202 research outputs found

    The Application of Mixed Reality Within Civil Nuclear Manufacturing and Operational Environments

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    This thesis documents the design and application of Mixed Reality (MR) within a nuclear manufacturing cell through the creation of a Digitally Assisted Assembly Cell (DAAC). The DAAC is a proof of concept system, combining full body tracking within a room sized environment and bi-directional feedback mechanism to allow communication between users within the Virtual Environment (VE) and a manufacturing cell. This allows for training, remote assistance, delivery of work instructions, and data capture within a manufacturing cell. The research underpinning the DAAC encompasses four main areas; the nuclear industry, Virtual Reality (VR) and MR technology, MR within manufacturing, and finally the 4 th Industrial Revolution (IR4.0). Using an array of Kinect sensors, the DAAC was designed to capture user movements within a real manufacturing cell, which can be transferred in real time to a VE, creating a digital twin of the real cell. Users can interact with each other via digital assets and laser pointers projected into the cell, accompanied by a built-in Voice over Internet Protocol (VoIP) system. This allows for the capture of implicit knowledge from operators within the real manufacturing cell, as well as transfer of that knowledge to future operators. Additionally, users can connect to the VE from anywhere in the world. In this way, experts are able to communicate with the users in the real manufacturing cell and assist with their training. The human tracking data fills an identified gap in the IR4.0 network of Cyber Physical System (CPS), and could allow for future optimisations within manufacturing systems, Material Resource Planning (MRP) and Enterprise Resource Planning (ERP). This project is a demonstration of how MR could prove valuable within nuclear manufacture. The DAAC is designed to be low cost. It is hoped this will allow for its use by groups who have traditionally been priced out of MR technology. This could help Small to Medium Enterprises (SMEs) close the double digital divide between themselves and larger global corporations. For larger corporations it offers the benefit of being low cost, and, is consequently, easier to roll out across the value chain. Skills developed in one area can also be transferred to others across the internet, as users from one manufacturing cell can watch and communicate with those in another. However, as a proof of concept, the DAAC is at Technology Readiness Level (TRL) five or six and, prior to its wider application, further testing is required to asses and improve the technology. The work was patented in both the UK (S. R EDDISH et al., 2017a), the US (S. R EDDISH et al., 2017b) and China (S. R EDDISH et al., 2017c). The patents are owned by Rolls-Royce and cover the methods of bi-directional feedback from which users can interact from the digital to the real and vice versa. Stephen Reddish Mixed Mode Realities in Nuclear Manufacturing Key words: Mixed Mode Reality, Virtual Reality, Augmented Reality, Nuclear, Manufacture, Digital Twin, Cyber Physical Syste

    A simple three-dimensional-focusing, continuous-flow mixer for the study of fast protein dynamics

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    We present a simple, yet flexible microfluidic mixer with a demonstrated mixing time as short as 80 μs that is widely accessible because it is made of commercially available parts. To simplify the study of fast protein dynamics, we have developed an inexpensive continuous-flow microfluidic mixer, requiring no specialized equipment or techniques. The mixer uses three-dimensional, hydrodynamic focusing of a protein sample stream by a surrounding sheath solution to achieve rapid diffusional mixing between the sample and sheath. Mixing initiates the reaction of interest. Reactions can be spatially observed by fluorescence or absorbance spectroscopy. We characterized the pixel-to-time calibration and diffusional mixing experimentally. We achieved a mixing time as short as 80 μs. We studied the kinetics of horse apomyoglobin (apoMb) unfolding from the intermediate (I) state to its completely unfolded (U) state, induced by a pH jump from the initial pH of 4.5 in the sample stream to a final pH of 2.0 in the sheath solution. The reaction time was probed using the fluorescence of 1-anilinonaphthalene-8-sulfonate (1,8-ANS) bound to the folded protein. We observed unfolding of apoMb within 760 μs, without populating additional intermediate states under these conditions. We also studied the reaction kinetics of the conversion of pyruvate to lactate catalyzed by lactate dehydrogenase using the intrinsic tryptophan emission of the enzyme. We observe sub-millisecond kinetics that we attribute to Michaelis complex formation and loop domain closure. These results demonstrate the utility of the three-dimensional focusing mixer for biophysical studies of protein dynamics

