Experimental results of high-current arcs driven supersonically in straight and circular channels

High current electric arc characteristics magnetically driven to supersonic velocities in straight and circular channel

Active people recognition using thermal and grey images on a mobile security robot

In this paper we present a vision-based approach to detect, track and identify people on a mobile robot in real time. While most vision systems for tracking people on mobile robots use skin color information, we present an approach using thermal images and a fast contour model together with a particle filter. With this method a person can be detected independently from current light conditions and in situations where no skin color is visible (the person is not close or does not face the robot). Tracking in thermal images is used as an attention system to get an estimate of the position of a person. Based on this estimate we use a pan-tilt camera to zoom to the expected face region and apply a fast face tracker in combination with face recognition to identify the person

Sharing Polarization within Quantum Subspaces

Given an ensemble of n spins, at least some of which are partially polarized, we investigate the sharing of this polarization within a subspace of k spins. We assume that the sharing results in a pseudopure state, characterized by a single purity parameter which we call the bias. As a concrete example we consider ensembles of spin-1/2 nuclei in liquid-state nuclear magnetic resonance (NMR) systems. The shared bias levels are compared with some current entanglement bounds to determine whether the reduced subspaces can give rise to entangled states.Comment: 7 pages, 3 figure

Localization for mobile robots using panoramic vision, local features and particle filter

In this paper we present a vision-based approach to self-localization that uses a novel scheme to integrate feature-based matching of panoramic images with Monte Carlo localization. A specially modified version of Lowe’s SIFT algorithm is used to match features extracted from local interest points in the image, rather than using global features calculated from the whole image. Experiments conducted in a large, populated indoor environment (up to 5 persons visible) over a period of several months demonstrate the robustness of the approach, including kidnapping and occlusion of up to 90% of the robot’s field of view

3D modeling of indoor environments by a mobile robot with a laser scanner and panoramic camera

We present a method to acquire a realistic, visually convincing 3D model of indoor office environments based on a mobile robot that is equipped with a laser range scanner and a panoramic camera. The data of the 2D laser scans are used to solve the SLAM problem and to extract walls. Textures for walls and floor are built from the images of a calibrated panoramic camera. Multi-resolution blending is used to hide seams in the generated textures

National BSUG audit of stress urinary incontinence surgery in England

Introduction and hypothesis The aim of the British Society of Urogynaecology (BSUG) 2013 audit for stress urinary incontinence (SUI) surgery was to conduct a national clinical audit looking at the intra- and postoperative complications and provide outcomes for these procedures. This audit was supported by the Healthcare Quality Improvement Partnership (HQIP) and National Health Service (NHS) England. Methods Data were collected for all continence procedures performed in 2013 through the BSUG database. All clinicians in England performing SUI surgery were invited to submit data to a central database. Outcomes data for the different continence procedures were collected and included intraoperative and postoperative complications and the change in continence scores at postoperative follow-up Changing trends in stress incontinence surgery were also assessed. Results We recorded 4993 urinary incontinence procedures from 177 consultants at 110 centres in England: 94.6% were midurethral slings; 86.7% (4331) were submitted by BSUG members with the remaining 13.3% submitted by non-BSUG members. Postoperative follow-up data were available for 3983 (80%) patients: 92.3% (3676) were very much better/much better postoperatively, and 4806 (96.3%) proceeded with no reported complications. There were 187 cases (3.7%) in which a perioperative complication was recorded. Pain persisting >30 days was reported in 1.9% of all patients. Conclusions Surgery for SUI has good outcomes in the short term. Midurethral synthetic slings have been shown to be safe and effective as a treatment option, with >90% being very much/much better at their postoperative follow-up

Practical Implementations of Twirl Operations

Twirl operations, which convert impure singlet states into Werner states, play an important role in many schemes for entanglement purification. In this paper we describe strategies for implementing twirl operations, with an emphasis on methods suitable for ensemble quantum information processors such as nuclear magnetic resonance (NMR) quantum computers. We implement our twirl operation on a general two-spin mixed state using liquid state NMR techniques, demonstrating that we can obtain the singlet Werner state with high fidelity.Comment: 6 pages RevTex4 including 2 figures (fig 1 low quality to save space

