1,136 research outputs found

    The Lorentzian distance formula in noncommutative geometry

    Get PDF
    For almost twenty years, a search for a Lorentzian version of the well-known Connes' distance formula has been undertaken. Several authors have contributed to this search, providing important milestones, and the time has now come to put those elements together in order to get a valid and functional formula. This paper presents a historical review of the construction and the proof of a Lorentzian distance formula suitable for noncommutative geometry.Comment: 16 pages, final form, few references adde

    Mol-CycleGAN - a generative model for molecular optimization

    Get PDF
    Designing a molecule with desired properties is one of the biggest challenges in drug development, as it requires optimization of chemical compound structures with respect to many complex properties. To augment the compound design process we introduce Mol-CycleGAN - a CycleGAN-based model that generates optimized compounds with high structural similarity to the original ones. Namely, given a molecule our model generates a structurally similar one with an optimized value of the considered property. We evaluate the performance of the model on selected optimization objectives related to structural properties (presence of halogen groups, number of aromatic rings) and to a physicochemical property (penalized logP). In the task of optimization of penalized logP of drug-like molecules our model significantly outperforms previous results

    Electronic Footprints in the Sand: Technologies for Assisting Domestic Violence Survivors

    Get PDF
    With the rapid growth and spread of Internet-based social support systems, the impact that these systems can make to society – be it good or bad – has become more significant and can make a real difference to people’s lives. As such, various aspects of these systems need to be carefully investigated and analysed, including their security/privacy issues. In this paper, we present our work in designing and implementing various technological features that can be used to assist domestic violence survivors in obtaining help without leaving traces which might lead to further violence from their abuser. This case study serves as the core of our paper, in which we outline our approach, various de- sign considerations – including difficulties in keeping browsing history private, our currently implemented solutions (single use URL, targeted history sanitita- tion agent, and secret graphical gateway), as well as novel ideas for future work (including location-based service advertising and deployment in the wild)

    Synchrotron x-ray scattering analysis of nylon-12 crystallisation variation depending on 3D printing conditions

    Get PDF
    7Nylon-12 is an important structural polymer in wide use in the form of fibres and bulk structures. Fused filament fabrication (FFF) is an extrusion-based additive manufacturing (AM) method for rapid prototyping and final product manufacturing of thermoplastic polymer objects. The resultant microstructure of FFF-produced samples is strongly affected by the cooling rates and thermal gradients experienced across the part. The crystallisation behaviour during cooling and solidification influences the micro- and nano-structure, and deserves detailed investigation. A commercial Nylon-12 filament and FFF-produced Nylon-12 parts were studied by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) to examine the effect of cooling rates under non-isothermal crystallisation conditions on the microstructure and properties. Slower cooling rates caused more perfect crystallite formation, as well as alteration to the thermal properties.openopende Jager B.; Moxham T.; Besnard C.; Salvati E.; Chen J.; Dolbnya I.P.; Korsunsky A.M.de Jager, B.; Moxham, T.; Besnard, C.; Salvati, E.; Chen, J.; Dolbnya, I. P.; Korsunsky, A. M

    Finite Element Modelling and Experimental Validation of the Enamel Demineralisation Process at the Rod Level

    Get PDF
    In the past years, a significant amount of effort has been directed at the observation and characterisation of caries using experimental techniques. Nevertheless, relatively little progress has been made in numerical modelling of the underlying demineralisation process. The present study is the first attempt to provide a simplified calculation framework for the numerical simulation of the demineralisation process at the length scale of enamel rods and its validation by comparing the data with statistical analysis of experimental results. FEM model was employed to simulate a time-dependent reaction-diffusion equation process in which H ions diffuse and cause demineralisation of the enamel. The local orientation of the hydroxyapatite crystals was taken into account. Experimental analysis of the demineralising front was performed using advanced high-resolution synchrotron X-ray micro-Computed Tomography. Further experimental investigations were conducted by means of SEM and STEM imaging techniques. Besides establishing and validating the new modelling framework, insights into the role of the etchant solution pH level were obtained. Additionally, some light was shed on the origin of different types of etching patterns by simulating the demineralisation process at different etching angles of attack. The implications of this study pave the way for simulations of enamel demineralisation within different complex scenarios and across the range of length scales. Indeed, the framework proposed can incorporate the presence of chemical species other than H ions and their diffusion and reaction leading to dissolution and re-precipitation of hydroxyapatite. It is the authors\u2019 hope and aspiration that ultimately this work will help identify new ways of controlling and preventing caries

    Convento franciscano en Orsay

    Get PDF
    Este es el primer conjunto monástico completo y totalmente equipado que se construye en Francia desde el siglo XVIII. Desde el punto de vista religioso representa gran interés, ya que significa la posibilidad de adaptarse, tanto en el interior como en el exterior, a las necesidades y exigencias de la Orden, situándonos siempre en el momento actual constructivo, estético y de comodidades toleradas por la regla
    corecore