372 research outputs found
A numerical sensitivity study -The effectiveness of RFID-based ore tracking through a simulated coarse ore stockpile and the impacts of key process variables
Available online 24 August 2023The ability to understand ore characteristics in real-time during mining processes is vital for ensuring product quality control. However, it is challenging to continuously track ore flow from the mine to the mill due to the blending of ore batches, especially within stockpiles. This paper presents a numerical study of copper ore tracking through a coarse ore stockpile. A discrete element model of a 3D stockpile was created using the EDEM software to evaluate the effectiveness of using RFID tags for ore tracking. To identify the primary variables and their effect on ore transport and tracking through the stockpile, a sensitivity study was conducted to investigate a range of process variables, such as ore size distribution, ore size range, RFID tag size, wall friction, the trajectory of charging particles and stockpile charging methods. The results show that the stockpile model is not sensitive to variables such as the ore size distribution, ore size range and RFID tag size, while wall friction, stockpile feed belt speed, segregation in the ore flow region and contact model have a significant effect on ore blending within the stockpile. It was found that the overall performance of RFID-based ore tracking through the stockpile is poor. For cases with only one or a few tags per ore batch the order in which the tags are read did not provide a good representation of the ore distribution for most scenarios This sensitivity study provides insights into new tracking strategies given the poor performance of RFID tracking shown by the simulation study.Juan Chen, Tien-Fu Lu, Dylan Peukert, Peter Dow
Some Consequences of Thermosolutal Convection: The Grain Structure of Castings
The essential principles of thermosolutal convection are outlined, and how convection provides a transport mechanism between the mushy region of a casting and the open bulk liquid is illustrated. The convective flow patterns which develop assist in heat exchange and macroscopic solute segregation during solidification; they also provide a mechanism for the transport of dendritic fragments from the mushy region into the bulk liquid. Surviving fragments become nuclei for equiaxed grains and so lead to blocking of the parental columnar, dendritic growth front from which they originated. The physical steps in such a sequence are considered and some experimental data are provided to support the argument
Up-regulation of a death receptor renders antiviral T cells susceptible to NK cell-mediated deletion
This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).This work was funded by the Medical Research Council (Clinical Research Training Fellowship to DP and grant G0801213 to M.K. Maini)
On a Poisson–Lie deformation of the BCn Sutherland system
A deformation of the classical trigonometric BCn Sutherland system is derived via Hamiltonian reduction of the Heisenberg double of SU (2n). We apply a natural Poisson–Lie analogue of the Kazhdan–Kostant–Sternberg type reduction of the free particle on SU (2n) that leads to the BCn Sutherland system. We prove that this yields a Liouville integrable Hamiltonian system and construct a globally valid model of the smooth reduced phase space wherein the commuting flows are complete. We point out that the reduced system, which contains 3 independent coupling constants besides the deformation parameter, can be recovered (at least on a dense submanifold) as a singular limit of the standard 5-coupling deformation due to van Diejen. Our findings complement and further develop those obtained recently by Marshall on the hyperbolic case by reduction of the Heisenberg double of SU (n,n)
Self-consistent field theory of polarized BEC: dispersion of collective excitation
We suggest the construction of a set of the quantum hydrodynamics equations
for the Bose-Einstein condensate (BEC), where atoms have the electric dipole
moment. The contribution of the dipole-dipole interactions (DDI) to the Euler
equation is obtained. Quantum equations for the evolution of medium
polarization are derived. Developing mathematical method allows to study effect
of interactions on the evolution of polarization. The developing method can be
applied to various physical systems in which dynamics is affected by the DDI.
Derivation of Gross-Pitaevskii equation for polarized particles from the
quantum hydrodynamics is described. We showed that the Gross-Pitaevskii
equation appears at condition when all dipoles have the same direction which
does not change in time. Comparison of the equation of the electric dipole
evolution with the equation of the magnetization evolution is described.
Dispersion of the collective excitations in the dipolar BEC, either affected or
not affected by the uniform external electric field, is considered using our
method. We show that the evolution of polarization in the BEC leads to the
formation of a novel type of the collective excitations. Detailed description
of the dispersion of collective excitations is presented. We also consider the
process of wave generation in the polarized BEC by means of a monoenergetic
beam of neutral polarized particles. We compute the possibilities of the
generation of Bogoliubov and polarization modes by the dipole beam.Comment: 16 pages, 15 figures. arXiv admin note: substantial text overlap with
arXiv:1106.082
The DIRC Particle Identification System for the BABAR Experiment
A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for Detection of Internally Reflected Cherenkov (Light). This paper will discuss the construction, operation and performance of the BABAR DIRC in detail
Cognitive Invariants of Geographic Event Conceptualization: What Matters and What Refines?
Behavioral experiments addressing the conceptualization of geographic events are few and far between. Our research seeks to address this deficiency by developing an experimental framework on the conceptualization of movement patterns. In this paper, we report on a critical experiment that is designed to shed light on the question of cognitively salient invariants in such conceptualization. Invariants have been identified as being critical to human information processing, particularly for the processing of dynamic information. In our experiment, we systematically address cognitive invariants of one class of geographic events: single entity movement patterns. To this end, we designed 72 animated icons that depict the movement patterns of hurricanes around two invariants: size difference and topological equivalence class movement patterns endpoints. While the endpoint hypothesis, put forth by Regier (2007), claims a particular focus of human cognition to ending relations of events, other research suggests that simplicity principles guide categorization and, additionally, that static information is easier to process than dynamic information. Our experiments show a clear picture: Size matters. Nonetheless, we also find categorization behaviors consistent with experiments in both the spatial and temporal domain, namely that topology refines these behaviors and that topological equivalence classes are categorized consistently. These results are critical steppingstones in validating spatial formalism from a cognitive perspective and cognitively grounding work on ontologies
Systematic Review of Medicine-Related Problems in Adult Patients with Atrial Fibrillation on Direct Oral Anticoagulants
New oral anticoagulant agents continue to emerge on the market and their safety requires assessment to provide evidence of their suitability for clinical use. There-fore, we searched standard databases to summarize the English language literature on medicine-related problems (MRPs) of direct oral anticoagulants DOACs (dabigtran, rivaroxban, apixban, and edoxban) in the treatment of adults with atri-al fibrillation. Electronic databases including Medline, Embase, International Pharmaceutical Abstract (IPA), Scopus, CINAHL, the Web of Science and Cochrane were searched from 2008 through 2016 for original articles. Studies pub-lished in English reporting MRPs of DOACs in adult patients with AF were in-cluded. Seventeen studies were identified using standardized protocols, and two reviewers serially abstracted data from each article. Most articles were inconclusive on major safety end points including major bleeding. Data on major safety end points were combined with efficacy. Most studies inconsistently reported adverse drug reactions and not adverse events or medication error, and no definitions were consistent across studies. Some harmful drug effects were not assessed in studies and may have been overlooked. Little evidence is provided on MRPs of DOACs in patients with AF and, therefore, further studies are needed to establish the safety of DOACs in real-life clinical practice
Desenvolvimento e avaliação de calorĂmetros por nitrogĂŞnio lĂquido e fluxo contĂnuo para medição de aporte tĂ©rmico
Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants
Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Peer reviewe
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