    Geotechnical Appraisal of the Thar Open Cut Mining Project

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    This paper is concerned with a slope stability appraisal of the proposed open cut mining operations in the Thar lignite field in Sindh, Pakistan. The Thar coalfield covers an area of approximately 9 000 km2 and is estimated to contain 193 billion tonnes of lignite resources. The design of safe high wall slopes is necessary to ensure mine safety and overall economical viability of the mining operations. In the Thar lignite field, the presence of three main aquifers induces pore pressure in the rock mass surrounding the lignite seams and makes high wall slopes potentially unsafe. It is, therefore, necessary to dewater the rock mass before commencing mining excavations. A proposed mine dewatering scheme to facilitate rock mass dewatering surrounding the mining excavations and a description of the slope stability analysis of the high wall using the software “SLIDE” version 5 is outlined. Three computer models with slope angles of 28o, 29o and 30o, incorporating a plane failure mode, were analyzed to investigate the stability of pit slopes. The generalized stratigraphy of borehole RE-25 has been used for the development of the computer models. The main conclusions of this study are that the slope angle of 28o is quite acceptable for a Stability Factor (SF) ≤ 1.3 whereas the excavated slopes with slope angles ≥ 29o are not safe against the plane failure for SF\u3e1.3. This assessment was followed by a slope stability analysis incorporating circular failure modes. Five models incorporating various slope angles ranging from 23o to 27o and one model incorporating combined slope angles of 23o in dune sand and 26o in the rest of the strata were developed and analysed. The main conclusions from this study are that the dune sand layer (having a thickness of 48 m) is acceptable for a SF of 1.3 at slope angle ≤ 23o, while the rest of the strata is acceptable for SF=1.3 at slope angles ≤ 26o. The overburden to lignite extraction ratio for this slope design has been calculated as 3:1 or 3 m3 of overburden over 1 t of lignite

    Sex‐specific alterations in whole body energetics and voluntary activity in heterozygous R163C malignant hyperthermia‐susceptible mice

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    Malignant hyperthermia (MH) is characterized by induction of skeletal muscle hyperthermia in response to a dysregulated increase in myoplasmic calcium. Although altered energetics play a central role in MH, MH‐susceptible humans and mouse models are often described as having no phenotype until exposure to a triggering agent. The purpose of this study was to determine the influence of the R163C ryanodine receptor 1 mutation, a common MH mutation in humans, on energy expenditure, and voluntary wheel running in mice. Energy expenditure was measured by indirect respiration calorimetry in wild‐type (WT) and heterozygous R163C (HET) mice over a range of ambient temperatures. Energy expenditure adjusted for body weight or lean mass was increased (P < .05) in male, but not female, HET mice housed at 22°C or when housed at 28°C with a running wheel. In female mice, voluntary wheel running was decreased (P < .05) in the HET vs WT animals when analyzed across ambient temperatures. The thermoneutral zone was also widened in both male and female HET mice. The results of the study show that the R163C mutations alters energetics even at temperatures that do not typically induce MH

    Dust properties in M31.I.Basic properties and a discussion on age-dependent dust heating

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    Context. Spitzer Space Telescope observations and dust emission models are used to discuss the distribution of dust and its characteristics in M31. Together with GALEX FUV, NUV, and SDSS images we studied the age dependence of the dust heating process. Methods.Spitzer IRAC/MIPS maps of M31 were matched together and compared to dust emission models allowing to constrain the dust mass, the intensity of the mean radiation field, the abundance of Polycyclic Aromatic Hydrocarbons (PAH) particles. The total infrared emission (TIR) was analyzed in function of UV and Optical colors and compared to predictions of models which consider the age-dependent dust heating. Results. We demonstrate that cold-dust component emission dominates the infrared spectral energy distribution of M31. The mean intensity of the radiation field heating the dust is low (typically U<2, where U=1 is the value in the solar surrounding). Due to the lack of submillimetric measurements the dust mass (M_{dust}) is only weakly constrained by the infrared spectrum. We show that across the spiral-ring structure of M31 a fraction >3% of the total dust mass is in PAHs. UV and optical colors are correlated to (TIR/FUV) ratios in \sim 670 pc-sized regions overall the disk of M31, although deviating from the IRX-beta relationship for starburst galaxies. We derived that in 83% of the regions analyzed across the 10kpc ring more than 50% of the energy absorbed by the dust is rediated at \lambda > 4000 \AA and that dust in M31 appears mainly heated by populations a few Gyr old even across the star-forming ring. The attenuation is varying radially peaking near 10kpc and decreasing faster in the inner regions of M31 than in the outer regions. We finally derived the attenuation map of M31 at 6"/px resolution (\sim 100 pc/px along the plane of M31).[abridged]Comment: 21 pages, 18 figures, accepted for publication in A&A. Only low resolution images included, full resolution images will be avaiable in the journal electronic version. Fig.14 and Fig.17 will be avaiable via CD

