar systems, with a small percent acquired via airborne lidar bathymetry for near‐shore areas. This study investigated an integrated approach for meeting NOAA’s hydrographic survey requirements for near‐shore areas of NOAA charts, using the existing topographic‐bathymetric lidar data from USACE’s National Coastal Mapping Program (NCMP). Because these existing NCMP bathymetric lidar datasets were not collected to NOAA hydrographic surveying standards, it is unclear if, and under what circumstances, they might aid in meeting certain hydrographic surveying requirements. The NCMP’s bathymetric lidar data are evaluated through a comparison to NOAA’s Office of Coast Survey hydrographic data derived from acoustic surveys. As a result, it is possible to assess if NCMP’s bathymetry can be used to fill in the data gap shoreward of the navigable area limit line (0 to 4 meters) and if there is potential for applying NCMP’s bathymetry lidar data to near‐shore areas deeper than 10 meters. Based on the study results, recommendations will be provided to NOAA for the site conditions where this data will provide the most benefit. Additionally, this analysis may allow the development of future operating procedures and workflows using other topographic‐ bathymetric lidar datasets to help update near‐shore areas of the NOAA charts