1,427 research outputs found

    Improving the conductance of carbon nanotube networks through resonant momentum exchange

    Full text link
    We present a mechanism to improve the conductivity of carbon nanotube (CNT) networks by improving the conductance between CNTs of different chirality. We argue generally that a weak perturbation can greatly improve the inter-tube conductance by allowing momentum-conserving tunnelling. The mechanism is verified with a tight-binding model, allowing an investigation of its impact for a network containing a range of chiralities. We discuss practical implementations, and conclude that it may be effected by weak physical interactions, and therefore does not require chemical bonding to the CNTs.Comment: 6 pages, 4 figure

    Toward a New Diversity and the Revitalization of hte Campus Spirit: A Bandung 2000 Conference for Students, Staff and Faculty

    Get PDF
    In this session, New Diversity programs are designed and proposed, aimed at enabling minority staff, students and faculty the kind of cultural inoculation needed to be able to address the concerns which plague most campuses

    Photophysics and photochemistry of DNA molecules : electronic excited states leading to thymine dimerization

    Get PDF
    We combine quantified natural transition orbital (QNTO) analysis with large-scale linear response time-dependent DFT (TDDFT) to investigate the concerted [2 + 2] thymine dimerisation reaction. This reaction is a main cause of UV-light induced damage to DNA, but its mechanism has remained poorly understood. QNTO analysis enables the electronic excitations of a molecule to be identified on the basis of their transition origins across a wide range of molecular geometries, allowing the participating excited states to be identified relatively straightforwardly. We identify a barrierless funnel that is responsible for the ultrafast reaction previously indicated in experiments. The reactive state is found to have crossings with several bright excited states, revealing how the initially populated bright states can decay rapidly to the reactive state. We also examine the contribution of environmental factors such as inclusion of the DNA backbone, which can affect the conformation of the potential energy surfaces of the relevant states

    A holistic multi-scale approach to using 3D scanning technology in accident reconstruction

    Get PDF
    Three-dimensional scanning and documentation methods are becoming increasingly employed by law enforcement personnel for crime scene and accident scene recording. Three-dimensional documentation of the victim’s body in such cases is also increasingly used as the field of forensic radiology and imaging is expanding rapidly. These scanning technologies enable a more complete and detailed documentation than standard autopsy. This was used to examine a fatal pedestrian-vehicle collision where the pedestrian was killed by a van whilst crossing the road. Two competing scenarios were considered for the vehicle speed calculation: the pedestrian being projected forward by the impact or the pedestrian being carried on the vehicle’s bonnet. In order to assist with this, the impact area of the accident vehicle was scanned using laser surface scanning, the victim was scanned using postmortem CT and micro-CT and the data sets were combined to virtually match features of the vehicle to injuries on the victim. Micro-CT revealed additional injuries not previously detected, lending support to the pedestrian-carry theory

    Risk Factors for Falls in Individuals With Lower Extremity Amputations During the Pre-Prosthetic Phase: A Retrospective Cohort Study

    Get PDF
    BACKGROUND: Falls in individuals with lower limb amputations (LLAs) pose significant health concerns. The literature is limited regarding falls during the preprosthetic phase of rehabilitation for persons with LLAs. OBJECTIVE: To determine the incidence of falls and identify factors associated with falls during the preprosthetic recovery phase. DESIGN: Retrospective chart audit. SETTING: Inpatient rehabilitation program. PARTICIPANTS: Four hundred forty individuals with LLAs (age ± SD = 61.93 ± 14.53 years, 73.18% male) who attended inpatient rehabilitation from 26 July 2011 to 21 August 2017. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASUREMENTS: The number of self-reported falls was recorded from the time of surgery to admission for inpatient rehabilitation. Outcomes of interest were any fall (1+ fall) and recurrent falls (2+ falls). A retrospective chart audit was performed on consecutive admissions to an inpatient rehabilitation program. RESULTS: The incidence of falls was 8.37 per 1000 patient-days. Falls were sustained by 60.9% of the sample. Unilateral transtibial amputation was independently associated with an increased risk of recurrent falls (relative risk [RR] 1.59, 95% confidence interval [CI] 1.13-2.23, P = .008). Diabetes mellitus was independently associated with an increased risk of any fall (RR 1.18, 95% CI 1.01-.38, P = .03). Finally, bilateral transtibial amputation was independently associated with a reduced risk of any fall (RR 0.59, 95% CI 0.39-0.90, P = .014). CONCLUSIONS: Consistent with the current literature, diabetes mellitus and a unilateral transtibial amputation were risk factors for falling, whereas a bilateral transtibial amputation and increasing age presented new findings as factors associated with decreased falling. LEVEL OF EVIDENCE: III

    Implicit moral evaluations: A multinomial modeling approach

    Get PDF
    Implicit moral evaluations-i.e., immediate, unintentional assessments of the wrongness of actions or persons-play a central role in supporting moral behavior in everyday life. Yet little research has employed methods that rigorously measure individual differences in implicit moral evaluations. In five experiments, we develop a new sequential priming measure-the Moral Categorization Task-and a multinomial model that decomposes judgment on this task into multiple component processes. These include implicit moral evaluations of moral transgression primes (Unintentional Judgment), accurate moral judgments about target actions (Intentional Judgment), and a directional tendency to judge actions as morally wrong (Response Bias). Speeded response deadlines reduced Intentional Judgment but not Unintentional Judgment (Experiment 1). Unintentional Judgment was stronger toward moral transgression primes than non-moral negative primes (Experiments 2-4). Intentional Judgment was associated with increased error-related negativity, a neurophysiological indicator of behavioral control (Experiment 4). Finally, people who voted for an anti-gay marriage amendment had stronger Unintentional Judgment toward gay marriage primes (Experiment 5). Across Experiments 1-4, implicit moral evaluations converged with moral personality: Unintentional Judgment about wrong primes, but not negative primes, was negatively associated with psychopathic tendencies and positively associated with moral identity and guilt proneness. Theoretical and practical applications of formal modeling for moral psychology are discussed

    ONETEP + TOSCAM: uniting dynamical mean field theory and linear-scaling density functional theory

    Get PDF
    We introduce the unification of dynamical mean field theory (DMFT) and linear-scaling density functional theory (DFT), as recently implemented in ONETEP, a linear-scaling DFT package, and TOSCAM, a DMFT toolbox. This code can account for strongly correlated electronic behavior while simultaneously including the effects of the environment, making it ideally suited for studying complex and heterogeneous systems containing transition metals and lanthanides, such as metalloproteins. We systematically introduce the necessary formalism, which must account for the non-orthogonal basis set used by ONETEP. In order to demonstrate the capabilities of this code, we apply it to carbon monoxide-ligated iron porphyrin and explore the distinctly quantum-mechanical character of the iron 3d3d electrons during the process of photodissociation.Comment: Contains 46 pages and 12 figures, including 5 pages of supplementary materia

    Assessing the Effect of High Performance Computing Capabilities on Academic Research Output

    Get PDF
    This paper uses nonparametric methods and some new results on hypothesis testing with nonparametric efficiency estimators and applies these to analyze the effect of locally-available high performance computing (HPC) resources on universities efficiency in producing research and other outputs. We find that locally-available HPC resources enhance the technical efficiency of research output in Chemistry, Civil Engineering, Physics, and History, but not in Computer Science, Economics, nor English; we find mixed results for Biology. Out research results provide a critical first step in a quantitative economic model for investments in HPC
    • …
    corecore