    TeV gamma-rays and neutrinos from photo-disintegration of nuclei in Cygnus OB2

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    TeV gamma-rays may provide significant information about high energy astrophysical accelerators. Such gamma-rays can result from the photo-de-excitation of PeV nuclei after their parents have undergone photo-disintegration in an environment of ultraviolet photons. This process is proposed as a candidate explanation of the recently discovered HEGRA source at the edge of the Cygnus OB2 association. The Lyman-alpha background is provided by the rich O and B stellar environment. It is found that (1) the HEGRA flux can be obtained if there is efficient acceleration at the source of lower energy nuclei; (2) the requirement that the Lorentz-boosted ultraviolet photons can excite the Giant Dipole resonance implies a strong suppression of the gamma-ray spectrum compared to an E_\gamma^{-2} behavior at energies \alt 1 TeV (some of these energies will be probed by the upcoming GLAST mission); (3) a TeV neutrino counterpart from neutron decay following helium photo-disintegration will be observed at IceCube only if a major proportion of the kinetic energy budget of the Cygnus OB2 association is expended in accelerating nuclei.Comment: To be published in Phys. Rev.

    Fifty Years of IMF Variation: The Intermediate-Mass Stars

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    I track the history of star count estimates of the Milky Way field star and open cluster IMFs, concentrating on the neglected mass range from 1 to 15 M{_\odot}. The prevalent belief in a universal IMF appears to be without basis for this mass range. Two recent estimates of the field star IMF using different methods and samples give values of the average logarithmic slope Γ\Gamma between -1.7 and -2.1 in the mass range 1.1 to 4 M{_\odot}. Two older estimates between 2 and 15 M{_\odot} disagree severely; the field IMF in this range is essentially unknown from star counts. Variations in Γ\Gamma among open cluster IMFs in this mass range have not decreased despite numerous detailed studies, even for studies using homogeneous data and reduction procedures and including only clusters with a significant mass range. These cluster variations \textit{might} be due to the combined effects of sampling, systematic errors, stellar evolution uncertainties, dynamical evolution, and unresolved binaries. If so, then the cluster data are consistent with a universal IMF, but are also consistent with sizeable variations. The cluster data do not allow an estimate of an average IMF or Γ\Gamma because the average depends on the choice of weighting procedure and other effects. If the spread in cluster IMFs is in excess of the effects listed above, real IMF variations must occur that do not depend much on physical conditions explored so far. The complexity of the star formation process seen in observations and simulations suggests that large realization-to-realization differences might be expected, in which case an individual cluster IMF would be in part the product of evolutionary contingency in star formation, and the function of interest is the probability distribution of IMF parameters.Comment: 18 pages, including 4 figures: invited talk presented at the conference on "IMF@50: The Stellar Initial Mass Function Fifty Years Later" held at Abbazia di Spineto, Siena, Italy, May 2004; to be published by Kluwer Academic Publishers, edited by E. Corbelli, F. Palla, and H. Zinnecke

    Synchrony and Physiological Arousal Increase Cohesion and Cooperation in Large Naturalistic Groups