Computational studies explain the importance of two different substituents on the chelating bis(amido) ligand for transfer hydrogenation by bifunctional Cp*Rh(III) catalysts

A computational approach (DFT-B3PW91) is used to address previous experimental studies (Chem. Commun. 2009, 6801) that showed that transfer hydrogenation of a cyclic imine by Et3N·HCO2H in dichloromethane catalyzed by 16-electron bifunctional Cp*Rh III(XNC6H4NX') is faster when XNC 6H4NX' = TsNC6H4NH than when XNC6H4NX' = HNC6H4NH or TsNC 6H4NTs (Cp* = η5-C5Me 5, Ts = toluenesulfonyl). The computational study also considers the role of the formate complex observed experimentally at low temperature. Using a model of the experimental complex in which Cp* is replaced by Cp and Ts by benzenesulfonyl (Bs), the calculations for the systems in gas phase reveal that dehydrogenation of formic acid generates CpRhIIIH(XNC 6H4NX'H) via an outer-sphere mechanism. The 16-electron Rh complex + formic acid are shown to be at equilibrium with the formate complex, but the latter lies outside the pathway for dehydrogenation. The calculations reproduce the experimental observation that the transfer hydrogenation reaction is fastest for the nonsymmetrically substituted complex CpRh III(XNC6H4NX') (X = Bs and X' = H). The effect of the linker between the two N atoms on the pathway is also considered. The Gibbs energy barrier for dehydrogenation of formic acid is calculated to be much lower for CpRhIII(XNCHPhCHPhNX') than for CpRh III(XNC6H4NX') for all combinations of X and X'. The energy barrier for hydrogenation of the imine by the rhodium hydride complex is much higher than the barrier for hydride transfer to the corresponding iminium ion, in agreement with mechanisms proposed for related systems on the basis of experimental data. Interpretation of the results by MO and NBO analyses shows that the most reactive catalyst for dehydrogenation of formic acid contains a localized Rh-NH π-bond that is associated with the shortest Rh-N distance in the corresponding 16-electron complex. The asymmetric complex CpRhIII(BsNC6H4NH) is shown to generate a good bifunctional catalyst for transfer hydrogenation because it combines an electrophilic metal center and a nucleophilic NH group

Implementation of NMR quantum computation with para-hydrogen derived high purity quantum states

We demonstrate the first implementation of a quantum algorithm on a liquid state nuclear magnetic resonance (NMR) quantum computer using almost pure states. This was achieved using a two qubit device where the initial state is an almost pure singlet nuclear spin state of a pair of 1H nuclei arising from a chemical reaction involving para-hydrogen. We have implemented Deutsch's algorithm for distinguishing between constant and balanced functions with a single query.Comment: 7 pages RevTex including 6 figures. Figures 4-6 are low quality to save space. Submitted to Phys Rev

Lycopodiella inundata: insights into plant-fungal associations in early vascular plants

Recent studies have revealed that extant basal vascular plants associate with a wide range of Mucoromycotina and/or Glomeromycota fungi, paralleling the same in non-vascular liverworts and hornworts. This dispels the long-held paradigm that these early diverging lineages harbour Glomeromycota exclusively. Endophytes belonging to both fungal lineages have also been reported, for the first time, in a Devonian plant (Horneophyton ligneri). Together these discoveries point to much more diverse plant-fungus interactions in early vascular plants than previously assumed, however our understanding of these remains limited. In order to gain further insights into these key partnerships, especially those involving the early diverging Mucoromycotina, we are developing the lycophyte Lycopodiella inundata as an experimental system. L. inundata sporophytes have been shown to harbour solely Mucoromycotina fungi but equally fundamental, the identity of its gametophyte endophyte remains unknown. Using molecular and cytological approaches, we confirm that young L. inundata sporophytes are colonized exclusively by Mucoromycotina and show that the cytology of colonisation - consisting of both inter- and intracellular phases - closely resembles that in Haplomitriopsida liverwort-Mucoromycotina partnerships and the corm of H. ligneri. Our current isolation, resynthesis and molecular studies will provide further insights into both host and fungi specificity.This is a poster presented The Rhynie Chert – our earliest terrestrial ecosystem revisited. For more information on the conference consult the above links