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    Separate research streams have identified synchrony and arousal as two factors that might contribute to the effects of human rituals on social cohesion and cooperation. But no research has manipulated these variables in the field to investigate their causal – and potentially interactive – effects on prosocial behaviour. Across four experimental sessions involving large samples of strangers, we manipulated the synchronous and physiologically arousing affordances of a group marching task within a sports stadium. We observed participants’ subsequent movement, grouping, and cooperation via a camera hidden in the stadium’s roof. Synchrony and arousal both showed main effects, predicting larger groups, tighter clustering, and more cooperative behaviour in a free-rider dilemma. However, synchrony and arousal interacted on measures of clustering and cooperation: such that synchrony only encouraged closer clustering — and encouraged greater cooperation—when paired with physiological arousal. The research has implications for understanding the nature and co-occurrence of synchrony and physiological arousal in rituals around the world. It also represents the first use of real-time spatial tracking as a precise and naturalistic method of simulating collective rituals

    Rise of the War Machines: Charting the Evolution of Military Technologies from the Neolithic to the Industrial Revolution

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    What have been the causes and consequences of technological evolution in world history? In particular, what propels innovation and diffusion of military technologies, details of which are comparatively well preserved and which are often seen as drivers of broad socio-cultural processes? Here we analyze the evolution of key military technologies in a sample of pre-industrial societies world-wide covering almost 10,000 years of history using Seshat: Global History Databank. We empirically test previously speculative theories that proposed world population size, connectivity between geographical areas of innovation and adoption, and critical enabling technological advances, such as iron metallurgy and horse riding, as central drivers of military technological evolution. We find that all of these factors are strong predictors of change in military technology, whereas state-level factors such as polity population, territorial size, or governance sophistication play no major role. We discuss how our approach can be extended to explore technological change more generally, and how our results carry important ramifications for understanding major drivers of evolution of social complexity. © 2021 Turchin et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This work was supported by: a John Templeton Foundation grant to the Evolution Institute, entitled "Axial-Age Religions and the Z-Curve of Human Egalitarianism" (HW, PF, PT); a Tricoastal Foundation grant to the Evolution Institute, entitled "The Deep Roots of the Modern World: The Cultural Evolution of Economic Growth and Political Stability" (PT); an Economic and Social Research Council Large Grant to the University of Oxford, entitled "Ritual, Community, and Conflict" (REF RES-060-25-0085) (HW); a grant from the European Union Horizon 2020 research and innovation programme (grant agreement No 644055 [ALIGNED, www.aligned-project.eu]) (HW, PF); a European Research Council Advanced Grant to the University of Oxford, entitled (Ritual Modes: Divergent modes of ritual, social cohesion, prosociality, and conflict" (HW, PF); a grant from the Institute of Economics and Peace to develop a Historical Peace Index (HW, PF, PT, DH); and the program (Complexity Science,) which is supported by the Austrian Research Promotion Agency FFG under grant № 873927 (PT)

    The mediating role of shared flow and perceived emotional synchrony on compassion for others in a mindful-dancing program

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    While there is a growing understanding of the relationship between mindfulness and compassion, this largely relates to the form of mindfulness employed in first-generation mindfulness-based interventions such as Mindfulness-Based Stress Reduction. Consequently, there is limited knowledge of the relationship between mindfulness and compassion in respect of the type of mindfulness employed in second-generation mindfulness-based interventions (SG-MBIs), including those that employ the principle of working harmoniously as a “secular sangha.” Understanding this relationship is important because research indicates that perceived emotional synchrony (PES) and shared flow—that often arise during participation in harmonized group contemplative activities—can enhance outcomes relating to compassion, subjective well-being, and group identity fusion. This pilot study analyzed the effects of participation in a mindful-dancing SG-MBI on compassion and investigated the mediating role of shared flow and PES. A total of 130 participants were enrolled into the study that followed a quasi-experimental design with an intervention and control group. Results confirmed the salutary effect of participating in a collective mindful-dancing program, and demonstrated that shared flow and PES fully meditated the effects of collective mindfulness on the kindness and common humanity dimensions of compassion. Further research is warranted to explore whether collective mindfulness approaches, such as mindful dancing, may be a means of enhancing compassion and subjective well-being outcomes due to the mediating role of PES and shared flow.N/
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